Photonic crystals in biology - NanoTR-VI

Poster Presentations3rd Day17 June 2010ID: F1244 - N11236 th Nanoscience and Nanotechnology Conference, İzmir, 2010

Poster Session, Thursday, June 17Theme F686 - N1123Electrical and photosensing properties of pentacene organic thin film transistorFahrettin YakuphanogluAbstract— The electrical and ultraviolet light responsive properties of the pentacene thin-film transistor with 240 nm poly-4-vinylphenol (PVP) dielectric layer thin film transistor have been investigated. The electrical parameters, saturation mobility,threshold voltage, gate voltage swing and an ON/OFF current ratio were determined to be 710 -1 cm 2 /V s, 10.0 V, 2.6 V/dec and3.8x10 2 , respectively. The transistor was characterized in respect of UV illuminations to investigate its potential for possible use asa UV detector. The performance of the transistor is indicates a UV photosensitivity in the off-state with a ratio of photocurrent todark current of 5.74x10 2 . The obtained results indicate that the organic pentacene thin film transistor can be used as a UVphotodetector.Organic thin-film transistors (OTFTs) have been extensivelyinvestigated due to their low-cost, low-temperature process,and compatibility with flexible substrate. Organic thin filmtransistors (OTFTs) have many unique advantages, such aslight weight, flexibility, and solution processability. Fromthese reasons, nowadays, many research groups havedeveloped OTFTs. Especially, solution processes includedspin coating, screen printing, ink jet, and nanoimprintlithography can be easily used in coating processes to formcircuits for disposable electronics on a plastic substrate.According to the reported investigation of active channelpentacene is a very promising candidate for organicelectronics. Several groups have recently demonstratedpentacene TFTs and their applications. However, to satisfy thehigh performance of OTFT, it is very important to select agate insulator material. That is, an insulator gate field-effecttransistor, the role of the insulator is at least as important asthat of the semiconductor. The insulator layer, especially theinsulator-semiconductor interface, has a significant effect onthe performance of OTFTs, because OTFTs operate inaccumulation region and the modulated charge lies within thearea (about 10 nm thick) close to the interface [8]. Therefore,many research groups have made much effort to be study onrelationship between organic semiconductor and dielectriclayer.In present study, pentacene thin-film transistor wasfabricated with 240 nm poly-4-vinylphenol (PVP) dielectriclayer. The electrical and photosensing properties of organicpentacene thin-film transistor fabricated on polyethersulphone(PES) substrate have been investigated. The transistorfabricated on PES showed p-type OTFT characteristics. Forphotosensing characterization, the output characteristics of thepentacene thin film transistor were measured under variousillumination conditions. The Electrical characteristics andphotoresponse properties of the transistor were performedunder dark and UV light illuminations by semiconductorparameter analyzer (Keithley 4200) using a white lamp (200W) and UV lamp with 366 nm.Fig.1a shows the drain current-drain voltage characteristics ofpentacene transistor under various gate voltages. The outputcharacteristics exhibit clear current saturation and pinch offbehavior.The drain current increases at negative voltages,indicating that the electrons are generated by the negative gatevoltages due to p-type FET characteristics with good gatecontrollability.-a--b-Fig.1. Output characteristics of pentacene thin filmtransistor a) under dark conditions b) under UV illuminationsFig1b shows the I ds -V ds plots of the transistor under UVilluminations (366 nm) for various voltages. The drain currentunder these illuminations increases due to photogeneration ofelectron–hole pairs in the active layer of the transistor. Thissuggests that the organic pentacene thin film transistor can beused as a UV photodetector.This work was supported by the Management Unit ofScientific Research Projects of Firat University (FÜBAP)(Project Number: 1947). Authors wish to thank FÜBAP.*Corresponding author: fyhan@hotmail.com6th Nanoscience and Nanotechnology Conference, zmir, 2010 615

Determination of Dielectric Anisotropy Properties of Poly(N-Vinylimidazole) Based Hydrogen BondedSide Chain Liquid Crystalline Polymer by 4-Cyano-4'-Pentylbiphenyl Nematic Liquid CrystalYeşim H. Gursel a , B. Filiz Senkal a , Fahrettin Yakuphanoglu b*a Istanbul Technical University, Department of Chemistry, 34469, Maslak, İstanbul, Turkeyb Fırat University, Department of Physics, 23119 Elazığ, TurkeyAbstract— The liquid crystal and dielectric anisotropy properties of poly(n-vinylimidazole) based hydrogen bonded side chainliquid crystalline polymer (HB-PLC) doped 5CB and pure 5CB liquid crystals have been investigated by polarized opticalmicroscopy and dielectric spectroscopy method. The polarized optical microscopy results show that HB-PLC exhibited anenantiotropic nematic phase on heating and cooling cycles. The real and imaginary parts of the dielectric constant dependence of thevoltage applied shows that HB-PLC dopant changes the dielectric parameters of the LCs. The dielectric behaviour of the LCs showsonly a relaxation process. Dielectric anisotropy () properties of the LCs changes from the positive type to negative type. It isevaluated that the dielectric anisotropy and relaxation properties of 5CB and 5CB/ HB-PLC LCs can be controlled by HB-PLCdopant.Recently, side chain liquid crystalline polymers (SCLCPs),which combine the unique properties of low-molar mass liquidcrystals and polymers, have been the subject of intensiveresearch mainly due to their interesting electrical and opticalproperties which makes them good candidates for applicationsin microelectronic devices ranging from optical data storageand non-linear optics to being the stationary phase in gaschromatography and high performance liquidchromatography. Side-chain liquid-crystalline polymers(LCPs) are usually prepared by covalently linking rigidmesogens to a polymer backbone through flexible spacers. Inrecent years, self-assembly through specific interactions, suchas hydrogen-bonding ionic, ionic-dipolar and charge transferinteractions 13 , has been recognized as a new strategy forconstructing side-chain liquid crystal polymers. Selfassembledmaterials formed by non-covalent bonding haveattracted much attention because these materials are goodcandidates for the next generation of materials for whichdynamic function, environmental compatibility, and lowenergy processing are required. The dielectric-spectroscopytechnique (DST) is a powerful technique successfully appliedfor understanding the molecular details [13]. The dielectricanisotropy is expressed as || , where ||and are the parallel and the perpendicular components of theelectric permittivity, respectively. Regarding the dielectricconstant, there are two structure types. One is named aspositive dielectric anisotropy (p-type) and its dielectricconstant along the director axis is larger than that along theaxes perpendicular to the director. is greater than zero inthis case. The other type is named as negative dielectricanisotropy (n-type), is less than zero. Variation of withrespect to the spot frequencies reveals that LC orientation hasp-type property at low frequencies, and as the frequencyincreases the dielectric anisotropy character shifts to n-type. Inpresent study, we have investigated dielectric anisotropyproperties of poly(n-vinylimidazole) based hydrogen bondedside chain liquid crystalline polymer (HB-PLC) doped 5CBand pure 5CB liquid crystals.To confirm the liquid crystalline nature of the HB-PLC andidentify the mesophase, hot-stage polarized optical microscope(POM) was used. The POM results showed that HB-PLCexhibited an enantiotropic nematic phase on heating andcooling cycles. As it was heated to 97 °C, the typical nematicschlieren texture appeared (Fig.1).Fig.2 Schlieren texture of polymer HB-PLC at 97 °C (400x)The plots of the capacitance-voltage (C-V)of (HB-PLC) doped5CB and pure 5CB liquid crystals for >0 and

Ultraviolet light detection characteristics of a-IGZO thin film transistor for photodetector applicationsSeongpil Chang a , Jae-Hong Kwon a , Jung-Ho Park a , Myung-Ho Chung a , Tae-Yeon Oh a , Hyun-Seok Bae a , Byeong-Kwon Ju a,† , and Fahrettin Yakuphanoglu ba) Display and Nanosystem Laboratory, College of Engineering, Korea University, Seoul 136-713, Republic of Korea.b) Fırat University, Faculty of Arts and Sciences, Department of Physics, Elazığ, Turkey.Abstract— The ultraviolet light responsive properties of the amorphous indium gallium zinc oxide thin film transistor have beeninvestigated. The a-IGZO transistor operate in the enhancement mode with saturation mobility of 6.99 cm 2 /V s, threshold voltageof 7.6 V, gate voltage swing of 1.58 V/dec and an ON/OFF current ratio of 2.45x10 8 . The transistor was subsequentlycharacterized in respect of UV illuminations in order to investigate its potential for possible use as a detector. The performance ofthe transistor is indicates a high-photosensitivity in the off-state with a ratio of photocurrent to dark current of 5.74x10 2 . Ourresults reveal that the amorphous indium gallium zinc oxide thin film transistor can be used as a UV photodetector.Transparent oxide semiconductors, such as zinc oxide (ZnO),indium tin oxide (ITO), zinc tin oxide (ZTO), gallium dopedzinc oxide (GZO) indium zinc oxide (IZO), and indiumgallium zinc oxide (IGZO) have attracted many researcherswith their great potential in optoelectronic applications such asflat panel displays, transparent electrodes in solar cells,transparent thin film transistors (TFTs), and flexibletransparent TFTs [1-7]. Moreover a-IGZO thin film transistorscan be used to detect the ultraviolet (UV). This property of a-IGZO thin film is very useful to apply the UV-detector. Inpresent study, we fabricated a-IGZO thin film transistor toinvestigate the photo-sensing characteristics of the transistorunder the illuminations of visible light and UV. Thermallyoxidized p-Si (100, ρ=0.005 Ωcm) is used as substrate.Thermally oxidized SiO 2 of 300 nm is used as the gateinsulator.And then, we deposited a-IGZO thin film by usingradio-frequency (RF) magnetron sputtering. Active layer ispatterned by photolithography and lift-off process. As thesource-drain (S/D) electrodes, molybdenum (Mo) of 100 nm isdeposited by using direct-current (DC) sputtering at roomtemperature.Our devices have channel width (W) of 150 μmand channel length (L) of 20 μm. Fig.1 shows schematicdiagram of a-IGZO TFTMo (Source / Drain, 100 nm)a-IGZO (80 nm)-a--b-Fig.2. Output characteristics of a-IGZO thin film transistorunder dark and UV illuminations.Fig.2a shows the drain current-drain voltage characteristicsof a-IGZO transistor under various gate voltages. The draincurrent increases at positive voltages, indicating that theelectrons are generated by the positive gate voltages due to n-type FET characteristics with good gate controllability. Thedrain current of the transistor reaches a saturation region,when the entire channel region is depleted of electrons, i.e,channel is pinched off.Fig.2b shows the I ds -V ds curves obtained under UVilluminations (366 nm) with V g =30 V. The drain current underthese illuminations increases due to photogeneration ofelectron–hole pairs in the active layer of the transistor. TheUV illumination increases strongly the drain current, becausethe photon energy of UV illumination at 366 nm is higher thanthe IGZO optical band gap.SiO x (300 nm)p-Si (100 oriented, ρ=0.005 Ωcm)Ag (Gate Electrode)Fig.1 Schematic diagram of a-IGZO TFTThe electrical characteristics and photoresponse properties ofthe transistor were performed under dark and UV lightilluminations by semiconductor parameter analyzer (Keithley4200) using a UV lamp with 366 nm.This work was supported by the Management Unit ofScientific Research Projects of Firat University (FÜBAP)(Project Number: 1947). Authors wish to thank FÜBAP.*Corresponding author: fyhan@hotmail.com6th Nanoscience and Nanotechnology Conference, zmir, 2010 1

Poster Session, Thursday, June 17Theme F686 - N1123Optical and Structural Characterization of Y 2 O 3 :Nd 3+ Phosphors via Thermal Decomposition MethodG. Bilir* and G. ÖzenDepartment of Physics, stanbul Technical University, Maslak-stanbul 34469, TurkeyAbstract: The Y 2 O 3 :Nd 3+ nanophosphors were synthesized by using thermal decomposition method. The powders were annealed at differenttemperatures to investigate annealing temperature dependence of the crystallite size. Average particle size of the products were calculated byusing Scherrer Formula from the X-ray diffractograms Luminescence measurement were performed for all samples at room temperature. AlsoSEM/EDS measurements were confirmed the calculated particle sizes from XRD diffractograms.Materials with nanostructure attracted considerable attentionbecause of potential applications in optoelectronics andphotonics[1-4]. Phosphor materials find wide applicationsranging from fluorescent lamp to luminescence immunoassay.These materials essentially convert one type of energy intovisible radiation and hence, phosphor materials are calledoptical transducer[5].In this work nanosized Y 2 O 3 samples doped with x=0.2, 0.5,1, 2, 5, 10 mol% Nd 3+ ions (Y 2-x Nd x O 3 ) were prepared bythermal decomposition of yttrium-neodymium alginate.Obtained products were annealed at 600, 800 and 1000 toinvestigate particle size dependence on annealing temperature.X-ray diffraction investigations were carried out withPhilips TM model(Cu-K) diffractometer at 40 kV in the 2 rangefrom 20 o to 60 o . Also SEM images of the samples were taken byusing JEOL 6335F model scanning electron microscope(SEM).Both of XRD and SEM measurements show that the particlesizes of Y 2 O 3 :Nd 3+ samples were ranging from 20nm to 40 nmwhich are consistent with the values reported in literature[6].Representative X-ray diffractograms and SEM images are givenin Figs.1-2.Princeton Instruments SP2500i model monochromator andActon series ID441-C Model InGaAs detector for thedetection.PL measurements were performed at room temperature andstrong PL intensities were obtained for all Nd 3+ dopedsamples. The PL spectra of all samples are consist of threespectral regions which were correspond to the 4 F 3/2 4 I 9/2 ,4 F 3/2 4 I 11/2 and 4 F 3/2 4 I 13/2 transitions of theNd 3+ . In Fig.2representative of PL of 0.5% Nd 3+ doped sample are given.Figure 3: PL of 0.5% Nd 3+ doped Y 2O 3Also in Fig. 4, the dependence of FWHM(full width at halfmaxima) of the transitions on annealing temperature is given.Figure 1: XRD patterns of the non-annealed Y 2O 3:Nd 3+ nanopowdersFigure 2: SEM images of the %0,5Nd doped Y 2O 3 annealed at 1000C (left) andnon-annealed (right)From SEM images also seen that the organiccomponent(alginate) from synthesis method which used toform yttrium alginate gels is exist for non-annealed samplesand it was observed for all samples. The emission spectra werecollected by using Apollo Instruments diode laser (Model No:S30-808-6) with 805.2 nm wavelength as an excitation source,Figure 4:Annealing temperature dependence of the FWHMSEM measurements were supported by Science Institute ofMarmara University with the project number FEN-CDRP-090409-0079*bilirg@itu.edu.trReferences[1]Promod and et al, Journal of Luminescence, 82 (1999) 187-193[2] Hai Huang and et al, Nanotechnology, 13 (2002) 318-323[3] Gino Tessari, Marco Bettinelli and et al., Applied Surface Science,144-145 (1999) 686-689[4] Michael Nazarov and et al, Optical Materials, 27 (2005) 1587-1592[5] T. Kim Anh and et al, Journal of Luminescence, 102-103 (2003)391-394[6] D. Tatar, H. Kaygusuz, F. Tezcan, FB. Erim, ML. Oveçolu, G.Ozen “Y2O3 Nanophosphors Synthesized by Combustion and ThermalDecomposition Techniques” 11th Annual Conference on NanoScienceand NanoTechnology, NSTI-NanoTech, Boston-USA (MO81-919)(June 1-5/2008)6th Nanoscience and Nanotechnology Conference, zmir, 2010 617

Poster Session, Thursday, June 17Theme F686 - N1123Comparison of The Dispersion Properties of The Solid-Core Photonic Crystal Fibers with a FixedDiameter of Holes and The Fixed Pitch Length at Wavelength Region of 0.8-2 mHalime Demir 1* and Sedat Özsoy 11 Department of Physics,Faculty of Science and Arts, Erciyes University, Kayseri 38039, TurkeyAbstract— In this work, for a solid core photonic crystal fiber with the triangular lattice, the dispersion of fundamental modeis examined at wavelength region of 0.8-2 m. The silica core is constituted by removing the 7 air hole. The claddingconsists of the two dimensional silica-air photonic crystal with the 4-ring of air holes. The dispersion properties wereinvestigated for different values of d/, first with fixed and then with fixed d. Here, d and represent the diameter of airholes and the pitch length, respectively. The results obtained are then compared and it is concluded that, for a dispersiontailoring, the configurations with fixed diameter are more effective than for fixed pitch length.In recent years, the photonic crystal fibers (PCFs) have asignificant interest due to their unique structures and newproperties [1-6]. Generally, photonic crystal fibers consist ofan arrangement of air holes in the cladding extending thewhole length of the fiber. Photonic crystal fibers arecategorized into two groups according to light guidingmechanism. One is the index guiding photonic crystal fiberand the other is the photonic band gap PCF. In the indexguiding PCF s , the core region is solid and the light is confinedin the central core as in the conventional fibers. The photoniccrystal fiber consists of the pure silica fiber with an array ofthe air-holes along the length of the fiber. The core isconstituted by removing the central hole from the structure.The higher effective refractive index of the surrounding holesforms cladding in which leading the index guiding mechanismanalogous to total internal reflection. Consequently, the lightguiding can be explained by the total internal reflection whichis also the way light is guided in step index fibers.PCFs have been shown to posses many importantproperties as the single mode operation over wide range ofwavelength, the highly tunable dispersion, the propagation ofhigh power densities without exciting unwanted nonlineareffects and the high birefringence. These properties have thepractical importance in design of sophisticated broadbandoptical telecommunication networks [7] and active sensorsystems [8]. In optical communication, dispersion plays asignificant role because it determines the information carryingcapacity of the fiber. Thus, it becomes necessary to know thedispersion properties of an optical fiber.In this work, the dispersion properties of solid-corephotonic crystal fibers with d/= 0.1-0.9 ratios are analyzedfor both the fixed diameter (d=0.84 m) and the fixed pitch(=4 m) at 0.8-2.0 m wavelength range.The cross-section of fiber used in the dispersioncalculations is shown in Fig.1. Here is the pitch length and dis the diameter of air- holes. The fiber core is silica and it isformed by removing 7 air-holes from the structure. Thecladding is the two dimensional photonic crystal with 4-ringsof the triangular lattice air-holes in the silica matrix.Fig. 1.The cross- section of the solid core PCFconsidered. is the pitch length and d isthe diameter of air-holes.The dispersion D is given as following [9]:2λ d neffD = −2c dλn is the effective index of guided mode andeffλ is the freespace wavelength. Firstly, for the fixed pitch length = 4.2m, the dispersion properties are investigated by varying thediameters of air-holes for the d/ values of (0.1, 0.3, 0.5, 0.7,0.9). Later, a similar investigation is executed for the fixeddiameter of air-hole with d=0.84 m, by varying the pitchlength corresponding to the same d/ values.The variations of the d/ ratios for a given wavelengthaffect the dispersion in a considerable manner. The variationof the d/ ratios also changes the zero-dispersion wavelengthwithin a large wavelength range comparatively. In the case offixed pitch, the variation of the d/ ratios does not affect thedispersion and zero-dispersion wavelength severely. As aresult, for a dispersion tailoring, the configurations with fixeddiameter are more effective.*Corresponding author: halimedemir@erciyes.edu.tr[1] J. C. Knight, T. A. Birks, P. St. J. Russell and D. M. Atkin, Opt. Lett. 21,1547-1549 (1996).[2] J. C. Knight, Nature 424, 847-851 (2003).[3] Arismar Cerqueira S. Jr., F. Luan et al., Opt. Express 14, 926-931 (2006).[4] T. A. Birks., J. C. Knight, , P. S. J. Russell., Opt. Lett. 22, 961-963 (1997).[5] A. Ortigosa-Blanch et al., Opt. Lett. 25, 1325-1327 (2000).[6] W. J. Wadsworth et al., J. Opt. Soc. Am. B 19, 2148-2155 (2002).[7] M. D. Nielsen, J. Folkenberg, N. Martensen and A. Bjarklev, OpticsExpress 12, 430-435 (2004).[8] S. Konorov , A. Zheltikov and M. Scalora, Optics Express 13, 3454-3459(2005).[9] J. K. Ranka and R. S. Windeler, Opt.& Photon. News, 20-25 (2000).d6th Nanoscience and Nanotechnology Conference, zmir, 2010 618

PP mPP vs.P =P,PP (1)P andPoster Session, Thursday, June 17Theme F686 - N1123Influence of Annealing Conditions on Optical Properties of ZnO Thin Films111111UDerya BaharUP P*, Göknil BabürP P, Sinan DikenP P, Tuba Aye TermeliP P, Banu ErdoanP P, Sava SönmezoluPPand Güven ÇankayaP1PDepartment of Physics, Faculty of Arts and Science, Gaziosmanpaa University, Tokat 60250, TurkeyAbstract-ZnO thin films were deposited on soda lime glass substrates by sol–gel spin-coating technique. The optical properties of ZnO thin filmsare investigated for different annealing temperatures. The optical band gaps of thin film are found to vary with annealing temperatures. Theobtained films are also transparent in the UV- visible region1Zinc oxide (ZnO) as a wide-band-gap semiconductor hasattracted much attention in current semiconductor research,due to its superior optical properties. In addition, ZnO is aversatile semiconductor material, which has attracted attentionfor its wide range of applications, such as thin films, solarcells, luminescent, electrical and acoustic devices andchemical sensors [1-2].In this paper, we report the investigation of ZnO thin filmsprepared by sol-gel spin coating process using zinc acetate(ZnAc). The optical characterization is investigated fordifferent annealing temperatures using Perkin Elmer Lambda35 UV-VIS Spectrometer at room temperature.Transmittance (%)100806040200200 400 600 800 1000 1200Wavelenght (nm)200 C 0300 C 0400 C 0500 C 0Figure 1. UV–VIS spectra of the ZnO thin film for varioustemperatures.In order to prepare a ZnO solution, first, 3.35gr zinc acetate(Zn(CHR3RCOO)R2R·2HR2RO, Merck), used as a precursor, wasdissolved in 50 ml ethanol [CR2RHR6RO, Merck] and stirred for 50min at 60 P PC in a magnetic mixture. Then, 5 ml glacial aceticacide [CR2RHR4ROR2R, Merck] and 1.5 ml hydrochloride acid (HCl,Merck) were added in the solution, and the final solution wassubjected to the magnetic mixture for 2 h. Here, glacial aceticacid and hydrochloride acid were used as an inhibitor to slowdown the zinc acetate fast hydrolysis. Prior to the coatingprocess, the glass was washed with water, ultrasonicallycleaned in ethanol for 20 min, and in acetone for 20 min,respectively. The deposition was carried out at a spinningspeed of 3000 rpm for 30 s. The spin coating procedure was0 0 0continuously repeated five times at 200P PC, 300P PC, 400P PC and0500P PC annealing temperatures on glass substrate.Fig. 1 shows the UV–VIS spectra ZnO thin films fordifferent annealing temperatures in wavelength range 300–1100nm. The transmission of the thin films of zinc oxidedecreases with the increase in annealing temperature. This canbe linked with the increase in the grain size, and indicating itshigh surface roughness and inhomogeneity [3].(h v) 2 (eV/m) 220161284200 C 0 , E g= 3.84 eV300 C 0 , E g= 3.74 eV400 C 0 , E g= 3.67 eV500 C 0 , E g = 3.58 eV02.4 2.8 3.2 3.6 4Photon energy (eV)Figure 2. UV–VIS spectra of the ZnO thin film for varioustemperatures.The optical band gap of the film was calculated by thefollowing relation [4]:(hv) = A (hv - ERgR) P7where A is an energy-independent constant between 10P8 -110PP, Eg is the optical band gap and r is a constant, whichdetermines type of optical transition, r = 1/2, 2, 3/2 or 3 forallowed direct, allowed indirect, forbidden direct andforbidden indirect electronic transitions, respectively [4]. The1/rr(hv)P hv curves were plotted for different r values andthe best fit was obtained for r = ½. The film at variousannealing temperatures shows a direct allowed transition. Theoptical band gap was determined by extrapolating the linear2portion of the plots to (hv)P 0. The optical band gaps of thethin film were found to be 3.84, 3.74, 3.67 and 3.58 eV at 200 °C,300 °C, 400 °C and 500 °C annealing temperature, respectively.The thicknesses of ZnO film were also determined fromtransmittance measurements in Fig.1 and found to be 1361, 692,939 and 660 nm, respectively. The optical band gap decreaseswith the increasing annealing temperatures. The decrease inthe optical band gap is attributed to the lowering of theinteratomic spacing, which may be associated with a decreasein the amplitude of atomic oscillations around theirequilibrium positions [5].In summary, the analysis of the transmission spectra showsthat ZnO thin films are transparent in the UV-visible regionirrespective of the annealing temperatures. This work waspartially supported by the Scientific Research Commission ofGaziosmanpaa University (Project No: 2009/29).*Corresponding author: HTbhr_dry@hotmail.comT[1] Y. Chen, D.M. Bagnall, Z. Zhu, T. Sekiuchi, K. Park, K. Hiraga,T. Tao, S. Koyama, M.Y. Shen, T. Goto, J. Cryst. Growth 181 (1997)165.[2] S. Saito, M. Miyayama, K. Koumoto, H. Yanagida, J. Am. Ceram.Soc. 68 (1985) 40–43[3] K. Liu, X. Wu, B. Wang, Q. Liu, Mater. Res. Bull. 37 (2002)2255.[4] J. Tauc, Mater. Res. Bull. 5 (1970) 721.[5] S. Sönmezolu, G. Çankaya,P PN. Serin, T. Serin, Int. Conf. onNanomaterials and Nanosystems, 10-13 August 2009, p. 129.6th Nanoscience and Nanotechnology Conference, zmir, 2010 619

PP mPP vs.P =P (1)P andPoster Session, Thursday, June 17Theme F686 - N1123The Effect of Different Spinning Times on Optical Properties of ZnO Thin Films111111UGöknil BabürUP P*, Sinan DikenP P, Tuba Aye TermeliP P, Banu ErdoanP P, Derya BaharP P, Sava SönmezoluP Pand Güven ÇankayaP1PDepartment of Physics, Faculty of Arts and Science, Gaziosmanpaa University, Tokat 60250, TurkeyAbstract-ZnO thin films were deposited on soda lime glass substrates by sol–gel spin-coating technique. The optical properties of ZnO thinfilms are investigated for different spinning times. The optical band gaps of thin film are found to vary with different spinning times. Theobtained films are also transparent in the UV- visible region.1Zinc oxide (ZnO) is an inexpensive, n-type semiconductorof wurtzite structure with a direct energy wide band gap of3.2–3.3 eV at room temperature and optical transparency inthe visible range. [1] Recently, ZnO thin films have beenstudied extensively due to their potential applications, astransparent electrodes in display, metal oxide semiconductorsin optoelectronic devices, and piezoelectric devices [2] .In this paper, we report the investigation of ZnO thin filmsprepared by sol-gel spin coating process using zinc acetate(ZnAc). The optical characterization is investigated fordifferent spinning times using Perkin Elmer Lambda 35 UV-VIS Spectrometer at room temperature.(Alfahv) 2 (eV/m) 2128430 sec, E g=3.75 eV90 sec, E g=3.74 eV100 sec, E g=3.76 eV120 sec, E g=3.74 eV180 sec, E g=3.79 eVTransmittance (%)1008060402030 sec90 sec100 sec120 sec180 sec0200 400 600 800 1000 1200Wavelenght (nm)Figure1. UV–VIS spectra of the ZnO thin film for various spinningtimes.In order to prepare a ZnO solution, first, 3.35gr zinc acetate(Zn(CHR3RCOO)R2R·2HR2RO, Merck), used as a precursor, wasdissolved in 50 ml ethanol [CR2RHR6RO, Merck] and stirred for 5min at 60 °C in a magnetic mixture. Then, 5 ml glacial aceticacide [CR2RHR4ROR2R, Merck] and 1.5 ml hydrochloride acid (HCl,Merck) were added in the solution, and the final solution wassubjected to the magnetic mixture for 2 h. Here, glacial aceticacid and hydrochloride acid were used as an inhibitor to slowdown the zinc acetate fast hydrolysis. Prior to the coatingprocess, the glass was washed with water, ultrasonicallycleaned in ethanol for 20 min, and in acetone for 20 min,respectively. The deposition was carried out at a spinningspeed of 3000 rpm for 30 s, 90 s, 100s, 120 s and 180 s,respectively. The spin coating procedure was continuouslyrepeated five times at 300 °C temperature different spinningtimes.Figure1 shows the UV–VIS spectra ZnO thin films fordifferent spinning times in wavelength range 300–1100nm.The transmission of the thin films of zinc oxide increases withthe increasing in spinning times.02 2.4 2.8 3.2 3.6 4Photon energy (eV)2Figure 2. The plot of (Alfahv)P P vs.different spinning times.hv of the ZnO thin films forThe optical band gap of the film was calculated by thefollowing relation [3]:r(Alfahv) = A (hv - ERgR) P7where A is an energy-independent constant between 10P8 -110PP, Eg is the optical band gap and r is a constant, whichdetermines type of optical transition, r = 1/2, 2, 3/2 or 3 forallowed direct, allowed indirect, forbidden direct andforbidden indirect electronic transitions, respectively [3]. The1/r(Alfahv)P hv curves were plotted for different r values andthe best fit was obtained for r = ½. The film at variousannealing temperatures shows a direct allowed transition. Theoptical band gap was determined by extrapolating the linear2portion of the plots to (Alfahv)P 0. The optical band gaps ofthe thin film were found to be 3.75, 3.74, 3.76, 3.74 and 3.79 eVat 30s, 90s, 100s, 120s and 180s spinning times, respectively. Thethicknesses of ZnO film were also determined from transmittancemeasurements in Figure1 and found to be 354, 664, 345, 280 and288 nm, respectively. The optical band gap increases with theincreasing spinning times, as expected. The increasing of bandgap values can be linked with the decreasing of film thickness.In summary, the analysis of the transmission spectra showsthat ZnO thin films are transparent in the UV-visible regionirrespective of the different spinning times. This work waspartially supported by the Scientific Research Commission ofGaziosmanpaa University (Project No: 2009/29).*Corresponding author: goknil_babur @hotmail.com[1] T.K. Gupta, J. Am. Ceram. Soc. 73 (1990) 1817.[2] J.B. Webb, D.F. Williams, M. Buchanan, Appl. Phys. Lett. 39(1981) 640.[3] J. Tauc, Mater. Res. Bull. 5 (1970) 721.6th Nanoscience and Nanotechnology Conference, zmir, 2010 620

PP mPP vs.P =P,PP (1)P andPoster Session, Thursday, June 17Theme F686 - N1123The Effect of Film Thickness on the Optical Properties of ZnO Thin Films111111UBanu ErdoanUP P*, Derya BaharP P, Göknil BabürP P, Sinan DikenP P, Aye Tuba TermeliP P, Sava SönmezoluPPand Güven ÇankayaP1PDepartment of Physics, Faculty of Arts and Science, Gaziosmanpaa University, Tokat 60250, TurkeyAbstract-ZnO thin films were deposited on soda lime glass substrates by sol–gel spin-coating technique. The opticalproperties of ZnO thinfilms are investigated for different film thickness. It showed that the optical band gaps of thin filmdecreased with increasing film thickness, onthe contrary, transmission of thin films increased with increasing film thickness.1Zinc oxide (ZnO) is one of the most important group II–VIsemiconductor materials. ZnO is one of the most promisingmaterials for the fabrication of the next generation ofoptoelectronic devices in the UV region and optical or displaydevices. As a matter of fact, simultaneous occurrence of bothhigh optical transmittance in the visble range, and lowresistivity make ZnO an important material in the manufactureof heat mirrors used in gas stoves, conducting coatings inaircrafts glasses to avoid surface icing, and thin filmelectrodes in amorphous silicon solar cell [1]. ZnO is also usedto fabricate piezoelectric micro-force sensor chip[2].In this paper, we report the investigation of ZnO thin filmsprepared by sol-gel spin coating process using zinc acetate(ZnAc). The optical characterization is investigated fordifferent film thickness using Perkin Elmer Lambda 35 UV-VIS Spectrometer at room temperature.Transmittance (%)100806040205 layer10 layer15 layer20 layer0200 400 600 800 1000 1200Wavelenght (nm)Figure1. UV–VIS spectra of the ZnO thin film for different filmthicknessIn order to prepare a ZnO solution, first, 3.35gr zinc acetate(Zn(CHR3RCOO)R2R·2HR2RO, Merck), used as a precursor, wasdissolved in 50 ml ethanol [CR2RHR6RO, Merck] and stirred for 50min at 60 P PC in a magnetic mixture. Then, 5 ml glacial aceticacide [CR2RHR4ROR2R, Merck] and 1.5 ml hydrochloride acid (HCl,Merck) were added in the solution, and the final solution wassubjected to the magnetic mixture for 2 h. Here, glacial aceticacid and hydrochloride acid were used as an inhibitor to slowdown the zinc acetate fast hydrolysis. Prior to the coatingprocess, the glass was washed with water, ultrasonicallycleaned in ethanol for 20 min, and in acetone for 20 min,respectively. The deposition was carried out at a spinningspeed of 3000 rpm for 30 s. The spin coating procedure wasrepeated for 5 layers, 10 layers, 15 layers and 20 layers on glasssubstrate at 300 ºC temperature.Figure 1 shows the UV–VIS spectra ZnO thin films fordifferent film thickness in wavelength range 300–1100nm.The transmission of thin films increases with increased thefilm thickness. The diffrerence related to the grain boundariesare observed as the film grows thicker. [3].(hv) 2 (eV/m) 2543215 layer, E g= 3.66 eV10 layer, E g= 3.59 eV15 layer, E g= 3.63 eV20 layer, E g = 3.64 eV02 2.4 2.8 3.2 3.6 4Photon energy (eV)2Figure2. The plot of (hv)P P vs. hv of the ZnO thin film for differentfilm thickness.The optical band gap of the film was calculated by thefollowing relation [4]:r(hv) = A (hv - ERgR) P7where A is an energy-independent constant between 10P8 -110PP, Eg is the optical band gap and r is a constant, whichdetermines type of optical transition, r = 1/2, 2, 3/2 or 3 forallowed direct, allowed indirect, forbidden direct andforbidden indirect electronic transitions, respectively[4]. The1/r(hv)P hv curves were plotted for different r values andthe best fit was obtained for r = ½. The film at variousannealing temperatures shows a direct allowed transition. Theoptical band gap was determined by extrapolating the linear2portion of the plots to (hv)P 0. The optical band gaps of thethin film were found to be 3.66, 3.59, 3.63 and 3.64 eV at 300 ºCannealing temperature. The thicknesses of ZnO film were alsodetermined from transmittance measurements in Figure1 andfound to be 302, 308, 385 and 695 nm, respectively. The opticalband gap decreases with the increasing film thickness.In summary, the analysis of the transmission spectrashows that ZnO thin films are transparent in the UV-visibleregion irrespective of the film thickness. This work waspartially supported by the Scientific Research Commission ofGaziosmanpaa University (Project No: 2009/29).*Corresponding author: bnrdgn@gmail.com[1] M. Suchea, S. Chiritoulakis, K. Moschovis, N. Katsarakis, G.Kiriakidis, Thin Solid Films 515 (2006) 551.[2] S.S. Lee, R.M. White, Sens. Actuators A 71 (1998) 153–157.[3]. C.J. Brinker, G.W. Scherer, Sol–Gel Science: The Physics andChemistry of Sol Gel Processing, Academic Press, New York, 1975,p. 87.[4] . Tauc, Mater. Res. Bull. 5 (1970) 7216th Nanoscience and Nanotechnology Conference, zmir, 2010 621

P mPP vs.P =P vs.P (1)P andP andPoster Session, Thursday, June 17Theme F686 - N1123Optical Properties of ZnO Thin Films Derived by Sol-Gel Process at Different Spinning Speeds111111USinan DikenUP P*, Tuba Aye TermeliP P, Banu ErdoanP P, Derya BaharP P, Göknil BabürP P, Sava SönmezoluP Güven ÇankayaPDepartment of Physics, Faculty of Arts and Science, Gaziosmanpaa University, Tokat 60250, TurkeyAbstract-In this research, we studied on the optical properties of ZnO thin films derived using sol-gel spin-coating technique at differentspinning speeds. The results show that optical band gap and transmittance varies with different spinning speeds and wavelengths.1Zinc oxide is a versatile material due to its unique optical,electronic and photo-catalytic properties and important area ofapplications in modern solid-state device technology. Themost common applications of doped and undoped ZnO thinfilms are surface acoustic wave devices, transparentconducting electrodes, heat mirrors, solar cells, gas sensors,ultrasonic oscillators and anti-static coatings. One of the maintechnological interests for ZnO thin films based devices lieson their very low cost [1,2].In this study, we focused on some optical properties of ZnOthin films prepared by sol-gel spin coating process using zincacetate (ZnAc). The optical characterization is examined fordifferent spinning speeds using Perkin Elmer Lambda 35 UV-VIS Spectrometer at room temperature.Transmittance (%)100806040201000 rpm2000 rpm3000 rpm4000 rpm0200 400 600 800 1000 1200Wavelenght (nm)Figure 1. UV–VIS spectrum of the thin films for various spinningspeeds.In order to prepare a ZnO solution, first, 3.35gr zincacetate (Zn(CHR3RCOO)R2R·2HR2RO, Merck), used as a precursor,was dissolved in 50 ml ethanol [CR2RHR6RO, Merck] and stirred0for 5 min at 60 P PC in a magnetic mixture. Then, 5 ml glacialacetic acide [CR2RHR4ROR2R, Merck] and 1.5 ml hydrochloride acid(HCl, Merck) were added in the solution, and the finalsolution was subjected to the magnetic mixture for 2 h. Here,glacial acetic acid and hydrochloride acid were used as aninhibitor to slow down the zinc acetate fast hydrolysis. Prior tothe coating process, the glass was washed with water,ultrasonically cleaned in ethanol for 20 min, and in acetone for20 min, respectively. The deposition was carried out at at 300°C for 30 s. The spin coating procedure was continuouslyrepeated five times at 1000 rpm, 2000 rpm, 3000 rpm and4000 rpm spinning speeds on glass substrate.Figure 1 shows that transmission of thin films increases withrising values of spinning speed. This situation is attributed tothe crystallite shape and the size, the roughness of the lm andthe characteristics of the grain boundaries, etc. [3].(h v) 2 (eV/m) 2121086421000 rpm, E g = 3.55 eV2000 rpm, E g = 3.69 eV3000 rpm, E g = 3.67 eV4000 rpm, E g = 3.72 eV02 2.4 2.8 3.2 3.6 4Photon Energy (eV)2Figure 2. The plot of (hv)P hv of the ZnO thin film for variousspinning speeds.The optical band gap of the film was calculated by thefollowing relation [4]:r(hv) = A (hv - ERgR) P7where A is an energy-independent constant between 10P8 -110PP, Eg is the optical band gap and r is a constant, whichdetermines type of optical transition, r = 1/2, 2, 3/2 or 3 forallowed direct, allowed indirect, forbidden direct andforbidden indirect electronic transitions, respectively [5]. The1/r(hv)P hv curves were plotted for different r values andthe best fit was obtained for r = ½. The film at variousspinning speeds shows a direct allowed transition. The opticalband gap was determined by extrapolating the linear portion of2the plots to (hv)P 0. The thicknesses of ZnO films werealso determined from transmittance measurements in Figure 1and found to be 1055, 733,494 and 338 nm, respectively. Theoptical band gaps of the thin film were also found to be 3.55,3.69, 3.67 and 3.72 eV at 1000, 2000, 3000 and 4000 rpmspinning speeds, respectively. The optical band gap increaseswith the rising spinning speeds.To sum up, the analysis of the transmission spectra showsthat ZnO thin films are transparent in the UV-visible regionirrespective of the spinning speeds. Besides the optical bandgap energy ranges between 3.55eV and 3.72eV.This work was partially supported by the Scientific ResearchCommission of Gaziosmanpaa University (Project No:2009/29).*Corresponding author: HTsinandiken@hotmail.comT[1] M. Berber et al., Scripta Materialia 53 (2005) 547.[2] R.M. Mehra et al., Materials Science-Poland Vol. 23, No3 (2005)685.[3] M. Smirnov, C. Baban, G.I. Rusu, Appl. Surface Science 256(2010) 2407[4] J. Tauc, Mater. Res. Bull. 5 (1970) 721.[5] N.F. Mott, E.A. Davis, Electronic Process in Non-CrystallineMaterials, Calendron Press, Oxford, 1979.6th Nanoscience and Nanotechnology Conference, zmir, 2010 622

PP andPoster Session, Thursday, June 17Theme F686 - N1123Photon Scanning Tunneling Microscopy System for Observing Optical Excitations at NanoscaleTunnel Junctions111Tansu ErsoyP P, Mehmet Selman TamerPUOuzhan GürlüUP P*1Pstanbul Technical University, Department of Physics, Maslak, 34469, stanbul, TurkeyAbstract-We are developing an optical system which is capable of collecting the photons emitted from the tunnel junction of a scanningtunneling microscope. These systems allow mapping the photon emission from a surface with sub nanometer spatial resolution. Electronic andoptical properties of nanostructures like quantum dots or quantum wires will be studied by this system.Images with atomic resolution of semiconductor and metalsurfaces can be obtained using scanning tunneling microscopy(STM) [1]. Moreover optical and electronic properties of thesesurfaces can be examined by STM at nanoscale [2]. Thetunneling current between the tip and the surface can exciteoptical transitions on the surface [3]. This is calledelectroluminescence due to inelastic tunneling. STM-lightemission experiment is a recently emerging and very usefultechnique for investigating optical properties of surfaces withnanometer resolution [4].Nanostructures have different characteristics from bulkmaterials. As the size of the materials approach to nanoscale,quantum effects appear, which is very important for deviceapplications [5]. If a semiconductor crystal becomes verysmall, motion of the charge carriers is restricted. Thisphenomenon is known as quantum confinement. This resultsin sharp electronic states in these structures. In order tounderstand quantum effects there are numerous studies fordeveloping nanostructures and methods for investigating theirelectronic and optical properties [4,5,6].Metals also behave unconventionally physical properties atnano scale. For instance Ag films coated on glass or mica hasa rough structure due to which the surface plasmon polaritonsare confined. These effects the optical properties of the filmsgreatly like giving the film unexpected color. Using thephoton scanning microscope one can study the local electroopticalproperties [7] of these films and their interaction withadsorbates.most efficient way [10] and they have to be spectroscopically.analyzed. Thus, electroluminescence spectroscopy atnanoscale can be performed.Figure 2. In inelastic tunneling, electrons that tunnel from the tip tothe surface lose some of their energy. Photons are generated in thisprocess. Energy lost due to excitations can be observed byconductivity measurements. They appear as peaks in the secondderivative of the tunneling current with respect to sample bias [9].Figure 3. A simple representation of photon STM setup.First we are planning to investigate optical properties ofmetal surfaces like vacuum evaporated rough Au or Ag filmson glass. Later on we will investigate core/shell quantum dotslike CdSe/ZnS. Optical behavior of QDs on gold surfaces willbe observed by STM induced light emission technique.Depending on structures and positions of QDs on gold surfacewe are expecting variations in their optical behaviors.Moreover, we will investigate the results of the interactions ofQDs with various surfaces and with their environments.*Corresponding author: HTgurlu@itu.edu.trTHFigure.1. (a) STM image of sputter coated Ag film on glass.(500 nm x 500 nm at Vs = 2.0 V and I = 5.0 nA.). (b) Photonmap of the surface due to inelastic tunneling [7].In this work, we are designing a setup which is suitable forSTM light emission experiments. When inelastic electrontunneling occurs at nanoscale tunnel junctions, photonemission is possible [8] (Figure.2). Our aim is to develop theexperimental setup which will allow investigating the systemsthat cause photon emission from these tunnel junctions.The main problem in these experiments is low photonefficiency in most of the physical systems to be investigated.Therefore the generated photons have to be collected in the[1] G. Binning, H. Rohrer, Ch. Gerber and E. Weibel, Phys. Rev.Lett. 50, p 120 (1983).[2] R. Berndt, R. Gaisch and W. D. Schneider, Phys. Rev. Lett. 74,102 (1995).[3] M,J. Romero, et al., Nanoletters 6, 2833 (2006).[4] T. Tsuruoka, Y. Ohizumi and S. Ushioda, App. Phys. Lett. 82,3257 (2003).[5] L. Turyanska, et al., App. Phys. Lett. 89, 092106, (2006)[6] R. Cingolani and R. Rinaldi, Phys. Stat. Sol. 234, 411 (2002).[7] T. Arai, K. Nakayama, Applied Surface Science 246, 193 (2005)[8] D. Fujita, K. Onishi, and N. Niori, Nanotechnology 15, 355(2004).[9] http://www.fkf.mpg.de/kern/research/nanooptics/pstm.1.html[10] N. J. Watkins, J. P. Long, Z. H. Kafafi, and A. J. Makinen, Rev.Sci. Inst. 78, 053707 (2007).6th Nanoscience and Nanotechnology Conference, zmir, 2010 623

PP mPP vs.P vs.P =P (1)P andPoster Session, Thursday, June 17Theme F686 - N1123The Coating Layers Dependence of Optical Properties of ZnO Thin Films111111UTuba Aye TermeliUP P*, Banu ErdoanP P, Derya BaharP P, Göknil BabürP P, Sinan DikenP P, Sava SönmezoluP Pand Güven ÇankayaP1PDepartment of Physics, Faculty of Arts and Science, Gaziosmanpaa University, Tokat 60250, TurkeyAbstract-We have prepared ZnO thin films using sol–gel spin-coating technique, and investigated the optical properties of these thin films fordifferent coating thickness.The film thickness increased with increasing coating layers, on the contrary, the optical band gaps of thin filmdecreased with increasing coating layers. This difference is attributed to the containing its high grain size, and inhomogeneity. Furthermore, theobtained films are transparent over %70-80 in the UV- visible region.1ZnO thin films now attract significant attention due to theirwide range of electrical and optical properties. They havepotential application in electronics, optoelectronics andinformation technology devices including displays, solar cellsand sensors [1,2].In this paper, we report the investigation of ZnO thin filmsprepared by sol-gel spin coating process using zinc acetate(ZnAc). The optical characterization is investigated fordifferent coating thickness using Perkin Elmer Lambda 35UV-VIS Spectrometer at room temperature.Transmittance (%)100806040203 layers5 layers7 layers9 layers12 layers0200 400 600 800 1000 1200Wavelenght (nm)Figure 1. UV–VIS spectra of the ZnO thin film for various coatinglayers.In order to prepare a ZnO solution, first, 3.35gr zinc acetate(Zn(CHR3RCOO)R2R·2HR2RO, Merck), used as a precursor, wasdissolved in 50 ml ethanol [CR2RHR6RO, Merck] and stirred for 50min at 60 P PC in a magnetic mixture. Then, 5 ml glacial aceticacide [CR2RHR4ROR2R, Merck] and 1.5 ml hydrochloride acid (HCl,Merck) were added in the solution, and the final solution wassubjected to the magnetic mixture for 2 h. Here, glacial aceticacid and hydrochloride acid were used as an inhibitor to slowdown the zinc acetate fast hydrolysis. Prior to the coatingprocess, the glass was washed with water, ultrasonicallycleaned in ethanol for 20 min, and in acetone for 20 min,respectively. The deposition was carried out at a spinningspeed of at 3000 rpm for 30 s. The spin coating procedure wasrepeated for 3 layers, 5 layers, 7 layers, 9 layers and 12 layerscoating thickness at the same temperature (400 ºC), respectively.Figure 1 shows the UV–VIS spectra ZnO thin films fordifferent coating layers in wavelength range 300–1100nm. Thetransmission of the thin films of zinc oxide decreases with theincrease in coating thickness, except 12 layers. This can belinked with containing its high grain size, and inhomogeneity [3].(Alfahv) 2 (eV/m) 214121086423 layers5 layers7 layers9 layers12 layers02 2.4 2.8 3.2 3.6 4Photon energy (eV)1/rFigure 2. The plot of (Alfahv)P hv of the ZnO thin film forvarious spinning speeds.The optical band gap of the film was calculated by thefollowing relation [4]:r(Alfahv) = A (hv - ERgR) P7where A is an energy-independent constant between 10P8 -110PP, Eg is the optical band gap and r is a constant, whichdetermines type of optical transition, r = 1/2, 2, 3/2 or 3 forallowed direct, allowed indirect, forbidden direct andforbidden indirect electronic transitions, respectively [4]. The1/r(Alfahv)P hv curves were plotted for different r values andthe best fit was obtained for r = ½. The film at variousannealing temperatures shows a direct allowed transition. Theoptical band gap was determined by extrapolating the linear2portion of the plots to (Alfahv)P 0. The optical band gaps ofthe thin film were found to be 3.57, 3.55, 3.43, 3.71 and 3.63 eV0at 400P PC in different coating layers, respectively. The thicknessesof ZnO film were also determined from transmittancemeasurements in Figure1 and found to be, 117, 294, 560, 975 and815 nm, respectively. It has shown that there is irregularrelation between optical band gap and coating layers.In summary, the film thickness increased with increasing coatinglayers, on the contrary, the optical band gaps of thin film decreasedwith increasing coating layers. This work was partially supportedby the Scientific Research Commission of GaziosmanpaaUniversity (Project No: 2009/29).*Corresponding author: HTt.aysedonmezoglu@hotmail.comTH[1] S. Bandyopadhyay, G.K. Paul, S.K. Sen, Sol. Energy Mater. Sol.Cells 71 (2002) 103.[2] Y. Natsume, H. Sakata, Thin Solid Films 372 (2000) 30.[3] S. Fujihara, C. Sasaki, T. Kimura, Appl. Surf. Sci. 180 (2001)341.[4] J. Tauc, Mater. Res. Bull. 5 (1970) 721.6th Nanoscience and Nanotechnology Conference, zmir, 2010 624

Poster Session, Thursday, June 17Theme F686 - N1123Plasmonics: Novel On-Chip InterconnectionsAbstract— We report antenna designs for surface plasmon polariton coupling to metal-insulator-metal waveguides. Theresulting plasmonic modes were tuned for maximum propagation length along the waveguide: for 1550 nm, we have observedmore than 40 micron propagation (along the length of the waveguide, +x direction) while for 532 nm this is below 10 micron.Our results lay the foundations for on-chip coupler-waveguide-photodetector interconnect technology.State-of-the-art on-chip and chip-to-chip technologies relyon copper interconnects. Ever increasing data transfer ratesand Moore’s Law dictate smaller devices packed into the samearea [1]. Besides, International Technology Roadmap forSemiconductor Industry reports project devices that processand transmit data faster. Interconnections, not chips, havebecome the limiting factor for the future of scaling. Copperinterconnects cannot meet the demanding data transfer raterequirements and have significant bandwidth limitations dueto RC time delays, resistive losses, and frequency dependentcross-talk at high modulation frequencies. In addition to theselimitations, electronic information transmission on a chip alsosuffer from impedance mismatch. On the device side, there isa high impedance and low capacitance, while transmissionlines have low impedance and high capacitance. Thismismatch limits the power transfer, even for the optimumcases [2-4].The incident light’s polarization significantly changes thecoupling efficiency. Because antennas couple SPP’s to thewaveguides in the near-field, the distance between the antennaand the waveguide was kept smaller than 50 nm. The antennashould not be connected to the waveguide either; otherwiseinterference of plasmonic modes reduces propagation length.Antenna and waveguide parameters were swept and the fieldprofiles were compared for metal layer thicknesses of 100,150 and 200 nm. The longest propagation length has beenachieved for 200 nm, while above 200 nm, the propagationlength is no longer enhanced by changing the thickness.Thinner arms (60nm) tend to propagate SPP’s over longerdistances. Reducing antenna gap enhanced local field betweenthe arms, but did not increase the propagation length.Surface plasmon polaritons (SPP) are collective electronoscillations along the interface of metal and a dielectric.Because of the fast decaying fields both inside the metal andthe dielectric, the mode field profile is highly confined alongthe interface. That is why; SPP’s can be a solution forachieving high integration densities, due to the smallattenuation lengths, i.e. 14 nm as our simulations show. SPP’sare proposed to be the data transfer medium for on-chipclocking and signaling. The proposed geometry fortransferring SPP’s is a metal-insulator-metal (MIM)waveguide structure where coupled SPP’s propagate along thetwo metal-insulator interfaces over long distances.In this work, we introduced a simple nanoantenna couplerand a metal-insulator-metal waveguide for demonstrating thepossibility of high density and reliable interconnects. Theinterconnect structure is as in Figure (a) and is placed on 500nm thick thermal oxide. Metallic nanoposts in front of thewaveguide behave as an antenna, increasing the coupling ofoptical field into the waveguide. The waveguide consists ofsilver cladding and silicon oxide core. The structure is excitedby plane waves from the left, propagating to the right. Thesimulations were repeated to optimize the structures over theantenna arm lengths and widths, gaps, metal layer thicknesses,and waveguide-to-antenna distances. The design wasoptimized for the longest propagation distance for thetelecommunication wavelength of free space = 1550 nm. Forefficient coupling, (i) arm length and the cladding width havebeen assumed to be equal, (ii) the arm gap and the core widthare taken as equal. Our simulations (not shown) indicated thatnot making these two assumptions significantly reducedcoupling efficiency.Figure: (a) Simulation volume, incident wave, nanoantenna and the waveguidestructure. (b) Top view of the interconnect. (c) E-field profile along the center of thewaveguide and the antenna (y=0 line), normalized with respect to incident field(d) E-field enhancement profile along the substrate and the interconnect interface,optimized for free space = 1550 nm (e) Normalized E-field intensity profile along thesubstrate and the interconnect interface, for free space = 780 nm.The propagation distances for = 532 nm, 780 nm,1550nm were 3, 9, about 50 μm, respectively. Metal’sabsorption progressively increases for shorter wavelengths.That is why; shorter wavelengths cannot propagate as long asin the 1550 nm case.The subwavelength nature of these interconnects enableshigh integration density. We are going to investigate thistechnique for noise immunity and broadband applications.This work was supported by TUBITAK 108E163, 109E044,EU FP7 PIOS.[1] Moore, G. E., Electronics, Vol. 38, No. 8, April 19, 1965[2] ITRS 2007 Edition,http://www.itrs.net/Links/2007ITRS/2007_Chapters/2007_Interconnect.pdf[3] Ali K. Okyay, PhD Thesis, Stanford University, September 2007[4] Gramotnev, Bozhevolnyi; Nature Photonics 4, 83 - 91 (2010)[5] L. Tang et. al., Nature Photonics 2, 226 - 229 (2008)6th Nanoscience and Nanotechnology Conference, zmir, 2010 625

Poster Session, Thursday, June 17Theme F686 - N1123Nanostructures constructed via self-assembly of nanoparticles using DNA hybridizationKemal Keseroglu 1 , Ismail Sayin 1 , Mehmet Kahraman 1 , Elif Hilal Soylu 2 , Semra Ide 2 ,Mustafa Culha* 11 Department of Genetics and Bioengineering, Yeditepe University, Kayisdagi, Istanbul 34755, Turkey2 Department of Physics Engineering, Hacettepe University, Beytepe, Ankara 06532, TurkeyAbstract— In this study, two different nanostructures are constructed with 13 nm gold nanoparticles (AuNPs) by using DNAmolecules. In the first one, the AuNPs are assembled into desired shaped and sized by using pre-designed DNA origamimolecules. As for the second nanostructure, the ODN-bound AuNPs are assembled by ten different DNA linkersindividually; and as a result, the formation of nano-cubic crystal structures is observed by SAXS.Nanoparticles (NPs) are used as buildingblocks for construction of sensors, diagnostic toolsand drug delivery agents [1-3]. However, thebiggest challenges for their use are to constructsuch nanoconstructs via assembly of NPs in desiredgeometry into two dimensional (2D) or threedimensional (3D) structures. Self-assembly of NPscan be achieved using the interactions betweenbiomacromolecules, for instance DNA, peptides,and carbohydrates [4]. Among them, DNA can beconsidered as an ideal molecule for attainingcomplex self-assembly due to its easily expectedsecondary structure and well understood ofhybridization properties.In this work, it is aimed to construct twodifferent nanostructures via self-assembly of goldnanoparticles (AuNPs) by the help of DNA. In thefirst one, 2D nanostructure is constructed. For thispurpose, after two DNA origami-A and B areprepared inspired from study of Hao Yan et.al [5]shown as figure 1, ten thymidine bases bounded 13nm AuNPs are incubated and let hybridize withthem. The constructed nanostructures by NPs areobserved under AFM (figure 2). 13 nm AuNPs areseen up and down side of DNA origami.Figure 3. Schematic representation of net formationafter DNA linker is added to two different ODN-bound13 nm AuNPsThe size of controlled aggregation of thestructure is measured by ZetaSizer. Although thesize of ODN-bound AuNPs is ~20 nm; after the tenDNA linkers added, up to ~200 nm sized structuresare constructed in the suspension. Additionally, thecrystal structure of the construct is observed withSAXS due to more importance of construction ofnano-cubic crystallization. In figure 4, it is seen thatthe AuNPs by the help of DNA linkers make cubicstructures in nano scale.DNA-bound 13nm AuNPOrigami-A Origami-B Origami-AFigure 1. Schematic representation of DNA-bound13 nm AuNP and Origami-A and B(a) (b) (c)(d)Figure 2. AFM images of (a) onlyOrigami-A, (b) AuNP boundOrigami-A, (c) Origami-A andOrigami-B, (d) AuNP boundOrigami-A and B complexFor the second nanostructure, ten differentDNA linker molecules are used to assemble twodifferent types of 13 nm AuNPs which bound withtwo different ODN that have conjugate sequenceswith the ten DNA linkers (figure 3).Figure 4. SAXS analysis after DNA linker is added.In summary, our study shows that it is possibleto construct desired nanostructures with a definiteshape and size using the DNA hybridization power.What is more, the construction of nano-cubiccrystal structures inspires us to use them both inmedicine and material science. This work wassupported by TUBITAK under Grant No. 108T605and Yeditepe University.*Corresponding author: mculha@yeditepe.edu.tr[1] Nyquist RM, Eberhardt AS, Silks LA, Li Z, Yang X,Swanson BI, 2000. Characterization of self-assembledmonolayers for biosensor applications, Langmuir, 16:1793–1800[2] Rosi NL, Mirkin, CA, 2005. Nanostructures inbiodiagnostics, Chem. Rev., 105: 1547–1562[3] Han G., Ghosh P., De M., and Rotello VM, 2007.Drug and gene delivery using gold nanoparticlesNanobiotechnology, 3: 40 45[4] Zhang S, 2003. Fabrication of novel biomaterialsthrough molecular self-assembly, Nature Biotechnology,21: 1171–1178[5] Yan H, Park SH, Finkelstein G, Reif JH, LaBean TH,2003. DNA-templated self-assembly of protein arraysand highly conductive nanowires, Science, 301: 1882–1884.6th Nanoscience and Nanotechnology Conference, zmir, 2010 626

PP and770 772 774 776 778 780 782 784 786 788 790Poster Session, Thursday, June 17Theme F686 - N1123Characterization of a Multilayer GaAs/AlGaAs Broadband Quantum Well Infrared Photodetectors11111UHülya KuruUP P*, Burcu ArpapayP P, Bülent ArkanP P, Bülent AslanP Uur SerincanP1PDepartment of Physics, Anadolu University, Eskiehir 26470, TurkeyAbstract-In this study, we report on the investigation of a multilayer GaAs/AlGaAs quantum well infrared photodetector designed for 8-12 mspectral range detection. Fabricated devices were characterized by performing various methods of measurements: current-voltage,photoluminescence and photoresponse as a function of applied bias.After developing the ability to grow multilayersemiconductor quantum structures, GaAs/AlGaAs multiplequantum wells (MQWs) have been intensively investigatedbecause of their potential applications in advanced optoelectronicdevices [1]. These studies resulted in a continuousimprovement of the performances and the appearance of noveldevices. In particular, infrared detectors based on intersubbandtransitions in GaAs/AlGaAs MQW structures exhibit manyadvantages over the conventional band-to-band HgCdTedetectors, and represent an interesting alternative for thedetection of the mid- and far-infrared regions (i.e. wavelengthslonger than 3μm) [1,2].The sample used in this study was grown by molecular beamepitaxy (MBE) on (100) GaAs substrate. It consists of 10periods of the following symmetric structure (from substrateto top): 40 nm of AlGaAs (20% Al) barrier, 6 nm GaAs QW,20 nm AlGaAs (20% Al), 10 nm graded AlGaAs (from 20%to 25% Al), 10 nm AlGaAs (25% Al), 5 nm GaAs QW. This10 repeat structure is sandwiched between a 6 nm GaAs QWand thick doped contact layers. The central parts of the wellsare Si-doped to have the active carriers in the structures. Thetop and bottom GaAs contact layers are 400 nm and 700 nm,18 2respectively and doped with 1×10PP cmP P. Mesas were definedby wet chemical etching and top and bottom contacts weremade by depositing Ge/Au/Ni/Au followed by annealing.Different size square devices (400 m, 600 m, 800 m, 1000m and 1500 m) having a ring top contact were fabricated totest the uniformity of the wafer and the quality of thefabrication. For the photoresponse (PR) measurements, samplewas mounted in a liquid nitrogen cooled dewar with ZnSewindow. A Bruker Equinox55 Fourier transform infraredspectrometer with a globar source was used. A 7 mW HeNelaser (632.8nm) was used as an excitation source inphotoluminescence experiments. For optical measurements,devices were illuminated through the top opening. Allmeasurements were performed at a cold head temperature of80 K.I(A)0.10.011E-31E-41E-580K1500*1500m 21000*1000m 2800*800m 2600*600m 21E-6-10 -8 -6 -4 -2 0 2 4 6 8 10Voltage(V)Figure 1. Current–voltage characteristics for the devices of differentsizes at 80K.Current-voltage characteristics measured at 80K are shownin figure 1. Figure 2 shows the PL signal coming from thequantum well states under different bias values at 80 K. Asseen in figure 3, spectral photoresponse of the devices are in7-12 m region as designed. And the response has voltagedependence: the maximum signal was obtained when thedevice is biased with 0.5 V.PL Intensity(a.u.)100090080070060050040030020010000 volt1 volt2 volt3 volt730 740 750 760 770 780 790 800 810 820 830 840Wavelength(nm)Figure 2. Photoluminescence signal under different bias values at80K.Photoresponse (a.u.)0.15 V0.30 V0.50 V0.80 V1.00 V1.30 V4 5 6 7 8 9 10 11Wavelength (m)Figure 3. Spectral photoresponse under different bias values at 80K.In summary, we reported on the experimentalobservations of a multilayer GaAs/AlGaAs QWIP.Photoresponse measurements have shown that the devices areworking the intended spectral region: 8-12 m atmosphericwindow. The voltage dependence of photoluminescence isused to probe the energy levels involved in certain transitions.This work was supported by TUBITAK under Grant No.TBAG-107T012. We thank Prof. Dr. Atilla Aydnl and Prof.Dr. Rait Turan for device fabrication and photoresponsecharacterization steps.*Corresponding author: hulya_kuru@hotmail.com[1] Levine B.F.1993 J. Appl. Phys. 74 R1[2]Liu H.C.2000 Intersubband Transitions in Quantum Wells:Physics and Device Applications I, Semiconductors and Semimetalsvol 62 ed R. K. Willardson and E. R. Weber (San Diego: Academic)pp129-9680K80K6th Nanoscience and Nanotechnology Conference, zmir, 2010 627

TTTandTTsizeTTdeconvolutionThybridPPTGaussianTfollowsTTandTPoster Session, Thursday, June 17Theme F686 - N1123Calculating the Homogeneous Spectrum of PbSe Quantum Dot based on Fourier-Wavelet Deconvolution112UA.A. AskariUP P*, L. RahimiP Pand A.R. BahrampourPPDepartment of Physics, Shahid Bahonar University, Kerman, IranPDepartment of Physics, Sharif University of Technology, Tehran, Iran21Abstract— Homogeneous absorption and emission spectra of PbSe quantum dots (QDs) with an average diameter of 6.8 nm is obtained byemploying a deconvolution procedure. Deconvolution is a noise sensitive process. To avoid numerical instabilities and noise amplificationduring deconvolution, an efficient, hybrid Fourier-wavelet algorithm is proposed. This technique predicts a large homogeneous line-width,which is in good agreement with the recently measured data.SemiconductorT Tnano-TTcrystalsT ThaveT TrecentlyT TattractedTTconsiderableT TattentionT TdueT TtoT TtheTT varietyT TofTTapplications,T TincludingT Tlasers,T TphotovoltaicT TsolarT Tcells,lightT TemittingT Tdiodes,T TfieldT TeffectT Ttransistors,T TetcT T[1-3].TTSemiconductor QDs,T TsuchT TasT TPbST TandT TPbSeT Thave aAbsorbance (a.u.)0.6 (a)0.40.21 1.5 2 2.5 30.4(b)0.30.20.100.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6relativelyT TlargeT effective TexcitonT TBohrT TradiusT T[4].T TThusTTtheT TregimeT TofT TstrongT Tquantum-confinementT TofT TbothT TtheT0.6 (c)0.2 (d)TelectronT TandT TholeT TcanT TbeT TmoreT TeasilyT TaccessedT TinT TtheseTTmaterials.T TFurthermore,T TtheT TleadT TchalcogenideT TQDsT TcanTThaveT TabsorptionT TandT TemissionT TspectraT TinT TtheT T1-2T TμmTTrange,T TwhichT TmakesT TthemT TappropriateT TcandidatesT TforTAbsorbance (a.u.)0.50.40.30.20.101 1.5 2 2.5 3Energy (eV)0.150.10.0500.6 0.7 0.8 0.9 1 1.1 1.2Energy (eV)TtelecommunicationsT TapplicationsT T[5].T TTheT Tline-widthT TofTTtheT TemissionT TandT TabsorptionT TspectrumT TdependsT TonT TbothTTtheT ThomogeneousT TandT TinhomogeneousT TbroadeningTTmechanisms.T TExcludingT TinhomogeneousT TbroadeningTTassociatedT TwithT TaT TdistributionT TofT TQDs,T TtheT TintrinsicTThomogeneousT Tline-width,T T,T TofT TanT TopticalT TtransitionT Tis TTinverselyT TproportionalT TtoT TdephasingT TtimeT TTR2 R( /T 2)TTDifferentT TmechanismT TsuchT TasT TphononT Tinteraction,TTlifetimeT TbroadeningT TandT Tcarrier-carrierT TinteractionT TcanTTare responsible forT the ThomogeneousT Tbroadening ofsemiconductor QDsT T[6].From the theory of optical line shapes, thehhomogeneous, , and inhomogeneous, , absorption ora , ea, eemission spectra can be related via the following equation, h a ea,e)0( v) P(R) ( v,R dR . (1)Here, P(R) is the probability distribution function of QDs withmean radius R. Equation 1 can be rewritten asha, e( v) g(v)a,e( v)(2)Where g()=P(R()) dR/d and * is the convolution operator.TThe convolutionT ToperatorT TsimplifiesT TtoT TscalarT TproductT Tin TTFourier'sT Tdomain,T TandT ThenceT TtheT ThomogeneousT TspectrumT TcanTTbeT TobtainedT TviaT TaT TprocedureT TasTTh1 Ga,e( v) F ( ) . (3)THere,T TGTa,eTRa,eRT TareT TtheT TFourierT TtransformsT TofT TgTTRa,eRTTrespectively.T TWhenT TtheT TinverseT TsystemT TisT Till-conditionedT TorTTnon-invertible,T TdeconvolutionT TleadsT TtoT TnonsenseT Tresults.T TToTTavoidT TnumericalT TinstabilitiesT TduringT the TdeconvolutionTTprocedure,T TweT TemployedT TaT TFourier-waveletT TinverseTTfilterT TforT TdeconvolutionT TandT TdenoisingT TsimultaneouslyT T[7].TFiguresT T(1-a)T TandT (T1-b)T TshowT TtheT TinhomogeneousTFigure 1. (a and b) Inhomogeneous spectra of PbSe QDs TwithTTanT TaverageT TdiameterT TofT T6.8±0.3T Tnm, T(c) Homogeneous spectraobtained via the deconvolution procedure. (d) Homogeneous(solid curves) and inhomogeneous spectra (dashed curves).Symlet 7 filter [7] TisT TusedT TandT TnumericalT TresultsT TareT TshownTTinT TfigureT T(1-c).T TFigureT T(1-d)T TillustratesT TtheT TnormalizedTThomogeneousT T(dashedT Tcurve)T TandT TinhomogeneousT T(solidTTcurve)T TspectraT TcorrespondingT TtoT T1sReR1sRhRT and some othertransitions Tsimultaneously.T TAtT TroomT Ttemperature,T TweT found TaTTlargeT ThomogeneousT TcomponentT T(FWHM25T TmeV TT), TTinTTcomparison toT TensembleT Tbroadening.T TThisT TsituationTTintensifiesT TinT TupperT Ttransitions.T TTheT TlargeT ThomogeneousT TlinewidthTTofT TPbST TandT TPbSeT TQDsT ThasT TbeenT TreportedT TbyT TPetersonTT[9] and Kamisaka [10].In summary, this paper proposed the deconvolutionalgorithm in order to obtain the homogeneousabsorption/emission spectrum from the inhomogeneous one.Deconvolution is an unstable process. To prevent numericalinstabilities during deconvolution, an optimal inverse filterbased on Fourier-wavelet algorithm is employed. Thesimulation results are in good agreement with theexperimental data.*Corresponding author: Askari.s.ali@Gmail.com[1] L.J. Zhao et al., Nano Lett. 6, 463 (2006).[2] V.I. Klimov et al., Science, 290, 314 (2000).[3] D.V. Talapin and C.B. Murray, Sciense, 310, 86 (2005).[4] A.L. Efros and A.L. Efros, Sov. Phys. Semicond. 16, 772 (1982).[5] A.R. Bahrampour et al., Opt. Commun. 282, 4449 (2009).[6] J.L. Skinner, Ann. Rev. Phys. Chem. 39, 463 (1988).[7] A.R. Bahrampour, A.A. Askari, Opt. Commun. 257, 97 (2006).[8] R. Koole et al., Small, 4, No.1, 127 (2008) .[9] J.J. Peterson and T.D. Krauss, Nano Lett. 6, 510 (2006).[10] H. Kamisaka et al., Nano Lett. 6, No. 10, 2295 (2006).TabsorbanceT TspectrumT TofT TanT TensembleT TofT TQDsT TofT TPbSeT TwithTTanT TaverageT TdiameterT TofT T6.8±0.3T TnmT T[8].T TAsT TtheseTT figuresTTshow,T TeachT TtransitionT TisT TmodeledT TwithT TaTTfunction.TTToT TobtainT ThomogeneousT Tspectrum,T TfromT TinhomogeneousTTversion,T TtheTT deconvolutionT TalgorithmT based on Tikhonov-6th Nanoscience and Nanotechnology Conference, zmir, 2010 628

Poster Session, Thursday, June 17Theme F686 - N1123Modal Analysis of Circularly Bent Coupled Optical WaveguidesN. Özlem Ünverdi 1* and N. Aydın Ünverdi 21 Department of Electrical-Electronics Engineering, Yldz Technical University, stanbul 34349, Turkey2 Department of Mechanical Engineering, stanbul Technical University, stanbul 34437, TurkeyAbstract— In this study, a pair of circularly bent, bare, weakly guiding, lossless, multimode and slab optical fibers located inthe same plane was analyzed. The impact of coupling on the modal propagation constant was investigated, and the couplingbetween even TE leaky modes was found to be stronger than the coupling between all other leaky modes.Radiation is tangent to the radiation caustic in circularly bentoptical waveguides. In this study, the interactions ofevanescent fields of optical waveguides are solved byconsidering the problems of determining the behaviour ofincident radiation on a convex surface and modal analysis [1,2].In optics, a beam is an idealized concept of infinitesimallythin light cluster. Light beams are modeled as lines in physicsand optical problems are solved based on geometricalprinciples. In this study, a pair of circularly bent, bare, weaklyguiding, lossless, multimode and slab optical waveguideswhich are surrounded by a simple medium as shown in Figure1, are considered as scattering objects, and the effect of one ofthe waveguide’s radiation on the other waveguide’s behaviouris examined by Geometric Theory of Diffraction (GTD) whichexplains the diffraction of very high frequency waves byasymptotic methods [3-6].utilized by considering the propagation directions of theoptical waveguides. It is obvious that, the coupled bare andslab optical waveguides considered in this study must be in thesame plane.In the analysis, the effective regions of optical waveguides inmutual coupling, which are amongst the important parametersof optical directional couplers, are determined. It is observedthat the effected region of one of the circularly bent coupledoptical waveguides by the other optical waveguide is equal tothe longer arc length between the points of common inner andouter tangents on the radiation caustic. On the other hand, theeffected region of the other waveguide by this waveguide isequal to the shorter arc length. It is concluded that the aboveobservations are independent of the propagation directions, inother words, of the feeding directions of the opticalwaveguides.In this study, in TE and TM leaky modes of opticalwaveguides, the variation in the modal propagation constantbecause of coupling is investigated. As a result of the analysis,it is proved that the coupling between even TE leaky modes ismore efficient than those amongst the other modes. As anatural consequence of coupling mechanism, it is observedthat the coupling amongst the leaky modes and radiationmodes is stronger than those amongst the evanescent fields ofthe guided modes.The authors express their sincere gratitudes to Dr. S. ÖzenÜnverdi for helpful discussions and suggestions.*unverdi@yildiz.edu.trFigure 1. A pair of circularly bent, bare and slab optical waveguides.The path of the light beam on the optical waveguide isdetermined by Fermat principle. In this study, it is assumedthat there are not singular points on the surfaces of theanalyzed optical waveguides, all the surface points areconsidered as regular. In spite of the fact that, according to theGeneral Relativity Theory, the light beams passing nearby theoptical waveguide without hitting it are bent towards thewaveguide, the present coupling analysis neglects this effect.In circularly bent optical waveguides, the radiation is in factinside the beam tube. However, in this study, where the mutualcoupling mechanism of optical waveguides is analyzed andeffective lengths are determined, the aforementioned beamtube is considered as a single beam. In determining theeffected region of an optical waveguide by the radiation of theother waveguide and the effective region of the radiatingoptical waveguide in the coupling phenomena, the “commoninternal tangent” and “common external tangent” concepts are[1] A. W. Snyder and J. D. Love, Optical Waveguide Theory, J. W.Arrowsmith Ltd., Bristol - Great Britain, 1983.[2] N. Ö. Ünverdi, “The Effect of Evanescent Fields of GuidedModes and Leaky Modes on Mutual Coupling of Straight and BentOptical Waveguides”, Ph.D. Thesis, Yıldız Technical University,Istanbul, Turkey, 1998.[3] W. H. Louisell, Coupled Mode Parametric Electronics, JohnWiley & Sons, New York, 1960.[4] C. A. Balanis, Advanced Engineering Electromagnetics, JohnWiley & Sons Inc., New York, 1989.[5] J. M. Senior, Optical Fiber Communications, Second Edition,Prentice-Hall, Cambridge, 1992.[6] M. N. O. Sadiku, Optical and Wireless Communications, CRCPress, New York, 2002.6th Nanoscience and Nanotechnology Conference, zmir, 2010 629

0BPP perP perP isinfiniteP atPoster Session, Thursday, June 17Theme F686 - N1123Semiconductor Nanostructure For 1.55 μm Optical Telecommunications Devices11111UI. AlghoraibiUP P*, C. ParantoenP P, A. Le CorreP P, N. BertruP P, S. LoualicheP1PLENS-FOTON, UMR CNRS 6082, INSA de Rennes, 20 avenue des buttes de Coësmes, Rennes Cedex 35043, FranceAbstract-In this paper, we compare laser performance of devices elaborated on both substrates. After quantum dot elaboration optimization, on(311) B substrates, laser emission at 1.59 μm on the ground state transition is obtained at room temperature (RT), A very low threshold currentdensity (Jth) of 21 A/cm² for the best QD lasers is measured. This value can be compared to the Jth of quantum well (QW) laser, which are in the22few hundred A/cmP P. On (100) substrates laser emission is observed at 1.45 μm for a current density of 375 A/cmP RT. The evolution of the Jthand of the emission wavelength as a function of temperature is studied on both structures. The changes are interpreted in terms of density ofstates and of form of the gain curve.Quantum Dot (QD) and quantum dash (QDHs) lasersstructures are expected to present improved characteristicscompared to bulk or quantum-well (QW) devices. In therecent past, very low threshold current densities (JRthR), chirplessoperation, temperature insensitive and high power laseremission have been reported. However, these performanceshave mainly been achieved using InAs QD active layers onGaAs substrate where the emission is still limited in the 1.3μm range. Much effort has been devoted to extend further thewavelength on GaAs, in order to reach the long haultelecommunication window (1.55 μm), but at the price ofhigher threshold current density and lifetime degradations.Because of a lower lattice mismatch (3.2%) compared toInAs/GaAs (7%), InAs nanostructures grown on InP substrateexhibit optical properties at longer wavelength. The nature ofthese nanostructures appears to widely depend on growthconditions and substrate orientation, nanosized QDs andelongated nanostructures referenced as QDHs can be obtained.The inset of the Figure 1 represents 1x1 m² atomic forcemicroscopy (AFM) images of QDs (Figure 1a) and QDHs(fig1-b) grown on InP(113)B and InP(001) substratesrespectively. QD and QDH dimensions and density have beendetermined. A mean diameter and height of 25 and 5 nm havebeen determined for QD nanostructures, as well as an-2important density of 1011 cmP deduced. Concerning theQDH AFM image, elongated structures are clearly evidenced,width, length and height being respectively 20, 700 and 2.2nm.In this paper, we report a record threshold current density for2a QD laser (JRthR = 23 A/cmP QD layer) grown on InPemitting close to 1.55 μm, as well as the achievement of a-1high gain (7cmP QD layer). The separated confinementheterostructure laser have been grown by gas source MBE in aRiber 32 system. The active region consists of three stackedof QDs or QDHs, separated by 30 nm GaR0.2RInR0.8RAsR0.435RPR0.565R(Q1.18 ) barriers, located at the center of the Q1.18 opticalwaveguide.On the basis of these optimized QD and QDH layers, broadarea lasers with 100 μm stripe width are then processed. Thefacets are left uncoated. The broad area lasers are tested atdifferent temperature from 100 °K to 350 °K under pulsedoperation (0.5 μs pulse width, 2 kHz repetition rate). Theroom temperature (RT) electroluminescence (EL) spectra fromthe both three QD and QDH stacked layer lasers are reportedin the Figure 1 for a 3.1 mm long cavity. Figure 1a shows theEL from InAs QD InP(113)B laser. At low injection (65A/cm²), the EL spectrum exhibits spontaneous emission,which is centered at 1.59 m with a full width at halfmaximum (FWHM) of 67 nm. Figure 1b represents the ELspectra from QDH laser structure. At low injection current(340 A/cm²), spontaneous emission is observed at 1.45 mwith a FWHM of 71 nm. The two lasers exhibit very lowthreshold current density which are at the state of art for QD22laser (JRthR=190A/cmP P) and QDH laser (JRthR=373A/cmP P).The lower threshold current density observed for the QDlaser confirms the higher carrier confinement afforded by theQDs. We have also measured the room temperature lasingcharacteristics of the lasers with different cavity lengths. Ascommonly observed for QD lasers.EL intensity (arb. units)a)1x10 -510 -610 -710 -8QDs10 -91.2 1.3 1.4 1.5 1.6Wavelength (m)300 KpulsedEL intensity (arb. units)b)-6 300 K10pulsed10 -710 -8QDHs10 -91.2 1.3 1.4 1.5Wavelength (m)Figure 1. Room temperature electroluminescence spectra underpulsed operation for several current densities. (a) For a laser cavitylength of 3.06 mm on InP(113)B substrate (J=65, 160, 208 and 220A/cm²), (b) for a laser cavity length of 3.14 mm on InP(001) substrate(J=340, 360, 373, 379 A/cm²). The inset of the1 represents 1x1 μm²of the corresponding (a) InAs QDs and (b) QDHs.The transparency current density are estimated to 21 and 173A/cm² for the QD and QDH lasers respectively .Thetransparency current density per layer as low as 7 A/cm² and60 A/cm² for the QD and QDHs laser respectively which areexceptional low values. This comparison high that QD lasersare good candidates to achieve low threshold and lowconsumption devices. The temperature dependences of the QDand QDH laser threshold current densities have been studied.The temperature dependences of the threshold currentdensities highlight the higher carrier confinement in the caseof QD lasers with a TR0R for temperature lower than 160K. The temperature dependence of the emission wavelength islower for the QDH lasers (0.35 nm/K) than for QD lasers(0.46 nm/K). This lower dependence can be the result of aflatter gain in the case of QDHs or can be due to a weakeroptical confinement in the case of QDH lasers.As a consequence, QD lasers are well suited to achieve verylow-threshold lasers with temperature insensitivity. On theother hand, QDH lasers can be useful for applications likedistributed feedback lasers where the emission wavelengthshift with the temperature is crucial and must be reduced.Finally, it could be very interesting to compare the dynamicbehavior of such lasers and determine the impact of highcarrier confinement on modulation properties.*Corresponding author: ibrahim.alghoraibi@gmail.com6th Nanoscience and Nanotechnology Conference, zmir, 2010 630

Poster Session, Thursday, June 17Theme F686 - N1123Graded-Index Antireflection Coatings for Nanostructured Photovoltaics, Light Emission andPhotodetectionAbstract— The problem of increasing Fresnel reflections around the resonance wavelength of quantum dots, wells and wiresis proposed to be greatly reduced by introducing and optimizing antireflection coatings for visible ( = 400-700nm), nearinfrared(telecommunication wavelengths, = 750-1400nm) and long wave infrared (microbolometer wavelengths, = 8-12m) given an upper limit for the coating thickness. Optimized simulation results show that reflection losses can be reducedbelow 0.1% over wide angular and spectral ranges.After the development of imaging, manipulation,deposition, etching and probing tools for the nanostructure ofmaterials, a vast range of nanomaterials have been introduced.The possibility of engineering the electronic band structure ofthe materials through changing the size of the material at thenanoscale enables researchers achieve novel optical,mechanical, electronic and thermal properties that areunavailable in nature, tunable over a wide range and highlystable. Applications that grew out of this have been the use ofquantum wells, quantum wires and quantum dots forenhancing photovoltaics[1], light emitting diodes[2], lasers[3]and photodetectors [4]. The ability to tune the luminescenceand absorption properties of nanoparticles embedded inside adielectric host comes with its own fundamental drawback:Fresnel reflections between air and the outermost layerincreases significantly around the resonance wavelength of thenanoparticle.Fresnel reflections increase as a function of refractiveindex mismatch between the outermost layer and air. TheFresnel reflection loss of bare silicon is about R=(3.6-1) 2 /(3.6+1) 2 =31.9%. The absorption spectra of nanoparticleshave Lorentzian resonance peaks and by Kramers-Krönigrelations and according to our ellipsometry measurements ofGe quantum dot layers embedded in Silicon (GeNC-in-Si),effective refractive index of the GeNC-in-Si layers increasesfrom n Si = 3.6 upto n effective = 5.1 due to the existence of thedots. Around the resonance wavelength of the nanomaterial,the refractive index mismatch increases and this causesreflection loss to increase beyond that of bare silicon, i.e. R =(5.1-1) 2 / (5.1+1) 2 =45.2%. The increase of index mismatcharound the resonance limits the full utilization of quantum dotsand this increases (i) internal reflections for LED’s, (ii)surface reflections of solar cells, (iii) pumping thresholdcurrent for lasers using nanomaterials as gain materials.For efficient light absorption in solar cells, we haveepitaxially grown Germanium quantum dot layers on siliconwafer. The deposition conditions were chosen deliberately toachieve very large quantum dot size dispersion and thusbroadband absorption enhancement of the whole sample. InFig. 1a, the effective refractive indices of the multilayerGermanium quantum dots in Silicon are compared with that ofbare silicon.In order to reduce surface reflections, producing refractiveindex gradient between air and the layers have been proposed[5, 6]. The layers can be fabricated using the technique calledoblique angle deposition [7]. In our study, we compared andoptimized exponential, linear, sinusoidal and polynomiallygraded refractive index profiles for the coatings.Figure1: (a) Ellipsometric measured refractive index spectra for bare silicon andthe quantum dot embedded sample. (b) Optimized % Reflection for visible,given 1 m total thickness limit. (c) Optimized % Reflection for near infrared,given 1 m total thickness limit. (d) Optimized index profile for long waveinfrared, given 10 m total thickness limit. (e) Optimized % Reflection for longwave infrared (= 8-12m). (f) Angular % Reflection for (e)Because of significant size dispersion of the nanocrystals,there is multitude of resonance wavelengths and this increasesthe sample’s refractive index broadband (Fig.1a). As asolution, graded index antireflection coatings (GIAR) forvisible have been optimized (Reflection spectrum shown inFig.1b). For near-infrared photodetection, GIAR wereoptimized with 1 micron total thickness limit (Fig.1c). Therefractive index profile of the optimized coating for nearinfraredis in Fig.1d.This work was supported by TUBITAK 108E163, 109E044,EU FP7 PIOS.[1] Conibeer, G. Materials Today, Vol. 10, No. 11, 4250[2] Nizamoglu, S., Demir, H. V., Nanotechnology 18 (2007) 405702[3] Strauf, S. et al. Physical Review Letters 96, 127404 (2006).[4] Wang, J. et. al., Science, Vol. 293. no. 5534, pp. 1455 - 1457[5] XI, J.Q. et.al., Nature Photonics, Vol. 1, March 2007, 176179[6] Chhajed, S. et. al. Applied Physics Letters, 93, 251108 (2008)[7] Kennedy, S. R., et. al. , Applied Optics, Vol. 42, No. 22, 4573 45796th Nanoscience and Nanotechnology Conference, zmir, 2010 631

PPP andPoster Session, Thursday, June 17Theme F686 - N1123Magneto-Optical and Optical Properties of Cerium Substituted Yttrium Iron Garnet Thin FilmsPrepared by Sol-Gel Process12211UYavuz ÖztürkUP P*, Mustafa ErolP P, Erdal CelikP P, Ömer MermerP brahim AvgnPPEge University Electrical and Electronics Department, 35100 Bornova, Izmir-TURKEY.PDokuz Eylul University, Department of Metallurgical and Materials Engineering, Tınaztepe Kampüsü, 35160 Buca, Izmir-TURKEY.21Abstract- Cerium doped yttrium iron garnet (CeRxRYR3-xRFeR5ROR12R; Ce-YIG) magneto-optical thin films were fabricated on Si (100) and fusedsilica substrates by using sol-gel method for magneto-optical applications. Ce doped YIG films with nano size regions fabricated with dipand spin coating from two different solutions prepared from Ce, Y and Fe-based precursors, solvent and chelating agent at low temperatureousing a sol-gel technique. Coated thin films annealed at the temperature range of 800 and 1000 P PC for 2 h in air. Optical, morphological,structural and magnetic properties were investigated by scanning electron microscopy (SEM), spectraphotometer, magneto-opticalmeasurement set up and vibrating sample magnetometer (VSM).Ce doped yttrium iron garnet (CeRxRYR3-xRFeR5ROR12R; Ce-YIG)is a promising material for magneto-optical applicationsbecause of its large specific Faraday rotation and lowpropagation loss [1,2]. The available Ce-YIG materialresearch has mainly on a single crystals and thin films [1-4]. Polycrystalline Ce-YIG and its optical and magnetoopticalproperties has rarely been investigated. In thisstudy, we have investigated optical properties of garnetfilms synthesized by using sol-gel method. Sol-gelprocessing offers considerable advantages such as bettermixing of the starting materials, excellent chemicalhomogeneity in the final product and coating large areaswithout expensive devices [5].We applied sol-gel process with following order. Ce, Yand Fe based precursor materials dissolved in methanoland glacial acetic acid (GAA) were used as a solvent forthe synthesis of materials. Si(100) and fused silica wereused as substrates. Ce-YIG gel solutions with completelysolved (Sol A) and unsolved cerium content (Sol B) weredip-coated and spin coated on the substrates at roomtemperature. This process was followed by heat treatmentoby annealing films between 800-1000 P PC for 2 hours inair.Figure1.a shows the SEM results of Ce:YIG annealed at1000 °C. There are two kinds of region observed. Darkerregions have less Si content compared to the lighterregions according to the EDS results. So as can be seenFig. 2.a there are interaction between substrate and garnetphase which leads to nucleation. Fig. 1.b shows SEMresult of Ce-YIG prepared with Sol B annealed at 800°C.magnetization value of Ce-YIG (43 emu/cc) is lower thanthat of bulk YIG (136 emu/cc) [6]. The magneto-opticalmeasurement set up was build up according to previouslypublished paper [7]. By using this set up faraday and kerreffects of the Ce doped YIG films were measured. Theoptical constant of these films were determined usingtransmittance and reflectance spectra.(a)Figure 2. VSM and magneto-optical result of Ce-YIG prepared(a) on fused silica with Sol A at 1000 °C and (b) on Si(00) withSol B at 800 °CAs conclusion, cerium-doped YR3RFeR5ROR12R garnet filmswere prepared on Si(100) and fused silica by two differentsol-gel method. Ce:YIG thin films were obtained withcubic YIG phase and good the surface quality. Wemeasured transmittance and absorption spectra and alsoshowed the agreement between magnetisation andmagneto-optical measurements.This work has been supported by The Scientific andTechnological Research Council of Turkey (TUBITAK).(b)* Corresponding author: yavuz.ozturk@ege.edu.tr(a)[1] O. Kamada, T. Nakaya, S. Higuchi, Sensors and Actuators A119 (2005) 345–348[2] M. Huang, S-Y. Zhang, Appl. Phys. A 74 (2002) 177–180[3] N. Inoue, K. Yamasawa: Elect. Eng. In Jpn. 117 (1996) 1[4] X. Zhou, W. Cheng, F. Lin, X. Ma, W. Shi, Applied SurfaceScience 253 (2006) 2108–2112[5] L.L Hench, J.K. West, Principles of Electronic Ceramics.John Wiley & Sons, New York (1990)[6] B. Lax, K.J. Buton, Microwave Ferrites and Ferrimagnetics,McGraw-Hill, NY, (1962)[7] S. Polisetty, J. Scheffler, S. Sahoo, Yi Wang, T. Mukherjee,Xi He, and Ch. Binek, Review Of Scientific Instruments 79(2008) 055107 _(b)Figure 1. SEM result of Ce:YIG prepared at 1000 °C (a) with SolA and 800 °C (b) Sol BThe magnetization curve of Ce-YIG phase observedwith VSM at room temperature. The measured saturation6th Nanoscience and Nanotechnology Conference, zmir, 2010 632

P25,Poster Session, Thursday, June 17Theme F686 - N11231Corrugated Dielectric Slab Embedded in Photonic Crystal Waveguides11ULokman AyasUP P* and Hamza KurtPPTOBB University of Economics and Technology, Department of Electrical and Electronics Engineering, Ankara, 06560 TurkeyAbstract- We performed studies on the square lattice photonic crystal (PC) structure with a corrugated dielectric slab placed at the center.Such modification created both index guided and gap guided modes in the dispersion diagram. Novel properties aroused such as sharpresonances with high group index. Sub-wavelength corrugated slab with PC waveguide enriches the spectral properties of photon that mayfind applications in various areas of optical communication.Photonic Crystals (PCs) are periodic opticalnanostructures that are designed to provide hosting light astrong interaction with matter. PhCs have been studiedextensively in recent years because of the ability to controlthe propagation of light. Despite these tremendousresearch efforts, there are awaiting problems to be solved.For example, the light coupling into narrow width deviceis an important problem. To avoid this problem we place adielectric slab with a variable width at the center of the PCwaveguide (PCW). As a result, the light does not need toexit the dielectric slab while propagating in the air regionof PCW. This reduces the strong back reflections that mayoccur at the entrance and exit surfaces.The symmetrically corrugated slab with circular dielectricholes is also selected to increase the light interaction withthe surrounding material. In general, there is a nonlineardispersion relation between frequency ( ) and wavevector(k). With these modifications in PCW, a lineardispersion relation can be attained. In this work, we used asquare lattice PC as shown in Figure 1. The circle radius is0.3a, a dielectric slab at the centerline has a width of 0.8aand corrugated dielectric slab’s half circles have 0.2a radiiholes. When we calculate the dispersion diagram, weobtain Figure 2. There is a gap guided TM mode whosedispersion relation shows an instantaneous change from apositive value to a negative value as presented Figure2aand 2b.changes very rapidly in a narrow k-space interval. Otherstructural parameters may help to produce additionalfeatures for manipulating photons at the micron or evennanometer scales. We will present these novelcharacteristics of the proposed photonic structure in theconference.In summary, we show that in nanostructure PCs themerging of wavelength-scale corrugated slab with PCWprovides novel spectral characteristics. A mode occurredthat has both positive and negative slopes in a smallinterval. It may possible to engineer such a behavior forslow light aims.This work was partially supported by TUBITAK underGrant No. 108T717.*Corresponding author: HTlayas@etu.edu.trT[1] J. D. Joannopoulos, R. D. Meade, and J. N. Winn, PhotonicCrystals: Molding the Flow of Light. Princeton, NJ: PrincetonUniv. Press, 1995.[2] TH. KurtT, H. Benisty, T. Melo, O. Khayam, and C.Cambournac, "Slow-light regime and critical coupling in highlymultimode corrugated waveguides,"T Journal of Optical Society ofAmerica BT pp. C1-C14 (2008)Figure 1. The square lattice P C with a corrugated dielectric slabinserted into the center of the structure.Figure 2. (a) Band-gap guided TM waveguide mode. (b) Thewave-vector versus group index value of the mode in (a).One of the most interesting result is shown in Figure 2. Itis shown in Figure 2a the dispersion relation of thephotonic band-gap guided mode. The group indexvariation of the same mode is indicated in Figure 2b. Ascan be seen from the figure, there is a sharp resonancebehavior of the group index. Such a property can be usedin the slow light applications because the group index6th Nanoscience and Nanotechnology Conference, zmir, 2010 633

Poster Session, Thursday, June 17Theme F686 - N1123Optical Properties of Fullerene C60 Thin Films Annealed at Different Temperatures in Air and Argon AtmospheresHüseyin Özgener 1 , Hasan Aydın 2 , Salih Okur 2*1 Izmir Institute of Technology, Faculty of Science, Department of Chemistry, Gulbahce Koyu Kampusu, 35430, Urla, Izmir,Turkey2 Izmir Institute of Technology, Faculty of Science, Department of Physics, Gulbahce Koyu Kampusu, 35430, Urla, Izmir,TurkeyAbstract- This study focuses on optical properties of fullerene (C60) thin films at different annealing temperatures in Air and Aratmospheres with a thickness of 65nm deposited on quartz substrate by thermal evaporation method. Schimazdu UV-2550 PCUV-visible recording spectrometer has been used for optical measurements. Our experimantal results show that optical bandedge exhibit stable in Ar environment with increasing annealing temperatures up to 400 0 C. On the other hand it degrades at theannealing temperatures above 280 0 C (melting point of C60) in air atmosphere. These results might be important for solar cellapplications made of C60 nanoparticles.C60 thin films, which show significant deviceperformance and optical properties, are mostly used inelectronic devices such as light emitting diodes [1], solarcells [2] and field effect transistors [3]. That’s why, there isan increasing interest in these materials over the last decades.In this study, we have investigated C60 thin films atdifferent annealing temperatures in atmosphere and argon gasconditions with thicknesses of 65 nm deposited on quartzsubstrates by thermal evaporation method (Nanovak). Duringthe deposition the vacuum chamber was about 8x10 -6 Torr.Optical Reflectance (R) and Transmittance (T) data havebeen obtained at normal incidense using a Shimadzu 2550UV-visible spectrometer. R and T measurements have beendone after annealing at 100 o C, 300 o C and 400 o C for 60minutes in air and argon atmospheres. The thickness of C60thin films were measured with a Dektak profilometer fromVeeco.Fig.1 shows the Transmittances and Reflectances of theannealed C60 thin films. Both transmittance and reflectanceare varying with increasing annealing temperatures in airatmosphere except the films annealed at relatively lowtemperatures below melting point of C60 e.g. at 25 0 C and100 0 C. The spectral features of C60 are visible in the UVregion below 400nm.Transmittance(%)10080604020Annealed atT 25 0 CT 100 o CT 300 0 CT 400 0 CR 25 0 CR 100 0 CR 300 0 CR 400 0 C(a)0200 300 400 500 600Wavelenght(nm)151050Reflectance(%)Transmittance(%)10080604020Annealed atT 250 CT 100 0 CT 300 0 CT 400 0 C(b)R 25 0 CR 100 0 CR 300 0 CR 400 0 C0200 300 400 500 600Wavelenght(nm)Annealed atFigure.1. Transmittance and Reflectance of C60 thin film annealed at 25,100, 300, 400 O C for 60 minutes in air atmosphere (a), and argon gas (b).Transmittance and Reflectance of C60 thin filmannnealed at 25, 100, 300, 400 0 C for 60 minutes in argongas are shown Fig.1(b). Both transmittance and reflectanceshow similiar behaviours at increasing annealingtemperatures in argon compared to air atmosphere.Figure.3.AFM Topography of C60 thin film annealed at 25 0 C (a) , 400 0 C (b)in air atmosphere and 400 0 C in argon gas (c).AFM Topographies given in Fig 2 show that C60 thin filmsurface annealed at 400 0 C in argon gas does not change so151050Reflectance(%)much, while the annealed films in air become very roughwith large aggregates after annealing at 400 0 C.The optical band gap can be expressed [4],where E g is the optical band gap, hυ is the incident photonenergy and α is the absorption coefficient shown as following[5],,where t is the thickness, T is the transmission and R is thereflectance.(.E) 2 x 10 12 (cm -1 eV) 21.2 10 4 Annealed at (a)1 10 4300 0 C25 o C 100 0 C8000400 0 C60004000200000 1 2 3 4 5 6E(eV)(.E) 2 x 10 12 (cm -1 eV) 26 10 4 Annealed at (b)25 o C100 0 C400 0 C300 0 C55 10 44 10 43 10 42 10 41 10 400 1 2 3 4 6E(eV)Figure.3. The change of optical band gap with annealing temperature atdifferent annealing temperatures in (a) air atmosphere and (b) argon gas.The (αhν) 2 versus energy plots of C60 thin films at differentannealing temperatures are shown in Fig.3. It is seen that thepeaks in the absorption band edges disappear with increasingannealing temperatures in air atmosphere. However the peaksin that of C60 thin films do not change with increasingtemperatures in argon gas. The absorption features startaround 1.56 eV corresponds to the so called onset energy gap(Q-band) while the absorption starting around 3.52 eVcorresponds to the fundamental energy gap (B- band or Soretband) [6] at room temperature. The results show that bothonset and fundamental energy gaps are changed withannealing process above the melting point up to 400 0 C in air,but there is little or no change for that annealed in Aratmosphere.As a summary, our experimantal results show that opticalband edge look stable in Ar environment with increasingannealing temperatures up to 400 0 C. On the other hand itdegrades at the annealing temperatures above 2800 C(melting point of C60) in air atmosphere. These results mightbe important for solar cell applications made of C60.*Corresponding author: salihokur@iyte.edu.tr,[1] Z. H. Huang, W. M. Su, and X. T. Zeng SIMTech technical reports(STR_V8_N4_02_STG), Volume 8 Number 4 Oct-Dec 2007[2] Nobuaki Kojima, Yusuke Sugiura, Masafumi Yamaguchi, Solar Energy Materials &Solar Cells 90 (2006) 3394–33983[3]Mihai Irimia-Vladu, Nenad Marjanovic, Marius Bodea, Gerardo Hernandez-Sosa,Alberto Montaigne Ramil, Reinhard Schwödiauer, Siegfried Bauer, Niyazi SerdarSariciftci, Frank Nüesch Organic Electronics 10 (2009) 408–415[4] E.A. Davis, N.F. Mott, Philos. Mag. 22 (1970) 903[5] T.S. Moss, Semiconductor Optoelectronics, Butterworths, London,1973.[6] M. M. El-Nahass, F.S. Bahabri and R. Al-Harbi, Egypt. J. Sol., 24, 1, (2001)6th Nanoscience and Nanotechnology Conference, zmir, 2010 634

PP TOBBPoster Session, Thursday, June 17Theme F686 - N11231Special Slow Light Properties of Photonic Crystal Waveguides11UKadir UstunUP P* and Hamza KurtPUniversity of Economics and Technology, Department of Electrical and Electronics Engineering, Ankara 06560, TurkeyAbstract- The drastic changes on the radii values of the side rows of a linear-defect triangular lattice photonic crystal waveguide results inunique dispersion curves with large constant group index and high bandwidth values. The delay of picosecond optical pulses were realized.Photonic crystals exhibit bandgap property that enables usto use them as cavities and waveguides. The light isconfined in the desired spatial regions by inducing defects inthe periodic structure. In addition to that property, photoniccrystal waveguides show dispersive characteristics so thatthe group velocity is very low in some regions near k-points(0, 0) and (0.5, 0). But at close proximity of these points, thestrong group velocity dispersion (GVD) distorts the pulseshape and information cannot be carried properly. So havinghigh group index ( n g ) values with small GVD and largebandwidth is an important research interest [1-5] because ofthe diverse applications of slow light in opticalcommunications, optical buffers and nonlinear optics [1]. Inthis work, we present a new type of dispersion diagram andcorresponding group index values that can be used for largebandwidth slow light.The photonic crystal used in this paper is a twodimensional photonic crystal with a triangular lattice. Theair holes are located in the dielectric media according to thelattice basis vectors. The waveguide is constructed by fillingthe center holes with dielectric material along the ( )direction as shown. We made investigations to find flatbands which yield constant group index n g , where the groupindex is defined as n g = c / vg, and small GVD as [3-5].We modified the side row circles of the waveguide andchanged the radii of these holes step by step symmetricallyalong the waveguide. This modification method isdemonstrated in Fig. 1(a). The dispersion diagrams andngvs. frequency plots are obtained for different values ofradii of the modified holes by evaluating the dispersiondiagram using PWM [6]. The result is shown in Fig. 1(b) forvarious cases that results in flat bands which produceconstant n region between k 0. 35 and k 0.45. Thegngvalues are ‘U’ shaped and the bottom of this ‘U’ shape isvery appropriate for obtaining high n g values with smallGVD and high bandwidth as it will be shown in a figure thatwill be presented in the conference . By looking at Fig. 1(c),we can say that increasing the radius of the circles decreasesthe constant ngvalues, but there is an increase in bandwidthof the constant group index region as will be presented inadditional figures in the conference.As the group index and bandwidth values are inverselyproportional, we decided to determine a figure of merit suchas delay-bandwidth product (DBP). The DBP versus radiusrelation is depicted in Fig. 1(d). As it is shown, the DBPalso increases as the radius increases. But this increase is notso rapid in spite of the drastic changes in ngand bandwidthvalues.Figure 1. (a) Triangular lattice structure with the inner row of holesmodified. (b) the different dispersion diagrams for different radiusvalues (radius is swept from 0.3625a to 0.450a). (c) Group indexvalues obtained in the linear regions of the dispersion diagrams withrespect to corresponding radii. (d) DBP values with respect tocorresponding radii alteration.frequency domain. The frequency domain calculations showthat ngdecreases and bandwidth increases as the radii of theside rows increases. On the other hand, the DBP increases asthe radii of the side rows are increased. The presented resultsobtained by simple geometrical modifications are promisingin terms of yielding large bandwidth and constant groupindex for slow light applications.The authors gratefully acknowledge the financial support of theScientific and Technological Research Council of Turkey(TUBITAK), Project no: 108T717.*Corresponding author: HTk.ustun@etu.edu.trT[1] T. F. Krauss, Nat. Photonics 2, 448 (2008).[2] M. Notomi, K. Yamada, A. Shinya, J. Takahashi, C.Takahashi, and I. Yokohama, Phys. Rev. Lett. 87, 253902 (2001).[3] L. H. Frandsen, A. V. Lavrinenko, J. Fage-Pedersen, and P. I.Borel, Opt. Exp. 14, 9444 (2006).[4] S. Kubo, D. Mori, and T. Baba, Opt. Lett. 32, 2981 (2007).[5] J. Li, T. P. White, L. O'Faolain, A. Gomez-Iglesias, and T. F.Krauss, Opt. Express 16, 6227 (2008).[6] S. Johnson and J. Joannopoulos, TOpt. ExpressT 8, 173 (2001).The aim achieved in this study is to find ways of obtainingconstant group index values with large bandwidths in the6th Nanoscience and Nanotechnology Conference, zmir, 2010 635

PPP*PPPoster Session, Thursday, June 17The Effects of Thermal Annealing on Optical Properties of GaInNAs/GaAs Quantum Well Structures111UHatice BasakUPP, Omer DonmezP P, Ayse ErolP P, M. Cetin ArkanP1P, Mika Saarnen 21PIstanbul University Science Faculty Physics Department 34134 Vezneciler, Istanbul, TurkeyPTampere University of Technology Optoelectronics Research Center P.O. Box 692 33101 Tampere, Finland2Theme F686 - N1123Abstract-We have studied the effects of thermal annealing on optical properties of the undoped GaR1-yRInRyRNRxRAsR1-xR / GaAs (x=0.005, y=0.40)heterostructures sqeuentially grown by Moleculer Beam Epitaxy (MBE). Photoluminescence (PL) technique is used for 1 and 3QWs as-grownand annealed samples. We showed that thermal annealing does not increase the PL intensity in all samples, but causes a blue-shift of effectiveband gap energy.GaInNAs/GaAs quantum well systems have been studiedintensively due to their unique physical properties. The largeband-gap bowing and the possibility of lattice matchingwith GaAs make GaInNAs quantum wells convenient forusing long-wavelength (from 1.2 to 1.6m) optical devices,e.g. laser diodes, dedectors [1, 2] and high efficient multijunctionsolar cells [3]. GaInNAs QWs are suitable to matchGaAs /AlAs distributed Bragg reflectors (DBRs) forVertical Cavity Surface Emitting Lasers (VCSELs).Additionally, compare with GaInAsP/InP structures,GaInNAs/GaAs structures have less temperaturedependence due to the stronger electron confinement.In this study, the photoluminesence (PL) measurementswere carried out to determine the effects of the thermalannealing on optical properties of the undoped as-grown(82) and annealed (82A) SQW and as-grown (83) andannealed (83A) 3QWs GaInNAs/GaAs structures. The PLmeasurements have been taken the temperature rangebetween T= 77 and 300K. The 514nm argon-ion laser wasused as an excitation source. Therefore, its energy enough toexcite both GaInNAs and GaAs layers. The laser beam waschopped with 65Hz frequency and focussed on the sample.The luminescence was dispersed and detected by using amonochromator and GaInAs a photodedector, respectively.Figure 1a and Figure1b show the PL spectra of the sample82 and sample 82A. The intensity of the PL peaks decreaseby increasing temperature due to electron-fonon interactions.Additionaly, the band gap energy of the samples decreaseby increasing temperature. The maxima of the peakscorrespond the e1-hh1 transition in the QWs.The temperature dependence of the PL peak energy plottedin Figure 2 for the samples. The temperature dependence ofthe PL peak energy is consistent with the semi-empiricalVarshni relation. Moreover, a blue-shift which means anincrease of e1-hh1 transition energies occurs as a result ofannealing process.PL(a.u.)54321077/290K110K130K150K170K190K210K230K250K275K300K0,92 0,94 0,96 0,98 1,00 1,02 1,04 1,06E(eV)82Figure 1. Temperature dependent PL spectra in a) 82 and b) 82APL(au)7654321077K90K110K130K150K170K190K210K230K250K275K300K1,00 1,02 1,04 1,06 1,08 1,10 1,12 1,14E(eV)82AI(a.u.)E g (eV)1,111,081,051,020,990,9650 100 150 200 250 300T(K)8282A8383AFigure 2. Temperature dependence of the PL peak energy in a) 82and 82A b) 83 and 83A samplesFigure 3a and 3b shows the temperature dependence of thepeak intensities for 82&82A and 83&83A samples,respectively. The PL peak intensity of 82 lower than 82A inall temperatures. However, for sample 83 PL peak intensityslightly higher than that of sample 83A in all temperatures.Hence, it is seen that thermal annealing increases PLintensity for 82A, but decreases for 83A. We can concludethat thermal annealing always does not improve the opticalquality especially at low temperatures as seen resultssamples for 83 and 83A.8765432108282A50 100 150 200 250 300T(K)I(a.u.)1210864208383A50 100 150 200 250 300Figure 3. Temperature dependence of the PL peak intensity for a)82&82A b) 83&83A samplesIn conclusion, the PL measurements have been taken to findthe effects of the thermal annealing on optical properties ofthe undoped SQW and 3QWs GaInNAs/GaAsheterostructures. PL measurements showed that thermalannealing cause blue-shift of effective band gap energy anddoes not increase the PL intensity in all samples.This study was partially supported by Scientific ResearchProjects Coordination Unit of Istanbul University,TUBITAK and COST which project numbers T-2526,108T721, MP0805, respectively.*Corresponding author: haticerecber@yahoo.com[1]Mitomo, J.O. et al, IEEE J selected topics in Quant. Electron .,(2005), 11, 1099-1102[2]Heroux J.B. et al., Appl. Phys. Lett., (1999),75, 2716-2718[3]Kurtz S.R., Allerman A.A., Jones E.D., Gee J.M., Banas J.J. andHammons B.E., Appl. Phys.Lett. (5),(1999), 74T(K)6th Nanoscience and Nanotechnology Conference, zmir, 2010 636

PisPPisisisP,PisPoster Session, Thursday, June 17Theme F686 - N1123Photoluminescent Properties of InN Thin Films12121233UÖ. DönmezUP P*, M. YlmazP P, A. ErolP P, B. UluP P, M.Ç. ArkanP P, A. UluPPA. O. AjagunnaP P, E. IliopoulosP P, A. GeorgakilasP1PIstanbul University, Science Faculty, Department of Physics 34134 Vezneciler, Istanbul, Turkey2PAkdeniz University, Faculty of Arts & Science, Department of Physics, Antalya, TurkeyPMicroelectronics Research Group, IESL, FORTH and Physics Department, University of Crete, P.O. Box 1385, 71110 Heraklion-Crete, Greece3Abstract-We report photoluminescence (PL) studies of InN epilayers grown by plasma-assisted molecular beam epitaxy with free-electron19 -3concentration of about 10PPcmP P. Band gap of InN layer is determined using the PL data obtained as a function of temperature and is calculatedby a model considering the high electron concentration effect, electron-electron and electron-ionized impurity interactions in non-parabolic k·pmodel. PL results indicate that the band gap of InN is 0.82eV at 8K. Electron effective mass is calculated as 0.097mR0 Rfor electron concentration19 -3of 10PPcmP3InN is in nature n-type semiconductor having free-electron21 -3concentrations as high as 10PPcmPP. Early studies of theinterband optical absorption carried out on InN thin films haveshown that band gap energy is about 2eV due to high carrierconcentration effects [1-2]. Recent studies showed that theband gap energy is about 0.65eV [3-6]. This means that usinggroup InN and In-rich InGaN have potential to optoelectronicdevices covering the spectrum from infrared to ultraviolet.In this study, Hall effect measurement has employed todetermine carrier concentration for two samples havingdifferent InN layer thicknesses as shown in Figure 1.Carrier Conc.(cm -3 )1,4E191,3E191,2E191,1E19800nm InN layer600nm InN layer1E1960 90 120 150 180 210 240 270 300Temperature (K)Figure 1. Temperature dependence of carrier concentration of 800 nmand 600 nm thick InN layersPL spectra of the samples with 800 nm and 600 nm InN layer19 -3thicknesses having electron concentrations 1.2x10PP cmPPisgiven in Figure 2. Observed peak energy is different from themostly accepted value of InN band gap in literature [3,4]. Theasymmetry observed in spectra are similar to those predictedby model of free-electron recombination band (FERB) [7]. Inthis model, the localized states in such a band tail can betreated as acceptor- like center distributed above the top of thevalance band and these centers are responsible for asymmetricPL behaviour. This band tail can be expressed as using,21/2 4e 31/2G 2 NiRs Rswhere, RRSR the Thomas-Fermi screening length, aRBR theeffective Bohr radius and NRR the carrier concentration [7].Non-parabolic dispersion effect on band gap energy has toinclude in determining the exact band gap of InN, as well asband tail effect in FERB model, that has been calculated byusing Kane the k·p theory [8].PL (arb. unit)0,080,04800nm InN layer600nm InN layer0,000,60 0,65 0,70 0,75 0,80 0,85 0,90 0,95Energy (eV)T=8KFigure 2. PL spectra of 800 nm and 600 nm InN layer at 8KAn analytical form of the conduction band dispersion obtainedby solving Kane’s two band k·p model is given by [3, 5]2 2 2 2 k 1 2 k Eck EG EG 4Epx EG2m0 22m0 where, ERGR the direct band gap energy, k is the wave numberand ERPR the momentum matrix element. Using this model wecalculated fundamental band gap of InN as 0.68eV andeffective mass as ~ 0.097mR0R.In summary, observed PL spectra is explained using FERBmodel. The band gap energy and effective mass of InN aredetermined considering high electron concentration effects.*Corresponding author: omerdonmez@istanbul.edu.tr[1] A.G. Bhuiyan et. al., J.Appl. Phys. 94, 2779 (2003)[2] E. Bellotti et. al., J. Appl. Phys. 85, 916 (1999)[3] J. Wu et. al., J. Appl. Phys. T94T, 4457 (2003)[4] G. Koblmüller,et.al., Appl. Phys. Lett. 89, 071902 (2006)[5] W. Walukiewicz et. al., Journal of Crystal Growth 269, 119-127(2004)[6] J.Wu et. al., Appl. Phys. Lett. 84, 2805-2807 (2004)[7] B. Arnaudov et. al., Phys. Rev. B 69, 115216 (2004)[8] E. O. Kane , J. Phys. Chem. Solids 1, 249 (1957)6th Nanoscience and Nanotechnology Conference, zmir, 2010 637

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 638

U NeslihanPPPPoster Session, Thursday, June 17Theme F686 - N112313 Dimensional L Shaped Photonic Crystal Waveguide111EtiUP P*, H. Sami SözüerP PP and Zebih ÇetinPPAbstract- We present theoretical studies on waveguide bends in a combination of 1 dimensional and 2 dimensional photonic crystal slab.In this work, we give a method to bend light on L shaped photonic crystal waveguide slabs with little loss.1The discovery of the photonic crystal waveguides (PCWs),which allow only certain electromagnetic wave modes topropagate inside the structure, has opened up new ways ofcontrolling light propagation in optical integrated circuitdesigns. By using photonic crystal slab waveguides, whichare 1 dimensional or 2 dimensional periodic structures with afinite thickness in the vertical direction, it is possible tofabricate light guiding optical materials by total internalreflection [1], that confines light to the slab, and bend themwith little loss by photonic crystal assistance.With conventional dielectric waveguides which dependentirely on total internal reflection, there is a problem inguiding light while turning through sharp edges and tightcurves because the angle of the incidence is too high for totalinternal reflection, resulting in most of the electromagneticfield being radiated out and lost.To cope with this problem, a 2 dimensional line defectwaveguide can be used [2-8]. The problem with 2dimensional line defect waveguides is that even smalldefects during manufacturing can greatly increaseattenuation, thus limiting their usefulness to guide light overlong distances. To overcome this difficulty, Notomi proposedusing a 1 dimensional slab waveguide which is not periodicin the direction of propagation, to reduce dispersion andattenuation [3]. But still in an optical circuit, one would wantto bend light through a 90 angle due to the confinedgeometry.In this work, we make use of the best of both worlds,namely, we use 1D slab waveguide of Notomi for the straightsections and a 2D slab waveguide for containig the light atthe corners. By this way, the wave would travel with littleloss through the straight sections, turns through sharp cornerwith little bending loss as well, reentering the 1D waveguideregion to travel for another long straight segment as shown infigure [1].Figure 2. 2D perfect square photonic crystal slab. There is a bandgap between 0.2 and 0.4 . The gray areas are unlocalized radiationmodes.Figure 3. Dispersion relations for 2D and 1D waveguides. The bigcrosses are localized TE-like modes of the 1DWG, while the big fullcircles are those of the 2D LDWG. The small dots show unlocalizedmodes. Matched modes for the two types of waveguides overlap,indicating good impedance matching between the 1D and 2Dwaveguides.Then choosing the proper defect size at 2D and 1Dstructes we created our waveguides and succeed to matchtheir modes as shown figure [3]. Thus, theoretically it ispossible to bend light in L shaped waveguide. It remains tobe seen actually what percentage of the light passes throughthe bend by FDTD calculations in the time domain.*Corresponding author: 2Tneslihaneti@iyte.edu.tr2TFigure 1. Photonic crystal waveguide slab, which is a periodicstructure with a finite thickness in vertical z-direction and combines1D and 2D slab waveguides.We used the data in [7] since preliminary evidenceshowed that it is possible to bend light by 90 degrees almostwithout loss, but with the difference that in our proposedstructure we studied the more realistic photonic crystalwaveguide slab which is finite in the z-direction. Firstly wefound the band diagram for the 2D perfect pc slab, shownin figure [2].[1]2TKrauss TF, DeLaRue RM, Brand S, "Two-dimensional photonicbandgapstructures operating at near infrared wavelengths"NATURE 383 pp. 699-702, (1996)[2] A. Mekis, J. C. Chen, I. Kurland, S. Fan, P. R. Villeneuve, and J.D. Joannopoulos, Phys. Rev. Lett. 77, 3787-3790 (1996).[3] H. Taniyama and M. Natomi and Y. Yoshhikuni, Phys. Rev.B.71, 153-103 (2005).[4] A. Chutinan and S. Noda Phys. Rev.B.62, 4488-4492 (2000).[5] S. G. Jhonson, S. Fan, P. R. Villeneuve, and J. D. Joannopoulos,Phys. Rev.B.60, 5751-5758 (1999)[6] Natalia Malkova, Sungwon Kim, and Venkatraman Gopalan,Appl Phys. Let. Vol 83, Number 8 (2003)6th Nanoscience and Nanotechnology Conference, zmir, 2010 639

PPoster Session, Thursday, June 17Theme F686 - N1123Photonic Crystal Assisted 120°P PWaveguide Bend111UUP P*, H. Sami SözüerP P, Neslihan EtiP P, Zebih ÇetinP1PDepartment of Physics, Izmir Institute of Technology, Urla Izmir 35430, Turkey0Abstract- In this study, we compare quantitavely the transmission properties of various 120P P bends carved into a 2D hexagonal photoniccrystal. We present transmission results through the bend based on numerical field computations by FDTD. The observed low bendingloss could make this structure a suitable candidate for use in future optical integrated circuit designs.1(a) (b) (c)Figure 1. (a) Two-dimensional perfect Photonic Crystal with hexagonal lattice. (b) Two-dimensional Waveguide. (c) One-dimensional LineDefect Waveguide.Employment of two-dimensional photonic crystals forfuture photonic integrated circuits is a topic under intenseinvestigation. Channel waveguides (WGs) designed inphotonic crystals (PhCs) and operated at frequencies withinthe photonic band gap are expected to provide waveguidingwith low losses and to allow sharp bends. The guidingmechanism is superior to traditional WGs which rely on totalinternal reflection (TIR). Various approaches for benddesigns have been done theoretically and experimentally[1-3]. Most of these works are based on the optimizationmethod for bends [4-5], adding or removing some rods in thebending region, in which the structure of the WG bends arealways much complicated, and even small defects duringmanufacturing can greatly increase attenuation, thus limitingtheir usefulness to guide light over long distances.To overcome this difficulty, we propose a simple methodfor guiding electromagnetic waves with little loss. Toaccomplish this, we use the 1D WG for the straight sections,but use a 2D line defect WG for the corners. Thus, the wavewould travel with little loss through the straight sections, andcan be bent through sharp turns with little bending loss aswell. As a result, light enters a 1D WG and passes from a 1DWG to the corner element 2D line defect WG, turns the sharpcorner with required angle and then, reenters the 1D WGregion to travel for another long straight segment.To obtain transmission results, firstly we looked fort helargest band gap for 2D hexagonal PhC, because it is this gapthat prevents light from leaking out when turning around thecorner. We also make sure that both the 1DWG and the2dWG support only a single mode inside this gap. Then thenecessary condition is satisfied for perfect transmissionbecause 2D line defect WG and 1D WG be single localizedmode in the frequency range of interest. We found a singlelocalized mode for optimum frequency that falls within the2D band gap of 2D hexagonal PhC. As a result the guideddefect mode passes through the sharp corner without beingscattered into the 2D PhC.(a)(b)Figure 2. The geometry of our proposed structure showing 1D WGand 2D WG segments.In our proposed structure, seen above, 2D PhC is ourcornering element to bend light by removing one row, withsilicon rods in silica background. Therefore, there are severalpossibilities for this corner element. The most appealingbeing the hexagonal lattice, since it possesses a commonband gap for both TE and TM modes. Also, this lattice ismost convenient for 60° and 120°P P(but for 90° turn would bethat of a square lattice, which was discussed elsewhere), soafter turning 60° or 120°, the line defect WG would be thesame as before. Because we can turn the waveguide andpreserve line defect geometry.Figure 3. (a) RgR=d*Corresponding author: 0Thediyesengun@iyte.edu.tr0T[1]Talneau, A., L. Le Gouezigoui N. Bouadma, M. Kafesaki, C. M.Soukoulis, M. Agio, 2002. Photonic-Crystal Ultrashort Bends with ImprovedTransmission and Low Reflection at 1.5μm. Applied Physics Letters 80:547-549.[2]Chutinan, A., M. Okano, S. Noda, 2002. Wider Bandwidth with HighTransmission ThroughWaveguide Bends in a Two-Dimensional PhotonicCrystal Slabs. Applied Physics Letters 80:1698-1700.[3]Chow, E., S. Y. Lon, J. R. Wendt, S. G. Johnson, J. D. Joannopoulos,2001. QuantitativeAnalysis of Bending Efficiency in Photonic Crystal Waveguide Bends at =1.55Wavelengths. Optics Letters26:286-288.[4]Ntakis, I., P. Pottier, M. De La Rue, 2004. Optimization of TransmissionProperties of Two-Dimensional Photonic Crystal Channel Waveguide BendsThrough Local Lattice Deformation. Journal of Applied Physics 96:12-18.[5]Notomi, M., H. Taniyama, Y. Yoshikuni, 2005. Propagation characteristicof onedimensionalphotonic crystal slab waveguides and radiation loss. Physical Review B71:153103-153106.6th Nanoscience and Nanotechnology Conference, zmir, 2010 640

Poster Session, Thursday, June 17Theme F686 - N1123Silicon Nanocrystal Hybridized Visible LEDs: A Low-Cost Path for Global LightingŞ. Burç Eryılmaz, Onur Tidin, Alper Yeşilyurt, Ali K. Okyay*Department of Electrical and Electronics Engineering, Bilkent University, Ankara 06800, TurkeyAbstract- We report UV LEDs coated with Silicon nanocrystals that emit in the visible spectrum. A broad emission from nanocrystals withpeak at 547 nm is observed when pumped with 375 nm LED light. Our results are promising for application of Silicon nanocrystals aswavelength converters in light emitting diodes for multicolor light generation.Semiconductor based solid state lighting has long surpassedfluorescence lamps and incandescent light bulbs in terms ofefficiency, safety and energy saving. Future roadmapsenvisage dramatic improvements in solid state lighting for thenext 10 years. By the year 2025, electricity consumptionwould decrease by at least 50%, and this corresponds toelectricity savings in United States around 525 TWh/year.This would also result in a worldwide reduction of greenhousegas emissions that is produced during the generation ofelectricity by about 87 Mt [1]. These reveal the reason for thegreat interest in semiconductor lighting technology.Research in semiconductor lighting includes theinvestigation of multicolor light emitting diodes. One methodfor producing these devices is using a wavelength convertingemitting layer on top of a primary light source. These devicesutilize electroluminescence of primary light source andphotoluminescence of wavelength converter layer.Nanocrystals, due to their tunable emission properties, havebeen preferable emitters. Due to quantum confinement effects,CdSe/ZnS core/shell nanocrystals were demonstrated to beefficient wavelength converters for multicolor light emittingdiodes [2]. Despite the efficiency and quality of the colorgenerated by this device, Cd based materials have high toxiceffects on the human and the environment, in addition to highmaterials costs. Silicon, being the second most abundantmaterial on the Earth’s crust and its low toxicity, makes it alow cost attractive. Recent advances have made it possible toproduce silicon nanocrystals with indirect-to-direct gaptransition with light emission in visible wavelength [3].In this work, we report light emission from siliconnanocrystals used as wavelength conversion layer on top ofultraviolet light emitting diode. UV light emitted from theLED pumps the nanocrystals, and light emission in visiblewavelength from the nanocrystals is observed.We purchased commercial UV LEDs from NitrideSemiconductors, Co., Ltd. with 375 nm peak as shown in Fig.1.a. Micrograph image of our LED is given in Fig. 1.b. Wedeposited silicon nanocrystals in solution of tetrahydrofuran(THF) on top of the UV LED by drop-casting. The device wasbiased using electrical probes and the electroluminescencespectrum was obtained using a fiber connected to aspectrometer. After this measurement, we repeated the dropcastingprocess to see the effect of increasing the amount ofnanocrystals. Electroluminescence spectra corresponding tomultidrop samples are given in Fig. 1.c including the bareLED as a reference.Luminescence of silicon nanocrystals are observed to have apeak emission wavelength at 547 nm when excited with 375nm light source. FWHM value is measured approximately 140nm. This broad emission can be useful for multicolor lightapplications. The reference UV LED has no measurableemission around these wavelengths, and the emission intensityincreases with the number of nanocrystal solution drops caston the LED.Figure 1: (a) UV LED emission spectrum (b) UV LED micrographimage (c) Electroluminescence measurementsIn summary, we demonstrated the application of Siliconnanocrystal on UV LEDs and obtained visible emission in theyellow-red region. Emitted light can be tuned by changing thesize of nanocrystals in production. This work has promisingresults for opening the way for low cost Silicon material to beused as wavelength converters in the form of nanocrystals. Forthis purpose, increasing the efficiency of these nanocrystalsshould be studied. This can be achieved by blending them intoa polymer and applying as a film. Recent results in plasmonicsto increase the fluorescence efficiency of silicon nanocrystalsalso stands as an alternative.This work was supported by TUBITAK 108E163, 109E044,EU FP7 PIOS.*aokyay@ee.bilkent.edu.tr[1] J. Y. Tsao, IEEE Circuits and Devices Magazine, 28,May/June 2004.[2] S. Nizamoglu et al., Nanotechnology, 18, 405702 (2007)[3] M. H. Nayfeh et al., Appl. Phys. Lett., 80, 842-843 (2002)6th Nanoscience and Nanotechnology Conference, zmir, 2010 641

PP*PPoster Session, Thursday, June 17Theme F686 - N1123Band Structure Calculations for 2D Photonic Crystals Based on Quantum-wire-superlattice11UNurgül AkncU,PPand Yüksel AyazP1PDepartment of Physics, Zonguldak Karaelmas University, Zonguldak 67100, TurkeyAbstract-The existence and properties of photonic band gaps in a two dimensionally periodic array of dielectric material is presented here by theelectromagnetic dyadic Green's function (DGF) formalism. As frequency poles of the DGF provide the explicit dispersion relations for transversemagnetic (TM) and transverse electric (TE) polarizations, the band structure of the photonic crystal for TM and TE modes is then numericallyexamined and dependence of the band gap frequencies on the inverse of the lattice period a, extracted from band structure calculations is shown.A photonic crystal (PhC) is composed of a periodicarrangement of dielectric material in two or three dimensions.If the periodicity and symmetry of the crystal and thedielectric constants of the materials used are chosen well,theband structure of such a crystal shows a photonic band gap(PBG) for one or both polarizations [1]. The bandgap regionsare determined from the dispersion relations forelectromagnetic waves by solving the wave equation set upfrom Maxwell equations. Although 2D PhCs are not generallythought of as thruly photonic bandgap materials due todiffraction losses, they still atract much interest because theyprovide a basis on the understanding of physical properties of3D PhCs, the real photonic crystals, which exhibit completephotonic bandgaps [2,3].In this work, the photonic band structure in a 2D PhC,consisting of a square array of dielectric material, isinvestigated by the electromagnetic DGF formalism [4] as amodel analysis, by explicitly determining the DGF (associatedwith the inhomogeneous wave equation of the electric field)for the dispersion relations for electromagnetic waves in thephotonic crystal.Firstly, the integral equation for the DGF of generalapplicability to photonic band structure calculations isexplicitly solved for the 2D photonic system at hand. Thecharacteristic equations associated with the dispersionrelations are analytically determined by the frequency poles ofthe DGF for TM and TE polarizations (Fig. 1).similar to silicon cylinders [5]. For GaAs wires-system thewidest gap from the band structure calculations as function ofwidth of the wires to period of the crystal ratio b/a is observedat around b/a= 0.008 (Fig. 2).Figure 2. Normalized frequency a/(2c) as a function of the inverseof the lattice period a.In summary, using the DGF foralism we have explored theexistence of PBGs for a square lattice of quantum wires. Bandgaps were only observed for TM polarization. Our analysis,which is exact within the assumption that the conductivitytensor of the composed nanostructure is a simple sum of itsconstituent conductivity tensors for the 2D periodic dielectricand the 3D homegeneous host material, also differs from thoseusing Green's functions in the literature in that they employasymptotic forms of the Green's functions, so being onlyapproximate. Further, our DGF analysis has the simplicity thatit does not require detailed boundary conditions in solving theinhomegeneous wave equation for the electromagnetic fieldspropagating in periodic dielectric structures. Its utility lies inthe facts that it provides a through analytic point of view inunderstanding propagation of electromagnetic fields andcarrying out photonic bandgap calculations in various kinds ofphotonic materials without resorting to much detailednumerical computations and that it is easily extended to 3Dphotonic problems for their bandgap calculations.Figure 1. Dispersion relations for the first six bands for TM and TEmodes.We next numerically solved for the band structure for bothpolarizations in the 2D photonic system including square arrayof GaAs wires embedded in homogeneous bulk dielectricmedium (AlGaAs) and then discussed the existence andproperties of photonic band gap. It was found that band gapsexist only for transverse magnetic polarization . which is*Corresponding author: HTnurozdede@yahoo.comT[1] Yablonovitch, E., 1993. J Opt. Soc. Am. B, 10(2): 283-295.[2] Busch, K., John, S., 1998. Phys. Rev. E 58, 3896.[3] Busch, K., 2002. C. R. Physique 3, 53–66.[4]Ayaz, Y., 1999. TElectrostatic and electrodynamic responseproperties of nanostructuresT. PhD Thesis, Stevens Inst. of Tech,USA.[5] De Dood, M. J. A., 2002. Opt. and Quant. Electr. 34: 145–159.6th Nanoscience and Nanotechnology Conference, zmir, 2010 642

PPPoster Session, Thursday, June 17Theme F686 - N1123Nano Isotopic Optical Centres in HPHT and CVD Synthetic Diamond Types1UHamida M. B. DarwishUP*1PPhysics Department, King Abdulaziz University, Jeddah, Kingdom of Saudi ArabiaAbstract - Eelectron irradiated synthetic diamond exhibited a number of new local vibrational moods (LVM) which have three fold splittingof their highest energy. The magnitude of the energies of each of these modes varies as the square root of the isotopic carbon of atomic masses.One of these centers is the zero Phonon line (ZPL) 389 nm (3.188eV) The second is the ZPL 420 nm (2.951eV).Synthetic and natural diamonds generated greatly renewedinterest to develop the optoelectronic applications and devicesthat are unaffected by high temperature or by other adverseenvironmental conditions such as heat spreaders, opticalwindows, electrical conductors, and nano-optoelectronicdevices that can be used in high industry purposes for such asmedical research and space searches and satellites. Also it canbe demanded as cutting tool or polishing in the iron and steel,car Factories and plants [1, 2].The physical properties of diamond exhibit that diamondfully transparent from infrared through the near ultraviolet [3].It has highest velocity of sound. It is a fully resistance to heat,radiation and chemical reaction and stable at roomtemperature and pressure. It a promising material it has aunique properties such as the highest semiconductor propertieswhich exceeds that of SiC [3]. So there is more reason forstudying diamond. But diamond is very expensive and rare innature. And the study of the different spectra manifested bynatural and synthetic may tell us more about how the formerwere created and how to grow the latter more efficiency. Nowsynthetic diamonds are available but nitrogen and boron arethe only impurities which can be introduced into them withsome degree of controlSynthetic diamond samples grown by two methodschemical vapour deposition (CVD) [4] and high pressure hightemperature (HPHT) [5, 6] have been investigated (afterirradiation by TEM) by Photoluminescence (PL) technique.This studying was preformed after annealing at elevated00temperatures between 773P PK and 1073 P PK. The investigationpredicts many numbers of new local vibrational modes (LVM)with optical isotopic centres, which split into three- folds asthe square root of carbon masses as shown in Figure 1 and 2.Figure 1. LVM of ZPL 389 nm for PL of PPC PPC doping HPHT0diamond sample annealed at 1073 P Pk. (Using UV laser)1312Figure 1 reveals PL spectrum of irradiated PPC PPC doping0HPHT diamond sample after annealing at 1073 P Pk by usingUV laser. The zero phonon line (ZPL) at the centre of 390 nmwith its local vibrational mood (LVM) is splitting into threefolds as the squire root of the isotopic carbon atomic masses atthe centres of 412.28 nm, 412.85 nm and 413.28 nm..Figure 2. LVM of the ZPL 420 nm for PL PPC PPC –doping HPHTdiamond sample by using UV. Laser (325nm)Figure 2 displays the local vibrational mood (LVM) of thesame sample associated; with the zero phonon line at thecentre 420 nm. Also this centre is divided into three folds asthe isotopic carbon masses at the centres of 449.25 nm, 449.85nm and 450.5 nm.The well known LVM of the centre 390 nm have been foundin all types of CVD and HPHT diamond samples (Carbon,Boron and Nitrogen-doping samples) that studied at this work.This LVM is splitting for the first time into three folds as thesquire roots of the isotopes of the atomic carbon masses. Alsothe investigation of HPHT electron irradiated carbon-doping13 1250-50 PPC/ PPC diamond samples predicts the centres 420 nmbesides the ZPL 390 nm and they are splitting as the squireroot of isotopic carbon masses, which have three–fold issplitting of their highest energy local vibrational modes. (Moredetails about this work will be written later) .This study was supported by KSA Ministry of HigherEducation, Bristol University-UK and diamond samplessupplier.*Corresponding author: hdarwish@kau.edu.sa[1] F. Bundy, H. T. Hall, M. M. Strong, R. H. Wentorf: Nature 176,50-51, (1955)[2] R. M. Chrenko, Phys. Rev. B7, Pp. 4560-4567, (1973)[3] J. Walker: Optical Absorption and Luminescence in Diamond,Rep. Prog,. Phys., 42, Pp 1605-1659, (1979)[4] K. Snail: Growth, Processing and Properties of CVD Diamond forOptical Application, Opt. Mater., Vol. 1, Pp. 235-258 (1992)[5] S. Yamaoka et al., Diamond & Related Materials, V. 9, Issue 8,1480-1486, (2000)[6] J. E. Field: The Properties of Natural and Synthetic Diamond,Academic press. London (1992)131213126th Nanoscience and Nanotechnology Conference, zmir, 2010 643

Poster Session, Thursday, June 17Theme F686 - N1123Morphology Characterization of Mechanically Exfoliated GrapheneGörkem Soyumer * , Cenk Yanık, Cem Çelebi, İsmet İ. KayaFaculty of Engineering and Natural Sciences, Sabanci University, İstanbul 34956, TurkeyAbstract— We fabricated graphene and few-layer graphene (FLG) sheets from highly oriented pyrolitic graphite (HOPG) bymechanical exfoliation technique. The obtained sheets were characterized with optical microscope, Raman spectroscopy, AFM and SEM todetermine their dimensions and shapes. The aim of our study was to obtain an optimized scheme that consistently yields single or doublelayer graphene sheets with large area.Graphene is an outstanding candidate as the material of futureelectronic devices. A considerable amount of work ondetermining the electrical properties of graphene has beendone since its discovery. This 2 dimensional pure carbonmaterial with a single layer honeycomb lattice is alreadyproven to be a useful material in electronic devices such asfield effect transistors. It has the highest carrier mobility atroom temperature, 15,000 cm 2 /Vs among most of the wellknown materials, and has the highest current carrying capacityof 10 9 A/cm 2 [1,2,3] which is several orders of magnitudebetter than presently used device interconnect conductors.Graphene is also mechanically the stiffest material andchemically very inert, hence it can sustain severe conditions.(Figure 2). FLG’s are also visible under Scanning ElectronMicroscope (SEM) (Figure 3). However SEM is not proven tobe useful for estimating the number of layers of graphenesheets.Figure 2. The optical microscope image of a monolayer graphene.Figure 1. AFM image of a FLG sheet. The measured averagethickness is 3 nm. 2.5 nm thicker caused by external forces.In order to produce single layer graphene, we used themechanical exfoliation technique. This technique involvesthinning the HOPG flakes by using ordinary scotch tapes orUV release tapes. Separated sheets were then transferred fromthe tape on to a 300 nm thick SiO 2 layer thermally grown on aSi substrate [4]. There are several parameters that influencethe yield, the probability of transferring largemonolayer/bilayer graphene sheets on to the wafer. Weidentify these parameters as the peeling speed and duration,type of the HOPG flakes and wafer cleaning procedure. Wetested these parameters to acquire statistical data that providethe yield factors.The structural characterization of graphene and few layergraphene (FLG) is done by optical microscopy (OM), atomicforce microscopy (AFM), and Raman spectroscopy. Ramanspectroscopy accurately identifies monolayer or bilayergraphene and is nondestructive. The thickness determinationaccuracy of AFM has also been tested (Figure 1). After havingmeasured the thickness, additional data fitting is essential fortrue thickness determination. Unlike Raman or AFM, OMdoes not give an absolute thickness value. However, OMprovides good contrast for fast initial inspection by human eyeFigure 3. SEM image of few layer grapheneCorresponding author: soyumer@su.sabanciuniv.edu[1] K. I. Bolotin et al., Solid State Commun. 146, 351 (2008).[2] X. Du et al., Nature Nanotech. 3, 491 (2008).[3] J. Moser, A. Barreiro, and A. Bachtold, Appl. Phys. Lett. 91,163513 (2007).[4] K. S. Novoselov et al., Science 306, 666 (2004).6th Nanoscience and Nanotechnology Conference, zmir, 2010 644

PPoster Session, Thursday, June 17Theme F686 - N1123Assembly of Peptide Coated Gold Nanoparticles on Surfaces1111Ismail SayinP P, Kemal KeserogluP P, Mehmet KahramanP Pand UMustafa CulhaUP P*1PDepartment of Genetics and Bioengineering, Yeditepe University, Istanbul 34755, TurkeyAbstract-The assembly of nanoparticles into the desired organizations and patterns is critically important for construction of higher structuresusing nanoparticles as building block. In this regard, we designed charged peptides that can stably bind the gold nanoparticles (AuNPs) to alterthe surface charge properties. Then, we investigate how the surface charge of the nanoparticles can influence the assembly of the AuNPs onsurfaces with different polarity from a drying droplet of their colloidal suspension.Self assembly of the biomolecule modified nanoparticles isextensively studied in recent years [1,2]. The main reasonbehind the use of biomolecule-modified nanoparticles is toutilize the existing weak interactions among biomolecules andbio-macromolecules such as hydrogen bonds, van der Waals,dipol-dipol and ionic interactions to control the nanoparticleassembly. The peptides are one of the target molecules thatare used in these studies because of their easy design andmanipulation of their charge and polarity properties comingfrom their side chains. One of the major factors influencingthe stabilization of the AuNPs in the aqueous environment isthe zeta potential (). Nearly -/+ 30 mV is needed for thestability of the nanoparticles and below these potentials thenanoparticles start to aggregate [3]. The charged peptides canbe used to stabilize the gold nanoparticles [4].In this work, we investigated the assembly of chargedpeptide modified AuNPs and their assembly after addition ofthe oppositely charged peptides into the modified goldcolloidal suspension. The rational behind this reason was tolook for any relationship between the surface chargeproperties of the nanoparticles and its affect on the assemblyof the nanoparticles in a drying droplet. The additions of theoppositely charged peptides cause surface potential changewhich is thought to influence the formation of uniquestructures. The peptides used in this regard are given inTable 1.Table 1. Peptides that were used in the experiments.Purpose Code peptide sequencesOverallChargeP1 Cys-Ser-Glu (-)Modificationof AuNPs P16 Cys-Ser-Glu-Asp-Ser-Asp-Glu-Ser Asp-Ser-Glu-Ser-Asp-Ser-Glu(-)Aggregation P3 Lys-Lys (+)Initiation P11 Lys-Arg-Arg-Lys (+)In this study, we first investigated the self assembledstructures occurred in suspension using SAXS and at the solidliquid interface with SEM and AFM. A correlation withsurface charge properties of the modified AuNPs andassembly behavior in suspension and at liquid-solid interfacewas investigated. The influence of the hydrophobic andhydrophilic surfaces on the behavior of the AuNPs was alsoinvestigated. It was observed that, on the hydrophilic surfaces,the modified AuNPs formed larger aggregates with thedecreasing value of the surface potential and the structures canbe seen all over the surface of the droplet area (Figure 1 andTable 2). On the hydrophobic surfaces, again the aggregatesizes were inversely proportional to the surface potential. Theaggregates were not spread all over the droplet area but theyformed at the near center area of the droplet.A)Figure 1. Aggregates/assemblies of modified AuNPs with differentzeta potentials on hydrophilic surfaces from a drying droplet.A)AuP1 + 1 L P11 B) AuP1 + 5 L P11Table 2. Zeta potential change after addition of the oppositelycharged peptides.AuNP-P11 L P11(+)5 L P11(+)In summary, the preliminary data shows that the structuresformed in the drying droplet are related to the zeta potentialson the AuNPs residing in colloidal suspension. The assemblyof the peptide modified gold nanoparticles differs with respectto the surface bound peptides and addition of the oppositelycharged peptides. The assembly of the nanopartices is alsoaffected from the polarity of the surface. The long term goal ofthis study is to find a way to nanoparticles by modifying thesurface charge properties of nanoparticles and the studies areconducted in this direction. This work was supported byTUBITAK under Grant No. 108T605.*Corresponding author: HTmculha@yeditepe.edu.trT10 L P11(+)AuNP-P1 (-) -30 mV -20 mV -10 mV -7 mV[1] Varpness, Z.; Peters, J. W.; Young, M.; Douglas, T. Nano Lett.2005, 5, 2306-2309.[2] Kramer, R. M.; Sowards, L. A.; Pender, M. A.; Stone, M. O.;Naik, R. R. Langmuir 2005, 21, 8466-8470.[3] J.A. Tullman, W.F. Finney, Y.-J. Lin, S.W. Bishnoi, Plasmonics 2(2007) 119.[4] R. L vy, ChemBioChem 2006, 7, 1141B)2 μm 2 μm6th Nanoscience and Nanotechnology Conference, zmir, 2010 645

P M.P andP M,Poster Session, Thursday, June 17Theme F686 - N11233D Silver Plasmonic Structure for Surface Enhanced Raman Scattering11Mehmet KahramanPUMustafa ÇulhaUP P*Genetics and Bioengineering Department, Faculty of Engineering and Architecture,Yeditepe University, Kayisdagi, Istanbul, TurkeyAbstract- The construction of highly reproducible and enhancing novel SERS substrate is achieved by controlling the inter-particle distance andaggregate size. In order to control aggregation size and number of nanoparticle in one aggregate, micro-well are prepared with the softlithography. In this method, first, the diluted latex microsphere (1.6 μm) are spread as a thin film using “convective assembly” method on aglass slide, then, polydimethylsiloxane (PDMS) is prepared on the latex thin film. Finally, the PDMS film is removed and latex particles arewashed with an organic solvent. The PDMS stamp with micro-wells is filled with concentrated AgNPs coated with CTAB for further analysisusing SERS. SEM and AFM were used for the characterization of the prepared surfaces. Rhodamine 6G is used as a probe molecule to7-9characterize the substrate. The enhancement factor and limit of the detection of the prepared substrates are found to be 3.7x10P Pand 1.0x10Prespectively.Nanosize metal particles and semiconductors have uniqueoptical, magnetic and electronic properties that do not have intheir bulk form. These properties have been used for manyapplications of science and technology such as; nanoscalechemical sensors, data storage, quantum dots lasers,electronics and SERS substrates [1-4]. The size, shape andtype of the noble metal and aggregate properties ofnanoparticles and inter-particle distance are the criticalparameters influencing SERS activity [5-8] due to theirinfluence on surface plasmons (SPs) that are responsible forthe major enhancement (electromagnetic enhancement)[9] inSERS mechanism. The inter-particle distance stronglyinfluences the enhancement factor and it was reported that theinter-particle distance must be 2-4 nm for the optimal SERSenhancement [10]. Although there is an effort to uselithographic methods to control inter-particle distance, thesemethods generally time consuming, expensive and needskilled personnel.In this study, 3D silver plasmonic structures were preparedwith the concentrated silver nanoparticles. First, thin film(Figure 1 A) of the latex was prepared using “convectiveassembly” method [11]. The experimental parameters such asconcentration of latex spheres, moving stage velocity anddropped volume were studied. Second, PDMS was preparedon the latex thin film by baking at 70 °C for 1 hour. Figure 1 Bshows SEM image of the micro-wells prepared with the 1.6m latex sphere on PDMS. As is seen, the size of the microwellsis slightly smaller (1.4 m) than the size of the latexnanoparticles. This is possibly due to the high viscosity of thepolymer mixture in which latex nanoparticles are completelyburied. Therefore, the size of prepared micro-wells decreasesabout 200 nm. Finally, micro-wells were filled using“convective assembly” method with the concentrated silvernanoparticles containing CTAB, which was used to increase ofthe hydrophobic property of the silver nanoparticles andcontrol inter-particle distance in the aggregates (Figure 1C).The enhancement factor was calculated using IRSERSR/IRBulkR x7CRBulkR/CRSERS Rformula and found as 3.0x10P P. This enhancementfactor is also consistent with 2-4 nm inter-particle distances[12]. The reproducibility of the prepared substrate was testedusing the peak height, area and intensity of the ten peaks at-11512 cmPP. The percent coefficient variance (CV) was foundto be about 10. Limit of the detection (LOD) of the substrate-9was 1.0x10PACFigure 1. A) SEM image of the prepared thin film of the 1600 nmlatex sphere, B) micro-wells of 1600 nm latex sphere, C) micro-wellsfilled with silver nanoparticles.In conclusion we demonstrate that novel SERS substratespossessing high sensitivity, enhancement factor andreproducibility by the controlling of the inter-particle distanceand aggregate size.This work was supported by TÜBTAK and YeditepeUniversity.*Corresponding author: HTmculha@yeditepe.edu.trT[1] A. P. Alivisatos, Science 271, 933 (1996).[2] L. E. Brus, Appl. Phys. A, 53, 465 (1991).[3] Y. Wang and N. Herron, J. Phys. Chem. 95, 525 (1991).[4] P. C. Lee and D. Meisel, J. Phys. Chem. 86, 3391 (1982).[5] S. R. Emory, W. E. Haskins, and S. Nie, J. Am. Chem. Soc. 120,8009. (1998).[6] T. Jensen, L. Kelly, A. Lazarides, and G. C. Schatz, Journal ofCluster Science 10, 295 (1999).[7] E. J. Zeman, and G. C. Schatz, J. Phys. Chem. 91, 634 (1987).[8] J. Jiang, K. Bosnick, M. Maillard, and L. Brus, J. Phys. Chem. B107, 9964 (2003).[9] M. Moskovits, Rev. Mod. Phys. 57, 783 (1985).[10] A. M. Schwartzberg, C. D. Grant, A. Wolcott, C. E. Talley, T. R.Huser, R. Bogomolni, and J. Z. Zhang, J. Phys. Chem. B 108, 19191(2004).[11] P. M. Tessier, O. D. Velev, A. T. Kalambur, J. F. Rabolt, A. M.Lenhoff, and E. W. Kaler, J. Am. Chem. Soc. 122, 9554 (2000).[12] J. Jiang, K. Bosnick, M. Maillard, and L. Brus, J. Phys. Chem. B107, 9964 (2003).B6th Nanoscience and Nanotechnology Conference, zmir, 2010 646

P onP viaPP wereP upPoster Session, Thursday, June 17Theme F686 - N1123Superhydrophobic Micropatterned Polymer Surfaces Synthesized by Using Styrene-Flurometacrylate Random Copolymers11UUur CengizUP P*, H. Yldrm ErbilP1PGebze Institute of Technology, Chemical Engineering Department, 41400, Gebze-KocaeliAbstract- In this work, we present a novel method for fabricating polymer thin films containing micro-patterned spherical particles varying inthe range of 400 nm to 8 m by dip-coating process in polymer solution. We can control the distribution of the particle size via adjusting theconcentration of the PS-ran-FMA copolymer, the solvent/non-solvent ratio and withdrawal speed of dip coater. Styrene-fluoromethacrylateorandom copolymer were synthesized in supercritical carbondioxide (scCOR2R) at 250 bar and 80 P PC using AIBN as a free radical initiator. It wasfound that the optimal concentration of polymer solution was 25 mg/mL and withdrawal speed of 41 cm/min to obtain the narrowest particledistribution on the surface. Surfaces containing the microparticles were characterized with the water contact angle measurement, opticalomicroscopy and SEM. Superhydrophobic surfaces having a water contact angle up to 160P obtained with this novel method.Polymer surfaces composed of two or three dimensionalrepeating uniform units are called “patterned polymeric1surfaces”P P. These patterned surfaces are referred to micropatternedand nano-patterned surfaces with respect to theirdimensions. The polymeric micro/nano patterns providesome new properties to the surface which change withrespect to chemical nature and shape of the material. Forinstance, Erbil et al. (2003) obtained micro-structured gellikeporous super-hydrophobic surfaces having a waterocontact angle of 160P the method of phase separationusing isotatic propylene (iPP) having a water contact angleoof 105P nonpatterned surfaces with different2solvent/insolvent couplesP P. There are other methods toform micro patterned polymeric surfaces. Recently Wanget al. have obtained micro and nano patterned polymericstructures via phase separation by dropping polymer1,4solution onto non-solventPP. This method is easier thansoft lithography method whose application is difficult andexpensive.In this study, uniform micro patterned polymericsurfaces were obtained with particle diameters changingbetween 400 nm and 8 μm. In the first step, p(ST-ran-FMA) copolymers were synthesized in sc-COR2R medium.Styrene and Perfluoromethacrylate (Zonly-TM, Dupont)monomers between 5-20 % in molar concentration wereocopolymerized in scCOR2 Renvironment at 250 bar and 80P PC.Polymerization in COR2 Rhas advantages such as being nontoxic,cheap and no requirement of extra purificationprocess for the produced copolymers.In the second step, thin copolymer film coatings wereproduced via dip coating glass slides into polymersolutions obtained by dissolving the copolymers in THF-MEK mixture (%50 wt) at room temperature and addingmethanol as a non-solvent with varying amount. Then theoptical and SEM images of the formed surfaces wererecorded and the contact angles of the surface weremeasured by using the KSV-CAM 200 goniometry.When the methanol volume fraction was low, scatteredform of particles with no specific geometry were observedwhich do not have any specific roughness. With the increasein the methanol amount, these particles were converted torepeating, and somewhat uniform spherical particles. Theincrease in the dipping rate, the particles shrink uniformly atthe beginning, but after a certain value of dipping rate, thenthe agglomeration of particles occurred. Figure 1 shows aSEM image of the surface obtained at an optimum dippingspeed and different methanol fraction. It is clearly seen fromthe results particle sizes decrease with the increase ofmethanol fraction. Spherical particles having differentdiameters between 2-4 m and 400-800 nm are shown infig.1a and 1b respectivelyFigure 1. SEM images of 25 mg/mL p(ST-ran-FMA) solution inTHF-MEK solvent mixture (50 wt %) with a) 21,4 b) 33.3 wt %omethanol at 22 P PC mixture temparatureIn summary, particles shape and dimensions and watercontact angle results were varied as a function of nonsolventand copolymer concentration. The increase in thenon-solvent fraction resulted in decrease of the particlediameter from 8 μm down to 400 nm, and increase in theoowater contact angle from 117P to 160P P.* Corresponding author: HTucengiz@gyte.edu.trT[1]Wang Y., Liu Z., Han B., Sun Z., Zhang J., Sun D. Adv.Funct. Mater. 2005, 15, 655.[2]Erbil H.Y., Demirel A.L., Avci Y., Mert O. Science 2003,299, 1377.[3]Xia Y.N., Whitesides G.M., Angew. Chem. Int. Ed. 1998, 37,550.[4] Wang Y., Liu Z.,Huang Y., Han B.,Yang G. Langmuir, 2006,22, 19286th Nanoscience and Nanotechnology Conference, zmir, 2010 647

PPPoster Session, Thursday, June 17Theme F686 - N1123Fabrication of Ta Nanohillock Array Using AAO/Ta Nanotemplate1222UNevin TaaltnUP P*, Sadullah ÖztürkP P, Necmettin KlnçP P, Zafer Ziya ÖztürkP21PKoç University, Department of Physics, 34450 Istanbul, TurkeyPGebze Institute of Technology, Department of Physics, 41400 Gebze-Kocaeli, TurkeyAbstract-In this study, Ta nanohillock arrays were fabricated with high surface area using AAO/Ta nanotemplate. AAO/Ta nanotemplate wasfabricated by using a two-step anodization of an Al film deposited on Ta foil using evaporation method. Ta nanohillocks were obtained viaanodization process as the nature of the Al-Ta bilayer. The characterization of the AAO/Ta nanotemplate and Ta nanohillock arrays weredetermined by Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX). As fabricated AAO/Ta nanotemplate wasapproximately 55 nm in diameters, Ta nanohillocks were obtained approximately 50 nm in diameters.Tantalum (Ta) is a attractive material for electronic industryas a capacitor due to it has a number of properties such asresistance to corrosion, low co-efficient of thermal expansionand high co-efficient of capacitance. Ta nanostructurescompared to Ta thin films are ideal for electronic devices asthey offer high surface area and high capacitive properties [1,2].In this study, Ta nanohillock arrays were fabricated withhigh surface area using AAO/Ta nanotemplate. AAO/Tananotemplate was fabricated by using a two-step anodizationof an Al film deposited on Ta foil using evaporation method.Al film was oxidized anodically in 0.3 M oxalic acid solution.Ta nanohillocks were obtained via anodization process as thenature of the Al-Ta bilayer. Fabrication of AAO/Tananotemplate and Ta nanohillocks were reported in details.The characterization of the AAO/Ta nanotemplate and Tananohillock arrays were determined by Scanning ElectronThe EDX spectrum from a fabricated Ta nanohillockconfirms the fabrication. The oxidation of the Ta foil resultsfrom Ta ions migrating outward and oxygen ions transportedthrough, and released from, the AAO barrier layer, whichdissolves at the tantala/alumina interface. The shape of the Tananohillocks depends on the nature of the Ta foil, anodisingsolution, and the resistivities of the tantala and alumina barrierlayer.Figure 2. EDX spectrum of a fabricated Ta nanohillock(a)In summary, simple fabrication of Ta nanohillocks usingAAO/Ta nanotemplate was reported in details. We believethat, this method offers a convenient route for fabrication ofother nanostructured capacitors.*Corresponding author: ntasaltin@ku.edu.tr[1] V. Surganov, A. Mozalev, Microelectron. Eng. 37/38 (1997) 329.[2] K. Shimizu, H. Habazaki, P. Skeldon, G.E. Thompson, G.C.Wood, J. Surf. Finish Soc. Jpn. 50 (1999) 2.Figure 1. (a) Top view of the Ta nanohillock array (b) Highmagnification top view of the Ta nanohillock array(b)Fabricated AAO/Ta nanotemplate was approximately 55 nmin diameters and as shown in Figure 1, Ta nanohillocks wereobtained approximately 50 nm in diameters. We couldcalculate the Ta nanohillocks density is approximately10 -21,2.10PPcmPP.6th Nanoscience and Nanotechnology Conference, zmir, 2010 648

P ·cm.PVPPPsPPPPP andPoster Session, Thursday, June 17Theme F686 - N1123Graphene Field Effective Transistor(FET)1234USelda SonuenUP P*, Selin ManukyanP P, Nihan ÖzkanP P, Hidayet ÇetinP Ahmet OralP1PFaculty of Engineering & Natural Sciences, Sabanc University, Istanbul, 34956, Turkey2PDepartment of Physics, Boaziçi University, 34342, Turkey3PDepartment of Physics Engineering, Istanbul Technical University, 34469, Turkey4PDepartment of Physics, Bozok University, Yozgat, Turkey2Abstract- A graphene field effect transistor was fabricated on a 35×9 μmP P few layer graphene sheet by ‘manolithography’, manuallyapplying the drain and source contacts using silver paint and using the silicon substrate as back gate. We investigated electrical properties ofthis graphene FET device.1Graphene is a mono layer of sp² bonded carbon atomspacked into a two-dimensional (2D) honeycomb lattice.Since it was known that two dimensional crystals werethermodynamically unstable, it was presumed thatgraphene didn't exist in the free state. However, graphenewas first prepared via mechanical exfoliation of graphitecrystals by Professor Andrew Geim's research group at theUniversity of Manchester [1].Even though graphene is the thinnest material everfabricated, it has remarkable electrical properties[1]. At theroom temperature, it’s mobility is reported between2 1 115,000- 40,000 cmPPand its electrical resistivity is6approximately 10P Because of its potential inelectronics applications, it has recently attracted a lot ofthe attention of the scientific community [2].In this work, we fabricated a graphene FET using silverpaints as drain and source contacts under opticalmicroscope as shown in Figure 1 and Figure 2, forelectrical characterization of graphene. The graphene isfound to be multilayer from Raman Spectrum obtaineddirectly on the channel. Then, we obtained I-V curves asshown in Figure 3 and Figure 4 using Keithley 2612Sourcemeter and the LabTracer 2.0 software. Wecalculated the transistor parameters from these data.Figure 3. I-V curves of graphene based FET.VRGR= -20/20 V(5 steps) with compliance of 0,01 A.Figure 4. IRDRversus VRGSR curveof graphene FET device.Figure 1. Optical microscope image of graphene withmagnification x50.This work is supported by TÜBTAK , Project Numbers107T720, 107T892 & 108T930, Ministry of Industry &Commerce, Project Number 410.STZ.2009-1 andNanoMagnetics Instruments Ltd.*Corresponding author: ssonusen@su.sabanciuniv.edu[1] Geim, A-K., and Novoselov, K-S.,.The rise of graphene,Nature Materials, 6, 183-191(2007)[2]Shishir, R-S., and Ferry, D.K.,. Intrinsic mobility in graphene,J. Phys., 21, 232204(2009)Figure 2. The device layout of graphene FET.6th Nanoscience and Nanotechnology Conference, zmir, 2010 649

Electron Beam Lithography Process Calibration and CorrectionNezih Ünal 1 , Martin Charlton 2 , Ulrich Hofmann 1 , Christoph Sambale 11 GenISys GmbH, Eschenstr. 66, D-82024 Taufkirchen-Munich, Germany2 University Southampton, School of Electronics and Computer Science, Southampton, SO17 1BJ, Great BritainPoster Session, Thursday, June 17Theme F686 - N1123Abstract – Proximity Effect Correction and Process Correction methods are well established today and in routine use. While traditional ProximityEffect parameters can be computed with sufficient accuracy using Monte Carlo methods, Process Effect parameters are accessible only throughexperimental procedures. We present an easy to adapt method for the calibration of e-beam proximity and process correction parameters for nanopatterning,consisting of i) an intelligently designed calibration pattern, exposed at different exposure doses, and ii) a base dose monitor todetermine the correct dose for different layout densities. We present the application of this method to 2D and 3D correction by dose modulation.Electron beam lithography (EBL) is the most commontechnology for patterning nano-scale devices. Electron beamscan be focused down to the 1nm range, but the resolution islimited by a large amount of effects as there are: electronscattering in the resist / substrate stack, resist material anddevelopment process effects. These effects cause imagingdistortions with different influence ranges and strength(proximity effects) where the exposure of neighboring featuresinteract with each other. As a result, the exposure becomesdependent on the local layout density. All these proximityeffects can be described by a point spread function (PSF).The state-of-the-arte PEC software Layout BEAMER [1]ensures (by dose modulation or shape modulation) that theabsorbed energy (AE) at features edges is uniform all over thelayout [2] – a widely used and proven correction target,leading to development reaching all edges at the same time.However the correction is only as good as the PSF used. Themost popular method for determining the PSF is Monte Carlo(MC) simulation. Commercially available Monte Carlosoftware such as Sceleton [3] calculate the PSF for differentacceleration voltages and stacks and provide sufficientaccuracy for the electron scattering effects. However, resistmaterial and process effects are not taken into account by MCsimulation. Experimental methods for PSF calibration coverall effects, but methods published earlier are either notaccurate or require a large amount of exposure and accurateSEM measurement, which is difficult without automatedmetrology (CD-SEM) [3].The key element of the method described in this paper is the“dose sensor”. We propose a checkerboard pattern (Fig. 1)with the square dimensions suitable to the inspection method(e.g. 500nm for optical, 250nm for SEM).The sensor is used in a calibration pattern with uniform densityover large field (Fig. 3) exposed with dose variation.Fig 3: Calibration pattern for base dose and EtaBase dose and Eta of the PSF can be determined by the bestexposure dose for the specific sensor. The PSF of an e-beamexposure can be approximated by double Gaussian (sufficientfor long range parameter). The absorbed energy at position xcan be calculated:E abs (x) = D(x) ⊗ PSF = D(x) ⊗ (1+2*η∗ρ Beta ) / (1+η)E abs : Absorbed energy, D(x): Exposure dose at position x;η: Eta, ρ Beta : Layout density in Beta rangePEC is adjusting the absorbed energy at all feature edges to beequal to dose to clear (D clear ). The exposure dose of largefeatures is set: D 50% = 1 = Base Dose = D size ~ 2 * D clearThe Base Dose is dependent on the resist sensitivity, butindependent of layout and stack. The PEC is adjusting the localdoses relative to base dose. The “base dose sensor” is exposed to50% layout density in Beta range. The best exposure in thecenter will determine the base dose.The local density in the corner region is 12.5%. The bestexposure dose will be: D 12.5% = (1+ η) / (1 + 0.25 * η) Eta = (D 12.5% - 1) / (1 - 0.25 * D 12.5% )After calibrating base dose and Eta, Beta can be determined byexposing following Beta calibration pattern (Fig. 4) with radiusvariation at base dose:Fig.1: Checkerboard dose sensor and reaction of corner to dosechange (for positive resist)As the infinite checkerboard pattern has the layout density of50% independent of the proximity influence ranges, thepattern is not sensitive to proximity effect at the optimum dose(base dose). The corners of the squares show a high sensitivityfor over- and underexposure. The sensitivity at the cornerdepend on the short-range blur (Fig. 2).Fig 4: Beta calibration pattern with dose sensor with radius variationThe sensor exposed to 50% layout density (showing bestexposure) will determine the correct Beta.unal @genisys-gmbh.com[1] Developed by GenISys GmbH, www.genisys-gmbh.com[2] J. Pavkovich, J. Vac.Sci. Technol., B, Vol.4, No.1, 1986[3] P. Hudek,Microelectronic Engineering 83 (2006) 780-783Fig 6th 2: Dose Nanoscience sensitivity and of Nanotechnology sensor at different Conference, short range zmir, blur 2010 650

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 651

PPmaximumPoster Session, Thursday, June 17Theme F686 - N1123An experiment investigation of GaAs/AlGaAs Solar Cells Efficiency11122ULeyla Baak BüklüUP P*, Aye ErolP P, M. Çetin ArikanP P, Ben RoyallPPand Naci BalkanP1PDepartment of Physics, Istanbul University, Istanbul, TurkeyPDepartment of Computing and Electronic Systems, Essex University, UK2Abstract- In this work, the efficiency of GaAs/AlGaAs solar cell which was formed by a top ring geometry by photolithography methodobtained. The efficiency and spectral response of the cells were investigated by I-V measurement and photoconductivity (PC) measurementsrespectively.Solar cell devices based on III-V semiconductors have anefficiency around 30% which is higher than Si based cells.Because the broader part of solar spectrum is covered bythese structures [1]. The band gap of ternary and quaternaryIII-V semiconductors can be tailored changing alloycompositions for example the band gap energy of GaR1-xRAlRxRAssemiconductors changes from 1,42eV (GaAs) to 2,16eV(AlAs).In this study epitaxially grown n on p GaAs/GaAlAs solarcell structure given in Figure 1 has been employed. GaAlAshaving Al concentration of 0,8 was added to the structure inorder to absorb solar energy starting from 1,6 eV.0,100,080,06Figure 3. I-V set-up3cm8cm13cm18cm23cm28cm33cmI (mA)0,040,020,00-0,020,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7V(Volt)Figure 1. The solar cell structureSolar cell structure was fabricated in ring contacts as mesastructures having contacts on the top of the structures usingphotolithography techniques as shown in Figure 2.Top layer was just for ohmic contacts and interior part ofthe ring removed after ring shaped gold deposition byselectively etching. Au/Ge:Au/Ni alloy was used as ohmiccontact to n type material on the top, Au:Zn/Au ohmiccontact to p type material at the bottom.Figure 4. I-V characteristic of solar cell has taken depending on thedistance between sample and UV lampThe efficiency of solar cell calculated using the equationgiven below.IscVocFF (1)PsWhere R PRs, power; FF, fill factor; IRscR, shortcircuitcurrent; VRoc, Ropen-circuit voltage. Using Equation 1,the efficiency of the solar cell calculated as 13%.5 35K43PC(a.u.)2Figure 2. Solar cell which formed by photolithographyFabricated structure was mounted on a ceramic holder withgold contact pads that was used for wiring. Sample contactsfrom the top and from the bottom layers were join to goldpaths by ultrasonic bonding.I-V measurements were taken in a light tight box with200W high pressure mercury lamp as shown in Figure 3.Obtained spectrum was taken at different intensities bychanging distance between light source and solar cell. Figure4 shows the obtained I-V curves were taken at different lightintensities by using inverse square law.101,2 1,4 1,6 1,8 2,0 2,2 2,4 2,6 2,8 3,0 3,2Energy(eV)Figure 5. Photoconductivity measurement of solar cell has taken35K, 100mV sensitivity and 100Hz frequencyAs seen from the Figure 5, PC spectrum of solar cell startsabsorbing at 1,5eV and peaks at 1.65eV.In summary, the efficiency of GaAs/AlGaAs structurecalculated from I-V curve and spectral response region wasobtained.*Corresponding author: lbbuklu@gmail.com[1] A.W. Bett1, F. Dimroth2, G. Stollwerck2, O.V. Sulima,1999, Appl. Phys. A 69, 119–1296th Nanoscience and Nanotechnology Conference, zmir, 2010 652

PPoster Session, Thursday, June 17Theme F686 - N1123Microwave-Assisted Deposition of Microwire Patterns of Metal Nanoparticles1UUursoy OlgunUP P*1PDepartment of Chemistry, Sakarya University, Sakarya 54187, TurkeyAbstract-Nanoparticles were self-assembled as organized microwire patterns on various substrates due to the stick-slip motion of the contactline during the microwave evaporation of solvent. The colloid solutions of 0.03% (w/v) nanoaluminum in 10% (v/v) poly(dimethylsiloxane)-acetone were used to self-assemble the microwire patterns of Al on glass substrates, which were dipped into the solution and held against thewall. Also, the colloids of 0.001% (w/v) nanosilver prepared in acetone solution of 33.3% (v/v) chloroform, 16.6% (v/v)poly(dimethylsiloxane) and 0.3% (v/v) Tween-20 were utilized for the deposition of the microwire patterns under the microwave heating at51-55 °C. The rapid self-assembly process was demonstrated under the microwave and the width of microwires was about 1-20 m dependingon the concentration of the nanoparticles. Processing of particles to produce surface patterns and their thin films will be presented.The microwave-assisted self-organization of colloidalparticles in confining aqueous droplets was reported for thepreparation of photonic band gap materials [1]. Themicrowave-assisted synthesis and the in-situ self-assembly ofcoaxial Ag/C nanocables have been studied [2]. Although themicrowave synthesis of metal nanoparticles has been studiedin the literature, the microwave processing of the colloids ofmetal nanoparticles has not been investigated in detail. Theevaporation induced self-assembly of zeolite patterns wasreported at room temperature recently [3].Here, the deposition of aluminum and silver microwires wasdirected by the evaporation-induced self-assembly ofnanoparticles under the microwave heating [4]. Compared tothe conventional heating, the microwave radiation had manyadvantages, such as very short time heating, homogeneousenergy transfer to the liquid and reduced bubble formation insolution. The formation of microwire patterns was due to thestick-slip dynamics of the contact line on the surface of thesubstrates. By using the microwave energy, the rapid selfassemblyof the microwires from the metal nanoparticles wasachieved within a few minutes for the first time.The contact line deposition of nanoparticles has been studiedby several groups to prepare micropatterns of variousmaterials. In this study, the effects of using microwave heatingwere explored for the first time to accelerate the particledeposition process. As shown in Figure 1, the role ofmicrowave during the stick-slip motion of contact line wasFigure 2: The images of nanoaluminum and nanosilvermicrowire patterns deposited on glass substrates at 55 C undermicrowave heating [4].20 °C without heating, at 40 °C with conventional heating andat 55 °C with microwave heating. As demonstrated in Figure2, the microwire patterns produced using the microwaveheating are very different for nano Al and Ag particles [4].In summary, it was demonstrated that the colloidal selfassemblyof particles under microwave is an efficient methodto produce micropatterns of nanoparticles. The microwiredeposition process presented in this study is relatively simplecompare to the previous patterning techniques. The use ofphotoresist layer, micropatterned mask, monolayer coatingand molded patterns is not required. As a result of thesefindings, it was concluded that the colloids of aluminum andsilver nanoparticles are suitable for the rapid self-assembly ofthe microwire patterns under the microwave heating.*Corresponding author: HTuolgun@sakarya.edu.trTFigure 1. The mechanism of microwire deposition demonstrated bythe stick-slip dynamics of the contact line [4].investigated using the colloids of nano Al and Ag particles.The colloid solutions of 0.03%(w/v) nanoaluminumcontaining 10%(v/v) PDMS were placed in glass vials and thedeposition of microwires on the wall surface was carried out at[1] S.H. Kim, S.Y. Lee, G.R. Yi, D.J. Pine, S.M. Yang, J. Am. Chem.Soc. 128, 10897, (2006).[2] J.C. Yu, X.L. Hu, L.B. Quan, L.Z. Zhang, Chem. Commun. 21,2704, (2005).[3] U. Olgun, V. Sevinç, Powder Tech. 183, 207, (2008).[4] U.Olgun. ACS Appl. Mater. Interfaces. 2(1), 28, (2010).6th Nanoscience and Nanotechnology Conference, zmir, 2010 653

Poster Session, Thursday, June 17Theme F686 - N1123Fabrication of Platinum Nanoparticles Using Amphiphilic Copolymer TemplateNuman HODA*, Burçin ACAR, Leyla BUDAMA, Önder TOPELAkdeniz University Department of Chemistry Antalya TurkeyAbstract-Production of nanoparticles with controlled size is important for their properties. In this study, production of Ptnanoparticles using PB-b-PEO amphiphilic copolymer template to control their size by loading different amount of precursor was tried.Synthesis of nanoparticles of metals, semiconductorsand magnetic crystals has been accomplished by severalmethods including amphiphilic copolymer template. Thesekinds of copolymers have ability to form micelles in dilutesolutions in selective solvents for one of the blocks [1].Metal salts can be encapsulated in the core of micelles bycomplexation or association, corona provides stabilization.Encapsulated metals are easily chemically reduced oroxidized to convert them their nanoparticles.The aim of study is to control Pt nanoparticles size byadding different amount of precursor to copolymermicelles.PB-b-PEO is a typical amphiphilic copolymer whichcan form micelle in aqueous solution. In characterizationof copolymer PB1800-b-PEO4000 (from Polymer Sources,Canada) micelles formed in aqueous solution,hydrodynamic diameter of micelles (D h ) was found to be52.4(±2) nm. DLS method also gives information aboutpolydispersity of the micelles and this was about 0.075.The cmc of PB-b-PEO diblock copolymer in aqueoussolution was estimated to be 2.94x10 -7 M by fluorescencespectroscopy.PB-b-PEO diblock copolymer micelles in aqueoussolution were used to as nanoreactor to produce Ptnanoparticles having certain sizes. To control particle sizeamount of salt to be added was changed. TEM Picture wastaken in 120 kV. The PB-b-PEO diblock copolymermicelles from TEM are showed in Fig. 1. Resultingpictures with different metal:polymer ratio (in mol) aregiven in Figs. 2.a-f with the size distribution.Figure 1. Micelles of PB-b-PEO in aqueous solutionFigure 2. Nanoparticles produced in a;(3:1) , b;(1:1), c;(1:5),d;(1:10), e;(1:15), f;(1:20), metal:polymer loading.When metal:polymer ratio is favor of metal for example, 3:1,micelles do not stabilize all of metal salt added according toFig.2a. In this figure, there are some agglomerates outside ofthe micelle. It may be understood that the complexationbetween metal salt and hydrophobic part of the copolymer isweak. It can be seen that in the other pictures nanoparticlesare dispersed homogeneously. The mean diameters ofnanoparticles for 1:1, 1:5, 1:10 and 1:20 ratios are 1.3(2),1.5(3), 1.4(3) and 1.1(2) nm, respectively. According toTEM pictures of nanoparticles obtained increasing amount ofmetal salt loading to micelles does not affect much the sizeof nanoparticles. This work was supported by AkdenizUniversity the Scientific Research Projects CoordinationUnit under Grant No. 2007.01.0105.007.*Corresponding Author: nhoda@akdeniz.edu.tr[1] G. Riess, Prog. Polym. Sci., 2003, 28, 1107.6th Nanoscience and Nanotechnology Conference, zmir, 2010 654

PPoster Session, Thursday, June 17Theme F686 - N1123Alternative Method to Production of Nano-Sized -SiAlON Powders111Onur EserP P, USemra KuramaUP P* and Göktug GünkayaP1PDepartment of Materials Science and Engineering, Anadolu University, Eskisehir, TurkeyAbstract-In this study, the optimum milling system was investigated by using sedimentation method. The effect of type of mediums anddispersants were researched by using sedimentation tests. After the optimization of milling medium wet milling system was used to decreasingparticle size of starting powders. All the milling time results were discussed related with the particle size of milled powder.There are some routes to prepare nano-sized SiAlONpowders such as plasma-chemical and laser synthesis [1], solgeland as a top-to-bottom process high-energy mechanicalmilling [2]. Although, this method promises very low particlesizes (~40 nm), would increase the cost of the initial powder[3]. In this study -SiAlON described as SiR4RAlR2ROR2RNR6R, anddoped with 5 wt.% YR2ROR3R. The weighed powders wereplanetary ball milled (Pulverisette 6 Fritsch, Germany) withSiR3RNR4R balls for 2 h in different solvent compositions (toluene,methyl ethyl keton, ethanol) and in different ratios. Thesolvent ratios were determined as given in the literature [4].The level of agglomeration, a critical parameter for theefficiency of the milling process, was determined using thesedimentation method. As explained in our previous study [5],the most dispersed solvent composition was determined for-SiAlON system in three kinds of dispersant (oleic acid,polyethyleneglicol, sodium tripolyphosphate). In the presentstudy polyvinylpyrrolidon was also investigated as analternative to the other three in the -SiAlON system. Theoptimum solvent ratio was investigated in an ethanol:toluenesystem of 70:30 vol. ratio with the highest sedimentationheight. The effect of the dispersant in the selected solventcomposition was investigated by addition of oleicacid, STPP(sodium tripolyphosphate), PEG (polyethyleneglicol) and PVP(polyvinylpyrrolidon) as dispersants (Figure 1).Sediment height (mm)130125120115110105100950 0.5 1 1.5 2 2.5 3PVP(wt. %)Time (h)Figure 1. Effect of amount of (a) PVP on sedimentation heightAccording to the result, the binary solvent system of ethanoland toluene (at a volume ratio 70:30) with 3 wt.% addition ofPVP shows the most dispersed behavior and is used as amilling medium for milling studies. The first powder producedby conventional method which has a powder:ball:alcohol ratioof 1:1.5:2 and the other powder produced by high-energymechanical milling in wet medium at 450 rpm for differenttimes up to 40 hours. For the characterization of the particlesize of the milled powders, two different types of method wereused in this study. One of these is the dynamic light scatteringmethod, and the average particle size of the milled powders isgiven in Fig. 2-3.The second method, BET, was used tomeasure the surface area of the powders an the mean particlesize of (DRBETR). Comparison of the results of both methodsshows that even though the particle size of powders decrease0.51.02.52.01.53.0by increasing milling time, from sample C to N50. There wasobserved differences in results. These differences can beexplained by the formation of agglomerates which are difficultto deform, even using ultrasonic treatment in the dynamic lightscattering method. However, in the BET method the diffusionof NR2R gas into agglomerates is possible, giving more realisticresults than the dynamic light scattering method.Particle Size (nm)7006005004003002001000Conventional51020Time (h)Figure 2. Particle size analyse of powder by dynamic light scatteringmethodParticle Size (nm)250200150100500Conventional51020Time (h)Figure 3. Particle size analyse of powder by BETAs a consequence, the high energy milling in a wet mediumsystem is an effective way to produce nano- -SiAlONstarting powders. The most efficient milling medium for the-SiAlON suspensions is investigated as 70 vol. % Ethanol-30vol. % Toluen with the addition of 3 wt% PVP. The minimum-SiAlON powder size was obtained as 92 nm after 50 hmilling in this medium.This work was supported by TUBITAK under Grant No.108T661.*Corresponding author: skurama@anadolu.edu.tr[1]. Bulic, F., Zalite, I., Zhilinska, N., 2004. Comparison of plasma-chemicalsynthesised SiAlON nano-powder and conventional prepared SiAlONpowder, Journal of the European Ceramic Society, 24: 3303-3306.[2]. Li, Q., Zhang, C., Komeya, K., Tatami, J., Meguro, T., Gao, L., 2003.Nano powders of -SiAlON carbothermally produced via a sol-gel process,Journal of Materials Science Letters, 22: 885-887.[3]. Xu, X., Nishimura, T., Hirosaki, N., Xie, R., Yamamoto, Y., Tanaka, H.,2005. Fabrication of -SiAlON nanoceramics by high-energy mechanicalmilling and spark plasma sintering, Nanotechnology, 16 : 1569-1573.[4] Eser, O. and Kurama, S., (2010). The effect of the wet-milling process onsintering temperature and the amount of additive of SiAlON ceramics,Ceramics International, doi:10.1016/j.ceramint.2009.12.025.[5] Eser, O., Kurama, S. and Gunkaya, G., 2010. The production of -SiAlON ceramics with low amount of additive, at low sintering temperature,J. The European ceram. Soc,. doi: 10.1016/j.jeurceramsoc.2010.01.024.3030404050506th Nanoscience and Nanotechnology Conference, zmir, 2010 655

1Effect of using sports equipment manufacturer nanotechnology to improvethe performance of players in someAli JifriKing Abdul Aziz UniversityThe research aimsThis research aims to identify the impact of sports equipment manufactured nanotechnology to improve the performance of the players.Research Methodology:The researchers Use:- Experimental approach to a single set, so that the sample is measured using the regularsport, and the tool manufacturer nano-technology.- Use descriptive approach researchers manner (analytical study) by using video imaging andanalysis of motor qualitative manner (Hay and Reid Hay and Reid Model) and quantitativeanalysis of motor using analysis software (E - human) computer-literate.Research community:Research involved some Arab and foreign countries, namely:- Saudi Arabia.- Arab Republic of Egypt.- Syrian Arab Republic.- State of Portugal.- State of Serbia.Research Sample:Sample was selected in the manner deliberate search of the players the following sports:1 - Tennis GroundThe number of players, five of the following countries (Saudi Arabia - Egypt - Syria -Portugal - Serbia) at this year's 9th Saudi ITF Junior Tennis Championships.2 – BasketballThe number of players from the four national team players for the Saudi youth inSaudi Arabia.3 - athleticsThe number of players from two national team players in Saudi, Saudi Arabia.Surveys:Conducted surveys to identify the safety procedures and imaging cameras and the program forthe analysis of motor as well as system calibration, the survey has shown safety proceduresand preparation.The baseline study:The baseline study was conducted in the period from 15/10/2009 to 1/12/2009.Statistical treatment:Data were processed statistically using the Search Results:Conclusions:1 - Performance skill and muscle to the players a sample search tools manufactured nanotechnologywas the best performance of the skill of motor tools manufacturer in thetraditional way.2 - tools manufactured nano-technology lead to improved performance of the skill of theplayers in sports tennis, basketball and athletics.Reference :- Ableism and general human performance enhancement : Demands On GoverningNew Technologies In Sports Increase ,Nano technology magazine for small science ,issue 9 , December 9, 2008- Ableism and general human performance enhancement : Demands On GoverningNew Technologies In Sports Increase ,Nano technology magazine for small science ,issue 9 , December 9, 2008

Poster Session, Thursday, June 17Theme F686 - N1123Electrical Force Microscopy and SKPM Investigations of Pb Doped CdS FilmsS.A. Klimova 1 , M. Arslan 2 *, S.V. Stetsyura 1 , M. Yavuz 2 , E.G. Glukhovskoy 1 , S.B. Venig 1 , Y. Elerman 21 University of Saratov State, Department of Nano- and Biomedical Technology, 410012, Saratov, Russia2University of Ankara, Department of Engineering Physics, Faculty of Engineering, 06100 Besevler, Ankara, TurkeyAbstract- The major focus of this work has been to observe structural and electrical properties of Pb doped CdS films. pHvalues of sub-phase can change the crystal structure. Furthermore, we found that surface potential values of these filmsdepended on pH changing.Scanning probe microscopy methods allow theinvestigation of a variety of sample surface propertieson a nanometer scale. As molecular electronicsadvance, the characterization of electrical propertiesbecomes more and more important [1].In this study, the structural properties ofmonolayers with Pb inclusions which were depositedon glass with Langmuir-Schaeffer method, wereobserved by using SEM (Fig.1, 2) and AFM. Inadditionally the electrostatic properties of films wereinvestigated in EFM and SKPM.Due to the localization of electrons in the polymerchain, changing the crystalline structure. It means thatcrystal forms of Pb are sensitive to pH changes. As itcan be seen from Figs. 1 and 2, the structure of the LBfilm is significantly altered by the changes of the pHsub-phase. Clusters are received when pH of the watersub-phase is 8 and the dendrites when 3. Variations ofpH are carry out for control of the surface of thematerial CdS. Metal ions diffuse forward into thesurface of CdS by annealing process with differenttemperature.Figure 1. (a) SEM image, and (b) hypermapping image ofdendriteFigure 3. AFM image (a) 2D (b) 3Dfor dendrite structure(pH: 3.0)Figure 4. AFM image (a) 2D (b)3D for cluster structure(pH: 8.0)For these films, surface potential (ΔV) values varyfrom 0.35 V at pH 3.0 to 0. .07 V at pH 8.0. Thisdecrease is due to the ionization of the monolayer atthe air/aqueous interface. Therefore, the pH has asubstantial influence on the stability of the films.In conclusion, for CdS with Pb Langmuir-and their electricalBlodgett thin films, grain sizeproperties effected by sub-phase either acidic mediumor basic medium [2].* melike.arslan05@gmail.com[1] Macromol.Rapid Commun. 30, 1167–1178 (2009)[2] Thin Solid Films 327–329, 56–59 (1998)Figure 2. (a) SEM image, and (b) hypermapping image ofclusterIn SEM images, Pb accumulations observed on thesurface of films. According to AFM images, theheight of the deposited pattern is about 1 μm fordendrites (Fig. 3) and 0.5 μm for clusters (Fig. 4). Fordendrite structure, large grains weree formed on top ofglass.6th Nanoscience and Nanotechnology Conference, zmir, 2010 656

HRbRPP andPandwillisPLevP )Poster Session, Thursday, June 17Theme F686 - N1123Measurement of ultralow magnetic fields with superconductor technology11UUgur TopalUP P* andP P DorosinskiiP1PTÜBTAK-UME P.K. 54 41470,Gebze-Kocaeli/TürkiyeAbstract-In this study we present a noval magnetic field measurement system for detection of ultra low magnetic fields (at the order of nT). Theproposed system is based on bulk superconducting sensor and works at liquid nitrogen temperature. We predict that the lowest detectedmagnetic field (1 nTesla) will be much smaller than that of conventional fluxgate magnetometers but it is larger than the SQUIDmagnetometer. On the other hand, working facility at liquid nitrogen and easy fabrication of the sensor element seems to be important advantagefor open area usage of the designed magnetometer, which is quite difficult by SQUIDs requring liquid helium usage.Magnetic sensors have some advantages compared tooptical, infrared, acoustic sensors and radars in the detectionof moving and static objects in the air, in the water or underthe ground. Magnetic sensors may better determine thelocation of those objects and their type may be more suitableto follow their motion. One of the most important reasons forusing magnetic sensors is the fact that the signal produced bymagnetic objects is practically not attenuated by theenvironment. The aim of the present project is to construct adigital magnetometer using High-Temperature superconductormaterials as a magnetic field sensor. These materials are veryeasy to produce, do not require liquid helium as in the case ofSQUID magnetometer, can be used in liquid nitrogen and are-10expected to result in the magnetic field sensitivity of 10PTesla. The idea behind this study can be summarized asfollows.The effects of AC and DC magnetic fields on High-Tcsuperconductors have been investigated by many groups [1-5].If an AC field (HRacR) with frequency of f is applied to high-Tc’s, magnetic field penetrates to the superconductor in caseits amplitude is bigger than the first critical field H Rc1R. Thennonlinear magnetization of the superconductor is expected.Such an nonlinear magnetization causes the generation of oddharmonics with frequency of (2n+1)f. Co-application of ACand DC fields will generate even harmonics. It may beexplained in details as follows. L. Ji et al. proposed thatcritical current is dependent on the local field, which iscontrary to the Bean critical state model [1,6]. If an AC field,H=HRacRcos(wt), is applied to a type II superconductor, JRcRonly depend on H and thus, Hwill be same for wt andwt+t. Then, M(wt)=-M(wt+) and so, symmetricalmagnetization curve is expected.nUsing Sin(nwt)=(-1)P Psinn(wt+) andnCos(nwt)=(-1)P PCosn(wt+), M(wt) will generate only oddharmonics.On the other hand, in case of DC field together with ACfield, H=HRdcR+HRacRcos(wt), situation is different. That is,antisymetrical magnetization is expected.In Anderson-Kim model, critical current density JRcRassumed to be equal to c/HRlocalR, where is pinning force andc speed of light. Ji et al. applied Anderson-Kim model to asuperconducting plate with thickness D for the cases ofHH* (H* is the field required for thepenetration up to plate center) and obtained magnetizationcurve. They assume that applied field H is between HRaR HRbR2 2and HRaR>HRbR(see Fig.1 left). They also define P P= HRaRP Psgn(HRaR)-2Psgn(HRbR) (sgn(x)=1 for x>0 , sgn(x)=-1 for x2H*P P PH*harmonic signal is proportional to H*P P/HRacR.In case of superconductor is under field ofH=HRdcR+HRacRcos(wt);HRaR=HRdcR+HRacR and HRbR=HRdcR-HRacR and for the case of P P

PErkanPoster Session, Thursday, June 17Theme F686 - N1123Nanoscale Surface Characterization of Materials by SEM Stereoscopic Imaging11UOrkun ErsoyUP P* andP P AydarP1PDepartment of Geological Engineering, Hacettepe University, Ankara 06800, TurkeyAbstract-Surface texture of different type materials were quantified using digital elevation models (DEM) reconstructed from stereoscopicimages acquired from different angles by scanning electron microscope (SEM). Nanoscale roughness parameters were measured on DEMs ofvolcanic ash, sphalerite, polymer beads with different surface textures. The implemented method presented in this study offers new insight forsurface characterization of different materials on nanoscale regions.Three-dimensional reconstruction from stereoscopic images(acquired at varying specimen tilt angles) is based on themeasurement of the disparity (parallax), which is the shift (inpixels) of the specimen features from one image to the other[1]. The resolution of the result is the same as the resolution ofthe SEM images. The parallax method for elevationmeasurement from stereo pairs consists of imaging the sameobject from two viewpoints at the same plane, so the parallax,or the object point displacement along an axis parallel to thestraight line through these viewpoints contained on theviewer's plane is proportional to the distance between theselected point and the viewer's plane, i.e. the local elevation isproportional to the local parallax.Detailed information about the method and surfacecharacterization of volcanic ash particles can be found in [2].In this study, we measured roughness parameters of surfaceson profiles (ISO 4287; ISO 11562; ASME B46.1-2002standards) set in images. Volcanic ash particles and sphaleritespheres are coarser than polymer beads and have higher valuesof roughness parameters (Figure 1).Mean peak to valley height of roughness profile for finer andcoarser beads are approx. 2 and 5 nm, respectively.Beside roughness measurements on nanoscale regions, it isalso possible to measure elements such as distance, heightsteps, angles etc. on reconstructed 3D models Here, we showDEM of a broken bead and step height between two differentlayers in polymer bead (Figure 2).Figure 2. Reconstructed model of a broken polymer bead. The heightstep measurement between two levels on bead surface gives approx.7 microns.In summary, SEM stereoscopic imaging offers new insightsfor surface characterization of particles on nano- and macroregions.After reconstruction of the 3D models of surfaces bythe implemented method, it is possible to quantify surfaceparameters of particles which become highly informative andvaluable in characterizing particle structure details.This work was partially supported by TUBITAK underProject No. 108Y063 and by Hacettepe University ResearchFoundation under Project No. 0701602009. We thank Prof.Dr. Ali Tuncel for providing polymer beads.*Corresponding author: oersoy@hacettepe.edu.tr[1] J.L. Pouchou et al, Microchimica Acta 139, 135 (2002).[2] O. Ersoy, J.Volc.Geotherm.Res. 190, 290 (2010).Figure 1. Reconstructed model of a volcanic ash particle and polymerbeads (from [2]).The average profile roughness values for volcanic ash andsphalerite spheres are approx. 65 and 14 nm, respectively.Volcanic ash particles have a mean peak to valley height ofroughness profile of approx. 550 nm while sphalerite has avalue of approx. 105 nm. Polymer beads with different sizesand surface textures were analyzed. Finer beads have averageprofile roughness value of approx. 0.280 nm. Coarser beadshave average profile roughness value of approx. 0.600 nm.6th Nanoscience and Nanotechnology Conference, zmir, 2010 658

PPP andPoster Session, Thursday, June 17Theme F686 - N1123Application of Nanotechnologies for Creation of 3D-imagery121,222UGrigoriy MunUP P* Ibragim SuleimenovP P, Nikolay SemenyakinPP, Dmitriy BobrovnikovP P, Lylya ZaitovaP121Gulnara GapparovaPPKazNU - Chemical faculty of Kazakh National University, Karasai Batyra 95, 050012 Almaty, KazakhstanPAIPET – Almaty Institute of Power Engineering and Telecommunications, Baitursynova 126, Almaty 050013, KazakhstanAbstract-The scheme of creation of 3D-imagery using a new approach of display screens design with nanoparticles using is suggested. 3Deffectis created at the expense of sequentially arranged layers; each of them possesses properties of separate display screen.The possibility of using of the phase transitions in solutionsof thermosensitive polymers for imagery reproduction wasdiscussed for the first time in [1]. The phase transition insolution of such polymer results in sharp increase of opticaldensity, i.e. solution starts to scatter the light effectively.Transition can be realized locally. In particular, in filling ofplane-parallel volume by thermosensitive polymer solutionthere is a possibility to realize the scheme when separatemedium areas acquire ability to scatter the light and the othersremain transparent.First type points are perceived as illuminated, secondtype – as dark since light from exterior source passes throughthem without scattering. In the simplest case local phasetransition can be provided by using the diminutive heatingelement (diode- resistive panel). The local heating can berealized also owing to using of solution own conductivity andaccompanying Joule heat release.Photograph of enlarged model, realized the principlesuggested, is shown at Figure 1. The model is realized on thebase of volume limited by plane-parallel glass walls and filledby (poly)N-isopropylacrylamide (PNiPAAM) aqueoussolution, MM = 135 000, CRpolR = 0,3%; solution layer thicknessis 5 mm.1Figure 2. Dependences of duration of phase transition on voltageU at various salt concentrations; RNaClR.=0,01(1), 0,02(2), 0,05(3)mol%, CRpolR = 0,1%; line (4) corresponds to frequency of framechange (= 1/24Hz).It is seen that parameter corresponding to accepted TVstandard is realized at quite high voltage and concentrations oflow-molecular salt only. It is necessary to emphasize thatincrease of phase transition speed is associated with nonlinearphenomenon proceeded in solution heated by electric current.The heating of solution of thermosensitive polymer results inalteration of its electroconductivity and this in turn affects thedistribution of current density.An alternative way of increase of conductivity isconnected to saturation of polymer solution by nanoparticles.In this case, marked nonlinear effects resulting inconsiderable increase of phase transition rate take place. Forillustration, the dependence of intensity of optical signalpassed through the solution on time is shown on pic.3. It isseen that the presence of nanoparticles results in appearance ofself-oscillations of high frequency.1JFigure1. Aggregative screen modelIt is seen that points where phase transition occurred areperceived indeed as bright and the other- as dark. The daylightwas used for obtaining of the photo. This emphasizes one ofthe advantages of systems of such type – they can work withdaylight without extra energy consumption for highlighting.Another advantage of screens of such type is totaltransparency in initial state (achieved by using of opticallytransparent electrodes). This allows to use several layerslocated one after another for obtaining of 3D-effect.However, direct use of phase transitions in thermosensitivepolymers faced with certain difficulties. The rate of phasetransition is relatively low and the conductivity of solutionrequires to be increased by additives of low-molecular salt.The dependence of phase transition duration on appliedvoltage at different concentrations of low-molecular salt isshown at Figure 2.0,750,50,250t, ms200 400 600 800Figure 3: Dependence of optical signal on time PNiPAAM solutioncontaining gold nanoparticles; CRpolymR = 2%, CRAuR = 0,05 %, V = 70 V)*Corresponding author: grigoriy.mun@kaznu.kz[1] I.E.Suleimenov, G.A.Mun et.al. 19th Polymer Networks Groupmeeting Larnaca, Cyprus, 22-26 June 2008. Pa 486th Nanoscience and Nanotechnology Conference, zmir, 2010 659

Poster Session, Thursday, June 17Theme F686 - N1123A New Method: Thickness Determination of Thin Films by Energy Dispersive X-raySpectroscopySedat Canli 1,2* , Mustafa Kulakci 3 , Urcan Guler 3 , Rasit Turan 2,31 Micro and Nanotechnology Department, Middle East Technical University, 06531 Ankara, Turkey2 Central Laboratory, Middle East Technical University, 06531 Ankara, Turkey3 Department of Physics, Middle East Technical University, 06531 Ankara, TurkeyAbstract- EDS is a tool for quantitative and qualitative analysis of the materials. In electron microscopy, the energy of theelectrons determines the depth of the region where the x-rays come from. By varying the energy of the electrons, the depth ofthe region where x-rays come from can be changed. Different quantitative ratios of the elements for different electronenergies can be obtained using a thin film. The thickness of a specific film on a specific substrate corresponds to a uniqueenergy-ratio diagram. In this study, it is shown that thickness of a thin film can be obtained by an appropriate analysis of theenergy-ratio diagram of the EDS data obtained from the film.Scanning Electron Microscopes (SEM) and EnergyDispersive X-ray Spectroscopy (EDS) methods arebeing widely used in materials and nanotechnologyresearches. Thin films are very important for severalindustries, such as electronic semiconductor industry,optical coating industry or photovoltaic cells. In thecurrent work, EDS was investigated as a potential toolto be used as a relatively easy methodology formeasuring the thickness of thin films.Silicon, the main material of semiconductortechnology was used as the substrate in this study.Gold, germanium and aluminum were coated onsubstrates by thermal evaporation method and SiO 2 wasgrown by the wet oxidation method. Corroborativethickness measurements were obtained by profilometerand ellipsometry.It is known that the electron beam generated by anSEM hits perpendicularly onto the surface of the filmsand the interaction volume changes with the appliedelectron energy. In the present study, energy values inthe range of 3keV to 30keV with steps of 1keV wereused.Figure 1: Monte Carlo electron trajectory simulations of theinteraction volume in Fe at (a) 10keV. (b) 20keV. (c) 30keV [1].At atomic scale, focused electrons hitting the sampleexcite inner electrons of the atoms. During therelaxation of the atoms, each atom radiatescharacteristic x-rays from K α , K β , L α , etc shells [2]. Thedetector collects and counts x-rays coming from thesample and constructs the spectrum. The EDS systemnormalizes and corrects the data using ZAFcoefficients, and finally gives ratios of the elements.Atomic percentage ratios of the coated elements ofvarying thicknesses were collected. The gold ratioobtained from this sample set can be seen in Figure 2.Gold Ratio (%)100806040200Voltage & Atomic Gold Ratio25 nm50 nm75 nm100 nm125 nm150 nm175 nmSEM Voltage (keV)0 5 10 15 20 25 30Figure 2: Atomic percent ratios obtained on gold films with differentthicknesses.Similar plots were separately obtained for eachelement and it was observed that different atomic ratiocurves were obtained for the same thicknesses ofvarying coatings.For a specific gold ratio (i.e. %50) we draw ahorizontal line and found corresponding SEM Voltage,for each film thickness. The collection of all dataobtained from all films at each thickness was used tointerpolate the data and construct a new graph ofvoltage vs. thickness. The reference graph was used asa tool to figure out the unknown thicknesses of thesefilms. These results were further correlated using theMonte Carlo simulation software called Casino.In summary, it was shown that specific thickness ofthin films on a substrate give unique atomic percentvoltage-ratio curves and these data can be used as atool to construct reference data for further thicknessdetermination. It is shown that this methodology canbe exploited for all elements of interest that were usedas a coating on thin films at nanoscale, which is madeavailable by the Monte Carlo simulations developedfor this particular study.* Corresponding author: canli@metu.edu.tr[1] Goldstein J.I. Scanning Electron Microscopy and X-rayMicroanalysis, New York 1992[2] Reimer L. Scanning Electron Microscopy, Springer-Verlag,Berlin 19986th Nanoscience and Nanotechnology Conference, zmir, 2010 660

PPPPPP*PP,PP andPoster Session, Thursday, June 17Theme F686 - N1123Topological Analysis of the Integer Quantum Hall Effect12,341UAylin YildizUPP, Afif SiddikiPPDeniz EksiP Ismail SokmenP1 Department of Physics, Dokuz Eylul University, Izmir 35160, Turkey2PDepartment of Physics, Istanbul University, Istanbul 34134, TurkeyPDepartment of Physics, Harvard University, Cambridge MA 02138, USA4PDepartment of Physics, Trakya University, Edirne 22030, Turkey3Abstract-We discuss the role of topology on the integer quantum Hall effect (IQHE). The characteristics of the edges as well as the bulkstates in a Hall bar with two identical square gates in the interior and a Corbino disc geometries with and without disorder have been analyzedin detail. The current distribution obtained from the Linear Response Theory (LRT) is presented for all systems.Vortices in Type II superconductors, Aharonov-Bohmeffect and many other examples put forward the important roleof topology in condensed matter physics. Since the discoveryof the quantum Hall effect [1], important topologicalinvestigations have been performed [2-5].The famous gauge invariance argument of Laughlin [2] isfundamental to the phenomena. Laughlin's argument, focussedon a closed cylinder with a strong magnetic field normal to itssurface, is threaded by a time dependent magnetic flux. Eachtime the flux was increased by one flux quantum, an electronwas argued to be adiabatically transferred from the inside tothe outside edge of the cylinder. This resulted in a flow ofelectrical current proportional to the electro-motive drivingforce, with a precisely quantized coeffcient of proportionality -the Hall conductance [2]. The Laughlin's argument waselaborated on by Halperin to a Corbino disc - a hollow discshaped sample [3]. Within a Corbino-disc geometry, thequantized Hall conductance could be understood as a discretetransfer of electrons between the inner and outer edges, onefor each magnetic flux quantum threading the bore of the disc.The importance of the edge state was first demonstrated bythis work.The equivalence of Hall bar sample enclosed on itself underthe periodic boundary conditions as well as gauge invarianceand Corbino disc topologies is one of the intriguing researchtopics. In this study we define two geometries - a Hall bar withidentical square gates in the interior region and a Corbino discas an annular 2DEG system surrounding a metallic contact[i.e., an electron reservoir (electrode)] and surrounded in turnby a second metallic contact as shown in Figure 1.The Hall bar geometry involve a physical edge which connectsthe probing contacts. A unique feature of Corbino disc is that,unlike other two-dimensional semiconductor devices, theirboundaries consist entirely of metallic contacts and no edgeconnects the contacts. This different sample configuration ledto the observation of completely different effects.The characteristics of the incompressible strips (IS) havebeen analyzed for both geometries with and without disorder.We apply the Thomas-Fermi Approximation (TFA) assumingthe electrostatic quantities vary slowly in the quantummechanical scale such as magnetic length [7]. We obtainedcircular ISs in Corbino disc near inner and outer annulus atT=5K temperature under the influence of B=8T, whichobviously confirm the edge picture for Hall conductancestressed by Halperin. Under T=4K, B=8.5T conditions theobtained edge states in the clean Hall bar sample are parallelto the straight line connecting source and drain. On the otherhand, the circular edge states in Corbino geometry cut thecorresponding line perpendicularly. With increasing magneticfield the existence of ISs in both systems is described by thebulk states. This picture is valid for a small magnetic fieldrange.In the presence of a small fixed current the system is locallyin thermal equilibrium. In this case the linearity between thecurrent density and the electric field is almost conserved thatthe Linear Response theory (LRT) is valid [8]. The Hallcurrent in Hall bar sample is carried by edge states for B=7.5Tand T=6K conditions, while with increasing the magnetic fieldup to 8T current penetrates the ISs around the gates.Our calculations show that the existence of disorderbroadens the ISs and the bulk picture is ascendent in bothsystems independent of the geometry.In summary, we analyze the edge or bulk states realizationsof the IQHE in a Hall bar with two identical square gates inthe interior and a Corbino disc geometries with and withoutdisorder. We conclude that the edge and bulk states areactually related and the topological characters of the Hall barand Corbino disc systems are quite different.*Corresponding author: HTaylin.yildiz@deu.edu.trTFigure 1. (a) Hall bar geometry with identical square gates in theinterior region (red squares). (b) Corbino disc geometry. The blueregions indicate the two-dimensional electron gas, the red areas aresource (S) and drain (D) elements and the yellow squares denotes themetallic contacts in both samples.[1] K. Von Klitzing, G. Dorda and M. Pepper, Phys. Rev. Lett. 45,494 (1980).[2] R. B. Laughlin, Phys. Rev. B 23(10), 5632 (1981).[3] B.I. Halperin, Phys. Rev. B 25, 2185 (1982).[4] G. Kirczenow, J.Phys.: Condens. Matter. 6, L583-L588 (1994).[5] E. Yahel, A. Plalevski, and H. Shtrikman, Superlattices andMicrostructures 22(4), 537 (1997).[7] A. Siddiki, R. R. Gerhardts, Phys. Rev. B 70 (2004) 195335.[8] K. Güven, R. R. Gerhardts, Phys. Rev. B 67 (2003) 115327.6th Nanoscience and Nanotechnology Conference, zmir, 2010 661

Poster Session, Thursday, June 17Theme F686 - N1123Fully Differential High Voltage Amplifier Design for Stick-slip NanopositioningNazmi Burak Budanur 1* , Devrim Yılmaz Aksın 1 , Oğuzhan Gürlü 21 Electronics & Communications Department, Istanbul Technical University, Istanbul 34469, Turkey2 Physics Department, Istanbul Technical University, Istanbul 34469, TurkeyAbstract – A fully differential high voltage amplifier to drive stick-slip piezoelectric actuators is designed. The amplifier consists of a fullydifferential amplifier and a common mode amplifier as ICs, and a power boosting stage with discrete components. By this design approach weachieve slew rates of 300 V/μs on high capacitive loads of 10 nF.The motivation of this work is to build a high resolutionnanopositioner to be used in the sample positioning stage of ascanning tunneling microscope (STM). Due to the stick-slipmotion principle, a high voltage (with an amplitude ofapproximately 300V) ramp signal with very high slew rates isneeded to drive piezoelectric ceramics with several hundredthsof grams of load on them. Period of the ramp signal should bein the range of 0.1s in order to make the motion in reasonabletime scales. Additionally, a high voltage and fast controlelectronic can be applied in other systems that require nanopositioning by means of piezo electric positioners.There are single ended examples of HV amplifiers inliterature with an operational amplifier in the input stagefollowed by class-AB power boosting output stages in whichthe output common mode is determined by a simple negativefeedback [1], [2]. Our design, shown in Figure 1, has threemain blocks: Input fully differential amplifier, class-AB poweramplifier and common mode feedback amplifier. Inputamplifier and the common mode amplifier are designed in0.35 micron CMOS technology with 3.3V sources, and thepower amplifier is build with discrete components with a155V DC source. Since the output common mode level is tobe determined at the half of the high voltage DC source,common mode sensing circuit divides the output voltage to asuitable level.We design and simulate our circuit on Cadence VirtuosoSpectre with SPICE models of discrete components and theAMS 0.35μm libraries. The power stage will be realized withdiscrete components whereas the low power sections will berealized through AMS. AC simulation result of the differentialloop is shown in Figure 2. As it is clear from the figure, theDC gain of the amplifier is 90dB, its gain band width productis 370kHz and its phase margin is 83 degree.Figure 2. AC Simulation result.In conclusion, a fully differential amplifier design with a300V/μs slew rate is done to drive stick-slip piezoelectricnanopositioners. This work is a collaborative project of ITUVLSI and nano scale surface science labs.* budanur@itu.edu.tr[1] Colclough, M. S., 2000, A Fast high-voltageamplifier for driving piezoelectric positioners, Review ofScientific Instruments, vol.71 pp. 4323-4324[2] Wang, D. H., Zhu, W., Yang, Q., Ding, W.M., 2009,A High-voltage and High-power Amplifier for DrivingPiezoelectric Stack Actuators, Journal of Intelligent MaterialSystems and Structures, Vol. 20 pp. 1987-2001Figure 1. HV Amplifier Design BlocksOne of the main advantages of the fully differentialapproach is the ability to use relatively low voltage devices.Since high voltage BJT and MOS transistors have largegeometries, parasitic capacitors of these devices determine thefrequency behavior of the whole circuit. It is possible to obtaina differential voltage on the load, approximately double of theDC source.6th Nanoscience and Nanotechnology Conference, zmir, 2010 662

Poster Session, Thursday, June 17Theme F686 - N1123Chemically specific dynamic characterization of photovoltaic andphotoconductivity effects of surface nanostructuresOkan Öner Ekiz,Koray Mizrak, and Aykutlu DânaUNAM-National Nanotechnology Research Center, Bilkent University, Ankara 06800, TurkeyAbstract— We report characterization of photovoltaic and photoconductivity effects on nanostructured surfacesthrough light induced changes in the X-Ray photoelectron spectra (XPS). The technique combines the chemicalspecificity of XPS and the power of surface photovoltage spectroscoy (SPV), with the addition of the ability tocharacterize photoconductivity under both static and dynamic optical excitation. A theoretical model that quantitativelydescribes the features of the observed spectra is presented. We demonstrate the applicability of the model on a multitudeof sample systems, including homo and hetero-junction solar cells, CdS nanoparticles on metallic or semiconductingsubstrates and carbon nanotube films on silicon substrates.X-Ray photoelectron spectroscopy (XPS) is a powerfulspectroscopic technique for characterization of surfaces withchemical specificity. The photoelectron spectra carriesinformation about binding states of different atomic specieswithin tens of nanometers of the surface, as well asinformation on local potential variations. If the emittedelectrons are not compensated by an external electron gun ordirectly from the substrate, local potentials can vary due tolocal conductivity variations that result in different amounts ofaccumulated charge. Overcharging by injection of excesselectrons were previously used for surface characterization. [1]Surface potentials can be shifted by direct application of avoltage to the substrate. Such shifts resulting from directvoltage stimulus were previously modeled for static anddynamic voltage excitations, taking into account conductivityand capacitances of surface domains.[2,6] Nanostructures areincreasingly finding application in photovoltaic technologies.Investigation of photovoltaic and photoconductivity effects innanowires, nanocrystals and nanocomposites are interestingfrom a fundamental scientific point of view.Conventional characterization techniques lack chemicalspecificity, and most of the time require precision fabricationof contacts on nanostructures using techniques such aselectron beam lithography or related lithographies withnanoscale resolution, especially if single nanoparticles areinvolved. Surface photovoltage spectroscopy (SPV) has beentraditionally applied to characterize photoinduced surfacephotovoltage changes upon illumination, using the KelvinProbe as a readout method for surface potential shifts. [7,8]Also, Kelvin probe microscopy has been used to observephotovoltaic effects on nanoscale structures. Chemicallyspecific readout of photoinduced surface potential changes is ahighly desirable analytical capability. Such chemicallyspecific measurements are not possible with conventionalKelvin probe measurements. Previously, XPS has been used toprobe the surface photovoltage of silicon surfaces.[9]Recently, Cohen[10,11] et al. demonstrated that surfacepotential shifts related to external illumination wereobservable in XPS spectra of composite semiconductorsurfaces. It was demonstrated that static or quasi-static shiftsof XPS peaks can be related to photovoltaic andphotoconductive effects. The shifts can be quantitativelystudied with films on conductive substrates. In this article wedemonstrate an approach that allows the study of photovoltaicand photoconductivity effects using the XPS, under static ormodulated illumination. Surface potentials of domains areinternally modulated due to both photovoltaic andphotoconductivity effects. We show that a circuit model canbe used to estimate the changes in spectra under static anddynamic illumination conditions. Light induced surfacepotential differences due to photovoltaic and photoconductiveeffects can be identified.Figure: Schenatic illustration of the described characterization method.*Corresponding author: ekiz@bilkent.edu.tr, aykutlu@unam.bilkent.edu.tr[1] Lau, W. M. A surface charging technique in photoemission spectroscopicstudies of dielectric-semiconductor structures. J. Appl. Phys. 1990, 67, 1504–1509.[2] Suzer, S. Differential Charging in X-ray Photoelectron Spectroscopy: ANuisance or a Useful Tool? Anal. Chem. 2003, 75, 7026 – 7029.[3]Suzer, S.; Sezen, H.; Ertas, G.; Dâna, A. XPS measurements for probingdynamics of charging. J. Electron Spectrosc. Relat. Phenom. 2010, 176, 52 –57.[4]Sezen, H.; Ertas, G.; Dana, A.; Suzer, S. Charging/Discharging of ThinPS/PMMA Films As Probed by Dynamic X-ray Photoelectron Spectroscopy.Macromolecules 2007, 40, 4109– 4112.[5] Filip-Granit, N.; van der Boom, M. E.; Yerushalmi, R.; Scherz, A.; Cohen,H. Submolecular Potential Profiling Across Organic Monolayers. Nano Lett.2006, 6, 2848 – 2851.[6]Cohen, H.; Maoz, R.; Sagiv, J. Transient Charge Accumulation in aCapacitive Self- Assembled Monolayer. Nano Lett. 2006, 6, 2462 – 2466.[7]Clabes, J.; Henzler, M. Determination of surface states on Si(111) bysurface photovoltage spectroscopy. Phys. Rev. B 1980, 21, 625–631. 14[8]Bardeen, J. Surface States and Rectification at a Metal Semi-ConductorContact. Phys. Rev. 1947, 71, 717–727.[9]Schlaf, R.; Hinogami, R.; Fujitani, M.; Yae, S.; Nakato, Y. Fermi levelpinning on HF etched silicon surfaces investigated by photoelectronspectroscopy. J. Vac. Sci. Technol. A 1999, 17, 164–169.[10]Cohen, H.; Sarkar, S. K.; Hodes, G. Chemically resolved photovoltagemeasurements in CdSe nanoparticle films. J. Phys. Chem. B 2006, 110,25508–25513.(19) Cohen, H. Chemically resolved electrical measurements in organic selfassembledmolecular layers. J. Electron Spectrosc. Relat. Phenom. 2010, 176,24 – 34.6th Nanoscience and Nanotechnology Conference, zmir, 2010 663

PPPP andPoster Session, Thursday, June 17Theme F686 - N1123Spectroscopic Investigation of Gold and Silver Nanoparticles Produced Using Femtosecond LaserPulses1121,31UBelgin GencUP P*, Erhan AkmanP P, Oral Cenk AktasP P, Elif KacarP Arif DemirPPLaser Technologies Research and Application Center, Kocaeli University, Kocaeli 41275, TurkeyPLeibniz Institute for New Materials ( INM), CVD/Biosurfaces Department, Saarbrücken, D-66123, Germany3PDepartment of Physics, Kocaeli University, Kocaeli 41380, Turkey21Abstract-In this study, we investigate the spectroscopic analysis of Au and Ag nanoparticles produced using fs laser pulses. The laserinducedplasma was generated by focusing a 355-nm, 6 ns pulse from a Q-switched Nd:YAG laser with pulse energy varied from 10 to 30 mJ.Spectroscopic measurements of the spectra emitted from laser-induced plasma are performed using Czerny-Turner type spectrometer(BAKI-S).Laser-induced breakdown spectroscopy (LIBS) is an usefulatomic emission spectroscopic technique. Laser producedplasmas at atmospheric pressure are useful for analysis of theelemental composition of solids, liquids, gases and aerosolsdue to its reliable advantages of lack of any difficult previoussample preparation and direct measurement capability [1,2].The use of metal particles for biomolecule detection,opticallimiting application has continued to make the laser andoptical spectroscopy of small metal particles an important areaof research [3]. The silver material is used in many products asbactericide [4], whereas gold material is explored for manypossible applications and its catalytic activity [5].In this study, UV-VIS spectral lines taken from gold andsilver plates were compared using nanosecond laser coupledUV-VIS spectrometer. Gold and silver nanoparticles spectrawere taken from liquid droplet and dried liquids on glasssurface. Absorption spectra of mixed gold and silver in liquidswere studied as function of particle concentrations.The experimental system for the current study is shownschematically in Figure. 1. In the first case, the samples wereablated using a Nd:YAG laser (Continum Surelite III)operating at the third harmonic (355 nm) with a repetition rateof 10 Hz and pulse duration of 6 ns. The energy of the laserpulse was monitored by an energy meter. The laser-inducedplasma were produced by focusing the laser beam with a 150mm plano-covex lens. Spectroscopic measurements of thespectra emitted from laser-induced Titanium plasma areperformed using Czerny-Turner type spectrometer (BAKI)developed in the Laser Technologies Research ad ApplicationCenter (LATARUM) of Kocaeli University. The wavelengthrange of the recorded spectrum between 365 nm and 565 nm isshown.Figure 2.Nd:YAG LaserDelayGeneratorPowerMeterHalf-WavePlatePrismaUV-VISSpectrometerBeamSplitterIC C DCameraIntensity (a.u)Intensity (a.u)6400540044003400240014009000800070006000500040003000405,548 nm Ag (I)421.259 nm Ag(I)365 415 465 515 565Wavelength (nm)380.192 nm Au (I)390.109 nm Au (I)406.507 nm Au (I)431.848 nm Au (I)443.727 nm Au (I)448.825 nm Au (I)462.056 nm Au (I)2000365 415 465 515 565Wavelength (nm)479.258 nm Au (I)521.908 nm Ag(I)514.744 nm Au (I)523.026 nm Au (I)Figure 2. The LIBS spectrum recorded by UV-VIS spectrometer(BAKI-S) (a) gold and (b) silver plates.In summary, we have reported on the element analysis ofgold, silver and mixed gold-silver nanoparticles by laserinduced breakdown spectroscopy. Our results show thatidentification of Au and Ag spectral emitted from very smallamount of volume is possible using LIBS technique.*Corresponding author: belgingenc@kocaeli.edu.tr[1] C. A. D'Angelo et. al., Spectrochimica Acta Part B 63, 367,(2008).[2] . Yalçn, Spectroscopic characterization of laser producedplasmas and investigation of physical plasma paratmeters, PhDthesis, METU.[3] V.K. Pustovalov et. Al. Laser Phys. Lett. 1, No.10, 516–520(2004).[4] J.R. Morones et al.,Nanotechnol. 16, 2346e2353 (2005).[5] M. Brust., C.J. Liely, Colloids Surf.A 202, 175e186, (2002).546.987 nm Ag(1)565.577 nm Au (I)Figure 1. Laser-induced breakdown spectroscopy system.Data Acquisitionand Analysis6th Nanoscience and Nanotechnology Conference, zmir, 2010 664

Poster Session, Thursday, June 17Theme F686 - N1123High Resolution AFM imaging in Liquid EnvironmentÜmit Çelik 1 , Demet Catcat 2 , H. Ozgur Ozer 3 , Ahmet Oral 41 Department of Materials Engineering, Istanbul Technical University, 34469, Turkey2 NanoMagnetics Instruments Ltd., 266 Banbury Road, Oxford OX2 7DL, UK.3 Department of Physics Engineering, Istanbul Technical University, Istanbul, 34469, Turkey4 Faculty of Engineering & Natural Sciences, Sabanci University, Istanbul, 34956, TurkeyAbstract – We developed a low noise atomic force microscope which can achieve high resolution imaging in liquidenvironment. We designed a tube piezoelectric scanner that can achieve atomic resolution sensitivity with 2 m scan range.We have worked on noise reduction in laser source and optical feedback noise. We used optical beam deflection method(OBD) method to measure deflection of cantilever and we worked on noise reduction in ODB sensor. In this study we willpresent the major noise sources in ODB method with theoretical and practical experimental comparison results.We have developed a high resolution afm which canoperate in liquid. This method offers the opportunityfor the visualization individual mobile molecules inreal-time as well as in real space under physiologicalenvironment at the molecular level. Spatial resolutionis very important issue in biological moleculesimaging, because biological molecules is generally at afew nanometers size. Recently, there has been a greatprogress in improving the spatial resolution fordynamic-mode in-liquid AFM [1, 2].In this work, we used SPM control electronic whichis supplied by NanoMagnetics Instruments Ltd.Firstly, we ensured that the scanner is working properlyfor atomic resolution imaging. We designed a tubepiezo scanner and made its characterization. Weanalysed frequnecy spectra of mechanical response ofthe scanner. We tested our scanner in air using contactmode afm and we achieved atomic resolution on micasurface(figure 1).The low noise characteristic of the deflection sensormakes it possible toobtain a maximum frequencysensitivity limited by the thermal Brownian motion ofthe cantilever(figure 2) in every environment[1]. Wedesigned a low noise deflection sensor and we didtheoritical and practical comparisons.Figure 2. Brownian motion of the cantilever with 350MHz Rfinjection in the air environmentThis work is supported by TÜBTAK andNanoMagnetics Instruments ltd.References:[1] T. Fukuma, K. Kobayashi, K. Matsushige, H. Yamada,True molecular resolution in liquid by frequency-modulationatomic force microscopy, Appl. Phys. Lett. 86 (2005)193108.[2] T. Fukuma, M. J. Higgins, S. P. Jarvis, Direct imaging oflipid-ion network formation under physiological conditionsby frequency modulation atomic force microscopy, Phys.Rev. Lett. 98 (2007) 106101.Figure 1. Atomic resolution image on mica surface.We have worked on laser noise reduction. The rfmodulation considerably reduces the mode hoppinginduced by the optical feedback. In addition, themultimode laser beam has a lower coherence than thesingle-mode does. Thus, the rf modulation also workswell to suppress the optical interference noise[1]. Wehave injected diffrent rf frequency with diffrentamplitudes to laser diode and we tried to find optimumconditions. We have also tried different commerciallaser diodes to make a comparison between them.6th Nanoscience and Nanotechnology Conference, zmir, 2010 665

Poster Session, Thursday, June 17Theme F686 - N1123Epitaxial Graphene Synthesis on Silicon Carbide SubstrateHüsnü Aslan 1 , 1 ,NihanÖzkan 2 ,and Ahmet Oral 11 Faculty of Engineering & Natural Sciences University, Istanbul, 34956, Turkey2 Department of Physics Engineering, Istanbul Technical University, 34469, TurkeyAbstract – Large scale single layer epitaxial graphene is going to be produced in the ultrahigh vacuum chamber andcharacterized by Atomic Force Microscope and Low Energy Electron Diffraction.Graphene, one atomic thick layer form of graphite,is composed of hexagonally arranged carbon atoms andthe layers between two graphene sheets are bonded byweak van der Waals interaction. Its unique electricaland mechanical properties have recently made it popularin both science and technology.Graphene could be produced by using several methodsboth chemically and mechanically. The most popularand the easiest method is called mechanicalexfoliation[1]. However, by using this method one canproduce small-area graphene layer. In order to obtainlarge scale graphene, the method called epitaxial growthon SiC or CVD can be used. This method includes twosteps. For the first step, SiC has to be etched byhydrogen gas in order to prepare suitable SiC surfacefor epitaxial growth. In this process, cleaned SiCsamples are annealed in a vacuum chamber with %5 H 2and %95 Ar gas flow. For the second step, SiC chip isheated in ultrahigh vacuum to temperatures between1000-1500°C in order to sublimate Si [2,3].In this work, we are planning to produce monolayergraphene on commercially available 4H-SiC(0001)sample. The growth process is going to be performed inan ultrahigh vacuum chamber equipped with e-beamheater and graphene layers are going to be characterizedby Low Energy Electron Diffraction (LEED). Inaddition to this, thickness of this graphene layer is goingto be measured by Atomic Force Microscope.ers107T720, 107T892 & 108T930 and NanoMagneticsInstruments Ltd.[1] Geim, A-K., and Novoselov, K-S.The rise of graphene,Nature Materials, 6, 183-191(2007).[2]Hass, J., De Heer, W.A., and Conrad, E.H. The growth andmorphology of epitaxial multilayer graphene, Journal ofphysics: Condensed Matter, 20, 323202 (2008).[3]Ramachandran V., Brady, M.F., Smith, A.R., Feenstra,R.M., and Greve, D.W. Preparation of atomically flat surfaceson silicon carbide using hydrogen etching, Journal ofElectronic Materials, 27, 308-312, (1998).Figure 1. AFM image of an SiC (0001) wafer beforehydrogen etching.6th Nanoscience and Nanotechnology Conference, zmir, 2010 666

PP mBar.P andPoster Session, Thursday, June 17Theme F686 - N1123Construction of a Combined Non-Contact Atomic Force Microscope & Scanning TunnellingMicroscope (nc-AFM/STM)1111UDerya GemiciUP P*, Hüsnü AslanP P, Özhan ÜnverdiP Ahmet OralP1PFaculty of Engineering & Natural Sciences, Sabancı University, Istanbul, 34956, TurkeyAbstract-A combined non-contact Atomic Force Microscope (nc-AFM) & Scanning Tunnelling Microscope (STM) operating in UltraHigh Vacuum(UHV) has been designed and constructed. The nc-AFM uses a fiber interferometer and Digiatl Phase Locked Loop for highresolution detection of cantilever displacements.In the early 1980's two IBM scientists, Binnig & Rohrer,developed a new technique for studying surface structureat atomic scale - Scanning Tunnelling Microscopy(STM).This invention was quickly followed by the developmentof a whole family of related techniques called ScanningProbe Microscopy (SPM). The most important SPMmethod is the Atomic Force Microscopy (AFM) where thetip-sample forces are measured to obtain topography of thesample even at the atomic scale. The inventions of STMand AFM revolutionised the surface science, helpingscientist to resolve the atomic structure of surfaces in realspace.In this work, we have designed and constructed acombined non-contact Atomic Force Microscope (nc-AFM) & Scanning Tunnelling Microscope (STM) basedon fiber interferometer for the imaging surfaces rangingfrom non-conducting to conducting and from hard to softand delicate samples in Ultra High Vacuum(UHV). Thedesign is based on our previous work [3,4] with substantialimprovement in vibration isolation and ease of assembly.UHV by imaging Gold evaporated on glass. STM imagesof this specimen is given in Figure 3.Figure 2. Optical Microscope images of home-made tungsten tipshave been used for the experimentFigure 3. The STM image of of gold surface at UHV,-11p < 3×10P IRT R= 0.3 nA & VRBiasR = 1 VThis work is supported by TÜBTAK , Project Number108T001, Ministry of Industry & Commerce, ProjectNumber 409.STZ.2009-1 and NanoMagnetics InstrumentsLtd.*Corresponding author: deryagemici@sabanciuniv.eduFigure 1. Photograph of the home made combined nc-AFM/STM.We have designed the combined microscope usingSolidworks CAD program, the parts are machined at theworkhops around Ankara. The final assembled nc-AFM/STM is shown in Figure 1 is mounted on a special8’’ CF flange. The base of the microscope is suspendedusing springs mounted on adjustable collars attached tofour posts. In order to damp the external vibrations eddycurrentdamping is used. Twenty eight SmCo magnetsattached separately to the posts on a magnet holder asshown in Figure 1 are surrounded by copper plates fixed tothe microscope base, the height of the magnet ring can beadjusted to set the desired damping coefficient. Tungstentips are etched in KOH solution as shown in Figure 2. Themicroscope is going to be mounted in a separate UHVsystem, but the initial tests are performed in our existingUHV system. Nc-AFM/STM is tested for STM only in[1] G. Binning, H. Rohrer ‘Scanning Tunnelling Microscopy’,Helvetica Physica Acta, 55,726 (1982)[2 ] S.Morita,R.Wiesendanger, E.Meyer ‘Noncontact AtomicForce Microscopy’ pg 11-76 principle of NC AFM andsemiconductor surfaces[3] M. Atabak, PhD Thesis, 2007, Bilkent University[4] M. Atabak, Ö. Ünverdi, H.Ö. Özer & A. Oral, J. Vac. Sci.Technol. B 27, 1001 (2009)6th Nanoscience and Nanotechnology Conference, zmir, 2010 667

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 668

PPPPPoster Session, Thursday, June 17Theme F686 - N1123Work Function Difference Measurements of Graphene, Graphite and SiOR2R Surfaces using KelvinProbe Force Microscope (KPFM)12342UNihan ÖzkanUP P*, Selda SonuenP P, Ümit ÇelikP P, Hidayet ÇetinP P, Ahmet OralP1PDepartment of Physics Engineering, Istanbul Technical University, Istanbul, 34469, Turkey2PFaculty of Engineering & Natural Sciences, Sabanci University, Istanbul, 34956, Turkey3PDepartment of Materials Engineering, Istanbul Technical University, 34469, Turkey4PDepartment of Physics, Bozok University, Yozgat, TurkeyAbstract-We predict that we can determine the work function difference between grahene and SiOR2R, graphite and SiOR2and also graphene and graphite. We prepared graphene flakes on SiOR2R substrate by mechanical exfolation method and obtained images oftopography and work function difference by Kelvin Probe Force Microscope.Kelvin Probe Force Microscopy (KPFM) is a new localprobe measurement method of work function of differentmetals with high spatial resolution. It depends on theKelvin method originally developed by William Thomson,also known as Lord Kelvin in 1898[1]. In 1991 KPFM wasdeveloped by Nonnenmacher et al. to look at differentmetal surfaces with high spatial resolution[2].In this work we modified the Atomic ForceMicroscope(AFM) supplied by NanoMagneticsInstruments Ltd. to perform the Kelvin Probe ForceMicroscopy measurements. Graphene flakes were preparedby mechanical exfoliation of graphite crystals with tapeand transfer onto Si(100) wafer with 300 nm thermal oxideas shown in Figure 1.Figure 2. a)Topography image of multi layer graphene andgraphite by KPFM b)Cross section of topographic KPFM scan ofgrapheneFigure 3. a) Work function difference image of multi layergraphene and graphite by KPFM b) Cross section of workfunction difference scan between graphite and SiOR2R of KPFMFigure 1. Optical microscope image of multi layer grapheneproduced by mechanical exfoliation method, x50 objective lens.There are different KPFM modes commonlyemployed[3] in the literature. We operated the KPFM inmulti-frequency mode in this work, topographical signalsand the Kelvin probe signal are simultaneously detected atfirst and second resonance frequencies of the cantilever,respectively. Thus topography of the surface and workfunction difference between the sample and tip aresimultaneously determined. The first resonance frequencyis used to obtain topography image as used in intermittentcontactAFM mode. The second resonance frequency isused to obtain the work function difference image of thesample, using a digital Lock-in Amplifier. An electricalcontact is carefully applied from the side of the flake usingsilver paint.We obtained topography images of multilayer and singlelayer graphene as well as graphite flakes deposited onSilicon and measured the thickness of graphene. KPFMimages of the samples were simultaneously obtained withthe topographic images. We could measure work functiondifference between the graphene, graphite and SiOR2R asshown in Figure 2 and Figure 3.RTopography and KPFM images from single layergraphene will also be presented [4].This work is supported by TÜBTAK , Project Numbers107T720, 107T892 & 108T930, Ministry of Industry &Commerce, Project Number 410.STZ.2009-1 andNanoMagnetics Instruments ltd.*Corresponding author: ozkan.nian@gmail.com[1] Lord Kelvin, Contact electricity of metals, Phil. Mag.,46,82(1897)[2 ] Nonnenmacher M., Oboyle M-P.,WickramasingheH- K., Kelvin probe force microscopy, Appl. Phys. Lett.,58 ,2921(1991)[3] Palermo V., Palma M., Samori P.,.Electronic Characterizationof Organic Thin Films by Kelvin Probe Force Microscopy, Adv.Mater., 18, 145–164(2006)[4] Filleter T., Emtsev K-V., Seyller Th., Bennewitz R.,.LocalWork Function measurements of Epitaxial Graphene, Appl Phys.Lett, 93,133117 (2008)6th Nanoscience and Nanotechnology Conference, zmir, 2010 669

T PeptideTPP,PP,PP andTT2429TTTTTT TTPoster Session, Thursday, June 17Theme F686 - N1123TNano and Micro Mechanical Study of Self-Assembled Peptide Amphiphile Nanofibers1111Yavuz Selim DadaPPAye Begüm TekinayPPAykutlu DanaPUMustafa Özgür GülerUP P*1PUNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, TurkeyAbstract-Peptide amphiphile nanostructures have been used for various tissue engineering applications. Peptide amphiphile molecules selfassembleinto nanofibers due to hydrogen bonding, hydrophobic interactions and electrostatic interactions. Three-dimensional network of thesenanostructures form hydrogels that are used to culture cells for tissue engineering applications. In this study, we investigate the relationshipbetween nanostructure and hydrogel mechanical properties. A direct relation between gel stiffness and -sheet forming tendency has beenobserved and it led us to measure the stiffness of individual nanofibers by AFM. Our results indicate that nano and micro mechanical propertiescan differ through self-assembly mechanism. This result is important in terms of characterization of peptide amphiphile materials and theirapplications in tissue engineering studies.amphiphiles are a group of molecules that containboth hydrophobic alkyl tail and bioactive peptide sequencewhich enables these molecules to form differentnanostructures when they come together. The amphiphiliccharacter of these molecules enables these molecules toassemble nanofibers and hydrophilic bioactive peptidesequences are presented on the periphery of the nanostructures[1]. These molecules can be easily programmed to selfassemble into nanofibers by changing pH, and electrolyteaddition [2,3]. These nanofibers assemble to form 3-Dnetworks that can mimic extracellular matrix. Structure andbioactivity of the nanostructures make these materialspromising for tissue engineering applications. Extracellularmatrix (ECM) differs in terms of structural features andbioactivity in each tissue. The rigidity of the ECM has beenshown to affect cell behavior; the cell motility [4], growth [5]and focal adhesion [6]. In addition, it has been shown that themechanical properties of the ECM environment affect stemcell differentiation [7]. In a recent study, it has been shownthat stiffness of these gels differs with regard to self assemblymechanism (pH and salt concentration) [8].the pH and the electrolyte addition on self-assemblymechanism was studied. It has been observed that thesemolecules form gel at low pH and with addition of CaClR2 Ratneutral pH. We studied the effect of the differences in pH andelectrolyte assembly with circular dichroism, FT-IR andrheology.We performed SEM in order to observe the nanofibernetwork. The stiffness of the hydrogels was measured by2+rheology and it has been observed that CaPPgels are stifferthan low pH gels. We also studied the secondary structureformation which is the main mechanism of self-assemblythrough these formulations by using circular dichroism andFT-IR. We observed elevated levels of -sheet structure incalcium formulations than the low pH formulation.We are currently measuring stiffness of individualnanofibers by AFM. The mechanical properties of thenanofibers formed are compared through differentformulations. The stiffness of the gels and individual fiberswill be studied to understand the relationship between them.*Corresponding author: HTmoguler@unam.bilkent.edu.trT[1] TM. O. Guler et al., TTBiomacromoleculesTT TT2006T,T TT7T, 1855-1863.T[2]T J. D. Hartgerink et al., Proc. Natl. Acad. Sci. U.S.A. 2002, 99,(8), 5133-5138.T[3]T J. C. Stendahl et al., Adv. Funct. Mater. 2006, 16, (4), 499-508.[4] TR. J. Pelham et al., MolTT. Biol. CellTT TT1996TT,TT TT7TT,TT TT2429 TT.[5] P. C. Georges et al., TJ. Appl. Physiol.TT TT2005T,T TT98T,(T4T),T TT1547TT TT1553T.[6] R. J Pelham et al., TProc. Natl. Acad. Sci. U.S.A. 1997T,T TT94T,(T25T),T TT13661TT TT13665T.[7] A. J. Engler et al., TCell TT2006T,T TT126T, (T4T),T TT677TT TT689T.[8] M. A. Greenfield et al.,T TTLangmuirTT TT26(5)T, (2010) 3641-3647.TFigure 1. Hydrogels formed by the 3-D network of peptideamphiphile nanofibers.In this study, we analyzed nano and micro mechanicalproperties of peptide amphiphile materials since cell-matrixinteraction occurs through individual nanofibers and comparedthese mechanical properties with the stiffness of hydrogel.There is a direct relation between nanofiber stiffness and gelstiffness. TWe first synthesized a negatively charged peptideamphiphile molecule at physiologic conditions containingbioactive amino acid sequence; arginine-glycine-aspartic acid“RGD”. The synthesis and purity of the molecule is verifiedby liquid chromatography-mass spectrometry. The effect of6th Nanoscience and Nanotechnology Conference, zmir, 2010 670

Poster Session, Thursday, June 17Theme F686 - N1123Design Of An Experimental Setup For Measuring Electrical Conductivity Of NanofluidsLevent Cetin*, Alpaslan Turgut, I. H. TavmanDokuz Eylul University Mechanical Engineering Department, 35100 Bornova/zmirAbstract- We represent a low cost instrumentation setup for measuring electrical conductivity of nanofluid. Theresulting setup is exploited to measure electrical conductivity of Alumina (Al 2 O 3 ) nanoparticles 25 nm diameter inethylene glycol for their different particle volume fractions. Approximately ten times increase in %5 particle volumefraction is observed.After the pioneering work of Choi[1] nanofluidsbecome a new class of heat transfer fluids. Theirpotential benefits and applications in manyindustries from electronics to transportation haveattracted great interest from many researchers bothexperimentally and theoretically. Most of theseresearches are related with the thermal conductivityand viscosity of nanofluids. On the other hand,electrical conductivity may give information on thestability of the suspensions. However, there are fewstudies concerning the electrical conductivity ofnanofluids[2].Instrumentation apparatus consists of a signalgenerator, two multimeters and a buffer circuit.System is driven with sinusoidal output from signalgenerator. Buffer circuit is exploited to isolateconductivity measurement cell and low powersignal source. Buffer circuit is designed using OP07opamp which has low offset value 75V [3].Measurement probe is a four point type. Theconfiguration of the linear four-point probe isshown in Figure. 1. Current is injected into a probeon one end (probe a on figure) and extracted fromthe probe on the other end (probe d on figure),while the voltage difference between the two centerprobes (b and c) is measured with a high inputimpedance circuit. Current is measured from probed to ground terminal of the circuit.d I (3)A VThe geometric parameters are unified by definingelectrode cell constant (d/A); where d is the lengthof the column of liquid between the electrodes andA is the area of the electrodes.Table 1 Cell geometryD [mm] A [mm 2 ] Cell coefficient [1 /mm]1.85 1,65 1,119879Conductivity of ethylene glycol is measured usingdesigned apparatus and using this reference valuewe observe the linear increase on electricalconductivity of Alumina (Al 2 O 3 ) nanoparticles 25nm diameter in ethylene glycol for their differentparticle volume fractions. Approximately ten timesincrease in %5 particle volume fraction is observed.Relative electrical conductivity1110 Al2O3-EG9876543210 1 2 3 4 5Particle volume fraction (%)Figure 2 Schematic representation ofinstrumentation setup.Figure 1 Schematic representation ofinstrumentation setup.The resistivity “” of the media is calculated usingOhm’s law:d VR (1)A IV A (2)I dFollowing the fact, Electrical conductivity is thereciprocal of electrical resistivity, it can beformulated as:In this study, an instrumentation setup using onthe shell electronics components and basic labequipment is designed. Using this system,electrical conductivity of the Alumina (Al 2 O 3 )nanoparticles in ethylene glycol is monitored.Corresponding Author levent.cetin@deu.edu.tr[1] Choi, S. U. S. 1995. Enhancing thermal conductivityof fluids with nanoparticles. In Developments andApplications of Non-Newtonian Flows. (FED 231), (99–105). New York: American Society of MechanicalEngineers.[2] Ganguly S, Sikdar S, Basu, S 2009, Experimentalinvestigation of the effective electrical conductivity ofaluminum oxide nanofluids Powder TechnologyVolume: 196 Issue: 3 Pages: 326-330 Published:DEC 22 2009[3] http://cds.linear.com/docs/Datasheet/OP07.pdf6th Nanoscience and Nanotechnology Conference, zmir, 2010 671

Poster Session, Thursday, June 17Theme F686 - N1123Physical properties of nanostructure thin films of fluorine-doped indium oxide prepared by spraypyrolysis techniqueS.M.Rozati, Z.BargbidiDepatment of physics, University of Guilan, Rasht 41335, IranEmail: smrozati@guilan.ac.irAbstract- In this research, indium oxide nanostructure undoped and doped with F were prepared on glass substrates using spraypyrolysis technique. Various parameters such as dopant concentration, deposition temperatures, amount of indium oxide powder werediscussed. Structural properties of these films were investigated by XRD & SEM. Electrical and optical properties have been studiedby Hall Effect and UV-Visible spectrophotometer respectively. The thickness of the films is determined by PUMA software. Thevariation in refractive index, extension coefficient and band gap of these films also were investigated.Transparent conducting oxide such as In 2 O 3 :F (IFO)because of their high optical transparency in the visibleregion, good electrical conductivity are important. There aremany applications for transparent conductive oxide ( TCO)films such as solar cells, liquid crystal display, and gassensors[1].TCO films have been prepared by various depositiontechniques such as vacuum evaporation, sputtering, spraypyrolysis, sol gel, etc [2-4].In this research, IFO thin films were prepared on glasssubstrates using spray pyrolysis technique. In 2 O 3 :F thin filmswere prepared by spraying a water solution containingindium chloride (0.2gr InCl 3 ) and NH 4 F used as dopant ontoglass substrates heated at different substrate temperatures.Deposition of parameters conclude: distance between thespray nozzle an substrates 25 cm, the carrier gas usingfiltered compressed air, the spray rate 19 lit/min, volume ofsolution is 40 ml.All the above mentioned parameters were kept constant andonly the concentration of NH 4 F (0-15wt%) and substratetemperature (400-600 ° C) were changed.In this work we first optimize the concentration of F wt%using electrical resistivity and optical transparency andsecondly focused on the effect of substrate temperature onstructural, electrical, optical properties of the samples with aconstant fluorine concentration of 2wt%.Concentration of F in these films have been varied from 0-15wt%. as a result, the resistivity decreased quickly withincreasing F concentration reaching a minimum of=1.35x10 -3 cm for an F concentration of 1wt%. For higherdopant content, the resistivity increased. The highertransmittance observed in the films for 2wt% of F doped.Since we were looking for a layer with both high transparentand good resistevity, we used figure of merit (FOM). Thusthe optimized layer with 2wt% of F concentration wasselected according to the most FOM [5].The X-ray diffraction result of IFO films in variousconcentration are shown that, films are polycrystalline andcrystallize in a cubic structure with preferential orientationalong (222) and (400). Note also that no characteristic peaksof impurity and dopant phases have been observed.For investigation of temperature effect on the growth mode,we fixed the doping concentration at 2wt% F and studied theeffect of the substrate temperature on the transparency. Fig. 1shows the variation of substrate temperature of IFO filmswith change in transmission. Films deposited at substratetemperatures of 400 to 450 °C exhibited less transmission invisible region, while by increasing the substrate temperaturewe get better transparency.The XRD results show that, films deposited at substratetemperature of 400 and 450 ° C, in addition to (222), (400)peaks have (211), (411), (341), (440), (622) peaks with highintensity. The presence and intensity of peaks decreased withincreasing substrate temperature; as a result crystallinityimproves leading to well-transmission and resistivity.Subsequently the amount of indium powder also wasinvestigated for the prepared films. Result show that theresistivity is decreased by increasing of indium powder buttransparency is decreased.The SEM results show that the size of crystals is in therange on nanometer. The size of particles changing withrespect to deposition parameters.Besides, the thickness of the films is determined by PUMAsoftware[6]. The variation in refractive index, extensioncoefficient and band gap of these films also wereinvestigated.In conclusion, the optimum IFO films were prepared using0.2gr InCl 3 with F concentration of 2wt% at substratetemperature of 575 ° C. With this condition sheet resistancewas 140 / and the optical transmission in visible regionwas 87.6%.T%1009080706050403020100400450500550575600-10150 200 250 300 350 400 450 500 550 600 650 700 750 800 850Wavlength(nm)Figure 1. Variation of substrate temperature of IFO films withchange in transmission.[1] Chopra, K.L., Major,S.,Pandya D.K.,TransparentConductors, Thin Solid Films, 1983. 102: 1-46.[2] Hartnalgel, H.L. Dawar, A.L., Jain. A.K., SemiconductingTransparent Thin Films,Paston Press,London,(1995).[3] Rozati, S.M., Mirzapour, S., Takwale, M.G., Marathe, B.R.,Bhide, V.G., Materials Chemistry and Physics, (1993), 34: 119.[4] Golshahi, S., Rozati, S.M., Martins, R., Fortunato, E., ThinSolid Films, 2009, 518: 1149-1152.[5] Haacke, G., J. Appl. Phys., (1976), 47: 4086.[6] Biring, E.J., Chambouleyron, I., Martinez, J.M., Estimationof the optical constants and the thickness of thin films usingunconstrained optimization, Journal of Computational Physics,1999, 155: pp. 862-880.6th Nanoscience and Nanotechnology Conference, zmir, 2010 672

Poster Session, Thursday, June 17Theme F686 - N1123Determination of Critical Micelle Concentration (cmc) of PB-b-PEO Diblock Copolymer by TwoDifferent MethodsÖnder TOPEL*, Burçin ACAR, Leyla BUDAMA, Numan HODAAkdeniz University Department of Chemistry, Antalya, TurkeyAbstract- Critical micelle concentration (cmc) was measured for PB 1800 -b-PEO 4000 amphiphilic diblock copolymer in aqueous solution bytwo different methods. The fluorescent probe technique was utilized with pyrene as a probe molecule, and the intensity of the scattered lightwas used in dynamic light scattering technique. The cmc values obtained by these two techniques are rather close each other.Micellization of block copolymers is an importantresearch area of colloid science in the last few decades.Block copolymers may have a soluble block whichconstitutes corona, and an insoluble block whichconstitutes core in selective solvents. In these solventsmicelles resemble different morphologies such as sphere,warm-like and lamellar. The self-assembled micelles havefound many applications in many areas such as drugdelivery systems, surface modification and viscosity andwater purification.Micelles are observed only above a certain concentrationwhich is the critical micelle concentration (cmc). The cmccan, most conveniently, be defined as that concentrationbelow which only single chains are present but abovewhich both single chains and micellar aggregates can befound. There are some methods to measure cmc such astensiometry, spectrofluorometry, and dye solubilization [1-3]. DLS (Dynamic Light Scattering) method is a rathernew method to determine cmc of diblock copolymermicelles [4]. In this study we report the cmc behavior ofPB 1800 -b-PEO 4000 (Polymer Sources, Canada) in aqueoussolution using two different methods, DLS andfluorometry.cmc1,5A series of block copolymer solutions ranging from1.72x10 -5 -4.31x10 -8 mol/L were prepared from aqueousstock solution of block copolymer PB-b-PEO (2%) whichwas stirred for 24 h at room temperature. These aliquotswere filtered with 0.45μm filter to get rid of largeagglomerates and dusts. The dispersion was filteredthrough a 0.45 mm filter. Size and distribution of themicelles were analyzed by means of a DLS instrument(Malvern Zetasizer Nano ZS) with a He-Ne laser beam at awavelength of 633 nm at 25°C and 173° of scatteringangle. The results of DLS measurements are expressed insize distribution by intensity.Intensity30025020015010050cmc00 5 10 15 20concentration x 10 7 (mol/L)Figure 2. Plot of concentration vs. DLS intensity10,50-10 -8 -6 -4 -2 0log cI1/I3By plotting concentration vs. intensity data, the cmcvalue is obtained from the intersection of the two curves(Figure 2). According to DLS results the cmc is found tobe 3.07x10 -7 mol/L. The cmc values by two differentmethods are rather close each other.This work was supported by Akdeniz University TheScientific Research Projects Coordination Unit underGrant No. 2007.01.0105.007.Figure 1. Plot of the fluorescence intensity ratio I 374 /I 385(from pyrene emission spectra) vs. log cFirst, the critical micelle concentration of copolymer inaqueous solution was determined using pyrene as afluorescence probe. The excitation spectra (350-450 nm)of the solutions were recorded with an emissionwavelength of 340 nm with the excitation and emissionbandwidths being set at 5 nm. The ratios of the peakintensities at 374 and 385 nm (I 374 /I 385 ) of the excitationspectra were recorded as a function of block copolymerconcentration. The cmc value was taken from theintersection of the tangent to the curve at the inflectionwith the horizontal tangent through the point at the lowconcentrations (Figure 1). The cmc of PB-b-PEO diblockcopolymer in aqueous solution was estimated to be2.94x10 -7 mol/L by fluorescence spectroscopy.*Corresponding Author:ondertopel@akdeniz.edu.tr[1] Birdi, K. S., 1997. Handbook of Surface and ColloidChemistry. CRC Press, Boca Raton, FL.[2] Dominguez, A., Fernandez, A., Gonzalez, N., Iglesias, E. andMontenegro, L, 1997. Determination of critical micelleconcentration of some surfactants by three techniques. J. Chem.Educ., 74 (10): 1227-1234.[3] Nakahara, Y., Kida, T., Nakatsuji,Y. and Akashi, M., 2005.New Fluorescence Method for the Determination of the CriticalMicelle Concentration by Photosensitive MonoazacryptandDerivatives. Langmuir, 21; 6688-6695.[4] App. Note: Surfactant micelle characterization using dynamiclight scatteringhttp://www.malvern.com/common/downloads/campaign/MRK809-01.pdf6th Nanoscience and Nanotechnology Conference, zmir, 2010 673

PPoster Session, Thursday, June 17Theme F686 - N1123Preparation of Anion Exchange Membrane and Its Characterization by AFM and EFM111UZeynep ÇolakoluUP P*, Nilay GizliP P, Mustafa DemircioluP1PDepartment of Chemical Engineering, Ege University, Bornova, 35100, zmir, TurkeyAbstract-For the selective removal of arsenic species from water, a heterogeneous anion exchange membrane was prepared onpolyethylene backbone containing quaternized immobilized N-methyl-D-glucamine (NMDG). Surface characterization and electrostaticconductivity of this material were investigated by atomic force microscopy (AFM) and electrostatic force microscopy (EFM). Roughnessvalues show that materials have no porosity, while positive values of surface skewness (1.398) point to extreme peaks on the membranesurface and surface kurtosis (2.174) lower than 3.0 to broader height distributions. Characterization of materials by AFM and EFM servedfor both optimization of preparation conditions and improvement of material properties.Safety in drinking water is a challenge by climate change.Arsenic is important due to high toxicity and its high levelssome cities in Turkey. Main forms of arsenic met in groundwaters are arsenite or arsenate anions. Therefore theseparation by ion exchange comes as the first alternativemethod for ground waters. Removal performance of arsenicmust be enhanced for a viable industrial application. The aimof this study is to produce the anion exchange membranesand to characterize them by using AFM and EFM. Recentstudies show hopeful results in the name of using anionexchange membranes for the purification of water sourcesfrom hazardous ions since these membranes have excellentelectrochemical properties [1].In this study, membranes were prepared by aheterogeneous method, in which powdered ion exchangeresin of NMDG was combined with polyethylene, pressedand heated up till 250°C and kept for 10 min. Then themembrane was subjected to morphological andelectrochemical characterization. The surface structure ofmembranes was observed by multimode AFM (RT-SHPM,NanoMagnetics Instruments). The membrane surfaces werescanned by aluminium reflex coated silicon probe (Tap300AI, NanoMagnetics Instruments) having the springconstant of 40 N/m and the resonance frequency of 300 kHzin dynamic mode. Scan area and speed were chosen as210x10 μmP Pand 5 μ/s, respectively.The roughness parameters such as root mean squareroughness (RMS), mean roughness (Ra), average meanheight (Hav), surface skewness (Ssk) and surface kurtosis(Sku) were obtained by using built-in software SPM 1.16.13.It’s found that surface skewness was positive 1.398 which isalso numerically greater than 1.0 indicates that it has extremepeaks on the surface [2]. Surface Kurtosis was found as2.174 which is lower than 3.0, so the membrane showsbroader height distributions [3]. Imaging by EFM, anotherAFM technique, is used to characterize materials forelectrical properties. In this technique, a conductive AFM tipinteracts with the sample through long-range Coulombicforces. These interactions change both oscillation amplitudeand phase of AFM cantilever, which are monitored to createEFM phase image [4]. In this study, the voltage levels werechosen as -4V and +4V for forward and backward potentials.Scan speed of 8μm/s was applied for the samples with the2area of 30 x 30μmP P.Figure 1. AFM and EFM Phase views of membranes.The image at the left in Figure 1 is an AFM image onwhich lighter regions show peaks on the sample surface, onEFM image (to the right) lighter regions representconductive areas. Various properties were observed bychanging the parameters such as area scanned, scan speed,applied voltage, head lift, rising and falling time in order todetermine the optimum conditions for measurement. As aresult, before delving into experimental tests andperformance studies requiring large amount of material andlaborious tasks in a separation process, characterization ofmaterials by AFM and EFM during preparation phase ofthem helps both to screen the alternatives and to optimize thepreparation conditions for the development of novelselective materials and the improvement of their properties.*Corresponding author: HTzeynepcolakoglu@hotmail.comT[1] Punita V. Vyas, B.G. Shah, G.S. Trivedi, P. Ray, S.K.Adhikary, R. Rangarajan, Characterization of heterogeneous anionexchangemembrane, Journal of Membrane Science 187 (2001)[2] J. F. Jørgensen, L. L. Madsen, J. Garnaes, K. Carneiro, K.Schaumburg, Calibration, drift elimination and molecular structureanalysis, JVST B, 12(3), 1698-1701 (1994)[3] J. F. Jørgensen, N. Schmeisser, J. Garnaes, L. L. Madsen, K.Schaumburg, L. Hansen, P. Sommer-Larsen. (1994) Dynamicsand structure of selfassembled organic molecules at the solidliquidinterface, Journal of Surface & Coating Technology 67, pp.201-11[4] F. M. Serry, K. Kjoller, J. T. Thornton, R. J. Tench, and D.Cook. Electric Force Microscopy, Surface Potential Imaging, andSurface Electric Modification with the Atomic Force Microscope(AFM).6th Nanoscience and Nanotechnology Conference, zmir, 2010 674

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 675

Poster Session, Thursday, June 17Theme F686 - N1123Investigation of Reverse Micellar System of Polystyrene-block-polyacrylic acid in TolueneBurçin Acar*, Leyla Budama, Önder Topel, Numan HodaAkdeniz University Department of Chemistry, Antalya-TurkeyAbstract- Reverse micellization of polystyrene-block-polyacrylic acid copolymer in toluene was investigated by dynamic light scatteringand transmission electron microscope. Micelles were found to be spherical and their hydrodynamic diameter was 79.9 nm.Amphiphilic block copolymers, consist of a hydrophilicblock and a hydrophobic block, are known to form intomicellar structures by self-assembling in nonpolar organicsolvents. Micelles formed from block copolymers havemany applications in scientific and technical fields, such asdrug-delivery system, synthesis of functionalnanoparticles, detergency, oil recovery and catalysis [1-7].Previous studies have demonstrated that polystyreneblock-polyacrylicacid (PS-b-PAA) forms reverse micellesin some organic solvents [8]. The polyacrylic acidconstitutes the core of the micelle and the polystyreneconstitutes the corona of the micelle.In this study, we have investigated micellizationbehaviour of PS 10912 -b-PAA 10269 copolymer in toluene bydynamic light scattering (DLS) and transmission electronmicroscopy (TEM). Polystyrene-block-poly(tertbutylacrylate)was first synthesized by ATRP and thenconverted into PS-b-PAA by hydrolysis. Micelles wereprepared just dissolving copolymer in toluene and heatingto 135°C then cooling to room temperature. DLS was usedto measure the hydrodynamic diameter of micelles (D h ),and TEM was used to characterize the morphology of themicelles. According to DLS measurements D h of themicelles is 79.9 nm (Fig. 1) and to TEM image, micellesare spherical (Fig. 2).Figure 2. TEM image of PS 10912 -b-PAA 10269 in tolueneThis work was supported by TÜBTAK under the GrantNo. TBAG-108T806.*Corresponding Author: burcinacar@akdeniz.edu.tr[1] D. Myers, Surfaces, Interfaces, and Colloids. Principles andApplications; VCH Publishers: New York (1991)[2] D. Langevin, In Reverse Micelles Biological andTechnological Relevance of Amphiphilic Structures in ApolarMedia; Luisi, P. L.; Straub, B. E., Eds.; Plenum Press: NewYork, p 287 (1982)[3] (a) K. Petrak, Brit. Polym. J. 22, 213 (1990) (b) K. Kataoka,G. S. Kwon, M. Yokoyama, T. Okano, Y. Sakurai, J. ControlledRelease, 24, 119 (1993)[4] (a) Fendler, J. H.; Fendler, E. J. Catalysis in Micellar andMacromolecular Systems; Academic Press: New York, (1975)[5] G. Riess, Colloids Surf A 153:99 (1999)[6] G. S. Kwon, K. Kataoka Adv Drug Deliv Rev 16:295 (1995)[7] M. Moffitt, A. Eisenberg, Macromolecules 30:4363 (1997)[8] Karine Khougaz,† Xing Fu Zhong,‡ and Adi EisenbergAggregation and Critical Micelle Concentrations of Polystyreneb-poly(sodiumacrylate) and Polystyrene-b-poly(acrylic acid)Micelles in Organic Media Macromolecules 29, 3937-3949 (19)Figure 1. DLS of PS 10912 -b-PAA 10269 micelles in toluene6th Nanoscience and Nanotechnology Conference, zmir, 2010 676

Poster Session, Thursday, June 17Theme F686 - N1123Direct measurement of humidity adsorption kinetics of Calix[4]arene derivative using QCM techniqueOmer Mermer 1* , Salih Okur 2 , Fevzi Sümer 1 , Mahmut Ku 3 , eref Ertul 4 , Mevlüt Bayrakç 4 , Mustafa Ylmaz 41 Ege University, Department of Electrical and Electronics Engineering Bornova/Izmir/TURKEY2 Izmir Institute of Technology, Department of Physics Urla/Izmir/TURKEY3 Selçuk University, Department of Chemical Engineering, Selçuklu/Konya/TURKEY4 Selçuk University, Department of Chemistry, Selçuklu/Konya/TURKEYAbstract— This study focuses on the optimization and characterization of calix[4]arene derivative based sensor film coated ona quartz substrate by drop casting method for use in the detection of humidity. The humidity adsorption and desorption kineticscalix[4]arene were investigated by Quartz Crystal Microbalance (QCM) technique. The Langmuir model was used todetermine the kinetic parameters such as adsorption, desorption rates and Gibbs free energy between relative humidity between11% and 97%. Our reproducible experimental results show that calix[4]arene films have a great potential for humidity sensingapplications at room temperature operations.Monitoring and control of humidity is essential forindustrial progress of the world such as petroleum industry,medical equipments, food industry and the manufacturer ofmoisture sensitive products. Furthermore clean rooms,greenhouses, research and developments labs are allenvironments that are highly effected by moisture levels andrequire constant monitoring [1–2].Quartz crystal microbalances (QCMs) have been widelyused in recently as promising gas sensor applications owing totheir high sensitivity and ease of measurement, since themeasured frequency shift is directly proportional to the masschange on a quartz crystal [1–2].Thin films of calix[4]arene derivatives have been widelyused in chemical sensors. Due to their zeolite-like capacityand selectivity, calix[4]arene became promising materials forsensor applications. The functional groups at the upper andlower rims determine their selectivity in host-guestinteractions and physical properties [3]. Calix[4]arenederivatives have been used in recent times as gas sensorsapplications [4,5].The frequency response curve QCM-based sensor tocyclic humidity change is depicted in Figure 2 for differentRH levels. The frequency shift of QCM decreases sharplywith increasing humidity concentrations while there is nochange in that of the empty QCM (adsorption process). On theother hand, during the desorption process, the humidity levelis turned back to the initial value, as a result, QCM recoversback to its initial resonance frequency value.Langmuir adsorption isotherm model is frequentlyused to describe adsorption and desorption kinetics of gasvapor molecules onto organic or inorganic films [6-7].According to this model, the rate of surface reaction forforming a monolayer on the surface is related to fractionalcoverage (), the humidity concentration, and the rateconstants for the adsorption (k a ) and desorption (k d ) processes.Figure 3 shows the experimental data and the fitting curve forfirst adsorption cycle. k a and k d fitting parameters determinedfrom the fit using Langmuir equation to the experimental dataare given by 62.49 M -1 s -1 and 0.0005 s -1 , respectively [8].108Figure1 Chemical formula and full name of special designcalix[4]arene.In this work, special design calix[4]arene molecules weredesigned and synthesized for increasing moisture capturingfeature. Chemical structure and full name of this molecule isgiven in Figure 1. We have used QCM technique for humiditydetection using a calix[4]arene thin film. We have obtainedvery good response and high repeatability characteristics. Theadsorption-desorption kinetics are analyzed and discussed indetails.f(Hz)0-2-4-6-8-10-12-1411%RH43%RH54%RH75%RH84%RH97%RH0 50 100 150 200 250 300 350time(s)Figure2 The frequency response curve QCM-based sensors tocyclic humidity change-f(Hz)642K'8.08k obs0.0455f( t)K(1ek a62.49( kobst)050 100 150 200time(s)k d0.0005)G (kJ/mol)Figure3 The experimental data (blue line) and the fit (red line)to the Langmuir adsorption isotherm equationIn summary, the QCM results show that calix[4]arenethin films are very sensitive to humidity and give reproducibleadsorption and desorption kinetic behavior to humiditychanges for short time periods. Our results open a new era tothe high-sensitivity and high-selectivity gas sensorapplications. This work was supported by TUBITAK underGrant No. TBAG- 109T240.-29.3*Corresponding author: omermermer@gmail.com[1] H. Aizawa, et al., Sens. Actuators B 101 (2004) 150.[2] H. Zeng, et al., Sens. Actuators B 122 (2007) 1[3] Koshets I. A., et.al.,Sens. Actuators B 106, (2005), 177[4] Ohira, Shin-I. , et.al., Talanta 2009, 77, 1814.[5] S. Okur,et.al., Talanta, Volume 81, Issues 1-2, 2010, Pages 248[6] D. S. Karpovich and G. J. Blanchard, Langmuir 1994,10, 3315[7] Y.L. Sun, et. al, Talanta 73, 857-861, 2007.[8] A. Erol, et.al., Sensors and Actuators B: Chem., 145, 2010, Pages 174-1806th Nanoscience and Nanotechnology Conference, zmir, 2010 677

PPPoster Session, Thursday, June 17Theme F686 - N1123Investigation of Crystal Structure of 4-(3-Benzylpiperidino)-propionylamino benzenesulfonamide byX-ray Powder Diffraction Method123erife YalçinP P, UHasan TürkmenUP P*, Mehmet AkkurtPPDepartment of Physics,Harran University, anlurfa 63000,TurkeyPDepartment of Chemistry,Harran University, anlurfa 63000,Turkey3PDepartment of Physics,Erciyes University, Kayseri 38039,TurkeyP21Abstract-The Crystal Structure of 4-(3-Benzylpiperidino)-propionylamino benzenesulfonamide [1] was synthesised by the reaction of 3-chloropropionylamino benzenesulfonamide and Benzylpiperidine, was characterised by X-ray powder diffraction method. Crystal Structure ofthis compound by X-ray powder diffraction method has not been studied before. In this study, we found crystal system of title compound astriclinic. We also investigated unit cell parameters, grain size analysis of the title compound (1). We hope that the results obtained in this studywould give some ideas about electrical, magnetical and optical features of this compound.CA inhibition with sulfanilamide discovered by Mann andKeilin [2] was the beginning of a great scientific adventurethat led to important drugs, such as the antihypertensives ofbenzothiadiazine and high-ceiling diuretics type, [3] thesulfonamides with CA inhibitory properties mainly used asantiglaucoma agents, [4,3,5] some antithyroid drugs, [3] thehypoglycemic sulfonamides, [6] and, ultimately, some noveltypes of anticancer agents.[7] The report of Krebs [8] thatmainly the unsubstituted aromatic sulfonamides of typeArSOR2RNHR2R act as strong CAIs, and that the potency of suchcompounds is drastically reduced by N-substitution of thesulfonamide moiety, constituted the beginning of extensivestructure–activity correlations, which led to some valuabledrugs during a short period of time.FW(S)*Cos(Theta)0.128* Fit Size Only: XS(nm) = 86.6 (130.0), Strain(%) = 0.0, ESD of Fit = 0.0, LC = 1.0(1)Figure 1. The scheme of the title compoundPowder diffraction is a scientific technique using X-ray,neutron or electron diffraction on powder or microcrystallinesamples for structural characterization of materials The mostimportant advantage of this method is that it doesn’t explainindividual atoms which occured molecule, it explains structureof whole molecule. In addition application of this method isvery fast and useful. And it doesn’t need large samples,structure of molecule doesn’t decompose while using thismethod. Different features of a powder diffraction pattern canbe exploited in the characterization of a material such as Unitcell dimensions, Presence of a crystalline impurity (orincorrect indexing), Symmetry Presence (or absence) ofamorphous material, Crystallite (domain) size. Of course,powder diffraction data is most commonly used as a"fingerprint"in the identification of a material.Diffraction datas of title sample was collected by RIGAKUmodel D-MAX 2000 powder diffraction system using copperradiation [ (CuK ) = 1.54056Å] at room temperature. And it waso 0scanned between 2 = 5P P- 90.0 P P. It was used JADE program forCrystal structure analysis of diffraction pattern according toHanawalt method. X ray diffraction pattern and grain size of thetitle compound (1).0.0000.080 Sin(Theta)0.396Figure 2. X ray diffraction pattern and grain size of the titlecompound (1)Treor90 computer program Dicvol com Ito compu terputer program programa = 11.888739 0.026612 Å a =12.4498 Å a = 10.2649 Åb = 13.958968 0.020446 Å b =12.4748 Å b = 11.9679 Åc = 11.581524 0.012098 Å c = 8.0520 Å c = 10.2650 Å = 118.975861 0.167434 ° =111.054 ° = 112.0734 ° = 106.036736 0.154640 ° = 95.595 ° = 116.3524 ° = 43.969582 0.068493 ° =128.538 ° = 75.7616 °3V = 1159.04 ÅP3V = 819.66 ÅP V =1042.41ÅPAs seen from table 2, result from computer programs, ito,dicvol and treor are adaptable with one another.*Corresponding author: hturkmen@harran.edu.tr[1] Hasan Turkmen et all..Bioorganic&Medicinal Chemistry letters,15, 2005, 367-372[2]. Mann T, Keilin D. Sulphanilamide as a specific carbonicanhydrase inhibitor. Nature 1940;146:164–165.[3] Maren TH. Carbonic anhydrase: Chemistry, physiology andinhibition. Physiol Rev 1967;47:595–781.[4]. Supuran CT, Scozzafava A. Carbonic anhydrase inhibitors andtheir therapeutic potential. Exp Opin Ther Patents 2000;10:575–600.[5].. Maren TH. Relations between structure and biological activity ofsulfonamides. Annu Rev PharmacolToxicol 1976;16:309–327.[6]. Drew J. Drug discovery: A historical perspective. Science2000;287:1960–1964.[7] Owa T, Nagasu T. Novel sulphonamide derivatives for thetreatment of cancer. Exp Opin Ther Patents 2000;10:1725–1740.36th Nanoscience and Nanotechnology Conference, zmir, 2010 678

PPPoster Session, Thursday, June 17Investigation of Crystal Structure of 4-(3-methylpiperazino)-propionylamino benzenesulfonamideby X-ray Powder Diffraction Method123Uerife YalçinUP P*, Hasan TürkmenP P, Mehmet AkkurtPPDepartment of Physics,Harran University, anlurfa 63000,TurkeyPDepartment of Chemistry,Harran University, anlurfa 63000,Turkey3PDepartment of Physics,Erciyes University, Kayseri 38039,TurkeyP21Theme F686 - N1123Abstract-In this study, The Crystal Structure of 4-(3-methylpiperazino)-propionylamino benzenesulfonamide was investigated by X-ray powderdiffraction method. Diffraction datas of the title sample was collected by RIGAKU model D-MAX 2000 powder diffraction system usingcopper radiation [ (CuK ) = 1.54056Å] at room temperature. It was used treor90 programe for Indexing diffraction peaks. In this study, we found thatcrystal system of the title compound is monoclinic. We also investigated unit cell parameters and grain size analysis of the title compound.Sulfonamides and their derivatives have been the subject ofinvestigation for many reasons. The sulfonamides areimportant constituent of many biologically significantcompounds. The chemistry of sulfonamides is of interest asthey show distinct physical, chemical and biologicalproperties. The sulfonamide derivatives are known for theirnumerous pharmacological activities, antibacterial, antitumor,insulin-release stimulation and antithyroid properties [1]. Thesulfonamides that inhibit the zinc enzyme Carbonic anhydrase(CA, EC 4.2.1.1) represent an important class of biologicallyactive compounds. Carbonic anhydrase inhibitors have beenextensively studied in the past due to their potentialapplications as drugs for treating diseases such as cancer,glaucoma, epilepsy, and as diuretics [2–10].In this study, It was decided to investigate Crystal Structureof4-(3-methylpiperazino)-propionylaminobenzenesulfonamideby x-ray powder diffraction method,because inhibitory activity of this compound [9] is in thenanomolar (nM) range. In addition these kinds of compoundshave been extensively studied in the past due to their potentialapplications as drugs. It is important to note that structure ofthis compound should be studied because it seems to bepromising compound (figure 1).Table 1. Unit cell parameters of the title compounda = 20.05826 Å = 90.000000b = 10.10002 Å = 96.0477c = 8.31361 A= 90.000000 3Unit cell volume: 1674.87 ÅPFigure2. The scheme of the title compound’s diffraction patternFW(S)*Cos(Theta)2.601* Fit Size Only: XS(nm) = 7.9 (1.5), Strain(%) = 0.0, ESD of Fit = 0.01626, LC = 0.754Figure 1. The scheme of the title compoundIn this study, crystal structure of sulfonamide derivates wasinvestigated by X ray powder diffraction meyhod.Diffraction datas of title sample was collected by RIGAKUmodel D-MAX 2000 powder diffraction system using copperradiation [ (CuK ) = 1.54056Å] at room temperature. And it wasoscanned between 2 = 5P P- 90.0 . It was used JADE programe forCrystal structure analysis of diffraction pattern according toHanawalt method. It was used treor90 programe for Indexingdiffraction peaks. X-ray diffraction pattern of the title compoundis given in Figure 2.As a result of the Treor90 program, crystal system of titlecompound was obtained as monoclinic and unit cell parameterswas obtained as in Table 1Grain size of the title compound is given in Figure 2. As seenin Figure 3, Grain size is nanometer size.0.0000.102 Sin(Theta)0.362Figure3. The scheme of the title compound’s grain size*Corresponding author: serifeyalcin@harran.edu.tr[1] T.H. Maren, Annu. Rev. Pharmacol. Toxicol. 16 (1976) 309–327.[2] C.T. Supuran, A. Scozzafava, A. Casini, Med. Res. Rev. 23(2003) 146.[3] C.T. Supuran, A. Scozzafava, Exp. Opin. Ther. Pat. 12 (2002)217.[4] C.T. Supuran, Exp. Opin. Invest. Drugs 12 (2003) 283.[5] T.H. Maren, G.C. Wynns, P.J. Wistrand, Mol. Pharmacol. 44(1993) 901.[6] A. Casini, F. Abbate, A. Scozzafava, S. David, A. Mastrolorenzo,C.T. Supuran, Bioorg. Med. Chem. Lett. 13 (2003) 841.[7] T.H. Maren, B.W. Clare, C.T. Supuran, Roum. Chem. Quart. Rev.2 (1994)259.[8] G. Liang, J.P. Baysb, J.P. Bowen, J. Mol. Struct. (Theochem) 401(1997) l65.[9] H. Turkmen, M. Durgun, S. Yilmaztekin, M. Emul, A.Innoocenti, D.Vullo, A. Scozzafava, C.T. Supuran, Bioorg. Med. Chem. Lett. 15(2005)[10] T.H. Maren, Drug Dev. Res. 10 (1987) 255.6th Nanoscience and Nanotechnology Conference, zmir, 2010 679

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 680

PP andPoster Session, Thursday, June 17Theme F686 - N1123Analytical Solution of an Electrokinetic Flow in a Nano-Channel using Curvilinear Coordinates111UMehdi MostofiUP P*, Davood D. GanjiP Mofid Gorji-BandpyP1PDepartment of Mechanical Engineering, Noshiravani University of Technology, Babol, IranAbstract-In this paper, an electrokinetic flow of an electrolyte in a 15 nm radius nano-channel will be studied. This study will be with existenceof the Electric Double Layer (EDL) and fully analytical. Governing equations for electrokinetic phenomena are Poisson-Boltzmann, Navier-Stokes, species and mass conservation equations. Induced electric potential force the electrolyte ions and decrease the mass flow rate. In thispaper, it is assumed that, zeta potential has small quantity. In this paper, after getting the equations set from the literature and transforming itinto curvilinear coordinates, the set will be simplified and be solved analytically for small zeta potentials in a nano-channel.One of the most important subsystems of the micro- andnano- fluidic devices is their passage or “Micro- and Nano-Channel”. Nano-channel term is referred to channels withhydraulic diameter less than 100 nanometers [1]. By decreasein size and hydraulic diameter some of the physical parameterssuch as surface tension will be more significant while they arenegligible in normal sizes.Concentrating surface loads in liquid – solid interface makesthe EDL to be existed. If the loads are concentrated in the endof nano-channels, a potential difference will be generated thatforces the ions in the nano-channel. However, induced electricfield is discharged by electric conduction of the electrolyte.Rice and Whitehead [2], Lu and Chan [3] and Ke and Liu[4] studied the flow in capillary tube. None of them solved theproblem based on the curvilinear coordinates system. Also, allof them studied the problem with existence of the pressuregradient while in the modern applications, the pressuregradient can be eliminated and consequently, solving theproblem considering this fact is necessary. In this paper, forsmall zeta potentials without pressure gradient will be studiedbased on the curvilinear coordinates in a capillary tube.In electrokinetic processes, for the most general form of thestudy, seven nonlinear equations govern an electrokineticprocess [5]. In this paper, by some simplifications that will bementioned later, this set will be made simpler.Next in this work, a very long nano- tube will beinvestigated. According to the fact that reference length of thetube according to x direction (L) is very larger than capillaryradius (R) and reference amount for theta ( ), we can neglectseveral terms of the equations. In addition, it is assumed that,electric potential in the x direction is constant. According tothese assumptions, the equations mentioned below will beavailable:1 r X p X m2(1)r r r 1r urr r 1 Xrr r r1 Xrr r rpm eE0RT2 F U0Xp Xm(2) Xp 0r(3) X m0r(4)By applying boundary conditions(no slip condition at walland free stream velocity in center of nano-channel for velocityfield and zeta potential at wall and finite amount of it at centerof the nano-channel for potential field), we have the followingfigures. Figures (a) and (b) show the results for velocity andpotential fields respectively.In summary, by considering curvilinear coordinates andusing Taylor series, some derivation of Developed BesselODE has been derived and solved for Poisson-Boltzmannequation. In addition, velocity profile in nano-tube has beenachieved for small amounts of zeta potentials. Results thoseare derived by curvilinear coordinates are in good agreementwith those of resulted by rectilinear ones in [5].Figure 1. Normalized distribution of potential as a function ofnormalized radius.Figure 2. Normalized velocity profile as a function ofnormalized radius.* Corresponding author: HTmehdi_mostofi@yahoo.comT[1] S. Kandlikar, et. al, Heat Transfer and Fluid Flow inMinichannels and Microchannels. Elsevier Limited, Oxford (2006).[2] Rice, C.L. and Whitehead, R. J. Phys. Chem., 69(11), 4017–4023(1965)[3] W.Y. Lo, and K. Chan. J. Chem. Phys., 143, 339–353 (1994)[4] H. Keh, and Y.C. Liu, J. Colloids and Interface Surfaces, 172,222–229 (1995)[5] Zheng, Z.: Electrokinetic Flow in Micro- and Nano- FluidicComponents. Ohio State University, (2003).6th Nanoscience and Nanotechnology Conference, zmir, 2010 681

Poster Session, Thursday, June 17Theme F686 - N1123Multi wall carbon nanotubes as a sensor and p-aminophenol as a mediator for rapid and sensitivedetermination of cysteamine in presence of tryptophanHassan Karimi-Maleh * Ali A. Ensafi,1 Department of Chemistry, Isfahan university of technology, Isfahan, IranAbstract— In this work, we describe the determination of two important biological compounds, cysteamine (CA) andtryptophan (TP) by electrochemical methods using multi wall carbon nanotubes as a sensor and p-aminophenol as a mediatorfor the first time. The proposed method was successfully applied to the determination of CA in both capsule andurine samples.Cysteamine (CA) or 2-mercaptoethylamine is the chemicalcompound with the formula HSCH2CH2NH2 [1]. It is thesimplest stable aminothiol and a degradation product of theamino acid cysteine. Under the trade name Cystagon,cysteamine is used in the treatment of disorders of cystineexcretion. Cysteamine cleaves the disulfide bond with cystineto produce molecules that can escape the metabolic defect incystinosis and cystinuria. It is also used for treatment ofradiation sickness [2]. Cysteamine crosses the plasma andlysosomes, and it reacts with crystallized cystine within thelysosomes to form cysteine and cysteine–cysteamine mixeddisulfides, which leave through the lysine porter [3]. Thecysteamine and its disulfide, cystamine, have been shown tobe neuroprotective in a number of cell culture and animalmodels [4]. Tryptophan (TP) is one of the 20 standard aminoacids, as well as an essential amino acid in the human diet. Itis encoded in the standard genetic code as the codon UGG.Several methods have been proposed for the determination ofcysteamine and trptophan in biological samples includingchromatography [5,6], electrophoresis [7], gaschromatography with flame photometric detection [8] ionexchange chromatography [9] and electrochemical methods[10, 11] using modified electrodes. Therefore, incontinuation of our studies concerning the preparation ofchemically modified electrodes [12-15], we have usedvoltammetric and electrochemical impedance spectroscopictechniques at pH 5.0 to demonstrate the electrochemicalbehavior of CA and TP on the multi-wall carbon nanotubespaste electrode modified with p-aminophenol as a mediator forthe first time. The results show that the proposed method ishighly selective and sensitive in the determination of CA andTP out performing any method reported in the literature onelectrochemistry for simultaneous determination of these twosubstances. The detection limit, linear dynamic range, andsensitivity to CA with carbon nanotubes paste electrodemodified with p-aminophenol (p-APMCNTPE) arecomparable to, and even better than, those recently developedwhich use voltammetric methods.Using differential pulse voltammetry, CA and TA in mixturecan each be measured independently from the other with apotential difference of 600 mV. Using the modified electrode,the kinetics of CA electrooxidation was considerablyenhanced by lowering the anodic overpotential through acatalytic fashion. The mechanism of CA electrochemicalbehavior at the modified electrode surface was analyzed byCyclic voltammetric (CV), chronoamperometric, andelectrochemical impedance spectroscopy (EIS) methods in anaqueous solution at pH=5.0. The electrocatalytic currentsincrease linearly with the CA and TP concentrations over theranges 0.5–300 mol L -1 and 10.0–650 mol L -1 , respectively.The detection limits for CA and TP will be equal to 0.15 and5.5 mol L -1 , respectively. The proposed method wassuccessfully applied to the determination of CA in bothcapsule and urine samples.*Corresponding author: h.karimi@ch.iut.ac.ir[1] wikipedia. February 06, 2010.[2] B.P. Lukashin and A.N. Grebeniuk, Radiatsionnaia biologiia,radioecologiia / Rossiskaia akademiia nauk, 41, 310, 2001.[3] L. Wood et al. Brain Research. 158, 158, 2007.[4] P. Lochman et al. Electrophoresis, 24, 1200, 2003.[5] M. Stachowicz et al. J. Pharm. Biomed. Anal. 17, 767, 1998.[6] H. Kataoka, et. Al. J. Pharm. Biomed. Anal. 11, 963, 1993.[7] A.J. Jonas and J.A. Schneider, Anal.Biochem. 114, 429 1981.[8] H. Kataoka, et. al. J. Chromatogr. B 657, 9, 1994.[9] M. Hsiung et. al. Biochem, Med. 19, 305, 1978.[10] J.B. Raoof et. al. J. Mater. Sci. 44, 2688, 2009.[11] J.B. Raoof. et. al.Electroanalysis, 20, 1259,2008.[12] A.A. Ensafi and H. Karimi-Maleh, J. Elecroanal. Chem. 640, 75, 2010.[13] A.A. Ensafi, et. al. J. Solid State Electrochem. In press.[14] H. Karimi-Maleh, et. al. J. Solid State Electrochem. 14, 9, 2010.[15] H. Karimi-Maleh et. al. J. Braz. Chem. Soc.20, 880, 2009.Figure 1. SEM image of a) p-APMCNTPE, and b) CNPE.6th Nanoscience and Nanotechnology Conference, zmir, 2010 682

PPPPPoster Session, Thursday, June 17Theme F686 - N11231Binary Memory Cells on the Base of Stimuli-Sensitive Macromolecules122UIbragim SuleimenovUP P*, Grigoriy MunP Pand Ellina MunPPAIPET – Almaty Institute of Power Engineering and Telecommunications, Baitursynova 126, Almaty 050013, Kazakhstan2PChemical faculty of Kazakh National University, Karasai Batyra 95, 050012 Almaty, KazakhstanAbstract-It is shown that macromolecules of thermosensitive polymer with hysteresis properties may be synthesized. It was shown theoreticallyand experimentally that systems with information recording density comparable to molecular can be produced on the base of such polymers.At present time, an active search of systems providing fordata recording at molecular and submolecular level takesplace. Search in this direction is stimulated by well-knownfact: the most compact data recording is realized in biologicalsystems.In the present work a base for elaboration of data recordingsystems using synthetic macromolecules were laid. It is shownthat in solutions of stimuli-responsive polymers hysteresisphenomena take place. The dependence of solution’s opticaldensity on temperature obtained under the solution heatingdiffers significantly from the analogous curve obtained underits cooling. This is the basis for realization of digital units.Poly-N-isopropylacrylamid (PNIPAM) aqueous solution(MM= 135 000 with concentrations 0,2 weight % wasanalyzed). The dependence of solution’s optical density underheating and cooling in quasistationary regime with thermostating was registered. The example of results obtained isshown at Figure 1. It can be seen that curves obtained differconsiderably from each other, besides, it is seen that there is atemperature span which two different states of system can berealized in.10,80,60,40,2D, rel. units2031 32 33 34 35 36 37Figure1. Temperature dependence of optical density of PNIPAMaqueous solution from the temperature, obtained at increase (1) anddecrease (2) of temperature.One of these states can be considered as logical zero, anotherone-as logical one; conversion between them can beconsidered as data recording. One should underline, that it isnot necessary for this conversion from one state to another toaffect system as a whole. This conclusion was demonstratedby the example of cross-linked analogue of explored polymer,i.e. gel (poly)N-isopropylacrylamide. It is known that suchnetwork is thermosensitive, i.e. its degree of swelling in waterand water solutions depends significantly on temperature.Firstly, it was experimentally shown that hysteresisphenomena, i.e. difference between dependences of degree ofswelling on temperature obtained under the heating andcooling of sample, takes place for gel of specified type too.Secondly, it was found that conversion from one state toanother can pass locally under sample’s weak heating andfollowing temperature adjustment up to the value TR01T,0PCR(Figure2). Net parts corresponding to different states, whichcan be put in accordance to logical zero and one, can existunder the same thermodynamic variables (temperature,pressure).Therefore, hydrogel sample showing local hysteresisphenomena can be considered as a medium suitable for datarecording. Dimensions of individual memory cell dependsignificantly on the network’s elastic properties and are quitebig. However, they can be decreased at the expense ofconversion to individual macromolecules.Figure 2. Temperature corresponds to two logical variablesTheory that confirm this conclusion for individualmacromolecules is developed in the work. This theory showsthat hysteresis phenomena of molecules of thermosensitivepolymer are caused by formation of intramolecular micelles.The formation mechanism is completely analogous to thatpassing in solutions of surfactants. The fact of existence ofhysteresis phenomena itself allows to conclude that under thecertain values of thermodynamic variables the fragments,which form or not form micelles, can co-exist in the samechain.Correlation of this conclusion with behavior of hydrogelmicroscopic sample shows that data recording can be realizedwith high density. Dimensions of individual digital unit aredetermined by dimensions of macromolecular chain fragmentscapable to form micelle. At least, under the condition of weakinteraction between individual macromolecules in solutionseach of them can quite possess the properties of binarymemory cell.We show, that complexes formed by such thermosensitivemacromolecules on the surface of solid body may be used asan alternative data recording system. Possibility of using ofsuch complexes for creation of adapters capable to be aconnecting-link between classic solid-state circuit componentand systems of information processing on the quasibiologicalbasis is discussed.* Correspondign author: Esenych@yandex.ru6th Nanoscience and Nanotechnology Conference, zmir, 2010 683

PT AdditionalT ThePoster Session, Thursday, June 17Theme F686 - N11231Decoders on Neural Network Base and its Physical Implementation111UIbragim SuleimenovUP P*, Sergei PanchenkoP P, Vasilyi VasinPPAIPET – Almaty Institute of Power Engineering and Telecommunications, Baitursynova 126, Almaty 050013, KazakhstanAbstract-It is shown, that there is possibility to realize encoder and decoder block codes on neural network basis, which can be designedon stimuli-sensitive polymer base.Reliable transmission is the one of the fundamentalproblems of theory and practice of telecommunications.Noise combating coding is one of important directions ofresearches in this field of science. Recently, using ofneural networks or similar to it objects is offering forensuring noise combating coding.It is known, that neural networks allow recognizingimages [1], including in those cases, when distortions ofinformation are large enough. Therefore using it allowsdecreasing noise significantly.Using of neural network decoders has number ofadvantages in compare to classical iterative decoders.Main advantage of it is parallel handling of code (parallelcalculations is fundamental property of neural networks),which can provide decreasing time of latency of decodingand encoding.However, nowadays neural networks are mainlyrepresented by integrated circuits, which can simulate notgreat number of neurons. Majority of neural networkmethods are realized by proper software.A scheme of physical implementation of neural networkbased on stimuli-sensitive polymers immersed bynanoparticles is proposed in present report.A model of unsupervised learning neural network, whichcan provide functions of decoding of N-dimension blockcode, was designed as the first stage of research. In case ofunsupervised learning neural network it is possible tocalculate and to specify coefficients of additive adder ofseparate neurons a priori. Using network has 3 layers ofkneurons (Figure 1). First (input) layer consist of M (M=2P P)neurons. It is called layer of images. Second layer also hasM neurons. It is intended for recognizing received codepattern. Last layer is intended for comparison ofrecognized code pattern and information message. It has Kneurons.Figure 1. Scheme of decoding neural networkFigure 2 illustrates feasible Tphysical realization of asingle neuron. The scheme contains:- Photodetector 1 which receives optical signalsincluding the signals generated by other neurons ofnetwork (in elementary case it is a photoresistor whichresistance depends on intensity of total optical signal);- controlling element 2 – the film with the changing oftransparency based on the stimulus-sensitive polymer;- additional light source 3 providing the transmissionof optical signal from one neuron to others;- optical communication links 4, which transmit thesignal from present neuron to others.Present system has all required properties of additiveadder under condition that the film transparencydependence on the control signal is nonlinear.Figure 2. Optical neuron scheme13The scheme Figure 1 is used for the demonstrativeness.In this work it is show that the scheme without theelectrical connections can be realized. It can be achievedthrough the use of light-sensitive polymers immersed bynanoparticles and having nonlinear permittivitydependence. In this case for the controlling of outputswitch 2 transparency the combined influence is used. Theinfluence represents the sum of the Tsignals entering theinput of the neuron, the signal from the additional lightsource and the source of the electromagnetic field, whichis common to all neurons of the system.light source 3 in this case serves for the losscompensations in the light transmission via the opticalchannel. Nanoparticles [2] provide increasing of polymersensitivity to external influences.paper also shows that the optical communicationchannels can be implemented integrative, i.e. it canprovide a large number of neurons at once. This can beachieved through the use of semitransparent elementscombined with the output switch 2.The disadvantage of this approach is that the set ofweighting coefficients is limited. However, Tto solve theproblem of decoding this is not a significant obstacle,since the code sequence can be selected from the setallowing the physical implementation on the basis ofphysical semitransparent elements.*Corresponding author: HTEsenych@yandex.ruT[1] Gorban A.N., Dunin-Barkovskiy V.L. Neiroinformatics (inRussian). Novosibirsk:1998[2] Ergozhin E.E., Zezin A.B. Suleimenov I.E., Mun G.A.Hydrophilic polymers in nanotechnology and nanoelectronics (inRussian). Almaty-Moscow: 2008, 216 p.246th Nanoscience and Nanotechnology Conference, zmir, 2010 684

PPPPoster Session, Thursday, June 17Theme F686 - N11233-D Fluorescence and Colored Patterns of Polydiacetylene Supramolecules1232Oktay Yarimaga,P PSumi Lee,P PYang-Kyu ChoiP P* and UJong-Man KimUP P*1PInstitute of Nanoscience and Technology, Hanyang University, Seoul, 133-791, Korea2PDepartment of Chemical Engineering, Hanyang University, Seoul, 133-791, Korea3PDepartment of Electrical Engineering, KAIST, 305-701, KoreaAbstract-We present the results of investigation on a polydiacetylene (PDA)-based thermal imaging system, both as a thermo-fluorescencesensor and a thermochromic display. By using raplica-molding of PDA supramolecules embedded to polyvinyl alcohol and a consequentback-side irradiation, it is posssible to obtain 3-dimentional colored image and morphological patterns on free-standing elastic film. Thesimilar method is also useful to fabricate a pixel of the thermochromic display. Morphological and optical properties of the generated patternsare very promising for micro-thermal imaging applications.Polydiacetylenes (PDAs) are unique materials in terms oftheir stress induced chromatic transitions [1]. They are one ofthe thermo-fluorescent materials, i.e. thermal stress inducesnon-fluorescent to fluorescent phase switching. And moreinterestingly, the fluorescence intensity strongly depends onthe temperature of the vesicles [2]. Up to date, most of theinvestigations on PDAs have focused on the generation andpatterning of different PDA derivatives in forms of selfassembledlayers, supramolecular structures and microclusters[3], [4]. Generation of colored images on batch typefilms by UV-light irradiation through a photo-mask is anotherelegant example of patterning techniques [5]. Although thereported investigations contributed to the ongoing course ofPDA-based chemo/thermo/bio imaging system development,we have realized that utilization of the pre-patterned structuresin the desired applications have been limited due to substrateselectiveness and challenges arising from the fabricationprocess. Accordingly, we have recently reported a novelmethod to fabricate 3-dimensional (3-D) colored andfluorescence images on a free-standing composite film [6].by mixing and stirring steps, replica molding process was usedto transfer the size and shape of the mold bearings to the PDA-PVA composite solid film. A UV-light irradiation from theback-side of the mold afforded polymerization of diacetylenevesicles to PDA with a color transition to blue, selectively onthe replicated features (Figure 1).Due to size reduction factor, the dimensions of the desiredpatterns should be designed carefully. “The smaller the moldpattern, the larger the size reduction factor” is the key conceptto consider. Replicated and polymerized blue color structurespossess very attractive properties in terms of elasticity,thermo-chromism, thermo-fluorescence and 3-D morphologywhich form the bases of a thermal imaging system.A similar approach has been effectively employed also todemonstrate thermochromic information display [7]. This timemicro-pixel array of PDA-embedded PVA composite wasformed on micro-heaters using replica-molding and blue-toredcolor transition of the pixels was achieved by supplyingthermal stress from the built-in micro-heaters.We will discuss the possible effects of dimensionalshrinking on heating and cooling cycle (response time) of thedisplay system and the advantages of having 3-D pixels interms of visible color contrast and fluorescence intensity.The authors gratefully thank to National ResearchFoundation of Korea for financial support throughInternational Research & Development Program(K20901000006-09E0100-00610). This work was supportedby the ERC program grant (No. R11-2007-045-03004-0) and agrant from the National Research Laboratory (NRL) program(No. R0A-2007-000-20028-0 and 20090083161) of theKorean Science and Engineering Foundation (KOSEF), whichis funded by the Korean Ministry of Education, Science andTechnology (MEST). We would like to thank to CAFDCcenter for their support.Figure 1. (a) PDA-embedded PVA film during peeling off froma mold after replica molding process and polymerization. (b)The blue film shifts color to red with thermal stress. (c) PDA isnot fluorescent in blue phase while in red phase it fluoresces. (d)3-D morphological structure of image patterns is very attractivefor construction of elastic fluidic micro-chips.In our knowledge, the methods dealing with micro-thermalanalysis are quite complicated and expensive. Present studywill focus on the generation and integration of PDA-basedthermochromic morphological and image patterns in order toimplement a thermal monitoring system, both as a sensor anda display. After embedding the monomer diacetylene vesiclesinto a host polymer matrix such as polyvinyl alcohol (PVA)*Corresponding author: HTjmk@hanyang.ac.krTH[1] D. H. Charych, J. O. Nagy, W. Spevak, M. D. Bednarski, Science261, 585 (1993).[2] R. W. Carpick, T. M. Mayer, D. Y. Sasaki, A. R. Burns,Langmuir 16, 4639 (2000).[3] J. H. Baek, H. Ahn, J. Yoon, J.-M. Kim, Macromol. RapidCommun. 29, 117 (2008).[4] T. Kim, R. M. Crooks, M. Tsen, L. Sun, J. Am. Chem. Soc. 117,3963, (1995).[5] J.-M. Kim, Y. B. Lee, S. K. Chae, D. J. Ahn, Adv. Funct. Mater.16, 2103 (2006).[6] O. Yarimaga, S. Lee, J.-M. Kim, Y.-K. Choi, Macromol. RapidComm. 31, 270 (2010).[7] O. Yarimaga, M. Im, B. Gu, T. W. Kim, Y. K. Jung, H. G. Park,Y-K. Choi, Proceedings of MEMS2008, 750-753 (2008).6th Nanoscience and Nanotechnology Conference, zmir, 2010 685

Poster Session, Thursday, June 17Theme F686 - N1123Defect Tolerance in Self-Assembled Networks with Mobile Nano-MachinesBirkan Polatoğlu*, Alper Rasim Çakır and Sema Oktuğİstanbul Technical University, Department of Computer Engineering, İstanbul 34469, TurkeyAbstract - We concentrated on network of finite number of nano-machines that are freely floating in their environment and that interact viamolecular communication. We improve the proposed defect tolerance mechanisms that are based on Reverse Path Forwarding routing algorithmin order to tolerate defects in self-assembled networks that contains mobile nano-machines. Our solution keeps the broadcast tree up-to-dateeffectively.Nanoelectronic devices are investigated as an alternativeto CMOS technologies recently. These devices are extremelysmall and thus need very low charge transfers to switch state[1]. The proposed properties of nanoelectronic devices providegreater device density and make them advantageous overCMOS. However the circuits using these devices aresusceptible to defects and faults because of these properties.Nano-machines can be interconnected to cooperate andshare information and overcome collaborative tasks.Communication between nano-machines can be performedthrough different technologies, such as electromagnetic,acoustic, nanomechanical or molecular. Molecularcommunication is the most promising technique in comparisonto other ones due to the size and natural domain of molecules.Molecular communication is inspired by the communicationamong living cells, and it is defined as the transmission ofinformation using molecules. Molecular communication takesplace in aqueous medium. Due to the organic and chemicalnature of the nano-machines and information molecules, thenanonetwork is highly sensitive to the environmentalconditions, such as temperature, humidity, medium viscosityand pH. The communication process can be negativelyaffected by sudden variations of these conditions [2].DNA self-assembly is a bottom-up fabrication techniquethat uses DNA as a scaffold material to attach electronicdevices. Self-assembly does not have control over theplacement of devices, so it is prone to higher defect rates thanthose produced by other techniques. Systems built usingbottom-up self-assembly of nanoelectronic devices will needto incorporate defect tolerance in their design in order tomaintain their advantage over CMOS [1].The presented defect tolerance mechanism in [1] does notrequire an external defect map, nor does it require redundancyof complex computational circuits. Reverse path forwardingalgorithm is used to map out defective nodes at startup and tocreate a broadcast tree of non-defective nodes. The interfacebetween the system and the micro-scale world are called via.The special broadcast packet is inserted into the network fromvias that are located one in each side center and one in thecenter of the NxN network. On receiving the special broadcastpacket, the node broadcasts it on its entire links, except thelink that it received the packet on [1].Nano-machines (nodes) in the proposed mechanism in [1]are immobile and each node is assumed to have fourtransceivers, so the maximum number of children of a node isfour. Transient and permanent faults during system operationare not handled as well. The broadcast tree is created in thebeginning by broadcasting the gradient packet and this tree isused for communication among the nodes. If one of the nodeson broadcast tree is deteriorated transiently or permanently,the links passing from this node will not be functional. Thechildren or the sub tree under the failed node or link areunreachable from vias and treated as defective nodes.Here, we concentrated on a system in which finite numberof nano-machines freely floating in their environment thatinteract via molecular communication. Each nano-machine inthe system is identified with a single-stranded DNA with thepurpose of unique addressing. Inspired from the living cells,nano-machine’s DNA is assumed as a database to store allsingle-stranded DNA sequences of the other nano-elements asa potential neighbor. In this nano-network environment it isassumed that all cells are taken from the same living creaturewhich will guarantee that all of the nano-elements have thesame DNA sequence or database. We propose new mechanismthat handles transient and permanent faults during systemoperation by improving the proposed framework on [1]. Wedefine a new state for the children of the failed nodes and callit ‘free non-defective’ state. In case of node failure inbroadcast tree, the nodes under the failed node change theirstatus from ‘non-defective’ to ‘free non-defective’. The nodesthat do not take packet from other nodes during specifictimeout interval set their status to ‘free non-defective’ as well.In molecular communication, after a certain time,information molecules disintegrate into other molecules andthey are not interpreted by receiver node. In their life time,molecules can travel by diffusion in average a certain maximaldistance called communication radius [3]. Each node cansend information molecule to the nodes in its communicationradius. The nodes in the communication radius of ‘free nondefectivenode’ will query the nodes around to find ‘free nondefective’ones. When a ‘free non-defective’ node identified,it is set as the child of the node sending the query and its stateis made ‘non-defective’. The broadcast tree that connects allreachable non-defective nodes is kept up-to-date by the help ofthis mechanism.In summary, our work introduces a new approach for thedefect tolerance in self-assembled networks that containmobile nano-machines by improving the mechanismsintroduced earlier in order to keep the broadcast tree up-todateeffectively. Currently, we are collecting data fromsimulation that we have improved for these enhancements.*Corresponding author: polatoglu@itu.edu.tr[1] J.P. Patwardhan, C. Dwyer, A. R. Lebeck, and D. J. Sorin, 2005.Evaluating the Connectivity of Self-Assembled Networks of NanoscaleProcessing Elements, NANOARCH '05.[2] I.F. Akyildiz, F. Brunetti, C. Blázquez, 2008. Nanonetworks: ANew Communication Paradigm, Elsevier Computer Networks 52.[3] J. Wiedermann, L. Petrů, 2008. Communicating Mobile Nano-Machines and Their Computational Power, Third International ICSTConference, NanoNet.6th Nanoscience and Nanotechnology Conference, zmir, 2010 686

PPPP Hans-EliasP andPoster Session, Thursday, June 17Theme F686 - N1123Hydroflown: A MEMS Based Underwater Acoustic Particle Velocity Sensor123M. Berke Gür,Pde BreePUTuncay AkalUP P*PDepartment of Mechatronics Engineering, Bahçeehir University, stanbul 34353, TurkeyPMicroflown Technologies, Han University of Applied Sciences, Arhhem 6826, The Netherlands3PSUASIS Ltd., TUBITAK MRC Campus, Gebze-Kocaeli 41470, Turkey21Abstract-An acoustic field is fully described by two different but related variables: the scalar acoustic pressure and the vector valued acousticparticle velocity. Conventional hydrophones measure the acoustic pressure variable only. However, it is the particle velocity that carriesdirectional information and provides a more complete description of the acoustic field. Hydroflown is a novel MEMS based underwater acousticparticle velocity sensor under development, when combined with a MEMS hydrophone is capable of completely measuring the underwateracoustic field. Unlike conventional accelerometer based underwater acoustic particle velocity sensors, the sensor will not exhibit resonance andis expected to have a flat frequncy response from dc to 20 kHz.An underwater acoustic wave is a propagating energypacket which causes a disturbance in the ambient pressure andinduces a small volumetric motion (whose rate is termed theparticle velocity). Although the amplitudes of the acousticpressure and particle velocity are related, the latter is a vectorvalued and hence, carries directional information regardingacoustic energy propagation. While the scalar valued acousticpressure is easily measured using a hydrophone, low costsensors capable of accurately measuring the particle velocityhas remained a major challenge. Several underwater sensorsdesigned for this purpose (all which are not commerciallyavailable) rely on accelerometers that are packaged such thatthe sensor is naturally buoyant in water [1,2,3].Recently, a novel MEMS based acoustic particle velocitysensor, called the Microflown, capable of measuring theparticle velocity in air was developed [4]. This paper outlinesthe preliminary concepts and work done for extending theMicroflown sensor to underwater applications. The newsensor is termed appropriately the Hydroflown. TheMicroflown measures the particle velocity using two paralleloriented platinum wire resistances. The wires are 200 nm thinand 5m wide (see Figure 1). When voltage is applied acrossthe wire terminals the wires heat up to 300°C. An acousticwave propagating perpendicular to the wires results in atemperature difference between the wires. The upstream wirewill cool down more compared to the downstream wire due toconvective heat transfer, which will result in a change in theresistance of the wires. The particle velocity is proportional tothe voltage change induced by the change in the resistance.The sensor has a flat frequency response from dc up to 20kHz.The Hydroflown sensor is to be manufactured by firstdepositing a 300nm layer of Silicon Nitride (SiR3RNR4R) on aSilicon wafer followed by the deposition of a photoresist. ThisSilicon Nitride layer is used as a mask for the wet chemicaletching process in the following steps. Next, a 200nmPlatinum layer is added using the sputter technique. Theresistive wires and the terminals are patterned from thisPlatinum layer using the lift-off technique. Afterphotolithography, the Silicon Nitride layer is removed usingreactive ion etching. Finally, the Silicon wafer is etched withanisotropic wet chemical etching using Potassium Hydroxide(KOH) to create the channel and the bridge.Although the working principle of the Hydroflown sensor isTable 1. A comparison of the acoustic properties of air andseawater.Property Air SeawaterSpeed of Sound (m/s) 340 1500Density (kg/m 3 ) 1,2 1025Acoustic Impedence (Pa s/m) 415 1,54×10 6Specific Heat (kJ/kg/K) 1,0 4,0Thermal Conductivity (W/m/K) 0,025 0,596similar to the Microflown sensor, the former is designed towork underwater. Since water will start to boil above 100°C,the sensor is required to be encapsulated in an acousticallytransparent package filled with another fluid with a higherboiling temperature. A comparison of the acoustic propertiesof air and seawater are presented in Table 1.In summary, Hydroflown, a novel underwater sensor formeasuring the acoustic particle velocity is introduced. Theworking principles of the sensor are defined. The lab tests ofthe sensor are currently in progress and the first sea trials arescheduled for the summer of 2010. The Hydroflown sensor isexpected to provide higher quality measurements with fewersensors compared to conventional pressure measuringhydrophone based systems. Initial applications of the sensorare planned for uniform line arrays. This work is supported bythe EUROSTARS Programme grant E!-4224 Hydroflown.*Corresponding author: tuakal@suasis.comFigure 1. A scanning electron microscope image of a bridgetype Microflown MEMS acoustic particle velocity sensor clearlyshowing the Platinum resistive wires and the terminals.[1] K. J. Bastyr et al., J. Acoust. Soc. Am. 106, 6 (1999).[2] W. D. Zhang et al., Sensors 9 (2009).[3] V. Shchurov, Vector Acoustics of the Ocean, engl. transl. (2006).[4] H.-E. de Bree, Acoust. Aust. 31 (2003).6th Nanoscience and Nanotechnology Conference, zmir, 2010 687

Poster Session, Thursday, June 17Theme F686 - N1123Implementation of DSMC Method to Nano Knudsen CompressorsNevsan engilEDA Ltd., Silikon Blok,No:22, ODTÜ Teknokent,06531, Ankara, TürkiyeAbstract- If density is low or characteristic length is micro/nano scale, it can be said that gas is rarefied. In rarefied gas conditions, gas startsflowing slowly from cold to hot. This phenomenon is called thermal creep or transpiration. Using thermal creep phenomenon, Knudsencompressors are built. In this study various properties of a nano scale Knudsen compressors are analyzed with direct simulation Monte Carlo(DSMC) method.Lately, a number of Micro/Nano Electro MechanicalSystems (MEMS/NEMS) have been developed. Thesedevices sometimes include mechanical systems work withthe fluids such as micro/nano size gas compressors. Thesecompressors have much potential in the area ofchromatography, spectroscopy, micro plasmamanufacturing and chemical sensors [1,2].If two gas reservoirs with different pressures andtemperatures are connected with a channel, gas startsflowing from high-pressure side to low-pressure side.When the reservoir pressures get equal, gas flow stopseven if reservoir temperatures are different. In micro/nanoscale lengths, gas is rarefied even if pressure isatmospheric. If gas is rarefied and a temperature gradientexists, gas flows slowly from cold region to hot region. Itis called thermal creep or transpiration phenomenon [3].Using this phenomenon, it is possible to construct variousmicro/nano size Knudsen compressors.The theoretical efficiencies of Knudsen pumps are highcompared to conventional vacuum pumps. Besides theyare very reliable because they include no moving parts.Recent technological development in the area of thermalisolation on MEMS/NEMS, enable to use high temperaturegradients to obtain high volume rates [1].Gas flows related with the MEMS/NEMS devices havehigh Knudsen numbers (Kn) similar to rarefied gases ofhigh atmosphere flights. Rarefied gas flows with highKnudsen number ( Kn 0.1) depart from local thermalequilibrium because of the inadequate molecule collisions.Consequently, the linear relations between not only shearstress and velocity gradient but also heat conduction andtemperature gradient are lost. As a result continuum basedNavier-Stokes and Euler equations cannot be used becausethese equations use linear constitutive equations [4].In rarefied gas flows with high Knudsen number( Kn 0.1) , both continuum equations with high ordernon-linear constitutive equations, like Burnett equations,and molecular based methods can be used. Burnettequations are not used widely because these equations aredifficult to solve and have both stability and complicatedboundary condition problems. In rarefied gas flows,generally molecular methods are preferred. Molecularmethods are based on the Boltzmann equation, which is amathematical model and difficult to solve both analyticallyand numerically. Only its simplified versions can besolved. Molecular dynamic (MD) is the best-knownphysical molecular method [3]. MD is generally used toanalyze liquid and dense gas flows. Because of the hugenumber of the molecules, only very small flow volumescan be analyzed for very small time durations. Directsimulation Monte Carlo (DSMC) is another physicalmolecular model. In this method molecule movements andcollisions are decoupled and one DSMC moleculerepresents many physical molecules [5]. DSMC consists offour main steps. The first step is “molecule movement”step. In this step, molecules move inside the flow area. Thesecond step is “molecule indexing” step. Molecules areindexed based on their cell information. The third step is“molecule collisions” step. Here molecules in the samecells undergo collisions with each other. The fourth step is“calculation of macroscopic properties” step. In this step,using microscopic molecule information, macroscopicvalues in each cell are calculated.In this study one stage and multi-stage Knudsencompressors are analyzed with DSMC method. Pumpingspeeds and maximum pressure ratios of Knudsencompressors will be reported together with boundaryconditions used.Figure 1. Reservoir pressure decreases with thermaltranspiration.sengiln@itu.edu.tr[1] S. McNamara and Y.B. Gianchandani, J., 2005. On-ChipVacuum Generated by Micro Machined Knudsen Pump,Microelectromech. Syst. 14, 4:741-745.[2] E.P. Muntz and S.E. Vargo, 2002. Microscale VacuumPumps in The MEMS Handbook, M. Gad-el-Hak, Ed. BocaRaton, FL: CRC.[3] G.E. Karniadakis and A. Beskok, 2002. Micro FlowsFundementals and Simulation, Springer-Verlag, New York.[4] S. Chapman and T.G. Cowling, 1970. The MathematicalTheory of Non-Uniform Gases, Cambridge University Press,New York.[5] G.A. Bird, 1994. Molecular Gas Dynamics and the DirectSimulation of Gas Flows, Clarendon Press, Oxford.6th Nanoscience and Nanotechnology Conference, zmir, 2010 688

Poster Session, Thursday, June 17Theme F686 - N1123Humidity Sensing Properties of Organic PVC-Bt6 Complex Thin FilmsSalih Okur 1 , Mavişe Şeker 1 , Nesli T. Yağmurcukardeş 1 , Gülşah Kurt 2 , Bedrettin Mercimek 3 , Mahmut Kuş 41 Izmir Institute of Technology, Department of Physics Urla/Izmir/TURKEY2 Aksaray University, Department of Chemistry, Aksaray/TURKEY3 Selçuk University, Department of Chemistry Education , Selçuklu/Konya/TURKEY4 Selçuk University, Department of Chemical Engineering, Selçuklu/Konya/TURKEYAbstract: Humidity adsorption and desorption kinetics of Benzoylthiourea derivative-PVC complexes (PVC-Bt6), modified using two-stepprocess, were measured for the first time by Quartz Crystal Microbalance (QCM) technique. Reproducible experimental results, obtained atroom temperature, show that PVC-Bt6 complexes exhibit good sensitivity for humidity.Poly(vinyl chloride) (PVC) has received great attention asit is a cheap and readily available material. It is known thatintroducing hydrophilic groups like thiol compounds intoPVC chains increases the intermolecular force and alsothis type of reaction can be performed in solution, melt orsuspension.[1-3] Benzoylthiourea derivates are sensitivedue to C=S groups.In this study we used PVC-Benzoylthiourea complex ashumidity sensor based on quartz crystal microbalancetechnique. PVC-Benzoylthiourea derivative (PVC-BT6)was synthesized by nucleophilic substitution reactions ofchlorine atoms. In this structure, PVC exposed to chemicalmodification processing several steps with amine andbenzoyl isothiocyanate. In Fig.1, the schematic diagram ofPVC-BT6 molecule is shown. This compound givescomplexes in different colours with MCl2 [M=Co(II),Ni(II), Hg(II) and Pt(II)] in PH = 3–5.Dektak 150 profilometer of Veeco. Relative Humiditywere obtained commercial humidity-temperature sensor. Aclosed box partly filled with saturated salt solutionsgenerates relative humidity in the free room above the saltwith good accuracy. The value of the relative humiditydepends on the type of salt used as given in the reference[3].dF/Hz511%022%11%22%-5 43%53%43%-1053%75%-1584%84% 75%94%-2094%dF/Hz-2597% (a)-300 500 1000 1500 2000 2500 3000Time/secdF/Hz50-5-10-15-20-2553%75%84%94%97% (b)0 200 400 600 800 1000Time/secFigure2.(a) QCM frequency shifts for different increasing anddecreasing RH values.(b) Comparison of QCM frequency shiftsfor different RH values.HNHNSCHH 2CNNHONSCH 2CHNOHFig.2 (a) shows the frequency response of PVC-Bt6 filmwhen the relative humidity increased and decreased stepby step between 11% and 97% RH for an equal timeintervals and (b) shows the comparison of frequency shiftsbetween 11% and 97% RH.30Figure1. The Schematic Diagram of PVC-Bt6 molecule.QCM with the model of CHI400A Series from CHInstruments was used to measure the change in theresonant frequency due to mass loading of water moleculesafter exposure of the crystal at different humidityenvironments e.g. at 11%, 22%, 43%, 55%, 75%, 84%,94%, 97% relative humidity (RH.Saurbey Equation is used to calculate the mass change(Δm) from the measured frequency change (Δf).22 f0mf (1)A where f 0 is resonant frequency of the QCM crystal, A isthe area of the gold disk coated onto the crystal, ρ is thedensity of the crystal and μ is the shear modulus of quartz.QCM consisted of AT-cut piezoelectric quartz crystal withresonant frequency of 8MHz, density (ρ) of 2.684g/cm3and shear modulus (μ) of 2.947x1011 g/cms2. PVC-Bt6complex was dispersed in tetrahidrofuran (THF) solventand coated on the quartz crystal by drop-casting method.The thickness of the film was measured as 450 nm with- F (Hz)2520151050upwarddownward20 30 40 50 60 70 80 90 100Relative Humidity (%)Figure3. QCM frequency shifts for increasing and decreasing RHvalues.Fig. 3 shows how the QCM frequency changes withincreasing and decreasing RH values. There is a clearlinear dependence.Our QCM measurements results exhibit that PVC-Bt6complex based sensor is very sensitive to the humiditychanges even at room temperature.*Corresponding author: salihokur@iyte.edu.tr[1] C. Mijangos, D. Lo´pez, Macromolecules 28, 1369 (1995).[2] Reineeke H., Lo´pez D., Mijangos C. J. Appl. Polym. Sci.1999;74:1178.[3] S. Okur, M. Kus, F. Özel, V. Aybek, M. Yilmaz, Talanta,81;1-2; 2010; 248.6th Nanoscience and Nanotechnology Conference, zmir, 2010 689

Poster Session, Thursday, June 17Theme F686 - N1123Routing Congestion Removing of Nano/CMOS FPGA circuitsHossein Hamidipour 1 , Parviz Keshavarzi 1 and Ali Naderi 1,*1 Electrical and Computer Engineering Faculty, Semnan University, Semnan, IranAbstract CMOS Molecular (CMOL) architecture basically called hybrid nanowire/ molecular/ semiconductor circuitwhich incorporates the nanodevices and nanowires crossbar into the CMOS IC implementation. CMOL technology uses theadvantages of nano and CMOS technology together. In this paper we have proposed a recursive method for removing therouting congestion in nano/CMOS (CMOL) FPGA circuits and route them successfully where CMOLCAD tool cannot routethem without congestion. CMOL FPGA architecture, with T basic cells and a latch cell per tile, uses K basic cells (which ispredefined by user), a latch cell for logic implementation and (T-K) cells for routing issue. When the circuit encounteredcongestion, CMOLCAD tool decreases K to route the circuits. In this proposed method, we keep and rank the placementsolutions in some of the last iterations of placement algorithm, according to the cost then use them for routing the circuitswith more options. If the routing on the highest priority placement solution has failed, this solution will be removed from theranking and another placement solution will be used according to the ranking. The results of applying the proposed methodon some of benchmark circuits indicate that we can route the failed routing nano/CMOS circuits without change the structure.Silicon technology continues to advance towards the end ofMoores Law, predicted with the end of CMOS scaling only 1015years away. The theorical and experimental [1, 2] results indicate thatthe plausible alternative for current technology is hybridsemiconductor/ nanodevices circuits. This structure uses thefunctionality of programmable diodes (latching-switches) in crossbarstructure (Fig. 1.a) beside the silicon chip. The functionality of suchdevices is illustrated in Fig.1.1b. CMOS Molecular (CMOL) [3]architecture basically called hybrid nanowire/ molecular/semiconductor circuit which incorporates the nanodevices andnanowire crossbar into the CMOS IC implementation. CMOLtechnology uses the advantages of nano and CMOS technologytogether.(a)proposed method routes the circuit without congestion by predefinedK or we test all of the kept solutions. In this procedure the cellconnectivity domain (A) is constant. In fact we use routing drivenplacement for nano FPGA circuits. For testing the feasibility andefficiency of the proposed method we have selected 10 circuits(MCNC benchmark and some of other circuits) that CMOLCAD toolcannot route them without congestion by predefined values of A andK. Each circuit has been implemented by original CMOLCAD andour proposed method. In original CMOLCAD, the circuits could notbe routed successfully on final placement platform but the proposedmethod can route these failed routing circuits successfully. Theresults show that our method results in only 1.5% and 1% increase inarea and timing cost respectively for total cost of ten circuits.Total analysis shows that the additional CPU time for running ourmethod for ten circuits is 26.5 seconds while total time forCMOLCAD is 313 seconds. This means only 8.5% increase in CPUtime for running our method.In this paper we first review the nano/CMOS hybrid circuits(CMOL) and then we discuss about their design automation andcongestion. Finally we explain our method and the results.In summary the proposed method by a recursive process routes thenano/CMOS circuits which had faced congestion in CMOLCAD. Itcan be seen that by paying negligible additional costs, we route thefailed routing circuits. This method can be added to CMOLCAD andother nano circuit CADs for removing congestion and route thecircuits successfully with higher probability.(b)Figure 1: (a) Nanowire/nanodevice crossbar (b) I-V curve of a twoterminalcrosspoint nanodevice-programmable diode.Each CMOL FPGA [4, 5] cell uses a basic inverter cell (I-Cell) anda latch. CMOL CAD utilizes basic and latch cells in square shapedtiles. Each tile has a latch cell and T basic cell surrounding thelatch. CMOL FPGA uses K basic cells (predefined by user) and alatch cell for logic implementation and (T-K) cells for routing (Fig.2). When the circuit encountered congestion, CMOLCAD tooldecreases K to route the circuit. This is a drawback for CMOLCADtool that cannot route the circuit with predefined K. In the proposedmethod, we keep and rank the placement solutions in some of the lastiterations of placement algorithm according to the cost then use themfor routing the circuits with more options. If the routing on thehighest priority placement solution has failed, this solution will beremoved from ranking and another placement solution will be usedaccording to the ranking. This procedure will be continued until theFigure 2: A fragment of two-cell CMOL FPGA fabric*Corresponding author: alinaderi1998@gmail.com[1] A. DeHon and K.K. Likharev, in Proc. ICCAD (2005 ).[2] P .J. Kuekes, G.S. Snider, and R.S. Williams, Sci. American 293(2005).[3] D.B. Strukov and K.K. Likharev, in Proc. FPGA, (2006)[4] D.B. Strukov and K. K. Likharev, Nanotechnology, (2005).[5] D.B. Strukov, Ph.D. Dissertation, (2006)6th Nanoscience and Nanotechnology Conference, zmir, 2010 690

Poster Session, Thursday, June 17Theme F686 - N1123The Design and Analysis of Novel MEMS Force AmplifierErgin KOSA 1 Umit SONMEZ 1 , Huseyin KIZIL 2 , Levent TRABZON 1,*1 Mechanical Engineering, Istanbul Technical University, Istanbul 34437, Turkey2 Metallurgical and Materials Engineering, Istanbul Technical University, Istanbul 34469, TurkeyAbstract — The compliant micro mechanisms achieve high amplification of forces that can be used as cutting forcein micro- and nano-fabrication. We designed a novel and simple micro-compliant system by SOI-MUMPs technology so thatinput force is multiplied by 11.1 times at the output.It is preferable to amplify the force of any actuator in microscaleapplications [1]. In this paper, we aim to get forceamplification by means of novel micro-compliant mechanism.The range of force amplifications in micro-compliant systemmakes it possible to explore very interesting applications inmicro- and nano-fabrication and unique research topics inmicro- and nano-technology. There are several approaches tofabricate micro-compliant systems and surfacemicromachining is one of the most utilized technology tofabricate micro-complaint system [2]One of the most crucial points in design of micro-compliantsystem is the elastic deformation of materials in the forceamplification scheme [3,4]. There are many advantages ofcompliant mechanisms, such as; no friction at the joints,monolithic structure, no wear under operating conditions, nolubrication needed and high precision [5,6]. Moreover, itenables us to manufacture the mechanism with less and singleparts without joints. This paper includes design, simulationand optimization of the micro compliant force amplifier. Therigid body model of micro mechanism is derived and positionanalysis is run by MATLAB and simulation of the microsystemis run by ANSYS.The system is designed by SOI-MUMPs fabricationtechnology [7]. The thickness and width of the elastic jointsare 25 and 3 microns, respectively. The system is composed oftwo stages with long rigid beams. The length of rigid beams inthe first stage is 500 and 600 μm and length of the rigid beamsin the second stage are 700 and 800 μm. Two rigid beams arelinked to each other by compliant hinges with length of 100 to300 μm. The micro compliant mechanisms are operated atsmall degrees at about from 0 to 10 degrees in which it isexpected to get high amplification factor. The amplificationfactor is defined as A=F /Fout in where the F in is input forceapplied to the system and F out is the output force obtainedfrom the micro mechanism.We designed various hingegeometries at the conjunction of the rigid beams, such astriangle, rectangle, and straight beams with small curvature.We analyzed each different design of micro amplifier atdifferent conditions.We aimed at examining the effect of curvature and length ofdifferent complaint hinges so that we designed flexible hingesin 150, 200, 300 microns lengths and we observed that whenthe length of beams decreases from 300 to 150 microns, theamplification factor increases. Moreover, the height of curveon the hinges improves magnification of forces as it decreasesfrom 30 microns to 10 microns.Since we utilize the SOI-MUMPs processes, theoptimization of micro-compliant system is limited by thefabrication design rules. The optimization also depends on theinput force and stiffness of materials so that different stiffnessFig. 1: Amplification factors for straight, triangular and rectangularhinges with different lengthsat the output point enables us to get a range of amplificationfactors.As a conclusion, we have designed a novel micro-compliantmechanism by SOI-MUMPs technology with different hingegeometries. We found that the amplification of factor is 9.9,8.5 and 7.8 for straight beams with length of 150, 200 and 300μm, respectively, as shown in Fig.1. The straight beams havesmall offset at the center and it is only 10 μm in height for all.The hinges with rectangle and triangle shapes, theamplifications are 11.1 and 8.9, respectively. Moreover,amplifications of the 200 μm straight beam with 10, 20, 30 μmoffsets at the center are 8.5, 7.0, 6.0, respectively. Thus, theoffset at the center and the length of straight beams affect themagnification factor of compliant system.* Corresponding Author: levent.trabzon@itu.edu.tr[1]M. B. Parkinson, B. D. Jensen and K. Kurabayashi, Proceedings ofDETC’01(2001)[2]J. Li, Z.S. Liu, C.Lu, Q. X. Zhang and A.Q.Liu, The 13th InternationalConference on Solid-State Sensors, Actuators and Microsystems (2005)[3] C. F. Lin and C. J. Shih, Tamkang Journal of Science and Engineering,Vol. 9, No 3, pp. 215-222 (2006)[4]G. Chena and Larry L. Howell, Precision Engineering 33 pp.268–274(2009)[5]C. B. W. Pedersen and A. A. Seshia, Journal of Micromechanics andMicroengineering pp. 234, (2004)[6]S. Kota, J. Hetrick, Z. Li and L. Saggere, IEEE/ASME Transaction onMechatronics, Vol.4, No:4 (1999).[7] www.memscap.com/mumps/documents/SOIMUMPs.dr.v4.pdf,14.03.20106th Nanoscience and Nanotechnology Conference, zmir, 2010 691

PPoster Session, Thursday, June 17Theme F686 - N1123A New Model to Calculate Pull-in Limit and Position of Electrostatic Fixed-Fixed Beam Actuator11UCevher AkUP P* and Ali YildizP1PDepartment of Electrical-Electronics Engineering, Mersin University, Mersin 33342, TurkeyAbstract-This paper present a new formula and model that has been developed to calculate pull-in limit of fixed-fixed cantilever MEMSactuators. In the model, we both determined a new pull-in limit and formulated the relationship between voltage and deflection. Formula is wellmatchedwith results of simulation that is based finite-element method.Electrostatic actuators have been very popular due to theirlow-power consumption, small dimensions, and easyfabrication. They have been used as a capacitive pressuresensor for measuring blood pressure [1], as a microwaveswitch [2], as an air flow sensor [3], as a micro-actuator forprobe-based data storage [4], as an inkjet head [5], and opticalscanners [6] is well known commercial applications.An electrostatic MEMS actuators consist of a two parallelplate, one is coated on a substrate and not movable (bottomelectrode), the other one (top electrode) is above it with aninitial gap and fixed from both end. The middle of topelectrode is free to move. When a voltage difference is appliedbetween electrodes, middle of top electrode will incline tobottom electrode (see Figure1).Figure 1. Bectrostaticactuator (Side wiew)For many years, researchers have used lumped model forelectrostatic MEMS actuators to calculate pull-in limit. It wasestimated as one-third of initial gap. However, when it ischecked by software which utilizes finite element method,pull-in limit seems to be at a different value. It appears to bearound 40% of initial gap (see Figure 2).and displacement. Values calculated from model are veryclose to those obtained from simulation. Model also delivers asimple formula. One can simply calculate required voltage fora desired displacement instead of utilizing numericaldistributed methods which is time consuming and requiresmore computing power.*Corresponding author: cevher.ak@mersin.edu.tr[1] Hin-Leung Chau, and K.D. Wise, “An ultraminiature solid-statepressure sensor for a cardiovascular catheter,” IEEE Trans. ElectronDevices, vol. 35(12), pp. 2355-2362, 1988.[2] Dooyoung Hah, and Euisik Yoon, “A Low-Voltage ActuatedMicromachined Microwave Switch Using Torsion Springs andLeverage,” IEEE Trans. Microwave Theory and Tech., vol. 48(12),pp. 2540-2545, Dec. 2000.[3] Yu-Hsiang Wang, and Chia-Yen Lee, “A Mems-based Air FlowSensor with a Free-Standing Micro-cantilever Structure,” Sensors,vol. 7, pp. 2389-2401, Oct. 2007.[4] Michel S.C. Lu, and Gary K. Fedder, “Position Control ofParallel-Plate Microactuators for Probe-Based Data Storage,” J.Microelectromech. Syst., vol. 13(5), pp. 759-769, Oct. 2004. 9[5] S. Kamusuki, M. Fujii, T. Takekoshi, C. Tezuka, and M. Atobe,“A high resolution, electrostatically driven commercial inkjet head,”Proc. IEEE MEMS 2000 conf., pp. 793-798, Miyazaki, Japan, 23-27Jan. 2000.[6] H. Schenk, P. Dürr, D. Kunze, H. Lakner, and H. Kück, “Anelectrostatically excited 2D-micro scanning-mirror with an in planeconfiguration of the driving electrodes,” Proc. IEEE MEMS 2000Conf., Miyazaki, Japan, 23-27 Jan. 2000, pp. 473-478.Figure 2. New modelIn this work, we proposed a new model which gives pull-inlimit of a fixed-fixed beam actuator at 40% of the initial gap.It is consistent with simulation results and previousexperimental models. In addition to pull-in limit, the newmodel demonstrates a good relation between applied voltage6th Nanoscience and Nanotechnology Conference, zmir, 2010 692

Poster Session, Thursday, June 17Theme F686 - N1123Comparative Study of Humidity Sensing Properties of PVC-Bt6-Cu and PVC-Bt6-Hg ComplexFilmsMavişe ŞEKER 1 , Salih OKUR 1 , Nesli T. YAĞMURCUKARDEŞ 1 , Gülşah KURT 2 , Bedrettin MERCİMEK 3 , Mahmut KUŞ 41Izmir Institute of Technology, Department of Physics Urla/Izmir/TURKEY2Aksaray University, Department of Chemistry, Aksaray/TURKEY3 Selçuk University, Department of Chemistry Education, Selçuklu/Konya/TURKEY4Selçuk University, Department of Chemical Engineering, Selçuklu/Konya/TURKEYAbstract: This study focuses on respectively the characterization of PVC-BT6-Cu complex and PVC-BT6-Hg complex films coated on aquartz surface by drop-casting method for humidity detection and comparison of these two thin films properties. The Resistance and quartzcrystal microbalance (QCM) were employed for the characterization. The change of resistance and resonance frequency was monitored withdifferent increasing and decreasing relative humidity (RH) values between 11% and 97%.The humidity adsorption and desorption kineticsof the PVC-Bt6-Cu complex and PVC-Bt6-Hg complex films was examined by QCM technique.Poly(vinyl chloride) (PVC) was modified withbenzoilizotiyosiyanat and amine derivative and PVCconnected benzoylthiourea ligand (PVC-Bt6) wasobtained.Then Cu and Hg complexes of this ligand weresynthesized.[1] In Fig.1 molecular structure of (a) PVC-Bt6-Cu complex and (b) PVC-Bt6-Hg complex are shown.CH 2 -CHCH 2 -CHCH 2 -CHCH 2 -CH2020%11%11 RH%11%11 RH00%22%22-20%43%43-20-40 %53%53-60%75Cu-PVCCu-PVC-40%75(under %84 RH)%84%84-80%94-60%94-100Hg-PVC (a) -80Hg-PVC (b)%97(under %84 RH)-120200 400 600 800 1000 1200Time/sec0 1000 2000 3000 4000 5000 6000Time/sec0dF/Hz1000dF/HzNNNNy = 4.1948 * e^(0.032107x) R= 0.98952100HNNSOCuSONHNHNNSOHgSONHN- f(Hz)Hgdownward10CuHgupwardCu(c)120 30 40 50 60 70 80 90 100Relative Humidity (%)(a)Figure 1. (a) Chemical structure of synthesized (a)PVC-Bt6- Cucomplex (b)PVC-Bt6- Hg complexQCM is a sensor that extremely sensitive to mass changesin the nanogram scale by measuring the change ofpositions of its resonance frequency and it responds to agiven increase of mass simultaneously, regardless of thespecies deposited.[2-3] We used in our study QCM withthe model of CHI400A Series from CH Instruments(Austin, USA) to monitor the change in the resonancefrequency of quartz crystals between gold electrodesowing to the fact that saturated aquatic solutions which itwas subjected. Relative humidity (RH) values of solutionswere 11%, 22%, 43%, 53%, 75%, 84%, 94% and 97%.1mg/1ml Cu complex and Hg complex were dissolved intetrahidrofuran (THF) solvent and 5μl of solutions werecoated onto QCM thermally evaporated gold electrodeswhich has 17μm separation and 120 nm thickness by dropcastingmethod. QCM frequency shifts and Resistanceversus Time values were observed depending on relativehumidity with Keitley 2420 Sourcemeter and commercialhumidity-temperature sensor.(b)Figure 2. (a) Comparison of QCM frequency shifts of PVC-Bt6-Cu complex and PVC-Bt6-Hg complex for different increasingand decreasing RH values.(b) QCM frequency shifts (Hz) as afunction of time (s) for relative humidity values 11% and %84.(c) The frequency response of PVC-Bt6-Cu and PVC-Bt6-Hgfilms covered QCM adsorption-desorption process at fixed pointrelative humidity conditions between 11% and 97% RH.In Fig.2(a) QCM frequency responses of PVC-Bt6-Cuand PVC-Bt6-Hg comlexes are occured step by stepdepending on the different relative humidity conditionsbetween 11% and %97. In Fig.2(b) We can see QCMfrequency shifts (Hz) as a function of time (s) for relativehumidity values of 11% and %84. The adsorption anddesorption data taken from Fig.2(a) shows an exponentialdependence on relative humidity RH as shown in Fig.2(c).Fig.2 shows the frequency response of PVC-Bt6-Hgcomplex based sensor is more sensitive than PVC-Bt6-Cucomplex based sensor for humidity changes at roomtemperature.*Corresponding author: salihokur@iyte.edu.tr[1] R. Navarro, K. Bierbrauer, C. Mijangos, E. Goiti, H.Reinecke, Polym. Degrad. Stab. 93, 585–591 (2008)[2] P. Payra, P.K. Dutta, Zeolites: a premier, in: S.M. Auerbach,K.A. Carrado, P.K. Dutta (Eds.), Handbook of Zeolite Scienceand Technology, Marcel Dekker Inc., New York, 2003.[3] S. Okur, M. Kus, F. Özel, V. Aybek, M. Yilmaz, Talanta,81;1-2; 2010; 248.6th Nanoscience and Nanotechnology Conference, zmir, 2010 693

Poster Session, Thursday, June 17Theme F686 - N1123Fabrication of Micro Channels with Angled Sidewall on Silicon by Nd:YAG Laser AblationAlperen Acemoglu, 1 Veysel Ozkapici 2,* ,Vural Kara 1 ,Omid Tayafeh 3 ,Huseyin Kizil 4 and Levent Trabzon 1,*1 Department of Mechanical Engineering, Istanbul Technical University, Gumussuyu, Istanbul 34437, Turkey2 BNM Fabrika Biyo Nano Mikro Tek. San. Ve Tic. Ekinciler Cad. 7/4 stanbul 34830, Turkey3 Department of Electronics and Communication Engineering, Istanbul Technical University, Maslak, Istanbul 34469, Turkey4 Department of Metallurgical and Materials Engineering, Istanbul Technical University, Maslak, Istanbul 34469, TurkeyAbstract— We present experimental results on microfabrication of micro channels with angled sidewall on silicon surface by Nd:YAG laser.The purpose is to create V-shaped deep micro channels on silicon surface for producing nano-sharp micro Si-knife. The results can be used tocharacterize the behavior of ablation process under different laser parameters to achieve optimal processing conditions for Si-micromicromachingin MEMS such as V-shaped channels, slots and singulation process of vias.Micro channels on silicon wafer play an important role inmany MEMS and NEMS applications. There are severalmicrofabrication processes for creating proper micro channelson silicon surface. Conventional chemical and mechanicalprocesses like etching, engraving and sawing have beensuccessfully applied on to fabrication of micro channels [1, 2].Although well developed and mature production process, theyare not suitable for all kind of MEMS application. That’s whylaser are widely used to create this kind of channels onmaterial, laser fabrication process is a non contact processtherefore preferred in our task.Lasers are a powerful tool for micromachiningapplications. A focused laser beam can easily be concentratedonto a small target of a few micron diameters. The lasermaterial-interaction in this target area will be controlled bylaser parameters such as wavelength, pulse energy and pulseduration which determine peak power density [3]. Certain setsof parameters can cause thermal effects for marking, cutting,and drilling.In our work, we have specially chosen to work withNd:YAG DPSS laser which has 1064 nm wavelength and 60W maximum power. There were limited survey on that, mostof the laser on literature was in the UV range with eitherfemto- or pico-seconds system, which are very expensive. Ourmain focus was creating those micro channels by nanosecondlaser with a wavelength of 1064 nm.One of the important findings in the study is to have U-shaped channels with laser beam directed on the Si-waferperpendicular. This observation is defined as tapering affectand it depends on the repletion of the laser ablation and depthof the channel produced in the ablation process [5]. Taperingaffect is around 30°- 40° for 10 – 50 μm deep channels andthey are roughly V-shaped channel as shown in Fig. 2a.Tapering affect was reduced to 10 °- 15° when channel depthis in between 51 and 150 μm.Main aim of this work is to create angled sidewallproduction on silicon wafer by laser. Then, we examined laserbeam ablation on Si-wafer by different angles with laser beam.By means of adjustable wedge, the Si is oriented as 30°-45°-60° degree with respect to incoming laser in order to seesidewall affect and channel-wall angles. The channel-wallangles should be 30°-45°-60° degrees after inclined Si-waferablation by laser if there is no tapering effect. We measuredchannel-wall angles by profilometer on each Si wafer ablatedby a different angle. We found that the channel-wall angles are38°-42°, 29°-34° and 19°-22° for ideally expected sidewallangel 60°, 45° and 30°, respectively. The difference betweenmeasured and expected angles is due to tapering effect in Silaser ablation.(a)(b)Figure 1: (a) Schematic drawings of angled channels set up (b) Angledmicro channel fabrication setup.We first studied ablation effect of perpendicular laserbeam on silicon surface. We observe and measure the effect oflaser on scribed or grooved channels by profilometre bychanging laser ablation velocity, frequency, power andrepetition. It is been showed that 40 – 100 μm wide and 5- 250μm deep groves can easily been produced by laser. There werebig debris or (HAZ) around the channel due to thermal affectof laser. As our expectation and previous literature info,ablation affect of laser increased by power, frequency,repetition increments and velocity decrements [3]. The degreeof ablation does not linearly depend on the aforementionedparameters; the relationship is very complex and wellexplained [4].Figure 2: (a) Optical microscope picture of micro channels produced by laser(b) Profilometre result graph of sidewall angel of laser ablated micro channel.This work was partially supported by TUBITAK under Grant No. 8080090*Corresponding authors: levent.trabzon@itu.edu.tr andveysel.ozkapici@bnmfabric.com[1] G.S. May,S.M.Sze, Fundamentals of semiconductor fabrication,JonhWilley & Sons, Inc.,(2004).[2] G. T. A. Kovacks, N. Maluf,G.W. Crabtree,Bulk Micromachining ofSilicon K. Petersen, IEEE, VOL. 86, NO. 8, (1998)Phys. Today 57, No. 12, 39 (2004).[3]A. Ostendorf, K. Koerber, T. Nether, T. Temme: “Material ProcessingApplications for Diode Pumped Solid State Lasers” In: Lambda Highlights,No. 57 , Göttingen (2000)[4] Holmes A.S., Pedder J.E.A., Boehlen K., Advanced laser micromachiningprocesses for MEMS applications, SPIE Proceedings Vol. 6261,(2006)[5] T. Otani,L. Herbst, M.Hegling.S.V.Govorkov, A.O. WiessnerMicrodrilling and micromachining with diode-pumped solid-state lasersBogdanovic et al., Appl. Phys. A 79, 1335–1339 (2004) (2003).6th Nanoscience and Nanotechnology Conference, zmir, 2010 694

PP andPoster Session, Thursday, June 17Theme F686 - N1123Electrokinetic Flow Modeling in a Porous Nanochannel using Curvilinear Coordinates111UMehdi MostofiUP P*, Davood D. GanjiP Mofid Gorji-BandpyP1PDepartment of Mechanical Engineering, Noshiravani University of Technology, Babol, IranAbstract- In this Paper, it is expected to model the behavior of the electrokinetics driven fluid in porous nanochannel. in this case, continuumtheory is no longer valid. As a result, it is necessary to model the Poisson-Boltzmann and Navier-Stokes using molecular simulation. Incontinue, for four typical nano-scale particles, porous media assumption is made and validity of the continuum theory in nano-scale isinvestigated.One of the most important subsystems of the micro- andnano- fluidic devices is their passage or “Micro- and Nano-Channel”. Nano-channel term is referred to channels withhydraulic diameter less than 100 nanometers [1]. Bydecrease in size and hydraulic diameter some of the physicalparameters such as surface tension will be more significantwhile they are negligible in normal sizes.Concentrating surface loads in liquid – solid interface makesthe EDL to be existed. If the loads are concentrated in theend of nano-channels, a potential difference will begenerated that forces the ions in the nano-channel. However,induced electric field is discharged by electric conduction ofthe electrolyte.Rice and Whitehead [2], Lu and Chan [3] and Ke and Liu[4] studied the flow in capillary tube. None of them solvedthe problem based on the curvilinear coordinates system.Also, all of them studied the problem with existence of thepressure gradient while in the modern applications, thepressure gradient can be eliminated and consequently,solving the problem considering this fact is necessary. In thispaper, for small zeta potentials without pressure gradientwill be studied based on the curvilinear coordinates in acapillary tube.In case of electrokinetic flows in porous media, references[5] – [7] can be mentioned in order to have some reviewabout it. In this work, a nano-tube with 15 nm radius will beinvestigated. Despite most of the works were done, in thiswork, curvilinear coordinates will be employed.Based on [8], in nano-scale, we should aware of thecompatibility of traditional theories that are used in greaterscales. On the other hand, in nano-scale, there areexperimentally proved limitations that, traditional theoriesTable 1. (a) Effect of four typical particle diameters on zetapotential in a 15 nm radius nano-tubeNormalizes ZetaRadius (nm)Potential for Particles1 0.062 0.224 0.568 0.84are no longer valid. In this paper, it is tried to trespass thoseborders and as a result, molecular simulation has beenemployed and the nano-tube is assumed to be porous. In thiscase, Poisson-Boltzmann equation must be solved [8].In simulation phase of the work, first of all, analyticaltreatment has been employed in order to have non-porousmedia results. Figure (a) shows the result in this case. Afterthat, some specific particle diameters have been investigatedin order to have achievements about the particle diametereffect on the zeta potential in nano-tube. In this paper,diameters of 1, 2, 4 and 8 nm are investigated. Table (a)shows the results of these four simulations. As thesimulation mentions, the greater the particle, the moresignificant the zeta potential. The zeta potential have beengiven in Table (a) are normalized by the wall zeta potentialin a non-porous similar nano-tube.In summary, by considering curvilinear coordinates andapplying it on a nano-tube, no porous media is investigated.Then, for some specific nano-scale particle diameters,simulation has been applied. In the case of particles, forgreater particles in comparison of the tube diameter,significant effects of particles have been occurred and as aresult, continuum mechanics are no longer valid. However,for smaller particles, it has been shown that, continuummechanics are valid at least for diffusion layer. Thisachievements are in good agreements with experimentalresults in [8].* Corresponding author: mehdi_mostofi@yahoo.comFigure 1. (a) Normalized distribution of potential as a function ofnormalized radius in a non-porous nano-tube with 30 nm diameter.[1] S. Kandlikar, et. al, Heat Transfer and Fluid Flow inMinichannels and Microchannels. Elsevier Limited, Oxford (2006).[2] Rice, C.L. and Whitehead, R. J. Phys. Chem., 69(11), 4017–4023 (1965)[3] W.Y. Lo, and K. Chan. J. Chem. Phys., 143, 339–353 (1994)[4] H. Keh, and Y.C. Liu, J. Colloids and Interface Surfaces, 172,222–229 (1995)[5] Coelho, D. et. al. J. Colloid Interface Sci. 181, 169 (1996).[6] Coelho, D. et. al. Fractals, 5, 507 (1997).[7] Marino, S. et. al. J. Colloid Interface Sci. 223, 292 (2000).[8] G. Karniadakis, et. al. Microflows and Nanoflows. Springer(2005).6th Nanoscience and Nanotechnology Conference, zmir, 2010 695

PPPoster Session, Thursday, June 17Theme F686 - N11232Vole Repeller Spider Robot with Artificial Muscle12UKadir SabancUP P*, Cevat AydnP1PSelcuk University Doganhisar Vocational School, Konya, TurkeyPSelcuk University Faculty of Agriculture, Agricultural Machinery Department, Konya, TurkeyAbstract-In this study, an example of using nitonel which is an alloy with shape memory at the robotic field. Nitonel material that is commonlyused in today movement technology, don’t pollute the environment, quiet operating, economic, easy controlled has been used as artificial muscle atthe robot. It is aimed to remove the rat that gives harm to crop at the field through designing an amplificatory and a sonant signal 25- 35 KHzamp on this robot.Today, using alloys with shape memory is generalized fastinto many technological areas. Alloys with shape memory isused various fields from temperature sensors at electronic toblood pressure test valves at the medicine, from automotiveradiator fans to robots with multi leg at the robotic [1, 2].When robot movement systems are generally examined, it isseen that hydraulic, pneumatic, electric motor systems that arecalled as traditional robot accelerator mechanisms are the mostcommon systems [3].In recent years, various studies have been achieved aboutworking principles, characteristics and application of nitonolwires at the robotic areas. Nitinol wires are used as artificialmuscle at multi leg and reptile robots [4,5,6].The working block diagram of vole repeller spider robotwith artificial muscle used in this study is shown in Figure 1and 2.Figure 1. Spider robot top viewFigure 2. Block diagram of systemThe Vole has an important place among the pests that areaccepted as general plant pests of culture plants. The vole isharmful for every kind of plant as field plants; wheat, barley,rye, oats, pulses, and industry and oil seeds, fruits vegetablegarden plants, meadow, young forest. They are active at daytime and night time especially at night time. They gives harmto crops through cutting, corroding, eating and polluting theamount at least tenfold section more than their eating section.The agricultural medicine has an important place to preventdisease, crop loss due to harmful and foreign plants. But theagricultural pest control with chemicals should be appliedsensitively, carefully and with minimum medicine lossbecause those medicines has negative effects on human health,environment and natural balance and increasing producingcosts [7].Various methods are used to struggle against to mouse andrat. Chemical methods are commonly used one. Poisonousfeed are mostly used at chemical applications. It has been seenthat many birds died because of eating poisonous wheat thatare used at vole struggle because those wheat are not placeswell in to the holes and left on open area. Also poisoning isseen at the children of families who are deal with agriculturebecause of contact or eaten those rat feed by the children.Ultrasonic rat repeller robot can be used at supplementary ofother methods. It is used at the area which is isolated fromvoles and invasion of vole again this isolated area isprevented. The rats/vole is very sensitive against to voice.Even a simple noise disturbs them. The point to take intoconsideration is to produce the noise which only disturbs thevole not human. The rodent kinds can hear up to 80 kHzfrequencies noises. However human ear can hear only 20Hz-20 Khz frequencies noises. In this study, the circuit on therobot will give 25-40 kHz frequency range so it is though thatthe vole will be dismissed from agriculture field. Also therobot won’t harm to the products at the land because it is lightnot heavy. Seperately spider robot doesn’t harm the crop in thefield because it is so light. Because of not using harmful toxicfor destroying mice and nature, natural balance will beprotected. Nitinol materials, getting widespread in ourcountry, are used in a robotic field.*Corresponding author: ksabanci@selcuk.edu.tr[1] Dilibal S., Sönmez N., Dilibal H., “Ni-Ti ekil Bellekli Alamlarve Teknolojik Kullanm Alanlar”, 3. Uluslar aras leri TeknolojilerSempozyumu, 2003[2] Dilibal S., Dilibal H., “Ituhand Robot El ve Mayn TemizlemeAlannda Kullanlabilirlii”, Savunma Teknolojileri Kongresi, 2002[3] Dilibal S., Güner E.,Akturk N., "Three-finger SMA Robot Handand ts Practical Analysis", Robotica, 20,175-180, 2002[4] Topba E., Akku N., “ekil Hafzal Alamlar ve EndüstriyelUygulamalar”, Makine Teknolojiler Elektronik Dergisi, Cilt 4 sayfa15-22,2007[5]Liu C.Y., Liao W.H. “A Snake Robot Using Shape MemoryAlloys” , International Conference On Robotics And Biomimetics,,August 22-26,2004, Shenyang, China[6] Raparelli T, Zobel P. B. and Durante F., "A Robot Actuated byShape Memory Alloy Wires,", Proc. Of International Symposium onIndustrial Electronics, Vol. 2, pp.420-423, 2002.[7]Dursun, E., 2000. Meme Anmasnn PülverizasyonKarakteristiklerine Etkileri. Ekin Dergisi Yl : 6, Say 21.[8]Sabanc K., ”Yapay Kas Kullanlarak Örümcek Robot Tasarm”,Yüksek Lisans Tezi, Selçuk Üniversitesi Fen BilimleriEnstitüsü,Konya,2005.6th Nanoscience and Nanotechnology Conference, zmir, 2010 696

Poster Session, Thursday, June 17Humidity Sensing Properties of Copper Phthalocyanine (CuPc) Thin FilmsTheme F686 - N1123Özgen SÖKE 1 , Salih OKUR 1 , Nesli T. YAĞMURCUKARDEŞ 11 Izmir Institute of Technology, Faculty of Science, Department of Physics, Gulbahce Koyu Kampusu, 35430, Urla, Izmir, TurkeyAbstract—This study focuses on the humidity adsorption and desorption kinetics of copper phthalocyanine (CuPc) nanoparticle thin filmprepared by drop cast method, were investigated by quartz crystal microbalance (QCM) technique. Reproducible experimental results show thatCuPc thin films have a great potential for humidity sensing applications at room temperature.Phthalocyanine (Pc) are the subject of a great deal withwide-ranging applications. Copper phthalocyanine (CuPc)thin films have potential applications as surfaceconductivity-based gas sensors, solar cells, dyes, field-effecttransistors , and organic light emitting diodes (OLEDs). Thehumidity adsorption and desorption studies of CuPc is veryimportant for many humidity and gas sensing deviceapplications. In Fig.1 molecular structure of copperphthalocyanine (CuPc) is shown. [1]- [6]F/Hz50-5-10-15-20-25(a)11%22%11%43%22%53%43%53%75%84% 75%84%94% 94%97%-300 1000 2000 3000 4000 5000 6000 7000Time(sec)- F (Hz)100101y = 0.45016 * e^(0.042563x) R= 0.99637y = 1.1664 * e^(0.033464x) R= 0.99547downwardupward0,10 20 40 60 80 100Relative humidity %(RH%)Fig.2 (a and b) The frequency response of Copper phthalocyanine (CuPc)thin films covered QCM adsorption–desorption process at fixed pointrelative humidity conditions between 11% and 97% RH.(b)Fig.1 Structure of Copper Phthalocyanine (CuPc)50%11 RH%11 RHQuartz crystal microbalance (QCM) is a technique that wasused to analyze the change in the resonant frequency. Thisresonant frequency is sensitive to mass changes of thecrystal. In our study, we used QCM with the model ofCHI400A Series from CH, after exposure of the crystalmass loading of water molecules at different humidityenvironments e.g. at 11%, 22%, 43%, 55%, 75%, 84%,94%, 97% relative humidity (RH). [1]- [6]The mass change (Δm) from the measured frequency change(Δf) is calculating to use Saurbey Equation ;22 f0mf A (1)where f 0 is the resonant frequency of the QCM crystal, ρ isthe density of the crystal, μ is the shear modulus of quartzand A is the area of the gold disk on the crystal.CuPc molecules (99% Purity) were solved in toluene with1mg/ml concentration and 5μl of solution were coated ontosurface of QCM by drop-casting method. After evaporationof toluene, thicknesses of CuPc film was measured as300nm with Dektak 150 profilometer of Veeco.Fig.2 (a) shows the frequency response of copperphthalocyanine (CuPc) film when the relative humidityincreased and decreased between 11% and 97% RH for anequal time(400sec) intervals and (b) show how the quartzcrystal microbalance (QCM) frequency changes withincreasing and decreasing RH values.F/Hz-5-10-15-20-2522%43%53%75%84%94%97%-300 200 400 600 800 1000120014001600Time(sec)Fig.3 Comparison of frequency shifts between 11% and 97% RH.Fig.3 shows the comparison of QCM frequency shifts for11%, 22%, 43%, 55%, 75%, 84%, 94%, 97% RH values.Our QCM and electrical measurements results show thathumidity sensing properties of Copper Phthalocyanine(CuPc) is very sensitive to humidty changes and reversibleadsorption/desorption behavior which is an indicative of agood humidity sensor even at room temprature.*Corresponding author: salihokur@iyte.edu.tr[1] S. Okur, M. Kus, F. Özel, V. Aybek, M. Yilmaz, Talanta, 81;1-2; 2010;248.[2] F.Young, M. Shtein, S.R. Forrest, Nature Mater.4,37,(2005)[3] Caronna, T.; Colleoni, C.; Dotti, S.; Fontana, F.; Rosace, G.J.Photochem. Photobiol., A, 184, 135 (2006)[4] Z. Bao, A. J. Lovinger, and A. Dodabaladur, Appl. Phys. Lett. 69, 3066(1996).[5]Yamashita M, Inui F, Irokawa K, Morinaga A, Tako T, Mito A,ApplSurf Sci, 130, 883 (1998).[6] A. Schmidt, L.K. Chau, A. Back, N.R. Armstrong, C.C. Leznoff, B.P.Lewer (Eds.), Phthalocyanines, Properties and Applications, New York:VCH, 1996. M6th Nanoscience and Nanotechnology Conference, zmir, 2010 697

Poster Session, Thursday, June 17Humidity Sensing Investigation of ZnO Nanostructures Using QCM TechniqueNurdan Asar 1 , Nesli Tekguzel Yagmurcukardes 2 , Ayse Erol 1 , Salih Okur 2 , M. Cetin Arikan 11 Istanbul University Faculty of Science Physics Department 34134 Vezneciler, Istanbul, Turkey2 Izmir Institute of Technology 35430 Urla, Izmir, TurkeyTheme F686 - N1123Abstract: ZnO nanostructures were synthesized via chemical sol-gel method in two different morphologies. Their humidity sensing properties were investigated byusing Quartz Crystal Microbalance (QCM) technique. It was found that the frequency shift of the ZnO nanostructures coated on QCM increases with increasing relativehumidity between 33-77 % at room temperature. The results show that humidity sensing properties are strongly dependent on morphology of the nanostructures.ZnO is one of the most important promising metal oxidesemiconductors for gas/vapour/humidity sensing applications and haspronounced sensitivity to gases such as NH 3 , NO 2 , CO, H 2 , ethanoland humidity [1-4]. It has been observed that ZnO nanostructuressynthesized in different morphologies compared with its thin film orbulk counterparts have much more sensitivity due to their highsurface to volume ratio and more chemically active centers [5].In this study we synthesized ZnO nanostructures by using chemicalsol-gel method. Crystal structure and morphology of ZnOnanostructures synthesized in different experimental conditions werecharacterized by X-Ray Diffraction (XRD) and Scanning ElectronMicroscopy (SEM).(a)(a)Samples S2 and S3 were synthesized with different molarities of Zn +2and OH - solutions. Samples dried in ambient air for 24 hours. As seenfrom the Figures 1 (a) and (b), the morphology of S2 is nanoparticlewhile the morphology of S3 is nanowire and both structures havediameter as ~ 20 nm. XRD patterns showed that both samples arecrystallized in hexagonal wurtzite structure.Humidity sensing investigations of ZnO nanostructures werecarried out using Quartz Crystal Microbalance (QCM) technique.Samples dispersed in ethanol were dropped on quartz crystal andexposed to various saturated salt solutions. The frequency responsesof the ZnO nanostructure sensors to relative humidity changingbetween 33-77% RH were measured at room temperature. Relativehumidity was recorded by commercial sensor simultaneously.(b)Figure 2: Frequency responses of S2 and S3 sensors under 33 – 77% relative humidityexposure at room temperature.(c)(d)Figure 2 shows response and recovery curves of the sensors. When%RH was decreased from 77 to 33%, frequencies of the sensors werebackshifted to their initial values. In comparison with nanowires,nanoparticles showed larger frequency shift.The experimental results demonstrated that ZnO nanoparticles aremore sensitive to humidity changes compared to nanowires due tohaving high surface to volume ratio and much more chemically activecenters.This work was supported by Scientific Research ProjectsCoordination Unit of Istanbul University. Project number 4907.Figure 1: (a-b) SEM images and (c-d) XRD patterns of samples S2 and S3, respectively.[1] Hongsith N., Choopun S., Mangkorntong P.,Mangkorntong N., 2005. CMU. J.Special issue on nanotechnology. vol. 4 No. 1: 15-20.[2] Sadek A. Z., Choopun S., Wlodarski W., Ippolito S. J., Kalantar Zadeh K., 2007.IEEE Sensors Journal. Vol. 7, No. 6.[3] Krishnakumar T., Jayaprakash R., Pinna N., Donato N., Bonavita A., Micali G. andNeri G., 2009. Sensors & Actuators: B. 143, 198.[4] Qi Q., Zhang T., Yu Q., Wang R., Zeng Y., Liu L., Yang H., 2008. Sensors andActuators B: Chemical. 638-643.[5] Hongsith N., Viriyaworasakul C., Mangkorntong P. , Mangkorntong N. , ChoopunS., 2008 Ceramics International 34: 823–826.6th Nanoscience and Nanotechnology Conference, zmir, 2010 698

Poster Session, Thursday, June 17Theme F686 - N1123Humidity Sensor applications based on Carbon Nanotubes (CNTs) modified with various Calixarenemolecules measured by a Quartz Crystal Microbalance (QCM)F. Nadi Gür 1* , S. Okur 1* , Nesli T. Yağmurcukardeş 1 , Mustafa Yılmaz 2 , Mahmut Kuş 31 Izmir Institute of Technology, Department of Physics Urla/Izmir/TURKEY2 Selçuk University, Department of Chemistry, Selçuklu/Konya/TURKEY3 Selçuk University, Department of Chemical Engineering, Selçuklu/Konya/TURKEYAbstract— We predict that CNTs modified with calixerene molecules has a strong potential to investigate as a humiditysensors. This study focuses on humidity sensing properties of CNTs modified with calixrene. The humidity adsorbtiondesorptionkinetics are tested by Quartz Crystal Microbalance (QCM) technique. According to the our experimental results,modified CNTs with calixerene film will be possible option and open new approaches for more reliable, high sensitive,reversible and cost effective electro-chemical sensor applications.The accurate measurements of humidity levels are veryimportant concerns in environmental fields, such as medical ordomestic applications for human comfort, industrial uses,agriculture, automobiles.Thus, the requirement for cheap,reliable and sensitive sensors are urgent.Across all over the world, researchers have beeninterested in CNT based sensors and CNTs have shown to bestrong potential for the revolutionary of sensors generations[1]. As can be seen from Fig.1, due to their small size, highstrength, high electrical and thermal conductivity, and largeeffective active area, CNTs have many advantages compare tothe bulk or thin films for electro-chemical sensor applications[1,2].repeatability characteristics. The adsorption-desorptionkinetics are analyzed and discussed in details. F (Hz)50%110 %22 (a)%43-50 %53-100-150%75%84%94 %94%75%84%11%22%43%53-200%97-2500 1000 2000 3000 4000 5000 6000Time (s)- F (Hz)1000100 F (Hz)500-50-100-150-200(b)%43%53%75%84%97-2500 200 400 600 800 1000 1200Time (s)y = 13.733 * e^(0.028238x) R= 0.99383y = 8.1544 * e^(0.034337x) R= 0.98145(c)downwardupwardFigure 1: SEM image of carbon nanotubes filmThin films of calixarene derivatives have been widely usedin chemical sensors. Due to their zeolite-like capacity andselectivity, calixarenes became promising materials for sensorapplications [3]. Calixarene derivatives have been used inrecent times as gas sensors applications [4]. It is also knownthat some calixarene derivatives adsorb water molecules. SalihOkur reported a humidity sensing properties of calixerenederivatives [5]. However we did not reach any application ofCNTs modified with calixerene molecules based on humiditysensor.QCM tehnique is a powerfull option to investigate sensingproperties of modified CNTs, since it is highly sensitive tomass changes 1 ng/ 2 [2]. QCM has been used widely tomonitor the change in mass loading by measuring the shift ofits resonant frequency [5].In this work, we firstly started with CNTs dissolved intoethanol and CNT film coated by drop-casting technique.Humidity measurements of CNT film were recorded andmonitored by QCM from %11 RH to %97 RH. According toFig.2 adsorbtion-desorbtion process are very fast andreversible. We have obtained very good response and high1020 30 40 50 60 70 80 90 100Relative Humidity (%)Figure 2: QCM frequency shifts (Hz) as a function of time (s) for differentincreasing and decreasing relative humidity values between 11% and 97% RH(a) and (b) The change in the QCM frequency vs varying RH values (c)In summary, both CNTs and Calixerene derivates show verygood response to humidity changes sensor applications.Modified CNTs with Calixerene molecules show highlysensitive responce to RH changes and can be used as costeffective sensor materials.*Corresponding author: salihokur@iyte.edu.tr ,fatihnadigur@gmail.com[1] Niraj Sinha, Jiazhi Ma, and John T. W. Yeow, Carbon Nanotube-BasedSensors,JNN Vol.6, 573–590, 2006[2] Y. Zhang, K. Yu, R. Xu, D. Jiang, L. Luo, Z. Zhu, Quartz crystalmicrobalance coated with carbon nanotube films used as humidity sensor,Sens. Actuators A 120 (2005) 142–146.)[3] Koshets I. A., et.al.,Sens. Actuators B 106, (2005), 177[4] Ohira, Shin-I. , et.al., Talanta 2009, 77, 1814.[5]Salih Okur, Mahmut Kus, Faruk Ozel, Mustafa Yılmaz,Humidityadsorption kinetics of water soluble calix[4]arene derivativesmeasured using QCM technique,Sensors and Actuators B 145 (2010) 93–976th Nanoscience and Nanotechnology Conference, zmir, 2010 699

Poster Session, Thursday, June 17Theme F686 - N1123Investigation of Humidity Sensing Properties of ZnS NanowiresS.Okur 1 , N.Tekgüze1 1 l, A. Erol 2 , N.Üzar 2 , M.Ç. Arıkan 21 Izmir Institute of Technology, Faculty of Science, Department of PhysicsGülbahce Koyu Kampüsü, Urla, Izmir,35430, Turkey2 Istanbul University, Science Faculty, Physics Department, Vezneciler, 34134 Istanbul, TurkeyAbstract— ZnS nanowires synthesized by the VLS (Vapor-Liquid-Solid) method and were investigated by Quartz Crystal Microbalance (QCM)method and electrical measurements. The synthesized nanowires were exposed to relative humidity (RH) between 33% and 100% undercontrolled environment. Our experimental results show that ZnS nanowires have a great potential for humidity sensing applications for roomtemperature operations.Semiconductor nanostructures have attracted great attention asmaterials for sensing gases and humidity due to their superior sensingfeatures such as very high surface to volume ratio, lower cost and easeto fabricate as a sensor compared to bulk or thin films [1]. Sensing andcontrolling of humidity is very important for many manufacturingenvironments such as food, automotive and electronics industries. ZnSnanostructures should be used as humidity and gas sensor due to theirhighly active surface properties.In this work, we explored the humidity sensing capability of ZnSnanostructures using QCM method, at which the measured frequencyshift is directly proportional to the mass change on a quartz crystal [2],and electrical measurements such as voltage-current (I-V), resistance-RH% and capacitance-frequency (C-f) from 33% RH to 100% RH.ZnS nanostructures were synthesized using VLS technique. Fig.1shows the morphology of the synthesized nanostructures is nanowireswith their diameters range from 60 nm to 300nm.decreases almost linearly with increasing RH. This decreasing ofresistance was about four orders. Typical I-V curves of ZnS nanowiressensor from 33% RH to 100% RH are shown in Fig.3b. These I-Vcurves are a straight line, showing ohmic behavior. Molecules ofmoisture interaction with semiconductor surfaces influence surfaceconductivity due to physical and chemical adsorption of watermolecules. Charge exchange occurs between adsorbed species from themoisture and the semiconductor surface. Conductivity of ZnSnanowires sensor increases with increasing relative humidity is relatedto amount of the absorption of moisture molecules on the surface ofZnS nanowires sensor.Resistance (Ohm)10 1110 1010 910 810 7y = 6,9462e+11 * e^(-0,11993x) R= 0,96093B10 12 30 40 50 60 70 80 90 10010 610 5Fig. 1: SEM image of the ZnS nanostructuresIn order to monitor humidity sensing properties, ZnS isultrasonically dispersed in ethanol and solution was applied on thesurface of quartz crystal and between the two gold (Au) electrodes bydrop-casting technique for QCM and electrical measurements,respectively. The dropped solution was dried at room temperature untilethanol was totally evaporated. The quartz crystal and electrodesloaded with ZnS nanowires were exposed to the relative humidity at thesame time. Fig. 2 shows the frequency shift of ZnS loaded QCM crystalunder varying relative humidity (RH) between 45 and 75% for fourhumidity adsorption/desorption cycles. During the adsorption ofmoisture molecules on the sensor surface the frequency shift decreaseswith increasing RH and goes to near saturation values, while frequencyshift decreases during the desorption. This is why ZnS nanowiresposses a large specific surface area, moisture molecules adsorb easilyon the sensor surface and the mass of quartz crystal increases withincreasing RH.dF/Hz0-200-400-600-800-1000dF/Hz Relative Humidity (%)400 200 400 600 800 1000 1200 1400Fig. 2: The frequency responses of an loaded QCM with drop-casted ZnSnanowires (red squares) comparing with relative humidity values of acommercial sensor (blue circles) for 4 humidity adsorption-desorption cyclesbetween 45% and 75% RH.Fig.3a shows the resistance variation of ZnS nanowires dependingon varying relative humidity. The resistance of ZnS nanowiresTime (s)8075706560555045Relative Humidity (%)Current (A)Relative Humidity (%)A0,020,0150,010,0050-0,005-0,01-0,015100 33%-0,02-6 -4 -2 0 2 4 6bVoltage (V)Fig. 3: a) The resistance variation, b) the I-V characterization of ZnS nanowiresunder varying relative humidityIn summary, the QCM and electrical measurements resultsshow that ZnS nanowires can be used for potential humiditysensor application.*Corresponding author:neslihanuzar@istanbul.edu.tr.[1] D.P: Norton, Y.W. Heo, M.P. Ivill, K. Ip, S. J. Pearton, M. F. Chisholm, T.Steiner, Materials Today, 34, 7, (2004)[2] Lukas Schmidt-Mende and Judith L. MacManus-Driscoll, 10, 40-48, 2008.90% %4384% 55%75%55% 84%90% 43%100% 33%6th Nanoscience and Nanotechnology Conference, zmir, 2010 700

Poster Session, Thursday, June 17Theme F686 - N1123Humidity Sensing Properties of Titanium Dioxide (TiO 2 ) Thin FilmsMehmet KABADAYI 1 , Salih OKUR 1 ,Nesli T. YAĞMURCUKARDEŞ 11 Izmir Institute of Technology, Faculty of Science, Department of Physics, Gulbahce Koyu Kampusu, 35430,Urla, Izmir, TurkeyAbstract- Humidity sensing properties of TiO 2 nanoparticle thin film that prepared by drop casting method were investigatedby quartz crystal microbalance (QCM) and electrical characterization. The results of our experiment show that TiO 2nanoparticles have a great potential for humidity sensing applications at room temperature.Pure titanium dioxide does not occur in nature but isderived from ilmenite of leuxocene ores. The TiO 2nanoparticles generally present in three crystal phases:anatase, rutile, and brookite. Due to its highphotocatalytic activity, anatase is used as a photocatalystto treat various waste waters [2].In our study we used commercially available millenniumPC 500 TiO 2 which has 5-10nm particle size, 99%anatase form and 250 m 2 /gr BET surface area. 1gr TiO 2dispersed in 20ml distilled water and kept into ultrasoniccleaner for 30 minute at 50 0 C. After waiting 10 minutesthe semi-transparant part of the dispersion was taken.And 5μl of the dispersion is coated over a glass substrateby drop-casting method. The thickness of the film wasmeasured as 450 nm with Dektak 150 profilometer ofVeeco. SEM image of drop casted millenium PC 500TiO 2 thin film is shown in Figure1.(1)where is resonant frequency (8MHz), A is thearea of the gold disk coated onto the crystal, ρ isthe density of the crystal (2.684g/cm 3 ), and μ is theshear modulus of quartz (2.947x10 11 g/cms 2 ).F/Hz20-2-4-611%22%43%53%84%75%94%84%94%97%-80 1000 2000 3000 4000 5000 6000210(a)Time/sec43%53%75%22%11%y = 0,698 - 0,067407x R= 0,9972y = 2,2276 - 0,077601x R= 0,99245(b)-1f/Hz-2-3-4-5upwarddownward-60 20 40 60 80 100Relative Humidity (%)Figure 2(aand b):Frequency change with different RH(%) valuesFigure 1. SEM image of drop casted millenium PC 500 TiO2 thin film.For the electrical characterizations, Au metal withhigh purity (99.9%) was thermally evaporated onthe TiO 2 film with a separation of 17 μl. Keithly2420 Sourcemeter was used to investigateelectronic parameters. To estimate the frequencychange due to mass loading of water molecules,QCM with the model of CHI400A Series from CHInstruments was used. Electrical characterizationand frequency changes were obtained with theexposure of the film at different relative humidity(RH) ratios. (11%, 22%, 43%, 55%, 75%, 84%,94%, and 97% RH.)To convert the measured frequency change to themass change, Sauerbrey Equation is used [3].Figure 2 (a and b) shows the frequency changes dueto different relative humidity values .The frequencyof the TiO 2 film is decreasing and increasinghumidity values from 11% to 97%.A positive frequency observed during the resonanceoscillations because of the behaviours of TiO 2films.Our experimental results give that TiO2nanoparticle sensor is sensitive to relative humiditychanges at room temperature[1] S. Okur, M. Kus, F. Özel, V. Aybek, M. Yilmaz, Talanta,81;1-2; 2010; 248.[2] Tetsuro, K., Toshiaki, O., Mitsunobu, I., et al.,Photocatalytic Activity of Rutile–Anatase Coupled TiO2Particles Prepared by a Dissolution–ReprecipitationMethod, J.Colloid. Interf. Sci., 2003, vol. 267, no. 2, pp.377–381.[3] G. Sauerbrey, Z. Phys. 155 (1959) 206.6th Nanoscience and Nanotechnology Conference, zmir, 2010 701

PPPPPPoster Session, Thursday, June 17Theme F686 - N1123Electrical and Optical Properties of Al Doped ZnO Film and Potential Applications of Gas Sensors1,21,21,21,2UO. SancakogluUPP*, M. ErolPP, M. BektasPP, F. EbeoglugilPP, H. SozbilenP3P, O. Mermer 2,3P, E. Celik 1,21PDokuz Eylul University, Department of Metallurgical and Materials Engineering, Tinaztepe Campus, 35160 Buca, Izmir-Turkey.2PDokuz Eylul University, Center for Fabrication and Application of Electronic Materials (EMUM), Tinaztepe Campus, 35160Buca, Izmir-Turkey3PEge University, Deparment of Electrical and Electronics Engineering, 35100, Bornova, Izmir-Turkey.Abstract-Undoped and Al doped semiconductor ZnO films on Si(100) and glass substrates were prepared by sol-gel technique. For thispropose, transparent solutions were prepared with Zn and Al based precursors. The solutions were deposited on glass substrates using spincoating technique which decreases the film thickness up to nanoscale and gives the coating a smooth characteristic. Deposited films were driedooat 300P PC for 10 min in order to remove hydrous and volatile content, subsequently films were heat treated at 500P PC for 5 min. to removeoorganic contents and then to obtain ZnO phase structure the films were annealed at 600P PC for 1 hour in air atmosphere. Finally the surfacemorphologies and roughness values of the films were determined via AFM (atomic force microscopy) and profilometer, respectively. Thestructural and optical properties of these films have been investigated by XRD (x-ray diffractometer) and optical properties such astransmittance spectrum, optical band gap, and optical constants (refractive index, extinction coefficient, real and imaginary parts of the dielectricconstant) of the films were determined.Zinc oxide (ZnO) has attracted extensive interest becauseof its important role in various applications, for example, gassensor [1], varistors [2], surface acoustic wave devices [3],optical waveguides [4] as well as blue/UV light emittingdevices [5]. In addition, ZnO has been considered as anexcellent candidate to replace indium tin oxide (ITO) and tinoxide (SnO2) as transparent conductive electrodes in flat paneldisplay and solar cell devices [6,7]. The advantages of zincoxide include inexpensiveness and relative ease oflithography. However, the electrical conductivity of un-dopedzinc oxide is not high enough for practical application. Furtherreduction of resistivity of zinc oxide can be achieved either bydoping group III elements such as B, Al, In and Ga to replacezinc atoms [8] or group IV elements, F, to substitute oxygenatoms [9].The structural and morphological properties ofsemiconductor oxides have a substantial effect on their optical,electrical and gas sensing properties. The controlledparticlesize and morphology facilitate the desired characteristics inthe materials. Several simplewet chemical routes like sol–gel,co-precipitation and Pechini route have been adapted to formnanostructures [10].specific acid-alcohol medium to remove the contaminationsand prepare the surface for sol-gel coating. The films weredeposited by the technique detailed in Figure 1.Figure 2 shows the x-ray diffraction spectra of the pureZnO film. It also represents the success of the coating process.Figure 2. X-ray diffraction spectra of the pure ZnO film.The structural and optical properties of the films will beshown in details. b)The authors are indebted to State Planning Foundation(DPT) and Dokuz Eylul University for financial support.*Corresponding author: orkut.sancakoglu@deu.edu.trFigure 1. Flow chart of sol-gel processing for ZnO thin films.In the present study; pure, and Al substituted ZnOR Rthin filmswere deposited on glass substrates by sol-gel method and spincoating technique. Si(100) and glass substrates weremechanically cleaned by using a new designed apparatus in a[1] K.S. Weibenrieder, J. Muller, Thin Solid Films 30 (1997) 30.[2] E. Olsson, L.K.L. Falk, G.L. Dunlop, R. Osterlund, J. Mater. Sci.20 (1985) 4091.[3] C.R. Gorla, N.W. Emanetoglu, S. Liang, W.E. Mayo, Y. Lu, M.Wraback, H. Shen, J. Appl. Phys. 85 (1999) 2595.[4] M.H. Koch, P.Y. Timbrell, R.N. Lamb, Semicond. Sci. Technol.10 (1995) 1523.[5] D.C. Look, D.C. Reynolds, C.W. Litton, R.L. Jones, D.B. Easton,G. Cantwell, Appl. Phys. Lett. 81 (2002) 1830.[6] G. Hass, J. Heaney, A.R. Toft, Appl. Opt. 18 (1975) 1488.[7] R. Barber, G. Pryor, E. Reinheimer, SID Digest Tech. 28 (1997)18.[8] G. Sberveglieri, B. Benussi, G. Coccoli, S. Groppelli, P. Nelli,Thin Solid Films 186 (1990) 349.[9] C. Grivas, S. Mailis, L. Boutsikaris, D.S. Gill, N.A. Vainos, P.J.Chandler, Laser Phys. 8 (1998) 326.[10] C. S. Navale, V. Ravi, I.S. Mulla, Sensors and Actuators B 139(2009) 466–4706th Nanoscience and Nanotechnology Conference, zmir, 2010 702

PPP,PP andPPoster Session, Thursday, June 17Theme F686 - N1123Development of a Humidity Sensor Using PEGR40R-Stearate11121Umut Alper TekinP P, Ramazan slamoluP P, Sevgi Klç ÖzdemirPPSalih OkurPPUEkrem ÖzdemirUP P*1PDepartment of Chemical Engineering, Izmir Institute of Technology, Izmir, 35430 Turkey2PDepartment of Physics, Izmir Institute of Technology, Izmir, 35430 TurkeyAbstract-A humidity sensor was developed using Polyoxyethylene Stearate (PEGR40R-St), which was drop-casted over a quartz crystalmicrobalance (QCM). The response time to different humidity levels were tested and found that the humidity sensor using PEGR40R-St wasresponded to the humidity changes much faster than that for a commercial humidity sensor.Relative humidity plays an important role in human life. Forthe comfort and health of humans, continuation of biologicalprocesses, preservation of goods, and proper operation ofmachines and devices, relative humidity needs to bemaintained at desired humidity level. Although a large numberof research has been conducted using different sensingmaterials with various sensing mechanisms, new materials andmethods are being sought for improving the current humiditysensors.[1-6] Use of a quartz crystal microbalance (QCM) hasreceived a lot attention to detect the various kinds of gaseaousand vapors of organics. The quartz crystal microbalanceconsists of a quartz crystal sandwiched between two metalgold electrodes. Applying an alternating electric potentialacross the crystal induces vibrational motion of the crystal.These vibration motions results in a transverse acoustic shearwave which propagates through the crystal. When a mass isdeposited on the top of the crystal, resonace frequencychanges, which in turn, the change in the resonant frequencycan be related to the mass coated on the electrode surface.Therefore, the use of this technique with a humidity sensingelement is expected promising to detect the humidity atvarious levels Being highly hydrophilic, polyethylene glycolstands as a very good candidate for humidity sensingapplications. In the present study, QCM surface was coatedwith PEGR40R-St with a drop-casting method. Hydrogen atomsof the water molecules are expected to make strong bondswith the ether oxygen atoms in the PEG chains, resulting ofaccumulation of water on the quartz crystal.Figure 1 shows the comparison of the PEG40-St and acommercial humidity sensor to the relative humidity change.As can be seen in the figure, the developed sensor respondedthe relative humidity change much faster than the commercialhumidity sensor.Figure 2 shows the repeatability of the PEGR40R-St to thehumidity change. The relative humidity values seen in thefigure were obtained from the commercial humidity sensor. Ascan be seen from the figure, the PEGR40R-St shows a promisingresult on the determination of the relative humidity. Thehysteresis seen in the figure was related to the data obtainedfrom the unattained equilibrium in the commercial humiditysensor due to its higher response times. The fact that theresponse time for the commercial sensor were found to bemuch higher. Therefore, we suggest that the PEGR40R-St couldbe developed as a humidity sensor with a much shorterresponse time.F, Hz500-50-100-150-200-250dF/Hz Relative Humidity (%)152 160 168 176 184 192 200Time/minFigure 1. Comparison of PEGR40R-St and a commercial humiditysensor to the relative humidity change.f (Hz)1000-100-200-300-400-500PEG Nanofilm20 30 40 50 60 70 80 90Relative Humidity (%)Figure 2. Repeatability of the PEG40-St humidity Sensor to therelative humidity change.1.run2.run3.run*Corresponding author: HTekremozdemir@iyte.edu.trT[1] Y. Zhang, K. Yu, R. Xu, D. Jiang, L. Luo, Z. Zhu, Quartz crystalmicrobalance coated with carbon nanotube films used as humiditysensor, Sens. Actuators A 120 (2005) 142–146.[2] F.P. Delannoy, B. Sorli, A. Boyer, Quartz crystal microbalance(QCM) used as humidity sensor, Sens. Actuators B 84 (2000)285–291.[3] P.R. Story, D.W. Galipeau, R.D. Mileham, A study of low-costsensors for measuring lowrelative humidity, Sens. ActuatorsB24–25(1995) 681–685.[4] P.G. Su, Y.L. Sun, C.C. Lin, Novel low humidity sensor madeofTiO2 nanowires/poly(2-acrylamido-2-methylpropane sulfonate)composite material film combined with quartz crystal microbalance,Talanta 69 (2006) 946–951.I[5] P.G. Su, Y.L. Sun, C.C. Lin, A low humidity sensor made ofquartz crystal microbalance coated with multi-walled carbonnanotubes/Nafion composite material films, Sens. Actuators B 115(2006) 338–343.[6] H.W. Chen, R.J. Wu, K.H. Chan, Y.L. Sun, P.G. Su, Theapplication of CNT/Nafion composite material to low humiditysensing measurement, Sens. Actuators B 104 (2005) 80–84.9080706050403020Relative Humidity (%)6th Nanoscience and Nanotechnology Conference, zmir, 2010 703

Poster Session, Thursday, June 17Theme F686 - N1123Nanodistance Measurement based on CD pick-up Head using Auto Offset Canceller AmplifierPezhman Sasanpour 1 , Mohammad Haghnegahdar 2 , Milad Taherian 2 and Bizhan Rashidian 1,2*1 Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran2 Department of Electrical and Electronics Engineering, Sharif University of Technology, Tehran, IranAbstract— We have designed and implemented system for detection of linear movement detection below 30 m. In linearregime focus error signal can be exploited as a criterion of displacement. In this regard optical pick-up head of CD drives andits quadrant photodiode and laser system can be used as a reliable system. In order to improve operation of system independentof environment light, we have added an additional system consisting amplifier + offset canceller after the module in order toomit background light noise and accordingly enhance the sensitivity and resolution of system.Precise displacement detection is one of important issuesin the nano science and nano technology. There are differentideas for detecting small scale movement with different levelsof accuracy. Among those, interferometery and capacitancesensors can be mentioned [1-3]. Using position sensitivephotodiodes and embedded quadrant photodiode system ofused in pickup head of optical disk drives, has found lots ofpotential applications [4-6]. Considering cost efficiency andeasily access, in addition to accuracy and sensitivity, we haveimplemented and improved a method of movement detectionbased on quadrant photodiode system used on optical pick-uphead of CD drives.The main idea in this method is exactly the same used inthe pickup head of CD/DVD for focus error detection andcorrection. In a usual pickup head light beam emitted from alaser diode after spreading over a grating is divided into 3separated light beam that are directed on the CD surface. Lightbeam reflected from CD surface will then be directed onto thecenter of quadrant photo diode. If position of CD is exactly onfocus plane of laser beam, reflected light beam on the quadphoto diode will have shape of circle. Otherwise reflection ofbeam on the surface of photo diode will not be a completecircle and it will be similar to ellipse. This elliptic figure willproduce different levels of power on each of photo diode.Focus error of CD in this system is defined (A+C)-(B+D).As it has been shown in figure 1, according to direction,focus error signal (FES) could be positive or negative. Byusing the FES in its linear regime, this system can be used as amethod for detection of displacement in linear direction.caADBC(A+C)(B+D)b(A+C)-(B+D)FE>0dADBC(A+C)(B+D)ADBC(A+C)(B+D)(A+C)-(B+D)FE=0(A+C)-(B+D)Figure1: (a) Microscopy image of quadrant photodiode (QPD)moduleused in optical pick-up head. (b) FES for Object in Focus plane.(c) FES for Object below focus plane. (d) FES for Object above focusplane.Figure 2 shows result of QPD signal obtained by movingobject. As it has been depicted linear region in this system is30 m.FE

Poster Session, Thursday, June 17Theme F686 - N1123Free vibration analysis of carbon nanotubes based on nonlocal continuum and gradientelasticity theoriesÖmer Civalek 1 , Bekir Akgöz, Hakan Ersoy1 Akdeniz University, Civil Engineering Department, Division of MechanicsAntalya-TURKIYE, Tel: + 90- 242-310 6319, Fax: + 90-242-310 6306Abstract- Free vibration analysis of single walled carbon nanotubes (CNT) is presented based on the Euler-Bernoulli beamtheory. The size effect is taken into consideration using the Eringen’s non-local elasticity theory. Gradient elasticity theory isalso adopted for modeling. The governing differential equations for CNT vibration is being solved using the differentialquadrature (DQ) method. Numerical results are presented to show the effect of nonlocal behavior on frequencies of CNT.The concept of carbon nanotubes (CNTs) was firstintroduced in 1991 by Iijima [1] in Japan. Reviews on thedevelopment and application of such nano structures havebeen presented [2]. So, the studies of mechanical behaviorsof carbon nanotubes have being attracted more and moreattentions of scientists in the world and also have become anew research area of applied mechanics [3,4]. In thepresent work, the consistent governing equations for thebeam model for CNTs are derived for free vibrationanalysis. Nonlocal beam and couple stress beam theoriesare adopted for modeling. It is known that, the stress stateof any body at a point x is related to strain state at the samepoint x in the classical elasticity. But this theory is notconflict the atomic theory of lattice dynamics andexperimental observation of phonon dispersion. As statedby Eringen [5] the linear theory of nonlocal elasticity leadsto a set of integropartial differential equations for thedisplacements field for homogeneous, isotropic bodies.According to the nonlocal elasticity theory of Eringen’s,the stress at any reference point in the body depends notonly on the strains at this point but also on strains at allpoints of the body. This definition of the Eringen’snonlocal elasticity is based on the atomic theory of latticedynamics and some experimental observations on phonondispersion. In the present manuscript two differentapproaches are used for modeling of carbon nanotubes.Euler-Bernoulli beam-nonlocal model [5]42 W22 WEI A W ( e0a)A 0 (1)42xxEuler-Bernoulli beam-gradient elasticity theory [6] Wx Wx4422EI g EI A 0 (2)447Table 1. First three frequencies (10) of S-S carbon8nanotubes via gradient theory ( L 510m ,312 2 2300kg/ m , m , t 510 10E 10 N /m )Modeg/L (DQ results)0.005 0.015 0.1251 0.10388 0.10669 0.113742 0.41065 0.41103 0.423013 0.91863 0.92007 0.934857Table 2. First three frequencies (10) of S-S carbon8nanotubes via nonlocal theory( L 510m ,312 2 2300kg/ m , m , t 510 10E 10 N /m )Mode (e 0 a) 2 (DQ results)0 2 41 0.10273 0.10158 0.099622 0.40967 0.40863 0.405533 0.9172 0.90864 0.90637[1] S. Iijima, Nature, 354, 56 (2001).[2] D. Qian, G.J. Wagner, W.K. Liu, Appl. Mech. Rev.,55, 495(2002).[3] C.M. Wang, V.B.C. Tan, T.Y. Zhang, J. Sound Vib.294, 1060 (2006).[4] J.N. Reddy, S.D. Pang, J. Appl. Phys. 103, 023511(2008).[5] A.C. Eringen, J. Appl. Phys., 54, 4703 (1983).[6] S.P. Beskou, D. Polyzos, D.E. Beskos, Struct. Eng.Mech. 15, 705(2003).[7] Ö. Civalek, Engineering Structures, 26, 171(2004).The results obtained by differential quadrature (DQ)method [7] using two higher order elasticity theories arelisted in Tables 1-2. In table 1, first three frequencies ofsimple supported (S-S) carbon nanotubes are listed fordifferent gradient parameter. It is shown that, thefrequencies are increased gradually with the increasingvalue of g for all modes. Nonlocal parameter also affectedon frequencies (Table 2). When the nonlocal parametersare increased, the values of frequencies are decreased,significantly. It is possible to say that, the classical beamtheories can not to capture to size effect on mechanicalbehavior of nano sized structures. So, it is suitable to usesome higher order continuum theory such as nonlocalelasticity theory or gradient strain theory to investigate thesize effect on mechanical behaviour of nano/microstructures.6th Nanoscience and Nanotechnology Conference, zmir, 2010 705

Poster Session, Thursday, June 17Theme F686 - N1123Hexagonal Boron Nitride (h-BN)/Polyimide Hybrid FilmsCanan Kızılkaya * , Yusuf Mülazim, M.Vezir Kahraman, Nilhan Kayaman Apohan, Atilla GüngörMarmara University, Department of Chemistry 34722 Istanbul/TurkeyAbstract - Polyimide (PI)/hexagonal boron nitride (h-BN) hybrid materials were prepared from a polyimide precursorand functionalized h-BN with a silane coupling agent by thermal imidization technique. Their surface morphologies,structures and thermal performances were determined. The thermal characteristics of PI/ h-BN hybrid films were foundto be better than the polyimide without h-BN.Aromatic polyimide films have aroused a great deal ofinterest as one of the attractive precursors for producingcarbon and graphite films in recent years. Compared withmost organic polymeric materials, PI exhibits superiorthermal stability and mechanical strength. Therefore, alarge number of PI compositions have been extensivelyinvestigated and most of them are well-suited for use asmatrix resins, adhesives, and coatings for highperformanceapplications in the aerospace, electric, andmicro-electronic industries [1,2].Boron nitride is a ceramic material that is isoelectronicwith carbon. Much like carbon, it exists in multipleallotropic forms. The most common structure of boronnitride is the hexagonal form (h-BN). Hexagonal boronnitride has a graphite-like structure with strong bondingwithin the planar, fused, six-membered rings and weak vander waals bonding in-between layers. Along the c-axis forh-BN, boron and nitrogen atoms are stacked above eachother in alternating layers [ 3]. Because of its properties, ithas found uses in heat conductivity applications, electricalinsulation applications, corrosion resistance applications,lubrication applications, personal care applications, and asa plastic additive [4].In the present study, Polyimide (PI)/hexagonal boronnitride (h-BN) hybrid materials were prepared from apolyamic acid as a polyimide precursor and modified h-BN with a silane coupling agent. Aminoalkoxysilane isone of the most widely adopted silane coupling agents forthe modification of various oxide surfaces. This agent,uses for surface treatment of the filler to improve theaffinity between filler and matrix, thereby significantlyincreasing the thermal properties of the composite. Insilane acts as a bridge to connect the ceramic filler and thepolymer matrix together, because it has two differentchemical structures at the two ends of the molecule. Themorphological, mechanical, and thermal properties of thepolyimide hybrid films with different h-BN content werecharacterized.In conclusion, h-BN containing PI hybrid materials wereprepared. ATR-FTIR study indicates that the inorganicnetwork had formed during imidization. Themorphological study proved that the h-BN particles in thepolyimide matrix is dispersed homogeneously. Thethermal stability of the hybrid materials improved with theincreasing amount of h-BN in the compositions. TheLimiting Oxygen Index results increased from 32.0 to42.6. The h-BN containing hybrid materials show fireresistance than the pure polyimide. The mechanicalproperties show that the polyimides/h-BN hybrid materialsare hard and brittle compared with pure polyimide. Thesolvent and chemical resistance experiments for allmaterials show good performance.Figure 1: SEM Micrographs of PI/h-BN 0.5*Corresponding author: ckizilkaya@gmail.com[1] C.Kızılkaya ,S. Karataş , N. K. Apohan , A. Güngör, Journalof Applied Polymer Science, 115, 3256-3264, (2010).[2] S Karatas, N.K. Apohan, H. Demirer, A. Gungor Polym.Adv. Technol., 18,490–496 (2007)[3] M.T. Huang, H. Ishida, Surf. Interface Anal.,37, 621–627(2005).[4] J. Eichler, C. Lesniak, J European Ceramic Society, 28,1105–1109, ( 2008)..6th Nanoscience and Nanotechnology Conference, zmir, 2010 706

Poster Session, Thursday, June 17Theme F686 - N1123UV CURABLE B/F/Si CONTAINING HYBRID MATERIALSBihter Zeytuncu, 1* M.Vezir Kahraman 2 and Onuralp Yucel 11 Applied Research Center of Materials Science and Production Technology, Istanbul Technical University, Istanbul 34469, Turkey2 Department of Chemistry, Marmara University, Istanbul 34722, TurkeyAbstract — A series of UV-curable boron/flour/silicon containing hybrid coatings prepared by anhydrous sol-gel technique.The chemical structure of hybrid coatings was characterized by FT-IR, RT-IR, 1 H-NMR and 29 Si-CP MAS-NMR techniques.UV curable coatings were applied on polycarbonate substrates. The physical and mechanical properties of UV-cured coatingssuch as pendulum hardness, pencil hardness, contact angle, gel content, MEK rubbing test, tensile test, abrasion resistance,chemical resistance, flame retardant, anti-stain and gloss were examined. Thermal gravimetric analysis (TGA) was made.Results of all analysis conducted on free films and coatings were discussed. The morphology of the hybrid materials wasexamined by SEM. The hybrids were nanocomposites.Sol-gel is widely used method for the preparation oforganic-inorganic hybrid based coating materials [1].Organic-inorganic hybrid materials combine theadvantages of either elasticity, impact resistance of organicpolymers and the high mechanical strength, chemicalresistance, thermal stability, optical qualities of theinorganic materials. The UV curable hybrid coatingsprepared by sol-gel method, have low cost, fast curing, lowviscosity and long time duration [2,3]. The UV curablehybrid coating materials have good adhesive, hardness,good mechanical and chemical properties, which aresensitive to the environment [4].The aim of this study was to prepare and characterizeUV-curable, boron/flour/silicon-containing epoxy acrylatebased organic-inorganic hybrid coatings having abrasionand flame resistant, anti-stain and high gloss properties.Therefore, in the first stage; borate ester was synthesized.Then, hybrid coatings having various concentrations ofboron/flour/silicon were prepared and applied on toPolycarbonate panels and were hardened by UVirradiation. The prepared hybrid coatings werecharacterized by the analysis of various properties such ashardness, abrasion and chemical resistance, flameretardancy, gloss and stress–strain tests. The thermal andmorphological behavior of the hybrid coatings was alsoevaluated.The solvent resistance of coatings was examined byperforming the MEK rubbing test. The solvent resistanceis excellent; exceeding 500 MEK double rubs while pencilhardness is greater than 5H, also indicative of highly crosslinkedfilm. The gel content of polymeric films was foundto be between 98 to 99,7 %. The cross-cut adhesionexperiment showed that 100 % adhesion was reached forall coatings. The chemical resistance of all hybrid coatingswas also investigated by immersing samples in variousreagents (10 % NaOH, 10 % HCl, 10 % H 2 SO 4 , Xylene)for 24 h time period. The general physical appearance ofsamples was perfect and no cracks were observed.Abrasion resistance is often characterized by the Taberabrasermethod measuring the mass decrease caused by themechanical degradation of protective layers that is treatedby abrading grinders. The high boron/flour/silicon contentdemonstrated a better protective performance incomparison to other formulations. The LOI values of thesecoatings increased from 20.4 to 23.1. The thermaloxidative stability of the hybrid coating was investigatedby thermo gravimetric analysis (TGA) technique in airatmosphere. The maximum weight loss temperature wasraised to 425 ◦C. The enhancement of incorporation ofB/F/Si on the thermal stability of epoxyacrylate resins wasthus demonstrated. Therefore it is concluded that thethermal stability of epoxy acrylate resin is enhanced byadding B/F/Si as a flame retardant. The morphology of thefractured surfaces was observed by scanning electronmicroscopy (SEM). Figure 1 presents the SEM image ofthe hybrid coating material. The SEM micrograph showspherical borosilicate particles are distributed within thehybrid system. The approximate particle size is less than100 nm.Figure 1: SEM micrograph of the hybrid coatingIn summary, UV curable boron containing organicinorganichybrid coating was prepared by anhydrous solgeltechnique. The properties of boron-containing hybridcoating materials such as hardness, chemical and abrasionresistance were improved. All hybrid coatings wereobtained crack free and transparent. The solvent andchemical resistance experiments proved that all the hybridmaterials are promising as a candidate for the relatedapplications. On the other hand thermal and flameretardantproperties of hybrid coatings were improved bythe increasing of B/F/Si content. The morphology studiesindicate that, the nanometer-scaled inorganic particlesdisperse homogenously in the hybrid system.*Corresponding author: bihter_zeytuncu@hotmail.com[1] Brinker, C.J.; Scherer, G.W.: "Sol-Gel Science: The Physicsand Chemistry of Sol-Gel Processing"; Academic Press, NewYork, USA, (1990).[2] Holman, R.; Oldring, P.; “UV& EB curing formulation forprinting inks, coatings and paintings”, London (1998).[3] Odian, G.: "Principles of Polymerization"; Fourth Edition;Wiley Interscience, New York, USA, (2004) 96.[4] Cho, J:; Kim, E.; Kim, H.K.; Hong, J.: “An investigation ofthe surface properties and curing behaviour of photocurablecationic films photosensitized by anthracene” Polymer Testing,21 (2002) 781.[5] Kahraman, M.V., Boztoprak,Y., Güngör, A., Apohan, A.K.,Progress in Organic Coatings 66 (2009) 52–58.6th Nanoscience and Nanotechnology Conference, zmir, 2010 707

Poster Session, Thursday, June 17Theme F686 - N1123The Maleimide Modified Epoxy Resins for the Preparation of UV-Curable Hybrid CoatingsZerrin Altınta *, Sevim Karata¸ Nilhan Kayaman-Apohan and Atilla GüngörMarmara University, Department of Chemistry 34722 Istanbul/TurkeyAbstract: In the present study, maleimide-modified epoxide resin containing UV-curable hybrid coating materials were prepared and coatedon polycarbonate substrates in order to improve their surface properties. The coating formulations with different compositions were preparedfrom UV-curable bismaleimide-based epoxy oligomer and sol–gel mixture. The thermal and morphological properties of these coatingsmaterials were investigated by using TGA and SEM techniques. The thermal characteristics of UV curable hybrid films were found to bebetter than without Bismaleimide and sol-gel precursor.Polymers of N-substituted maleimides and theirderivatives having a rigid imide ring in the backbone areknown as high performance polymers. Among them,bismaleimides (BMIs) have attracted much attentionbecause of their high-temperature resistance, high glasstransitiontemperature, excellent chemical and corrosionresistance, and low cost. Bismaleimide resins are anaddition-type polyimide class of macromolecularcompounds produced from bismaleimide monomers andcontain unsaturated end groups. Bismaleimides cappedprepolymers are cured into a highly cross-linked networkby additional reactions without the evolution of volatileby-products. However, due to their high cross-link density,they are often brittle, resulting in low impact and fracturetoughness. Introduction of a long, flexible epoxy chain intothe backbone of bismaleimides is expected to reduce crosslinkdensity and also to improve fracture toughness bydissipating the impact energy along the entire molecularchain [1].Currently, to meet the demand of highly miniaturizedelectronic devices, non-linear optical applications, and thedevelopment of next generation spacecrafts, furtherimprovement in the high performance polymers is needed.Organic–inorganic hybrid coatings offer the opportunity tocombine the desirable properties of organic polymers(elasticity, processability) and inorganic solids (hardness,chemical inertness, and thermal resistance). Close to theexcellent properties of the obtained coatings,photopolymerization process itself affords advantages suchas very high reaction rates at room temperature and spatialcontrol of polymerization. These materials manifest someadvantages such as low optical propagation loss, highchemical, and mechanical stabilities as well as goodcompatibility with different surfaces to be coated [2-3].Hence, in this work, a novel bismaleimide wassynthesized by the reaction of cycloaliphatic diepoxidewith N-(carboxyphenyl) maleimide. Afterwards, thehybrid coatings based on UV-curable bismaleimide cappedcycloaliphatic epoxy oligomer were prepared by sol–gelmethod to investigate the coating properties. The hybridmaterials were characterized by analysis of hardness,gloss, adhesion, and stress–strain. The thermal andmorphological behaviors of the coating were alsoevaluated.Table 1. TGA analysis of coating networksSamples60CF25CF-35BMI25CF-35BMI-5Si25CF-35BMI-10Si25CF-35BMI-15SiFirstweightloss( O C)355360355360355Max.weightloss( O C)445445445445445Finalweightloss( O C)595625630635645In conclusion, a series of UV-curable organic-inorganichybrid coatings were prepared based on sol–gel reactionsfor TEOS and MAPTMS in the presence of epoxymodified Bismaleimide oligomer (BMI) and urethaneacrylate oligomer (UA). Incorporation of bismaleimidemodified epoxy resin into the organic part stronglyincreased the thermal resistance of hybrid samples. Uponincreasing the inorganic content of the coating material,thermal, mechanical, and other properties, such ashardness, gloss, contact angle, and abrasion resistance,were also improved. Corona-treated polycarbonate testpanels facilitated the adhesion of the coating materials. Allhybrid coatings were obtained crack-free and transparent.Furthermore, the increase in the contact angle data of thehybrid coatings demonstrated the formation ofhydrophobic surface.*Corresponding author: altintas_zerrin@hotmail.com[1] F. Yılmaz, L. Cianga, Y. Gu¨ ner, L. Toppare, Y. Yacı,Polymer, 45, 5765, (2004).[2] H. Tang, W. Li, X. Fan, X. Chen, Z. shen, O. Zhou, Polymer,50,1414 (2009).[3] L. A. White, J. W. Weber, L. J. Mathias, Polym. Bulletin , 46,339, (2001).6th Nanoscience and Nanotechnology Conference, zmir, 2010 708

PP m)Poster Session, Thursday, June 17Theme F686 - N1123Characterization and Bactericidal Activity of Melt Blended Polyethylene Nanocomposite FilmContaining Silver Nanoparticles12UMaryam JokarUP P*, Russly Abdul RahmanP1PIslamic Azad University, Damghan Branch, Damghan, Iran , (2) University Putra Malaysia (UPM), Selangor, MalaysiaAbstract- Silver nanoparticles were incorporated into low density polyethylene (LDPE) by melt blending and subsequent hot pressing.Polyethylene glycol was added as compatiblizer agent. Polyethylene-silver nanocomposites were characterized by atomic force microscopy(AFM). Antimicrobial activity of silver nanocomposites against Escherichia coli and Staphylococcus aureus was evaluated. LDPE-silvernanocomposite resulted in increasing lag time and reducing maximum bacterial concentration significantly (p

PPoster Session, Thursday, June 17Theme F686 - N1123Preparation of Nano-Silver Containg Uv-Curable, Abrasion And Flame Resistant NanocompositeCoatings And Investigation of Their Antimicrobial Properties111URaife Deniz TokerUP P* , Nilhan Kayaman ApohanP P, Mehmet Vezir KahramanP1PDepartment of Chemistry, Marmara University, 34722 Goztepe , Istanbul, TurkeyAbstract- Nano-sized silver or silver salts containing nanoparticles, due to their larger surface area compared to microparticles, interact withbacteria and viruses more quickly and give reaction. In this study was to prepare UV-curable abrasion and flame resistant nanocompositecoatings having antimicrobial properties. The hybrid coating formulations with various sol-gel content were applied on to Polycarbonatepanels and were hardened by UV irradiation. In addition, the free films were prepared by pouring the formulations into a Teflon® mold. Toinvestigate the antimicrobial effect of Ag on the coating, nano-sized Ag containing nanocomposite coatings were prepared. The chemical29structure of hybrid coatings was characterized by FT-IR and PPSi -NMR techniques. Thermal and mechanical properties of the coatings weredetermined. Abrasion, hardness, gloss, and adhesion tests of the materials were performed. SEM and AFM investigation were made fordetermining the size of the Ag nanoparticles. The growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia colibacteria on the prepared plates was examined.Polymers containing the phenyl phosphine oxide grouphave been studied extensively for a number of applications inrecent years .Among them , phosphorus containing polymersshowed significant improvement in flame retardancy of thenanocomposite. Phosphine oxide moiety provides a stronginteracting site for imparting miscibility with several system.Connell and co-workers at NASA longly have developed aseries of phenyl phosphine oxide containing polymers fordurability in space environments [1,2].Metal nano materials like cooper, gold , zinc , titanium ,silver, magnesium show good antibacterial properties becauseof their large suface area but silver nanoparticals effecantcyagainst bacteria , viruses , and other eukaryotic microorganizm.[3]Inreen years , the synthesis of organic-inorganic hybridmaterialshave attracted considerablethe desired propertiessuch as; abrasion, impact resistance, thermal stability etc.[4]The sol gel route is the most commonly applied method forthe preparation of organic-inorganic hybrid at nano, micro –scale.In this study in the first stage; bis (4-methylphenyl)methylphosphine oxide was obtained from the reaction ofdichlorophosphine oxide and p-bromofluorobenzene. Then,after a series of progressive reactions, synthesis oftrimethoxysilane end-capped bis[(4- -hydroxyethoxy)phenyl] methyl phosphine oxide urethane was performed.Figure 2. AFM and SEM micrograph of the silver nanoparticles incompositeTo investigate the antimicrobial effect of Ag on the coating,nano-sized Ag containing nanocomposite coatings wereprepared. Thermal and mechanical properties of the coatingswere determined. Abrasion, hardness, gloss, and adhesiontests of the materials were performed. SEM and AFMinvestigation were made for determining the size of the Agnanoparticles. The growth of Gram-positive Staphylococcusaureus and Gram-negative Escherichia coli bacteria on theprepared plates was examined.*Corresponding author: HTdeniztoker84@hotmail.comTFigure 1. bis[(4- -hydroxyethoxy)phenyl] methyl phosphineoxideurethaneAnd by adding spesific ratios of methacryloxypropyltrimethoxysilane (MPTMS), a mixture was prepared wheresol-gel technique was used. In the second stage, urethaneacrylate based oligomers from IPDI, HEMA and PPG400were synthesized and in the third stage, silver nanoparticleswere synthesized by using AgNOR3R.The hybrid coating formulations with various sol-gelcontent were applied on to Polycarbonate panels and werehardened by UV irradiation. In addition, the free films wereprepared by pouring the formulations into a Teflon® mold.[1] Connell JW, Smith Jr JG, Hergenrother PM. Polymer1995;36:5e11;[2] D.J. Riley, A. Gungor, S.A. Srinivasan, M. Sankarapandian, C.Tchatchova, M.W.Muggli, T.C.Ward, J.E. McGrath, Polym. Sci.Eng. 37 (1997) 9.[3] Frattini A, Pellegri N, Nicastro D, de Sanctis O. Mater ChemPhys 2005;94:148.[4] G. Kickelbick, Prog. Polym. Sci. 28 (2003) 114.6th Nanoscience and Nanotechnology Conference, zmir, 2010 710

PP DepartmentPP ChemistryPoster Session, Thursday, June 17Theme F686 - N1123Application of Artificial Neural Networks for Kinetic Investigation of Thermal Degradation Process inNanocomposites111,21UM. KhanmohammadiUP P*, M. Ahmadi AzqandiP P, A. Bagheri GarmarudiPP, N. KhoddamiP21Department, Faculty of Science, IKIU, Qazvin, Iranof Chemistry & Polymer Laboratories, Engineering Research Institute, Tehran, IranAbstract-Polyimide-Silica Hybrid nanocomposite samples were prepared by sol-gel technique. Specimens from the hybrid nanocomposite weresubmitted to thermogravimetric afnalysis and thermal degradation kinetics of hybrid nanocomposite was investigated by thermogravimetricanalysis. The kinetic parameters were obtained via the chemometric data processing of mass loss curves. The non-linear fitting method based onParticle Swarm Optimization (PSO) algorithm was used to fit the mass loss curves at three heating rates and to adjust the non-linear curves. PSOis a population based stochastic optimization technique inspired by social behavior of bird flocking or fish schooling. PSO shares manysimilarities with evolutionary computation techniques such as Genetic Algorithms (GA). The system is initialized with a population of randomsolutions and searches for optima by updating generations. However, unlike GA, PSO has no evolution operators such as crossover andmutation. Moreover, the activation energy, order of reaction and pre-exponential factor of degradation for the nanocomposite containingdifferent amount of inorganic filler was determined by PSO-ANN and then being compared with other methods e.g. pseudo first-order. It wasconcluded that PSO algorithm is stronger and more efficient in comparison with other methods for predication of kinetic parameters.Particle swarm optimization (PSO) is a population basedstochastic optimization technique inspired by social behaviorof bird flocking or fish schooling [1]. PSO shares manysimilarities with evolutionary computation techniques such asGenetic Algorithms (GA). The system is initialized with apopulation of random solutions and searches for optima byupdating generations [2,3]. However, unlike GA, PSO has noevolution operators such as crossover and mutation. In PSO,the potential solutions, called particles, fly through theproblem space by following the current optimum particles.Each particle keeps track of its coordinates in the problemspace which are associated with the best solution (fitness) ithas achieved so far. (The fitness value is also stored.) Thisvalue is called pbest. Another "best" value that is tracked bythe particle swarm optimizer is the best value, obtained so farby any particle in the neighbors of the particle. This location iscalled lbest. When a particle takes all the population as itstopological neighbors, the best value is a global best and iscalled gbest. The particle swarm optimization concept consistsof, at each time step, changing the velocity of (accelerating)each particle toward its pbest and lbest locations (local versionof PSO). Acceleration is weighted by a random term, withseparate random numbers being generated for accelerationtoward pbest and lbest locations.Nanocomposite was prepared by sol-gel technique. In thismethod, tetraethoxysilane (TEOS), 10% wt solution ofpolyamic acid in DMAc and water was used as precursors.Specimens from the Polyimide-Silica Hybrid nanocompositewere submitted to thermogravimetric analysis using theTA2100 (TA Instruments) thermal analyzer. The mass of thesamples ranged from 5 to 10 mg and the analysis was done ina flowing of nitrogen atmosphere (50 ml/min). The experimentwas conducted by heating samples at a constant linear heatingrates of 5 °C/min, 10 °C /min, 20 °C /min up to 700 °C.Theresulting curves are percentages of remaining nano composite.PSO algorithm was used in fitting of non-linear curves thatwere used in order to obtain the kinetic parameters as functionof temperature and different heating rates, which could fit theweight loss curves. In this way, the mathematical modelingwas based on bellow equation: AW .inEa(n 1)w R10.Ea2.3150.4567RT (1 W11n1nf) Wfwhere: w is residual mass fraction (g); Win is initial mass ofspecimen (g); A is pre-exponential factor; Ea is activationenergy (J/mol); n is order of reaction; b is heating rate(°C /min); R is gas constant (8.31451 J/mol.K); T istemperature (K) and wRf Ris final mass fraction (g). The methodis based on linear fitting of model related to the obtainedparameters. PSO has been successfully applied in manyresearch and application areas. It was demonstrated that PSOgives reliable results in kinetic investigation of thertmaldegradation. Another reason of PSO attraction is the fewparameters which are needed to be adjusted. One version, withslight variations, works well in a wide variety of applications.We found PSO algorithm is more efficient than other methodsin the predication of kinetic parameters.*Corresponding author: mrkhanmohammadi@gmail.com[1] Zhang C, Li Y and Shao H, Proceedings of the World Congresson Intelligent Control and Automation (WCICA), 2, 1065-1068,2000.[2] Peng J, Chen Y, and Eberhart R, Proceedings of the FifteenthAnnual Battery Conference on Applications and Advances, 173-177,2000.[3] Chatterjee A and Siarry P, Computers & Operations Research,33, 859-871, 20066th Nanoscience and Nanotechnology Conference, zmir, 2010 711

Poster Session, Thursday, June 17Theme F686 - N1123Fabrication and physical properties of EPDM/NBR/organoclay NanocompositesM. Ersali 1 *, N. Fazeli 1 , Gh. Naderi 21 Islamic Azad University, Science and Research Branch, Polymer Engineering Group,P.O.Box 14155/4933,Tehran, Iran2 Iran Polymer and Petrochemical Institute, Polymer Processing Society , P.O.Box 14965/115, Tehran, IranAbstract Different blends based on 70 %(wt) ethylene propylene diene monomer rubber (EPDM) and 30 %(wt) acrylonitrile butadiene rubber(NBR) with various amount of organoclay (OC) were prepared. The effect of organoclay on structures of the samples was investigated by X- rayDiffraction (XRD). The obtained results show an intercalated structure. The effect of organoclay on cure characteristics and physical propertiesof the samples was investigated. It has been observed that incorporation of organoclay into polymeric matrix increases the viscosity and crosslinkdensity and shortens the scorch time and optimum cure time of the compounds. Significant improvement in abrasion resistance and compressionset of EPDM/NBR nanocomposites were observed. The rebound resilience of nanocomposites decreased with increasing of the organoclaycontent.It has been long years that elastomeric blends have attractedthe attentions. Some of their advantages are ease of processability, better properties and manufacturing more inexpensiveproduct. EPDM/NBR blends have both properties of eachrubber such as oil and hydrocarbon resistance, ozone, heat andgood process ability since it contains two types of polar andnon polar rubbers [1]. nanoclay addition to polymer blendscauses more improvements in their properties. This group ofmaterials has attracted the attentions because of improvingmechanical and thermal properties[2], diffusivity [3] andflammability resistance [4]. Since EPDM basednanocomposites have good oxygen, heat and ozone resistanceand can be applied in different applications such as profiles,cable insulation, jackets, weather and heat resistantproducts[5]. On the other hand, NBR based nanocompositeshave attracted attentions because of NBR excellent oilresistance, good tensile strength and abrasion resistance andalso its applications such as static gaskets, oring, seal forvalves, shafts for crankshafts, high pressure resistant hoses forhydraulic applications[6].The aim of this article was developing and makingEPDM/NBR nano-composites through a melt compoundingprocess by using organo-clay in the above blend and alsostudying the effect of organo-clay on curing characteristics,morphology and properties of the blend.Figure 1 shows XRD patterns for pure organoclay(OC) andnanocomposites.Figure 1- X-ray diffraction patterns of (a) OC 20A, (b) EPDM-NBR-7%OC,(c) EPDM-NBR-5%OC, (d) EPDM-NBR-3%OC.As it can be seen, the characteristic diffraction peak of cloisite20A is located at 2 =3.4 corresponding to a basal interlayerspacing of 25.98 A. For nanocomposite samples the mentionedpeak has been shifted to lower angle at 2 =2.59 (equals tod 001 =34.09 A). The increase in basal spacing of layers denotesthe introduction of rubber chains inside the layers of nanoclayand presentation of an intercalated structure innanocomposites. Obviously, the increase in the amount oforganoclay has not changed the location of the peak (andconsequently the space between the layers) but caused theintensity of peak to be increased.As it can be seen, the optimum curing time and scorch timedecreased when organoclay was increased. In fact, the existingammonium in organoclay facilitated the vulcanization anddecrease curing time[7]. The maximum and minimum torqueincreased with organoclay.Rebound resilience decreased when organoclay contentincreased. Abrasion resistance improved by addition oforganoclay. This improvement was observed in allnanocomposites. When the content of organoclay increased,higher abrasion resistance was obtained and Relative volumeloss decreased. Improvement in abrasion resistance isprobably due to improvement in polymer chains crosslinkdensity and decrement of the free chains. Compression setincreases with organoclay, this means that permanent setdecreased.In this research work, different samples of EPDM/NBRnanocomposites were prepared. XRD results showed that in allnanocomposites, rubber chains have been introduced into theorgano-clay layers and extended the spaces, so thatintercalated structures have been obtained. Study of curingcharacteristics of the samples showed that the addition oforganoclays to the blends reduces optimum curing and scorchtime. This is due to the formation of complexes betweenquaternary amine groups in organoclay and zinc salt or sulfurwhich accelerates the curing process. Moreover, it has beenconcluded that the more the amount of nano-clays, the higherthe crosslink density. Finally, physical properties of thenanocomposites were measured. It has been shown that theaddition of organoclay to the blends increaseds abrasionresistance and compression set of the samples and decreasestheir Rebound resilience. This is due to the intercalation ofchains inside the layers in addition to the higher crosslinkdensity of nanocomposites.*Corresponding author: Mohammad.Ersali@gmail.com[1] Mitchell. J. M, J Elast and Plast., 9, 329-340 (1977)[2] A. Usuki, Y. Kojima, M. Kawasumi, A. Okada, A. Fukushima, T.Kurauchi, O. Kamigaito, J Mater Res. 8 (1993) 1179.[3] G. Choudalakis and A.D. Gotsis, Eur. Polym. J. 45 (2009) 967-984.[4] A.B. Morgan, Polym. Adv. Technol. 17 (2006) 206-217.[5] Y.W. Chang, Yang, Y., Ryu, S. and Nah, C. Polymer International, 51(4)(2002) 319 324.[6] W. G. Hwang, K. H. Wei, C.M. Wu, Polymer 45 (2004) 5729 5734.[7] M. Arroyo, M.A. Lopez-Manchado, B. Herrero, Polymer. 44 (2003) 2447.6th Nanoscience and Nanotechnology Conference, zmir, 2010 712

Poster Session, Thursday, June 17Theme F686 - N1123Gradient Modeling of Strengthening and Softening in Inelastic Nanocrytalline Materials withReference to the Triple Junction and Grain BoundariesBabur Deliktas 1 * and George Z. Voyiadjis 21 Department of Civil Engineering, Mustafa Kemal University, Hatay, Iskenderun 31200, Turkey1 Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, USAAbstract-The work presented here provides a generalized structure for modeling polycrystals from micro to nano size range. The polycrystalstructure is defined in terms of the grain core, the grain boundary and the triple junction regions with their corresponding volume fractions.Depending on the size of the crystal from micro to nano different types of analyses are used for the respective different regions of the polycrystal.The analyses encompass local and nonlocal continuum or crystal plasticity. Depending on the physics of the region dislocation based inelasticdeformation and/or slip/separation is used to characterize the behavior of the material. The analyses incorporate interfacial energy with grainboundary sliding and grain boundary separation. Certain state variables are appropriately decomposed to energetic and dissipative components toaccurately describe the size effects. Additional entropy production is introduced due to the internal subsurface and contacting surface.This new formulation does not only provide the internal interface energies but also introduces two additional internal state variables forthe internal surfaces (contact surfaces). One of these new state variables measures tangential sliding between the grain boundaries and the othermeasures the respective separation. A multilevel Mori-Tanaka averaging scheme is introduced in order to obtain the effective properties of theheterogeneous crystalline structure and to predict the inelastic response of a nanocrystalline material. The inverse Hall-Petch effect is alsodemonstrated. The formulation presented here is more general and it is not limited to either polycrystalline or nanocrystalline structured materialsHowever, for more elaborate solution of problems a finite element approach needs to be developed.The material modeling of nanocrystallines has beenemphasized recently by Gleiter (2000). He pointed out theoutstanding possibilities of the so called, microcrystallinematerials that are usually defined as the single or multi phasepolycrystalline metallic materials with grain sizes typicallyless than 100nm. It has been well recognized thatnanaocrystalline materials may exhibit increased strength andhardening, improved toughness, reduced elastic modulus andductility, enhanced diffusivity, higher specific heat, enhancedthermal expansion coefficient, and superior soft magneticproperties in comparison with conventional polycrystallinematerials (Ashby, 1970; Hall, 1951; Petch, 1953).The plastic deformation mechanisms of nanocrystallinestructure are much more complicated than those of thepolycrystalline material. Few of the controversial issues of theplastic behavior of the nano/polycrystalline materials are inregard to the work hardening and strengthening in suchmaterials. For example, experimental studies reported by Qingand Xingming (2006) showed that when the grain size ofnanocrystalline is greater than a critical value, the Hall-Petch(H-P) relation is satisfied for a wide range of nanocrystallinematerials. However, as the grain size of metals decreasebeyond the critical value, the H-P slope becomes negative.The so called inverse softening effect of the H-P relation isobserved for some nanocrystalline materials (Nieh and Wang,2005; Tjong and Chen, 2004; Zhao, et al., 2003). This inverseHall–Petch phenomenon was first explained in terms ofporosity in nanocrystalline materials. This explanation wasproved incorrect when high quality NC materials wereproduced and, they still exhibited a negative Hall–Petch slope(Khan, et al., 2000). To understand the inverse Hall–Petchphenomenon, numerous studies were conducted. Many modelsare based on the rule of mixtures and on the competition oftwo or more mechanisms (Carsley, et al., 1995). Meyers et al.(2006) and Qiang and Xingming (2006) presented veryapproximate models based on the rule of mixtures as incomposite materials in order to show the inverse softeningeffect of the H-P relation.The computational methods available for simulatingnanocrystalline materials are clearly imperfect but they maybe capable of providing important insights into the behaviorof nanoscale materials. Therefore, in this paper, thetheoretical bases for modeling the inelastic behavior of thematerial is based on the thermodynamic framework andconstitutive laws given in the works of Voyiadjis andDeliktas (Voyiadjis and Deliktas, 2009a; b) where thetheoretical concepts have been elaborated in detail. Thepresent treatment is different than that previously proposedby Voyiadjis and Deliktas (Voyiadjis and Deliktas, 2009a; b)in that this new formulation does not only provide theinternal interface energies but also introduces two additionalinternal state variables for the internal surfaces (contactsurfaces). By using these internal state variables togetherwith displacement and temperature, the constitutive model isformulated as usual by state laws utilizing free energies andcomplimentary laws based on the dissipation potentials. Oneof these new state variables measures tangential slidingbetween the grain boundaries and the other measures therespective separation. A homogenization technique isdeveloped to describe the local stress and strain in thematerial. The material is characterized as a composite withthree phases: the grain core, the grain boundaries and triplejunctions. The model presented for a general case is thenapplied to pure copper under uniaxial tensile load. The resultsare compared with the experimental data.The geometrical representation of the RVE proposed bydifferent authors (Mecking and Kocks, 1981; Pipard, et al.,2009) can be conceptually described by three regions such asthe grain core, the grain boundary, and triple junctions withtheir corresponding internal interfaces, respectively. In thiswork the simplified nanocrystalline structure shown in Figure1b is represented as a 2D triangle representative volumeelement (RVE) of a composite material with three phases;grain core, grain-boundary, and triple junction (see Figure 1).6th Nanoscience and Nanotechnology Conference, zmir, 2010 713

PPPPPPPoster Session, Thursday, June 17Theme F686 - N1123Evaluation of Permeability of Masterbatch-Based PA6/nanoclay Composite Films11UMohammad FasihiUP0F P*and Mohammad Reza Abolghasemi0TPTechnology of Polymer Research Group, Iranian Academic Center for Education, Culture and Research (ACECR), Branch of AmirkabirUniversity of Technology, Tehran, Iran,Abstract-This study focuses on the effect of the nanoclay masterbatch on the extent of exfoliation and barrier properties of PA6/organoclaynanocomposite films. Gas permeability through nanocomposite films decreased significantly just by loading a small amount of nanoclay.Theoretical models fit the experimental data appropriately.Over the last decades, a great deal of researches have beendevoted to the different fields of polymer-layered silicatenanocomposites which have shown promising improvements[1-3]in properties, at low filler volume fraction.POne of the great attractive applications of polymer-layeredsilicate nanocomposites is the field of packaging. Thereduction of oxygen permeability is of crucial importancesince oxygen as an atmospheric component which promotesthe spoilage mechanism of food. Incorporating layered silicateinto the polymeric matrix, ordinarily, improves gas barrierproperties of the polymer by reducing the volume available forgas transport as well as making a more tortuous path for[4-6]penetrant molecules. PThe current study examined the effect of nanoclaydispersion by using particulate nanoclay and nanoclaymasterbatch, on morphology and oxygen permeability ofpolyamide-6 /layered silicate nanocomposite films bearingdifferent concentrations of nanoclay, as a potential candidatefor good packaging applications. Furthermore, thepermeability data has also been compared to the theoreticalmodels.XRD results showed flat diffraction profile and the absenceof any basal reflections indicated that the ordered layers ofnanoclays in the nanocomposites have been disrupted.With regards to the crystalline structure, all films exhibited aostrong reflection at 21.5P distinguished t crystal form which showed that the loading of nanoclay didnot alter crystal structures in thin films.Although XRD scan results suggested only a low degree ofintercalation, the morphology observed with TEM indicatedthe presence of both intercalated and exfoliated structures. Thegeneral impression obtained from TEM was that the use ofmasterbatch builds up a higher degree of exfoliation thatconfirms the better properties of masterbatch-basednanocomposites. The maximum aspect ratio of the layers asdeduced from the TEM micrographs was about 210 in allsamples.Oxygen permeability was reduced by a factor of 4 over thepure polyamide by incorporation of 3 wt% nanoclay. As thenanoclay loading was increased to 7 wt%, only a slightimprovement in permeation resistance was observed.Several studies on modeling the barrier properties ofpolymer nanocomposite have been performed based on the[7],tortuous pathway concept by Cussler.P Fredrickson and[8,9]Gusev et al.P Bharadwaj improved Nielsen’s model by[6]simply introducing a new order parameter. P Another model[10]called NG model was developed by Ghasemi et al.PPThetheoretical models fit the experimental data properly.In summery, we showed improvements in oxygen barrierand mechanical properties by increasing the silicate content. Inparticular, nanocomposite films based on masterbatchexhibited the best performances. XRD scans and TEMmicrographs collectively demonstrated the good dispersionand orientation of silicate platelets inside the matrix, as well asthe possible presence of polymer-clay interactions. Thetheoretical model fitted the experimental data very well.Figure 1. TEM images of specimens (a) particulate nanoclay-basedfilms (b), (c) masterbatched-based films*Corresponding author:mohammadreza.abolghasemi@gmail.com[1] Ke, Y., Long, C., Qi, Z, J. Appl. Polym. Sci. 1999, 71, 1139-1146.[2] Becker, O., Cheng, Y., Varley, J. R., Simon, G. P,Macromolecules 2003, 36, 1616-1625.[3] Alexandre, M., Dubois, P. Mater. Sci. Eng. 2000, 28, 1-63.[4] H. Yamamoto, Y. Mi, S.A. Stern, J. Polym. Sci., Part B:Polym. Phys. 1990, 28, 2291-2304.[5] Fornes, T. D., Paul, D. R., Polymer 2003, 44, 4993-5013.[6] Liu, L., Qi, Z., Zhu, X. J. Appl. Polym. Sci. 1999, 71, 1133-1138.[7] Yang, W.H. Smyrl, E.L. Cussler, J. Membr. Sci. 2004, 231,1-12.[8] G. H. Fredrickson, J. Bicerano, J. Chem. Phys. 1999, 110,2181-2188.[9] A.Gusev, H.R. Lusti, Adv. Mat., 2001, 13, 1641-1643.[10] E. Ghasemi, A. H. Navarchian, “Modeling the Effects ofSilicate Layer Orientation on Barrier Properties of Polymer/ClayNanocomposites”, proceeding of 9th International Seminar onPolymer Science and Technology (3TISPST3T 2009), Tehran, Iran.6th Nanoscience and Nanotechnology Conference, zmir, 2010 714

PPPPoster Session, Thursday, June 17Theme F686 - N1123Electrical Behaviours of Flame Retardant Huntite and Hydromagnesite Reinforced PolymerComposites for Cable Applications1,21,2UHüsnügül Ylmaz AtayUPP*, Erdal ÇelikPPDepartment of Metallurgical and Materials Engineering, Dokuz Eylul University, 35160 Izmir, TurkeyPCenter for Fabrication and Applications of Electronic Materials, Dokuz Eylul University, 35160 Izmir, Turkey21Abstract - As huntite and hydromagnesite mineral undergoes an endothermic decomposition with water and carbon dioxide release, it hasbeen studied as flame retardant filler for polymers in potential electrical applications. In this study, the electrical properties of flame retardanthuntite and hydromagnesite mineral reinforced polymeric composites were investigated. Phase and microstructural analysis of huntite andhydromagnesite powders were undertaken using XRD and SEM-EDS preceeding the fabrication of the composite materials. The mineralswith different particle size and content were subsequently added to ethylene vinyl acetate copolymer to produce composite materials. Afterthe fabrication of composites, their electrical properties such as conductivity, dielectric constant, specific resistance, impedance, capacitanceand dissipation factor were investigated as a function of particle size and loading level. It was concluded that conductivity increased withdecreasing particle size to nanoscale.Due to their low weight and ease of processing, the useof polymers is arised by their remarkable combination ofproperties in our daily life. Even though to be used in somany areas and show great facilities, polymers are alsoknown for their relatively high flammability. Beside, mostof them are accompanied by corrosive or toxic gases andsmoke which are produced while the combustion iscontinuing [1]. So that, it is rising as an important issue toextent polymers’ usage for obtaining their fire resistingproperty for the applications [2]. Hence some ancillarymaterials are used to make polimers fire resistant. They areadded into the compound whose application propertiesbecame closely related to the physical properties of theadditive itself. Huntite/hydromagnesite is a halojen freeinorganic mineral that can be used as a flame retardantadditive to the flammable polymeric materials. Itseffectiveness comes from the fact that it decomposesendothermically and consumes a large amount of heat,while also liberating water, which can dilute any volatilesand thus decrease the possibility of fire (Equations 1 and2) [3]. Decomposition begins at somewhat highertemperature, near 400°C, and consumes 1244 J/g [4].MgR4R(COR3R)R3R(OH)R2R.3HR2RO 4MgO + 3COR2R+4HR2RO (1)MgR3RCa(COR3R)R4R 3MgO + CaO + 4COR2R (2)In the present work, a series of composites wereprepared using an ethlylene vinyl acetate copolymermatrix and different concentrations ofhuntite/hydromagnesite mineral to ethylene vinyl acetatecopolymer to evaluate the electrical properties. In thissense, properties of complex conductivity, impedance,capacitance, dissipatation factor, dielectric constant andspecific resistance measurements were performed tohuntite hydromagnesite reinforced plasticcompositesamples.. Only conductivity test results is shown here (Figure 1).The result shows that decreasing the size to nano scalemakes the polymer composite more conductive. On theother hand, in spite of the fact that it seems to be changingthe conductivity related with the loading level, it can beexpressed that increasing filler amaount increased thepolymer’s conductivity. The increase in conductivity withthe increasing of the filler amount mainly stems from theestablishing of conducting networks in the polymer matrix[5]. In addition, we have a good aggrement with theliterature [6] that finer particles may support thismechanism as the ionic conductivity of the polymercomposite increased. In toher words, for both size effectand the loading level effect tests, it can be seen thatfrequency assists helps to increase conductivity of thecomposites. The other electrical properties such asdielectric constant, specific resistance, impedance,capacitance and dissipation factor were improved withchanging particle size and content.Complex Conductivity (S/cm)(a)0,350,300,250,200,150,100,050,00-0,0510 μm1 μm0.1 μm0,0 2,0x10 6 4,0x10 6 6,0x10 6 8,0x10 6 1,0x10 7Frequency (Hz)Complex Conductivity (S/cm)0,320,300,280,260,240,220,200,180,160,140,120,100,080,060,040,020,00-0,0249%55%61%64%67%69%0,0 2,0x10 6 4,0x10 6 6,0x10 6 8,0x10 6 1,0x10 7(b)Frequency (Hz)Figure 1. Conductivity of huntite/hydromagnesite reinforcedplastic composite materials as a function of frequency accordingto (a) particle sizes and (b) contents of reinforced powderThe authors would like to acknowledge to Likya MinelcoMadencilik Sti. and Minelco Specialities Limited.*Corresponding Author: HThgulyilmaz@gmail.comTH[1] O’Driscoll, Mike. (1994). Industrial Minerals December.[2] F. Laoutid, L. Bonnaud, M. Alexandre, J.-M. Lopez-Cuesta,Ph. Dubois (2008). Materials Science and Engineering R[3] Ahmed Basfar, and H. J. (2009) Journal of Fire Sciences.[4] Haurie, L., at al. (2006). Polymer Degr. And Stability 91 (5)989-994.[5] Guohua Chen at al (2007).Mat. Chem. and Phy. 104 240–243[6] Zhaoyin Wena at al. (2003) Solid State Ionics 160 141– 1486th Nanoscience and Nanotechnology Conference, zmir, 2010 715

Poster Session, Thursday, June 17Theme F686 - N1123PEG assisted synthesis of Mn 3 O 4 Nanoparticles: Structural and Magnetic StudyA.Baykal 1 *, M.Toma 1 , Z.Durmus 1 , H.Kavas 2 and M.S.Toprak 31 Department of Chemistry and 2 Physics, Fatih University, B. Cekmece, 34500 Istanbul, Turkey3 Functional Materials Division, Royal Institute of Technology - KTH, SE16440 Stockholm, SwedenAbstract- In this work, Mn 3 O 4 nanoparticles have been successfully synthesized by polyethylene glycol (PEG)-assistedhydrothermal route for the first time. X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), transmissionelectron microscopy (TEM) and vibrating scanning magnetometry (VSM), electron spin resonance (ESR) were used for thestructural, morphological and magnetic investigation of the products, respectively.Among magnetic materials, manganese oxide(Mn 3 O 4 ) as a magnetic transition metal oxide is animportant material. Nanometer-sized manganese oxide(Mn 3 O 4 ), with notable increased surface area and greatlyreduced size, is expected to display better performance inthese aspects of application [1]. In this study the crystallitesize from X-ray diffraction pattern and particle size fromtransmisson electron micrographs were calculated as 23±1nm and 24.5±1.5 nm respectively. Transmisson electronmicroscopy (TEM) analysis also showed thepolycrystalline nature of the product. Magneticcharacteristics of Mn 3 O 4 NP were evaluated by electronspin resonance (ESR) measurements in the temperaturerange of 24 °K – 294 °K and the Curie temperature wasobserved as 43 K. Also the magnetic phases occured innano sized Mn 3 O 4 are detected below Tc by this method.The room temperature paramagnetic characteristic areverified by vibrating scanning magnetometry (VSM).1st Derivatives of EPR Absorbtion Peaks0 1000 2000 3000 4000 5000 6000 7000Applied Magnetic Field (Oe)294 K266 K230 K202 K175 K153 K122 K104 K74 K50 KFigure 2. First derivatives of EPR absorption peaks vs appliedmagnetic field at various temperatures above 50 °K.Intensity (a.u)..............................................112expfitD= 23 nm= 1 nm.......................................................................200................103211....................................................004...........................................................22020 30 40 50 602(Degree).....................................................................204......................................................015..................................................................312........................................................................303.......................................................321................................................................224........................................................................116...........................................................400Figure 1. XRD pattern and line profile fitting of Mn 3 O 4 NP’s viaPEG assisted hydrothermal route.ESR analysis showed antiferromagnetic interactingspins at >50 °K and ferromagnetic interacting alignment

P indicatingP forforPP curvesP existingP atP andPPoster Session, Thursday, June 17Theme F686 - N11231Polyol Synthesis of PVP–MnR3ROR4R Nanocomposite1123Z. DurmusP P, UA. BaykalUP P*, H. Kavas,P P, M.S. ToprakP2PDepartment of Chemistry,P PDepartment of Physics, Fatih University, B.Çekmece, 34500 Istanbul, TurkeyP3PFunctional Materials Division, Royal Institute of Technology - KTH, SE-16440 Stockholm, SwedenAbsract- We report on the synthesis of polyvinyl pyrrolidone (PVP)-MnR3ROR4R nanocomposites via a polyol route. The capping of PVP aroundMnR3ROR4R nanoparticles was confirmed by FTIR spectroscopy, the interaction being via bridging oxygens of the carbonyl (C=O) and thenanoparticle surface. Tc and TRBR PVP-MnR3ROR4 Rnanocomposite were observed at 42 K and 28.5 K respectively.MnR3ROR4R is known to crystallize in the normal spinelstructure with a tetragonal distortion elongated along the c-axis. Manganese ions are placed in the tetrahedral A-sites2+3+(MnPP) and octahedral B-sites (MnPP) [1-4]. The FTIRspectra of PVP and PVP-MnR3ROR4R nanocomposite areshown in Fig. 1. It is worth noting that the C=O stretch-1band is present at 1660 cmP pure PVP and afterformation of PVP-MnR3ROR4R nanocomposite this stretching-1red shifts of ~20 cmPa strong interactionbetween MnR3ROR4R nanoparticles and C=O of PVP hostmatrix.Magnetization (emu/g)0,30,20,1FC (100 Oe)ZFC-dM/dT-dM/dTFC0 20 40 60 80ZFC% Transmittance (a.u.)PVPPVP/Mn 3O 4295829234000 3500 3000 2500 2000 1500 1000 500Wavenumber (cm -1 )Figure 1. FTIRnanocomposite.28822855In plane C–H bendingof different –CH 21660spectra of (a) pure PVP (b) PVP-MnR3ROR4RCrystalline phase was identified as MnR3ROR4R and thecrystallite size was obtained as 6±1 nm from X-ray lineprofile fitting. As compared to the average particle size of6.1±0.1 nm obtained from TEM analysis in Fig. 2, whichreveal nearly single crystalline nature of thesenanoparticles.Relative Frequency3530252015c)1642–C–N stretching–C–N stretchingD=6,1 nm=0,10,00 20 40 60 800 20 40 60 80Temperature, (K)Figure 3. Zero-field-cooled (ZFC) and field-cooled (FC)magnetization curves PVP-MnR3ROR4R nanocomposite.The sample has hystheresis with small coercivity andremanenet magnetization at 40 K, resembling thesuperparamagnetic state. a.c. conductivity measurementson PVP-MnR3ROR4 Rnanocomposite revealed a conductivity in-7 -1the order of 10PP S·cmP lower frequencies (Fig. 3). Theconductivity changes with respect to frequency can be+2explained by electronic exchange occuring between MnP+3’and MnP in sublattice of spinel lattice. The P’’of PVP-MnR3ROR4 Ras a function of frequency arefound to be slightly temperature dependent.* Corresponding author: hbaykal@fatih.edu.tr[1] Z. Durmu., A. Baykal, H. Kavas, M. Direkçi, M.S. Toprak,Polyhedron, 28, 2119-2122 (2009).[2] T. Ozkaya, A. Baykal, H. Kavas, Y. Koseoglu, M.S. Toprak,Physica B 403 (2008) 3760–3764.[3] A. Baykal, Y. Koseoglu, M. Senel, Cent. Eur. J. Chem. 5(1)2007 169–176.[4] Z. Durmu, H. Kavas, A. Baykal, M.S. Toprak, Cent. Eur. J.Chem. 7(3) 2009 555-559.10505,0 5,5 6,0 6,5 7,0 7,5Diameter (nm)Figure 2. TEM micrograph of PVP-MnR3ROR4R and calculatedhistogram from several TEM images with a log-normal fitting.6th Nanoscience and Nanotechnology Conference, zmir, 2010 717

PPPR2R PIN(80)PPgPP OzlemPPoster Session, Thursday, June 17Theme F686 - N1123Synthesis and Characterization of Polyindole/TioR2R Nanocomposites111Bekir SahanP ErolPUH. Ibrahim UnalUP P*1PSmart Materials Research Lab. Department of Chemistry, University of Gazi, Ankara, TurkeyAbstract-Polyindole/TiOR2R nanocomposites are synthesized by in-situ polymerization using FeClR3R as an oxidizing agent in the presence ofsodium dodecybenzenesulfonate (Na-DBS) surfactant at two compositions with high yields. Characterizations of the polyindole (PIN) andpolyindole/TiOR2R nanocomposites were carried out by using various techniques namely: elemental analysis, FTIR, particle size, conductivity,magnetic susceptibility, density, TGA, XRD, SEM and TEM measurements.Polymer and metal oxides have been studied for manyyears for their independent electrical, optical, and mechanicalproperties. The combination of semiconducting andmechanical properties of conjugated polymers with theproperties of metals or semiconducting inorganic particleshas brought new prospects for wide application areas [1].One of the widely studied metal oxide is TiO R2R because of itsunique optical, electrical, chemical, high photocatalyticactivity, photoelectric conversion efficiency, electrokinetic,colloidal and electrorheological properties [2-3]. Among theclasses of inherently conductive polymers, PIN is muchinterested one due to its several advantages such as fairlygood thermal stability, electrochromic properties, high redoxactivity and stability [4]. Therefore, PIN has received asignificant amount of attention in the past several years andmay be a good candidate for applications in various areas,such as electronics, electrocatalysis, anode materials inbatteries, anticorrosion coatings and electrorheology. PINand its derivatives have been synthesized either by anTable 1. Some physical characteristics of the materials.CodingConductivity-(S cmP1 4)x10PMagneticsusceptibility(XRgR,cm1 7P)x10P-Density-3(g cmP P)PIN 1.03 21.27 0.94 21*PS-PIN 1.40 11.55 0.95 20TiOR2R(10)/PIN(90) 0.12 32.88 0.98 18TiOR2R(20)/PIN(80) 0.11 87.701.03 19*PS-TiOR2R(10)/PIN(90) 7.74 8.39 1.02 19*PS-TiO (20)/ 4.32 9.661.06 18*Where S denotes the presence of surfactant.Positive magnetic susceptibility values were indicatedthat conducting mechanism in the PIN and PIN/TiOR2Rnanocomposites were polaron in nature. The presence ofNa-DBS surfactant and increased percentage of TiOR2R wereobserved to slightly enhance the density of the materialssynthesized. It was observed that, the thermal stabilities ofthe PIN/TiOR2R nanocomposites were higher than PIN asexpected, which is an important parameter for industrialapplications such as vibration damping inelectrorheological fluids. Expected distinctive XRDpatterns of PIN/TiOR2R nanocomposites were identical tothose of TiOR2R nanoparticles reported in the literature, withan implication of deposited PIN on the surface of TiOR2Rparticles and had no effect on the degree of thecrystallinity of TiOR2R. SEM and TEM results revealed themorphologies of the materials and indicated thehomogeneous distribution of the components in the PINand PIN/TiOR2R nanocomposites. In conclusion, PIN/TiOR2Rnanocomposites were successfully synthesized, suitable forfurther zeta-potential measurements, electrorheologicalParticlesizes(μm)electrochemical, a chemical oxidative, emulsion, orinterfacial polymerization [5-6].In this study PIN/TiOR2R nanocomposites were synthesizedespecially to investigate their colloidal properties andelectrorheological activities in order to use as vibrationdamping material in shock absorbers in future studies. Forthis purpose, first PIN, then four types of PIN/TiOR2Rnanocomposites were synthesized without and with thepresence of 7%Na-DBS, and all the codings are given inTable 1. Elemental analysis results indicated that thenanocomposites were successfully prepared with desiredamounts of surfactant and composition. FTIR results showedthe expected distinctive absorptions belonging to both PIN,TiOR2R proofed the formation of both homopolymer andPIN/TiOR2R nanocomposites. Conductivities of the materialswere observed to increase with the inclusion of surfactantonto the PIN and PIN/TiOR2R nanocomposite surfaces(Table 1).(solidification of dispersions under the influence ofexternal electric field in milliseconds, repeatedly andreversibly) studies, creep-recovery tests and vibrationdamping experiments, which will be the second part of thisstudy.* HTCorrespondingTH author: hiunal@gazi.edu.tr[1] Q.-T. Vu, M. Pavlik, N. Hebestreit, J. Pfleger, U. Rammelt,W. Plieth, Electrochim. Acta 51, 1117 (2005).[2] Q.-T. Vu, M. Pavlik, N. Hebestreit, U. Rammelt, React.Funct. Polym. 65, 69 (2005).[3] J.J.M. Halls, K. Pichler, R.H. Friend, S.C. Moratti, A.B.Holmes, Appl. Phys. Lett. 68, 3120 (1996).[4] G. Nie, X. Han, J. Hou, and S. Zhang, J. Electroanal. Chem.604, 125 (2007).[5] Z. Cai, M. Geng, and Z. Tang, J. Mater. Sci. 39, 4001 (2004).[6] H. Talbi, B. Humbert, and D. Billaud, Synth. Met. 84, 875(1997).6th Nanoscience and Nanotechnology Conference, zmir, 2010 718

PPPoster Session, Thursday, June 17Theme F686 - N1123Synthesis and Properties of Photosensitive Polyimide–Titania Nanocomposite Thin Films121Süleyman KöytepeP P, H. brahim AdgüzelP P, UTurgay SeçkinUP P*1PDepartment of Chemistry, University of Inonu, Malatya, TR Türkiye 442802PDepartment of TPhysicsT, University of Inonu, Malatya, TR Türkiye 44280Abstract-In this study, synthesis, morphology, and properties of high refractive index photosensitive polyimide–titania hybrid materials arereported. Soluble polyimides with acyridine orange groups (PI 1-5) was first synthesized from 3,6-bis(dimethylamino)acridine and five variousdianhydride. The titania domain size in the hybrid materials analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD)was around 40–100 nm. The prepared optically transparent films had tunable refractive index (1.583

Poster Session, Thursday, June 17Theme F686 - N1123Synthesis of Noncarbon Nanotubes/ conductive Polymer nanocomposite in free solvent mediaG.R. Kiani 1* and A. Rostami 21 Department of Applied Chemistry, Faculty of Science, University of Maragheh, Maragheh, Iran2 School of engineering, emerging technologies, University of Tabriz, Tabriz, IranAbstract- Conducting polymer/ halloysite nanotubes composite were obtained by a mechanochemical reaction in thesolid state by milling system. The halloysite nanotubes(HNT) were coated with 2, 5- dithienyl pyrrole(SNS) via thein situ chemical oxidation polymerization. The characterization by transmission electron microscopy showed thatthe nanotubes were completely covered with conducting polymer. The nanocomposite was characterized usingFTIR, X-ray diffraction, TGA and transmission electron microscopy. The conductivity of the nanocomposite wasfound to be 0.0066 (cm) -1 . (HNT) provide a new avenue for the preparation of nanocomposites.Conducting polymer nanotubes have recentlybecome the object of numerous investigationsbecause of their great potential in deviceapplications, such as transistors [1], sensors [2],actuators and batteries [3], and so on. Holloysite hasa wide variety of biological and non-biologicalapplications. It has been used for storing molecularhydrogen [4], for catalyst conversions andprocessing of hydrocarbons [5] and for removingenvironmental hazardous species [6].HNT and SNS in the presence of ammoniumpresulphate were placed in the ball milling apparatusand the mixture was milled for 30 minute at roomtemperature (25 Hz). The black powder of HNT-SNSnanocomposite was washed with water, and ethanol,then the dried in vacuum.TEM images of halloysite nanotubes (HNT) andHNT-SNS show that the halloysite nanotubes werecoated with 2, 5- dithienyl pyrrole(SNS) via the insitu chemical oxidation polymerization. Also it isobvious that the poly SNS layer with the thickness ofabout 40 nm was only coated onto the outer surfacesof the HNTs.Figure2: FT-IR spectras of a) HNT b) HNT-SNS nanocompositeThe conductivity of the HNT-SNS nanocompositewas found to be 0.0066 (cm) -1 and the conductivityvalue was acceptable.Figure1: TEM images of a) HNT b) HNT-SNS nanocomposite.Figure 2 shows the IR spectra of HNT, HNT-SNSproduct. The bands at 790 and 750 cm 1 in the HNTspectrum are assigned to the translational vibrationsof the external OH groups as well as the out-of-planeOH bending according to the literature. Also thebands in 1600 and 3500 cm -1 for SNS in Fig 2bshows C=C and N-H respectively.Fig. 3 shows the XRD for the HNT andnanocomposite. It is obvious that the SNS has anamorphous structure so that it appears in 15-35 (2)in the nanocomposite structure.Figure 3: X-ray diffractograms of HNT and HNT-SNS.In summary, HNT/ conducting polymernanocomposite were synthesized first time usingmilling system and its characteristics weredetermined. The halloysite nanotubes offer analternative to carbon nanotubes due to their viabilityand low cost.*Corresponding author: kiani1348@gmail.com andkiani_gholamreza@yahoo.com[1] A.N. Aleshin, Adv. Mater. 18, 17 (2006).[2] M. Kanungo, A. Kumar and A.Q. Contractor, Anal. Chem. 758,5673 (2003).[3] R.H. Baughman, Science 308, 63 (2005).[4] X. Wang and M. L. Weiner US Patent Specification0233199 (2005)[5] R. Klimkiewicz and B. D. Edwarda J. Phys. Chem.Solids 65 459 (2004).[6] Z. Lin and R. W. Puls Environ. Geol. 39 753(2000).6th Nanoscience and Nanotechnology Conference, zmir, 2010 720

Poster Session, Thursday, June 17Theme F686 - N1123Synthesis and Characterization of Polyimide-silver Nanocomposite Containing Chalcone Moieties inThe Main Chain by UV-radiationKhalil Faghihi 1 *, Meisam Shabanian 11 Organic Polymer Research Laboratory, Department of Chemistry, Faculty of Science, Arak University, Arak, 38156, Iran,Abstract-The soluble polyimide (PI)-silver nanocomposite (PISN) 6a containing chalcone moieties as a photosensitive group was synthesizedsuccessfully by a convenient ultraviolet irradiation technique. A precursor such as AgNO 3 was used as the source of the silver particles.Polyimide 6 as a source of polymer was synthesized by the one-step synthesis of polyimide from polycondensation reaction of 4,4'-diaminochalcone 4 with pyromellitic anhydride 5 in the presence of iso-quinoline solution. The resulting composite film was characterized by FTIRspectoscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry (TGA) and diffrantial scanning calorimetry(DSC).There is intense interest in the synthesis and properties ofmetal clusters and nanoparticles prepared in both aqueous andorganic solutions and prepared in condensed state, forinstance, polymers, zeolites and glasses. Clusters,nanoparticles and its containing materials are potentiallyuseful in a wide range of application, including highly activecatalysts [1], magnetic materials, quantum dots andminiaturization of electronic devices and nonlinear opticalmaterials [2-5]. In this work, we investigated the preparationof new polyimide (PI)-silver nanocomposite by convenientultraviolet irradiation technique at room temperature. Thesilver nanoparticles were homogeneously dispersed in the PImatrix and the PI–silver nanocomposites exhibited anultraviolet–visible (UV-vis) absorption peak, corresponding tothe characteristic surface plasmon resonance of silverparticles.Polyimide 6 as a source of polymer was synthesized by theone-step synthesis of polyimide from polycondensationreaction of 4,4'-diamino chalcone 4 with pyromelliticanhydride 5 in m-cresol solution and in the presence of isoquinolineas a base (Figure 1).Figure 2. SEM image of polyimide-silver nanocomposite 6aIn summery in this work, a polyimide-silver nanocompositecontaining chalcone moieties was successfully prepared by aconvenient reduction of silver by ultraviolet irradiationtechnique. From the SEM and XRD investigations, the silvernanopaticles homogeneously dispersed in the PI matrix. In theUV–vis absorption spectra of the PI-silver nanocomposite, theabsorption peak due to the surface plasmon resonance of silverparticles was observed at 418 nm. Because of the goodthermal properties and Due to presence chalcone moieties inpolymer backbone, these silver/PI nanocomposites can bephotosensitive and has the potential for use inmicrofabrication of conductive components in microelectronicindustry.*Corresponding author: k-faghihi@araku.ac.irFigure 1. Synthetic route of PI 6The soluble PI–silver nanocomposite was prepared by usingultraviolet irradiation is presented. A precursor of the silverparticles AgNO3 was used. The XRD pattern of the solublePI-silver nanocomposite 6a. shows five diffraction peaks inthe XRD patterns of samples 6a widen greatly, indicating theformation of the nanometer scale of silver particles in the PIsilvernanocomposite. Figure 1 containing diffraction signalsat 2h values of 38.2 º, 45.3 º, 66.1 º, 75.5 º and 83.7 attributedto the diffraction planes (1 1 1), (2 0 0), (2 2 0), (3 1 1) and (22 2) of fcc silver nanoparticles confirming the presence ofsilver nanoparticles in the nanocomposites. The SEMmicrograph of the PI-silver nanocomposite 6a in figure 1shows that the silver nanoparticles were homogeneouslydispersed in polyimide matrix (Figure 1).0B[1] Lewis, L.N. Chemical Review 93: 2693-2730 (1993).[2] Huang, J.C., Qian, X.F., Yin, J., Zhu, Z.K. and Xu, H.J.Materials Chemistry and Physics 69: 172-175 (2001).[3] Robin, E.S. and David, W.T. Chemistry Material 16: 1277-1284 (2004).[4] Henglein, A. Chemical Review 89: 1861-1873 (1989)[5] Kobayashi, T. and Iwaki, M. Surface and CoatingsTechnology: 196, 211-215 (2005).6th Nanoscience and Nanotechnology Conference, zmir, 2010 721

Poster Session, Thursday, June 17Theme F686 - N1123Intercalation of laurate anions into Mg-Al layered double hydroxide:Synthesis and characterizationNathalie Gerds, †‡* Jens Risbo, † Christian B. Koch, ‡ Vimal Katiyar, § David Plackett § and Hans Christian B. Hansen ‡† Department of Food Science, Faculty of Life Sciences, Rolighedsvej 30, University of Copenhagen, DK-1958 Frederiksberg C, Denmark,‡ Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871Frederiksberg C, Denmark and§ Solar Energy Programme, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, 4000 Roskilde, DenmarkAbstract—Laurate anions were intercalated into Mg-Al layered double hydroxide (LDH) using coprecipitation under constant pH. Forcomparison LDH-laurate was also prepared by anion-exchange and reconstruction from calcined LDH. Different synthesis conditions wereinvestigated showing that a crystalline LDH-laurate phase can be obtained by combining an Mg-Al-ratio of 2:1 with a stoichiometrical amount ofdecanoic acid and post- synthesis hydrothermal treatment at 75°C for 12h. Powder X-ray diffraction and Fourier-Transform IR-spectraconfirmed the intercalation of the laurate anions in the interlayer. From the TEM and SEM micrographs it can be seen that the particlemorphology has a nanoporous structure containing interconnected platelets with a particle size in the range of 100-250 nm. Our work showedthat LDH-laurate can be prepared by coprecipitation with comparable characteristics to that of the compound produced using the ion-exchangemethod.Intercalation of organic anions into layered double hydroxides(LDHs) is required for the successful development ofpolymer–LDH nanocomposites. Surfactant-intercalated LDHhave been commonly used as nanofillers in polymers owing totheir nanoscale structure and excellent enhancement ofphysical (e.g., barrier) and chemical properties [1].Furthermore, LDHs can be used in controlled release drugdelivery systems and removal of organic pollutants from soiland water [2-3]. Intercalation of long-chain anion surfactantinto the LDH is an attractive way to make the interlayer spaceacceptable for polymers. The modification of the host materialresults in hydrophobic surface character of the layercompound and yields an extension of the interlayer distance.There are relatively few reports on the intercalation of longchaincarboxylates into LDH using coprecipitation methods.Most of the published LDH investigations using acoprecipitation method were conducted with organic anionscontaining sulfonates [4-5]. The objective of this work was tocreate a fast, cost effective and environmentally friendlypreparation method using long-chain carboxylates. In ourresearch decanoate (laurate) anions have been intercalated intoMg-Al-LDH by coprecipitation in the presence of an ethanoliclaurate solution kept at constant pH.In our study, we showed that the direct synthesis can result ina multi-phase system. X-ray diffraction analysis identified thepresence of two series of basal reflection peaks demonstratingthat two layered compounds were formed. Hence, in order todistinguish the LDH-laurate phases and the by-products,laurate-intercalated Mg-Al-LDH was prepared by the ionexchangeand reconstruction method and used as referencematerial. Furthermore, the influence of the Mg-Al-ratio of 2:1and 3:1 was investigated.It was found that the solvent system, the Mg:Al ratio and theconcentration of the carboxylic acid are critical parameters inthe direct synthesis. An Mg-Al-ratio of 2:1 causes theformation of the intercalated LDH-laurate phase whereas anMg-Al-ratio of 3:1 and excess of laurate anions favours theformation of Mg-laurate as a co-existing secondary phase. Apure crystalline LDH-laurate phase was obtained bycombining an Mg-Al-ratio of 2:1 with a stoichiometricalamount of decanoic acid and post-synthesis hydrothermaltreatment at 75°C for 12h. The powder X-ray-diffractionpattern of the laurate-intercalated LDHs prepared by thedifferent synthesis routes shows that the intercalated form hasa hydrotalcite-like structure.a) b)Figure 1: a) Scanning electron micrograph and b) transmission electronmicroscope images from an LDH-laurate sample prepared by the directsynthesis.The observed basal spacings are almost the same regardless ofthe synthesic route. This suggests that the laurate anions areintercalated as a monolayer in which the carboxylate chains lieperpendicular to the brucite-like layers. Fourier-Transform IRspectraconfirmed the intercalation of the laurate anions in theinterlayer. Transmission electron microscopy (TEM) andscanning electron microscopy (SEM) were used to study thecrystal morphology structure. Typically, the different samplesshow similar plate–like morphology with particle sizes in therange of 100-250 nm. The direct synthesis results in ananoporous structure consisting of interconnected platelets asseen in Figure 1a-b. This work is part of the current NanoPackproject (http://www.nanopack.dk) funded by the DanishStrategic Research Council.*Corresponding author: ng@life.ku.dk[1] H.B. Hsueh and C.Y. Chen. Polymer 44, 5275 (2003).[2] Y.W. You et al., Colloids Surf. A: Physicochem. Eng. Aspects 205,161 (2002).[3] B.X. Li et al., Int. J. Pharm. 287, 89 (2004).[4] B. Wang et al., Mater. Chem. Phys. 92 190 (2005).[5] H. Zhang et al., J. Solid State Chem. 180, 1636 (2007).6th Nanoscience and Nanotechnology Conference, zmir, 2010 722

Poster Session, Thursday, June 17Theme F686 - N1123A Rheological Model For Determining Degree Of Exfoliation In Polymer/Clay Nanocomposites1 Hossein Ebrahimiand Ahmad Ramazani S. 21 Islamic Azad University ( South Tehran Branch), Tehran,Iran2 Department of Chemical and Petroleum Engineering, Sharif University of Technology,Tehran,IranAbstract— We present a conformational based model for prediction rheological behavior of nanocomposite. The EVA/clayand EVA/PE/clay nanocomposites with different nanoclay contents were prepared by melt mixing. The model calculations forthe start-up viscosity are compared with experimental result. Then, a relation for determining degree of exfoliation ofnanoparticles in polymeric matrix was derived.The degree of exfoliation, intercalation and dispersion ofpolymer/clay nanocomposites traditionally characterized byX-ray diffraction (XRD) and transmission electronmicroscopy(TEM); while both are effective tools, they are stilllimited in that they only probe a small volume of the sampleand can be costly for routine characterization ofnanocomposites. Further, XRD nor TEM alone cannotaccuracy describe the level of clay dispersion and polymernanocomposite structure. Rheologyical investigation givesimportant information about the structure formation during thesynthesis of polymer/clay nanocomposites.In this study, a conformational based model for predictionrheological behavior of nanocomposite was presented. Theconformational rheological models relate the stress tensor tothe molecular conformation change concept during andso it seems that these models can be extendedphenomenologically for a system, which includes polymer andparticles. In this model two micro structural state variablecalled conformation tensor c and orientation tensor show thestate of deformation of polymer molecules and orientation ofparticles during flow, respectively.For a non-compressible polymer fluid with amicrostructure represented by a second order symmetrictensor, c, the Poisson bracket formalism leads to the followingequations for the time evolution of c [1, 2 and 3]:c1 . . 1 ( . cc. ) ( cc. ) :t2 2c2( c. )cIn wich is a fourth-order tensor, called the mobilitytensor, is the rate of strain tensor, is the vorticity tensor , stress tensor, and is the Helmholtz free energy.To derive the time evolution equations for orientation tensor , nanoparticles will be modeled inside the framework of thetime evolution equation for the fiber orientation tensor byFolgar and Tucker, 1984; Advani and Tucker 1987[4]:d a , 1 1 . . . . ( a a. . a a. 2 : aa) 2cI ( 0a)dt2 , 2 , ,.in wich and are respectively the rate-of-strain tensor andthe vorticity tensor. is related to the aspect ratio of the fibers.( =[(l/d) 2 - 1]/[(l/d) 2 +1], l and d represent respectively thefiber length and diameter, 0 is a constant equal to 3 for a 3Dorientation and 2 for a 2D orientation introduced in order tosatisfy the constraint tr a = 1. C I is the interaction coefficientparameter. With some modification in the above equations,we derive a new class of equations that can analyze the effectsof different parameters to model. This model developed forintercalate and exfoliated systems.To prove the model, the EVA/clay and EVA/PE/claynanocomposites with different nanoclay contents wereprepared by melt mixing. The model calculations for the startupviscosity are reasonably in agreement with theexperimental results both in exfoliated and intercalatedsystems. Comparing experimental results and modelcalculation was derived a relation that determineapproximately degree of exfoliation of system.*Corresponding author: ebrahimi_h@yahoo.com[1] H. Eslami, A. Ramazani S. A., H. A. Khonakdar, Macromol. TheorySimul. 12, 524-530(2004).[2] A. Ramazani, M.Grmela, A. Kadi, J. Rheol. 3, 51(1999).[3] A. Ramazani, A. Ait-Kadi, M. Grmela, J. Non-Newtonian Fluid Mech. 73,241(1997).[4] J.S. Cintra, Jr and C.L. Tuker III, J. Rheol. 39(6), 1095, (1995).[5] R. Guenette and M. Grmela, J. Non-Newtonian Fluid Mech. 45,187(1992).[6] M. Grmela, P. J. Carreau, J. Non-Newtonian Fluid Mech. 23, 271(1987).[7] A.N.Beris,B.J.Edwards, Thermodynamics of flowing systems, 1 st edition,OxfordUniversityPress,NewYork(1994).[8] R.B. Bird, R.C. Armstrong and O. Hassager, Dynamics of PolymericLiquids: vol. 1, Fluid Mechanics, 2 st edition, Wiley-VCH, New York (1987).[9] A. Ramazani, A. Ait-Kadi, M. Grmela, J. Non-Newtonian Fluid Mech.73,241(1997).[10] M. Rajabian, C. Dubois, M. Grmela and P.J. Carreau, Rheol. Acta 47,701 (2008).6th Nanoscience and Nanotechnology Conference, zmir, 2010 723

P onPP toP coordinatedPPoster Session, Thursday, June 17Theme F686 - N1123The Study of Effect of Au(III) ion on the Thermal Degradation of Different Copolymers via DirectPyrolysis Mass Spectrometry111UCeyhan Kayran UP P, Tugba OrhanP Pand Jale HacalogluP P*1PDepartment of Chemistry, Middle East Technical University, 06531 Ankara, TurkeyAbstract- In this work, thermal degradation of different copolymers namely, polystyrene-block-poly(2vinyl pyridine) (PS-b-P2VP),polyisoprene-block- poly(2vinyl pyridine) (PI-b-P2VP) and poly(2vinyl pyridine)-block-polymethylmetacrylate (P2VP-b-PMMA) and the effect3+of coordination of AuP thermal degradation mechanisms were studied via direct pyrolysis mass spectrometry. The metal functionalcopolymers were also characterized by classical techniques such as TEM, ATR-FT-IR and UV-vis spectrometry.Today’s material science deals increasingly withnanostructures, i.e., with structures of characteristicdimension between 1 and 100 nm [1]. For building upsmaller structures, nature may serve as a model, where byself-organization and building up compartments, individualmolecules are integrated into larger functional units andstructural hierarchies. One single self-organization step isoften not sufficient to realize functional systems. Thesynthesis of metal clusters in micro compartments of selforganizedpolymer systems offers the advantage to restrictthe size growth of the particles to a predefined diameter andto prevent the particles from further aggregation. If the microcompartments are arranged on a superlattice, this kind ofsynthesis leads the nanoparticles to become also integratedinto the lattice. This gives rise to the formation ofnanostructured inorganic/polymer hybrid materials. Theextremely large inorganic/polymer interface can bestabilized by attaching appropriate ligands to the polymerblocks [2, 3]. Weakly coordinated metal complexes serve asprecursor materials which, by complex formation with theligands, can be solubilized into the polymer compartments.There should not be too strong complexation between theprecursor and the ligand, as otherwise, there will be nofurther reaction to the elementary metal.Recently, methods of synthesizing nanoclusters in microphaseseparated diblock copolymers havingpolyvinylpyridine blocks have been reported that providegreater control over cluster formation [4, 5].In this work, synthesis and characterization ofnanostructural metal ion composites and the effect of3+coordination of Au PPon thermal degradation of differentcopolymers having 2vinylpyridine unit, (polystyrene-bpoly(2vinylpyridine)(PS-b-P2VP), polyisoprene-bpoly(2vinylpyridine) (PI-b-P2VP) and poly(2vinylpyridine)-b-polymethylmetacrylate (P2VP-b-PMMA)) were studied.The samples were characterized via classical techniques suchas TEM, ATR-FT-IR, UV-vis spectrometry. TEM imagesproved the formation of nanoparticles. The disappearance ofcharacteristic peaks due to pyridine stretching and bendingmodes in the FTIR spectra of the samples confirmed thecoordination of metal ions to the pyridine nitrogen.Furthermore, the peak due to CO stretching of PMMAdecreased in intensity while a new absorption peak appeared,which revealed that electron deficient gold (III) ion preferscoordination from both donor atoms of PMMA (namelycarbonyl oxygen and pyridine nitrogen) in order tocompensate its electron deficiency.In the UV-Vis spectra of metal functional copolymers,namely, Au-PS-b-P2VP, Au-P2VP-b-PMMA, Au-PI-b-P2VP the sharp absorption peak at around 290-320 nm wasattributed to a LMCT transition from vinylpyridine nitrogen3+to AuPPion since electron deficient Au(III) ion was ready toaccept electron from pyridine nitrogen. The pyrolysis mass3+spectrometry analysis showed that coordination of AuPPtopyridine nitrogen of poly(2-vinylpyridine) unit ofcopolymers affected thermal behavior almost similarly. Inthe case of P2VP-b-PMMA, besides the coordination of3+3+AuP P2VP unit, coordination of electron deficient AuPto carbonyl group of PMMA results a drastic change in thethermal stability of PMMA based products as shown inFigure 2.41---------------569---------------3Figure 1. Thermal degradation mechanism of MMA monomer.20.00 40.00 60.0020.00 40.00 60.0020.00 40.00 60.00Figure 2. Evolution profiles of MMA monomer during the3+pyrolysis of P2VP-b-PMMA, and AuPP2VP-b-PMMAThis work was partially supported by TUBITAK underGrant No. TBAG-106T656.*Corresponding author: ckayran@metu.edu.tr[1] S. Förster, M. Konrad, , J. Mater. Chem., 13, 2671 2003).[2]J.F., Ciebien, R.T., Clay, B.H.,Sohn, R.E., Cohen, New J.Chem., 685-691(1998)[3]A., Haryono, W.F., Binder, Small, 2, 600-611(2006)[4]T., Hashimoto, M., Harada, N., Sakamoto, Macromolecules, 32,6867-6870(1999)[5]E. T. Tadd, et al., Mat. Res. Soc. Symo. Proc., 703, 33-42(2002)10069416th Nanoscience and Nanotechnology Conference, zmir, 2010 724

PP andPoster Session, Thursday, June 17Theme F686 - N11231Poly(Vinyl Chloride)/Kaolinite Nanocomposites111UYasemin TurhanUP P*, Mehmet DoanP Mahir AlkanPPBalikesir University, Faculty of Science and Literature, Department of Chemistry, 10145 Balikesir, TurkeyAbstract- Nanocomposites of poly(vinyl chloride) (PVC) have been prepared by solution intercalation method using both natural andmodified kaolinites. Kaolinite was modified with dimethyl sulfoxide (DMSO) to expand the interlayer basal spacing. The characterization ofPVC/kaolinite nanocomposites was made by X-ray diffraction (XRD) and transmission electron microscopy (TEM); the interactions betweenkaolinite and PVC was discussed by FTIR-ATR; the thermal stability was determined by simultaneous DTA/TG. FTIR-ATR confirmshydrogen bonds formed between dimethyl sulfoxide molecules and the inner surface hydroxyl groups of kaolinite. XRD and TEM resultsgive evidence that kaolinite was dramatically intercalated into nanoscale and homogenously dispersed in the PVC matrix. Thermogravimetricanalysis indicated that introduction of clay to the polymer network resulted in an increase in thermal stability. Ultraviolet (UV) absorbanceexperiments showed that nanocomposites have a higher UV transmission than PVC film.The synthesis and characterization of new and novelmaterials are one of the main objectives of advancedmaterial research. Polymer nanocomposites, especiallypolymer-layered silicate nanocomposites, have become avaluable alternative to conventionally filled polymers andare of current interest because of the fundamental questionsthey address and their potential technologicalapplications.[1-4]In this study, we synthesed nanocomposites with differentrelative compositions based on PVC and both natural andmodified kaolinites by solution intercalation method.Modified kaolinit was prepared with succunimide via questdisplacementreaction. Figures 1, 2 and 3 show thesereactions.the formation of residue and improve the thermal stability ofthe polymer matrix. The intercalated composites exhibitbigger UV transparency, but this transparency decreases withincrease in kaolinite amount. TEM results have showed thatthe nanocomposites have both intercalated and exfloitedmorphology as shown Figure 4.Figure 1. Quest-displacement reactionFigure 4. Processing of nanocomposite and tem image of clay andnanocomposite0,71nm +Ultra saund field120 h stirring1,11 nmThe work was financially supported by Balikesir UniversityResearch Fund (Project 2008/20).DMSOFigure 2. Intercalation of kaolinite with DMSO.( :O, :H, :S,: C )Figure 3. Quest-displacement reaction of DMSO betweenSIM.( :O, :H, :S , :N, :C )As a result, a series of nanocomposite materials consistingof PVC and layered kaolinite clay were prepared byeffectively dispersing of the inorganic nanolayers ofkaolinite clay in PVC matrix by the solution intercalationmethod FTIR-ATR, XRD, TEM, DTA/TG, BET and UV-Vis spectrophotometer experiments were carried out tocharacterize the morphology and properties of thenanocomposites. By means of intercalation of kaolinite withDMSO, the basal spacing of a natural kaolinite expandedfrom 0.71 to 1.11 nm as shown in Figure 2. It has also beenobserved that the organophilicity of kaolinite was enhanced.The intercalation of KDMSO with SIM are intercalated inthe interlayer spaces of kaolinite by guest-displacementmethod as shown in Figure 3.Evidence from several spectroscopic and thermalanalysis shows that SIM replaces the DMSO molecules. Theincorporation of nanoparticle with polymer results in anincrease in thermal stability. The nanocomposites enhance*Corresponding author:yozdemir@balikesir.edu.tr[1] Pinnavaia, T.J., Beall, G.W.,2000. Polymer-ClayNanocomposites. United Kingdom, U.K: Wiley Series in PolymerScience; Wiley Chichester.[2] Viville, P., Lazzaroni, R., Pollet, E., Alexandre, M., Dubois, P.,Borcia, G., Pireaux, J. J.,2003. Surface characterization of poly(_-caprolactone)-based nanocomposites,, Langmuir, 19: 9425–9433.[3] Alexandre, M., Dubois, P., 2000. Polymer-layered silicatenanocomposites:Preparation, properties, and uses of a new class ofmaterials,, Mater. Sci.Eng., 28 (1-2): 1–63.[4] Turhan, Y., Doan, M.,Alkan, M., 2010. Poly(vinylchloride)/Kaolinite Nanocomposites: Characterization and Thermaland Optical Properties,, Ind. Eng. Chem. Res.,49: 1503-1513.6th Nanoscience and Nanotechnology Conference, zmir, 2010 725

PPPPP,PP,P(PR RmPoster Session, Thursday, June 17Theme F686 - N1123Differential Scanning Calorimetry Investigation of Conductive Nanocomposites Based on EVACopolymer and Expanded Graphite112113444UI. H. TavmanUP P*, K. SeverP P, Y. SekiP P, A. EzanPPA. TurgutPPI. Özdemir P P, I. KrupaP P, M. OmastovaP P, I. NovakP1PMechanical Engineering Dept., Dokuz Eylul Univ., 35100 Bornova Izmir, Turkey2PTDepartment of Chemistry, Dokuz Eylül University, Buca, 35160 zmir, TurkeyPFaculty of Engineering, Bartin University, Bartin, TurkeyPPolymer Institute, SAS, Dúbravská cesta 9, 842 36 Bratislava, Slovakia43Abstract- Polymers which are normally insulating materials, may be made electrically and thermally conductive by the addition ofconductive fillers. In this study the nanocomposites consist of the ethylene- vinyl acetate copolymer (EVA) as base material, the conductivefillers used are expanded graphite (EG) and untreated graphite (UG). Nanocomposites containing up to 50 weight % of filler material wereprepared by mixing them in a Brabender Plasticorder. A differential scanning calorimetry study reveals us a decrease in glass transitiontemperature of the composite with increase in particle content.During the last decade there has been an increasinginterest in the field of polymer nanocomposites since themodification of polymer matrix with small amounts ofnanoparticles proved to be effective in enhancing themechanical, electrical, thermal, fire retardant, barrier andoptical properties of a variety of polymers. Polymergraphitenanocomposites are interesting due to theirpotential conductive properties. Graphite is found in naturein the form of graphite flakes or powder of various particlesizes. Graphite flakes, such as clays, are composed oflayers, normally smaller than 100 nm in thickness[1]. Ifthe appropriate process conditions are applied, graphitenanocomposites offer the potential to produce materialswith excellent mechanical, electrical, and thermalproperties at reasonable cost, which opens up many newapplications[2]In this study Ethylene- vinyl acetate copolymer (EVA)containing 14 wt% of vinyl acetate (VA) was used asmatrix material. Its melt flow index is 9.8 g/10min(190°C/2.16 kg). The filler materials were expandedgraphite (EG) and untreated graphite (UG). Ethylenevinylacetate copolymer (EVA) – graphite mixtures wereprepared in a Brabender Plasticorder PLE 331 internalmixer at 150 °C for a total mixing time of 10 min, themixing chamber capacity being 30ml. The rotors turned at35 rpm in a counter-rotating fashion with a speed ratio of1.1. After 10 minutes, the mixing chamber of theBrabender apparatus was opened and the resulting mixturetaken out. The resultant mixture was then put in acomression moulding die and compressed in acompression molding press at 120°C, under 40 kP pressurefor one minute to obtain samples in the form of sheets of1mm in thickness. During the mixing process theexpanded graphite exfoliates. The exfoliation processstarts on the edges of EG grains and the exfoliated graphiteflakes have nano-sized dimensions with bigger surfaceareas compared to micro-sized dimensions of the UGpellets.The glass transition (TRgR), melting(TRmR), crystallization(TRcR) temperatures, as well as melting(hRmR) andcrystallization (hRcR) enthalpies for pure EVA and alsonanocomposites 6 and 15 weight % of EG; 6 and 15weight % of UG were measured by DSC at aheating/cooling rate of 10 °C /min. The results obtainedusing Perkin-Elmer DSC were given in Table 1. There wasa decrease in glass transition temperature of thenanocomposites with respect to pure EVA, the decrease isslightly stronger for EG filled samples then UG filledsamples. The melting(TRmR) and crystallization (TRcR)temperatures were practically unchanged for thenanocomposites.The EVA- EG nanocomposite showed a lowerpercolation threshold of electrical conductivity which isabout 5% of volumetric filler content, compared to about15% of volumetric filler content for EVA-UG composites.Electrical conductivity of EVA- EG nanocomposites wasalso higher than electrical conductivity of EVA-UGcomposites filled with micro-sized filler at the sameconcentrations.Table 1. DSC analysis results of EVA/UG and EVA/EG nanocompositesT g T hRm TRc hRcSample Code oooPC) (P PC) (j/g) (P PC) (j/g)Pure Eva -28.2 87.71 89.53 72.71 -6.49EVA-EG94/6 -32.32 87.39 74.67 73.25 -8.01EVA-UG96/4 -30.58 88.23 76.14 73.25 -7.53EVA-EG85/15 -33.35 87.74 60.55 73.92 -2.75EVA-UG85/15 -31.39 87.55 67.11 73.41 -5.01TRgR: Glass transition temperatureTRmR: Melting temperatureTRcR: Crystallization temperaturehRmR: Melting enthalpyhRcR: Crystallization enthalpyThis research was supported by the Scientific Support ofthe bilateral Project No. 107M227 of TUBITAK and SASand partly by the project VEGA No. 2/0063/09.*Corresponding author: HTismail.tavman@deu.edu.trT[1] Guterres, J-M, Basso, N.R.S, Galland, GB, 2010,Polyethylene/Graphite Nanocomposites Obtained by In SituPolymerization, Fabiana De C. Fim, Journal of Polymer Science:Part A: Polymer Chemistry, 48: 692–698.[2] H. Fukushima,H. , Drzal, L-T., Rook, B. P. , Rich, M. J.,2006, Thermal Conductivity of Exfoliated GraphiteNanocomposites, Journal of Thermal Analysis and Calorimetry,85(1): 235–238.6th Nanoscience and Nanotechnology Conference, zmir, 2010 726

Poster Session, Thursday, June 17Theme F686 - N1123Synthesis and Thermal Properties of Polymer-Clay NanocompositesSemra Karaca 1 *, Ahmet Gürses 2 , Mehtap (Ejder) Korucu 1 and Metin Açıkyıldız 21 Atatürk University, Faculty of Science, Department of Chemistry, Erzurum, 25240, Turkey2 Atatürk University, K. K. Education Faculty, Department of Chemistry, Erzurum, 25240, TurkeyAbstract- Clay mineral-polymer nanocomposites are prepared by dispersing solid organo clay minerals in two different polymermatrices, namely polyethylene (PE) and poly ethylene oxide (PEO) via two methods: melt intercalation and solution intercalation,respectively. The organo clay minerals are prepared by adding different amounts of surfactant corresponding to the CEC of thepristine clay mineral. The characteristics of the organo clay minerals are obtained by XRD, IR spectroscopy, DSC measurements. Theamount of added surfactant has a direct effect on the interlayer separation and organophilicity–hydrophilicity balance of the claymineral. Differential scanning calorimetry results indicated that the crystallization degree of samples are significantly different thanthat of virgin polymer both PEO/OMMT and PE/OMMT nano-composites.Polymer composites are widely used in applicationssuch as transportation, construction, electronics andconsumer products. The properties of particle-reinforcedpolymer composites are strongly influenced by thedimensions and microstructure of the dispersed phase.Recently, there has been a growing interest in thedevelopment of polymer-clay nanocomposites 0H[1-4].Nanocomposites constitute a new class of material thatinvolves nano-scale dispersion in a matrix. Stronginterfacial interactions between the dispersed clay layersand the polymer matrix lead to enhanced mechanical,thermal and barrier properties of the virgin polymer 1H[1,2].Since clay is hydrophilic, it is necessary to make itorganophilic via cation exchange, typically withalkylammonium cations 2H[3,4].In the present study, non-polar polyethylene and polarpolyethylene oxide are intercalated in the solid organo claymineral prepared with different amounts ofsurfactant(CTAB).The influence of the amount of CTABadded to the clay on the final nanocomposites structure isstudied. The thermal properties of the organo clay-polymernanocomposites are determined. It was seen from XRDdiagrams, the amount of surfactant added has a directeffect on the final organo clay mineral structure. Theinterlayer distance of the montmorillonite (OMT) increaseswith increased amounts of adsorbed surfactant, confirmedby XRD pattern. The nanocomposites were synthesizedby polyethylene oxide and polyethylene via solutionintercalation and melt intercalation methods by adding thechanging amounts of polymers to the all of organo-clays.Solution intercalation facilitates production of thin filmswith polymer and oriented-clay intercalated layers.According to the XRD, FT-IR results, it can be said thatclay has been intercalated and flocculated in polymermatrix.DSC analysis is generally one of the most convenientmethods for analyzing first order transition like meltingand crystallization. The nanocomposite samples withvarying concentration of clay were subjected to DSCanalysis. From the DSC plots the melting point(T m ),crystallization point (T c ) and the enthalpy of crystallizationand melting were determined. The value of heat of fusion,measured by DSC method, is commonly used to calculatethe degree of cyrstallinity(%X c ) .The results are given onTable 1. As shown from Table 1, the enthalpy of fusionand crystallization initially increases at lowerconcentration up to 2.0 % of loading and decreases withfurther increase in clay concentration for PEO/OMMTnanocomposites.Table 1.The variation of Fusion Enthalpies with their CEC valuesand polymer content for PE/OMMT and PEO/OMMTnanocompositesFusion Enthalpy(J)PE, (wt %) PEO, (wt %)CEC*100 98 95 92 100 98 95 920.5 89.4 93.2 86.8 89.4 101.6 146.7 144.1 143.61.0 89.4 86.3 80.2 83.2 101.6 138.4 139.8 130.81.5 89.4 87.5 79.9 80.5 101.6 153.9 129.0 132.72.0 89.4 81.3 84.0 81.6 101.6 151.5 138.8 122.1*(meq/100 g)The initial increase in T m and X c is attributed to the factthat clay platelets act as nucleating centres and favourcrystallization by providing a higher level of nucleationdensity. The decrease in crystallization degree withaddition of clay can be explained by considering twopossibilities like slowing down of kinetics ofcrystallization and blockage of crystalline growth frontcaused by the clay platelets, dispersed in an irregular arrayin the nanocomposite. The melting enthalpy andcrystallization degree initially increased up to 2.0% ofloading of clay, then decreased up to 5.0% and thenincreased again in 8.0% of clay content for OMMT0.5-PEnanocomposite while it decreased up to 5.0%of loadingand then increased for OMMT1.0-PE and OMMT1.5-PEnanocomposites. But, in OMMT2.0-PE, it decreased upto 2.0%of clay content, then increased up to 5.0% and thendecreased. This decrease may be attributed to higherinterfacial area and adhesion between the PE- matrix andclay platelets, which would act to reduce the mobility ofcrystallizable chain segments.*Corresponding author: 3Hskaraca@atauni.edu.tr[1] P. Meneghetti ,S. Qutubuddin, ThermochimicaActa,442,74(2006).4H[2] Y. Kojima, M. Kawasumi, A. Usuki, A. Okada, Y.Fukushima, T. Kurachi and O. Kamigaito, J. Mater. Res. 8, 1185(1993).5H[3] R.A. Vaia, H. Ishii and E.P. Giannelis, Chem. Mater. 5, 1694(1993).6H[4] S. Qutubuddin and X. Fu In: M. Rosoff, Editor, Nano-Surface Chemistry, Mercel Dekker, Inc., New York 653 (2002).6th Nanoscience and Nanotechnology Conference, zmir, 2010 727

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 728

PPPoster Session, Thursday, June 17Theme F686 - N1123The Effect of Nanometer Size Mica Fillers on Mechanical Properties of Polyurethane112UAysel Ersoy YilmazUP P*, Ayten KuntmanP Pand Bulent AydemirP1PDepartment of Electrical-Electronics Eng, Istanbul University, Istanbul 34380, Turkey2PTubitak UME, National Metrology Institute, Gebze, Kocaeli 41470, TurkeyAbstract-In this study mechanical properties of nanometer size mica added polyurethanes were investigated experimentally. At first micaparticles at 1 nanometer size were prepared, and then polyurethane samples with different nanometer size mica concentrations were prepared.Except 10 % mica filler concentrations the resulting nano composites compressive strength is increased.Today in many engineering applications, more than oneclass of materials is used together. At this point additives andfillers gain extra importance due to their significant impact onelectrical, thermal, mechanical and environmental propertiesof the resulting composite. Polyurethanes have a wide rage ofapplications including coatings, adhesives, fibers, thermalinsulator, electrical insulators, etc. However they have somedisadvantages such as low mechanical strength, low thermalstability, low electrical properties, etc. During the last decadeseveral studies has been done to improve these propertiesusing nano size particles [1-5].In this study polyurethane nano composite with various micaconcentrations is studied. To investigate the change inmechanical properties compressive strength tests were doneaccording to the ASTM D1621-04a standard.In this study micas were modified with aminolauric acid andthe preparation procedure was briefly given. Biotite(KMg2.5Fe2+0.5AlSi3O10(OH)1.75F0.25 ) which has adensity of 2,9 g/cm3 is used as mica filler. To a suspension ofaminolauric acid (8.61 g, 40 mmol) in 1,000 ml distilledwater, concentrated HCl (4.17 g, 40 mmol) was added. Themixture was stirred at 80 C until getting a clear solutionindicating the formation of ammonium salt. To this solution, asuspension of 20 g of mica in 1,000 ml of distilled water wasadded with mechanical stirring at 80 C. The stirring wascontinued over night. The resulted white precipitate wascollected by suction filtration. The precipitate was suspendedin hot distilled water with mechanical stirring for 1 h toremove the adsorbed salts. This process was repeated severaltimes until no chloride ions were detected in the filtrate whenadding 0.1 M AgNO3. The precipitate was dried in a ventedoven at 60 oC for 3 days and then at 80 oC under 0.01 atm.vacuum for 24 h.All the polyurethane nano composite samples were preparedunder the same laboratory conditions. The desired weights ofpolyurethane, mica and %0.01 Di butyltin dilaurate catalystwas mixed for 5 minutes. Then the mixture was heated to 100oC and 25% polymeric (methylenediphenylene diisocyanate)MDI was added. The new blend was poured into the mouldand pressed for 10 minutes with the help of clamps. Mouldwas placed in a degasser under high vacuum to remove any airand potentially water vapor from the system. 24 h later themould was opened and the samples were cut in the dimensionsof 1mm by 50mm by 50mm. The highest content of mica inpolyurethane samples was limited to 10 % by weight for nanofillers due to dispersion and processing problems.The mechanical tests to determine compressive strength werecarried out on samples prepared according to the ASTMD1621-04a standard. The experiments were carried out with aZwick tensile test machine at National Metrology Institute inTUBITAK. For the compressive strength tests, the sampleswere shaped into 12.3 mm diameter, 25.4 mm long cylinders.The test parameters can be adjusted with TestXpert software.Tests were performed at a speed of 1.00 mm/min. All testswere performed at 23 C (room temperature).Table 1. Compressive strength test results for 1 nm particle sizeMaterial Type Compressive Strength (GPa)Pure PU 9,056PU+%1 11,426PU+%3 11,600PU+%5 9,541PU+%10 7,816The preparation of PU nanocomposite foams were describedin this study. Clay dispersion is affect by chemical process.With the inclusion of 3% micas, nanocomposite show asmaller cell size than pure polyurethane samples. Dependingon the chemical structure of polyurethane, as high as 28%increase in compressive strength were observed in PU-micananocomposite. However increasing the filler content to 10%mica concentration opposite effect was observed in PUnanocomposite 13.6% decrease in compressive strength wereobserved. Preparation of polyurethane nanocomposite is acomplicated process where many factors could effect bubblenucleation and bubble growth and in turn the compressivestrength. For applications in electrical insulators, compressivestrength is a very important property to calculate the mass ofcover material upon the bare cable conductor. According tothe results from this study cell size in polyurethane nanocomposite is decreased and compressive strength isremarkably increased at 3% mica addition. However detailedmechanism on how nano size mica particles affect mechanicalproperties of polyurethanes needs further investigation.*Corresponding author: aersoy@istanbul.edu.tr[1] R. A. C. Altafim, C. R. Murakami, S. C. Neto, L. C. R. Araújo,G. O. Chierice, “The Effects of Fillers on Polyurethane Resin-basedElectrical Insulators”, Materials Research, Vol 6, No 2, pp. 187-191,2003.[2] X. Cao, L. J. Lee, T. Widya, C. Macosko, “Polyurethane/claynanocomposites foams: processing, structure and properties”,Polymer , Vol. 46, pp.775-783, 2005.[3] J.H. Chang, Y. U. An, “Nanocomposites of Polyurethane withVarious Organoclays: Thermomechanical Properties, Morphology,and Gas Permeability”, Journal of Polymer Science: Part B: PolymerPhysics, Vol. 40, pp. 670–677, 2002 .[4] F. Saint-Michel, L. Chazeau, J.-Y. Cavaille, “Mechanicalproperties of high density polyurethane foams: II Effect of the fillersize”, Composites Science and Technology Vol. 66, pp. 2709–2718,2006. .[5] K.J. Yao, M. Song, D.J. Hourston, D.Z. Luo, “Polymer/layeredclay nanocomposites: 2 polyurethane nanocomposites”, PolymerCommunication, Vol. 43, pp.1017-1020, 2002.6th Nanoscience and Nanotechnology Conference, zmir, 2010 729

Poster Session, Thursday, June 17Theme F686 - N1123MWCNT-Al 2 O 3 Hybrids Dispersed in Epoxy CompositesSeda Aksel 1 , Özge Malay 1 , Dominik Eder 2 , Yusuf Z. Menceloğlu 1, *1 Sabanci University, Materials Science and Engineering Program, İstanbul,34956, Turke.2 University of Cambridge, Department of Materials Science and Metallurgy, Cambridge, UKAbstract— This work aims to investigate dispersion state and thermo-mechanical properties of aluminium oxide (Al 2 O 3 ) coated multi- walledcabon nanotubes (MWCNTs) in epoxy matrix. MWCNT-inorganic hybrids were introduced as an efficient filler to reduce entangledagglomerates in epoxy resin with improved thermal and mechanical characteristics.Carbon nanotube (CNT)-inorganic hybrids are a new class ofmaterials that carbon nanotubes are coaxially coated withinorganic components. These materials show superior optical,mechanical, electrical and thermal properties with respect to thephysical nature of inorganic component [1].Previous studies which focus on addition of inorganicnanoparticles into carbon nanotube/epoxy nanocomposite alsoproved that inorganic nanoparticles diminish the agglomerationof carbon nanotubes in polymeric matrix [2]. This workprimarily concentrates on coating of carbon nanotubes withaluminium oxide (Al 2 O 3 ) in order to improve dispersion ofcarbon nanotubes in epoxy matrix and to characterize CNT-Al 2 O 3 /epoxy nanocomposites prior to its use for specificapplications with respect to enhanced thermal, mechanical andelectrical properties.Multi-walled carbon nanotubes (MWCNTs) which wereprepared by chemical vapor deposition (CVD) method, wereused in this study. The average diameter of the nanotubes is 70nm and the length range is 100-200 μm. MWCNTs were coatedwith inorganic components via sol-gel process. Benzyl alcoholwas used to functionalize hydrophobic surface of MWCNTs viathe π-π interaction between the aromatic MWCNT surface andbenzyl ring of benzyl alcohol [1,3].MWCNTs, benzyl alcohol functionalized MWCNTs andAl 2 O 3 –MWCNT hybrids were used as filler and eachnanocomposite film contains 0.05 wt% filler. The polymermatrix used for the composites was an epoxy based system withamine hardener.Solid State13 C-NMR spectroscopy of functionalizedMWCNTs clearly shows the presence of -CH 2 group bonded tohydroxyl group (-OH) on the surface of MWCNTs by the peakat 62 ppm. Al 2 O 3 coating on MWCNTs hybrid was confirmed byXRD and SEM/EDX analyses as shown in Figure 1 (a,b). Inaddition to graphite peaks at 2θ values of 26 and 44 in the XRDplot of MWCNTs, alumina peak was observed at 39 for Al 2 O 3 -MWCNT hybrid. Weight percentage of aluminium and oxygenin the sample detected by EDX analysis also confirmed thatsample was derived from the Al 2 O 3 molecules in Figure 2 (a,b).Optical microscope images in Figure 3 (a,b,c,d), which showdispersion state of MWCNTs in uncured epoxy resin, demostratethat degree of filler dispersion increases along with functionalizedMWCNTs and hybrids.Figure 3. MWCNT dispersion in uncured epoxy matrix (a) 0.05 wt%MWCNTs (b) 0.05 wt% functionalized MWCNTs (c) 0.05 wt%MWCNT-Al 2 O 3 hybrids (d) 0.05 wt% MWCNT, 0.2 wt% Al 2 O 3 hybrids.MWCNT-Al 2 O 3 hybrids could be homogeneously dispersed inepoxy resin due to the less attractive forces between carbonnanotubes. SEM (Scanning Electron Microscopy) images inFigure 4 (a,b,c) show that functionalization of MWCNTs anduniform coating by Al 2 O 3 decrease the degree of agglomeration.Since the free surface area of carbon nanotubes reduces, weakelectrostatic forces provided via inorganic coating decreases theentanglement degree.(a) (b) (c)Figure 4. SEM image of (a) MWCNTs (b) BA-functionalized MWCNTs(c) MWCNT-Al 2 O 3 hybrids.Addition of MWCNTs decreases the glass transition temperature(Tg) due to lower cross-linking degree of the epoxy matrix.Addition of benzyl alcohol and coating MWCNTs by Al 2 O 3reduces the decrease of Tg with respect to increase in dispersionstate of the filler. On the other hand, 3-point bending analysisreveals that both flexural strength and flexural modulus of thenanocomposites increases via functionalization of the MWCNTs.In summary, MWCNTs were uniformly coated with an inorganiccomponent, Al 2 O 3 . New filler type was developed to attain novelAl 2 O 3 -MWCNT/epoxy nanocomposite materials.*Corresponding author: yusufm@sabanciuniv.eduFigure 1.a. XRD Plotof the MWCNTsFigure 1.b. XRD Plot of theAl 2 O 3 -MWCNT HybridsFigure 2.a. EDX Spectrum Figure 2.b. EDX Spectrum ofof the MWCNTs the Al 2 O 3 -MWCNT Hybrids[1] Eder, D., Windle, A. H., 2008. Carbon-Inorganic Hybrid Materials:The Carbon-Nanotube/TiO 2 Interface, Advance Materials 20: 1787-1793.[2] Sumfleth, J., Prado, L.A, Sriyai, M., Schulte, 2008. K., Titania-dopedmulti-walled carbon nanotubes epoxy composites: Enhanceddispersion and synergistic effects in multiphase nanocomposites, Polymer49: 5105-5112.[3] Eder, D., Windle, A. H., 2008. Morphology control of CNT-TiO 2hybrid materials and rutile nanotubes, Journal of Materials Chemistry18: 2036-2043.6th Nanoscience and Nanotechnology Conference, zmir, 2010 730

Poster Session, Thursday, June 17Theme F686 - N1123Synthesis And Properties Of Clay-Cellulose-Polyester Nano-Hybrid materialsErkan Bahçe 1 , Süleyman Köytepe 2 and Turgay Seçkin 2 *1 Department of Mechanical Engineering, University of Inonu, Malatya, TR Türkiye 442802 Department of Chemistry, University of Inonu, Malatya, TR Türkiye 44280Abstract-Polyester in which cellulose and clay reinforced particles are uniformly distributed are prepared. Novel hybrid polyester/cellulose/claycomposites are structurally elucidated by means of FTIR, SEM, XRD and thermal analytical techniques. The selected polymer for thecomposites preparation was commercial polyester. The composites were prepared using a mixer. The polyester, cellulose and the variousproportions of clay were mixed at 90 ºC during selected time considered adequate for a homogeneous mixture. The extracted composites werethen dried using the vacuum oven for 24 hours.Recent advances in polymer–clay nanocomposites due to thepioneering work of researchers at Toyota on nylon-6/claynanocomposites have demonstrated an improvement in bothphysical and mechanical properties [1]. Because of thenanoscale structure, polymer–clay nanocomposites possessunique properties which include an improvement inmechanical (modulus, strength, toughness), thermal (thermalstability, decomposition, flammability, coefficient of thermalexpansion), and physical (permeability, optical, dielectric,shrinkage) properties [2]. Nanocomposites have beendemonstrated with many polymers of different polaritiesincluding polystyrene, polycaprolactone, poly(ethylene oxide),poly(butylene terephthalate), polymethylmethacrylate,polyamide, polyimide, polyester, polyether, epoxy,polysiloxane, and polyurethane. Similarly, cellulose and othernatural fibres are increasingly being used as reinforcementsfor enhancing the strength and fracture resistance of polymericmatrices because of their low density, low cost, renewabilityand recyclability as well as excellent mechanicalcharacteristics that include flexibility, high specific strengthand high specific modulus [3]. These unique properties areparticularly desirable in applications as composite materialsfor automobiles, armour, sports, and marine industries.Natural fibers can be produced in many types of reinforcementcomposites, such as continuous and discontinuousunidirectional fibers, random orientation of fibers, etc. Bytaking the advantages from those types of reinforcedcomposites such as produced good properties and reduced thefabrication cost, they had been used in the development ofautomotive, packaging and building materials. They can bespun into filaments, thread or rope. They can be used as acomponent of composite materials.Natural fibers are now emerging as viable alternatives toglass fibers either alone or combined in composite materialsfor various applications. The advantages of natural fibers oversynthetic or man-made fibers such as glass are their relativelyhigh stiffness, a desirable property in composites, low density,recyclable, biodegradable, renewable raw materials, and theirrelatively low cost. Besides, natural fibers are expected to giveless health problems for the people producing the composites.Natural fibers do not cause skin irritations and they are notsuspected of causing lung cancer [4]. The disadvantages aretheir relatively high moisture sensitivity and their relativelyhigh variability of diameter and length. The abundance ofnatural fibers combined with the ease of their processability isan attractive feature, which makes it a covetable substitute forsynthetic fibers that are potentially toxic [5].Figure 1. The sutructure of the cellulose (reference should be definedas the square paratheses) [6].Paint on ships, bridges, military vehicles and airplanes mustbe removed from the surfaces in order to allow detail surfacein sections, to perform other works and repair operations, andto keep the weight down to acceptable levels. In the past,chemical have been used for removing paints. Due to thedevelopment of tougher paint systems to meet the increasingdemands of the industry, more aggressive chemical paintstrippers have been developed. These aggressive paintstrippers are very efficient in doing the job, but they arehazardous and toxic to the environment and generate largeamounts of hazardous waste. The present invention is amethod of stripping paint from the painted surface comprisingthe step of cleaning the painted surface with a media(polyester) comprising hard shell pit particles sized between12 mesh and 50 mesh.In this study, the selected polymer for the compositespreparation was commercial polyester, the composites wereprepared using a mixer. The polyester, cellulose and thevarious proportions of clay were mixed at 90 ºC duringselected time considered adequate for a homogeneous mixture.The extracted composites were then dried using the vacuumoven for 24 hours.It is an advantage of the present invention that the paintstripping method generates less toxic waste than most prior artmethods. It is another advantage of the present invention thatthe method is both effective and efficient. Other advantages,features, and objects of the present invention will becomeapparent after one of skill in the art has reviewed thespecification and claims.*Corresponding author: 0Htseckin@inonu.edu.tr[1] L. An, , H.M.Chan, , N.P. Padture, B.R. Lawn, J. Mater. Res. 11,204 (1996)[2] A.K. Bledzki, J. Gassan, Prog. Polym. Sci., 24, 221 (1999)[3] X. Fu, S. Qutubuddin, Mater. Lett. 42, 12 (2000)[4] I. Isik, U. Yilmazer, G. Bayram, Polymer, 44, 6371 (2003)[5] B.Z. Jang, Y.K. Lieu, J. Appl. Polym. Sci. 30, 3925 (1985)[6] R. Young, Cellulose structure modification and hydrolysis. NewYork: Wiley (1986).6th Nanoscience and Nanotechnology Conference, zmir, 2010 731

PP InstitutePP DepartmentPoster Session, Thursday, June 17Theme F686 - N1123Investigation of Natural Vibration Frequency of Graphene Sheet111,2Arman FathizadehP P, Masoumeh OzmaianP Pand UReza NaghdabadiUPP*1for NanoScience and Technology, Sharif University of Technology, Tehran, Iranof Mechanical Engineering, Sharif University of Technology, Tehran, Iran2Abstract- In this study, the vibration analysis of SLGs using molecular dynamic (MD) simulation as well as beam theory is reported for differentdimensions. Using these results, parameters that affect the answers obtained by continuum theory can be modified for more accurate results andlower computational cost.In recent years, graphene sheets have attracted lots ofinterests because of their unique properties. It could be one ofthe prominent materials for the nanoelectronic devices in thefuture. But still limited work has been done on studying themechanics of graphene sheets.Recently, some numerical and analytical models have beenproposed for the study of vibrational behavior of single andmultilayer graphene sheets (MLGS) [1-3]. Behfar andNaghdabadi investigated the vibration behavior of MLGSembedded in an elastic medium [1]. Kitipornchai et al. carriedout an analysis based on a continuum-plate model for MLGSsby considering the Van der Waals force between the plates [2].Sakhaeepour et al. calculated fundamental frequencies ofsingle layer graphene sheet (SLGS) using molecularmechanics method [3].Modeling in this paper is carried out by two methods,continuum theory and MD simulation. Consider a SLGSdoubly clamped in two ends. The sheet is of length L, width isw, thickness t, density and the Young’s modulus E. Thefundamental frequency according to the Euler-Bernoulli beamtheory is given by [4](1) L Lwt1/222At E A T 0.572 2where A is 1.03 for doubly clamped beam and T is the tensionin the graphene sheet. The thickness is taken to be 0.34 nm(Van der Waals radius for carbon atoms), the density is 22503kg/mP Pand the Young modulus is 1.02 TPa.1/2the system of atoms to vibrate in the first mode. Then with aFourier analysis on variation of position of atoms or potentialenergy of the system with time, corresponding frequency ofthe system can be obtained.In order to investigate the fundamental frequency of SLGS,results are obtained for different dimensions by MDsimulation as well as beam theory. As it can be seen in table 1,by increasing the aspect ratios of the graphene sheets, theresults obtained by the beam theory get nearer to the MD's.There are many adjustable parameters which can affect theresults of continuum model. The most important parametersare the parameter A, thickness and Young modulus of theequivalent beam (t, E), and mass distribution in the continuummodel. A has a significant effect on the fundamentalfrequency. Effect of (t, E) is also important and their valuesfor graphene are still under discussion. The mass distributionshows a little effect on frequency, especially for bigger sizesin which atomic spacing is negligible relative to sheet size.Present study may be used as a new method of adjusting theseparameters for graphene to achieve more accurate results withcontinuum models.Table 1. Comparison of the fundamental frequency obtained usingMD simulation and continuum beam theory.Dimensions (GHz)Length(nm) L/W MD Beam theory8.98 2.18 395.78 265.7812.32 6.22 185.42 225.1524.47 12.36 94.21 110.0535.54 17.95 56.07 48.89Figure 1. Molecular dynamics method used for calculating firstnatural frequency of grapheme sheets. This figure shows a vibratinggraphene sheet with aspect ratio of 6.22 schematically.The molecular dynamics simulation is performed for 4different aspect ratios ranging from 1000 to 3000 atoms.These simulations are done with LAMMPS software [5] andusing well-known REBO interaction potential which has beenshown to be the most accurate one for study of mechanicalproperties of carbon nanostructures [6]. In order to model thedoubly clamped boundary condition, two rows of atoms in theSLGS are fixed in two ends while the other sides are free. Allof the atoms in the sheet are placed in such a way that they areinitially at the position at the first mode shape of the sheetwith velocity equal to zero. Then in a NVE ensemble, we let*Corresponding author: naghdabd@sharif.edu[1] K. Behfar, R. Naghdabadi, Comp. Sci. Tech., 65, 1159–1164(2005).[2] S. Kitipornchai, X. Q. He, K. M. Liew, Phys. Rev. B, 72, 075443(2005).[3] A. Sakhaee-Pour, M.T. Ahmadian and R.Naghdabadi,vNanotechnology, 19, 085702 (2008).[4] S. Timoshenko and D. H. Young, W. Weaver, New York, 425–427 (1974).[5] LAMMPS, An open source code for molecular dynamicssimulation, HThttp://lammps.sandia.gov/TH.[6] D. Brenner, et al., J. Phys.: Condens. Matter.,14, 783–802(2002).6th Nanoscience and Nanotechnology Conference, zmir, 2010 732

PPP HR3RBOR3Poster Session, Thursday, June 17Theme F686 - N1123Performance of Zinc Borate Nanoparticles as an Anti-Wear Additive in Mineral Oil1211USevdiye Atakul SavrkUP P*, Mehmet GönenP P, Devrim BalköseP P, Semra ÜlküP1Pzmir Institute of Technology, Department of Chemical Engineering, Gülbahçe Köyü, Urla, zmir, Turkey2PPresent address: Süleyman Demirel University, Department of Chemical Engineering, Isparta, TurkeyAbstract- Inorganic borates as a lubricating oil additive received extensive attention in recent years due to the remarkable tribologicalproperties such as wear resistance, friction-reducing ability and oxidation inhibition. This study reports the synthesis of nano-sized zinc borate,its characterization as well as its performance in mineral oil as a lubricating additive. Zinc borate nanoparticles with different morphologieswere prepared by two different raw materials groups. Spherical crystals were successfully synthesized by precipitation reaction in aqueoussolutions of NaR2RBR4ROR7R·10HR2RO and ZnNR2ROR6R·6HR2RO, whereas supercritical ethanol drying method is applied to prepare broccoli type speciesafter the precipitation step in aqueous solutions of HR3RBOR3R and ZnO. The lubricants were prepared by dispersing the zinc borate particles withsorbitan monostearate (Span 60) which was used as a surface modifier. The tribological properties of the mineral oil were determined by fourballwear test machine and the results indicated that wear scar diameter is reduced by 54.78% for the lubricant including zinc borate dried bysupercritical ethanol drying compared to that of the mineral oil.The increasing interest of petrochemical industries onimproving the performance of their products (lubricants,greases, gasoline, among others) has been simultaneouslygenerating great incentives to develop additives that are ableto supply the commercial demand of the competitive industrialmarkets. For tribology applications, particles as additives inbase oil have been investigated widespreadly. These studiesrefer to synthesis and preparation of especially nanoscaleparticles, and their tribological properties and mechanisms[1,2]. The lubrication performance of a lubricant relies partlyupon the thickness of the tribofilm under the severe conditionscontrolled by several parameters such as load, temperature,sliding speed and the mechanical properties of the film. Avariety of mechanisms have been proposed to explain thelubrication enhancement of the nanoparticles suspended inlubricating oil. Ball bearing effect and protective filmmechanisms have direct effect of the nanoparticles onlubrication enhancement, whereas mending and polishingeffects have secondary effect on surface improvement [3].This study aims to investigate the tribological properties ofmineral oil including zinc borate nanoparticles and to exposethe effect of morphology of the particles on anti-wearproperty.In this project, first group of zinc borate species wereobtained by the homogenous precipitation method describedby Ting et al. using ZnNR2ROR6R·6HR2RO, NaR2RBR4ROR7R·10HR2RO andammonia [4]. Second group of zinc borate nanoparticles were3prepared by 4.7mol/dmPRwith the stoichiometricamount of ZnO. Supercritical ethanol drying of submicronzinc borate was performed at 250 °C, 6.5 MPa for obtainingnano zinc borate particles. All zinc borate samples werecharacterized by SEM, TGA, DSC, FTIR, and XRD. Thelubricants were prepared by adding sorbitan monostearate(Sigma Aldrich) and zinc borate particles into the mineral oilat 70 °C. They were mixed by both a homogenizer (OMNIGLH) and a magnetic stirrer (Yellowline MSH Basic) for 2minutes and 2 hours, respectively. Tribologicalcharacterization of the lubricants was carried out by a fourballwear test machine (made by Falex Corp.) The test ballswere chrome alloy steel, No. E-52100 with a diameter of 12.7mm. The wear and friction test was performed at 392 N andthe test duration was 1h. After the test, the morphology ofworn surfaces of the balls run in the lubricant was obtained bySEM. Moreover, elemental composition of the ball wornsurfaces was determined by EDX analysis.SEM images of zinc borate nanoparticles produced bydifferent raw materials groups are shown in Figure 1. Thezinc borate obtained by ZnNR2ROR6R·6HR2RO andNaR2RBR4ROR7R·10HR2RO includes spherical crystals (Figure 1a). Onthe other hand, zinc borate crystals dried by supercriticalethanol have broccoli type morphologies. Table 1 reports thetribological properties of the lubricants. It was revealed thatsorbitan monostearate had a dramatic role in the reduction ofwear scar diameter from 1.402 to 0.656 mm. When thenanoparticles dried by supercritical ethanol were used aslubricating oil additives, wear scar diameter is reduced to0.634 mm.(a)(b)Figure 1. SEM images of super critical ethanol dried nanoparticlesobtained from zinc borates a) ZnNR2ROR6R·6HR2RO and NaR2RBR4ROR7R·10HR2ROand b)HR3RBOR3R and ZnOTable 1. Tribological properties of lubricantsWear Scar FrictionSample AdditiveDiameter (mm) CoefficientL1 - 1.402 1.645L2 Span 60 0.656 1.635L3ZB dried bySCE +Span 600.634 1.601SEM analysis shows that the worn surface of the balllubricated with L3 lubricant including zinc borate andsurfactant exhibits much smoother surfaces without severescuffing. Additionally, EDX analysis reveals that boron andzinc elements are also adsorbed by the worn surface of theball.TÜBTAK (project number: 105M358), OPET PetrolcülükA. and Izmir Institute of Technology Centre for MaterialResearch are greatly appreciated.HT*Corresponding author: sevdiyeatakul@iyte.edu.trT[1] Zhang M., Wang X., Fu X., Xia Y., 2009. Performance andanti-wear mechanism of CaCOR3 Rnanoparticles as a green additive inpoly-alpha-olefin, Tribology International, 42:1029-1039.[2] Choundary R.B., Pande P.P., 2006. Lubrication potential ofboron compounds: an overview. Lubrication Science, 14: 211-222.[3] Lee K., Hwang Y., Cheong S., Choi Y., Kwon L., Lee J., KimS.H., 2009. Understanding the role of nanoparticles in Nano-oillubrication, Tribology Letters, 35: 127-131.[4] Ting C., Cheng D.J., Shuo W.L., Gang F., 2009. Preparationand characterization of nano-zinc borate by a new method, Journalof Material Processing Technology, 209:4076-4079.6th Nanoscience and Nanotechnology Conference, zmir, 2010 733

andPCPPoster Session, Thursday, June 17Preparation and Characterization of Poly (3-Hydroxybutyrate) Homo and CopolymersNanocomposite Films1111Onur GökbulutP P, Burcu KayaP P, Okan AknP Pand UFunda TihminliogluUP P*1PDepartment of Chemical Engineering, zmir Institute of Technology, Urla, 35430, TurkeyTheme F686 - N1123Abstract- This study aims to prepare and investigate the characteristic properties of Poly (hydroxybutyrate) (PHB) andpolyhydroxybutyrate-co valerate (PHB/HV) copolymers layered silicate nanocomposites. Nanocomposites were prepared via meltintercalation method by dispersing orgonamodified layered silicate nanoclays. The effects of clay loading and the polymer type on the watervapour, OR2R COR2R barrier properties were measured. In addition, Differential Scanning Calorimetry (DSC) and mechanical properties ofthe films were performed. Mechanical properties of the chitosan composites were enhanced with the addition of clay . The enhancement inthe barrier properties were obtained upto certain clay content in composites.Among many different materials that mankind is dependenton plastics are the most important ones considering theirwidespread usage in food packaging, textile, communication,transportation, construction, medical industries. Currently,plastics and synthetic polymers are mainly produced usingpetrochemical materials that cannot be decomposed. Inaddition the amount of plastic waste increases every year.Therefore in the last decades there has been a significantincrease in the development of biodegradable thermoplasticpolyesters due to ongoing concerns about the disposal ofconventional plastics and the increasing difficulty inmanaging solid wastes.Poly (hydroxyalkanoates), PHAs, comprise a family ofbiopolymers that has attracted much attention recently due tosimilar properties to conventional materials such aspolypropylene, polyethylene, polystyrene, and PET. Bacterialbiopolymers such as Poly (3-hydroxybutyrate) (PHB) and itscopolymers with valerate (PHB/HV) are biodegradablethermoplastic polyesters and one of the most widelyinvestigated members of the family of PHAs. PHB and itscopolymers present good mechanical, thermal and barrierproperties. PHB is a partially crystalline thermoplastic andhas a high melting temperature. However PHB suffers fromlow melting stability, brittleness and lack of transparency [1].Thus, recent studies are objected to improve the properties ofPHB and its copolymers by addition of nanoclays. Surfacemodified clays have been studied as advanced additives toimprove or balance thermal, mechanical, fire resistance,surface, or conductivity properties of nanocomposite due totheir high surface to volume ratios and the subsequentintimate contact that they promote with the matrix at lowfiller additions [2]. In essence, three different methods areused to synthesize polymer-clay nanocomposite; meltintercalation, solution and situ polymerization.PHB and PHB-HV /layered silicate nanocomposites in thepresent study are prepared via melt extrusion. Natural PHBand its copolymer PHB-HV (2% and 12%) were purchasedfrom Goodfellow Inc. and dried under vacuum at 80°C fortwo days before use. As clay, organophilic surface modifiedmontmorillonite called Cloisite® 15A purchased fromSouthern Clay Products, Inc. Polymers and nanoclay aremelted extruded by using a Thermofisher twin screw extruderwith varying weight percentages of clay at a temperature of180 °C and a screw speed of 50 rpm. The extrudedcomposites are dried under vacuum at 50 °C. The samples ofPHB, PHB-HV and their nanocomposite are finallytransformed into films by compression molding in a hot-plateohydraulic press at 175 P PC and 5 Metric tons of pressureduring 5 min. The polymer sheets are cooed to roomtemperature under constant pressure.The effect of filler concentration on the water vapor, OR2Rand COR2 Rpermeability, mechanical and thermal properties ofthe composite films were evaluated. The structure ofnanocomposites and the state of intercalation of the clay werecharacterized by Phillips X’Pert Pro MRD with Cu Kradiation (=1.54 nm) under a voltage of 40 kV and a currentof 40 mA. Samples were scanned over the range ofdiffraction angle 2 = 0.25-30°. Thermal properties of thepolymer and the nanocomposite films are studied by a DSCtechnique with a Shimadzu Calorimeter at a heating rate 10oP/min. Morphology of polymers and their nano compositesare analyzed by XRD and TEM. As a result of morphogicalanalyses , intercalated structure were obtained . The extent ofintercalation depends on the amount of silicate and the natureof organic modifier present in the layered silicate .According to results of permeability measurements; thenanocomposite films exhibit good barrier properties ascompared to their unfilled polymer films. The water vaporand gas permeability values of the composite films decreasedsignificantly depending on the filler concentration and thetype of filler used. The decrease in water vapor and gaspermeability of PHB and PHB-HV- clay nanocompositefilms are believed to be due to the presence of ordereddispersed clay nanoparticle layers with large aspect ratios inthe polymer matrix. This causes an increase in effective pathlength for diffusion of water vapour and gas into polymermatrix.*Corresponding author: HTfundatihminlioglu@iyte.edu.trT[1] M. D. Sanchez-Garcia ; E. Gimenez ; J. M. Lagaron ,Morphology and Barrier Properties of Nanobiocomposites ofPoly(3-hydroxybutyrate) and Layered Silicates Wiley InterScience2008 , DOI 10.1002/app.27622[2] Reguera, J.; Lagaron, J. M.; Alonso, M.; Reboto, V.; Calvo, B.;Rodriguez-Cabello, J. C. Macromolecules 2003, 36, 8470.[3] Cabedo L.; Plackett D.;Gimenez E.; Lagaron J.M., Studying theDegradation of Polyhydroxybutyrate-covalerate during Processingwith Clay-Based Nanofillers Received 31 March 2008; accepted 22September 2009, DOI 10.1002/app.29945[4] Pralay Maiti, Carl A. Batt, and Emmanuel P. Giannelis, NewBiodegradable Polyhydroxybutyrate/Layered SilicateNanocomposites , Biomacromolecules 2007, 8, 3393-34006th Nanoscience and Nanotechnology Conference, zmir, 2010 734

P ionsPP haveP contactPoster Session, Thursday, June 17Theme F686 - N1123The Creation of Hydrophobic Clay Surfaces with Long Chain Hydrocarbon111UH. Hasan YolcuUP P*, Ahmet GürsesP P, and Metin AçkyldzP P,1PAtaturk University, K.K. Education Faculty, Dep. of Chemistry, 25240 ErzurumAbstract- In this study, the presence of lotus effect for the clay modified by using long chain hydrocarbon was investigated. It wasfound the powder sample comparison with pellet form exhibits super hydrophobic character. This may be attributed to the changing ofroughness on the surface of modified clay particles depending on pressing and to the creating of higher energy surface with the adsorption oflong chain hydrocarbon onto interlayer region of clay.Non wettable surfaces with high water contact angle(WCA) and facile sliding of drops are called superhydrophobic surface. Superhydrophobic surfaces with0water contact angles larger than 150P received a lotof research attention, due to important applications rangingfrom self cleaning materials to microfluidic devices [1, 2].Many surfaces in nature are highly hydrophobic and selfcleaning (e.g. lotus leaves). The design synthesis andapplication of new kinds of super hydrophobic and selfcleaning organic or inorganic material will be essential andimportant task to fulfill [3].The clay sample was purified by sedimentation, dried atvacuum oven and sieved to give a 38-85 m (>%92) sizefraction using ASTM Standard sieves. Different amountsof hydrocarbon (0.05-1.0 g) was mixed with 500 mLaqueous solutions of CTAB (100, 200, 240, 260, 300, and320 mg/L). The mixture was shaken at 293 K, for 30 minsand 1g clay sample was added to this mixture and shakenfor 30 mins in a thermostatic shaker at 200 rpm. Themodified clay samples which produced by aboveprocedure were filtered through filter paper of Whatman41 and dried at 383 K in a vacuum oven for 2 h.and water droplets leads to gaining the hydrophobiccharacter of samples. But the powder organoclay hassuperhydrophobic character, probably due to lotus effect.The variation of initial CTAB concentration doesn’tsignificantly affect the contact angles of the pellet andpowder samples (Figure 2).Figure 2. Effect of initial CTAB concentration on the contactangleIntensity (counts)200016001200800Raw clay*Corresponding author: HThasanyolcu@atauni.edu.trT[1] M. Ma and R. M. Hill. Curr. Opin. Colloid Interface Sci. 11,193-202 (2006).[2] A. Tuteja, et al. Science. 318, 1618 -1622 (2007).[3] X , Feng and L, Jiang,. Adv. Mater. 18, 3063-3078 (2006).[4] H.Y. Erbil et al, Science. 299, 1377 (2003).40002 12 22 322Theta (deg)Figure 1. X-ray diffraction spectrums for raw clay and producedorgano-clayThe XRD patterns shows the intensities of peaks for theorgano-clay sample were significantly decreased withcompared the raw clay. This attributed to the presence ofexfoliated clay layers. It can be said that the basal spacingincreases, depending on ion-exchange occurred between+CTAP bounded hydrocarbon and the cations in theinterlayer region of clay (Figure 1).In this work, the contact angles for the powderorganoclay sample and pellet form were compared. It was0found that powder samples have 146P angleindicating the presence of lotus effect. On the other hand,the surface roughness of modified clay particles changesdepending on pressing and the contact angle values0measured on the pellet reduce to about 90 P P. This showsthat the effect of surface roughness on the hydrophobiccharacter is predominant comparison with surface energy.Water droplets cannot penetrate into the pores of thehydrophobic surfaces due to the trapped air [4]. In the bothforms, the reducing of contact areas between the surface6th Nanoscience and Nanotechnology Conference, zmir, 2010 735

PP scatteringPYusufPP CorrespondingPoster Session, Thursday, June 17Theme F686 - N1123Polymer-Nano-Particle Interaction Influence on The Rheology of Non-Newtonian Fluids11UBurcu ÖzelUP P* andP P Z. MenceloluP1PFaculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956, TurkeyAbstract-The aim of the present study is to systematical investigation of physicochemical parameter influence on the rheology of shearthickening/shear thinning behaviour of nano particles integrated polymeric fluids (also referred to as colloidal nanoparticle suspension, CNS) toshed a light on the mechanism behind the dilatant behaviour of CNS, which is an ongoing controversial issue in the relevant literature.Most of the chemical and allied processing industriesencountered non-newtonian flow behavior; namely shearthinning and shear thickening. Shear thinning is a decrease ofviscosity with increase shear rate, although less common, theopposite effect shear thickening occur in various kinds offluids. Shear thickening is often observed in highlyconcentrated colloidal dispersions, characterized by significantincrease in viscosity with increasing shear rate.There has been significant effort to understand the thestructural origin of the shear thickening and differentexplanations have been given; namely, the hydrodynamicclustering and order-to-disorder transition. According to orderdisorder transition (ODT), monodisperse particles hexagonallypacked within the layers but flow instability induce theparticle break out of their ordered layer cause increase inparticle interaction and induce rise in viscosity of the[1]suspension at the critical shear rate.PPThe second theory,hydrodynamic clustering, involves the hydrodynamic force[2-4]driven flocculation of particles.PPThese theories were[1-5]concluded from light/neutronPexperiments as[2,3]well as from Stokesian Dynamic simulationsP howeverODT theory investigated by these techniques can not explainthe shear thickening behavior of polydisperse and irregularparticle suspensions. All concentrated suspensions under rightconditions can exhibit the shear thickening behaviour,however, the exact conditions and the origin of shearthickening behaviour are not well understood.In this study, we studied the effect of constituent parameters;particle size, concentration, surface chemistry, continuousphases, molecular weight and polarity of polymeric phase onthe rheology of non-newtonian fluids.The most important parameter for the shear thickeningbehavior is the colloidal interactions between filler particlesand polymeric fluids. To be able to study the effect of thecolloidal interactions on the rheology of CNS, hydrophobic /hydrophilic fumed silica in the continuous liquid phase withdifferent degrees of polarity have also been studied.Viscoelastic characterization indicate that colloidalinteractions between particles and continuous phase andinteraction strenght can be tailored by modifying the surfacechemistry of silica particles or changing the polarity of thecontinuous phase (see figure). The relative strength of theinteractions between particle-liquid, liquid-liquid and particleparticledetermine whether dispersion is sol or gel. Sol showsshear thickening behavior under shear while gel shows shearthinning behavior.Although substantial number of researches have been studyon the rheology of non-newtonian flow, the nature of the shearthickening behavior of colloidal suspension are not clearlyunderstood until recently. Hydrodynamic clustering and orderdisorder transition theories are not reasonable model toexplain our results because most of the studies in literatureinvestigate the rheology of suspensions that are composed ofmonodisperse/nonagglomerated sphere particle. In our case,primary flow units are composed of flocs which arepolydisperse, irregular and anisotropic structures, flocstructure was observed in cryoscopic transmission electronmicrographs and observed hydrodynamic radius wassupported by dynamic light analysis. We designed anexperiment in order to support new theory about the origin ofshear thickening. Polyethylene glycol and hydrophilic fumedsilica is known to exhibit shear thickening behaviour. In thisHTpreliminaryTH study, lithyum chloride is dissolved inpolyethylene glycol to make it conductive hence mixture iscomposed of insulating particles and conductive continuousmedia. Conductivity of system was measured during viscosityanalysis and decrease in conductivity of system at criticalshear rate give a clue about the mechanism of this rheologicalbehaviour. Decrease in conductivity at critical shear rateindicate that effective volume fraction of insulating particleincrease therefore resistivity of system increase. As aconclusion, we believe that shear thickening is not driven bythese two theories that are suggested by publications. It is dueto shear driven reduction of cluster size, as a consequence,well disperse particles increase of the effective volumefraction of particles in dispersion.abFigure 1. Viscoelastic characterization of (a) shear thickening (b)shear thinning fluids*author: burcugenc@su.sabanciuniv.edu[1] R.L. Hoffmann, J.Colloid Interface Science 1972, 16, 155–173[2]G.Bossis, J.F.Brady, J.Chem.Phys. 1989, 91, 1866–1874[3] D.R.Foss, J.F.Brady, J. Fluid Mech. 2000, 407, 167-200[4] B.J.Maranzano, N.J.Wagner, J. Rheol. 2001, 45 , 1205–1222[5] H.M.Laun, R.Bung, S.Hess, W.Loose, O.Hess, K. Hahn,E.Hadicke, R. Hingmann, F.Schmidt and P.Lindner, J. Rheol. 1992,36, 743.6th Nanoscience and Nanotechnology Conference, zmir, 2010 736

Poster Session, Thursday, June 17Theme F686 - N1123Preparation and Characterization of Corn Zein Nanocomposite Filmsfor Food Packaging ApplicationsIl KURTULU 1 , Onur ÖZÇALIK 1,2 and Funda TIHMINLIOLU 1,2,*1 Department of Chemical Engineering, zmir Institute of Technology, zmir 35430, Turkey2 Materials Science and Engineering Interdisciplinary Master’s Programme , zmir Institute of Technology, zmir 35430, TurkeyAbstract – Potential of novel corn zein-nanocomposite (CZNC) stand-alone films for gas and water vapor barrier applicationsin food packaging was investigated. Nanocomposites were prepared by dispersing organomodified layered silicate (OMLS)nanoclays within corn zein biopolymer matrix utilizing solution intercalation and melt intercalation methods together.Characterization results showed exfoliated structures of nanoclays within the zein matrix. Improvements in mechanical,thermal and water vapor barrier properties due to exfoliated nanoclays were obtained.Biopolymers offer a noticeable potential of replacingconventional petroleum based polymers in food packagingmaterials. In the last decades extensive research on biobasedmaterials have been conducted and today biopolymerapplications began to be used instead of conventionalpolymers in the industry. Recent advances in nanotechnologyand nanocomposite applications are also remarkable andattractive for biopolymer materials.Food packaging holds an indispensable part of modernlife. As distinct from the past, most of the food products usedtoday are being consumed far from their origin and also aftermonths as well for most of the products. Since introduction ofcheap and useful thermoplastics such as polyethylene andpolypropylene in 1950s, polymers replaced conventionalpackaging materials such as glass or metal and introduced newsolutions and high standards for food packaging. Today theamount of polymeric food packaging waste generated is aserious problem. The amount of waste generated is huge, andrecovery of polymeric materials is very low even compared toglass and metal packaging wastes. For example, in the case ofpolypropylene; which is used in single and multi-layerpackaging with other polymers so characterized as a materialhard to separate and identify in the waste; the recovery ratio isjust about 0.25% according to EPA 2006 statistics [1].Advances in the biopolymeric materials field, which arecapable of complete degradation in the nature, madebiopolymers advantageous alternatives over non-degradableconventional polymers.Protein based biopolymers including corn zein can beprocessed in to films and have excellent barrier to gases andmoderate barrier to water vapor. Characteristic disadvantagesof biopolymers such as low mechanical strength anddependency of their characteristics to moisture should beimproved by utilization of nanocomposite applications thatdraw attention in many fields of material science.Nanocomposite applications enabled researchers andindustry to produce a new era of polymeric compositematerials with enhanced mechanical, barrier, thermal andfunctional properties. Ordered dispersion of nano-sizedparticles, named exfoliated structures, lead to significantimprovements in polymer properties that can not be achievedby conventional composites.Although there are some studies concerning the utilizationof nanocomposite applications of protein based polymers suchas wheat gluten and soy protein [2,3,4], to our knowledgethere is no study related to corn zein nanocomposite films.In this study, novel corn zein nanocomposite stand-alonefilms were developed to examine their feasibility with varyingnanoclay content as an alternative food packaging material forbarrier needs. The (OMLS) content of the samples waschanged from 0% to 5% (weight clay/weight corn zein).Desirable barrier properties of zein films were enhanced byusing two widely used nanocomposite production techniques;solution and melt intercalation; together. First solutionintercalation method was used in the preparation of thesamples. Sonication was utilized for the dispersion of OMLSnanoclays within the corn zein biopolymer chains. Then theprepared solution was poured in to icy water and corn zeinnanocompositeprecipitates were collected and kneaded afterthey dry in an oven with controlled humidity. In the later partof the preparation, a twin-screw extruder suitable fornanocomposite applications with L/D ratio of 40 and 10heating zones integrated with a granule blade was used toprocess the organoclay intercalated precipitates in to granules.Finally, the nanocomposite compounds were pressed in hotpress (Carver) in order to obtain the films to be cut in therequired dimensions for the analysis.Results of the study showed good dispersion ofnanoclays, predicted as successful intercalated and exfoliatedstructures depending on the clay content characterized byXRD analysis. Mechanical tests showed increased YoungModulus in CZNC and decreases in elongation at break valuesas was reported by many researchers for nanocomposites. Thewater vapor permeability of the CZNC showed significantdecreases depending on the clay content. Enhanced propertiesin characterized films are believed to be due to the presence ofordered dispersed clay nanoparticle layers with large aspectratios and good interaction of clays with corn zein chains inthe polymer matrix.*Corresponding author: fundatihminlioglu@iyte.edu.tr[1] Marsh , K., Bugusu, B., 2007. “Roles, Materials, and EnvironmentalIssues”, Journal of Food Science. Vol. 72, pp. 39-55[2] Chen, P. and Zhang, L., 2006. “Interaction and Properties of HighlyExfoliated Soy Protein/ Montmorillonite Nanocomposites”,Biomacromolecules,7 (6), pp. 1700-1706[3] Yu, J., Cui, G., Wei, M., Huang J., 2007, “Facile Exfoliation of RectoriteNanoplatelets in Soy Protein Matrix and Reinforced BionanocompositesThereof”, Journal of Applied Polymer Science, Vol. 104, 3367–3377[4] tunc, S., Angellier, H., Cahyana, Y., Chalier, P., Gontard, N., Gastaldi, E.,2007, “Functional properties of wheat gluten/montmorillonite nanocompositefilms processed by casting”; Journal of Membrane Science, Vol.289, pp.159–1686th Nanoscience and Nanotechnology Conference, zmir, 2010 737

PP toPoster Session, Thursday, June 17Theme F686 - N1123Thermal and Mechanical Properties of Layered Silicate Chitosan Nanocomposite Films11Hale OguzluP Pand UFunda TihminliogluUP P*1PDepartment of Chemical Engineering, zmir Institute of Technology, Gulbahce-Urla 35430,zmir,TurkeyAbstract-This study investigated thermal, chemical, morphological and mechanical properties of layered silicate chitosan nanocompositefilms. The films were prepared by solvent casting method with using different clay contents. Films were characterized by X-Ray Diffraction(XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Transmission Electron Microscopy(TEM). Furthermore, dynamic mechanical analysis (DMA) of the films was performed and storage modulus, loss modulus, damping and glasstransition temperature were measured. Mechanical properties of the chitosan composites were enhanced with the addition of clay. Melt behaviorand degradation temperatures did not change significantly with addition of clay. Morphological studies showed partially exfoliated/ intercalatednanocomposites structures.In recent years, many researches have been aimed toimprove biodegradable properties of polymeric materials,thus; the use of natural polymers has grown extensively. [1]Chitosan is the most abundant natural polymer found in theexoskeletons of crustaceans and insects and in the cell wall offungi and microorganisms which is the deacetylated productof chitin, poly(N-acetyl-D-glucosamine), The disadvantage ofchitosan based-materials is poor physical properties accordingto synthetic polymers. [2] Therefore, the reinforcing fillerssuch as layered silicates can be used to in order to improvephysical properties of chitosan films. The most widely usedlayered silicates are clays having nano-scale dimensionsshown in Figure 1.a Developing chitosan nanocomposites byinserting chitosan chains into interlayer of clay can improve itsmechanical properties.Figure 1. (a)The crystal structure of silicate layers (b) three mainmorphology achievable in nanocomposites structure [3]In the generation of nanocomposites, two specificcharacteristics of layered silicates play an important role. Thefirst one is the ability of silicate sheets to disperse intoindividual layers while the second characteristic is theprobability to modify their surface chemistry through ionexchange reactions with organic and inorganic cations. [4].Depending on the surface properties, level of dispersion andthe strength of interfacial interactions between the polymermatrix and layered silicate (modified or not), three differenttypes of polymer/layered silicate composite structure areachievable which can be seen in Figure 1.bTo enhance dispersion the following experimental procedurewas applied. Firstly chitosan solution was in aqueous aceticacid solution. The solution was mixed and clay solutions withvarious clay contents were prepared by dispersing appropriateamounts of clays. After swollen of clays, sonication processwas applied Clay solutions were added slowly into thechitosan solutions. The 2 %, 4 %, 8 % and 10 % (w/w) claychitosan solutions were obtained. The final solutions werestirred and placed into sonicator. Finally, the films were driedat 50 °C1-1The FTIR spectra between 600 cm-P 4000 cmPPof thenanocomposites were recorded using Shimadzu-FTIR 8400spectrometer. The structure of nanocomposites and the state ofintercalation of the clay were characterized by Phillips X’PertPro MRD with Cu K radiation (=1.54 nm) under a voltageof 40 kV and a current of 40 mA. Degradation temperature ofthe samples were measured by differential scanningcalorimetry DSC, TA instruments Q10 under nitrogen flow of50 mL/min. Glass transition temperatures, loss modulus,storage modulus and damping of the films were measured bydynamic mechanical analyzer, TA instruments.From the XRD experiments, the basal spacing of the clays inpolymer nanocomposites were determined around 2.0 nm.Partial exfoliation and intercalation of the clays were obtained.Thermal results of the composites were tabulated in In Table1. The endothermic peaks indicate the water loss, whileexothermic peaks indicate the degradation temperatures ofpolymer and polymer nanocomposites. Degradationtemperatures of chitosan based nanocomposites were lowerthan the degradation temperature of pure chitosan. Moreover,the mechanical properties were improved with the addition ofclay.Table1.Thermal properties of pure chitosan and chitosan/claynanocompositesEndothermic Peak Exothermic PeakSamples°C (DRminR)°C (DRmaxR)Pure CS 123.85 297.56CS/2 wt % clay 125.55 282.13CS/4 wt % clay 121.89 268.42CS/8 wt % clay 129.26 286.28CS/10 wt % clay 124.50 283.89In conclusion, the results of the study showed that gooddispersion of clays, predicted as partially exfoliated andintercalated morphology depending on the clay content ascharacterized by XRD and TEM. The improvement inmechanical properties of the nanocomposites was obtained.The thermal properties of the nanocomposites films did notchange significantly with the addition of the clay.*Corresponding author: HTfundatihminloglu@iyte.edu.trT[1] M. Kolybaba et al. Science ,297, 5582, (2002)[2] N.V. Majeti and R. Kumar, React. and Funct. Polymers.46, 1–27(2000)[3] G.Choudalakis and A.D. Gotsis European Poly. Journal 45, 4(2009)[4] S. S.Ray and M. Okamotov,Progress in Polymer Science, 28, 11(2003)6th Nanoscience and Nanotechnology Conference, zmir, 2010 738

PPPPPP andPE.Poster Session, Thursday, June 17Theme F686 - N1123Preparation and SEM Characterization of Nanocomposites Based on HDPE and Graphite Powder12223445M. SarkanatP P, UI. H. TavmanUP P*, K. SeverP P, A. TurgutP P, Y. SekiP P, P ErbayP P, F.GünerP Pand I.Özdemir P2*1PMechanical Engineering Dept., Ege University, 35100 Bornova Izmir, TurkeyPMechanical Engineering Dept., Dokuz Eylul Univ., 35100 Bornova Izmir, Turkey3PTDepartment of Chemistry, Dokuz Eylül University, Buca, 35160 zmir, TurkeyPPetkim Petrokimya Holding A.., 35801 Aliaa-zmirPFaculty of Engineering, Bartin University, Bartin, Turkey54Abstract-Polymers which are in general insulating materials, may be made electrically and thermally conductive by the additionof conductive fillers such as graphite, carbon black, metal and metal oxide powders or fibers. In this study the conductive fillersused were nanosized graphite particles, the base material was high density polyethylene (HDPE). Nanocomposites containing upto 30 weight % of filler material were prepared by mixing them in a Brabender Plasticorder. SEM investigations of thecomposites prepared have been performed.Heat buildup in electronic components, lighting,transformer housings, and other devices that produceunwanted heat can limit service life and reduce operatingefficiency. Traditionally, metals which are good thermalconductor, has been used for thermal managementequipment such as heat sinks and heat exchangers. Butmetal parts are heavy and costly to produce. In recentyears, they are being replaced by injection molded orextruded heat-conducting plastic compounds that providelightweight cooling solutions. Advantages include designflexibility, parts consolidation, corrosion and chemicalresistance, reduction of secondary finishing operations,and the processing benefits of plastics. Polymers which ingeneral have low thermal conductivities (0.1-0.5 W/m.K)are made conductive by compounding conductive fillerssuch as graphite fibers and ceramic particles. Somethermally conductive plastics may offer up to 500 times (to100 W/mK) the conductivity of base polymers. Thesematerials can be used to tailor the thermal conductivity toindividual applications, providing the ability to dissipateheat precisely and efficiently.Various fillers, including metallic powders, are used toproduce thermally conductive polymers. Graphite powdersor fibers are frequently used especially for an improvementof electrical conductivity, antistatic properties as well asthermal conductivity of plastics, [1], [2]. The recentadvancement of nano-scale compounding techniqueenables the preparation of highly electrically conductivepolymeric nanocomposites with low loading of conductivefillers. Nanocomposites may offer enhanced physicalfeatures such as increased stiffness, strength, barrierproperties and heat resistance, without loss of impactstrength in a very broad range of common synthetic ornatural polymers. In this study the conductive filler wasgraphite with an average particle size of 400 nm and purityof 99.9%, the matrix material was high density3polyethylene (HDPE) with a density of 0.968 g/ cmP amelt index of 5.8 g/10 min, supplied by Petkim A..-zmir. Nanocomposites containing up to 30 weight % ofgraphite powder filler material were prepared by mixingthem in a Brabender Plasticorder at 180°C for 15 minutes.The mixing chamber of the Brabender apparatus was thenopened and the resulting mixture is taken out, then afterpassing through the rollers the mixture was solidified. Theresultant mixture in then put in a compression molding dieand compressed in a compression molding press at 180°C,under 40 kP pressure for five minutes to obtain samples inthe form of sheets of 1mm in thickness.SEM micrographs of graphite–HDPE composites areshown in Figure 1. It can be seen that the graphite powderare dispersed uniformly in the matrix as seen in figure 1.abcFigure 1. SEM micrographs of Graphite reinforced HDPEcomposites a) %4 by weight Graphite reinforced HDPE, b) %10by weight Graphite reinforced HDPE, c) %20 by weight Graphitereinforced HDPEThis research was supported by the Scientific Support ofthe bilateral Project No. 107M227 of TUBITAK and SASand partly by the project VEGA No. 2/0063/09.* corresponding author: HTismail.tavman@deu.edu.trT[1] Krupa,I., Chodák,I., 200, Physical Properties of thermoplastic/graphite composites, Eur. Polym. J., 37(11) 2159-2168.[2] Krupa,I., Novak,I., Chodák,I., 2004, HTElectrically andthermally conductive polyethylene/graphite composites and theirmechanical propertiesTH, Synthetic Metals, 145, 245-252.6th Nanoscience and Nanotechnology Conference, zmir, 2010 739

PP andPoster Session, Thursday, June 17Theme F686 - N1123Optimization of Surface Modified Polymer/MWCNTs Nanofibers as Reinforcement inNanocomposites111UElif ÖzdenUP P*, Yusuf MencelioluP Melih PapilaP1PFaculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956, TurkeyAbstract -The focus of this study is to fabricate composite nanofibers containing MWCNTs and to incorporate them in making reinforced andtoughened nanocomposites. A systematic understanding of the electrospinning process parameters for composite nanofibers was obtained andan emprical relationship between the parameters and the average fiber diameter was established by response surface methodology (RSM).Mechanical tests under flexural loads are reported to demonstrate the effect of the composite nanofiber reinforcement.Nano- to submicron-scale fibers are also recently exploredfor their reinforcing ability in composites. Carbon nanotubes(CNTs) have been widely considered as a filler material dueto their unique electrical and mechanical properties such aselectrical conductivity, high specific strength and stiffness[1]. There are numerous attempts to fabricate CNTsembedded electrospun polymeric nanofiber webs, to enhancemechanical properties of the nanofibrous structure [2,3].However, these composite nanofibers have not beenembedded into polymer matrices to produce nanocomposites.As reported in our previous work [4], surface reactive P(Stco-GMA)nanofibers are promising materials in reinforcingand toughening of the epoxy resin. For its extension,multiwalled carbon nanotubes (MWCNTs) reinforcedpolymer composite fiber webs have been fabricated using theelectrospinning technique.The solutions of P(St-co-GMA)/DMF at various MWCNTsconcentrations (1% wt, 1,5% and 2 % wt) were prepared andstirred magnetically for 24 hour to obtain homogeneity. SincePSt has aromatic ring, long term stabilization of MWCNTs inelectrospinning polymer solution has been successfullyachieved during nanofiber formation, which was alsoprovided by the Dynamic Light Scattering (DLS) analysis.An electrical bias potential (via Gamma High Voltage ES30P-20W) was applied to the polymer solutions contained in2-ml syringe, which has an alligator clip attached to thesyringe needle (diameter 300 m). The applied voltage wasadjusted to 15kV, while the grounded collector was placed at10 cm away from the syringe needle. A syringe pump(NewEra NE-1000 Syringe Pump) was used to maintain asolution flow rate of 30 l/hr during electrospinning.The three level factorial design of experiments wasimplemented to investigate and identify the significance oftwo process parameters (one is the polymer concentration andthe other is the MWCNTs concentration) on the average fiberdiameter, as seen in Figure 1. The morphologies and the fiberdiameters of PSt-co-GMA/MWCNTs fibrous webs wereevaluated by scanning electron microscope (SEM - LEO1530VP). A quantitative relationship between the polymerand the MWCNTs concentration parameters and the averagefiber diameter was sought by response surface methodology(RSM). SEM images demonstrated that P(St-co-GMA)/MWCNTs composite nanofibers were considerablythinner (200 - 550 nm) than P(St-co-GMA) nanofibers (400 –800 nm). This is attributed to the shear thinning effectassociated with the MWCNTs. Due to the shear thinningbehavior, shear viscosity decreased and resulted in reducedfiber diameter along with the increase on conductivity.Considering homogeneity of webs, uniformity and lowvariance in nanofiber diameter, electrospinning solution at30% polymer concentration and 1% MWCNTs concentrationwas preferred.In order to assess the mechanical performance due to theP(St-co-GMA)/MWCNTs composite fibers, they were firstcut into 12 mm x 50 mm pieces. Next, the fiber mats wereembedded into the epoxy resin per our procedure [4].Thermal-mechanical properties of the neat epoxy and thecomposite nanofiber reinforced nanocomposites wereinvestigated by using a dynamic mechanical thermal analyzer(Netzsch DMA 242). The storage moduli of the 30 wt% PStco-GMA/MWCNTs(1 wt%) composite nanofiber, atreinforced nanocomposites are about 20 times higher than theneat epoxy, at weight fraction of the nanofibers being as lowas 2% at 80 C. Mechanical response of nanowebs, at variousMWCNTs and polymer concentration, embedded into epoxyis also underway.Figure 1. The morphology of fibers at applied voltage 15 kV atpolymer concentrations from 25% to 30% wt and MWCNTsconcentrations from 1% to 2% wt with a constant tip-to-collectordistance of 15 cm.*Corrresponding author: HTelifozden@su.sabanciuniv.eduT[1] Treacy, M. M. J.; Ebbesen, T. W.; Gibson, J. M. 1996Exceptionally High Young’s Modulus Observed for IndividualCarbon Nanotubes. Nature, 381, 678–680.[2] Seoul C.; Kim Y.T.; Baek C.K;, 2003, Electrospinning ofPoly(vinylidene fluoride)/Dimethylformamide Solutions withCarbon Nanotubes, Journal of Polymer Science: Part B: PolymerPhysics, Vol. 41, 1572–1577.[3] Sen R.;, Zhao B.; Perea D.; Haddon R. C.; 2004 Preparation ofSingle-Walled Carbon Nanotube Reinforced Polystyrene andPolyurethane Nanofibers and Membranes by Electrospinning, NanoLetters, 4 (3), 459-464.[4] Ozden E.; Menceloglu Y.; Papila M. "ElectrospunPolymer/MWCNTs Nanofiber Reinforced Composites“Improvement of Interfacial Bonding by Surface ModifiedNanofibers”" , 2009 MRS Fall Meeting Symposium FF proceedings.6th Nanoscience and Nanotechnology Conference, zmir, 2010 740

Poster Session, Thursday, June 17Theme F686 - N1123Structural hybrid composites with Polymer/MWCNTs reinforced nanocomposite interlayers*Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956, TurkeyAbstract— The focus of this study is to investigate toughening of conventional carbon fiber/epoxy prepregs by using surfacereactive nanofibers containing MWCNTs as nanocomposite interlayers. Electrospun P(St-co-GMA)/MWCNTs nanofiberswith the average diameter of 500 nm are laid up between carbon fiber prepreg plies and the hybrid composites are cured byvacuum bagging. Mechanical flexural tests of the hybrid composites are carried out. The results demonstrated significantimprovement in flexural modulus and strength due to reinforced nanocomposite interlayers.Interlaminar modes of failure are of concern in laminatedcomposite applications, particularly under shear and impactloading conditions. Poor interlaminar strength is usuallyconsidered as polymer matrix dominated problem for whichthe toughened and reinforced nanocomposites can providesubstantial improvement. As reported in our previous work,the surface reactive P(St-co-GMA)/MWCNTs nanofibers arepromising materials in reinforcing and toughening the epoxyresin [1]. Moreover, it was indicated [2] that nanofiberssupport the load and resist crack opening and delamination.Here P(St-co-GMA)/MWCNTs composite fiber mats wereincorporated as interlayer reinforcement.Inhouse P(St-co-GMA) copolymers were first dissolved inDMF at %30 wt polymer concentration. The solutions werestirred magnetically for 24 hour to obtain homogeneity andthen electrospun to produce the non-woven fiber mats. Syringepump (NewEra NE-1000 Syringe Pump) was utilized tocontrol the solution electrospinning. Applied voltage was adjusted to 15kV whilethe grounded collector was placed 10 cm away from thesyringe needle.The fiber mats were placed between the prepreg plies toform reinforced interlayers by two different approaches. In thefirst method, nanofibers were electrospun onto a collector andpeeled later to be laminated between successive plies. Second,P(St-co-GMA) were directly electrospun onto the conductivecarbon fiber prepregs that were later stacked. Considering theefficiency of production, first method was preferred. Curingcycle was completed 36 hours at 100°C.The laminates with and without nanofiber reinforcednanocomposite interlayers were tested using Universal TestingMachine-ASTM D790 standard in 3 point bending mode.Different ply orientations were considered. Lay-up sequenceswere prepared as laminates of (0/0/0), (0/90/0) and (90/0/90)and hybrid composites of (0/m/0/m/0), (0/m/90/m/0) and(90/m/0/m/90) where “m” stands for fibrous mat interlayers.Preliminary results suggested that the interlaminar strengthof the laminates were improved by using the reactivenanofibrous webs as interlayer reinforcement. Significantimprovement in flexural modulus up to 15% was achieved bythe hybrid composites compared to laminates without thenanocomposite interlayers. Depending on the ply orientations,flexural strength and modulus values of hybrid compositesdiffered (See Figure 1). 0/0/0 lay-up sequence did notdemonstrate significant improvement, in preliminary tests.That would be related to vacuum in curing process or anyexperimental error while laying up. Flexural tests of 0/0/0 and0/m/0/m/0 specimens were repeated. Flexural Modulus (E y )and strength (S F ) of toughened and untoughened composites in0/0/0 lay-up were still low compared to sequences. Nanowebsenhanced the E y and S F in 0/0/0 lay-up while reinforcing thenanocomposite interlayers as in 0/90/0 and 90/0/90orientations.In order to investigate the failure mode of the composites,Scanning Electron Microscopy (SEM) was utilized. SEMmicrographs revealed that failure mode in hybrid compositesdiffer from composites without the interlayers, as shown inFigure 2.Figure 1 Flexural Strength and Flexural Modulus of reinforcedand unreinforced prepregs in 0/0/0, 0/90/0, 90/0/90 sequences.Figure 2 Failure Mode of Toughened Carbon/ Epoxy Prepregs(left) and P(St-co-GMA)/MWCNTs (right-small) nanofibers andnanofibrous webs @100*Presenting author: kaanbilge@sabanciuniv.edu[1] Ozden E.; Menceloglu Y.; Papila M. "ElectrospunPolymer/MWCNTs Nanofiber Reinforced Composites “Improvementof Interfacial Bonding by Surface Modified Nanofibers”" , 2009MRS Fall Meeting Symposium FF proceedings.[2] Gao Y.; Sagi S.; Zhang L.; Liao Y.; Cowles D. M.; Sun Y.; FongH. 2008 J. App. Polym. Sci. 110, 2063–2070.6th Nanoscience and Nanotechnology Conference, zmir, 2010 741

PPPPoster Session, Thursday, June 17Theme F686 - N1123The Surface Modification of ZnO and its Effect on the Properties of Polymer Nanocomposites123Hande Celebi,P PGoknur Bayram,P Pand UAydin DoganUP P*PDepartment of Chemical Engineering, Anadolu University, Eskisehir 26555, TurkeyPDepartment of Chemical Engineering, Middle East Technical University, Ankara 06531, TurkeyPDepartment of Materials Science and Engineering, Anadolu University, Eskisehir 26555, Turkey231Abstract- Polymer nanocomposites based on thermoplastic poly(ether ester) and zinc oxide (ZnO) were prepared by melt mixing using a microcompounder.The electrical, thermal and mechanical properties of the nanocomposites with various ZnO concentrations were investigated. Theresulting properties depend on the matrix-filler and filler-filler interactions were detailed as the aim of this study.In recent years polymer nanocomposites have attracted greatinterest and have a wide potential application in diverse areas[1]. They combine the properties of inorganic materials andpolymers in a unique structure such as ease of processing,chemical stability of polymers and high modulus and electricalbehavior of inorganic fillers [2]. Some of the properties ofthese materials differ from both the polymer matrix andinorganic nanoparticles.Thermoplastic elastomers are a new and important class ofengineering polymers, with the properties of vulcanizedrubbers and processability typical of thermoplastic elastomers[3]. These materials combine good low temperature flexibilitywith an excellent mechanical and thermooxidative stability upto high temperatures and a good resistance against manychemicals [4].ZnO has received broad attention in materials research dueto its versatile properties, ease of preparation and low cost [5].Because of its prominent properties, it can be potentially usedas catalysts, gas sensors, semiconductors, varistors,piezoelectric devices, UV shielding materials and antibacterialagents [2].The objective of this study was to prepare and characterizemultiblock thermoplastic poly(ether ester) and theircomposites. This study consisted of three parts. In the first partof the study, the copolymers of poly(butylene terephthalate) –poly(tetramethylene ether) glycol (PBT-PTMEG) weresynthesized by the two stage polycondensation method.In the second part, zinc oxide (ZnO) particles weresynthesized by homogeneous precipitation method. This wetchemical route for the synthesis of nanostructures is a valuablealternative to conventional processing methods. Water-basedchemical methods offer numerous advantages like beingenvironmentally benign, using cheap and easy handle startingproducts and low cost, uncomplicated equipment, whilerequiring only a new energy input [5]. The synthesizedparticles, which were approximately 300 nm in dimension(Figure 1) were modified with polyvinylpyrrolidone (PVP) toimprove the compatibility between the polymer matrix. Theparticles were investigated by HFourier Transform InfraredSpectroscopyH (FTIR), Scanning Electron Microscopy (SEM)and TX-Ray Diffraction (TXRD) analysis. The mass of adsorbedPVP on the particle surface was measured as 80 % bythermogravimetric analysis.Figure 1. SEM micrograph of synthesized ZnO particlesIn the last part of the study, composites were prepared byintroducing the fillers into the copolymers by using a meltcompounder. The influence of ZnO modification andconcentration on the properties of the nanocomposites wasstudied by SEM, mechanical, thermal and electrical analysis.SEM investigations showed homogeneous dispersion of thefillers in the matrix. The mechanical properties weredetermined by tensile tests. The tensile strength of thenanocomposites decreased with increasing ZnO content. Onthe other hand, the elastic modulus values of the compositesincreased with the incorporation of ZnO particles. There was asharp decrease in elongation at break values with increasingfiller content. It was found that addition of ZnO increasedthermal stability, while it decreased coefficient of thermalexpansion of the composites at low temperatures. Theinteraction of the polymer-matrix was improved bymodification of ZnO particles with PVP. Its effect was seen onthe mechanical properties of composites. However compositesincluded modified ZnO as fillers had lower thermalconductivity values than the composites with unmodifiedZnO. The electrical resistivity of composites remainedconstant until 15 wt % ZnO concentration and then started todecrease by 3-4 orders of magnitude. There was not a greatdifference in electrical resistivity values of thepolymer/unmodified ZnO composites when compared topolymer/modified ZnO composites. The results showed thatZnO filled elastomers could be used as thermal interfacematerials and as antistatic materials.*Corresponding author: adogan@anadolu.edu.tr[1] E. Tang, G. Cheng, X. Ma, Powder Technology, 161, 209 (2006).[2] S.C. Tjong, G. D. Liang, Materials Chemistry and Physics, 100, 1(2005).[3] Z. Roslaniec and D. Pietkiewicz, in Handbook of ThermoplasticPolyesters, edited by S. Fakirov (Wiley, Weinheim, 2002), p. 581[4] W. Gabrielse, M. Soliman, K. Dijkstra, Macromolecules, 34,1685 (2001).[5] H. V. Rul, D. Mondelaers, M. K. Bael, J. Mullens, J. Sol-Gel SciTechn, 39, 41 (2006).6th Nanoscience and Nanotechnology Conference, zmir, 2010 742

P461–464.Poster Session, Thursday, June 17Theme F686 - N1123The Effect of TiCN Coatings on Frictional Properties of Orthodontic Archwires11111Uengül DanmanUP P*, Soner SavaP P, Gülfem IkP P, Tancan UysalP Pand Ahmet YacP1PErciyes University, Kayseri-TurkeyAbstract-One of the main problems in the orthodontic treatment is the frictional forces on the archwires. The geometry of an archwire and thecoatings applied on archwires affect these forces. In this study, the archwires were coated with TiCN by using dc reactive magnetron sputteringmethod. It was found that the coefficient of frictions of the TiCN coated archwires were much lower than those of uncoated archwires.Hard ceramic coatings deposited by PVD (Physical VapourDeposition) techniques have been widely used in differentindustries because of their excellent coating properties: highhardness, good wear, corrosion and oxidation resistance,chemical resistance and good adhesion to the substrate. Today,in the field of biomedical applications - such as surgical tools,implants, lenses, stents, and materials used in dentistry - Ti,TiN, ZrN, TiAlN, DLC, etc. are successfully used as single ormultilayered or nanolayered coatings. These coatings alsohave good bio-conformity with the human body [1-6].The objective of this study was to shorten the activetreatment time in the orthodontic treatment by reducing thestatic and dynamic friction between the brackets andarchwires. It was clearly seen that the friction was affected notonly archwire geometry and materials but also surface qualityof archwires. Today, esthetic brackets are preferred to thetraditional ones and, therefore, frictional forces on archwiresare increased. These forces affect the movement of thearchwire and extend the duration of the treatment. Therefore,low frictional coatings are very important for orthodonticarchwires.In this study, the archwires were coated with TiCN by usingdc reactive magnetron sputtering method with the optimumdeposition parameters. The dynamic and static frictionalforces and surface roughnesses of the TiCN-coated anduncoated archwires (NiTi, BTi (TMA) and stainless steelarchwires, 0.017"x0.025" and Ø0.016" in dimensions) weremeasured. Then, the friction coefficients of TiCN coated anduncoated archwires were determined by using CSEM testerunder the frictional forces (10 mm/min progress speed and 10N load were used as test parameters) and the results werediscussed comparatively.The friction tests showed that TiCN coated archwires hadlower coefficient of friction values than those of uncoatedarchwires. The coefficient of frictions of the TiCN coated B-Ti, Ni-Ti archwires as shown in the Fig.1b were foundsuperior to the stainless steel in spite of the roughness ofstainless steel was lower than the others (Figure 1a). In theliterature it was not encountered that friction and roughnesswas definitely related each other [1-7].These findings indicate that TiCN coated B-Ti archwireshowed lowest friction coefficient but these results are nearthe values of TiCN coated Ni-Ti archwires. The obtainedresults are in good agreement with the literature.Figure 1. a) RRaR surface roughness, b) coefficient of friction values ofthe coated and uncoated archwires of different geometry.This study was supported by the Office of Scientific ResearchProjects in Erciyes University (Project no: FBT-09853).*Corresponding author: sdanisman@erciyes.edu.trT[1] TProbst, J., Gbureck, UT., Thull, R., 2001, Surface and CoatingsTTechnology, 148, 226-233.[2] Vadraj, A., Kamaraj, M., 2007T, Tribology International, 40, 82-88.T[3] TPaschoal, A.L., Vanânco, E.C., Canale L.C.F., Slva, O.L.,Huerta-Vlca, D., Motheo A.J., 2003T, 27 (5), T[4] Kobayashi, S., Ohgoe, Y., Ozeki, K., Sato, KT., Sumya, T.,Hrakur, K.K., H. Aok, H., 2005, 14, 1094– 1097.T[5] Ohgoe, Y. et al., T2006, Thin Solid Films, 497, 218–222.[6] Redlich, M., Katz, A., Rapoport, L., T Wagner, H.D., Feldman Y.,Tenne RT., T2008,T TDental Materials, Article in Pres.T[7] Kusy, R.P., Whitley, J.Q., Mayhew, M.J., Buckthal, J.E., 1988,Angle Orthod., 58 (1), 33-45.6th Nanoscience and Nanotechnology Conference, zmir, 2010 743

PPoster Session, Thursday, June 17Theme F686 - N11231Dilatation Fields Of The NiSiR2R/Si Bicrystal1UHülya ÖztürkUP P*PAhi Evran University, Faculty of Sciences and Arts, 40100, Krehir, TurkeyAbstract- The elastic displacement and dilatation fields are derived in the frame of the classical isotropic elasticity theory by using a Fourierseries analysis for the two media, one of the media tends to infinity and the other one has the thickness of h. These two media are supposed toobey classical Hooke’s law and are assumed to be elastically isotropic. The dilatation fields depend on thickness of h. Applications werepresented for the NiSiR2R/Si bicrystal.Because of the fact that the diffusion paths of vacancies andatomic species are orthonormal curves to equi-dilatationsurfaces, it is important to determine the dilatation fields.Several authors have investigated dilatation fields of bicrystals[1-3]. Dilatation fields have been calculated in the twoisotropic media which have biperiodic networks of misfitdislocations in their interfaces. Interfacial dislocationsnetworks produce in each medium the displacement and stressfields whose components can be developed in Fourier series[2,4].Limiting boundary conditions have been investigatedbecause the elasticity problem is too difficult in the generalcase. Along the interface normal forces are transmitted [5-6]and along the free surface there are no applied stresses [7].Therefore, for x 2h the 2 j( j = 1, 2, 3) are zero. Therelative interfacial displacement fields u 1and u vary3linearly versus x and x between two parallel dislocation1 3lines spaced with a , respectively.In this study, partly based on some previous formulations[2,3,8] used for an epitaxial layer deposited on a substrate, itwas present the relative displacement (Figure 1) and dilatation(Figure 2) curves for the NiSiR2R/Si bicrystal.-10.00Dilatation50.0030.0010.00-30.000.00 20. 00 40.00 60.00h (nm)Figure 2. Dilatation for misfit dislocations placed at the interface ofNiSiR2R/Si bicrystal.[(u1+) -(u1-)] (nm)0.200.100.00*Corresponding author: HThozturk@ahievran.edu.trTH[1] Bouzaher A, and Bonnet, R, Phil Mag A, 66 (1992) 823.[2] Bonnet R, Phil Mag A, 73 (1996) 1193.[3] [3] Öztürk, H, Çakan N, Saraçolu H, Soylu S, Bul of Pure and App.Sci, 22D (2003) 101.[4] Bonnet R, Phil Mag A, 43 (1981)1165.[5] Bonnet R, Loubradou M and Pénission J M, Phys Rev Lett, 69(1992)104.[6] Lucas C A, and Loretto D, Appl Phys Lett, 60 (1992) 2071.[7] Mura T, Micromechanics of Defects in Solids, (Kluwer AcademicPubl., Netherlands) (1991) 178.[8] Öztürk H, Trans Indian Inst Met, 60 (2007) 577.-0.10-0.20-20.00 -10.00 0.00 10.00 20.00x1 (nm)Figure 1. Relative displacement along the Ox axis for misfit1dislocations placed at the interface of NiSiR2R/Si bicrystal.6th Nanoscience and Nanotechnology Conference, zmir, 2010 744

Poster Session, Thursday, June 17Theme F686 - N1123New Trends in Tribology and Nano- Mesoscale TribologyY. SoydanSakarya University, Faculty of Mechanical Engineering, Turkey.Abstract—In this paper, the author presents a review of new trends in tribology among which are the micro to meso and nanoscaletransition, the development of new experimental apparatus, nanotribological applications of bioengineering, biomimetic, automotive,manufacturing, lubrication, surface engineering, magnetic storage systems materials, micro or nanoelectromechanical systems etc.Tribology is the science of interacting surfaces in relativemotion. Nanotribology can be defined as the investigationsof interfacial processes occurring during friction,nanoindentation, thin-film lubrication, and wear at thenanometer scale. Understanding and controlling matter at thenanoscale interests researchers in the sciences and industrybecause materials properties at the nanoscale can be verydifferent from those at a macro scale. Nanotribology today,widely uses many new instruments designed over the last 50years, such as AFM [1], the FFM [2], SFA, STM and QCMare able to perform experiments on well characterized modelsystems at the nanoscale [3]. From the technical point ofview, however, some difficulties take place if wear is spottedwith a friction force microscope. The suggested approach isbased on the combination friction force and dynamic forcemicroscopy [4]. Studies on origin of tribological features atthe atomic scale, since they highly depends on the surfaceinteractions, using sophisticated experimental andcomputational tools should be utilized in order to provide adeeper understanding of friction in nanoscale [5].Fig.2. Schematic image of skin structure with different layers [9]The tribological applications in current engine materialsare argued in scientific community. Several suggestedinterfaces are going to be considered with a brief history ofmaterials used and some explanation of future trends [11].Tribology associated with the maintenance of productionequipment is called maintenance tribology [10].Control of the structure and composition of coatings atthe nanoscale is an interesting scientific subject combinedwith an industrial challenge. In recent years, numerousexciting developments have been done in the fields oftribological and solid lubricant coatings (Fig.3). One of mostimportant development is the coating for dry and near drymachining applications. No doubt that such coatings willbecome available in the near future [12].Fig.1. Example of MEMS components after laboratory wear test [9].Additionally, MEMS/NEMS and BioMEMS/BioNEMS arealso used in electromechanical, electronics, chemical, andbiological applications. Therefore, MEMS/NEMS materialsneed to exhibit good mechanical and tribological propertieson the micro/nanoscale. Methods need to be developed toenhance adhesion between biomolecules and the devicesubstrate. Fig.1 shows a polysilicon, multiple microgearspeed reduction unit after laboratory wear tests conducted[6].Biologically inspired design or adaptation or derivationfrom nature is named as “biomimetics.” Several creaturesincluding insects, spiders, and lizards, have developed aunique clinging skill that utilizes dry adhesion [7]. On theother hand, for most people, cleaning and maintenance oftheir skin is a daily process. A systematic characterization ofthe friction and adhesion properties of skin and skin creamare also carried out on the nano- and macroscale, which isessential to develop better skin care products and advancebiological, dermatology, and cosmetic science (Fig.2) [8].Moreover, process tribology plays an important role inthe automobile manufacturing industry. It mainly concernsabout friction, lubrication and wear during the metal formingprocessing where four elements of die, work, lubricant andexternal conditions [10].Fig.3. Historical development of tribological coatings and solid lubricantfilms over the past 25 years on this subject.* Corresponding author: soydan@sakarya.edu.tr[1] Deng H, Scharf TW, Barnard JA., J Appl Phys 1997;81:5396–8.[2] Schonherr H, Vancso GJ., Macromole cules 1997;30:6391–4.[3] O.M. Braun, A.G. Naumovets, Surface Science Reports 60 (2006)[4] J. E. Schmutza at al., Wear 268 (2010)[5] C.A.Charitidis, Int. Journal of Refractory Metals & Hard Mat.28 (2010)[6] B. Bhushan, Microelectronic Engineering 84 (2007).[7] B. Bhushan, Conference on Trends in Nanotribology, 2009[8] W. Tanga, B. Bhushan, Colloids and Surfaces : Biointerfaces 76 (2010)[9] A. Shai, H.Maibach, R. Baran, Handbook of Cosmetic Skin Care, 2001.[10] Y. Tsuchiya, Rev,ew of Toyota CRDL, 34, 1999.[11] E. P. Becker, Tribology International 37 (2004) .[12] C. Donneta, A. Erdemir, Surface and Coatings Technology, (2004).6th Nanoscience and Nanotechnology Conference, zmir, 2010 745

PPP andP (.cm).Poster Session, Thursday, June 17Theme F686 - N11230BTemperature Dependent Electrical Conductivity of Ardel D-100 / MWCNT Nanocomposite121Murat ÇalkanP P, Dolunay akarPUMerih SerinUP P*1PDepartment of Physics, Yildiz Technical University, stanbul 34210, Turkey2PDepartment of Chemistry, Yildiz Technical University, Istanbul 34210, TurkeyTAbstractT-In this work, ARDEL D-100/MWCNT (1.5 wt%) nanocomposite was studied. The characterization of the electrical properties ofprepared nanocomposite with respect to the temperature were studied. Direct-current measurements with a continuously changing temperatureof sample were presented. The resistivity of the ARDEL D-100 was decreased by 10 order of magnitude onaddition of 1.5wt%of MWCNT.Multiwalled carbon nanotubes (MWCNTs) areconsidered to be the ideal reinforcing agent forhigh-strength polymer composites, because of theirfantastic mechanical strength, high electrical and thermalconductivity and high aspect ratio [1].ARDEL D-100 which is high engineering thermoplasticand an amorphous aromatic polyester of bisphenol-A withterephthalic and isophthalic acid (50/50) was studied. It hashigh heat-deflection temperature, high impact strength andgood electrical properties [2].Our aim was to obtain an insight of the mechanism of theconductivity of ARDEL D-l00/MWCNT nanocompositeand to determine the characteristic glass transitiontemperature, Tg, of the sample. For this purpose, thecharacterization of the electrical properties of preparednanocomposite with respect to the temperature werestudied. Direct-current measurements with a continuouslychanging temperature of sample were presented.ARDEL D-100/MWCNT (1.5 wt%) nanocomposite wasprepared by melt mixing at 300 °C, 50 rpm in 5 min. Thiswas carried out in the Leibniz Institute of Polymer ResearchDresden. The film of melt compounded ARDEL D – 100 /MWCNT (1.5wt%) nanocomposite was prepared viasolvent casting method on glass substrate.The volume resistivity of melt mixing sample wasdetermined by measuring the DC resistance on the pressedplates. The measurement was performed on strips cut fromthe pressed sheets using a four-point text fixture combinedwith a Keithley DMM 2000 electrometer. Prior to themeasurement, the surface of the sample was cleaned withethanol. This was carried out in The Leibniz Institute ofPolymer Research Dresden.For the electrical characterization, dark conductivity ofproduced films were measured as a function of temperatureusing a Janis liquid nitrogen vacuum cryostat, having athermocouple in good thermal contact with the sample.Samples were placed on top of a copper plate that is heatedby a bolt heater embedded within.Temperature was controlled by Lakeshore TemperatureController 331. Dark conductivity measurements wereaccomplished using a programmable Keitley 6517A digitalelectrometer/voltage source interfaced to a computer.The temperature dependence of conductivity wasmeasured as the temperature being increased at a constant-1rate of 3K minPP. The film thickness was determinedfrom the area formed by spreading polymer solution withknown volume and concentration.The change in the conductivity of the sample wasexperimentally measured under a constant electrical field.-6The measurements were carried out in l0PPTorr vacuum andthe dark. The electrical conductivity of the polymer wasmeasured in AI/ARDEL D-100/MWCNT/A1 structureover the temperature range of 300-520K.The volume resistivity of pure ARDEL D-100 was14measured as 1.54x10P The volume and specificresistivity of the nanocomposite sample was measured as453.5lxl0P P(.cm) and 8.56 xl0P P(.cm), respectively, at roomtemperature.In summary, we showed that the resistivity of the ARDELD-100 was decreased (conductivity increased) by ten ordersof magnitude on addition of 1.5wt% MWCNT.The electrical conductivity values of ARDEL D-100/MWCNT with increasing temperature, which would beuseful for a wide range of applications, were achieved. Thisnanocomposite film showed semiconductor behavior withthe exponential variation of inverse temperaturedependence of electrical conductivity. Therefore, it ispossible to explain the conduction mechanism of thenanocomposite by using existing solid state theory.This work was partially supported by the Leibniz Instituteof Polymer Research Dresden, and by Yildiz TechnicalUniversity, Scientific Research Project Coordination, underGrant No. BAPK-2001-01-01-01 andBAPK-2007-01-01-07.*Corresponding author: serin@vildiz.edu.tr[1] EW. Wong, PE. Sheehan, CM. Lieber. Science, 277:1971–5,(1997).[2] D. Sakar, O. Cankurtaran and F. Karaman, Journal ofApplied Polymer Science, 98(6): 2365-2368 (2005).6th Nanoscience and Nanotechnology Conference, zmir, 2010 746

PP,PP*PPoster Session, Thursday, June 17Theme F686 - N1123Tribological Properties of Al/AlR2ROR3R Nano-composite Surface Layer on Al-based Substrate111Aziz Shafiei ZarghaniPPSeyed Farshid Kashani-BozorgPPand Abbas Zareie-HanzakiP1PSchool of Metallurgy and Materials Engineering, University of Tehran, Tehran, IranAbstract-Friction stir processing technique was employed for the production of Al/AlR2ROR3R nano-composite surface layer on Al-based substrate;Nano-size AlR2ROR3R particulates were introduced into the stir zone and dispersed uniformly within it by optimizing the process parameters. Microhardness value and wear resistance of the fabricated layer and the untreated substrate were evaluated. The micro hardness value of the surfacenano-composite layer was found to be improved by almost three times of that of the as-received Al alloy. Also, significant improvement in wearresistance was exhibited by surface nano-composite layer as compared to the as-received substrate. The improved wear resistance of surfacenano-composite layer is attributed to its greater micro hardness value (due to grain refinement of the Al matrix and uniform dispersion of nanosizeAlR2ROR3R particulates).Metal matrix composites reinforced with hard ceramicparticulates can offer relatively higher strength, stiffness, andsuperior wear resistance than those of the un-reinforced matrixmaterial. Surface modification processes can provide hardsurface with enhanced wear properties while the materialretains its internal ductility and toughness. Friction stirprocessing (FSP) is a solid state processing technique to obtainsurface modified/composite layers with fine-grainedmicrostructure [1-2]. The aim of the present investigation wasevaluation of wear performance of surface nano-compositelayer produced using FSP.An A6082 aluminium substrate with a thickness of 7 mmwas used. A groove was machined through the center of thesubstrate. Nano-size AlR2ROR3R powder with an average particlesize of ~50nm was filled in groove. The FSP unit was amodified form of a conventional miller machine. A hardenedH-13 tool steel pin was used. A tool rotation rate of 1250 rpmwas used, and the rotating tool was traversed at a speed of 135mm/min along the long axis of the work piece. Samples weresubjected to various numbers of FSP passes from one to four.Fig. 1 shows that uniform dispersion of AlR2ROR3R was achievedusing four FSP passes. The dark regions in images are AlR2ROR3RFigure 1. Secondary electron image of the surface nanocompositelayer fabricated using four FSP passes at fixed toolrotation rate and travel speed.particles which have been verified using energy dispersivespectroscopy, and the white particles are strengtheningprecipitates of A6082 alloy which are dispersed in the Almatrix. The grain size of Al matrix was refined by the FSP. Itseems that the grain refinement was caused due to dynamicrecrystallization during the FSP. However, the FSP with thenano-size AlR2ROR3R particles more effectively reduced the grainsize of the A6082 alloy matrix. For example, some matrixgrains of the surface nano-composite layer produced by fourFSP passes were less than 300 nm while the grain size ofA6082 extruded bar was 120m. The surface nano-compositelayer produced using four FSP passes exhibited almost a threetimes increment of the hardness value of the parent Al alloy(312 compared to 110 Hv).Figure 2. The wear loss weight of the as-received substrate andsurface nano-composite layer fabricated using four FSP passesas a function of sliding distance.The wear loss of as-received Al and surface nano-compositelayer fabricated using four FSP passes were measured by apin-on-disc wear testing machine against hardened GCr15steel disc with hardness of about 60 HRC under 40N appliedload. It may be noted that wear loss is considerably reduced(to almost two or three orders of magnitude) due to FSPcomposite surfacing (Fig. 2). The superior wear behavior isattributed to improved micro hardness in the surface layerbecause of the presence of hard ceramic particles and grainrefinement.In this investigation, Al/AlR2ROR3R surface nano-compositelayer was successfully fabricated by the FSP and tribologicalbehavior was studied. Hardness and wear resistance of thesurface nano-composite layer produced by four passes issuperior to those of the matrix alloy; this is attributed toimproved micro hardness in the surface layer because of thepresence of hard ceramic particles and grain refinement.*Corresponding author: fkashani@ut.ac.ir[1] R.S. Mishra and Z.Y. Ma, Mat. Sci. and Engine. R 50, 1(2005).[2] R.S. Mishra et al. Mat. Sci. and Engine. A 341, 307 (2003).[3] Y. Morisada et al. Mat. Sci. and Engine. A 419, 344 (2006).[4] A. Shafiei-Zarghani et al. Mat. Sci. and Engine. A 500, (2009).6th Nanoscience and Nanotechnology Conference, zmir, 2010 747

PP tiltP andP editionPoster Session, Thursday, June 17Theme F686 - N1123Fabrication of Surface Nano-composite Layer on Mild Steel Using Friction Stir Processing Technique11A. AbediPUS.F.Kashani-BozorgUP P*1PSchool of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran, Tehran, IranAbstract-Friction stir processing technique was employed for the fabrication of surface nano-composite layers on a mild steel substrate. The SiCpowder was inserted into the groove which was passed by the hardened rotating tool. Optimizing the rate of tool rotation/advancing speed anddepth of the groove resulted in surface nano-composite layer with uniform dispersion of nano-size SiC particulates. The fabricated surface nanocompositelayer showed to have a maximum micro hardness value of ~480HV compared to ~136HV of the untreated substrate.Mild steel is used as a structural material in the industry andconstruction. However, the wear resistance property of mildsteel is considered to be poor in certain applications.Dispersion of hard ceramic particles in the metallic matrix hasreceived considerable interest due to improvement of strength,stiffness and wears resistance as compared to the monolithiccounterparts [1]. Friction stir processing (FSP) is a solid statetechnique for the fabrication of surface composite layer. InFSP, a rotating tool consisting of a shoulder and a probe isplunged into a work piece and then travels in the expecteddirection. The tool serves two primary functions: heating anddeforming the material. After extreme levels of plasticdeformation and thermal exposure, the processed zonenormally exhibits significant microstructural refinement [2]. Incomparison with other surface modification techniques (highenergy laser treatment, plasma spraying, etc), FSP is carriedout at the temperatures below melting point of substrate [3]. Inthis work, FSP was carried out by high power conventionalmiller machine. Mild steel plate with a thickness of 10mm andnano-size SiC powder with an average size of ~70nm wereused as substrate and reinforcement particulates, respectively.The tool material has smooth frustum shape; it was made ofWC that inserted to mild steel body. This was applied due to0reducing the risk of brittle fracture of WC. A 3P angle wasapplied to the tool. For lying SiC nano-particles, a groove withdepth and width of 1.5 and 1 mm was machined thorough thework pieces, respectively. A “technological hole” was drilledto mild steel plate in initial of a groove. This hole can easeprocess and decrease wear of tool in plunging phases. Toavoid surface oxidation of the FSP zone, argon shielding was5 3employed around the tools at a flow rate of 10P PmmP P/sec. Inorder to achieve the favorite result, several rotational andtransverse speeds were employed; uniform dispersion nanoparticleswas obtained using 1000 rpm and 55 mm/min asrotational and advancing speeds, respectively. Microstructuralobservations of cross-section of the friction stir processedzone were performed by scanning electron microscopy.Samples were prepared by wire cut in 3×1.5×1 cm pieces.These samples were mechanically ground with abrasive paperand polished with 3m diamond, and then etched in a solutionconsisting of 5ml nitric acid and 95ml ethanol solution. Alsomicro hardness was measured by 200gram load for 12s, in 3mm under surface, transferring the entire stirred zone into basemetal.Experimental results revealed that a defect-free friction stirprocessed zone was obtained at the applied parameters. Theupper surface showed very smooth quality and there arealmost no prominences or dispersion. The friction stirprocessed sample displayed several microstructurally distinctregions including the stir zone along the processed centerline,heat affected zone (HAZ) surrounding the stir zone and basemetal. Using suitable depth of groove, the SiC particles werewell dispersed within the stir zone as shown in Figure 1. Nodiscernible defect and porosities were observed.Figure 1. Secondary electron image of the fabricated nano-compositesurface layer exhibiting uniform dispersion of SiC nano-particles.If the groove is superficial, a composite layer with low SiCcontent is acquired. On the other hand, if a deep groove isused, clustering of particles is occurred. So depth of thegroove should be selected optimal. Non-uniform distributionwas resulted using relatively high transverse speed. Alsoscattering of nano-particles was observed out of the groovedue to high rotational speed. Increase in FSP passes can resultin more dispersion of nano-particles [3]. The microstructure ofstir zone was characterized by the presence of acicular ferrite.The chaotic arrangement of the plates represents fine grainedinterlocking morphologies. Acicular ferrite is formed in thesame temperature range as bainite (approximately 400 too600P PC) by the same type of transformation mechanism [4].According to the observed microstructure, the majorcontributions to the hardness of the surface composite layersfabricated by FSP are (1) the fine grain size of the Fe-basedmatrix due to severe plastic deformation and (2) Orowanstrengthening due to fine dispersion of nano-size SiC particles.A maximum hardness value of ~480 HV was achieved, whilethat of the as-received base metal was ~136 HV.*Corresponding author: HTfkashani@ut.ac.irT[1] Clyne T.W., Whithers P.J. Cambridge University Press,Cambridge, United Kingdom, (1993).[2] Fujii H., Cui L., Tsuji N., Maeda M., Nakata K. and Nogi K.,Material science and Engineering A 429,(2006).[3] Shafiei-Zarghani A, Kashani-Bozorg S. F., and Zarei-Hanzaki A,Material Science and Engineering A 500, (2009).nd[4] Bhadeshia H.K.D.H, “ Bainite in steels”, 2P , Institute ofthe materials, London, (2001).6th Nanoscience and Nanotechnology Conference, zmir, 2010 748

PPPP PMohsenP,PP andPoster Session, Thursday, June 17Theme F686 - N11233Study the Effect of Carbon Nanotube Orientation on the Shear Modulus of SWCNT/polymerComposites using Hierarchical MD/FE Multiscale Modeling111,23Abbas MontazeriP P*,P P SadeghiPPReza NaghdabadiP Hasehm Rafii-TabarP12PInstitute for Nano Science and Technology, Sharif University of Technology, Tehran, IranPDepartment of Mechanical Engineering, Sharif University of Technology, Tehran, IranPDepartment of Medical Physics and Biomedical Engineering, and Research Centre for Medical Nanotechnology and Tissue Engineering,Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran.Abstract- In this paper, a combination of molecular dynamics (MD) and finite element method (FEM) is used to predict the effect of CNTorientation on the shear modulus of nanocomposites containing SWCNTs as reinforcing elements. The results show that in the case of 45 orientation, SWCNTs have the most effect on the shear modulus of polymer composites.Recent experimental and theoretical investigations havedemonstrated that substantial improvements in the mechanicalproperties of polymers can be obtained by using small volumefractions of carbon nanotubes as reinforcing materials.Various properties such as elastic modulus and break strength,yield strength, max strain, buckling behavior, hardness,ductility and toughness, fatigue life and fatigue properties,creep performance and glass transition temperature have beenmeasured in these studies. A noticeable void in currentliterature is the lack of a computational model for determiningthe shear modulus of these nanocomposites. Meanwhile, thestudy of shear deformation is of particular interest as not onlyit is a basic mode of deformation at the microscopic level, butit also could be used to create high orientation throughout alarge cross section of polymer material. Highly orientedpolymers are well-known to exhibit enhanced mechanicalproperties. Furthermore, shear failure is one of the mostfamous failure mechanisms of nanotube reinforcedcomposites. In addition, shear deformation of nanocompositeshas a great effect on the shear-based production techniques ofthese nanostructures like shear mixing methods.The objective of the present article is to analyze the effect ofsingle-walled carbon nanotube alignment on the shearmodulus of SWCNT-reinforced polymer composites using anew hierarchical MD/FE multiscale method. To achieve thisend, first, a transverse-isotropic elastic model of SWCNTs isformulated that combines methods from continuum elasticitytheory and molecular dynamics simulation. This model isemployed to predict the transverse-isotropic elastic propertiesof SWCNTs. MD simulations are used to model themechanical behavior of SWCNTs under axial, torsional andradial loadings. Also, continuum-based models using thelinear elasticity theory were employed to model themechanical behavior of SWCNTs under these loadingconditions. The methodology developed herein combines aunit cell continuum model with MD simulations to determinethe transverse-isotropic elastic constants of SWCNTs. Theseatomically informed carbon nanotubes are used in a finiteelement simulation in the next step to investigate the effect ofsingle-walled carbon nanotube alignment on the shearmodulus of CNT-based nanocomposites. Also, continuumbasedfinite element formulation was implemented to analyzethe polymer matrix. Using this hierarchical MD/FE multiscalemodel, we could obtain the shear properties of thesenanocomposites based on the interatomic interactions ofSWCNT atoms with negligible computational costs.Figure 1. (a) A Schematic illustration of the four loading conditionsof SWCNTs: (a) axial tension, (b) torsion, (c) uniform radial pressure(end view), and (d) non-uniform radial pressure (end view).The results depicted the noticeable effect of adding SWCNTsas reinforcement on the shear deformation of polymers.Increasing the carbon nanotube orientation from 0° caused anincrease in the shear modulus of the polymer up to 45° andthen, the reinforcement role of SWCNT decreased. Note thatin 90°, there was not any change in the shear modulus ofpolymer due to addition of the SWCNT. The fact thatmaximum shear modulus of nanocomposite appears in thecase of 45° carbon nanotube orientation, arises from thetransverse-isotropic elastic properties of SWCNTs as depictedby the hybrid MD/continuum model presented in this work.The results revealed that longitudinal Young’s modulus of theSWCNT was much greater than this elastic constant in thetransverse direction. Hence it was anticipated that in the caseof 45° where the resultant tensile force of the shear forcesimposed on the side walls corresponds to the axial direction ofthe SWCNT, the maximum increase in the shear modulus ofSWCNT-reinforced composites should be obtained. Oursimulation results confirmed the idea.*Corresponding author: a_montazeri@mehr.sharif.edu6th Nanoscience and Nanotechnology Conference, zmir, 2010 749

PP andPPoster Session, Thursday, June 17Theme F686 - N11230BElectrical and Magnetic Properties of La0.67Ca0.33MnO3SrTiO 3 Nanocomposites111UShailendra Singh RajputUP P*, Leena JoshiP Sunita Keshri (Shaw)P1PDepartment of Applied Physics, Birla Institute of Technology, Mesra, Ranchi-835215, IndiaAbstractA composite series, has been studied in order to investigate the influence of STO phase onstructural and magneto transport properties of LCMO phase. By X ray diffraction and scanning electron microscopy we find that there is nointerdiffusion between the LCMO and STO phases. The EDX results show that the grains which are smaller in size and mainly distributed atthe grain boundaries and on the surfaces of LCMO grains are of STO phase. Measurements of resistivity on these samples reveal that parentsample shows a distinct metal insulator transition. The series exhibits a conduction threshold at , up to which extrinsictransition temperature decreases along with an increase in extrinsic magnetoresistance; whereas above these trends of variation arereversed. The magnetic phase transitions have been studied by the temperature variation of real () component of AC susceptibility as shownbelow. The parent LCMO sample undergoes a PM FM transition at . After addition of STO, remains almost same.Recently extensive research in nanotechnology andnanoscience is being carried out worldwide. Ananocomposite material composed of two differentnanometer-sized crystallites would have significantlyhigher contact area between the two compounds, and maytherefore posses an enhanced magneto electric effect. Oneof the most serious problems in the practical application ofnew manganite colossal magnetoresistance (CMR)materials remains to be their in sufficient magnetoresistive(MR) response at room temperature in weak magneticfields, used in most of the potentially interesting devices[1]. Much effort has been made to enhance the propertiesof these materials, such as synthesizing CMR–insulatorcomposites. These extrinsic effects rely on the existence ofan insulating tunneling barrier separating theferromagnetic grains. Such attempts include LCMO BTO[2], LCSMO CoFeR2ROR4R [3] etc and so on. Most of suchresults show enhancement in MR. Our previous work hasshown that making LSMO-based composite provides anefficient way to enhance and control electrical transportand MR [4]. In present report the magnetic and electricproperties of a series of CMR ferroelectric (FE)composites have been studied.A composite series where= 0.0, 0.10, 0.15, 0.20, 0.30 and 0.40 samples wereprepared in two steps. In this process firstly single phaseLCMO was prepared by pyrophoric method. It was thenmixed with fine powder of STO (Alfa Aesar, 99.99%) inrequired ratio and pressed into pellets. The pellets wereResistivity(cm)x=0.40x=0.30x=0.20x=0.10x=0.050 100 150 200 250 300T (K)Figure 1. Temperature variation of resistivity for compositefinally sintered at 900 C in air for 2 hr, and then slowlyfurnace cooled to room temperature..The XRD and SEM analysis exhibits that the compositesconsist of two phases: one is LCMO perovskite phase; theother is STO phase, which clearly indicates thecoexistence of LCMO and STO phases. The variation ofresistivity as a function of temperature in zero fields for allcomposites in the temperature range 10–300K is shown inFigure 1. The parent LCMO sample shows metal- insulator(M-I) transition at a temperaturefollowed bya broad hump. In all grown composites of this series, asmall peak corresponding to M-I transition of parentLCMO occurs at 240K. With the increase of STO contentupto to , decreases and resistivity () atincreases as shown in Figure. But for , a reversetrend is observed, i. e. again increases with a smalldecrease in resistivity. The magnetic phase transitions havebeen studied by the temperature variation of real ()component of AC susceptibility. The LCMO sampleundergoes a PM-FM transition at Tc ~270K. After addition (Arbitrary unit)x=0.40x=0.30x=0.20x=0.10x=0.00 50 100 150 200 250 300T (K)Figure 2. Real part of AC susceptibility for all samplesof BTO, Tc remains almost same indicating thatstoichiometry of LCMO phase within the grains remainsessentially unchanged. Since STO is nonmagnetic in themeasured temperature range, the ferromagnetic order ofthe composites comes up only from LCMO.In summery a nanocomposites series has been preparedby pyrophoric method. From XRD, and SEM results thecoexistence of both the phases has been confirmed. Theparent sample shows a distinct transition at .From resistivity data it is concluded that for this series,conduction threshold occurs at STO content. S.Keshri gratefully acknowledges Department of Scienceand Technology (DST), India for financial assistance. L.Joshi and S. S. Rajput gratefully acknowledge Council ofScientific and Industrial Research and DST, India forproviding fellowship, respectively.* Corresponding author: HTShailendra.phy@gmail.comT[1] Daughton, J-M., 1999. GMR application, J. Magn. Magn. Mater,192: 334-342.[2] Keshri, S., Joshi, L., Rout, S-K., 2009. Influence of BTO phase onstructural, magnetic and electrical properties of LCMO, J. ofAlloys and Compd., 485: 501-506.[3] Xiong, C-S., et al., 2009. Electrical properties and magnetoelectriceffect measurement in La0R.7RCaR0.2RSrR0.1RMnOR3R/xCoFeR2ROR4Rcomposites, J. of Alloys and Compd. 474: 316-320.6th Nanoscience and Nanotechnology Conference, zmir, 2010 750

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 751

Poster Session, Thursday, June 17Theme F686 - N1123Effect of Both Silane-Grafted and Ion-Exchanged Organophilic Clay in Structural, Thermal andMechanical Properties of Unsaturated Polyester NanocompositesSinan enDepartment of Polymer Engineering, Yalova University, 77100 Yalova, Turkey /Advanced Technologies Research and Development Center, Bogazici University, 34342 stanbul, Turkey.Abstract— Unsaturated polyester (UPE) resin including styrene monomer was mixed with montmorillonite (MMT) claywhich was modified with cetyl trimethly ammonium bromide and trimethoxy vinyl silane. The exfoliated nanocompositestructure having better thermal and dynamic mechanical properties was obtained when the MMT clay was modified in thepresence of both modifiers.Polymer-clay nanocomposites have attracted anincreasing attention due to impressive enhancements ofmaterial properties due to nanometer size of filler dispersioncompared to pure or conventionally filled polymers. There aretwo types of polymer-clay nanocomposite structures, namelyintercalates, where polymer chains intercalate between thelayers and exfoliates, where silicate layers are completelydelaminated in the polymer matrix [1]. Since improvements inmany properties depend on the degree of dispersion of thenanoparticles, exfoliated nanocomposites are generally thetarget of many nanocomposite studies. In situ polymerizationwas the first method used to synthesize polymer-claynanocomposites. The thermoset-clay nanocompositesincluding phenol resins [2], epoxy resins [3] and unsaturatedpolyester resins [4] as polymer matrices were obtained by insituintercalative polymerization method in which polymerresin, dissolved in a polymerizable monomer such as styrene,is intercalated between clay layers and then followed bycrosslinking reaction.In this study, UPE - MMT clay nanocomposites havebeen synthesized by in situ method. The MMT clay wasorganically modified with cetyl trimethyl ammonium bromideand also with trimethoxy vinyl silane. These modificationagents were used both individually and together. The cetyltrimethyl ammonium bromide is expected to intercalatebetween the clay layers through ion-exchange reaction whilethe silane agent grafts onto edge and surface hydroxyl groupsin montmorillonite clay. Thereby, for “double” modifiedMMT clay, reactive double bond in vinyl silane couplingagent can participate in the polymerization reaction from bothsurface and edges of ammonium ion-intercalated clay layers,which may lead to a completely exfoliated nanocompositesstructure. Differences in dynamic mechanical and thermalproperties as well as the morphology of the resultantnanocomposites were all discussed by paying attention to theMMT modification mechanisms.XRD analysis gave the values of the interlayer spacing ord-spacing of the NaMMT and the modified clays which wereobtained from the peak position of the d 001 reflection in thediffraction patterns The XRD result showing a decrease ofdiffracting angle which in turn increase in interlayer distanceproved succesful intercalation of MMT clay layers with cetylammonium salt through the ion-exchange reaction. In the caseof the ‘double-modifed’ clay-containing nanocomposite,UPECetViSiM-C, an exfoliated structure was obtained withthe absence of any d 001 reflection in the XRD region. Thisresult may be attributed to the good swelling of CetViSiMMTin UPE resin and homogeneous and fine dispersion of it in thematrix, as well as promotion of polymerization both betweensilica layers, and from surfaces and edges of the clay with thehelp of reactive double bond present in the ViSi modifier. Themorphology of the exfoliated nanocomposite was alsoinvestigated by AFM analysis showing that very thindispersion of CetViSiMMT clay platelets were oriented in allpossible directions to one another in the matrix as aconfirmation of XRD peak disappearance. Accordingly, theexfoliated UPECetViSiM-C nanocomposite was found to havethe highest thermal stability and better dynamic mechanicalproperties (Table 1), even with a clay content as low as 3 wt%.Table 1. DMA data for neat UPE and UPE nanocompositesMaterials E’ at 60°C(MPa)E’ at 80°C(MPa)Neat UPE 1458 204UPECetM-C 1625 247UPEViSiM-C 1743 259UPECetViSiM-C 1840 390Fracture surfaces of UPE and its nanocomposites wereinvestigated by scanning electron microscopy (SEM) usingbackscattered imaging (Fig. 1). SEM images of the fracturesurfaces showed that presence of CetViSiMMT clay with ahomogeneous and nano-sized dispersion in the polymermatrix, led to crack propagation along a more ‘rougher’ path.On the other hand, the UPECetM-C exhibited a heterogenousfracture surface, which may be probably due to its intercalatedstructure.Figure 1: SEM micrographs of the fracture surfaces of (a) neatUPE; (b) UPECetM-C; (c) UPECetViSiM-C and (d) UPEViSiM-C.*Corresponding author: sinans@yalova.edu.tr[1]. S.S. Ray, and M. Okamoto, Prog. Polym. Sci., 28, 1539 (2003).[2]. T. Lan, P.D. Kaviratna, and T.J. Pinnavaia, Chem. Mater., 7, 2144 (1995).[3]. D.C. Lee, and L.W. Jang, J. App. Polym. Sci., 68, 1997 (1998).[4]. D.J. Suh, Y.T Lim, and O.O. Park, Polymer, 41, 8557 (2000).6th Nanoscience and Nanotechnology Conference, zmir, 2010 752

%R0R 8)PP sodiumP0,P sodiumP ,0P sodiumP ,Poster Session, Thursday, June 17Theme F686 - N1123Culture and Fatty Acid Composition of the Green Alga, Botryococcus braunii Kütz. as an Energy FuelCell111111UGamze TuranUP P*, Edis KoruP P, Safak Seyhaneyildiz-CanP P, Hatice TekogulP P, Tugba SonmezisikP P, Semra CirikP1PEge University, Fisheries Faculty, Aquaculture Department, 35100 Bornova, Izmir, TurkeyAbstract-The result of this work demonstrated that B. braunii is a potential algal fuel resource with high lipid content (56.31 ± 0.03, % dryweight) and its biomass production and lipid synthesis stimulated by culture conditions.Due to continued use of fossil fuels is not sustainable as theyare a finite resource and their combustion lead toenvironmental problems, the recent investigations started tofocus on more renewable energy resources.As an alternative energy resource Biodiesel is anenvironmentally friendly and renewable fuel source obtainedfrom vegetable oils and used in diesel motors. Since some ofterrestrial plants, such as soybean, canola, corn, coconut andpalm tree oils used in food purposes and they require hugeareas to grow, in recent years studies on microalgae asrenewable fuel resources gained more attention due to theirsurprising ability to grow in unused areas.Microalgal lipid production is very important for the aquaticecosystem. Algae can synthesize methabolites such as fattyacids, sterols, carotenoids and lipids that have similarcomposition found also in the terrestrial plants. The lipidsproduced by algae and stored as unsaturated fatty acids are themain energy resources of the aquatic invertebrate and fishspecies. Additionally, these lipids are considered as potentialdiesel fuel resources [1]. Colonial green alga Botryococcusbraunii Kütz., (Chlorophyceae) is distributed in fresh andbrackish water lakes and reservoirs and produces lipids athigh levels. For this reason, in many studies related with lipidanalysis B. braunii was used as experimental algal species [1,2]. In generally, the lipids are stored at the cell wall of B.braunii [3, 4, 5].In this study, biomass and lipid production of Botryococcusbraunii Kütz UTEX 572 cultured under different conditionswere investigated. During the study, B. braunii was cultivatedat three different temperature, five different sodium nitrate andtwo different salinity levels. Effects of temperature level,nitrate and salinity concentrations on the biomass and lipidproduction were tested during the experiments.B. braunii was cultivated at 10 °C, 20 °C, 30 °C. Five-1-1different Bristol mediums includes 0 g.LP 0.125 g. LP 0.25-1-1-1g.L PP, 0.5 g. L PP, ve 1 g.LP nitrate were used asnutrient mediums. Two different salinity levels ( %R0R andalso applied in 1, 3, and 5 cm in depth glass-panelphotobioreactor experiments. Cell number, optic density anddry weight of the algae were measured daily. At the end of theexperiment, algae were collected, dried and prepared for lipidextraction, total lipid determination and fatty acid compositionstudies.-1The highest biomass production (0.564 0.2 g.LPP) was found-1in the experimental group cultivated in 0.5 g.LPnitrate Bristol medium, at 20 °C. The highest lipid production(56.31 ± 0.03, % dry weight) found in the algal group wherethe nutrient medium does not contain sodium nitrate and 200PC was applied. The most productive group according to bothhigh biomass and lipid production was B. braunii was grown-1in 0.125 g. LP nitrate medium at 20 °C. The biomasswas found to be higher in 1 cm glass-panel photobioreactorwhere the salinity was %R0R the lipid production was higherin 3 and 5 cm glass panel photobioreactor. The fatty acidcomposition of B. braunii was including; behenic (% 0.41),eicosenoic (% 1.01), linoleic (% 9.92), linolenic (% 9.50),margaric (% 0.28), methyl cis 11, 14, 17 eicosatrienoic (%0.23), oleic (% 59.04), palmitic (% 16.62), pentadecanoic (%0.18) and stearic (% 2.50) acids.The present work was supported by TUBITAK under Grantnumber 107Y013*Corresponding author: HTgamze.turan@ege.edu.trT[1] Lee, S.L., Yoon, B.D., Oh, H.M., 1998. Rapid method for thedetermination of lipid from the green alga Botryococcus braunii.Biotechnology Techniques, Vol. 12, pp. 553–556.[2] Yamaguchi, K., Nakano, H., Murakami, M., Konosu, S.,Nakayamo, O., Kanda, M., Nakamura, A. and Iwamoto, H., 1987.Lipid Composition of a Green Alga Botryococcus braunii.Agriculture and Biological Chemistry. 51, 493-498.[3] Largeau, C., Casadevall, E., Berkaloff, C., and Dhamelincourt, P.,1980. Sites of accumulation and composition of hydrocarbons inBotryococcus braunii. Phytochemistry 19, 1043–1051.in the DarwinRiver Resevoir. Biotechnology and Bioengineering. 22, 1637-1656.[4] Metzger, P., Largeau, C., and Casadevall, E., 1991. Lipids andmacromolecular lipids of the hydrocarbon-rich microalgaBotryococcus braunii. Chemical structure and biosynthesis. In: Herz,W., Kirby, G.W., Steglich, W., Tann, C. (Eds.), Progress in theChemistry of Organic Natural Products 57.Springer, Vienna, pp. 1–70.[5] Metzger, P., and Largeau, C., 1999. Chemical of Botryococcusbraunii. In: Cohen, Z. (Ed.), Chemicals from Microalgae. Taylor &Francis Ltd., London, pp. 205–260.6th Nanoscience and Nanotechnology Conference, zmir, 2010 753

PP forP forP edit.PPoster Session, Thursday, June 17Theme F686 - N1123Characterization of Sputtering Deposited AgGaSe2 Thin Films111UHakan KaraaaçUP P*, Mehmet ParlakP Pand Çidem ErçelebiP1PDepartment of Physics, Middle East Technical University, Ankara 06531, TurkeyAbstract- The single phase of AgGaSeR2R thin films were deposited onto soda-lime glass substrate by sequentially deposition of Ag and GaSeusing DC and RF sputtering. Physical properties were investigated by carrying out several type of measurements and the convenience of thismaterial to be used in the solar cell structure was determined.Nowadays, I-III-VIR2R ternary compounds have beenattracting considerable attention due to their interestingphysical properties. These compounds are regarded to be theternary analog of the II-VI binary materials. I-III-VIR2Rsemiconductors crystallize with the structure calledchalcopyrite being a super lattice of II-VI binary’s (zincblende) structure [1]. I-III-VIR2R ternary compounds arepotential candidates for photovoltaic applications [2], nonlinearoptics [3], light-emitting diodes [4], and frequencyconversation applications [5].AgGaSeR2R is a well-known ternary semiconductor. It’s ofparticular interest due to owing optical non-linear propertiesused in many applications like the generation of second andthird harmonic frequencies of COR2R laser output [6-8]. It is alsofound that AgGaSeR2R is a good candidate for the preparation ofschottky diodes [9], X- and Gamma-ray detector [10], andsolar cells [11].AgGaSeR2R thin films were deposited onto soda-lime glasssubstrates by a combination of DC and RF sputtering. Theoptimization of single layers of Ag and GaSe was performedby conducting several deposition cycles with the sameparameters before the sequentially deposition ofGaSe/Ag/GaSe/Ag/GaSe/Ag/GaSe/Ag/GaSe thin film layersonto soda-lime glass substrates kept at constant temperatureoaround 250 P PC to form AgGaSeR2R thin film.Results of energy dispersive analysis of X-rays (EDXA)indicated a Ga-rich composition and that there is aconsiderable effect of annealing temperature on variation inamount of constituent elements in AgGaSeR2R thin film. Thestructural analysis of the as-grown and films annealed betweenoo350 P PC and 600 P PC has been carried out by X-ray diffraction(XRD) measurements. Results revealed that all films arepolycrystalline in nature and Ag metallic phase exists in theamorphous AgGaSeR2R structure up to annealing temperatureoo450 P PC. When the annealing temperature raised to 600 P PC itwas observed that the Ag phase disappears perfectly and thestructure is consisting of single phase AgGaSeR2R with (112)preferred orientation. The crystalline sizes of the annealed filmoobetween 350 P PC and 600 P PC were calculated from the XRDmeasurements and compared with grain sizes measured fromthe recorded scanning electron microscopy (SEM)micrographs. In addition, from the lattice parameters found forAgGaSeR2R thin film, some structural anomalies parametersrelated to chalcopyrite compounds like anion displacementand tetragonal distortion parameters have been calculated andcompared with previously reported values.Optical properties of AgGaSeR2R thin films were studied bycarrying out transmittance and reflectance measurements inthe wavelength range of 325-1100 nm at room temperature.By using the obtained spectral data for transmittance andreflection, the absorption coefficient and optic band gap valuesfor as-grown and annealed samples were calculated. Thefound energy values indicated that AgGaSeR2R thin film showsthe characteristic optical structure related to I-III-VIR2Rchalcopyrite compounds. That’s the crystal-field and spinorbitsplitting levels were resolved by observing band to band,the crystal-field to conduction band minimum, and spin-orbitlevel to conduction band minimum transitions withcharacteristic energy values reported previously. Thecalculated energy values for these transitions were found to be1.77 eV, 2.00 eV, and 2.25 eV, respectively for film annealedoat 550 P PC and there is a fair agreement with previouslyreported data. The levels originating from the crystal-field andspin-orbit interaction were also observed from thephotospectral response measurements with the almost sameenergy values obtained from the absorption measurements(1.77 eV, 2.00 eV, and 2.25 eV respectively for sampleoannealed at 550 P PC).Finally, the temperature dependent conductivity and Halleffect measurements were carried out in the temperature rangeoof 100-430 K for as-grown and film annealed at 450 P PC ando550 P PC. The electrical resistivity of the films was in the rangeof 30-1000 -cm and indicated n-type conduction confirmedfrom the hot-probe and Hall effect measurements. Based onHall effect measurement results it is found that there isdecrease in mobility and increase in carrier concentrationfollowing to increasing annealing temperature. The room14temperature carrier concentration calculated to be 9.6x10P-315 -316 -3cmPP, 1.7x10PP cmPP, and 6.6x10PP cmP as-grown, filmsooannealed at 450 P PC and 550 P PC, respectively. The room2 -1temperature mobility values were found to be 6.4 cmP P (Vs)PP,2 -12 -13.7 cmP P (Vs)PP, and 3 cmP P (Vs)P as-grown and filmsooannealed at 450 P PC and 550 P PC, respectively.*Corresponding author: karaagac@metu.edu.tr[1] J. L. Shay, J. H. wernic, Ternary Chalcopyrite Semiconductors,Growth, Electronic Properties and Applications, Pergamon, Oxford,1975[2] L. L. Kazmerski, Nuovo Cimento D 2 (1983) 2013[3] B. F. Levine, Phys. Rev. B, 7 (1973) 2600[4] J. L. Shay, L. M. Schiavone, E. Buehier, J. H. Wernic, J. Appl.Phys. 43 (1972) 2805[5] F. K. Hopkius, Laser Focus World 31 (1995) 87[6] P. G. Schunemann, S. D. Setzler, T. M. Pollak, J. Cryst. Growth211 (2000) 257[7] G. C. Bhar, S. Das, D. V. Satyanarayan, P. K. Datta, U. Nundy,Y. N. Andreev, Opt. Lett. 15 (1995) 2057[8] E. Takaoka, K. Kato, Opt. Lett. 24 (1999) 902[9] P. Ribinson, J. I. B. Wilson, Inst. Phys. Conf. Ser. 35 (1977) 229rd[10] G. F. Knoll, Radiation detection and Measurement 3P(New-York; Willey), (1999)[11] Y. Satyanarayana Murty, O. M. Hussain, B. S. Naidu, P. J.Reddy, Mater. Lett. 10 (1987) 5046th Nanoscience and Nanotechnology Conference, zmir, 2010 754

PPPoster Session, Thursday, June 17Theme F686 - N1123Hydrothermal Synthesis of LiMnR2ROR4R Cathode Active Nanoparticles for Li-ion Batteries11UEmrah BulutUP P* and Mahmut OzacarP1PDepartment of Chemistry, Art and Science Faculty, Sakarya University, Sakarya 54187, TurkiyeAbstract- Spinel LiMnR2ROR4R cathode active nanoparticles for li-ion batteries were synthesized by hydrothermal route at low temperatures. TheLiMnR2ROR4R nanoparticles synthesized via hydrothermal technique were investigated by X-ray diffraction (XRD) and scanning electron microscopyLithium-ion batteries are nowadays widely used forportable systems, such as telephones, computers andtelecommunication devices. One of the most studiedmaterials in this field is spinel lithium manganese oxide(LiMnR2ROR4R), which is considered as a promising alternativeto LiCoOR2R, currently used in the lithium-ion batteries.LiMnR2ROR4R is a cubic spine1 with space group symmetryFd3m. The lithium ions are located on the 8a tetrahedral sitesof the structure; the manganese ions are positioned on the16d octahedral sites. The oxygen ions, which are cubicclose-packed(ccp) occupy the 32e positions.Figure 2. SEM images of LiMnR2ROR4R cathode active nanoparticlesFigure 1. Tunnel structure of spinel LiMnR2ROR4RMoreover, spinel LiMnR2ROR4R has attracted much interest inthe last decade because it presents a phase transition aroundroom temperature attributed to a charge ordering process [1].LiMnR2ROR4R has received much attention as a cathode materialbecause of the high voltage required for lithium insertion andits lower price, availability and better compliance withenvironment compared to LiCoOR2R and LiNiOR2R [2-4]. Inrecent years, nanostructures have received intensive attentionbecause of both their fundamental importance and the widerange of their potential applications in many areas. Most ofthe nanostructured electrode materials are synthesized by thelow-temperature treatment processes such as soft chemical[5], sol-gel [6] and hydrothermal methods [7]. Thehydrothermal synthesis can control the particle size and thecrystalline nature of the product.Here we synthesized LiMnR2ROR4R cathode activenanoparticles. We have chosen the spinel LiMn R2ROR4R becauseit is the most promising cathode material based on low cost,large deposits, and nontoxicity. LiMnR2ROR4R nanoparticlesobtained via hydrothermal synthesis were between 100 and180 nm in range.Figure 3. XRD pattern of spinel LiMnR2ROR4R cathode activenanoparticles*Corresponding author : HTebulut@sakarya.edu.trT[1] J. Rodriguez-Carvajal, G. Rousse, C. Masquelier, M. Hervieu,Phys. Rev. Lett. 81, 4660, (1998).[2] M. M., Thackeray, P. J., Johnson, L. A., Depicciotto, P. G.,Bruce, J. B., Goodenough, Mater. Res. Bull. 19, 179, (1984).[3] Thackeray, M. M.; Dekock, A. J. Solid State Chem. 74, 414,(1988).[4] Jayalakshmi, M.; Mohan Rao, M.; Scholz, F. Langmuir, 19,8403, (2003)[5] J. Luo, Y. Wang, H. Xiong, Y. Xia, Chem. Mater., 19, 4791,(2007).[6] Y. K., Sun, Ind. Eng. Chem. Res., 36, 4839, (1997).[7] H. J., Yuea, X. K., Huanga, D. P., Lva, Y. Yanga,Electrochimica Acta 54, 5363, (2009).6th Nanoscience and Nanotechnology Conference, zmir, 2010 755

Poster Session, Thursday, June 17Theme F686 - N1123Preparation of multi-layered Pt/Co cathodes for proton exchange membrane fuel cells (PEM) bydc- magnetron sputteringOguz Kaan Ozdemir 1,2 , Ali Sems Ahsen 2 , Osman Ozturk 2 , Evelina Slavcheva 31 Yildiz Tech Univ, Dept Met & Mat Engn, Istanbul, Turkey2 Nanotechnology Research Canter, Gebze Institute of Technology, Kocaeli, Turkey3 Institute of Electrochemistry and Energy Systems-Bulgarian Academy of Sciences, Sofia, BulgariaAbstract- In order to investigate the effect of Co layers in the cathode electrode a series of unalloyed multilayer Pt/Co thin films weredeposited by dc magnetron sputtering upon a thin Ti sublayer sputtered on the top of a conductive micro porous carbon diffusion layer.Proton exchange membrane (PEM) fuel cells arepromising power source due to their good energyconversion efficiency and high power density of their fuelsources [1]. Nevertheless, the achieved substantialprogresses in the PEM fuel cells are not broadly utilizeddue to their cost and durability. Precious Pt catalyst is themost important cost factor in the PEM fuel cells. Therefore,many researches are focusing on the development ofcompact unit and reducing the loads on the catalysts [2].The Thin film deposition method of magnetron sputtering(MS), which is widely used for integrated circuitmanufacturing, recently finds application as an alternativecatalyst preparation and electrode assembling technique.This method allows deposition of thin compact films upon aselected substrate material such as either gas diffusion layeror Nafion, and ensures simplicity of the catalystspreparation as well as improved stability, durability, andutilization [3-5].In our study, a series of unalloyed multilayer Pt/Co thinfilms were deposited by dc magnetron sputtering upon athin Ti sublayer sputtered on the top of a conductive microporous carbon diffusion layer. In order to investigate theeffect of Co on the oxygen reduction reaction, differentcompositions (70:30, 50:50, 30:70 Pt/Co atomic ratio) wereemployed, while the amount of Pt was constant(21 μg.cm -2 ). Each electrode was investigated using theconventional electrochemical methods of cyclicvoltammetry and steady state polarization curves in 0.5MH 2 SO 4 as well as a membrane electrode assembly, MEA,cathode in a single hydrogen PEM fuel cell. The cyclicvoltammograms, CV, were used to calculatethe electrochemically active surface area, EASA, of theelectrode under study, applying the well establishedprocedure of integration the area under the hydrogen adsorption / desorption peaks and using the value of 210mC.cm -2 (the charge required for adsorption of hydrogenmonolayer on 1 cm 2 of smooth Pt electrode) as a correctionfactor [6].The electrocatalytic activity of Pt/Co films toward theoxygen reduction was assessed applying the method oflinear sweep voltammetry, LSV, and Koutecky–Levichplots. The rotation disc electrode, RDE, polarization curvesshow characteristic behavior reported in the literature forOxygen Reduction reaction, ORR, on Pt in acid solutionswith a well distinguished region of kinetic mixed, anddiffusion limited reaction rate. Exchange current density, j o ,is known to be a qualitative measure for the intrinsicactivity of the catalyst, and its calculation has beenexplained elaborately in our previous study [7].Table 1. EASA and Kinetic parameters.SampleName(Pt/Co)EASA(m 2 .gr -1 )b(V.dec -1 )j oap(A.cm -2 )jo(A.cm -2 )70:30 28,789 -0,192 0,00426 1,48E-0850:50 51,826 -0,181 0,00338 6,53E-0930:70 52,461 -0,168 0,00557 1,06E-08As show in Table 1, 30:70 Pt/Co atomic ratios has thehighest EASA. Moreover, its apparent exchange currentdensity is higher than other two samples, too. Figure 1shows the polarization curves of a series of MEAs withdifferent Pt/Co atomic ratios.E (V)10,80,60,40,270:3050:5030:700 200 400 600 800 1000J (mA.cm -2 )As shown in Figure 1, among the three MEAs coatedwith 70:30, 50:50, 30:70 cathode catalyst layer obtained bysputter-deposition, consistent with the CV and RDEanalysis, the coated MEA with 30:70 Pt/Co atomic ratiodemonstrates the best cell performance. The polarizationcurve shows a high current density of 974 mA.cm -2 at 0.4V. Microstructure and electrochemical studies indicatedthat the additional Co layers sputter-deposited in cathodeelectrode might change the microstructure of the electrodemembraneinterface as well as vary charge transfer andmass transport properties of MEAs [8].This research has been carried out in the frame of theproject EVRENA-108M139.*Corresponding author: 0Hoguz_kozdemir@hotmail.com[1] R. O’Hayre at al., Journal of Power Sources 109, 483-493,(2003).[2] C.L. Chang et al., Surface & Coatings Technology, 201, 4442-4446, (2006).[3] W. Zhen-Bo at al., Int J Hydrogen Energy, 34, 4387-94,(2009).[4] H. Andrew at al., J Electrochem Soc, 149, A280-7, (2002).[5] H. Kuo-Lin at al., J Power Sources, 156, 224-31, (2006).[6] Bard AJ., Faulkner L., 2001. In: Electrochemical methods:fundamentals and applications, (p. L849–57) , vol. 341. NewYork: Wiley.[7] O. Ozturt at al., International Journal of Hydrogen Energy, InPress, (2010).[8] Z. Tang at al., J Appl Electrochem, 39, 1821-1826, (2009).6th Nanoscience and Nanotechnology Conference, zmir, 2010 756

PP andPoster Session, Thursday, June 17Theme F686 - N11231TiOR2R Nanofibers Produced by Electrospinning11UAli E.DenizUP Tamer UyarP P*PUNAM- Institute of Materials Science & Nanotechnology, Bilkent University, Ankara 06800, TurkeyAbstract-TiOR2R nanofibers having anatase structure are obtained by using electrospinning technique and its morphology and structure areanalyzed by SEM, EDX, and XRD.Electrospinning is a versatile and cost-effectivetechnique to produce multi-functional nanofibers fromvarious polymers, sol-gels, metaloxides, ceramics, etc [1].Electrospun nanofibers have several remarkablecharacteristics such as large surface area, nano range poresizes and unique physical and mechanical properties.These superior properties and multi-functionality of thesenanofibers enable them to be used in many areas includingbiotechnology, textiles, filtration, environment and energy[2].Various polymeric nanofibers are produced to be used infuel cells and solar cells [3,4]. By electrospinningtechnique, not only polymeric nanofibers are created butalso inorganic nanofibers can also be obtained. Moreover,these metaloxide nanofibers are very important for energyapplications, for instance, TiOR2R nanofibers can be used isused in solar cell applications [5,6].In this study we produced TiOR2R nanofibers byelectrospinning technique. Titanium dioxide (TiOR2R)nanofibers were obtained by electrospinning of the sol-gelsolution, which contains TiOR2R sol precursor (Titanium(IV)-isopropoxide), polyvinylpyrrolidone (PVP), andsolvent (glacial acetic acid and ethanol). PVP nanofiberswhich include Titanium (IV)-isopropoxide were calcinedat 500 °C for 3 h. After calcination, organic part (polymer,PVP) was totally removed and TiOR2R nanofibers havinganatase structure were obtained. The diameter of the TiOR2Rfibers was in the range of 40 nm to 600 nm.*Corresponding author: HTuyar@unam.bilkent.edu.trT[1] Chronakis I-S, 2005 Novel nanocomposites and nanoceramicsbased on polymer nanofibers using electrospinning process,Journal of Materials Processing Technolog, 167:283-29 [2]Greiner A., Wendorff J-H., 2007 Electrospinning: A FascinatingMethod for the Preparation of Ultrathin Fibers, Angew Chem IntEd.,46:5670–5703[3] Chen Y., Guo J., Kim H.,2010 Preparation of poly(vinylidenefluoride) / phosphotungstic acid composite nanofiber membranesby electrospinning for proton conductivity, Reactive andFunctional Polymers, 70:69-74[4] Chou C., Huang J., Wu C., Lee C., and Lin C.,2009Lengthening the polymer solidification time to improve theperformance of polymer/ ZnO nanorod hybrid solar cells, SolarEnergy Materials and Solar Cells, 93:1608-1612[5] Stathatos E., Chen Y., Dionysiou D-D., 2008 Quasi-solidstatedye-sensitized solar cells employing nanocrystalline TiOR2Rfilms made at low temperature, Solar Energy Materials andSolar Cells, 92:1358-1365 [6] Mane R-S., Hwang Y-H.,Lokhande C-D., Sartale S-D., and Han S., 2005 Roomtemperature synthesis of compact TiOR2R thin films for 3-D solarcells by chemical arrested route, Applied Surface Science,246:271-278a) b)Figure 1. a) SEM Image of PVP nanofibers before calcination b)SEM Image of TiOR2R nanofibers after calcinations.a) b)Figure 2. a) EDX Image of TiOR2 Rnanofibers b) Chemical MapImage of TiOR2R nanofibers. Ti is coloured as a blue colourTAs a conclusion, in this study we have succeeded toproduce TTiOR2R nanofibers having anatase structure byelectrospinning technique.T The morphology of the TTiOR2RnanofibersT was examined by Scanning ElectronMicroscope (SEM)T. The structural Tcharacterization wasperformed by using TEnergy dispersive X-ray analysis(EDX) and X-Ray Diffraction (XRD).6th Nanoscience and Nanotechnology Conference, zmir, 2010 757

Poster Session, Thursday, June 17Theme F686 - N1123Plasmonic phase shifts and light-trapping in SOI photodetectors and nc-Si solar cellsMumtaz Murat Arik * , Birol Ozturk, Hui Zhao, Eric SchiffDepartment of Physics, Syracuse University, Syracuse, New YorkAbstract- We report our work on the measurement of photoconductances in SOI devices with and without silver nanoparticle layers. Thesilver nanoparticles were fabricated by thermal annealing of evaporated silver thin films and by nanosphere lithography. Since these devicesare not deposited onto textured substrates, they exhibit prominent interference fringes in their quantum efficiencies. An important effect thatwe have found in both nc-Si:H solar cells and SOI is a shift of the interference fringes that is induced by the nanoparticle layer. We presentexperiments and calculations indicating that the fringe-shift is a consequence of optical phase shifts by surface plasmon resonance of the metalnanoparticles.An interesting alternative to texturing in thin film solar cellsis "plasmonic" light-trapping based on specular cells andusing an overlayer of metallic nanoparticles to produce lighttrapping.While this type of light-trapping has not yet beendemonstrated for nc-Si:H solar cells, significant photocurrentenhancements have been reported on silicon-on-insulatordevices with similar optical properties to nc-Si:H [1,2].Here, we report our work on plasmonic light-trapping onsilicon-on-insulator (SOI) photodetectors and nc-Si:H solarcells. We observed that the photocurrent ratios in SOIphotodetectors are affected by interference fringes, which aresubstantially shifted by the metal nanoparticle monolayers.The measurements of the normalized photoconductancespectra for SOI samples are shown in the upper panel andinset of Fig.1. The gray curves show the correspondingspectra when there was a Ag-np monolayer on top of the LiF. panel of the figure expands on this spectral region. In thelower panel we have plotted the ratio of thephotoconductances with and without the Ag-np film. Thevalue of 11 at 1025 nm is consistent with previous reportssuggesting that the Ag-np film leads to a pronouncedenhancement of photocarrier generation. It is important tonote that the fringes for the sample with the Ag-np layer are"red shifted" from the fringes seen without the Ag np film;we have indicated this shift as in the figure. This red-shiftmodifies the interpretation of the photocurrent ratio. Thesmooth lines through the photoconductance measurementsPhotoconductanceG/(eF) (10 -3 cm 2 /V)Photoconductance ratio0.40.30.20.10.0108642X 0.5SOI600 8001000 UnprocessedFringe-averaged+Ag0700 800 900 1000Wavelength (nm)Figure 1. (upper) Normalized photoconductance spectraG p eF for LiF-capped SOI structures with and without a Agnanoparticle film. The inset shows the spectra over a wider range.Solid lines (without symbols) are averaged to remove interferencefringes. (lower) Ratios of photoconductances with and without theAg film; the solid line is the ratio of the fringe-averagedphotoconductances.are "processed" to remove the fringes; the smooth line in thelower panel indicates the ratio of these "fringe-removed"curves. The enhancement now reaches a reduced value ofabout 5 [3].We speculate that the ratios of unprocessed photocurrentspectra reported in previous SOI work [1,2], which alsoexhibit the very strong oscillations seen in the lower panel ofFig. 1 and even larger ratios, are due to similar effects.In Figure 2, we also plot phase shifts for Ag-np filmsdeposited on the top ITO layer of nc-Si:H solar cells. Thefilms were prepared by thermal annealing and by nanospherelithography [4]. The associated phase shift is negative,corresponding to a blue shift of the interference fringes.Phase-shift (radians)-1-2700 800 900 1000Wavelength (nm)Figure 2. Optical phase shifts by silver nanoparticle films as inferredfrom interference fringe shifts in photocurrent spectra. Results areshown for films on LiF-capped SOI and on nc-Si:H solar cells with atop ITO layer. The silver nanoparticle films were created byannealing (“ann”) and by nanosphere lithography (“nsl”) ofevaporated silver. Note the differing signs of the phase shift.The difference in signs for the Ag-np films on Si and onITO is striking. This result is expected from the smallersurface plasmon resonance frequency when a Ag-np isproximate to silicon (index of refraction n ~ 3.5) than whenit is proximate to ITO (n ~ 1.9) [5].This research has been partially supported by the U. S.Department of Energy through the Solar America Initiative(DE-FC36-07 GO 17053). Additional support was receivedfrom the Empire State Development Corporation through theSyracuse Center of Excellence in Environmental and EnergySystems.*mumtazmurat@yahoo.com3210SOI (ann)nc-Si (ann)nc-Si (nsl)[1] Stuart H.R. and Hall D.G., Appl. Phys. Lett 69, 2327 (1996)[2] Pillai S. et.al., J. of Appl. Phys., 101 093105 (2007)[3] Ozturk B., Zhao H., Schiff E.A., Guha s., Yan B., Yang J,To be submitted for publication.[4] Ozturk B., et.al., Mater. Res. Soc. Symp. Proc. Vol. 1153,1153-A07-14 (2009).[5] Ozturk B., Zhao H., Schiff E.A., Damkaci F., Guha s., YanB., Yang J, Submitted to Mater. Res. Soc. Symp. Proc. (2010)6th Nanoscience and Nanotechnology Conference, zmir, 2010 758

groupsgroupsPPP reduction)groups,P andPoster Session, Thursday, June 17Lithium-Iron Phosphates as Cathode Active Materials for Lithium-Ion Batteries122UAhmet ÖrnekUP P*, Emrah BulutP Mahmut ÖzacarP1PSakarya University, Institute of Sciences and Technology , 54187 Sakarya, Turkiye2PSakarya University, Department of Chemistry, 54187 Sakarya, TurkiyeTheme F686 - N1123+Abstract – The transition metal ions connect the diphosphate anions forming a three-dimensional network with channels filled by LiP Pcations expected to exhibit high mobility. All compounds order magnetically at low temperatures due the Fe-Fe interactions. Lithiumiron phosphate (LiFePR2ROR7R) as cathode active material was synthesized by sol-gel method. Synthesized LiFePR2ROR7R was characterized byXRD, SEM and EDS.The use of nano scale layered transition-metal oxides aspositive electrode materials for lithium secondary batterieshas been studied extensively. Recently, there has beenconsiderable interest in nanocompounds built with3-phosphate anions such as PO or P 4-4 2 O 7 species becausethey undergo frameworks where tunnels are accessible for+ +mobile cations such as alkali (NaP P, LiP P) ions. They belongto the wide class of insertion compounds which can beused as positive electrode materials in advanced lithiumioncells. Also, lithium-ion oxide conductors based onphosphate framework offer some advantages in practicalapplications due to lower cost, safety, environmentalbenignity, stability and low toxicity [1-3].Among them, lithium pyrophosphates LiMPR2ROR7R (M:transition metal) have been subjected to intense researchfor the past few years, mainly due to the high mobility oflithium ions which promotes the insertion/extractionreactions. Indeed, there are a large number of crystallinematerials containing PR2ROR7R in the literature with thegeneral formula LiMPR2ROR7R. These phosphates exist indifferent structures: LiVPR2ROR7R, LiFePR2ROR7R, LiCrPR2ROR7Rcrystallize in the space group P21. In the case of3+LiFePR2ROR7R, lithium could be inserted (FePat+2.95 V against Li/LiP P. Nevertheless, the extraction oflithium from LiFePR2ROR7R takes place at high potentials as a3+ 2+result of the high oxidizing power of the FePP/FePP redoxcouple [1].The diphosphate LiFePR2ROR7R, in which the POR4R tetrahedraare linked by bridging oxygen to give PR2ROR7Rcrystallizes in the monoclinic system (P2R1R space group).The PR2ROR7R are connected to the FeOR6R octahedron bysharing two oxygen corners, each belonging to a POR4R unit(Fi g. 1).This induces a 3D framework in which channelscollinear to the [0 0 1] direction are formed and where thelithium ions are located. Moreover, these compounds maypresent interesting magnetic properties, as iron atoms areconnected through super-super exchange paths, involvingdiphosphate groups (made of two corner-sharing POR4Rtetrahedra). Furthermore, all distances and angles in thestudied diphosphates are in good agreement with manyother condensed phosphates reported before [1, 3, 4].The crystallinity of nano LiFePR2ROR7R was assessed fromXRD patterns as shown in Fig. 2.Figure 2. The XRD pattern of LiFePR2ROR7*Corresponding author: ahmetornek0302@hotmail.com[1] H. Bih et al., J. Solid State Chem. 182, 821 (2009).[2] A.A. Salah et al., Spectrochim. Acta Part A 65, 1007 (2006).[3] G. Rousse et al., Solid State Sci. 4, 973 (2002).[4] A.A. Salaha et al., J. Power Sources 140, 370 (2005).Figure 1. Structure of nano LiFePR2ROR7R. Lithium ions are locatedin tunnels delimited by FeOR6R octahedra and POR4R tetrahedra [1]6th Nanoscience and Nanotechnology Conference, zmir, 2010 759

PP ionicPP ,PPoster Session, Thursday, June 17Theme F686 - N1123Synthesis and Characterization of -BiR2ROR3R Based Solid Electrode Doped with TaR2ROR5R122UErsay ErsoyUP P*, Handan ÖzlüP Soner ÇakarP P, Caner BilirP2P, Orhan Türkolu 21PNide University, Faculty of Artz and Science, Department of Chemistry, Nigde, 51100, Turkey2PErciyes University, Faculty of Science, Department of Chemistry, Kayseri, 38039, TurkeyAbstact- In this study, the producing of type (fcc) solid electrolytes were investigated in the binary system of BiR2ROR3R-TaR2ROR5R. It was aimedthat the improving of electrical conductivity, thermal and micro structural properties of fabricated electrolyte materials for the solid oxidefuel cell (SOFC) applications. The single phase -BiR2ROR3R type materials were manufactured in the stoichiometric doping range of TaR2ROR5R;0. 1 x 0.23 by the solid state reaction technique. The electrical conductivity and XRD patterns of the obtained samples were measured andcharacterized.Solid oxide fuel cells (SOFCs) can provide a highefficient and clean energy conversion in a variety ofapplications anging from small auxiliary power units tolarge scale power plants. The fluorite type of oxides aremost studied as solid-oxide electrolyte materials becauseof their chemical and thermal stability. ZrOR2R, CeOR2R andBiR2ROR3R based materials can be given as the examples of themost popular solid electrolytes which are intensivelyused a major component of SOFC [1]. Generally, thesesystems can show different degree of oxygen ionicelectrical conductivity depending on the temperature anddoping concentration of some other oxide compounds. Onthe other hand, fcc type BiR2ROR3R-based materials has a2-relatively higher OP electrical conductivity at lowertemperatures than other well-known ZrOR2R or CeOR2R-basedsystems. Therefore, in the present study, we focused on theproducing of -BiR2ROR3R type solid electrolytes [2,3].The binary system of (BiR2ROR3R)R1-xR(TaR2ROR5R)RxR has beenstudied in the stoichiometric range of x; 0.1 x 0.23.Forthe stabilization of fcc type solid solution, small amountsof TaR2ROR5 Rwere doped into the monoclinic -BiR2ROR3 Rby thesolid state reactions. The powder mixture of BiR2ROR3 RandTaR2ROR5R were mixed in a ball mill and placed in aluminacrucibles. The resultant mixtures were heated at 700,oo750 P PC for 48 h respectively, then fired at 800 P PC for 24 h.XRD patterns of the produced materials were measured forthe phase analysis.stainless holder ~5 tone. The disk–shaped pellets wereosintered at 750 P PC for 12 h in air atmosphere.(a)(b)Figure 2. The temperature dependence of total conductivity (RTR)for - BiR2ROR3R phase (a)18 mol % TaR2ROR5 Raddition, b- 20 mol %TaR2ROR5 RadditionFigure 1 shows as an example of observed XRD patternsof -BiR2ROR3 Rdoped with 18 mol % TaR2ROR5R. The XRDpatterns of other -phase samples were quite similar withthe given figure. XRD results indicated that -BiR2ROR3R typesolid solution were obtained between the stoichiometricrange of 0.17 x 0.22 Some measured electricalconductivities are seen in fig.2. These measurementsresulted that the obtained single phase samples has anoxygen ionic electrical conductivity and solid electrolytecharacter. On the other hand, 18 mol % TaR2ROR5R dopingelectrolyte material has a higher degree of electrical-1 -1oconductivity (RTR=-1,9953 ohmPPcmPP, at 808 P PC) thanother doped systems. Therefore, we supposed that thissolid electrolyte can be used for the fabrication of SOFCsystem which can have a high performance of theelectrochemical energy production.This work wassupported by TUBITAK under Grant No. 108T377.Figure 1. The measured XRD patterns of -BiR2ROR3Rdoped with 18mol % TaR2ROR5R; (a) after heating at 700 °C. (b) after heating750P P°C. (c) after heating at 800 °C,The conductivity (RTR) measurements were made onagglomerated powders which were pelletized at roomtemperature (diameter 10 mm, thickness ~5 mm ) in a*Corresponding author: HTersayersoy@gmail.comT[1] Fruth V., Ianculescu A., Berger D., Preda S., Voicu G., TeneaE., Popa M., Journal of the European Ceramic Society, 26, 3011-3016, 2006.[2] Ling, C. D., Journal of Solid State Chemistry , 148, 380- 405,1999.[3] Turkoglu, O., Belenli, I., J. Therm. Anal. Calorim., 73, 1001-1012, 2003.6th Nanoscience and Nanotechnology Conference, zmir, 2010 760

PPPoster Session, Thursday, June 17The Synthesis and Characterization of LaRxRSrR1-xRMnOR3R Cathode Electrode for the Application of SolidOxide Fuel Cell1121UHandan ÖzlüUP P*, Soner ÇakarP P, Ersay ErsoyP P, Orhan TürkoluP21PErciyes University, Faculty Of Science, Department Of Chemistry, Kayseri, 38039, TurkeyPNide University, Faculty Of Artz And Science, Department Of Chemistry, Nigde, 51100, TurkeyTheme F686 - N1123Abstact – In this study, we planned the improving of the cathode electrode for the solid oxide fuel cell application. For this aim, the LaRxRSrR1-xRMnOR3R perovskite type cathode electrode materials were produced by the solid state reactions. The electrical conductivities, XRD, porosity andmicro structural aspects of the cathode materials were investigated.Solid oxide fuel cell (SOFC) technology has been underdevelopment for a broad range of power generationapplications. The attractiveness of this technology is itsefficient and clean production of electricity from a varietyof fuels. Most cathode materials used in SOFC today arelanthanum oxide-based perovskite materials (crystalstructure ABOR3R). In high-temperature SOFC, strontiumdopedLaMnOR3 R(LSM) is used. Perovskite material ismixed ionic and electronic conductivity are discussed inrelation to their potential application as cathode for SOFC[1,2].In this study, experimental results indicated that the nonstoichiometriccompositions of LaRXRSrR1-xRMnOR3R (x=0.2, 0.3,and 0.4) exhibit the best properties of the cathodeelectrode. The solid mixture of LaR2ROR3R, SrCOR3R, MnOR2Rpowders were used as starting materials for the synthesisof LaRXRSrR1-xRMnOR3R type materials. The powders were mixedby using ball mill and placed in alumina crucibles. Theprepared solid mixtures were heated at 900 and 1000°C for48 respectively. According to XRD results (Figure 1), ahexagonal type of LaRXRSrR1-xRMnOR3R perovskite were obtainedin the stoichiometric range of x; 0.1

PP lightPoster Session, Thursday, June 17Theme F686 - N1123ZnO/CuR2RO Inorganic Solar Cells1110BYakup HameP P, UTeoman ÖzdalUP P*, Hüseyin arP P, Erdem AslanP1P and Hüsnü nci 1PPMustafa Kemal University, Electric-Electronic Engineering Department, skenderun, Hatay, Turkey1Abstract -In this work thin film photovoltaic produced and investigated. Bilayer structured device has ZnO and CuR2RO inorganic oxide layersas n-type and p-type materials, respectively. Both oxide layers deposited by electrochemical deposition method on to pre cleaned Indium tinoxide (ITO) coated glass substrate. As a top electrode Al thermally coated and ITO/ZnO/CuR2RO/Al structure obtained. Finally, I-V curve of2thin film obtained and investigated by illumination under 100 mW/cmP intensity.There has been an active search for cost-effectivephotovoltaic devices since the development of the first solarcells in the 1950s [1]. A significant fraction of the cost ofsolar panels comes from the photoactive materials andsophisticated, energy-intensive processing technologies.Zinc oxide (ZnO), as a transparent conductive oxide, is oneof the most attractive materials for last several decays. ZnO,has a wide field application for industrial and scientificresearches due to transparent and conductive properties. ZnOhas a big interest because of bandgap of 3.3 eV at T300 KTwhich is an advantage for Toptoelectronic applications.However, ZnO has large exiton-binding energy (T60 meV).ZnO thin films have attracted many researchers to work onbecause of its unique electrical, optical and acousticcharacteristics that making it suitable for various fields ofapplications especially in photovoltaics [2]. ZnO films whichdeposited by ECD method generally obtain in aqueous alkalior neutral zinc salt solvents.Cuprous oxide (CuR2RO), as a non-toxic and active electrodehas a big attractive for photovoltaic applications.CuR2RO semiconductor material has an ability to absorb visiblewavelength with band-gap energy of 2,1 eV. Furthermore, ithas been predicated that CuR2RO is promising for photovoltaicapplications, with a theoretical energy conversion efficiencyof 20% [3]. CuR2RO thin films have been prepared by varioustechniques like thermal oxidation, chemical vapor deposition(CVD), anodic oxidation, reactive sputtering, pulse laserdeposition, electrodeposition, plasma oxidation [4-10].Cathodic electrodeposition of CuR2RO is a good method tocontrol easily the particle size and the film thickness [11].ITO coated glass sonicated in acetone, 2-propanol, ethanoland pure water for 15 minutes respectively. Deposition ofZnO and CuR2RO obtained in a three electrode system. Duringthe deposition, solution unstirred and temperature keptconstant. Finally, Al top electrode thermally coated on todevice as an ohmic contact.Electrical characterization of device obtained under 1002mW/cmPPlight intensity. Current-Voltage (IRSCR-VROCR)measurements of device obtained with Keithley 4200HT-TTSCSTT(semiconductor characterization systemTH). Scanning electronmicroscopy (SEM) image of ZnO layer and estimatedschematic of ITO/ZnO/CuR2RO/Al thin film structure whichfabricated in room temperature given in Figure 1 and Figure 2respectively.Figure 2. ITO/ZnO/CuR2RO/Al structure.In this work ZnO/CuR2RO bilayer solar cell fabricated andelectrical and photovoltaic properties investigated.This work is partially supported by The Scientific andTechnical Research Council of Turkey; with project referenceNumber 107M270.*Corresponding author: HTteomanozdal@hotmail.comT[1] D. M. Chapin, C. S. Fuller, G. L. Pearson, J. Appl. Phys., Vol.25, 676, 1954.[2] T. Pauporte, D. Lincot, Electrochim. Acta, Vol. 45, 3345, 2000.[3] H. Tanaka, T. Shimakawa, T. Miyata, H. Sato, T.Minami, Appl. Surf. Sci. Vol. 244, 568, 2005.[4] S. C. Ray, Solar Energy Materials & Solar Cells, Vol. 68, 307,2001.[5] T. Maruyama, Solar Energy Materials & Solar Cells, Vol. 56, 85,1998.[6] M. Masui, T. Muranoi, R. Urao, Y. Momose, M.R. Islam, and M.Takeuchi, Materials Chem. & Phys., Vol. 43, 283, 1996.[7]HTŠmith, M.TH, Gotovac, V., HTAljinovi, Lj.TH, HTLui-Lavcevi, M.TH,Surface Science, Vol. 335, 171, 1995.[8] T. Mahalingam, J.S.P. Chitra, S. Rajendran, and P.J. Sebastian,Semiconductor Sci. and Tech., Vol. 17, 565, 2002.[9] T.J. Richardson, J.L. Slack, and M.D. Rubin, ElectrochimicaActa, Vol. 46, 2281, 2001.[10] C.A.N. Fernando, P.H.C. de Silva, S.K. Wethasinha, I.M.Dharmadas, T. Delsol, and M.C. Simmonds, Renewable Energy,Vol. 26, 521, 2002.[11] Edited by G. Hode, Electrochemistry of nanomaterials, Wiley-VCH, Weinheim, 2001.Figure 1. SEM image of ZnO layer.6th Nanoscience and Nanotechnology Conference, zmir, 2010 762

Poster Session, Thursday, June 17Theme F686 - N1123Hydrothermal preparation and electrochemical properties of Sm 3+ and Gd 3+ ,codoped ceria-based electrolytes for intermediate temperature-solid oxide fuel cellsSibel Dikmen 1 , Hasan Aslanbay 1 , Erdal Dikmen 21 Department of Chemistry, Suleyman Demirel University, Isparta 32260, Turkey2 Department of Physics, Suleyman Demirel University, Isparta 32260, TurkeyAbstract- The structure, ionic and electronic conductivities of Ce 0.8 Sm 0.2-x M x O 2- (for M: Gd, and La, x = 0-0.1) solid solutions, prepared forthe first time hydrothermally, are investigated. The uniformly small particle size (23-64 nm) of the materials allows sintering of the samplesinto highly dense ceramic pellets at 1300-1400 o C, significantly lower temperature, compared to that at 1600-1650 o C required for ceria solidelectrolytes prepared by solid state techniques. The maximum conductivity, 700ºC 6.50 10 -2 Scm -1 , E a = 0.59 eV, is found at x = 0.1 for Gdcodoping.The electrolytic domain boundary (EDB) of Ce 0.8 Sm 0.1 La 0.1 O 2- has been found to be lower than that of singly doped samples.These results suggest that co-doping can further improve the electrical performance of ceria-based electrolytes.Fuel cells are electrochemical devices that directly convertthe chemical energy of a fuel into electrical energy in ahighly clean, cheap and efficient way [1]. Electrolytes usedfor fuel cells are usually the main components determiningthe performance of the cell. A typical solid oxide fuel cellelectrolyte, 8mol% yttria-stabilized zirconia (YSZ), havingthermal and mechanical strength both toward anode reductionand cathode oxidation requires to operate at hightemperatures (800–1000 C) to provide high level of ionicconductivity. This limits the range of materials used forinterconnection, electrodes and sealing due to the corrosionof metallic components [2]. Some singly doped-electrolytes,such as Ce 1x Gd x O 2 (GDC), Ce 1x Sm x O 2 (SDC),Ce 1x Y x O 2 (YDC), etc., show high oxide ion conductivity atintermediate temperatures (500–700C) [3–5].Substitution ofthe Ce 4+ cations by a lowervalent metal ion (e.g., M 3+ ) in thelattice results in the oxygen vacancy formation and increasesthe ionic conductivity.The ceria-based electrolytes easily develop n-type electronicconduction when exposed to the reducing atmosphere of thefuel cell anode which decreases the fuel cell efficiency. It istherefore important to make efforts towards the reductionof electronic conductivity. The dependence of totalconductivities of Ce 0.8 Sm 0.2x Gd x O 2 as a function of oxygenpartial pressure has been shown in Fig. 2. As can be seen, thetotal electrical conductivity ( t ) is predominantly ionic andremains constant at moderate P O2 , whereas at low P O2 , thetotal electrical conductivity increases as P O2 decreases and ispredominantly electronic..0.50.40.10 Ce 0.8Sm 0.2-xGd xO 2-0.05In this research, with the aim to develop new ceria-basedelectrolyte materials with improved electrochemicalproperties, Sm 3+ and Gd 3+ co-doped ceria materials wereprepared for the first time hydrothermally.Similar to the previously reported systems [6–7], theelectrical conductivity of Ce 0.8 Sm 0.2x Gd x O 2 increasessystematically with increasing gadolinium substitution andreaches a maximum for the composition Ce 0.8 Sm 0.1 Gd 0.1 O 2 ,( 700 C 6.50×10 2 Scm 1 ) Fig. 1)-1.0-2.0t(Scm -1 )0-25 -20 -15 -10 -5 0log PO (atm) 2Ce Sm Gd O 0.8 0.2-x x 2-0.30.20.1x = 0-3.0-4.0-5.0-6.0-7.0x = 00.050.10.150.20Fig.2 Oxygen partial pressure dependence of the totalconductivity of Ce 0.8 Gd 0.2x Sm x O 2 solid solutions at 973 K.The data are fitted with t = i +kP O21/4.From these results we can conclude that co-doping with Sm 3+and Gd 3+ can lead to an improvement of the stability of ceriabasedelectrolytes at intermediate temperatures.This study was supported by TUBTAK under the Grant No:106T536.-8.010 12 14 16 18 20 22 2410000/T (K -1 )Fig.1 Arrhenius plots of the ionic conductivity ofCe 0.8 Gd 0.2x Sm x O 2 solid solutions*Corresponding author: sdikmen@fef.sdu.edu.tr[1] S. Dikmen, Journal of Alloys and Compounds, 491 , 106 (2010)[2] H. Inaba, H. Tagawa, Solid State Ion., 83, 1 (1996)[3] S.W. Zha, C.R. Xia, G.Y. Meng, J. Power Sources, 115, 44 (2003)[4] D.J. Kim, J. Am. Ceram. Soc., 72 (8), 1415 (1989).[5] S.J. Hong, A.V. Virkar, J. Am. Ceram. Soc., 78 (2) (1995) 433–439.[6] S. Dikmen, P. Shuk, M. Greenblatt, Solid State Ion., 126, 89 (1999).[17] S. Dikmen, P. Shuk, M. Greenblatt, H. Gocmez, Solid State Sci., 4, 585(2002)6th Nanoscience and Nanotechnology Conference, zmir, 2010 763

Poster Session, Thursday, June 17Theme F686 - N1123A Novel Method of Nanocomposite Thin Film Synthesis for the use of Third Generation PV CellsA. Kuday Karaaslan 1* , Abdullah Ceylan 21 Institute of Natural and Applied Science, Nanotechnology and Nanomedicine Division, Hacettepe University, Ankara 06800, Turkey2 Department of Physics Engineering, Hacettepe University, Ankara 06800, TurkeyAbstract— Our ongoing project is on synthesizing photovoltaic Ge-ZnO nanocomposite thin films by utilizing a method thatcombines a custom made cluster deposition source with a conventional sputtering system and eventually obtain thecharacteristic properties of highly efficient third generation solar cells.Third generation photovoltaic cells, in other wordsadvanced thin film PV cells are one of the hottest researchtopics of nanotechnology for energy applications. Researchers,scientists and engineers among universities worldwide arefocused on increasing the efficiency and lowering the cost ofsolar cells by means of nanofabrication.Our approach in increasing photoconversion efficiency 1 isbroadening the spectral response of PV cells by embeddingGermanium (Ge) semiconductor nanocrystals with differentsizes and concentrations into a thin film of wide band gapsemiconductor Zinc Oxide (ZnO, Eg= 3.2 eV). The mostimportant advantage of this method is the ease ofindependently controlling the mean size and the concentrationof Ge nanocrystals in ZnO matrix. In order to be able to formaforementioned Ge-ZnO structures, combined magnetronsputtering system including a DC Magnetron SputteringSystem with cold trap and cooling funnel that has beendesigned and integrated to a current RF Magnetron SputteringSystem by our research group.Figure 1. Schematic illustration of the method for synthesizingGe-ZnO nanocomposite thin films.We thank our technician Uygar Tombuloglu for his contributions.*Corresponding author: kuday@hacettepe.edu.tr[1] “Quantum Dot Solar Cells,” in Next Generation Photovoltaics,Eds, Institute of Physics, London, (2004) (A. Marti and A. Luque).6th Nanoscience and Nanotechnology Conference, zmir, 2010 764

Poster Session, Thursday, June 17Theme F686 - N1123Hydrogen Storage and Release Mechanisms in MOF-5M. MANI-BISWAS 1 , T. CAGIN 1,21 Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA2 Department of Chemical Engineering, Texas A&M University, Texas, TX 77843-3122, USAAbstract- Metal organic framework MOF-5 is a hybrid porous crystalline material. It has high porosity and largesurface area and hence potential application in gas storage, catalysis, drug delivery, etc. For applications as a gasstorage material, it is important to find out a suitable gas delivery mechanism. Here we propose such amechanism by taking advantage of near shear instability of MOF-5. Using molecular simulation we show that athigh pressure MOF-5 gets deformed to 55% of its original volume. We also show that during this deformationprocess; MOF-5 passes through certain stages from where, by decreasing the pressure, 100% reversibility can beachieved. Based on this behavior, a purely mechanical process is proposed for gas (H 2 ) storage and release.Keywords: Hydrogen storage, Metal organic frameworks, Molecular Dynamics, sorption simulation, mechanical instability.Metal organic frameworks (MOF) are hybridporous crystalline materials. They have the highestpore size, low density and large surface area of anycrystalline material 1-4 . In general, MOFs are madeup of metal oxide clusters positioned at the verticesand connected by organic linkers. For example, thesimplest structure MOF-5 (IRMOF-1) is made upof Zn 4 O clusters are positioned at the corners of thecubic cell and connected by benzene dicarboxylate(BDC) linkers. The framework molecules take uponly a small fraction of the available space in thecrystal and about 80 % of the volume is free toaccommodate any guest molecule 1 . MOFs can beeasily prepared in the laboratory and have goodthermal stability (till 300-400 0 C) 3 . All theseproperties make MOFs suitable for applicationssuch as gas storage/separation, catalysis, molecularrecognition, etc. 5, 6 MOFs have potential to adsorbgases like H 2 , CH 4 , CO 2 , N 2 , Ar, etc. and theadsorption capacity may be improved by changingthe functionality of the linker and thus increasingMOF-guest interaction energy, incorporating openmetal sites, catenation of framework, etc 4 . MOFfilled containers have demonstrated enhancedstorage capacity (44% more hydrogen, 4 timesmore Xenon and 3 times more propane) comparedto empty containers 5 , further strengthening thepotential of MOFs as gas storage medium.Studies on the mechanical property have revealedthat MOF-5 is a soft material and it is nearlyunstable 7-8 , implying that the crystal is flexibleenough to transform to a new structure in thepresence of an external stimulus. Single-crystal-tosingle-crystaltransformations by exchange of guestmolecule or by varying temperature condition havebeen reported for some MOFs 9 and thesetransformations have been implicated in controlleddelivery of the guest molecules. Here we show bytheoretical methods, that at high pressure MOF-5undergoes reversible structural transformation i,evolume compression/decompression stages whichmay be continued for number of cycles. Takingadvantage of the cyclic nature of MOF-5deformation under pressure, a purely mechanicalgas storage and delivery system has been proposed.We considered hydrogen as a representative gasand performed simulations with hydrogen filledMOF-5. Given the pore size of MOF-5 (availablevolume ~ 11267 Å 3 ), at 100 MPa and at roomtemperature, ~167 molecules of hydrogen can beentrapped inside the crystal (considering density ofhydrogen at this condition is 49.25 kg/m 3 ). Thisamounts to 7wt % H 2 per gm of MOF-5. Underpressure as the crystal deforms the entrapped gaswill be released, which may be used further. In theproposed process, using pressure inducedmechanical gas delivery system, efficiency as highas 90% may be achieved.*Corresponding author: cagin@che.tamu.eduREFERENCES[1] Li, H.; Eddaoudi, M.; O.Keeffe, M.; Yaghi, O.M. Nature, 1999, 402, 276-279.[2] Eddaoudi, M.; Kim, J.; Rosi, N.; Vodak, D.;O'Keeffe, M.; Yaghi, O. M. Science, 2002, 295,469-472.[3] Rosi, N.; Eckert J., Eddaoudi M.; Vodat D.T.;Kim J.; O'Keeffe, M.; Yaghi, O. M Science, 2003,300, 1127-1129.[4] Rowsell, J. L.C. Yaghi, O. M. Angew. ChemInt. Ed. 2005, 44, 4670-4679.[5] Mueller, U. Schubert M.; Teich F.; Puetter H.;Schierle-Arndt K.; Pastre J. J. Mater. Chem., 2006,16, 626-636.[6] Ferey, G. Chem. Soc. Rev. 2007, 37, 191-214.[7] Han, S. S. and Goddard III, W. A. J. Phys.Chem. C, 2007, 111 (42), 15185 -15191.[8] Mattesini, M.; Soler, J. M.; Yndurain, F. Phys.Rev. B 2006, 73, 094111 1-8.[9] Wu, C-D.; Lin, W. Angew. Chem. Int. Ed.2005, 44, 1958-1961.6th Nanoscience and Nanotechnology Conference, zmir, 2010 765

PPoster Session, Thursday, June 17Theme F686 - N1123Synthesis and Characterization of CuInSR2R Quantum Dots for New Generation Hybrid Solar Cells1111Cihan ÖzsoyP P, Banu AydnP P, UCeylan ZaferUP P*, Sddk çliP1PSolar Energy Institute, Ege University, Izmir 35100, TurkeyAbstract-CuInSR2R nanoparticles with different semiconductor properties depending on chemical compositions, different particle sizes andsurface properties have been synthesized and used as n-type semiconductor in hybrid solar cell. Solar cell performances were investigated understandart AM1.5 conditions. Charge recombination and charge transport properties in conjugated polymer: QD bulkheterojunction film wasinvestigate by of Electrochemical Impedance Spectroscopy (EIS).Nanocrystalline materials have attracted a great deal ofattention from researchers in various fields for both theirfundamental size-dependent properties and their manyimportant technological applications [1].Among the various nanocrystals, transition metalchalcogenide nanocrystals have been investigated for manyapplications, including biological labeling, light emittingdiodes, and photovoltaic devices. Quantum dot (QD) solarcells have the potential to increase the maximum attainablethermodynamic conversion efficiency of solar photonconversion up to about 66% by utilizing hot photogeneratedcarriers to produce higher photovoltages or higherphotocurrents. [2]Especially Copper Indium Sulfides (CuInSR2R) and CopperIndium Sellenides (CuInSeR2R) quantum dots are the mostattractive for photovoltaic applications. Energy level ofCuInSR2 Ris suitable to use as both p- and n- type semiconductorin solar cells.Characterizations of products were carried out severalanalysis techniques (UV-Vis, XRD, TEM, XPS etc.)Figure 3. XRD pattern of CuInSR2R productsDistribution(1/nm)0.150.100.05Particle-/Pore-size Distribution(Volume)0.000.00 5.00 10.00 15.00 20.00 25.00Particle/Pore diameter(nm)Figure 4. Particle size distribution of nano-particles.CuInS2:MDMO-PPV (1:1)Figure 1. Energy levels of materials that used in fabrication of solarcellWe do the synthesis of these quantum dots (QD) withvarious synthetic routes with different uniform sizes, shapesand make a structural, optical, electrochemicalcharacterization. We are able to synthesize a uniform multygram quantity in one-pot reaction [3, 4].QDs were used as n-type semiconductors in combination ofconjugated polymers such as poly-3-heyxl thiophene (P3HT)and Poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenyl vinyl](MEH-PPV) and poly-[2-(3,7-dimethyloctyloxy)-5-methyloxy]-para-phenylene-vinylene (MDMO-PPV) whichare p-type materials. Two different configuration of solar cellinvestigated in the frame of this work. Geometrical structuresare shown in the figure below:Figure 2. Hybrid solar cell structures a) mixture b) double layerCurrent Density (mAcm -2 )0,040,030,020,010,00-0,01-0,02-0,03-0,04-0,05Isc [mA/cm 2 ] : 0,029Voc [mV] : 140FF : 0,42MPoweroutput [mW/cm 2 ] : 0,0017Vmp [mV] : 90Imp [mA/cm 2 ] : 0,018Efficiency [%] : 0,00170,0 0,1 0,2Applied Bias (V)Figure 5. Photovoltaic performance of QD:MDMO-PPV based solarcell.*Corresponding author: HTceylan.zafer@ege.edu.trT[1] C. Czekelius, M. Hilgendorff, L. Spanhel, I. Bedja, M.Lench, G.Müller, U. Bloeck, D. Su, and M. Giersig,Adv. Mater. 11 (1999) 8,643[2] A. J. Nozik Physica , 14( 2002) 115-120.[3] Park, J.; An, K.; Hwang, Y.; Park, J.-G.; Noh, H.-J.; Kim, J.-Y.;Park,J.-H.; Hwang, N.-M.; Hyeon, T. Nat. Mater. 2004, 3, 891-895.[4] Sang-Hyun Choi, Eung-Gyu Kim and Taeghwan Hyeon, J. AM.CHEM. SOC. 2006, 128, 2520-25216th Nanoscience and Nanotechnology Conference, zmir, 2010 766

Poster Session, Thursday, June 17Theme F686 - N1123Hydrogen Chemisorption on Metal Loaded Carbon NanotubesGülah Ozan 1* , Saadet Kayıran Beyaz 2 , Nalan Tekin 2 , M. Efkan Kibar 31 Gebze Institute of Technology, Department of Chemistry, 41400 Gebze / Kocaeli-TURKEY.2 Kocaeli University, Faculty of Science and Arts, Department of Chemistry, 41380 Izmit / Kocaeli- TURKEY.3 Kocaeli University, Faculty of Engineering, Department of Chemical Engineering, 41380 Izmit / Kocaeli- TURKEY.Abstract— Metal doped or metal decorated carbon nanotubes (CNTs) are the most capable materials for hydrogen storage bychemisorption. Using CNTs for hydrogen storage has been one of the hottest topics in science and technology. We havedeveloped nickel doped materials by wet chemistry method and measured the hydrogen absorption capacity of these materials.The comparison of absorption capacities between materials is discussed in the light of characterization results.Hydrogen storage is an essential prerequisite for thewidespread deployment of fuel cells, particularly in transport.The US Department of Energy (DOE) has announced a 6.0wt% target for hydrogen storage on-board automobiles [1, 2].Sorption in solids is one of the way for increasing hydrogenstorage. Nanostructured carbons are being investigated aspotential hydrogen adsorbents since they are cheap, light andporous materials. CNTs can easily and dependably accept andrelease substantial quantities of hydrogen by physisorption andchemisorption mechanisms [3]. Many works are devoted tomeasure and calculate hydrogen adsorption capacity of carbonnanomaterials. According to the works done by Monte Carlosimulations, it is observed that hydrogen storage is less than1% at room temperature when it is absorbed with variouscarbon materials such as SWCNTs, MWCNTs, and GNFs.These works show that the physisorption is not sufficent forstore the quantity of hydrogen given in DOE target [4-6]. Forthis reason the researchers have tried to create more attractivenanocarbons surface for creating strong interaction withhydrogen. The chemisorption mechanism could provide thehydrogen storage capacity which can fulfill the technologicalnecessity [3]. The aim of this work is to study the hydrogenchemisorption on Ni doped materials.In this study, three different Ni doped materials wereprepared using active carbon (AC), Al 2 O 3 and multi walledcarbon nanotubes (MWCNTs). MWCNTs were synthesizedby Chemical Vapor Deposition (CVD) method using acetyleneas a carbon source and nickel as catalyst. MWCNTs werepurified by thermal oxidation in air at temperature at 350 ºCfor 2h in order to remove amorphous carbon and were treatedwith 3M HCl solution in order to remove metal catalyst.Carboxylic acid functionalized MWCNTs (f-MWCNTs) havebeen obtained by treatment of concentrated H 2 SO 4 /HNO 3 (v:v,3:1). 15 % Ni doped f-MWNTs, Al 2 O 3 and AC were preparedfrom Ni(NO 3 ) 2 .6H 2 O by wet chemistry method. Formerly, f-MWNT, Al 2 O 3 and A.C. was ultrasonically dispersed inethanol for 3h and Ni(NO 3 ) 2 .6H 2 O solution was added andultrasonicated in order to obtain homogenous metal dispersionon these materials. Ni doped materials were centrifuged anddried at 60 ºC for 4 days in vacuum oven. The synthesizedMWCNTs, f-MWCNTs were characterized by TEM, SEM,FT-IR, EDX, Raman, and BET techniques. The specificsurface area of the 15% Ni doped materials are 222 m2/g for f-MWCNTs, 114m2/g for Al 2 O 3 and 362m2/g for AC. Thehydrogen chemisorptions capacity of obtained Ni dopedmaterials was measured using Micromeritics, ASAP 2020,Surface Area and Porosity Analyzer. Figure clearly shows thatMWCNTs were successfully synthesized and doped with Nimetal atoms.acFigure: (a) HRTEM image of MWCNTs, (b) Raman Spectrum of MWCNTs,(c) SEM image of 15 % Ni doped f-MWCNT and (d) EDX result of 15 % Nidoped f-MWCNTIn summary, we have successfully developed nickeldoped materials and measured the hydrogen absorptioncapacity of these materials. The comparison of absorptioncapacities between Ni doped materials are discussed in light ofcharacterization results. The absorption results will bepresented during the conference.This work was partially supported by TUBITAK underGrant No. 106T502, 109T619 and by Kocaeli Universityunder Grant No. BAP 2007/70. BET characterization and H 2chemisorption studies were done at AYARGEB at KocaeliUniversity Teknopark Inc.*Corresponding Author: gozan@gyte.edu.tr[1] A. Anson, M. Benham, J. Jagiello, M. A. Callejas, A. M. Benito,Nanotechnology, 15 (2004) 1503-08.[2] B. Weinberger, F. D. Lamari, Int J Hydrogen Energy, 34 (2009)3058-64.[3]. Y.Yürüm, A. Taralp, T.N., Vezirolu, Int J Hydrogen Energy, 343784-98 (2009).[4] S. K. Beyaz, F. L. Darkrim, B. P. Weinberger, P. Gadelle, L.Firlej and P. Bernier, Int. J. Hydrogen Energy, 34 (2009) 1965-70.[5] S.B. Kayıran, F.D. Lamari, D. Levesque, Journal Of PhysicalChemistry B, 108 / 39 (2004) 15211-15.[6] D. Levesque, A. Gicquel, F.L. Darkrim , S.B. Kayıran, Journal OfPhysics-Condensed Matter, 14 / 40 (2002) 9285-93.bd6th Nanoscience and Nanotechnology Conference, zmir, 2010 767

Poster Session, Thursday, June 17Theme F686 - N1123Biosynthesis of metal nanoparticles using EntrobacteriaceaeEshrat Gharaei-Fathabad 1 , Soheyla Honary 2 , Masoumeh Eslamifar 3 , Zahra Khorshidi 11- Department of Biotechnology, Sari Faculty of Pharmacy, Mazandaran University of MedicalSciences2- Department of Pharmaceutics, Sari Faculty of Pharmacy, Mazandaran University of MedicalSciences3- Department of Microbiology, Faculty of Hygiene, Mazandaran University of Medical SciencesAbstract:Many biotechnological applications such as remediation of toxic metals employmicro-organisms such as bacteria and the detoxification often occurring via reductionof the metal ions.The main objectives of the present study were to investigate the biosynthesis of zerovalentmetal nanoparticles in the supernatant of the Entrobacteriaceae medium ofcultures.Ten different pure colonies of Entrobacteriaceae isolated from waste water, werecultured in Luria Bertani broth medium .After reaching to the exponential growth, thesupernatant were examined for the ability to produce metal nanoparticles. For that, 1Molar solution of CuSo4, AgNo3 and FeSo4 added to the reaction matrix. Thereaction was done in a dark and anaerobic environment at 37 ° C. After 2 days, it wasobserved that the color of the solutions in flasks turned. The nanoparticles wereexamined using UV-Visible Spectroscopy, Transmission Electron Microscopy (TEM)analyses and Zeta potentials.It was found that exposure of culture supernatanant of some Entrobacteriaceaemainly E.coli, to these metal ions lead to the formation of metal nanoparticles. Thesilver, copper and iron nanoparticles were in the range of 20-80, 90-110 and 5-60 nmin dimension respectively.The main conclusion is that the bio-reduction method is a good alternative to theelectrochemical methods for producing nanoparticles.Keywords: bio-reduction, E coli. Entrobacteriaceae, metal nanoparticles6th Nanoscience and Nanotechnology Conference, İzmir, 2010 767-1

Poster Session, Thursday, June 17Theme F686 - N1123CRYSTALLIZATION OF THIN Si FILM FABRICATED BY ELECTRON BEAMEVAPORATION ON GLASS SUBSTRATE FOR SOLAR CELLL APPLICATIONSM. Karaman a , Ö. Tüzün b , R. Turan a , . Oktik ba Department of Physics, Middle East Technical University, 06531 Ankara, Turkeyb Department of Physics, Mula University, 48000 Mula, TurkeyE-Mail: mkaramanm@gmail.comAbstractAmorphous, nanocrystalline andpolycrystalline silicon thin films fabricatedon glass substrate are of great interest forlow-cost and high efficiency solar cells.There are various techniques to fabricatesuch kind of cells[1]. Solid PhaseCrystallization (SPC) technique isfavourable due to its easy production andresulting high quality, such as largergrained, less defective thin films. However,its long crystallization annealing is thedisadvatage for industrial productionapplication[2]. This important problem issolved by a novel annealing technique thatconsists of two-step annealing. These arelow-temperature annealing (475 o C for 8h) tostart the nucleation with a lower nucleationrate and high-temperature annealing (900 o Cfor 1h) to reduce the annealing timedramatically. In this approach, novel SPCprocess results larger grain size with lowerdefects compared to conventional lowtemperatureSPC process while the hightemperatureannealing reduces thecrystallization time. This two step annealingprocesses lead to a phase transformationfrom a fully amorphous phase to ananocrystalline phase and finally apolycrystalline phase in the film. This workaims to undertand the basic kintics in thesetransformation processes.Ex situ doped amorphous silicon isdeposited by electron beam evaporationsystem with a depositon rate of 3Å/sec, andcrystallized by classical thermal process.The structural analysis of the films formedby this novel annealing process is analyzedby optical microscopy, scanning electronmicroscopy (SEM), electron back scatteringdiffraction (EBSD) technique, and RamanSpectroscopy. Raman spectroscopy allowedus to monitor the crystallinity of the grownlayer. It also provided infromation about theFigure1. Raman measurement after 475°C 8h+900°C60min annealing processstructures formed at nanoscale. Dopingprofile of boron through the active layer isstudied by secondary ion mass spectroscopy(SIMS). Results show that structures withnanometer dimension are observable evenafter high temeparture annealings.[1] T. Baba, M. Shima, T. Matsuyama, S. Tsuge, K.Wakisaka, S. Tsuda, In: Proc. 13 th European PhotovoltaicSolar Energy Conf. (1995) 1708.[2] T. Baba, T. Matsuyama, T. Sawada, T. Takahama, K.Wakisaka, S. Tsuda, MRS Symp. Proc. 358 (1995) 8956th Nanoscience and Nanotechnology Conference, zmir, 2010 768

PandPoster Session, Thursday, June 17Theme F686 - N1123Illumination Dependence of Equivalent Circuits Parameters for Organic Solar Cells from Single I-VPlot1UOmer MermerUP P*1PEge University, Department of Electrical and Electronics Engineering Bornova/Izmir/TurkeyAbstract-In this paper, we present a simulation study for a newly prepared organic solar cell, based on a composite of poly (2-methoxy- 5-(20-ethylhexyloxy)-1, 4-phenylenevinylene (MEH-PPV) with [6, 6]-phenyl C60 butyric acid methyl ester (PCBM). Photo-current density vs.voltage (J–V) characteristics, for the cell, which were experimentally studied earlier, has been revisited here. The variation of equivalent circuitparameters with respect to different illumination intensity were studied in detail and compared with experimental data of P3HT:PCBM solarcell. The experimental data showed good agreement with theory.Conducting polymers are of great topical interest. They havefound applications in the design and development of thin,light-weight, flexible and low-cost electronic devices [1].Extensive research is being done on organic light emittingdiodes, solar cells, display devices, transistors, lasers andsensors [2–5]. Solar cells are among the best technologicalalternatives to today’s conventional energy sources and are thesolution to the energy crisis. Their cost-effectiveness and easyprocessing have attracted the attention of researchers towardsthe development of organic solar cell (OSC) devices. Therehas been very fast progress in the performance of organic solarcells and an efficiency of 6.5% has been achieved in aP3HT:PCBM system [6]. Further improvement in theperformance needs understanding of the physics behind theoperation of these devices. Despite the rapid progress oforganic devices towards commercial applications, devicemodeling is of prime importance in understanding the physicsbehind the charge carrier transport in these devices. Thedevice modeling is useful for the prediction of chargetransport properties of the devices and facilitates better devicedesign.The indium tin oxide (ITO)/poly(ethylene-dioxythiophene) :poly(styrenesulphonate) (PEDOT : PSS)/P3HT : PCBM/Alorganic bulkheterojunction (BHJ) solar cells was fabricatedand measured their I-V characteristics in the dark and underdifferent illumination intensities according to previouslypublished procedure [7].FF(%)2120.52019.52.21.81.61.4191.220 40 60 80 100Radiation (mW/cm2)2efficiencyCurrent density(mA/cm2)12111098765420 40 60 80 100radiation (mW/cm2)Figure 1. Variation of a)Jsc and Voc and b) FF and efficiency ofP3HT:PCBM solar cell device with the illumination intensity.Figure 1 shows the effect of illumination intensity on thevarious parameters of the P3HT :PCBM solar cell devicestudied in this paper. The variation of the illuminationintensity is observed to have a significant effect on theperformance of the solar cell device.The current–voltage relation for a solar cell underillumination is given by [8]0.870.860.850.840.830.82Voc(V)I I Iphph Id Ip Is exp qnkT V IRs( V IRs) 1 RpWhere IRphR, IRsR, n, RRsR RR being the photocurrent, theshRdiode saturation current, the diode quality factor, the seriesand the shunt resistances, respectively.Good agreement between the experimental data andequation (1) has also been observed under differentillumination intensities. The modelled characteristics showgood agreement with the measured characteristics for the samevalues of the diode parameters in the dark and under differentillumination intensities except the parallel resistance (Rp),which is observed to decrease with the increment in theillumination intensity. Figure 2 shows the dependence ofseries and shunt resistance on the different illuminationintensities.Rs(ohm)1151101054500400035003000250020001500100100020 30 40 50 60 70 80 90 100Radiation (mW/cm2)Figure 2. Variation of Rs and Rp of P3HT:PCBM solar cell devicewith the illumination intensity.In summary, we have modeled the dark and illuminated I-Vcharacteristics of an organic solar cell device. Theexperimental data showed good agreement with theory. Thepresent model explains the behavior of the solar cell devices indifferent experimental conditions, such as differentillumination intensity and temperature.*Corresponding author: omermermer@gmail.com[1] S. C. Jain, et.al. Conducting Organic Materials and Devices, 2007[2] E. Bundgaard, et.al., 2007 Sol. Energy Mater. Sol. Cells 91, 954[3] C.J. Brabec, et.al. 2005 Adv. Funct. Mater. 11, 15[4] S.R. Forrest, 2004 Nature 428 911[5] H. Sirringhaus 2005 Adv. Funct. Mater. 17, 2411[6] J. Y.Kim J Y, et.al., 2007 Science 317, 222[7] S. Alem, et.al., Applied Physics Letters, 84, 2004, 2178.[8] A. Moliton, et al., Polymer International, 55 , 2006, 583Rp(ohm)6th Nanoscience and Nanotechnology Conference, zmir, 2010 769

Poster Session, Thursday, June 17Theme F686 - N1123Undesired Phase Formations Between Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ Cathode and La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85Electrolyte for SOFCsYeliz EKINCI 1 , Ridvan DEMIRYUREK 2* , Omer KARAKOC 2* , Shalima SHAWUTI 2 , Cinar ONCEL 2 and M. Ali GULGUN 21 Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, Istanbul 34469, Turkey2 Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956, TurkeyAbstract Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) is promising material as a cathode for La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85 (LSGM) based SOFCs. For this aim,BSCF-LSGM powders were characterized by the XRD, SEM and EDS techniques to observe the formation of undesired phases in thetemperature range of 700-1100 °C. Formation of new phases began around 900 °C. No new phases were observed below this temperature.SrLaGa 3 O 7 , BaLaGaO 4 and Ba 6 La 2 Co 4 O 15 could be undesired phases which were strongly observed at 1100 °C.The main obstacle in front of SOFC’s commercializationis their high operating temperatures [1]. Efforts to reduce theoperating temperature brings along some problems with them.There is a substantial increase in electrochemical resistance ofthe fuel cell components (anode, cathode and electrolyte) andan increase of electrode polarization resistance [2]. To tacklethese problems, novel materials has been under an intensestudies. Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3−δ (BSCF) cathode andLa 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85 (LSGM) electrolyte materialcombination offers promising results. LSGM is preferredbecause of its high oxygen ion conductivity, 10 -1 S cm -1 [3] at800 °C and high oxygen diffusion rate. The electronicconductivity pattern over a wide range of oxygen partialpressures (10 − 20 to 1 atm) can be assumed negligible atintermediate operating temperatures [3]. BSCF is a mixedoxygen ionic and electronic conducting oxide in the latticeform of perovskite [2]. High activity to reduce the oxygenelectrochemically and high oxygen diffusion rate at 773-873°C makes BSCF worthy of investigation [3]. However use ofBSCF cathode and LSGM electrolyte together may causeformation of some undesired phases. These undesired phasescould decrease the efficiency of the whole system.In this investigation, the temperature range at whichundesired reactions between the cathode candidate and theLSGM electrolyte take place and the phases that are formedwere studied. BSCF used in this study was synthesized bycombined EDTA-citrate (EC) method [4]. The temperature ofthe formation of reaction products was determined by XRD.LSGM and BSCF powders are mixed in the ratio of 1:1. XRDmeasurements are done on the powders heat treated at roomtemperature (RT), 700 C, 800 C, 900 C, 1000 C, and 1100C (Figure 1). Formation of new phases began around 900 C.No new phases were observed below this temperature. Thephase that was strongly consumed in the reactions above 1100°C was BSCF. The disappearance of XRD peaks belonging toBSCF phase can be observed in Figure 1.The new phases that form as a result of the reactions betweenthe cathode and electrolyte are suspected to be SrLaGa 3 O 7,BaLaGaO 4 and Ba 6 La 2 Co 4 O 15 .Figure 2 shows the secondary electron and back scatteredelectron images of a particle that shows reacted as well asoriginal powder regions. EDS analyses taken from regionswith different BSE contrast in Figure 2 confirmed theassignments of the phases that appear in these reactions. EDSresults also indicated that extensive solid solution in thesystem is possible. This could open a whole new series ofmixed oxides that are suitable for SOFC applications.Figure 2. SEM micrographs of mixture of BSCF-LSGM powders at1100 °C (a) the secondary electron (b) the back scattered electron*Presenting authors: demiryurek@su.sabanciuniv.edu,okarakoc@su.sabanciuniv.edu[1] Liu, B., Zhang, Y., and Zhang, L., 2008. Journal of PowerSources. Volume 175, Issue 1, Pages 189-195[2] Zhou, W., Ran, R., and Shao, Z., 2009. Journal of Power Sources,Volume 192, Issue 2, Pages 231-246[3] J. Peña-Martíneza, D. Marrero-Lópezb, J.C. Ruiz-Moralesb, B.E.Buergler, P. Núñez and L.J. Gauckler, 2006. Solid State Ionics,Volume 177, Issue 19-25, Pages 2143-2147[4] Lee, S., Lim, Y., Lee, E., Hwang, H., and Moon, J, 2005. Journalof Power Sources, Volume 157, Pages 848-854(a)(b)Figure 1. The XRD patterns of mixture of BSCF-LSGM powders6th Nanoscience and Nanotechnology Conference, zmir, 2010 770

Poster Session, Thursday, June 17 Theme F686 - N1123Enhanced Photocatalytic Activity Of Dye-Sensitized SolarCells With Optimized CathodeBerk H. Giray a , Hermann Tempel b,c , Saygin Aras c , Özlem Soydas c , Jörg J.Schneider b , and Deniz Üner c,*a Aselsan Inc., 06172, Ankara / TURKEYb Eduard-Zintl Institut Technische Universität Darmstadt, Petersenstrasse 18 64287 Darmstadt, GERMANYc Middle East Technical University, Chemical Engineering Department, 06531, Ankara / TURKEY*uner@metu.edu.trAbstract. In this study the effect of CNT modified TiO 2 thin films on the performance of Dye Sensitized SolarCells (DSSC) is studied. Furthermore, the effect of the thermal decomposition temperature of Pt layer on thecathode surface was also investigated. The CNT loadings and Pt decomposition temperatures were optimized forthe efficiencies of the DSSCs.Keywords: dye sensitized solar cells, carbon nanotubes, Pt loadings, metal support interaction.PACS: 81.40.Tv - Optical and dielectric properties related to treatment conditions:http://www.aip.org/pacs/index.htmlINTRODUCTIONSince the introduction of DSSC from Grätzel andO’Regan [1] , numerous studies have been done tooptimize the working electrode. But still theefficiencies are limited to less than 10-15% [2] . Themajority of the studies focus on the anode side of theDSSCs. However, there is also room for improvementin the catalysis going on at the Pt nanoparticles overthe cathode surface.EXPERIMENTALPt layer was coated by brushcoating of platisol(Solaronix Switzerland). After coating the platinumprecursor was decomposed by heat treatment at 400°Cfor 5 min. Afterwards sintering at temperatures from400°C to 550°C were applied. The working electrode(anode) was prepared by doctor blade technique. Theprecursor solution was Ti-Nanoxide T20 (Solaronix)was the choice of anatase. It is a paste containing 11weight % anatase with uniform particle diameter of 20nm.CNTs were incorporated into the working electrodeTiO 2 by stiring ethanol, anatase nanopowder,tetratitaniumisopropoxide, nitric acid, polyethyleneglycoland pluronic at 50°C for 20h. This sol wasapplied onto the FTO glass slides by spincoatingtechnique [3] .RESULTS AND DISCUSSIONThe amount of Ru-Dye [Solaronix Ru-535]adsorbed increased upon incorporation of activatedcarbon on the anode. But, it should be rememberedthat a larger amount of dye not always leads to highercurrent in the DSSC. Figure 1 shows the TiO 2 layerwith incorporated CNTs.The effects of the different sintering parameters on thecathode surface morphology were reported in terms ofthe effect on the cell efficiency and the fill factor inTable 1. It is seen that the catalytic I - /I 3 - reactions atthe cathode side is influenced by the Pt particle sizes.Further characterization is in progress.FIGURE 1. SEM image of TiO 2 film withincorporated CNTs.TABLE 1. Effect of different annealing conditions onthe cell performance [4]particles size P FF ηT( o C) (nm)(mW) (%)none 89 24,50 0.454 2.36450 83 25,80 0.466 2.48500 69 29,60 0.471 2.85550 67 30,00 0.474 2.89ACKNOWLEDGMENTSFinancial support of BMBF Germany andTUBITAK (107M447) Inten-C joint program andTUBITAK (108M631) is acknowledged. METUCentral laboratories and the Metallurgical andMaterials Engineering Department are kindlyacknowledged for the SEM measurements.REFERENCES1. Grätzel and O’Regan, Nature, 353, 1991, 737.2. Hodes G. Electrochemistry of nanomaterials, VCH-Wiley, Weinheim, 2000.3. H. Itai, H. et al. Chemistry Letters,No. 9, 37, 2008, 940.4. H. B. Giray M.S Thesis, 2010, METU, Ankara.6th Nanoscience and Nanotechnology Conference, zmir, 2010 1

PPoster Session, Thursday, June 17Theme F686 - N1123Crystal Structure Predictions for Hydrogen Storage Materials and Ammonia Dynamics inMagnesium Ammine from DFT and Neutron Scattering1UAdem TekinUP P*1PInformatics Institute, Istanbul Technical University, 34469 Maslak Istanbul TurkeyAbstract- By combining several computational methods, the lowest energy crystal structures of Mg(NHR3R)RnRClR2R with n=6,2,1,Mg(BH4)2, LiBH and MgNH were searched. Furthermore, NHR3R ab- and desorption mechanisms involved in metalammines wereinvestigated using a combination of DFT and quasi-elastic neutron scattering measurements.Hydrogen and ammonia both have great potential ascarbon-neutral energy carriers for the future. However, thereare still some major challenges waiting to be addressedconcerning the production, storage, and the everyday use ofhydrogen and ammonia. In addition to gas or liquid forms ofstorage (which are not efficient), hydrogen can also be storedwith high capacity in the condensed phase in the form ofmetal hydrides, carbon nanotubes, metal–organicframeworks, metal borohydrides and metalammines.Details of absorption and desorption mechanisms ofNHR3R/HR2R in different storage mediums are based on the crystalstructure. This point becomes more delicate if the crystalstructure is unknown, as in the case of the low temperaturestructure of Mg(NHR3R)R6RClR2R. Therefore, a new crystal structureprediction method based on Simulated Annealing (SA) [1] isimplemented and first applied to Mg(NHR3R)RnRClR2R with n=6,2,1[2]. In metal ammines, hydrogen bonds between NHR3R'shydrogens and chlorine atoms are important to stabilize themetal complex. This fact is exploited in the SA search toconstruct crystal structures by maximizing the number ofhydrogen bonds within a (2×2×2) cut-through lattice usingonly several bond length constraints. SA optimizations foundall the experimentally known structures and predicted theC2/m structure for the uncharacterized low temperature phaseof Mg(NHR3R)R6RClR2R.Then the SA method applied to one of the promising metalborohydride, Mg(BHR4R)R2R [3], which stores 14.9 % wt ofhydrogen. These SA optimizations successfully yieldedpreviously proposed I4m2 and F222 symmetry structures ofMg(BHR4R)R2R. Further optimizations the Density FunctionalTheory (DFT) level indicated that the ground state structureof Mg(BHR4R)R2R is the one with I4m2 symmetry.In the last decade, LiBHR4R has been proposed as a promisinghydrogen storage medium due to its high gravimetric (18.5 %3wt hydrogen) and volumetric (121 kg H/mP P) hydrogendensity. Although a considerable amount of papers have beenpublished on LiBHR4R, a clear theoretical structuredetermination seems to suffer from a lack of methodologicalapproach. Therefore, the potential energy surface of LiBHR4Rwas investigated by the SA method and DFT calculations. Anew stable orthogonal structure with Pnma symmetry wasfound [4], which is 9.66 kJ/mol lower in energy than theproposed Pnma structure [5]. For the high temperaturestructure, a new orthorhombic P2/c structure was proposed,which is 21.26 kJ/mol over the ground-state energy andshowed no lattice instability.Li – Mg – N – H systems composed of Mg(NHR2R)R2R and LiHwith various ratios can reversibly store hydrogen at moderateoperating conditions. Depending on the Mg/Li ratio differentproducts may be formed. Amongst them, the crystal structureof magnesium imide (MgNH) is unknown. Therefore, the SAmethod was also applied to find the ground-state structure ofMgNH. A new stable tetragonal phase with P4/nmmsymmetry was found as the lowest-energy structure of MgNH[6].Using the structures of Mg(NHR3R)RnRClR2R with n=6,2,1 foundby the SA method, NHR3R rotation and diffusion processes inthese metalammines were investigated using a combinationof DFT and quasi-elastic neutron scattering measurements.DFT calculations involving bulk diffusion of NHR3R correctlyreproduced the trends observed in the experimentaldesorption enthalpies. In particular, for n = 6, 2, 1, there is agood agreement between activation barriers and experimentalenthalpies. The release of NHR3R in magnesium ammine is thusfound to be limited by bulk diffusion.Figure 1. Calculated (dotted line) versus experimental (solid line)desorption enthalpies for the different desorption steps, 6 2, 21, and 1 0, of magnesium ammine. The lowest activationbarriers obtained for NHR3R diffusion are shown in squares [2].Ammonia dynamics study was supported by EuropeanCommission DG Research (contract MRTN-CT-2006-032474/Hydrogen). I thank Riccarda Caputo (from EMPA)and Deniz Cakir (from University of Twente) for their DFTcalculations for Mg(BHR4R)R2R and LiBHR4R and MgNH,respectively.HT*Corresponding author: adem.tekin@be.itu.edu.trT[1] Corona A, Marchesi M, Martini C, Ridella S., 1987.Minimizing Multimodal Functions of Continuous Variables withthe ``Simulated Annealing'' Algorithm, Assoc. Comput. Mach.,Trans. Math. Software, 13: 262-280.[2] Tekin A, Hummelshøj J. S., Jacobsen H. S., SveinbjörnssonD, Blanchard D, Nørskov J. K., Vegge T., 2010. Ammoniadynamics in magnesium ammine from DFT and neutronscattering, Energy Environ. Sci., DOI: 10.1039/b921442a.[3] Caputo R., Tekin A., Sikora W., Züttel A., 2009. Firstprinciplesdetermination of the ground-state structure ofMg(BH4)2, Chem. Phys. Lett., 480: 203-209.[4] First principles determination of ground-state structure ofLiBHR4R, Tekin A, Caputo R., Züttel A., 2010. Submitted to Phys.Rev. Lett.[5] Soulié J-Ph., Renaud G., erny R., Yvon K., 2002. Lithiumboro-hydride LiBHR4R I. Crystal structure, J. Alloys. Compd.346:200-205.[6] Cakir D, Tekin A, Brocks G., 2010. The crytsal structure ofMgNH: a computational study, Submitted to Phys. Rev. B.6th Nanoscience and Nanotechnology Conference, zmir, 2010 771

PPPoster Session, Thursday, June 17Theme F686 - N11231Effect of Concentration on Roller Electrospinning121UF.YenerUP P*, O.JirsakP P R.GemciPPTextile Engineering Depatment, Engineering& Architecture Faculty, Kahramanmaras Sutcu Imam University, Campus of Avsar, 46100,Kahramanmaras, Turkey2PNonwoven Department, Textile Engineering Faculty, Technical University of Liberec, Halkova 6, 46117, Czech RepublicAbstract- In this study we studied the effect of concentration on Roller Electrospinning Method. Firstly we solved PVB in isopropanol byusing different concentrations as 6%, 7%, 8%, 9%, 10%wt of PVB polymer. Later we compared fiber characteristics for each solvent. Weinvestigated that fiber diameter increases with increasing of concentration. In higher concentrations, the resultant fibers were more regular.Nanofibers can be produced from a wide range ofpolymers. These fibers have extremely high specificsurface area due to their small diameters, high surface perweight ratio, good barrier characteristics against themicroorganism and fine particles, high surface energy,good strength per unit weight, and covering effects, etc [1].….One of the electrospinning is Nanospider (RollerElectrospinning) which is the only method for using inindustry nanofibers continuously. This method wasinvented by Jirsak in Technical University of Liberec(Czech Republic), 2003 [2].In this work, we used Roller Electrospinning withPolyvinly Butyral (molecular weight of 60,000)+Isopropanol in different concentrations. Theseconcentrations were in 6%, 7%, 8%, 9%, 10%wt of PVB.Conductivity, surface tension, viscosity tests were done.Increasing the concentration increased the viscosity. Resultof viscosity are shown in figure 1.6% PVB60+PROƒ = f (Á)7% PVB60+PROƒ = f (Á)8% PVB60+PROƒ = f (Á)9% PVB60+PROƒ = f (Á) 0.5010% PVB60+PROƒ = f (Á)0.45Figure 2. Fabric throughput (g/min/m) of PVB solution indifferent concentrations.According to figure 2 9%wt of PVB solution had a goodthroughput but diameter (avr. Dia: 1,5μm) rather high asshown in figure 3-a. 10%wt of PVB nanofibers had anaverage diameter as 180nm as shown in figure 3-b butthroughput was not high.0.400.35ƒ in Pas0.300.250.200.150.10HAAKE RheoWin 3.61.00000.050 1200 2400 3600 4800 6000Á in 1/sFigure 1. Viscosity of PVB solution in different concentrations.In next step we compared the SEM images of samplesand we observed that the diameter increased withincreasing of concentration too. The fiber uniformity wasincreased with increasing of concentration.In summary we calculated the throughput of nano webin g/min/m is shown in figure 2.(a)(b)Figure 3. (a) PVB nanofiber with 9%wt of PVB polymer, (b)PVB nanofiber with 10%wt of PVB polymerThis work was partially supported by TechnicalUniversity of Liberec. We thank to all technicians in TUL.*Corresponding author: HTfyener@ksu.edu.trT[1] An Introduction to Electrospinning and Nanofibers SeeramRamakrishna, Kazutoshi Fujihara, Wee-Eong Teo.Teik-ChengLim & Zuwei Ma National University of Singapore[2] O. Jirsak, F. Sanetrnik, D. Lukas, V. Kotek, L. Martinova,andJ. Chaloupek, Patent WO 2005024101 (2005).6th Nanoscience and Nanotechnology Conference, zmir, 2010 772

Poster Session, Thursday, June 17Theme F686 - N1123Nanotechnology Applications in Food IndustryGonca Susyal 1 * Neriman Badatlolu 11 Department of Food Engineering, Celal Bayar University, 45140 Manisa, TurkeyAbstract- In this review, we focus on the advantages and disadvantages of nanotechnology applications that are used in food industry toimprove quality of products and food packaging materials and the development of smart foods. We will also discuss the implications of foodnanotechnology and identify current problem areas in nanotechnology in view of the potential risks of nanomaterials for health and theenvironment, as well as regulatory issues.Nanotechnology generally refers to objects that are onebillionthof a meter in diameter (nanometer). The principle ofnanotechnology is that materials with known properties andfunctions at their normal sizes take on different and oftenuseful properties and functions at their nanosizes [1]. Whenthe reduction in size of structures leads to step changes inproperties, that provide radical new solutions to problems andnew commercial opportunities, these types of applications areconsidered to be examples of what has been termedevolutionary nanotechnology [2].In the food industry, several novel applications ofnanotechnologies have become apparent, including the use ofnanoparticles, such as micelles, liposomes, nanoemulsions,biopolymeric nanoparticles and cubosomes, as well as thedevelopment of nanosensors, which are aimed at ensuringfood safety [2,3]. Also, nanotechnologies cover many aspects,such as disease treatment, food security, new materials forpathogen detection, packaging materials and delivery systems[4].Figure 1. Application matrix of nanotechnology in food science andtechnologyAs it applies to the food industry, nanotechnology involvesusing biological molecules such as sugars or proteins as targetrecognitiongroups for nanostructures that could be used, forexample, as biosensors on foods [1,5,6]. Such biosensorscould serve as detectors of food pathogens and othercontaminants and as devices to track food products [7].Nanotechnology may also be useful in encapsulation systemsfor protection against environmental factors. In addition, it canbe used in the design of food ingredients such as flavors andantioxidants [4]. The goal is to improve the functionality ofsuch ingredients while minimizing their concentration. As theinfusion of novel ingredients into foods gains popularity,greater exploration of delivery and controlled-release systemsfor nutraceuticals will occur [8].Although nanotechnology can potentially be useful in allareas of food production and processing, many of the methodsare either too expensive or too impractical to implement on acommercial scale. For this reason, nanoscale techniques aremost cost-effective in the following areas of the food industry:development of new functional materials, food formulations,food processing at microscale and nanoscale levels, productdevelopment, and storage [1,2,7]. Besides, nanotechnologyhas the potential to improve the environment, both throughdirect applications of nano-materials to detect, prevent, andremove pollutants, as well as indirectly by usingnanotechnology to design cleaner industrial processes andcreate environmentally responsible products and to providemore sensitive detection systems for air and water qualitymonitoring [10].It is important to note that nanomaterials, owing to theirincreased contact surface area, might have toxic effects in thebody that are not apparent in the bulk materials. In addition,there might be potential and unforeseen risks for their use infood-packaging materials [3]. While nanotechnology mightprovide solutions for certain environmental problems,relatively little is known at present about the environmentalimpact of nano-particles. Current studies indicate that somenanomaterials are toxic and they can impact biodegradation,transformation and adsorption of some other contaminants inthe environment [10].However, there are social and ethical issues of usingnanotechnology in the food sector that must be considered.Currently, the potential risks of nanomaterials to human healthand to the environment are unknown. Governments shouldconsider appropriate labeling and should also set downregulations that will help to increase consumer acceptability[3]. At this stage of (lack of) knowledge of nanotoxicology itis unavoidable that risk assessors need as much information aspossible about nanoparticals and their appearance andbehavior in biological matrices and organisms [4].*Corresponding author: 0Hgoncasusyal@gmail.com[1]Richardson, S.M.N., Journal of the American Dietetic Association,2007, 1494-1497.[2] Chau,C.F., Wu,S.H., G.C.,Yen, Trends in Food Science &Technology,18, 2007, 269-280.[3] Sozer,N., Kokini,J.L., 2009, Trends in Biotechnology,27,2, 82-89.[4] H. Bouwmeester et al. / Regulatory Toxicology andPharmacology 53 (2009) 52–62[5] Baeummer, A. (2004), Food Technol. 58, 51–55[6] Vo-Dinh, T. et al. (2001), Sensors Actuat. B. 74, 2–11[7] Azeredo,H.M.C., Food Research International 42 (2009) 1240–1253[8] Haruyama, T. 2003, Adv. Drug Delivery Rev. 55: 393-401.[9] Kaplan,.., Karanfil,T., Kiti,M., 7. Ulusal Çerce MühendisliiKongresi, 2007, 845-848.6th Nanoscience and Nanotechnology Conference, zmir, 2010 773

PPoster Session, Thursday, June 17Theme F686 - N11231Carrageenan Nanocomposite as Agrochemical Carrier1UGholam Reza MahdaviniaUP P*PDepartment of Chemistry, Faculty of Science, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran.Abstract- Nanocomposite hydrogels based on kappa-carrageenan were synthesized using sodium montmorillonite as nano-clay. Acrylamideand methylenebisacrylamide were used as monomer and crosslinker, respectively. The nanocomposite hydrogels were investigated by XRD,DSC, and SEM techniques. Sequsterene Fe as agrochemical was loaded into nanocomposite and release of this active agent was studiedaccording to Flick's law.Polymer hydrogels are three-dimensional hydrophilicnetworks that can absorb, swell, and retain aqueous fluids upto hundreds of times of their own weight [1]. The higherproduction cost and low gel strength of these hydrogels,however, restrict their application widely [2]. To improvethese limitations, inorganic compounds with low cost can beused. The introduction of inorganic fillers to a polymer matrixincreases its strength and stiffness properties. Because of theirwater retention property and subsequently, the slow release ofwater from swollen hydrogels, hydrogels with high swellingcapacity are of special interest as potential water retainersystems for agriculture fields [3,4]. Also, in the field ofagriculture, the slow release of water from the polymericmatrix opens another potential area of application that isrelated to load of agrochemicals into hydrogels. In the swollenhydrogels containing agrochemicals, not only the waterreleasing takes place, but also the agrochemical will bereleased together with water.In this work, we attempted to synthesis of nanocompositehydrogel using sodium montmorillonite and carrageenan asclay and biopolymer segment, respectively. In briefly, claywas dispersed in water and then carrageenan dissolved in claydispersed solution. After that, acrylamide andmethylenebisacrylamide were added as monomer andcrosslinker, respectively. Ammonium persulfate was added asinitiator. After synthesis, Sequsterene Fe was loaded intohydrogels and release of that was evaluated according toFlick's law.Nanocomposite hydrogels based on Carra were synthesizedusing solution polymerization. Na-MMt was used as clay.in nanocomposite and it can be concluded that the clay layersare completely exfoliated.The kinetic of sequsterene release from nanocompositehydrogels containing various content of clay was examinedusing Flick's law [5]:n(MRtR/MRR)=ktPwhere MRtR/MRR is the fraction released agrochemical at time t, kis the rate constant and n is the release exponent. The releaseis Fickian if n be 0.5. for n=0.5-1, the release will be non-Fickian. The curve of Ln(MRtR/MRR) against Ln(t) is illustrated inFigure 2. According to data from the Figure 2, the n values areshown in Table 1. The results show non-Fickian release fornanocomposites containing various content of clay.Ln(Mt/Mx)-3-2.5-2-1.5-1-0.50NC1NC2NC3NC4NC54 4.5 5 5.5 6Figure 2 Ln(MRtR/MRR) against Ln(t)Ln(t)Table 1. n values for nanocomposites containing various content ofclayNC1 NC2 NC3 NC4 NC5n 0.66 0.58 0.66 0.68 0.63Figure 1. XRD patterns of pristine clay and nanocomposite[1] R. Po, J. Macromo. Sc.-Re. Macromol Chem Phys C34(4), 607(1994).[2] W. Wang, A.Wang Carbohyd. Polym. 77, 891 (2009).[3] Z. Zhuo, R. Zhuo Eur. Polym. J. 37, 1913 (2001).[4] G. R. Mahdavinia, S. B. Mousavi, F. Karimi, G. B. Marandi, H.Garabaghi, S. Shahabvand Express Polym. Lett. 3, 279 (2009).[5] S. Swarnalatha, R. Gopi, A.G. Kumar, P.K. Selvi, G. Sekaran J.Mater. Sci: Mater. Med. 19, 3005 (2008).The XRD patterns of pristine clay and nanocomposites areshown in Figure 1. As shown in this figure, the XRD profile ofpristine Na-MMt shows a diffractive peak at 2=7.6corresponding to the distance of clay sheets with d spacing11.61 Aº. Stirring of clay for 24 h subsequently in situpolymerization of AAm in the presence of MBA crosslinkerleads to a nanocomposite hydrogel that the XRD profile of thishydrogel shown in Figure 1. No diffraction peak was observed6th Nanoscience and Nanotechnology Conference, zmir, 2010 774

PPPoster Session, Thursday, June 17Theme F686 - N11231Biological Control of Fusarium root-rot of Sorghum11Awatif AbidP and UM. Al-JudibiUP P*PDepartment of Biology – Micrbiology , king Abdulaziz University, Jeddah, Saudi ArabiaAbstract-Among the potential biological control agents in this study, resulted reduction in root dry weight compared to reduction recorded forthe control inoculated with F. oxysporum alone. 100% of the roots from the control treatment rendered growth compared to an incidence rangingfrom 20-55% for plants treated with the biological control agents Both chlorophyll and carbohydrate increased and the maximum enhancementwas recorded when B. subtilis used as antagonist.Sorghum is used to prepare various dishes in different parts of theworld. It can be used in production of fermented and unfermentedbread, stiff porridge, thin porridge, steamed cooked products, boiledwhole or pearled, snack foods, alcoholic beverages, and nonalcoholicbeverages. The sorghum flour is used to prepared local bread know asKhamir in Gizan province, Saudi Arabia[1].Several members of the Genus Fusarium cause root diseases insorghum leading to serious yield losses. Among the major pathogensin this group are Fusarium oxysporum Schlectend, F.moniliformeSheld,F.graminearum Schwabe and F. tricinctum (Corda)Sacc[2].Soil-borne diseases have been controlled more recently by means ofcertain beneficial bacteria that are indigenous to the rhizosphere ofplants[3]. The rhizosphere, representing the thin layer of soilsurrounding plant roots and the soil occupied by the roots, supportslarge and metabolically active groups of bacteria[4] known as plantgrowth promoting rhizobacteria (PGPR)[5]. PGPR are known torapidly colonize the rhizosphere and suppress deleteriousmicroorganisms as well as soil borne pathogens at the root surface[6].These organisms can also be beneficial to the plant by stimulatinggrowth[7].In this study, The antagonistic bacteria were grown in nutrient brothon a rotary shaker at 28±2°C and 180 rpm for 24 h. The suspensionwas centrifuged at 5000 rpm for 15 min. The pellets were resuspendedin quarter strength sterile Ringer’s (Merck) solution togive a final concentration of 100 cfu/ml using the viable plate countmethod. Also, spore suspension of fungal antagonists was prepared(100 cfu/ml).In Vitro Antagonistic Activity: A 4 mm agar disc from fresh PDAcultures of F. oxysporum was placed at the centre of the PDA platefor each antagonist and incubated at 28±2°C for seven days. The radiiof the fungal colony towards and away from the bacterial colonywere measured. In Vitro Root Colonization: The antagonists weretested for their ability to colonize sorghum roots in vitro, using amodification of the methods by Patten and Glick[8]. The treatmentsin the in vivo biocontrol experiment were: Plants inoculated withF.oxysporum and antagonist, a non-inoculated control (Control a) andplants inoculated with F. oxysporum on its own (Control b). The noninoculatedcontrol was treated with sterile barely seed without fungaland antagonist inoculum. The plants were irrigated twice daily withtap water. All the in vitro and in vivo experiments were arranged in arandomized block design in three replications and each experimentwas repeated twice. Four weeks later, plants were removed from thesoil and the roots washed with sterile distilled water. Roots wereexcised from the plants and data collected for analysis. Data includedroot and crown rot severity assessed on a rating scale of 0-4 . (0= noinfection, 1= 1-25% infection, 2= 26-50% infection, 3= 51-75%infection and 4= 76-100% infection in the root region.The test bacterial and fungal antagonists showed variations ininhibition of mycelial growth, whereas Bacillus subtilis, B.lecheniformis and B. cereus resulted in 67.7%, 57.5% and 47.7%inhibition of mycelial growth of F. oxysporum, respectively (Table1). The maximum inhibition achieved by B.subtilis was 67.7%. Forfungal antagonists Trichoderma harzianum and T.viride resulted in57.7% and 49.8% inhibition of mycelial growth of F.oxysporum,respectively. Control plates not treated with the bacterial isolateswere completely covered by the phytopathogens showing noinhibition. The mean mycelial growth inhibition of the most effectivebacterial and fungal isolates revealed that the inhibition was highlysignificant (p = 0.05). Results from the greenhouse pot experimentdemonstrated that T.viride and B.subtilis resulted in more than 80%suppression of root rot whilst T.harzianum and B. cereus resulted indisease reduction of more than 75% The reduction in fresh weight ofroots amounted to 93.6% in the control treatment inoculated withF.oxysporum alone, whereas 71.1%,54.5% and 5.9% reduction infresh root weight was recorded for the treatments inoculated withboth the pathogen and B.subtilis, B.lecheniformis and B.cereus,respectively; 66.8% and 54.5% reduction in fresh root weight wasrecorded for the treatments inoculated with both the pathogen andT.harzianum and T.viride respectively. Root dry weight of the controltreatment inoculated with only F.oxysporum decreased by 94.5% inrelation to the non-inoculated control. Among the potential biologicalcontrol agents in this study, B. cereus and B.subtilis resulted in 42.3and 65.9% reduction in root dry weight respectively compared to the94.5%reduction recorded for the control inoculated withF.oxysporum alone.Table 1. Inhibition of mycelial growth of Fusarium oxysporum and in vitroroot colonization of sorghum roots by antagonistic strainsAntagonist strain Inhibition of mycelial growth (%) In vitro colonization (cfu/cm rootsx105)Control 0.0a 0.3aBacteria-------------------------------------------------------------------------------------------------------------------------------------------------------Bacillus subtilis 67.7b 16.9b-------------------------------------------------------------------------------------------------------------------------------------------------------B. lecheniformis 57.5bc 0.4c-------------------------------------------------------------------------------------------------------------------------------------------------------B. cereus 47.7cd 16.1b-------------------------------------------------------------------------------------------------------------------------------------------------------FungiTrichoderma harzianum 57.7bc 12.3d-------------------------------------------------------------------------------------------------------------------------------------------------------T. viride 49.8cd 1.0eValues within a column followed by the same letter are not significantly different (p=0.05) level according to Duncan's multiple range test.In most biocontrol investigations, a large number of antagonistsare commonly isolated in a short period of time and screened in vitrofor antagonistic activity. However, tests based on in vitro mycelialinhibition and root colonization do not always correlate withbiocontrol efficacy under natural conditions[9]. All promisingisolates from the current study were therefore further evaluated undergreenhouse conditions. The effective colonization of sorghum rootsby isolates such as B.cereus, B.subtilis and T.harzianum might havecontributed to their capability to inhibit infection of sorghum roots byF.oxysporum and reduce root and crown rot. All four bacterialisolates inhibited F.oxysporum both in the dual culture assay and inthe greenhouse experiments.* Corresponding author: aamaljudaibi@kau.edu.sa[1]Gassem, M., 1999. Study of the microorganisms associated with the fermented bread(khamir) produced from sorghum in Gizan region, Saudi Arabia.[2] Forbes, G.A., G.N. Odvody, J.M. Terry, 1986. Seedling Diseases. In: Compendium ofSorghum Diseases. R.A. Frederikson, Editor, American Phytopathological Society, St.Paul, MN., pp: 78.[3] Thomashaw, L.S., 1997. Biological control of plant pathogens. Curr. Opin. Biotech.,77: 343-347.[4] Bais, H.P., R. Fall, J.M. Vivanco, 2004. Biocontrol of Bacillus subtilis againstinfection of Arabidopsis roots by Pseudomonas syringae is facilitated by biofilmformation and surfactin production. Plant Physiol., 134: 307-319.[5] Kloepper, J.W., J. Leong, M. Teintze, M.N. Schroth, 1980. Enhanced plant growth bysiderophores produced by plant growth promoting rhizobacteria. Nature., 268: 885-886.[6] Rangajaran, S., L.M. Saleena, P. Vasudevan, S.Nair, 2003. Biological suppression ofrice diseases by Pseudomonas spp. under saline soil conditions. Plant Soil, 251: 73-82.[7] Bloemberg, G.V., B.J.J. Lugtenberg, 2001. Molecular basis of plant growthpromotion and biocontrol by rhizobacteria. Curr. Opin. Plant Biol.,4: 343-350.[8] Patten, C.L., B.R. Glick, 2002. Role of Pseudomonas putida indole acetic acid indevelopment of the host plant root system. Appl. Environ. Microbiol., 68: 3795-3801.[9] Paulitz, T.C., T. Zhou, L. Rankin, 1992. Selection of rhizosphere bacteria forbiological control of Pythium aphanidermatum on hydroponically grown cucumber. Biol.Control, 2: 226-237.6th Nanoscience and Nanotechnology Conference, zmir, 2010 775

PPoster Session, Thursday, June 17Theme F686 - N1123Food Pathogen Detectıon by Usıng Nano-Bıosensor11USemih OtlesUP P*, Buket YalcinP1PDepartment of Food Engineering, Ege University, Izmir 35100, TurkeyAbstract- Nanosensors can be defined as sensors based on nanotechnology. The aim of some nanobiosensor projects at potentially highvolume applications in the public health sector, as preventing food poisoning where markets might be significant, while the other aim toimprove on existing clinical practises by allowing the more quantification and rapid detection of bacteria and viruses.In the recent years many workers are starting to combinenanotechnology with various biosensing techniques todevelop the so-called “nano-biosensors”. This strategycould be seen as the key to yielding devices whichdemonstrate rapid responses combined with highsensitivities. Indeedy, these trait have nearly becomestandard attributes of this technological combination andarise from the extremely high surface and small sizenanostructures’ areas as nanotubes, nanowires andnanoparticles. Mainly biosensors can be a thrillingalternative to the traditional methods for the detection oftoxins and pathogens in food. The physicochemical orphysical transducer directing, generally specific biologicalevent’s real-time survey such as antigen-antibodyinteraction, biological receptor compounds’s such asenzyme, nucleic acid, antibody, etc. combination are usedby biosensors.Depending on the signal transduction method, biosensorscan be divided into six groups; mass, magnetic,electrochemical, micromechanical, optical, and thermalsensors.The biosensors usage main advantages, in comparisonwith other methods, is, low cost of analysis, the suitabilityto be integrated in automated assays, the short analysistime and the possibility to perform in situ real-timeanalysis. However, in the biosensors’ field for food safety,there is still a lack of portable, integrated systems.Over recent years the works are shown in the literaturerelated with the biosensor usage in food safety andadditionally a lot of effort has gone into the developmentand study of biosensors for food pathogen detection.Biosensors have demonstrated potential for food microbialanalysis, even if their performance stil needs improvement[5].Nanosensors gather information about nanoparticles.Therefore, they have applications in monitoring fooddeterioration, soil health and water or air quality. Theyhave potential as cheap and simple industrial-processmonitoring devices [3].The foodborne pathogens’ identification and detectioncontinue to lean on conventional culturing techniques.These are time-consuming, elaborate and should becompleted in a microbiology laboratory and areconsequently not suitable for on-site monitoring. The needfor a more reliable, rapid, sensitive and specific method ofa target analyte detecting, at low cost, is the focus of manyresearch. Biosensor technology has the potential toincrease sensitivity and specificity, speed up the detection,enable high-throughput analysis, and to be used for criticalcontrol points monitoring in food production.*Corresponding author: semih.otles@ege.edu.tr[1] Bogue, R. 2005. Developments in biosensors – where aretomorrow’s markets. Emerald Group Publishing Limited [ISSN0260-2288], 25/3, R180–184.[2] Bogue, B. 2008. Nanosensors: a review of recent progress.Emerald Group Publishing Limited [ISSN 0260-2288], 28/1(2008), R12–17.[3] Connolly, C. 2008. Nanosensor developments in someEuropean universities. Emerald Group Publishing Limited [ISSN0260-2288], 28/1 (2008), R18–21.[4] Florescu, M., Barsan, M., Pauliukaite R., Brett, C. M. A.2007. Development and Application of Oxysilane Sol – GelElectrochemical Glucose Biosensors Based on CobaltHexacyanoferrate Modified Carbon Film Electrodes. WILEY-VCH Verlag GmbH&Co. KGaA, Weinheim, No. 2-3, R220 –226.[5] Palchetti, I., Mascini, M. 2008. Electroanalytical biosensorsand their potential for food pathogen and toxin detection. AnalBioanal Chem (2008) 391, R455–471.6th Nanoscience and Nanotechnology Conference, zmir, 2010 776

Poster Session, Thursday, June 17Theme F686 - N1123 6th Nanoscience and Nanotechnology Conference, zmir, 2010 777

PPoster Session, Thursday, June 17Theme F686 - N11231Biomimetic and Its Applications in Textile Field11URıza AtavUP P*, Osman NamırtıPPNamık Kemal University, Faculty of Engineering, Department of Textile Engineering, Corlu/Tekirdag 59860, TurkeyAbstract- Biomimetics, is the art of taking natural adaptive strategies used by plants or animals and translating them into HengineeringH designs.Understanding of the functions provided by objects and processes found in nature can guide us to imitate and produce nanomaterials,nanodevices and processes. This article focuses on the biomimetic applications in textile field.Biomimetics is the art of taking natural adaptive strategiesused by plants or animals and translating them intoHengineeringH designs that can be used to implement products ortools [1]. The subject of copying, imitating, and learning frombiology was coined Bionics by Jack Steele and Otto H.Schmitt coined the term Biomimetics in 1969 [2]. Nature is thelargest laboratory that ever existed [3]. Understanding of thefunctions provided by objects and processes found in naturecan guide us to imitate and produce nanomaterials,nanodevices and processes [4]. In recent years, somebusinesses are learning how to design products for energyefficiency from the original designer herself: Mother Nature.[5]. Biology offers a great model of imitation, copying andlearning, and also as inspiration for new technologies [6].Benefits from the study of biomimetics can be seen in manyapplications, including stronger fiber, multifunctionalmaterials, superior robots, and many others [2].The lotus plant (a white water lily) grows in the dirty, muddybottom of lakes and ponds, yet despite this, its leaves arealways clean [7]. In 1982 botanist Wilhelm Barthlottdiscovered in the lotus leaf a naturally self-cleaning, waterrepellentsurface. Barthlott patented his discovery, calling itthe “Lotus Effect” [8].Material made by imitating wood’s design is 50 times moredurable than other synthetic materials in use today. Wood iscurrently imitated in materials being developed for protectionagainst high-velocity particles, such as shrapnel from bombs orbullets [7].Most of the materials in nature consist of composites [7]. Thestructures of biocomposites are highly controlled from thenanometer to the macroscopic levels, resulting in complexarchitectures that provide multifunctional properties [14]. Thefiberglass technology has existed in living things since the dayof their creation. A crocodile’s skin, for example, has much thesame structure as fiberglass [7].Many insects, such as butterflies, use structural colorationdue to the presence of scales [4]. Morpho butterflies remain avibrant blue throughout their lives, without ever needing acoat of paint to spruce up a dull finish. The scales on theirwings are made of many layers of proteins that refract light indifferent ways, and the color we see often is due entirely to theplay of light and structure rather than the presence ofpigments. It has inspired a new biomimetic fabric that refractslight like the butterfly’s wings [15]. Teijin Fibers Limited ofJapan produces Morphotex® fibers. No dyes or pigments areused. Rather, color is created based on the varying thicknessand structure of the fibers [16].*Corresponding author: HTratav@nku.edu.trTFigure 1. (a) Lotus plant and rain droplets sitting on its leaf [9] (b)lotus effect [10]Because the resistive drag opposing the motion of swimmers’bodies is of great importance, many swimmers choose newlyde-signedswimsuits that are made out of a fabric which wasdesigned to mimic the properties of a shark’s skin [7]. Anelectron micrograph reveals shark skin’s secret to speed:tooth-like scales called dermal denticles [8].The spider generates the silk fiber that is continuous andinsoluble in water [4], furthermore according to scientistsspider thread is one of the strongest materials known [7].Figure 2. The spider web [11] and the stress/strain curve of spidersilk [12]The chameleon is well known for its capability to changetheir body color [13]. Technology, USA, is aimed at makingclothes, bags and shoes able to change colors the same way asthe chameleon does. The cost of a color-changing man’s jacketis around $10,000 [7].[1] HThttp://www.wisegeek.com/what-is-biomimetics.htmT[2] Bar-Cohen, Y., 2005, Proceedings of the SPIE Smart StructuresConference, San Diego, Vol. 5759-02[3]HThttp://trs-new.jpl.nasa.gov/dspace/bitstream/2014/38536/1/05-3755.pdfT[4] Bhushan, B., 2009, Phil. Trans. R. Soc. A, Vol. 367, pp. 1445–1486[5] HThttp://www.bnet.com/2403-13501_23-236571.html T[6] Bar-Cohen, Y., 2006, Biomimetics: Biologically InspiredTechnologies, CRC Press (TISBN 10:T 0-8493-3163-3)[7] Yahya, H., 2006, Biomimetics: Technology imitates Nature, Globalpublishing[8]HT http://ngm.nationalgeographic.com/2008/04/biomimetics/clarkphotography[9TH]HThttp://www.bilkent.edu.tr/erz_web/nanoteknoloji_2008_erzurum.pdfT[10] Ozdogan, E., Demir, A., Seventekin N., 2006, Tekstil veKonfeksiyon Dergisi, Vol. 3, pp. 159-163[11] HThttp://hawtaction.com/2008/05/08/spider%20silk.jpgTH[12] HThttp://www.wallstreetreportonline.com/KBLB/images/spider1.jpgTH[13] http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/39359/1/05-3012.pdf[14] Sarikaya, M., 1999, TProceedings of the National Academy ofSciences, TTVTTol. 96, NTTo. 25, pp. TT14183-14185[15]HThttp://io9.com/5241512/an-iridescent-butterfly-gives-rise-tonaturally-bright-fabrics-of-the-futureTH[16]http://www.asknature.org/product/4c0e62f66bcccabf55a1f189da30acb36th Nanoscience and Nanotechnology Conference, zmir, 2010 778

PPP*PPoster Session, Thursday, June 17Theme F686 - N11231Dendrimers and Their Applications in Textile Finishing12URza AtavUPPand Arzu YavaPPNamk Kemal University, Faculty of Engineering, Department of Textile Engineering, Corlu Tekirdag 59860, Turkey2PPamukkale University, Faculty of Engineering, Department of Textile Engineering, Knkl Denizli,20070, TurkeyAbstract-Dendrimers are nanoparticles that can be precisely designed and manufactured for a wide variety of applications. Due to their uniquephysical and chemical properties, dendrimers have wide ranges of potential applications in textile finishing. This paper reveals a review on theproperties and the use of dendrimers in textile finishing processes.Polymer chemistry and technology have traditionallyfocused on linear polymers, which are widely in use [1], butover the last 20 years it has created a number of non-linearvariations which are commonly denoted as “macromoleculararchitectures”. One of the new architectures is “dendrimer”[2]. Dendrimers are nanoparticles that are designed andmanufactured for a wide variety of applications [3].The name “dendrimer” is originated from ancient Greekwords “” and “”, which mean “tree” and “part”,respectively [4]. They were first discovered in the early 1980’sby Tomalia et al. [5]. From this year on a number of thepatents related to the dendrimers have been increased and itreached to 1022 by 2005 [6]. Dendrimers are produced in aniterative sequence of reaction steps [7]. Core molecule isreferred to as “generation 0 (GR0R)”. Each successive repeat unitalong all branches forms the next generation [8].Figure 1. Dendritic structure [9]Dendrimers are generally prepared by using either adivergent method or a convergent method [5];- Divergent method: The dendrimer is built up from a centralpolyfunctional core. In a repeated reaction cycle the buildingblocks are added layer by layer.- Convergent method: First complete wedges are prepared,which are subsequently coupled to a central core [2].Due to their unique physical and chemical properties,dendrimers have wide ranges of potential applications intextile finishing. Literature related to the use of dendrimers intextile finishing can be divided into three groups:I) Improvement of Fiber Dyeability: Burkinshaw et al.(2000) and Feng et al. (2007) iTnvestigated the salt-freedyeability of cotton fabrics with reactive dyes via pretreatingcotton with amino-terminated hyperbranched polymers T[10-11]. Hou-cai et al. (2005) improved the dyeability of cottonfabrics with direct dyes by pretreating cotton with dendrimers[12]. De-suo et al. (2008), treated silk fibers withhyperbranched polymers and investigated the fiber dyeabilitywith Lanasol dyes [13]. Atav and Yurdakul (2010), determinedthat dendrimer applied mohair and angora fibers could be dyedwith reactive dyes at lower temperatures (90°C), withoutcausing any decrease in color yield [14]. Burkinshaw et al.(2002) improved the dyeability of polypropylene fiber withdisperse dye via incorporating the hyperbranched polymer intopolypropylene prior to fiber [15].II) Providing Water, Oil and Soil Repellent Properties onFibers: Water repellent finishing on fabrics is conventionallyimparted by incorporation of low surface energy compounds,while recent approaches are based on the use of nanoparticlessuch as dendrimers to enhance water repellency [16].Figure 2. Orientation of dendrimer product on textile surface [17]III) Providing Antimicrobial Property on Fibers: It isbelieved that dendrimers with amine functional groups couldbe converted into effective antimicrobial agents. Ghosh et al.modified the poly(amidoamine) G-3 dendrimer and applied itto the Cotton/Nylon blend fabric. An antimicrobial test of thetreated-fabric against Staphylococcus aureus exhibitedsignificant biocidal activities [5].*Corresponding author: ratav@nku.edu.tr[1] Klajnert, B., Bryszewska, M., 2001, Acta Biochimica Polonica,Dendrimers:Properties and Applications, Vol.48, No.1, (pp. 199-208)[2] Froehling, P.E., 2001, Dendrimers and Dyes, Dyes and pigments,Vol. 48, No. 3, (pp. 187-195)[3]HTwww.robbiehymancopywriting.com/RHC_writing.../white_papers_DNT.pdfTTH[4] Teobaldi, G., Zerbetto, F., 2003, Molecular Dynamics andImplications for the Photophysics of a Dendrimer-Dye Guest-HostSystems, J. Am. Chem. Soc., Vol. 125, No. 4, (pp. 7388-7393)[5] Ghosh, S., Yadav, S., Vasanthan, N., Sekosan, G., 2010, A studyof Antimicrobial Property of Textile Fabric Treated with ModifiedDendrimers, Journal of Applied Polymer Science, Vol. 115, No. 2,(pp. 716–722)[6] Twww.foley.com/files/tbl_s31Publications/.../dendrimers_rutt.pdf[7] HThttp://cientifica.eu/files/Whitepapers/dendrimers_WP.pdf T[8] HThttp://www.essortment.com/all/whatisdendrime_rsnz.htm T[9] HThttp://www.scribd.com/doc/23984864/DENDRIMERSTH[10] Burkinshaw, S.M., Mignanelli, M., Froehling, P.E., Bide, M.J.,2000, The Use of Dendrimers to Modify the Dyeing Behaviour ofReactive Dyes on Cotton, Dyes and Pigments, Vol. 47, No. 3, (pp.259-267)[11] Feng, Z., Yu-yue1, C., De-suo1, Z., Yan-rong, H., 2007, Effectsof HBP-NH_2 modification on salt-free reactive dyeing of cottonfabric, Dyeing & Finishing, Vol. 22[12] Hou-cai, X., Yun-jun, L., Guo-ping, L., Hui-min, T., 2005, Useof Low Generation Polyamidamine Dendrimers in Cotton Dyeing,Textile Auxiliaries, Vol. 7[13] De-suo, Z., Hong, L., Feng, Z., Yu-yue1, C., Wen-quan, L.,2008, Effects of HBP-HTC Modification on the Silk Fabric Dyedwith Lanasol Dyes, Silk, Vol. 11[14] Atav, R., Yurdakul, A., 2010, The Use of Dendrimers to ObtainLow Temperature Dyeability on Mohair and Angora Fibers, IndustriaTextila Magazine, Vol. 4 (Article in Press)[15] Burkinshaw, S.M., Froehling, P.E., Mignanellia, M., 2002, HTTheEffect of Hyperbranched Polymers on the Dyeing of PolypropyleneFibresTTH, TDyes and Pigments, Vol. 53, No. 3, (pp. 229–235)[16]HThttp://www.dti.unimi.it/~rizzi/gruppodelcolore/Atti5confGdC/Rosace%20et%20al.pdfT[17] HThttp://www.rudolf.de/innovations/hydrophobic-future/bionicfinish/first-product.htmT6th Nanoscience and Nanotechnology Conference, zmir, 2010 779

PP DepartmentNanoscienceTPPoster Session, Thursday, June 17Theme F686 - N11232+Selective Solid Phase Extraction of PbPP in Environmental Samples on Multiwalled Carbon Nanotubes121UHossein TavallaliUP P*, Mohammad ali KarimiP P, Hossein AsvadP2of Chemistry &T1PDepartment of Chemistry of Payame noor university, Shiraz, IRANand TNanotechnology Research LaboratoryT (NNRL), Payame Noor University (PNU),Sirjan 78185-347, IranAbstract- Multiwalled carbon nanotubes (MWNTs) were used as solid phase extractor for Pb(II), ion as dithizone (DZ) chelates, in the presentstudy. The influences of the experimental parameters including pH of the solutions, amounts of MWNTs, amounts of DZ, eluent type andvolume, sample volume etc. on the quantitative recoveries of analyte ion were investigated. The presented method has been applied to thedetermination of analytes in food and environmental samples with satisfactory results.Trace metal analysis is an important part of studies inanalytical chemistry. In order to prevent the interference effectof matrix and to determine the low levels of trace metal ions inthe real samples by flame atomic absorption spectrometryusually requires an efficient preconcentration step in order tobring the concentration of the analyte within the dynamicmeasuring range of the detection limit. The separationenrichment techniques have been used to improve thesensitivity and selectivity of the trace analysis of the metalions. Few methods including cloud point extraction [1–3]solvent extraction [4], co precipitation [5,6] membranefiltration [7], etc have been reviewed for the enrichment ofheavy metal ions in-off line or on-line performance.Nowadays, in the solid phase extraction studies transitionmetals at trace level, investigation of the usage of newmaterials as solid phase extractor is an important ratio. At thispoint, carbon nanotubes (CNTs) have been proposed as anovel solid phase extractor for various inorganic and organicmaterials at trace levels [8–11]. CNTs are one of the mostcommonly used building blocks of nanotechnology.CNTs are one of the most commonly used building blocks ofnanotechnology. CNTs can be visualized as a sheet of graphitethat has been rolled into a tube, and divided into multiwalledcarbon nanotubes (MWNTs) and single-walled carbonnanotubes (SWNTs) according to the carbon atom layers inthe wall of the nanotubes [12]. Liang et al. have proposed apreconcentration system based on the adsorption of copperions at trace levels on multiwalled carbon nanotubes [11]. Asolid phase extraction procedure for trace rare earth elementsin various samples on multiwalled carbon nanotubes prior totheir inductively coupled plasma atomic emissionspectrometric determinations has been presented [13]. Thepotential usage of multiwalled carbon nanotubes as a solidphase extraction adsorbent for the preconcentration of traceCd, Mn and Ni has been investigated by Liang et al. [14]. Li etal. have studied on the adsorption of lead [15] and cadmium[16] ions on carbon nanotubes.In the presented paper, a preconcentration–separationprocedure for traces lead ion as their Dithizon chelates onmultiwalled carbon nanotubes the effects of matrix ions ofnatural waters and some transition metals on the recoveries ofthe analyte ion were also examined in the model solutions.Tests of addition/recovery for analyte ions in real sampleswere performed with satisfactorily results. The detection limits1(3 s) for the analyte ion was in the range of 0.30–0.60 μg lPP.The concentrations of analyte in standard reference materialssuch as (NIST RM 8418 Wheat gluten) pretreated by thepresented method were measured with FAAS and theanalytical values were well agreed with the certified valuesand the reference values without the interference of majorcomponents.*Corresponding author: Tavallali@yahoo.com[1] J.L. ManZoori, A. Bavili-Tabrizi, Anal. Chim. Acta 470, 215(2002).[2] J.L. ManZoori, G. Karim-Nezhad, Anal. Sci 19, 579 (2003).[3] J. Li, P. Liang, T.Q. Shi, H.B. Lu, Atom. Spectrosc. 24, 169(2003).[4] A.M. Aziz-Alrahman, J. Environ. Anal Chem. 22, 251 (1985).[5] J. Nakajima, Y. Hirano, K. Oguma, Anal. Sci. 19, 585 (2003).[6] L. Elci, M. Soylak, B. Ozean, Anal. Lett. 36, 987 (2003).[7] M. Soylak, I. Narin, U. Saracoglu, L. Elei, M. Dogan, Anal. Lett.37 (40), 767 (2004).[8] Y. Bakircioglu, S.R. Segade, E.R. Yourd, I.F. Tyson, Anal. Chim.Acta 485, 9 (2003).[9] A. Wasey, R.K. Bansal, B.K. Puri, A.L.I. Rao, Talanta 31, 205(1984).[10] S. Akman, N. Tokman, Talanta 60, 199 (2003).[11] S. Saracoglu, M. Soylak, M. Dogan, L. Elci, Anal. Sci. 19, 259(2003).[12] Q.X. Zhou, W.D. Wang, J.P. Xiao, J.H. Wang, G.G. Liu, Q.Z.Shi, G.L.Guo, Comparison of the enrichment efficiency of multiwalled carbonnanotubes, C18 silica, and activated carbon as the adsorbents for thesolid phase extraction of atrazine and simazine in water samples,Microchim. Acta 152, 215–224 (2006).[13] P. Liang, Y. Liu, L. Guo, Determination of trace rare earthelements byinductively coupled plasma atomic emission spectrometry afterpreconcentration with multiwalled carbon nanotubes, Spectrochim.Acta 60B 125–129 (2005).[14] P. Liang,Y. Liu, L. Guo, J. Zeng, H.B. Lu, Multiwalled carbonnanotubes as solid-phase extraction adsorbent for thepreconcentration of trace metal ions and their determination byinductively coupled plasma atomic emissionspectrometry, J. Anal. Atom Spectrom. 19 1489–1492 (2004).[15] Y. Li, S.Wang, J.Wei, X. Zhang, C. Xu, Z. Luan, D.Wu, Leadadsorptionon carbon nanotubes, Chem. Phys. Lett. 357 263–266 (2002).[16] Y. Li, S.Wang, Z. Luan, J. Ding, C. Xu, D.Wu, Adsorption ofcadmium(II) from aqueous solution by surface oxidized carbonnanotubes, Carbon 41 1057–1062 (2003).6th Nanoscience and Nanotechnology Conference, zmir, 2010 780

Poster Session, Thursday, June 17Theme F686 - N1123Morphology of the Electrospun Nylon-66 and Polybutylene terephthalate NanofibersFatma Kayacı and Tamer Uyar*UNAM-Institute of Materials Science & Nanotechnology, Bilkent University, Ankara, 06800, TurkeyAbstract – This work covers our recent studies on fabrication of polymeric nanofibers by electrospinning technique.Nanofibers/nanowebs of Nylon-66 (PA66) and Polybutylene terephthalate (PBT) have been obtained by electrospinning andthe morphology of the resulting nanofibers/nanowebs was investigated by scanning electron microscope (SEM) .Electrospinning is the most versatile method forfabrication of nanofibers, since it is a simple andcost effective technique. The nanofibers can beelectrospun from a wide range of polymers that aresoluble in various solvent systems. In addition, theability to produce nanofibers/nanowebs which haveunique properties like small pore size, large surfacearea to volume ratio, high porosity makeelectrospun nanofibers more attractive for manyapplications such as filtration, textile, tissueengineering, wound healing, release control,sensors, energy, etc [1-6]. Electrospinning is asimple process in which a polymer solution or meltis subjected to high voltage (10 kv- 60 kv) and thefibers which have diameter in the range of fewmicrons to few hundred nanometers are produced inthe form of nonwoven [4-8].Nylon-66 is an important semi-crystallinethermoplastic polymer having mechanical strength,chemical resistance, toughness, and dimensionalstability. Therefore, nylon-66 is one of the mostused polymers for numerous applications such astechnical texiles, filtration, and especiallyengineering field [7,8]. Polybutylene terephthalate(PBT), a linear polyester of aromatic nature, is alsoone of the important engineering plastics due to itsgood mechanical, and thermal properties [9].In this study, Nylon 66 and PBTnanofibers/nanowebs were obtained byelectrospinning. Formic acid/chloroform (75/25)and hexafluoroisopropanol (HFIP) were used assolvent for Nylon-66 and PBT, respectively.Polymer concentration, tip-to-collector distance andapplied voltage were optimized in order to obtainbead-free uniform nanofibers.Fig.1.SEM images of electrospun fibers from formic acid/chloroform (75/25) solution (a) 5% PA66, (b) 10% PA66Different fiber morphologies were obtained forNylon-66 and PBT electrospun nanofibers whendifferent polymer concentrations were used (fig.1and fig.2). Beads were formed when the polymerconcentration was low for both of polymers. Whenthe polymer concentration was increased, typicalcircular fibers were obtained for PBT; however,ribbon-like fibers were obtained for Nylon-66because of the rapid evaporation of the solvent. Itwas also observed that the diameter of the fiberswere increased as the polymer concentrationincreased or tip-to-collector distance and appliedvoltage decreased.Figure 2. SEM images of electrospun fibers HFIPsolutions (a) 15% PBT, (b) 20% PBT* Corresponding author (uyar@unam.bilkent.edu.tr)[1] Ramakrishna, S.; Fujihara, K.; Teo, W.; Yong, T.;Ma, Z.; Ramaseshan, R., Electrospun nanofibers: solvingglobal issues. Materials today 2006, 9 (3), 40-50.[2] Li, D.; Xia, Y., Electrospinning of nanofibers:Reinventing the wheel? Advanced Materials 2004, 16(14), 1151-1170.[3] Fang, J.; Niu, H.; Lin, T.; Wang, X., Applications ofelectrospun nanofibers. Chinese Science Bulletin 2008,53 (15), 2265-2286.[4] Huang, Z.; Zhang, Y.; Kotaki, M.; Ramakrishna, S., Areview on polymer nanofibers by electrospinning andtheir applications in nanocomposites. Composites Scienceand Technology 2003, 63 (15), 2223-2253.[5] Greiner, A.; Wendorff, J., Electrospinning: afascinating method for the preparation of ultrathin fibers.Angewandte Chemie-International Edition 2007, 46 (30),5670-5703.[6] Burger, C.; Hsiao, B.; Chu, B., Nanofibrous materialsand their applications. 2006.[7] Jeong, J.; Jeon, S.; Lee, T.; Park, J.; Shin, J.;Alegaonkar, P.; Berdinsky, A.; Yoo, J., Fabrication ofMWNTs/nylon conductive composite nanofibers byelectrospinning. Diamond & Related Materials 2006, 15(11-12), 1839-1843.[8] Pan, Z.; Liu, H.; Wan, Q., Morphology andMechanical Property of Electrospun PA 6/66 CopolymerFilament Constructed of Nanofibers.[9] Xiao, J.; Hu, Y.; Wang, Z.; Tang, Y.; Chen, Z.; Fan,W., Preparation and characterization of poly (butyleneterephthalate) nanocomposites from thermally stableorganic-modified montmorillonite. European PolymerJournal 2005, 41 (5), 1030-10336th Nanoscience and Nanotechnology Conference, zmir, 2010 781

Poster Session, Thursday, June 17Theme F686 - N1123Functional Electrospun Nanofibers from Biocompatible PolymersAslı Çelebioğlu and Tamer Uyar*UNAM-Institute of Materials Science & Nanotechnology, Bilkent University, Ankara, 06800, TurkeyAbstract – In this study, we have electrospun nanofibers/nanowebs from polymers which are known for theirbiocompatibility. We produced uniform nanofibers/nanowebs from poly(vinyl alcohol) (PVA),poly(caprolactone) (PCL), poly(ethylene oxide) (PEO), cellulose acetate (CA) and polyvinylprolidone (PVP).Electrospinning is the most versatilemethod for producing ultrafine fibers which havediameter at micro/nano size. Many different kindsof natural and synthetic polymers can be used toobtain nanofiber/nanoweb structures by using thistechnique. Electrospinning method bases onapplying high voltage to solutions/melts ofpolymers. The diamater, uniformity andmorphology of fibers are controlled by processparameters such as; applied voltage, feed rate, tip tocollector distance and the polymer/solvent typesthat is used. The unique properties like largesurface area to volume ratio, small pore size withhigh porosity and design flexibility makeelectrospun nanofibers more attractive for manyapplications such as filtration, biomedical, energy,packaging, functional textiles, etc [1-4].Biomedical field is one of the mostimportant application areas for nanofibers/nanowebs since they are applicable in tissueengineering, drug release and wound healing, etc.The size similarity between nano-sized materialsand biological systems and having high porositymake these nanofibers /nanowebs suitable andeffective for biomedical applications [5, 6].In this work; poly(vinyl alcohol) (PVA),poly(caprolactone) (PCL), poly(ethylene oxide)(PEO), cellulose acetate (CA) and polyvinylprolidone (PVP) were electrospun for producingnanofibrous materials which have possibilities to beused in biomedical area such as medical textiles,scaffolds for tissue regeneration, wound dressing,drug delivery systems, etc. In order to obtainhomogenous, bead-free nanofibers/nanowebs, theoptimization of the electrospinning process hasbeen achieved by varying polymer concentrationsand the process parameters like applied voltage,feed rate, tip-to-collector distance, etc. Themorphology of produced nanofibers was examinedby using scanning electron microscope (SEM).The effect of polymer concentration on themorphology of electrospun nanofibers is shown infig. 1. As seen from SEM images, at low polymerconcentrations beaded fiber structures were formedbut at higher polymer concentrations uniformnanofibers were obtained. Moreover, we observedthat tip-to- collector distance and applied voltagehave also effect on the morphology of the resultingfibers.a) b)c) d)e) f)Figure1. SEM images of electrospun (a) 8% (b) 12% CA,(c) %10 (d) %15 (PVP), (e) %3 (f) %4 PEO nanofibers* Corresponding author (uyar@unam.bilkent.edu.tr)1. Reneker, D.H. and A.L. Yarin, Electrospinningjets and polymer nanofibers. Polymer, 2008.49(10): p. 2387-2425.2. Teo, W. and S. Ramakrishna, A review onelectrospinning design and nanofibreassemblies. Nanotechnology, 2006. 17: p. R89-R106.3. Li, D. and Y. Xia, Electrospinning ofnanofibers: reinventing the wheel? AdvancedMaterials, 2004. 16(14): p. 1151-1170.4. Huang, Z.-M., et al., A review on polymernanofibers by electrospinning and theirapplications in nanocomposites. CompositesScience and Technology, 2003. 63(15): p.2223-2253.5. Greiner, A. and J. Wendorff, Electrospinning: afascinating method for the preparation ofultrathin fibers. Angewandte Chemie-International Edition, 2007. 46(30): p. 5670-5703.6. Ramakrishna, S., et al., Electrospun nanofibers:solving global issues. Materials Today, 2006.9(3): p. 40-50.6th Nanoscience and Nanotechnology Conference, zmir, 2010 782

TTPPoster Session, Thursday, June 17Theme F686 - N11231Nanotechnology Applications in Military11UOksan OralUP P*, Esra DırgarPPEge Universitesi Bergama Technical and Business College,35700, Bergama-Izmir-TurkeyAbstract-Nanotechnology will play a major role in the development of the new generation of army uniforms and equipment. Military personnelon land, sea, and in the air face many complex hazards which are deliberately aimed at maiming or killing them. In this paper; the improvementson the application areas of military clothing used nanotechnology are mentioned.Military personnel on land, sea, and in the air face manycomplex hazards which are deliberately aimed at maiming orkilling them. Hence, it is inevitable for them to wearprotective clothing likebody armour, chemical and biological(C&B) protective clothing, etc[1].Researchers are working furiously to field defense nanotechnology for military application. Battle science laboritoriesare in hyperdrive to produce nanoscopic assemblers ornanogears to manipulate atomic matter and serve as replicatorswith endless production possibilities T[2].Nanobots and nano technology can be used to createinnovative non woven textiles teeming with military potential.They offer promise as light weight ballistic protection, woundsealing properties, vitals tracking, and environmentaladaptation to heating, cooling, and porous to non-porousmembranes that can react to weather T[2].Development of nanotechnology-based protective clothingfor defence personnel is one of the important areas where allthe major powers of the world are making efforts to doresearch and develop new materials. Ballistic clothing, barrierclothing against chemical and biological materials, selfdecontaminantfabrics, and biomimicked fabrics based onnanotechnology are the thrust area of research in this field. [1].In this paper; the improvements on the application areas ofmilitary clothing used nanotechnology are mentioned.Nanostructures and nanocomposites are being developed forthe following defence applications: Lightweight protective clothing Flexible antiballistic textiles Chemical and biological warfare protection and selfdecontaminatingnanofibre fabricsAdaptive suits like switchable fabrics for improvedthermal control, switchable camouflage. Microsensors for body and brain sensing,environmental and situational awareness, integratedinto a smart suit or a smart helmet.Wearable and/or flexible displays for visual feedbackauxiliary supports: Flexible/rigid textiles for additionalstrength, exoskeletons, and robotics to asist the human tasks[1].Researchers are developing nanotechnology-based materials,including protective lightweight uniforms and "smart" gear. Afew examples of "smart" functionality are items that can:Change colors on command to camouflage inchanging environments—even manipulate light tomake soldiers invisible in the field.Change a shirtsleeve into a splint or a pant leg into arigid cast in the field if a soldier is injured.Possess built-in sensors of each soldier's physicalcondition and location in the battlefield so commandposts can monitor soldiers from a distance.Weave radio communications materials directly intothe uniform's fabric—providing soldiers flexibilityand lighter loads.Automatically administer medicines and transmitvital signs to distant medics—who could thenpotentially perform medical triage on soldiers in thefield.Provide impact protection materials and systemsincluding ballistic and shrapnel.Provide chemical and biological protection materialsand systems [3].CommunicationsData CollectionData TransmissionsReffiling BusConnects To HightThroughputFigure 1. Dynamic battle suit enabled by integrated systems ofnanothecnologies [4].*Corresponding author: HToksan.kansoy@ege.edu.trTPhysiological MonitoringMedicines, Wound HealingAgentsThermal ManagementOn-demand Chem, Bio,Ballistic ProtectionMechanical PerformanceEnhancementInformation backplaneNetworks of sensors. Mechanical actuators, Chemical reaktors,Storage reservoirs linked, controlled and refilled by multi-channel,Hallow fibres that disburse and harvest information, Fluits, Energy[1] Thilagavathi, G., Raja1, A.S.M. , and Kannaian, T.,(2008),”Nanotechnology and protective clothing for defencepersonel” Defence Science Journal, Vol. 58, No. 4, pp. 451-459[2]HThttp://www.tacticalwarfightergear.com/tacticalgear/catalog/ nanotechnologymilitary.phpT[3]HThttp://www.isa.org/InTechTemplate.cfm?Section=InTech&template=/ContentManagement/ContentDisplay.cfm&ContentID=26714TH (2003)[4] Altmann, J., (2006), Military nanotechnology, dangers, preventivearms control, and challenges to the international system,Understanding Complex Systems Conference, May, 2006, USA.6th Nanoscience and Nanotechnology Conference, zmir, 2010 783

Poster Session, Thursday, June 17Theme F686 - N1123Analyzing The Effects Of Different Solvents On The Needle Electrospinning Of PolyurethaneNanofibersZerrin Yılmaz 1 , Oldrich Jirsak 2 , Nurcan Kurtoğlu 1 and Yasemin Korkmaz 1¹Textile Engineering Department, Engineering& Architecture Faculty, Kahramanmaras Sutcu Imam University, Campus of Avsar,46100, Kahramanmaras, Turkey²Nonwoven Department, Textile Engineering Faculty, Technical University of Liberec, Halkova 6, 46117, Czech RepublicAbstract: In this study, we investigated the effect of different solvents and tetraethylammoniumbromide (TEAB) salt on the spinnabilityof polyurethane nanofibers via needle electrospinning. Firstly, polymer of polyurethane in the fiber form was solved indimethylformamide (DMF) and dimethylacetamide (DMAA) by using 5% and 6% wt concentrations of polyurethane with TEAB andwithout TEAB salt. Then the fiber properties were examined. As result, the fiber diameter increased with TEAB+DMF solution;however, it decreased with TEAB+DMAA solution. It was also observed that viscosity increased with TEAB salt with both DMF andDMAA solvents.In the textile sector, fibers, yarns, fabrics, finishing,electronical textiles and fiber modifications arecomponents of nano technology applications [1].Polyurethanes are one of the most widely usedpolymers in biomedical, filtration, protective clothes,composites, sensor and wound healing applications.Therefore, it is very important to investigate thespinnability of polyurethane nanofibers [2].At this study, polyurethane (PU) in the fiber form wasused with 5% and 6% wt concentrations indimethylformamide (DMF) and dimethylacetamide(DMAA) solvents with tetraethylammoniumbromide(TEAB) and without TEAB salt. Ultrasonic bath wasused to solve the PU. Solution properties of conductivity,surface tension and viscosity were measured. Result ofviscosity are shown in figure 1.Figure 2: (a) 6% wt of PU nanofiber by using DMF with TEAB(b) 6% wt of PU nanofiber by using DMAA with TEABFigure 3: Diameter of PU nanofibers by using DMF with teaband without teab.Figure 1. Viscosity of Polyurethane at different solutions.Later, the SEM images of samples were compared toanalyze fiber properties of PU nanofibers. As seen inFigure 2-a, fibers are more regular than Figure 2-b.Fiber diameter increased with increasing theconcentration of TEAB salt with DMF which was alsoreported in the literature [2]. However, it decreased withTEAB+DMAA solution. (Fig. 3 and 4)Figure 4. Diameter of PU nanofibers by using DMAA with teaband without teab.This work was supported by Technical University ofLiberec. We thank to Nonwoven Department ofTextile Engineering Faculty in TUL.Corresponding author: zerrin-yilmaz@hotmail.com[1] E.Özdoğan, A.Demir and N. Seventekin; Nanotechnology and itsapplications in textile industry, Tekstil ve Konfeksiyon, 4/2006 225-229[2] F.Cengiz and O.Jirsak; The Effect of Salt on the RollerElectrospinning of Polyurethane Nanofibers; Fibers and Polymers2009, Vol.10, No.2, 177-1846th Nanoscience and Nanotechnology Conference, zmir, 2010 784

Poster Session, Thursday, June 17Theme F686 - N1123Nanotechnology Applications in Aquaculture and Seafood IndustriesErkan Can 1 *, Volkan Kzak 1 , Murathan Kaym 1 , Banu Kutlu 1 , afak Seyhaneyldz Can 2 , Nida Demirta 1 and Esin Bac 11 Fisheries Faculty, Tunceli University, Tunceli 62000, Turkey2 Tunceli Vocational School, Tunceli University, Tunceli 62000, TurkeyAbstract - Aquatic protein resources are preferable because of positive health effects and important food features of composition. At thispoint, fisheries and aquaculture industries perform new scientific and technological innovations to produce more qualified end products.Recently, nanotechnology which is a new technology and started to use in lots of sectors, applications in fisheries are rapidly increase.Nanotechnology; is the design, production andapplication of structures, devices and systems innanometer scales. Nanomaterials are manufactured to haveunique physical or chemical properties which arise fromtheir small size, shape, surface area, conductivity orsurface chemistry and have found numerous applicationsin many areas. Compared to macro particles, biggersurface area per mass causes biologically more active nanoparticle [1]. Nanotechnology holds promise for medicationand nutrition because materials at the nanometerdimension exhibit novel properties different from those ofboth isolated atom and bulk material [2].Aquatic protein resources are preferable because ofpositive health effects and important food features ofcomposition. At this point, fisheries and aquacultureindustries perform new scientific and technologicalinnovations to produce more qualified end products.Recently, nanotechnology which is a new technology andstarted to use in lots of sectors, applications in fisheries arerapidly increase.Nanotechnology have a wide usage potential in fisheries,aquaculture and seafood industries. For instance,production of more effective fish feed for aquaculturespecies by application of nanotechnology. According tothe some studies, nanoparticles of elements like selenium,iron, etc. sources supplemented in diet could improve thegrowth of fish [2,3]. New materials obtained by thenanosciences can be used in the different aspects offisheries and aquaculture. These include; antifouling infishing and aquaculture nets, antibacterial substances foraquaculture tanks and new packaging materials for seafoodproducts transports, new devices for detection of shelf lifeof sea products, etc. [4].The technology can be applied foruse in aquariums and commercial fish ponds to reduce thecost of water treatment [5]. Researchers believe thatnanotechnology may have the potential to providefishponds that are safe from disease and pollution. Another application possibility of nanotechnology is usage ofdifferent conservation and packaging techniques to provideseafood safety by delaying enzymatic and microbialspoilage [6]. Nanofiltration and reverse osmosis processesis used to decrease salinity of drilling water which is usedin seafood washing and processing. Nanofiltration makespossible to have a standardization of the water quality [7].As the interest in the potential benefits of nanoparticleshas increased, there is also increasing concern over theirpotential toxic effect resulting from use or unintentionalrelease into the environment. Most of the emergingliterature on the toxicity of nanoparticles has focused onrespiratory exposure in mammalian models and theimplications for human health and these studies confirmthat nanoparticles can have toxic effects [8]. The novelproperties of nanoparticles are increasingly studied, little isknown of their interactions with aquatic organisms.Adverse effects of some nanotechnological applications onenvironment should be taken into consideration.*Corresponding author: ecanengineer@hotmail.com[1]M. Kutlay, Nano Teknoloji Riskleri Çaltay, (2009).[2]X. Zhou, G. Qing, W. Yanbo, W. Li, Aquaculture, 291, 78–81,(2009).0B[3]Anonim,0Hhttp://www.azonano.com/Details.asp?ArticleID=1331#_Nano-Aquaculture-Fish_FarmingLoo, (2005)[4]Anonim,www.sintef.no/upload/Fiskeri_og_havbruk/AQUANOR/.../Jose-NANO.pdf, (2010)[5]Anonim,1Hhttp://www.nicaonline.com/webboard/index.php?topic=8050.0, (2010)[6]S. Dursun, N. Erkan, M. Yeilta, Journal ofFisheriesScience.com, 4(1): 50-77, (2010)[7]K. Walhaa, B.R. Amara, F. Quemeneurb, P. Jaouenb, 219,231–239, (2008).[8]C.J. Smith, B.J. Shaw, R.D. Handy, Aquatic Toxicology 82:94–109, (2007).6th Nanoscience and Nanotechnology Conference, zmir, 2010 785

PPPoster Session, Thursday, June 17Theme F686 - N1123Comparison of Antibacterial Properties of Ion Implanted and Conventional Nano Particle TreatedMedical Textiles1112221Ali AkpekP P, E.Esin Hames KocabasP P, Ozkan GubeP P, Efim OksP P, Georgy YushkovP P, Alexey NikolaevP Pand P PUAhmet OztarhanUP P*1PDepartment of Bioengineering,Faculty of Engineering,Ege University, Bornova, 35100 zmir, Turkey2PHigh Current Electronics Institute, Akademichesky Ave., 2/3.Tomsk, 634055, RussiaAbstract- The antibacterial properties of Ag and Ti+O implanted hospital textiles were compared to the ones which were treated with NanoParticle based liquid solutions.Ion beam implanted textiles were produced at HCEI (HighCurrent Electric Institute) in Tomsk,Russia in cooperationwith Ege University Surface Modification Laboratory(picture1.). Conventionel Nano Textile Technology appliedfabrics were obtained from Belgium and China.In this work, the antibacterial properties of Ag and Ti+Oimplanted hospital textiles were compared to the ones whichwere treated with Nano Particle based liquid solutions. It wasobserved that Conventional Nano Textile Technology basedtextiles have better antibacterial properties for %100 Cottontextiles (Alpaka Cotton).However, ion implanted polyestertextiles (%75 Polyester-%25 Cotton mixed fabric) have betterantibacterial properties than the ones treated with NanoParticle based liquid solutions.The reason for this could bethat the polyester textiles have structures suitable for ionimplantion where as 100% cotton textiles have structuressuitable for Nano Particle based liquid solutions (picture.2(a)and (b)). It was observed that, the surface treated cotton andpolyester hospital textiles can sustain antibacterial propertiesafter 30 washes and also found that Silver (Ag) and TitaniumDioxide (TiOR2R) have equal antibacterial properties.Test Bacteria; Staphylococcus aureus, ATCC 6538 (Grampositive organism) was used as a test bacteria. Test bacteriamake a fresh transplant from stock culture before theexperiments.To evaluate the antibacterial activity of the ion-implantedand Nano Textile based textiles, an American NationalStandard (ATCC Test Method 100-1993) [1] was used. All thesamples were washed 30 times with detergent at 49C inshaking condition according to the AATCC 124 Test method[2]. Experiment repeated for the washed samples to detect theeffect of the washing of the antibacterial activity.Bacterial colonies were counted as bacteria per sample.Antibacterial Efficiency Reduction is calculated by theformula;R=100x[(B-A)/B]R= (%) Antibacterial Efficiency ReductionB= Bacterial Colonies accounted from Petri dishes belongs tountreated swatches just after from the inoculation(Result of Contact time detection; T0)A= Bacterial colonies accounted from Petri dishes belongs totreated swatches (Ion Implantation or Nano TextileTechnologies)24 hours later from the inoculationTo evaluate the antibacterial activity of the ion-implanted andNano Textile based textiles, an American National Standard(ATCC Test Method 100-1993) [1] was used.Test Bacteria; Staphylococcus aureus, ATCC 6538 (Grampositive organism) was used as a test bacteria. Test bacteriamake a fresh transplant from stock culture before theexperiments.Culture Medium; All experiments were implemented usingnutrient broth/agar medium consisting; peptone 5 gr, beefextract 3 gr, distilled water 1 L.This work may pioneer the study of antibacterial and someother effects of ion implantation on textiles.Figure.1. Surface modification laboratory.[1] AATCC Test Method 100-1993, An American NationalStandard Antibacterial Finishes on Textile Materials[2] AATCC 124-2006 Test Method Appearance of fabricsAfter repeated home laundering(a) (b) (c)Figure 2. (a) cotton fabric, (b) PES fabric, (c) Conventional nanoantibacterial textile*Corresponding author: aoztarhan@smmib05.net6th Nanoscience and Nanotechnology Conference, zmir, 2010 786

PPPPPPoster Session, Thursday, June 17Theme F686 - N1123Fabrication of Aligned Silk Fibroin Nanofibers by Electrospinning1234Gamze DoanP P, UGüldemet BaalUP P*, Ali Bora BaltaP P, Ouz BayraktarP1 Department of Textile Engineering, Uak University, Uak 64100, Turkey2PDepartment of Textile Engineering, Ege University, zmir 35100, TurkeyPDepartment of Biotechnology and Bioengineering, zmir Istitute of Technology, zmir 35430, Turkey4PDepartment of Chemical Engineering, zmir Istitute of Technology, zmir 35430, Turkey3Abstract- Aligned nanofibers provide some advantages in fabrication of scaffolds for tissue engineering. In this study, silk fibroin nanofiberswere fabricated by an electrospinning unit with a rotating drum as a collector at three different drum speeds (surface velocity), and the influenceof drum speed on fiber size and alignment were investigated.Tissue engineering is a field of regenerative medicine,which deals with the development of tissue substitutes(scaffolds) to repair, maintain, or improve the function ofdiseased or damaged tissues. Mimicking of cellmicroenviroment as close as possible when designingscaffolds is the key issue in tissue engineering [1].Electrospun biopolymer nanofibers have potential uses asscaffolds, due to their resemblance to natural extra cellularmatrix (ECM), high surface area to volume ratio and highporosities [2]. The ECM is a nano fibrous network whichholds cells and tissues together and provides a controlledenvironment inside which migratory cells can move andinteract with each other [3].Several natural or synthetic biodegrable polymers have beenturned into scaffolds for tissue engineering. Silk fibroin (SF)is a great candidate for this purpose. It has a slow degradationrate, good mechanical properties, high oxygen permeabilityand it is non-toxic [4, 5].One of the most widely used method for the fabrication ofnanofibrous scaffolds is electrospinning. This method involvesthe ejection and stretching of a polymer solution or melt froma capillary tube by electrostatic forces. In electrospinningmethod, stationary collectors are used for the production ofrandom nanofiber bundles. Rotating targets such as disks anddrums are used for the fabrication of aligned nanofibers [6, 7].Alignment of nanofibers plays an important role in repairingtissues that have structural orientation in one direction such asmuscle and nerve tissues. According to contact guidancetheory aligned nanofiber scaffolds can exhibit more ECMproduction than random nanofiber scaffolds [8]. These alignednanofiber scaffolds also have a more dense structure and highstrength value compared to random nanofiber scaffolds [9].In this study, aligned nanofibers were fabricated from silkfibroin (SF) by utilizing an electrospinning set up with arotating drum and the effects of the surface velocity of therotating drum on fiber size and alignment of fibers wereinvestigated.Silk fibroin solution was prepared using 98% formic acid.The concentration of SF in the solution was 6 wt%. Appliedvoltage was 20 kV. Flow rate was set to 7 μL/min. Distancebetween the collector and the needle tip was adjusted to 11.2cm. All of these parameters were kept constant, except thesurface velocity of the rotating drum. Electrospinning wasperformed at three different surface velocities: 50, 100 and150m/min. Results revealed that the influence of drum speedon fber alignment and fber size was significant. Figure 1shows the SEM image of silk fibroin nanofibers collected at asurface velocity of 150 m/min. Average fiber diameterdecreased when surface velocity of the drum increased.Average fiber diameters were 80, 69, and 65 nm for thesurface velocities of 50, 100 and 150, respectively.Figure 1. SEM image of silk fibroin nanofibers collected onto a drumwith a surface velocity of 150 m/min.*Corresponding author: guldemet.basal@ege.edu.tr[1] Venugopal J., Prbhakaran M.P., Low S., Choon AT, Zhang Y.Z.,Deepika G., Ramakrishna S., 2008. Current Pharmaceutical Design,14, 2184-2200.[2] Subbiah T., Bhat G.S., Tock R.W., Parameswaran S., RamkumarS.S., 2005. Journal of App. Polymer Science, Vol. 96, 557–569.[3] http://themedicalbiochemistrypage.org/extracellularmatrix.html[4] Lia C., Veparia C., Jina H.J., Kima H.J., Kaplan D.L., 2006.Biomaterials, 27, 3115–3124.[5] Wang S., Zhang Y., Wang H., Yin G., Dong Z., 2009.Biomacromolecules, 10, 2240–2244[6] Fennessey S.F., Farris R.J., 2004. Polymer, 45, 4217-4225.[7] Bazbouz M.B., Stylios G.K., 2008. European Polymer Journal,44, 1–12[8] Venugopal J., Low S., Choon A.T., Ramakrishna S., 2008.Journal of Biomed. Mat. Res. Part B, App. Biomaterials, 84 (1), 34-48.[9] Kumbar, S.G., James, R., Nukavarapu, S.P., and Laurencin, C.T.,2008. Biomed. Mat., 3, 15pp.6th Nanoscience and Nanotechnology Conference, zmir, 2010 787

PPPPPoster Session, Thursday, June 17Theme F686 - N1123Electrospinnability of Hyaluronic Acid123UGamze DoanUP P*, Güldemet BaalP P, Ali Bora BaltaP P, Ouz BayraktarP1PDepartment of Textile Engineering, Uak University, Uak 64100, Turkey2PDepartment of Textile Engineering, Ege University, zmir 35100, TurkeyPDepartment of Biotechnology and Bioengineering, zmir Istitute of Technology, zmir 35430, Turkey4PDepartment of Chemical Engineering, zmir Istitute of Technology, zmir 35430, Turkey3Abstract- Natural biopolymer nanofibers have advantages in tissue engineering applications due to their good biocompatibility,biodegradability, and resemblance to native extracellular matrix which enhances the tissue regeneration. Hyaluronic acid, a naturalbiopolymer existing in human body, is commonly used in scaffold fabrication. One recent fabrication technique for the creation of scaffoldsis electrospinning. However, electrospinability of hyaluronic acid is very poor due its high viscosity. This study reveals the problems faced inelectrospinning of hyaluronic acid and focuses on determining proper solvent systems and blends which allow the successful production ofhyaluronic acid nanofibers.4Hyaluronic acid attracts much attention in tissueengineering applications since it is a basic component ofextra cellular matrix [1]. Hyaluronic acid is an anionicpolysaccharide composed of alternating units of glucuronicacid and N-asetyl-glucosamine (Fig.1). It is hydrophilic,non-immunogenic and possesses high viscosity [2]. Highsurface tension and viscosity of hyaluronic acid makes itvery difficult to electrospin.Viscosity is one of the most important parameters thataffects nanofiber formation in electrospinning process.Intrinsic viscosity is a function of molecular weight.Viscosity of hyaluronic acid with molecular weights of 40,1000, 3000 and 7000 kDa at zero shear rate are 2.1, 36,3000, and 20000 mPas, respectively [3]. Besides molecularweight, concentration, temperature, and solvent type arethe other parameters that affect solution viscosity. As theconcentration of hyaluronic acid solution is raised from1%wt to 4%wt the viscosity of the solution increases 15times[4].Figure 1. Chemical Structure of Hyaluronic AcidIn order to overcome the high surface tension andviscosity problems of hyaluronic acid, several researcherstried to electrospin HA by dissolving it in different solventsystems, blending it with synthetic polymers likepolyethylene oxide [2, 4, 6] and making somemodifications on the electrospinning equipment [7].In this study hyaluronic acid with a molecular weight of1600 kDa was dissolved in different solvent systems.Water, ethanol, dimethyl formamide, and sodiumhydroxide were chosen as solvents. Different combinationsof these solvents were used to prepare HA solutions forelectrospinning. In addition, HA was blended with PEGand PVA in different weight ratios. All of the solventsystems resulted in electrosprayed droplets. Neitheruniform nor beaded nanofiber formation was obtained.Electrospinning of HA was achieved by blending it withPVA at high PVA weight ratios. As seen in Figure 2, evenat high PVA ratios only beaded nanofibers were formed.Figure 2. SEM image of 1% wt PVA:HA (97:3) nanofibers*Corresponding author: gamze.dogan@usak.edu.tr[1] Wang T.W., Spector M., 2009. Development of hyaluronicacid-based scaffolds for brain tissue engineering, ActaBiomaterialia, 5, 2371–2384.[2] Schiffman J.D., 2009. Determination of the electrospinningparameters for biopolyelectrolytes and their modifcations, DrexelUniversity, Doctor of Philosophy Thesis, 300 p.[3] Bergmann G., Kölbel R., Rohlmann A., 1987. Biomechanics:Basic and Applied Research, Martinus Nijhoff Publishers,Dortrecht, The Netherlands, 275-276.[4] Brenner E.K., 2009. Investigation into the Electrospinning ofHyaluronic Acid, Drexel University, Master of Science Thesis,93 p.[6] Young, D.S., 2006. Hyaluronic Acid Based Nanofibers viaElectrospinning, North Carolina State University, Master ofScience Thesis, 97 p.[7] Um, I.C., Fang, D., Hsiao, B.S., Okamoto, A., and Chu, B.,2004. Electro-Spinning and Electro-Blowing of Hyaluronic Acid,Biomacromolecules, 5, 1428-1436.6th Nanoscience and Nanotechnology Conference, zmir, 2010 788

Poster Session, Thursday, June 17Theme F686 - N1123Application Areas of Nanotechnology in Textile Industry; An Example of Nano-FiltrationÖzgün Can 1 * Gizem Karakan 2 and Melek Krt 31 Department of Textile Design, Suleyman Demirel University, Isparta 32200, Turkey2 Department of Textile Technology, Akdeniz University, Antalya-Serik 07500, Turkey3 Department of Chemistry, Suleyman Demirel University, Isparta 32260, TurkeyAbstract- In our study the production of filtration with the help of nanotechnology, the production of nanofibers being used in nano-filtrationby electrospinning also with the other methods and the parameters that affect the filtration are tried to be analyzed beneath thecurrent datas.Nanotechnology is defined as the design, production andapplication of the structures by using the nano dimensioneddevices and systems with combination of the atoms andmolecules [1,2]. Today, in textile sector nanotechnology isused for fibers, yarns, fabrics, finishing as well as the smarttextiles. By the application of nano particules on textilematerials many characteristics of textile products improve andhigh performance properties can be provided.Filtration may be defined as a separation of one materialfrom the other. The main purpose of the filtration is theincreasement of the filtrated material’s pureness. Fabrics forfiltration is generally being used for vacuum cleaners, powerstations, petrochemical factories, waste water channels as wellas in chemical and cosmetics sector and mostly in cigarettefilters. Depending on the fabric type, dust adsorption capacityranges between the percent of %25 and %99.9. The cloggingtime is also an important parameter for filtration [3].Figure 2. Filtration of pollen spor with nano fibers [5]The aim of this study is the considering the importance ofnanotechnology and its usage with the matter ofelectrospinning method and the other methods beneath thecurrent datas in production of nano filtration which plays abig role in increasement of the material’s purity, directeffectiveness to the energy savement and productivity as wellas the recyclement of the valuable materials.*Corresponding author: 0Hozguncan@sdu.edu.trFigure 1. Filtration Mechanism [4]In the filtration mechanism, particles having the smallerdiameters comparing to the fiber’s join to the fiber surfacewith the help of the statically electric occurring on the fiberused for filtration. Big diameter particles easily diverge withthe help of their weight. And hence the filtration mechanismoccurs. The fibers with lower diameters and their becomingcloser increases the influence of the filtration.An electrospinning device is used for producing nanofiberswith the diameter of 50-500 nanometer. The surface structureof nonwovens made of those fibers have smaller porescomparing to the ones produced with other fibers andadditionally they have larger surface areas. And hence aneffective filtration is provided.[1] . Erkoç.“Nanobilim ve Nano Teknoloji” METU Toplum veBilim Merkezi, p.7, (2008).[2] E. Ozdoan, A. Demir, N.Seventekin,“Nanoteknoloji ve TekstilUygulamalar”, Tekstil ve Konfeksiyon, 16(3):159 – 163 (2006).[3] 1Hhttp://www.tekstilteknik.com/Referanslar/Tekniktekstiller.asp[4] S. Adanur. “Technical Texiles”, Auburn University Departmentof Textile Engineering Auburn, AL 36849 USA (2006).[5] R.,R.Hedge, A.Dahiya, M.G. Kamath,“Nanofiber -nonwovens”,2Hhttp://web.utk.edu/~mse/pages/Textiles/Nanofiber%20Nonwovens.htm.6th Nanoscience and Nanotechnology Conference, zmir, 2010 789

PPPPoster Session, Thursday, June 17Theme F686 - N1123The Use of Organoclay in Textile Waste Water Treatment112UE. Perrin Akçakoca KumbasarUP P*, Seniha ElemenP Pand Saadet YaparPPDepartment of Textile Engineering, Ege University, Izmir, TurkeyPDepartment of Chemical Engineering, Ege University, Izmir, Turkey21Abstract- In this study organoclay was used as sorbent for textile dyes. The results obtained from the batch adsorption experiments showed thatorganoclay has very strong sorption ability for textile dyes.Textile wet processing involves the use of a variety ofchemicals including various classes of dyes and auxiliaries.These components have negative environmental impact suchas the exceptionable coloring on the surface waters. Thereforethe methods for decoloration become important issue in recentyears [1].In principle, decoloration is possible with one or more of thefollowing methods: adsorption, precipitation, chemicaldegradation, photo degradation and biodegradation.Adsorption appears to be a good method for the treatment oftextile industry effluents [2]. The process of adsorption isbeing increasingly used for ecofriendly and economicdecoloration process of textile dye effluents. There are manyworks on the adsorption systems; however dye adsorption is acomplicated process because of the nature of dye and theirbehavior in aqueous solutions [1].for 24h. The supernatants were analyzed by using a UVspectrophotometer and adsorbed amounts were determinedfrom the difference between initial and final concentrations.The change in % decoloration with dye concentration wasgiven in Figure 1.Figure 2. (A), (B) and (C) Decoloration of reactive, dispers anddirect dyes with SAMPLE I; (D), (E) and (F) Decoloration ofreactive, dispers and direct dyes with SAMPLE II, respectively.Figure 1. Structure of the clayThere are many sorbents for decoloration. In this work weexplored organoclay as sorbent for textile dyes. Clay mineralshaving layered structure and a high surface area have beeneasily modified to obtain in predescribed properties for aspecial application [3,4]. For instance, they are modifiedthrough the replacement of inorganic exchange cations withquaternary alkylammonium derivatives to have anorganophilic material.In this work, two different types of organoclay synthesizedby using Hexadecyltrimethylammonium (HDTMA) cations inan amount equivalent to 100 % of cation exchange capacity ofclay (CEC) in a research laboratory in the ChemicalEngineering Department [5]. The synthesis conditions werethe same for both of the samples except the last step, drying.At this step, the samples were dried by using a freeze dryerand/or an oven. For the preceeding parts of the work, the claysdried using oven and freeze dryer will be defined as SAMPLEI and SAMPLE II, respectively.The adsorption behavior of reactive, dispers and direct dyeswere studied by conducting batch adsorption experiments at30 °C. The dispersions containing dye and clay were shakenAs shown in the Figure, Sample I and II have decolorationefficiencies about %90 and %70, respectively. The increase in% decoloration with increasing dye concentration indicatesthat the oven dried clay will also be successful in highconcentration.It was observed that the organoclay has potentiality in theremoval of textile dyes through adsorption. Also two types oforganoclay were compared by their sorption isotherms and itwas found that the clay dried using freeze dryer moresuccessful than the oven dried clay.HT*Corresponding author: perrin.akcakoca@ege.edu.trTH[1] Noroozi, B., Sorial, G.A., Haghi, A.K., 2008. Achievements inTextile Dyes Removal Using Adsorption, Polymers ResearchJournal, 2 (1), 29-58.[2] Ceyhan, Ö., Baybas, D., 2001. Adsorption of Some Textile Dyesby Hexadecyltrimethylammonium Bentonite, Turk J Chem 25 , 193 -200.[3] Bergaya, F., Lagaly, G., 2001. Surface modifictaion of clayminerals, Applied Clay Science, 19, 1–3.[4]Yılmaz, N., Yapar, S., 2004. Adsorption properties of tetradecylandhexadecyl trimethylammonium bentonites, Applied ClayScience, 27, 223-228.[5]Yapar, S., 2009. Physicochemical study of microwave-synthesizedorganoclays, Colloids and Surfaces A; Physicocherm, EngineeringAspects,345, 75-81.6th Nanoscience and Nanotechnology Conference, zmir, 2010 790

PPoster Session, Thursday, June 17Theme F686 - N1123Formation of Self-Assembled Alpha-Lactalbumin Nanotubes and Alpha-Lactalbumin Nanoparticlesand Their Behavior in Model Gastro-Intestinal System11Sibel KarakayaP P* and UNihan BaUP1PEge Univ., Fac Engn., Dept. Food Engn., zmir, TurkeyAbstract- In this study, alpha-lactalbumin nanotubes and nanoparticles have been formed by using whey as a starting material.Model molecule Brillant Blue encapsulation capacity of nanoparticles and release of nanoencapsulated Brillant Blue molecule inmodel gastro-intestinal system have also been investigated.The field of nanotechnology has experienced significantgrowth over the last ten years. Currently, the market ofnanotechnology products in the food industry approaches theUS$ 1 billion and has to potential to grow more than US$ 20billion in the next decade [1]. In recent years, the use ofenzymatic hydrolysis to improve functional properties offood proteins and induce specific structural changes inproteins causing the resultant peptides to self-assemble intohighly ordered and well defined nanostructures has attractedmajor attention from scientific area as well as food industry[2]. Whey as a rich source of protein is a waste productobtained from cheese manufacturing. Whey components willincreasingly be preferred as ingredients for functional foodsand nutraceuticals[3]. The growth of -lactalbumin nanotubesand their dimensions was analyzed. Alpha-lactalbumin waspurified from bovine milk. The cylinder diameter wascalculated to be 19.9 (2) nm and the cavity 8.7 (7) nm [4].In the present study, self-assembled -lactalbuminnanotubes and -lactalbumin nanoparticles and behavior of -lactalbumin nanoparticles in model gastro-intestinal systemwere investigated. Nanotubes were imaged by usingTransmission Electron Microscopy (TEM).For the isolation of -lactalbumin from whey, protein wasprecipitated by the procedure of salting out (80% saturatedsalt solution) at isoelectric point. SDS-Page analysis showedthat pure -lactalbumin could be obtained (Figure 1).50 °C in the presence of calcium cation (ratio of molecalcium/mole -lactalbumin: 2.263) are shown in Figure 2.Figure 2. TEM image of nanotubesStandardmarkerBA- lb-lacEncapsulation capacity of -lactalbumin nanoparticles wascalculated as 86.076%. In vitro release of nanoencapsulatedBrillant Blue molecule after model gastro-intestinal digestionwas 42.49%.In conclusion, this study revealed that nanotubes could beformed via self assembly of -lactalbumin isolated fromwhey and encapsulation with -lactalbumin nanoparticlescould be an alternative to microencapsulation.StandardmarkeraAt isoelectricpointSalting outSalting out atisoelectricpoint-lacbFigure 1. a) protein fraction of whey, b) protein fraction ofdialysates isolated from whey by using different precipitationmethod. BA: Bovine serum albumin; - lb: -lactoglobulin; -lac: -lactalbuminHT*Corresponding author: sibel.karakaya@ege.edu.trT[1] Acosta, E., 2009. Bioavailability of nanoparticles in nutrientand nutraceutica delivery, Current Opinion in Colloid andInterface Science, 14: 3-15.[2] Ipsen, R. and Otte, J., 2007. Self-assembly of partiallyhydrolysed -lactalbumin, Biotechnology Advances, 25: 602-605.[3] Smithers, G. W., 2008. Whey and Whey proteins from “gutterto gold”, International Dairy Journal, 18:695-704.[4] Graveland-Bikker, J. F., Fritz, G., Glatter, O., Kruif, C. G.,2006. Growth and structure of -lactalbumin nanotubes, Journal ofApplied Crystallography, 39: 180-184.TEM image of nanotubes obtained from partial hydrolysesof -lactalbumin by protease and subsequent incubation at6th Nanoscience and Nanotechnology Conference, zmir, 2010 791

PPoster Session, Thursday, June 17Theme F686 - N11231Development of -lactalbumin Protein Nanotubes by Self-Assembly11UÖzgür TarhanUP P*, ebnem HarsaPPzmir Institute of Technology, Food Engineering Department, Gülbahçe Campus, 35430, Urla, zmir, TurkeyAbstract-Proteins extracted from various food sources are important matrices providing novel features to processed foods. Recently, they havebeen under research attractively for the fabrication of self-assembled nano-tubular structures, promising novel applications in foodnanotechnology concept. The second major whey protein -lactalbumin (-La) have been reported to produce nanotubes through self-assemblywhen partially hydrolyzed. In this study, development of -La nanotubes by self assembly and characterization of them through particle sizedistribution and morphology by spectrophotometric and microscopic methods were reported.Food grade nanoscale structures such as protein andpeptide nanotubes can be produced by breaking up the bulkmaterials and building up the novel supramolecular structurefrom molecules through self-assembly. These nanostructures may have unique properties providing potentialapplications in food technology. Enzymatic hydrolysis leadsto breakdown of the proteins through smaller protein/peptidefragments depending on degree of hydrolysis. Then naturallyoccurring self-assembly, which may identified byspontaneous diffusion and specific association of moleculesthrough non-covalent interactions, gives rise to fabrication ofnovel structures from these fragments [1]. Self-assembly is a‘bottom up’ approach for the production of nano structures.The second most common whey protein, -La was selectedas the model protein to fabricate nanotubes in this study.Few studies reporting -La nanotubes are present in currentliterature [2, 3]. In the presented study, formation of proteinnanotubes from -La by self-assembly and characterizationof them by DLS, SEM and AFM were targeted.Three percent (v/w) of -La protein was dissolved in 75mM Tris-HCl, pH 7.5, and CaClR2R was added with the ratio of1:2 (-La:CaClR2R). Enzymatic hydrolysis of the protein wasstarted by the addition of 4 % BLP (w/w). After mixing, itwas incubated at 50 ºC for 1.5 h for the hydrolysis andformation of - La nanotubes through self-assembly [4].Then, the developing structures were examined by SEM andAFM and their particle sizes were determined by DLS (atfixed angle 90º and 633nm), at certain time intervals ofincubation.Figure 1 represents SEM images of the nanostructuresformed. The length of them reaches to 1 m. Graveland-Bikker et.al., also reported approximately 1μm long -Lananotubes obtained due to self assembly. In addition, AFMimages indicated similar structures (image not shown).The particle size distributions, of the nanostructuresdeveloped, obtained by zeta-sizer are given in table1. Theaverage size at the end of 90 minute-incubation was nearly191 nm. This may be probably corresponding to the width ofthe tubular structures. As it is compared with SEM results,the width of the structures is seen as nearly 200 nm.Actually, it is the hydrodynamic diameter measured by DLS.thTable 1. Particle size distribution data at 90P P minSize (nm)% classintensity volume number127,9 0 0,6 1,1156,3 1,6 25,6 26,1190,9 98,4 49,4 48,9233,2 0 24,4 23,9In conclusion, nano scale structures can be developedthrough self-association of peptide units after partialhydrolysis of -La protein. More comprehensive results areexpected in the following experimental studies.*Corresponding author: ozgurapaydin@iyte.edu.tr[1]Rajagapol, K., Schneider, J.P., 2004. Self-assembling peptidesand proteins for nanotechnological applications, Current Opinion inStructural Biology, 14: 480-486.[2]Ipsen R. and Otte, J., 2003. Nano-structuring by means ofproteolysis Rheology of novel gels from -lactalbumin, AnnualTransactions of the Nordic Rheology Society, 11: 89-93.[3]Graveland-Bikker, J. F., Fritz, G., Glatter, O., de Kruif, C.G.,2006. Growth and structure of -lactalbumin nanotubes, Jour.ofAppl. Crystallography, 39, 180–184.[4]Graveland-Bikker, J. F., Ipsen, R., Otte, J., de Kruif, C.G., 2004.Influence of calcium on the self-assembly of partially hydrolyzed -lactalbumin, Langmuir, 20: 6841-6846.Figure 1. SEM image of protein nanostructures6th Nanoscience and Nanotechnology Conference, zmir, 2010 792

PPPPPoster Session, Thursday, June 17Theme F686 - N1123Use of Nanotextile Materials in Filtration1123Nuriye KoçakP P, Mustafa ahinP P, UOnur TekoluUP P*, Erkan KalpcP P, Celalettin ÖzdemirP1PScience Fac.,Chemistry Dept., Selçuk University, Konya 42075, Turkey2PVoc. High Sch , Text. Dept., Giresun University, Giresun 28100, Turkey3PEdc. Fac. Biology Dept., Selçuk University, Konya 42090, Turkey4PEng.-Arc. Fac. Env. Eng. Dept., Selçuk University, Konya 42075, TurkeyAbstract-It is quite difficult to refine textile industry wastewater and remove the colour of azodyes in that wastewater.Using advanced tecniquescauses high cost.In our work; it is started to produce nano-chitosan particules with nano-particules in labratory environment and we have statedthat important refining efficiency will be taken when the zeta potential and the structure of nano-chitosan particules are analysed. Besides;in thiswork it is stated that in our country we should produce nano-textile materials and their applicability must be searched in detail in order todecrease the environmental pollution caused by industrial reasons to the minimum level.4Nanoscience and nanotechnology have begun to enter in ourlifes in various fields.Starting with textile industry Thesefields extends from chemical industry,molecular biology andgenetic engineering to the environmental engineering [1].Forexample in environmental applications;it is stated that byusing nono-sized iron high efficiency has been obtained inremoving various hidrocarbones which are chlorinated,andefficient removing is provided due to the absorbtion ofpollutants like trihalometans, 1,2-diklorobenzen with carbonnano-tubes [2, 3, 4].Nowadays we call for the technologies which use less rawmaterials and provides alternative refining methods, reductionin environmental pollution and less wasteproduction.Nanotechonology has an important role in themethods of pollution control.With the help of nano-materialsand nano-appliances the efficiency of energy and procuct canbe increased; the chemical use and waste production can bedecreased [5].Refining textile industry waste water and removing colour ofazodyes in wastewater is very difficult. .Using advancedtecniques causes high cost.In our work; it is started to producenano-chitosan particules in nano-particular environment andwe have stated that vital refining efficiency will be taken whenthe zeta potential and the structure of nano-chitosan particulesare analysed. Studies of refining about them are supposed tobegin soonIn addition to these in this work; it is stated that in ourcountry we should produce nano-textile materials and theirapplicability must be completely searched in order to decreasethe environmental pollution caused by industrial reasons to theminimum level.The most important applications ofnanotechnology textile field are the production of nano andmicro fibre and forming textile surface from the fibres [6].Nano-sized materials are more reactive than macroscobicsizedmaterials because they have small size ,high surface areaand distinctive crystal forms.[7].The characteristics ofmicrofiber liquid filters are;high water transition speed,easycleaning and high performance of leaking. (keeping particulesin micrometre sizemikrometer) [8].The most important parameter which affects the filtrationperformance is the thinness of the fiber which is used as afiltration performance and it is possible to reach any wantedthinness level.The textiles that are produced from microfibers make perfecteffect for gas and liquid filtration because of their thin andfirm structures.Especially the textiles like 0,05 dtex polipropilen (surfacewithout tissue) that are produced from super thinmicrofibers,with the high electric voltage application, gainpermanent embarkation and draws absorbs dust particles.Thetextiles that are produced from microfibers can have greateffect in gas and liquid filtration[9, 10].According to the researches it is stated that in industrialprocesses filtration textiles increases the purity of the productand production efficiency and provides energy saving,recycleand rise in pollution control[11].In our country, in systems like waste refining units,chimneyand dust emission systems,vacuum cleaners etc and inenvironment, the applicability of textiles which are producedfrom microfibers used in nanotechnology must be searched indetail.*Corresponding author: HTonur.tekoglu@giresun.edu.trT[1] UK Royal Society, 2004, The Royal Society and the RoyalAcademy of Engineering. Nanoscience and Nanotechnologies:Opportunities and Uncertainties,http://www.nanotec.org.uk/finalreport.htm (22July 2009).[2]Elliott, D.W., Zhang, W.-X., 2001, Field Assessment of NanoscaleBimetallic Particles for Groundwater Treatment, EnvironmentalScience and Technology, 35/15:4922-4926.[3]Peng, X., Li, Y., Luan, Z., Di, Z., Wang, H., Tian, B., Jia, Z.,2003, Adsorption Of 1,2-Dichlorobenzeze From Water To CarbonNanotubes, Chemical Physics Letters, 376/1:154-158.[4]Lu, C.S., Chung, Y.L., Chang, K.F., 2005, Adsorption ofTrihalomethanes from Water With Carbon Nanotubes, WaterResearch, 39/6:1183-1189.[5]US.EPA, 2007, Nanotechnology White Paper,www.epa.gov/osa/pdfs/nanotech/epa- nanotechnologywhite- paperfinal-July-2009.pdf.[6]kiz, Y., 2006, Tekstilde Nanoteknoloji, Bilim ve Teknik, Aralk(1), HThttp://www.nano.bilkent.edu.tr/Basin/NanoTekstil.pdfTH, (April,2010)[7]Masciangioli, T. ve Zhang W-X., 2003, EnvironmentalTechnologies at the Nanoscale, Environmental Science andTechnology, 37/5:102-108.[8] Purane, S.V., ve Panigrahi, N.R., 2007, Microfibers,microfilamnets and their applications, Autex Research Journal, 7:3.[9] Kaynak, H. K., Babaarslan, O., 2009, Mikroliflerin TekstilEndüstrisindeki Yeri ve Önemi, Tekstil Teknolojileri ElektronikDergisi 3,3:70-83.[10] Purane, S.V., ve Panigrahi, N.R., 2007, Microfibers,Microfilamnets and their Applications, Autex Research Journal, 7, 3,148-158.[11] Can, Ö., 2008, Endüstride Kullanlan Teknik Tekstiller ÜzerineBir Aratrma, Tekstil Teknolojileri Elektronik Dergisi, 3:31-436th Nanoscience and Nanotechnology Conference, zmir, 2010 793

PPoster Session, Thursday, June 17Theme F686 - N11231Nanotechnology and Its Applications in Food Sector1USeval Sevgi KrdarUP P*PMehmet Akif Ersoy University Vocational Higher Education School, Food Processing Department 15 100 Burdur-TurkeyAbstract- In this rewiew summarized the application of nanotechnology relevant to food sector.Nanotechnology applications are expected to bring a rangeof benefits to the food sector, including new tastes, texturesand sensations, less use of fat, enhanced absorption ofnutrients, improved packaging, traceability and security offood products [1]Several applications of nanotechnology are available(Figure 1)UFood ProcessingNanocapsules for improving bioavailability ofneutraceuticals in standard ingredients such ascooking oilsNanoencapsulated flavor enhancersNanotubes and nanoparticles as gelation andviscosifying agents.Nanocapsule infusions of plant-based steroids as areplacement for meat cholesterolNanoparticles that selectively bind and removechemicals or pathogens from foodNanoemulsions and nanoparticles for beteravailability and dispersion of nutrientsAltria, Nestle, Kraft, Heinz and Unilever, as well as smallnanotech start-up companies[4]Nanoparticles are already on the market. An inventory ofconsumer products incorporating nanotechnology identified580 nano-products, and classified them into eight categories(Figure 2). Of the 580 nano-products, 12% were classified as‘Home and Garden’ and the largest category was ‘Health andFitness’ which accounted for 61% of the total (Figure 1).These products were further subdivided as: ‘Food’;‘Cooking’; ‘Storage’; and ‘Supplements’ (Figure 3).NanotechnologyUFood Packaging Applicationsmproved packagings(gas and moisture barriers,tensile strenght)Shelf life extention via active packagingNanoadditivesntelligent packagingDelivery and controlled release of neutraceuticalsAntibacterial or self-cleaning packagingMonitoring product conditions during trasportationFigure.2. Nano-productsFigure 1. Potential application of nanotechnology in the food andfood packaging [1,2]Worldwide sales of nanotechnology products to the foodand beverage packaging sector increased from US$ 150million in 2002 to US$ 860 million in 2004 and are expectedto reach to US$ 20,4 billion by 2010[2]. In a surveyperformed by Israel and The USA in march 2006, it wasfound that over 200 manufacturers currently market productsidendified as “nanoproducts”. Approximately 60% of theseproducts were for “health and fitness” and 9% were for “foodand beverage products[3]. The nanofood sector (the termrefers to the use of nanotechnology techniques, materials ortools for production, processing or packaging of food) iscurrently led by USA, followed by Japan and China.However, Asian countries (led by China) are expected to bethe biggest market for nanofood by 2010[4]. It has beensuggested that the number of companies currently applyingnanotechnologies to food could be as high as 400 . A numberof major food and beverage companies are reported to have(or have had) an interest in nanotechnology. These includeFigure 3. TDistribution of nanotechnology products classified as‘Food and Beverage’ [5]HT*Corresponding author: skirdar@mehmetakif.edu.trT[1] http://www.nap.edu/catalog/12633.html[2] Sozer, N., Kokini, J.L., 2009. Nanotechnology and istapplications in food sector. Trendsin Biotechnology, 27:82-89[3] Chau C.F., 2007. The development of regulations for foodtechnology. Trends Food Sci. Technol. 18:269-280[4] Smith, J.P., Hoshino, J., Abe, Y., 1995. Interactive packaginginvolving sachet technology. In M.L.Rooney (Ed.), Active foodpackaging (pp. 143-173). Glasgow: Blackie Academic andProffesional[5] http://orgprints.org/167866th Nanoscience and Nanotechnology Conference, zmir, 2010 794

PPoster Session, Thursday, June 17Theme F686 - N11231Nanotechnology and Its Applications in Food Sector1USeval Sevgi KırdarUP P*PMehmet Akif Ersoy University Vocational Higher Education School, Food Processing Department 15 100 Burdur-TurkeyAbstract- The rapid development in food industries improved tastes, colour, flavour, texture and consistency of foodstuffs,increased absorption and bioavailability of nutrients and health supplements, new food packaging materials with improvedmechanical, barrier and antimicrobial properties, nano-sensors for traceability and monitoring the condition of food during transportand storage.Nanotechnology can assist a wide field of food processingarea. The principle of nanotechnology in food processing isfocusing more on food preservation and interactive foods.The advantages of nanotechnology in food processing is todevelop the texture of food components, encapsulate foodcomponents or additives, developing new tastes andsensations, controlling the release of flavours and increasingthe bioavailability of nutritional components. On the otherhand, the success of these advancements will be dependenton consumer acceptance and the exploration of regulatoryissues. Food producers and manufacturers could make greatstrides in food safety by using nanotechnology, andconsumers would reap benefits as well[1].Many major areas in food production may benefit fromnanotechnology which is development of new functionalmaterials, microscale and nanoscale processing, productdevelopment and methods, instrumentation design forimproved food safety and biosecurity, storage, transportationand traceability [2,3]. The rapid development in foodindustries improved tastes, colour, flavour, texture andconsistency of foodstuffs, increased absorption andbioavailability of nutrients and health supplements, new foodpackaging materials with improved mechanical, barrier andantimicrobial properties, nano-sensors for traceability andmonitoring the condition of food during transport andstorage[3]. Fig. 1 shows the effect of nanotechnology in foodindustries[4].Table 1. Examples of nanotechnology researches, nanoproducts andapplications of nanotechnology in foodprocessing .CategoryFoodProcessingExamples of the different applications•Interactive foods and beverages give desiredflavours and colors (on-demand delivery) bythe addition of nanocapsules which burst atdifferent microwave frequencies•National Nanotechnology Initiative hasexplored the applications of nanotechnologyin water purification and treatment focusingon the areas such as membranes andmembraneprocesses, biofouling and disinfection, andcontaminants removal•Development of nano-scale formulations ofdifferent traditional herbal plants by reducingthe herbs to nanoscale powder or emulsion•Micronization of ganoderma spore toultrafine powder by top-down approach,resulting in the rupture of cell walls andrelease of potential active ingredients•Frying oil refining catalytic device (made ofnanoceramic material) inhibits thermalpolymerization of frying oil and reduce offodors•Micrometres long stiff hollow nanotubesmade of milk protein by self-assembly havepotential to be used as novel ingredients forviscosifying, gelation, nanoencapsulation,and controlled release purposesHT*Corresponding author: skirdar@mehmetakif.edu.trTFigure 1. Controlled release of nanotechnology in food .There are a large number of potential applications ofnanotechnologywithin the food industry (Table 1).[3]The applications of nano-based technology in food industrymay include nanoparticulate delivery systems (micelles,liposomes, nano-emulsions, biopolymeric nanoparticles andcubosomes) for food safety and biosecurity (nano-sensors andnano-toxicity [5][1] Chau, C. F., Wu, S. H. and Yen, G. C. 2006. The developmentof regulations for food nanotechnology. Trends in Food Scienceand Technology 18:269-280.[2]http://www.finduddanelse.dk/Nanotechnology in/foodprocessing packaging and safety. accessed on 24/03/2010.[3] Abbas, K.A., Saleh, A.M., Mohamed , A., MohdAzhan,N.,2009. The recent advances in the nanotechnology and itsapplications in food processing: A review. Journal of Food,Agriculture & Environment Vol.7 (3&4 ) : 1 4 - 1 7 .[4] http://www.nanoisrael.org/download/nanowater1/US-IL%Accessed on 24/03/2010.[5] Chaudry, Q., Scotter, M., Blackburn, J., Ross, B., Boxall, A.,Castle, L., Aitken, R. and Watkins, R. 2007. Applications andimplications of nanotechnologies for the food sector. FoodAdditives and Contaminants 25(3):241-258.6th Nanoscience and Nanotechnology Conference, zmir, 2010 795

PPoster Session, Thursday, June 17Theme F686 - N1123Synthesis of Nano Silica Based Sol-Gel Dendritic Materials for the Removal of Atrazine from Water111UAyber YldrmUP P, Aylin ÖzkanP Pand Turgay SeçkinP P*1PDepartment of Chemistry, University of Inonu, Malatya, TR Türkiye 44280Abstract-In this study, synthesis, nano silica was prepared by Stöber method and modified with -aminopropyltriethoxysilane by sol-gelmethod and surfactant modified atrazine captivator was covalently attached to the matrix as dendritic group The present study demonstrates anovel approach for preparing nano materials with atrazine removal capacity.The broadleaf herbicide atrazine is one of the most widelyused herbicides for weed control during the production ofcorn, sorghum, and other crops [1] Although many Europeancountries have banned its use, over 60 million pounds ofatrazine are used annually. As a result, atrazine is the mostcommonly detected herbicide in ground and standing waterand this herbicides have been linked to health risks in animalsand humankind.Currently, the best available technology for removal ofatrazine from groundwater is activated charcoal. Alternativemethods for the removal of atrazine from groundwater includeengineered organoclays, molecularly imprintedpolymers,engineered microorganisms, oxidation strategies ,photodegradation using ultraviolet light, nano- orultrafiltration, and polar polymeric supports. The use ofreactive solid supports for the selective removal of atrazinefrom water has not been reported. Reactive resins have beensuccessfully applied to the efficient removal of electrophilicand nucleophilic compounds from solutions. However,applications have been limited mainly to organic andcombinatorial synthesis. Here, we describe a strategy for thesequestration of atrazine and its major metabolites. Thestrategy is presumably generalizable across many of thetriazine herbicides, as well as other select herbicides such asmetolachlor [2-3]amine and cyanuric chloride in THF and attached to the silicamatrix by covalent bonding between amino groups of thematrix and the chloro group of the dendrimer.Conventional characterization methodology was used tocharacterize the nano materials which includes FT-IR, SEM-EDAX, TGA, DTA and DSC analysis.The authors wishes to thank Inonu University ScientificResearch Center for the support 2010-22 and 17.*Corresponding author: ayberyildirim@gmail.com[1] (a) For recent efforts see: Kim, J.-B.; Huang, W.; Miller, M. D.;Baker, G. L.; Bruening, M. L. J Polym.Sci Part A: Polym Chem2003, 41, 386–394. (b) Barner, L.; Zwaneveld, N.; Pham, Y.; Davis,T. P. J Polym Sci Part A: Polym Chem 2002, 40, 4180–4192. (c)Blomberg, S.; Ostberg, S.; Harth, E.; Bosman,A. W.; Van Horn, B.Hawker, C. J. J Polym.Sci Part A: Polym Chem 2002, 40, 1309–1320. (d) Luo, Hutchison, J. B.; Anseth, K. S.; Bowman, C. N.JPolym Sci Part A: Polym Chem 2002, 40, 1885–1891.[2] (a) Tomalia, D. A.; Frechet, J. M. J. J Polym SciPart A: PolymChem 2002, 40, 2719–2728. (b) Frechet,J. M. J. J Polym Sci Part A:Polym Chem 2003, 41, 3713–3725.3. (a) Lee, B. Y; Oh, J. S.Macromolecules 2000, 33,3194–3195. (b) Mayr, M.; Buchmeiser, M.R.;Wurst, K. Adv Synth Catal 2002, 344, 712–719.NNNNNNNNNNNNNNNNNNFigure 1. Surfactant modified silica surfaceThis paper describes the selection of nucleophilic groups foratrazine sequestration using solution phase competitionreactions; the use of these groups on a solid support for thesequestration of atrazine, its metabolites, and another triazineherbicide; and the evidence for covalent attachment.In this work, nano silica was prepared by Stöber method andmodified with -aminopropyltriethoxy silane by means of solgelmethod. Surfactant dendrimer was prepared with t-octyl6th Nanoscience and Nanotechnology Conference, zmir, 2010 796

Poster Session, Thursday, June 17Theme F686 - N1123Nanotechnology Applications in AgricultureA. Ahmet Yücer 1* , Ö. Faruk Sarıoğlu 2 and Turgay Tekinay 21 Republic of Turkey, Ministry of Agriculture and Rural Affairs, Agricultural Research General Directorate, Yenimahalle, Ankara, Turkey2 UNAM – Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, TurkeyAbstract— Nanotechnology is having an impact on many different fields. With increasing population and dwindlingresources, it is certain that novel approaches for food and agriculture are required. There is ongoing research in applications ofnanotechnology in food industry and agriculture. Ministry of Agriculture and Rural Affairs of Turkey started research andeducation collaborations with universities to be on the frontiers of agricultural nanotechnology field.World population increasing and there is a need to getproducts cheaply and through sustainable methods. There is anongoing effort to get better products through noveldevelopments in food industry and agriculture. Newdevelopments in nanotechnology are expected to have impactin food industry and agriculture [1,2]. Basic areas in thesefields that nanotechnology could have an impact are:− Pathogen and Contaminant Detection− Tracking & Food Security− Increasing Efficiency in Agriculture− Environmental Issues and Agricultural WasteSome solutions to problems in these areas are:Nanosensors for Pathogen and Contaminant DetectionThere have been different techniques to detect pathogensand contaminants in food, animals and agricultural products.Pathogen contamination in these products often leads to healthproblems during consumption and economic problems due toloss of the products. Bacteria and virus contamination usuallyresults in illness and sometimes fatality. The most likely areathat nanotechnology will have a revolutionary impact isanalysis and detection of contamination [3]. Use ofnanobiosensors to detect the health of agricultural productsand livestock and surface and airborne pathogens would beimmensely helpful in the field. It is expected that thesenanosensors would be cheaper and give quick results. Thiswould facilitate their use in the fields, since they would notrequire expensive laboratory infrastructure.Nanosensors and Nanomaterials for Food SecurityA very important application of nanotechnology would betracking of agricultural products and food security. Throughdesign and use of novel systems, individual shipments couldbe tracked. New sensors could be developed that would showchanges in temperature or humidity. Also, packaging materialscould be changed so there would be no pathogen adhesion,which lowers the risk for contamination.Through development of novel nanomaterials moreeffective and biodegradable chemicals could be synthesized.These nanomaterials could be used during food preparationand conservation and also could be used in the packaging[4,5].Automation using nanoelectronics and nanosensors isimportant to increase efficiency in agriculture. Using datagathered from nanosensors and nanodevices, there would bebetter management and less use of drugs, fertilizers, and water[6].Nanomaterials for Environmental IssuesUse of nanotechnology in these areas could be nanoscalebasedchemical treatment, bio-nanomechanical systems, andnanofiltration [7].To be in the frontiers of agri-nanotechnology moreinformation exchange is needed between scientists in theacademia, scientists in the Ministry and policy specialists.Ministry of Agriculture and Rural Affairs is starting tocollaborate with universities to educate the research personneland direct research towards nanotechnology. First of suchcollaborations are being done with Bilkent University,UNAM.*Corresponding author: ayucer@tagem.gov.tr[1] Kuzma and VerHage, Project on Emerging Nanotechnologies,Nanotechnology in Agriculture & Food Production (2006).[2] Scott, Chen, Cooperative State Research, Education and ExtensionService, Nanoscale Science and Engineering for Agriculture and FoodSystems, (2003)[3] Skottrup et al., Biosen Bioel. 24, 339 (2008)[4] Joseph and Morrison, Nanoforum Gateway, Nanotechnology inAgriculture and Food, (2006).[5] ElAmin. www.foodnavigator.com/news/ng.asp?id=72022, (2007)[6] Kim et al., J Env Mon, 11(10), 1810 (2009).[7] AzoNano. http://www.azonano.com/details.asp?ArticleID=114 (accessed 24 March 2010), (2007)Nanodevices for Smart Treatment Delivery Systems andSensitive Agriculture6th Nanoscience and Nanotechnology Conference, zmir, 2010 797

Poster Session, Thursday, June 17Theme F686 - N1123Research İn To Visual Effects Of Retro-Reflective Yarns On Weaving Fabrics AndTheir Relationship With Nano TextilesNesrin Önlü¹*¹Department of Textile &Fashion Design, Fine Arts Faculty,Dokuz Eylül University,İzmir,TurkeyAbstractRetro reflective yarns are mostly used in combination with industrial products for protective garment puposes.However, retroreflectiveyarns could also be utilised in order to obtain a variety of different effects in which shimmering and brightness arewelded together in designing unity. Thanks to nano technology glass beads in retro-reflective yarns could be included in threadsurfaces also, even if fabrics woven with such yarns could be uni-colored, they could appear as patterned or even multicoloredthrough the light source available.Key words: Retro-reflective yarn, woven fabric,double and single layer woven structure,shimmering, puffy.IntroductionNanotechnology is a field of material design where thesmallest man made devices encounter the atoms andmolecules of the natural world(for comprative purposes, ananometre is a billionth of a metre, the diameter of an atom isabouth a quarter of a nanometer, average diameter of ahuman hair is 10,000 nanometer). It has the potential to bringabout a revolution in surface design because it promises totake the imitation of natural materials to an advanced level ofprecision [1].The main use of nanotechnology in textiles is a coating.Schoeller have developed a coating that makes it difficult fordirt to stick and easy to wash off. The design is inspired bythe surface of the lotus leaf [2] .While what one recalls firstconcerning nano textiles is that one provides items with suchaspects as impermeability,being stain repellant, flameretardant etc. by combining nano- size materials with fiber,yarn and fabric surface, retro-reflective yarns could beassessed within the context of nano textiles. Reflective abilityis normally given by coating, reflective inks fabrics in specialprocess. Rebecca Early designs original textiles for fashion,and her work demonstrates that in the 1990s new technologyis exploited not only for the materials and techniques but alsofor inspration.She experiments with the latest micro fibrefabrics combined with revolutionary methods of printing andnewly –developed inks,including ‘retro-reflective’ ink. Unlikeother reflective inks, this throws light back to its source,using a principle similar to that of the ‘cat’s eye’ in roads.Itis manufactured by Reflective Technology Industries Ltd. whomake special tap efor protective and safety clothing.Theirtechnique is to suspend microscobic aluminium-coated glassspheres in the ink, which can be either oil or water-basedmaking it suitable for wide range of fabrics.It can also bemixed with any screen-printing pigment for colours thatthrow back coloured light[3].Nowadays technology offers a solution where the yarn isretro-reflective. This fact helps us to solve alot of problemsand allow us to design innovative new products to meet toever changing market demands [4] .Surface of recently progressed retro-reflective yarnsincludes thousands of light reflective glass beads ormicroprisms which reflect light back to where it has come inproctective purpose garments woven with such yarns.Therefore, both brightness does not dis appear and vision canbe reflected.abFigure 1: Reflective Property of Retro-ReflectiveMaterials[5]a-Light reflected upon an ordinary object b-Object withretro reflective materialThe study designed and produced weaving fabricsconsidering light reflectiblity of retro-reflective yarns. Itspurpose is to explore visual effects and pattern aspectsappearing when daylight is exposed to artificially lit and darkmedia due to combination of light reflectivity in retroreflectiveyarns with source of yarns, weave, density andstructure in different raw material.For this purpose; reflective yarns have been used withfilms manufactured by all the glass beads, the role of which isto reflect incoming light back to its original light source,which means that the glass beads act as spherical lenses andreturn the incoming light to the light source when thereflecting layer is set in its focus point[4]MaterialIn the sample woven fabrics, 20/2 Ne Cotton and 20/2Ne bambu yarn were used as warp yarn and, 17 Nm retroreflectiveyarn( 63.3 glass beads, 10.7 resin,18.6 PET,7.4PA),Bekinox VN*12/1x275/100Z/316L (4 Nm) stainlesssteel, metallic fancy yarn, , yarn with elastan [ 28/1Nm PES(%60) 78dtex lycra (%40) ],linen, cotton,bamboo were usedas weft yarn. The properties of the yarns in sample fabricswere located in Table 1.The weaves of sample woven fabrics are plain and weftrib. Woven structures of them are single and double layer andovershot weave structures (Table 2). Density in reed is 20threads in cm in single layer and 10 threads in cm in doublelayers respectivelly. Density of weft ranges in 12- 17-19threads in cm.These fabrics were produced on automatic Sulzer Rutishuttle loom an they are in 100 cm width.16th Nanoscience and Nanotechnology Conference, zmir, 2010 798

PPP MP MPoster Session, Thursday, June 17Theme F686 - N1123Investigatons on Solar Degradation of Acid Orange 7 (C.I. 15510) In Textile Waste Water With MicroAnd Nano Sized Titan Dioxide11,2USongül Karaaslan AksuUP P* and eref GüçerP1,21PDepartment of Chemistry, Faculty of Science & Arts, Uluda University, Bursa 16059 , TurkeyPBUTAL - Bursa Test and Analysis Laboratory, The Scientific and Technological Research Council of Turkey, Bursa 16190, TurkeyAbstract- Solar photo degradation of dyes is not effective in a treatment of textile waste water. Catalytic activation is necassery in order tohave suitible kinetics. Titan dioxide is seem to be effective for dye degradation. Changing the size of catalyst and dopped with other metals (suchas Sn IV) its activity might be improved . Our results shown that solar degradation of studied dye is posiple in a hour radiations.Textile waste water treatment nowadays is stillenvironmental problem. Azo dyes represent the largest classof textile dyes in industrial use, accounting for 50% of allcommercial dyes [1]. Due to the large number of aromaticspresent in these molecules and the stability of dyes, most azodyes are non-biodegradable [2] and conventional treatmentmethods are ineffective for decolorization and degradation.Physical methods such as adsorption, biological methods(biodegradation) and chemical methods such as chlorinationand ozonation are the most frequently used methods forremoval of the textile dyes from wastewater. Others areflocculation, reverse osmosis and adsorption onto activatedcarbon. Since they are not destructive but only transfer thecontamination from one phase to another, a different kind ofpollution is faced and further treatments are required. Namely,advanced oxidation processes have been extensivelyinvestigated [3]. Among these processes, heterogeneousphotocatalysis is found as an emerging destructive technologyleading to total mineralization of most of organic pollutants. Inmost cases, the degradation is conducted for dissolvedcompounds in water with UV-illuminated TiOR2R. Amongvarious semiconducting materials most attention has beengiven to TiOR2R because of its high photocatalytic activity,resistance to photo-corrosion, low cost, non-toxicity andfavorable band-gap energy. That is why TiOR2R has realadvantage in the photo-catalytic activity [4–5]. A furtherimportant advantage is the fact that the process can bepowered by natural sunlight [6–8], thus reducing significantlythe electrical power requirements and operating costs. Itshould be noted that with visible light, the photo-degradationprocesses proceed by different routes, involving for exampleelectron transfer from the excited state of the dye moleculesadsorbed on the TiOR2R surface into the conduction band ofTiOR2R.The aim of this study is to investigate the photo catalyticactivities of Acid Orange 7 (AO 7) dye which is frequentlyused in textile industry. The rate constant of photo catalyticreactions were determined by using simulation of solar lightand titanium dioxide as a catalyst . The dye content wasdetermined by using VIS spectrometry with the wavelength ofAO7: 485 nm and with using derivative spectroscopy. Inkinetic studies, the most important parameters which effect theobservations were matrix of dye solutions, light intensity andthe structure of catalyst. Relevant kinetic data are summarizedTable 2.Table 1. Summary of rate constants for the degradation of solutionsSample k t R1/2R (min)-55,71x 10P AO 7 0,00012 1,50E+08Textile waste water 0,00010 1,75E+08-55,71x 10P O7 +0,02 g TiOR2R 0,0147 47Textile waste water+0,02 g TiOR2R 0,00010 1,75E+08Textile waste water+0,02 g (Ti,Sn)OR2R 0,008 87Using FTIR spectroscopic data, it was shown that dye islinked to three Titanium surface metallic cations through twooxygen atoms from the sulfonate group and the oxygen atomof the carbonyl group of the dyes (Fig 1).Figure 1. Proposed adsorption mode of AO7 on the surfaceScanning electron microscopy (SEM) was employed thecharacterized surface morphology of the catalyst. It can beseen from Fig. 2Figure 2. SEM images of AO7- TiOR2It was shown that decomposition was completed in a hour.*Corresponding author: songulkar@yahoo.com[1] C. Rafols, D. Barcelo. Journal of Chromatography A, 777 177-192 (1997)[2] S. Liakou, S. Pavlou, G. Lyberatos, Water Sci. Technol. 35 (4)279–286 1997) .[3] C. Guillard, H. Lachheb, A. Houas, M. Ksibi, E. Elaloui, J.M.Herrmann, J. Photochem. Photobiol. A: Chem. 158 27–36 (2003).[4] K. Nagaveni, G. Sivalingam, M.S. Hegde, G. Madras, Appl.Catal. B: Env. 48 83–93 (2004) .[5] C.E. Bonancea, G.M. Nascimento, M.L. Souza, M.L. A.Temperini, C.Paola, Appl. Catal. B: Env. 69 34–42(2006) .[6] M. Saquib, M. Muneer , Dyes Pigments;53: 237-49 (2002).[7] V. Augugliaro, C. Baiocchi, A.B. Prevot, E. Garc´a-Lopez, V.Loddo, S. Malato, et al. Chemosphere;49.1223–30 (2002).[8] M. Stylidi, DI Kondarides, XE Verykios, Appl Catal B Environ40:271-86 (2003).6th Nanoscience and Nanotechnology Conference, zmir, 2010 799

Poster Session, Thursday, June 17Theme F686 - N1123Nanotechnology in Higher Education in OIC CountriesM.Yahaya 1 , I.Ho Abdullah 3 , M.M.Salleh 2 and C.C.Yap 11School of Applied Physics, Faculty of Science and Technology,Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia2Institute of Microengineering and Nanoelectronics,Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, MalaysiaFaculty of Social 3 Faculty of Social Sciences and Humanities SciencesUniversiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, MalaysiaAbstract. Nanotechnology is acknowledged as potentially one of the most beneficial for the developmentof developing countries. This paper reports on the survey conducted in drawing up a roadmap fornanotechnology in higher education. The Nanotechnology Survey is designed to elicit three dimensions innanotechnology in higher education, namely the perception of the importance of nanotechnology, the currentstatus of institutional contribution to capacity building in nanotechnology and the curriculum aspects ofnanotechnology programmes in higher education. The survey reveals that in general, there is high level ofresearch activities in nanoresearch conducted in OIC member countries. 71.2 % of respondent indicated thatfaculty members in their respective institutions are conducting and managing research programs in the areasof nanotechnology and nanoscience. Generally, nanotechnology knowledge is already incorporated in thescience and engineering programs at 78.7% of the institutions and universities surveyed.6th Nanoscience and Nanotechnology Conference, zmir, 2010 800

PPPPoster Session, Thursday, June 17Theme F686 - N1123The Effects of Two Different Types Silver Nanoparticles on Survival of Sac Fry Rainbow Trout(Oncorhynchus mykiss)123USayed Ali JohariUP P* , Mohammad Reza KalbassiP Pand Saba AsghariP1PPhD Student, Member of Young Researchers Club, Islamic Azad University, Science and Research Branch, Tehran, I. R. Iran2PDepartment of Fisheries, Marine Science Faculty, Tarbiat Modares University, I. R. Iran3PMember of Young Researchers Club, Islamic Azad University, Science and Research Branch, Tehran, I. R. IranAbstract- We studied responce of sac fry rainbow trout to powder and colloidal silver nanoparticles by calculating Median lethal concentration(LCR50R) of these two AgNPs forms. 96h LCR50 Rvalues were 0.25 and 36.93 ppm for colloidal and powder AgNPs respectively. Our resultsdemonstrate that colloidal nanosilver is more toxic to sac fry rainbow trout compare to powdered type.Manufactured nanomaterials are materials with diametersranging from 1 to 100 nanometers (nm), while nanotechnologyis one of the fastest growing sectors of the hi-tech economy[1]. Although the applications of nanoparticles are increasingbroadly in every field, concerns about their environmental andhealth impacts remain unresolved. The use of nanomaterials isalso likely to result in their release into aquatic environmentsand may pose risks to aquatic ecosystems [2,3]. The aquaticecotoxicology of engineered nanomaterials is a relatively newand evolving field.Silver nanoparticles (AgNPs), have been, and continue to be,recognized world wide as either a cure or as a preventive forbacterial, fungal, and viral diseases [4]. Few researchers,however, have investigated the toxicity of silver nanomaterialsin aquatic environments, especially in the case of fishes.In this study, the lethal effects of two forms of silvernanoparticles (powdered and colloidal forms) were surveyedon sac fry rainbow trout. This stage of life cycle of fishes isecotoxicologically important because the sac fry are stillreceiving nutrition from the yolk and haven’t any alimentaryrelation to environment. Therefore results of this stage, willshown only external impacts of chemicals on fishes.The colloidal silver nanoparticle, type L (commercial name:Nanocid, 4000ppm Ag concentration, 10 nm average size) wassupplied from Pars Nano Nasb Co. Ltd, (Tehran, I. R. Iran).This product registered by United States Patent ApplicationNo: HT20090013825TH [5].The silver nanoparticle powder (99% pure, 20nm average size)was purchased from Xuzhou Hongwu Nanometer Material Co.1Ltd, (Jiangsu China). A Stock solution of 500 mg lPPdispersedAgNPs was prepared after considering the recommendationsof the manufacturer. First 100mg suspending reagent wasadded to 1 litter of deionized water, after stirring on magnetstirrer, 500 mg AgNPs powder was added to this solution andstirring was continued for 24 hours.Sac fry rainbow trout (n=480) from same brood of theholding stock were randomly selected two days after hatching,and exposed in a 1L cylindrical glass beaker containing thedesired concentration of the test chemical in the statisticexposure regime. Logarithmic series of nanosilverconcentrations were choice according to OECD guideline forthe testing of chemicals [6]. The selected concentrations were0.1, 0.32, 1, 3.2, 10, 32, and 100 ppm for each chemical. Eachconcentration was tested in triplicate, plus three control groupsfor each form of AgNPs. Ten healthy sac fry rainbow troutwere tested in each replicate (30fish/treatment).Calculated LCR50R values of colloidal nanosilver at 24, 48, 72and 96 h were 2.75, 0.44, 0.35 and 0.25 ppm, respectively.About powdered silver nanoparticles, LCR50R values werecalculated to be 186.42, 69.37, 36.93, and 28.25 ppm at 24,48, 72 and 96 h respectively.In summary, we think that more investigation about riskspotentials of silver and other nanoparticles should be attendedbefore they become more and more prevalence in routineapplications by all people in the world. Special attentionshould be spending about fishes as some important part ofaquatic environments. More studies should be carrying outabout chronic effects of lowest doses of AgNPs on fishes suchas Rainbow trout. Also other life stages of fishes should beconsidered in such nanoecoltoxicological studies.Table 1. Magnitude of MATC, LOEC, NOEC of colloidal andpowdered silver nanoparticles on sac fry rainbow trout during 96hParameter MATC NOEC LOECColloidal AgNPs 0.025 0.01 0.08Powdered AgNPs 2.825 1 7.10Figure 1. Agglomerated colloidal (Left) and powdered (Right) silvernanoparticles in contact with fish mucus. Aggregated nanoparticleswere trap under gill operculum and inside the mouth of fishes*Corresponding author: HTsajohari@gmail.comT[1] Y. J. Chae et al., Aquat. Toxicol, 94, 320-327 (2009),[2] M. N. Moore, Environ. Int. 32, 967–976 (2006),[3] R. D. Handy et al., Ecotoxicology 17, 396–409 (2008),[4] A. R. Shahverdi., et al Nanomedicine: Nanotechnology, Biology,and Medicine 3, 168–171 (2007)[5] J. Rahman Nia, US Patent application docket 20090013825(2009)[6] OECD 215, Fish, Juvenile Growth Test, (2000)6th Nanoscience and Nanotechnology Conference, zmir, 2010 801

0T0T0T0T AsPPPP werePoster Session, Thursday, June 17Theme F686 - N11232TStudy of Vegetation in Selected Area in South of Jeddah Provence12TUAreej Ali BaeshenUP P*1Department of Biology, Science college,- King Abdulaziz University, Jeddah, Saudi ArabiaAbstract-Saudi Arabia is covering a large area of the Arabian Peninsula which located in diverse terrain, multiple climatic conditions(Showdary and Aljwayed,1999). As for the soil in the Saudi arabia are regarded as young and immature or incomplete to lack of humidityand exposure to erosion (Abu Al-Fath, 1999).0T The study area lies south of Jeddah (Waziriya district). Located Jeddah on the Red Sea at thejunction of latitude 31 -21° North and longitude 4 - 39° East. (the General Presidency of Meteorology and Environmental Protection, 2004).0T2Study area in the southern city of Jeddah (Waziriya district) and we took 4 locations at random each covering 10 × 10 mP also taken 102small quadrates inside their respective area of 1 × 1 mP then we restricted the plant species and Tarpfha and calculate: density. frequencyand coverage and the importante value with a graphic representation of results.Species recorded in the study area 9 species shown inTable 1 were divided in 4 locations were randomly chosenin the region. The absolute density difference from theplant to another. Had the highest absolute density in theplant A.adscensionis,. And the highest density relative tothe same plant, in 0T 0Tlocation 1. In the locations (2.3,4) hadthe highest absolute and relative density of the plant Z.simplex.0TAl- Nafeil, Abdul Latif Hammoud. (2004). Geographic plant forSaudi Arabia. I 1. King Library Fahd National.0TRiyadh. Kingdom of Saudi Arabia. 659 p. 0T0TShowdary, Shaukat Ali and 0TAljwayed0T, Abdul Aziz al-Abbas.(1999). Vegetation of Saudi Arabia. National Center for Researchon Agriculture and Water, Ministry of Agriculture and Water,Kingdom of Saudi Arabia. 689 p.The highest value for the absolute frequency was in theplant A. adscensionis and plant Z. simplex value of 90% inlocation 1. And the highest value of the relative frequencyin the same plants. The highest values of the absolute andrelative coverage of the plant Z. simplex in all the selectedlocations, recorded the highest coverage in the location 2.0T0THigh water content of the soil in a depth of 30 cm from adepth of 10 cm and in all locations. The highest watercontent at the location (3) to a depth of 10 cm. 0T1TThat all the0T1Tlocation0T1Ts recorded values ranging from 7.6 - 8.3.1T.There are 9 plant species at selected area, rangingbetween grasses and shrubs. vegetation of the coastal plainand a little and limited to certain plant species with largeroot system which (Al-Nafei, 2004). A study of vegetationdifference in the values of the intensity, frequency andcoverage was recorded Z. simplex higher absolute andrelative density in most locations, which indicates theabundance of this type of plant in the study area. About thesame plant as the highest values of the absolute andrelative cover and this shows the rapid spread of the plantduring the period suitable for growth in the study area.for the soil analysis high soil water content to a depthof 30 cm and 10 cm depth in all sites and this of courseafter the return to a deeper level of the soil for the sun'sheat, which reduces the evaporation of water from it. Itwas also noted the pH values ranged between 7.6 and 8.3,which means that the soil is neutral to lowalkaline.0T*Corresponding author: abaaeshen@kau.edu.sa0TAbu Al-Fath, Hussein Ali. (1991). Ecology. Deanship of LibraryAffairs, King Saud University. Riyadh. Kingdom of SaudiArabia.0TThe General Presidency of Meteorology and EnvironmentProtection. (2004). Data temperature, precipitation, wind,humidity, station Jeddah.6th Nanoscience and Nanotechnology Conference, zmir, 2010 802

PPP SchoolPP SchoolPoster Session, Thursday, June 17Theme F686 - N11231Generel Aspects of Some Risk Factors in Nanotechnology123UGülah AlbayrakU P P*, Kymet GüvenP P, Alaettin GüvenPPGraduate School of Science, Departmant of Biotechnology, Anadolu University, Eskiehir 26470, Turkey2of Science, Departmant of Biology, Anadolu University, Eskiehir 26470, Turkey3of Science, Departmant of Chemistry, Anadolu University, Eskiehir 26470, TurkeyAbstract-This study aims to give general idea about the risks of nanotechnologyThere are lots of commercial uses in Nanotechnology.It hasan important roles in our lives and it will exponentially have asignificance in our future life. As this technology is used anddeveloped, we must understand any potential risks to humanhealth, safety and the environment. In this work, I want topoint out some risks about this developing area.Nanotechnology is expected to be the basis of many of themain technological innovations of the 21st century. Researchand development in this field is growing rapidly throughoutthe world. [1]It is a broad and complex field of research andmanufacturing with many discrete decision-points. Forexample, some decisions might be based upon an ability topredict which nanomaterials will have favorable chemicalcharacteristics and lower toxicities, to identify importantknowledge and technology gaps, and to develop effectivecommunication with stakeholders and the general public [2].Nanoparticles include carbon nanotubes, metal nanowires,semiconductor quantum dots and other nanoparticles producedfrom a huge variety of substances. Responsible developmentof any new materials requires that risks to health and thegeneral environment associated with the development,production, use and disposal of these materials are addressed.This is necessary to protect workers involved in productionand use of these materials, the public and the ecosystem.However, it also helps inform the public debate about thedevelopment of these new, potentially beneficial, materials.Assessment of health risks arising from exposure tochemicals or other substances, requires understanding of theintrinsic toxicity of the substance, the levels of exposure (byinhalation, by ingestion or through the skin) that may occurand any relationship between exposure and health effects [1].Toxicity depends on dose and administration, even table saltis toxic in high doses [3]. Fact is, that every new technology isinherently risky - plenty of people are being injured or killedevery year by electricity, cars, chemicals, or nuclear energy,just to name a few. In order to reap the benefits of a newtechnology and make it acceptable to society there has to be ageneral perception that the risks are fully understood, can bemanaged and it is clear who is responsible for what. All of thatis currently missing in nanotechnology. Although the speedand scope of nanotechnology risk research - and the emergingfield of nanotoxicology - is picking up, a lot of this work isstand-alone research that is not being coordinated within alarger framework [4].TFigure 1. Epithelial cell with intracellular nanoparticles[1]*Corresponding author:albayrakgulsah@gmail.com[1] http://www.iom-world.org/research/nanoparticles.php[2]http://www.nanolawreport.com/2007/06/articles/risk-assessmentfor-nanomaterials-current-developments-and-trends/[3] Understanding Risk Assessment of Nanotechnology, Trudy E.Bell[4] http://www.nanowerk.com/spotlight/spotid=3701.php6th Nanoscience and Nanotechnology Conference, zmir, 2010 803

PPoster Session, Thursday, June 17Theme F686 - N1123Value Engineering for Nanomaterial Applications in Construction1UJulide DemirdovenUP P*1PDepartment of Architecture, Yeditepe University, Istanbul, TurkeyAbstract - How often have you heard the expression “It’s a great idea, but where has it been done before?” There is considerable interest inacademia, the investment community and among manufacturers about the exciting opportunities offered by nanoscale materials. Although manyapplications for nanotechnology remain theoretical, construction is one area where several applications have already emerged. While current useis limited, the market is expected to approach huge demand within ten years. Can nanotechnology be the reference of the constructionprofessionals in terms of value engineering approach? In this study we are searching for the respond of the question by giving nanomaterialexamples represented in global markets for diversified phases of a project life-cycle. We will briefly look at Tthe highly developing constructionsector in Turkey with contractors operating nationwide as well as abroad.T TA large number of the countries in the region rely on Turkey as amajor supplier of building materials and construction services. There should be a share for nanomaterials. TTDecision makers in the building industry have one goal:deliver a project on time and on budget. They go to greatlengths to avoid any uncertainty that might threaten thisobjective. Their aversion to risk can stifle innovation in thedelivery process. But barriers to innovation may be barriers togood business. Sometimes the parameters of a project crossthe bounds of experience, where traditional methods areknown to be at their limits. In these cases, innovation, with itsinherent uncertainty, may offer a solution with more promiseand less risk [1].Nanomaterial producers promise numerous benefits fromnano-enhanced construction products, including lowmaintenance windows, long lasting scratch resistant floors,super strong structural components, improved longer lastinghouse paint, healthier and safer indoor climates, self cleaningskyscrapers, antimicrobial steel surfaces, improved industrialbuilding maintenance, lower energy consuming buildings andlonger lasting roads and bridges. The use of nanomaterialsallows product manufacturers to offer longer productwarranties. Building owners are expected to enjoy lowermaintenance costs while consumers can look forward tohouses that maintain themselves [2]. Can nanotechnology bethe reference of the construction manager?Value engineering and cost reduction are often confused.The distinction, however, is important. Value engineering is aprocess that considers cost in the context of other factors: life-cycle cost, quality durability maintainabilityCost reduction, on the other hand, considers only first cost.Although tight budgets make cost reductions a fact of life, theowner needs to know exactly what he or she is buying. Valueengineering gives a "better solution," while cost reductions canreduce the quality or quantity of the project to save money. Tobring a framework to the value engineering discussions, theowner sets the criteria with the help of the designer and theconstruction professional. Generally, these criteria fall into afew categories: best cost best function best aesthetic valueDetermining the best cost can be done effectively with a lifecyclecost analysis. Figure 1 shows the design phase of aproject in the life-cycle [3].Figure 1. The four phases of project design.While nanomaterials are already making inroads into certainconstruction applications, many obstacles remain towidespread adoption of this technology, including theconservative nature of construction contractors, thecomplicated nature of building codes and the sometimes toohigh expectations of consumers. In addition, material andmanufacturing costs remain an issue in cost sensitive, largevolume applications while concerns over health and safety arealso at the forefront of discussions. Some suppliers will beable to overcome these factors and establish significantmarkets for nanomaterials in construction applications, whileother products are expected to remain only niche marketcuriosities.TTurkey is primarily self-sufficient in conventional buildingmaterials. However, imported building materials are alsoincreasingly being used, especially in modern world-classhotels, tourist centers, and in the country's more affluentresidential areas.TT TThis study analyzes the market demand ofconstruction professionals for nanomaterials in construction byusing value engieering method. It also considers marketenvironment factors, details industry structure and profiles ofleading industry players [4].*Corresponding author: HTjbozoglu@gmail.comT[1] H. Sommer, Prj. Mng. for Building Construction 163, (2009).[2] Nanotechnology in Construction, HTwww.marketresearch.comTrd[3] F. E. Gould & N. E. Joyce, Const. Prj. Mng., 3P P. Ed 132, ( 2009).[4] Construction and Building Materials Industries in Turkey,HTwww.dtcsee.um.dkT6th Nanoscience and Nanotechnology Conference, zmir, 2010 804

PPPoster Session, Thursday, June 17Theme F686 - N1123Titanium Dioxide (TiOR2R) Genotoxicity in Human Lymphocytes Assessed By The Alkaline CometAssay1111221UFunda DemirtaUP P*, Gökçe TanerP P, Fatma ÜnalP P, Zekiye SuludereP P, Özlem ErolP P, Halil brahim ÜnalP P, Deniz YüzbaoluPPDepartment of Biology, Gazi University, Ankara 06500, TurkeyPDepartment of Chemistry, Gazi University, Ankara, 06500, Turkey21Abstract -In this study the genotoxicity of nano Titanium dioxide (TiOR2R) (

PPPPPoster Session, Thursday, June 17Theme F686 - N11231Flame Atomic Absorption Spectrometric Determination of Silver Ion After Preconcentration onModified Iron Oxide Magnetic Nanoparticles121UMohammad Ali KarimiUP P*, Hossein TavallaliP P, Asghar Askarpoor KabirP P, Maryam Kazemi pourP3P, Najmeh Afsahi 3PDepartment of Chemistry & Nanoscience and Nanotechnology Research Laboratory (NNRL), Payame Noor University (PNU), Sirjan 78185-347, Iran2PDepartment of Chemistry, Payame Noor University (PNU), Shiraz, Iran3PDepartment of Chemistry, Islamic Azad University of Kerman, Kerman, IranAbstract—In this research first we have synthesized magnetite nanoparticles (MNPs) and alumina coated magnetite nanoparticles (ACMNPs)and then a simple and new method has been developed for the separation/preconcentration of trace amounts of silver ion from aqueous samplesfor subsequent measurement by flame atomic absorption spectrometry (FAAS) based on the adsorption of its dithizone (DTZ) complex onmodified alumina-coated magnetic nanoparticles. The preconcentration factor of the adsorbent at optimum conditions was found as 100. The-1relative standard deviation and the detection limit for measurement of Ag(I) in our experiments were less than 3.4 % (n =10) and 0.52 ng mLP P,respectively. The practical applicability of the developed sorbent was examined using water and wastewater samples.In recent years, great attention has been paid to theapplication of nano-structure materials, especially nanosizedmagnetic particles. These materials have been used in variousscientific fields such as biotechnology, engineering,biomedical, environmental and material science [1-3].A distinct advantage of these is that magnetic nanoparticles(MNPs) can be readily isolated from sample solutions by theapplication of an external magnetic field. Surface modificationof magnetic nanoparticles is a challenged key for differentapplications and can be accomplished by physical/chemicaladsorption of organic and inorganic species [4,5]. Solid phaseextraction (SPE) is a routine extraction method fordetermining trace level contaminants in environmentalsamples [6]. Many research groups have explored theapplication of several nanosized SPE adsorbents such asnanoparticles (NPs), nanocomposites and nanotubes [7,8]. Inthis study, at first step the magnetic nanoparticles weresynthesised and then coated with alumina subsequentlymodified with DTZ as extractor, with aid of sodium dodecylsulfate (SDS), based on the ion pair formation and simplephysical adsorption. DTZ was incorporated into the innerhydrophobic part of produced admicelles in ammoniacalmixture of DTZ, SDS and alumina-coated magneticnanoparticles (ACMNPs) was acidified to produce anassemble (abbreviated as DSIACMNPs) suitable forpreconcentration and determination of silver(I) ion . Silverions are adsorbed on DSIACMNPs were isolated by anadscititious magnet and the adsorbed analyte was eluted withthiourea solution and quantified using according Figure 1.To enable practical application of ACMNPs, it is mostimportant that the sorbents should possess superparamagneticproperties. Magnetic properties were characterized VSM andresult show both of the magnetic nanoparticles (MNPs andACMNPs) exhibited typical superparamagnetic behavior dueto not exhibiting hysteresis, remanence and coercivity. Themodified ACMNPs were also confirmed by FT-IR, SEM,TEM and XRD analysis. The result shows that the theparticles are hemi-spherical and diameters of MNPs andACMNPs are is in the range of 4-9 and 16-21 nm, respectivelyand revealed that the resultant nanoparticles were pure FeR3ROR4Rwith a spinel structure and the immobilized process did notchange its crystal phase and confirm binding mechanism too.In this study, the new adsorbents of DSIACMNPs wereprepared easily and low-costly, utilized conveniently andharmless to environment. These sorbents were successfullyapplied for convenient, fast, simple and efficient enrichmentof trace amounts of silver ions from environmental water andwastewater samples. Magnetic separation in the methodshortened analysis times greatly. The main benefits of themethodology were: no use of toxic organic solvent, simplicity,low cost, enhancement of sensitivity, and rapid analysis time(total time of a single determination is about 27 min) and lowLOD. Easy regeneration is another property of ACMNPs, andthe experiments have proved that these ACMNPs can bereused at least 4 times on average without the obviousdecrease of recovery after wash/calcine procedures.Furthermore, it avoids the time-consuming column passing(about 1 h in conventional SPE method) and filtrationoperation, and no clean-up steps were required.*Corresponding author: ma_karimi43@ yahoo.comFigure 1. Procedure for magnetic solid-phase extraction.Optimal experimental conditions including SDS and DTZconcentrations, pH, sample volume, eluent conditions and coexistingions have been studied and established.[1] M. Faraji, Y. Yamini, M. Rezaee, J. Iran. Chem. Soc. 7, 1 (2010).[2] C. W. Lu, Y. Hung, J. K. Hsiao, M. Yao, Nano Lett. 7,149(2007).[3] S. Zhang, X.Zhao, H.Niu, Y. Shi, J. Hazard. Mater. 167, 560(2009)[4] J.S. Suleiman, B. Hu, H. Peng, C. Huang, Talanta 77, 1579(2009).[5] J. S. Becker, O. R. T. Thomas, M. Franzreb, Sep. Purif. Technol.65, 46 (2009).[6] V. Camel, Spectrochim. Acta B 58, 1177–(2003).[7] J. D. Li, X. L. Z hao, Y. L. Shi, J. Chromatogr. A 1180, 24(2008).[8] A. Stafiej, K. Pyrzynska, Microchem. J. 89, 29 (2008).6th Nanoscience and Nanotechnology Conference, zmir, 2010 806

PP HNOR3R.Poster Session, Thursday, June 17Theme F686 - N11231Separation/Preconcentration of the Trace Amounts of Nickel in Tea, Spinach and Water SamplesUsing Modified Magnetic Nanoparticles and its Determination by FAAS11UMohammad Ali KarimiUP P* Manijeh KafiPPDepartment of Chemistry &TNanoscienceT and TNanotechnology Research LaboratoryT (NNRL), Payame Noor University (PNU), Sirjan 78185-347, IranAbstract-A new, simple, fast and reliable solid-phase extraction (SPE) method has been developed to separation/preconcentration of traceamounts of nickel ion from environmental water samples using dimethylglyoxim (DMG) /sodium dodecyl sulfate (SDS)-immobilized aluminacoatedmagnetic nanoparticles (DSIACMNPs) and its determination by flame atomic absorption spectrometry (FAAS). The coating of aluminaon FeR3ROR4R NPs not only avoids the dissolving of FeR3ROR4R NPs in acidic solution, but also extends their application without sacrificing their uniquemagnetization characteristics. This method avoided the time-consuming column-passing process of loading large volume samples in traditionalSPE through the rapid isolation of DSIACMNPs with an adscititious magnet. The preconcentration factor of the adsorbent at optimumconditions including time, pH value, sample volume, eluent concentration, amount of SDS and DMG found as 95 %. The relative standard-1-1deviation and the detection limit for measurement of Ni(II) in our experiments were less than 4.0 % (n =6, 0.1 μg mlP P) and 1.0 ng mLP P,respectively. The practical applicability of the developed sorbent was examined using tea, spinach, water and wastewater samples.Solid phase extraction (SPE) is a preconcentrationtechnique of quickly growing significance in trace metaldeterminations with atomic absorption spectrometry [1].SPE has several interesting attribute compared with thecustomary removal techniques. It is well enough simple,cheap, can be used in the field, needs comparatively little toxicsolvents, and can be easily mechanized [2]. Flame atomicabsorption spectrometric analysis of heavy metal ions in realsamples is clearly hard, because of complex formation andconsequential matrices [3-6]. Separation/preconcentration stepmake better the analytical detection limit, raise the sensitivityby several order of size, enhances the preciseness of the resultsand make easy the calibration [7]. Using magnetic micro andnanoparticles for separation and preconcentration in analyticalchemistry is opening a new method that is rapid, simpler andmore exact than old ones. The greatest promote of this methodis that longed for materials are separated from solution by asimple and dense process while less secondary wastes areproduced.In this work, magnetic nanoparticles (MNPs) weresynthesised and then coated with alumina (ACMNPs) andmodified with DMG with aid of SDS (abbreviated asDSACMNPs), based on the ion pair formation and simplephysical. This structure is suitable for preconcentration anddetermination of nickel ion. Nickel ions are adsorbed onDSACMNPs were isolated by an adscititious magnet and the1adsorbed analyte was eluted with 1.0 mol LPOptimum experimental conditions including SDS and DMGconcentrations, pH, sample volume, eluent conditions and coexistingions have been studied and established.To enable useful application of ACMNPs, it is mostimportant that the sorbents should hold superparamagneticproperties. Magnetic properties were characterized VSM andresult show both of the magnetic nanoparticles (MNPs andACMNPs) exhibited typical superparamagnetic behavior dueto not exhibiting hysteresis, remanence and coercively. Themodified ACMNPs were also confirmed by FT-IR, SEM,TEM and XRD analysis. The result shows that the theparticles are hemi-spherical and diameters of MNPs andACMNPs are is in the range of 4-8 and 15-20 nm, respectivelyand revealed that the resultant nanoparticles were pure FeR3ROR4Rwith a spinel structure and the immobilized process did not changeits crystal phase and confirm binding mechanism too.In summary we showed that DMG immobilized onmodified ACMNPs were capable and successfully forseparation and preconcentration of nickel ions from largevolume of the equeous solution and real samples using atomicabsorption spectroscopy. This method is simple, rapid andsensitive and very suitable for adsorption nickel ions. Easyregeneration is another property of ACMNPs, and theexperiments have proved that these ACMNPs can be reused atleast 3 times on average without the obvious decrease ofrecovery after wash/calcine procedures.Figure 1. SEM images of FeR3ROR4 Rnanoparticles (a) and aluminacoated FeR3ROR4 Rnanoparticles (b).aThe authors are grateful for the financial support of theNanoscience and Nanotechnology Research Laboratory(NNRL) of Sirjan Payam Noor University for this work.*Corresponding author: ma_karimi43@yahoo.com[1] A.M. Naghmush, K. pyrzynska, M. Trojanowicz, Talanta 42,85(1995).[2] R .Lima, K.C. Leandro, R.E. Santelli, Talanta 43,977 (1996).[3] A. Tumuklu, M.G. Yalcin, M. Sonmez, Pol. J. Environ. Stud. 16,651 (2007).[4] Q.M. Li, R.Z. Ouyang, G.F. Zhu, G.G. Liu, Chem. Res. Chin.Univ. 21, 622 (2005).[5] M. Saqib, M. Jaffar, M.H. Shah, J. Chem. Soc. Pak. 29, 125(2007).[6] M. Soylak, L. Elci, M. Dogan, J. Trace Microprobe Tech. 19,329 (2001).[7] L.H.J. Lajunen, A. Kubin, Talanta 33, 265 (199b6th Nanoscience and Nanotechnology Conference, zmir, 2010 807

PPoster Session, Thursday, June 17Theme F686 - N1123Modified Iron Oxide Magnetic Nanoparticles as A New Solid Phase Extractor for Separation andPreconcentration of Pb(II) in Opium and Heroin Samples and its Determination by FAAS111Mohammad Ali KarimiP P, Abdolhamid Hatefi-MehrjardiP P, UAsghar Askarpour KabirUP P*1PDepartment of Chemistry & Nanoscience and Nanotechnology Research Laboratory (NNRL), Payame Noor University (PNU), Sirjan,78185-347, IranAbstract-We exhibit a new extractive preconcentration procedure for the determination of trace amounts of lead in opiate samples. Thisextraction method is based on adsorption of dithizone-lead complex on modified iron oxide magnetite nanoparticles. The amounts of lead in fiveopium and heroin samples were in the range of 8 to 30 g/g and 3 to 17 ng/g respectively. The effects of various parameters such as pH, volumeof sample and eluent, type and concentration of eluent, sample volume, amount of adsorbent and interfering ions have been studied. Resultsshowed a good linear range and precision (RSD=4.6 %, n = 5). The performance of purposed method for the analysis of these samples wastested by spiking lead ion to samples and recovery was investigated.Lead is a heavy metal commonly exists in the environment.It can either be an acute or chronic toxin.P PCar exhausts,contaminated food, industrial emission and soils are the mostimportant sources of lead exposure. Exposure to any of theabove mentioned sources of lead through ingestion, inhalation,or dermal contact can cause significant toxicity [1].Opiate materials are one of hazardous material and nothave any healthy control. Salesmen and smugglers may addlead to opium during the process of opium preparation toincrease the weight of opium for more benefits. Severalreports have found lead poisoning symptoms in opiumaddicted patients, and also there are many non specificsymptoms mimicking lead poisoning in opium addictedpatients. Therefore, it seems evaluation of blood lead level inopium addicted patients to be important [2-4].Nanometer-sized materials have used highly in the allScientifics because of their special properties [5,6]. we usemagnetite nanoparticles (MNPs) that are superparamagnetitewith high area, as solid phase extractor. In addition, these nanosized solid phase extractors can separate rapid and completelyfrom sample solutions with aid of a generally magnate.Figure 1. Procedure for magnetic solid-phase extraction.In this study, alumina-coated magnetite nanoparticles(FeR3ROR4R/AlR2ROR3R NPs) were successfully synthesized andmodified by dithizone (DTZ) with aid of sodiumdodecylsulfate (SDS) in acidic media to form mixedhemimicelles for the extraction of Pb(II) from standardsamples. Experimental factors affecting the extractionefficiency were studied. In next step the adsorbed lead ionswas eluted with nitric acid solution (4.0 M) for determinationwith flame atomic absorption spectroscopy (FAAS). Then thismethod was applied to extraction and preconcentration ofPb(II) in opium and heroin samples.The magnetic nanoparticles (MNPs), alumina-coatedmagnetic nanoparticles (ACMNPs) and DTZ immobilized onSDS (abbreviated as DSIACMNs) were characterized byXRD, SEM, TEM and FT-IR spectroscopy.That showed the MNPs and ACMNPs aresuperparamagnetite, pure FeR3ROR4R with a spinel structure andthe immobilized process did not change its crystal phase,5.7±3 nm for MNPs and 18.9±2 nm for ACMNPs at sizes,demonstrate excellent dispersibility and the immobilizationprocedure was achieved successfully.Ten samples of opium and heroin were selected randomlyfrom the samples seized by Police Department in Sirjan City.For opium samples treatment, the samples were burnt inelectric burner at 700°C for 30 minutes and afterwards theywere dissolved in a solution of nitric acid/water (1:1). Afterone day, the solutions were warmed, filtered, neutralized withconc. NHR3R and treated according general procedure. Forheroin samples, 0.5 g of each was dissolved in nitricacid/water (1:2), filtered, neutralized and treated accordinggeneral procedure.In summary, the new adsorbents of DSIACMNPs wereprepared easily and low-costly. These sorbents weresuccessfully applied for convenient, fast, simple and efficientenrichment of trace amounts of silver ions from opium andheroin samples. Magnetic separation in the method shortenedanalysis times greatly. Easy regeneration is another propertyof ACMNPs, and the experiments have proved that theseACMNPs can be reused at least 4 times on average withoutthe obvious decrease of recovery after wash/calcineprocedures. Furthermore, it avoids the time-consumingcolumn passing (about 1 h in conventional solid phaseextraction method) and filtration operation, and no clean-upsteps were required. We have a high performance in analyticalparameters.The authors are grateful for the financial support of theNanoscience and Nanotechnology Research Laboratory(NNRL) of Sirjan Payam Noor University for this work.* Corresponding author: a_askar_kabir@yahoo.com[1] G. Lochitch, Clin.Biochem. 26, 371 (1993).[2] B.L. Chia, C. K. Leng, F.P Hsii, M.H. Yap, Y.K.. Lee, Br. Med. J.1, 354 (1973).[3] A.D.Beattie, P.J. Mullin, R.H. Baxter, M.R. Moore. Scott. Med. J.24, 318 (1979).[4] E.J .Fitzsimons, J.H. Dagg. Br. J. Clin. Pract. 36, 284 (1982).[5] G.P. Rao, C. Lu, F.S. Su, Sep. Purif. Technol. 58, 224 (2007).6th Nanoscience and Nanotechnology Conference, zmir, 2010 808

PNanoscienceTPoster Session, Thursday, June 17Theme F686 - N1123Determination of Mercury(II) in Water and Wastewater Samples by Cold Vapor AtomicAbsorption Spectrometry After Sepration/Preconcentration with 2-MercaptobenzothiazoleImmobilized on Alumina-Coated Magnetic Nanoparticles1Mohammad Ali KarimiP P, Laleh Sotudehnia KoraniP P, UAsghar Askarpour KabirUP P*PDepartment of Chemistry &T11and TNanotechnology Research LaboratoryT (NNRL), Payame Noor University (PNU), Sirjan 78185-347, IranAbstract- In this work first we have synthesized alumina coated magnetite nanoparticles (ACMNPs) and then a simple and newmethod has been developed for the separation/preconcentration of trace amounts of mercury ion from aqueous samples for subsequentmeasurement by cold vapor atomic absorption spectrometry (CVAAS) based on the adsorption of its 2-mercaptobenzothiazolecomplex on modified ACMNPs. The preconcentration factor of the adsorbent at optimum conditions was found as 100. The relative-1standard deviation and the detection limit for measurement of Hg(II) in our experiments were less than 2.3% (n =5) and 0.04 ng mLP P,respectively. The practical applicability of the developed sorbent was examined using water and wastewater samples.1Determination of mercury in environmental samples is ofgreat importance nowadays, because mercury is particularlytoxic element and a widely distributed environmental pollutantbecause it is widespread in the lithosphere and in waterInorganic mercury, especially soluble mercury species, can betransformed into methyl mercury by the action ofmicroorganisms and can be accumulated in the tissue of fishesand birds [1,2]. So, its concentration should be kept underpermanently controlled conditions. We use solid-phaseextraction (SPE) for separation and preconcentration traceamounts of Hg(II) in different water samples for subsequentmeasurement by CVAAS technique [3-5].In this method, MNPs of FeR3ROR4R were synthesized and thenin alcoholic environment their surface coated with AlR2ROR3R andsodium dodecyl solfate (SDS). In the after stage a chelatingagent of 2-mercaptobenzothiazol (MBT) for separation thisionR Rhave been immobilized on modified ACMNPs(abbreviated as MISACMNPs), as the adsorbent for thepreconcentration of mercury ion from aqueous samplesolutions, has been presented. Then isolated by an adscititiousmagnet and the adsorbed Hg ions were eluted with HBrsolution. The MNPs, ACMNPs and MISACMNPs werecharacterized by XRD, SEM, TEM and FT-IR spectroscopy.The influence of various parameters such as acidity, elutingagents, SDS and MBT concentrations, sample volume, NPsamounts, interfering ions, time for adsorption and desorption,etc have been studied and established in details.In order to check the applicability of the proposed method itwas applied to the seperation/preconcentration anddetermination of mercury in water and wastewater samples.According obtained results, the added mercury ions can bequantitatively recovered from the water samples by theproposed procedure. This sorbent was successfully applied forconvenient, fast, simple and efficient enrichment of traceamounts of mercury ions from environmental water andwastewater samples.Easy regeneration is another property of ACMNPs, and theexperiments have proved that these ACMNPs can be reused atleast 3 times on average without the obvious decrease ofrecovery after wash/calcine procedures. Furthermore, it avoidsthe time-consuming column passing (about 1 h inconventional SPE method) and filtration operation, and noclean-up steps were required.A comparison of the represented method with the otherreported methods showed that the detection limit of theproposed method is comparable to those in reported methods.The authors are grateful for the financial support of theNanoscience and Nanotechnology Research Laboratory(NNRL) of Sirjan Payam Noor University for this work.Figure 1. SEM images of FeR3ROR4 Rnanoparticles (a) and alumina coatedFeR3ROR4 Rnanoparticles (b).*Corresponding author: a_askar_kabir@yahoo.com[1] B.C. Mondal, D. Das, A.K. Das, Anal. Chim. Acta 450, 223(2001).[2] F.W. Fifield, P.J. Haines, Environmental Analytical Chemistry,2nd ed (Lackwell Science Ltd, Oxford, UK, 2000).[3] Q. He, X. Chang, H. Zheng, N. Jiang, and X. Wang, Inter. J.Environ. Anal. Chem. 88, 373(2008).[4] C.M.F. Hernandez, A.N. Banza, E. Gock, J. Hazard. Mater. 139,25 (2007).[5] E.M. Soliman, M.B. Saleh, S.A. Ahmed, Talanta 69, 55 (2006).6th Nanoscience and Nanotechnology Conference, zmir, 2010 809

PPoster Session, Thursday, June 17Theme F686 - N11231Nanotechnology in Water Resources1ULevent YUP P*PIstanbul Technical University, Civil Engineering Faculty, Hydraulic Division, 80626, Maslak, Istanbul, TurkeyAbstract-One challenge is the removal of industrial water pollution, such as a cleaning solvent called TCE, from ground water.Nanoparticles can be used to convert the contaminating chemical through a chemical reaction to make it harmless. Studies have shown thatthis method can be used successfully to reach contaminates dispersed in underground ponds and at much lower cost than methods whichrequire pumping the water out of the ground for treatment. Another challenge is the removal of salt or metals from water. A deionizationmethod using electrodes composed of nano-sized fibers shows promise for reducing the cost and energy requirements of turning salt waterinto drinking water. The third problem concerns the fact that standard filters do not work on virus cells. A filter only a few nanometers indiameter is currently being developed that should be capable of removing virus cells from water. See the following section for more aboutthe potential of nanotechnology in removing contaminates from water.The PNNL researchers, led by Donald R. Baer, Ph.D.,technical group leader at PNNL's William R. WileyEnvironmental Molecular Sciences Laboratory, firstsynthesized and characterized the nanoparticles using avariety of advanced microscopy and spectroscopytechniques. Once the nanoparticles were syntheisized andcharacterized, Tratnyek and his students studied theirreactivity using electrochemical techniques they developedto help them systematically measure the microscopicparticles. University of Minnesota scientists also helpedwith microscopy and some reactivity studies."Our team's study results show how the breakdown ofcarbon tetrachloride is influenced by some very subtle andtransient differences between the two types of nano-iron,"said Tratnyek.One of the nano-irons studied, a commercially availableproduct of iron oxide with a magnetite shell high in sulfur,quickly and effectively degraded carbon tetrachloride to amixture of relatively harmless products. "This was anexciting find because it may provide the basis for effectiveremediation of real field sites with groundwater that iscontaminated with carbon tetrachloride," said Tratnyek."Furthermore, since it may be possible to emplace nanosizediron deep into the subsurface by injecting it throughdeep wells, this approach may be suitable for remediationof very deep plumes of carbon tetrachloride contaminatedgroundwater, such as the one at the Hanford site inRichland, Washington."The other nano-iron studied by the OHSU-PNNL-University Of Minnesota team had a shell, or coating, highin oxidized boron. While the oxide-coated iron also rapidlydegraded the carbon tetrachloride, the primary product waschloroform, a toxic and persistent environmentalcontaminant.*Corresponding author: lyilmaz@itu.edu.tr6th Nanoscience and Nanotechnology Conference, zmir, 2010 810

PPPPPPPP,PPPoster Session, Thursday, June 17Theme F686 - N11231Liquid Crystal Displays (LCD) Role in Different Aspects in Social LifeSönmez ArslanP1,2 345*, Ömer PolatP P, S.Eren San PPSelahattin SönmezsoyP PandP PRamazan Kaynak 6PDepartment of Materials Science Engineering, Nanotechnology Center,Gebze Institute of Technology, Kocaeli,41400, Turkey2PDepartment of Chemistry, Batman University, Batman ,72100, TurkeyPDepartment of Sience, Bahcesehir University, Istanbul, 34353, TurkeyPOrganic Electronics Group, Department of Physics, Gebze Institute of Technology, Kocaeli,41400, Turkey5PDepartment of Sociology, Batman University, Batman ,72100, Turkey6PDepartment of Management,Gebze Institute of Technology, Kocaeli,41400, Turkey43Abstract- Social, economical, and environmental effects of Liquid Crystal Displays(LCD) which have been using widely in televisions,computers, mobile phones, cameras, video cameras, bill boards were discussed. The periods before and after introducing of LCDs were comparedin terms of Energy, Information Technology ,Communication Technology, Environment, and Social Life. Advantages of LCDs were explaineddepending on development of Nanotechnology in displays. LCDs’latest position was evaluated.………………………………………………………………………………………………………….In the begining of 1960s Liquid Crystal Displays (LCDs)have entered to our life. When we go back to 1970s LCDshave been observed in calculators and watches[1]. They hadonly black and white displays at that time. LCDs helped somuch in daily life comparing with mechanical wristwatch andabacus in those years depending on that technology. LCDsimportant role in social life, starting to development beginningfrom primitive technology to Nanotechnology, have beenincreasing day by day. At present, LCDs are involved inhuman life in different aspects such as communication,information technologies, entertainment, cultural and artisticactivities.abFigure 1. a) Early wrist watch(1960s) b) Black-white LCD in watchIn view of energy and usage, TV screens made of LCDsexhibit low energy consumption with respect to televisionsproduced by Cathode Ray Tube(CRT). This situation makesLCDs more advantages to televisions made of CRT. Forinstance, televisions made in small size with LCDs can beused with low voltage (around 10 Vs). So even a couple ofbatteries are capable of usage of LCD TV.[2] This caseenables us to use TVs with LCDs in a wide range of places(without electrical sources) which we can never have thischance to use TVs with CRT.In point of information technologies, mobility feature ofLCDs have shown in movable computers such as laptops.Low energy consumption concept, decrease in size andincrease in mobility have made our life much easier bycomputers produced with LCDs such as laptops as mentionedabove than desktop computers.[3] With the help of LCDtechnology improving of laptops, today, access to informationand usage of laptops are possible in every single moment ofdaily life.Importance of LCDs in communication technology hasoutcome with progressing of mobile phones[4]. Beforeintroducing mobile technology to our life, regular phones wereplaying partially role. Entering with mobile communication toour life, communication put into effect in every moment ofdaily life. Improvement of LCDs technology has been playingmost important role in progressing of mobile phones.In point of environmental aspects of LCDs we see that:LCDdoes not emit that much of radiation compared to televisionwith CRT. When we compare them regarding emittingradiation, radiation emitted with sight almost approaches tozero in LCDs which leads to positive effect on environmentalpollution and human health. All displays with LCD like TV,computer compared to displays with CRT has been helping usin terms of environment and human health.[5]When we consider LCDs in view of social aspect, we cantell that they occupy important role. Starting from crowdedentertainment places and shopping centers and places whereoffical services are served, on deck of ferries, at ports, onpublic and private transportations etc., by serving LCDs is ansignificant indicator of LCDs that they have played veryeffective role in social life. Besides, nanotechnology hasbrought a new perspective to advertising sector by introducinggiant size of LCDs resuls in activity and new dimention incommercial life.To sum up, replacing TVs with CRT with LCD technologythe world has started a new period considering energy saving,economy, environment and social communication. It is notdifficult to say from now on that the role and impact of LCDsin our rotuine life will be more effective as nanothechnologydevelops and become a piece of our lives.*Corresponding author: HTarslanso@gyte.edu.trTH[1] Castellano J. A. , Liquid Gold: The Story of Liquid CrystalDisplays and the Creation of an Industry, World ScientificPublishing, Singapore, 2005.[2] M.T.Chena, C. C. Linb, Int. Jrn of Industrial Ergonomics, 34,167–174 , (2004)[3] A. Dhir, The Digital Consumer Technology Handbook, NewnesPublications, U.S.A. (2004)lic[4] D. Mentley, “Miniature display market and technology trends,”presentedat the Flat Information Displays Conf., Monterey, CA, Dec. (1998)[5] M. L. Socolof , J.G. Overly, J.R. Geibig, Jrn. of CleanerProduction, 13, 1281-1294, (2005)6th Nanoscience and Nanotechnology Conference, zmir, 2010 811

Poster Session, Thursday, June 17Theme F686 - N1123Sociological Value of Statement of Nanotechnology Discoveries and InnovationsProf. Dr. Hacı DuranSocial Sciences Education Department, Adıyaman University, ADIYAMANAbstract- The main point of interest in relation to our subject is the symbolization of 19 th century technologicalinnovations by universal dissemination, the symbolization of 20 th century technological innovations by administrations thatkeep everything under control at all times, and despite which the emergence of chaos and confusion about the way ofperception of technological innovations in the field of nanotechnology. In this research, a discussion will be opened aboutthe way that the nanotechnology industrial discoveries are perceived and transformed into a mindset..Nanotechnology has become a current issue with itsinventions and innovations which will directly affectand change the social structure, power relations,education, health issues and family life followingagricultural, industrial, energy and informationprocessing technologies.Technological discoveries and innovations have,throughout history, affected power relations, socialstructures and cultures. Most of the radical changesthat took place in the history of humanity havetherefore been associated with means of productionwhich determined the form of production.Agricultural revolution facilitated settlements andestablishment of cities, industrial revolutionfacilitated mass production, capitalist markets,institutionalization of colonial regimes, formation ofemployment markets and establishment of modernlife styles. Improvement of information technologiesbeyond all expectations caused changes in political,economic and cultural relations in many fields. Itcreated new domains of power. Many researcheshave been conducted about social, legal and ethicaleffects of information technologies. Those researchesstill continue today. Political, ideological and socialdiscussions about industrial and agriculturalrevolutions still endure despite the fact that thoserevolutions have completed their historical process.If we look at the discoveries and innovations thathave been enforced in the field of nanotechnology,(we see that) the history of humanity has encountereda new revolution before properly processing thechange in the field of information technologies.Futurists such as Jacques Attali have recently beenvoicing that innovations in information andnanotechnology will create hyper-classes. It is saidthat innovations in nanotechnology will bringhumanity face to face with social structures whichhave different features whereas before, socialstructures used to be formed according to distributionof wealth, tribal customs, and organizational politicalmovements.In this presentation, perception of innovations in thefield of nanotechnology by the society and the waysthat these are transformed into statements will beemphasized. Data for our research comprise of newsthat appeared in the visual and cyber media inconnection with the subject. Perception, outlining,presentation, visualization and interpretation of thenews related to nanotechnology constitute theinfrastructure for the statement of nanotechnology.Therefore, how the nanotechnology innovations areperceived by the public will be understood.The way that a technological and industrialinnovation is perceived also affects the types of socialrelations that that innovation will entail. Meaningsplaced upon the nanotechnology innovations aretherefore of great importance. Philosophical,sociological and social psychological disciplinesalways discuss the relationship between the actualself of something and the meaning given to it. Thesame goes for nanotechnology inventions, discoveriesand innovations.It is known that there are numerous evaluations andpredictions in movies and science-fictionpublications. For example it is also known that afictional literature is created based upon the effects ofthe 19 th Century scientific discoveries and industrialinnovations. Works of Jules Gabriel Verne areexamples of such efforts. George Orwell's novelsabout the effects of technological improvements onsocial order in the first half of the 20 th century arealso such examples.The main point of interest in relation to our subjectis the symbolization of 19 th century technologicalinnovations by universal dissemination, thesymbolization of 20 th century technologicalinnovations by administrations that keep everythingunder control at all times, and despite which theemergence of chaos and confusion about the way ofperception of technological innovations in the field ofnanotechnology. In this research, a discussion will beopened about the way that the nanotechnologyindustrial discoveries are perceived and transformedinto a mindset. G. Myrdal, “Implicit values in Economics”, ThePhilosophy of Economics, ed. D.M. Hausman,Cambridge University Press , Cambridge, 1984 Dora, B. Russell, Endüstri Toplumunun Geleceği, BilgiYayınevi, Ankara, 1979 J. Baudrillard, Simülarklar ve Simülasyon, çev. OğuzAdanır, Doğubatı, Ankara, 2005 P.S. Cohen, Moders Social Theory, Heineman, London,1978 M. Sahlins, Tarih Adaları, çev: Hakan Arslan, Dostyay., Ankara, 1998 C.Ginzburg, Güç İlişkileri, çev.Durdu Kundakçı, Dostyay. Ankara 2006 J.Gray, Post Liberalizm, çev., Müfit Günay, Dost yay.,Ankara 2004 J.L. Greau, Kapitalizmin Geleceği, çev. Işık Ergüden,Dost yay., Ankara 2007 H.Duran, Endüstri Çağının Dinamikleri, Değişim yay.İstanbul 2002 J. Attali, 21. Yüzyıl Sözlüğü, çev: Kosta Sarıoğlu,Güncel Yayıncılık, İstanbul 19986th Nanoscience and Nanotechnology Conference, zmir, 2010 812

PPoster Session, Thursday, June 17Theme F686 - N1123Industrial Pollution Prevention (P2) Activities Versus Nano-Production and Impacts onEnvironment1UTaner AltunokUP P*1PÇankaya Üniversitesi, Müh. Mim. Fakültesi, Endüstri Müh. Bölümü, 06530 Balgat, Yüzüncüyıl / AnkaraAbstract--Pollution prevention(P2) at the source of production instead of pollution control after waste streams occurred is preferred activitynowadays. Nanotechnology has the potential to improve the environment, both through direct applications of nano-materials to detect,prevent, and remove pollutants and toxic materials, as well as indirectly by using nanotechnology to design cleaner industrial processes andcreate environmentally responsible products and to provide more sensitive detection systems for air and water quality monitoring. In thispaper polluton prevention activities are examined in detail in terms of nano production structures/properties. It is expected to have that nanoproduction has less negative environmental impact on ecosystem and humanbeing, also providing us better methods to deal with pollution ofhazardous materials on environment.Nanotechnology is considered to play a key role in thearranging of current environmental engineering andscience. Cost-effective technologies for remediation,pollution detection, catalysis and others are underdevelopment [1]. There is a big expectation thatnanotechnological applications and products will lead to acleaner and healthier environment [2]. Maintaining andre-improving the quality of water, air and soil, so that theEarth will be able to support human and other lifesustainably, are one of the great challenges of our time.The scarcity of water, in terms of both quantity andquality, poses a significant threat to the well-being ofpeople, especially in developing countries. Great hope isplaced on the role that nanotechnology can play inproviding clean water to these countries in an efficient andcheap way [3]. On the other hand, the discussion about thepotential adverse effects of nanoparticles has increasedsteadily in recent years and is a top priority in agencies allover the world [4, 5]. Statistics shows that the hits for asearch for risk related to nanotechnology in the Web ofScience is increasing. The same properties that can bedeleterious for the environment can be advantageous fortechnical applications and are exploited for treatment andremediation.The toxicity of some nanoparticles can be used for waterdisinfection where killing of microorganisms is intended,whereas the same property is unwanted Nanotechnology.The catalytic activity of a nanoparticle can beadvantageous when used for the degradation of pollutants,but can induce a toxic response when taken up by a cell.The high sorption capacity of certain nanoparticles isexploited for the removal of organic and inorganicpollutants while this property may also mobilizesequestered pollutants in the environment. The engineeringof nanoparticles that are easily taken up by cells will havea huge impact on medicine and pharmacological research,but the dispersion of such particles in the environment canlead to unwanted and unexpected effects. By using theseproperies of nanotechnology in terms of pollution controlmay be Preferred, because it is possible use it extensivelyfor treatment of waste streams.But critical part of today’s approach is to pollutionprevention at the source. For this reason in terms ofpollution prevention (P2) the total system must beanalyzed simultaneously to find the minimum economicoption. Experience in all industries teaches that processesthat minimize waste generation at the source are the mosteconomical. For existing plants, the problem is even moreacute. Even so, experience has shown that wastegeneration in existing facilities can be significantlyreduced( greater than 30 % on avarage) while at the sametime reducing operating costs and new capital investment.Drivers to begin P2 programs are; Legal requirement,Public image and societal expectations, Large incentive forreducing new capital investment in end-of-pipe treatment,Significant return by manufacturing costs, Need toincrease revenues from existing equipment, Corporategoal, ncreasing effectiveness by using Nanotechnology,In summary, polluton prevention activities are examinedin detail in terms of nano production structures/properties.It is expected to have that nano production has lessnegative environmental impact on ecosystem andhumanbeing, also providing us better methods to deal withpollution of hazardous materials on environment.*Corresponding author: HTtaltunok@cankaya.edu.trT[1] Environmental Protection Agency, US EnvironmentalProtection Agency Report EPA 100/B-07/001, EPAWashingtonDC 2007.[2] T.Masciangioli,W. X. Zhang, Environ. Sci. Technol. 2003,37, 102A.[3] T. Hillie, M. Munasinghe, M. Hlope, Y. Deraniyagala,Nanotechnology, water and development,Meridian Institute,2006.[4] K. A. D. Guzman, M. R. Taylor, J. F. Banfield, Environ. Sci.Technol. 2006, 40, 1401.[5] M. C. Roco, Environ. Sci. Technol. 2005, 39, 106.6th Nanoscience and Nanotechnology Conference, zmir, 2010 813

PPoster Session, Thursday, June 17Theme F686 - N11231Nanostructures of Nature & Insecta1UAysel KekilliogluUP P*PKrkkale University, Faculty of Arts and Sciences, Department of Biology, Yahihan, 71450, Krkkale TurkeyAbstract-Nanotechnology is the production and use of materials with purposely engineered features close to the atomic or molecular scale.Nanotechnology deals with putting things together atom by atom and with structures so small they are invisible to the naked eye. It providesthe ability to create materials, devices and systems with fundamentally new functions and properties. As materials at the nanoscale oftenexhibit very different physical, chemical, and biological properties than their normal size counterparts, for many decades, nanotechnologyhas been developed with cooperation from researchers in several fields of studies including physics, chemistry, biology, material science,engineering, and computer science which is originally learned from nature. For instance, Some researchers have reported a cheap andeffective way to print nanoscale structures onto surfaces: they use stamps created from the delicately patterned wings of cicadas. Cicadasare not the only insects with nanostructures on their wings. In nature, the researchers explained, patterns on the nanometre scale abound:butterflies' iridescent colours arise from tiny pillared structures which scatter light; lotus plants repel water because of nanometre-sized waxcrystals on their surface. This study, examines the current phenomenon of rapidly increasing nanotechnology in natural world withnanostructures that teaches mankind a lot within the context of especially Insecta.*Corresponding author: akekillioglu@hotmail.com6th Nanoscience and Nanotechnology Conference, zmir, 2010 814

PPoster Session, Thursday, June 17Theme F686 - N11231Nanotechnology& Biotechnology1UAysel KekilliogluUP P*PKrkkale University, Faculty of Arts and Sciences, Department of Biology, Yahihan, 71450, Krkkale TurkeyAbstract-As part of the world’s developing vision, biotechnology which has the potential to maximise for the benefit of nationalor international economy, society and the environment; there are new challenges in this sector including a growing demand for healthy, safefood; an increasing risk of disease; and threats to agricultural and fishery production from changing weather patterns. However, creating abio economy is a challenging and complex process involving the convergence of different branches of science. Nanotechnology has thepotential to revolutionize the agricultural and food industry with new tools for the molecular treatment of diseases, rapid disease detection,enhancing the ability of plants to absorb nutrients etc. Smart sensors and smart delivery systems will help the agricultural industry combatviruses and other crop pathogens. In the near future nanostructured catalysts will be available which will increase the efficiency of pesticidesand herbicides, allowing lower doses to be used. Nanotechnology will also protect the environment indirectly through the use of alternative(renewable) energy supplies, and filters or catalysts to reduce pollution and clean-up existing pollutants. In this study it is argued that; thereis a mutual relation between biotechnology and nanotechnology for the protection of environment and human health.*Corresponding author: akekillioglu@hotmail.com6th Nanoscience and Nanotechnology Conference, zmir, 2010 815

PPoster Session, Thursday, June 17Theme F686 - N1123Nanotechnology and The Effects to The Labor Market Conditions in Turkey1Unci KuzgunUP P*1PDepartment of Economics, Hacettepe University, Ankara 06800, TurkeyAbstract-Nanotechnology will become predominant and leading to deep transformation in labor relations in Turkey. There are two importantpolicy targets such as employability and adoptability which constitute the labour market conditions based on the nanotechnology. Firms andemployees should adopt themselves to the continuously changing and growing labour market conditions.In the recent years, nanotechnologies creates a new processin the in labor relations. It is accepted that it will becomepredominant and leading to deep transformation in the laborrelations [1].With this framework, this study aims to discussthe efficiency of nanotechnology to the labor marketconditions in Turkey.The employability and adaptability have been accepted twoimportant policy targets which constitute the labour marketconditions based on the nanotechnology. The employability oflabour force and adaptability of firms and employees are mainindicators in the effects of nanotechnologies to the labormarket conditions. Demand for labor force and expectations offirms are continiously changing by nanotechonology .[2]Employability of labour force is important in the newprocess. It means improving the skills and qualifications of theworker who search for jobs through training, advancededucation, re-education counselling services[3]. In themeanwhile, the employability of labor force in Turkey can bediscuss from the point of nanotechnologies.Main indicator of the quality and potential efficiency of thelabour force is the level of education. In Turkey, 65% of totallabour force, 65,7% of total employment ,and 59,1% of totalunemployment are illiterate and/or have education less thanhigh school [3] Highest rates of participation in labour forceare observed among the university graduates. Whileparticipation rate in the labour force is 19.4% for the illiterate,46.4% for those with an education level below high school and56.7% for high school or equivalent school graduates; itreaches to approximately 78.6% in higher education graduates.Table 1. Educational Level of Labor Force , 2007 (%)LaborEmpl. Unempl.LFPRForceRate RateIlliterate 4,6 19,4 18,4 5,0Less than HighSchool60,4 46,4 42,1 9,3High School 21,9 56,7 49,5 12,8UpperVocational- 66,1 58,3 11,8SecondaryTertiary 13,1 78,6 71,0 9,6Total 100,0 47,8 43,1 9,9Source: SPO,2009 Annual Program, Table.IV.47.p.145Table 1 shows that an important part of the participation tothe economic activities in Turkey are unqualified or lowqualified individuals. It will create the problem for employingof labor force based on high technologies.In Turkey, the quantity of labor force when not accompaniedby expansion of quality doesn’t deliver positive results. Thus,it can be said that there is an inconsistency between thequalifications of labour force acquires as a result of educationand the ones demanded by the labour market. This issue willreflect to the demand for labour force ofnanotechnology in negative way. Nanotechnologies will notcreate the employment possibilities for the low qualified laborforce.There is a relationship between nanotechnology and qualitytraining of labor force. Current structure of labour force inTurkey, this relationship shows a negative picture with respectto the efficiency of the labour force and using thenanotechnologies depending on it.[4] Turkey must encourageand give priority to investment in labor force’s educationaland training level take most advantages of thenanotechnology. So, parallel to the using nanotechnology,Turkey should also increase the ability of labor force such as; critical and creative thinking and knowledge, teamwork ability, sense of responsibility, ability to use ofexperiences, ability of long-term think,adequate cognitive capacity,computer literacy, mathematics, knowledge of foreignlanguages.All this also means, training of labor force as well as a needfor flexible and quasi-permanent patterns of teaching andlearning under the new conditions of labor market based onthe nanotechnologies.On the other hand, the nanotechnologies will create theirlabour market conditions. The concept of work place, andworking-time will be changed in the sectors based onnanotechnologies. So, the adoptability is vital to the newconditions of nanotechnology for firms and employees. Thefirms and employees should adopt themselves to thecontinuously changing and growing labor market conditions.Inthe frame work of the using nanotechnology, the firms willcreate the new employment strategy based on the newemployment types. For that reason, new flexible workingmodels and new employment types should be developed withthe using of nanotechnology in the next years.Finally, the firms based on nanotechnologies will createtheir own inherent labor market. With the other words, thefirms used nanotechnology will create their career market. Thenanotechnologies will have on peculiar working conditionsworking conditions. A number of conclusions can be madefrom the result of this study. They are as follows:Organization of production,Working-time,Wage,Work conditionsConcept of work place,New flexible working models,New employment types*Corresponding author: kuzgun@hacettepe.edu.tr[1]TUBTAK, “2023 Dünyasnda Türkiye”. HThttp:/TT/tubitak.gov.tr/tubitak_content_files/vizyon2023/.../Ek11b.pptTH p.35.(2008)[2]MEB,“Hayat Boyu Örenme Stratejisi Belgesi Türkiye 2009” ikmep.meb.gov.tr/tr/dosyalar/LLL.Strategy.Paper.Turkey.2009.doc.p.18.(2009)[3]SPO, 2009 Annual Program,p.145, (2007)[4]MEB,“Hayat Boyu Örenme Stratejisi Belgesi Türkiye 2009” ikmep.meb.gov.tr/tr/dosyalar/LLL.Strategy.Paper.Turkey.2009.doc.p.37.(2009)16th Nanoscience and Nanotechnology Conference, zmir, 2010 816

Poster Session, Thursday, June 17Theme F686 - N1123Effects of dehydrating conditions on Dermatophagoides farina and Dermatophagoides pteronyssinusNada O. EdreesDepartment of Biology, Faculty of Sciences for Girls, king Abdelaziz university .Jeddah , Kingdom of Saudia arabiaE-mail : nada_algalb@hotmail.comnedrees@kau.edu.saAbstractHouse dust mites have lived in human contact from time immemorial dander or dead skin constitutes the major organiccomponent of house dust ecosystem . Because the mites feed on dander , dust mite and human association will continue to coexist as part of our environment . Efficient house – draying practice is the best form of control to reduce infestation , keepinghome dray ( Nadchatram , 2005). Sensitization and development of allergic respiratory disease result from complex genetic andenvironmental interactions . Specific measures to reduce indoor allergen exposure when vigorously applied may reduce the riskof sensitization and symptoms of allergic respiratory disease (Bush , 2008) . Survival experiments with D.farnae andD.pteronyssinus were. In environments containing water vapor below the CEA , more water is transpired than absorbed from theatmosphere and thus dehydration occur . An increase in temperature seems to increase the rate of dehydration . When exposed todehydrating condition (35% , 25% ,15% RH) . D.pteronyssinus and D.farinae exhibited increase mortality in response to anincrease of temperature . The lower mortality for males may be accounted for by their larger surface area to volume ratio , whichresult in transpiration occurring at a greater rate than in females .Key word: Dermatophagoides pteronyssinus , Dermatophagoides farina , humidity, dehydration , saudia Arabia .IntroductionThe house dust mite Dermatophagoides farinae ,Dermatophagoides pteronyssinus are the major sources of indoor allergensand are therefore considered important health problems worldwide . Many allergic individuals (hay fever , asthma , atopicdermatitis ) are sensitive to these mite ( Adgate , et al ,2008 ; Van Gysel et al , 2007, Edrees ,2008d) The worm , humidenvironment in modern homes favours the dust mite population , most homes contain one or more species of these house dustmite (Wu et al , 2009) . Carpets , mattresses , bedding , pillows, pillow covers , and clothing may contain breeding populationof house dust mite . Saudi Arabia is a fast developing country situated in the middle of the Arabian Peninsula . Due to thevariation in geography and climate . Particularly humidity of the regions which vary significantly . Riyadh in the central regionis considered to have low humidity . While humidity in western coastal region , Jeddah and southern region of Abha iscomparatively higher . which helps house dust mites thrive , in autumn and winter not during summer specially in Jeddah due tothe increasing of temperature up to 50°C (Edrees , 2009) .In Jeddah most homes contain both D.farinae ,D.pteronyssinus (Edrees,2006,2008 a,b,c). However , special precautions areimportant when individuals are susceptible or sensitive to house dust mite .This the extremely important for a possible integratedcontrol that can be taken to eliminate house dust mite and their allergens from the indoor environment .Most adult of D.farinaeand all adult of D.pteronyssinus cannot survive when exposed to 45°c for at least 48hr . Dehydration and survival of the housedust mite D.farinae and D.pteronyssinus at specific ambient conditions , was undertaken to determine the possibility oftemperature and humidity manipulation as a natural control method (Arlian 1975 , Brandt & Arlian ,1976). The purpose of thisstudy was to systematically investigate survival of D.pteronyssinus and D.farinae Exposure to specific relative humidity andtemperatures , determine whether these additives would increase mortalities during dehydration .Matrrial and mehodD.farinae and D.pteronyssinus used for experimentation were obtained from thriving pure laboratory culture at 75% RH and25°C , as described by Arlian (1975) incubator to provide the desired temperature . the critical equilibrium activity(CEA) of adultfemales to be 0.70 and 0.73 (70% and 73%RH) , respectively , (Robert ,et al 1976) .Statistical analysis :The data in tables ( 1 , 2 ,3) are presented as mean ± . The statistical analysis between the mites species andthe different six of each species were performed using paring " t – test " (Armitage , 1974 ) . All statistical were computed bySPSS 14 .Exposure to specific relative humidity and temperatures : Survival experiments with D.farnae and D.pteronyssinus wereconducted by placing 10 adults of 1 sex together in a glass vial containing a sufficient amount of yeast for food. Eight to 15 vials(100 mite) were used per experiment . The vials were constructed from 5 mm diam. X 20 mm lengths of glass tubing . To confinethe mite , the ends were plugged with a nylon mesh screen by inserting a Teflon washer into each end of the cage . An averagedistance of 10 mm was maintained between the plugs . After being equilibrated at 25°C and 75% RH for 24 hr , the vials weresuspended in closed ,4-oz(0.12-liter)bottles containing the appropriate glycerol solution to maintain the desired test RH'S. In turn, these bottles were placed in a BOD (Biochemical Oxygen Demand ) incubator to provide the desired temperature . Survivalcounts were made every 42 hr until 100%mortality was achieved (Robert et al ., 1976) . In this study the relative humidity isrecorded after each 48 it showed gradually decreasing (75% RH , 65% RH , 55% RH , 45% RH , 35 RH %,25 RH %, 15% RH ), during the gradually increasing of temperature( 32°C , 37°C , 42°C, 44°C , 46°C , 48°C , 50°C ) .RESULTSIncreasing in mortality is recorded gradually by increasing temperature which consequently lead to decrease thehumidity as a result of dehydration, the investigation had been recorded each 48 hours to count the survival mites . Thecalculated of mortality and survival in test population male, at specific time intervals when exposed to various temperature andhumidity were shown in tables. male have tolerated desiccation better than fmales at all RH tested at all temperature regimestested( tables 1,2,3) .6th Nanoscience and Nanotechnology Conference, zmir, 2010 817

Poster Session, Thursday, June 17AFM and Kelvin Probe Study of Emulsifier Incorporated PhospholipidsSaliha Zeyneb Akinci 1 , Tugce Bekat 2 , Sevgi Kilic Ozdemir 2,* , Salih Okur 3Theme F686 - N11231 Biotechnology Program, Izmir Institute of Technology, Gulbahce Campus, Izmir, Turkey2 Department of Chemical Engineering, Izmir Institute of Technology, Gulbahce Campus, Izmir, Turkey3 Department of Physics, Izmir Institute of Technology, Gulbahce Campus, Izmir, TurkeyAbstract- Monolayers of DSPC (1,2-dipalmitoyl-snglycerol-3-phosphocholine) and PEG 40 St (Polyoxyethylene glycol) stearate at differentcompositions (9:1 and 8:2) were analyzed with atomic force microscopy (AFM) in the Kelvin Probe (KP) mode. The effects of the compositionand the medium on compactness of the monolayer were investigated.Contrast agents for ultrasound comprise micron sized of gas(microbubbles) stabilized by a shell of biocompatiblematerial. These agents alter the scattering character of theblood under ultrasound, creating contrast with respect to theimaged tissue [1]. Microbubbles are administrated to thepatient during imaging and are expected to recirculate in theblood stream until the imaging is complete. Viability of themicrobubbles in the systemic circulation is closely related tothe shell structure. In this study, DSPC and PEG 40 St are usedas the main constituents of the microbubbles. A mixture ofDSPC/PEG 40 St at predetermined compositions was spread atair-water interface and transferred to a substrate for atomicforce microscope imaging using Langmuir-Blodgett (LB)film method. Mainly, DSPC/PEG 40 St mixtures atcompositions of 9:1 and 8:2 were analyzed both in pure waterand phosphate buffer saline at 110 mM (PBS).Monolayers showed more homogeneous and compactbehavior in buffer solution compared to pure water for bothcompositions. Additionally, the 8:2 mixed monolayersindicated more homogeneous structure both in the pure waterand buffer solution in comparison to 9:1 mixed one.As shown in Figure 1, this comparison was also performedwith the bare gold monolayer as reference monolayer in orderto evaluate the differences between surface potential values.Figure 2 shows the height profile along the scan and surfacepotential measurement of 8:2 DSPC/PEG 40 St mixture coatedfilms both in pure water and PBS. The characterization of theLangmuir-Blodgett (LB) films with AFM in Kelvin Probemode shows that 8:2 mixed monolayer in buffer solutionhave higher surface potential values than 9:1 mixed one bothin pure water and PBS (data not shown).height (nm)5040302010050gold film surface8:2 DSPC-PEG 40 St. in pure water subphase8:2 DSPC-PEG 40 St. in buffer subphase0 1 2 3 4 5x (nm)PURE GOLDabMAG_V40308:2 DSPC-PEG 40 S (PURE WATER)8:2 DSPC-PEG 40 S (110 mM PBS)2010e0-1.5 -1 -0.5 0 0.5 1 1.5 2BIAS VOLTAGEFigure 2. Surface height profile along the scan and surface potentialmeasurement of DSPC/PEG 40 St LB monolayer films with Kelvinprobe force microscope for 8:2 DSPC/PEG 40 St monolayer in purewater and PBS solution at 110 mM, and also pure gold monolayer asa reference.cdThe surface potentials have been measured as 0.030184 V forbare gold substrate, 0.4894 V and 0.43V for the 8:2DSPC/PEG 40 St monolayer in pure water and PBS,respectively. Surface roughnesses have been measured as0.544479 nm for bare gold substrate, 0.903692 nm and4.41735 nm for 8:2 DSPC/PEG 40 St monolayer in pure waterand PBS, respectively.Figure 1. Characterization of LB films at 5 m (a) topography and(b) surface potential of pure gold (as a reference); (c) topographyand (d) surface potential of 8:2 DSPC/PEG 40 St monolayer in purewater; (e) topography and (f) surface potential of 8:2 DSPC/PEG 40 Stmonolayer in 110 mM PBS solution.According to these investigations of emulsifier incorporatedphospholipids, we surmise that the increase in homogeneityand the surface potential of the monolayers may be resultingfrom intermolecular interactions between the moleculesforming the monolayer and the medium. The effect of themedium on the molecular interactions and the compactness ofthe monolayer will also be tested on microbubble formation.*sevgikilic@iyte.edu.tr[1] Moriyasu F. et al., Am. J. Roentgenol, 193:86; 2009.6th Nanoscience and Nanotechnology Conference, zmir, 2010 818