Photonic crystals in biology

Poster Presentations 

1st Day 2nd Day 3rd Day 

Poster section Poster section Poser section 

15 June 2010 16 June 2010 17 June 2010 

ID: A18-B702 B754-F1166 F1244-N1123 

6 th Nanoscience and Nanotechnology Conference, İzmir, 2010

Poster Session, Tuesday, June 15 

Theme A1 - B702 

Absorption Hypothesis: Attachment of Beetles to Nanoporous Substrates 

Elena Gorb 1 *, Solveig Kleinz 1 and Stanislav Gorb 1 

1 Department of Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, 24098 Kiel, Germany 

Abstract-Traction experiments with ladybird beetles showed that forces on nanoporous substrates were significantly lower t hat those on solid 

surface samples. The comparison of the evolution in contact angles of the two fluids, polar water and non-polar mineral oil, showed that porous 

substrates absorbed both polar and non-polar fluids, whereas solid surface samples did not. Thus, the reduction of insect attachment on 

nanoporous surfaces may be explained by (1) the absorption of the secretion fluid from insect adhesive pads by porous media and/or (2) the 

effect of surface roughness. 

It has been repeatedly reported that micro- and 

nanostructured waxy surfaces of plants strongly reduce insect 

attachment. To explain anti-adhesive properties of such 

substrates, four hypotheses have been previously proposed: (a) 

roughness hypothesis; (b) contamination hypothesis; (c) fluid 

absorption hypothesis; and (d) wax dissolving hypothesis [1]. 

Recently, only the two first hypotheses ([2 – 6] for (a) and [7 – 

9] fo r (b)) were proven. To date, the wax d issolving 

hypothesis and the fluid absorption hypothesis have not been 

experimentally tested. In the present study, we used 

nanoporous substrates with the same pore diameter (220 – 235 

nm), but different porosity (area of voids in a material surface, 

normalized over the total area), in order to test the fluid 

absorption hypothesis, claiming that the structured wax 

coverage of plants may absorb the fluid from the setal surface 

of insect adhesive pads and by this reduce the adhesion force. 

We performed traction force measurements with tethered 

seven-spotted ladybird beetles Coccinella septempunctata L. 

(Coleoptera, Coccinellidae), walking on five different 

substrates [10]: (1) smooth glass plate; (2) smooth solid Al 2 O 3 

(sapphire) disc; (3 – 5) three types of nanoporous Al 2 O 3 discs 

(back side of anodisc membranes Whatman, Schleicher and 

Schuell, Whatman International Ltd., Maidstone, UK) having 

the porosity of 28, 42 and 51%. Forces were measured with a 

load cell force transducer (10g capacity, Biopac Systems Ltd., 

Santa Barbara, CA, USA). Both males (n=10) and females 

(n=10) were used in the experiments. 

We found that the forces ranged from 0.16 to 16.59 mN in 

males and from 0.32 to 8.99 mN in females. The highest force 

values were obtained on the smooth surfaces, where males 

generated considerably higher forces compared to females. On 

all three porous substrates, the forces were significantly 

reduced, and the only difference was obtained between 

nanoporous membranes having the highest and lowest 

porosity. Males produced essentially lower forces than 

females on porous samples [10]. 

The reduction of insect attachment on nanoporous 

substrates may be explained by (1) possible absorption of the 

secretory fluid from insect pads by porous media and (2) 

surface roughness, reducing real contact area between tenent 

setae of insect adhesive pads and substrate. 

To examine the ability of porous substrates to absorb fluids, 

we performed additional absorption experiments with solid 

and nanoporous surfaces samples using a high-speed optical 

contact angle measuring device OCAH 200 (DataPhysics 

Instruments GmbH, Filderstadt, Germany). The comparison of 

the evolution in contact angles of the two fluids, polar water 

and non-polar mineral oil (Mobil DTE Medium, viscosity 43.4 

mm 2 •s at 40°C [11]), showed that porous substrates absorbed 

both polar and non-polar fluids (figure), whereas solid surface 

samples did not. Since the beetle secretion or at least a part of 

it consists of oily substances, we can conclude that adhesion 

reduction in our traction experiments at least partially can be 

explained by the ability of nanoporous substrates to adsorb 

non-polar lipid-like fluids. 

contact angle [ ° ] 

70 

60 

50 

40 

30 

20 

10 

0 

0 10 20 30 40 50 60 

30 

25 

20 

15 

10 

5 

absorption 

absorption 

0 

0 10 20 30 40 50 60 

time [s] 

(a) 

(b) 

Figure 1. The evolution in contact angles of water (a) and oil (b) 

on the nanoporous surface sample with the porosity of 42%. 

This work was partially supported by the SPP 1420 priority 

program of the German Science Foundation (DFG) 

“Biomimetic Materials Research: Functionality by 

Hierarchical Structuring of Materials” (project GO 995/9-1). 

The first author thanks Naoe Hosoda (NIMS, Tsukuba, Japan) 

for fruitful discussions. 

*Corresponding author: egorb@zoologie.uni-kiel.de 

[1] E.V. Gorb and S.N. Gorb, Entomol. Exp. Appl. 105, 13 (2002). 

[21] S. Gorb, Attachment devices of insect cuticle (2001). 

[3] A. Peressadko and S. Gorb, Proc. 1st Int. Conf. Bionik, 257 

(2004). 

[41] D. Voi gt et al., J. Insect Physiol. 54, 765 (2008). 

[51] E. Gorb and S. Gorb, Entomol. Exp. Appl. 130, 222 (2009). 

[6] J. M. Bullock and W. Federle, J. Exp. Biol. 212, 1876 (2009). 

[7] L. Gaume et al., Arthropod Structure & Development 33, 103 

(2004). 

[8] E. Gorb et al., J. Exp. Biol. 208, 4651 (2005). 

[9] E. Gorb and S. Gorb, Ecology and biomechanics: A mechanical 

approach to the ecology of animals and plants, 147 (2006). 

[10] E. Gorb et al., Proc. 9th Biennial ASME Conf. on ESDA, 1 

(2008). 

[11] M. Varenberg and S. Gorb, Adv. Mater. 21, 483 (2009). 

6th Nanoscience and Nanotechnology Conference, zmir, 2010 208



Phosphorus Containing Novel Polyimide/Silica Nanocomposite Materials via Sol-Gel Technique 

Canan Kızılkaya *, Sevim Karataş , Nilhan Kayaman Apohan , Atilla Güngör 

Marmara University, Department of Chemistry 34722 Istanbul/Turkey 

Abstract- In this work, the high temperature capability and fire-resistance of phosphorus-containing polyimide/ silica 

(PI/SiO 2 ) nano hybrid films were synthesized by sol-gel reaction and thermal imidization.The silica content in the hybrid 

films was varied from 0 to 20 wt %. The thermal, mechanical, optic, electrical and surface properties of the hybrid films 

have been investigated and compared to pure PI. 

Organic-inorganic nanocomposite materials prepared by 

the sol-gel technique are an important class of newgeneration 

materials, which combine the desirable 

properties of an inorganic component (heat resistance, 

retention of mechanical properties at high temperatures 

and low thermal expansion) and those of organic polymer 

(toughness, ductility and processability) [1,2]. 

Polyimides (PI) are promising materials used for a wide 

range of applications because of their high glass transition 

temperature, good heat resistance, low dielectric constant, 

and excellent mechanical properties. The sol–gel process is 

a unique and versatile approach among the various 

methods used to produce polyimide/SiO 2 hybrid materials 

.The nature of the interfaces between SiO 2 particles and 

polyimides matrix, the content and size of SiO 2 particles, 

greatly affect the properties of the hybrid materials. Strong 

interfaces in which covalent bond should be formed 

between SiO 2 particles and polyimides matrix, are needed 

for obtaining excellent properties [2,3] . 

Polymers containing the phenylphosphine oxide 

(PPO)group have been studied extensively for a number of 

applications in recent years. These polymers are the most 

important ones both due to good their thermal and 

chemical stability, excellent mechanical properties, very 

good fire retardancy. Polyimides containing phosphine 

oxide moieties display good flame resistance and excellent 

adhesion properties. It has been proven that the 

phenylphosphine oxide moiety provides a strong 

interacting site for imparting miscibility with several 

systems [2-5]. 

In this work, a series of novel phosphine oxide 

containing polyimide / silica nanocomposite materials 

were prepared via sol-gel technique and imidization. The 

silica content in the hybrid coating materials was varied 

from 0 to 20 wt%. The FTIR and 29 Si-NMR spectra 

showed that the fully condensed inorganic network had 

formed during the imidization. Tensile modulus and 

hardness of the polyimide/silica coating materials 

increased gradually with increasing inorganic content due 

to the enhanced interfacial interaction between PI matrix 

and silica particles. The thermal analysis of the coating 

materials showed that the degradation of PI was largely 

reduced with incorporation of silica and also the flame 

retardancy of the nanocomposite increased. The 

morphology studies indicated that, the silica particles in 

the polyimide matrix are dispersed homogeneously and the 

particle size is in the range of 30-55 nm. Furthermore, it 

was observed that optical transparencies of the hybrid 

coating materials decreased due to the introduction of 

higher silica content into the polyimide matrix and the 

increasing contact angles demonstrated the formation of 

hydrophobic nanocomposite surface. 

(a) 

Figure 1: SEM micrographs of (a) PI/SiO2-15 (b) Si mapping of 

PI/SiO2-15. 

*Corresponding author: ckizilkaya@gmail.com 

[1] S Karatas, N.K. Apohan, H. Demirer, A. Gungor Polym. 

Adv. Technol., 18,490–496 (2007) 

[2] C.Kızılkaya ,S. Karataş , N. K. Apohan , A. Güngör, Journal 

of Applied Polymer Science, 115, 3256-3264 (2010). 

[3] M. Çakır, S Karataş, Y.Menceloğlu, N.K.Apohan, A. 

Güngör, Macromol. Chem. and Phys., 209 , 919 , (2008). 

[4] C.J Cornelius, E. Marand, Polymer , 43, 2385( 2002) 

[5] Y.Delaviz, A. Güngör, J.E. McGrath, H.W Gibson, Polymer, 

34, 210 (1993). 

(b) 




Piezoelectric properties of 0.65Pb(Mg 1/3 ,Nb 2/3 )O 3 -0.35PbTiO 3 ceramics prepared from 

nanopowders 

M. Ghasemifard a , S. M. Hosseini a , H. Ghasemifard b 

a Department of Physics (Materials and Electroceramics Laboratory), Ferdowsi University of Mashhad, Mashhad, Iran, 

b Department of Medical Enginearing, Azad University of Mashhad, Mashhad, Iran 

Abstract- The piezoelectric properties of relaxor ferroelectric 0.65Pb(Mg 1/3 Nb 2/3 )O 3 –0.35PbTiO 3 (0.65PMN–0.35PT) ceramics 

prepared by a sol-gel combustion method have been investigated as a function of sintering temperatures. The XRD results show 

that the phase structure is near the morphoteropic phase boundary (MPB). The highest piezoelectric coefficients were observed 

for the samples sintered at temperature of 1200 o C. In comparison with pure PMN, the substitution of 35% PT results in the 

decrease of sintered temperature and peculiar relaxation behavior. 

Relaxors ferroelectric based on the PMN-PT ceramics 

display excellent piezoelectric/electrostrictive properties along 

with a variety of compositional modification, because of the 

volatilization of PbO and the differences of the reactive 

temperature between Pb-Nb and Pb-Mg [1-3]. The major 

problem in synthesis pure PMN-PT ceramics with perovskite 

structure is the formation of pyrochlore phases such as PbO, 

Pb 3 Nb 4 O 13 , Pb 2 Nb 2 O 7 and Pb 5 Nb 4 O 15 . A successful method to 

overcome these problems is a sol-gel processing [4] which leads 

to approximately pure perovskite phase at low temperature with 

an improvement in the properties of PMN-PT ceramics. An 

additional benefit of this processing is that it leads to small 

particles which cause pretty high density of ceramics. We have 

already managed to prepare PMN-PT nanopowders by sol-gel 

combustion [5]. This method provided a very fine particles and 

a higher piezoelectric constant compared to traditional mixed 

oxide processing. The aim of this paper was to investigate the 

effect of sintering temperature on the 0.65PMN-0.35PT 

ceramics prepared by a new sol-gel combustion processing 

method. We also have discussed the results of piezoelectric 

properties for the samples made from PMN-PT as a function of 

sintering temperature. 

Nanopowders of (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 -(x)PbTiO 3 (PMN- 

PT) with x=0.35 were synthesis by sol-gel combustion method 

using metal organic and salts precursors as starting materials [5, 

6]. X-ray diffraction patterns of PMN-PT powders are shows in 

Fig.1. The presence of a monoclinic phase at 850 o C can be 

identifying from Fig. 1. The XRD results reveal the existence of 

a perovskite-type phase for gel-combustion method in all 

temperature. 

Fig. 1 XRD spectra of samples of the PMN-PT 

Fig. 2 shows the microstructure of the PMN-PT ceramics 

sintered at different temperatures. With the increase of sintering 

temperature, the grain size increases. 

Fig. 2. SEM micrographs of surface of PMN-PT ceramics 

The grain size has strong effects on dielectric properties and 

polarization of piezoelectric materials [7]. The electrical 

parameters are summarized in Table 1. 

Table 1. Various parameters on some electrical properties 

Temperature 

( o C) 

Grain size 

(μm) 

Density 

(gr/cm 3 ) 

d 33 

(pC/N) 

1100 - 7.26 149 4.98 0.33 

1150 - 43.7 375 5.01 0.48 

1200 1.5 7.86 484 5.86 0.54 

1250 2 8.02 552 6.03 0.57 

1300 3.5 7.76 515 5.13 0.56 

[8] 2.8** 7.86 - - - 

[9] * - - 2200 - 0.92 

*PMN-0.32PT single crystal. **S.T.=1240 o C 

In general, the results of measurement indicated most electrical 

and piezoelectric parameters are maximum for the samples sintered at 

temperature of 1250 o C. 

*Corresponding author: mahdi572@yahoo.com 

[1] D. S. Paik, S. Komarneni, V. 34, (1999), 2255-2491. 

[2] M. Lejeune, J . P . Bilot, Ceram. Int. 8(3) (1982) 99. 

[3] O. Bouquin, M. Lejeune, J . P . Bilot, J. Amer. Ceram. Soc. 74(5), (1991), 

1152. 

[4] P . Raindranathan, S. Komarneni, A. S. Bhalla, R. Roy, J. Amer. Ceram. 

Soc. 74(12), (1991), 2996. 

[5] M. Ghasemifard, S.M. Hosseini, Gh. Khorrami, Ceramic international, 35, 

(2008), 2899-2905. 

[6] M. Ghasemifard, S.M. Hosseini, M. M. Bagheri-Mohagheghi, N. 

Shahtahmasbi, J. Physica E, Article in press, (2009). 

[7] M. Alguero, A. Moure, L. Pardo, J. Holc, M. Kosec, Acta Mater. 54 (2006) 

501–511. 

[8] S. E. Park, T. R. Shrout, J. Appl. Phys., 82, (1997), 1804–1811. 

[9] T.R. Shrout, Z.P. Chang, N. Kim, S. Markgraf, Ferroelectrics Lett. Sect., 12, 

(1990), 63–69. 

Q m 

k p 




Electros pun Hybrid Scaffolds for Bone Tissue Repair 

1 * 

1 urkey. 

Abstract-The aim of this study is to develop novel hybrid (blend&layer by layer) tissue scaffolds for bone tissue repair by using electrospinning 

method. PCL (poly--caprolactone), chitosan and hydroxyapatite (HA) nanoparticles were used as components for hybrid structures. 15 wt % of 

PCL and 8 wt % of chitosan concentrations and 90/10 vol % PCL/chitosan weight ratio were selected in order to obtain uniform and bead free 

fabrics. Detailed characterization studies performed in this study showed the desired properties of scaffolds for bioapplications. The control of 

suitability of the developed hybrid scaffolds for cell culture applications by using osteoblast cells is under process. 

Nanofibrous materials have been extensively studied as 

scaffolding materials in tissue engineering and regenerative 

medicine, due to the fact that the extracellular matrices (ECM) 

of native tissues are nanofeatured structures, and cells attach 

and proliferate better on nanofeatured structures than bulk 

materials [1,2]. Recently, researchers have investigated 

electrospinning of blend polymers as candidate materials for 

biomedical applications because polymer blends have 

provided an efficient way to fulfill new requirements for 

material properties. Blends made of synthetic and natural 

polymers can present the wide range of physicochemical 

properties and processing techniques of synthetic polymers as 

well as the biocompatibility and biological interactions of 

natural polymers [3,4]. In addition, many researchers have 

reported that incorporation of calcium carbonate (CaCO 3 ) or a 

type of calcium phosphate such as hydroxyapatite (HA) 

helped to improve osteoblast proliferation and differentiation 

[5,6]. 

In the present contribution, novel PCL (poly--caprolactone) 

and chitosan blend and layer by layer structures of hybrid 

scaffolds filled with hydroxyapapite (HA) nanoparticles were 

developed by using electrospinning method. PCL, due to its 

slow degradation rate, is a good candidate to be used in bonescaffolding 

applications. Chitosan is favorite for 

bioapplications because of its biocompatible property and low 

cost. HA nanoparticles (50-200 nm) prepared and 

characterized in our previous study [7] were used. 

In the first stage of the work, various solution/process 

parameters such as concentration, PCL/chitosan weight ratios, 

applied electric voltage, tip-collector distance were studied for 

optimization of scaffolds. After optimization studies, the 

concentrations for pure and hybrid (blend and layer by layer; 

PCL/Chitosan/PCL&Chitosan/PCL/Chitosan) PCL and 

chitosan scaffolds were chosen as 15 wt % of PCL and 8 wt % 

of chitosan in order to obtain desired nanofabric structures 

(uniform, bead free). The weight ratios of PCL and chitosan 

were determined as 90/10 vol % for blend PCL/chitosan 

scaffolds. PCL/Chitosan/PCL layer by layer structure was 

selected for further studies. Applied electric voltages, tipcollector 

distances were determined for each scaffolds. For the 

HA modification of the scaffolds different concentrations (1.5, 

5, 10, 20 wt%) of HA nanoparticles were added to 

PCL/chitosan solutions before electrospinning process. In 

addition to naked eye observation SEM analysis was also used 

for the optimization of structures. 

In the characterization stage, the prepared scaffolds were 

first morphologically examined by SEM analysis. By using 

computer software program (ImageJ, USA), average fiber 

diameters, HA and inter fibers porosity sizes of scaffolds were 

calculated from obtained SEM photographs. 

Wettabilities of electrospun scaffolds were measured using 

sessile drop water contact angle measurement by a optical 

contact angle measurement (KSV, Finland) systems. The 

contact angle measurement study showed that hydrophobic 

characteristic of PCL scaffolds was decreased by adding 

chitosan and HA components. The samples were cut in 

rectangular strips with dimensions 40 mm × 5 mm, and tensile 

properties were characterized by tensile testing machine 

(Llyod Instruments LK-5K, UK) equipped with a 500 N load 

cell. Elastic modulus, tensile strength and strain at break (%) 

values of samples were determined as a result of mechanical 

tests. FTIR-ATR analysis in the range of 500-4000 cm -1 

wavelength was used for the chemical structure confirmation 

of the prepared scaffolds. The obtained spectra showed that 

the hybrid scaffolds represent the characteristic peaks of PCL, 

chitosan and HA components. Swelling properties of 

PCL/chitosan scaffolds were examined by PBS absorption 

tests. In order to investigate the effect of chitosan on 

biodegradation of prepared scaffolds, biodegradation studies 

were carried out for the 7 th , 14 th , 21 st 

and 28 th 

days of 

incubation in DMEM/F12 with chicken egg white lysozyme 

medium. Additionally, controlled release of BSA (Bovine 

Serum Albumin) studies was performed to have an idea about 

the effect of HA nanoparticles with different weight ratios on 

bone tissue repair. 

In summary, the characterization studies carried out in this 

work showed the desired properties of scaffolds for 

bioapplications. In the future part of this work, the control of 

suitability of prepared and well/detailed characterized hybrid 

PCL/chitosan scaffolds for cell culture applications will be 

performed by using osteoblast cells. This work was fully 

supported by TUBA/LOREAL under “Young Women in 

Science” program. Dr. 

“Young Woman in Science” in Materials Science at 2009 with 

this project. 

*Corresponding author: 1Thtsasmazel@atilim.edu.tr 

[1]J.A. Matthews, G.E. Wnek, D.G. Simpson, et al. 

Biomacromolecules 3, 232 (2002). 

[2] M. Pattison, S. Wurster, T. Webster, K. Haberstroh, Biomaterials 

26, 249 (2005). 

[3] Y. You, S.W. Lee, et al. Polymer Degradation and Stability 90, 

441 (2005). 

[4] S. Aparna, S.V. Madihally, Biomaterials 26, 5500 (2005). 

[5] A. G. A. Coombes, S. C. Rizzi, M.Williamson, J. E. Barralet, 

S. Downes, W. A. Wallace, Biomaterials 25, 315 (2004). 

[6] K. Fujihara, M. Kotaki, S. Ramakrishna, Biomaterials 26, 4139 

(2005). 

[7] A.P. Sommer, M. Çehreli, et al. Crystal Growth&Design 5, 21 

(2005). 




Fas t Track Preparat ion of ZnO nanorods in Water 

M. A. Shah 1 *, F.M.Al-Marzouki 1 and A.A. Al-Ghamdi 1 

1 Department of Physics, Faculty of Sciences, King Abdul Aziz University, Jeddah 21589, Kingdom of Saudi Arabia 

Abstract-We will present a fast, soft, economical and bio-safe synthesis of hexagonal-shaped zinc oxide (ZnO) nanorods at very low temperature 

of ~120 o C simply by using metallic zinc powder and de-ionized (DI) water without the use of any additives or amines. The product is believed to 

be bio-safe and bio-compatible and can be readily used for medicine besides other applications. 

Nanostructures of zinc oxide (ZnO), including particles, 

rods, wires, belts, tubes, cages, walls, flowers and rings have 

scattered a great deal of attention in recent years because of 

their useful electronic and optoelectronic properties and 

novel application in catalysis, paints, wave filters, UV 

detectors, transparent conductive films, varistors, gas 

sensing, solar cells, sun screens and other cosmetic products. 

Moreover, the wide range of morphological diversity in the 

nano-regime has made this material a promising candidate in 

the field of nanotechnology and opened up new possibilit ies 

for the fabrication of high performance devices based on 

these nanostructures. Among the various nanoforms, one 

dimensional (1D) nanostructures have received considerable 

attention due to their potential interests for understanding 

fundamental physical concepts and for efficient field 

emission that has enormous commercial applications such as 

field emission flat panel displays, x-ray sources, parallel 

beam electron microscopy and vacuum microwave 

amp lifiers [1]. 

Synthesis of nanomaterials forms a vital aspect of the 

science of nanomaterials and chemical methods have proved 

to be more effective and versatile than physical methods and 

have, therefore, been employed widely. While nanomaterials 

have been generated by physical methods too such as laser 

ablation, arc discharge and evaporation, chemical methods 

have proved to be more attractive as they provide better 

control over the size and shape, which is one of the essential 

features in nanoscience. Chemical synthesis of nanomaterials 

has been reviewed by few authors but innumerable 

improvements and better methods are being reported 

continually in the last few years [2,3]. 

In this work we will explore the formation of ZnO 

nanostructures by the reaction of zinc metal with DI water at 

very low temperature of 120oC. The simple reaction is 

carried out in absence of any additives and/or amines. The 

synthesized ZnO products were characterized in terms of 

their structural and optical properties. By the morphological 

investigations using FESEM, it was observed that the grown 

products are hexagonal-shaped ZnO nanorods with the 

diameters and lengths in the range of 70-90 nm with several 

micrometers. The EDS and XRD pattern confirmed the 

composition and crystallin ity of the grown nanorods and 

revealed that the grown products are pure ZnO with the 

wurtzite hexagonal phase. The optical properties of grown 

products were characterized by room-temperature 

photoluminescence spectroscopy which confirmed the good 

optical properties for the grown products. 

[2] H. Wie, Y. Wu, N. Lun, and C. Hu, Mater. Sci. Eng. A Vol. 

393, 80 (2005). 

[3] Z.W. Pan, Z.R. Dia and Z.L. Wang, Science Vol. 291, 1947 

(2001). 

*Corresponding author: 0Tmashahnit@yahoo.com 

[1] C. X. Xu, Y. Liu, and G. Wang, Solid State Communication 

Vol. 122, 175 (2002). 




Additive Free Synthesis of Aluminum Oxide Nanostructures 

F.M.Al-Marzouki 1 and M. A. Shah 1 * 

Department of Physics, Faculty of Sciences, King Abdu l Aziz University, 

Jeddah 21589, Kingdom of Saudi Arabia 

1 

Abstract- Water which is well known inexpensive and an environmentally benign solvent have been used for the synthesis of aluminum oxide 

(Al 2 O 3 ) nanostructures. We will present an economical and bio-compatible synthesis of aluminum oxide nanorods at very low temperature of 

~180 o C without using any additives or surfactants. This is the first report where nanostructures of Al2O3 have been prepared at such a low 

temperature and by such a simple technique. The formation of Al 2 O 3 structures by the reaction of metals with DI water is suggested to occur due 

to the oxidation of aluminum in presence of water. The reported method besides being organics free is economical, fast and free of 

pollution, which will make it suitable for large scale production. 

Innovations at the intersection of medicine, biotechnology, 

engineering, physical sciences and information technology 

are spurring new directions in R&D, commercialization and 

technology transfer. The future of nanotechnology is likely 

to continue in this interdisciplinary manner. 

Nanotechnology is the next industrial revolution, and all 

most all industries will be radically transformed by it in a 

few years. Ceramics are regarded as versatile materials and 

aluminum oxide (Al2O 3 ), one of the ceramic materials 

commonly known as sapphire is known to exist in a number 

of metastable polymorphs in addition to the 

-Al 2 O 3 or corundum form. 

-Al 2 O 3 

is an important form of alumina 

because of its porous structure and high catalytic surface 

activity. This material has been widely used as catalysts, an 

adsorbent and as a support for industrial catalysis in 

hydrocarbon conversion. Owing to their brittleness, ceramics 

have been regarded as materials of modest performance 

especially under tension or bending conditions [1]. 

A number of synthetic routes including, the sol-gel 

chemistry, spray pyrolysis, precipitation, solovothermal and 

physical methods are being extensively used for the 

synthesis of Al2O 3 nanostructures [2,3]. The other 

techniques are technically complex, requires high 

temperature, harsh growth conditions, expensive 

experimental setup, complicated control processes and use of 

excessive organics/amines. Seeking a simple approach for 

low cost, lower temperature, larger scale production and 

controlled growth without additives is desired [4]. 

To this end, we present a novel and simple method for 

-A l 2 O 3 nanorods without catalysts or any 

other additive. The route is based on a simple reaction of 

aluminum powder and double distilled water at 180 o C 

without using any catalyst or any other additive. Moreover, 

the synthesis time is very short and the morphology could be 

controlled by varying reaction time. The aim of the study is 

to provide the feasibility of the simple route for the 

preparation of aluminum oxide nanostructures. Systematic 

studies are underway and will be presented during 

conference. 

Corresponding author: 0Tmashahnit@yahoo.com 

[1] Fang X, Zhang L. J. Mater. Sci. Tech.22, 1 (2006). 

[2] Y.Z Jin, Y.Q Zhu, K Brigatt, H. Kroto, D.R.M Waltan, Appl. 

Phys. A 89, 1008 (2003). 

[3] X.S.Fang, C.H.Ye, L.D.Zhang, T. Xie Adv. Mater 17 (2005) 

1661 

[4] M.A.Shah and A.M. Asiri, Int. J. Modern Phy. B, Vol. 23, 2323 

(2009). 




Preparation and characterization of silver nanoparticles by an eco-friendly approach 

Reda El-Sh ishtawy 1 * Abdullah Asiri 1 and Maha Al-Otaibi 1 

Department of Chemistry, Faculty of Science, King Abdul-Aziz University, Jeddah 21589, PO Box 80203, Saudi Arabia 

1 

Abstract-This work reports on an environmentally benign method for the preparation of AgNPs in aqueous solution using glucose as the 

reducing agent in water/ micelles system, in which cetyltrimethylammonium bromide (CTAB) was used as capping agent (stabilizer). 

Spectrophotometric method was used to monitor the formation of AgNPs under different conditions such as a) concentration of sodium 

hydroxide, b) concentration of glucose, c) concentration of silver nitrate d) concentration of CTAB, and e) reaction time were used so as to find 

out the optimum conditions for the preparation of AgNPs. 

Silver nanoparticles (AgNPs) have received much more 

attention in recent years due to their unique physical, optical, 

electrical, magnetic, and chemical properties and their 

potential application in molecular electronic field [1]. 

Therefore, extensive research has gone into developing 

suitable preparation techniques to form AgNPs. These include 

chemical reduction, microorganisms induced reduction as well 

as photochemical and high energy radiation induced reduction 

of silver salt solution. Among these methods, chemical 

reduction is the most extensively investigated method [2-6]. 

Figure 1 shows the UV-vis absorption spectrum of a diluted 

solution of AgNPs in which we can see a narrow absorption at 

403 nm (plasmon band) indicating the presence AgNPs. The 

size of the AgNPs were determined with the help of 

transmission electron microscope (Fig. 2). Also, a comparative 

kinetic formation of AgNPs using ultrasonic and conventional 

heating conditions were made and the result obtained indicates 

(Figure 3) that the rate of formation of AgNPs using ultrasonic 

condition was about 1.5 times better than that obtained using 

conventional heating. The result indicates the necessity of 

using CTAB as capping and stabilizing agent for AgNPs. 

nanoparticles. A future work is being under investigation to 

explore the viability of using AgNPs in different biomedical 

and photonic applications. 

Figure 2. TEM image of the as-prepared silver nanoparticles. 

ln(At-Af) 

1 

0 

-1 0 2 4 6 8 10 12 14 

-2 

-3 

-4 

-5 

-6 

-7 

-8 

yUS = -0.5891x + 0.2431 

R2 = 0.9943 

yCH = -0.3864x - 0.0064 

R2 = 0.9693 

Time (min) 

25 Times diluted sample Concentrated sample 

Figure 3. Plots of ln(A t -A f ) versus time of AgNPs formation under 

ultrasonic and conventional conditions. Prepartion condition:[Ag 

NO 3 ] = 2.5 mM; [glucose] = 2.5 mM; [CTAB] = 0.5 mM; [NaOH] = 

25 mM at 50 o C. 

*Corresponding author: elshishtawy@hotmail.com 

Figure 1. UV–vis spectrum of the as-prepared silver nanoparticles (25 

times diluted sample). Prepartion condition: [Ag NO 3 ] = 2.5 mM; 

[glucose] = 2.5 mM; [CTAB] = 0.5 mM; [NaOH] = 25 mM and 

reaction time was 20 min at 50 o C. 

In conclusion, uniform AgNPs have been successfully 

prepared in glucose/CTAB micelles. CTAB displays excellent 

properties in the preparation and stabilization of silver 

[1] N.G.Khlebtsov, L. A. Dykman, J. Quant. Spectrosc. Radiat. 

Transfer, 111, 1–35 (2010) and references cited therein. 

[2] R. Janardhanan, M. Karuppaiah, N. Hebalkar, T. N. Rao, 

Polyhedron, 28, 2522–2530 (2009) and references cited therein. 

[3] K.K. Ghosh, S. Kolay, J. Dispersion Sci. Technol., 29, 676–681 

(2008). 

[4] V. K. Sharma, R. A. Yngard, Y. Lin, Adv. Colloid Interface Sci., 

145, 83–96 (2009) and references cited therein. 

[5] Y. Yin, Z-Y. Li, Z. Zhong, B. Gates, Y. Xia,S. Venkateswaran, J. 

Mater. Chem., 12, 522–527 (2002). 

[6] N. R. Jana, L. Gearheart,C. J. Murphy, Chem. Commun., 2001, 

617–618. 




Structure of unsupported s mall Al nanoparticles; Molecular dynamics study 

Amir Chamaani 1 * Reza Darvishi Kamachali 2 Ehsan Marzbanrad 3 Alireza Aghaei 3 Yashar Behnamian 4 

1 New materials Department, Materials and Energy Research Center (MERC), P.O. Box 14155-4777, Tehran, Iran 

2 ICAMS, Ruhr-University Bochum, Bochum 44801, Germany 

3 Ceramic Department, Materials and Energy Research Center (MERC), P.O. Box 14155-4777, Tehran, Iran 

4 Chemical and Materials Engineering Department, University of Alberta Edmonton AB, T6G 2V4, Canada 

Abstract-A classical molecular dynamics simulation has been used to study the structure of unsupported small Al nanoparticles. Our results 

support the existence of a core-shell structure for the common truncated octahedron shape of Al nanoparticles, in terms of cohesive energy. 

However, there is a critical size below which the core-shell model cannot be applied, because the entire structure of Al nanoparticles below this 

size consists of merely a surface zone. 

The cohesive energy of nanoparticles determines their 

physical and thermodynamic properties, such as melting point, 

thermal stability and structure. Different models have been 

developed to account for cohesive energy, including the BE 

model [1], SAD model [2], Xie’s model [3] and so on. Most 

recently, the core-shell model [4-5] has been used to describe 

the structure of nanoparticles, in which the core of the particle 

is the same as the bulk material, and the surface shell is not 

caused by large dangling bonds. This concept has already been 

used in particular models to calculate the cohesive energy of 

metallic nanoparticles. In these models [1, 3], the entire 

structure of the nanoparticle is divided into two sections: a 

bulk and a surface zone. In other words, the cohesive energy 

of a nanoparticle is considered to consist of the cohesive 

energies of the bulk zone and of the surface zone. This study is 

a qualitative investigation of the structure of a common shape 

(truncated octahedron) for Al nanoparticles. 

In this study, the simulation was performed in NVT 

ensemble, using a semi-emp irical potential (glue) [6]. The 

expressions for and details of the potential used can be found 

in aforementioned paper. The primary structure of our 

nanoparticles was the truncated octahedron structure from an 

ideal Al crystal. The number of atoms in each nanoparticle 

was either 79, 201, 586, 1289, 2406 or 4033, with a particle 

size ranging from 1–5 nm. A bulk simulation of 864 Al atoms 

using periodic boundary conditions (pbc) was carried out to 

serve as a comparative case. The Verlet velocity algorithm 

was employed for motion equations, and a simple redial 

distribution counter function was used to calculate energy 

distributions. The systems were divided into the maximum 

possible redial layers for which every layer included at least 

one atom. 

The cohesive energy versus the distance to center of Al 

nanoparticles and the corresponding bulk value is shown in 

Figure (1). Unlike Al bulk (864 atoms with pbc), the cohesive 

energy of Al nanoparticles at a specific temperature is not 

constant: receding from center to surface, cohesive energy 

deviates from the bulk value. Indeed, internal atoms of large 

nanoparticles (nanoparticles which consist of more than 201 

atoms) have the bulk cohesive energy (-3.34 eV/atom), but 

surface atoms have a lower cohesive energy. Because of this 

separation between surface and interior atoms of large Al 

nanoparticles, the whole structure of large nanoparticles can 

be consider as having two parts: the core of the nanoparticle 

(the bulk zone), and the shell of the nanoparticle (the surface 

zone). The bulk zone in large nanoparticles consists of atoms 

which have the bulk cohesive energy, whereas surface zone 

atoms have a lower cohesive energy. Furthermore, as shown 

in Figure (1), with decreasing nanoparticle size, the bulk zone 

gradually decreases, and below a crit ical size it co mpletely 

disappears. Under our conditions, the critical size is about 1.6 

nm (201 atoms). Therefore, the entire structure of 

nanoparticles below the critical size consists of only a surface 

zone. These nanoparticles cannot be considered to have a 

core-shell structure and it is better to define them simply as 

surface materials. Recently, Qi [4-5], using mo lecular 

dynamics simulation, suggested that nanoparticles of all sizes 

can be regarded as having a core-shell structure, even small 

ones. However, according to our results, the structure of very 

small nanoparticles consists of only a surface zone; the 

cohesive energies of the two smaller nanoparticles (201 and 79 

atoms) are composed of only the cohesive energy of their 

surface zones. Consequently, the validity of the BE and Xie 

models, which are based on the core-shell model, is called into 

question for small nanoparticles. 

Figure 1. Cohesive energy of Al nanoparticles and bulk counterpart versus 

distance to center 

In summary, we investigated the structure of unsupported Al 

nanoparticles in terms of the radial distribution of cohesive 

energy. Our results show that the structure of nanoparticles 

can be described by the core-shell model. However, there is a 

critical size below which there is no bulk zone; the whole 

structure of nanoparticles of this size consists of the surface 

zone. Therefore, the validity of some cohesive energy models 

based on the core-shell model, such as the BE and Xie models, 

may not hold true for very small nanoparticles. 

*Corresponding author: amir_chamani@merc.ac.ir 

[1] W.H. Qi, B.Y. Huang, M.P. Wang et al., Phys. Lett. A 370, 494 

(2007). 

[2] W.H.Qi, M.P.Wang, J.Mater.Sci.letter. 21, 1743 (2002). 

[3] D Xie, M.P.Wang and W.H.Qi, j.phys.condens.matter.16, L401 

(2004). 

[4] W.H.Qi, B.Huang, M.P.Wang, J. comput.theor. nanoscience. 6, 

1546 (2009). 

[5] W.H. Qi, S.T. Lee, chem.phys.lett. 483, 247–249 (2009). 

[6] F. Ercolessi, J. B. Adams, Europhys. Lett. 26, 584 (1994). 




New stationary phase based on stabilized by o rga nic liga nds gold nanoparticles on silica surface for 

HPLC 

Irina Ananieva 1 *, Yana Elfimova 1 , Aleksandr Majouga 1 , Nikolay Zyk 1 and Oleg Shpigun 1 

1 Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia 

Abstract-New nanohybrid materials for HPLC based on gold nanoparticles supported on silica gel and stabilized by 

L-cystein, pyridine, citrate and ascorbic acid are synthesized. The possibility of separation of different model compounds in normal-phase 

mode of chromatography is studied. 

Nowadays gold nanoparticles attract a great deal of 

attention in a wide variety of scientific fields and technology 

due to their unique chemical and physical properties, which 

are directly related to chemical composition, size and 

surface structural characteristics of nanoparticles [1]. 

Materials based on gold nanoparticles have already found 

widespread application in medicine, optoelectronics, 

catalysis, biochemical sensors development [2]. It seems to 

be very perspective to use gold nanoparticles supported on 

oxide surface and stabilized by sulfur-bearing organic 

ligands for creation of new class of separation materials for 

liquid chromatography. Due to the specific structures and 

additional interaction between gold nanoparticles on the 

stationary phase surface and separating compounds a good 

resolution of different organic compounds may be achieved. 

The main advantage of these selectors is covalent attaching 

of organic ligands on the surface of nanoparticles that allows 

to synthesize a stable sorbent and obtain reproducible data. 

Nanohybrid materials have been synthesized by follow 

method. In the first one gold nanoparticles with the 10 nm 

size have been prepared by reduction H[AuCl 4 ] in an aqua 

solution by sodium citrate, and then they have been 

adsorbed on silica gel. In the last stage citrate-ions have 

been substituted for such organic ligands as L-cystein 

(column 1), pyridine, ascorbic acid. The scheme of the 

synthesized stationary phase with organic ligand is 

presented on Figure 1. 

aminopyridines had the greatest capacity coefficients on all 

stationary phases, and the retention rose with the growth of 

investigating compounds polarity because of the increasing 

of dipole-dipole interactions. The increase of capacity 

coefficients well correlates with the increase of of 

aminopyridines. The smaller capacity coefficient of 2- 

aminopyridine (pKa 6.67) in comparison with 3- 

aminopyridine (pKa 6.16) can be explained by steric 

hindrance of NH 2 -group. The greatest retention time of all 

model compounds was observed for the stationary phase 

containing pyridine as the modificator because of strong - 

Chromatogram of aminopyridine separation 

is presented on Figure 2. 

Figure 2. Chromatogram of separation of aminopyridines. Column 

1 (1004,0 mm) . Mobile phase: hexane/i-propanol 

(90/10). Injection volume 20 l. 1 - 2-amino-5-chlorinepyridine; 2 

- 2-amino-5-methylpyridine; 3 - 2-amino-4-methylpyridine; 4 – 2- 

aminopyridine. 

Figure 1. Layout view of the adsorption of modified gold 

nanoparticles on the silicon oxide’s surface. 

In order to estimate the retentive ability of prepared 

nanohybrid sorbents such model compounds as anilines, 

phenols, aminopyridines, some optically active compounds 

were used in normal-phase mode of HPLC. Previous 

research have shown that the optimum mobile phase was 

90% hexane/10% isopropanol. It was found that 

Obtained results show that new nanohybrid materials 

based on stabilized by L-cystein, pyridine and citrate gold 

nanoparticles on silica surface are very perspective for 

further investigation. 

This work was supported by the Russian Foundation for 

Basic Research (09-03-00519-). 

*Corresponding author: irishan@mail.ru 

[1] M. Brust, M. Walker, D. Bethell, D. Schiffrin, R. Whyman, J. 

Chem. Soc., Chem. Commun., 801-802 (1994). 

[2] Kimling J., Maier M., Okenve B., Kotaidis V., Ballot H., Plech 

A., J. Phys. Chem. B. 110 15700 (2006). 




L-cystein go ld nanoparticles on silica surface for HPLC separation 

Yana Elfimova 1 *, Irina Ananieva 1 , Aleksandr Majouga 1 , Nikolay Zyk 1 and Oleg Shpigun 1 

1 Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia 

Abstract-New nanohybrid material for HPLC based on gold nanoparticles supported on silica gel and stabilized by 

L-cystein is synthesized. The possibility of separation of -blockers and amino acids in different modes of chromatography is 

studied. 

Gold nanoparticles play an important role in applied 

science and technology because they exhibit unique 

chemical and physical properties which depend on their 

shape, size, and local environment [1]. Materials based on 

gold nanoparticles are widely used in the field of chemistry, 

biology, material science and physics. The dimensions of 

gold nanoparticles allow using them for the creation of a 

new class of separation materials for liquid chromatography. 

We suggest new sorbent based on the gold nanoparticles 

supported on silica gel and stabilized by L-cystein for the 

separation of different organic compounds including 

optically active compounds. 

Optically active compounds attract great attention because 

of their widespread application in many fields of science, 

particularly in pharmaceutics. Compounds that have optical 

isomers in many cases exhibit different pharmacological and 

toxicological properties. This fact has stimulated the 

application of enantiomerically pure products. -blockers 

play an important role among optically active compounds. 

-blockers are drugs that slow the heart rate, decrease 

cardiac output, lessen the force with which the heart muscle 

contracts and reduce blood vessel contraction. They do this 

by blocking beta-adrenergic receptors in various parts of the 

body. Another important class of optically active 

compounds is amino acids. Amino acids 

co-exist in biological liquids of living organisms though 

D- and L-isomers play different roles. That is why the 

problem of enantioseparation of different amino acids is 

very actual nowadays. HPLC has many applications in the 

fields of determination of amino acids. The commonly used 

method performance is the determination of amino acids as 

hydrophobic derivatives in reverse-phase mode on the 

hydrophobic stationary phase. In the present time much 

works in chiral separations have been directed to the 

development of new chiral selectors. 

Gold nanoparticles with average 10 nm size have been 

synthesized by reduction H[AuCl 4 ] in an aqua solution by 

sodium citrate, and then they have been modified by 

L-cystein. Prepared nanoparticles have been adsorbed on 

silica gel. The scheme of the synthesized stationary phase 

with L-cystein as organic lidand is presented on Fig.1. 

Obtained material has been tested for ability of 

-blockers 

and aminoacids. The best separation of aminopyridines was 

achieved in the normal-phase mode using 90% hexane/10% 

isopropanol as a mobile phase. The retention of 

aminopyridines rises with the growth of investigating 

compounds polarity because of the increasing of dipoledipole 

interactions. 

We studied t-blockers enantioseparation 

in normal-phase and polar-organic modes of 

chromatography. The best results were observed for 

pindolol at use of a mobile phase – acetonitrile / methanol / 

CH 3 COOH / triethylamine (60/40/0.2/0.2). 

The separation of amino acids was performed in the ion 

exchange variant of chromatography with 

spectrophotometric detection at 210 nm. We used 0.05M 

borate buffer (pH 7.7) as the mobile phase. Because a small 

molecule of L-cystein was used as a chiral selector the best 

enantioseparation was achieved for such a small molecules 

of amino acids as leucine and valine. Chromatogram of 

enantioseparation is presented on Fig.2. 

Figure 2. Chromatogram enantioseparation of pindolol. Column 

(100 . Mobile phase: 

acetonitrile/methanol/CH3COOH/threeethylamine (60/40/0,2/0,2). 

Injection volume 20 l. 

This work was supported by the Russian Foundation for 

Basic Research (09-03-00519-). 

*Corresponding author: elfimova_16@list.ru 

Figure 1. Layout view of the adsorption of modified gold 

nanoparticles on the silicon oxide’s surface. 

[1] A. Vasil’kov, S. Nikolaev, V. Smirnov, A. Naumkin, I. Volkov 

and V. Podshibikhin, Mendeleev Commun. 17, 268-270 (2007). 




Investigation of CdS Langmuir-Blodgett Thin Films by Using EFM Technique 

S.A. Klimova 1 , M. Yavuz 2 *, S.V. Stetsyura 1 ,M. Arslan 2 , E.G. Glukhovskoy 1 , S.B. Venig 1 , Y. Elerman 2 

1 University of Saratov State, Department of Nano- and Biomedical Technology, 410012, Saratov, Russia 

2University of Ankara, Department of Engineering Physics, Faculty of Engineering, 06100 Besevler, Ankara, Turkey 

Abstract- In this study, the CdS LB films with 

different pH values have been studied by EFM. The surface potentials of 

films were calculated from EFM phase-voltagee curves. It was found that surface potential and EFM phase decrease with 

increasing pH. 

Recently, structural investigations of Langmuir- 

Blodgett (LB) films are increased rapidly for various 

device applications ranging from biosensors to 

nanostructured electronic devices [1]. This is due to 

their precise thickness control and welll ordered 

structure. 

One extensively studied semiconducting 

material 

is CdS which is distributed in fatty acid. The 

electronic properties of LB films for different pH 

values (pH 3 and 8) were investigated by using 

Electrical Force Microscopy from NT-MDTT (Model: 

Solver Pro-M). Semi-contact imaging was 

done in 

height mode and some images are presented herein. 

For imaging, the scanning velocity 8.37 μm/s. A Pt 

coated cantilever was used and the cantilever’s freeinterleave 

resonant frequency was about 76 kHz. The 

scan lift height was 50 nm. In EFM – phase 

measurement for small force gradient the phase shift 

is; 

QdF 

arcsin 

 

kdz 

 

arcsin 

 

kdz 

2 

QdC 

2 

 

U 

 

2 

 

 

 

(1) 

where k is the spring constant (2 N/m) and 

Q is the 

quality factor (260) of the cantilever. 

In this study, the CdS LB films were investigated 

with different bias voltage (±7 V) by EFM. For 

obtaining surface potential from EFM measurements, 

we selected a bright point in topography image. Fig. 1 

is a plot of phase shifts at different biases. The data 

were fitted in the range of -5 V to +5 V using a least 

squares method to give the solid curve. 

The fit function used was 

2 

arcsin A V V 

0 

B 

 

where A represents the constant parameter 

(Q/2k)d 2 C/dz 2 , and B represents an offset to 

0 o when 

V=V 0 [2]. 

Table 1. Calculated A, B, and V 0 parameters for films 

pH 3 pH 8 

A (V -2 ) 3.42x10 -3 2.69x10 -3 

B ( o ) 0.0137 0.049 

V 0 (V) 0.579 -0.396 

For pH 3 and pH 8 samples, surface potentials (SP) 

and electrostatic force gradients (dF/dz) were 

calculated from the EFM phase data along a 0.45 μm 

length by using A, B, and V 0 parameters. Some amine 

groups are transformed from a positive charged 

species to a neutral charge, reducing surfactant- 

than the 

polymer interactions for pH values greater 

optimum [3]. According to EFM phase, 

surface 

potential and electrostatic force gradient curves, while 

the pH values were increasing, electrical properties 

decreased. 

*murat_yavuz59@yahoo.com 

[1]Swalen J. D., Allara D. L., Andrade J. D., 

Chandross E. A., Langmuir, 3, 393 (1987). 

[2]Lei C. H., Das A., Elliott M. and Macdonald J. E. 

IOP Nanotechnology 15, 627-634 (2004). 

[3]Stroeve P. and Hwa M. J., Thin Solid Films 284- 

285, 561-563 (1996). 

(2) 

Figure 1. Topography and EFM Phase-Voltage curve for (a) pH:3, and (b) pH:8 CdS LB films 




Preparat ion of mag netic nanoparticles with surfactant-controlled size and shape 

Aysel Bayrak 1 ,Sema Vural 1 ,Yavuz Çelik 1 , Turgay Seçkin 1 * 

1 Department of Chemistry, University of Inonu, Malatya, TR Türkiye 44280 

Abstract-This manuscript describes a simple one-pot reaction that affords cobalt iron oxide nanoparticles with unprecedented dimensions as 

large as 30 nm in monodisperse form. Unique synthetic method, which requires no multiple growth steps typical of other methods, utilizes the 

thermal decomposition of metal precursor complexes in the presence of speci 

and shape of these unusually large magnetic nanoparticles (MNPs) can be manipulated at will simply by adjusting the surfactant composition, 

leading to enhanced control over the dimensions of the nanoparticles because of the surface-differentiating in 

the produced ferrites were investigated by X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and vibrating sample 

magnetome-ter (VSM). 

Monodisperse magnetic nanoparticles (MNPs) with 

controlled sizes and shapes are of great interest for 

fundamental science and for both existing and developing 

technological applications. The morphology of MNPs strongly 

in 

especially their magnetic and electrical properties. More 

speci 

strongly depend on the size, shape, functionality, and 

magnetization of the MNPs. 

Cobalt ferrite (CoFe 2 O 4 ), with a partially inverse spinel 

structure, is one of the most important and most abundant 

magnetic materials. As a conventional magnetic material, with 

a Curie temperature (TC) around 793 K, CoFe 2 O 4 is well 

known to have large magnetic anisotropy, moderate saturation 

magnetization, remarkable chemical stability and a mechanical 

hardness, which make it a good candidate for the recording 

med ia[1,2]. CoFe 2 O 4 ultrafine powders [3–4] and films have 

attracted considerable attention for their wide range of 

technological applications such as transformer cores, 

recording heads, antenna rods, memory, ferro fluids, 

biomedical application and sensors, etc.. Over recent years, 

the chemical solution routes were successively emerging as 

effective, convenient, less energy demanding and less 

materials consuming synthetic techniques for material 

preparation. However, the hydrothermal route is one of the 

most used ones, owing to its economics and the high degree of 

compositional control. In addition, the hydrothermal synthesis 

requires neither extremely high processing temperature nor 

sophisticated processing. For example, ferrites can be prepared 

via the hydrothermal method at a temperature of about 150 C, 

whereas the solid-state method requires a temperature of 800 

C. Hydrothermal synthesis of several ferrites has been 

reported. However, there is little report on the synthesis of 

single-crystalline CoFe 2 O 4 nanorods. We present here a 

simple hydrothermal route without a preformed template for 

the preparation of CoFe 2 O 4 nanorods. 

The growth rate has been shown to be an important factor in 

controlling the shape of magnetic nanoparticles. Moreover, the 

wet chemical synthesis of monodisperse large nanoparticles 

typically involves precise control over the growth rate by 

using a high concentration of metal cation and controlling the 

strength of binding between various ligands and the emerging 

metal surface. 

In a typical procedure for the preparation of CoFe2O 4 , 1 g of 

cationic surfactant cetyltrimethylammonium bromide (CTAB) 

was dissolved in 35 ml deionized water to form a transparent 

solution. Then ferric chloride hexahydrate (FeCl3.6H2O) of 1 

g was added to the solution. After 10 min stirring, 

stoichiometric amount of CoCl 2 was introduced into the 

mixed solution under vigorous stirring. Deionized water was 

added to make the solution for a total volume of 40 ml, and 

pH of the solution was adjusted to 11.0. Before being 

transferred to a Teflon-lined auto-clave of 50.0 ml capacity, 

the solution mixture was pretreated under an ultrasonic water 

bath for 30– 40 min. Hydrothermal synthesis was carried out 

at 130 ºC for 15 h in an electric oven without shaking or 

stirring. Afterwards, the autoclave was allowed to cool to 

room temperature gradually. The black precipitate collected 

was washed with distilled water three times in an ultrasonic 

bath to remove any possible impurities. The solid was then 

heated at 80 ºC and dried under vacuum for 2 h. 

Figure 1. X-ray diffraction patterns of the prepared CoFe 2 O 4 

particles and nanorods via hydrothermal for 15 h without CTAB (a) 

andwith CTAB (b). 

The product morphology changes from tetrapods, nanorods, 

and nanoparticles as the reaction temperature increases from 

40 to 70 C with various surfactants. 

We note that monodisperse particles of this size represent an 

ideal compromise for many applications, offering the potential 

for both a strong magnetic moment and electrical properties. 

We also evaluated the key magnetic characteristics of our 

iron-manganese oxide nanoparticles. In particular, magnetic 

hysteresis loops and magnetic relaxation were measured for 

these particles at room temperature. The superparamagnetic 

nature of these particles is characterized by M-H hysteresis 

loop behavior at 290 K and rapid relaxation. 

*Corresponding author: 1Ttseckin@inonu.edu.tr 

[1] Mornet, S.; Vasseur, S.; Grasset, F.; Duguet, E.J. Mater. 

Chem.2004, 14, 2161. 

[2] Gleich, B.; Weizenecker, J.Nature2005,435, 1214. 

[3] Mannix, R. J.; Kumar, S.; Cassiola, F.; Montoya-Zavala, M .; 

Feinstein, E.; Prentiss, M.; Ingber, D. E.Nat. Nanotechnol.2008,3, 

36. 

[4] Weitschies, W.; Ko¨titz, R.; Bunte, T.; Trahms, L.Pharm. 

Pharmacol. Lett.1997,7,1. 




Preparat ion of mag netic nanoparticles with controlled morphology 

Aysel Bayrak 1 ,Sema Vural 1 , Turgay Seçkin 1 * 

1 Department of Chemistry, University of Inonu, Malatya, TR Türkiye 44280 

Abstract-Cobalt, Nickel and zinc ferrites nanoparticles have been synthesized using the hydrothermally technique. Effects of synthesis 

conditions on the crystal structure, crystallite size, lattice parameter, microstructure and magnetic properties of the produced spinel ferrites were 

investigated by X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). 

Since the beginning of this century, 2000, science and 

engineering has seen a rapid increase in interest for materials 

at the nano-scale. Nano-materials have attracted such a strong 

interest because of the physical, electronic, and magnetic 

properties resulting from their quantum size [1]. The potential 

for nano-technology is immensely diverse with potential 

applications in the fields of electronics, biomedical devices, 

energy applications, military uses, and waste management [2]. 

Nano-materials could be utilized to design nano-transistors, to 

develop and deliver medicines for locally treating diseases and 

ailments within the body, and for the creation new age 

weapons and armor for military applications [3]. Within the 

field of nano-materials under worldwide research is the subset 

of magnetic nanomaterials and magnetic nanoparticles. 

Magnetic nanoparticles are of great interest for researchers 

from a wide range of disciplines, including magnetic fluids, 

catalysis, biotechnology/biomedicine, magnetic resonance 

imaging, data storage, and environmental remediation. In 

recent years, simple and reproducible methods to synthesis 

magnetic nanocrystals with desired size, shape and selfassembly 

have drawn much attention due to its unique size 

dependant properties such as magnetic, optical, electronic and 

surface reactivity [2-3]. Insights into of these unique 

properties are not only important for fundamental 

understanding but also have technological importance. Among 

the nanocrystals, magnetic nanoparticles and its dispersions 

have been used in various fields such as biomedical [4], 

optical, electronics, chemical and mechanical. In addition, 

these nanoparticles serve as ideal systems for fundamental 

studies such as superparamagnetism, magnetic dipolar 

interactions and to understand molecular interactions at 

emulsion droplet interface and. 

There are many techniques for the synthesis of magnetic 

nano-particles including: micro-emulsion, hydrothermally 

synthesis, reduction of metal-salts, gas-phase reduction of 

meta l comp le xes, thermolysis of metal-poly mer co mple xes, 

and thermal decomposition of metal-carbonyl complexes. In 

this paper, the hydrothermally synthesis will be discussed 

because it is a technique which has successfully been utilized 

to synthesize magnetic nano-particles. 

In this study, we investigated the formation of magnetic 

oxide nanoparticles in a continuous hydrothermal reactor that 

allows us to essentially separate the effects of nucleation, 

growth, and agglomeration. Factors that affect the size, sizedistribution, 

and morphology of nanoparticles can then be 

isolated. We are particularly interested in using near-crit ical 

and supercritical water in the continuous hydrothermal 

environment because of the tunability of their properties by 

small changes in temperature and pressure. We have produced 

nanoparticles of, cobalt iron oxide (CoFe 2 O 4 ) nickel iron 

oxide (NiFe 2 O 4 ) and zinc iron oxide (ZnFe 2 O 4 ) 

In a typical procedure for the preparation of CoFe 2 O 4 , 1 g of 

cationic surfactant cetyltrimethylammonium bromide (CTAB) 

was dissolved in 35 ml deionized water to form a transparent 

solution. Then ferric chloride hexahydrate (FeCl 3 .6H 2 O) of 1 

g was added to the solution. After 10 min stirring, 

stoichiometric amount of CoCl 2 was introduced into the mixed 

solution under vigorous stirring. Deionized water was added to 

make the solution for a total volume of 40 ml, and pH of the 

solution was adjusted to 11.0. Before being transferred to a 

Teflon-lined auto-clave of 50.0 ml capacity, the solution 

mixture was pretreated under an ultrasonic water bath for 30– 

40 min. hydrothermal synthesis was carried out at 130 C for 

15 h in an electric oven without shaking or stirring. 

Afterwards, the autoclave was allowed to cool to room 

temperature gradually. The black precipitate collected was 

washed with distilled water three times in an ultrasonic bath to 

remove any possible impurit ies. The solid was then heated at 

80 C and dried under vacuum for 2 h. Other nanoparticles 

synthesized with the same method. 

Figure 1. M–H hysteresis loops of CoFe 2 O 4 ,NiFe 2 O 4 and ZnFe 2 O 4 

nanop articles 

Nickel zinc ferrites Ni x Zn 1x Fe 2 O 4 , nanoparticles have been 

successfully synthesized using the hydrothermally synthesis 

technique. The micrographs of nanoparticles show that they 

have agglomerated morphologies consist of nanosized 

spherical particles. 

*Corresponding author: tseckin@inonu.edu.tr 

[1] U. Ghazanfar, PhD Thesis, Punjab University, Pakistan, 2005. 

[2] A.C.F.M. Costa, A.P. Diniz, V.J. Silva, R.H.G.A. Kiminami, 

D.R. Cornejo,A.M. Gama, M.C. Rezende, L. Gama, J. Alloys 

Compd. (2008), 

[3] U.R. Lima, M .C. Nasar, R.S. Nasar, M.C. Rezende, J.H. Araújo, 

J. Magn. Magn. Mater. 320 (2008) 1666. 

[4] D.-L. Zhao, Q. Lv, Z.-M. Shen, J. Alloys Compd. 480 (2009) 

634. 




Nanoparticle Doped YBCO Films Prepared by Chemical Solution Deposition Method 

Isil Birlik, 1* Erdal Celik 1 and Bernhard Holzapfel 2 

1 Department of Metallurgy and Materials Engineering, Dokuz Eylül University, Izmir, 35160, Turkey 

2 Leibniz Institute for Solid State and Materials Research, Institute for Metallic Materials, Helmholtzstrasse 20, D-01069, Dresden, Germany 

Abstract— In the present work, a study of introducing BaZrO 3 nanoparticles inside the YBCO matrix as artificially pinning 

centers by chemical solution deposition method is presented. YBCO films with Zr doping have been prepared by the 

trifluoroacetate metal-organic deposition (TFA-MOD) method through acetate based precursor chemical powders 

and dissolving different amounts of Zr (IV)-penthanedionate into the precursor solution. Three different doped 

solutions were prepared with 6, 12 and 18 mol% BaZrO 3. These results prove this method is a promising technique 

for the nanostructuration of coated conductors. 

Chemical solution deposition methodologies have shown to 

be a low-cost way to the production of coated conductors and 

the most promising method for large scale applications. The 

performance of YBCO thin films especially for power 

applications are controlled by their critical current density 

under magnetic field conditions. They need to carry a high 

critical current density under high magnetic fields. An increase 

in coated conductor performance can be achieved by pinning 

of the quantized flux lines by nanoscale crystalline defects and 

impurities[1, 2]. The way for flux pinning in the YBCO 

structure can be the use of nanoparticles-modified substrate 

surfaces, mixing rare earth doping and introducing nano-sized 

BaMeO 3 particles in to the structure as artificial pinning 

centers. Among these approaches, BaZrO 3 (BZO) 

nanoparticles in YBCO thin films are one of the most popular 

ones which can prevent the vortex motion at high fields. The 

amount of dopant in the structure needs to be high enough to 

generate the density of defects, which is needed to enhance 

flux pinning in magnetic fields. However, excess amounts of 

this nonsuperconducting content can suppress the self-field and 

in-field J c values significantly [3]. 

and and scans were collected to determine the out-of-plane 

and in-plane alignments of the films respectively. Size of the 

BZO nanoparticles were estimated with the Scherrer formula. 

Surface morphology of films was observed by Scanning 

Electron Microscope (SEM) as shown in Figure 1. The critical 

transition temperature (T c ) and critical current density (J c ) of 

the films were measured by an inductive method. Transport 

measurements up to 6 T at 77 K on bridges of 0.8 mm length 

and 50 m width were carried out with a physical properties 

measurement system (PPMS). 

As a result, we showed that chemical solution deposition 

method lead to a significant improvement of pinning properties 

of the YBCO films suggesting that artificial pinning centers 

successfully generated. These results prove this method is a 

promising technique for the nanostructuration of coated 

conductors. 

This work was funded by the EU-FP6 Research Project 

”NanoEngineered Superconductors for Power Applications“ 

NESPA no. MRTN-CT-2006-035619. 

*Corresponding author: isil.kayatekin@deu.edu.tr 

[1] Strickland N M, Long N J, Talantsev E F, Hoefakker P, Xia J, Rupich M 

W, Kodenkandath T, Zhang W, Li X, Huang Y 2008 Physica C 468 183-189 

[2] Engel S, Thersleff T, Hühne R, Schultz L and Holzapfel B 2007 Applied 

Physics Letters 90 

[3] Chen Y, Selvamanickam V, Zhang Y, Zuev Y, Cantoni C, Specht E, 

Paranthaman M P, Aytug T, Goyal A and Lee D 2009 Applied Physics Letters 

94 

Figure 1: Surface morphologies of (a) pure and (b) 6 mol% BZO doped 

YBCO film. 

YBCO films with Zr doping have been prepared by the 

trifluoroacetate metal-organic deposition (TFA-MOD) method 

through acetate based precursor chemical powders and 

dissolving different amounts of Zr (IV)-penthanedionate into 

the precursor solution. Three different doped solutions were 

prepared with 6, 12 and 18 mol% BaZrO 3 . Film deposition on 

10 mm x 10 mm STO (100) single crystal substrate was 

performed by spin coating technique. We tried to show how 

nanoparticles density can be finely tuned through the control of 

dopant concentration. Spin coated samples were heat treated. 

X-Ray Diffraction (XRD) was carried out using a Philips 

diffractometer with Co K radiation to ascertain the phase 

purity of the undoped and doped films. BZO nanoparticles 

were detected in the doped YBCO films by x-ray diffraction 




Evaluation and characterization of nanocrystalline hydroxyapatite powder prepared by a sol–gel 

method 

Feray Bakan 1 *, Oral Laçin 1 and Hanifi Saraç 1 

1 Department of Chemical Engineering, Erzurum 25240, Turkey 

Abstract-A novel water-based sol-gel method to synthesize nano crystalline hydroxyapatite with calcium nitrate tetrahydrate and ammonium 

dihydrogenphosphate as starting calcium and phosphorous precursors is presented. The p hase transformations, composition and microstructural 

features in the nano crystalline samples were studied by thermo analytical methods (STA), infrared spectroscopy (IR), X-ray 

powder diffraction analysis (XRD) and transmission electron microscopy (TEM). It is proposed that the nano-structure of hydroxyapatite 

will have the best biomedical properties in the biomaterials applications. 

In recent years synthetic hydroxyapatite, 

[Ca 10 (PO 4 ) 6 (OH) 2 ], has been recognized as one of the 

most important bone substitute materials in orthopedics 

and dentistry because of its chemical and biological 

similarity to the natural Ca phosphate mineral present in a 

biological hard tissue Different type of clinical 

applications of hydroxyapatite involve repair of bone 

defects, bone augmentation, as well as coating for human 

body metallic implants, proteins purification, drug delivery 

agent for anti-tumor and antibodies in the treatment of 

osteomyelitis and HA has also been used as an acidic 

catalyst for different chemical reactions [1]. All these HA 

specific applications are dependent on properties such as 

particle size, dimensional anisotropy, morphology, real 

microstructure, etc. which are of critical importance for 

optimization and applications. 

Several different HA synthesis techniques have been 

developed due to its growing importance and applications 

[2,3]. Main techniques being used are solid-state reaction 

[4], co precipitation [5,6], and hydrothermal method [7] 

and sol–gel route [8–9]. Among these methods, an 

increasing attention has been given to the sol–gel method, 

due to advantages such as: the possibility of mixing the 

calcium and phosphorus precursors at a molecular level 

and that it requires incomparably milder conditions for the 

synthesis process, compared with the conventional 

methods [10]. 

In this study, hydoxyapatite (HA) nanoparticles with 

approximetaly 20 nm diameter was synthesized using a 

novel water-based sol-gel route with calcium nitrate 

tetrahydrate (Merck) and ammonium dihydrogenphosphate 

(Carlo Erba) as starting calcium and phosphorous 

precursors respectively. The effects of reaction 

temperature, reaction time, aging time and sintering 

temperature on particle size were carried out and results 

were compared with literature findings. The crystalline 

degree and morphology of the obtained nanopowder are 

dependent on the sintering temperature. 

Fourier transform infrared (FTIR) spectroscopy analysis 

was carried out to identify the functional groups. In order 

to investigate the thermal behaviour of the particles STA 

analysis was carried out. Transmission electron 

microscope (TEM) was used to observe the particle 

morphology and size of the powders. Phase analysis was 

performed by X-ray diffractro metry (XRD) and the mean 

crystallite size of the particles (n m), was calculated fro m 

the XRD line broadening measurement using the Scherrer 

equation [11]. 

The prepared crystalline nanopowder HA is able to 

improve the contact reaction and the stability at the 

artificial/natural bone interface for medical applications. 

[1] Sebti, S., Tahir, R., Nazih, R., Saber, A., & Boulaajaj, 

S.,2002. Hydroxyapatite as a new solid support for the 

Knoevenagel reaction in heterogeneous media without solvent. 

Applied Catalysis A, 228, 155–159. 

[2] J.W. Evans, T.L.C. De Jonge, Production of Inorganic 

Materials, Macmillan, New York, 1991. 

[3] D.W. Hess, K.F. Jensen, T.J. Anderson, Rev. Chem. Eng.3 

(1985) 130. 

[4] R. Ramachandra Rao, H.N. Roopa, T.S. Kannan,J. Mater. Sci. 

Mater. Med. 8 (1997) 511. 

[5] A. Cuney Tas, F. Korkusuz, M. Timicin, N. Aakas,J. Mater. 

Sci. Mater. Med. 8 (1997) 91. 

[6] S.H. Rhee, J. Tanaka, J. Am. Ceram Soc. 81 (1998) 3029. 

[7] H.S. Liu, T.S. Chin, L.S. Lai, S.Y. Chiu, K.H. Chung, 

C.S.Chang, M.T. Lui, Ceram. Int. 23 (1997) 23. 

[8] P. Layrolle, A. Ito, T.S. Teteishi, J. Am. Ceram Soc. 81 

(1998) 1421. 

[9] T.K. Anee, M. Ashok, M. Palanichamy, S.N. Kalkura, Mater. 

Chem. Phys. 80 (2003) 725. 

[10] D.M. Liu, T. Troczynski, W.J. Tseng, Biomaterials 22 

(2001) 1721. 

[11]Jenkins, R., Snyder, R.L., 1996. Introduction to X-ray 

Powder Diffractometry. John Wiley and Sons, New York. 

* Corresponding author:0Tferaybakan@atauni.edu.tr 




Preparation of aluminum-doped zinc oxide (AZO) nano particles by hydrothermal synthesis 

Nadir Kiraz 1,2,* , Esin Burunkaya 1,2 , Ömer Kesmez 1,2 , Zerin Yeil 1,2 , Meltem Asiltürk 3 , Erturul Arpaç 1,2 

1 Department of Chemistry, Akdeniz University, 07058, Antalya, Turkey 

2 NANOen R&D Ltd., Antalya Technopolis, Akdeniz University Campus, Antalya, Turkey 

3 Prof.Dr.Hikmet Saylkan Research and Development Laboratory for Advanced Materials, nönü University 44280, Malatya, Turkey 

Abstract-Aluminum doped zinc oxide (AZO) nano particles were synthesized by hydrothermal method. Synthesized particles have 

amphiphilic character, thus they can be dispersed in both polar and non-polar media. The obtained powder is intended to be utilized in the 

form of thin films for optical purposes, due to the high refractive index of AZO. 

Zinc oxide (ZnO) has attracted scientific and 

technological attention due to its employment in various 

fields such as in varistors [1], in piezoelectric transducers 

[2], in organic light emitting diodes [3], in gas sensing 

devices [4], as transparent conductive oxide in solar cells 

[2]; in addition to its widespread utilization in paints and 

ceramics. Doping of ZnO with impurities such as Al, In 

and Ga results in formation of an n-type semiconductor 

and decreases electrical resistivity [5]. Aluminum doped 

ZnO (AZO) is taking the place of indium tin oxide (ITO) 

in many applications due to its lower cost, non-toxicity, 

chemical and thermal stability [5,6]. Another attractive 

property of AZO is its high refractive index [7]. 

Aluminum doped zinc oxide (AZO) nanometric 

particles were synthesized by hydrothermal method. 

Aluminum nitrate, aluminum sec-butoxide and zinc nitrate 

were used as the starting materials and n-propanol, 2- 

buthanol were used as solvents. Ratio of Al 2 O 3 in ZnO was 

kept at 10 wt%. Reaction was conducted in a Teflon 

autoclave at 175-225 o C for 5 h. Ratios of alcohol, H 2 O 

and HCl to zinc nitrate were altered and 6 different sets of 

parameters were investigated. Obtained products were 

subjected to powder-XRD, particle size measurement and 

TEM examination. Single phase AZO particles smaller 

than 10 nm were obtained when alcohol to zinc nitrate 

ratio was increased from 10 to 35. 

Figure 2. TEM image of AZO-6 particles 

This provided preserving the nanometric particle size of 

the ZnO powder. Synthesized particles have amphiphilic 

character; therefore it is possible to disperse them in both 

polar and non-polar media. They can be utilized in the 

form of thin films for optical and electronic purposes. 

This study was support by NANOen. We thank Nedim 

ERNÇ for his contrubition. 

*nadirkiraz@akdeniz.edu.tr 

Figure 1. XRD patterns of the products obtained from the 

systems 

The aim of this study is to synthesize crystalline AZO 

nanoparticles through a hydrothermal route, without an 

additional calcination step for crystallization. For this 

purpose; ratios of acid, water and alcohol to zinc nitrate 

were altered in addition to alteration of synthesis 

temperature. Crystalline ZnO could be obtained as a result 

of hydrothermal treatment at 225 o C, thus calcination step 

at higher temperatures was eliminated. 

[1] Gupta, T. K., 1990. Application of zinc-oxide varistors, J. 

Am. Ceram. Soc., 73:1817-1840 

[2] Vale, G. G., Hammer, P., Pulcinelli, S. H., Santilli, C. V., 

2004. Transparent and conductive ZnO : Al thin films prepared 

by sol-gel dip-coating, J. Eur. Ceram. Soc., 24:1009-1013 

[3] Kim, H., Horwitz, J. S., Kim, W. H., Makinen, A. J., Kafafi, 

Z. H., Chrisey, D. B., 2002. Doped ZnO thin films as anode 

materials for organic light emitting diyotes, Thin Solid Films, 

420-421, 539-543 

[4] Baruwati, B., Kumar, D. K., Manorama, S. V., 2006. 

Hydrothermal synthesis of highly crystalline ZnO nanoparticles: 

A competitive sensor for LPG and EtOH Sensor. Actuat., 

119:676-682 

[5] Yim, K., Lee, C., 2006. Optical properties of Al-doped ZnO 

thin films deposited by two different sputtering methods, Cryst. 

Res. Technol., 41:1198-1202 

[6] Singh, A. V., Kumar, M., Mehra, R. M., Wakahara, A., 

Yoshida, A., 2001. Al-doped zinc oxide (ZnO:Al) thin films by 

pulsed laser ablation, J. Indian Inst. Sci., 81: 527-533 

[7] Schuler, T., Aegerter, M. A., 1999. Optical, electrical and 

structural properties of sol gel ZnO : Al coatings, Thin Solid 

Films, 351:125-131 




Effect of tert-Amine Catalysts on Preparation of nano-SiO 2 Particles and 

Antireflective Films via Sol-Gel Method 

Ömer Kesmez a,b ,*, Esin Burunkaya a , b , Nadir Kiraz a , b , Zerin Yeil a , b , Erturul Arpaç a , b 

a Akdeniz University, Faculty of Science and Art, Department of Chemistry 07058 Antalya, Turkey 

b NANOen R&D Ltd., Antalya Technopolis, Akdeniz University Campus, 07058Antalya, Turkey 

Abstract-SiO 2 sols were prepared by hydrolysis and condensation reactions of tetraethyl orthosilicate through a one step acid or a two step 

acid+base catalysis process, in the presence of nitric acid and 4 different base catalyzers, namely trimethylamine, triethylamine, 

tripropylamine and tributylamine. Effect of sol aging duration on film thickness and light transmittance properties of the films was 

investigated with respect to type of base catalyst. 

Silica (SiO 2 ) particles are utilized in various fields such 

as biotechnology, pharmacy, microelectronics [1], 

mechanical polishing; as well as in catalysts, ceramics, 

coatings, pigments, tribological applications [2] and as 

filler material in polymers [1,3,4]. One important 

application area of SiO 2 nanoparticles is antireflective 

(AR) coatings. AR films, which reduce the reflective 

losses of light, have been used in applications such as shop 

windows, video display panels, cathode ray tubes and solar 

panels [5]. 

Present study focuses on SiO 2 particle size control by 

changing the amine (base) catalyst type and concentration 

in sol-gel synthesis. For this purpose, 4 types of amines, 

namely trimethylamine (TMA), triethylamine (TEA), 

tripropylamine (TPA) and tributylamine (TBA) were 

utilized at 3 different concentrations. Size distribution of 

the SiO 2 particles and light transmittance of the films 

obtained from these particles were measured in 

predetermined durations, thereby effect of aging duration 

on these properties was investigated with respect to type of 

base catalyst. 

In order to investigate the optical properties, 2mm thick, 

5x10 cm soda-lime glass substrates were coated by dipping 

them into the SiO 2 colloidal sol and withdrawing at 200 

mm/min speed. After drying in air at room temperature, 

the coated glass samples were cured at 450 o C for 30 min. 

Glass samples containing nanometric SiO 2 films were 

subjected to optical and morphological analyses. 

. 

from E3 system was 1.83 nm. The average roughness 

results were in parallel with the results of particle size 

measurements. 

In summary effect of 4 different base catalyzers, namely 

trimethylamine, triethylamine, tripropylamine and 

tributylamine on particle growth of SiO 2 in sol-gel 

synthesis was investigated. Particle growth was seen to be 

faster in the amine catalyzed systems than in the one step 

acid catalyzed system. The highest rate of growth was in 

triethylamine catalyzed system. Thicknesses of the films 

obtained by dip coating from the prepared sols were 

measured to be in the range of 100-400 nm. Films obtained 

from one step acid catalyzed system presented an increase 

in the light transmittance of 4.8 percent; whereas 

acid+base catalyzed films provided an increase of about 

5.7 percent in the first 4 days of aging. 

Technical and financial support of NANOen is gratefully 

acknowledged. 

*Corresponding author: omerkesmez@akdeniz.edu.tr 

[1] Y. Sun, Z. Zhang, C.P. Wong, Study on mono disperse 

nano-size silica by surface modification for underfill 

applications, J Colloid. Interf. Sci. 292 (2005) 436-444. 

[2] X. Li, Z. Cao, Z. Zhang, H. Dang, Surface modification in 

situ of nano-SiO 2 and its structure and tribological properties, 

Appl. Surf. Sci. 252 (2006) 7856-7861. 

[3] I.A. Rahman, M. Jafarzadeh, C.S. Sipaut, Synthesis of 

organo-functionalized nanosilica via a co-condensation 

modification using -aminopropyltriethoxysilane (APTES), 

Ceram. Int. 35 (2009) 1883-1888. 

[4] K. Nozawa, H. Gaihanou, L. Raison, P. Panizza, H. 

Uskihi, E. Sellier, J.P. Delville, M.H. Delville, Smart control of 

monodisperse sober silica particles: effect of reactant addition 

rate on growth process, Langmuir 21 (2005) 1516-1523. 

[5] S. Lien, D. Wuu, W. Yeh, J. Liu, Tri-layer antireflection 

coatings (SiO 2 /SiO 2 - TiO 2 /TiO 2 ) for silicon solar cells using a 

sol-gel technique, Sol. Energ. Mat. Sol. C. 90 (2006) 2710– 

2719. 

Figure 1. AFM images and line profiles of E1 and E3 systems 

after 1 day of sol aging. [1] 

AFM figures of the films obtained form E1 

(concentration of TEA is 0,214 mole: 150 g SiO 2 sol) and 

E3 (concentration of TEA is 0,374 mole: 150 g SiO 2 sol) 

systems after 1 day of aging are presented in Figure 1. It 

can be seen that particle size of the film obtained from E3 

system is much larger than that of the film obtained from 

E1. The effect of amine concentration can be clearly seen 

in these figures. The particle size of SiO 2 is seen to 

increase with increasing amine concentration. The rms 

roughness of the film obtained from E1 system was 

determined as 1.37 nm whereas that of the film obtained 




Antibacterial and Anticorrosive Glassy Films Prepared on Surface by Sol-Gel Method 

Zerin Yeil 1,2,* , Ömer Kesmez 1,2 , Esin Burunkaya 1,2 , Nadir Kiraz 1,2 , Erturul Arpaç 1,2 

1 Akdeniz University, Faculty of Science and Art, Department of Chemistry 07058 Antalya, Turkey 

2 NANOen R&D Ltd., Antalya Technopolis, Akdeniz University Campus, 07058Antalya, Turkey 

Abstract— Preparation and characterization of glass films consisting of SiO 2 , Li 2 O, Na 2 O, K 2 O or MgO in varying 

compositions on stainless steel substrates by sol-gel method. Silver nitrate was also introduced into the sols for obtaining 

antibacterial effect. Obtained films had high adherence to the substrates and they were also durable in acidic, basic or NaCl 

environments. They also present a powerful antibacterial effect against E. coli. 

Stainless steels (SS) are an important of class 

alloys and are often used in many fields such as 

automotive, construction, nuclear, chemical and 

food industries. However, corrosion at atmospheric 

conditions is the major problem for some stainless 

steels. Additionally, for applications of stainless 

steel as kitchenware, medical apparatus and 

facilities of food processing, the existing and 

breeding of microorganism on the surface of 

stainless steel products do not meet health criteria. 

Stainless steel is known to be affected by 

microbiologically induced corrosion (MIC) attack 

[1,2]. Usually, MIC consists of adherence of 

bacteria or microorganisms to the surface of a 

material and alteration of the composition of the 

material [1]. Recently, researchers have focused on 

this area, and ways for preventing MIC have been 

suggested. Baena and co-workers [3] have 

demonstrated that incorporation of Cu and Ag may 

add antibacterial property to stainless steel. 

Sreekumari et al. [4] has found that Ag is more 

effective than Cu and Ni. Zhao et al. [5] has 

suggested that surface ion-implantation using N + , 

O + and SiF 3 + can be effective in inhibiting the 

bacterial adherence. Nanostructure has also been 

shown to be effective against induced corrosion 

attack [1]. 

The aim of this work was to obtain a hard, 

sctracth and corrosion resistance, and antibacterial 

thin films on SS substrates. 

Stainless steel substrates were coated with the 

prepared coating solution by spin coating method. 

The coated substrates were cured at 200-350 o C for 

2-3 h. 

Figure 1. Surface photographs of (b) glass film coated 

stainless steel (a) uncoated stainless steel after corrosion 

test. [1] 

stainless steel having glassy coating slightly 

corroded at the end of 22 day period (Fig.1b). 

a 

Uncoated Surface 

b 

Coated Surface 

Figure 2. The bacterial test results for E.coli are shown 

in Figure. 

In summary homogonous films having 300 ± 20 

nm thickness were formed by spin coating. 

Obtained films were scratch resistant and also 

durable in acidic, basic or NaCl environments. The 

films containing 3 % AgNO 3 was found to have a 

powerful antibacterial effect against E. coli. 

*Corresponding author: zerinyesil@hotmail.com 

[1] Lo KH, Shek C H, Lai JKL (2009) Recent 

developments in stainless steels. Mat. Sci. 

Eng. R-Reports 65: 39-104. 

[2] De Damborenea JJ, Cristóbal AB, Arenas MA, 

López V, Conde A (2007) Selective dissolution of 

austenite in AISI 304 stainless steel by bacterial 

activity. Materials Letters 61: 821-823. 

[3] Baena M, Marquez MC, Matres V, Botella J, 

Ventosa A (2006) Bactericidal activity of copper and 

niobium-alloyed austenitic stainless steel. Current 

Microbiology: 53, 491-495. 

[4] Sreekumari KR, Nandakumar K, Takao K, 

Kikuchi Y (2003) Silver containing stainless steel as a 

new outlook to abate bacterial adhesion and 

microbiologically influenced corrosion. ISIJ 

International 43 (1): 1799 2806. 

[5] Zhao Q, Liu Y, Wang C, Wang S, Peng N, Jeynes 

C (2008) Reduction of bacterial adhesion on ionimplanted 

stainless steel surfaces. Med. Engin. Physic 

30 (3): 341- 349. 

The results of NaCl corrosion tests are shown in 

Figure 1. It can be seen that the uncoated stainless 

steel was severely corroded in 24 h (Fig.1a), but 




Synthesis and surface modification of magnetic nanoparticles for Hemoglobin immobilization 

Keziban Atacan 1 * and Mustafa Ersoz 1 

1 Department of Chemistry, Selcuk University, Konya 42075, Turkey 

Abstract-We aim at the processes of immobilization of Hemoglobin via the silane coupling agent and the subsequent cross-linking with 

glutaraldehyde. Then, characterization of stepwise changes of nanoparticles were carried out. 

In the field of biotechnology and biomedicine preparation 

and processing of magnetic nanoparticles have been motivated 

for the last several decades due to their strong magnetic 

property and lob toxicity. Magnetic nanoparticles has many 

applications in biological and medical fields, such as the 

immobilization of proteins, peptides, and enzymes [1], 

bioseparation [2], immunoassays [3], drug or gene delivery 

[4], magnetic resonance imaging (MRI) [5], etc. 

*Corresponding author: keziiiban@gmail.com 

[1] C. Xu, K. Xu, H. Gu, X. Zhong, Z. Guo, R. Zheng, X. Zhang, B. 

Xu, J. Am. Chem. Soc.126, 3392 (2004). 

[2] P.S. Doyle, J. Bibette, A. Bancaud, J. Viovy, Science 295, 2237 

(2002). 

[3] D. Wang, J. He, N. Rosenzweig, Z. Rosenzweig, Nano Lett. 4, 

409 (2004). 

[4] J. Won, M. Kim, Y.W. Yi, Y.H. Kim, N. Jung, T.K. Kim, Science 

309, 121 (2005). 

[5] J.M. Perez, L. Josephson, T. O’Loughlin, D. Hçgemann, R. 

Weissleder, Nat. Biotechnol. 20, 816 (2002). 

Figure 1. Magnetite nanoparticle modified with APTES for 

Hemoglobin immobilization 

In this study, we have prepared iron oxide particles using 

molar ratio of Fe3+:Fe2+ = 1.75:1. The aminosilane agent of 

aminopropyltriethoxysilane (APTES) is considered as a 

candidate for modification on the surface of Fe3O4 NPs 

directly, for the advantages of the biocompatibility as well as 

high density of surface functional group of –NH2, allowing 

for connecting to other targeting biomolecules. In the paper, 

the APTES/Fe3O4 NPswere prepared with coprecipitation 

method, and then the amino-functionalized magnetic NPs 

were activated by using glutaraldehyde (GA) method. 

Hemoglobin was selected as a model protein to covalent 

immobilize on the magnetic NPs (Figure 1). 

The morphology and properties of these magnetic NPs were 

examined by Fourier transform infrared spectroscopy (FTIR), 

thermal gravimetric analysis (TGA) and magnetization 

measure ment. Displaying immobilization of hemoglobin to 

modified magnetic NPs, high saturation magnetization, the 

superparamagnetic Hemoglobin modified Fe3O4 NPs are of 

significance for magnetic applications in various bioprocesses, 

biomedical devices and biomedicine. 




Modeling of Atomic Evol utions in Equiatomic FeCo–Au Nanoalloys 

Muratahan Aykol, 1 * Amdulla O. Mekhrabov 1 and M. Vedat Akdeniz 1 

Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06531, Turkey 

1 

Abstract-In this study, influences of varying particle size and shape on atomic ordering of equiatomic B2-type FeCo nanoalloys with Au 

additions are revealed as a function of temperature by pseudopotential theory combined with Monte Carlo simulation. The bulk limit is 

determined as 5 nm above which long range order does not differ much from that of bulk alloy, but due to free boundaries, all nanoalloys show a 

diffuse B2-disorder transition (ODT), in contrast to the well defined ODT temperature of ~1000 K of bulk FeCo. When alloyed with 

Au, B2rface-initiated 

disordering effect. In addition, Au atoms tend to segregate near particle surface as degree of order diminishes. 

FeCo nanoparticles with very high magnetic moments have 

potential use in biomedical applications such as drug delivery, 

hyperthermia treatment of cancer and magnetic resonance 

imaging. Although synthesis of FeCo nanoparticles with 

controllable size and shape distributions [1,2] is made 

possible, degree of retained long range order (LRO) and 

nature of order disorder transition (ODT) still remain intact 

[3]. Magnetic anisotropy can be significantly affected by the 

LRO, which is controlled by particle size, shape and thermal 

history. Moreover, to overcome the biocompatibility issues, 

particles are generally coated by Au atoms, which can also 

alter the LRO significantly. 

Canonical ensemble Monte Carlo (MC) method with a rigid 

B2 lattice and an Ising-type Hamiltonian being composed of 

ordering energies of pairs are utilized to reveal the response of 

degree of LRO to varying particle size and shape in near 

equiatomic B2-(Fe 0.5 Co 0.5 ) 100-X Au X nanoparticles (a = 2.87 

Å) from room temperature to higher temperatures. The 

exchange energies of atoms (ordering energies) are evaluated 

via pseudopotential theory [4] and its combination with MC 

methodology was successfully applied to bulk FeCo-V alloys 

by the author’s group recently [5]. First five coordination 

spheres are taken into account since exchange interactions are 

relatively weak in FeCo system in the first coordination 

sphere. Bulk simulations involve periodic boundaries while 

nanoparticles have free boundaries and no additional treatment 

was conducted for surface potentials. The number of MC-steps 

to attain equilibriu m varies for each particle, ranging between 

10 4 and 10 7 steps. Since the quality of generated random 

numbers is of utmost importance in MC simulations for the 

convergence of the system, an extremely powerful pseudorandom 

number generator of periodicity of 2 19377 called 

Mersenne-Twister was utilized for generation. ODT 

temperature (T odt ) was determined from inflection point of 

LRO vs. T plots. 

In pure FeCo nanoparticles, T odt drop is not extensive (See 

Figure 1) as also experimentally observed by Turgut et al [2]. 

Xu and Wang [1] synthesized FeCo-Au nanoparticles in which 

a FeCo core – Au shell type structure exists, but there is 

considerable amount of Au dissolved in the core as observed 

from their concentration profiles. Thus, nanoparticles are 

supersaturated with Au. The result of such Au supersaturation 

in B2-FeCo nanoparticles is shown in Figure 1. Since a finite 

system cannot show a distinct phase transition thus LRO of 

particles show diffuse responses to temperature, T odt 

decreasing with decreasing particle size. Au has a strong 

disordering effect on B2-FeCo structure as also shown in 

Figure 1. Cubic particles have a higher disordering tendency 

with increasing Au content. 

There is a great tendency of Au-atoms to locate near surface 

of particles. When LRO is lost, Au-self-clustering increases 

inside particles. In cubic particles, Au atoms show higher 

surface segregation tendencies. This might be beneficial for 

Au coating. However, it seems that if nanoparticles are Audoped 

with supersaturation, due to long range interactions 

present, Au atoms cannot escape to surfaces readily as 

expected. They tend to segregate near surface but cannot form 

a layer over surface. This phenomenon becomes more clarified 

since even at high temperatures which lacks the LRO and 

avoids any preferential site occupation for Au, a layer 

formation is hindered for entrapped Au and a clustering 

slightly inwards form the surface forms up. 

Figure 1. ODT temperatures (T odt ) for cubic and spherical FeCo 

nanoparticles with varying Au contents and dimensions. “Size” is 

edge length for cubes and diameter for spheres. 

The outcome of the current study can be summarized as 

follows. First of all, rate of loss of order with increasing Audoping 

is very high and no LRO can be expected if dissolved 

Au is more than ~6 at.%. For all part icles, T odt decreases with 

decreasing particle size but particles larger than 5 nm have 

ODT behavior not much different than corresponding bulk 

alloys. Cubic particles are much more disorderable than 

spherical ones, due to sharp corner defects. In the ordered 

states, Au atoms prefer Fe sites since Co-Au interactions are 

stronger. Moreover, if the synthesis of FeCo-Au nanoalloys 

employs a state which is Au-supersaturated, Au atoms tend to 

segregate near surface but may not escape outside easily due 

to long range interactions. This may also cause Au leakage 

from shell to core in Au-coated nanoparticles and result in loss 

of LRO. These should be taken into account in direct synthesis 

of FeCo-core/Au-shell type particles for biocompatibility and 

organic molecule attachments. 

*Corresponding author: e129665@metu.edu.tr 

[1] Y. Xu and J. Wang, Appl. Phys. Lett. 91, 233107 (2007). 

[2] Z. Turgut et al., J. Appl. Phys. 81, 4039 (1997). 

[3] A. Hütten et al., J. Magn. Magn. Mat. 293, 93 (2005). 

[4] A.O. Mekhrabov and M.V. Akdeniz, Acta Mater. 47, 2067 

(1999). 

[5] M . Aykol, A.O. Mekhrabov and M. V. Akdeniz, Intermetallics, in 

press (2010). 




Preparation of zinc nitride (Zn 3 N 2 ) nanopowders and their optical properties. 

Waheed S. Khan * , Chuanbao Cao 

Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, P. R. China 

Abstract- Zinc nitride (Zn 3 N 2 ) nanopowders were prepared by nitridation of aqueous ammonia treated zinc precursor under ammonia 

gas reaction (150 sccm) at 600 o C for 120 minutes inside horizontal tube (HT) furnace. The as-prepared product was characterized by 

XRD, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Using Scherrer formula, particles size of 

nanopowders was found to be 40-50 nm. Room temperature photoluminescence (PL) spectrum exhibited a broad ultraviolet (UV) 

emission band at 389 nm corresponding to near band edge emission of zinc nitride. These studies indicated the potential of the zinc nitride 

for applications in the UV-light emitting devices. 

Over the past few years, zinc nitride (Zn 3 N 2 ) has attracted 

much research focus due to its n-type conduction, high 

electron mobility of about 100 cm 2 V -1 s -1 at room 

temperature [1], wide band gap of 3.2 eV [2-3] and its use as 

channel layer in TTFTs [4]. The other most important aspect 

associated with zinc nitride is its conversion into p-type ZnO 

[5]. The band gap of zinc nitride has been a controversial 

issue as it has no single agreed value but different values 

ranging from 0.9 eV [6] to 3.2 eV [2]. One main reason of 

this variation is different preparative routes of zinc nitride. 

Practical applications of Zn 3 N 2 demand the resolution of this 

controversy. It is comparatively a new material and 

researchers have started exploring its electronic, optical and 

electrical properties since 1993. Most of the stress on zinc 

nitride work has been on its thin film/polycrystalline structure 

and few reports can be found on nanostructured zinc nitride 

[3, 7]. 

In the present work, we report the synthesis, 

characterization and optical properties of Zn 3 N 2. About 2 

gram zinc powder (99.9%) mixed with aqueous ammonia was 

loaded in alumina boat and shifted to the centre of the 

horizontal tube (HT) furnace. The precursor was heated at 

600 o C for 2h under NH 3 gas flow of 150 sccm. A black color 

product was obtained in the boat on cooling to room 

temperature. The crystal structure and phase purity were 

tested by XRD analysis. All the diffraction peaks in XRD 

spectrum of black powder were indexed to the cubic 

structured zinc nitride (Zn 2 N 3 ) with lattice parameter a=0.976 

nm matching very well with that given in JCPDS data (Card 

No. 035-0762). No other phase like Zn, ZnO was observed in 

the product. The particle size of zinc nitride nanopowders 

was calculated by using Scherrer‘s equation with the help of 

XRD data. Energy dispersive x-ray spectroscopy (EDS) 

exhibited the presence of zinc and nitrogen in the product. A 

small peak of oxygen was also observed in EDS possibly due 

to the inclusion of oxygen on the surface while measurement 

procedure. 

Figure (a) presents SEM image of a particular portion of zinc 

nitride product prepared at 600 o C under ammonia gas flow 

for 120 minutes. From SEM micrographs, it can be clearly 

observed that zinc nitride consists of nanoparticles with 

average dimensions much less than 100 nm which is very 

close to the values calculated by Scherrer formula. 

Room temperature PL emission spectrum of Zn 3 N 2 

nanopowders measured at an excitation wavelength of 325 

nm using Xe lamp source is shown in Figure (b). The 

spectrum exhibits a very prominent and broad peak at 389 nm 

in ultraviolet (UV) region which corresponds to band gap of 

Zn 3 N 2 . This value is very close to the reported values of 3.2 

eV [2, 3] estimated by PL spectra. The UV band at 389 nm 

Figure: (a) SEM image of zinc nitride nanopowders. (b) Room 

temperature PL spectrum of Zn 3 N 2 product. 

riginates from near band-edge transition of cubic zinc nitride 

[3] and can possibly be attributed to the excitonic emission 

caused by radiative recombination of electrons and holes [8]. 

The absence of the emission bands in the visible region 

indicate the non-existence of defects and hence purity of the 

product. PL investigations of zinc nitride nanopowders 

demonstrate the promise of the material for UV-light emitting 

devices. 

In conclusion, we have successfully synthesized Zn 3 N 2 

nanopowders via nitridation of aqueous ammonia mixed zinc 

source at 600 o C for 2 hours. The structural, compositional 

and morphological characterizations were performed by 

XRD, EDS and SEM tests. The room temperature PL studies 

of zinc nitride exhibited a broad emission UV band 

corresponding to the band gap of the product. This feature 

indicates the promise of the zinc nitride for applications in 

UV-light emitting devices. 

This work was supported by National Natural Science 

Foundation of China ((20471007). We are thankful to Higher 

Education Commission (HEC) Pakistan for providing 

financial support for presenting this paper in the 6th 

Nanoscience and Nanotechnology Conference (NanoTR6- 

2010) held in Turkey. 

*Corresponding author: waheedskhan@yahoo.com 

[1] Futsuhara, M., Yoshioka, K. and Takai, O., Futsuhara, M., 1998. 

Thin Solid Films 322: 274 . 

[2] Kuriyama, K., Takahashi, Y., Sunohara, F.,1993. Phys. Rev. B 

48: 2781. 

[3] Zong, F., et al., 2005. Appl. Phys. Lett. 87: 233104. 

[4] Aperathitis, E., et al., 2009. Thin Solid Films 518: 1036. 

[5] Kambilafka, V., et al., 2007. Superlattices Microstruct. 42: 55. 

[6] Paniconi, G., et al., 2008. J. Solid State Chem. 181: 158. 

[7] Waheed S. Khan, Chuanbao Cao, 2010. J. Crys. Growth (In 

press). 

[8] Kaminska, E., et al., 2005. Phys. Status Solidi (c) 2: 1119. 




Rapid detection of Escherichia coli by nanoparticle bas ed immunomag netic separation and SERS 

Burcu Guven 1 , Nese Basaran Akgul 1 , Erhan Temur 2 , Ugur Tamer 2 1 * 

1 Department of Food Engineering, Faculty of Engineering, Hacettepe University, Beytepe 06800, Ankara, Turkey 

2 Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey 

Abstract- Detection of microbial pathogen in food is the solution and to the prevention and recognition of problems related to 

health and safety. In this study, a method combining immunomagnetic separation (IMS) and surface-enhanced Raman 

scattering (SERS) was developed to detect Escherichia coli (E. coli). The ability of the 

immunoassay to detect E. coli in real water samples was investigated and the results were compared with the experimental 

results from plate-counting methods. 

Nanomaterials can be conjugated with different 

biomolecules such as nucleic acids 1, peptides and 

proteins, antibodies 2, carbohydrates, and antibiotics 3. 

One of the most important research field of nanoscience 

and nanotechnology is the control and detection of various 

microorganisms 4. The major advantage of using 

nanomaterials instead of microbeads is the higher capture 

efficiency due to the high surface-to-volume ratio. Other 

advantages of using nanoparticles include faster reaction 

kinetics and minimal sample preparation 5. 

Escherichia coli (E. coli), which found in large numbers 

among the intestine of humans and other warm-blooded 

animals spread abroad in natural environment, is the major 

cause of infection outbreaks with serious consequences 6. 

More recently, several rapid assays for detecting E. coli 

based on different measuring principles, such as 

polymerase chain reaction immunoassay, optical assay 

etc., have been developed. Although these methods 

shortened the detection time varying from several hours to 

one day, many of these methods are still time-consuming 

and poor in sensitivity. In recent years, due to magnetic 

properties, low toxicity and biocompatibility, magnetic 

nanoparticles (MNPs) receive considerable attention. 

In this study a method combining immunomagnetic 

separation (IMS) and surface-enhanced Raman scattering 

(SERS) was developed to detect 

Escherichia coli (E. coli). Polyclonal antibody specific 

for the E. coli antigen was added to gold coated magnetic 

nanoparticles to create antibody-coated beads. Then gold 

coated nanoparticles which are treated with 5,5 - 

0Tdithiobis (2-nitrobenzoic acid (DTNB)) are interacted 

with gold coated magnetic nanoparticles and the 

calibration curve was obtained in surface-enhanced Raman 

scattering. The capturing efficiency was examined in 

different E. coli concentrations (10 1- 10 7 ). 

The selectivity of the developed sensor was examined 

with Enterobacter aerogenes, Enterobacter dissolvens, 

which did not produce any significant response (Figure 1). 

compared with the experimental results from platecounting 

methods. There was no significant difference 

between the methods that were compared (p>0.05). This 

method is rapid and sensitive to target organisms. 

This work was partially supported by TUBITAK under 

Grant No. TBA G-107T682. 

*Corresponding author: ihb@hacettepe.edu.tr 

1 Q. Zhang, L. Zhu, H. Feng, S. Ang, F.S. Chau, and W.-T. Liu, 

Microbial detection in microfluidic devices through dual staining 

of quantum dots-labeled immunoassay and RNA hybridization. 

Anal. Chim. Acta 556, 171–177 (2006). 

2 T. Elkin, X. Jiang, S. Taylor, Y. Lin, H. Yang, J. Brown, S. 

Collins and Y.-P. Sun, Immuno-carbon nanotubes and 

recognition of pathogens. ChemBioChem. 6, 640–643 (2005). 

3 P. Li, J. Li, C. Wu, Q. Wu and J. Li, Synergistic antibacterial 

effects of b-lactam antibiotic combined with silver nanoparticles. 

Nanotechnology 16, 1912–1917 (2005). 

4 P.G. Luo, F.J. Stutzenberger, Nanotechnology in the 

Detection and Control of Microorganisms. Advances in Applied 

Microbiology, Volume 63 (2008). 

5 M. Varshney, L. Yang, X.L. Su, Y.Li, Magnetic nanoparticleantibody 

conjugates for the separation of Escherichia coli 

O157:H7 in ground beef. (2005). 

Journal of Food Protection 68, 1804–1811. 

6 Y. Cheng, Y. Liu, J. Huang, K. Li, W. Zhang, Y. Xian, L. Jin, 

Combining biofunctional magnetic nanoparticles and ATP 

bioluminescence for rapid detection of Escherichia coli. Talanta 

77 1332–1336 (2009). 

SERS Intensity counts/s 

4500 

4000 

3500 

3000 

2500 

2000 

1500 

1000 

500 

0 

Enterobacter 

aerogenes 

Enterobacter 

di ssol vens 

Escherichia coli 

Figure 1. The SERS intensities of E. aerogenes, E. dissolvens, 

and E. coli at fixed concentration. 

The ability of the immunoassay to detect E. coli in real 

water samples was investigated and the results were 



Synthesis of Pyrogallol-Formaldehyde Nano Resin and Usage as an Adsorbent 

Mustafa Can 1 *, Emrah Bulut 2 and Mahmut Özacar 2 

1 Sakarya University, Institute of Sciences and Technology , 54187 Sakarya, Turkey 

2 Sakarya University, Department of Chemistry, 54187 Sakarya, Turkey 


Abstract- Pyrogallol (PG) and formaldehyde condensation reaction was carried out to prepare the pyrogallol-formaldehyde nano resin 

(PGNR). Polymerization of formaldehyde with PG was performed at optimal conditions obtained from literature to establish the nano 

resin formulation. Obtained nano resin was used as adsorbent for adsorption of rhodium (III) ions from solutions. PGNR was 

characterized by SEM, EDS and FTIR-ATR spectroscopy, respectively. 

Conventional syntheses of polyphenol resins are 

classified into chemical and enzymatic methods. In the 

chemical methods, phenol reacts with formaldehyde in 

acidic or alkaline media, forming novolac and resol resins. 

These polymers characteristically possess high mechanical 

strength, durability to chemicals, and insulation properties, 

and thus have applications in the automobile and electrical 

industries. The phenol unit in polyphenol as an electron 

donor is oxidized to quinone, and the nobel metal ions 

accept electrons from the polyphenol, generating nobel 

metal particles. Nobel metal particle growth via electrontransfer 

reactions between organic molecules and metal 

ions has been used in the field of nanobiotechnology to 

develop novel bioelectronics and biosensor systems [1]. 

Pyrogallol (PG) consist of an aromatic ring bearing three 

adjacent hydroxyl groups (position 1,2 and 3), leaving 

three free sites on the ring. Reactivity considerations show 

that the hydroxyl functions enhance the reactivity of 

positions 4 and 6. The remaining position (5) whould have 

the same degree of activation as phenol. These three 

possible reactive sites permit the eventual formation of a 

tridimensional network during polymerization as in the 

case of phenol. Thus, we decided to study the reactivity of 

PG in the synthesis of PGNR [2]. 

Alkaline-catalyzed PGNR are prepared similar to phenolformaldehyde 

resins. There are two steps leading to 

formation of PGNR: methylolation and condensation 

reactions. 

Adsorption capacity of PGNR was found to be 32 mg/g 

Rh (III) from Langmuir isotherm. The morphology and 

size of PGNR was investigated using SEM and the SEM 

image was showed in Fig. 1. The FTIR spectra analysis of 

PG, PGNR and Rh adsorbed PGNR were caried out [2, 3]. 

Figure 2 represent the FTIR-ATR spectra of PG, PGNR 

and Rh adsorbed PGNR. The main bands and their 

assigments in PG are as follows: stretching vibrations of 

the aromatic ring (C-C)/(C=C) at 1620, 1518, 1483, 

1361 cm -1 , stretching vibrations of the phenolic group 

(C-OH) at 1518, 1313, 1286, 1242, 996 cm -1 , bending 

vibrations of the phenolic group (C-OH) at 1483, 1362, 

1186, 1156 cm-1 and bending (C-H) at 1138, 1061 cm -1 . 

Formation of PGR leads to obvious changes in FTIR 

spectra: complete disappearance of the bands at 1518, 

1362, 847 to 762 cm -1 , shiff of the band at 1043 to 

996 cm -1 . The band intensities between 1314 and 

1061 cm -1 are reduced and some of them are combined in 

the spectrum of the PGNR. This situation may be 

attributed to the phenolic –OH groups. Also, the formation 

of –CH 2 – O – CH 2 – linkage appeared at 1198 cm -1 . The 

peak intensities at 1517 and 1483 cm -1 is reduced due to 

the formation of – CH 2 – linkage [4-6]. When the spectra 

Figure 1. SEM image of PGNR 

Figure 2. FTIR spectra of PG, PGNR and Rh adsorbed PGNR 

of Rh adsorbed PGNR were compared with the spectrum 

of the PGNR, the small peak serias at 1294 and 1043 cm -1 

are combined and reduced peak intensities, because of 

PGNR-Rh complex formation between Rh and some 

phenolic groups of PGNR [4-6]. This study was supported 

by the Scientific Research Projects Commission of Sakarya 

University (Project number: 2009 50 02 005). 

*Corresponding author: 0Tmstfacan@gmail.com 

[1] K. Hamamoto, H. Kawakita, K. Ohto, and K. Inoue, React. 

Funct. Polym. 69, 694 (2009). 

[2] J. M. Garro-Galvez and B. Riedl, J. Appl. Polym. Sci. 65, 399 

(1997). 

[3] S. Kim and H.J. Kim, J. Appl. Polym. Sci. 17, 1369 (2003). 

[4] Y.K. Lee, H.J. Kim, M. Rafailovich and J. Sokolov, Int. J. 

Adhes. 22, 375 (2002). 

[5] M. Özacar, C. Soykan 

102, 786 (2006). 

[6] I. Mohammed-Ziegler and F. Billes, J. Mol. Struct. 618, 259 

(2002). 




Inve stigation of SERS of orga nic molecule bridge d go ld nanoparticles: Synthesis and 

charac terization 

Remziye Gü zel 1 *, , 2 3 and Ali Osman Solak 3 

1 

2 Dum 

3 Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey 

Abstract -We describe the short range SERS effect of AuNP by bridging them with an organic molecule, HS(CH 2 ) 2 CONHPhSH, which 

has very low inherent sensitivity of Raman scattering. The nanoparticles are contacted by S(CH 2 ) 2 CONHPhS- linker bridges in which 

presence of different heteroatoms and functionalities makes it interesting for characterization by XPS, UV, RAIRS, EIS, TEM, Fluorescence 

microscopy and SERS. 

In recent years, investigation of nanomaterials, especially 

metal nanoparticles, has attracted much importance, because 

of their interesting chemical, mechanical and physical 

properties and potential applications in nanoelectronic and 

optoelectronic devices. Nowadays, much effort has been 

committed to fabrication of metal nanocomposites, including 

alloys, core-shell and mixed particles, due to their valuable 

non-linear optical properties in optical switches [1,2], in 

catalysis [3,4] and in surface-enhanced Raman scattering 

(SERS) [5]. Nanostructured materials that can be tailored to 

achieve greater mechanical properties along with their 

electrical, optical, thermal and other functional properties are 

essential for future applications in many industry sectors. The 

electronic conduction of many different metal/organic/metal 

systems has been studied experimentally [6]. The thiol group 

forms a strong chemical bond to the gold surface. In the case 

of physisorption, the molecule is bound to the surface by 

weak Van der Waals forces [7]. 

In this work, we describe the short range SERS effect of 

AuNP by bridging with an organic molecule, 

HS(CH 2 ) 2 CONHPhSH, which has very low inherent 

sensitivity of Raman scattering. We construct the 

AuS(CH 2 ) 2 CONHPhSAu assembly in a step by step fashion 

which allows us to follow the route of synthesis 

spectroscopically and to investigate the individual SERS 

effects of mono nanoparticles on the organic bridge. To 

achieve this goal, firstly we describe the monolayer 

attachment of mercaptopropionic acid (MPA) to the AuNPs 

to construct MPA self assembled gold nanoparticles, 

AuS(CH 2 ) 2 COOH. In the second step, the carboxylic acid 

terminated self assembled monolayer (SAM) film 

surrounding the AuNPs is activated with N-(3- 

dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride 

(EDC) to bind 4-aminothiophenol (ATP) to the 

AuS(CH 2 ) 2 COOH forming a dithiol terminated protective 

organic film (AuS(CH 2 ) 2 CONHPhSH). Lastly, Au 

nanoparticles are bridged to this structure through the 

terminal SH groups to construct the organic film bridged 

AuS(CH2) 2 CONHPhSAu assembly. Then, we have 

investigated the enhancement of the Raman signals of the 

organic wire between metal nanoparticles by the 

accumulation of the MPCs and assemblies on the glassy 

carbon (GC) surface. The nanoparticles are contacted by - 

S(CH 2 ) 2 CONHPhS- linker bridges in which presence of 

different heteroatoms and functionalities makes it interesting 

for characterization by XPS, UV-Vis, RAIRS, EIS, 

Fluorescence microscopy and SERS. We emphasize the 

effect of plasmon coupling on the 

S(CH 2 ) 2 CONHPhS- bridge between Au and Au 

nanoparticles. This effect can be exploited to build new 

nanostructure architectures in the fabrication of single 

molecule detection biosensors. 

Formula 

Structure 

AuS(CH 2 ) 2 COOH 

O 

S OH 

AuS(CH 2 ) 2 CONHPhSH 

O 

S NH 

AuS(CH 2 ) 2 CONHPhSAu 

O 

S NH 

Figure 1. Formula and structures of MPCs and nanoparticle-organic 

molecule assembly forms [1]. 

I would like to thank Prof. Dr. Ali Osman SOLAK who 

presenting us his research laboratory for our experiments 

*Corresponding author: 0Tguzel.remziye@gmail.com 

[1] Twardowski, M., Nuzzo, R- G., 2002. Chemically mediated 

grain growth in nanotextured Au and Au/Cu thin films: Novel 

substrates for the formation of self-assembled monolayers, 

Langmuir, 18: 5529-5538. 

[2] Lal, S., Taylor, R-N., Jackson, J-B., Westcott, S-L., 

Nordlander, P., Halas, N-J., 2002. Light interaction between gold 

nanoshells plasmon resonance and planar optical waveguides, J. 

Phys. Chem. B 106: 5609-5612. 

[3] Tsai, S-H., Liu, Y-H., Wu, P-L., Yeh, C-S., 2003. Preparation 

of Au-Ag-Pd trimetallic nanop articles and their application as 

catalysts, J. Mater. Chem. 13: 978-980. 

[4] Wang, A-Q., Liu, J-H., Lin, S-D., Lin, T-S., Mou, C-Y., 2005. 

A novel efficient Au-Ag alloy catalyst systems: preparation, 

activity, and characterization, J. Catal. 233: 186-190. 

[5] Lu, L., Zhang, H., Sun, G., Xi, S., Wang, H., 2003. 

Aggregation-based fabrication and assembly of roughened 

composite metallic nanoshells: Application in surface-enhanced 

raman scattering, Langmuir 19: 9490-9493. 

[6] Reed M.A., Zhou, C., Muller, C-J., Burgin, T-P., Tour, J-M., 

1997. Conductance of a molecular junction, Science, 278: 252-254. 

[7] Mujica, V., Kemp, M., Ratner, M.A., 1994. Electron 

conduction in moleculer wires. I.A scattering formalism, J. Chem. 

Phys. 101: 6849-6856. 

S 

SH 




The Adsorption and Conformational Properties of Polyelectrolyte Complexes on the Oppositely 

Charged Surface 

Sedat Ondaral 1 *, Caroline Bergholtz Ankerfors 2,3 , Lars Wågberg 2 

1 Department of Pulp and Paper Technology, Karadeniz Technical University, 61080 Trabzon, Turkey 

2 Fibre and Polymer Technology, Royal Institute of Technology, SE-100 44 Stockholm, Sweden 

3 Eka Chemicals AB, 445 80 Bohus, Sweden 

Abstract-We investigated how PEC’s adsorption properties and conformation behaviors change on silicon o xide surface depending on the 

molecular weight of polyelectrolytes. The findings of the present study are remarkably giving a new insight about the PEC’s properties related 

to their use and performance. 

By mixing oppositely charged polyelectrolytes in water, 

polyelectrolyte complexes can be formed, which is driven by 

the increase of entropy due to the release of small ions from 

the double layers around the individual polyelectrolytes. The 

main interaction force for complexation of two oppositely 

charged polyelectrolytes is Columbic forces. Additionally, 

hydrogen bonding, charge transfer, dipole-dipole and 

hydrophobic forces play role in the different complexation 

system. 1-2 Co mplexation can result in the three different form, 

soluble, colloidaly stable and coacervate complexes, 

depending on the factors such as mixing ratio, polyelectrolyte 

concentration, pH, electrolyte concentration, nature of ionic 

groups, temperature and preparation conditions. 3-5 Their uses 

have grown rapidly in the large scale industrial applications, 

such as coatings, binders, flocculants, as well as in 

biotechnical and biomedical applications, for few decades. 6-9 

For these application, it is very important to determine how 

the properties of PEC change with such factors mentioned 

before as well as adsorption and conformational behaviors of 

PEC in both solution and on the surface. 

In the present study, we mainly focused on the adsorption 

properties and conformational behaviors of PECs prepared by 

combining poly(allylamine hydrochloride) (PAH) and 

poly(acrylic acid) (PAA) by using a confined impinging jet 

(CIJ) mixer. The adsorption properties of PECs were 

investigated with the aid of Stagnation Point Adsorption 

Reflectometry (SPAR) and Quartz Crystal Microbalance with 

Dissipation (QCM-D) using SiO2 surfaces. We found that the 

PEC-A, which prepared with higher molecular weight 

PAH/PAA, showed a higher adsorption to the SiO 2 surfaces 

compared to the PEC-B, which prepared with lower molecular 

weight PAH/PAA. The adsorption of the PEC-A also showed 

a larger change in the dissipation (D), fro m the QCM -D 

measurements, indicating that the adsorbed layer had a 

relatively lower viscosity and a lower shear modulus for the 

PEC-A. We also determined that “how PEC’s conformation 

changes on the oppositely charged surface” by means of 

Atomic Force Microscope (AFM). Complementary 

investigations of the adsorbed layer using AFM showed that 

the adsorbed layer was significantly different for PEC-A and 

PEC-B and that the change in properties with adsorption time 

was very different for the two types of PECs. PEC-A showed 

a coalescence type of behaviour whereas this was not detected 

for the PEC-B, as shown in Figure 1. The exact reason to this 

difference in behaviour is not known but size determinations 

of the complexes in solutions showed that they were very 

stable over time and therefore, the coalescence behaviour was 

concluded to be initiated by the interaction between the 

complexes and the surface. AFM results for the PEC-A 

showed the existence of two types of complexes with similar 

size but different mechanical properties, i.e. collapsing 

behaviour, when in contact with the surface. This could most 

probably be linked to the phase separation of the complexes 

during their preparation. 

Figure 1. AFM images (amplitude mode) of PEC-A and PEC-B on 

silicon oxide surface after different adsorption periods (image size 

5x5 m). 

In summary, these results show that the higher adsorption 

amount and higher surface coverage of PECs can be achieved 

by increasing molecular weight of polyelectrolytes used for 

preparation of PEC. That is promising for the future 

application studies related to enhancing the PEC’s 

performance especially as a binder. This study was conducted 

in the laboratories of Fibre Technology Department (Royal 

Institute of Technology, Stockholm-Sweden). 

*Corresponding author: 2Tondaral@ktu.edu.tr 

[1] Thünemann, A. F.; Müller, M.; Dautzenberg, H.; Joanny J.-F.; 

Löwen H., Springer-Verlag Berlin Heidelberg, Germany, 2004, 166, 

113. 

[2] Kovacevic, D.; Borkovic, S.; Pozar J., Colloids and Surfaces A: 

Physicochem. Eng. Aspects, 2007, 302, 107. 

[3] Philipp, B.; Dautzenberg, H.; Linow, K.-J.; Kötz, J.; Dawydoff, 

W., Adv. Polymer Sci. 1989, 14, 91. 

[4] Gärdlund, L.; Wågberg, L.; Norgren, M., J. Colloid Interface Sci. 

2007, 312, 237. 

[5] Kabanov, V. in Multilayer Thin Films. G. Decher and J. B. 

Schlenoff, Wiley-VCH Verlag GmbH,Weinheim, Germany, 2003, 

47-86. 

[6] Hubbe,M.A.; Moore, S.M.; Lee, S.Y., Ind. Eng. Chem. Res. 

2005, 44, 3068. 

[7] Malay, Ö.; Y O., Journal of 

Thermal Analysis and Calorimetry, 2008, 94, 749. 

[8] Fredheim, G.; Christensen, B.E., Biomacromolecules 2003, 4, 

232. 

[9] Wan, A.C.A.; Tai, B.C.U.; Schumacher, K.; Schumacher, A.; 

Chin, S.Y.; Ying, J.Y., Langmuir, 2008, 24, 2611. 




Effect of Nanocrystallization on Magnetic Properties of Bulk Amorphous 

Fe 75-X Co X Nd 3 Zr 2 Y 3 B 17 alloys 

Mehmet Yıldırım * , M. Vedat Akdeniz and Amdulla O. Mekhrabov 

Novel Alloys Design and Development Laboratory (NOVALAB), Department of Metallurgical and Materials Engineering, 

Middle East Technical University, Ankara 06531, Turkey 

Abstract- It was shown that Fe 75-X Co X Nd 3 Zr 2 Y 3 B 17 alloys have soft magnetic properties in amorphous state, whereas they show 

single phase hard magnetic behavior after annealing due to containing nanocrystalline hard magnetic Nd 2 Fe 14 B phase and Fe 3 B 

and/or α-Fe soft magnetic phases. 

Fe-based bulk metallic glasses (BMG) have attracted 

considerable interest for engineering and technological 

applications because of their superior mechanical and 

magnetic properties [1-3]. Up to now, Fe-based BMG’s are 

classified into following three groups according to their 

magnetic behavior: 1. non-ferromagnetic alloys such as Fe– 

Mn–Mo–Cr–C–B [4], 2. soft magnetic alloys such as Fe-(Al, 

Ga)-metalloid [5] and (Fe, Co)–B–Si–Nb [6] and 3. hard 

magnetic alloys such as Fe–Co–Nd–Dy–B [7] and Nd (Pr)– 

(Fe, Co)–Al [8]. Among these, the B-rich Fe-Co-RE-B hard 

magnetic alloys containing rare earth elements such as Nd, Pr 

and Dy is a new class of Fe-based bulk glassy alloys that are 

potential materials for bulk permanent applications such as 

motors, speakers, sensors, magnetic recorders, telephone 

receivers and MRI systems. Lower rare earth content, lower 

melting temperature, higher glass forming ability and the 

appearance of glass transition and supercooled liquid region 

before crystallization are the advantages of this type of alloys 

over rare-earth (RE) rich Fe-RE-Co-B alloys. 

Figure 2. Hysteresis curves for amorphous and nanocrystalline 

Fe 75 Nd 3 Zr 2 Y 3 B 17 alloys. 

Fe 75 Nd 3 Zr 2 Y 3 B 17 alloy has fully amorphous structure in the 

as-cast state (Figure 1). However, after annealing formation 

of Nd 2 Fe 14 B and α-Fe phases exist. Amorphous alloy has soft 

magnetic behavior, while after annealing due to the 

exchange-coupled interaction between hard magnetic 

Nd 2 Fe 14 B phase and α-Fe soft magnetic phases their 

hysteresis loop seem to be single-hard magnetic behavior 

(Figure 2). 

This work is supported through The Scientific and 

Technological Research Council of Turkey, TUBITAK, for 

the support through National Scholarship Program for PhD 

Students and METU-ÖYP Program. 

* ymehmet@metu.edu.tr 

Figure 1. XRD patterns for amorphous and nanocrystalline 

Fe 75 Nd 3 Zr 2 Y 3 B 17 alloys. 

In this study, we have investigated the effect of 

nanocrystallization on magnetic properties of bulk 

amorphous Fe 75-X Co X Nd 3 Zr 2 Y 3 B 17 alloys with x = 0, 5, 10 

and 15. Samples were produced by a commercially available 

centrifugal casting machine under high purity Ar atmosphere. 

Amorphous nature of the samples was verified by XRD 

analysis. Thermal stability of the alloys was investigated by 

thermal analysis measurements using a differential scanning 

calorimeter (DSC). The magnetic properties such as 

saturation magnetization (M S ), coercivity (H C ), remnantmagnetization 

(M R ) and maximum energy-product were 

measured using a vibrating sample magnetometer (VSM). 

[1] A. Inoue, T. Zhang, N. Nishiyama, Mater. Trans. JIM 34 

(1993) 1234. 

[2] A. Inoue, T. Zhang, N. Nishiyama, Mater. Trans. JIM 32 

(1991) 1005. 

[3] A. Peker, W.L. Johnson, Appl. Phys. Lett. 63 (1993) 2342. 

[4] V. Ponnambalam, S.J. Poon, G.J. Shiflet, V.M. Keppens, R. 

Taylor, G. Petculescu, Appl. Phys. Lett. 83 (2003) 1131. 

[5] A. Inoue, J.S. Gook, Mater. Trans. JIM 36 (1995) 1180. 

[6] B.L. Shen, A. Inoue, C.T. Chang, Appl. Phys. Lett. 85 (2004) 

4911. 

[7] W. Zhang, A. Inoue, Appl. Phys. Lett. 80 (2002) 1610. 

[8] A. Inoue, Mater. Sci. Eng. A 226–228 (1997) 351. 19: 15-25. 




A comparat ive study o f the Mn, Co an d Zn bas ed spinel ferrite nanoparticles synthesized using 

coprecipitation technique 

Abdul Hafeez 1 , Yasir Jamil 2 * and M. Raza Ahmad 3 

1 University College of Education, Faisalabad, Pakistan 

2 

Department of Physics, University of Agriculture, Faisalabad, Pakistan 

Ferrites are a class of compounds with the formula AB2O 4 , 

where A&B represents various metal cations. In the present 

work fine Zinc. Manganese and cobalt ferrite nanoparticles 

were prepared using the co-precipitation technique. The 

synthetic technique involved the co-precipitation of iron 

(Fe+3) and metal (+2) ions from aqueous solutions using 

NaOH base to create fine particles. This technique provides 

greater homogeneity of the particles. The microstructural 

studies were performed using x-ray diffraction technique. 

Samples of ferrites were synthesized at different digestion 

temperatures. In case of zinc the maximum magnetization 

was found for samples having digestion temperature of 

55 o C. The crystallite e sizes of the samples increased with 

increase in the digestion temperature from 55 o C to 85 o C. 

However the particle size decreased at digestion temperature 

of 95 o C. The particle size description matches well in 

previously reported work. The surface morphology and 

magnetic properties were also performed using SEM and 

VSM. The magnetic properties of zinc ferrite samples 

resembled those of ideal soft ferrite with almost no 

hysteresis loss. Fine manganese ferrite (MnFe 2 O 4 ) particles 

with metal to hydroxyl ion concentration ratios of 0.1 and 

0.2 were prepared The surface morphology and magnetic 

properties showed that the particles were of narrow size 

distribution with good properties of soft ferrites. 

It has been found that the magnetization of ferrite nano 

particles synthesized by co-precipitation depends mostly on 

parameters such as reaction temperature, pH of the 

suspension, initial molar concentration etc. Cobalt ferrite 

samples were prepared from the mixed Fe2+ and Co2+ 

solutions, which were made from their stock solutions and 

had a constant initial total iron ions concentration and 

amounts of Co2+ ions. The size and size distribution was 

controlled by controlling the nucleation and growth rates[1]. 

X-ray Diffraction (XRD) confirmed the formation of singlephase 

cobalt ferrite nanoparticles in the range 15–48nm 

depending on the annealing temperature and time. The size 

of the particles increases with annealing temperature and 

time while the coercivity goes through a maximum, peaking 

at around 28 nm . 

We may conclude that the coprecipitation technique has 

resulted in very good soft ferrites of zinc, cobalt and 

manganese. The crystallite sizes were varied by varying the 

concentration ratios, changing digestion times, varying 

digestion temperatures and applying microwave digestion. 

The magnetic properties were found to be dependent on the 

particle size. 

*Corresponding Author: yasirjamil@yahoo.com 

[1]Teixeira F, T Ogusawara and S Nobrega, 2006. Investigation of 

Sintered Cobalt –zinc Ferrite by Co precipitation at different 

temperatures. Materials research, 9(3): 257-262. 




Conception of nanorobot’s deve lopment bas e on polyme r complexes with s mall molecules 

Bayana Yermukhambetova 1 *, Ibragim Suleimenov 2 , Grigoriy Mun 1 , Galiya Irmukhametova 1 , Laura Boranbayeva 

3 

and Nazym Zhunusbekova 

1 KAZNU - Chemical faculty of Kazakh National University, Karasai Batyra 95, 050012 Almaty, Kazakhstan 

2 AIPET – Almaty Institute of Power Engineering and Telecommunications, Baitursynova 126, Almaty 050013, Kazakhstan 

3 ICS - Institute of Chemical Science, Ualikhanova 106, 050010 Almaty, Kazakstan 

Abstract-The approach for creation of structures with atomic accuracy which is using nanorobots synthesized on base of polymeric complexes 

with smaller molecules has been suggested. 

1 

Creation of structures with atomic precision is one of the 

most important tasks of nanotechnology. The different 

approaches are offered for solving this problem. Their review 

is given in [1]. 

In present work it is shown that there are some conditions 

when polymeric complexes with s mall molecules can be 

considered as simplest type of nanorobots. Such structures 

allow achieving desired disposition of specified molecules 

(atoms, ions) on the surface (or, that is the same, to record 

information with accuracy close to the atomic level). 

We could consider the complex formed by diphilic polymer 

which is sensitive to external influences and to some smaller 

mo lecule for its transport. Changing of state of diphilic 

macro molecule allows releasing smaller mo lecule at the 

addressing. For example, changing of hydrophilichydrophobic 

balance, which is reasoned by external stimulus, 

resulted in destruction of complex and thereby providing 

address delivery of smaller molecule (atom or ion). 

Such type of complexes can be provided by additional 

charges with the help of covalent bonds (copolymer with 

dissociating functional groups may be used); they can be made 

magnetoactive, etc. This provides controlled movement of 

nanorobots, particularly, to support the scan similar to 

television for recording of information into the structures 

formed on the surface. 

Possible scheme of information recording in nanosized 

systems with help of nanorobots is shown in Figure 1. 

Nanorobot is the complex formed by diphilic stimuli-sensitive 

polymer and ion of metal, which is able to form coordination 

bonds with functional groups of surface. 

During the reaction between complex-nanorobot and surface 

the ion of metal can find oneself in random “cell”, in principle 

(Figure 1a). However application of electric field, on 

condition that nanorobot has electrostatic charge, allow 

removing nanorobot in some fixed position (otherwise 

extremely right or extremely left position). Further the rate of 

its migration along the surface at external electric field is 

regulated value. (Probably the migration can proceed by 

mechanism similar to hole conductivity of semiconductors). 

Therefore appearing of nanorobot in certain module can be 

provided by setting of the removing time of nanorobot within 

the range of network surface (Figure 1b). Moreover, in case of 

application of scan similar to TV one the nanorobot can be 

moved in two coordinates. 

On the last stage the separation of nanorobot body from ion 

of metals takes place (Figure 1c). This permits to record 

information and/or to form certain structure. 

The theory of complexes formed by macromolecules and 

ions with the same charges having controlled stability due to 

this reason has been developed as the first step for realization 

of proposed conception. 

The example of such complexes is the product of reaction 

between ions of metal, for example cuprum, with triple 

copolymer containing hydrophobic units, cationic polymer 

units and units providing formation of coordination bonds. 

a 

c 

b 

Figure 1. The scheme of information recording in nanosized systems 

with help of nanorobots. 

Electrostatic charge of cationic groups is regulated value, for 

example due to reaction of protonation of amine groups. 

Therefore by changing of protonation degree the controlled 

destruction of complex can be achieved. 

However developed theory shows that complex stability 

management can be also realized due to changing of 

macromolecule coil size even when charge density of 

polymeric chain is fixed. Particularly, contraction of coil leads 

to increasing of electrostatic forces of repulsion between ion 

and similarly charged units of macromolecules that result in 

destruction of complex. Controlling of coil size is provided by 

introduction of hydrophobic groups in polymer composition. 

Such types of effects are well studied during last few decades 

[2]. 

The theory also predicts that the number of metal ions, 

which are sorbet by separate coil, can be regulated by using of 

the same method. Particularly, some conditions exist when 

reactions between single ion and macromolecule containing 

same-sign electrostatic charge take place. 

*Corresponding author: 1TBaya_2010@mail.ru 

[1] E.E. Ergozhin, A.B.Zezin, I.E.Suleimenov and G.A. Mun, 

Hydrophilic polymers in nanotechnology and nanoelectronics (in 

Russian). Almaty-Moscow: 2008, 216 p. 

[2] G.A.Munet al., Macromol. Chem. Phys., 208, 979 (2007) 

 

 


400 450 500 550 600 



Surface Modification of Colloidal Oil Soluble CdS x Se 1-x Quantum Dots with Thiolated 

Organic Surfactants 

1 

Caner Ünlü and Serdar Özçelik 1 *, 

1 Izmir Institute of Technology, Faculty of Science, Department of Chemistry, Urla-Izmir 35430 

Abstract-This is the first demonstration about synthesis and ligand exchange of colloidal alloyed quantum dots by the two phase method. 

We first synthesized CdS x Se 1-x quantum dots by a modified two phase synthesis method in toluene by using trioctylphosphineoxide (TOPO) 

as surfactant and then exchanged surface chemistry of the quantum dots with different organic surfactants consisting of thiol groups, such as 

3 – Mercaptopropionic acid (3 – MPA) , N – Acetyl L – Cysteine (NAC) and Cysteamine. Quantum dot s passed to aqueous medium from 

oil medium with a loss in quantum yields. Fluorescence spectra of the surface exchanged quantum dots shifted towards red around 10 nm. 

Bawendi et.al. developed a simple method to synthesize 

monodisperse semiconductor colloidal nanoparticles. [1] 

They become popular because of their unique optical 

properties such as high quantum yield, larger extinction 

coefficient and photostability, etc. Usually quantum dots 

were successfully synthesized in oil media, such as 

toluene, heptane, hexane, etc. But these quantum dots 

dispersible in oil medium are not preferred for use in 

biological applications. However, Alivisatos et.al showed 

that quantum dots can also be prepared in water and 

therefore can be used as fluorescent labeling agent in cells. 

This utilization extends the applications of quantum dots to 

biomedical fields [2]. 

For biological applications, quantum dots must be water 

dispersible. There are several methods to make quantum 

dots water dispersible. The most studied method is the 

ligand exchange method. Basically, quantum dots with 

high quantum yields prepared in oil based solvents, and 

then the hydrophobic surfactants exchanged with 

hydrophilic ones. Water dispersible quantum dots surface 

chemistries are designed to provide reactive groups such as 

amine (–NH2), carboxy l (– COOH) or mercapto (–SH) 

groups for direct conjugation to biomolecules. 

In this study, we reported synthesis of colloidal 

CdS x Se 1-x alloyed quantum dots in toluene and surface 

modification of them with different thiolated organic 

surfactants, 3 – MPA, NAC and cysteamine. 

P 

P 

O 

O 

CdSSe 

O 

O 

P 

P 

NAC 

H 3 C 

N + 

O 

COOH 

were achieved with some degree of loss in the yield 

(Figure 2). The quantum yield of water dispersible 

CdS x Se 1-x dropped from %60 to %10. Also, fluorescence 

spectra of water dispersible CdS x Se 1-x quantum dots shifted 

to red about 10 nm when it is compared to the TOPO 

capped spectra of quantum dots (Figure 3). This project is 

supported by DPT and TUBITAK (Grant No: 108T446) 

a) b) 

Figure 2. a) Luminescence image of TOPO, 3 – MPA and NAC 

capped quantum dots with the same size. b) Luminescence image 

of 3 – MPA capped CdS x Se 1-x quantum dots with different size 

Normalized Intensity 

Wavelength (nm) 

Normalized Intensity 

450 500 550 600 650 


Figure 3. Change in fluorescence spectrum of quantum dots 

after ligand exchange procedure. Red lines correspond to TOPO 

capped CdS x Se 1-x quantum dots while black lines correspond to 

3 – MPA capped CdS x Se 1-x quantum dots. 

*Corresponding author: 0Tserdarozcelik@iyte.edu.tr 

[1] Murray, C. B., Noms, D. J., and Bawendi, M. G. ,1993. 

Journal of American Chemical Society 115: 8706-8715 

[2] Bruchez, Jr M., Moronne, M., Gin, P., Weiss, S., Alivisatos, 

AP., 1998. Science. 281:2013-2016 

HOOC 

O 

N + 

H 3 C 

S 

S 

CdSSe 

S 

CH 3 

S N + 

O 

COOH 

HOOC 

N + 

O 

CH 3 

Figure 1. Illustration of Surface Modification of TOPO capped 

CdS x Se 1-x quantum dots with NAC 

Highly luminescent and monodisperse TOPO capped 

colloidal CdSxSe 1-x alloyed quantum dots were 

synthesized by a modified two phase method at mild 

conditions in toluene. Oil dispersible CdS x Se 1-x collo ids 

possessed quantum yields around 60 %. Surfaces of the 

oil dispersible CdS x Se 1-x quantum dots were modified by a 

new method developed by us. As a result, 3 – MPA, NAC 

and cysteamine capped alloyed CdS x Se 1-x quantum dots 




Synthesis and compos itional tunable spectral properties of CdSe x Te 1-x ternary alloys 

Seda Özdemir 1 , Gü lçin Ünal 1 ,Serdar Özçelik 1 * 

 

1 

Abstract-We synthesized ternary CdSe xTe 1-x colloidal nanocrystals and showed that the spectral properties of the alloy were tuned by the 

composition of the alloy. The photoluminescence spectra spans from 450 to 650 nm . The PL quantum efficiency reached up to 22%. XRD 

analysis proved that crystal structure of the alloy is zinc-blend. The size of the nanocrystal is 5.0 nm. The level of cytotoxicity was found to 

be 2.5 μg/ml for PC3 and MCF7 cells. 

Colloidal semiconductor nanocrystals are important class 

of nanoscale materials because of inexpensive synthesis 

and continuous tunability of their physical, specifically 

optical, properties. Understanding relationship among 

chemical composition and physical properties of ternary 

alloyed nanocrystals is crucial for the advancement of new 

technological applications. Controlling spectroscopic 

properties of alloyed nanocrystals by the ratio of alloying 

elements may yield significant improvement in 

performance [1,2]. 

The goal of this study was to produce and characterize 

water-dispersible lu minescent alloyed CdSe x Te 1-x 

semiconductor nanocrystals, which may be suitable for 

bioimaging. We synthesized CdSe x Te 1-x colloidal 

nanocrystals utilizing wet-chemistry techniques at low 

temperature (100 o C) and in one-step. The characteristic 

PL wavelengths of synthesized nanocrystals by varying the 

alloy composition showed emission in a range from 450 to 

650 nm (Figure 1). Alloyed ternary nanocrystals have 

%17 photoluminescence quantum yield. After coating the 

nanocrystals with CdS shell the photoluminescence 

quantum yield of the alloys increased up to % 22. 

Figure 2. XRD signals of the alloys increasing amount of Te 

causing the shift. 

Alloyed nanocrystals contain toxic element such as Cd. 

MTT assay was used to determine the level of cytotoxicity 

of CdSe x Te 1-x nanocrystals. The lethal concentration for 

 

Confocal microscopy indicates that the nanocrystals were 

accumulated in the cytoplasm of the cells. 

Figure 3. MTT assay for MCF7 cells. 

This study was supported by TUBITAK (Grant no 

108T446) and DPT. 

Corresponding author: serdarozcelik@iyte.edu.tr 

[1] Gu, Z., Zou, L., Fang, Z., Zhu, W., Zhong, X., 2008, One pot 

synthesis of highly luminescent CdTe/CdS core/shell 

nanocrystals in aqueous phase, Nanotechnology 19, 135604. 

[2] Thakar, R., Chen, Y., Snee, P.T., 2007, Efficient emission 

from core/(doped)shell nanoparticles: Applications for chemical 

sensing, Nano Letters, Vol. 7, No. 11, 3429-3432. 

Figure 1. Normalized emission spectrum of CdSe x Te 1-x 

nanocrystals and photographs of the alloys under visible and UV 

light illumination. 

The crystal structure of the alloy was found to be zinc 

blende. XRD signal shifts to lower angles by increasing 

the amount of Te in the alloy (Fig. 2). 




Electrostatic modeling of contacts considering integer quantum Hall systems 

Deniz Eksi, 1* Ozge Kilicoglu 1 and Afif Siddiki 2,3 

1 Trakya University, Department of Physics, 22030 Edirne, Turkey 

2 Istanbul University, Department of Physics, 34134 Vezneciler / Istanbul, Turkey 

3 Harvard University, Department of Physics, 02138 Cambridge / MA, USA 

Abstract-In this work, we calculate electron and current density distributions in the edge and bulk of 2D 

samples, namely focusing on ideal and non-ideal contacts. A three dimensional Poisson equation is solved selfconsistently 

to obtain the potential profile in the absence of an external magnetic field for gate and etching 

defined devices. In the presence of a perpendicular magnetic field, we obtained the locations of the 

incompressible strips, taking into account electron-electron interaction within the Thomas-Fermi theory of 

screening. Using a local version of Ohm’s law, together with a relevant conductivity model, we also calculate 

the current distribution. We observed that the incompressible strips can be on the edge or at the center of bulk 

under the presence of different magnetic fields. 

Regardless of what system one is interested in 

theoretically, the metallic contacts deposited on the two 

dimensional charge systems are the most important 

ingredients of the measurement. Up to now no 

comprehensive study of contacts is accessible in the 

literature that both take into account interactions, device 

geometry, impurities and formation incompressible and 

compressible regions, which exist due to Landau 

quantization. 

Ι 

It is a formidable task to model the sudden change of 

density of states (DOS) near the contacts, while at the 

metallic region the DOS is approximately infinite, whereas 

at the 2D system the DOS is either constant (without 

magnetic field B) or varies between no DOS at the Fermi 

energy (incompressible [1,2]) and high DOS 

(compressible, with a degeneracy of eB/h). Here, we 

present our self-consistently calculated results which takes 

into account Landau quantization and direct Coulomb 

interactions at a mean-field approximation level [3]. As 

seen from in Figure1 e, the ideal contacts are modeled as 

equipotential lines, where no density poor region resides 

just in front of the contacts. In Figure1 a and c, the nonideal 

contacts are described by density fluctuations near 

the transition region, as indicated by experiments [4,5] 

which essentially influence the current distribution 

drastically. 

We investigated theoretically the current and density 

distributions considering high B fields and intermediate 

electron density concentrations in the close proximity of 

the contacts, together with the entire sample. Our results 

point that, the assumption of ideal contacts cannot be 

justified, when considering density inhomogeneities, 

hence, models based on ideal contacts has to be revised 

[6,7]. Moreover, we present clearly the formation of hotspots 

depending on the current amplitude and field 

direction. 

The authors would like to acknowledge the 

Scientific and Technical Research Council of Turkey 

(TUBITAK) for supporting under grant no 109T083. 

* Corresponding author: denizeksi@gmail.com 

Figure 1: The color coded ( x, y) 

ν for = 

Ω 3.72, 3.02, 2.26 

and k 

BT 

E 0 F 

= 0.058, 0.094, 0.11 (a,c,e) and corresponding 

current distribution indicated by the arrows. The calculations are 

done for a fixed external current driven in the y direction 

−4 

j x, 

y = 0,84× 

10 A m . The 2DES is 150 nm below the 

( ( ) 

) 

surface. 

[1] D. B. Chklovskii, B. I. Shklovskii, and L. I. Glazman, Phys. 

Rev. B 46, 4026 (1992). 

[2] A. M. Chang, Solid State Commun. 74, 871 (1990). 

[3] A. Siddiki and R. R. Gerhardts, Phys. Rev. B 70, 195335 

(2004). 

[4] E. Ahlswede, J. Weis, K. von Klitzing, and K. Eberl, Physica 

E 12, 165 (2002). 

[5] O. Goektas, Ph.D. thesis, Stuttgart University, 2009. 

[6] B. I. Halperin, Phys. Rev. B 25, 2185 (1982). 

[7] M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986). 




Effects of Artificial Pinning Centers on NdBa 2 Cu 3 O 7-δ Thin Films Prepared by PLD 

Erdal Sönmez 1* , Mücahit Yılmaz 2 , Mehmet Yılmaz 1 , Refik Dilber 1 , Bahattin Düzgün 1 and Mehmet Ertuğrul 3 

1 K. K. Education Faculty, Department of Physics, Ataturk University, Erzurum, Turkey 

2 Education Faculty, Department of Physics, Selcuk University, Konya, Turkey 

3 Engineering Faculty, Department of Electric-Electronic, Ataturk University, Erzurum, Turkey 

Abstract— In this study, the effect of artificial pinning centers (APC) on the critical properties of NdBa 2 Cu 3 O 7-δ (Nd-123) superconductive thin 

films grown on Ni-W metallic substrates was investigated. Nd-123 superconductive ceramic materials were prepared by solid state reaction 

technique and then this ceramic material was used as target for the producing Nd-123 superconductive thin films with pulsed laser deposition 

(PLD). APCs were prepared with the deposition of Nd 2 O 3 by PLD. The obtained superconductive thin films were characterized by x-ray 

diffraction (XRD) analysis, morphological investigations of scanning electron microscopy (SEM) and atomic force microscopy (AFM) images, 

and electrical analysis such as R-T and I-V measurements. As a result of these analyses, it was determined that APCs had important role for the 

flux pinning and it provide the increasing about 25% for the critical current value (J c ). 

For many practical applications of high temperature 

superconductors, high critical current densities (J c ), especially 

in the presence of large magnetic fields, are required. High 

temperature superconductivity (HTS) coated conductors 

should employ the optimized flux pinning centers such as 

intrinsic or extrinsic imperfections, which can prevent the 

motion of flux lines, in order to achieve high J c values in the 

presence of high magnetic fields [1-3]. Due to the short 

coherence length in high temperature superconductors, 

nanosized non-superconducting regions are necessary to act as 

effective pinning centers in NdBa 2 Cu 3 O 7-δ (Nd-123) [4-5]. 

In the study, we have grown epitaxial Nd-123 films via 

pulsed laser deposition. Stoicheiometric Nd-123 powder was 

synthesized by using commercially available powders of 

Nd 2 O 3 , BaCO 3 , and CuO with purities of over 99,9% via 

solid-state synthesis at 920 ◦C for 24 h. After, Nd-123 films 

were prepared with a configuration of Ni–3 at.%W 

(50μm)/MgO (30nm)/STO(200nm)/CeO 2 (30nm) via pulsed 

laser deposition using a Kr-F excimer laser (wave length 

θ=248nm) at a repetition rate of 10 Hz at a substrate 

temperature (Ts) of 790 0 C in 1%O 2 /Ar gas at a deposition 

pressure of 800 mTorr. The laser energy density and substratetarget 

distance were 1,5 J cm −2 and 6,5 cm, respectively. 

Besides, to control the density of Nd 2 O 3 nanoislands that they 

will serve as artificial pinning centers (APCs), 1, 5, 10, 25, 50 

and 100 laser pulses for Nd 2 O 3 target ablation were selected. 

Afterwards the films were cooled to room temperature within 

an hour in 500 Torr of oxygen and after depositing sputtered 

Ag electrodes onto the films. Transport properties of the 

samples were measured using the standard four-probe method. 

Phase and textural analysis was undertaken using X-ray 

diffraction (XRD). Surface morphology of films were 

investigated by using scanning electron microscopy (SEM) 

and atomic force microscopy (AFM) images. 

(a) 

(b) 

Figure 2. AFM images of samples a)APCs b)3-D image of Nd-123 

thin film 

Typical AFM image of samples prepared by the 25-pulse 

PLD process is shown in Fig. 2 (a). The Nd 2 O 3 nanoisland 

were formed randomly on the substrates, and each nanoisland 

was isolated and homogeneously distributed. Fig. 2 (b) reveals 

that roughness of the film is 11 nm. 

Figure 3. Temperature versus J c curve of the Nd-123 films at 0 T 

APCs were successfully introduced into Nd-123 thin films 

by the deposition of uniformly distributed Nd 2 O 3 nano-island 

grown on substrate. The density and size of nano-islands were 

controlled by the deposition parameters and AFM. The critical 

current of the Nd-123 thin films grown on substrates with 

nano-islands was enhanced. We reached that best performance 

in Nd-123 thin film prepared with 25 pulses on substrate. This 

condition has been observed by the direct AFM that Nd 2 O 3 

nano-islands effectively generated APCs inside Nd-123 film. 

Fig. 3. show that APCs had important role for the flux pinning 

and it provide the increasing about 25% for the critical current 

value (J c ). 

*Corresponding author: esonmez@atauni.edu.tr 

Figure 1. X-ray diffraction of the Nd-123 thin films 

[1] M. Murakami et al., 1989. Jpn J. Appl. Phys. 28 1189. 

[2] S. Neesleshwar et. al., 1999. Mat. Sci. & Eng. B. 65 164-169. 

[3] K. J. Song et. al., 2006. Physica C 445-448, 656-659. 

[4] P. Mele et. al., 2005. Physica C 426-431, 1108-1112. 

[5] P. Mele et. al., 2006. Physica C 445-448, 648-651. 

6th Nanoscience and Nanotechnology Conference, İzmir, 2010 239



Synthesis of Pyrogallol Stabilized Gold Nanoparticles 

Emrah Bulut 1 * and Mahmut Özacar 1 

1 Sakarya University, Department of Chemistry, 54187 Sakarya, Turkiye 

Abstract-Stable gold nanop articles have been synthesized by reducing HAuCl4 with pyrogallol as both the reducing and stabilizing agents. 

Gold nanoparticles prepare through the reduction of trivalent gold ions to metallic gold, which is accompanied by the simultaneous 

oxidization of the hydroxyl groups of pyrogallol. Then the pyrogallol serves as surfactant to prevent aggregation of gold nanoparticles. A 

reaction mechanism for the reduction of HAuCl4 by pyrogallol is proposed. 

The construction of functional noble metal nanocrystals 

has received increasing interest because their unique optical, 

magnetic, and catalytic properties can be tuned by 

controlling the size, shape, chemical composition, surface 

and interfacial structure, and they have potential 

applications such as in catalysis, biodiagnostics, plasmonics, 

and surface-enhanced Raman spectroscopy [1]. Both 

academia and industry have paid more attention to nano 

gold catalysts and predicted more extensive and increasing 

application prospects [2]. Gold particles of nanometer or 

micrometer size and with unique morphologies are 

particularly attractive materials because of their outstanding 

properties. Consequently, many published reports have 

focused on the preparation of various colloidal 

goldmorphologies, including cubes, belts, rods and wires, 

disks and plates, and urchin-like shapes, among others [3]. 

In recent years, many chemical and physical methods have 

been used to prepare a variety of gold nanoparticles; these 

methods include seed-mediated growth use of reverse 

micelles, phase transfer reactions, thermolysis, radiolysis, 

photochemistry, and sonochemistry. Among these, chemical 

methods are still the preferred method for the preparation of 

gold nanoparticles. The size and shape of gold nanoparticles 

are controlled by the ratio of HAuCl 4 

to the chemical 

reducing agent in the preparation with examples such as 

sodium citrate, borohydride, or other organic compounds. In 

addition, high molecular weight polymers, thiol derivatives 

and other ligands, used as capping regents, are often used to 

control the particle size and shape, prevent aggregation, and 

improve function of the particle surface for application in 

bio-analytical methods [4, 5]. 

In the present study, gold nanoparticles are prepared using 

pyrogallol acting as both the reducing and stabilizing agent. 

A novel method was applied to synthesize gold 

nanoparticles by using pyrogallol which have reduction 

effect with involving -OH groups and keeps the prepared 

particles stable because of its molecular structure. Pyrogallol 

is a polyphenolic compound that may be used as a reducing 

agent, which is obtained from the hydrolysis of natural plant 

polyphenols. Here, we tried firstly to use it as reducing 

agent to prepare nano gold, and gold nanoparticles were 

facilely synthesized by reducing HAuCl4 with pyrogallol at 

room temperature. Since phenolic compounds are easily 

oxidized to form quinones, it was speculated that the 

product of pyrogallol reduction of HAuCl 4 might be a 

quinoid compound. The quinoid compound with keto-enol 

system might be produced by pyrogallol reduction of 

HAuCl 4 and absorbed on the surface of gold nanoparticles. 

A proposed reaction mechanism for the reduction of 

HAuCl 4 by pyrogallol can be ezpressed as shown in Fig. 1 

[4, 6]. 

Produced gold nanoparticles were characterized by XRD, 

SEM and EDS. SEM image, Fig. 2, show that the major 

morphologies of the particles were polygonal plates, 

including triangle and hexagonal shapes. 

HO 

- 3 + 2AuCl 4 Au 0 + 3 + 6H + + 8Cl - 

OH 

OH 

Figure 1. Reduction mechanism of gold ions to the metallicgold 

Figure 2. SEM micrograph of the gold nanoparticles 

Figure 3 shows the XRD pattern of gold nanoparticles., 

Several peaks are observed at 2 = 38.1, 44.4, 64.6, 77.5, 

81.6 and 98.01 o in the diffraction pattern which are in good 

agreement with metallic gold peaks. All facets of single 

crystals parallel to the grid are preferentially along {111} 

planes. Such features indicate the faceted morphology of 

gold microplates and their inherent anisotropy, which is 

important since many optical and electronic properties will 

depend on the orientation of crystal materials [5]. 

Figure 3. XRD pattern of the gold nanoparticles 

*Corresponding author: 0Tebulut@sakarya.edu.tr 

[1] F.-R. Fan, J. Am. Chem. Soc. 130, 6949 (2008). 

[2] J. Li et al., Environ. Sci. Technol. 42, 8947 (2008). 

[3] G. Lin et al., Crystal Growth & Design 10, 1118 (2010). 

[4] W. Wang et al., Colloids and Surfaces A: Physicochem. Eng. 

Aspects 301, 73 (2007). 

[5] L. Wang et al., J. Phys. Chem. B 109, 3189 (2005). 

[6] T. Ogata and Y. Nakano, Water Res. 39, 4281 (2005). 

O 

O 

OH 




Electron rich surfactant capped CdS nanoparticles for hybrid solar cells 

Mahmut Kus 1 *, Alessandra Operamolla 2 , Serhad Tilki 1 ,Esma Yenel 3 3 , Omar Hassan Omar 4 , Francesco 

Babudri 2 , Gian luca M. Farino la 2 

1 Selçuk University, Faculty of Engineering and Architecture, Department of Chemical Engineering, Konya, Turkey 

2 Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, I-70126 Bari, Italy 

3 Selçuk University, Department of Chemistry, Konya Turkey 

4 CNR-ICCOM, Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, I-70126 Bari, Italy 

Abstract-We prepared some oligoarylenes bearing thiolic groups as novel semiconducting surfactants for CdS nanoparticles. Two phase 

synthetic route was used for synthesis of CdS nanoparticles. New surfactants were capped during synthesis or after synthesis by ligand 

exchange. The new nanohybrid structures were characterized by TEM, XRD, optical absorbance and fluorescence emission. 

Colloidal nanocrystals (NCs) have been attracting much 

interest thanks to their excellent and tunable optical 

properties and perspectives of application in fields such as 

optoelectronic, photocatalysis and biological labeling [1- 

5]. Semiconductor quantum dots (QDs) can be fabricated 

via several techniques [6-9]. Oil soluble surfactants such 

as trioctylphosphine oxide (TOPO) and oleic acid (OA) are 

usually adopted in the synthesis for NPs solubilization. 

TOPO or OA capped quantum dots can find interesting 

application in polymer-hybrid light emitting diodes 

(PLEDs). In such devices these electron-inactive surfactant 

are generally preferred to prevent the quenching of light 

emitted by the QDs. However, in solar cells this approach 

is not convenient, because QDs are supposed to take part 

in electron transfer processes. and surfactants such as 

TOPO and OA usually behave as insulators causing the 

drop of the current. 

In this study, we prepared some oligoarylenes bearing 

thiolic groups as novel semiconducting surfactants for CdS 

nanoparticles. We previously reported the synthetic 

procedure to the new compounds [10]. The molecular 

structures of oligoarylenes are given in figure 1. 

R 

I R=H 

II R=alkyl chain 

Figure 1. Molecular structures of oligoarylenes 

S 

Two phase method was used to synthesize CdS 

nanoparticles. New surfactants were capped during 

synthesis or after synthesis by ligand exchange. The new 

nanohybrid structures were characterized by TEM, XRD, 

optical absorbance and fluorescence emission. 

Figure 2a shows scheme of oligoarylene capped CdS 

nanoparticles. It is well known, thiol groups can easily 

anchor to nanoparticles surface. Optical absorption spectra 

(b) shows crystal growth of CdS by reaction time. 

SH 

SH 

Abs 

1.5 

1 

0.5 

a 

0 

250 400 600 

800 

Wavelength [nm] 

b 

Figure 2. Scheme of oligoarylene capped CdS nanoparticles (a) 

and optical absorption of CdS nanoparticles synthesized in 

different reaction time. 

*Corresponding author: mahmut_kus@yahoo.com 

[1] Klabunde, K. J. Nanoscale Materials in Chemistry; Wiley- 

Interscience: New York, 2001. 

[2] Fendler, J. H. Nanoparticles and Nanostructured Films; 

Wiley-VCH: Weinheim, Germany, 1998. 

[3] Weller, H. Angew. Chem., Int. Ed. Engl. 1993, 32, 41. 

[4] Rogach, A. L.; Talapin, D. V.; Shevchenko, E. V.; 

Kornowski, A.; Haase, M.; Weller, H. AdV. Funct. Mater. 2002, 

12, 653. 

[5] Alivisatos, A. P. Science 1996, 271, 933. 

[6] D. Bimberg, M. Grundmann, N.N. Ledentsov, M.H. Mao, Ch. 

Ribbat, R. Sellin, V.M. Ustinov, A.E. Zhukov, Zh.I. Alferov, J.A. 

Lottet al, Phys. Status Solidi B 224 (2001) 787. 

[7] A. Agostiano, M. Catalano, M.L. Curri, L. Chiavarone, M. 

Della Monica, P.M. Lugara`, L. Manna, V. Spagnolo, J. Phys. 

Chem. B 104 (2000) 8391. 

[8] C.B. Murray, D.J. Norris, M.G. Bawendi, J. Am. Chem. Soc. 

115 (1993) 8706. 

[9] Daocheng Pan, Qiang Wang, Shichun Jiang, Xiangling Ji, 

and Lijia An, J. Phys. Chem. C 2007, 111, 5661-5666 

[10] A. Operamolla, O. Hassan Omar, F. Babudri, G. Farinola, 

F. Naso, J. Org. Chem. 2007, 72, 10272-10275. 




The Effect of the Quantum Point Contacts and Impurities on an Electron in the 2D Electron Gas 

Engin Cicek 1 , Mustafa Ulas 2 and Afif Siddiki 3,4 

1 Department of Physics, Trakya University, 22030 Edirne, Turkey 

2 Kirklareli University, Physics Department, Faculty of Arts and Science, Kavakli-Kirklareli, Turkey 

3 Istanbul University, Faculty of Sciences, Physics Department, Vezneciler-Istanbul, 34134, Turkey 

4 Harvard University, Physics Department, Cambridge, 02138 MA, USA 

Abstract— In this work, we investigate the geometrical effects of the single and double quantum point contacts (QPCs) and 

impurity effects on a two dimensional electron gas (2DEG) in the AlGaAs/GaAs heterostructure. For a realistic calculation we 

take into account the crystal growth parameters and the sample geometries. Next, we solve the three dimensional Poisson 

equation using the numerical techniques. We show that the QPC’s shape and impurity properties strongly changes the 

distribution of the two dimensional electron gas (2DEG) and the subband energies of the electron which is the located in the 

2DEG. 

In the last decade, low-dimensional heterostructure 

systems such as thin films (2D), wires (1D) and quantum dots 

(0D) [1-3] have received a great deal of attention because of 

their interesting physical properties [4] and their technological 

applications in electronic and optical devices. Fabrication 

techniques affect the electronic properties of the sample so 

that for a realistic calculations the real sample properties are 

taking into account [5]. 

Here we define a square unit cell, with a surface pattern 

(1.5x1.5 m 2 ) where we process three different techniques 

(gate, etch and trench gate defined) at the each edge of the 

sample in the same direction with 0.5 m. For gate defined 

samples we applied -1.8 V to the gates on the surface, whereas 

for etch defined samples we etched 62.8 nm from the surface 

and for trench gate samples we etch the samples 31.4 nm and 

place gates on this plane with a -1.8 V bias. QPCs are located 

on the surface with a -1.8 V. The two unlike QPC geometries 

(X 2 -X 8 ) are used with three different distances of the QPC’s 

tips. A single impurity is set in the heterostructure at various 

positions and distances from the 2DEG. To obtain the electron 

and potential profiles we solved the electrostatics of the 

system in three dimensions with using a code developed on a 

fourth order grid, which was successfully applied in previous 

studies [6,7]. For a realistic calculation we take into account 

the crystal growth parameters, gate patterns, surface images, 

densities, QPC and impurity properties explicitly. Our results 

can enlighten the experimental structures. In our work, 2DEG 

is located 314 nm below the surface and we dope the 

heterostructures with two donor layers. The upper donor layer 

is 40 nm below the surface and its density is 1.7x10 16 m -2 , 

whereas the other donor layer is located 165 nm below the 

surface with a fixed doping surface density of 2.5x10 15 m -2 . 

These donor layers are distributed homogeneously. We 

compare the electron density distributions and potential 

profiles where we create the 2DEG with different techniques 

(etching, gate and trench gated defined structures), QPC 

shapes and impurity positions. 

As a result, the edge properties of the 2DEG is strongly 

affected by the shape of the QPC, impurity position and the 

which process procedure is used. We can solve the 3D Poisson 

equation iteratively and take into account these properties and 

wafer properties of the sample. So that we obtain deep insight 

of the realistic samples. 

a) 

b) 

Figure: The electron densities of the samples with two different 

shape of the QPCs ((a)X 8 shape (b)X 2 shape) for the trench 

gated structures with a same QPC distances (100nm). It is clear 

from the graphs the X 8 shape QPC is deplete the electrons more 

efficiently. 

*Corresponding author: engin_cicek79@hotmail.com 

[1] H. Akiyama, T. Someya, and H. Sakaki, Phys. Rev. B 53, R10520 

(1996). 

[2] H. Akiyama, T. Someya, and H. Sakaki, Phys. Rev. B 53, R4229 

(1996). 

[3]M. Ulas, E. Cicek and S.S. Dalgic, phys. stat. sol. (b) 241, 2968 

(2004) 

[4] U. Woggon (Ed.), Optical Properties of Semiconductor Quantum 

Dots (Springer, Heidelberg, 1997). 

[5] S. Arslan, E. Cicek, D. Eksi, S. Aktas, A. Weichselbaum, and A. 

Siddiki, Phys. Rev. B 78, 125423(2008). 

[6] A. Weichselbaum and S. E. Ulloa, Phys. Rev E 68, 056707 

(2003). 

[7] A. Weichselbaum and S. E. Ulloa, Phys. Rev B 74, 085318 

(2006). 




UV-Irradiated Synthesis of Silver Nanoparticles in Gallic Acid Solution 

Emrah Bulut 1 * and Mahmut Ozacar 1 

Department of Chemistry, Art and S cience Faculty, Sakarya University, Sakarya 54187, Turkiye 

1 

- 

Abstract-A rapid and facile aqueous-phase UV irradiated method was applied to synthesize silver nanoparticles. Released electrons, (e aq ) which 

formed by irradiation of gallic acid, were used as a reducer to form metallic silver nanoparticles from Ag + cations. 

In recent years, the use of noble metal nanoparticles in 

various fields of research has increased dramatically. This is 

due to not only the bulk properties of noble metals, such as 

chemical stability, electrical conductivity and high catalytic 

activity but also the unique optical, electrical, catalytic 

properties that are a consequence of nanometer dimensions 

[1-3]. Also the antibacterial activity of silver ions and their 

biological impact have been demonstrated by many workers 

[4]. Silver nanoparticles are especially important and thus 

many methods are used for their synthesis i.e. chemical, 

electrochemical and sonoelectrochemical reactions [5-8]. 

In this work, a rapid and facile aqueous-phase method was 

applied to synthesize silver nanoparticles. Gallic acid was 

used as both reducing and stabilizing agent. Mixture of gallic 

acid and silver nitrate solutions was irradiated by UV lamb 

to form silver nanoparticles. In this photochemical reduction, 

hydrated electrons or free organic radicals formed by 

irradiation of UV light reduce the metal ions to metals. It is 

strongly anticipated that these radicals can reduce metal ions 

to metals. 

HO 

HO 

HO 

Figure 2. Molecular structure of gallic acid 

COOH 

Characterizations of the resulting nanoparticles were 

performed by X-Ray Diffraction (XRD), Scanning Electron 

Micrographs (SEM) and Electron Diffraction Spectrometry 

(EDS). Role of the experimental conditions on the particle 

size are presented and discussed. The sizes of silver 

nanoparticles were found to be in the range of 50-150 nm 

using SEM. Also the crystallography of the particles is face 

centered cubic structure which was investigated by XRD 

patterns. 

Figure 3. XRD and EDS Patterns of the silver nanoparticles 

*Coresponding author: 1Tebulut@sakarya.edu.tr 

Figure 1. SEM image of the silver nanoparticles 

Gallic acid was used as a stabilizer as well as a reducing 

agent like other polyphenols as mentioned at previous work 

[9], with involving –OH groups and keeps the prepared 

particles stable because of its molecular structure. Also UV 

induced gallic acids have a strong reactive activity with some 

active species such as hydroxyl radicals (·OH) and can 

released the e - aq with the irradiation of a UV light which is a 

potential reducing agent for some metal cations. However it 

stabilizes the newly born Ag 0 clusters and can influence the 

growth of the nucleation and hence particle size and shape. 

No other reducing agents were used during silver 

nanoparticles synthesis. Effects of reactant concentrations on 

the fabrication of nanoparticles were investigated. 

[1] P. Magudapathy, P. Gangopadhyay, B.K. Panigrahi, K.G.M. 

Nair, S. Dhara, Physica B 299, 142 (2001). 

[2] A. Vaskelis, A. Jagminiene, L. Tamasauskaite–Tamasiunaite, R. 

Juskenas, Electrochimica Acta 50, 4586 (2005). 

[3] J. Xu, X. Han, H. Liu, Y. Hu, Colloids and Surfaces A: 

Physicochem. Eng. Aspects 273 179 (2006). 

[4] F. Mafune, J. Kohno, Y. Takeda, T. Kondow, H. Sawabe, J. 

Phys. Chem. B 104, 9111 (2000). 

[5] Y. Socol, O. Abramson, A. Gedanken, Y. Meshorer, L. 

Berenstein, A. Zaban, Langmuir 18, 4736 (2002). 

[6] J. Zhu, X. Liao, H.Y. Chen, Mater. Res. Bull. 36, 1687 (2001). 

[7] C.R.K. Rao, D.C. Trivedi, Mater. Chem. and Phy. 99, 354 

(2006). 

[8] E. Verne, S. Di Nunzio, M. Bosetti, P. Appendino, B. C. Vitale, 

G. Maina, M. Cannas, Biomaterials 26, 5111 (2005). 

[9] E. Bulut, M. Özacar, Ind. Eng. Chem. Res. 48, 5686 (2009). 


P 



Structural, surface and catalytic properties of individual and binary Ni and Ce oxides system 

N. M. Deraz 1 

PChemistry Department , College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia 

1 

Abstract-NiO, R CeOR2 and R NiO/CeOR2 catalysts were prepared obtained by ceramic and wet impregnation routes followed by 

calcination at 400 °C, respectively. The crystalline phases produced by calcination the mentioned temperature were characterized 

by XRD measurement. The microstructure, surface and catalytic properties of the calcined products of various solids were 

determined by transmission electron microscope, nitrogen adsorption at °C and isopropanol dehydrogenation at different 

temperatures. The results reveled that the crystallite sizes, specific surface areas and catalytic activity of individual o xides were 

smaller than those of binary system. The binary oxides calcined at 400 1T°1TC constituted of well crystalline Ni and Ce oxides. A 

portion of NiO dissolved in R CeOR2 lattice in the binary oxides system by heating at 400 °C and the other portion remained as a 

separate phase. The dissolution process resulted in the formation of Ni-Ce-O compound with subsequent decrease in the degree of 

crystallinity of NiO and CeOR2 Rphases. The activation energy of the catalytic reaction was determined for various investigated 

solids and was found to be dependent on the nature of the as-prepared system. 

Metal oxides as catalytic materials were used in many 

important commercial catalytic reactions [1-5]. There are 

various parameters, such as suitable support and doping with 

certain foreign cations, must be considered in order to improve 

the catalytic activity and selectivity of these oxides employed 

in some different industrial reactions [1-3]. The supporting on 

a suitable carrier results in an increase in the dispersion of 

catalytically active constituents and increases their thermal 

stability via hindering their grain growth [1, 5]. The catalytic 

activity of most of transition metal oxides can be greatly 

improved by their loading on a suitable support such as 

alumina, silica, magnesia and ceria [1-5]. 

Nickel has emerged as a possible alternative catalyst due to 

its low cost but tends to deactivate by coke formation. The use 

of suitable support and/or dopant such as R CeOR2 as support in 

the preparation of traditional Ni based catalysts can contribute 

to enhance the catalytic activity and reduce the coke formation 

[6]. The important role of ceria played in catalytic reactions, is 

suggested to be the generation and participation of surface 

oxygen species and anionic vacancies [7, 8]. Various studies 

have shown that the redox properties of metal oxide can be 

significantly enhanced if additional elements are introduced 

into its lattice depending upon forming a solid solution [7, 8– 

10]. Previous studies on Pt and Cu supported on R CeOR2 

catalysts have shown that strong metal-ceria interactions, by 

formation of solid solution in the mixed o xides catalyst [7, 11, 

12]. The strong metal-to-support interaction appeared as one 

of the reasons of the observed high catalytic activity and 

stability during the hydrocarbons’ partial oxidation and 

oxidative steam reforming. 

The catalytic conversion of isopropanol has been probed in 

the past by many workers over various solids like clays [13], 

perovskites [14] aluminophosphates [15-17] spinel ferrite [18] 

and ceria [19]. On acidic catalytic surfaces the reaction 

proceeds via dehydration to alkenes while on metallic or basic 

surfaces via dehydrogenation to ketone and/or aldehyde. The 

ceria based catalysts have been extensively scrutinized in 

redox applications [19]. Such applications stem from the wellknown 

ability of cerium oxides to store oxygen when in 

oxidative atmosphere and release it when in reductive one. 

In the present work, a comparative study on the structural, 

morphological, surface and catalytic properties of the 

individual and binary Ni and Ce oxides has been determined. 

Since the metal- support interaction often plays a key role in 

determining the details of the previous properties; one 

objective of this investigation is to establish the relationship 

between the surface and catalytic characteristics and the 

metal-support interaction by applying the Ni/Ce mixed oxide 

o 

catalysts calcined at 400 P PC to R NR2 adsorption and catalytic 

conversion of isopropanol. 

*Corresponding author: 2Tn.deraz@yahoo.com2T 

[1] N. M. Deraz, M.M. Selim and M. Ramadan, Mater. Chem. Phys. 

113 (2009) 269. 

[2] N. M. Deraz, Colloid. Sur. A 207 (2002) 197. 

[3] N.M. Deraz, Colloid. Sur. A 218 (2003) 213. 

[4] N. M. Deraz, Chin. J. Catal. 29(8)(2008)687. 

[5] N. M. Deraz, Appl. Sur. Sci. 255 (2009) 3884. 

[6] L. Wenying, F. Jie, X. Kechang, React. Kinet. Catal. Lett. 

64(1998)381. 

[7] N. Laosiripojana, S. Assabunsrungrat, J. Power Sources 

158(2006) 1348. 

[8] A. Trovarelli, C. de Leitenburg, G. Dolcetti, Chemtech. 

27(1997) 32. 

[9] H. S. Potdar, H.-S. Roh, K.–W. Jun, Ji M, Z.-W. Liu, C atal. Lett. 

84(2002)95 

[10] Yisup N, Cao Y, Feng W-L, Dai Ws-L, Fan K–N (2005) Catal 

Lett 

99:207 

[11] Pino L, Vita A, Cordaro M, Recupero V, Hegde MS (2003) Appl 

Catal A 243:135 

[12] L. Pin 

A 306(2006) 68. 

[13] A.K. Ladavos, P.N. Trikalitis, P.J. Pomonis, J. Mol. Catal. A: 

Chem. 106 (1996) 241. 

[14] P.N. Trikalitis, P.J. Pomonis, Appl. Catal. A 131(1995)309. 

[15] D.E. Petrakis, P.J. Pomonis, A.T. Sdoukos, J. Chem. Soc. 

Faraday Trans. 85 (1989)3173. 

[16] D.E. Petrakis, P.J. Pomonis, A.T. Sdoukos, J. Chem. Soc. 

Faraday Trans. 87 (1991) 1439. 

[17] K.M. Kolonia, D.E. Petrakis, A. K. Ladavos, PCCP 5 (2002) 

217. 

[18] N.M. Deraz, M.K. El-Aiashy, Suzan A. Ali, Adsorp. Sci. 

Technol. 27(8)(2009), In Press. 

[19] N.M. Deraz, A. Alarifi, Adsorp. Sci. Technol. 27(4)(2009)413. 




Characterization of NiS and SrS nanoparticles synthesized by solid-gas reaction of sulfidizing gas 

mixture 

Halil Guler 1 and Figen Kurtulus 1 * 

Balikesir University, Faculty of Science, Chemistry Department, , Balikesir 10145, Turkey 

1 

Abstract- In this study, the sulfidizations of NiO, SrNO 3 and SrCO 3 were investigated by using solid-gas reactions under sulfidizing gas 

mixture, which contains the gas mixture of carbonyl sulfide (COS), carbon disulfide (CS 2 ) and sulfur (S 2 ). The powder crystalline forms of 

nickel sulfide (NiS) and strontium sulfide (SrS) were prepared purely by solid-gas reaction technique. The product crystalline phases were 

characterized by the X-Ray Diffraction (XRD) technique. XRD data of the NiS and SrS were in good agreement with the Joint Committee 

for Powder Diffraction Systems (JCPDS) card numbers, 2-1280 and 8-489 in series. The crystalline grain sizes of samples were estimated by 

using Debye Scherrer formula. The grain sizes of the products are in the range of nano sizes. In light of this study, it could be proposed that 

the compounds, NiS and SrS could be prepared purely through sulfidizing gas mixture by solid-gas reactions under cooling of a nitrogen 

atmosphere. 

Metal chalcogenide nanocrystals such as NiS, ZnS, SrS, 

CdS and PbS have attracted great interest in recent years 

owing to their unique properties in physics and chemistry 

that significantly differ from those of their bulk 

counterparts. These types of material usually show novel 

0,9 

optical, electronic and magnetic properties due to their 

D 

peculiar quantum-size effect and large specific surface 

B cos 

B 

areas. Therefore, these metal sulfides have important 

applications in the field of opto-electronic technology and 

fabrication of photo catalysis materials [1,2]. Nickel 

sulfide nanoparticles have been used as IR detectors, solar 

storage devices, photoconductive materials and 

hydrodesulfurization catalysis [3,4]. The electromagnetic 

property of the nickel sulfide (NiS) is also interesting since 

it transforms fro m a paramagnetic metal to an 

antiferromagnetic semiconductor upon cooling under the 

transition temperature Tt 

~379 0 C [5]. Finally, the SrS 

was used to obtain an efficient blue phosphor light for the 

full color thin film electro lu minescent (TFEL) display 

products for many years [6]. 

On the experimental practice, the NiS and SrS were 

prepared separately through solid gas reaction of 

sulfidizing gas mixture of COS, CS 2 , and S 2 with the 

initial reactants of NiO and SrNO 3 (and also SrCO 3 ). 

The XRD patterns of the products NiS and SrS are given 

in Figure 1. As shown, the experimental XRD data of the 

NiS and SrS were in good agreement with the ICDD card 

numbers 2-1280 (crystal system was unidentified) and 8- 

489 (cubic structure, a = 6.020Å, space group = Fm3m and 

Z = 4), respectively. We obtained the same XRD patterns 

for the SrS with the sulfidization of the raw materials, 

SrNO 3 and SrCO 3 . It could be concluded that both initial 

reactants could be used as an initial reactant for the 

synthesis of SrS. 

The crystalline grain sizes of the synthesized products of 

the metal sulfides, NiS and SrS, were calculated by using 

Debye Scherrer formula [7]. The Scherrer equation is 

written as follows: 

(1) 

Where in the equation (1), is the wavelength of the X-ray 

radiation and B is the full width at half maximum of peak 

of the XRD pattern. The grain sizes (D) of the NiS and SrS 

were calculated as 25.871 and 98.690 nm, respectively. 

The results show that the crystalline grain sizes of the NiS 

and SrS have in the range of nano extension. 

In light of this study, it could be proposed that the 

compounds, NiS and SrS could be prepared in nano 

extention and purely through sulfidizing gas mixture by 

solid-gas reaction under cooling of a nitrogen atmosphere. 

*Corresponding author : fdemiral@balikesir.edu.tr 

[1] I. Honma, S. Hirakawa, K.Yamada, J.M. Bae. Solid State 

Ionics, 118, 29 (1999). 

[2] M.L. Curri, R. Comparelli, P.D. Cozzoli, G. Mascolo, A. 

Agostiano. Mater. Sci. Eng., C, Biomim. Mater., Sens. Syst., 23, 

285 (2003). 

[3] W.J.J.Welters, G. Vorbeck, H.W. Zandbergen, J.W. Dehaan, 

V.H.J. Vansaten, R.A. Vansaten. J. Catal. 150, 155(1994). 

[4] S.D. Sartale, C.D. Lokhande. Mater. Chem. Phys., 72, 101 

(2001). 

[5] D.W. Bishop, P.S. Thomas, A.S. Ray. Mater. Res. Bull., 33, 

1303 (1998). 

[6] Sey-Shing. Sun Displays, 19, 145 (1999). 

[7] B.D. Cullity, Elements of X- ray diffraction, 2nd Edition, 

AddisonWesley, Reading, MA (1978). 

 

100 

311 

222 

110 

331 

420 

400 

200 

220 

102 

a) 

b) 

111 

101 

103 

201 

200 

004 202 

2 theta(degree) 

Figure 1. XRD patterns of a)NiS and b)SrS. 




Synthesis and Characterization of ZnO Nano Powde rs Used in Rubber Technology 

1 *, Ali Murat Soydan 2 and Cem Bulent Ustundag 3 

1 Kocaeli University, Faculty of Engineering, Department of Metallurgical and M aterials Engineering, Kocaeli 41380, Turkey 

2 Gebze Institute of Technology, Faculty of Engineering, Department of Materials Science and Engineering, Gebze/Kocaeli 41400, Turkey 

3 Yildiz Technical University, Vocational School Ceramic Department, Maslak/Istanbul 34398, Turkey 

Abstract-In this study synthesis and characterization of nano sized ZnO powders, which are commonly used in various industrial applications 

especially used in tire industry, were done. Zn(NO 3 ) 2 , NH 3 and NaOH were used as raw starting materials. Nano sized Z nO powders were 

produced by applying chemical (precipitation) and thermal processes to raw materials. Contrary to the product morphology of American and 

French techniques known at the literature, it is observed that the obtained powders were in spherical structure with considerably high specific 

surface area (~39 m 2 /g) and nano particle size distribution (5–300 nm). 

ZnO usage in tire manufacturing technology as an 

activator for tire vulcanization, as a direct accelerator and 

hardening filler at “neoprene” and “Thiokol” type synthetic 

rubber processing, is really important [1]. Especially it’s 

usage as a reinforcement material for the resistance of the 

tires against shearing and tearing becomes really essential 

at high speed tires [2]. For this types of applications, 

homogeneous ZnO distribution at the structure and 

complete wetting to prevent the porosity formation is 

required [2]. Because of the stick/needle like structure of 

ZnO manufactured by American and French techniques, it 

is really hard to obtain complete wetting and consequently 

%100 reinforcement at tire manufacturing [2]. For this 

reason spherical ZnO powders are desired. ZnO; has 

various areas of usage such as varistor, gas sensors, 

catalysts and pigments. And also added to glass structure as 

a stabilizer in order to increase the chemical stability. By 

the way ZnO helps to set the properties such as chemical 

resistance, index of refraction and dielectric constant of the 

glass[3]. At all these kinds of applications chemical 

composition (impurity), morphology (spherical powder 

structure), micro structural properties, particle size and 

distribution (powders with high specific surface area) of the 

ZnO is really important. These powder properties strongly 

depends on the manufacturing process and process 

parameter [3, 4]. 

There are 3 commonly used technique in ZnO 

manufacturing: a) American Process, b) French Process and 

c) Wet (chemical) Process. At American technique the 

manufactured ZnO powders are in needle structure [5]. 

After a controlled grinding process, specific surface area of 

the powder is known to be around 1-2 m 2 /g [5]. By the way 

ZnO manufactured by French technique has a complex 

structure. Zn is obtained by the burning of the metal [5]. 

After a controlled grinding process, specific surface area of 

the powder is found to be around 4-5 m 2 /g [5]. ZnO 

manufactured by different chemical techniques is highly 

pure and depending on the process control high quality 

powders with high specific surface area around 4-75 m 2 /g 

can be obtained [5]. 

In this study nanocrystalline ZnO powders were produced 

by using chemical techniques. Precipitation and Sol-gel 

methods are widely used as chemical processes in literature 

[6]. Despite the fact that powders manufactured with sol-gel 

method exhibits better powder characteristics and better 

performance especially at ceramic applications, it’s high 

unit costs makes precipitation, which is simple and carry 

lower costs, more favorable. Product characteristics at ZnO 

production with the precipitation method from Zn(NO3) 2 , 

ZnCl 2 and ZnSO 4 solutions can be controlled by chancing 

the process parameters (temperature, catalyst type, feeding 

amount, speed and contact surface ) [6-9]. But at both 2 

methods, due to the draying treatment at production stage 

powder size becomes massive and the agglomerates are 

hard. Consequently a grinding operation must be applied to 

the powders before forming, in order to use at composite 

material manufacturing or etc. At grinding process 

undesired manufacturing results like high costs and 

impurities can come across. 

In this study precipitation technique is modified and 

applied to a different system. By combining methods such 

as precipitation and spray pyrolysis, nano sized ZnO 

powders with high purity and high quality were obtained. 

Manufacturing of ZnO powders with desired powders 

characteristics such as spherical structure, controlled grain 

size and high wetting ability can be obtained and the 

formation of agglomerates can be eliminated with changing 

parameters like the fluid environment of Spray Pyrolysis 

machine, working pressure and temperature. Thermal, 

physical and micro structural characterizations were done 

by using Differential Thermal Analysis (DTA), 

Thermogravometric Analysis (TG), X-ray Diffraction 

(XRD), Scanning Electron Microscope (SEM), 

Transmission Electron Microscope (TEM), BET and 

Nanosizer apparatus. 

The requirement for a grinding operation at the spherical 

agglomerates could be eliminated by the nano sized 

manufactured ZnO powders with nano crystalline structure. 

Powders are μm sized, spherical soft agglomerates, which 

can be easily broken and disperse at forming operations. 

This work was supported by TUBITAK; project No. 

108M 124. 

*Corresponding author: oyildiz@kocaeli.edu.tr 

[1] – orisi ve 

 

15-16 Eylül 1997 – Ankara 

[2] US Patent, Application No. 20050027054 “Rubber 

composition containing nanoscaled zinc oxide particles”, 

Goodyear Tire & Rubber Co., February 2005 

[3] -Seramik Malzemeler, Metalurji 

 

[4] E. Sokullu; http://www.teknointel.com; Lastik Sanayiinde 

ZnO'in Rolü 

[5] Th. Guilmin, BPRI Latex, 2003 

[6] C.-H. Lu, C.-H. Yeh, Materials Letters, 33 (1997) 129–132 

[7] M. Castellano, E. Matijevic, Chem. Materials, 1 (1989) 78 

[8] T. Tsuchida, S. Kitajima, Chemistry Letters, 19 (1990) 1769. 

[9] D. Chen, X. Jiao, G. Cheng, Solid State Communications, 113 

(2000) 363–366 

[10] S. Sahoo, M. Maiti, A. Ganguly, J.J. George, A.K. 

Bhowmick, Journal of Applied Polymer Science, 105 (2007) 

2407–2415 

[11] S. Sahoo, A.K. Bhowmick, Journal of Applied Polymer 

Science, 106 (2007) 3077–3083. 




A rapid synthesis and charac terization of nano-crystalline CoCr 2 O 

4 

Figen Kurtulus 

1 and Gulsah Celik 2 * 

1 Balikesir University, Faculty of Science, Chemistry Department, Balikesir 10145, Turkey 

2 Balikesir University, Science Institute, Balikesir 10145, Turkey 

Abstract- Nanocrystalline cobalt chromite (CoCr 2 O 4 ) was synthesized by rapid microwave method using Cr(NO 3 ) 3·9H 2 O and 

Co(NO 3 ) 2·6H 2 O raw materials with molar ratio 1:2. The synthesized product was characterization by powder X-ray diffraction and Fourier 

Transform Infrared Spectroscopy. Nanocrystalline CoCr 2 O 4 (ICDD Card no:78-0711) crystallizes in the face-centered cubic system, space 

group Fd 3 m (227), with cell parametres a = 8.334 Å and V = 578.97 Å 3 . The cristalline grain size of CoCr 2 O 4 was calculated as 83,5 nm 

by Debye Scherrer Formula. 

In recent years, spinel-type oxides based on 3d 

transitation metals have been the subject of increasing 

fundamental and applied research because of their catalytic 

properties [1,2]. Spinels are represented by the Formula 

AB 2 O 4 , in which A ions are generally divalent cations 

occupying tetrahedral sites and B ions are trivalent cations 

in octahedral sites; this is the structure of most chromites 

[3]. On the other hand, magmetism of small particles has 

generated increasing interest due to their unique magnetic 

properties as well as their technological applications [4-7]. 

CoCr 2 O 4 , has been widely used as dye, catalyst and 

substrate for film growth [8]. However, few articles have 

reported the synthesis and magnetic of CoCr 2 O 4 

nanocrystallites [9]. Synthesis of nanocrystalline cobalt 

chromite by different route like co-precipitation method, 

thermolysis of polymer-metal complex precursor at a high 

temperature for a long time or at low temperature for a 

relatively short time have been attempted in the literature 

[9,10]. The goal of this study is to synthesis 

nanocrystalline Co Cr 2 O 4 by an alternatie and relatively 

new microwave asisted method and investigate its 

structural properties 

A rapid synthesis route of nanocrystalline CoCr 2 O 4 is as 

follows: Cr(NO 3 ) 3·9H 2 O and Co(NO 3 ) 2·6H 2 O were 

grounded in a agate mortar in a 1:2 molar ratio, and 

transfer into a porcelain crucible in powder form and 

subjected to microwave treatment in a domestic 

microwave oven (2.45 GHz, 750 W). The final product 

was homogenized. Structural properties of the material 

was determined by XRD (PANanalytical X’Pert PRO). 

Fig. 1. shows the XRD pattern of synthesized product. 

Comparison of the XRD pattern with the Standard ICDD 

result in corresponds to CoCr 2 O 4 (ICDD Cart no:78- 

0711). The broad XRD lines indicate that the product is in 

the range of nanosize. Few characteristic peaks of 

impurities, indicating other forms of cobalt oxide (ICDD 

Cart no:72-1474), CoO, were detected. 

 

KT-MD29-2030 

+ + 

+ 

+ 

* 

+ 

20 30 40 50 60 70 

2 theta(degree) 

Figure 1. XRD pattern of CoCr 2 O 4 

FT-IR analysis performed for p repared sample and 

spectra are presented in Fig. 2. Two significant peaks 

are 

observed in the range of 400-650 cm 

for the sample; the 

vibration frequency at 648,31 cm -1 is characteristic Co-Ostretching 

modes in tetrahedral sites, whereas vibration 

+ 

+ 

+ CoCr 2O 4 

* CoO 

* + + 

* + 

551,32 cm -1 corresponds to the Cr-O in an octahedral 

environment. The absorption band observed at ~ 1650 cm -1 

prove the presence of absorbed water on the surface of the 

nanocrystals. 

%T 

1652 

Figure 2. FT-IR spectrum of CoCr 2 O 4 

In summary, Co Cr 2 O 4 nanoparticles were successfully 

prepared by a rapid microwave method. Nanocrystalline 

CoCr 2 O 4 (ICDD Card no:78-0711) crystallizes in the facecentered 

cubic system, space group Fd3 

m (227), with cell 

parametres a = 8.334 Å and V = 578.97 Å 3 . Average 

particle size was calculated from XRD pattern by Debye 

Scherrer Formula [11]. Scherrer demonstrated in 1918 that 

the size of a diffracting crystallite is directly related to the 

width of the X-ray diffraction peaks arising from its 

crystalline structure. For crystallite sizes less than about 

100 nm, this size-induced peak-broadening effect may be 

measured accurately enough to deduce an average grain 

size in the sample. The grain size (D) of the CoCr 2 O 4 was 

calculated as 83,5 nm. The result shows that the crystalline 

grain size of the CoCr 2 O 4 has in the range of nano 

extension. 

*Corresponding author : 0Tgulsahcelik@bau.edu.tr 

[1] R. Sundararajan, V. Srinivasan, Appl. Catal. 73, 165 (1991). 

[2] Y. Liang, R. Tong, W. Xiaolai, J. Dong, S. Jishuan, Appl. 

Catal. B 45, 85 (2003). 

[3] N. Russo, D. Fino, G. Saracco, V. Specchia, Catal. Today 

119, 228 (2006). 

 

 

[5] V.F. Puntes, K.M. Krishnan, A.P. Alivisatos, Science 291, 

2115 (2001). 

[6]Phys. Rev. B 51, 

2995 (1995). 

[7] H.L. Huang, J.J. Lu, Appl. Phys. Lett. 75, 710 (1999). 

[8] G. Hu, Y. Suzuki, Phys. Rev. Lett. 89, 276601 (2002). 

[9] L. Shandong, Z. Guoxia, B. Hong, H. Zhigao, L. Heng, G. 

Rongquan, D. Youwei, J. Magn. Magn. Mater. 305, 448 (2006). 

[10] S.D. Li, H. Bi, Z.J. Tian, F. Xu, B.X. Gu, M. Lu, Y.W. Du, 

J. Magn. Magn. Mater. 281, 11 (2004). 

[11] B.D. Cullity, Elements of X- ray diffraction, 2nd Edition, 

AddisonWesley, Reading, MA (1978). 

cm -1 

648 551 




A Compact Nanostructure Enhanced Heat Sink with Flow in a rectangular channel 

Muhsincan Sesen 1 ,Berkay Arda Kosar 1 , Berk Ahmet Ahishalioglu 1 , Wisam Khudhayer 2 , Tansel Karabacak 2 and Ali Kosar 1,* 

1 Sabanci University, Tuzla 34956, Turkey 

2 University of Arkansas at Little Rock, Little Rock, AR, 72204, USA 

Abstract— This paper reports a compact nanostructure based heat sink. The system has an inlet and an outlet valve similar to 

a conventional heat sink. From the inlet valve, pressurized deionized-water is propelled into a rectangular channel (of 

dimensions 24mmx59mmx8mm) which houses a flat plate, on which ~600 nm long copper nanorods with an average diameter 

of 150 nm are integrated to copper thin film coated on silicon wafer surface. Forced convective heat transfer characteristics of 

the nanostructured plate are investigated using the experimental setup and compared to the results from a flat plate of copper 

thin film deposited on Silicon substrate. The nanorods integrated on the flat plate act as fins over the plate which enhances the 

heat transfer from the plate. 

In the design processes of many mechanical and chemical 

devices one of the key issues of saving energies and achieving 

compact designs is the enhancement of heat transfer [1]. As 

heat transfer is enhanced, the cooling process becomes more 

efficient. In designing of heat exchangers for spacecrafts, 

automobiles, MEMS devices and micro-processors it is really 

important that the heat exchanger is kept compact and 

lightweight [2]. For the purpose of making compact and 

efficient heat exchangers, heat transfer enhacement with 

nanostructures could be considered as a futuristic candidate. 

Recently, many studies have been going on for enhancing 

the convective heat transfer by enlarging the transfer surface 

using extended surfaces like fins and ribs [1,3-5]. These 

modifications enlarge the heat transfer surface area and 

provide high heat transfer rates but their drawback is increased 

friction factor and unwanted pressure drops. Using pin-fin 

structures causes pressure losses which is a significant 

problem in many thermo-fluid applications and designs [1]. 

These pressure losses occur because of the friction force 

formed due to the increased flow resistance imposed by pinfins. 

copper thin film deposited on Silicon substrate, to enhance 

heat transfer via single-phase flow in a rectangular channel. 

Heat transfer coefficients of the system were reduced for a 

constant heat flux scenario up to 6.5W/cm 2 and it has been 

shown that the nanostructured plate enhances heat transfer 

significantly because the surface area is greatly enhanced and 

thus heat removal takes place more effectively. The advantage 

of such a system is that it does not cause any significant extra 

pressure drop and thus does not raise friction factor. Pin-fin 

geometry imposed by nanorods on the plate (integrated to the 

channel wall) is on the nanoscale order so that the friction 

forces induce minor pressure losses. 

Figure 1. Cross-section views of glancing angle deposited (GLAD) Cu 

 

To achieve positive effects on heat transfer coefficients 

with diminishing length scale and high heat transfer 

performance due to enhanced heat transfer area, 

nanostructured surfaces have been used in more recent studies. 

Nanostructured surfaces have been most widely employed in 

pool boiling [6,7]. Different from the state of the art, this 

paper utilizes nanostructures in a forced convective heat 

transfer scheme so that their potential could be exploited from 

a different perspective. 

For this purpose, this article proposes a nanostructured 

flat plate, on which vertical copper nanorods of length 

~600nm and average diameter ~150nm are integrated to 

Figure 21.5PSI and 2.5PSI 

*Corresponding author: kosara@sabanciuniv.edu 

[1] Kunugi, T., Muko, K., Shibahara, M., Superlattices and Microstructures, 

35, pp. 531-542, 2004. 

[2] Stone, K.M., ACRC TR-105, 1996. 

[3] Zamfirescu, C., and Feidt, M., Heat Transfer Engineering, 28(5), pp. 451- 

459, 2007. 

[4] Zamfirescu, C., and Bejan, A., Int. J. of Heat and Mass Transfer, 46, pp. 

2785–2797, 2003. 

[5] Qu, W., and Siu-Ho, A., J. Heat Transfer, 130(12), pp. 124501-124504, 

2008. 

[6] Sesen, M., Khudhayer, W., Karabacak, T., Kosar, A., Micro&Nano 

Letters, (in press), 2010. 

[7] Li, C., Wang Z., Wang P.-I., Peles Y., Koratkar N., and Peterson G., 

Small, 4(8), pp. 1084–1088, 2008. 




Synthesis and Structural Characterization of LiZn 0.5 Mn 1.5 O 4 Cathode Materials 

Burçak Ebin*, Sebahttin Gürmen, Cüneyt Arslan 

Metallurgical and Materials Eng. Dept., Istanbul Technical University, Istanbul 34469, Turkey 

Abstract – LiZn 0.5 Mn 1.5 O 4 nanoparticles were synthesized by ultrasonic spray pyrolysis method as a cathode material 

in lithium ion batteries. Stoichiometrically dissolved lithium, manganese and zinc nitrates in distilled water were used 

as precursor solution. The product characteristics, such as particle size and morphology, chemical composition, 

crystal structure and crystalline sizes were investigated by X-ray diffraction (XRD), scanning electron microscope 

(FE-SEM) and energy dispersive spectroscopy (EDS). 

Developments in electronically industry have 

increased the demand of portable energy storage 

devices with low cost, environment friendly and 

high energy density. Lithium ion batteries have 

satisfied this demand to a greater degree than other 

battery systems. Although, the commercial cathode 

material for lithium ion batteries is layer structured 

LiCoO 2 , it has some drawbacks such as high cost, 

toxicity and instability at high potential [1-3]. 

Therefore, many researchers have been extensively 

studying alternative materials that have high energy 

density and cycling performance [2-5]. 

Among the promising candidates for the cathode 

materials, the spinel LiMn 2 O 4 has economical and 

environmental advantages as compared to the 

layered compounds [6-7]. However, there is 

problem of capacity fading during charge/discharge 

cycling of the LiMn 2 O 4 cathode material due to 

fracture of the structure [1,3,6-8]. 

Different studies realized to increase the 

performance of this material by partial substitution 

of monovalent and multivalent cations for 

manganese ions [1,7]. It is reported that zinc doping 

to the LiFePO 4 cathode structure enlarge the lattice 

volume without any damage to structure and 

deintercalation and intercalation of the lithium ions, 

the doped zinc atoms protect the crystal [8]. In this 

study, zinc doped spinel LiMn 2 O 4 structure to 

increase the stability of the structure and spinel 

structured LiZn 0.5 Mn 1.5 O 4 nanoparticles formed by 

ultrasonic spray pyrolysis method. 

Spinel LiZn 0.5 Mn 1.5 O 4 cathode particles were 

fabricated by ultrasonic spray pyrolysis method 

from mixer of lithium nitrate, zinc nitrate and 

manganese nitrate. Metal nitrates with atomic ratio 

Li:Zn:Mn=1:1/2:2 dissolved in a distilled water to 

prepare precursor solution and the total 

concentration of the total metal nitrates was 0.35 

mol/dm 3 . Aerosol droplets of the precursor solution 

was generated by ultrasonic atomizer with 1.3 MHz 

frequency, and then aerosol droplets was introduced 

into the furnace at 800°C by air carrier gas with the 

500 ml/min flow rate. The pyrolyzed particles were 

calcinated at 600°C for 2 h under air atmosphere. 

The crystalline phase and size of the samples were 

investigated by X-ray diffraction. Scanning 

electron microscope was used to determine particle 

size and morphology. Also, energy dispersive 

spectroscopy (EDS) was used to determine the 

chemical composition of the samples. 

Figure 1. SEM image of LiZn 0.5 Mn 1.5 O 4 nanoparticles 

Figure 1 shows that spherical LiZn 0.5 Mn 1.5 O 4 

nanoparticles, nearly 50 nm particles size, were 

synthesized by ultrasonic spray pyrolysis method. X- 

ray diffraction patterns indicate that particles have 

spinel structure with simultaneous 1:1 tetrahedral and 

1:3 octahedral cation ordering. Zn 2+ and half of the 

Li + cations occupy tetrahedral sites and Mn 4+ and 

other half of the Li + cations occupy octahedral sites 

in the structure. 

This study has been supported by ITU-BAP with 

a grant number 33242. 

*Corresponding author: ebinb@itu.edu.tr 

[1] C.H. Lu, et al., Mater. Chem. Phys., 112:, 115-119 (2008). 

[2] S.H. Park, S.W. Oh, Y.K. Sun, J. Power Sources, 146, 622-625 

(2005). 

[3] S.H. Park, et al., Electrochimica Acta, 49, 557-563 (2004). 

[4] X. Cao, et al., Mater. Res. Bull., 44, 472-477 (2009). 

[5] X. Sihi, et al., Mater. Chem. Phys., 113, 780-783 (2009). 

[6] I. Taniguchi, D. Song, M. Wakihara, J. Power Sources, 109, 

333-339 (2002). 

[7] I. Taniguchi, Mater. Chem. Phys., 92, 172-179 (2005). 

[8] K. Matsuda, I. Taniguchi, J. Power Sources, 132, 156-160 

(2004). 

[9] H. Liu, et al., Electrochem. Commun., 8, 1553-1557 (2006). 




Investigation of nucleation and growth mechanism during formation of poly(azure A) 

Emrah Kalyoncu, Kader Dacı, brahim Hakkı Kaplan, Ezgi Topçu, Murat Alanyalıolu* 

Department of Chemistry, Sciences Faculty, Atatürk University, Erzurum 25240, Turkey 

Abstract—Nucleation and growth mechanism during formation of poly(AA) films on gold substrates was intestigated. Repeated potential 

cycling by using cyclic voltammetry and potential controlled electrolysis techniques have been performed to synthesize poly(AA) thin films on 

gold working electrodes in the solution containing 0.1 mM AA and 0.1 M phosphate solution (pH:6.2). Chronoamperometry, STM (Scanning 

Tunneling Microscopy), AFM (Atomic Force Microscopy), and UV-vis. absorption spectroscopy techniques were applied for the characterization 

of prepared polymeric films. 

Dye polymer films show excellent catalytic and 

photoelectrochemical properties and have been applied for 

batteries and electrodes, electrochromic devices, light emitting 

diodes, and immobilizitaion of enzymes [1,2]. Dye polymer 

films must have a well-ordered surface to be used in these 

technological applications. Electropolymerization is one of the 

simple and useful method to obtain dye polymer films. In the 

electropolymerization process, deposition of polymeric dye 

film on the electrode surface is achieved by constant or cycled 

potential oxidation of a dye-containing solution. Azure A is a 

derivative of phenothiazine dye material (Figure 1). 

for progressive case. Growth of nuclei is slow for 

instantaneous nucleation and fast for progressive nucleation 

[7,8]. According to Li and Albery [9], two possible 

mechanisms are possible for polymer films: Progressive twodimensional 

layer-by-layer nucleation and instantaneous threedimensional 

nucleation and growth. In this study, 

chronoamperometry data (Figure 2) that is obtained during 

potential controlled electrolysis has been compared with 

theoretical data to determine the nucleation and growth 

mechanism of poly(AA). 

. 

Figure 1. Chemical structure of azure A 

The redox behaviour of dyes has been under study for nearly 

65 years [3-7]. Chen et al. [6] prepared poly(AA) films in 

different pH’s and found that the optimum pH of the 

electrolysis solution is 6.0. It is known that the film growth of 

polymeric films of dyes is related to the upper potential limit 

besides pH value of the solution [4,5]. 

In this study, we have investigated nucleation and growth 

mechanism during the formation of poly(AA) films on gold 

substrates. Repeated potential cycling by using cyclic 

voltammetry and potential controlled electrolysis techniques 

have been performed to synthesize the thin films of poly(AA) 

on gold working electrodes. In all cases, an Ag/AgCl (3M 

NaCl) electrode served as reference electrode, and a Pt wire 

electrode was used as counter electrode. In the solution 

containing 0.1 mM AA and 0.1 M phosphate solution 

(pH:6.2), the potential of working electrode was kept at 

different upper potential limit of 0,90, 0.95, and 1.00 V. We 

have investigated nucleation and growth mechanism of 

poly(AA) film by using chronoamperometry technique. 

Nucleation and growth term can be described as either 

instantaneous or progressive. The current densities for these 

two cases are 

2 

J ins 

= at exp( −bt) 

for the instantaneous case and 

2 

3 

= ct exp( −dt) 

J prog 

Figure 2. Experimental current-time transients for different electrooxidation 

potential values. The non-faradaic charging currents in the absense of AA 

have been subtracted from these data 

STM (Scanning Tunneling Microscopy), and AFM (Atomic 

Force Microscopy) techniques was applied to investigate 

poly(AA) film surface structure. We have also studied the 

optical properties of the prepared polymeric films by using 

UV-vis. absorption spectroscopy. 

This work was partially supported by Atatürk University 

under Project No. BAP-2009/245. 

* Corresponding author: malanya@atauni.edu.tr 

[1] K. Naoi, H. Sakai, S. Ogano, J. Power Sources 20, 237 (1987) 

[2] G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science 270, 1789 

(1995) 

[3] R. Brdicka, Z. Elektrochem. 48, 278 (1942) 

[4] A. A. Karyakin, A. K. Strakhova, E. E. Karyakina, S. D. Varfolomeyev, A. 

K. Yatsimirsky, Bioelectrochem. Bioenergetics 32, 35 (1993) 

[5] J. Liu, S. Mu, Synthetic Metals 107, 159 (1999) 

[6] C. Chen, S. Mu J. Appl. Polym. Sci. 88, 1218 (2003) 

[7] M. Alanyalioglu, M. Arik, J. Appl. Polym. Sci. 111, 94 (2009) 

[8] A. Bewick, M. Fleiscmann, H. R. Thirsk, H. R. Trans Faraday Soc. 58, 

2200 (1962) 

[9] F. Li, W. Albery, J. Electrochim Acta 37, 393 (1992) 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 




Antibody Targeting of Doxorubicin Loaded Nanoparticles to 

HER2 Expressing Cancer Cells 

G. Petek en, F. Gürkan A ırcan, Ufuk Gündüz 

Middle East Technical University, Biological Sciences 

Abstract- Doxorubicin was encapsulated into PLGA nanoparticles with single emulsion solvent evaporation method. Trastuzumab 

was adsorbed on the surface of nanoparticles for targeting to HER2 expressing mammary cancer cells. 

Delivery of anti-cancer drugs using biocompatible 

nanoparticles are likely to provide protection from 

degradation, better adsorption, reduced frequency of 

administration, and improved therapeutic index. The next 

generation of drug delivery systems includes surface 

modified nanoparticles in order to get a selective drug carrier 

system. Targeting can be achieved via antibodies against 

proteins over-expressed on cell membrane. Between 25% and 

30% of breast cancers overexpress human epidermal growth 

factor receptor 2 (HER2-neu), which is associated with 

poorer prognosis and resistance to treatment [1]. 

Trastuzumab is a humanized monoclonal antibody that is 

currently used as a treatment for the cancer type that 

expresses HER2 receptor. In this study, anti-cancer drug 

doxorubicin was loaded into Poly (lactic-co-glycolic acid) 

(PLGA) nanoparticles. Active targeting of nanoparticles via 

adsorption of trastuzumab on their surface was aimed. BT- 

474 cell line which over-express HER2 receptor was used. 

Anticancer drug doxorubicin was encapsulated by PLGA 

polymer by using a modified single emulsion solvent 

evaporation technique [2]. Doxorubicin was solubilized in 

chloroform containing triethylamin. PLGA was dissolved in 

this solution. Solution was than added drop wise into the 

aqueous phase containing 2% PVA under magnetic stirring 

at. Chloroform was evaporated. Hardened nanoparticles were 

obtained by centrifugation and washed with distilled water. 

Adsorption of trastuzumab was achieved by 24 hours 

incubation of antibody with doxorubicin loaded nanoparticles 

at different pH values with different antibody nanoparticle 

ratios. The incubations were done in PBS at pH values of 5.0, 

7.0 and 9.0 with the antibody nanoparticle ratios of 1:1 and 

2:1. Amount of the antibody adsorbed on the nanoparticles 

was determined by protein assay. Incubation at pH 5.0 and 

with the nanoparticle antibody ratio of 1:2, adsorption of 

antibodies on nanoparticles’ surface was at maximum. 

Surface analyses of unmodified doxorubicin loaded and 

trastuzumab adsorbed nanoparticles were done. Scanning 

electron microscopy images showed that trastuzumab 

adsorption changed the structure of nanoparticles (Figure 1). 

During incubation with antibody, nanoparticles were swelled 

and their surface became smoother. 

Cellular targeting and uptake of unmodified and antibody 

coated nanoparticles were investigated with BT-474 cell 

culture. Equal amounts of unmodified and coated 

nanoparticles were added to the cells and incubated for 4 

hours. The cells were then washed to remove nanoparticles 

not internalized by the cells or bound to the cell surfaces. 

Fluorescence microscopy was then performed. It was 

observed that there were significantly higher amounts of 

nanoparticles around and inside the BT-474 cells when the 

nanoparticles were covered with trastuzumab antibody 

(Figure 2). 

a) b) 

Figure 2. BT-474 cell line incubated with a) unmodified 

nanoparticles b) trastuzumab adsorbed nanoparticles 

Coated nanoparticles were more likely to be bound to the 

cells than non-coated nanoparticles. Results indicated 

increased interaction of nanoparticles with the cells when 

they are coated with antibody. Increased interactions may be 

helpful in internalization of the drug and increasing potency 

of the therapy. 

While nanoparticles are known to increase the bioavailability 

of doxorubicin, trastuzumab adsorption can target the 

doxorubicin loaded nanoparticles to HER2 expressing cell. 

Further research is in progress in order to indicate specific 

targeting of coated nanoparticles to HER2 expressing BT-474 

cells. 

ufukg@metu.edu.tr 

[1] Slamon DJ, Godolphin W, Jones LA, et al. Studies of the 

HER-2/neu proto-oncogene in human breast and ovarian cancer. 

Science 1989;244:707-712. 

a) b) 

Figure 1. Scanning electron micrograph of a) unmodified 

nanoparticles b) trastuzumab adsorbed nanoparticles 

[2] X.S. Wu, Preparation, characterization, and drug delivery 

applications of microspheres based on biodegradable 

lactic/glycolic acid polymers. In: WiseEncyclopedic handbook of 

biomaterials and bioengineering, Marcel Dekker, New York 

(1995), pp. 1151–1200. 




Nanoporous Zeolites with Antimicrobial Activity 

1 2 , Selami Demirci 2 , Nurcan Baç 1 * 

1 

2 Genetics and Bioengineering Department Yeditepe University, 

Abstract-Antibacterial and antimicrobial activity of silver, copper and zinc zeolites are studied using Escherichia coli, Pseudomonas 

aeruginosa, Candida albicans and Staphylococcus aureus. Results indicated that distinct microbial growth inhibition zones are clearly 

visible. 

Zeolites are nanoporous crystalline alu minosilicates with 

a framework structure that consists of three dimensional 

networks of SiO 4 and AlO 4 tetrahedra linked by shared 

oxygen atoms, and contain ions like Na + or K + . This is a 

highly ordered special molecular structure composed of 

uniform nanoscale channels and cavities, unlike their 

ordinary powdery appearance. It is well known that some 

kind of metallic particle, such as silver, copper and zinc, 

have antibacterial capabilities. In order to facilitate the 

particle handling and to reduce health risks, particles in 

inorganic matrix are being studied as antibacterial agents. 

These materials present high antibacterial activity, low 

toxicity, chemical stability, long lasting action period and 

thermal resistance versus organic antibacterial agents. Due 

to the stability of these particles supported on a matrix, 

they can be used in paint or polymers as a bactericide 

agent for coat hospital equipment, as well as fittings for 

public places, public transport, paints, toys and kitchen, 

school and hospital utensils. 

In the present work, zeolites are ion exchanged with a 

metal ion such as Ag, Zn or Cu, they show antimicrobial 

effect [1, 2]. 

There are many types of zeolites like Zeolite A, Zeolite 

X, Zeo lite Y etc. In this work, Zeolites A and X are 

synthesized using sodium aluminate and colloidal silica 

(Ludox) or sodium metasilicate under hydrothermal 

conditions Compositions of ingredients vary according to 

the type of zeolite [3,4]. The synthesis gel is vigorously 

shaken for the homogenization, and is placed into high 

density polyethylene (HDPE) bottles and processed in a 

convection oven at 90 ºC for zeolites A and X.. After a 

predetermined time, the sample bottles are removed and 

the zeolite product is filtered and dried. Preliminary 

characterization is done by an optical microscope followed 

by SEM (Scanning Electron Microscope) images. The 

zeolites synthesized in sodium form are then ion 

exchanged with silver copper and zinc at different 

concentrations for antimicrobial activity [1, 3]. 

The antimicrobial activity starts as soon as silver, copper 

and zinc ions are released from the zeolite crystals into the 

system containing microorganisms. In this study we 

examined the antimicrobial activity of silver zeolites 

against three bacterial species Escherichia coli, 

Pseudomonas aeruginosa, Staphylococcus aureus etc., and 

various yeast and fungus. Microbial growth inhibition zones 

were evaluated for Escherichia coli, Staphylococcus aureus., 

some other bacteria and for yeasts at 37 °C, and for 

Pseudomonas aeruginosa at 28 °C, and for fungus at room 

temperature. 

Figure 1. Scanning electron micrograph of Ag + -A 

Results with Zeolite A, X show that silver, copper, or 

zinc zeolites inhibit microbial growth. 

*Corresponding author: nbac@yeditepe.edu.tr 

[1] Hagiwara, Z., Hoshino, S., Ishino, H., Noara, S., Tagawa, K., 

Yamanaka, K., U.S. Patent, 4,775,585, 1988. 

[2] Matsumura, Y., Yoshikata, K., Kunisaki, S., Tsuchido, T., 

Applied and Environmental Microbiology, 69, 7, 4278-4281 

(2003) 

[3] Kamisoglu, K., Aksoy ,E. A., Akata, B., Hasirci, N., Bac, 

N.,Jour. Appl. Polymer Sci. 10 2854-2861 (2008) 

[4] Warzywoda J., Bac, N., Jansen, J. C., Sacco, A., Jour. Crystal 

Growth 220 140-149 (2000) 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 




Physical Properties of Cu-nanoparticles: A Molecular Dynamics Study 

H.Y 1 *, H.H.Kart 1 ,andT.Ç 2 

1 

2 

Department of Chemical Engineering, Texas A&M University, Texas, TX 77843-3122, USA 

Abstract- The physical properties of Cu nanoparticles diameters ranging from 1 nanometers to 10 nanometers are studied using Molecular 

Dynamics (MD) simulations. The interactions between atoms are represented by Quantum Sutton-Chen (Q-SC) many-body interaction 

potential suitable for transition metals. This method is suitable for modeling large systems for a very long time scales. Molecular dynamics 

simulations of the Cu-nanoparticles are performed at temperatures ranging from 100 K to well beyond melting temperature for the 

nanoparticles using the MPiSiM code to study their behavior at low temperatures as well in the molten state. Simulation results such as 

kinetic energy, potential energy, heat capacity and latent heat of the fusion are compared with the available experimental bulk results. 

Nanoparticles with diameter of 1 nanometer (nm) to 10 

nm exhibit physical, chemical and electronic properties 

different from those of bulk atoms and single molecules 

due to the large fraction of surface atoms. The physical 

properties of nanoparticles are expected to change 

gardually from molecular to bulk crystaline as the number 

of atoms increases. Studies of physical properties of 

nanoparticles in this range by experiments presents 

difficulties. It is well known that the melting temperature 

decreases with the number of atoms in the nanoparticles 

[1-3]. Metal nanoparticles (Cu) are important for various 

applications [4,5]; eg. they are used as interconnects for 

computers and as antibacterials. They may also have 

potential applications in the future applications in thermal 

management systems, gas separations, in microelectronics. 

Hence, it is important to understand the physical properties 

of copper nanoparticles. 

It is also shown that the order of values of heat capacity 

and latent heat of fusion are compatible with the bulk ones 

of theoretical and experimental data for the copper. 

* Corresponding author: hyildirim053@pau.edu.tr 

[1] H. Gleiter, Prog. Mater. Sci. 33, 223 (1989). 

[2] M. Yaedon, J. C. Yang, R. S. Averback, J. W. Bullard and J. 

M. Gibson, NanoStruct. Mat. 10, 731 (1998). 

[3] Y. Qi, T. Cagin, W. L. Johnson, W. A. Goddard III, J. Chem. 

Phys. 115, 385 (2001). 

[4]http://www.azom.com/details.aspArticleID=1066. 

[5] A. M. Mazzone, Phil. Mag. B 80, 95 (2000) 

[6 

(2009). 

[7] H. H. Kart, M. Tomak and T. Cagin, Modeling Simul. Mater. 

Sci. Eng. 13, 1 (2005). 

[8] T. Cagin, Y. Qi, H. Li, Y. Kimura, H. Ikeda, W. L. Johnson, 

and W. A. Goddard III, MRS Symp. Ser. 554, 43 (1999). 

Figure 1. The variation of total energy as a function of diameter 

for Cu nanoparticles. 

In this work, we apply molecular dynamics (MD) 

methods using the quantum Sutton-Chen (Q-SC) [6-8] 

many body force field to simulate the nanoparticles with 

the diameter size from 1 nm to 10 nm to investigate the the 

thermodynamical properties of the Cu nanoclusters at low 

and high temperatures. In summary, we have shown that 

MD approach is a reliable method to study the physical 

properties of the nanoparticles. Melting temperatures of 

the copper nanoparticles decrease as the size of the 

nanoparticle decreases as seen in Fig. 1. The bond leght of 

the atoms is increased as a function of temperature as 

shown in Fig. 2. 

100 K 300 K 700 K 1500 K 

Figure 2. Typical snapshops of 2-nanometer size Cu 

nanoparticles at various temperatures. 




Thermodynamical Properties of Pd-Au and Pt-Au Core-Shell Nanoparticles: 

A Molecular Dynamics Study 

S. Kaya 1 , S.Ozdemir Kart 1* , T. Cag 2 

1 

2 

Department of Chemical Engineering, Texas A&M University, Texas, TX 77843-3122, USA 

Abstract- The thermodynamical properties of Pt-Au and Pd-Au core-shell nanoparticles are studied at constant temperature and constant 

volume (TVN) molecular dynamics simulations with the use of quantum corrected Sutton-Chen potential energy function. The nanoparticles 

have the spherical core-shell structures with two different diameters of 5 nm and 10 nm. The spherical Pd or Pt is covered with the spherical 

Au shell with five different concentrations. The pure metals (Pd, Pt and Au) with the same particle sizes are also studied to compare with the 

results of core-shell nanoparticles. The melting temperature is determined by examining the behaviour of the total energy as a function of the 

temperature. Simulation results such as kinetic energy, potential energy, heat capacity, and latent heat of the fusion are presented. The effects 

of the concentration of shell atoms on the physical properties for both core-shells interested in this study are also investigated. 

In recent years, metallic nanoparticles attract growing 

interest due to their unique properties -differing greatly 

fro m bulk- resulting fro m the large fraction of surface 

atoms. Furthermore, core-shell nanoparticles are of 

particular interest in applications ranging from catalysis to 

optical, magnetic and electronic applications because the 

properties of nanoparticles can change with not only size 

and but also chemical composition [1-4]. Core-shell 

nanoparticles are made up of core material coated with 

another material. The design of new nanoparticle 

functionalized with size, composition and atomic 

distribution necessitate the understanding of the structure 

and properties of core-shell nanoparticles. In this study, we 

are particularly interested in the thermodynamic and 

structural properties of both Pd-Au and Pt-Au core-shell 

nanoparticles. We have performed molecular dynamics 

simulations for five different core-shell concentrations by 

utilizing Quantum Sutton-Chen potential [5-6]. They are 

arranged as Pd(Pt) n-xAu x , where, n is the mu ltip lier of the 

lattice parameter to produce the radius of the 

nanoparticles. Here, n is taken as 6 and 12, respectively, 

for 5 nm and 10 nm core-shells while x is set as 0, 1, …6 

for the small size core-shell and 0, 2, 4, … 12 for the large 

size of the one. The total energy, melting temperature, 

specific heat and latent heat of the fusion are calculated as 

a function of temperature and concentrations. Atomic 

distribution of these core-shell nanoparticles at various 

temperatures are shown in Figure 1. Melting temperatures 

of the core-shell nanoparticles increase with not only the 

size of the spherical nanoparticles, but also the number of 

the core atoms of Pd or Pt. Core atoms such as Pd coated 

by Au are redistributed among the Au shell atoms at high 

temperature as shown in Figure 1. c) and d). 

Figure 1. Typical snapshop of Pd 4 Au 2 core-shell paricles: halfdisplayed 

a)- 300K, b) 1200 K, c) 2000 K and d) full-structure 

displayed at 2000K 

*Corresponding author: ozsev@pau.edu.tr 

[1] F. Delogu, Phys. Rev. B 76, 235421 (2007). 

[2] E. E. Zhurkin, T. V. Hoof, and M. Hou, Phys. Rev. B, 75, 

224102 (2007). 

[3] Y. H. Chui, G. Grochola, I. K. Snook, and S. P. Russo. Phys. 

Rev. B 75, 033404 (2007). 

[4] Z. Yang, X. Yang, and Zhijun Xu, J. Phys. Chem. C 112, 

4937 (2008). 

[5] Y. Qi, T. Cagin, W. L. Johnson, W. A. Goddard III, J. Chem. 

Phys. 115, 385 (2001). 

[6] H H Kart, G. Wang, I. Karaman an 

(2009). 

a) 300 K 

b) 1200 K 

c) 2000 K d) 2000 K 




Production of Iron Oxide Nano Particles from Different Precursors 

Abstract— We produced monodisperse iron oxide nano particles between 6-21 nm from iron acetyl acetonate, iron oxide 

hydroxide, iron oleate and iron acetate procursors at different experimental conditions. It was observed that around 15 nm 

particles produced from iron oxide hydroxide and iron oleate precursors were more reliable, simple and economic. 

Iron nano particles have a great interest because of 

magnetic, electric and catalytic properties [1-7]. Particulaly, in 

Fischer-Tropsch synthesis (FTS), which produces sulfur and 

aromatic free fuel, liquid hydrocarbons can be produced from 

synthesis gas (CO + H 2 ) over iron catalysis. Iron nano 

particles also play an important role in the carbon nanotube 

production. In these proseses, iron catalysis are prefered 

because of catalytic activity and economy [8-9]. 

In this work, we explored the production of 

monodisperse iron nanoparticles between 6-21 nm from four 

different iron precursors by a thermal decomposition process. 

The precursors used were iron acetyl acetonate (Fe(acac) 3 ), 

iron oxide hydroxide (FeOOH), iron oleate and iron acetate 

(Fe(ac) 2 ). In the experiments, some experimental parameters 

were changed in order to tune the particle diameter of the iron 

oxide nanoparticles. The tables of experimental condititions as 

follows 

Table 1. Experimental conditions for Fe(acac) 3 [1-4] 

Ex. No 1 2 3 4 

Fe(acac) 

Precur. 

3 Fe(acac) 3 Fe(acac) 3 Fe(acac) 3 

3mmol 2mmol 2mmol 2mmol 

O.Acid O.Acid O.Acid O.Acid 

Surf.-1 

9 mmol 2mmol 2mmol 2mmol 

O. Amine O. Amine O. Amine O. Amine 

Surf.-2 

Red.A. 

9 mmol 

1,2 Hex. 

Diol 

15 mmol 

2mmol 

1,2 Hex. 

Diol 

10 mmol 

2mmol 

1,2 Hex. 

Diol 

10 mmol 

2mmol 

1,2 Hex. 

Diol 

10 mmol 

Solv. 

1-oct. 1-oct. 1-oct. 1-oct. 

20 mL 20 mL 20 mL 20 mL 

Temp. 315 o C 315 o C 315 o C 315 o C 

Part. S. 6 nm 8 nm 10 nm 14 nm 

At 100 o C, 

30 min., at 

At 100 o C, 

30 min,. at 

At 100 o C, 

30 min., at 

Explan. 

At 200 o 200 o C, 1 h. 200 o C, 1 h. 200 o C, 2 h. 

C, 

and at 315 and at 315 and at 315 

2 hour and 

at 315 o C, 1 h. 

C, 1 h. 

C, 1 h. 

C, 1 

waiting, waiting waiting 

hour 

seed were seed were seed were 

waiting 

taken from taken from taken from 

1st. 

experiment 

2nd. 

experiment 

3 th. 

experiment 

(Precur.: precursor, surf.; surfactant, red.a; reducing agent, solv.; 

solvent, part. s.; particle size, explan.; explanation, O.; oleic, Hex. 

Diol.: hexadecenediol, oct: octadecene) 

Table 2. Experimental conditions for FeOOH [5] 

Ex. No 1 2 

Precur. FeOOH, 6mmol FeOOH, 6mmol 

Surf.-1 O.Acid, 18 mmol O.Acid, 36 mmol 

Solv. 1-oct., 20 mL 1-oct., 24 mL 

Temp. 315 o C 315 o C 

Part. S. 10 nm 17 nm 

Explan. At 315 o C, 1.5 h. waiting At 315 o C, 1.5 h. waiting 

Table 3. Experimental conditions for Fe oleate [6] 

Ex. No 1 2 

Precur. Fe Oleate, 4 mmol Fe Oleate, 4mmol 

Surf.-1 O.Acid, 2 mmol O.Acid, 2 mmol 

Solv. 1-oct., 29 mL 1-oct., 29 mL 

Temp. 315 o C 315 o C 

Part. S. 12.5 nm 15 nm 

Explan. At.320 o C, 30 min waitinig 

At.220 o C, 30 min and 

at.320 o C, 30 min waitinig 

Table 4. Experimental conditions for Fe(ac) 2 [7] 

Ex. No 1 2 

Precur. Fe(Ac) 2 ,8mmol Fe(Ac) 2 ,6mmol 

Surf.-1 O.Acid, 3.6 mmol O.Acid, 10 mmol 

Solv. TOA, 20 mL TOA, 15 mL 

Temp. 260 o C 260 o C 

Part. S. 21.5 nm 14 nm 

Explan. 

At 220 o C, 20 min. and at 

260 o C, 40 min. waiting 

At 260 o C, 1.5 h. waiting 

(TOA.; tri octyl amine) 

Fe(acac) 3 precursor 14 nm FeOOH precursor 17 nm 

Fe oleate precursor 15 nm Fe(ac) 2 precursor 14 nm 

Figure 1. TEM pictures of some iron oxides produced from 

different precursors. 

In summary, iron oxide nano particles having 14 nm. 

diameter were produced at the end of the four stage process 

by iron acetylacetonate precursor. When iron oxide hydroxide 

precursor were used, increasing the surfactant amount as two 

times increased the particle size from 10 nm to 17 nm. In the 

case of iron oleate precursor, when waited at 220 o C for 30 

min. during the reaction, the particle size increased from 12.5 

to 15 nm. in a one stage reaction. The second experimental 

conditions of iron acetate in Table 4. gave more monodisperde 

nano particles than first experimental condition. Our results 

showed that iron oxides produced from iron oxide hydroxide 

and iron oleate precursors were more reliable, simple and 

economic. 

I acknowledge support from the Scientific and Technological 

Research Council of Turkey (TUBITAK) through grant no. 

BIDEB-2219. 




Analysis of Osteoblast and Fibroblast Cell Adhesion on ISO 5832-2 Grade-4 Titanium Samples in 

vitro Implanted by Nano Tachnological Methods with Low Ene rgy 

P.Kes 1 , A.Oztarhan 1 , S.G.Iz 1 , I.D.Gurhan 1 , 

1 Ege University, Faculty of Engineering, Department of Bioengineering, Izmir, TURKEY 

Abstract-The aim of this study is to understant the cell attachment behaviour of osteoblasts and fibroblasts on zirconium implanted “ISO 

5832-2 Grade 4” titanium samples, which are used in implant dentistry attachment zirconium ion implanted with the help of MEVVA Ion 

Implantation technology, which is one of the most important surface modification technologies and which has ascendant specifications when 

compared with coating, investigation of on ion implanted surfaces. In the light of this aim, the material for ion implantation is chosen as 

titanium which is the most common material used dentistry. Zirconium element known as 100% tissue compatible is chosen for creating 

ions. In this study attachment of osteoblasts and fibroblasts on is investigated in vitro for comparing the roughnesses and ion implantation 

surface modification. With this study, in case of zirconium ion implantation on “ISO 5832-2 Grade 4” titanium samples known as 

biocompatible, the increase of in vitro fibroblast and osteoblast cell attachment is observed. Also this study has proved the attachment of 

fibroblast and osteoblast cells on rough surfaces is beter than other surfaces, once again. 




Effect of surfactants on the synthesis of Zn-Al layered double hydroxides 

Ceren Yılmaz, Uğur Ünal, Funda Yağcı Acar 

1 Department of Chemistry, Koç University, Istanbul 34450, Turkey 

Abstract— In the current study, the effect of various surfactants on the crystallization of Zn-Al layered double hydroxide was 

investigated. Synthesis in the presence of dodecyl sulfate resulted in ring-like and rose-like structures depending on the 

concentration. We have also found that replacement of the surfactant with laurate salt resulted in the formation of large ZnO 

platelets intercalated with the surfactant formation. The crystallization mechanism was discussed. 

Layered double hydroxides (LDHs) are hydrotalcite-like 

layered compounds composed of piled-up positively charged 

brucite-like layers and charge balancing anions as well as 

water molecules in the interlayer domain. The general formula 

of layered double hydroxides is represented by [M 2+ 1-x 

M 3+ x(OH) 2 ] q+ [A n- x/n·mH 2 O], where M 2+ and M 3+ are divalent 

and trivalent metal cations, and A is n-valent interlayer guest 

anion, which might be Cl - , CO 2- 3 , NO - 3 , OH - , etc [1]. 

The synthesis of LDHs can be carried out with various 

methods. Coprecipitation in the presence of NaOH or 

hydrolysis of ammonia releasing agent result in well 

crystallized LDH crystals [2]. In this study, we have 

investigated the crystallization and intercalation behavior 

LDHs in the presence of surfactants. 

LDHs were synthesized in the presence of surfactants at 

different concentrations and concentrations below and above 

critical micelle concentration. Zn/Al ratio was 2 and the 

concentration of ammonia releasing agent was 2.33 times 

higher than the total metal cation concentration. Reaction was 

carried out at 90 0 C under continuous stirring. Sampling 

during the reaction was done at different times in the range 24- 

120 h in order to observe the crystallization of LDHs. 

Characterization was carried out with X-ray diffraction, 

scanning electron microscopy, Fourier Transform infrared 

spectrometer, UV-vis absorbance spectroscopy and 

Inductively coupled plasma spectroscopy. 

For the LDHs, synthesized under critical micelle formation for 

dodecyl sulfate we have observed platelet like structures. 

When the concentration increased above critical limit, ring 

like structure was observed. The ring formation was attributed 

to the crystallization of LDH at the anionic end of the 

surfactant where metal cations are concentrated in the 

beginning of the reaction. According to SEM micrographs we 

have speculated that the crystallization starts with the 

formation of central metal hydroxide seed and the 

crystallization occurs in a circular path around the central seed 

[3]. The mechanism is under investigation. 

An important observation during the study was the formation 

of large ZnO platelets and Al 3+ was not embedded in the 

crystal structure when the synthesis was carried out in the 

presence of laurate salt. Energy dispersive X-ray spectroscopy 

(EDX) study showed that the platelets are mainly formed from 

zinc and oxygen. According to XRD data as seen in figure 1, 

ZnO was crystallized as a layered structure and laurate 

molecules are placed between the layers. The size of ZnO 

platelets is in the range 10-50 m in length as seen in figure 2. 

Further study about the structure and properties of ZnO 

platelets is in progress. 

In conclusion, we have presented the crystallization of LDHs 

under different surfactant concentrations. The type of the 

surfactant has also substantial effect on the crystallization 

behavior. 

We are grateful to Assoc. Prof. Mehmet Ali Gülgün for doing 

the SEM and XRD analysis of the powders. The work was 

supported by Koc University. 

Figure 1. XRD pattern of the LDH synthesized in the presence 

of laurate salt. 

Figure 2. SEM micrograph of ZnO structure formed in the 

presence of laurate salt. 

Corresponding author: fyagci@ku.edu.tr 

[1]S. Miyata, Clays Clay Miner. 23 (1975) 369. 

[2] A. de Roy, C. Forano, J.P. Besse, in: V. Rives (Ed.), 

Layered Double Hydroxides: Present and Future, Nova 

Science Publishers, New York, 2001 p. 1 

[3] K. Okamoto, N. Iyi, T. Sasaki, Appl. Clay Sci., 37, (2007) 

23-31. 




Effect of defects on the radiat ion sensitivity o f PECVD Ge doped amorphous SiO x 

Sedat A 1 , 1 1 2 

1 TURKEY 

2 Department of Physics, 

Abstract- In this study, optical properties of Ge nanocrystals in SiOx structures are investigated by using Raman, photoluminescence 

spectroscopy and electron spin resonans (ESR) techniques. Ge nanocrystal in silicon oxide thin films have been grown with different flow 

rate of GeH 4 , SiH 4 and N 2 O by plazma enhanced chemical vapor deposition (PECVD) technique. We report experimental investigation by 

ESR measurements of room temperature -ray irradiation effects in PECVD Ge doped amorphous SiO x . 

Electronically active defects have a very significant 

influence on the electronic transport and optical properties, 

leading to compensation effects or to fast nonradiative 

recombination. Ge-related defects that are cause of 

attenuation for the waveguides, thus leading to detrimental 

losses of part of the transmitted signals [1-2]. The 

identification of the specific defects, sensitive to radiation, 

is therefore of crucial importance to make clear the 

microscopic origin of technologically relevant processes. 

Various experiments have shown that this defect centre 

can be produced by either two-photon absorption of 

excimer laser light (KrF, XeCl or ArF), single-photon 

absorption of light from a KrCl excimer lamp [3] or by 

ionizing radiation such as x- or -rays. In the interaction of 

radiation with Ge-doped silica new defects are induced. 

These defect centers are usually named Ge-related 

paramagnetic point defects (GECs). 

Electron paramagnetic Resonance (EPR), one of the 

most powerful techniques for determining point defects in 

semiconducting crystals. The aim of our work is to 

determine the paramagnetic point defects as well as the 

defect concentration in the gamma ray irradiation with 

annealed and as-grown germano-silicate PECVD grown 

samples which consist of 45, 90 and 120 sscm Ge-doped 

ratios no EPR activities were found before the -ray 

irradiation. After -irradiation at 300 K, an electron spin 

resonans (ESR) signals emerged for all of the samples. The 

characteristic splittings are observed, there is a ESR line at 

g = 2.0055 which can be attributed to a typical a-center, 

identical to Si dangling bonds (DB) in the amorphous 

silicon/o xide matrix surrounding the crystalline core. In 

addition, the spectra shown contain overlapping ESR 

signals of several centers the region near g = 2 and these 

EPR signals closely resembles the spectra of the least two 

different Ge-related paramagnetic point defects (GECs) 

previously reported in the literature. 

*Corresponding author: sedatagan@kku.edu.tr 

[1] Origlio G., Girard S., Cannas M., Ouerdane Y., Boscaino R., 

Boukenter A., Journal of Non-Cristaline Solids , 355, 1050 

(2009). 

[2] Agnello S., Alessi A., Gelardi F.M., Boscaino R., Parlato A., 

Grandi S. and Magistris A., Eur. Phys. J.,B 61, 25 (2008). 

[3] Messina F., Cannas M., Boscaino R., Grandi S. and 

Mustarelli P., Phys. Stat. sol. (c), 4, Number 4, 200673788 

(2007). 

800 

600 

400 

1100-45-2 

1100-90-6 

1100-120-0D 

200 

0 

-200 

-400 

-600 

-800 

-1000 

3425 3450 3475 3500 3525 3550 

G 

Figure 1. The EPR spectrum as recorded in the sample 45, 90 

and 120 at 1100 K annealed. 




Fabrication of D-Shaped Fiber Optic Waveguide Sensors with Nanostructured Surfaces 

for Biological & Chemical Detections 

Mustafa M. Aslan, 1* Sergio B. Mendes 2 and Kerim Allakhverdiev 1,3 

1 Materials Institute, TUBITAK Marmara Research Center, Gebze- Kocaeli, Turkey 

2 Department of Physics, University of Louisville, Louisville, KY 40209, USA 

3 Institute of Physics ANAS, Baku, Azerbaijan 

Abstract— In this study, we present fabrication and characterization of D-shaped fiber optic waveguides (FOWs) that are 

capable of measuring absorbance and fluorescence of biological and chemical alterations in a thin cover layer. The results are 

encouraging to expend this study for surface nanostructuring of the FOWs. Also future work for surface nanostructuring with 

coated Au single nanoparticles and colloids is summarized. 

Optical waveguides(OWs) have been widely used for 

many biological and chemical sensing applications [1]. They 

are generally in two distinct forms: pre-shaped waveguides 

in predetermined geometries such as fibers (fiber optic 

waveguides-FOWs) and planar waveguides that involve 

deposition of high refractive index film on a planar surface 

(planar optical waveguides-POWs). In general, FOWs are 

preferred for sensing applications to avoid complicated and 

expensive fabrication process and it is easy to setup. 

In this study, we present fabrication and 

characterization of D-shaped FOWs that are capable of 

measuring absorbance and fluorescence of biological and 

chemical alterations in a thin cover layer. Also future work 

for surface nanostructuring of the FOWs is summarized. The 

FOW is assembled using a stepped-index multimode fiber 

and silicon V-shaped groove. The silicon wafers are etched 

along its crystalline plane to form a V-groove. The striped 

fiber is assembled using an optical grade epoxy into V- 

groove. Fibers need to be polished near their cores, while the 

highest possible quality of the polished surface should be 

maintained, and thereby evanescent fields in fiber cladding 

can be effectively exploited in order to increase sensitivity 

for better detection of biological or chemical changes on the 

surface [2]. Polishing of multi-mode fibers embedded in 

silicon V-shaped grooves in order to get flat sensor surface 

and increase sensitivity serves two distinct purposes. The 

first (rough) polishing step is done with a 1 m aluminum 

oxide slurry. This step is to remove the excess epoxy from 

the surface of the device and to approach the core of the 

fiber. The second step is fine polishing uses a 0.5 m cerium 

oxide slurry. This polishing step continues to polish nearer 

into the core increase sensitivity, but also allows for a 

smooth active surface (RMS = 0.7 nm). As the final step for 

the fabrication, custom-made patch cables that consist of a 

section of fiber-optic cable and an FC connectors are 

epoxed and hand polished. Each patch cable is tested for loss 

and then can be spliced onto the FOW sensor using a fusion 

splice machine. A schematic cross-sectional image of the 

FOW sensor, a side-polished multi-mode fiber with a radius 

of curvature R, is shown in Fig. 1(a) whereas overall view of 

the fabricated FOW sensor is shown in Fig. 1(b). D-shaped 

FOWs are tested and calibrated using blue dextran to take 

bulk absorption measurements. The results are promising. 

Measured absorption curve for 20 μM blue dextran with 

fabricated FOW sensor is shown in Fig. 2. 

Nanostructuring of the FOWs will be done by coated 

single and colloid gold (Au) nanoparticles deposited on the 

sensor’s surface to increase sensitivity and better sensor 

response can be achieved especially for Raman scattering 

[3]. Development and control of the sensor’s second output 

(scattering) will provide significant advantages, allowing the 

study of the organization of biological and chemical 

molecules on a surface. Also the FOWs may allow for 

Surface Enhanced Raman Scattering (SERS) measurements 

and possible completely integrated Raman Spectroscopy. 

Utilizing the evanescent fields from the exposed core of a 

multimode fiber allows for a robust chip that may be used 

remotely. The structure of the sensor also is conducive to 

fully integrated measurements. 

Figure 2. Blue dextran absorbance curve measured with the FOW 

sensor. 

*Corresponding email: mustafa.aslan@mam.gov.tr 

(a) 

(b) 

Figure 1. (a) Cross section of the D-shaped FOW and (b) overall 

view of the fabricated FOW sensor. 

Some part of this study was done at University of Louisville, KY, 

USA. Authors would like to thank: Dr. Tark Baykara, Dr. Rodrigo 

S. Wiederkehr, Courtney L. Byard, Nathan A Webster, and staff of 

Micro and Nano Fabrication Facility, University of Louisville. 

[1] R.A. Potyrailo et al., Fresenius J Anal Chem 362, 373 (1998). 

[2] S.M. Tripathi et al, Journal of Lightwave Tech.26, No 13, 1980- 

85 (2008). 

[3] S.W. James and R.P. Tatam, J. Opt. A: Pure Appl. Opt. 8, S430 

(2006). 




Density profiles and inertia moments of interacting bosons in anisotropic harmonic 

confinement 

A I. Mese 1 , P Capuzzi 2 , S. Aktas 1 , Z Akdeniz 3 and S E Okan 1 


2 Consejo Nacional de Investigaciones Cient´ıficas y Técnicas and Departamento de F´ısica,FCEyN, 

Universidad de Buenos Aires, Buenos Aires, RA-1428, Argentina 

3 Physics Department, Piri Reis University, 34940 Tuzla, Istanbul, Turkey 

Abstract— We investigate the structural properties of a system, consisting of N strongly 

coupled charged bosonic atoms (Rubidium), moving in two dimensions, and interacting through a 

repulsive K 0 (r) potential [1] inside anisotropic two-dimensional harmonic traps, with N in the range 

from 4 to 9. Increasing the anisotropy of the confinement potential can drive the system from a twodimensional 

(2D) to a one-dimensional (1D) configuration. After that, we calculated inertia moment 

depending on the anisotropy parameters and particle numbers. 

Interest in a two-dimensional (2D) fluid of charged 

bosons was greatly stimulated by the work of Nelson and 

Seung [1], who showed that a fluid of flux lines in strongly 

type-II superconducting materials can be mapped onto this 

model system in statistical mechanics. The interaction 

potential law is given by V ( r) 

V0K 

0( 

r / r0 

) , with V0 

a coupling-strength parameter and K 0 x the modified 

Bessel function behaving as lnx at short distances. 

Following an early variational Monte Carlo study [2], the 

transition between an Abrikosov lattice and a 

homogeneous liquid of vortices was studied within this 

mapping by means of the dislocation mechanism of 

melting [3] and the density functional theory of freezing 

[4]. A first-order transition from an Abrikosov lattice to a 

bosonic superfluid of entangled vortices has also been 

demonstrated by the path-integral Monte Carlo method 

[5]. A triangular Abrikosov lattice is, of course, equivalent 

to the Wigner lattice for a 2D Coulomb system. 

In this work we use this very simple theoretical 

method to evaluate the structure of small crystallites of 

vortex lines within the Nelson–Seung mapping, by means 

of self-consistent variational calculations on the 

anisotropic harmonic trapped bosons with repulsive 

interactions using a Gaussian wavefunction approximation 

[6]. We investigate the density profiles of the ground state 

configurations and compare with recent experiment [7] 

and published numerical results [8]. In figure 1, we 

calculate inertia moment as a function of coupling constant 

for N=4, 5, 6 and 9 particles. 

I x 

/ I y 

I x /I y 

80 

70 

60 

50 

40 

30 

20 

10 

= 1.0 

= 0.9 

= 0.8 

= 0.7 

= 0.6 

= 0.5 

= 0.4 

= 0.3 

= 0.2 

= 0.1 

0 

0 1 2 3 4 5 6 

V0 

/ w 

100 

80 

60 

40 

20 

0 

= 1.0 

= 0.9 

= 0.8 

= 0.7 

= 0.6 

= 0.5 

= 0.4 

= 0.3 

= 0.2 

= 0.1 

0 1 2 3 4 5 6 

V0 

/ w 

a) b) 

I x /I y 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

= 1.0 

= 0.9 

= 0.8 

= 0.7 

= 0.6 

= 0.5 

= 0.4 

= 0.3 

= 0.2 

= 0.1 

0 1 2 3 4 5 6 

V0 

/ w 

c) d) 

I x / I y 

50 

40 

30 

20 

10 

0 

= 1.0 

= 0.9 

= 0.8 

= 0.7 

= 0.6 

= 0.5 

= 0.4 

= 0.3 

= 0.2 

= 0.1 

0 1 2 3 4 5 6 

Figure 1 We showed the ratio of inertia moments as a function of 

coupling parameter for different anisotropy values. 

Corresponding author: aihsanmese@yahoo.com 

[1] Nelson D R and Seung H S, Phys. Rev. B, 39 9153, 1989 

[2] Xing L and Tesanovic Z 1990 Phys. Rev. Lett. 65 794 

[3] Ma H-R and Chui S T 1991 Phys. Rev. Lett. 67 505 

[4] Sengupta S, Dasgupta C, Krishnamurthy H R, Menon G I and 

Ramakrishnan T V 1991 Phys. Rev. Lett. 67 3444 

[5] Nordborg H and Blatter G 1997 Phys. Rev. Lett. 79 1925 

[6] A. I. Mese et al., J. Phys.: Condens. Matter 20 , 335222, 2008 

[7] M Saint Jean and C Guthmann, J. Phys.: Condens. Matter 14 

(2002) 13653–13660 

[8] S. W. S. Apolinario, B. Partoens, and F. M. Peeters, Physical 

Review E 72, 046122 2005 

V0 

/ w 




Characterization of Gold Nanoparticles Produced by Femtosecond Laser 

E. Akman 1 , C.K.Akkan 2 , O.C. Aktas 2 , B.Genc 1 , E.Kacar 1,3 , A.Demir 1 

1 Laser Technologies Research and Application Center, Kocaeli University, Kocaeli 41380, Turkey 

2 Leibniz Institute for New Materials ( INM), CVD/Biosurfaces Department, Saarbrücken, D-66123, Germany 

3 University of Kocaeli, Faculty of Education, 41380 Umuttepe, Kocaeli, Turkey 

Abstract; Due to their size dependent optical properties, gold nanoparticles have been widely used in various biomedical applications such as 

biosensing, medical diagnostics and therapeutics. For medical applications, production of nanoparticles under nontoxic conditions has a crucial 

importance. Since the precursor has always required in chemical process, laser-induced ablation from a solid target has emerged as a 

alternative method to solve the toxocity problem. In this experiment, we have produced gold nanopaticles in aqueous solutions using 

femtosecond laser. The effects of laser energy have been examined by analysing the UV/VIS spectrum and SEM image. 

Nanoparticles are defined as stable colloid solutions of 

clusters of atoms with sizes ranging from 1-100 nm. At this 

nanoscale, gold nanoparticles possess different optical 

characteristics when compared to the bulk gold, most 

remarkable characteristic is the changing of the colour from 

yellow to ruby red when bulk gold is converted into 

nanoparticulate gold. [1]. This alteration of the colour of the 

gold nanoparticle is the basic detection mechanism in 

biosensor applications [2]. As the absorption bands are 

related to size and aspect ratio of metal and semiconductor 

nanoparticles, UV/VIS absorption spectroscopy is one of the 

most widely used method for characterizing the optical 

properties and electronic structures of nanoparticles [3]. 

In this current study, the synthesis of the gold 

nanoparticles have been carried out using a pulsed 

Ti:Sapphire laser, which operates at 1kHz repetition rate with 

a pulse width of

P 

P 

P Hacettepe 

P Hacettepe 

P 

P 



Preparation and Characterization of Bacterial Polyester Based Nanoparticlesfor Targeted Delivery of 

Etoposide 

1 

2 

3 

1 

2,3 

UEbru KlçayUP P, Eylem GüvenP P, Mustafa TürkP P, Baki HazerP P, Emir Baki DenkbaP 

P* 

1 

2 

3 

PKaraelmas University, Chemistry Department, Physical Chemistry Division, , Zonguldak, Turkey 

University, Nanotechnology and Nanomedicine Division, 06532, Beytepe, Ankara, Turkey 

University, Chemistry Department, Biochemistry Division, 06532 Beytepe, Ankara, Turkey 

4 

PKırıkkale University, Biology Department, Biochemistry Division, Kırıkkale, Turkey 

Abstract-Tumour-specific nano-structured drug delivery systems have received much attention due to their unique accumulation at tumour 

region. Among them polymeric nanoparticles made from natural polymers have drawn major attention due to higher stability, maneuverability 

for industrial manufacture, and opportunity for further surface nanoengineering. Aim of this study was to to prepare and characterize etoposideloaded, 

folic acid conjugated poly(3- hydroxybutyrate-co-3 hydroxyhexanoate) (PHBHHx) nanoparticles for using in targeted cancer therapy. 

Resulting data showed that etoposide-loaded and folic acid modified PHBHHX nanoparticles show promise for targeted delivery of etoposide to 

cancer cells. 

Nanotechnology is an emerging multidisciplinary field for 

current research and development in all technical disciplines. 

Nanoparticulate drug delivery systems which are nanometric 

carriers used to deliver drugs or biomolecules have received 

great attention over the last decades. Polymeric nanoparticles 

have been widely investigated for both diagnosis and targeted 

treatment of cancer; because they (a) can show controlled 

release properties, (b) can pass through the smallest capillary 

vessels and avoid rapid clearance by phagocytes, (c) can 

penetrate cells and tissue gap in order to arrive at target 

organs, (d) can reduce side effects of drugs, (e) can increase 

drug efficacy, etc [1,2]. 

Polyhydroxyalkanoates (PHAs) are a promising class of new 

emerging biopolymers. They are the polyesthers of 

hydroxyalkanoate produced by a variety of bacterial species as 

an intracellular carbon and energy compound under nutrientlimiting 

conditions with excess carbon. There has been 

considerable interest in using them as drug carriers due to their 

biodegradability and biocompatibility. A newer member of 

PHA family, poly(3-hydroxybutyrate-co-3 hydroxyhexanoate) 

(PHBHHx), is currently being produced in large scale [3,4]. 

Studies have demonstrated that PHBHHx, a microbially 

synthesized polyester with good biodegradability and 

biocompatibility, as well as strong mechanical properties, 

consequently, is very promising for biomedical applications. 

In the presented study poly(3-hydroxybutyrate-co-3- 

hydroxyhexanoate) nanoparticles were prepared to use in 

targeted cancer therapy. PHBHHX nanoparticles were 

prepared by solvent evaporation technique using 

dichloromethane as the solvent and tween-80 as the emulsifier. 

Morphological evaluations of the prepared nanoparticles were 

investigated by using atomic force microscopy (AFM). Effect 

of stirring rate, amount of surfactant and polymer 

concentration on nanoparticle size were investigated by Zeta 

Size Analyser. The size of the smallest nanoparticles obtained 

was in the range of 190-220 nm. Etoposide, an antineoplastic 

agent was loaded into nanoparticles and drug release profiles 

were obtained. 16-30 % drug loading was observed in drug 

loading studies depending on the initial drug content. Release 

studies of etoposide were also evaluated. For ‘active’ targeting 

of cancerous cells; nanoparticles were modified with folic acid 

as the model ligand for targeting nanoparticles to cancer cells. 

The receptor for folic acid is upregulated in many human 

cancers, including malignancies of the ovary, kidney, brain, 

breast myeloid cells and lung. Therefore it can be utilized as a 

useful target for tumor-specific drug delivery [5]. Different 

concentrations of folic acid was used in order to investigate 

the effect of ligand concentration on ligand binding efficiency. 

Ligand binding efficiency was found to be between 71-93%. 

Additionally physicochemical structures of nanoparticles were 

analyzed by using FTIR and the system was optimized for 

further in vitro and in vivo applications. 

Obtained results showed that etoposide-loaded and folic acid 

modified PHBHHX nanoparticles show promise for targeted 

cancer therapy. 

*Corresponding author: denkbas@hacettepe.edu.tr 

[1] Paul, D.R., Robeson, L.M. ‘’Polymer nanotechnology: 

Nanocomposites’’, Polymer 49 (2008) 3187-3204. 

[2] Ferrari, M. Cancer nanotechnology: Opportunities and challenges. 

Nat Rev Cancer (2005) 161–71. 

[3] Bayram, C., Denkbas, E.B., Kiliçay, E., Hazer, B., Çakmak, H.B. 

‘Preparation and Characterization of Triamcinolone Acetonideloaded 

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx) 

Microspheres’ Journal of Bioactive and Compatible Polymers 2008; 

23; 334. 

[4] Zinn, M., Witholt, B., Egli, T. ‘’Occurrence, synthesis and 

medical application of bacterial polyhydroxyalkanoate’’Advanced 

Drug Delivery Reviews, 53 (2001) 5-21. 

[5] Lu, Y., Low, P.S. ‘’Folate-mediated delivery of macromolecular 

anticancer therapeutic agents’’ Advanced Drug Delivery Review,. 54 

(2002) 675-693. 




Electrolysis and Characterization of Nanoporous Platinum 

A.Cahit Karaoglanli 1,2* Elif Tastaban 2 and Esref Avci 2 

1 Department of Metallurgical and Materials Engineering Bartin University, Bartin 74100, Turkey 

2 Department of Metallurgical and Materials Engineering, Sakarya University, Sakarya 54187, Turkey 

Abstract— In this study, a change of the DC electrical conductivity of a nanoporous platinum was observed when surface 

charge was induced on the nanomaterial by making it a working electrode in an electrochemical cell. Existing and reasonable 

new technological applications of solids deviation from charge neutrality are discussed. 

Most materials studied and/or used technologically today 

are electrically neutral, i.e the positive and negative electric 

charges are balanced. The properties of these materials are 

varied prodominantly by modifying the atomic structure [1]. 

The basic idea is that the immersion of a nanoporous 

material in an electrolyte leads to induced charges on the 

surface regions of a material by the application of a potential 

across the electrolyte– material interface, where a capacitive 

double layer is formed. The voltage range has to be restricted 

where no adsorption or reaction takes place at the electrode 

[1,2]. As many properties of solid materials depend on their 

electronic structure, significant deviations from charge 

neutrality result in materials with new, yet mostly unexplored 

properties such as modified electric, ferromagnetic, optical 

etc. properties. Weissmuller et al. reported the charge-induced 

reversible strain in nanoporous platinum metal. A practical 

application of this effect as actuators was also demonstrated. 

Similarly, the magnetization of nanoporous Ni–Pd alloys was 

also observed to be tunable by externally applied voltages on 

the material in an electrochemical cell. Similarly, 

electrochemical charging of thin gold films was studied by 

Anderson and Hansen in Na 2 SO 4 electrolyte and by Tucceri 

et al. in H 2 SO 4 electrolyte, where a change in resistance 

proportional to the surface charge was also observed [3-6]. 

*Corresponding author: karaoglanli@bartin.edu.tr 

[1] Gleiter, H., Scripta mater. 44, 1161–1168, Germany, (2001). 

[2] Gleiter, H.,Weissmuller, J.,and Wollersheim, Acta Mater.49, S.737-745, 

(2001). 

[3] J. Weissmuller, R.N. Viswanath, D. Kramer, P. Zimmer, 

R. Wurschum, H. Gleiter, Science 300, 312, (2003). 

[4] D. Kramer, R.N. Viswanath, J. Weissmuller, Nano Lett. 

4,793, (2004). 

[5] C. Lemier, S. Ghosh, R.N. Viswanath, G.T. Fei, J. 

Weissmuller, Mater. Res. Soc. Symp. 876E (2005). 

[6] Bansal, C., Sarkar, S., Mishra, A.K., Abraham, T.,Lemierb, 

C., Hahn C., Scripta Materialia 56, S:705-708, (2007). 

In this study, a change of the DC electrical conductivity of a 

nanoporous platinum was observed when surface charge was 

induced on the nanomaterial by making it a working electrode 

in an electrochemical cell. Existing and reasonable new 

technological applications of solids deviation from charge 

neutrality are discussed. 

This work was partially supported Germany 

Forschungszentrum, Institute of Nanotechnology. 




Observation of the ground and excited states in a zero-dimensional semiconductor nanostructure 

under the magnetic field 

Saban Aktas, 1* Figen Karaca Boz 1 , Abdullah Bilekkaya 2 and Sevket Erol Okan 1 

1 Department of Physics, Trakya University, Edirne 22030, Turkey 

2 Department of Electronics, Trakya University Edirne Vocational College of Technical Sciences, Edirne 22100, Turkey 

Abstract— The ground and excited states in a zero–dimensional semiconductor nanostructure (quantum dot) have observed as 

a function of the dot radius under a magnetic field. The energies of the 1s, 1p, 1d and 1f states of a spherical quantum dot have 

been calculated using the fourth order Runge-Kutta method without magnetic field and the variational method with magnetic 

field within the effective mass approximation. It is shown that the energies in quantum dot with a small radius very small 

change with magnetic field, whereas energy changes with large radius are affected by the magnetic field. 

The experimental progress has made possible the 

fabrication of zero-dimensional semiconductor nanostructure 

(quantum dot) which impose quantum confinement in three 

directions to a charge carrier [1].The 1s-1s transition energies 

in spherically layered semiconductor quantum dots (QDs) 

were compared with the experimental results [2] and it was 

found that thick CdS outer layers prevent the charge carriers 

from escaping from the particles. Recently, the energies of 

electronic levels of the spherical QD has been presented by 

Özmen et al. [3,4]. Wenfang Xie found that the linear and 

nonlinear optical absorption coefficients are strongly affected 

by the confinement strength of QDs, and the external magnetic 

field [5,6]. 

In this work, we will focus on studying the energies of 

ground (1s), first (1p), second (1d), and third (1f) excited 

states of the spherical QD. The Hamiltonian of the QD in the 

effect of a magnetic field can be written in reduced units, 

2 2b 

1 2 2 2 

H i r sin v( 

r) 

. (1) 

r 

4 

The above equation has been solved using the Runge–Kutta 

numerical method without the magnetic field (B=0). The 

Hamiltonian in the presence of the magnetic field has been 

calculated using the variational approach. The binding energy 

E B of the hydrogenic impurity is defined as the difference 

between the energies with and without the impurity. Namely, 

E n 0( b 0) 

and E ni ( b 1) are obtained from Eq.1. Thus, the 

impurity binding energy in the QD is 

E B 

E ( b 

. 

n0 

0) E ni 

( b 1) 

Fig. 1 shown the binding energies of 1s, 1p, 1d, and 1f 

states as a function of the magnetic field for R Dot = 2a* value. 

The barrier height is given as V=Q c 1.247x for the Al 

concentration x=0.25 in the unit of eV., where Q c is the 

conduction band offset parameter taken to be Q c =0.60. As 

seen from the figure, the binding energies increase with 

increasing the magnetic field. The character of the binding 

energy for 1s state is different than other states. 

E B 

(R*) 

3,2 

2,7 

2,2 

1,7 

1,2 

0 5 10 15 20 

B(T) 

Figure 1: The binding energies of 1s, 1p, 1d, and 1f states as a function 

of the magnetic field for R Dot = 2a* value. 

In summary, we showed that the energies of the ground and 

excited states in zero-dimensional semiconductor 

nanostructure as a function of magnetic field for various the 

dot radius. For small dot radii, the contribution of the 

magnetic field is very small. The contribution to the energy of 

the magnetic field becomes dominant for large dot radii. These 

results are a good agreement with the results of our previous 

studies [6,7]. Our results might be useful for some devices in 

the future. This work was partially supported by Trakya 

University under Grant No. TUBAP 739-754-759-886-929- 

2008(58). 

. 

*Corresponding author: sabana@trakya.edu.tr 

[1] M. A. Reed et al., Phys. Rev. Lett. 60, 535 (1988) 

[2] D. Schooss, A. Mews, A. Eychmüller, H. Weller, Phys. Rev B 49 17072 

(1994). ( and references therein) 

[3] A. Özmen et al., Optics Comm., 282 3999 (2009). 

[4] B. Çakır et al., Superlattices and Microstructures, (In Press) 

[5] Wenfang Xie, Commun. Theor. Phys. 51, 923 (2009) 

[6] F. K. Boz et al. Appl. Surf. Sci. 255, 6561 (2009) 

[7] F. K. Boz et al. Appl. Surf. Sci. 256, 3832 (2010) 

1s 

1p 

1d 

1f 




The electronic properties of the multilayered spherical quantum dot under a 

magnetic field 

S E Okan 1 , A.Bilekkaya 2 , F.K.Boz 1 and S.Aktas 1 


2 Department of Electronics, Trakya University Edirne Vocational College of Technical Sciences, 

Edirne 22100, Turkey 

Abstract— We investigate the binding energy of an impurity located at the center of 

multilayered spherical quantum dot (MSQD) is reported as a function of the dot and barrier 

thickness for different alloy compositions under the influence of a magnetic field. The binding 

energy has been calculated using the fourth order Runge–Kutta method without magnetic 

field within the effective mass approximation. 

With the advent of modern micro-fabrication 

technology, semiconductor quantum dot (QD) 

structures are of considerable interest in fundamental 

science and device applications. The impurity states 

in a quantum dot (QD), which play an essential role 

in technological applications, are studied for 

understanding the electron and the impurity states in 

the confined systems. [1,2] 

In this work we use the fourth order Runge– 

Kutta method without magnetic field within the 

effective mass approximation [3]. A variational 

approach has been employed if a magnetic field is 

present. Our results show that the structural 

confinement is very effective for thin MSQD, and the 

influence of magnetic field is more effective 

according to the geometric effect for thick MSQD. If 

the dot thicknesses are closer to the barrier thickness, 

the abrupt deviations of the binding energy can be 

observed by changing the strength of the applied 

external magnetic field [4]. 

In figure 1, we showed the binding energy as 

a function of equal dot and barrier thickness for 

different magnetic fields and alloy concentrations x = 

0.20, 0.25, 0.30, respectively. 

E B 

(R*) 

6,0 

4,5 

3,0 

1,5 

0,0 0,4 0,8 1,2 1,6 

Figure 1: The binding energy as a function of equal dot and 

barrier thickness for different magnetic fields and alloy 

concentrations. 

Corresponding author: serolok@yahoo.com 

References 

R in 

=R out 

=R B 

(a*) 

x=0.20 

x=0.25 

x=0.30 

B=5 T 

B=0 

[1] J.-L. Zhu, J.-J. Xiong, B.-L. Gu, Phys. Rev. B 41 (1990) 

6001 

[2] N. Porras-Montenegro, S.T. Perez-Merchancano, Phys. Rev. 

B 46 (1992) 9780 

[3] F.K. Boz, S. Aktas, A. Bilekkaya, S.E. Okan, Appl. Surf. Sci. 

255 (2009) 6561. 

[4] F.K. Boz et al., Applied Surface Science 256 (2010) 3832– 

3836 




3 

Nanostructures for lithium ion batteries 

1* 1 , Erdal Sönmez 1 , 2 and Mehmet Ertugrul 3 

1 K. K. Education Faculty, Department of Physics, Ataturk University, Erzurum 25240, Turkey 

2 K. K. Education Faculty, Department of Chemistry, Ataturk University, Erzurum 25240, Turkey 

Engineering Faculty, Department of Electric-Electronic, Ataturk University, Erzurum 25240, Turkey 

Abstract—Nanostructure materials are currently of interest for lithium ion battery because of their high surface area, 

porocity, etc. It was observed that lithium ions transport, battery stability and batteries specific capacities increased by using 

nanostructures. Moreover depending on the characteristic of nanostructures internal resistance along the path of electronic 

conductivities has been decreased and that of the high charge/discharge rate has been observed. 

Nowadays nanomaterial’s sciences have started to use for 

lithium ion battery applications [1,2]. Recently the 

nanostructured materials have used to be energy storage 

devices such as high charge/discharge rate lithium ion 

batteries [3]. This newly developed energy storage devices can 

be used for requiring high power applications such as electric 

and hybrid electric vehicles. The reason for that is advantage 

of this type next-generations battery, electrode materials used 

in battery have high charge/discharge rate. Rechargeable 

lithium ion batteries consist of positive electrode (cathode), 

negative electrode (anode) and Li-ion containing electrolyte 

[4]. 

As the classic lithium ion batteries LiCoO 2 cathode 

material and graphite as the anode materials were used. 

During the charge process Li ions are extracted from the 

LiCoO 2 and continuously inserted graphic carbon electrode. 

Fig. 1. Schematic of an insertion electrode based rechargeable 

lithium ion battery. 

Discharge process occurs in reverse charge process. So, Li 

ions are extracted from the negative electrode a continuously 

inserted positive electrode. The classical insertion/extraction 

process is shown in Fig. 1 [4]. 

The cathode half reaction is: 

LiCoO 2 1-x CoO 2 + xLi + + xe - 

The anode half reaction is : 

xLi + + xe - +6C x C 6 

Overcharge up to 5.2 V leads to the synthesis of cobalt 

(IV) oxide, as evidenced by X-ray diffraction (XRD) [5]. 

LiCoO 2 + +CoO 

2 

In lithium ion batteries lithium ions are transported to anode 

oxidizing of transition metal Co from Co 

+3 to Co +4 in LiCoO 2 a 

cathode material and transported to cathode with this metal Co 

reducing from Co +4 to Co +3 during discharging 

As active cathode materials in lithium ion batteries use of 

LiMO2 type structure is common. (M: Co, Ni, Mn, V) 

According to the charge/discharge state these structure tend to 

give Li + or receive Li + . 

Materials also used as cathode should be easily prepared, 

must have high operating voltage and high capacity. The 

research purposed of synthesizing and development of LiCoO 2 

materials is to improve the performance of these materials. The 

purpose of these studies was prepared as LiCoO 2 particles of 

various sizes and dimensional. Template –prepared LiCoO 2 

have been demonstrated to show much improved electrode 

performance than that their bulk form and even outperform the 

nanoparticles counterparts obtained without template [6]. 

LiNiO2, which is used as a cathode material, is attractive for 

the researchers for having low redox potential and being 

affordable. Yet preparing LiNiO 2 stoichiometrically is a rather 

hard process. So, doping cobalt to LiNiO 2 enables to have the 

suitable cathode material. As the result of these works, the XRD 

results of the structures of LiNixCoyO2 nanotube doped with 

LiCoO 2 and cobalt are similar to the XRD result of these 

materials bulked state. The difference between these two can be 

regarded as in the XRD results of the nanotubes, the cells are 

broadened and the bulk density is lowered. The reason of these 

differences is the size of the small particles of the 

nanostructures.[7] 

*Corresponding author: mehmetyilmaz@atauni.edu.tr 

[1] J. Maier, et al., Nat. Mater, 4 805 (2005). 

[2] A.S. Arico, et al., Nat. Mater.4 366, (2005) . 

[3] H. Zhou, et al., Angew. Chem. Int. Ed.44 797, (2005) . 

[4] C. Jiang et al., Nanotoday 4 24(2006). 

[5] G.G. Amatucci et al., J.Elect. Soc. 143 1114-1123 (1996). 

[6] E. Ozcelik and G. Ozkan, J.Fac.Eng.Arch., Gazi.Univ. 21 423- 

425 (2006). 

[7] F. Cheng et al. Chem. Mater. 20 667-681 (2008). 




Synthesis and Characterization of ternary PbS x Se 1-x thin films via Electrochemical Co-deposition 

Methods 

Fatma Bayrakçeken, Ümit Demir, Tuba Öznülüer* 

Department of Chemistry, Arts and Sciences Faculty, Atatürk University, Erzurum 25240, Turkey 

Abstract - Thin films of PbS x Se 1-x were electrodeposited on Au (1 1 1) substrates by using a practical electrochemical method, based on 

the simultaneous underpotential deposition (UPD) of Pb, S and Se from the same solution containing Pb(CH 3 COO) 2 ,SeO 2 ,Na 2 S and 

EDTA at a constant potential. PbS x Se 1-x nanofilms were characterizated by X-ray diffraction (XRD), atomic force microscopy (AFM), 

FTIR spectroscopy techniques. AFM, XRD, and FTIR results revelead that ternary lead chalcogenide nanofilms having high crystallinity 

were deposited at a kinetically preferred (200) orientation on the Au (111) substrates. 

The lead salts (PbS, PbSe and PbTe) and their alloys are 

narrow band gap semiconductors which have been studied in 

the field of IR detection and thermoelectric devices [1]. 

More recently, further interest in the different lead-salt alloys 

has been created as a result of experiment in high-resolution 

spectroscopy and in air pollution measurement using tunable 

lead-salt diyote lasers. In addition to infrared detectors and 

emitters, narrow gap semiconductors have potential 

application in magnetoresistive and Hall effect devices as 

well as in thermoelectric devices. 

Emphasis is placed on the ternary alloy systems of PbS x Se 1-x , 

Pb 1-x Sn x Se, PbSn 1-x Se and Hg 1-x Cd x Te due to scope for 

regulation of their physico-chemical properties through 

variation of composition. It is possible to vary such 

electrophysical characteristics as type of conductivity 

concentration of main current carrier, band gap (E g ) etc. 

Individually, both the lead salt compounds PbS and PbSe 

have been widely used as radiation dedectors sensitive to 

near-infrared wavelengths[2]. Mixed compounds of the form 

PbS x Se 1-x, however, offer potentially useful dedectors of 

intermediate wavelength, broad band, and perhaps unique 

response. Lead chalcogenides films have been prepared by 

atomic layer epitaxy (ALE), chemical bath deposition 

(CBD), and electrochemical deposition[3]. Demir et al. have 

recently reported atom-by-atom electrochemical 

codeposition method to prepare PbS[4], ZnS[5] and CdS[6] 

thin films on Au(111). In this study, we also have shown that 

the highly oriented PbS x Se 1-x thin films have been 

successfully prepared by an electrochemical co-deposition 

method, which based on the upd or surface-limited reaction 

of Pb, Se and S at pH 4.5. The appropriate co-deposition 

potentials based on the underpotential deposition (upd) 

potentials of Pb, Se and S have been determined by the 

cyclic voltammetric studies. The films were grown from an 

electrolyte of 2.5 mMPb(CH 3 COO) 2 ,2 mM Na 2 S, 0.3 mM 

SeO 2 and EDTA in acetate buffer (pH 4.5) at a potential of 

-0.02 V vs. Ag|AgCl (3 M KCl). 

The bandgap values of the PbS x Se 1-x films were 

determined by absorbance measurement in the wavelength 

range 1280-5000 nm using Fourier transform infrared 

spectrophotometer. X-ray diffraction patterns were used to 

determine the sample quality, crystal structure and lattice 

parameter of the films. PbS x Se 1-x thin films were found to be 

single crystalline in nature as confirmed by XRD patterns 

and have a predominantly rock salt (NaCl) structure 

(Figure 1). The morphological investigation of PbS x Se 1-x 

films revealed that the film growth follows a 3D nucleation 

and growth mechanism. In conclusion, morphology and 

structure analyses confirm that high-quality ternary thin 

films could be prepared by this UPD-based electrochemical 

technique. 

Intensity/ a.u. 

PbSe xS 1-x (200) 

Au(111) 

20 25 30 35 40 45 50 55 60 

2/deg 

Figure 1. XRD patterns of PbSe x S 1-x thin film on Au (111) 

electrode after potential controlled deposition at -400 mV, pH 4.5; 

(a) 30 minutes and (b) 1 hour. 

*Corresponding author: toznuluer@gmail.com 

[1]S. Kumar, M. Hussain, P. T. Sharma, M. Husain Journal of 

Physics and Chemistry of Solids 64, 367 (2003) 

[2]B. A. Riggs J. Electrochem. Soc. 107, 708 (1967). 

[3]M. Alanyalioglu., F. Bayrakceken, Ü. Demir, Electrochim. Acta 

105, 10588 (2009) 

[4]T. Oznuluer, I.Erdogan, I.Sisman and U Demir Chemistry of 

Materials 17, 935 (2005) 

[5] T. Oznuluer, I.Erdogan, I.Sisman and U Demir Lagmuir 22, 

4415 (2006) 

[6] İ.Sisman,M.Alanyalioglu and Ü.Demir J.Phys.Chem.C 111, 

2670 (2007) 

b 

a 




Phos phine oxi de bas ed polyurethane / silica nanocompos ites via nonisocyanate route 

1,2 1 , Nilhan Kayaman-Apohan 1 *, 

 

3 , Atilla Güngör 1 

1 Marmara University, Department of Chemistry, 34722 Göztepe-Istanbul/ Turkey 

2 Trakya University, Department of Chemistry, Edirne/ Turkey 

3 -Istanbul/ Turkey 

Abstract-The main objective of this work is to develop environmentally friendly and flame-resistant polyurethane-silica nanocomposite coatings. 

For t his purpose, a novel carbonate modified bis (4-glycidyloxy phenyl) phenyl phosphine oxide (CBGPPO) was synthesized to prepare 

nanocomposites via nonisocyanate route. The cupping, impact and gloss measurements were performed on aluminum panels, and the tensile test, 

gel content, thermal and morphological analyses were conducted on the free films. 

Applications of polyurethane (PU) materials have 

significantly increased in comparison with some other 

thermosetting polymer materials. Conventional polyurethanes 

have good mechanical properties but they are porous and 

possess poor hydrolytic stability and insufficient permeability. 

The involvement of toxic components, such as isocyanates, in 

their fabrication process makes the production extremely toxic 

and dangerous. In this sense, a pioneering method, which 

depends on the reaction between cyclocarbonate oligomers 

and primary amine oligomers, has been developed for 

environmental-friendly PU manufacturing. Cyclocarbonates 

that can be synthesized from corresponding epoxy precursors 

are attracting research interest due to their potential use in the 

preparation of green, porous free and moisture insensitive 

polyurethanes.[1,2] 

A feasible approach for improving flame retardation of 

polyurethanes involves the synthesis of phosphorus containing 

polyurethanes. Since traditional halogen-based flameretardants 

have disadvantages such as the potentiality of 

corroding metal components and toxic corrosive fumes of 

hydrogen halide during the combustion, halogen-free flameretardants 

for polymers have attracted more attention from 

scientists in recent years.[3,4] 

Therefore, eight different formulations of nanocomposites 

were prepared to investigate the effects of silica and phosphine 

oxide based cyclocarbonate oligomer on the coating 

properties. 

Table 1. Formulation ratios of naocomposites 

KOD 

SOL- 

JEL 

% 

CPPG 

(g) 

1 

2 

3 

4 

5 

6 

7 

8 

CBGPPO 

(g) 

HMDA 

(g) 

CPPG(100)- 

CBGPPO(0)-Si(0) 0 8 - 1.534 

CPPG(75)- 

CBGPPO(25)-Si(0) 0 6 2 1.663 

CPPG(50)- 

CBGPPO(50)-Si(0) 0 4 4 1.86 

CPPG(100)- 

CBGPPO(0)-Si(20) 20 8 - 1.63 

CPPG(75)- 

CBGPPO(25)-Si(20) 20 6 2 1.76 

CPPG(50)- 

CBGPPO(50)-Si(20) 20 4 4 1.96 

CPPG(75)- 

CBGPPO(25)-Si(10) 10 6 2 1.71 

CPPG(75)- 

CBGPPO(25)-Si(5) 5 6 2 1.687 

impact, cupping, gel content and stress-strain tests. Thermal 

behaviors and morphologic properties of the coatings were 

also investigated. Incorporation of silica and CBGPPO into 

formulations increased modulus and hardness of the coatings. 

It was also observed that, the thermal stability of hybrid 

coatings enhanced with the addition of silica and CBGPPO. 

O 

O 

CH 2 

-CH-CH 2 O P O CH 2 

-CH-CH 2 

O 

CH 2 

-CH-CH 2 O P O CH 2 

-CH-CH 2 

O 

O 

O 

Figure 1. Synthesis reaction of CBGPPO 

1500 psi CO 2 

TBAB 

80 C 

2 saat 

This work was supported by TUBITAK (The 

Scientific&Technological Research Council of Turkey) 

Research Project under grant Project Number: 106T083. 

*Corresponding author: 6Tnapohan@marmara.edu.tr 

[1] Türünç, O., Kayaman-Apohan, N., Kahraman, M.V., 

Men Gungor, A., 2008, J Sol-Gel 

Sci Techno l, 47, 290-299. 

[2] Figovsky, O.L.; Shapovalov, 2002, L. M acrool Symp, 187, 325- 

332. 

[3] Kahraman, M.V.; Kayaman-Apohan, N.; Arsu, N.; Güngör, A., 

2004, Progress in Organic Coatings, 51, 213-219. 

[4] Karatas,S.; Hosgor,Z.; Menceloglu,Y.; Kayaman-Apohan,N.; 

Gungor,A., 2006, J.Appl. Polym. Sci., 102, 1906-1914. 

O 

O 

O 

O 

Nanocomposite coatings were prepared by curing these 

formulations with diamine thermally and their characterization 

was performed by analyses of various properties such as 




CeO x /Al 2 O 3 thin films on Stainless Steel substrate-new understanding of the surface states by 

dynamic X-ray Photoelectron spectroscopy 

Ivalina Avramova* and Sefik Suzer 

Department of Chemistry, Bilkent University, Ankara 06800, Turkey 

Abstract— The CeO X /Al 2 O 3 thin films on stainless steel substrate have been a sbject of the investigation under electrical 

stimuli by using XPS. 

The continuously increasing requirement for the properties 

of the materials with possible catalytic or electronic 

applications is a motivation for developing of new technique 

for their deposition and better understanding of surface state 

manners. Cerium dioxide (CeO 2 ) has been of great interest 

during the last years due to its multiple applications in several 

key areas of thin film technology. Ceria has a potential 

application in the area of optoelectronics [1], the high ionic 

conductivity has attracted interest for application as gas 

sensors [2] and electrolyte or anode materials for intermediate 

temperature solid oxide fuel cells [3]. 

The oxide films of Ce and Al were prepared 

electrochemically. The deposition of the films proceeded in a 

working electrolyte consisting of saturated absolute univalent 

alcohol with different contents of AlCl 3 x 6H 2 O and CeCl 3 x 

7H 2 O salts. The cathodic deposition was performed in a 

voltostatic regime at different forming voltages in the interval 

3–8 V. The deposition time was 60 min. The cathode substrate 

used was a stainless steel (20.0% Cr, 5.0% Al, 0.02% C, and 

balance Fe) electrode. 

XPS measurements were done using a K-Apha electron 

spectrometer with Al K X-rays (monochromatic). The close 

situated filament make available low-energy electrons for 

charge neutralization. Samples were electrically connected 

through the sample holder, which have been grounded or 

subjected to external, square wave pulses in the range 10 -3 to 

100kHz, during record of the X-ray photoelectron spectra. 

The electrochemically deposited CeO x /Al 2 O 3 thin films on 

stainless steel substrate with different amount of Ce loading 

have been subjected to square wave pulses with amplitude of 

10V during record of X-ray photoelectron spectra. 

As a result of applied ±10V when frequency changes, the 

oxygen, aluminium and cerium photoelectron peaks are split 

in to a doublet and the resulted Binding Energy (BE) 

differences were evaluated. 

On Figure 1 are shown the Ce3d photoelectron spectra 

recorded at low and high frequency and compared with the 

ground one, for the CeOx/Al 2 O 3 thin film having high Ce 

loading. The recorded spectra are complex due to the 

presence of Ce 4+ and Ce 3+ states on the surface. 

The binding energy difference at low frequency region less 

than 20eV is well pronounced in case of low Ce loading see 

Figure 2. The sample having high Ce loading show less 

difference. The BE difference become independent of 

frequency changes and reaches 20eV at high frequency region. 

The conductivity of the films changes by the Ce loading, 

due to the surplus of Ce 4+ or Ce 3+ or a smaller amount of these 

states on the surface of the oxides. When Ce 3+ states are 

predominant on the surface, the thin films behave as isolator, 

while the increase of Ce 4+ states on the oxide surface makes 

the film more conductive. 

BE difference, eV 

20,2 

20,0 

19,8 

19,6 

19,4 

19,2 

19,0 

18,8 

18,6 

18,4 

18,2 

1E-4 1E-3 0,01 0,1 1 10 100 1000 10000 100000 

frequency, Hz 

O1s peak 

Al2p peak 

Ce3d peak 

Figure 2. Binding Energy differences versus frequency for the 

CeO x /Al 2 O 3 with low Ce loading on stainless steel substrate. 

Ce 4+ Ce 4+ Ce3d 

Ce 4+ 

Ce 4+ 100kHz 

Ce 3+ Ce 4+ 

Ce 3+ 

Ce 4+ 

ground 

0.001Hz 

930 920 910 900 890 880 870 860 

BE, eV 

* iva@fen.bilkent.edu.tr 

[1] Petrova N. L., Todrovska R. V. and Todorovsky D. S., 2006. 

Spray-Pyrolysis Deposition of CeO 2 Thin Films Using Citric 

Complexes as Starting Materials, Solid Stat. Ion., 177: 613-21. 

[2] Durrani S. M. A., Al-Kuhaili M. F., and Bakhtiari I. A., 2008. 

Carbon Monoxide Gas-Sensing Properties of Electron-Beam 

Deposited Cerium Oxide Thin Films, Sens. Actuators B,134: 934-9. 

[3] Park J. -Y., Yoon H., and Wachsman E. D., 2005. Fabrication 

and Characterization of High-Conductivity Bilayer Electrolytes for 

Intermediate-Temperature Solid Oxide Fuel Cells, J. Am. Ceram. 

Soc., 88: 2402 -8. 

Figure 1. Ce3d spectra at different frequency for the CeO x /Al 2 O 3 

with high Ce loading on stainless steel substrate and compared 

with the spectrum at ground state. 




Preparation of Ag Nanotags for SERS Applications 

Seda Kibar 1 , Mürvet Volkan 1, * 

1 Department of Chemistry, Middle East Technical University, Ankara 06531, Turkey 

Abstract- For biological applications with SERS method, Ag nanotags were constructed. Through this aim, Ag nanoparticles 

were coated with silica and doped with a Raman-active dye, brilliant cresyl blue. Surface of these particles were functionalized 

with amino groups for attachment of biological molecules. 

Studies of preparation of SERS nanotags are 

focused on Ag, providing higher enhancement than 

Au do, due to the strong extinction and scattering 

spectra resulting from its localized surface plasmon 

resonance (SPR) [1,2]. Hence, in this study, silver 

NPs was prepared and, for colloidal stabilization and 

further surface modifications, a homogeneous shell of 

inorganic material, silica [3] was deposited on and 

labeled with brilliant cresyl blue, BCB. 

Ag nanoparticles were prepared by 

co-reduction of silver nitrate, AgNO 3 with sodium 

citrate [4]. Silica coated Ag NPs was constructed 

according to the Stöber process consisting of 

hydrolysis and co-condensation of 

tetraethylorthosilicate, TEOS, a silica precursor [5]. 

Different silica thickness was achieved with different 

molar ratio of TEOS to Ag NPs. The size and 

morphology of both Ag NPs and silica coated Ag 

NPs were measured using SEM and silica thickness 

was seen as ranging from 74 nm to 17 nm. 

Followings are the SEM images and UV spectra of 

Ag and silica coated-Ag Nps: 

Figure 3. Raman spectrum of dye-doped SiO 2 (Ag) NPs 

For highest BCB intensity, optimization of silica 

thickness was studied and optimum thickness was 

decided as 36 nm: 


with different silica thickness 

For further biological applications, surface 

was modified with amino groups using APTS [6]. 

Figure 1. SEM images of Ag and SiO 2 (Ag) NPs 

Abs 

2.000 

1.800 

1.600 

1.400 

1.200 

1.000 

0.800 

0.600 

0.400 

0.200 

0.000 

0 200 400 600 800 1000 

wavelength, nm 

Figure 2. UV spectrum of Ag and SiO 2 (Ag) NPs 

Ag NPs 

SiO2(Ag 

Dye-doping in silica matrix was studied 

through two different routes, embedding and 

impregnation. Raman studies showed that dye doped- 

SiO2(Ag) prepared by embedding gives higher 

intensity and provides more stability: 


with different silica thickness 

*Corresponding author: murvet@metu.edu.tr 

[1] Y. Yang, J. Shi, G. Kawamura, M. Nogami, Scripta 

Materialia 58, 862 (2008). 

[2] L. Lu, H. Wang, Y. Zhou, S. Xi, H. Zhang, J. Hu, B. 

Zhao, Chem. Commun., 144 ( 2002). 

[3] E. Mine, A. Yamada, Y. Kobayashi, M. Konno, L. M. 

Liz-Marzán, J. Colloid Interface Sci. 264, 385 (2003). 

[4] G. V. P. Kumar, S. Shruthi, B. Vibha, B. A. A. Reddy, 

T. K. Kundu, C. Narayana, J. Phys. Chem. C 111,4388 

(2007). 

[5] Y. Kobayashi, H. Katakami, E. Mine, D. Nagao, M. 

Konno, L. M. Liz-Marzán, J. Colloid Interface Sci. 283, 

392 (2005). 

[6] S. L. Westcott, S. J. Oldenburg, T. R. Lee, N. J. Halas, 

Langmuir 14, 539 (1998). 



Synthesis and Characterization of Palladium Nanoparticles Stabilized by Tannic Acid 

Emrah Bulut 1 ,Mustafa Can 2 *, Hilal Köse 1 and Mahmut Özacar 1 

1 Sakarya University, Department of Chemistry, 54187 Sakarya, Turkey 

2 

Sakarya University, Institute of Sciences and Technology, 54187 Sakarya, Turkey 


Abstract-Palladium nanop articles were prepared with the sol-gel method using tannic acid as reducing and stabilizing agent. The OH 

groups of tannic acid oxidized by the reduction of palladium ions and then formed metallic palladium nanop articles stabilized by the 

tannic acid derivatives. Formed palladium nanop articles were characterized by XRD, SEM and EDS. 

Nanoscale materials have received considerable attention 

because the particles in the nanometric size range are 

thought of as a bridge between molecules and bulk 

materials. These nanomaterials often exhibit very 

interesting chemical, optical, electronic, and magnetic 

properties that are unachievable in bulk materials. 

Moreover, ultrafine particles of noble metals have 

attracted particular interest because their increased number 

of edges, corners, and faces gives them a high 

surface/volume ratio and therefore they are useful in 

various fields of chemistry. Because of these unique 

characteristics, metal nanoparticles are being intensively 

studied for applications in catalysis, optoelectronics, 

preservatives, and biosensing, biological labeling, 

controlled drug delivery, etc. [1-3]. 

Catalysis provides a natural application for nanoparticles 

because their large surface area-to-volume ratio allows 

effective utilization of expensive metals. Without a 

suitable support, however, metal particles aggregate, 

reducing surface area and restricting control over particle 

size. To overcome this problem, catalytic nanoparticles 

have been stabilized by capping ligands that range from 

small organic molecules to large polymers. Encapsulation 

by polymers is advantageous because in addition to 

stabilizing and protecting the particles, polymers offer 

unique possibilities for modifying both the environment 

around catalytic sites and access to these sites [2-5]. 

More recently, with the development of nanotechnology, 

this purpose may be achieved via stabilizing them by 

synthetic polymers. Ideally, the stabilizers should have 

moderate affinity towards metal nanoparticles, so that the 

aggregation of metal nanoparticles can be prevented. In 

this study, we describe “tannic acid-stabilized method” for 

the preparation of palladium nanoparticles. The general 

characteristic of tannic acid are able to chelate with many 

kinds of metal ions through their dense ortho-phenolic 

hydroxyls, and capable of scavenging free radicals so as to 

prevent metal species from oxidation. The property of 

tannic acid implies that it could be used as an ideal 

stabilizer for preparing stabilized-metal nanoparticles. It is 

reported that silver nanoparticles have been successfully 

prepared by using polyphenols as the stabilizers [6-7]. 

Using a tannic acid as the stabilizer, our research group 

also developed a facile route for the synthesis of Pd(0) 

nanoparticles. 

In the present study, palladium nanoparticles are 

prepared using tannic acid acting as both the reducing and 

stabilizing agent. A novel and facile method was applied 

to synthesize palladium nanoparticles that have catalysts 

feature by using tannic acid which have reduction effect 

with involving -OH groups and keeps the prepared 

particles stable because of its mo lecular structure. 

The tannic acid stabilizes the newly born Pd 0 clusters and 

can influence the growth of the nucleation and hence 

particle size. No other reducing agents were used during 

palladium nanoparticle synthesis. Pd 2+ 0 reaction 

occurs in aqueous tannic acid above 50 o C. 

Characterization of the resulting nanoparticles by X-Ray 

Diffraction (XRD) and Scanning Electron Micrographs 

(SEM) are presented in Figure. 1 and 2. 

Figure 1. SEM image of Pd nanoparticles 

Figure 2. XRD pattern of Pd nanoparticles 

* Corresponding author: mstfacan@gmail.com 

[1] A. Nemamcha, J.-L. Rehspringer and D. Khatmi, J. Phys. 

Chem. B 110, 383 (2006). 

[2] P.S. Roy, J. Bagchi and S.K. Bhattacharya, Transition Met. 

Chem. 34, 447 (2009). 

[3] S. Kidambi and M. L. Bruening, Chem. Mater. 17, 301 

(2005). 

[4] N. Karousis et al., J. Phys. Chem. C 112, 13463 (2008). 

[5] X. Huang et al., Catal Lett. 133, 192 (2009). 

[6] E Bulut and M. Özacar, A Facile Aqueous-Phase Route to 

Synthesis of Silver Nanoparticles and Nanosheets, 4. Ulusal 

-13 Haziran, 2008, 

 

[7] E. Bulut, M. Özacar, Ind. Eng. Chem. Res. 48, 5686 (2009). 




Ab-initio Investigation of Structural Properties of 6H-SiC {0001} Surfaces 

Ahmet Cicek 1 *, Oguz Gulseren 2 and Bulent Ulug 1 

1 Department of Physics, Faculty of Arts and Sciences, Akdeniz University, Antalya 07058, Turkey 

2 Department of Physics, Bilkent University, Ankara 06800, Turkey 

Abstract-Structural properties of unreconstructed 6H-SiC surfaces are studied by using pseudopotential plane-wave calculations based on 

density functional theory. Surface truncation is observed to lead to relaxation of outermost atoms such that the Si or C atoms at the surface move 

inwards in the growth direction, while the adjacent atoms of the other species move outwards. Intra- and inter-layer separations are observed to 

vary more significantly for the topmost bilayer. It is seen that at least 12-bilayer slab structures must be considered for an adequate description 

of 6H-SiC {0001} surfaces. 

The {0001} surfaces of hexagonal SiC polytypes, especially 

6H, are recently under intense investigation due to ease of 

epitaxial graphene growth [1-4]. Growth mechanisms and 

geometry of the reconstructions on 6H SiC surfaces are not 

easy to treat in theoretical studies, where simple cases such as 

 

3 3R30 

reconstruction for the Si-terminated [5-7] and 

2x2 reconstruction for the C-terminated face [8] are in itially 

treated. Surface is defined by a finite number of bilayers (BL) 

permitting computationally-affordable investigations. Since 

the introduced stress propagates through the surface and 

charge separation occurs at the two faces terminated by Si and 

C atoms, a thorough study must investigate the minimum slab 

thickness to describe the surface [10]. 

In this work, structural properties of unreconstructed 

6H-SiC {0001} surfaces are investigated by ab-initio 

calculations under Generalized Gradient Approximation 

(GGA) and Local Density Approximation (LDA). First, 

structural properties of the bulk are investigated by geometry 

optimization [9]. The optimized bulk geometry is utilized as 

the starting configuration for geometry optimization of the 

surfaces. The investigated 6H-SiC (0001) and (000 1 ) surfaces 

are demonstrated in Figure-1. Important entities in the 

investigations are intra- and inter-layer separations of BLs, 

denoted by d i and z i in Figure-1(a)., respectively. 

Figure 1. Unreconstructed 6H-SiC {0001} 1x1 surfaces for geometry 

optimization computations employing (a) and (c) 6 bilayers, (b) and 

(d) 12 bilayers. 

Computations are carried out by employing slabs of 6 and 12 

BLs. Vacuum distance between adjacent supercells is 20A 0 

and cut-off energy is 50Ry, where 12x12x2 and 12x12x1 

Monkhorst-Pack meshes are employed for 6-BL and 12-BL 

slabs, respectively. For geometry optimization, Broyden- 

Fletcher-Goldfarb-Shanno (BFGS) algorithm is employed 

where 1, 2, 3, 4 or 6 topmost BLs are relaxed for 6-BL and 1, 

2, 3, 6, 7, 8 or 9 topmost BLs are relaxed for 12-BL slabs. 

Ideal bulk 6H-SiC is composed of ABCACB… stacking of 

atoms where neighboring atoms around any atom form a 

regular tetrahedron with d i=z i /3. However, both LDA and 

GGA computations reveal that small displacements take place 

so that d 1 =62.6p m and z 1 =187.1p m for LDA, wh ile 

d 1 =63.5p m and z 1 =189.8pm for GGA. 

Relaxed slab geometries show that the outermost surface 

atom moves towards the surface and the next atom of the other 

species moves outwards. Displacement of the top Si atoms is 

around 5pm inwards and the neighboring C atoms move 

approximately 2.5 p m outwards for the (0001) surface for 

LDA computations. For GGA, considerably smaller 

displacements are observed. On the other hand, C atoms of the 

(000 1 ) surface are displaced more significantly, where LDA 

results reveal around 17pm shifts inwards. The outward 

displacement of the Si atoms of the (000 1 ) surface is around 

8pm. Again, smaller displacements are observed for GGA. 

Comparisons of results for 6 and 12 BL slabs show that 

atomic displacements do not converge as the number of 

relaxed BLs is increased for the case of 6-BL slabs, whereas 

convergence is achieved for 12-BL slabs. 

In summary unreconstructed {0001} surfaces of 6H-SiC, 

the surface must be described by at least 12 bilayers, where 

relaxation of 3 or 6 BLs is sufficient for obtaining optimized 

surface geometry. 

This study is supported by Akdeniz University Scientific 

Research Projects Coordination Unit (Project No: 

2008.01.0105.010) and by TUBITAK (Grant No: 107T720). 

*Corresponding author: acicek@akdeniz.edu.tr 

[1] W. A. de Heer, C. Berger, X. Wu, P. N. First, E. H. Conrad, X. 

Li, T. Li, M. Sprinkle, J. Hass, M. L. Sadowski, M. Potemski ve G. 

Martinez, Solid State Comm. 143, 92 (2007). 

[2] Th. Seyller, A. Bostwick, K. V. Emtsev, K. Horn, L. Ley, J. L. 

McChesney, T. Ohta, J. D. Riley, E. Rotenberg, ve F. Speck, Phys. 

Stat. Solidi B 245 (7), 1436 (2008). 

[3] H. Huang, W. Chen, S. Chen ve A. Thye Shen Wee, 2 (12), 2513 

(2008). 

[4] U. Starke ve C. Riedl, J. Phys.: Condens. Matter 21, 134016 

(2009). 

[5] A. Mattausch ve O. Pankratov, Phys. Rev. Lett. 99, 076802 

(2007). 

[6] A. Mattausch ve O. Pankratov, Phys. Stat. Solidi (b) 245 (7), 1425 

(2008). 

[7] F. Varchon, R. Feng, J. Hass, X. Li, B. Ngoc Nguyen, C. Naud, P. 

Mallet, J.-Y. Veuillen, C. Berger, E. H. Conrad ve L. Magaud, Phys. 

Rev. Lett. 99, 126805 (2007). 

[8] L. Magaud, F. Hiebel, F. Varchon, P. Mallet ve J.-Y. Veuillen, 

Phys. Rev. B 79, 161405(R) (2009). 

[9] P. Käckell, B. Wenzien ve F. Bechstedt, Phys. Rev. B 50 (23), 

17037 (1994). 

[10] J. Soltys, J. Piechota, M. Lopuszynski ve S. Krukowski, arXiv: 

cond-mat.mtrl-sci (30.11.2009). 

[11] M. Sabisch, P. Krüger ve J. Pollmann, Phys. Rev. B 55 (16) 

10561 (1997). 




The Synthesis and characterizat ion of Zinc Oxide (ZnO) in difficult crystalline structure 

Alisah Cagatay C 1 , Sule Erten-Ela 1 *, Siddik Icli 1 , 

1 Solar Energy Institute, Ege University, Bornova, 35100 Izmir, Turkey 

Abstract-ZnO nanopowder has been successfully synthesized by a microwave-assisted solution approach and a solution phase reaction. An 

efficient microwave method and simple solution reaction method are presented to synthesize ZnO nanostructures. We investigated the effects of 

surfactant, growth temperature, annealing to control the morphologies of ZnO nanostructures. 

One-dimensional (1D) nanostructures such as nanowires, 

nanobelts, and nanorods, whose lateral dimensions fall in 

the range of 1–100 nm, have attracted a lot of interest and 

have been extensively researched in recent years because of 

their peculiar and interesting physical properties and 

potential device applications [1–3]. Among these important 

materials, zinc oxide (ZnO) has been given considerable 

interest because of its attractive optical functions based on the 

large binding energy of excitons and biexcitons (60 and 15 

meV, respectively) as well as its multifunctional physical 

properties. Notable applications of 1D ZnO nanostructures 

include the fabrication of nanometer scale electronic 

devices such as light-emitting diodes [4], nanolasers [5,6], 

gas sensors [7,8], field-effect transistors [9], and dyesensitized 

solar cells [10]. 

Semiconductor-assisted photocatalysis has attracted 

considerable attention among advanced oxidation process 

(AOP) as a promising tool for implementing the large-scale 

purification of waste waters at low cost. This methodology 

exploits the strong reactivity of hydroxyl radicals in driving 

oxidation processes, ultimately leading to the extensive 

mineralization of a variety of environmental 

contaminants[11,12]. ZnO is the one of the most suitable 

material for photocatalytic degradation in the presence of 

sunlight. [13,14]. 

In this work, we report the synthesis, structural 

characterization of ZnO nanostructures using a microwave 

method and solution phase method to prepare different 

morphologies of nanostructures by adjusting the amount of 

NaOH, growth temperature, surfactant, annealing. Structural 

characterization of nanostructures were done by scanning 

electron microscopy (SEM). 

We acknowledge financial support from Scientific and 

Technological Research Council of Turkey, TUBITAK. 

*Corresponding author: sule.erten@ege.edu.tr 

[1] C.B. Murray, C.R. Kagan, M.G. Bawendi, Science 270 (1995) 

1335. 

[2] J. Hu, T.W. Odom, C.M. Lieber, Acc. Chem. Res. 32 (1999) 435. 

[3] Z.W. Pan, Z.R. Dai, Z.L. Wang, Science 291 (2001) 1947. 

[4] R. Könenkamp, R.C.Word, C. Schlegel, Appl. Phys. Lett. 85 

(2004) 6004. 

[5] M.H. Huang, S. Mao, H. Feick, H. Yan, Y. Wu, H. Kind, E. 

Weber, R. 

Russo, P. Yang, Science 292 (2001) 1897. 

[6] J.-H. Choy, E.-S. Jang, J.-H. Won, J.-H. Chung, D.-J. Jang, Y.-W. 

Kim, 

Adv. Mater. 15 (2003) 1911. 

[7] Q.H. Li, Y.X. Liang, Q.Wan, T.H.Wang, Appl. Phys. Lett. 85 

(2004) 6389. 

[8] X. Wang, J. Zhang, Z. Zhu, Appl. Surf. Sci. 252 (2006) 2404. 

[9] S. Ju, K. Lee, D.B. Janes, M.-H. Yoon, A. Facchetti, T.J. Marks, 

Nano Lett. 5 (2005) 2281. 

[10] M. Law, L. Greene, J.C. Johnson, R. Saykally, P.Yang, Nat. 

Mater. 4 (2005) 455. 

[11] R. Andreozzi, V. Caprio, A. Insola, R. Marotta, Catal. Today 53 

(1999) 

51. 

[12] J.M. Hermann, Catal. Today 53 (1999) 115. 

[13] F.D. Mai, C.S. Lu, C.W. Wu, C.H. Huang, J.Y. Chen, C.C. 

Chen, Sep. Purif. Technol. 

62 (2008) 423. 

[14] A.H. Akyol, C. Yatmaz, M. Bayramoblu, Appl. Catal. B: 

Environ. 54 (2004) 19. 

Figure 1. SEM images of ZnO nanorods 

By using microwave method and solution phase method, 

ZnO nanostructures with different morphologies were 

successfully synthesized. Effects of the reaction conditions on 

the morphological characterization were discussed. 




Synthesis of Novel Organic Liga nds for Gold Nanoparticles Decoration and Architectures Based on 

Them 

Alexander Majouga 1 *, Roman Antipin 1 , Elena Beloglazkina 1 , Renata Ro mashkina 1 , Polina Rudakovskaia 1 ,Nikolay Zyk 1 

1 Lomonosov Moscow State University, Chemistry Department, Leninskie Gory 1/3, Moscow, Russia, 119991 

Abstract 

At present time the research on gold nanoparticles is one of the most important topic in chemistry, in life and materials 

science. This is mostly due to the versatility of these systems: the properties of gold nanoparticles can be used in a high range 

of applications thanks to the combination of their particular and unusual optical and electronic properties. The multi-scale 

organization of metal nanoparticles is a key step in their application as macroscopic nanodevices. Well organized 

nanostructures often display valuable chemical, optical, catalytic, electronic and magnetic properties, that are distinctly 

different from those of their component parts or those of larger mass. 

Nowadays our research work is deals with synthesis of new organic sulfur-containing ligands with additional donor atoms 

and investigation of their adsorption properties on gold surface and gold nanoparticles. At present time numerous sulfurcontaining 

compounds (such as thiols, disulfides, diaryldisulfides, dithiocarbamates, sulfides and thiourea derivatives) are 

widely applied for gold nanoparticles modification, but, unfortunately the adsorption of organic ligands involving terminal 

donor groups hasn’t been developed yet, in spite of the fact that interaction of such nanoparticles with transition metal ions 

would result in obtaining new nano-hybrid materials on the basis of gold nanoparticles. In addition, compared with pure 

organic compounds, the metal-ligand complexes provide rich redox, optical and electronic properties, which enable them to be 

good building blocks for constructing functional hybrids. 

Synthesis of gold nanoparticles, their properties, principle possibility of 2D and 3D aggregates formation will be concerned 

in presentation. 

07-03-00584), RSC and Nanochemtech Ltd. for financial support of this work. 

*Corresponding author: majouga@org.chem.msu.ru 




Study on Absorbance of CdS Thin Films from CBD 

M. Celalettin Baykul 1 *and Baris Altiokka 2 

1 

2 Bilecik Vocational School, Bilecik University, Bilecik 11210 Turkey 

Abstract-Cadmium sulfide (CdS) thin films have been grown on a glass substrate from aqueous solution by the chemical bath deposition (CBD). 

The films are produced at 80±1°C. The band gaps of CdS thin films were found to be between 2,39 and 2,51 eV. The structural 

properties and surface morphology of CdS thin films have been studied X-ray diffractometer and Scanning Electron Microscope 

(SEM). 

CdS is a promising material because of their applications in 

optoelectronics, photo catalysts, solar energy conversion, X- 

ray detectors, nonlinear optical material and as a window 

material for hetero-junction solar cells because it has usually a 

high absorption coefficient [1]. The good quality of a thin film 

solar cell (CdS/CdTe) strongly depends on the crystalline 

quality and compactness of the CdS layers [2]. Although 

chemical bath deposition has been used as a technique for 

preparing films since 1910, utilization of CBD semiconductors 

in photovoltaic devices is much more recent. It started in 1990 

with the integration of CdS buffer layers in combination with 

sputtered zinc oxide, ZnO, films and led to a new generation 

of high efficiency solar cells [3]. 

In this work, CdS thin films were deposited by CBD on 

glass substrates. The substrates are placed in the bath for 

different deposition time varying from 10 to 50 min. The 

chemical baths were consisting of aqueous solutions with total 

volume of 55mL of CdCl 2 (0,004-0,02M), KOH (0,1-0,5M), 

NH 4 NO 3 (0,3-1,5M) and CS(NH 2 ) 2 (0,04-0,2M). CdS thin 

films have been also produced on the same glass substrate by 

adding another CdS layers. 

The optical properties of CdS thin films were analyzed using 

UV/vis spectrometer. 

Absorbance 

1,2 

1,0 

0,8 

0,6 

0,4 

0,2 

0,0 

450 500 

Wavelenght (nm) 

550 

Figure 1. Optical absorption spectra of CdS thin films (a) 

minimal molarities of bath concentration (b) maximal molarities 

of bath concentration 

Figure 1 shows the optical absorptions spectra of the CdS 

thin films that were produced using two different molarities of 

solution. Figure 2 shows the optical absorption spectra of the 

CdS thin films according to deposition times. Figure 3 shows 

the optical absorption spectra of the CdS thin films according 

to the added CdS layers. 

The structural properties were studied by XRD. The surface 

morphologies were performed by Scanning Electron 

a 

b 

Absorbance 

1,0 

0,9 

0,8 

0,7 

0,6 

0,5 

0,4 

0,3 

0,2 

0,1 

0,0 

400 450 500 


550 

Figure 2. Optical absorption spectra for the deposition times (a) 

10 minutes (b) 20 minutes (c) 30 minutes (d) 50 minutes 

Absorbance 

4,0 

3,5 

3,0 

2,5 

2,0 

1,5 

1,0 

0,5 

0,0 

450 470 490 510 530 550 


Figure 3. Optical absorption spectra (a) main layer (b) for 

additional one CdS layer (c) for additional two CdS layer 

Microscope. The elemental analysis were performed by 

Energy Dispersive X-ray spectroscopy 

Conclusion 

The Energy band gaps of the CdS thin films are 

between 2,39 and 2,51 eV, 

CdS thin films have cubic zincblende structures 

*Corresponding author: 1Tcbaykul@ogu.edu.tr 

[1] Vineet Singh and Pratima Chauhan, Journal of Physics and 

Chemistry of Solids 70 (2009) 1074–1079 

[2] S. Soundeswaran at all, Materials Letters 58 (2004) 2381– 2385 

[3] J. Herrero at all, Thin Solid Films 361-362 (2000) 28-33 

a 

b 

c 

d 

a 

b 

c 




Characterization of Deposited Pd-Zr Thin Films By Moleculer Beam Epitaxy 

1 *, Abdullah Cahit Karaoglanli 1 and Esref Avci 3 

1 Department of Metallurgy and Materials Engineering, Sakarya 54187, TURKEY 

2 Department of Metallurgy and Materials Engi 

Abstract-The results of MBE growth and annealing of Pd-Zr alloys are described in this study. The thin films of Pd- Zr alloy s have been 

deposited onto Si wafers.Pd80-20Zr, Pd81-19Zr, Pd83-17Zr and Pd85-15Zr thin films have been pre heated at 60 °C for 1 hour ,in addition we 

applied heat treatment at 400 °C and 800 °C for 24 hours. The characterization of the manufactured thin films before and after heat treatment 

processes have been performed by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and EDX analysis. 

Molecular beam epitaxy is also used for the deposition of 

some types of semiconductors. MBE (molecular beam 

epitaxy) techniques allow the epitaxial growth of different 

compounds. 

Doping of Si molecular beam epitaxy (MBE) layers at low 

growth temperatures is a widely accepted method[1].The 

atoms or molecules in the gas deposit on the substrate to 

form the growing solid layer. Typically, each element is 

delivered in a separately controlled beam, so the choice of 

elements and their relative concentrations may be adjusted 

for any given layer, thereby defining the composition and 

electrical characteristics of that layer layer composition[2]. 

In this study, the thin films of Pd-Zr alloys have been 

deposited onto Si wafers. We used for the substrate [111]- 

oriented Si single crystal wafers. Pd80-20Zr, Pd81-19Zr, 

Pd83-17Zr and Pd85-15Zr thin films were pre heated at 

60 °C for 1 hour. In adition to this, we applied to the samples 

a heat treatment at 400 °C and 800 °C for 24 hours. 

The characterization of the manufactured thin films before 

and after heat treatment processes have been performed by 

scanning electron microscopy (SEM), X-ray diffractometer 

(XRD) and EDX analysis. 

The results of analysis showed that nanocrystallines has 

been modificated in the range of 400 °C and 800 °C. 

This study was supported by Forschungzentrum Karlsruhe, 

*Corresponding author: eliftastaban@gmail.com 

[1] [Thompson, K.D. Hobart, M.E. Twigg, S.L. Rommel, N. Jin, 

P.R. Berger, R. Lake, A.C.Seabaugh, P.H. Chi, D.S. Simons, Thin 

Solid Films 380 (2000) 145., 

[2] www.veeco.com 


P 



Langmuir–Blodgett Films of Tripodal-oxy-Schiff Base 

1 

1 

1 

1 

Ulkay Hilal GabberUP P*, Ziya Erdem KoçP P, Leyla GürfidanP P, Ozlem OuzhanP P, Mustafa ErsözP 

1 

PSelcuk University Department of Chemistry Campus 42075 Konya Turkey, 

1 

Abstract-In this study, self-assembled monolayers (SAMs) of Schiff base on Si wafer was obtained through a Langmuir Blodgett method 

between [2,4,6-tris(p-formylphenoxy)-1,3,5-triazine] (TRIPOD) and 3-amonopropyl trimethoxysilane (APTES). The surfaces parameters 

where analyzed by contact angle measurement sand atomic force microscopy (AFM), surface infrared spectroscopy (FTIR) etc. 

An important class of compounds consists of substituted 

s-triazine derivatives which have anticancer, antitumor, 

antiviral and antifungal activity. These compounds have 

been used in the treatment of depression and hence gained 

a considerable importance. These are valuable bases for 

estrogen receptor modulators and are also used as bridging 

agents to synthesize herbicides and in the production of 

drugs or polymers [1]. 

In this study, we were synthesized of tripodal-oxy-Schiff 

base derivatived which was named [2,4,6-tris(pformylphenoxy)-1,3,5-triazine]. 

Monolayers of schif base 

derivative was formed at the air/water interface using the 

Langmuir technique and was then investigated by onto Si 

wafers and studied using microscopic and spectroscopic 

methods. Silane monolayer is prepared on Si wafer 

surfaces using the techniques of Langmuir Blodgett 

deposition and solid liquid chemical adsorption. 

Two methods are commonly used to prepare silanized 

surfaces: Langmuir–Blodgett deposition and solution 

adsorption [2]. The 

Langmuir–Blodgett technique offers the advantage of 

maintaining accurate control over surface pressure during 

the deposition process. The LB technique is a valuable 

method to produce ultra-thin films. LB technology is 

known as a useful method for the formation of welloriented 

film of bio/organic material on a solid substrate, 

because it can control the degree of order [3]. LB films are 

fabricated by passing a substrate through the surface of an 

aqueous subphase on which is floating and ordered 

monomolecular organic layer. A film deposition is called 

reactive if there are strong intermolecular interactions 

between the monolayer and the substrate or between the 

depositing monolayer and the previously deposited 

monolayer [4]. Langmuir–Blodgett deposition was 

performed for selected compressed films. The substrates 

were Si wafers that were pretreated with an oxidizing 

mixture o 50:50 hydrogen peroxide and sulfuric acid for 

15 min followed by rinsing with Milli-Q water. In each 

case, deposition was performed immediately after the 

target pressure was attained. Varying surface pressures 

were used during deposition, and deposition speeds 

between 5 and 10 mm/min were used. In each case only a 

single molecular layer was deposited, and the 

corresponding transfer ratio was recorded. 

A 250 μl of solution is spread over a LB at air/water 

interface and a time of 30 min is allowed for solvent 

evaporation. The surface pressure against area/molecule 

isotherm was recorded using simple fitler paper. The 

transfer pressure is also controlled. 

In summary, this study demonstrates the construction of 

self-assembled arrays of silica particles on the micro- and 

nanopatterns reflecting the structures of the functionalized 

si wafer fabricated from LB films. The silica particles on 

the patterns of the functionalized templates are strongly 

adsorbed due to the electrostatic interaction between the 

amino groups of silica particles and the functional groups 

on the Schiff bases. The present method will be important 

in the fabrication of nanoparticles at the 

micrometer/nanometer length scale for the applications to 

sensors, photonic materials, optoelectronic materials and 

catalysts. 

This project was supported by To COST 43 and 

TUBITAK, (Grant No: TBAG-U/182 (106T718). 

*Corresponding author: HTihilalg@gmail.comT 

[1] Z.E. Koc and H. I. Ucan, transit. Met. Chem, 32 597 

(2007). 

[2] K. Paso, R. M.L. Helberg, S. Raae, J. Sjoblom, Journal of 

Colloid and Interface Science 325 228 (2008). 

[3] J. Cabaj, J. Sooducho, A. Nowakowska-Oleksy, Sensors 

and Actuators B 143 508 (2010). 

[4] L.Y. Zhang, M. P. Srinivasan, Coll. Surf. A: Physicochem. 

Eng. Asp. 193 15 (2001). 




PRODUCTION AND ISOCYANATE FUNCTIONALIZATION OF NANO-BOEHMITE 

PARTICLES 

Gülden EROĞLU 2 , Güngör GÜNDÜZ 1,2 , Üner ÇOLAK 3 , Bora MAVIS 4 

1 Middle East Technical University, Polymer Science and Technology Department, 06531, Ankara, Turkey 

2 Middle East Technical University, Chemical Engineering Department, 06531, Ankara, Turkey 

3 Hacettepe University, Nuclear Engineering Department, 06800, Ankara, Turkey 

4 Hacettepe University, Mechanical Engineering Department, 06800, Ankara, Turkey 

Abstract— The purpose of this research is production of nano-boehmites to be used in PU-based nanocomposite surface coatings with enhanced physical and 

mechanical properties. For this purpose aluminum hydroxide (AH) was transformed to nano-boehmite (NB) particles in a hydrothermal reactor. Crystalline 

structure of NBs was examined by XRD and conditions for 100% transformation was determined. 1,6-diisocyanatohexane (HDI) and 4,4'-methylene diphenyl 

diisocyanate (MDI) were used as surface grafting agents to react with hydroxyl groups on the surface of the NB particles for the functionalization of NB particles. 

The extend of functionalization of NBs was investigated by Fourier Transform Infrared (FTIR) spectroscopy. It was found that the reaction between isocyanates 

and hydroxyl groups on the surface of NB was near complete. 

The emphasize in the contemporary research and development 

of coating materials is on the development of functional materials. 

Especially, the development and dissemination of nano-technology 

applications influenced the production of nano-particles and their 

utilization in diverse areas. In coating applications, siloxanes based 

on tetra ethoxy silane (TEOS) are generally used to improve the 

scratch resistance of the coatings. However, TEOS’s high cost puts a 

burden to its wide use. 

The aim of this work is to produce nano-boehmites by using a 

low cost starting material like aluminum hydroxide and functionalize 

nano-boehmites for the synthesis of scratch resistant coatings. 

The work was carried out in two main steps; (i) NB production 

by hydrothermal synthesis and (ii) functionalization of NB particles 

with two different diisocyanates. 

In the first step, NB particles were obtained by using AH, acetic 

acid and ammonia. Needle-like, plate-like and cube-like 

morphologies are the three different types of NB that were 

synthesized. Time, pH, temperature and concentration of the acid and 

base in the solution are the main parameters of hydrothermal 

synthesis. pH is the most important factor that determines the 

structure of NBs. Needle-like NB was produced in acidic pH, 

whereas cube and plate-like NB were produced in basic pH. Platelike 

structure was used in the functionalization step because of having 

high aspect ratio. For producing plate-like NB, firstly, acidic acid was 

used to peptize and improve the dispersion of AH. After that, 

ammonia was used to adjust the pH of the solution. In hydrothermal 

reactor, AH was converted to NB completely. Figure 1 shows the 

SEM micrographs of NBs. 

Figure 1: SEM micrograps of (a) cubic-like boehmites (b) platelike 

nanoboehmites 

It is expected that the reaction between isocyanate groups and 

hydroxyl groups on the surface of the AH will enhance physical and 

mechanical properties of products. Therefore, in the second step, 

plate-like NBs were functionalized by using HDI and MDI. Toluene 

was used as a solvent and di-butyl tin dilaurate was used as a catalyst. 

Functionalization reaction takes place between OH groups on the 

surface of NBs and N=C=O groups of the diisocyanates. 

Diisocyanates were selected due to having two reactive groups and 

while one of the cynate would react with surface OH groups, the 

other one would be free. The critical, but undesirable point in the 

functionalization process is the reaction of the two cyanates with OH 

groups on different surfaces at the same time. In order to avoid this 

reaction, excess amount of diiscocyanates were added to the medium. 

The amount of catalyst and diisocyanate were optimized. 

(a) 

(b) 

Fiugre 2: FTIR analysis of (a) 1g MDI, 0.05 ml catalyst and 1 g 

boehmite, (b) 3 ml HDI, 0.1 ml catalyst and 1 g boehmite 

Figure 2 shows FTIR results of the functionalized NBs. Peak at 

2270 cm -1 is due to asymetric stretching vibrations of –NCO which 

indicates that the cyanates were grafted to the surface of the 

boehmites. Peaks at 1540 and 1510 cm -1 are assigned to bending of 

the –NH bonds. Absorption peaks at 1600 and 1640 cm -1 are 

attributed to stretching of C=O bonds. The peaks at 1230, 1750, 2900 

and 2825 cm -1 can be assigned as stretching of C-N (amid groups) 

bonds, stretching of ester groups, symmetric and asymmetric 

stretching vibrations of methyl groups, respectively. 

In future work, functionalized NBs will be used to produce PU 

nanocomposites with enhanced mechanical and physical properties. It 

is believed that the PU nano-composites will be used in surface 

coatings due to their potentially high scratch resistance. 

Acknowledgement:This work is supported by TUBİTAK under 

Grant No. MAG–108M204. 




Size and magnetic field effects on InAs/GaAs self assembled quantum dot nanostructure 

1 

Imen Saïdi, Karim Sellami 1 *and Kaïs Boujdaria 1 

Laboratoire de physique des matériaux, Faculté des Sciences de Bizerte, 7021 Jarzouna, Tunisia 

Abstract-In this present work we investigated theoretically, within the effective mass approximation, the electron and hole states in InAs/GaAs 

self assembled quantum dots under an external magnetic field. First, using the k.p theory, a theoretical 40x40 model was performed to calculate 

the InAs and GaAS semiconductor band structure, and extract the different physical parameters. Then, using an accurate numerical 

diagonalization method on Fourrier-Bessel function basis over a large cylinder domain, we calculated numerically the electron and hole eigen 

energies and associated wave functions. We considered thereafter the effect of the magnetic field and quantum dot size variation on the charge 

carrier energy levels. It is clearly found that the electron and hole energy spectra changes significantly when the quantum size parameters are 

modified as well as the magnetic field. Given this striking nanostructure size dependent property, these systems provide the opportunity to 

control and tune their optical and electronic properties through t heses parameters. 

Self-Assembled Quantum dots, commonly referred to as 

self-organized quantum dots, form spontaneously under 

certain growth conditions during molecular beam epitaxy or 

metal organic chemical vapor deposition, as a consequence of 

lattice-mismatch between the semiconductor deposited 

material and underlying substrate [1]. The resulting 

semiconductor nanostructures consist of three dimensional 

islands standing on a two-dimensional wetting layer. Such 

islands can be subsequently buried to realize quantum 

confinement. In the past 15 years, self assembled quantum 

dots have provided vast opportunities for physical research 

and technological applications, including quantum 

cryptography, quantum computing, optics and optoelectronics. 

Consequently, 0Tworldwide efforts in both theory and 

experimental investigations have driven the fascinating 

aspects of these nanostructures, including growth, 

characterization, and applications of quantum dots into an 

advanced multidisciplinary field [2]. 

In the frame work of the effective mass approximation the 

electron (hole) hamiltonien is written as: 

2 

2 

P meh ( ) ceh ( ) 

2 ceh 

( ) 

H Vconf i ge( h) 

BB. 

 

2meh 

( ) 

2 2 2 

m eh 

where is the electron (hole) masse calculated through the 

( ) 

Luttinger parameters extracted from a 40-band k.p model [3]. 

ceh 

is the electron (hole) cyclotron frequency which is 

( ) 

written as function of the magnetic field B as: eB 

. 

ce( h) 

g is the Landé Factor [4], and is the spin operator. meh 

( ) 

V denotes the quantum dot confinement potential that takes 

conf 

into account the shape of the nanostructure chosen as a 

truncated cone as represented below. This potential can be 

expressed as V ( r) 

V0 (1 D( 

z, 

)) 

, where V 0 

is the band offset 

potential and D is the quantum domain wich is written as: 

QD 

WL 

D( z, 

) 

D ( z, 

) 

D ( z, 

) 

where and D WL stands for 

respectively the quantum and wetting layer domains. 

Using an accurate numerical diagonalization method on a 

Fourrier Bessel basis over a large cylinder domain, the 

electron (hole) states can be written as: 

n, 

n, c 

 

ij 

n 

ij , 

n ij 

n in 

e i 

j 

where: nij reh 

i e Jn( e 

)sin z, with Z and R are 

R Z 

n 

respectively the height and the radius of large cylinder. is 

i 

n 

the ith root of the n-order Bessel function J , and 

n 

c 

i , 

is the 

j 

normalization constant. 

We calculated numerically the electron and hole eigen 

energies and associated wave functions in a truncated cone 

shaped InAs/GaAs quantum dot. Our result revealed that this 

calculation method provide more accurate results compared to 

the commonly used variationnal method. 

It is clearly shown that the electron and hole energy spectrum 

changes significantly as function of the quantum dot radius. 

We notice that from a definite radius R d , the charge carrierstates 

begin to appear in the quantum dot, and if R



Effect of Ru and Al substitutions on sol-gel derived ZnO thin films. 

M. Bektas 1,2, ,M.Erol 1,2 *, O. Sancakoglu 1,2 , M. Faruk Ebeoglugil 1,2 and Erdal Celik 1,2 

1 Dokuz Eylul University, Department of Metallurgical and Materials Engineering, 35160 Buca, Izmir- Turkey. 

2 Izmir- 

Turkey. 

Abstract-In this study, ZnO thin films were deposited on glass substrates via sol-gel technique for sensor applications. Transparent solutions 

were prepared from Zn, Ru, Al based precursors. The solutions were deposited on glass substrates by using spin coating technique which 

provides thin and smooth films. Deposited films were dried at 300 o C for 10 min in order to remove hydrous and volatile content, 

subsequently to remove organic content films were heat treated at 500 o C for 5 min and then they were annealed at 600 o C for 1 hour to 

obtain ZnO based films in air atmosphere. Finally the surface morphology and roughness of the films were determined via AFM (atomic 

force microscopy) and profilometer respectively. The phase structure was determined by XRD. 

The importance of zinc oxide (ZnO), among other metal 

oxides, is increasing due to many applications. Thin films 

of zinc oxide combine interesting properties such as nontoxicity, 

good electrical properties, high luminous 

transmittance, excellent substrate adherence, hardness, 

optical and piezoelectric behaviour and its low price. ZnO 

has relatively high physical and chemical stabilit ies, and 

hence it has many high temperature applications [1]. 

Zinc oxide (ZnO) is an important multifunctional 

material with applications such as transistors, gas sensors, 

solar cells, nanocantilevers, etc [3]. Although efforts are 

continuing for CO gas sensing using the hetero structure of 

SnO2 and ZnO [2], experimental results on pure ZnO for 

CO sensing is lacking and it may be related to rapid grain 

growth and densification. For gas sensors, it is necessary 

to have a porous microstructure with small particle size 

yielding large ratio of the surface area to the bulk [2]. 

Th in film sensors (the film thickness is typically less 

than 1 μm) are of interest because of their relatively small 

size and low power consumption. In accordance to the 

parameters above, sensing capacity is related to the 

microstructure and phase structure of the films. By this 

way small additions of substitutional elements to the films 

which effects the microstructure and sensing capacity. 

For the high conductivity and good optical 

transmittance, 1TAl-doped ZnO (AZO) films have drawn 

considerable attention for transparent conducting 

electrodes. Undoped ZnO usually contains various 

intrinsic defects such as Zn vacancies, interstitial Zn, O 

vacancies, interstitial O, and antisite O (O Zn ). These 

intrinsic defects form either acceptor level or donor level 

in the band gap that would greatly affect the luminescent 

properties of ZnO . By introducing extrinsic dopant Al, the 

defect environment is changed whether the Al atom 

substitutes the zinc atom or it occupies the interstitial site 

[4]. Undoped ZnO responses perceptibly to LPG while Ru 

doped sample highly senses ethanol vapors [5]. Scientific 

studies about this topic point out that substitution causes 

change in the electrical properties and particle size. Also 

substitution is important in selective sensing of gases or 

substances. 

In this research; pure, Ru and Al substituted ZnO thin 

film were deposited on glass substrates. A sol-gel route 

was derived to produce thin films. The precursors which 

were used to produce sols were listed in Table 1. 

Spin coating technique provides nanoscale and smooth 

films to be deposited. Thus the films were deposited by 

technique mentioned above nano scale pores and nano 

scale island like structures can be obtained. The decrease 

in the pore size of a sensor from micron scale to nano scale 

provides high efficiency and selectivity about gas or 

substance sensing. 

Table 1. Chemicals used to produce ZnO thin films. 

Precursor Amount Precursor Amount 

ZnCl2 0,225 g Methanol 8 mL 

AlCl3 0,012 g Glacial Acetic Acid 0,5 mL 

RuCl 3 0,011 g Triethanolamine(TEA) 0,5 mL 

In order to deposit thin films on to the glass substrates 

spin coating technique was employed. The coating regime 

was represented in Figure 1. 

Cycles (rpm) 

1000 

800 

600 

400 

200 

0 

0 20 40 60 80 100 120 

Time (sec.) 

Figure 1. Spin coating regime of solutions 

Finally the structure, morphology, electronic properties, 

gas sensing capacities will be accompanied by using x-ray 

diffractometer (XRD) and energy dispersive spectroscopy 

attached scanning electron microscopy (SEM-EDS), 

atomic force microscopy (AFM) in details. 

The authors are indebted to State Planning Foundation 

(DPT) and Dokuz Eylul University for financial support. 

*Corresponding author: m.erol@deu.edu.tr 

[1] T. Ivanova, A. Harizanova, T. Koutzarova, B. Vertruyen, 

Study of ZnO sol–gel films: Effect of annealing 

[2] Hyun-Wook Ryu, Bo-Seok Park, Sheikh A. Akbar, Woo-Sun 

Lee, Kwang-Jun Hong,Youn-Jin Seo, Dong-Charn Shin, Jin- 

Seong Park, Gwang-Pyo Choi, ZnO sol–gel derived porous film 

for CO gas sensing, Sensors and Actuators B 96 (2003) 717–722 

[3] Min Yang, Dejun Wang, Liang Peng, Qidong Zhao, Yanhong 

Lin, Xiao Wei, Surface photocurrent gas sensor with properties 

dependent on 

Ru(dcbpy)2(NCS)2-sensitized ZnO nanoparticles, Sensors and 

Actuators B 117 (2006) 80–85 

[4] Mingsong Wang, Ka Eun Lee, Sung Hong Hahn, Eui Jung 

Kim,Sunwook Kim, Jin Suk Chung, Eun Woo Shin, Chinho 

Park, Optical and photoluminescent properties of sol-gel Aldoped 

ZnO thin films, Materials Letters 61 (2007) 1118–1121 

[5] Shalaka C. Navale , V. Ravi, I.S. Mulla, Investigations on Ru 

doped ZnO: Strain calculations and gas sensing study, Sensors 

and Actuators B 139 (2009) 466–470. 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 




Microbial Synthesis of Gold Nanoparticles Using Rhodopseudomonas palustris NU51 

Strain 

Ayfer Caliş 1 ,Ayten Ozturk 2 ,Erhan Piskin 1 

1 Department of Bioengineering, Hacettepe University, Ankara 06800, Turkey 

2 Department of Biology, Nigde University, Nigde 51100, Turkey 

Abstract__ In this study, photosynthetic bacteria Rhodopseudomonas palustrisNU51 strain was screened to produce gold 

nanoparticles. R. palustris found successfully produce gold nanoparticles. For controlling size and shape of nanoparticles, pH 

values changed ranged from 7 to 4. R. palustris biomass and aqua HAuCl 4 incubated and gold nanoparticles characterised. 

Nanotechnology is an emerging field in the area of 

interdisciplinary research, especially in biotechnology [1]. 

Nanotechnology collectively describes technology and 

science involving nano scale particles (nanoparticles) that 

increases the scope of investigating and regulating the 

interplay at cell level between synthetic materials and 

biological systems [2]. The current interest in nanomaterials 

is focused on the controllable properties of size and shape 

because the optical,electronic, magnetic, and catalytic 

properties of metal nanoparticles strongly depend on their 

sizes and shapes [3]. Currently, there are various chemical 

and physical synthetic methods aimed at controlling the 

size and distribution of nanoparticles. Most of these 

methods, however, utilise toxic and expensive chemicals, 

and problems are often experienced with nanoparticle 

stability, agglomeration of particles and the inability to 

control crystal growth [4]. 

Figure 1: UV visible spectra of gold nanoparticles by R.palustris (1x10 -3 M 

aqueous HAuCl 4,pH 6) 

[10]. Phototrophic bacteria are ubiquitous in fresh and 

marine water soil, wastewater, and activated sludge. They 

are metabolically the most versatile among all procaryotes: 

anaerobically photoautotrophic and photoheterotrophic in 

the light and anaerobically chemoheterotrophic in the dark, 

so they can use a broad range of organic compounds as 

carbon and energy sources [11]. 

In this study we explored phototrophic bacteria 

Rhodopseudomonas palustris NU51 strain that isolated 

from Akkaya lake have been chosen to synthesize gold 

nanoparticles at room temparature through a single step 

process (Figure 2b). Photosynthetic bacteria 

Rhodopseudomonas palustris were cultured in the 

medium containing puryvate, yeast extract, NaCl, NH 4 Cl 

and KH 2 PO 4 at pH 7 and room temparature. 1 g wet 

weight of bacteria biomass obtained from growth medium 

and resuspended in 1x10 -3 M aqueous HAuCl 4 . The 

reactants pH were adjusted pH 4, 5, 6, 7 using 0,1 M 

NaOH solution. All the experiments were conducted at 

room temparature and 48 h. After 48 h reaction colour 

change was observed. Different shape and size were 

obtained due to pH change. Particle size was measured 

with Zeta Sizer. The colour of the reaction turned pale 

yellow to pale purple. This colour change indicates gold 

nanoparticle. Gold nanoparticles analyzed with UV 

spectrophotometer (Figure 1, Figure 2a). The results 

indicates that max absorption attributed at surface 

plasmon resonance band (SPR) of the gold nanoparticles. 

Results show that R.palustris produce gold nanoparticle 

extracellularly. 

*Corresponding author: ayfercalis@hotmail.com 

(a) 

(b) 

Figure 2: (a) UV visible spectra of gold nanoparticles by R.palustris 

(1x10 -3 M aqueous HAuCl 4,pH 7) (b) Rhodopseudomonas palustris NU51 

Currently, there is a growing need to develop 

environmentally benign nanoparticle synthesis process that 

does not use toxic chemicals in the synthesis protocols. An 

important aspect of nanotechnology is the development of 

synthesis of metal nanoparticles is a big challenge [5]. So 

the attractive procedure is using microorganisms such as 

bacteria and fungi to synthesize gold nanoparticles recently 

[6]. Microorganisms produce gold nanoparticles with 

different sizes: Bacillus subtilis 5-25 nm [7]; 

Rhodopseudomonas capsulata 10-20 nm [8], Escherichia 

coli 20-25 nm [9], Pseudomonas aeruginosa 15-30 nm 

[1] K. Natarajan, S. Selvaraj, V.R. Murty, Digest Journal of 

Nanomaterials and Biostructures, 5, 135-140, (2010) 

[2] Du L, Jiang H, Liu X, Wang E, Electrochemistry Communications 9, 

1165-1170, (2007) 

[3] S. He, Y. Zhang, N. Gu, Biotechnol. Prog., 24, 476-480, (2008) 

[4] Y. Govender, T.L. Riddin, M. Gericle, C.G. Whiteley, J.Nanopart 

Res, 12, 261-271, (2010) 

[5] G. Singaravelu, J.S. Arockiamary, V. G. Kumar, K. Govindajraju, 

Colloids and Surfaces B:Biointerfaces, 57, 97-101, (2007) 

[6] S. He, Z. Guo, Y. Zhang, S. Zhang, J. Wang, N. Gu, Materials 

Letters, 61, 3984-3987, (2007) 

[7] D. Fortin, T.J. Beveridge, In: Aeuerien E (ed) Biomineralization, 7- 

22, (2000) 

[8] S. He, Y. Zhang, Z.Guo, N. Gu, 2008, Biotechnology Progress 24: 

476-480, (2008) 

[9] K. Deplanche, R.D. Woods, I.P. Mikheenko, R.E. Sockett, L.E. 

Macaskie, Biotechnology and Bioengineering 101: 873-880, (2008) 

[10] M.I. Husseiny, M.A. Ei-Aziz, Y. Badr, M.A. Mahmoud, 

Spectrochimica Acta Part A: Molecular and Biomolecular 

Spectroscopy 67: 1003-1006, (2007) 

[11] H.J. Bai, Z.M. Zhang, Y. Guo, G.E. Yang, Colloids and 

Surfaces B: Biointerfaces, 70, 142-146, (2009) 


P 

P 

P,P 



Structural and Optical Characteristics of CdSe Quantum Dots 

1 

2 

1 

1 

1 

M.R. KarimP P, A.K. TürkoluP 

PN. AtmacaP P, N. YavariniaP P, and UHilmi ÜnlüUP P* 

1 

PIstanbul Technical University, Department of Physics, Maslak 34469, Istanbul, Turkey 

2 

PTUBITAK UME, Optik Grubu Lab, PK.54, Gebze, Kocaeli, Turkey 

Abstract-CdSe quantum dots (QDs) were prepared by a vacuum heating method in which the particle size was controlled mainly by changing 

different reaction temperatures. The synthesis CdSe QDs were characterized with UV-Vis absorption spectroscopy, atomic force microscopy 

(AFM) and transmission electron microscopy (TEM). The quantum dots sizes at the first excitonic absorption peak increase with increasing 

temperatures. The diameters of resulting CdSe QDs were about 4-5 nm with narrow size distribution both UV-Vis absorption spectra and TEM 

results. 

CdSe quantum dots are probably the most extensively 

investigated object among chemically grown semiconductor 

nanoparticles since the introduction of the “size quantization 

effect” in the earlier eighties [1-2]. Semiconductors (II-VI) 

have attracted considerable attention to understand the size 

dependence of their optical properties and various applications 

such as biological sensors, laser diodes, solar cells [3]. 

The CdSe nanocrystals were synthesized by using 

modifications of R. He and H. Gu’s method [4]. 0.69g 

cadmium acetate and 2.5 mL oleic acid were dissolved with 10 

mL phenyl ether in three neck flask. The reaction mixture was 

heated 140 °C. under stirring and continuous nitrogen flow, 

and then the mixture was cooled. 3 mL 1M TOPSe was added 

to mixture, rapidly, heated to 155 °C.-180 °C. and 1-25 min. 

The purposed method was done 1 mL aliquot crude solution 

was washed with methanol and isolated by centrifugation. 

After fine isolation of growth CdSe, the precipitation was 

5.2 

5 

Figure 2. AFM image of CdSe quantum dots at 160 °C. 

grown at 160 °C. for 1 minute. The mean particle diameter is 

around 4 nm, in good agreement with Figure 1. 

4.8 

10 Min 




Size (nm) 

4.6 

4.4 


4.2 

4 

3.8 

155 160 165 170 175 180 

Temparature (°C) 

Figure 1. Size effect at the first peak absorption of CdSe QDs 

dissolved with different volume of hexane. 

The reaction process was monitored by UV-Vis absorption 

with aliquots taken from different time and temperature. Fig. 1 

shows that nanoparticle size increases with increasing 

temperature. 

Atomic force microscopy (AFM) allows imaging of 

description of size and shape of the particles in solutions. At 

higher reaction temperature larger particles were obtained. 

High temperature results high rate attaching and larger particle 

size and quick growth of the particle (Figure 2). 

The diameter and narrow size distribution of the crude CdSe 

QDs were determined by TEM. A representative example was 

presented in Figure 3, for a sample of CdSe quantum dots 

Figure 3. TEM image of CdSe quantum dots at 160 °C 

In summary, TEM and AFM results revealed that CdSe 

quantum dots were well-ordered crystallized with average 

particle sizes 4-5 nm, which accords well with UV-Vis 

spectrum results. 

The authors would like to acknowledge the financial support 

provided by TUBITAK under Grant No.TBAG-105T463. 

*Corresponding author: HThunlu@itu.edu.trT 

[1] Rossetti, R., Nakahara, S. & Brus, L. E. J. chem. Phys. 79, 1086 

(1983) 

[2] Al. L. Efros, A.L. Efros. sov; Phys. Semiconducd., 16, 772(1982) 

[3] A. P. Alivisatos, Science 271, 933 (1996). 

[4] T R. He, H. Gu, Colloids and Surfaces A: Physicochem. 

Eng.Aspects, 272 (2006) 111-116. 




Biological and Green Synthesis of Silver Nanoparticles 

Mehrdad Forough 1 and Khalil Farhadi 2 * 

1 Department of Chemistry, Faculty of Science, Payam-e-Noor University, Khoy, Iran 

2 Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran 

Abstract -The synthesis of stable silver nanoparticles by bio-reduction method , using aqueous extract of Manna of hedysarum plant 

as reducing agent of Ag + to Ag 0 , and Soap-root (Acanthe phyllum bracteatum) plant extract as a stabilizing agent has been 

investigated. Various spectroscopic methods such as X – ray diffraction Analysis (XRD) , energy – dispersive spectroscopy (EDX) ,scanning 

electron microscopy (SEM) and UV-Vis spectroscopy were used to characterize the nanoparticles obtained. The energy dispersive 

spectroscopy (EDX) of the nanoparticles dispersion confirmed the presence of element silver signal no peaks of the impurity were 

detected. Comparison of experimental results showed that the diameter of prepared nanoparticles in solution is about 29-68 nm. 

In recent years noble metal nanoparticles have been the 

subject of focused researches due to their unique optical, 

electronic, mechanical, magnetic and chemical properties that 

are significantly different from those of bulk materials [1]. 

These special and unique properties could be attributed to 

their small sizes and large surface area. Many techniques of 

synthesizing silver nanoparticles have been reported, such 

as chemical reduction of silver ions in aqueous solutions, 

with or without stabilizing[2], chemical and photo reduction 

in reverse micelles[3]. Since noble metal nanoparticles, are 

widely applied to human contacting area[4] there is a growing 

need to develop environmentally friendly processes of 

nanoparticles synthesis that do not use toxic chemicals. 

Biological methods of nanoparticles synthesis using 

microorganism[5-6], have been suggested as possible ecofriendly 

alternatives to chemical and physical methods. 

Sometimes , the synthesis of nanoparticles using plants or 

parts of plants could prove advantageous over other biological 

processes by eliminating the elaborate processes of 

maintaining the microbial cultures [7]. 

In the present work, we investigate the synthesis of stable 

silver nanoparticles with bio-reduction method using two 

plants that, one of them acts as a reducing agent and the 

other acts as a stabilizing agent. Aqueous extract of Soaproot 

( Acanthe phylum bracteatum ) was employed as a 

stabilizer and aqueous extract of Manna of hedysarum was 

employed as a reductant. In this work we also compared 

the synthesis of silver nanoparticles by monitoring the 

conversion using UV – Vis spectroscopy. 

First, the aqueous extracts of plants were prepared by simple 

physicochemical methods, purified and then filtered. For 

preparation of silver nanoparticles, 10 ml of prepared 

extract of Soap-root ( Acanthe phylum bracteatum) plant as 

a stabilizing agent was added to 100 ml of 0.003 M 

aqueous AgNO 3 solution and after 5 min, 15 ml of 

aqueous extract of manna of Hedysarum was added to 

mixture for reduction of Ag + ions. The silver nanoparticles 

solution thus obtained was purified by several centrifugation. 

After freeze drying of the purified silver nanoparticles ,the 

structure, composition and average size of the synthesized 

silver nanoparticles were analyzed by scanning electron 

microscopy (SEM), X-ray diffraction spectroscopy (XRD) and 

energy dispersive X-ray microanalysis spectroscopy (EDX). 

Also the purified powders of silver nanoparticles were 

subjected to FT-IR spectroscopy measurement. It is well 

known that silver nanoparticles exhibit yellowish – brown 

color in aqueous solution due to excitation of surface 

plasmon vibrations in silver nanoparticles. Figure (a ) shows 

the photographs of samples .The silver containing solution 

(left flask) is colorless but changes to brownish color on 

completion of the reaction with manna of hedysarum 

extract (right flask). 

(a) 

Figure 1. ( a). Solution of silver nitrate (3 mM) before (left) and 

after (right) addition plant extract.(b) Scanning electron 

micrograph of the silver nanoparticles obtained. 

The energy dispersive spectroscopy (EDX)of the 

nanoparticles dispersion confirmed the presence of element 

silver signal and no peaks of the impurity were detected. 

Scanning electron microscopy has provided further insight 

into the morphology and size details of the silver 

nanoparticles. Comparison of experimental results, showed 

that the diameter of prepared nanoparticles in solution is 

about 29-68 nm.Figure (b) shows the scanning electron 

micrograph of the of silver nanoparticles that obtained with 

treated 3.0 mM silver nitrate solution with plant extract in 

86 °C for 13 min. 

*Corresponding author: 1Tkhalil.farhadi@yahoo.com1T 

[1] Mazur M. Electrochemistry Communications 6, 400 (2004). 

[2] Liz-Marzan LM, Lado-Tourino . Langmuir 12, 3585 (1996). 

[3] Pileni MP, Pure Appl Chem 72, 53 (2000). 

[4] Jae YS, BEAM SK, Bioprocess Biosyst Eng 32, 79 (2009). 

[5] Klaus T ,Joerger R, Olsson E, Granqvist C-G, Proc Nalt Acad Sci 

crystalline USA 96, 13611(1999). 

[6] Konishi Y , Uruga T,J Biotechnol 128, :648 (2007). 

[7] Shankar SS, Rai A, Ahmad A, Sastry M, J Colloid Interface Sci 

275, 496 (2004). 

(b) 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 




Preparing ZnO:Mn Nanoparticles: A Comparison Between Sol Gel and Gel Combustion Method 

Majid Ebrahimizadeh Abrishami, 1 Seyed Mohammad Hosseini 1 , Ebrahim Attaran Kakhki 1 and Mahdi Ghasemifard 1 

1 Matterials and Electroceramics Lab., Department of Physics, Ferdowsi University, Mashhad, Iran 

Abstract— We prepared ZnO:Mn nanoparticles using two different routes which are sol gel and gel combustion. TEM images 

showed that the size of nanoparticles, prepared using gel combustion method, were 40% smaller than the other. The effect of 

synthesis process on structural and optical properties was investigated by XRD analysis and UV absorbance spectra. 

Zinc oxide (ZnO) holds a great position in fabricating the 

electronic devices due to remarkable electrical and optical 

properties such as piezoelectricity, controllable conductivity, 

large band gap energy (3.3eV), transparency in the visible 

range and etc [1,2]. Furthermore, ZnO is considered for 

spintronics applications with magnetic ions (Co, Ni, V, Fe and 

Mn) doping. In this direction, Mn doped ZnO has became a 

reasonable choice for Diluted Magnetic Semiconductors 

(DMS). Even, ferromagnetic state was reported below and 

above room temperature [3]. However, in recent years, 

synthesis of nanopowders of ZnO, MnO and doping ZnO with 

transition metals by different routes such as wet chemical 

methods like sol-gel [4], co-precipitation [5], and combustion 

[6] in nanotechnology is custom in worldwide. 

In this work, Zn 1-x Mn x O (x = 0.00, 0.06 and 0.10) 

nanoparticles were synthesized using two different wet 

chemical methods which are sol gel and gel combustion. The 

starting materials were comprised of zinc and Mn acetates, 

diethanolamine and acetic acid. Process of preparing cations 

solution with no particulates and precipitates, stable sol and 

clear gel in both methods were similar. In the sol gel method, 

the acceptable gel was fired directly on hot plate and 

calcinated at 400C. But, we synthesized the ZnO:Mn 

nanopowders with adding nitric acid as a fuel, in gel 

combustion method. 

TEM images presented that the ZnO:Mn nanoparticles, 

prepared using gel combustion method, were smaller in size. 

As shown in Figure, the acceptable homogeneity in size 

distribution and spherical shapes of particles were clearly 

observed in samples prepared using two different routes. 

Next, we investigated the structural properties of 

nanopowders using X-ray diffractometer. XRD patterns 

showed that all the samples were crystallized in single phase 

wurtzite structure and no impurity phases were explored. In 

other words, the Mn solubility was clearly increased. 

Furthermore, the Full Width at Half Maximum (FWHM) of 

XRD reflection peaks were more broadened in samples 

prepared using gel combustion method. In addition, XRD 

analysis confirmed that the growth in Mn concentration 

resulted in increasing lattice parameters in samples 

synthesized using both techniques. 

Also, we consider the optical properties using UV 

diffractometer. UV absorbance spectra of all nanopowders 

have only one characteristic peak which is gradually shifted to 

lower wavelengths with increasing Mn content. This peak 

illustrates the optical absorbance edge. In this case, we 

determined the optical band gaps E g of samples using Morales 

approach [7]. This investigation showed the decreasing E g 

with increasing Mn content. However, the values for E g , 

extracted from UV absorbance spectra of nanoparticles 

prepared using gel combustion method, were more severely 

decreased with increasing Mn content. 

Table. The variation in structural and optical properties of ZnO:Mn 

nanopowders due to Mn doping and synthesis process. 

Sol gel 

Gel Combustion 

Mn content (x) 0.00 0.06 0.10 0.00 0.06 0.10 

latt. const. a (Å) 3.247 3.248 3.249 3.246 3.247 3.248 

latt. const. c (Å) 5.198 5.201 5.202 5.196 5.199 5.201 

absorb. edge (nm) 379.9 382.9 385.9 370.0 395.0 410.0 

E g (eV) 3.22 3.14 3.12 3.22 3.10 3.02 

Figure: TEM images of ZnO nanoparticles prepared using (a) sol gel 

method. (b) gel combustion method. 

In summary, we showed that different routes to prepare 

nanoparticles have effect on structural and optical properties. 

Our results open a new window to control the synthesis 

process, size of particles, lattice constant changes and band 

gap energy variations and etc. 

*Corresponding author: ebrahimizadeh@ymail.com 

[1]M. Ohtaki, K. Araki and K. Yamamoto, J. Elect. Mater. 38, 1234 

(2009). 

[2]S. S. Kwon, W. K. Hong, G. Jo, J. Maeng, T. W. Kim, S. Song and 

T. Lee, Adv. Mater. 20, 4557 (2008). 

[3]M. Ebrahimizadeh Abrishami, S. M. Hosseini, E. Attaran Kakhki 

and A. Kompany, Mod. Phys. Lett. B, in press (2010). 

[4]Q. Xu, S. Zhou and H. Schmidt, J. Allo. and Comp., 

doi:10.1016/j.jallcom.2009.08.033. 

[5] R. S. Yadav, A. C. Pandey, S. S. Sanjaya, Chalcogenide Lett. 6, 

233 (2009). 

[6]N. Riahi-Noori, R. Sarraf-Mamoory, P. Alizadeh and A. 

Mehdikhani , J. Ceram. Process. Res. 9, 246 (2009). 

[7]A. E. Morales, E. S. Mora and U. Pal, Revista Mexicana de 

Físicas, 53, 18 (2007). 




Synthesis and Characterization of ternary PbS x Se 1-x thin films via Electrochemical Co- deposition 

Methods 

Fatma Bayrakçeken 

1 , Ümit Demir 1 and Tuba Öznülüer 1 * 

1 Department of Chemistry, Arts and Sciences Faculty, Atatürk University, Erzurum 25240, Turkey 

Abstract-Thin films of PbS x Se 1-x were electrodeposited on Au (1 1 1) substrates by using a practical electrochemical method, based on the 

simultaneous underpotential deposition (UPD) of Pb, S and Se from the same solution containing Pb(CH 3 COO) 2 ,SeO 2 ,Na 2 S and EDTA at 

a constant potential. PbS x Se 1-x nanofilms were characterizated by X-ray diffraction (XRD), atomic force microscopy (AFM), FTIR 

spectroscopy techniques. AFM, XRD, and FTIR results revelead that ternary lead chalcogenide nanof ilms having high crystallinity were 

deposited at a kinetically preferred (200) orientation on the Au (111) substrates. 

The lead salts (PbS, PbSe and PbTe) and their alloys are 

narrow band gap semiconductors which have been studied 

in the field of IR detection and thermoelectric devices [1]. 

More recently, further interest in the different lead-salt 

alloys has been created as a result of experiment in highresolution 

spectroscopy and in air pollution measurement 

using tunable lead-salt diyote lasers. In addition to infrared 

detectors and emitters, narrow gap semiconductors have 

potential application in magnetoresistive and Hall effect 

devices as well as in thermoelectric devices. 

Emphasis is placed on the ternary alloy systems of 

PbS x Se 1-x ,Pb 1-x Sn x Se, PbSn 1-x Se and Hg 1-x Cd x Te due to 

scope for regulation of their physico-chemical properties 

through variation of composition. It is possible to vary 

such electrophysical characteristics as type of conductivity 

concentration of main current carrier, band gap (E g ) etc. 

Individually, both the lead salt compounds PbS and PbSe 

have been widely used as radiation dedectors sensitive to 

near-infrared wavelengths[2]. Mixed compounds of the 

form PbS x Se 1-x, however, offer potentially useful 

dedectors of intermediate wavelength, broad band, and 

perhaps unique response. Lead chalcogenides films have 

been prepared by atomic layer epitaxy (ALE), chemical 

bath deposition (CBD), and electrochemical deposition[3]. 

Demir et al. have recently reported atom-by-atom 

electrochemical codeposition method to prepare PbS[4], 

ZnS [5] and CdS [6] thin films on Au (111). In this study, 

we also have shown that the highly oriented PbS x Se 1-x thin 

films have been successfully prepared by an 

electrochemical co-deposition method, which based on the 

upd or surface-limited reaction of Pb, Se and S at pH 4.5. 

The appropriate co-deposition potentials based on the 

underpotential deposition (upd) potentials of Pb, Se and S 

have been determined by the cyclic voltammetric studies. 

The films were grown from an electrolyte of 

2.5 mMPb(CH 3 COO) 2 ,2 mMNa 2 S, 0.3 mM SeO 2 and 

EDTA in acetate buffer (pH 4.5) at a potential of -0.02 vs. 

Ag|AgCl (3M NaCl). 

The bandgap values of the PbSxSe 1-x films were 

determined by absorbance measurement in the wavelength 

range 1280-5000 nm using Fourier transform infrared 

spectrophotometer. X-ray diffraction patterns were used to 

determine the sample quality, crystal structure and lattice 

parameter of the films. PbS x Se 1-x thin films were found to 

be single crystalline in nature as confirmed by XRD 

patterns and have a predominantly rock salt (NaCl) 

structure (Figure 1). The morphological investigation of 

PbS x Se 1-x films revealed that the film growth follows a 3D 

nucleation and growth mechanism. In conclusion, 

morphology and structure analyses confirm that highquality 

ternary thin films could be prepared by this UPDbased 

electrochemical technique. 

PbSexS1-x (200) 

ity / Au(111) 

s 

n 

te 

In 

20 25 30 35 40 45 50 55 60 

2/deg 

Figure 1. XRD patterns of PbSe x S 1-x thin film on Au (111) 

electrode after potential controlled deposition at -400 mV, pH 

4.5; (a) 30 minutes and (b) 1 hour. 

*Corresponding author: toznuluer@gmail.com 

[1]S. Kumar, M. Hussain, P. T. Sharma, M. Husain Journal of 

Physics and Chemistry of Solids 64, 367 (2003) 

[2]B. A. Riggs J. Electrochem. Soc. 107, 708 (1967). 

[3]M. Alanyalioglu., F. Bayrakceken, Ü. Demir, Electrochim. 

Acta 105, 10588 (2009) 

[4]T. Oznuluer, I.Erdogan, I.Sisman and U Demir Chemistry of 

Materials 17, 935 (2005) 

[5] T. Oznuluer, I.Erdogan, I.Sisman and U Demir Lagmuir 22, 

4415 (2006) 

[6] 111, 

2670 (2007) 

b 

a 




Interlamellar Controlled/Living Radical Copolymerization of 

Maleic Anhydride and Itaconic Acid with Butylmethactylate 

Via Preintercalated RAFT-Agent/Organoclays Complexes 

Zakir M. O. Rzayev, Ernur A. Söylemez, 

Department of Chemical Engineering, Faculty of Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey 

Abstract– We have developed a new approach for the synthesis of polymer nanocomposites using a bifunctional reversible addition-fragmentation chain transfer 

(RAFT) agent, two types of organo-montmorillonites, such as a non-reactive dimethyldodecyl ammonium (DMDA)-MMT and a reactive octadecyl amine (ODA)- 

MMT organo-clays), and a radical initiator. This simple and versatile method can be applied to a wide range of monomers and donor-acceptor type 

monomer/comonomer systems for the preparation of completely exfoliated nanoarchitectures for high performance engineering nanomaterial applications. 

In the last years, many researchers attempt to utilize the 

controlled/living polymerization methods [1-6] for the preparation of 

the polymer/silicate nanocomposites. Of the methods used in the 

preparation of polymer-silicate nanocomposites, in situ polymerization 

offers the ability to impart significant control over both the polymer 

architecture and the final structure of the composite. The 

polymer/silicate nanocomposites, with well-dispersed (exfoliated) 

silicate layers, can be produced using atom transfer radical 

polymerization (ATRP) and nitroxide-mediated polymerization (NMP) 

methods. The interlamellar controlled/living radical (co)polymerization 

of monomers using reversible addition-fragmentation chain transfer 

(RAFT) technique in the presence of mineral clay has been scarcely 

investigated. It is known that RAFT polymerization method does not 

rely on a metal catalyst and can polymerize a wide range of monomers, 

theoretically all those monomers that can polymerize via a radical 

intermediate. 

In this work, we have been described our preliminary results on 

synthesis and characterization of new RAFT...O-MMT complexes as 

the reactive RAFT-nanofillers and their utilization in the interlamellar 

controlled/living complex-radical copolymerization of MA and IA with 

BMA as a internal plastisization agent in-situ processing to prepare 

new generation of polymer nanocomposites with complete exfoliated 

nanoarchitectures, lower (2.5 wt. %) and controlled content of organo- 

MMT, molecular weight, and polydispersity of matrix-polymer chains. 

Synthetic partways of these pre-intercalated complexes and functional 

copolymer/organo-clay nanosystems can be represented as follows: 

Figure 1. SEM images (scale: 1 m at x1000 magnification) of (a) MA and 

(b) IA containing nanosystems prepared by controlled/living radical RAFT 

copolymerization in the presence of RAFT...O-MMT complexes. 

Figure 2. TEM images of (a) MA and (b) IA-containing nanocomposites. 

SEM and TEM images of synthesized nanocomposites were illustrated in 

Figures 1 and 2. In the case of reactive organoclay (ODA-MMT), relative fine 

distributed morphology was observed. As seen from these images, the dispersed 

phase significantly reduced in the IA containing nanosystem and in the nanocomposites 

prepared with RAFT…ODA-MMT complex. This observed fact can 

be explained by chemical in situ processing through amine/anhydride (or acid) 

reactions which are carried out in nano scale between silicate galleries. 

We have developed a facile and effective strategy for the design and synthesis 

of polymer/organo-silicate nanoarchitectures by an interlamellar complexradical 

RAFT copolymerization method. Unlike the known methods , the novel 

approach involves the use of physically and chemically modified and intercalated 

RAFT/organo-MMT nanofillers in interlamellar complex-radical copolymerizations 

of functional monomer systems and synthesis of well exfoliated 

polymer/silicate layered nanocomposites with a relatively low concentration of 

organo-MMT (2.5-5.0 wt. %) and high performance thermal and mechanical 

properties. This strategy can also be broadly utilized to other hydrophilic/ 

hydrophobic polymer/silicate hybrid nanomaterials. 

Scheme: Complex-radical interlamellar controlled/living RAFT 

copolymerization. 

*Corresponding author: zmo@hacettepe.edu.tr 

1. Matyjaszewski K. et al. J. Am. Chem. Soc. 1997, 119, 674. 

2. Hawker,C. J. Acc. Chem. Res. 1997, 30, 373. 

3. Puts R. D., Sogah, D.Y. Macromolecules 1996, 29, 3323. . 

4. Kato M., Usuki, A. In Polymer-Clay Nanocomposites; Pinnavaia, T. J., Beall, 

G. W., Eds.: John Wiley & Sons: New York, 2000, p 97. 

5. Zeng C. H., J. Macromol. Sci. Part C: Polym. Rev. 2005, 45, 171. 

6. Di J., Sogah, D. Y. Macromolecules 2006, 39, 1020. 




Synthesis, Structure and Properties of Pre-intercalated 

Monomeric Organoclays and Their Nanocomposites 

Ernur A. Söylemez* 1 , Zakir M. O. Rzayev 2 , 

1 Nanotechnology and Nanomedicine Division, Hacettepe University, Beytepe, 06800 Ankara, Turkey 

2 Department of Chemical Engineering, Faculty of Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey 

Abstract— Functional copolymer/organo-silicate [octadecyl amine (ODA) surface modified montmorillonite (MMT)] layered 

nanocomposites have been synthesized by interlamellar complex-radical copolymerization of pre-intercalated complexes of 

maleic anhydride (MA)...ODA-MMT and itaconic acid (IA)...ODA-MMT as ‘nano-reactors’ with n-butyl methacrylate (BMA) 

as an internal plasticization comonomer. It was demonstrated that intercalation and exfoliation in situ processes are 

accompatied by physical (H-bonding) and chemical (amidization/imidization) interfacial interactions of monomers with 

ODAMMT which are responsible for the formation of nanostructural hybrid architectures. 

Maleic anhydride (MA) and itaconic acid (IA) 

monomers are readily available at low cost. MA is prepared 

by catalytic oxidation of n-butane or petrochemical fraction of 

C 4 -C 5 by using vanadium-containing catalysts. IA is obtained 

from renewable resource by fermentation with Aspergillus 

terrus. Both the MA and IA are related to class of difficulty 

polymerizable strong electron-acceptor monomers because of 

their stecally demanding natures, but they are more reactive in 

copolymerization with various vinyl, allyl and acrylic 

comonomers. Now these monomers are important raw 

materials used in the manufacture of high performance 

engineering and bioengineering polymer materials which are 

widely used in microelectronics, nanotechnology, agriculture, 

construction, shipbuilding, space technology, medicine, 

pharmacy, membrane technology, biotechnology, etc. These 

polyfunctional monomers may be also utilized in synthesis of 

a wide range of copolymer/organo-silicate nanocomposite 

materials. However, known investigations in this field were 

predominantly focused on the use of MA (or IA) copolymers, 

especially graft copolymers, in various thermoplastic 

polymer blends and nanocomposites as reactive 

compatibilizers [1-7]. 

This work presents the synthesis, characterization and 

composition property relationship of two silicate layered 

nanocompositesn with different compositions such as 

poly(MA-co-n-butylmethacrylate)s and poly(IA-co-n-BMA)s– 

ODA-MMT. Nanocomposites were prepared by the complexradical 

interlamellar copolymerizations of pre-intercalated 

MA...ODA-MMT and IA...ODA-MMT monomer complexes 

with different amounts of BMA comonomer in methyl ethyl 

ketone (MEK) at 65 o C under nitrogen atmosphere. 

Figure: SEM images of (a, b) poly(MA-co-BMA(1:3)–ODA-MMT and (c, d) 

poly(IA-co-BMA) (1:3)–ODA-MMT nanocomposites 

The results of the comparative XRD, SEM and thermal 

analyses of copolymers and their nanocomposites indicate that 

the observed effects of interlayer complex formation and 

amidization/imidization reactions play an important role in 

interlamellar copolymerization and intercalation/exfoliation 

in situ processes , as well as in the local chain folding and 

crystallization process via strong H-bonding and covalent 

amide/imide linkages formation.Therefore, complex-formation 

between anhydride/acid units and reactive dodecylamine 

groups of organoclay layered surface increases the force of 

interfacial interaction between organic (copolymerchains) and 

inorganic phases. These pre-intercalated reactive complexes 

also play an important role as compatibilizers in the 

formation of nanostructural architectures with given thermal 

properties and well-dispersed surface morphology. 

Scheme: Complex-formation, amidization and interlamellar complexradical 

copolymerization 

*Corresponding author: esoylemez@gmail..ccom 

[1] H. Nasegawa, et. al. J. Appl. Polym. Sci. 93, 758 (2004). 

[2] D. H. Kim, P. D. Fasulo, et al. Polymer 48, 5308 ( 2007). 

[3] S. C. Tjong, Y. Z. Meng , A. S. Hay, Chem. Mater. 14, 44 (2002). 

[4] G. D. Liu, L.C.Zhang, et al. J. Appl. Polym. Sci. 98, 1932 (2005). 

[5] M. Alexandre, P. Dubois, Mater. Sci. Eng.R: 28, 1 (2000). 

[6] Z.M.O. Rzayev, A.Yilmazbayhan, E. Alper, Adv.Poly.Tech.26, 41 (2007). 

[7] E. Söylemez, N. Çaylak, Z.M.O. Rzayev, eXPRESS Polym. Lett. 2, 639 

(2008). 




The effect of Cu/Fe substitution on the crys tallization behav ior and mag netic properties of ferrimagnetic 

glass ceramic rich with magnetite 

S. A. M. Abdel-Hamed0T 1 and M. A. Marzouk 1 * 

1 Glass Research Department, National Research Center, Dokki, Cairo, Egypt 

Abstract-Ferrimagnetic glass-ceramic with high quantity of magnetite (~60%) were synthesized from the system Fe 2 O 3 .CaO.ZnO.SiO 2 . 

The influences of adding different amount of CuO and melting temperature on the crystallization of magnetite were studied. The X-ray 

diffraction patterns show the presence of nanometric magnetite crystals in a glassy matrix after cooling from melting temperature. The 

crystallization of magnetite was increased by increasing amounts of CuO added and melting temperatures. TEM were used t o study the 

microstructure. Magnetic hysteresis cycles were analyzed using a vibrating sample magnetometer with a maximum applied field of 10 kOe, 

at room temperature, in quasi-static conditions. From the obtained hysteresis loops, the saturation magnetization (Ms), remanance 

magnetization (Mr) and coercivity (Hc) where determined. 




Immobilization and Characterization of Thermophilic Recombinant Esterase on Chitosan Nanoparticles 

1 ,Taylan Turan 1 and 1 * 

zmir Institute of Technology, Faculty of Science, Department of Chemistry, Gülbahce Köyü Kampüsü, Urla, Izmir, 35430, Turkey 

1 

Abstract— Immobilization of biologically important molecules on myriad nano-sized materials has attracted great attention. Through this 

study, homemade esterase enzyme was obtained using recombinant DNA technology. Enzyme over expression in Escherichia coli and 

purification were carried out successfully. At the next step, chitosan was synthesized from chitin by deacetylation process and degree of 

deacetylation was calculated as 89% by elemental analysis. Characterization of chitosan was studied by applying FT-IR (Fourier Transform 

Infrared Spectroscopy). After preparation of chitosan and chitosan/esterase enzyme nano-particles, their surface morphologies and structures 

were examined by AFM (Atomic Force Microscopy) and SEM (Scanning Electron Microscopy). In order to investigate the characterization of 

esterase enzyme immobilized on chitosan nano-particles, the experimental studies in terms of activity, substrate specificity, the effect of 

temperature and pH on the activity, optimum temperature and pH values, the effect of variety of metals, inhibitors and detergents on activity and 

thermal stability are being under examination. The characterization data of enzyme immobilized chitosan nano-particles will be compared with 

free enzyme for their potential uses as biocatalysts in variety of biotechnological applications. 

Recently the majority of industrial enzymes produced by 

micro-organisms are being utilized widely and their utilization 

on very diverse area of industry is increasing rapidly in the 

world day by day. Especially, enzymes from thermophiles 

have many advantages for industrial applications because they 

are very thermo stabile and thermo active under high 

temperatures. In that study, we have used recombinant 

thermophilic esterase enzyme from Balçova Geothermal 

region [1]. Esterase enzymes are special interest in a variety of 

biotechnological applications because of their many useful 

properties. 

Immobilization of enzymes is very important not only for 

reuse of them but also for use them more efficient. As 

compared to free enzymes in solution immobilized enzymes 

are more robust and more resistant to environmental changes. 

Therefore, many kinds of immobilization techniques have 

been improved for many years on various supports and by 

different methods. One of the most used biopolymer as 

immobilization carriers, chitosan offer a unique set of 

characteristics: biocompatibility, biodegradability to harmless 

products, nontoxicity, physiological inertness, antibacterial 

properties, heavy metal ions chelation, gel forming properties 

and hydrophilicity, and remarkab le affin ity to proteins [2]. 

Recently, researchers have indicated that nano-sized materials 

can be used for immobilization of enzymes. To the best of our 

knowledge, studies of enzyme immobilization on Chitosan 

nano-particles have been rarely reported. In this study, 

chitosan nano-particles were prepared by ionic gelation 

methodology. Thermophilic recombinant esterase was initially 

over-expressed in E.coli and then purified by one-step affinity 

chromatography with high yield and good purity. 

Thermophilic recombinant esterase was immobilized on 

chitosan nano-particles and conditions for the immobilization 

and characterization of the immobilized enzyme were studied 

systematically. Figure 1 shows AFM images of 

Chitosan/Recombinant-Esterase Nano-particles. Figure 2 

shows SEM images of chitosan nano-particles and 

chitosan/Recombinant-Esterase nano-particles. 

a) b) 

Figure 2. SEM images of a) Chitosan nano-particles, b) 

Chiosan/Esterase nano-particles. 

As a result of our studies, it is expected that the immobilized 

enzy me will exh ibit remarkab ly improved stability properties 

to various parameters, such as temperature, reuse and storage 

time. Thus nano-particles will be suitable for an immobilized 

enzyme carrier. 

*Corresponding author: gulsahsanli@iyte.edu.tr 

[1] Tekedar, H., 2009. Molecular Cloning, Overexpression and 

Characterization of Thermostable Esterase and Lipase from 

Thermophilic Bacillus sp., Master’s Thesis, IYTE. 

[2] Krajewska, B., 2004. Application of chitin- and chitosan-based 

materials for enzyme immobilizations: a review, Enzyme and 

Microbial Technology, 35: 126-139. 

[3] Tang, Z. X., Qian, J. Q., Shi, L. E., 2007. Preparation of Chitosan 

Nanop articles as carrier for immobilzed enzyme, Appl. Biochem. and 

Biotech., 136: 77-96. 

Figure 1. AFM images of Chitosan /Recombinant-Esterase Nanoparticles 




Arsenic Removal by Aggregated Nanoparticle Media 

Yelda Meyva 1 *, Süer Kürklü 1 , Nilay Gizli 1 , 1 

Department of Chemical , Turkey 

1 

Abstract- Arsenic, which is a toxic and accumulating substance in human body, has recently attracted great interest due to the high levels in 

drinking water supplied from underground resources. Novel separation methods for the removal of arsenic use innovative products 

developed by using nano materials. Among the commercial products, Adsorbsia GTO and MTM, are studied as adsorbents through batch 

experiments in order to obtain the kinetics and mechanism of As(V) sorption. It is found that Adsorbsia GTO has larger sorption capacity 

than MTM has, sorption equilibrium is best fitted by Freundlich Isotherm and transfer rate can be modelled by Liquid Film Diffusion. 

Arsenic (As) is a widespread toxic contaminant in water 

and is classified by the International Agency for Research 

and Cancer (IARC) as a human carcinogen [1]. World 

Health Organization (WHO), in 1993, recommended the 

maximum total arsenic amount as 10 g/L. In 2002, the 

USEPA lowered the maximu m contaminant level (M CL) 

 

the new MCL became restrictive in January 2006, the 

WHO, the European Union, and several countries recently 

lowered the recommended or required arsenic limit to 10 

[2-5]. In Turkey also in 2006, with a standard TSE 

266 prepared by Ministry of Health, the maximum arsenic 

concentration is lowered to 10 ppb level. 

In this study, arsenic was selected as a target 

contaminant because of its potential health and regulatory 

concerns. Also, it has an ability to be adsorbed onto metal 

oxide surfaces by forming inner-sphere bidentate ligands 

[6]. Most heavy metals such as Pb 2+ , Cu 2+ and Ni 2+ occur 

as cations in water while arsenic is an oxy-anion forming 

element. This is particularly unique in its sensitivity to 

mobilization at the pH values typically found in natural 

waters. Although arsenic can exist in four different 

oxidation states ( 

form in oxygen-rich environments. Under natural pH 

conditions, species H 2 AsO 4 and HAsO 2 4 are the 

dominant anions in water. As pH increases, the fraction of 

divalent and trivalent arsenate anions also increases. Thus, 

the treatment by adsorption is important because arsenic 

cannot be reduced to harmless by-products unlike other 

oxy-anions, such as ClO 4 or NO 3 , can [7]. 

In this study, two types of commercially available 

aggregated nanosized materials, Adsorbsia GTO and 

MTM ® containing different type of metal oxides, were 

chosen for the removal of arsenic from aqueous solution. 

While Adsorbsia GTO contains TiO 2 nanoparticles, MTM 

consists of a light weight granular core with a coating of 

manganese dioxide. First of all, the adsorption capacities 

of these materials were obtained and compared with each 

other. The capacity of Adsorbsia GTO is estimated as 19.9 

mg As (V)/g-adsorbent while MTM has 0.35 mg As (V)/gadsorbent 

capacity. Since TiO 2 based adsorbent exhibits 

the higher As (V) sorption capacity , Adsorbsia GTO was 

chosen as adsorbent for the studies followed. 

For this purpose, both equilibriu m and kinetical 

properties of GTO for the sorption of As(V) have been 

investigated. Equilibrium behaviour of GTO has been best 

characterized with Freundlich adsorption isotherm. Five 

different kinetic models have been applied to fit the data 

obtained by a series of batch experiments to find out the 

mass transfer mechanism of the processes. The results of 

statistical analysis indicate that the rate is determined by 

the film d iffusion. 

After this point, fixed bed column studies will be 

conducted in order to obtain data to be modelled for design 

purpose. 

This study is supported by Ege University Research 

Foundation by contract no: 09MÜH052. 

*Corresponding author: 0Tyeldameyva@gmail.com 

[1] US Department of Health and Human Services (Ed.), 

Toxicological profile for arsenic, US Department of Health and 

Human Services, Washington DC, 2000. 

[2]World Health Organisation (WHO), Guidelines for Drinking 

Water Quality, 1993, p. 41 

[3]EPA, Technologies and Costs for Removal of Arsenic from 

Drinking Water, EPA- 600-S-05-006, Office of Water (4606), 

Environmental Protection Agency, Washington DC., 2000 

[4]EPA, National Primary Drinking Water Regulations; Arsenic 

and Clarifications to Compliance and New Source Contaminants 

Monitoring, Final Rule, Federal Register, 66(15), 6975, 2001. 

[5]EPA, Arsenic Treatment Technology Evaluation Handbook 

for Small Systems, EPA-816-R-03-014, Office of Water (4606), 

Environmental Protection Agency, Washington DC., 2003. 

[6] Hristovski, K., Baumgardner, A., Westerhoff P., 2007. 

Selecting metal oxide nanomaterials for arsenic removal in fixed 

bed columns: From nanopowders to aggregated nanoparticle 

media. Journal of Hazardous Materials 147 (2007) 265–274. 

[7] Mohan D., Pittman C. U., “Arsenic removal from 

water/wastewater using adsorbents”—A critical review, 2007. 




Electrochemical Synthesis of Ordered Graphene Structures 

1 *, Duygu Ekinci 2 , Ümit Demir 2 

1 Atatürk University, Erzurum Vocational and Training School, Dept. of Chemistry, Erzurum, Turkey 

2 Atatürk University, Faculty of Science, Dept. of Chemistry, Erzurum, Turkey 

Abstract-We report an electrochemical method for the formation of ordered graphene structures on Au (111) electrode by the 

electrochemical reduction of graphite oxide (GO). The electrochemical reduction of GO was carried out by two ways: i- direct 

electrochemical reduction from the aqueous solution of GO and ii- the electrochemical reduction of adsorbed GO onto Au substrate. The 

characterization of reduced GO (RGO) was performed by Fourier transform infrared spectroscopy (FT-IR), scanning tunneling microscopy 

(AFM-STM ), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). 

Graphene is a single layer of carbon atoms in a closely 

packed honeycomb two-dimensional (2D) lattice [1]. 

Graphene is used in nanocomposites and microelectrical 

devices such as field-effect transistors, ultrasensitive 

sensors, ultracapacitors etc, due to its unique electronic 

properties [2]. In literature, the synthesis of graphene is 

generally achieved with the chemical reduction in the 

presence of reducing agent such as hydroquinone, NaBH 4 

and hydrazine. In this study, graphene structures on Au 

(111) are also electrochemically synthesized from graphite 

oxide (GO) which contains oxygen functional groups such 

as epoxides, -OH and –COOH groups [3]. 

Figure 1. Cyclic voltammograms of GO in aqueous solutions 

containing 0.1 M KNO 3 . 

Figure 2. (a) STM images of graphene layers, (b) Atomic scale 

STM image of graphene. 

*Corresponding author: hdogan@atauni.edu.tr 

[1] G. Wang, J. Yang, J. Park, X. Gou, B. Wang, H. Liu and J. 

Yao, J. Phys. Chem. C, 112 (22), 8192 (2008). [2] G.K. 

Ramesha and S. Sampath, J. Phys. Chem. C Lett., 113, 7985 

(2009). 

[3] Z. Wang, X. Zhou, J. Zhang, F. Boey and H. Zhang, J. of 

Phys. Chem. C Lett., 113, 14071 (2009). 

[4] T.S. Sreeprasad, A.K. Samal and T. Pradeep, J. Phys. Chem. 

C., 113, 1727 (2009). 

[5] H.Guo, X. Wang, Q. Qian, F. Wang and X. Xia, ACS Nano, 3 

(9), 2653 (2009). 

[6] E. Stolyarova, D. Stolyarov,L. Liu, K.T. Rim, Y. Zhang, M. 

Han, M Hybersten, P. Kim and G. Flynn, J. Phys. Chem. C, 112, 

6681 (2008). 

GO was prepared from graphite powder by using a 

modified Hummer method [4]. Cyclic voltammetry 

technique was used to determine the electrochemical 

reduction potentials of GO (Figure 1). Synthesized GO 

were reduced by two methods. First, GO was directly 

reduced from a solution (pH:2) containing GO on Au 

electrode at -500 mV. Secondly, GO was adsorbed onto 

Au substrate in pH=2 buffer solution and then was reduced 

electrochemically in an aqueous solution containing 0,1 M 

KNO 3 . 

GO reduced in solution phase, was characterized by X- 

ray diffraction (XRD), X-ray photoelectron spectroscopy 

(XPS) and Fourier transform infrared spectroscopy (FT- 

IR). XRD patterns showed that the structure of GO is 

changed to (002) crystal structure of graphite [5]. 

Furthermore the C1s XPS spectra of GO and graphene 

were confirmed the formation of the RGO. 

Morphological investigations done by STM and AFM 

indicate the formation of the ordered graphene 

nanostructures (Figure 2). Atomic scale STM image of the 

GO films on Au (111) electrode shows that the atomic 

structures of graphene has hexagonal carbon atoms and the 

distance between the atoms is about 2.5 Å, which is in 

good agreement with literature data [6]. 


P 

P 

P 



Synthesis, Characterization of Nanodots Embedded into PP-g-PEG Amphiphilic Graft Copolymer 

1* 

2 

1 

Özlem A. KalaycıP 

P, Baki HazerP P, Turgay AtalayP 

1 

PDepartment of Physics, Zonguldak Karaelmas University, Zonguldak 67100, Turkey 

PDepartment of Chemistry, Zonguldak Karaelmas University, Zonguldak 67100, Turkey 

2 

Abstract—The synthesis, CdS and Cd Acetate nanoparticles salts embedded in novel amphiphilic comb-type graft 

copolymers having good film-forming properties have been described. Amphiphilic comb-type graft copolymers were 

synthesized by the reaction of chlorinated polypropylene (PP) (Mw = 140,000 Da) with polyethylene glycol (PEG) (Mn = 

2,000 Da) at different molar ratios. Cd nanoparticles embedded graft copolymers were prepared by reducing solutions of the 

salts of CdS and Cd Acetate. 

The interest in the synthesis and characterization of 

nanoparticles embedded amphiphilic block and graft 

copolymers has increased recently due to their possible 

applications in the fields of biology and material sciences. 

Nanoparticles show properties that are often different from 

those of their corresponding bulk materials. Size provides 

important control over many of the physical and chemical 

properties of nanoscale materials including luminescence, 

conductivity, and catalytic activity allowing application of 

these species in optical systems, catalysis, and biomedical 

technology [1]. 

In this study, a series of various polypropylene- g- 

polyethyleneglycol (PP-g-PEG2000) graft copolymers was 

prepared by using chlorined- polypropylene and 

polyethyleneglycol 2000. Some inorganic salts aqueous 

solutions were mixed into tetrahydrofurane solution of 

amphiphilic copolymer to obtain inorganic nanoparticles 

embedded into polymer composites. Scanning Electron 

Microscopy were used to characterize polymer composites 

micrograph . [2,3]. 

Figure 2. SEM micrograph of Cd Acetate nanoparticle salts 

embedded PP-g- PEG. 

The average particle diameter of nanoparticles were found to 

be 10 and 170 nm, from the high resolution Scanning electron 

microscopy (SEM). SEM micrographs of the cadmium 

nanoparticles embedded graft copolymer samples are shown in 

Fig. 1., Fig. 2., respectively. 

This study was supported by Zonguldak Karaelmas 

University Scientific Research Projects (grant# 2008-70-01- 

01, grant# 2008-13-02-02, grant# 2008-13-03-01). 

Figure 1. SEM micrograph of CdS nanoparticle salts embedded PPg-PEG. 

*Corresponding author: ozlem_altunordu@yahoo.com.tr 

[1] Alivisatos AP (1996) Perspectives on the physical chemistry of 

semiconductor nanocrystals. J Phys Chem 100:13226–13239 

[2] El-Sayed MA (2001) Some interesting properties of metals 

confined in time and nanometer space of different shapes. Acc Chem 

Res 34:257–264 

[3] Kalaycı, Ö.A., Cömert B.F., Hazer, B., Atalay, T., Cavicchi, A. 

K., Çakmak, M, 2009. Synthesis, characterization, and antibacterial 

activity of metal nanoparticles embedded into amphiphilic comb-type 

graft copolymers, Polym. Bull.,DOI:10.1007/s00289-009-0196-y 




Synthesis, Characterization of The Amphiphilic Polymer Composites Containing 

SiO 2 Nanoparticles 

Özlem A. Kalayc 1* , Baki Hazer 2 , Turgay Atalay 1 

1 Department of Physics, Zonguldak Karaelmas University, Zonguldak 67100, Turkey 

2 Department of Chemistry, Zonguldak Karaelmas University, Zonguldak 67100, Turkey 

Abstract—The synthesis, spectroscopic characterization, SiO 2 nanoparticles embedded in novel amphiphilic comb-type graft 

copolymers having good film-forming properties have been described. Amphiphilic comb-type graft copolymers were 

synthesized by the reaction of chlorinated polypropylene (PP) (Mw = 140,000 Da) with polyethylene glycol (PEG) (Mn = 

2,000 Da) at different molar ratios. SiO 2 nanoparticles embedded graft copolymers were prepared by reducing solutions of the 

salts of SiO 2 and the copolymer in tetrahydrofuran. 

The interest in the synthesis and characterization of 

nanoparticles embedded amphiphilic block and graft 

copolymers has increased recently due to their possible 

applications in the fields of biology and material sciences [1]. 

Size provides important control over many of the physical and 

chemical properties of nanoscale materials including 

luminescence, conductivity, and catalytic activity allowing 

application of these species in optical systems, catalysis, and 

biomedical technology [2]. 

In this study, a series of various polypropylene- g- 

polyethyleneglycol (PP-g-PEG2000) graft copolymers was 

prepared by using chlorined- polypropylene and 

polyethyleneglycol 2000. SiO 2 inorganic salts aqueous 

solutions were mixed into tetrahydrofurane solution of 

amphiphilic copolymer to obtain inorganic nanoparticles 

embedded into polymer composites [3].The concentration of 

the SiO 2 nanoparticles in the graft copolymer is also listed in 

Table 1. Solution properties, UV-Vis, Fluorescence spectrum 

analysis, Scanning Electron Microscopy were used to 

characterize polymer composites. 

Table 1.Prepartion conditations of the hybrid polymers. 

Sample Silicat Au +3 NaBH 4 

Name (Drop) (Drop) (Drop) 

S1 8 8 10 

Figure 3. SEM micrograph of the hybrid polymer samples. 

The SiO 2 nanoparticle embedded copolymers in toluene was 

observed at a maximum wavelength (max) of 307 and 529 

nm in the UV–VIS absorption spectra, respectively (Fig. 1.). 

Fluorecence spectrum curve of nanoparticle embedded 

amphiphilic graft copolymer is shown Fig. 2. The average 

particle diameter of nanoparticles were found to be 20 nm 

from the high resolution scanning electron microscopy (SEM) 

and energy dispersive X-ray spectroscopy (EDS). SEM 

micrograph of the SiO 2 nanoparticles embedded graft 

copolymer sample is shown in Fig. 3. 

Figure 1. UV-visible spectra of the hybrid polymer samples. 

Figure 2. Fluorescence spectra of the hybrid polymer samples. 

This study was supported by Zonguldak Karaelmas 

University Scientific Research Projects (grant# 2008-70-01- 

01, grant# 2008-13-02-02, grant# 2008-13-03-01). 

*Corresponding author: ozlem_altunordu@yahoo.com.tr 

[1] Alivisatos AP (1996) Perspectives on the physical chemistry of 

semiconductor nanocrystals. J Phys Chem 100:13226–13239 

[2] El-Sayed MA (2001) Some interesting properties of metals 

confined in time and nanometer space of different shapes. Acc Chem 

Res 34:257–264 

[3] Kalayc, Ö.A., Cömert B.F., Hazer, B., Atalay, T., Cavicchi, A. 

K., Çakmak, M, 2009. Synthesis, characterization, and antibacterial 

activity of metal nanoparticles embedded into amphiphilic comb-type 

graft copolymers, Polym. Bull.,DOI:10.1007/s00289-009-0196-y 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Effect of Toluene on Nano Calcite Production by Carbonation Route 

Murat Molva 1 and Ekrem Özdemir 1 * 

1 -Izmir, Turkey 

Abstract- Nano size calcium carbonate crystals were produced in 20 mM Ca(OH) 2 by CO 2 diffusion in the presence of toluene as an or ganic 

additive. Based on the X-ray diffraction, the main crystal morphology was calcite with the crystallite size of 30-35 nm. Scanning electron 

microscopy indicated the maximum dimensions of the crystals up to 200 nm. According to the FTIR analysis, chemical structure of the 

precipitates had some differences after the addition of toluene and crystallinity was occurred in different chemical structures. 

Crystallization of calcite occurs in the presence of varying 

complexity of organic molecules. Those organic molecules 

may influence the morphology of crystals during calcium 

carbonate precipitation. Studies on the interaction of 

macromolecules with calcite suggest that these molecules can 

bind specifically to certain crystal planes during crystal 

growth, thereby modifying the final morphology attained [1]. 

On the other hand, solubility of CO 2 increases in the presence 

of some organics [2]. Amphiphilic property of some organic 

solvents may have a great influence on structural framework 

and solvating degree of additives, dielectric constant of 

solution, polarity, and interaction between the ions (such as 

Ca 2+ ) in the solution. At room temperature, some organic 

solvents, such as hexane, toluene, and benzene can not 

exhibit amphiphilic property since they are not miscible in 

water. Molecular structural framework and solvating degree 

of additive may affect the initial formation of crystallization 

by blocking of growth site and confining the reaction 

solutions with organized media and can lead to high localized 

accumulation of ionic charge with high spatial density, 

thereby, determining the size, shape and organization of the 

crystal forms. Thus, it can be speculated that the amphiphilic 

property of organic solvent plays an important role in 

determining the calcite crystal morphology [3,4]. Organic 

solvents and water have co-effect on the polymorph and 

morphology of CaCO 3 particles at room temperature. 

Various unusual crystal morphologies, such as dendriteshaped, 

flower-like, wheatgrass-like, needle-like, whiskers, 

double-taper-like, cubical, spherical etc. can be obtained 

depending on the experimental conditions [3]. 

In this study, nano size calcite crystals were produced via 

carbonation route, where the CO2 was diffused through the 

surface of a stirred reactor containing various concentrations 

of Ca(OH) 2 slurry in the presence of toluene (merck, >99.9 

%) as an organic additive. The ratio of the mixture (toluene / 

water) varied fro m 5 % to 20 % (v/v) and stirring rate was 

400 and 800 rpm. pH and conductivity were monitored 

during the tests and characterization of nano crystals was 

expressed by SEM, XRD and FTIR. 

Figure 1 shows the SEM images of the nano crystals which 

were obtained in the presence of 5 % (a) at 400 rpm and (c) 

at 800 rpm, and 20 % toluene (b) at 400 rpm and (d) at 800 

rpm, respectively. The crystallite sizes were calculated fro m 

Debye Scherrer Equation as 30-35 nm using XRD data. 

Figure 2 shows the FTIR data for the calcite with and 

without addition of toluene and found that there are some 

structural diferrences in the calcite morphology as indicated 

in v 1 , v 2 , v 3 , and v 4 orientations. 

Effect of toluene on size, shape, and morphology of the 

produced calcite will be discussed in detail during the 

presentation. 

(a) 

(c) 

(b) 

(d) 

Figure 1. SEM images of the nano crystals in the presence of 

toluene: (a) 5 %, 400 rpm, (-b) 20 %, 400 rpm (c) 5 %, 800 rpm, (d) 

20 %, 800 rpm 

abs 

6 

5 

4 

3 

2 

1 

0 

2510-2530 

(v 1 +v 3 ) 

2500 

calcite with toluene 

calcite without toluene 

2000 

1797-1831 

(v 1 +v 4 ) 

1500 

1000 

wavelength (cm -1 ) 

Figure 2. FTIR spectra of the nano crystals (20 mM Ca(OH) 2 , CO 2 , 

H 2 O and 20 % toluene). 

1420-1450 

v 3 

1084 -1100 

875-885 

v 2 

711-748 

v 1 

v 4 

0T*Corresponding author: ekremozdemir@iyte.edu.tr 

[1] Meldrum F.C., Hydeb S. T., Morphological influence of 

magnesium and organic additives on the pre precipitation of calcite, 

Journal of Crystal Growth 231 (2001) 544–558 

[2] Brooks B.W, Shilimkan R.V, Manufacture of calcium carbonate 

dispersions in lubricating oil, Colloid and Polymer Science 257 

(1979) 981-983 

[3] Lei, M., Li, P. G., Sun, Z. B. and Tang, W. H. (2006) Effects of 

organic additives on the morphology of calcium carbon ate particles 

in the presence of CTAB. Materials Letters 60, 1261-1264 

[4] Dickinson, S. R. and McGrath, K. M. (2004) Aqueous 

precipitation of calcium carbonate modified by hydroxyl-containing 

compounds. Crystal Growth & Design 4, 1411-1418 

500 




Experime ntal Design on Nano Calcite Production 

Murat Molva 1 and Ekrem Özdemir 1 * 

1 -Izmir, Turkey 

Abstract- Based on the carbonation route, nano calcite crystals were produced by Ca(OH) 2 – CO 2 - H 2 O system in the presence of different 

organic solvents (methanol, ethanol, hexane, toluene and benzene). A three factor – two level (2 3 ) full factorial methodology was studied to 

understand the combined and interaction effects of Ca(OH) 2 amount, organic solvent / water ratio, and the stirring rate on the precipitation 

time. Regression model equations were derived as functions of the main three factors to predict the reaction times for the intermediate, lower 

or upper values of the factor levels. Effects of these factors on shape were also determined by X-ray diffraction and scanning electron 

microscopy. 

At room temperature, some organic solvents, such as 

hexane, toluene and benzene can not exhibit amphiphilic 

property since they are not miscible in water. However, these 

organic solvents can exhibit amphiphilic property to some 

extent under vigorous stirring. Thus, generally, molecular 

structural framework and solvating degree of additive may 

affect the initial formation of crystallization by blocking of 

growth site and confining the reaction solutions with 

organized media and can lead to high localized accumulation 

of ionic charge with high spatial density, thereby determining 

the size, shape, and organization of the crystal forms. 

Therefore, it can be speculated that the amphiphilic property 

of organic solvent plays an important role in determining 

both polymorph and morphology of CaCO 3 [1,2]. Various 

unusual crystal morphologies, such as dendrite-shaped, 

flower-like, wheatgrass-like, needle-like, whiskers, doubletaper-like, 

cubical, spherical etc. can be obtained depending 

on the experimental conditions [1,3]. 

pH and conductivity curves were obtained by CO2 injection 

in the presence of various organic additives (methanol, 

ethanol, hexane, toluene and benzene) / water mixtures and 

Ca(OH) 2 . Methanol and ethanol were miscible in water. On 

the other hand, hexane, toluene and benzene were immiscible 

in water but they were used above their solubility limits. 

Therefore, mixtures of water and solvents were formed in 

order to obtain attraction with the Ca(OH) 2 powders. 

Ca(OH) 2 in mixtures was both below the solubility limit (20 

mM ) and above the solubility limit (40 mM). The main 

intention of the usage of those additives was to modify the 

precipitate morphologies and create a database for the 

precipitation time with different additives. 

The experimental design and optimization study reports the 

effects of Ca(OH) 2 amount in slurry, additives (methanol, 

ethanol, hexane, toluene, benzene) and stirring rate on 

precipitation time. A 2 3 full factorial methodology with three 

factors involving two levels of each variable (40 runs with 1 

replicates, totally 40 experiments) were carried out to 

determine the significant parameters and the interaction 

effects. Factors and their levels for screening design of 

experiments are given in Table 1. 

Tables 2 give the contributions for the effects of three main 

factors and their interaction effects. Sign (+) refers to positive 

effects of factors on the response (precipitation time), and 

sign (-) represents the negative effects of factors on the 

precipitation time. If a factor represented by a (+) sign, this 

factor increase the precipitation time, if it is represented by a 

(-) sign, it decreases the precipitation time. For examp le, 

hexane and toluene increase the precipitation time 

individually. Factor C (stirring rate) has negative effects on 

precipitation time for all sets. A striking example can be 

given to understand the interaction effect: when the methanol 

and benzene concentrations were increased, the precipitation 

time decreased, however, when Ca(OH) 2 amount was 

increased together with methanol and hexane, the 

precipitation time was seen to decrease. Further details will 

be discussed during the presentation. 

Table 1. Factors and their levels for screening design of 

experiments 

Low High Response 

Factors 

A - Ca(OH) 2 20 mM 40 mM 

B - Additives 

Ethanol 

Methanol 

Hexane 

Toluene 

Benzene 

5 % 20 % 

C- Stirring 400 rpm 800 rpm 

Precipitation 

time 

(minutes) 

Table 2. Sign of standardized effects of the main factors and their 

interactions. (A: Ca(OH)2 B: Additive C: Stirring Rate) 

0T*Corresponding Author: ekremozdemir@iyte.edu.tr 

Main 

Interactions 

SET Additive A B C AB AC BC ABC 

1 Methanol + + - - - + - 

2 Ethanol + + - + + - - 

3 Hexane - - - + - + - 

4 Toluene + - - + - - + 

5 Benzene + + - - - - - 

[1] Lei, M., Li, P. G., Sun, Z. B. and Tang, W. H. (2006) Effects of 

organic additives on the morphology of calcium carbonate particles 

in the presence of CTAB. Materials Letters 60, 1261-1264 

[2] Dickinson, S. R. and McGrath, K. M. (2004) Aqueous 

precipitation of calcium carbonate modified by hydroxyl-containing 

compounds. Crystal Growth & Design 4, 1411-1418 

[3] Carmona, J. G., Morales, J. G., and Clemente, R. R. (2003). 

"Rhombohedral-scalenohedral calcite transition produced by 

adjusting the solution electrical conductivity in the system 

Ca(OH) 2 -CO 2 -H 2 O." Journal of Colloid and Interface Science, 

261(2), 434-44 







Abstract—Nucleation and growth mechanism during formation of poly(AA) films on gold substrates was intestigated. Repeated potential 

cycling by using cyclic voltammetry and potential controlled electrolysis techniques have been performed to synthesize poly(AA) thin films on 

gold working electrodes in the solution containing 0.1 mM AA and 0.1 M phosphate solution (pH:6.2). Chronoamperometry, STM (Scanning 

Tunneling Microscopy), AFM (Atomic Force Microscopy), and UV-vis. absorption spectroscopy techniques were applied for the characterization 

of prepared polymeric films. 






















. 


The redox behaviour of dyes has been under study for nearly 

65 years [3-7]. Chen et al. [6] prepared poly(AA) films in 

different pH’s and found that the optimum pH of the 




In this study, we have investigated nucleation and growth 

mechanism during the formation of poly(AA) films on gold 

substrates. Repeated potential cycling by using cyclic 













two cases are 

2 




2 

3 


J prog 

Figure 2. Experimental current-time transients for different electrooxidation 

potential values. The non-faradaic charging currents in the absense of AA 

have been subtracted from these data 

STM (Scanning Tunneling Microscopy), and AFM (Atomic 

Force Microscopy) techniques was applied to investigate 

poly(AA) film surface structure. We have also studied the 

optical properties of the prepared polymeric films by using 

UV-vis. absorption spectroscopy. 





[2] G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science 270, 1789 

(1995) 


[4] A. A. Karyakin, A. K. Strakhova, E. E. Karyakina, S. D. Varfolomeyev, A. 

K. Yatsimirsky, Bioelectrochem. Bioenergetics 32, 35 (1993) 




[8] A. Bewick, M. Fleiscmann, H. R. Thirsk, H. R. Trans Faraday Soc. 58, 

2200 (1962) 





The Interaction of Electromagnetic Waves from Single Sheet of Spherical Nano-Elements Meshed on 

Spherical Shell 

Taner Sengor 

Department of Electronics and Communication Engineering, Yildiz Technical University, Istanbul 34349, Turkey 

Abstract—Possibilities creating nano-structures providing unnatural electromagnetic characteristics are given. Co-rings in 

nano-metric dimensions lying on different azimuth and/or equatorial planes are defined as nano-element providing such 

possibilities. These nano-elements are meshed on spherical shells. The interaction of electromagnetic wave with both of 

nano element and meshed spherical surface are studied. For an example, the necessary configurations for both of the 

electromagnetically effective cloaking and the optically effective cloaking (invisibility) are given for this purpose. 

The loops are used at meta-material applications, 

frequently. The using of circular loop combinations on nonplanar 

substrates is offered in this paper to consider in both of 

artificial material studies and cloaking applications [1]. Two 

basic combinations are used: i) Parallelly located circular loop 

lying on latitude circles on a spherical core. We call this 

element smooth ring ball. ii) Intersecting circular loop lying 

on meridian circles on a spherical core. We call this element 

cross ring ball. The circular loop is located on a spherical core 

having the radius a, that is sufficiently small. The magnitudes 

of the currents on the circular loops must be sufficiently large. 

These necessary conditions give a chance to generate TM θ 

waves, which we call principal wave. Additionally using of 

materials having time independent permittivity and θ- 

independent permeability brings the property of TE waves to 

the previous TM θ waves. We call the last TM θ -TE waves 

secondary wave. The arrangements at the circumstance of the 

ring balls bring the property of TM r waves to the waves under 

the discussion. The last property enforces to bring the 

behavior of TE θ waves to the principal wave; therefore the 

principal wave gains the property of TEM θ waves. The last 

property enforces adding the behavior of TM waves to the 

principal wave. So the wave under the discussion gains the 

property of TEM waves. After all, the use of suitably built up 

layers of almost zero epsilon material and/or perfectly 

conducting material brings the behavior of TE r waves to the 

waves under the discussion. The final wave is gained a 

propagation characteristic fitting on the propagation 

characteristics of TEM θ waves and almost TEM r waves. 

The above said characteristic gives a way to produce 

suitable objects with spherical shapes in nanometer scale; 

those change the RCS of objects and therefore provide us to 

built structures demonstrating effective electromagnetic 

cloaking property. We call this structure effective 

electromagnetic cloaking device. 

In summary, several compositions of nano rings on 

spherical substrates are studied. The necessary conditions for 

both of the electromagnetically effective cloaking and the 

optically effective cloaking are generated. 

*Corresponding author: sengor@yildiz.edu.tr 

[1] T. Sengor, " Properties of a non-planar metamaterial elements: ring 

resonators on a spherical substrate, " The First International Congress on 

Advanced Electromagnetic Materials in Microwaves and Optics, Italy, 

Rome, Metamaterials 2007 Congress, 22-26 October 2007. 

[2] T. Sengor, Metamaterials Congress, Aug 30th-Sept 4th 2009, London, UK 




Hydrothermal Synthesis of SrMgZnSi 2 O 7 :Eu 3+ Phos phor 

Nevzat Külcü 1 * , Fatih Mehmet Emen 2 , 1 , Sevda Sönmez 1 , Aynur Gürbüz 1 and Tülay Çetin 1 

1 Department of Chemistry, Mersin University, Mersin,33342, Turkey 

2 Department of Chemistry, Kirklareli University, Kirklareli,39300, Turkey 

Abstract-SrM gZnSi 2 O 7 :Eu 3+ nanophosphor was prepared under hydrothermal conditions at 200 o C and 6h. The luminescence properties were 

investigated and lifetime calculations were carried out. It is determaned that the red emission is caused by the band at 615 nm. 

Nanophosphors have been extensively investigated during 

the last decade due to their application potential for various 

high-performance and novel displays and devices. Synthesis 

of nanophosphors is generally done by different routes such as 

colloidal, capping, cluster formation, sol-gel, electrochemical 

etc., are being followed. Chemical precipitation in presence of 

capping agents, reaction in microemulsions, sol-gel reaction 

and autocombustion are commonly used techniques for 

synthesis of nanophosphors. 

Recently, alkaline earth silicates doped with rare earth ions 

have attracted research interests in the field of 

photoluminescence since they are suitable hosts with high 

chemical stability. The phosphors with an akermanite-type 

structure are the host structures that have been researched 

intensively [1–3]. Eu 2+ , Dy 3+ co-doped Sr 2 MgSi 2 O 7 phosphor 

was found to emit a blue–green light peaking at 476 nm upon 

UV illumination and show a long afterglow [1]. Toda et al. 

have been prepared Sr2MgSi2O7:Eu 2+ ,Dy 3+ and 

Ca2MgSi2O7:Eu 2+ , Dy 3+ phosphors, and they show a bright and 

long-lasting phosphorescence [2]. 

In this work, we synthesized SrMgZnSi 2 O 7 :Eu 3+ phosphor 

by hydrothermal method. Sr(NO 3 ) 2 , Mg(NO 3 ) 2 , Zn(NO 3 ) 2 

and TEOS solution mixture were reacted at 220 o C and 3 days 

in high pressure hydrothermal unit. The white solids was 

filtered and washed with water and dried. Then dried solids 

heated at 800 o C and 6 h. Excitation and emission lifetime 

properties were studied by photoluminescence spectra. 

band is broad and belongs typically to the 5 D 0 7 F j (j=0-4) 

electronic transition of Eu 3+ ions. 3+ 

ions reside in a position which has a low local symmetry. 

Then the luminescence lifetime of phosphor were 

calculated by using the following equation. 

I = A e (-t/ ) 

Where, I: Intensity; : lu minescence lifetime; A:constant. 

As a result the luminescence lifetime is found as 1.765 ms. 

In summary, a new red SrMgZnSi 2 O 7 :Eu 3+ phosphor has 

been successfully synthesized by hydrothermal method. 

Phosphor has four emission bands between 590-700 nm. The 

lifetime of the trap was calculated to be 1.765 ms. This red 

emission phosphor may be used in display panels and 

fluorescence lamp phosphors The particle size distribution 

and surface morphology analysis will be studied by SEM 

technique. 


Grant No. TBA G-107T392. 

*Corresponding author: nkulcu@yahoo.com 

[1] Y. Lin, Z. Tang, Z. Zhang, X. Wang, J. Zhang, J. Mater. Sci. Lett. 

20 1505, (2001). 

[2] K. Toda, Y. Imanari, T. Nonogawa, J. Miyoshi, K. Uematsu, M. 

Sato, J. Ceram. Soc. Jpn. 110 (4), 283, (2002). 

[3] L. Jiang, C. Chang, D. Mao, J. Alloys Compd. 360 (1–2) 193, 

(2003). 

Figure 1. Excitation and Emission spectra of SrMgZnSi 2 O 7 :Eu 3+ 

phosphorus 

We investigated photoluminescence spectra of 

SrMgZnSi 2 O 7 :Eu 3+ phosphor as detailed its excitation and 

emission spectra are shown in the figure. In the excitation 

spectrum, three absorption bands have been observed. While 

the broad absorption band is attributed to Eu-O chargetransition 

and the other two weak band that observed at 308 

and 389 nm are attributed to 4f electronic transition of 

Eu 3+ ions. In the emission spectrum were observed four 

emission bands which observed at 590 nm, 615 nm, 651 nm 

and 700 nm, but the band at 615 nm cause a red emission. This 




Shape and Size Controlled Synthesis of Zinc Oxide Powder 

by Solvothermal Method 

A. Gürkan YILMAZOĞLU, M. Ozan ÖZER, Ender SUVACI 

Department of Materials Science and Engineering, Anadolu University, 26480 Eskisehir, Turkey 

Abstract— In this study, effects of synthesis parameters on nucleation and growth of ZnO particles and 

subsequently on particles’ shape and size during solvothermal process have been investigated. Various particle 

shape and size were obtained by using different solvent compositions with various alcohol to water ratios. The 

powder, synthesized in 100% alcohol, has a hexagonal plate-like morphology and particle size ranging from 10 to 

15μm. These particles are organometalic complexes of zinc and calcination of them results in zinc oxide 

structures. 

Zinc oxide is a material with great potential for a variety of 

applications, such as optical waveguides, surface acoustic 

wave devices, varistors, transparent conductive oxides, 

chemical and gas sensors, and UV-light emitters.[1,2] Its wide 

bandgap (~3.37 eV at room temperature[1]) makes ZnO a 

promising material for photonic applications in the UV or blue 

spectral range. In addition, ZnO doped with transition metals 

shows great promise for spintronic applications.[3] ZnO 

exhibits sensitivity to various gas species, namely ethanol 

(C2H5OH), acetylene (C2H2), and carbon monoxide (CO), 

which makes it suitable for sensing applications. Moreover, its 

piezoelectric property (originating from its noncentrosymmetric 

structure) makes it suitable for 

electromechanical sensor or actuator applications. In addition, 

ZnO is biocompatible which makes it suitable for biomedical 

applications. Furthermore, ZnO is a chemically stable and 

environmentally friendly material. Consequently, there is 

considerable interest in studying ZnO in the different size and 

shape for different application areas. 

In this study, effect of alcohol to water ratio on size and shape 

of ZnO powder was investigated during solvothermal 

synthesis. Various particle shape and size were obtained by 

using different solvent compositions with various alcohol to 

water ratios. The powder, synthesized in 100% alcohol, has a 

hexagonal plate-like morphology and particle size ranging 

from 10 to 15μm. These particles are organometalic 

complexes of zinc and calcination of them results in zinc 

oxide structures. On the other hand, when the amount of water 

in solvent concentration increases, the powder shapes becomes 

a square plate and further addition of water results in rod 

shapes zinc oxide particles with were grown in 

direction. 

In experimental studies, as zinc source and pH regulator 

zincnitratehexahidrate (Zn(NO)3.6H 2 O, Merck), and 

hexametilentetramine (HMT, C 6 H 12 N 4 , Merck) and alcohol 

water system to prepare the starting solution for synthesis. 

Seven different alcohol/water ratio solutions were studied in 

this study. In 100% alcohol system, organo-zinc complex 

hexagonal platelets formed. In 90% alcohol 10% water and 

80% alcohol 20%water solutions were developed organo-zinc 

square-like plates. At 60% alcohol 40% water ratio solution 

system, water start to be dominated in system, and the 

powders were formed rod-like shape and ZnO formation. 

After this point decreasing the alcohol/water ration the 

powders shape were rod-like structure with increasing aspect 

ratio. 

c 

a 

Figure: (a) In 100% alcohol solution synthesis were developed hexagonal 

platelet particles. (b) Square plates synthesized in 80% alcohol 20% water 

solution. (c) 40% alcohol 60% water solution, particles formed like rod grown 

direction. (d) In 100% water solution rod ZnO were synthesized. 

[1] U. Özgür, Ya. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Doğan, V. 

Avrutin, S.-J. Cho, H. MorkoA, J. Appl. Phys. 2005, 98, 041301. 

[2] R. Triboulet, J. Perriere, Prog. Cryst. Growth Charact. Mater. 2003, 47, 65. 

[3] R. Janisch, P. Gopal, N. A. Spaldin, J. Phys. Condens. Matter 2005, 17, 

R657. 

b 

d 




Synthesis of SnO 2 Nanoparticles via Sol-Gel Method 

Hilal Kose 1 *, Emrah Bulut 1 1 

1 Department of Chemistry, Arts and Sciences Faculty, Sakarya University, 54187, Sakarya, Turkey 

Abstract- SnO 2 nanop articles fabricated at different pH values by sol-gel method. Sols were prepared from aqueous solution of tin(II) 

chloride at room temperature. SEM and XRD analysis were performed to characterize nanoparticles. The results indicate the 

nanocrystalline nature of the SnO 2 particles. 

Tin oxide (SnO2), cassiterite structure, is a typical wide 

band gap n-type semiconductor (3.8 eV) [1] and, one of the 

most widely used semiconductor oxides due to its chemical 

and mechanical stabilit ies. The electrical and chemical 

properties of SnO 2 have been extensively studied because of 

its application as transparent electrodes for solar cells, liquid 

crystal displays; antistatic coatings and gas sensors; anodes 

for lithium ion batteries, transistors, catalyst supports; nano 

and ultra filtration membranes and anticorrosion coatings [2]. 

Recently tin oxide-based materials have received 

considerable attention as promising anode materials for Liion 

batteries due to their high capacity [3]. SnO 2 

nanoparticles can be obtained by different techniques. 

Among the processing techniques, sol-gel offers advantages 

such as low cost, low temperatures processing and also 

precise control of stoichiometry [4]. 

In this work, sol-gel method was applied to synthesize 

SnO 2 nanoparticles at different pH values. The SnO 2 

precursor solution was prepared from tin chloride by 

dissolving SnCl 2·2H 2 O in 50 ml of deionized water. The 

solution was in the form of turbid nature during the first 

period of the dissolving and then the color was returned to a 

transparent nature when acetic acid was added. The addition 

of acetic acid was also aimed to prevent rapid hydrolysis for 

obtaining nucleation of nano sized species in the solution. 

After stirring a few hours, the solution pH was adjusted to 7, 

8, 9, and 10 by using ammonia solution (%25). Then the 

solution stirred for 24 h. The resultant sols washed and 

centrifuged 5 times with deionized water. Finally, sols dried 

at 150 o C for 2 hours and precalcination was performed at 

300 o C. Subsequently, the calcination temperature was 

increased to 400 o C and the sols were calcinated for two 

hours at treatment. 

of spherical nanoparticles in diameter under 100 nm were 

obtained. 

Figure 2. XRD diffraction of SnO 2 nanop articles. 

Figure 2 shows the XRD patterns of the powders obtained 

at the peak positions in each sample agree well with the 

reflections of SnO 2 (cassiterite). The XRD diffraction peaks 

are evidenced that a crystalline type of SnO 2 was obtained. 

As can be seen from the Figure 2, the width of the reflections 

is considerably broadened, because of nanocrystalline do main 

size. 

In summary, SnO 2 nanoparticles were obtained from solgel 

method. Strong acidic conditions enhanced the hydrogen 

bonding among the protonated nanocrystallites, leading to a 

high degree of agglomeration, while in higher pH value 

solutions; the coordinated water molecules should suppress 

the agglomeration among the freshly formed nanocrystallites 

[2]. Because of this reason, synthesis of SnO 2 nanoparticles 

was performed at higher pH values such as 7, 8, 9 and 10. 

The size o f nanocrystallines decreased with reducing pH 

value to 7. The broad XRD peaks and SEM image indicate 

the nanocrystalline nature of the SnO2 particles. The small 

grain size obtained in the present work is believed proper 

optimization of the precursor colloidal solution used and 

process parameters such as low heat treatment temperature. 

*Corresponding author: 0Thkose@sakarya.edu.tr 

Figure 1. SEM image of SnO 2 nanop articles prepared by sol-gel 

technique at pH 7. 

Scanning electron microscopy (SEM) analysis was used 

to investigate the morphology of the as-synthesized SnO2 

samples. As shown in Figure 1, SnO 2 nanoparticles consist 

[1] J. Rockenberger, U. Felde, M. Tischer, L. Troger, M. Haase, 

H. Weller, 2000. Near edge X-ray absorption fine structure 

measurements (XANES) and extended x-ray absorption fine 

structure measurements (EXAFS) of the valence state and 

coordination of antimony in doped nanocrystalline SnO 2 , J. Chem. 

Phys. 112: 4296. 

[2] Zhang, J., Gao, L., 2004. Synthesis and characterization of 

nanocrystalline tin oxide by sol–gel method, Journal of Solid 

State Chemistry, 177: 1425-1430. 

[3] Ning, Y., Jianhua, W., Yuzhong, G., Xiaolong, Z., 2008. 

SnO 2 Nanofibers Prepared by Sol-Gel Template Method, Rar e 

Metal Materials and Engineering, 37: 4. 

[4] Hamd, W., Wu, Y-C., Boulle, A., Thune, E., Guinebretière, R., 

2009. Microstructural study of SnO 2 thin layers deposited on 

sapphire by sol–gel dip-coating, Thin Solid Films, 518: 1–5. 




Nanosized Mg/Al-Hydrotalcites as Catalysts using Microwave Assisted Eco-Friendly for Rapid 

Synthesis of Pyrazolo[1,5-a]Pyrimidine Derivatives 

Mohamed Mokhtar 1 *, Sulaiman N. Basahel 1 , Islam H. Abd El-Maksod 1 , Tamer S.Saleh 2 

1 Department of Chemistry, King Abdulaziz University, Jeddah80203, Saudi Arabia 

2 Green Chemistry Department, National Research Centre, Dokki, Cairo, Egypt 

Abstract-Synthetic nanosized Mg-Al-hydrotalcite is found to be a mild and efficient catalyst for the synthesis of Pyrazolo[1,5-a] Pyrimidine 

derivatives in quantitative yields. Exclusive synthesis of Pyrazolo[1,5-a] Pyrimidine derivatives using Mg-Al-Hydrotalcite realized by 

compatible basic sites of catalyst used. The present eco-friendly catalytic system is a potential alternative to soluble bases. 

Py razo lo[1,5-a]Pyrimidine derivatives mo iety is a privileged 

class of pharmacophore, as compounds bearing this structural 

unit possess a broad spectrum of biological activities[1,2] they 

have potent analgesic effects [3], also, pyrazolo[1,5- 

a]pyrimidine derivative zaleplon is an ideal nonbenzodiazapine 

sedative/hypnotic drug mainly used for 

insomnia [4]. The various reported methodologies involve the 

use of piperidine in ethanol under reflux for 8 hours [5], and 

pyridine under reflux for 4 hours [6], or in drops of piperdine 

under microwave irradiations [7]. Ho wever, these 

methodologies have one or more disadvantages such as the use 

of high boiling solvent, hazard solvent; also yield of reaction 

O 

+ 

NMe 2 

R 

1 2 

2,4 R 

a Me 

b Ph 

c p-OCH 3 Ph 

NH 2 

MW 

N NH Catalyst 

R 

N 

R 

NH 

2 

3 

1 

N 

H 

N 

Ph 

3 

NMe 2 

O 

-Me 2 NH 

-H 2 O 

N 

4 

N 7 

Figure 1. Synthesis of Pyrazolo[1,5-a] Pyrimidine derivatives. (a) 

One of the most stable structures of the Ti-C 60 complex where the Ti 

atom (blue) is bonded to a double bond with four hydrogen molecules 

attached (red). (b) The local structure of the Ti-C 60 double bond. (c) 

Replacing the end carbon atoms shown in (b) by H results in an 

ethylene molecule. This suggests that we may simply use the 

ethylene molecule to hold Ti atoms, which then binds multiple 

hydrogen molecules 

4 

5 

Ph 

6 

not more than 70%. It is now widely accepted that there is an 

urgent need for more environmentally acceptable processes in 

the chemical industry [8]. Thus, use of heterogeneous solid 

base catalysts instead of the classical homogeneous liquid base 

catalysts makes separation of the product easier and produces 

neither corrosion nor emulsion. 

Layered double hydroxides (LDHs) or hydrotalcite like 

materials (HTs) represent basis of new environment-friendly 

technologies, involving cheaper and more efficient ways for 

carrying out chemical reactions [9-11]. In this work, we 

developed more benign effective methods for the synthesis of 

derivatives of Pyrazolo[1,5-a]Pyrimidine for bio logical 

screening purposes using nanosized Mg/Al hydrotalcite 

(MgAl-HT) catalysts. 

We first studied the effect of microwave irradiation on the 

reaction in absence of catalysts then in the presenence of assynthesized 

Mg/Al-HT (MgAl-HT-AS), hydrotalcites calcined 

at 200 o C (MgAl-HT-200) , hydrotalcites calcined at 450 o C 

(MgAl-HT-450), and their rehydrated forms (MgAl-HT-200- 

RH and MgAl-HT-450-RH), respectively. We found no 

reaction takes place in assistance of microwave irradiations 

alone. The reaction carried out using MgAl-HT-AS catalyst 

showed 92 % yield of the desired product in about 18 min. 

The catalytic activity of the tested catalysts could be 

summarized in the following manner: MgAl-HT-AS >MgAl- 

Ht-200 > MgAl-HT-200-RH > MgAl-HT-450 > MgAl-HT- 

450-RH. 

We next discussed the effect of durability for the more 

efficient catalyst by reusing the same catalyst five times, 

taking the time to complete reaction as indication of catalytic 

activity. The time taken to reach 100% conversion after five 

time reusing the catalyst was 15, 20 and 21 min. for the 4a,4b 

and 4c products, respectively. 

In summary, one of the more promising classes of solid 

bases is hydrotalcites, we have developed an efficient method 

for synthesis of Pyrazolo[1,5-a]Pyrimidine derivatives by an 

eco-friendly Mg/Al-HT catalyst, under microwave irradiation, 

a significant high yield and short reaction time was observed 

in using as-synthesized hydrotalcites than other activated 

hydrotalcite catalysts. 

This work was supported by Deanship of scientific Research 

at King Abdulaziz University under Grant No. MS-104T536. 

*Corresponding author: 1Tmmokhtar2000@yahoo.com 

[1] M. S. A. El-Gaby, A. A. Atalla, A. M. Gaber; K. A. Abd Al- 

Wahab; IL Farmaco. 55, 596 (2000). 

[2] S. Selleri, F. Bruni, C. Costagli, A. Costanzo, G. Guerrini, G. 

Ciciani, B. Costa, C. Martini; Bioorganic & Med. Chem.7, 2705 

(1999). 

[3] I. Makoto, O. Takashi, S.Yasuo, H. Kinji, O. Masayuki, Y. 

Tsuneo; US Patent 98,43,951, (1998). 

[4] J. Hedner, R. Yaeche, G. Emilien, I. Farr, E. Salinas; Int J Geriatr 

Psychiatry. 15, 704 (2000). 

[5] M.R. Shaaban, T. S. Saleh, A. M.Farag; Heterocycle. 71, 1765 (2007). 

[6] A. A. Elassar, A. A. El-Khair, Tetrahedron. 59, 8463 (2003). 

[7] K. M. Alzaydi, Molecules. 8, 541 (2003). 

[8] C. Christ, Ed. Production Integrated Environmental Protection 

and Waste Management in the Chemical Industry, Wiely-VCH, 

Weinheim, 1999. 

[9] A. Corma, V. Fornés, F. Rey, J. Catal.148, 205 (1994). 

[10] J. I. Di Cosimo, C. R. Apesteguía, M. J. L. Ginés, E. Iglesia, J. 

Catal. 190, 61 (2000). 

[11] Y. Ono, J. Catal. 216, 406 (2003). 




Effects of External Fields on Semiconductor Two-Dimensional Structures 

Figen Karaca Boz , 1* Bahadr Bekar 2 and Saban Aktas 1 

1 Department of Physics, Trakya University, Edirne 22030, Turkey 

2 Kean Vocational College, Trakya University. Edirne –Kean 22800, Turkey 

Abstract—We have investigated the presence of the laser and the electric fields on semiconductor two-dimensional structures. 

The ground state energy has been calculated with finite different method under effective mass approximation. Within a 

variational scheme, the binding energy is obtained as a function of the laser dressing parameter for the different electric field 

values. The results show that the electronic properties strongly depend not only on the laser dressing parameter, but also on the 

applied electric field and the shape of the semiconductor two-dimensional structure. 

In recent years, there has been much interest in the study 

of the laser and electric field effects on the electronics 

properties of the semiconductor two-dimensional structure [1- 

4]. The advances in experimental progress has made possible 

the fabrication of two-dimensional semiconductor (quantum 

well) which impose quantum confinement in one directions to 

a charge carrier. The quantum wells (QWs) with several of 

confining potential shapes such as square, parabolic, graded, 

inverse parabolic, V- and inverse V-shaped have been studied 

by many researchers [5-8]. These studies have been shown 

that the applied of an electric field to these structures causes a 

polarization of the carrier distribution. It has been reported 

that the binding energy of an on-center impurity in lowdimensional 

systems decreases with increase of the laser 

dressing parameter. 

In this work, the binding energy is investigated as a 

function of the laser dressing parameter for the different 

electric field values for various QWs. Fig. 1 shown the laser 

dressed potential for different values of the laser parameter for 

the double square QW. The barrier height is given as V= 

39.30R*. As seen from the figure, the potential shape of the 

double square QW changes depend on the laser parameter. 

x 

,V x 

1,0 

0,8 

0,6 

0,4 

0,2 

0,0 

-1,0 -0,8 -0,6 -0,4 -0,2 0,0 0,2 0,4 0,6 0,8 1,0 

x 

0 a* 

0 a* 

0 a* 

a* 

0 a* 

Figure 1: The laser-dressed potential of the double square QW for 

different values of the laser parameter. 

The variation of the binding energy as a function of the 

laser dressing parameter in double square QW with the well 

width 1a* and the barrier width 0.4a* for different electric 

field values given in Fig.2. As the laser dressing parameter 

increases, the magnitude of the binding energy decreases. 

E B 

(R*) 

11,2 

10,8 

10,4 

10,0 

9,6 

9,2 

F= 0 kV/cm 

F= 20 kV/cm 

F= 40 kv/cm 

F= 60 kv/cm 

Z i 

= 0 a* 

8,8 

0,0 0,1 0,2 0,3 0,4 0,5 

a* 

Figure 2: The binding energy as a function of laser parameter for different 

values of the electric field. 

In summary, we showed that the changes in energy can be 

controlled by changing the laser dressing parameter together 

with electric field. These results might be providing important 

results in the device applications. This work was partially 

supported by Trakya University under Grant No. TUBAP 739- 

754-759-886-929-2008(58). 

. 

*Corresponding author: figenb@trakya.edu.tr 

1. H.S.Brandi, A.Latgé, L.E. Oliveira, Physica Status Solidi 210, 671 (1998). 

2. Q Fanyo., A.L.A.Fonseca, O.A.C. Nunes, Phys. Rev. B 54 16405 (1996),. 

3. F. M. S.Lima,et al., Phys. Rev. B. 75, 073201 (2007). 

4. Yamanouchi K., et al. “Progress in Ultrafast Intense Laser Science 

I.”Springer,2006 

5. E. Kasapolu, H Sari., I. Sökmen. Physica B 390, 216 (2007) 

E. Kasapolu, I. Sökmen, Physica B 403, 3746 (2008) 6. 

H.Sari, E. Kasapolu, I. Sökmen, Physics Letters A 311, 60 (2003). 

6. B. Bekar,Yüksek lisans tezi, Edirne-2010 

7. L.M. Burileanu, E.C. Niculescu, N. Eseanu, A. Radu, Physica E 41 856 

(2009) 

8. E.C. Niculescu,L. M. Burileanu, A. Radu, Superlatt. Microstruct., 44 173 

(2008) 




Nanocoatings Materials and their Applications in Building Construction 

Fahriye Hilal Halicioglu 

Department of Architecture, Dokuz Eylul University, Izmir 35160, Turkey 

Abstract- This paper focuses on nanocoatings and their properties and future applications, several of these applications will 

be successful in recent years. Nanocoatings have gained much interest recently. Nanoscale coatings are particularly suited to 

protecting the surface of various building materials such as glass, concrete, wood, steel. Significant efforts are underway to 

control the nanocoatings via innovative approaches. Though various coating materials are now in wide use for numerous 

applications, there has been continued demand for novel coatings with desirable properties for many other applications. This 

paper also offers a possibility of a revised understanding of the relationship between nanocoatings and the building 

construction in the understanding of innovative nano approaches. 

There has been a great deal of interest in nanocoatings over 

the last few years. Nanocoatings are used to insulate both 

new and existing building materials, or to protect wood, 

metal, and masonry, without the hazardous off-gassing of 

many other coatings [1]. The use of nanomaterials for selfcleaning, 

antimicrobial, fungicidal, and related applications 

for various types of surfaces is more recent but has quickly 

become widespread. Most nano-based products intended for 

these applications use coatings, paints, or films that contain 

nanoparticles and that are applied or bonded to conventional 

materials. Some applications, however, have surface layers in 

which nanoparticles have been directly intermixed into the 

base material. Three primary technologies drive applications 

in these areas: the ability to make hydrophobic (waterrepelling) 

surfaces, hydrophilic (water-attracting) surfaces, 

and photocatalytic surfaces (see Figure 1). In glasses, the 

self-cleaning action normally comes from coatings with 

thicknesses at the nanoscale that have particular 

photocatalytic and hydrophilic (water-attracting) properties. 

In several applications, the glass is first coated with a 

photocatalytic material, normally titanium dioxide (TiO2). 

The photocatalytic coatings produce chemical reactions when 

subjected to ultraviolet (UV) light that help in oxidizing 

foreign substances and decomposing them [2]. 

Hydrophobic (water repelling; drops form beads) 

Hydrophilic 

(water attracting; 

drops flatten out) 

Photocatalytic (UV-induced 

reactions that cause decomposition 

of dirt molecules) 

Figure 1. Basic approaches for self-cleaning, easy-cleaning, and 

antimicrobial functions [2] 

Given the wide range of possible applications, from 

window glass and cement to textiles, self-cleaning coatings 

may become an important labor-saving and sustainable 

device (see Figure 2) [3]. 

conventional self-cleaning self-cleaning 

glass glass 

concrete 

Figure 2. Self-cleaning glass and concrete [4, 5] 

A wide range of materials can be coated with solgel 

technique (see Figure 3). The sol-gel technique involves the 

evolution of inorganic nanoscale networks in a continuous 

liquid phase through the formation of colloidal suspension 

and the following gelation of the sol. With proper planning 

these new materials can have enhanced properties due to the 

interaction of the individual material components at 

nanolevel [6]. Materials processed by this method can be 

metallic, inorganic, organic and hybrid, ranging from highly 

advanced materials to common materials, from optics to 

architecture. The relevance of the sol-gel technique basically 

consists of improvement of processing and properties of 

conventional materials and creation of novel materials [3]. 

Figure 3. The sol-gel [6] 

In this paper, the current developments in nanocoatings and 

their applications in building construction is summarised. 

Based on the ongoing evolutions in nanotechology, 

nanocoatings are explained. Finally, an overview is given of 

the different product developments performed to obtain 

nanotech approaches. Nanotechnology has very high impact 

in developing a new generation of coatings with enhanced 

functionality and a wide range of applications. Although 

nanocoatings are realizing many key applications in building 

construction, a number of key technical and economic 

barriers exist to widespread commercialization. These include 

impact performance, the complex formulation relationships 

etc. If nanotechnology is to change how we design and how 

we live, then a study of nanocoatings implications for 

building construction is clearly needed. Many nanocoating 

materials are already available to architects and builders, and 

are beginning to transform our buildings. Looking further 

ahead, nanocoatings now in research and development will 

likely have a significant impact on building within the next 

twenty years. 

*Corresponding author: hilal.halicioglu@deu.edu.tr 

[1] Elvin, G., Nano opportunities in building construction for big changes, 

http://www.architectmagazine.com/curtain-walls/the-nano-revolution.aspx, 

The Nano revolution. 

[2] Ashby, M. F., Ferreira, P. J., and Schodek, D. L., 2009. Nanomaterial 

product forms and functions, pp. 403-440, Oxford, UK. 

[3] Cannavale, A., Fiorito, F., Manca, M., Tortorici, G., Cingolani, R., and 

Gigli, G., 2010. Multifunctional bioinspired sol-gel coatings for architectural 

glasses, Building and Environment, 45, 12331243. 

[4] Chin, W. J., Nanotechnology in building and construction 

http://jazz.nist.gov/ts/220/external/TEDCO%20presentations/Sampling%20- 

%202.ppt 

[5] http://www2.arch.uiuc.edu/elvin/nanocoatings.htm 

[6] http://www.vtt.fi/files/research/ama/newmaterials/nano_sol-gel.pdf 


P 

P 

P and 


Synthesis and Characterization of Polymers with Triptycene Unites by Photopolymerization and 

Polystyrene Possessing Triptycene Units in The Main Chain by Combination of Atrp and Click 

Chemistry Processes 

1 

ULokman TorunUP 

1,2 

P*, Sahin AtesP 

P, Binnur AydoganP P, Yasemin D. YukselP 

1 

PChemistry Institute, TUBITAK MRC, Gebze, Kocaeli, 41470, Turkey 

PIstanbul Technical University, Department of Chemistry, Maslak, 34469, Istanbul, Turkey 

2 

2 

2 

2 

Yusuf YagciP 


Abstract-We predict that a single ethylene molecule can form a stable complex with two transition metals (TM) such as Ti. The resulting TMethylene 

complex then absorbs up to ten hydrogen molecules, reaching to gravimetric storage capacity of ~14 wt%. Our results are quite 

remarkable and open a new approach to high-capacity hydrogen-storage materials discovery. 

In this work, we herein report synthesis, characterization and 

photocuring behavior of a new cross-linker based on triptycene 

molecule. Photopolymerizations were performed with the formula 

tions containing triptycene hydroquinone diacrylate (THDA) 

together with monofunctional monomers glycidyl methacrylate 

(GMA), 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl 

ethacrylate (HEMA), and 2-ethylhexyl methacrylate (EHMA), by 

using 2,2-dimethoxy-2-phenylacetophenone (DMPA) as the 

photoinitiator. Comparative photopolymerization studies were 

also performed by using structurally similar cross-linker, 

hydroquinone diacrylate (HDA) which does not possess 

triptycene unit. Photopolymerization kinetics was analyzed for 

different compositions of monofunctional monomers and crosslinked 

agents by using photo-differential scanning calorimeter 

(photo-DSC). Each monofunctional monomer was reacted with 

varied percentages of a difunctional monomer HDA and THDA 

respectively to observe the influence of triptycene based crosslinker 

on rate of polymerization [1]. 

Figure 2. Synthesis of the cross linkers. 

Photopolymerizations of several monomers using either HDA 

or THDA were followed by DSC under identical conditions of 

2 

temperature (30 °C) and UV light intensity (18.4mWcmP P). 

Schematic representation of photoinduced cross-linking is shown 

in Figure 3. As can be seen triptycene units are chemically 

incorporated to the network after photocuring process. 

Figure 1. Overall process for copolymerization of azide terminated 

bifunctional polystyrene (NR3R-PS-NR3R) by “click” chemistry. 

In addition, In this work, we report synthesis of polystyrene 

possessing triptycene unit in the main chain by the combination of 

ATRP and click chemistry process. Bromine terminal groups of 

polystyrene obtained by ATRP converted to azide functionality 

by simple nucleophilic substitution by using NaNR3R. Bisalkyne 

functional triptycene compound was independently synthesized 

for the subsequent click reaction. Bisazide and bisalkyne 

functional compounds with long alkyl chain were also prepared 

and used as comonomers [2]. The cross-linkers were synthesized 

by the acylation of the respective hydroquinone compounds with 

acryloyl chloride (Figure 2). 

The H NMR spectrum of HDA showed characteristic peaks for 

acrylic protons at 5.6 ppm, 6.0 ppm and 6.4 ppm, and aromatic 

protons at 7.1 ppm. In the spectrum of THDA, while the signal at 

8.9 ppm corresponding to –OH protons of the precursor TH 

completely disappeared, new signals originating from acrylic 

protons appeared at 6.1 ppm, 6.5 ppm and 6.7 ppm. 

Figure 3. Schematic representation of photoinduced cross-linking of vinyl 

monomers using triptycene hydroquinone diacrylate (THDA). 

In conclusion, in the first part we report synthesis of polystyrene 

possessing triptycene moiety in the structure by combination of 

ATRP and “click” chemistry. The intermediates and the resulting 

polymers were caharacterized by spectral and thermal analyses 

methods. The effect of the triptycene moiety on the thermal 

properties was demonstrated. In the light of present study and the 

general behavior of triptycene molecules in polymer chains it is 

expected that polymers with enhanced properties such as ductility 

and stiffness can be obtained by ATRP combined with “click” 

chemistry. Further studies on the investigation of these properties 

are now in progress. 

In the second part, we report synthesis of a new cross-linker 

possessing triptycene moiety in the structure and characterized. 

Moreover, its photopolymerization behavior in the UV curable 

formulations containing different monofunctional monomers was 

studied. Comparative kinetic studies revealed that the 

polymerization kinetics are governed mainly by the structure of 

the monofunctional monomer employed in the formulation and 

triptycene type cross-linker acts in a manner similar to the 

conventional cross-linkers. In the light of present study and the 

general behavior of triptycene molecules in polymer chains it is 

expected that cross-linked networks with enhanced properties 

such as ductility and stiffness can be obtained by photoinitiated 

free radical polymerization. 

*Corresponding author: lokman.torun@mam.gov.tr 

[1] Sahin Ates, Binnur Aydogan, Lokman Torun, Yusuf Yagci Polymer 51 

(2010) 825–831. 

[2] Sahin Ates, Yasemin Yuksel Durmaz, Lokman Torun, Yusuf Yagci, In 

press. Journal of Macromolecular Science. 




Facile preparation method to tune size (12 - 500 nm) of luminescent silica nanoparticles 

Gülay Durgun 1 , Özlem Gezici 1 , Serdar Özçelik 1 *, 

Izmir Institute of Technology, Faculty of Science, Department of Chemistry, Urla-Izmir 35430 

Abstract-We report a simple method to systematically prepare dye doped silica nanoparticles with continuously tunable size in the range 

from 12 to 500 nm. The results of dynamic light scattering and electron microscopy proved that nanoparticles are highly monodisperse even 

at the scale of 12 nm. We showed that initial amounts of ethanol and ammonia are instrumental to tune the size of particles. We 

demonstrated silica network providing photostability as protective layer for dye molecules against solvents, fluorescence quenchers and pH. 

Moreover, we found that the particles are not cytotoxic upto 1 mg/ml with 72 hours of incubation period. 

The dye-doped silica nanoparticles are one of the most 

widely preferred material for labeling in bioanalysis and 

biotechnological applications. Silica shell which is 

thought to be biocompatible and non-toxic [1] protects dye 

molecules from the surrounding environment and 

encapsulates thousands of fluorescent dye molecules in its 

network [2], providing photostability and signal 

enhancement respectively [3]. 

In general, two main methods have been used for the 

synthesis of silica-based nanoparticles (Np); reverse 

microemulsion and Stöber method. These methods offers 

certain advantages with some limitations. 

In our study, we report a facile synthesis method to 

produce uniform Nps in the range from 12 to 466 nm by 

using Stöber method (Figures 1 and 2). The influence of 

the amount of reagents on the particle size, monodispersity 

and photophysical properties of the Nps are investigated in 

detail. 

Figure 3. Absorption and fluorescence spectra of FITC doped 

silica Nps, showing linear realtionship between the size and the 

amount of FITC encapsulated. 

In the second part of the our study, we showed that the 

silica network provided photostability. The FITC doped 

silica Nps within the size range from 12 to 250 n m are not 

toxic against MCF7 and PC3 cell lines. This project is 

supported by DPT and TUBITAK (Grant No: 108T446) 

(a) 

(b) 

Figure 1. SEM images of silica Nps with size of 450 and 40 nm. 

Figure 2. DLS results of Nps with size of 466, 255, 31 and 12 

nm, respectively. 

We determined the amount of dye (0.02- 

encapsulated in the Nps by disintegrating the silica 

network at high pH (0.1M NaOH). When we compared 

size of Np and its dye content, we observed a linear 

relationship (Figure 3). 

Figure 4. MTT assay of the silica Nps for the cell lines of MCF7 

and PC3. 

*Corresponding Author: serdarozcelik@iyte.edu.tr 

[1] Rosi, N.L., Mirkin, C.A., Chem. Rev. 2005,105,1547. 

[2] Zhao, X., Bagwe, R. P., Tan, W., Adv . Mater. 2004, 16, 173- 

176. 

[3] Bringley, J. F., Penner, T.L., Wang, R., Harder, J. F., 

Harrison, W. J., Buonemani, L., Journal of Colloid and Interface 

Science , 2008, 320, 132–139. 




Terahertz Emission from Rectangular Mesa Structures of Superconducting Bi 2 Sr 2 CaCu 2 O 8+ 

Fulya Türkolu 1 , Lütfi Özyüzer 1 , Hasan Köseolu 1 , Yasemin Demirhan 1 , Ylmaz imsek 2 

Sascha Preu 3 , Daniel Ploss 3 , Stefan Malzer 3 , Huabing Wang 4 , and Paul Müller 2 

1 Department of Physics, Izmir Institute of Technology (IZTECH), 35430, Izmir, Turkey, 

2 Physical Institute III, University of Erlangen-Nurnberg, Erlangen, Germany, 

3 Max Planck Optics Group, University of Erlangen-Nurnberg, Erlangen, Germany, 

4 National Institute for Materials Science, Tsukuba, Japan 

Abstract— Rectangular intrinsic Josephson junction mesa structures of superconducting Bi 2 Sr 2 CaCu 2 O 8+ (Bi2212) can be used as a source of 

continuous, coherent and polarized terahertz (THz) radiation. In this work, we obtained THz emission from 60x300 μm 2 rectangular mesa 

structures. The frequency of the generated waves was determined as 0.537 THz by Michelson interferometer setup. The voltage per junction 

satisfies the Josephson voltage-frequency relation. 

Many people at science and technology are interested in the 

electromagnetic waves in terahertz frequency range (0.1-10 

THz) because of their wide-ranging applications including 

security, medicine, quality control and environmental 

monitoring [1]. The observation on generation of THz 

radiation emitted from lateral dimension of high temperature 

superconductor (HTS) Bi 2 Sr 2 CaCu 2 O 8+ (Bi2212) and 

responses to THz waves increase the importance of these 

HTSs [2]. Single crystal of HTS Bi2212 forms natural 

superconductor-insulator-superconductor (SIS) layered 

junctions, which are called intrinsic Josephson junctions (IJJ). 

The stacks of IJJs in Bi2212 can be used such a voltagefrequency 

converter and their large energy gap allows the 

emissions at THz frequency range. Recently, it is 

demonstrated that rectangular IJJ mesa structures of Bi2212 

can be used as a source of continuous, coherent and polarized 

THz radiation [2]. Strong THz-emission was observed when 

the voltage across the mesa was adjusted in such a way that 

the Josephson frequency of the IJJ matches the cavity 

resonance [2]. It is shown that all THz emitting mesas are 

below a certain underdoped level, which has relatively small 

critical current in contrast to optimally doped and overdoped 

Bi2212 [3]. Because of small critical current, large area mesas 

fabricated from underdoped crystals cause less heating and 

backbending occurs after the cavity resonance in voltage scale. 

In this work, single crystals of Bi2212 grown by TSFZ 

method were used. Mesa shaped photoresist mask was 

patterned using optical photolithography process and the 

rectangular mesa structures with required sizes (60x300 to 

100x300 μm 2 ) were fabricated using Ar-ion beam etching as 

explained in ref. [3]. Since it is known that thickness of an IJJ 

is 1.5 nm as shown in figure 1, the number of IJJs in mesa is 

calculated from mesa height. The heights of fabricated mesas 

are about 800 nm, so we expect approximately 533 IJJs. 

In order to characterize the Bi2212 mesas, c-axis resistance 

versus temperature (R-T) and current-voltage behavior (I-V) 

were measured in a He flow cryostat. During I-V 

characterization, Si composite bolometer was used to detect 

the THz emission. The c-axis R-T measurements of the mesas 

exhibit underdoped behavior of Bi2212 single crystal. Some of 

the hysteretic quasiparticle branches are observed in the I–V 

characteristics. All of the curves show backbending above 1.5 

V because of high doping level of Bi2212, number of 

junctions and surface area of mesa. THz emission 

characteristics of one of the 60x300 μm 2 mesa at 22 K shows 

that bolometer signal is increasing at back bending region of I- 

V curve. It indicates that local mesa temperature is increasing 

and bolometer detects the heating of the mesa. THz emission 

was obtained before heating severely affects the local mesa 

temperature, near 0.61 V. Michelson interferometer setup was 

used to form an interference pattern as in Figure 2. As shown 

in figure, signals detected by bolometer indicate that 

wavelength of the emission is 558 m and so the emission 

frequency is 0.537 THz for 60 μm wide mesa. We observed 

that the cavity resonance and applied voltage satisfies the 

Josephson voltage-frequency relation. 

Power (a.u.) 

-3.4 

-3.45 

-3.5 

-3.55 

-3.6 

-3.65 

0.537 THz 

-4 -2 0 2 4 

Delay Stage Position/mm 

Figure 2: Interference patterns detected by bolometer 

This research is supported in part by the TUBITAK 

(Scientic and Technical Council of Turkey) project no. 

108T238. 

*Corresponding author: fulyaturkoglu@iyte.edu.tr 

Figure 1: Atomic view and crystal structure of Bi2212 

[1] M. Tonouchi, Nature Photonics 1, 97-105 (2007) 

[2] L. Ozyuzer et al., Science 318, 1291 (2007) 

[3] L. Ozyuzer et al., Supercond. Sci. and Technol. 22,114009 (2009) 




The fabrication THz emitting mesa by reactive ion beam etching 

of superconducting Bi2212 with Ta/PR and PR'/Ta/PR masks 

Hasan Köseolu 1 , Fulya Türkolu 1 , Yasemin Demirhan 1 , Lütfi Özyüzer 1 , Huabing Wang 2 

1 Department of Physics, Izmir Institute Technology, 35430 Izmir, Turkey 

2 National Institute of Materials Science, Tsukuba, Japan 

Abstract— The perfect rectangular terahertz wave emitting superconductor Bi2212 mesas have difficulties in fabrication because of layered 

structure. Mesa lateral angles should be close to 90 degrees to obtain intrinsic Josephson junctions (IJJs) with same planar dimensions for 

synchronization and powerful emission of IJJs. Since thick photoresist (PR) layer shades the lateral dimension of mesa and also is etched 

away during ion beam etching, we patterned Ta/PR and PR'/Ta/PR masks on Bi2212. We used selective ion etching to overcome this problem. 

The reactive ion beam etchings have done with ion beam of Ar, N 2 and O 2 and we have obtained mesas about 1 μm thick with lateral angle of 

approximately 50 to 75° which is better than the mesas fabricated with single layer mask. 

Terahertz (THz) radiation is a part of the electromagnetic 

spectrum, lying between microwaves and the far-IR. This 

region has frequencies ranging from 0.1–10 THz and 

wavelengths from 0.03 mm to 3 mm. Electromagnetic waves 

with frequency below and above the THz frequency range are 

widely generated by semiconducting electronics based on 

high-speed transistors and the photonics based on the 

semiconducting laser, respectively. However, in this frequency 

range there are still lacks of THz sources and difficulties in its 

generation although their functional advantages in many 

application areas entail the evolution of the THz sources in 

science [1]. Nowadays, the research on THz radiation sources 

with high power, low cost and portable has been increasing. 

Since they are planned to use in technological areas, they 

should be continuous, coherent and frequency tunable as well. 

Therefore the research has gone towards the novel THz 

sources which include technology of high temperature 

superconductors (HTSs) layered structure [2]. 

High temperature superconducting Bi 2 Sr 2 CaCu 2 O 8+ 

(Bi2212) single crystals have natural junctions called intrinsic 

Josephson Junctions (IJJs). They play an important role for 

generation of THz radiation when a static voltage is applied 

along the c-axis of Bi2212 (ac Josephson effect) [3]. 

Generation of powerful THz radiation requires mesas with 

large lateral dimension but there are difficulties in fabrication 

of perfect rectangular mesa. It should be close to 90 degrees to 

obtain IJJs with same planar dimensions for synchronization 

of IJJs [4]. 

Thick photoresist (PR) layer (single layer mask) shades 

the lateral dimension of mesa during ion beam etching. 

Therefore, we patterned multilayer masks on Bi2212 and used 

selective ion etching to overcome this problem [5]. Therefore, 

in this study, to fabricate the smooth rectangular prism shape 

with large area, high thickness and high lateral angle, we used 

three different masks that are single layer mask and two 

different multilayer masks, which are Ta/PR and PR/Ta/PR. 

During the mesa fabrication, thermal evaporation was 

used to deposit the Au layer. Ta layer was deposited by DC 

magnetron sputtering. Photolithography process was applied 

to cover the PR’ layer and pattern the mesa shaped PR. 

After the preparation of the mesa shaped PR pattern, 

sample is mounted into the ion beam etching system that 

produces ion beam accelerated through the surface of sample 

to etch down some area unprotected by PR layer on crystal. 

By these masks, reactive ion beam etchings have done with 

the ion beam of Ar, N 2 and O 2 and we have obtained mesas 

with almost 1 μm thick and high lateral angle. 

Figure 1: AFM measurement of HC06 (Bi2212/Au/PR/Ta) 

Table 1: AFM analysis results of fabricated mesas 

Mesa height and lateral angle Edge 1 Edge 3 

HC09 (Bi2212/Au) 570 nm - 12° 650 nm - 13° 

HC06 (Bi2212/Au/PR/Ta) 860 nm - 75° 770 nm - 35° 

HC07 (Bi2212/Au/PR/Ta) 930 nm – 50° 820 nm - 42° 

SG12–1 (Bi2212/Au/Ta) 860 nm - 51° 870nm - 52° 

The improved lateral angle of a mesa can be seen in Fig. 1 

which shows AFM image of one of the edges. Table 1 shows 

AFM analysis results of the fabricated mesas. The results 

indicate that mesas with thickness of about 1 μm can be 

fabricated. Using multilayer masking technique instead of 

single layer, the lateral angle of mesas can increase 

approximately 50 to 75°. This is most important achievement 

of this study. 

THz cryostat system was used to examine electrical 

properties of mesas. R-T measurements of the Bi2212 single 

crystals were obtained between 300 and 10 K and sharp phase 

transitions to superconducting state were observed. I-V 

measurements was obtained below Tc, and hysterical 

tunneling behavior of the Bi2212 mesas and many number of 

quasiparticle branches such a voltage jumps were observed as 

seen Ref. [6]. During I-V measurements, the bolometric 

measurements were done to detect emission from the Bi2212 

superconducting mesas. 

This research is supported in part by the TUBITAK 

(Scientic and Technical Council of Turkey) project no. 

108T238. 

*Corresponding author: hasankoseoglu@iyte.edu.tr 

[1] M. Tonouchi, Nature Photonics 1, 97-105 (2007) 

[2] M. Tachiki et al., Phys. Rev. B 50, 7065 (1994) 

[3] L. Ozyuzer et al., Science 318, 1291 (2007) 

[4] A. E. Koshelev et al., Phys. Rev. B 77, 014530 (2008) 

[5] Y. Nagai et al., IEEE Transactions on Magnetism 27, 1622 (1991) 

[6] L. Ozyuzer et al. Supercond. Sci. Technol. 22, 114009 (2009) 




Diamagnetic Susceptibility in Quantum Well 

Hasan Akbas 1 * and 1 

1 Department of Physics, Trakya University, Edirne 22030,Turkey 

Abstract-The d iamagnetic susceptibility of a hydrogenic donor placed in Si,Ge,GaAs quantum wells with infinite confinement 

potential has been investigated as function of the well sizes using anisotropic effective masses. For the Ge the diamagnetic 

susceptibility is found to be 

The diamagnetic plays an important roles in optical and 

transport phenomena of semiconductor nanostructers. The 

optical properties of quantum wells are of significant 

importance in possible device applications. A few physical 

quantities that depend on the donor wave function directly 

are diamagnetic susceptibility, polarizab ility and oscillator 

strengths. 

In present work, we study a hydrogenic impurity within 

an infinite quantum well with anisitropic effective mass of 

electron. Therefore, the motion of the electron in the 

longitudinal directions is different from that in the 

transverse direction. 

The aim of this work is to obtain the diamagnetic 

susceptibility of the hydrogenic donor and to understand 

how the transverse and longitudinal parts of susceptibility 

reflect charge in the quantum well size. The calculation of 

the donor wawe function are performed using effective 

mass approximation within a variational approach. 

The Hamiltonian of the hydrogenic donor impurity, 

in the cylindrical coordinate system is 

(a.u.) 

0 

-0.04 

-0.08 

-0.12 

-0.16 

-0.2 

dia 

 

z 

0 200 400 600 800 1000 

L(A o ) 

Figure 1. Variation of the transverse, longitudial, 

and total susceptibility as function of the well width 

for Ge. 

where and denote transverse and longitudinal 

effective masses of electron , respectively , and is a 

static dielectric constant. The confining potential is given 

by 

The anisotropy destroys spherical symmetry of the 

hydrogenic donor. We therefore choose two-parametric 

trial wave function of the ground state. 

 

where and are the variational parameters. The ground 

state donor binding energy is given by 

The diamagnetic susceptibility of the hydrogenic donor 

is given by 

= 

We calculate a binding energy of the hydrogenic donor 

with various effective mass anisotropy parameters; 

, GaAs , Si and 

Ge . Our results of the binding energy agrees 

with results in . 

The variation of for and 

Ge is given in Fig 1. 

In case of small , Ge 

, total susceptibility is 

found to be 

Corrresponding author: 0Thasan22ak@yahoo.com 

[1] P.Andreev, T.V.Pavlova, PhysicaE 40, 1551,2008, 

Hydrogenic impurity states in semiconducting nanostructers with 

anisotropic effective mass. 

[2] 

Microstructures 46 ,817,2009 ,The diamagnetic susceptibilities of 

donors in quantum wells anisotropic effective mass. 




Stabilizing Liquid Crystal Mesophases for Rigid Mesostructured Metal Sulfides/Selenides 

Yurdanur Türker 1 *, Halil I. Okur 1 , Nazli Böke 1 , Ö 1 

Department of Chemistry, Bilkent University, Ankara 06800, Turkey 

1 

Abstract- LC templating (LCT) can be used to synthesize meostructured/mesoporous metals, metal oxides, and II-VI semiconductors. By 

using LCT approach, we have investigated, to the best of our knowledge, the first mesostructured metal sulfide thin films, at 11 Cd(II)/P85 

mole ratio upon exposing the LC mesostructure to H 2S (g) reaction. However, since the metal ion content is still low, phase separation occurs 

over the films in time and also, at high metal ion contents, formed HNO 3 become problematic. However, stable mesostructured MS/Se can be 

- 

synthesized upon addition of TiO 2 polymerizing agent to LC system since it can rigidify the mesostructure and allow aging to remove NO 3 

ions before H 2 S/Se (g) reactions. In order to perform calcination process to remove surfactants, the LC mesophases are being rigidified further 

by increasing metal ion content by use of charged surfactants. 

The mesoporous materials were discovered in the early 90s 

using surfactant templating approach [1]. This approach has 

been used to synthesize many mesostructured metal oxides 

[2], metals [3] and II-VI semiconductors [4]. In 2001, Dag et 

al. have discovered a new form of LC mesophase of 

transition metal aqua complexes (TMS), [M(H 2 O) 4 ](NO 3 ) 2 , 

and non-ionic surfactants or Pluronics at high metal salt 

concentrations [5]. The coordinated water molecules of the 

TMS mediate the formation of the LC mesophase through 

hydrogen bonding (M-OH 2 ---(OCH 2 CH 2 ) x -R) with ethylene 

oxide units of the surfactant molecules [4b,5-8]. Controlling 

the quantity and the type of counter ion allows one to control 

the structure of salt-surfactant LC mesophases [7]. LC 

templating (LCT) can be used to synthesize 

meostructured/mesoporous metals, metal oxides, and II-VI 

semiconductors. 

By using the LCT approach, we have synthesized 

mesostructured Metal Sulfides (MS) at high salt 

concentrations by mixing Pluronics with TMS in a dilute 

media. We have investigated that the reaction between the 

thin films of TMS – P85 (EO26PO 40 EO 26 ) LC mesophase 

with a relatively high metal salt content, 11.0 mole ratio of 

Cd(II)/P85, and H 2 S (g) at room temperature enables us to 

synthesize, to the best of our knowledge, the first 

mesostructured metal sulfide thin films.[9] However, since 

the metal ion content of TMS-Pluronic mesophase is still low 

to fully mimic the LLCM during the H 2 S/Se reaction to form 

the stable mesostructured MS/Se film samples, the inevitable 

result is the slow phase separation of the film samples in time 

due to release of the excess surfactant molecules out of the 

mesostructured films as shown in Figure A. 

In order to synthesize stable mesoporous MS/Se film 

samples, it is required to increase the metal ion content of the 

Pluronic/TMS binary LC system so that it can fully mimic 

the LLCM during calcination processes and H2S/H 2 Se (g) 

reactions. Besides, at such high metal ion content, high 

amount of nitrate ions form HNO 3 during H 2 S/H 2 Se (g) 

reactions which causes decomposition of MS/Se back to their 

nitrates. Therefore, the LC mesophase must be rigidified 

enough to resist further calcinations at high temperatures 

before H 2 S/Se (g) reactions. TiO 2 and SiO 2 are the proper 

templates since they can form rigid walls upon controlling 

their polymerization. 

Recently, we have shown by EISA approach, we could 

obtain rigid well-ordered mesostructured Cd(II)-TiO 2 films 

until 13 Cd(II)/P123 mo le ratio at 60 TiO 2 /P123 mo le ratio. 

Here, by the help of TiO 2 also, 90% of nitrate ions could be 

removed by aging at relatively low temperatures, at which 

mesostructure could still retain, before H 2 S/Se (g) reactions. 

Under those conditions, the stable CdS and CdSe 

nanoparticles can be synthesized in the channels of 

mesostructured titania films in one-pot and no phase 

separation occurs since the mesostructure is rigid enough as 

shown in Figure B [10]. However, in order to calcine at high 

temperatures to remove the surfactant, the mesostructure is 

required to be rigidified more. 

Figure 1. A) Phase seperation occurs at mesostructured CdS/P85 

thin film in time. B) No phase seperation occurs at mesostructured 

CdS/TiO 2 /P123 thin film. 

The role of the charged surfactants in order to increase the 

metal salt contents in LC systems has been recently 

investigated [11]. By using charged surfactants in Cd(II)- 

TiO 2-P123 system, CTAB (Cetyltrimethylammonium 

Bro mide (C 16 H 33 N(CH 3 ) 3 Br)), Cd(II)/P123 mole ratio could 

be increased to 20 at 60 TiO 2 /P123. This high metal ion 

content films are going to be calcined at 350 ºC and then, 

exposed to H 2 S/H 2 Se (g) reactions to synthesize MS/Se films. 

They are going to be characterized to clarify if the films are 

rigid enough to perform calcination process. 

 

107T837, UNAM-Regpot (203953) and TÜBA for the 

financial support. 

*Corresponding author: yurdanur@fen.bilkent.edu.tr 

[1] C. T. Kresge, M. E. Leonowicz, W. J. Roth, J. C. Vartuli and J. 

S. Beck, Nature 359, 710 (1992). 

[2] O. Dag, I. Soten, O. Celik, S. Polarz, N. Coombs and G. A.Ozin, 

Adv. Func. Mater. 13, 30 (2003). 

[3] a) G. S. Attard, P.N. Barlett, N.R.B. Coleman, J.M. Elliott, 

J.R.Owen and J.H.Wong, Science 278, 838 (1997). b) Y. Yamauchi, 

T. Momma, T. Yokoshima, K. Kuroda and T. Osaka, J. Mater. 

Chem. 15, 1987 (2005). 

[4] a) P.U. Braun, P. Osenar and S.I. Stupp, Nature 380, 325 (1996). 

b) O. Dag, S. Alayoglu, C. Tura and O. Celik, Chem. Mater. 15, 

2711 (2003). 

[5] O. Celik and O. Dag, Angew. Chem. Int. Ed. 40, 3800 (2001). 

[6] A.F. Demirors, B.E. Eser and O. Dag, Langmuir 17, 4157 

(2005). 

[7] C. Albayrak, G. Gulten and O. Dag, Langmuir 19, 876 (2007). 

[8] O. Dag, S. Alayoglu and I. Uysal, J. Phys. Chem. B. 108, 8439 

(2004). 

[9] Turker, Y.; Dag, Ö. J. Mater. Chem. 2008, 18, 3467. 

[10] Okur, H. I.; Turker, Y.; Dag, Ö. Langmuir 2010, 26, 538. 

[11] Albayrak, C.; Soylu, A. M.; Dag, Ö. Langmuir 2008, 24, 

10592. 




Oxidat ive coupling o f methane for ethylene preparat ion: catalys t and nanocatalys t pe rformance 

Ali Farsi 1 *, Ali Moradi 1 , Sattar Ghader 1 , Seyed Soheil Mansouri 1 and Vahid Shadravan 1 

1 Department of Chemical Engineering, Shahid Bahonar University of Kerman, Kerman, Iran 

Abstract – The main goal of this work is to study the catalysts and nano-catalysts performance in OCM reaction. Also, about 80 various 

catalysts and nano-catalysts have been collected and their main parameters such as, method of preparation, temperature of reaction, C 2 yield and 

selectivity and catalyst test reactor and methane conversion has been studied. Experimental results showed that the conversion of methane over 

the nano-catalysts was higher than that obtained from the catalysts prepared conventionally. A better low-temperature activity has also been 

achieved with a higher yield of C 2 hydrocarbons. 

Natural gas is a mixture of predominantly methane 

combined with other hydrocarbons and non-hydrocarbons such 

as N2, CO 2 and H 2 O. The geographical distribution of 

methane (natural gas) is given in Figure 1. In order to make an 

efficient utilization of natural gas; we must consider 

transforming it into mo re valuable chemicals. Higher 

hydrocarbons are more useful for chemical industries. 

Figure 1. Geographical distribution of proven natural gas reserves 

Since 1982 there has been much research on the Oxidative 

coupling of methane (OCM) process. The main obstacle for 

converting methane directly to more valuable products by 

heterogeneous catalysis is the low selectivity at high 

conversions; the products are more reactive than methane. The 

main goal of this work is to study the catalysts and nanocatalysts 

performance in OCM reaction. Also, about 80 

various catalysts and nano-catalysts have been collected and 

their main parameters such as, method of preparation, 

temperature of reaction, C 2 yield and selectivity and catalyst 

test reactor and methane conversion has been studied. 

Experimental results showed that the conversion of methane 

over the nano-catalysts was higher than that obtained from the 

catalysts prepared conventionally. A better low-temperature 

activity has also been achieved with a higher yield of C 2 

hydrocarbons. 

*Corresponding author: 0Tali.farsi@gmail.com 

[1] Goodwin, A.R. H.; Hill, J.A. J. Chem. Eng. Data 2009, 54 , 

2758. 

[2] Graf, P.O.; Ph.D. dissertation, University of Twente, 2008. 

[3] BP Statistical Review of World Energy 2007 

[4] Veser, G.; Frauhammer, J.; Friedle, U. Catal. Today 2000 ,61 , 

55. 




Protein Adsorption and In vitro Biodegradat ion of MEVVA Ion Implanted Chitosan Membranes 

1 , Emel Sokullu Urkaç 2 ,Ahmet Öztarhan 2 , Funda Tihminlioglu 3 * 

1 Biotechnology and Bioengineering Department, zmir Institute of Technology, Urla,zmir,Turkey 

2 Bioengineering Department, Ege University,Bornova,zmir,Turkey 

3 Chemical Enginzmir Institute of Technology,Turkey 

Abstract-This study investigates the effect of ion implantation on the protein adsorption behavior and in vitro degradation of chitosan films 

before and after the ion implantation. The chitosan films were prepared by solvent casting method for dense films, and dry/wet phase 

separation method is used to obtain asymmetric chitosan membranes. Characterization studies of these membranes were performed by using 

Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). The 

ion implantion effect on the contact angle changes, water absorption, protein adsorption and biodegradation mechanism on the films were 

also investigated. 

Chitosan has been studied for various practical 

applications because of functions such as biodegradability, 

low toxicity, and acceleration of fibroblast formation in 

animal body, acceleration blood clotting, drug delivery, 

antimicrobial act ivity and high solubility in water. 

In this study, we attempted to prepare and characterize 

the chitosan membrane surfaces induced by metal–gas 

(MEVVA) ion implantation. Chitosan membranes were 

prepared in two different microstructures to investigate the 

structure effects on the protein adsorption and in vitro 

degradation. Dense and asymmetric chitosan membranes 

prepared by dissolving in acetic acid solution. For dense 

membrane production, solvent casting method was used. 

For asymmetric membrane preparation dry/wet phase 

separation method was used by using 20 minutes pre 

treatment time. By changing this time pore size and 

thickness of the membrane is changed that also effects the 

membrane properties like diffusion ratio, water absorption, 

degradation time etc. 

Chitosan membranes were implanted by C and C+N ions 

by using MEVVA ion implanter with 10 16 cm -2 dose, and 1 

pps frequency, 20 kV acceleration voltage. 

Protein adsorption onto the foreign surface occurs within 

seconds of implantation. This shows that cells arriving at 

the biomaterial surface probably interact with the adsorbed 

protein layer rather than directly with the material itself 

[1]. Thus, the initial protein adsorption onto a biomaterial 

surface plays a key role in how the body responds to an 

implanted biomaterial. 

In nature, biodegradation is time independent as long as 

the eco-system is kept in balance. In biomedical 

applications, the time scale of biodegradation is critical 

since it has a significant limitation for the material’s 

application area. For examp le, in the tissue applications, 

the degradation rate of polymeric material must be equal to 

time of the tissue formation rate of the organism. [2] 

In the protein adsorption studies, HSA is used at pH=7. 

Adsorption of the protein onto membrane was carried at 

37 ºC. 

The effects of microstructure and ion implantation on the 

in vitro degradation behavior of chitosan membranes were 

studied at 37 ºC in PBS solution. The change in molecular 

weight using viscosity measurements and mass as a 

function of degradation time was monitored. 

FTIR peaks of the films were shown in Figure 1. For 

the treated membrane, the peaks at 2925 cm -1 , 1375 cm -1 , 

and 1060 cm -1 decrease remarkably. These results show 

the changes in hydrophilicity after ion implantation. After 

ion implantation membrane surfaces increases 

hydrophobicity which is in agreement with the contact 

angle studies as seen in Table 1. 

Figure 1. FTIR results of dense chitosan membranes 

Table 1. Contact angle change after ion implantation 

Sample 

Contact Angle 

Chitosan 68 

C Implanted Chitosan 76 

C+N Implanted Chitosan 84 

The SEM picture of the assymetric chitosan membrane is 

shown in Figure 2. Pore size of the membrane was 

changed by the changing pre-treatment time. 

Figure 2: SEM image of asymmetric chitosan membrane 

Corresponding author: 0Tfundatihminlioglu@iyte.edu.tr 

[1] S. Lousinian, and S. Logothetidis, Optical properties of 

proteins and protein adsorption study, Biomaterials: Protein– 

Surface Interactions (2007) 84: 479–485. 

[2] G. Lu, L. Kong, Baiyang Sheng, Gan Wang,,Yandao Gong, 

Xiufang Zhang, Degradation of covalently cross-linked 

carboxymethyl chitosan and its potential application for 

peripheral nerve regeneration, European Polymer Journal 43 

(2007) 3807–3818. 




The Influence of Nanoparticles on Performance of Portland Cement Paste and Mortar 

Ali Farsi 1 *, Mohamad Mehdi Afsahi 1 ,Sattar Ghader 1 , Vahid Shadravan 1 , Seyed Soheil Mansouri 1 , Shahla Ahmadi Pour 1 

and Akbar Danaei 2 

1 Department of Chemical Engineering, Shahid Bahonar University of Kerman, Kerman, Iran 

2 Kerman Momtazan Cement Company, Kerman, Iran 

Abstract- In this work we discus about Sol-Gel Chemistry Based Nanocomposites method and preparation of nano particles for addition into 

the Portland cement. Then the influence of nano particles on several Portland cements is investigated. Addition of nano particles to Portland 

cement can improve its physical properties such as compressive strength and p ermeability coefficient. 

Portland cement is usually a mixture of limestone (calcium 

carbonate, CaCO 3 ) and a second material as a source of 

alu mino-silicate. The principal clinker minerals of the 

Portland cement are Tri-calciu m silicate, C3S (A lite), 

Calciu m silicate, b-C2S (Belite), Tri-calciu m alu minate, 

C3A, and Ferrite phase; Tetra-calcium alumino ferrite, 

C4AF (Celite). In recent years, the use of nano-particles has 

received particular attention in many applications to fabricate 

materials with new functionalities. When ultra-fine particles 

are incorporated into Portland-cement paste, mortar or 

concrete, materials with different characteristics from the 

conventional materials were obtained. Nano particles 

enhanced the compressive strength of cement paste much 

more than silica fu me. It is due to the filling effect and 

pozzolanic reaction activation. It was concluded that the rate 

of pozzolanic reaction depends on the Blaine surface area 

available for react ion. Nano aluminate and silicate have been 

integrated with cement mortar as a new building material For 

and durability of the material. In this work we discus about 

Sol-Gel Chemistry Based Nanocomposites method and 

preparation of nano particles for addition into the Portland 

cement. Then the influence of nano particles on several 

Portland cements is investigated. Addition of nano particles 

to Portland cement can improve its physical properties such 

as compressive strength and permeability coefficient. - In 

this work we d iscus about Sol-Gel Chemistry Based 

Nanocomposites method and preparation of nano particles 

for addition into the Portland cement. Then the influence of 

nano particles on several Portland cements is investigated. 

Addition of nano particles to Portland cement can improve 

its physical properties such as compressive strength and 

permeability coefficient. 

*Corresponding author: ali.farsi@gmail.com 

[1] B. Yilmaz, A. Olgun, Cem. Concr. Compos. 30 (2008) 194. 

[2] N. Voglis, G. Kakali, E.Chaniotakis, S. Tsivilis, Cem Concr 

Compos. 27 (2005) 91. 

[3] M.S. Morsy, S.S Shebl, J. Ceram. Silicaty. 51 (2007) 40. 

[4] J. Jortner, C.N.R. Rao, Pure. Appl. Chem. 74 (2002) 1491. 

instance Nanoparticles of SiO 2 (NS) can fill the spaces 

between particles of gel of C–S–H, acting as a nano-filler. 

Furthermore, by the pozzolanic reaction with calcium 

hydroxide, the amount of C–S–H increases which results in a 

higher densification of the matrix that improves the strength 

[5] M.J. Pitkethly Material. Today. 7 (2004) 20. 




Numerical Simulat ion of Nano Particles in a Fluidize d Bed 

Afsin Gungor 1 * 

1 Department of Mechanical Engineering, Nigde University, Nigde 51245, Turkey 

Abstract-In this study, two dimensional numerical model is developed to simulate the hydrodynamic characteristics of nano particles such as the 

solids fraction and bed pressure drop in a fluidized bed. The model results are compared with and validated against experimental data given in 

the literature for the solids fraction in the bubble phase and emulsion phase, and for bed pressure drop as a function of superficial velocity. 

Nano-particles of 1–100 nm in diameter provide unique 

physical and chemical properties in numerous applications. 

The processing and handling of the nano-particles are very 

important in the applications. In this respect, the fluidization 

of the nano-particles to provide good gas and solids mixing, 

high mass and heat transfer efficiency, and continuous 

processing, can make a process more efficient [1]. The 

fluidization characteristics of nano-particles were investigated 

by many scholars [2-4] from various aspects. According to 

Geldart's classification [1], nano-particles are categorized in 

Group C which is a category of particles that is hard to 

fluidize due to strong cohesiveness or inter-particle forces. 

However, many researchers [3-6] have found that a variety of 

nano-particles displayed good fluidization similar to Group A 

particles. Until now, two types of nano-particle fluidization, 

termed agglomerate particulate fluidization (APF) and 

agglomerate bubbling fluidization (ABF) [4, 6], have been 

reported. Many researchers are attracted by the surprisingly 

smooth and uniform fluidization characteristics of APF [3, 5, 

6]. Wang et al. [5] reported the multi-staged agglomerate 

(MSA) of some nano-powders and revealed that the formation 

of a MSA structure is the key issue for good fluidization. The 

formation of a MSA structure leads to the resulting significant 

characteristics of these nano-powders, namely, extremely 

loose structure and low density of the agglomerates, which 

reduces the interparticle forces sharply. The reduction in the 

inter-particle forces plays a crucial role in changing the 

fluidization performance of the particles [7]. 

As nano-technology has brought about a new realm into 

chemical engineering, a natural question arises: besides the 

unique technologies and processes developed on nano-scales, 

whether or not the legacy of our traditional engineering 

practices could still be preserved or extended by miniaturizing 

the macro-scale equipment and processes. Considering the 

difficulties in conducting microscopic experiments and/or 

measurements, proper simulation methods may well serve as 

convenient and effective tools in seeking such possibilit ies [1]. 

From this point of view, in this study, two dimensional 

numerical model is developed to simulate the hydrodynamic 

characteristics of nano particles such as the solids fraction and 

bed pressure drop in a fluidized bed. The model results are 

compared with experimental data given in the literature for the 

solids fraction in the bubble phase and emulsion phase, and for 

bed pressure drop as a function of superficial velocity. 

In the first step, simulation results are compared with 

experimental results obtained from test unit (transparent 

polymethylmethacrylate) of 5 cm in diameter and 1 m in 

height for bed pressure drop as a function of superficial 

velocity [8]. The particles are Aerosil R974 hydrophobic 

silica. The primary particle size and particle density of the 

powder were 12 nm and 2200 kg/m 3 respectively, with a bulk 

density of 30 kg/m 3 . 

In the second step, simulation results are compared with 

experimental results obtained from test unit (transparent 

polymethylmethacrylate) of 28 cm in diameter and 2 m in 

height for the solids fraction in the bubble phase and emulsion 

phase [7]. The particles are R972, a co mmon synthetic silicon 

dioxide. The average primary particle size is 16 nm, the 

particles have a primary density of 2560 kg/m 

3 , but the bulk 

density is unusually low and is 31.85 kg/m 3 . The fluidization 

experiments are carried out at room temperature and ambient 

pressure. 

Pressure drop/Bed weight 

per unit area (-) 

0.9 

0.6 

0.3 

Experiment 

Model prediction 

0 

0 0.4 0.8 1.2 1.6 2 

Superficial velocity (cm/s) 

Figure 1. Comparison of model pressure drop predictions [8] 

As shown in Figure 1, bed pressure drop increases with 

superficial velocity. On the other hand, with the increase of 

gas velocity, the pressure drop curves do not show a plateau as 

a general coarse particle (either Group B or A) bed does. 

Model pressure drop predictions are in good agreement with 

experimental data [8]. 

The existence of a bubble phase and emulsion phase and the 

difference in properties between the two phases such as the 

solids fraction lead to the spatial inhomogeneity in the 

bubbling and turbulent fluidization regimes. However, as a 

result of this study, the fluidization in the NAFB is more 

homogeneous not only on the scale of the macroscopic 

phenomena but also on the scale of the micro-phase structure. 

*Corresponding author: 1Tafsingungor@hotmail.com 

[1] C. Hou, and W. Ge, Chem. Eng. Sci., 62, 6794 (2007). 

[2] D. Geldart, Powder Technol., 7, 285 (1973). 

[3] W. Zhaolin, M. Kwauk and L. Hongzhong, Chem. Eng. Sci., 53 

(3) 377 (1998). 

[4] A.W. Pacek and A.W. Nienow, Powder Technol., 60, 145 (1990). 

[5] Y.Wang, G.S. Gu, F.Wei and J.Wu, Powder Technol., 124, 152 

(2002). 

[6] C. Zhu, Q. Yu, R.N. Dave and R. Pfeffer, AIChE J., 51, 426 

(2005). 

[7] C. Huang, Y. Wang and F. Wei, Powder Technol., 182, 334 

(2008). 

[8] X.S. Wang, V. Palero, J. Soria and M.J. Rhodes, Chem. Eng. Sci., 

61, 5476 (2006). 




 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 




Dras tically e nhanced visible-light photodegradat ion of water pollutants ove r n-Titanium dioxide via 

I - and S 2 SO 3 

= 

Abdullah M. Asiri 1,2 *, Saleh A. Bazaid 3 , Muhammed S. Al-Amoudi 3 , Abdulmajid A. Adam 3 

1 Chemistry Department, Faculty of Science, King Abdul Aziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia 

2 The Center of Excellence for Advanced Materials, King Abdul Aziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia. 

3 Faculty of Science, Taif University, P.O. Box 80203, Jeddah 21589, Saudi Arabia 

Abstract- Doping of TiO 2 with metals or non-metals improve the catalyst activity in the photodegaradation of pollutants in water than 

untreated photocatalyst. 

Many organic compounds are present as pollutants in 

wastewaters that are emitted from industrial and normal 

households. These pollutants can be found in ground water 

wells and surface waters. These compounds can be treated by 

different processes: adsorption in waste materials [1], 

electrochemical oxidation [2] , membranes [3], coagulation 

[4], Fenton or photo-Fenton oxidation [5-6], foam flotation 

[7], adsorption using activated carbon [8], combined 

coagulation/carbon adsorption [9].However, these processes 

are nondestructive and generate secondary pollutants. One 

way to destroy pollutants without generating secondary toxic 

materials is photoctalysis [10]. Fig. 1 shows the stages in the 

photoinduced processes of the photomineralization of organic 

contaminant in presence of TiO 2 . In this process the 

pollutants decompose to CO 2 , H 2 O and inorganic acids. 

The aim of this study is to evaluate photoctalytic degradation 

of Rhodamine 6G (Figure 1 and 2) and the parameter 

affecting their degradation. 

Doping of TiO2 with metals or non-metals improve the 

catalyst activity in the photodegaradation of pollutants in 

water than untreated photocatalyst. However, the preparation 

techniques involve complex procedures that need expensive 

materials such as metallic sources and/or organic materials as 

a source of non-metal dopants and high temperatures for 

calcination steps, thus hindering their use and production for 

large scale preparations. Thus, the search for a way to 

improve the rate of photodegradation of hazardous pollutants 

has veered off to search for inexpensive techniques that 

enhance the mineralization of pollutants and yet be 

environmental friendy. The photocatalytic removal of 

Rhodamine 6G under sunlight from water using undoped n- 

TiO2, doped S-TiO 2 , N-TiO 2 and n-TiO 2 with 0.1 mmol/Lit. 

of KI or Na 2 S 2 O 3 is reported here. Kinetic studies were 

investigated and it showed first order. KI and Na 2 S 2 O 3 with 

n-TiO 2 enhanced the rate of Rhodamine 6G degradation 

better than the doped catalyst. An 80% degradation of 

Rhodamine 6G was realized in 80 mint. with n-TiO 2 + 

Na 2 S 2 O 3 compared with only 37% with doped N-TiO 2 When 

Na 2 S 2 O 3 used with bulk TiO 2 the rate degradation of the dye 

decrease from 94% to only 31 % in 80 min. which reveals 

that inorganic anions can act as active site blockers with bulk 

TiO 2 and rate enhancers with n-TiO 2 .The enhancement of 

photodegradation rate by Na 2 S 2 O 3 can be linked to the direct 

or indirect formation of SO .- 3 or S .- . 

H 3 

C 

H 

CH 2 

CH 

H 2 

C 3 

N O N + Cl - 

H 

H 3 

C 

CH 3 

OC 2 

H 5 

O 

TiO 2 

Figure 2. No interaction with TiO2 due to absence of anchoring 

groups 

This research was supported by Taif University (Grant No. 

345/430/1) and is gratefully acknowledge. 

0T*Corresponding author aasiri2@kau.edu.sa 

[1] J. M. Petibone, D. V. Cwiertny, M. Scherer, V. H. Grassian, 

Adsorption of Organic Acids on TiO2 Nanoparticles: Effects of 

pH, Nanoparticle size, and Nanoparticle Aggregation, 2008, 

Langmuir, 24: 6659-667. 

[2] A. Kathiravan, P. Sathish Kumar, R. Renganathan, S. 

Anandan, 2009, Photoinduced electron transfer reactions between 

meso-tetrakis(4-sulfonatophenyl)porphyrin in colloidal metalsemiconductor 

nanoparticles, Colloids and Surfaces A: 

Physicochem. Eng. Aspects, 333, 175-181. 

[3] N. Daneshvar, ED. Salari, A. R. Khataee, 2003, 

Photocatalytic degradation of azo dye acis red 14 in 

water:investigation of the effect of operational parameters, J. 

Photochem. Photbiol A: Chem 157, 111-116. 

[4] J. Hoigne, 1997, Inter-calibration of OH radical sources on 

water quality parameters, Water Sci. and Technol. 35 (4) 1-8. 

[5] J. Chen, M. Liu, J. Zhang, X. Ying, L. Jin, 2004, 

Photocatalytic degradation of organic wastes by electrochemically 

assisted TiO2 photocatalytic system, J. Environ. Manage. 70 43- 

47. 

H 3 C 

H 

CH2 

CH 

H 2 C 3 

N O N + Cl - 

H 

H 3 C 

CH 3 

OC 2 H 5 

H 3 C 

H 

CH2 

CH 

H 2 C 3 

N O N 

H 3 C 

CH 3 

OC 2 H 5 

O 

O 

Figure 1. Molecular structure of Rhodamine 6G. 




Precipitation and characterizat ion of nano-zinc oxi de and laye red zinc hydroxyc hloride from aqueous 

zinc chloride solutions 

Seyed Behnam Ghaffari *, Javad Moghaddam 

1 Faculty of Materials Engineering, Sahand University of Technology, Sahand New Town, Tabriz, Iran 

1 

2 

Abstract-Various shapes of wurtzite-type ZnO nanoparticles were selectively produced in a simple aqueous system prepared by mixing ZnCl 2 

and MgO and Ca(OH) 2 as neutralizing agents at 95 °C for one hour. Layered zinc hydroxychloride (ZHC) synthesized when magnesium oxide 

was used and the elipsoidal particles of zinc oxide were obtained after calcination of the ZHC at 520 °C for 4 hours while nanorods were grown 

by destabilization ZHC with NaOH. Nanorods directly were obtained by neutralization with Ca(OH) 2 (lime) when the pH static neutralizing 

approach was selected while elipsoidal nano particles were prepared when aqueous zinc chloride solution was dropped into lime solution. The 

techniques of XRD, TGA–DTA, FT-IR, BET and FESEM were applied for the characterization of the produced materials. 

Zinc oxide is a wide bandgap semiconductor material with 

many promising properties for blue/UV optoelectronics, 

transparent electronics, spintronic devices and sensor 

applications [1]. Depending on the adopted synthesis method, 

zinc oxide nanocrystals would show various morphologies 

under different formation mechanisms [2]. The size and 

morphology are important parameters to determine the 

physical and physicochemical properties of ZnO crystals [3]. 

Layered zinc hydroxychloride (Zn 5 (OH) 8 Cl 2 -H 2 O:ZHC), 

which is one of the basic zinc salts has received attention in 

applications such as catalyst and adsorbent. [4] 

In this paper, we selectively produced nanoparticles and 

nanorods of ZnO and layered zinc hydroxychloride crystals by 

homogeneous precipitation method using a simple mixing 

technique of Zncl2 and MgO or Ca(OH) 2 as neutralizing 

agents. This work also would provide fundamental 

information for shape control of nanoparticles prepared 

through the crystal growth in aqueous solutions. Final 

products characterized by means of powder X-ray diffraction 

(XRD) and field-emission scanning electron microscope 

(FESEM), The Brunauer-Emmett-Teller (BET) and fourier 

transform infrared spectra (FTIR). 

We first studied the condition of precipitation of zinc oxide 

and ZHC from aqueous zinc chloride solutions. Neutralization 

was carried out by slowly adding a certain amount of 

magnesium oxide till the mole ratio of Zn/Mg=3.0 was 

reached. The addition of MgO must be substoichiometric to 

obtaine zinc oxide with high quality [5]. Zinc oxide is stable 

in the pH range of 8-11. Neutralization with MgO can reach a 

maximum pH of 8, which decrease as temperature increases to 

an extent that only pH 6 can be reached at 85°C and zinc 

hydroxychloride is stable under this situation [5]. Zinc 

hydroxychlorides are destabilized through the action of dilute 

chloride solution at high pH and temperature to convert the 

zinc hydroxychlorides to zinc oxide. The pH was adjusted 

using NaOH and lime. After fixing the pH of 11, solid 

remained in contact with the solution for one hour, to obtain 

zinc oxide (route 1). We found that the ZHC also can be 

converted to zinc oxide by calcination. The ZHC was calsined 

in air at 520 °C for four hours, based on it 

' s decomposition 

temperature obtained from TGA-DTA analysis. By using 

Ca(OH) 2 as neutralizing agent, a direct neutralization was 

performed [5]. The addition of lime was stoichiometric to the 

concentration of zinc present in the aqueous zinc chloride 

solution. In route 2 , the pH static neutralizing approach (with 

lime) was selected and in route 3, aqueous zinc chloride 

solution was dropped into lime solution. 

Figure 1. FESEM images of (a) ZHC (b) zinc oxide prepared through 

route 1 (c) route 2 and (d) route 3. 

The crystalline ZnO and ZHC materials produced were 

analyzed and characterized with a variety of techniques. The 

XRD patterns, were verified the formation of wurtzite-type 

ZnO. The FESEM images show that ZnO nanorods with a low 

aspect ratio can obtain with destabilization the ZHC (route 1). 

ZnO nanorods with a high aspect ratio were obtained at pH 11 

through neutralization with lime (route 2) while ellipsoidal 

nanoparticles obtained in route 3. The morphology of ZnO 

particles would be governed by the balance of the nucleation 

and crystal growth determined by the reaction route. The 

FESEM images of ZnO obtained after calcinations shows 

spherical particles. The nanostructured character of the 

produced zinc oxide and ZHC was verified by employing the 

Williamson-Hall method in XRD patterns, FESEM 

examination and BET measurements. 

In summary, nanosized ZnO powders were successfully 

obtained by neutralization of aqueous ZnCl 2 solutions with 

Ca(OH) 2 .ZnO also is formed on destabilization and 

calcination of the ZHC after neutralization with MgO. Various 

shapes of wurtzite-type ZnO crystals including nanomeric 

ellipsoidals, nanorods were prepared. The morphology of ZnO 

particles would be governed by the balance of the nucleation 

and crystal growth determined by the reaction route. 

*Correspondign author: behnamghaffari@yahoo.com 

[1] Chennupati. Jagadish, Stephen. Pearton. 2006. 

[2] Yang Liu, Jian-er Zhoua, Andre Larbot, Michel Persin., Journal 

of Materials Processing Technology, 189, 379–383, 2007. 

[3] Tetsuo Kawano, Hiroaki Imai, Colloids and Surfaces A, 

Physicochem. Eng, Aspects 319, 130–135, 2008. 

[4] Hidekazu Tanaka, Akiko Fujiok, , M aterials Research Bulletin 45, 

46–51, 2010. 

[5] Allen, US Patent 6,395,242. 2002. 




Nano-sized Copper Borate Production 

Meltem Sünger 1 , Elif T 1 , Burcu Alp 1 , Devrim Balköse 1 * 

1 

Abstract – Copper bor ate particles with nano-sized thickness were obtained using Span 60 as modifying agent. Effects of Span 60, 

temperature and experiment duration on morphology and chemical structure of copper borates were investigated. 

For most living cells, copper is known to be an essential 

micronutrient. Although in larger doses, the copper ion 

shows an algaecide, bactericide, fungicide, insecticide, and 

moldicide activity. According to this preservative property 

copper compounds are used for algal control, wood 

treatment, antifouling pigments, and crop fungicides, in 

recent years0T [1]. However, since some fungi are 

resistant to copper, combinations with other additives 

which cause considerable environmental concern have 

always been used. Borate, used as a fire retardant and a 

preservative, has low toxicity in mammalian and minimal 

environmental impact that make it an ideal additive for 

environmentally friendly wood preservatives [2]. Due to 

being the most frequently use of copper as biocide for 

wood preservation, a study of nano-sized copper borate is 

desired to be produced for this purpose. 

Experimentally, sodium borate solution with Span 60 

was reacted with copper nitrate and by the reaction below 

copper borate precipitate was obtained. Procedure was 

followed from the study of Yunhui Zheng et al. [3]. 

Instead of phosphate ester Span 60 was used to control the 

thickness. Reaction conditions are as reported in Table 1. 

Na 2 B 4 O 7 10H 2 O + Cu (NO 3 ) 2 2.5H 2 O 

xCu OyB2O 3 zH 2 O + 2Na(NO 3 ) 

Samples were analyzed by SEM, X-ray, FTIR, thermal 

and elemental analysis that the coefficients x, y, z are 

defined. 

Table 1. Sample definitions and and reaction conditions. 

Sample Mixing Rxn 

Time (h) 

Span 

60 

Rxn 

Temp ( o C) 

1 instantaneous 2 - 40 

2 Dropwise 2 - 40 


4 Dropwise 4 + 40 






In all Figures the numbers represents sample numbers 

given in Table 1. FTIR spectra in Figure 1 showed isolated 

OH groups at 3700 cm -1 . B-O at 1420 cm -1 , O-NO 2 at1356 

cm -1 streching peaks. Figure 2 demonstrates the XRD 

patterns of all copper borate samples that peaks represent 

the existance of Cu 2 (OH) 3 NO 3 in the products acording to 

the study of Seong-Hun Park et al. [4]. In Figure 3 the 

samples were thermally stable up to 248 o C. 30 % mass 

loss occured above this temperature with endothermic 

enthalpy change of 738 j/g due to elimination of water 

from the system. It could be clearly observed from Figure 

4, products are hexagonal shaped plates with 

 

Figure 1. FTIR spectra of 

copp er borates. 

a 

Figure 2. X-ray patterns of copper 

Figure 3. Thermal behavior of produced copper borate samples; 

a-TGA thermograms, b-DSC curves. 

2 4 

Figure 4. SEM microphotographs of produced copper borate 

 

Consequently thermally stable copper borate particles 

with planar shapes having 500 nm thickness were obtained 

even for 2 h heating time at 40 o C. 

*Correspondign author: devrimbalkose@iyte.edu.tr 

[1] Freeman, M. H., McIntyre, C. R., 2008. A Comprehensive 

Rewiev of Copper Based Wood Preservatives with a Focus on 

New Micronized or Dispersed Copper Systems, Forest Products 

Journal, 58, 6-27. 

[2] Abbott, W., Woodward, B., West, M., 2000. Efficacy of 

Copper Borax Preservative Against Wood Decay, American 

Wood-Preservers' Association, 97, 806-808. 

[3] Zheng, Y., Wang, Z., Tian, Y., Qu, Y., Li, S., An, D., Chen, 

X., Guan S., 2009. Synthesis and performance of 1D and 2D 

copper borate nano/microstructures with different morphologies, 

Colloids and Surfaces A: Physicochem. Eng. Aspects 349 156– 

161. 

[4] Park, S., Kim, H. J., 2004. Unidirectionally Aligned Copper 

Hydroxide Crystalline Nanorods from Two-Dimensional Copper 

Hydroxide Nitrate, J. AM. CHEM. SOC., 126, 14368-14369. 

b 




Large Area Micropatterned Polymer Surfaces from Polypropylene/Polyethylene Copolymer 

and Polystyrene Blends 

Nevin Atalay Gengeç*, H. 

Gebze Institute of Technology, Chemical Engineering Department, 41400, Gebze- 

Abstract- In this study, a novel method for fabricating polymer thin films having cylindrical micro-patterns varying in the range of 2 to 

30 m on the surface is presented. These large area micropatterned surfaces were prepared by dip-coating process using polymer blend 

solutions. Static contact angles and surface morphology of these thin films were determined by using KSV CAM 200 contact angle 

apparatus and optical microscopy. The change in the surface morphology of the thin film coatings with the change in the solvent/nonsolvent 

ratio of polymer solutions, and also coating conditions were investigated. We can control the distribution of the pattern 

diameter via adjusting solvent/non-solvent ratio and the withdrawal speed of the dip coater. 

The properties of polymer blends are determined mainly 

by the miscibility of the components and their 

structures. 1,2 Polymer mixtures demix during the rapid 

solvent casting process due to intrinsic immiscibility of 

the polymer component in the blend. In general, the 

resultant phase-separated morphology is far from the 

thermodynamic equilibrium and the relaxation toward 

equilibrium can be hindered by kinetic barriers formed by 

the non-equilibrium phase morphology. Surface 

segregation is a result of a balance of surface tension 

forces and bulk mixing thermodynamic forces. 3,4 The 

surface properties of the polymer coatings can be 

modified by applying plasma treatment, surface grafting, 

film deposition under vacuum, etc. Most of these methods 

are comparatively expensive and difficult to apply on a 

large area scale. However, Erbil et al. obtained microstructured 

gel-like porous superhydrophobic surfaces via 

phase separation using isotatic propylene (iPP) solutions 

with different solvent/non-solvent ratio and this method is 

easier and cheaper than other methods. 4 

In this study, large area micro patterned surfaces were 

prepared by dip coating using mixed polymer solutions 

and pattern diameters ranging from 2m to 40 m were 

obtained. Polystyrene and polypropylene/polyethylene 

copolymer (PS-PPPE) blend solutions were prepared 

separately in tetrahydrofuran (THF) at 60 o C and then 

these solutions were mixed as 50:50 (wt %) blend 

composition. Glass slides were dip coated in these 

polymer blend solutions at different dipper speeds at 60 

o C. In some recipes, varying amounts of ethanol was 

added as a non-solvent. The change in the surface 

morphology of the thin coatings with the change in the 

solvent/non-solvent ratio (THF/EtOH) of polymer 

solutions, and also coating conditions such as dipper 

speed and temperature were investigated. Static contact 

angles and surface morphology of thin films containing 

micro-patterns were determined by using KSV CAM 200 

contact angle apparatus and optical microscopy, 

respectively. 

Pillar diameters were decreased from 20 m to 2 m with 

the increase in the dipping rate and also the heterogeneity 

of the pillar diameters on surfaces was decreased with the 

dipping rate. Figure 1 shows the optical microscopy 

images of the surfaces obtained at the optimum dipping 

speed and different methanol fractions. It is clearly seen 

from the results that the pillar diameters increased with 

the increase of methanol fraction. When methanol volume 

fraction was low, scattered form of particles with uniform 

cylindrical geometry were observed which have their 

diameters around 2 m. With the increase in the methanol 

amount in the solution, these particles diameters were 

increased up to 30 m. 

(a) 

(b) 

Fig1. Optical microscopy images of 25 mg/mL PS/PPPE solution in 

THF (50 wt %) with a) 0,5, b) 10 wt % methanol at room temparature 

In summary, particles shape and dimensions were varied 

as a function of non-solvent in the solution and dipping 

rate. The water contact angle of the surfaces is constant 

around 116 o . Equilibrium contact angle and contact angle 

hysteresis results will be discussed at presentation. 

* Corresponding author: natalay@gyte.edu.tr 

1. Olabisi O., Robeson L.M., Shaw M.T., London: 

Academic Press; 1979. 

2. Paul D.R., Newman S., Polymer blends, vol. 1. New 

York: Academic Press; 1978. 

3. Khayet M., Vazquez Alvarez M., Khuble K.C., 

Matsuura T., 2007, 601, 885 

4. Erbil H.Y., Demirel A.L., Avci Y., Mert O. Science 

2003, 299, 1377. 




Equilibrium and kinetic study on boron uptake by Monodisperse-Nanoporous Poly(GMA-co-EDM) 

Particles Containing N-Methyl-D-Glucamine 

1 Saba Samatya, 2 Nalan Kabay, 1 Ali Tuncel* 

1 Hacettepe University, Chemical Engineering Department, Ankara, Turkey 

2 Ege University, Chemical Engineering Department, Izmir, Turkey 

Abstract— A relatively new method of polymerization, ‘modified seeded polymerization’ has been used for the synthesis of 

monodisperse nanoporous poly(glycidyl methacrylate-ethylene dimethacrylate) particles are proposed for boron removal. The 

covalent attachment of boron selective ligand N-methyl-D-glucamine onto poly(GMA-co-EDM) particles were followed for 

the synthesis of sorbents. 

Boron is a naturally occurring element that is widely 

distributed at low concentrations in the environment. Boron is 

rare, being found in dry regions of the world such as Turkey, 

which has the largest boron reserves in the world. Although 

boron is essential for plant life and small amounts of boron are 

even claimed to be beneficial for human, high levels may be 

toxic [1]. There are several physicochemical treatment 

processes typically used to remove boron from water and 

wastewater. These are adsorption with inorganic adsorbents, 

ion exchange, solvent extraction, membran processes and 

ultrafiltration [2]. Basically, the only method utilized to 

separate boron from liquid media has been the use of ion 

exchange resins. The chemistry of boron indicates that 

molecules with vic-diols are capable of forming neutral boron 

esters or tetra alkyl borate type of compounds, even in 

aqueous solutions. Design of new boron-specific sorbents is 

based mostly on this key principle [3]. 

Our interest has been much focused on the development of 

monodisperse-porous Poly(GMA-co-EDM) Particles. 

Monodisperse polymer particles, of which size is in the order 

of micrometers, have been of great interests in many 

applications, including standard calibrations, biomedical 

examinations, chromatographic fillers, spacers, ink additives, 

and catalytic substrates [4]. Uniform, macroporous particles 

have usually been obtained with seeded polymerization 

techniques. In fact, many recent advances in the synthesis of 

monodisperse polymer particles are strongly based on the 

seeded polymerization technique [5]. 

A representative SEM photo (Figure 1) shows the surface 

morphology of poly(GMA-co-EDM) particles. Based on SEM 

evaluation, the average size of poly (GMA-co-EDM) particles 

were 9.0 μm. The SEM photo indicates that poly(GMA-co- 

EDM) particles have a highly porous-surface predominantly 

including macropores. NMDG was covalently attached to the 

particles (Figure 2). 

Figure 1. A representative SEM photo of poly(GMA-co-EDM) particles 

Figure 2: Schematic illustration of the functionalization of poly(GMA-co- 

EDM) with NMDG 

Figure 3. Equilibrium isotherm on uptake of boron from aqueous solution 

As seen in Fig.3, the maximum uptake value (Q o ) of 12 mg 

boron per g-dry resin 

Figure 4. Removal of boron by versus time by poly(GMA-co-EDM)NMDG 

resin 

Figures 4 indicates uptake of versus time. The removal of 

boron increased with time and reached the equilibrium in 10 

min with a 98.8 % boron removal. The sorbent has been 

shown to be efficient in chelation with boric acid and can be 

used for removal of boric acid at ppm levels. 

BOREN (Project Number: 2008-G-0192). We are grateful to 

TUBITAK for post doc fellowship for S.Samatya. We also 

thank to Prof. A.Ozdural, Hacettepe University for allowing to 

use ICP equipment for boron analysis. 

*Corresponding author: Ali Tuncel atuncel@hacettepe.edu.tr 

[1] J.Q. Jiang, Y. Xu, J. Simon, K. Quill and K. Shettle, Water Sci. Technol. 

53 73 (2006). 

[2] N. Kabay, I. Yilmaz, S. Yamac, S. Samatya, M. Yuksel, U. Yuksel, M. 

Arda, M. Saglam, T. Iwanaga and K. Hirowatari, React. Funct. Polym., 60 

163(2004). 

[3] B. F.Senkal, N. Bicak, Polymer supported iminodipropylene glycol 

functions for removal of boron, React. Funct. Polym, 55: 1, 27-33 (2003). 

[4] S.I. Kim, T. Yamamoto, A. Endo, T. Ohmori, M. Nakaiwa, J. Ind. Eng. 

Chem. 127 69(2006). 

[5] Unsal E, Çamlı ST, Tuncel M, Şenel S, Tuncel A, React Func Polym, 61 

(2004) 353. 




Submicron Sized Boric Acid Particles Production By Wet Milling 

Mehmet Ikbal Isik 1* Emine Bakan 1 Ozgenur Kahvecioglu 1 Servet Timur 1 

1 Metallurgical & Materials Engineering Department, Istanbul Technical University, 34469 Istanbul, Turkey 

Abstract— Submicron sized boric acid particles are being used in traditional lubrication oils due to providing low friction 

coefficient while it is friendly to environment. In the present study, size and morphology changes of wet milled boric acid 

particles were investigated and characterized by SEM, XRD, BET, TG-DTA and MasterSizer. It is seen that increasing 

time of milling results in a smaller particle formation and more homogen size distribution. 

Submicron sized particles have received increasing interest 

in miscellaneous fields of science during the last years [1-3]. 

Size reduction by using mechanical milling is simple and 

widely used process in industrial or laboratory scale [4,5]. 

High energy ball milling is based on collisions between 

particles and balls that causes smaller particles formation. 

Boric acid (H 3 BO 3 ) also known as boracic acid, orthoboric 

acid, boron trihydroxide, borofax, bortrac, dia flea-mate, flea 

prufe, trihydroxyborane, trihydroxyborone, three elephant, 

hydrogen orthoborate, sassolite, acidum boricum, a well 

known antiseptic and pesticide is a colorless, odorless white 

crystalline solid [6]. Major process parameters that are 

altering particle size and morphology can be summarized as 

miller type, milling atmosphere, milling media, ball to 

powder ratio, milling time and milling temperature. In this 

study, all these parameters were kept constant except milling 

time. 

For further understanding of production of boric acid 

particles some of other techniques were studied [7]. Dry 

milling and flame spray synthesis of boric acid particles 

were investigated within our research group. Fig. 1-a shows 

120 min dry milled and Fig. 1-b shows flame spray 

synthesized boric acid particles SEM images. 

a 

b 

Figure 1. SEM image of boric acid particles produced by 

different techniques; (a) 120 min dry milled and (b) flame spray 

synthesized. 

Precursor material used for high energy ball milling was 

high purity boric acid powder. Ball to powder ratio (BPR) 

was kept constant in all set of experiments as 10:1. Milling 

process was done with stainless steel balls and containers 

using 15 ml of hexane as dispersant media. Experimental 

milling durations were chosen as 30-90-150-210 minute. In 

order to remove moisture boric acid precursor powder was 

heated to 85 o C and kept at this temperature for 24 hours. 

TG-DTA analysis (Fig. 2) showed that boric acid 

decomposition does not occur at 85 o C. After moisture 

removal, powder is prepared for further process stages. 

As it is well known, X-ray diffraction patterns of 

materials show an alteration when size reduction achieved. 

XRD patterns of wet milled particles showed broadening 

that proves size reduction. MasterSizer was used to get 

Weight (mg) 

Temperature ( o C) 

Figure 2. Thermo gravimetric-differential thermal analysis of 

high purity boric acid. 

size and size distribution of particles and BET analyses for 

specific surface area determination. Size distribution of 

particles becomes more homogen and finer particles were 

formed with increasing milling time. However, there is no 

doubt that agglomeration will create a great challenge in 

longer milling time while energy consumption increases and 

energy efficiency goes down. 

In conclusion, it is showed that; 

•Wet milling is capable of producing submicron sized 

boric acid particles. 

•Stainless steel balls and container are found to be proper 

for milling boric acid powders. 

•Increasing milling time provides finer particle size and 

better size distribution. 

•Temperature increases caused by collisions is found to be 

negligible. 

Special thanks to Prof.Dr. M. Lütfi Öveçoğlu, Asst.Prof.Dr. Nuri 

SOLAK, Hüseyin Sezer, Ph.D. Hasan Gökçe, M.Sc. Şeyma Duman 

*Corresponding author: isikme@itu.edu.tr 

[1] A. G. Gnedovets, A. V. Gusarov, I. Smurov, Applied Surface 

Science, 154-155 (2000) 508-513 

[2] L.C. Santa Maria, M.A.S. Costa, J.G.M. Soares, S.H. Wang, 

M.R. Silva, Polymer, 46 (2005) 11288-11293 

[3] S.S. Dukhin, Y. Shen, R. Dave, R. Pfeffer, Advances in 

Colloid and Interface Science, 134-135 (2007) 72-88M.L. 

Steigerwald, L.E. Brus, Annu. Rev. Mater. Sci. 19 (1986) 471. 

[4] A. Calka, D. Wexler, A.Y. Mosbah, Journal of Alloys and 

Compounds, 434-435 (2007) 463-466 

[5] T. Isobe, Y. Hotta, K. Watari, Materials Science and 

Engineering: B, 148 (2008) 192-195 

[6] Material Safety data for boric acid, 

http://msds.chem.ox.ac.uk/BO/boric_acid.html (2005). 

[7] M.I. Isik, M.Sc. thesis, Flame Sythhesis of Nano-boric Acid, 

Istanbul Technical University (2007). 

Microvolt (μV) 




Synthesis and Characterization of CdTeFe 3 O 4 Magnetic Nanoparticles 

 

1 , Tülay Oymak 1 , 1 * 

1 Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, Ankara 06500, Turkey 

Abstract- A simple chemical method for the fabrication of magnetic-fluorescent nanocomposite materials composed of magnetic nanoparticles 

and quantum dots at room temperature is described. The nanosutructures were characterized with fluorescence spectrometry, TEM, EDAX and 

magnetic measurements. 

Recent advance in nanotechnology have led to a new class 

of labelling based on semiconductor quantum dots (QDs). 

Surface passivated QDs exhibit high stablity, large absorption 

coefficients, size tunable flurescence. These properties have 

made QDs an ideal for labeling with broad applications 

especially in in biochemistry [1-2]. The combination of 

magnetic and fluorescent properties in one nanocomposite 

provides new nanoscale photonic devices which would be 

manipulated using an external magnetic field [3]. In 

immunoassays, QDs are usually used in labeling of secondary 

antibodies. Those QD labeled antibodies can be used after the 

IMS of the target molecule in order to detect the target. But the 

paramagnetic microparticles used in IMS cause partial or 

complete quenching of QDs and lowers the sensitivity of the 

analyze. Therefore, development of magnetic nanoparticles 

which do not cause any quenching would be favorable in 

bioassays and in some applications like fluorescence 

resonance energy transfer (FRET) two different fluorescence 

molecules are used as a donor and acceptor. Development of a 

nanoparticle which has both magnetic and fluorescence 

properties would be an important advance for such systems. 

In this work, we describe a simple synthesis method for the 

magnetic-florescent, CdTeFe 3 O 4 , nanocomposite material in 

aqueous medium, at room temperature. Characterization of the 

core-shell structured Fe 3 O 4 -CdTe nanoparticle proved that the 

resulting nanoparticles composed of Fe 3 O 4 core and the CdTe 

shell. Rapid and room temperature reaction synthesis of CdTe 

coated magnetic nanoparticle and subsequent surface 

modification may provide binding properties for sensing 

application. 

To synthesize CdTe coated iron nanoparaticle, the seed 

mediated synthetic method was carried out. First, The Fe3O 4 

nanoparticles were prepared by coprecipitation of Fe (II) and 

Fe (III). Fe(II) / Fe(III) ratio is kept as 0.5 in an alkaline 

solution. Briefly, 1.28 M FeCl 3 and 0.64 M FeSO 4 7H 2 O were 

dissolved in deionized water. The solution was then strirred 

vigorously until the iron salts were dissolved. Subsequently, a 

solution of 1M NaOH was added dropwise into the mixture 

with stirring for 40 minutes. 

After the preparation of the of Fe3O 4 core, CdTeFe 3 O 4 

nanocomposite particles were prepared by bubling the gaseous 

tellerium hydride produced by the hydride generation system 

through the solution composed of Fe 3 O 4 , 0.03 M CdCl 2 and 

0.03 M citrate for 5 minutes. The magnetically active 

nanoparticles were collected by a magnet and the supernatant 

solution was discarded. The residue was diluted with 5 mL 

ethanol and treated with 3-mercaptopropionic acid and shaked 

for four hours. The excess of mercaptopropionic acid was 

removed by centrifugation. The magnetic separation of these 

nanoparticles was easily accomplished and the resulting 

nanoparticles were characterized with Transmission Electron 

Microscopy (TEM), UV-Vis, X Ray Diffraction (XRD) and 

magnetic properties of the nanoparticles were also examined 

by vibrating sample magnetometer. 

Typical morphology of resulting nanoparticles is shown in 

Figure 1. 

Figure 1. TEM image of CdTeFe 3 O 4 , nanoparticle 

The fluorescence spectrum of the nanoparticle is given in 

Figure 2. 

R.I. 

120 

80 

40 

0 

650 675 700 725 750 

Wavelength, nm 

Figure 2. The fluorescence spectrum of the CdTeFe 3 O 4 

nanoparticle exc = 330 nm 

*Corresponding author: 1Tnertas@gazi.edu.tr 

[1] Sheikh, S. H.; Abela, B. A.; Muchandani, A., Anal Biochem. 

2000, 283(1), 33-38 

[2] Chan, W.C.; Nie, S., Science, 1998, 281(5385), 2016-2018 

[3]Corr, S. A.;Rakovich Y. P.; Gun’ko Y. K., Nanoscale Res. Lett., 

2008, 3, 87-104 




Synthesis and Characterization of Electrospun Ba 0.6 Sr 0.4 TiO 3 Nanofibers and 3-3 Nanocomposites 

Yahya Toprak, 1 Ebru Menur Alkoy 2 and Sedat Alkoy 1,* 

1 Department of Materials Science and Engineering, Gebze Institute of Technology, Kocaeli 41400, Turkey 

2 Faculty of Engineering, Maltepe University, Istanbul 34857, Turkey 

Abstract— Barium strontium titanate – Ba 0.6 Sr 0.4 TiO 3 (BST) nanofibers with diameters of 50–200 nm were prepared 

using electrospun BST/polyvinylpyrrolidone (PVP) fibers by calcination for 1 h at temperatures in the range of 650–800ºC 

in air. The morphology and crystal structure of calcined BST/PVP nanofibers were characterized using SEM and XRD. 

Nanocomposites with 3-3 phase connectivity were prepared by infiltrating an epoxy matrix phase into the nanofiber mats. 

Dielectric properties of the BST/epoxy nanocomposites were evaluated for tunable microwave dielelectric applications. 

BST powders were also prepared by gelation and drying of BST precursor sol-gel solutions. Dried gels were then 

calcined, ground, pressed and sintered to obtain dense BST ceramics. Electrical properties of BST ceramics were 

determined through dielectric and PE hysteresis measurements. 

Barium strontium titanate - Ba 1x Sr x TiO 3 (BST) is a 

perovskite type material with a ferroelectric-paraelectric 

transition temperature that can be tuned from 30 to 400 K by 

varying the Ba/Sr ratio [1]. Solid solutions with x = 0.2 to 

0.5 are normally used to shift the transition temperature to, 

or just below, room temperature. BST solid solutions have 

unique combination of large dielectric constant, high 

tunability, low dc leakage, low loss tangent, and stable 

operation at high temperature [2]. With this combination of 

favorable properties, BST finds niche in tunable microwave 

devices such as microwave tunable phase shifters, tunable 

filters, and high-Q resonators for radar and communication 

applications [3]. Fiberization of the functional ceramics 

expand their utility into the micro and nanodevices, and 

incorporation of these fibers into composite structures 

provides an added flexibility and mechanical integrity [4]. 

Electrospinning represents a simple and versatile method for 

preparing ceramic fibers in the nanoscale range [5]. 

In the preparation of BST precursor sol-gel solution 

barium acetate, strontium acetate and titanium isopropoxide 

were used as source materials. A mixture of acetic acid and 

2-methoxyethanol with 1:2 mix ratio was used as solvent. 

Poly(vinylpyrrolidone) (PVP) was used as the carrier 

polymer. The Ba:Sr molar ratio was 0.6:0.4 and the molarity 

of the final precursor solution was 0.27 M. Various PVP 

additions from 5 to 30 wt% were studied. The electric field 

during the electrospinning process was varied from 10 to 20 

kV/cm and the pumping rate from 1 to 5 l/h. 

Electrospun BST/polyvinylpyrrolidone (PVP) fibers were 

obtaind by calcination for 1 h at temperatures in the range of 

650–800ºC in air. The morphology and crystal structure of 

calcined BST/PVP nanofibers were characterized using 

SEM and XRD. Nanocomposites with 3-3 phase 

connectivity were prepared by infiltrating an epoxy matrix 

phase into the nanofiber mats. Dielectric properties of the 

BST/epoxy nanocomposites were evaluated for tunable 

microwave dielelectric applications. BST powders were 

also prepared by gelation and drying of BST precursor solgel 

solutions. Dried gels were then calcined, ground, pressed 

and sintered to obtain dense BST ceramics. Electrical 

properties of BST ceramics were determined through 

dielectric and PE hysteresis measurements. 

X-ray diffraction patterns presented in Fig. 1 for calcined 

BST powders indicate that a calcination temperature of 

700ºC was enough to obtain pure BST phase with perovskite 

structure. The scanning electron micrograph shown in Fig. 

2 indicates that nanofibers with diameters ranging from 50 

to 200 nm can be obtained without the formation of 

undesired beads. 

Figure 1. XRD pattern of BST powders calcined at 700ºC-1 h. 

Figure 2. SEM micrograph of the as deposited BST/PVP 

nanofibers. 

The dielectric constant of the bulk BST ceramic pellets 

were as high as 2000 with a dielectric loss of less than 2% 

measured at room temperature at 100 kHz. The polarization 

vs. electric field hysteresis loops indicates a ferroelectric 

behavior with a remnant polarization of 5 C/cm 2 and a 

coercive field of 15 kV/cm measured under an electric field 

of 50 kV/cm. 

*Corresponding author: sedal@gyte.edu.tr 

[1] K.V. Saravanan et al., Mater. Chem. Phy. 105, 426 (2007). 

[2] S. Maensiri et al., J. Colloid Interface Sci. 297, 578 (2006). 

[3] D.Y. Lee et al., J Sol-Gel Sci Technol 53, 43 (2010). 

[4] E.M Alkoy et al., J. Amer. Ceram. Soc. 92, 2566 (2009). 

[5] R. Ramaseshan et al., J. Appl. Phys. 102, 111101 (2007). 




Preparat ion of ZnO-CeO 2 ceramic nanofibers via a n electros pinning technique 

Didem Tascioglu 1 , Nesrin Horzu m Polat 1 , Mustafa M. Demir 1 * 

Department 

1 

Abstract-Mixed metal oxide fibers based on cerium oxide and zinc oxide were produced by combination of electrospinning and calcination 

processes. 

Porous ceramic materials are attractive materials that have 

found applications in sensors [1], filtration [2], catalysts [3, 

4], membrane and adsorption of liv ing cells for scaffolds in 

tissue engineering [5]. There are various ways to produce 

porous ceramic materials with high surface area; however, 

electrospinning appears to be the most convenient method 

among the others due to the following advantages. (i) high 

surface area from per unit volume of polymer (ii) ease of 

implementation. In a typical electrospinning process, a high 

potential difference is applied to a polymer solution droplet 

suspended at the tip of a needle of syringe. Charge is collects 

on surface of this droplet, and as the electrical potential 

overcomes the surface tension of the solution, the droplet 

continues and forms a Taylor cone. The solution ejected from 

the tip of the Taylor cone travels through the air to collector 

screen and collects as nonwoven fibers. 

This study is aimed to synthesize ZnO-CeO 2 ceramic 

nanofibers via the electrospinning and calcination processes. 

Counts/s 

500 

400 

300 

200 

100 

0 

(111) 

(100) 

(002) 

(200) 

(101) 

(220) 

(102) 

(311) 

(110) 

20 30 40 50 60 

CeO 2 

ZnO 

(103) 

(222) 

2 theta 

Figure 1. X-ray diffraction pattern of ZnO-CeO 2 composite 

fibers containing the 2.5:1 molar ratio and reference patterns of 

pure ZnO and CeO 2 . 

Figure 1 indicates the X-ray diffraction pattern of 

synthesized ZnO-CeO 2 ceramic nanofibers. All reflections 

are matched well with the reference patterns of hexagonal 

zinc oxide and face centered cubic ceria that means the 

calcined fibers are mixture of ZnO-CeO 2 crystals. 

Figure 2 presents SEM images of elecrospun fibers before 

and after calcination process. The fibers initially contain 

precursor salts (CeNO 3 ) 3 .6H 2 O and Zn(CH 3 COO) 2 .2H 2 O 

and PVA. The diameter of fibers is in range of 100-175 nm. 

Upon application of calcination process at 500 ºC, the 

diameter is reduced to 40-85 nm most probably due to the 

removal of polymeric component of the system. It has to be 

mentined here that the morphology of fibers remain 

unchanged, i.e. removal of organics does not lead to 

undesirable shape change. The sensor application of the 

resulting fibrous semiconductor material is ongoing. 

(a) 

(b) 

Percentage 

Percentage 

50 

40 

30 

20 

10 

50 

40 

30 

0 

0 

40 55 70 85 100 115 130 145 160 175 

Fiber Diameter (nm) 

20 

Calcination 

20 

10 

10 

0 

0 

40 55 70 85 100 115 130 145 160 175 

Fiber Diameter (nm) 

Figure 2. SEM micrographs and diameter distributions for (a) 

precursor fibers (the molar ratio of Zn:Ce is 2.5:1) (b) the 

calcined at 500ºC. 

*Corresponding author: mdemir@iyte.edu.tr 

[1] Songa, X., and Liub, Li. 2009. Characterization of electrospun 

ZnO–SnO 2 nanofibers for ethanol sensor. Sensors and Actuators A 

154 (pp. 175–179). 

[2] Yoon K., Kim K., Wang X. F., Fang D. F., Hsiao B.S., Chu B. 

2006. High flux ultrafiltration membranes based on electrospun 

nanofibrous PAN scaffolds and chitosan coating. Polymer, 47, (pp. 

2434–2441). 

[3] Demir M. M., Gulgun M. A., Menceloglu Y. Z.,Erman B., 

Abramchuk S. S., M akhaeva E. E. Khokhlov A. R., Matveeva V. G., 

Sulman M. G. 2004. Palladium nanoparticles by electrospinning 

from poly(acrylonitrile-co-acrylic acid)-PdCl 2 solutions. Relations 

between preparation conditions, particle size, and catalytic activity. 

Macromolecules, 37, (pp. 1787–1792). 

[4] Demir M. M., Ugur G., Gülgün M. A., Menceloglu Y.Z. 

2008. Glycidyl-methacrylate-based electrospun mats and catalytic 

silver nanoparticles. M acromolecular Chemistry and Physics, 209, 

508–515. 

[5] Nisbet D. R., Forsythe J. S., Shen W., Finkelstein D.I., 

Horne M. K. 2009. Review paper: A review of the cellular 

response on electrospun nanofibers for tissue engineering. Journal 

of Biomaterials Applications, 24,(pp. 7–29). 

50 

40 

30 

20 

10 

50 

40 

30 




Liquid Crystal Displays (LCD) Role in Different Aspects in Social Life 

Sönmez Arslan 1,2* ,Ömer Polat, 3 S.Eren San 4 , Selahattin Sönmezsoy 5 , Ramazan Kaynak 6 

1 Department of Materials Science Engineering, Nanotechnology Center,Gebze Institute of Technology, Kocaeli,41400, Turkey 

2 Department of Chemistry, Batman University, Batman ,72100, Turkey 

3 Department of Sience, Bahcesehir University, Istanbul, 34353, Turkey 

4 Organic Electronics Group, Department of Physics, Gebze Institute of Technology, Kocaeli,41400, Turkey 

5 Department of Sociology, Batman University, Batman ,72100, Turkey 

6 Department of Management,Gebze Institute of Technology, Kocaeli,41400, Turkey 

Abstract— 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 compared in terms of Energy, Information Technology ,Communication Technology, Environment, 

and Social Life. Advantages of LCDs were explained depending 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 LCDs 

have been observed in calculators and watches[1]. They had 

only black and white displays at that time. LCDs helped so 

much in daily life comparing with mechanical wristwatch and 

abacus in those years depending on that technology. LCDs 

important role in social life, starting to development beginning 

from primitive technology to Nanotechnology, have been 

increasing day by day. At present, LCDs are involved in 

human life in different aspects such as communication, 

information technologies, entertainment, cultural and artistic 

activities. 

a 

b 

Figure: a) Early wrist watch(1960s) b) Black-white LCD in watch 

In view of energy and usage, TV screens made of LCDs 

exhibit low energy consumption with respect to televisions 

produced by Cathode Ray Tube(CRT). This situation makes 

LCDs more advantages to televisions made of CRT. For 

instance, televisions made in small size with LCDs can be 

used with low voltage (around 10 Vs). So even a couple of 

batteries are capable of usage of LCD TV.[2] This case 

enables us to use TVs with LCDs in a wide range of places 

(without electrical sources) which we can never have this 

chance to use TVs with CRT. 

In point of information technologies, mobility feature of 

LCDs have shown in movable computers such as laptops. 

Low energy consumption concept, decrease in size and 

increase in mobility have made our life much easier by 

computers produced with LCDs such as laptops as mentioned 

above than desktop computers.[3] With the help of LCD 

technology improving of laptops, today, access to information 

and usage of laptops are possible in every single moment of 

daily life. 

Importance of LCDs in communication technology has 

outcome with progressing of mobile phones[4]. Before 

introducing mobile technology to our life, regular phones were 

playing partially role. Entering with mobile communication to 

our life, communication put into effect in every moment of 

daily life. Improvement of LCDs technology has been playing 

most important role in progressing of mobile phones. 

In point of environmental aspects of LCDs we see that:LCD 

does not emit that much of radiation compared to television 

with CRT. When we compare them regarding emitting 

radiation, radiation emitted with sight almost approaches to 

zero in LCDs which leads to positive effect on environmental 

pollution and human health. All displays with LCD like TV, 

computer compared to displays with CRT has been helping us 

in terms of environment and human health.[5] 

When we consider LCDs in view of social aspect, we can 

tell that they occupy important role. Starting from crowded 

entertainment places and shopping centers and places where 

offical services are served, on deck of ferries, at ports, on 

public and private transportations etc., by serving LCDs is an 

significant indicator of LCDs that they have played very 

effective role in social life. Besides, nanotechnology has 

brought a new perspective to advertising sector by introducing 

giant size of LCDs resuls in activity and new dimention in 

commercial life. 

To sum up, replacing TVs with CRT with LCD technology 

the world has started a new period considering energy saving, 

economy, environment and social communication. It is not 

difficult to say from now on that the role and impact of LCDs 

in our rotuine life will be more effective as nanothechnology 

develops and become a piece of our lives. 

*Corresponding author: arslanso@gyte.edu.tr , arslanso@hotmail.com 

[1] Castellano J. A. , Liquid Gold: The Story of Liquid Crystal Displays and 

the Creation of an Industry, World Scientific Publishing, 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, Newnes 

Publications, U.S.A. (2004)lic 

[4] D. Mentley, “Miniature display market and technology trends,” presented 

at the Flat Information Displays Conf., Monterey, CA, Dec. (1998) 

[5] M. L. Socolof , J.G. Overly, J.R. Geibig, Jrn. of Cleaner Production, 13, 

1281-1294, (2005) 




Tyrosinase-Fe 3 O 4 -Chitosan Nanobiocomposite Film for Biosensor Application 

 

1 and -Ozkan 1 * 

1 Izmir Institute of Technology, Chemical Engineering Department, Gulbahce Koyu, 35430- 

Abstract- Tyrosinase-Fe 3 O 4 -chitosan nanobiocomposite film was prepared in order to determine the pesticide residue as a biosensor 

application in the following research. The immobilized tyrosinase enzyme on the Fe 3 O 4 -chitosan nanocomposite prepared by coating of 

chitosan onto the Fe 3 O 4 nanoparticles was also characterized by the measurements of atomic force microscopy (AFM), Fourier transform 

infrared (FTIR) spectra, thermogravimetric analysis (TGA) and differential scanning calorimetric analysis (DSC). 

Contaminated pesticide residues for ground water, raw food 

materials and processed foods results form the application of 

organophosphate pesticides (OP) to increase the amount and 

quality of the product [1]. Reliable analytical procedures are 

required in order to determine the pesticide residue at low 

level. Spectrophotometric and chromatographic techniques 

are analytical methods commonly used [2]. These methods 

have a number of disadvantages such as expensive 

instrumentation requirement, highly trained personnel, time 

consumption, and difficulties in adaptation for field analysis. 

In recent years enzyme electrodes show remarkable 

advances for the detection of toxic compounds based on 

enzymatic reactions. Tyrosinase enzyme is one of the 

appropriate enzymes to detect the pesticide residue depending 

on the inhibition mechanism directly related to decrease in 

the amount of enzymatically produced quinones while 

substrate (catechol) is consumed [3] as shown in Figure 1. 

Figure 2. The illustration of tyrosinase immobilized on Fe 3 O 4 - 

chitosan nanocomposite 

The morphology of the (a) Fe 3 O 4 nanoparticles, (b) 

chitosan film, (c) Fe 3 O 4 nanoparticle-chitosan and (d) 

tyrosinase-Fe 3 O 4 -chitosan nanobiocomposite films were 

characterized with AFM. The binding mechanism of each 

material was characterized by using FTIR spectra. TGA and 

DSC were performed to reveal the formation of 

nanobiocomposite material. 

Corresponding author: 0Tfehimeozkan@iyte.edu.tr 

Figure 1. Basic reaction mechanism of tyrosinase on catecol 

The effective immobilization of tyrosinase on the electrode 

surface is the key issues for the development of tyrosinase 

biosensors. The immobilization methods can be classified as 

chemical (covalent cross-linking and covalent binding) and 

physical (physical entrapment, micro encapsulation, and 

adsorption) methods [4]. In recent years magnetic 

nanoparticles are becoming the focus of researchers due to 

lots of properties. Especially Fe 3 O 4 has significant properties 

such as strong superparamagnetism, low toxicity and large 

surface area provides high enzyme loading [5]. However this 

nanoparticle tends to aggregate and therefore stabilizers such 

as surfactants, metal nanoparticles and polymeric compounds 

have been used. As a natural polymer, chitosan has the 

characteristic of biodegradable, biocompatible, bioactive, 

nontoxic, film forming ability, physiological inertness and 

high mechanical strength [6]. 

In this study, Fe3O 4 -chitosan nanocomposite was prepared 

to immobilize the tyrosinase enzyme on it. This 

nanobiomaterial was characterized for the development of 

tyrosinase biosensor used in determination of pesticide 

residue as the future work. 

For this aim tyrosinase solution was prepared in phosphate 

buffer solution (PBS) at pH 6.5. Acetic acid was used for the 

preparation of chitosan solution. The Fe 3O 4 nanoparticle 

suspensions was prepared by dispersing the particle in double 

distilled water with ultrasonication. Then tyrosinase 

solutions, chitosan solutions and Fe 3 O 4 nanoparticles were 

mixed with a specific volume ratio in order to obtain 

tyrosinase-Fe 3 O 4 -chitosan nanobiocomposite film (Figure 2). 

[1] Ingrid Walz I., Schwack W., 2007. Cutinase inhibition by 

means of insecticidal organophosphates and carbamates Part 1: 

Basics in development of a new enzyme assay, Eur. Food. Res. 

Technol., 225: 593-601. 

[2] Poerschmann, J., Zhang, Z., Kopinke, F.D., Pawliszyn, J., 

1997. Solid Phase Microextraction for Determining the 

Distribution of Chemicals in Aqueous Matrixes, Anal. Chem., 69: 

597–600 

[3] Munoz J.L.-Molina F., Varon R., Rodriguez-Lopez 

-Canovas F., Tudela J., 2008 Calculating molar 

absorptivities for quinones: Application to the measurement of 

tyrosinase activity, J. Comput. Aided Mol. Des., 22: 299-309. 

[4] Buerk D.G., 1993. Biosensors; Theory and Applications. 

U.S.A. 

[5] Gu, H. W.; Xu, K. M.; Xu, C. J.; Xu, B., 2006. Biofunctional 

Magnetic Nanoparticles for Protein Separation and Pathogen 

Detection, Chem. Commun., 941-949. 

[6]Barbara K. , 2004. Application of chitin- and chitosan-based 

materials for enzyme immobilizations: a review, Enzyme and 

Microbial Technology, 35: 126–139 

. 



Hydrothermal synthesis of indium tin oxide for transparent and reflective thin films 

Meltem Asiltürk a, * , Esin Burunkaya b,c , Nadir Kiraz b,c , Ömer Kesmez b,c , Ertuğrul Arpaç b,c 

a Inonu University, Department of Chemistry, Malatya, Turkey 

b Akdeniz University, Department of Chemistry, Antalya, Turkey 

c NANOen R&D Ltd, Antalya, Turkey 


Abstract- Indium tin oxide (ITO) used as optical material with high refractive index was hydrothermally synthesized 

from a mixture of indium(III) chloride and tin(IV) chloride. Surface of the ITO particles was modified with different 

modifying agents used as a copolymer for coatings and then, thin films of surface modified ITO nanoparticles was 

deposited on glass and silicon-wafers by the spin-coating method. It was found that particle size of ITO powder is 

finer than 10 nm and particles have high transmittance in visible region but it has low transmittance in infrared 

region. Surface of ITO particles can easily modify a ligand, and thus it can use in applications of thin film. Thickness 

of films is about 515 nm. Refractive index of films is 1.7-1.8. 

Indium tin oxide (ITO) is an advanced ceramic 

material with many electronic and optical applications 

due to its excellent properties of high conductivity (104 

-1 cm -1 ) and high transparency (85–90%) to visible 

light [1, 2]. For many applications, especially in 

microelectronics and optoelectronics, with optical and 

IR-blocking coatings, it is important to use ITO 

powders comprising nanoscale particles. The high 

electrical property is originated from the creation of a 

conducting carrier–oxygen vacancy with the addition 

of dopant (Sn 4+ ) to the matrix (In 2 O 3 ). The oxygen 

vacancies act as doubly ionized donors and contribute 

at a maximum two electrons to the electrical 

conductivity. In 2 O 3 exists in two different 

crystallographic structures, i.e. rhombohedra and cubic 

forms. High electrical conductivity is normally 

achieved by the stabilization of the cubic phase [3–5]. 

For this reason, there are very large numbers of 

possible uses for indium tin oxide systems, and, 

accordingly, there have also been a very large number 

of investigations into their preparation. 

For many applications, especially in microelectronics 

and optoelectronics, with optical and IR-blocking 

coatings it is important to use ITO powders comprising 

nanoscale particles. Such nanoscale particles have an 

average particle size of preferably from 5 to 30 nm. 

Many techniques such as solvothermal, microemulsion, 

sol-gel, coprecipitation, and hydrothermal method have 

been used to prepare nanocrystalline ITO powders [6- 

11]. Among these chemical techniques, the main 

advantages of hydrothermal synthesis are related to 

homogeneous nucleation processes, ascribed to 

elimination of the calcinations step to produce very low 

grain sizes and high purity powders [12]. 

In this work, we prepared ITO powders without 

additional heat treatment after the hydrothermal 

synthesis. Prior to the surface modification, ITO sol 

was prepared without using dispersant in ethanol and 

then, surface of ITO particles was modified different 

chemical compounds. With the coating solutions which 

have modified ITO particles, we coated glass substrate 

and Si-wafers by spin coating method. 

The results showed that ITO powders were well 

crystallized. They have dominant cubic crystalline 

structure. The particle size of ITO powder is < 10 nm. 

ITO particles have high transmittance in visible region 

but it has low transmittance in infrared region. Surface 

of ITO powders can easily modify a ligand, and thus it 

can use in applications of thin film. Thickness of films 

is about 515 nm. Refractive index of films is 1.7-1.8. 

Figure 1. TEM micrograph of ITO nanoparticles 

This study was financially supported by TÜBİTAK (Turkey) 

as a research projects with grand no 107M253. 

* masilturk@inonu.edu.tr 

[1] J.H. Hwang, D.D. Edward, D.R. Kammler and T.O. 

Mason, Solid State Ionics, 129 (2000), 135–144. 

[2] C. P. Udawatte and K. Yanagisawa, J. Solid State Chem., 

154 (2000), 444–450. 

[3] P. S. Devi, M. Chatterjee, and D. Ganguli, Mater. Lett., 

55 (2002), 205-210. 

[4] N. Nadaud, N. Legueux and M. Nanot, J. Solid State 

Chem., 135 (1998), 140-148. 

[5] N. C. Pramanik, S. Das and P. K. Biswas, Mater. Lett., 56 

(2002), 671-679. 

[6] J.S. Lee, S.C. Choi, J. Eur. Ceram. Soc. 25 (2005) 3307- 

3314. 

[7] M-K. Jeon, M. Kang, Mater. Lett., 62 (2008), 676-682. 

[8] D.H. Lee, Y.J. Chang, G.S. Herman, C.H. Chang, Adv. 

Mater., 19 (2007) 843-847. 

[9] C. Goebbert, R. Nonninger, M.A. Aegerter, H. Schmidt, 

Thin Solid Films, 351 (1999), 79-84. 

[10] J. E. Song, D.K. Lee, H.W. Kim, Y. II. Kim, Y.S. Kang, 

Coll. Sur. A, 257-258 (2005), 539-542. 

[11] K. Yanagısawa, C. P. Udawatte, J. Mater. Res., 15(6) 

(2000), 1404-1408. 

[12] F. Sayilkan, M. Asilturk, S. Erdemoglu, M. Akarsu, H. 

Sayilkan, M. Erdemoglu, E. Arpac, Mater. Lett., 60(2) 

(2006), 230-235. 




Synthesis of Silver Nanoparticles Using Reverse Micelle System 

Leyla Budama*, Burçin Acar, Önder Topel, Numan Hoda 

Akdeniz University Department of Chemistry, Antalya-Turkey 

Abstract-In this study, silver nanoparticles were synthesized using reverse micelles of polystyrene-block-polyacrylic acid as 

nanoreactor. Reduction of silver ions to Ag 0 was performed by NaBH 4 . Formation of nanoparticles was confirmed by UV-vis 

spectrophotometer and transmission electron microscope. 

Nanoparticles have attracted considerable and increasing 

attention in the academic research area and industry last 

few decades. Because of the novel physical and chemical 

properties different from bulk systems, nanoparticles are 

used in a variety of material science and engineering such 

as optics, electronics, magnetic media and catalysis [1-6]. 

Among various metal nanoparticles silver nanoparticles 

are of special interest due to their unique optical and 

electrical properties, as well as for their potential 

biomedical applications [7-9]. Many strategies have been 

developed for the preparation of silver nanoparticles, 

including micro emulsion techniques [10], organic-water 

two phase synthesis [11], and aqueous solution reduction 

[12–14]. 

In this present research, silver nanoparticles were 

produced using reverse micelle as nanoreactor. 

Polystyrene-block-polyacrylic acid (PS-b-PAA) 

copolymer used as reverse micelle forming agent in 

organic solvent. PS block forms corona and PAA block 

forms core of the micelle. Firstly, copolymer was 

synthesized by ATRP and characterized NMR and GPC. 

After dissolving copolymer in toluene, AgNO 3 was added 

to solution as nanoparticle precursor. When AgNO 3 was 

reduced to Ag 0 by adding NaBH 4 , colour of the solution 

turned to brown-yellow confirming the formation of Ag 

nanoparticles. UV-vis spectrum of solution has shown 

characteristic absorption peak between 400-450 nm 

illustrated in Figure 1. After a drop of solution was cast on 

carbon coated cupper grid and solvent was evaporated, 

film was analyzed by TEM. Figure 2 shows TEM image of 

Ag nanoparticles. The mean diameter of nanoparticles is 

12(3) nm. This work was supported by TUBITAK under 

the Grant No. TBAG-108T806. 

Figure 1. UV-vis spectrum of Ag nanoparticles in PS-b-PAA 

micelles. 

Figure 2. TEM image of Ag nanoparticles. 

*Corresponding Author: leylabudama@akdeniz.edu.tr 

[1] Y.G. Sun, Y. N. Xia, Science 298, 2176-2179 (2002) 

[2] T. S. Ahmadi, Z. L. Wang, T. C. Green, A. Henglein, M. A. 

El-Sayed, Science 272, 1924-1926 (1996) 

[3] T. K. Sau, C. J. Murphy, J. Am. Chem. Soc. 126, 8648-8649 

(2004) 

[4] T. Sakai, P. Alexandridis, Chem. Mater. 18, 2577-2583 

(2006) 

[5] Y. -S. Shon, E. Cutler, Langmuir 20, 6626-6630 (2004) 

[6] T. Linnert, P. Mulvaney, A. Henglein, H. Weller, J. Am. 

Chem. Soc. 112, 4657-4664 (1990) 

[7] M. Lessard-Viger, M. Rioux, L. Rainville, D. Boudreau 

Nano Lett. 9, 3066 (2009) 

[8] A. C. Templeton, D. E. Cliffel, R. W. Murray J. Am. Chem. 

Soc. 121, 7081 (1999) 

[9] D. D. Evanoff, G. Chumanov, Chem. Phys. Chem. 6, 1221 

(2005) 

[10] L. Motte, M. P. Pileni, Influence of length of alkyl chains 

used to passivate silver sulfide nanoparticles on two- and threedimensional 

self-organization. J Phys Chem, B 102(21):4104–9 

(1998) 

[11] B. A. Korgel et al. Assembly and self-organization of silver 

nanocrystal superlattices: ordered "soft spheres". J Phys Chem, B 

102(43): 8379–88 (1998) 

[12] P. C. Lee, D. Miesel, Adsorption and surface-enhanced 

raman of dyes on silver and gold sols. J Phys Chem 86:3 391–5 

(1982) 

[13] L. Rivas et al. Growth of silver colloidal particles obtained 

by citrate reduction to increase the Raman enhancement factor. 

Langmuir 17(3): 574–7 (2001) 

[14] T. Yonezawa, S-Y Onoue, N. Kimizuka Preparation of 

highly positively charged silver nanoballs and their stability. 

Langmuir 16(12): 5218–20 (2000) 




Smart Fe rrogels in Drug Delivery Systems: Preparat ion and Characterizat ion 

1 * 1 

Istanbul University, Engineering Faculty, Chemistry Department, , Istanbul 

1 

Abstract- In this study gelatin/acrylic acid ferrogels were carried out by focusing its application on drug delivery. These ferrogels consist of 

a magnetic core and polymers shell. Enarofril Maleat was chosen as a model drug and gelatin /acrilic acid was also chosen as shell materials 

due to their compatibility and nontoxicity. The core of the ferrogel was fabricated by using Fe(II) and Fe (III) ions. The results indicated that 

the blended gels was more effective than crosslinked gels to drug delivery in this work. The ferrogel can lead to a succesful application for 

drug loaded and controlled release systems. The drug release rate can be controlled through changing the magnetic field strength. 

Nowadys there has been intensively research on the 

magnetic biodegradable polymer gels as they are subjected to 

drug delivery studies [1]. Gelatin, biopolymer has important 

place in varies industries such as medicine, pharmaceutics, 

textile industry and paper industry. Gelatin can be obtained 

from the nature abundantly. It can be biologically 

degradation and has nontoxic nature with the excellent 

physical and chemical properties [2,3]. 

at 228 nm. Figure 2, Figure 3 and Figure 4 show the 

comparative studies of the swelling behavior, drug loaded 

and drug release. 

S welling (% ) 

12000 

10000 

8000 

6000 

4000 

2000 

In drug s oln, in 

magnetic field at 22 °C 

In drug s oln at 37 °C 

In drug s oln at 22 °C 

in dis till water,22 °C 

0 

0 30 60 90 120 150 180 210 240 270 


Figure 2.Swelling rate of ferrogel in different condition 

1.2 

1 

Figure 1. Chemical structures of enalapril maleate, enalaprilat and 

diketopiperazine derivative. 

Drug loading 

0.8 

0.6 

0.4 

0.2 

0 

In magnetic field at 22 °C 

37 °C 

22 °C 

0 30 60 90 120 150 180 210 240 270 


Smart ferrogels were prepared by coprecipitating Fe(II)/ Fe 

(III) (1/2)(w/w) ions in 150 ml solution by 25% ammonia 

solution. The precipitates were washed several times with 

distilled water. The mixtu re of gelatin/acrylic acid was also 

prepared by mixing 2 % homogenous gelatin solution with 

3.4 ml acrylic acid. The ferrous/ferric nanoparticles were 

added into this solution by vigirous stirring. Finally the 

magnetic hydrogel was dried out in the hood at room 

temperature for 2 days. The surface morphology of the 

hydrogel was observed by using scanning electron 

microscope (SEM) and magnetic properties of the samples 

were characterized by magnetometer. The characterization of 

the hydrogels was analysed by Fourier transform infrared 

spectrscopy (FTIR). 

The gels were immersed in the distilled water and Enarofril 

Maleat solution (1% w) at 22 °C and 37°C to obtain the 

swelling ratio. The experiments were repeated by applying a 

magnetic field. The swelling ratio of gelatin/acrylic acid 

ferrogels was calculated from the following equation: 

SR= (W s -W d )/W d 

Where W s , W d is the weight of hydrogel swollen to 

equilibriu m and the weight of the dried hydrogel, 

respectively. 

The crosslinked ferrogels were also prepared by using the 

same pocedure mentioned above. Gluteraldehyde was used as 

crosslinker. The amount of Enarofril Maleat released from the 

drug loaded ferrogels were found by UV spectrophotometer 

Figure 3. Drug loading on ferrogel in different condition 

Drug release 

0.25 

0.2 

0.15 

0.1 

0.05 

In magnetic field at 22 °C 

37 °C 

22 °C 

0 

0 50 100 150 200 250 300 


Figure 4. Drug release in different condition 

Maximum swelling capacity of the gels was obtained at 37 °C 

and applying magnetic field increases the amount of swelling of the 

gel at 22 °C. Drug release can be controlled by changing magnetic 

field strength in this system. 

*Corresponding author: 1Taylin_yalcin07@hotmail.com 

[1] B. Gaihre, M. S. Khil, H. Kyoung Kang, H. Y. Kim, J Mater Sci: 

Mater Med 20, 573–581 (2009) 

[2] T.Y. Liua, S.H. Hua, KK.H. Liua, D.M. Liub, S.Y. Chena, J 

Magnet and Magn Mater. 304, 397–399 (2006). 

[3]P. Bertoglio, S. E. Jacobo, M. E Daraio J Appl Polym. 115, 

1859-1865 (2010). 




Performance of Silver Doped PEDOT Polymer Film as a SERS Substrate 

Üzeyir Doğan, 1* Murat Kaya, 1 Atilla Cihaner 2 and Mürvet Volkan 1 

1 Department of Chemistry, Middle East Technical University, Ankara, Turkey 

2 Department of Materials Engineering, Atılım University, Ankara, Turkey 

Abstract - A new and simple polymer substrate for inducing Surface Enhanced Raman Scattering (SERS) has been 

investigated. This new SERS substrate consists of an ITO slide as a solid support electrochemically covered with poly (3,4 

ethylenedioxythiophene) (PEDOT) and fine silver particles. 

Raman spectroscopy is an analytical technique that is 

widely used to characterize chemical substances in samples 

[1] because of having different signal patterns for different 

Raman active substances. However, the sensitivity of the 

technique is very low. Surface enhanced Raman scattering 

(SERS) overcomes this disadvantage of Raman 

spectroscopy. A major factor in the large enhancement 

associated with SERS is the strong electromagnetic field 

enhancement close to the surface produced by surface 

plasmons, which are the result of the coupled oscillations of 

the conductance electrons of metals and the electromagnetic 

field component of the incident light [2,3]. When an analyte 

is brought into contact with nanoparticles of metals such as 

silver [4] or gold [5] the strong field enhances the Raman 

effect. 

Conducting polymers have a wide range of applications 

in the field of optical, electronic, electro-chromic devices, 

and sensors etc. Among them, poly (3,4 

ethylenedioxythiophene) (PEDOT) (Figure 1) is considered 

to be a good applicant for its regioregular polymerization, 

low bandgap, stability and optical transparency. The recent 

technological interests are in the synthesis of conducting 

polymers incorporated with metal nanoparticles for varied 

applications. Conducting polymers are widely employed as 

support materials for dispersing the metal particles [6]. 

Figure 2. Raman spectrum of 10 -7 M BCB 

Additionally, the homogeneity of the surface in terms of 

its SERS activity (Figure 3) and shelf life of the substrates 

were examined. 

Figure 3. Raman spectrum of 10 -7 M BCB at different points on the 

same substrate. 

Figure 1. Poly(3,4-ethylenedioxythiophene) or PEDOT 

In this study, we investigated a new SERS active 

substrate using electrochemical method. Briefly, the surface 

of indium tin oxide (ITO) coated glass surface covered 

with variable amounts of PEDOT polymer and doped with 

variable amounts of silver nanoparticles. The effects of 

several experimental conditions of preparation were 

investigated using low concentrations of brilliant cresyl blue 

(BCB). Figure2 shows the characteristic SERS signal of 10 -7 

M BCB acquired with the prepared substrate. The spectral 

evaluations of this compound closely matched with those 

reported in literature. 

* murvet@metu.edu.tr 

[1] Smith, E., Dent, G., 2005. Modern Raman spectroscopy. A 

practical approach. Wiley, England 

[2] Raether, H., 1988. Surface Plasmons. Springer-Verlag, Berlin 

[3] Schatz, G-C., Van Duyne, R.P., 2002. Handbook of Vibrational 

Spectroscopy. Wiley, Chichester 

[4] Li, S-Y., Cheng, J., Chung, K-T,. 2008. Surface-enhanced 

Raman spectroscopy using silver nanoparticles on a precoated 

microscope slide, Spectrochimica Acta, Part A 69: 524–527 

[5] Joo, S-W., 2004. Surface-enhanced Raman scattering of 4,4- 

bipyridine on gold nanoparticle surfaces, Vibrational 

Spectroscopy, 34: 269–272 

[6] S. Harish , J. Mathiyarasu , K. L. N. , V. YegnaramanJ Appl 

Electrochem (2008) 38:1583–1588 




Preparation and Characterization of Zn-Rice Husk Char 

Esra Alt intig 1 * 

1 Department of Chemistry, Sakarya University, Sakarya 54180, Turkey 

Abstract- In this study, rice husk was used as precursor for the preparation of activated carbon by chemical activation with ZnCl 2 . Rice husk 

charcoal supporting zinc (RH/Zn) was prepared by activation and chemical reduction. The RH/Zn composites were characterized by FTIR, 

XRD, EDS, zinc particle size and distribution, zin ion (Zn +2 ). Scanning electron microscopy (SEM) showed that the Z n particles were 

distributed uniformly on the RH matrix. The Zn content and surface morphology of the RH/Zn composites depended on the initial concentration 

of ZnNO 3 , and the higher the Zn content, the smaller the specific surface area obtained on the RH. 

Rice is one of the major crops grown throughout the world, 

sharing equal importance with wheat as the principal staple 

food and a provider of nourishment for the world's population 

Concern about environmental protection has aroused over the 

years from a global viewpoint. Rice husk ash, the most 

appropriate representative of the high ash biomass waste, is 

currently obtaining sufficient attraction, owning to its wide 

usefulness and potentiality in environmental conservation. [1]. 

Activated carbons are produced through physical or 

chemical activation. Chemical activation can be accomplished 

in a single step by carrying out thermal decomposition of raw 

material with chemical reagents. The most widely used 

chemicals include zinc chloride (ZnCl 2 ), phosphoric acid 

(H 3 PO 4 ), and potassium hydroxide/carbonate (KOH/K 2 CO 3 ) 

[2]. 

In this study, rice husk was used as precursor for the 

preparation of activated carbon by chemical activation and 

Zn-RH active carbon was prepared by exchanging Na ions 

with Zn ions in active carbon. 

90 

%T 

80 

70 

water bath maintained at 60 o C for one week. NaCl solution 

was replaced every day. This sample was washed with 

deionized water several times and dried in oven at 110 o C. In 

ion exchange study, Zn(NO 3 ) 2 .5H 2 O was used as a cation 

source. The experiments were conducted by treating Na-RH 

with a series of solutions at 0.1 N containing different 

proportions of two com peting cations in polyethylene bottles 

placed in a shaker at 25 o C for 2 days [3]. The masses of RH 

were varied between 0.1 and 1 g, whereas the solution 

volumes were changed from 5 to 25 ml to ensure evenly 

distributed data along the ion exchange isotherm. Solid and 

solution phases were separated by centrifuging at 4000 rpm. 

Initial and final concentrations of the exchanging zinc and 

sodium were determined. In addition, FTIR (Fourier 

Transform Infrared Spectroscopy), X-ray diffraction (XRD), 

and element analysis (EDS), The Brunauer Emmett Teller 

specific surface area (S BET ) studied the chemical 

characteristics of RH and Zn-RH char particles. 

In summary, we showed that an efficient Rice husk 

supporting zinc was prepared by activation and chemical 

reduction. The RH/Zn structures were characterized by zinc 

particle size. Distribution and morphology of nanoparticles 

have been characterized using FTIR, XRD, SBET . Scanning 

electron microscopy (SEM) showed that the Zn particles were 

distributed uniformly on the RH matrix. Rice husk carbon is 

thus potential alternatives to commercially available activated 

carbon as they have high selectivity and are efficient with low 

production costs. 

*Corresponding author: altintig@sakarya.edu.tr 

4000 

FTIR 

3500 

3000 

2500 

Figure 1. FTIR Spectrum of RH active carbon. 

2000 

1750 

1500 

1250 

1000 

750 

1/cm 

Table 1. The elemental analysis results of Zn-RH active carbon 

El t. Line Intensity Error Conc Units 

(c/s) 2-sig 

C Ka 165.21 8.127 57.222 wt.% 

O Ka 78.35 5.596 30.754 wt.% 

Na Ka 14.08 2.373 0.803 wt.% 

Si Ka 136.03 7.374 3.782 wt.% 

Cl Ka 5.92 1.539 0.178 wt.% 

Fe Ka 3.40 1.166 0.247 wt.% 

Zn Ka 18.87 2.747 7.013 wt.% 

[1] Fooa, K.,Y. and Hameed, B., H., 2009. Utilization of rice husk 

ash as novel adsorbent: A judicious recycling of the colloidal 

agricultural waste, Advances in Colloid and Interface Science, 152: 

39-47. 

[2] Ucar, S., Erdem , M., Tay, T., Karagoz, S., 2009. Preparation and 

characterization of activated carbon produced from pomegranate 

seeds by ZnCl 2 activation, Applied Surface Science, 255: 8890–8896. 

[3] Top, A., Ulku, S., 2004, Silver, zinc, and copper exchange in a 

Na-clinop tilolite and resulting effect on antibacterial activity, Applied 

Clay Science, 27: 13– 19. 

We first prepare the active carbon from rice husk. The rice 

husk powder was prepared though a carbonization treatment at 

700 °C. Prior to surface modification, the husk were grinded 

and then sieved into a desired particle size of 10-40μm. Then 

RH Powder was prepared by stirring NaCl solution at 500 rpm 

in a 2000-ml closed beaker placed in a constant temperature 




The investigation of structural, electronic and mechanical prope rties of LiPt 3 B: first-principles study 

Sezgin A 1 * 1 

1 Department of Physics, Gazi University, Teknikokullar, 06500, Ankara, TURKEY 

Abstract- The structural, electronic and mechanical properties of LiPt 3 B compound have been investigated by using first-principles within 

plane-wave density functional theory. The behaviors of the structural parameters under pressure are studied. It is shown from calculated 

density of states, partial density of states and band structure that this compound exhibits metallic character. By means of calculated elastic 

constants, mechanical stability of LiPt 3 B is investigated. However, micro-hardness of the compound is calculated by using the parameters 

obtained from first-principles. 

Since the discovery of superconductivity in MgB 2 [1], 

searching new superconducting materials composed of light 

elements and transition metals have attracted considerable 

interest [2]. In this context, it was found that some lithium 

ternary borides such as LiBC [3,4], Li 2 Pt 3 B [5,6], Li 2 Pd 3 B 

[5,6] are superconductor. Therefore, in this study, the 

structural, electronic and mechanical properties of LiPt 3 B 

were investigated. 

Crystal structure of LiPt 3B is shown in Fig.1(a) and (b) [7]. 

There are three boron, three lithium and nine platinum atoms 

in the unit cell. Space group is P-62m (No:189). As a special 

interest, the unit cell consists of lithiu m atoms and Pt 6 B 

triangular prisms (see Fig1.b). 

Figure 1. (a) Crystal structure of LiPt 3 B and (b) its Pt 6 B sub-unit. 

Pink, purple and blue spheres stand for boron, lithium and platinum 

atoms, respectively. 

By mean of first-principle calculation within density functional 

theory, lattice parameters, band structure and elastic constants were 

calculated. It was found that a=9.284Å and c=2.784Å, and these 

values are in good agreement in the Ref.[7]. Calculated band 

structure were plotted in Fig.2 and from this figure, LiPt 3 B 

has a metallic character. 

Table 1. Calculated single crystal elastic constants in GPa unit and 

mechanical properties such as bulk modulus, shear modulus, Young 

modulus and Poisson ratio. V and R subscript stand for Voigt and 

Reuss. 

c 286.385 

11 

c 410.897 

33 

c 35.629 

44 

c 146.741 

12 

c 120.366 

13 

c 69.822 

66 

B 195.401 

V 

B 192.634 

R 

G 67.962 

V 

G R 53.968 

G (GPa) 60.965 

B (GPa) 194.018 

E (GPa) 125.016 

v 0.158 

It is shown that due to calculated elastic constants of 

LiPt 3 B satisfy mechanical stability conditions, it is 

mechanically stable. 

Furthermore, microhardness of LiPt 3B was calculated by 

using Simunek’s method [8,9].and was found as 15.74 GPa. 

Individual bond hardnesses were tabulated in Table 2. From 

Table 2, strengths of Pt-B bonds are higher than that of Pt- 

Pt bonds. Other word, hybridization between Pt and B 

atoms are stronger than that of between Pt and Pt atoms, 

and as a result of this tendency, Pt-B bonds are more 

dominant than Pt-Pt bonds on the mechanical properties. 

Table 2. Individual bond strengths and total hardness for LiPt 3 B. 

Zi Zj Ri Rj ni nj dij ei ej Sij Bond H 

10 3 1.387 0.98 2 6 2.148 7.210 3.061 0.182 Pt-B 15.74 

10 10 1.387 1.387 10 9 2.805 7.210 7.210 0.029 Pt-Pt 

In conclusion, LiPt 3 B has metallic character. It is 

mechanically stable, but it is not a superhard material. Pt-B 

bonds are stronger than Pt-Pt bonds. 

This work is supported by the State of Planning 

Organization of Turkey under Grant No. 2001K120590. 

*Corresponding author: sezginaydin@gazi.edu.tr 

Figure 2. Calculated band structure along high symmetry 

directions in the first Brillouin zone for LiPt 3 B. 

Calculated single crystal elastic constants were listed in 

Table I with other mechanical properties. 

[1] J. Nagamatsu, N. Nakagawa, T.Muranaka, Y. Zenitani, J. 

Akimitsu, Nature 410, 63–64 (2001) 

[2] Physica C 460–462, 89–90 (2007) 

[3] H. Rosner, A. Kitaigorodsky, and W. E. Pickett, 

Phys.Rev.Lett. 88, 127001 (2003) 

[4] Z.Liu, X.Chen, Y.Wang, Physica B 381, 139-143 (2006) 

[5] U. Eibenstein and W.Jung, Journal Of Solid State Chemistry 

133, 21-24 (1997) 

[6] H. Takeya et al., Physica C 445–448, 484–487 (2006) 

[7] R.Mirgel, J.Wung, J.Less-Common Met.144, 87-99 (1988) 

[8] A.simunek, J.Vackar, Phys.Rev.Lett. 96, 085501 (2006) 

[9] A.Simunek, Phys.Rev.B 75, 172108 (2007) 




UV-Vis Spectra and Fluorescence Properties of CdSe Nanocrystals 

N. Atmaca 1 , M. R. Karim 1 , N. Yavarinia 1 ,H. Ünlü 1 * 

1 Istanbul Technical University, Department of Physics, Maslak 34469, Istanbul, Turkey 

Abstract-CdSe quantum dots have been synthesized from a solution including cadmium acetate, oleic acid, diphenyl ether and trioctylphosphine, 

selenide heated under stirring and argon flow. Optical absorption and fluoresence spectra were used to characterize the optical properties of CdSe 

quantum dots. We found t hat the absorption and emission peaks shifts to higher wavelengths as temperature increases. 

Semiconductor quantum dots are tiny clusters of 

semiconductor material, fabricated length scales between 

nanometers and a few microns. Quantum dots (QDs) are 

important because of their power to emit a particular wave 

length.Also the size and shape of these structures can be 

completely controlled. QDs can be used to make optical 

devices such as photo detectors[1] and emitters[2] to be used 

for quantum computing applications[3,4], 

nanoelectronics[5,6], and biological applications[7]. 

Cadmium acetate and oleic acid were dissolved with 

diphenyl ether in three neck flask. The mixture was heated 

140 0 C under stirring and continuous argon flow.When 

temperature rised to 140 °C, we waited for one hour. Then 

the mixture was cooled to 70 °C. After then 

trioctylphosphine- selenide solution having 200 °C 

temperature under the vacuum was added to mixture and 

heated to 110-140 °C. Samples were taken to tubes for 1, 5, 

10, 15, 20, 25, 30 minutes. After samples cooling to room 

temperature, centrifuged them to remove excess insoluable 

organics and salts that may have formed during the reaction. 

A precipitation using hexane as the solvents and methanol as 

the nonsolvent is repeated three times to narrow the size 

distribution and remove excess organics. The reaction 

process was monitored by UV-Vis absorption and 

fluorescence spectra as a function of time and temperature. 

Fluorescence intensity (a.u.) 

50 

45 

40 

35 

30 

25 

20 

15 

10 

5 

140 0 C 

0 

440 450 460 470 480 490 500 510 520 530 540 550 


Figure 2. Fluorescence emission spectra of CdSe QDs at 20 min. At 

different temperatures. 

In conclusion, both the emission and absorption peaks 

increase with increasing temperatures due to the increasing 

particle size. 

The authors would like to acknowledge the financial 

support provided by TUBITAK under Grant No.TBAG- 

105T463. 

110 0 C 

120 0 C 

130 0 C 

1.8 

Absorbance (a.u.) 

1.6 

1.4 

1.2 

1 

0.8 

0.6 

0.4 

0.2 

130 0 C 

0 

380 400 420 440 460 480 500 520 540 


110 0 C 

. 

Figure 1. Absorption spectra of CdSe QDs at 1 min. at different 

temperatures. 

120 0 C 

140 0 C 

*Corresponding author: 0Thunlu@itu.edu.tr 

[1] L. W. Ji and at all, Solid State Electronics 47, 1753-1756 

(2003). 

[2] S.Coe and at all,Nature,420, 800-803 (2002). 

[3]X.Li and at all,Sience. 301, 809-811 (2003) 

[4] E.Biolatti and at all, Phys. Rev. Letter,85, 5647-5650 (2000). 

[5]I.Amlani and at all,Sience. 284, 289-291 (1999) 

[6]M.Girlanda and at all, Applied Phys.Letter. 75, 3198-3200 

(1999) 

[7]P.Alivisatos,Nature Biotechnology. 22, 47-52(2004) 

Figure 1 showed that the absorption peaks for 1 min. of 

CdSe quantumdots samples at 110 °C, 120 °C, 130 °C, 

140 °C) were 424, 446, 464 and 476 n m respectively. Figure 

2 also showed that the emission peaks of fluoresence spectra 

for 20 min. of CdSe QD samples at those temperatures were 

488, 490, 506 and 516 n m respectively. These two results 

had some differences, because peaks not only depend on 

temperature but also on time. Those results had same 

characteristics i.e. peaks increased with increasing 

temperature. 


P 

P 

P 

P , 

P 



Structural and Electrical Properties of Ru Doped ZnO Film Fabricated by Sol-Gel Technique and 

using for Gas Sensing 

1 

,1 

1 

1 

UMurat BektasUP P*, M.ErolP P, O. SancakogluP P, M. F. EbeoglugilP H. SözbilenP 

3P, Ömer Mermer 2,3 

1,2 

P, and Erdal CelikP 

1 

PDokuz Eylul University, Department of Metallurgical and Materials Engineering, Tınaztepe 35160 Izmir-TURKEY. 

PDokuz Eylul University, Center for Fabrication and Application of Electronic Materials (EMUM), Tınaztepe 35160 Izmir-TURKEY. 

3 

PEge University, Deparment of Electrical and Electronic Engineerings, Bornova, 35100 Izmir-Turkey 

2 

Abstract-In this study, ZnOR Rthin films were deposited on glass substrates via sol-gel technique for sensor applications. Transparent solutions 

were prepared from Zn and Ru based precursors. The solutions were deposited on glass substrates by using spin coating technique which 

o 

provides thin and smooth films. Deposited films were dried at 300 P PC for 10 min in order to remove hydrous and volatile content, 

o 

o 

subsequently to remove organic content films were heat treated at 500P 

PC for 5 min and then they were annealed at 600P PC for 1 hour to 

obtain ZnO based films in air atmosphere. Finally the surface morphology and roughness of the films were determined via AFM (atomic 

force microscopy) and profilometer respectively. The phase structure was determined by XRD. The electrical conductivity of the film 

dependence of temperature was measured to identify the dominant conductivity mechanism. The optical parameters of the film were also 

determined by using spectrophotometer. 

The importance of zinc oxide (ZnO), among other metal 

oxides, is increasing due to many applications. Thin films 

of zinc oxide combine interesting properties such as nontoxicity, 

good electrical properties, high luminous 

transmittance, excellent substrate adherence, hardness, 

optical and piezoelectric behaviour and its low price. ZnO 

has relatively high physical and chemical stabilities, and 

hence it has many high temperature applications [1]. 

Zinc oxide (ZnO) is an important multifunctional 

material with applications such as transistors, gas sensors, 

solar cells, nanocantilevers, etc [2]. Sensors for toxic gases 

have attracted much attention due to the growing concern 

of environmental protection and safety. The major 

applications of gas sensors are domestic or industrial 

security, environmental and emission monitoring,medical 

and agribusiness controls, etc. [3]. Although efforts are 

continuing for CO gas sensing using the hetero structure of 

SnO2 and ZnO [3], experimental results on pure ZnO for 

CO sensing is lacking and it may be related to rapid grain 

growth and densification. For gas sensors, it is necessary 

to have a porous microstructure with small particle size 

yielding large ratio of the surface area to the bulk [4]. 

Undoped ZnO responses perceptibly to LPG while Ru 

doped sample highly senses ethanol vapors [5]. Scientific 

studies about this topic point out that substitution causes 

change in the electrical properties and particle size. Also 

substitution is important in selective sensing of gases or 

substances. 

In this research; pure, Ru substituted ZnOR Rthin film were 

deposited on glass substrates. A sol-gel route was derived 

to produce thin films. 

The sol–gel spin coating method has distinct advantages 

such as cost effectiveness, thin, transparent, 

multicomponent oxide layers of many compositions on 

various substrates, simplicity, excellent compositional 

control, homogeneity and lower crystallization 

temperature [6]. 

Surface morphology of Ru-ZnO thin film obtained by 

Atomic Force Microscopy (AFM) and illustrated in 

Figure1. Spin coating technique provides nanoscale and 

smooth films to be deposited. Thus the films were 

deposited by technique mentioned above nano scale pores 

and nano Scale Island like structures can be obtained. The 

decrease in the pore size of a sensor from micron scale to 

nano scale provides high efficiency and selectivity about 

gas or substance sensing. 

Figure 1. Surface morphology of Ru-ZnO thin film obtained by 

Atomic Force Microscopy (AFM) technique 

Electrical parameters of pure ZnO and Ru doped ZnO 

films will be determined by using conductivity 

measurement. Optical transmittance and reflectance 

spectra will also be measured in the wavelength range of 

325–800 nm by using V-530 JASCO UV/VIS 

Spectrophotometer. Based on these data, optical 

parameters are calculated according to well-known 

formulas [6]. Finally using of resistance and capacitance 

measurement techniques will be used for the 

characterization of the gas sensing properties (such as 

sensitivity, selectivity, and time responses). 

The authors are indebted to State Planning Foundation 

(DPT) and Dokuz Eylul University for financial support. 

*Corresponding author: HTmurat_bektas3585@hotmail.comT 

[1] T. Ivanova, A. Harizanova, T. Koutzarova, B. Vertruyen, , 

Materials Letters, in press, 2010 

[2] M. Yang, D. Wang, L. Peng, Q. Zhao, Y. Lin, X. Wei, 

Sensors and Actuators B 117 (2006) 80–85 

[3] E. Celik, U. Aybarc, M. F. Ebeoglugil, I. Birlik, O. Culha, , J 

Sol-Gel Sci Technol (2009) 50:337–347 

[4] H.-W. Ryu, B.-S. Park, S. A. Akbar, W.-S. Lee, K.-J. 

Hong,Y.-J. Seo, D.-C. Shin, J.-S. Park, G.-P. Choi, Sensors and 

Actuators B 96 (2003) 717–722 

[5] S. C. Navale , V. Ravi, I.S. Mulla, Sensors and Actuators B 

139 (2009) 466–470 

[6] M. Caglar, et.al., Applied Surface Science 255 (2009) 4491– 

4496 




Mercury (II) removal from Aqueous Solution by Using Modified Ordered Mesoporous Carbon 

Nuran Böke 1,2 , Ziboneni Godongwana 1 , Leslie Petrik 1 * 

1 Department of Chemistry, University of the Western Cape, Cape Town 7535, South Africa 

2 Department of Chemical Engineering, Ege University 35100, Turkey 

Abstract- Modified mesoporous carbon (MOMC) was applied to remove Hg (II) from contaminated model aqueous solutions. Batch adsorption 

experiments were carried out to evaluate the adsorption behaviour of Hg (II) onto MOMC. The Langmuir adsorption model fitted to the 

experimental data with a regression coefficient of R 2 =0.9796. 

Ordered mesoporous carbons (OMC) exhibit both well – 

ordered mesoporosity and graphitic character. Because of their 

regular pore size and pore shape and also large surface area, 

these materials have great potential in environmental 

processes. But in some processes, such as adsorption, the 

material must have some additional specifications such as 

binding sites. In this study we prepared an modified OMC 

(MOMC) which has functional groups for Hg (II) b inding and 

used it in adsorption of Hg (II) from model contaminated 

aqueous solutions. 

In the first stage of the work SBA-15 was synthesized by 

using a triblock copolymer (P123) [1]. OMC materials have 

been synthesized using SBA-15 as ordered mesoporous silica 

template. Chemical vapour deposition (CVD) was applied 

using liquid petroleum gas (LPG) as the carbon source as a 

rapid and simple route to prepare OMC [2]. LPG infiltrated 

the mesoporous silica template, and thermally decomposed to 

form a structurally robust, ordered mesoporous carbon 

material analogous to SBA-15 after removal of the silica 

template. 

In an effort to enhance mercury removal from the aqueous 

solution, OMC was modified by a combined treatment of 

nitric acid and (3-mercaptopropyl) triethoxysilane to introduce 

sulphur containing functional groups into the structure of 

mesoporous carbon [3]. 

Batch adsorption test were done for adsorption of 

mercury(II) onto MOMC. 10 mg adsorbent and 50 mL of 

Hg(II) solution with the desired concentration at pH=5.5 

placed into the capped flasks [4]. Duplicates for each 

concentration were placed in a shaker at 25 o C. 

After a predetermined time of shaking the solid adsorbent 

and liquid were separated by filtration through a filter paper. 

Filtered solutions collected in capped bottles. These solutions 

were diluted in 100 mL volumetric flasks to adjust the 

concentrations of them into the measurement range of the 

UV/VIS spectrophotometer. For measuring Hg(II) 

concentration of the samples and standard solutions the 

method given by Ramakirishna et al. was followed [5]. In this 

method Hg(II) is determined as ternary complex with 

rhodamine 6G and iodide. 

The adsorption isotherm of Hg(II) removal by MOMC is 

shown in Figure 1 as dots. 

The Langmuir isotherm model was applied to analyze the 

adsorption equilibriu m of Hg (II) on M OMC[6]. 

and rate of adsorption, respectively. The linear plot of C e /Q e 

versus C e showed that the adsorption follows the Langmuir 

isotherm model for Hg (II) adsorption. The values of Q o and b 

were calculated from the slope and intercept of the plot, and 

the values obtained were Q o =250 mg/g and b=0.0386 L/mg, 

respectively. Using Q o and b values the Langmuir isotherm 

was obtained. The Langmuir isotherm can be seen in Fig. 1 as 

a continuous curve. 

Figure 1. Adsorption isotherms of Hg(II) removal by MOMC. Ce : 

equilibrium Hg(II) concentration, Qe: amount of Hg(II) adsorbed at 

equilibr ium time 

In summary, adsorption of Hg (II) could be described by 

Langmuir model, (regression coefficient R 2 =0.9796). The 

Langmuir isotherm constants were found as Q o =250 mg/g and 

b=0.0386 L/mg, respectively. 

*Corresponding author: 1Tlpetrik@uwc.ac.za 

[1] J. Parmentier et al., J Phys. and Chem. of Solids 65 139–146 

(2004). 

[2] P. Ndungu et al., Microporous and Mesoporous Materials 116 

593–600 (2008). 

[3] A. Walcarius, Analytica Chim. Acta 508 87–98(2004). 

[4] Chemosphere 52 835–841 (2003). 

[5] T.V. Ramakirishna et al., Anal. Chim. Acta 84 369-375 (1976). 

[6] K. Kadirvelu et al., Carbon 42 745–752 (2004). 

C e /Q e = C e /Q o + (1/b* Q o ) 

[1] 

where, C e is the equilibriu m concentration (mg/L) and Q e is 

the amount of Hg(II) adsorbed (mg/g) at equilibriu m time. Qo 

and b are Langmuir constants related to adsorption capacity 




Melting evolution and diffusion behavior of bimetallic CuAu nanoparticles studied molecular 

dynamics simulations 

Serap Senturk Dalgic 1 * and Unal Domekeli 1 

1 Department of Physics, Trakya University, Edirne, 22030, Turkey 

Abstract-Molecular dynamics calculations have been performed to study the melting evolution and atomic diffusion behavior of bimetalic 

CuAu nanoparticles with the number of atoms ranging from 1286 to 26066 (diameters around 3–9 nm) The interactions between atoms are 

described using the quantum Sutton – Chen (Q-SC) many – body potential. The obtained results reveal that the melting temperatures of 

nanoparticles are inversely proportional to the reciprocal of the nanoparticle size, and are in good agreement with the predictions of the 

liquid-drop model. The melting process can be described as occurring in two stages, firstly the stepwise premelting of the surface region, and 

then the abrupt overall melting of the whole nanoparticles. The heat of fusion of nanoparticles are also inversely proportional to the 

reciprocal of the nanoparticle size. In addition, surface energies and entropies have been calculated for each sized CuAu nanoparticle at 

melting point. The diffusion is mainly localized to the surface region at low temperatures and increases with the reduction of nanoparticle 

size, with the temperature being held constant. 

Bimetallic nanoparticles are of particular interest in 

applications because the nanoparticle properties can vary 

dramatically not only with size, as occurs in pure 

nanoparticles, but also with chemical composition. Cu-Au 

is a well-known model bimetallic alloys system, which is 

famous for the existence of a temperature-induced orderdisorder 

transition and the capability of forming 

thermodynamically stable long period superlattice structure 

[1]. On the other hand, size and shape effects on formation 

enthalpy and melting process of Cu-Au nanoparticles have 

been studied in recent years and results have been reported 

in literature [2-6]. 

In this work, we have studied the melting evolution and 

diffusion behavior of bimetallic CuAu nanoparticles using 

molecular dynamics calculations with the quantum Sutton- 

Chen (Q-SC) potential. The whole melting process is traced 

from the changing of the local structure, atomic diffusion 

and thermodynamics properties such as the atomic energy, 

surface energy, heat of fusion and entropy. All spherical 

nanoparticles started with geometries constructed from a 

large cubic FCC (L1 0 

for CuAu) crystal structure using a 

series of spherical cutoff centered at a core of cubes. The 

stable structure at 0 K is obtained through the initial 

configurations annealed fully at T=300 K and then cooled 

to T=0 K at a cooling rate 0.5 K/ps. In order to get an 

energy-optimized structure during heating at a given 

temperature for bulk systems it is performed molecular 

dynamics under constant temperature and constant pressure 

conditions (NPT) with a periodic boundary conditions. For 

the nanoparticles, we used the constant volume and 

constant temperature (NVT) molecular dynamics without 

the periodic boundary conditions. The temperature is 

controlled by Nose-Hoover thermostat. Newtonian 

equations of motion are integrated using the Leapfrog 

Verlet method with a time step 2 fs. For the simulation of 

the bulk system and nanoparticles the heating process 

consists of a series of MD simulations with temperature 

increments T=50 K and relaxing time 100ps. However, 

for a temperature near the melting region, we used smaller 

temperature increment, T=10 K, and the relaxation time 

still keeps 100 ps. 

The experimental observation of the melting phenomena 

on a particle is just the surface liquid skin resulted by 

surface premelting. Using molecular dynamic simulation, 

the melting process and melting mechanism of 

nanoparticles can be analyzed size. In Figure 1, we show 

snapshot views of the MD sample with 2708 (D=4nm) at 

different temperature. It is observed that CuAu particle with 

D=4nm diameter melts at approximately 800 K. 

T=300K T =500K T=800K 

Figure 1. Snapshot views of the MD sample with N=2708 

(D= 4 nm) at a series of temperatures during heating. 

To conclude, the melting evolution of bimetallic CuAu 

nanoparticles with the number of atoms ranging from 1286 

to 26066 under heating condition is investigated by the 

molecular dynamics simulations using Q-SC potentials. It 

has been found that the melting point is inversely 

proportional to the reciprocal of the nanoparticle size and 

the results are in good agreement with the theoretical 

analysis from the liquid drop model [7]. The evolution of 

atomic configuration and energy with temperature reveals 

that the melting process of CuAu nanoparticles can be 

described in two stages, the stepwise premelting from the 

surface region and the sudden melting in the interior region. 

Owing to the two stages melting, the heat of melting for 

nanoparticles should involve two parts. As the particle size 

decreases, the heat of fusion, surface energy and entropy 

decreases correspondingly. We have also studied the 

structural evolution of CuAu nanoparticles with different 

temperature. Radial distribution functions are adopted to 

explore structural transition. The atomic diffusion in 

nanoparticles is mainly localized to the surface regions 

before the melting temperature and increases with the 

reduction of particle size at the same temperature. 

*Corresponding author: dserap@yahoo.com 

 

13 657 (2005). 

[2] W.H.Qi, B.Y. Huang, M.P. Wang, Physica B 404 1761 

(2009). 

[3] S. Darby, T. V. Mortimer-Jones, R.L.Johnston and C. 

Roberts, J. Chem. Phys. 116, 1536 (2002). 

[4] J. L. Rodriguez-Lopez, J. M. Montejono-Carrizales, M. Jose- 

Yacaman, Appl. Surf. Sci. 219, 56 (2003). 

[5] F. Delogu, Nanotechnology 18 (2007) 235706. 

[6] Y.J. Li, W.H.Qi, B.Y.Huang, M.P.Wang, S.Y.Xiong, J. Phys. 

and Chem. Sol. Article in press. 

[7] K.K. Nanda, S.N. Sahu, S.N. Behera, Phys. Rev. A 66, 

013208 (2002). 




Melting evolution of Fe nanoparticles from molecular dynamics simulations 

Serap Senturk Dalgic ,1 *, Cem Canan 1 and Oguz Gulseren 2 

1 Department of Physics, Trakya University, Edirne, 22030, Turkey 

2 Department of Physics. Bilkent University. Bilkent, Ankara 06800, Turkey 

Abstract–In order to study the melting properties of bcc metal iron nanoparticles, molecular dynamics calculations have been performed for 

various nanoparticles with different number of atoms. The modified analytic embedded atom method (MAEAM) interatomic potentials are 

used to describe the interaction between Fe atoms. The melting process can be described as occurring in two stages, firstly the stepwise 

premelting of the surface layer with a thickness of 2–3 times the perfect lattice constant, and then the abrupt overall melting of the whole 

nanoparticle. The melting point and heat of fusion of nanoparticles are inversely proportional to the reciprocal of the nanoparticle size. We 

have also studied the structural evolution of Fe nanoparticles with different temperature. Radial distribution functions are adopted to explore 

structural transition. In addition, dynamic properties of Fe nanop articles such as diffusion coefficient (D), mean square displacement (MSD) 

have been calculated. 

There are various reasons for the great interest in iron 

(Fe) nanoparticles. Generally, magnetic nanoparticles are 

receiving a lot of attention today because of several 

possible applications. Hence, owing to its magnetic 

properties, there is special interest in iron. Indeed, iron 

nanoparticles have attracted special attention because they 

may be used in power-transformer cores and magnetic 

storage media as well as for catalysis (see the good review 

about the synthesis, properties and applications of Fe 

nanoparticles of Huber [1]). Iron nanoparticles can be 

produced in both forms, i.e. in crystalline and amorphous 

phases, and much attention has been paid to the latter in 

recent years [2]. We found only a few works related to the 

computer simulation of crystalline Fe nanoparticles [3–5]. 

In the present study, the melting process of Fe 

nanoparticles with the number of atoms ranging from 2741 

to 44375 (diameters around 4–10 nm) has been simulated 

by using modified analytic embedded atom method 

(MAEAM) [6]. During melting process, we have studied 

mean atomic energy changes with respect to the 

temperature for bulk Fe and four Fe nanoparticles. Then, 

we have also interested in how the melting temperature and 

heats of fusion depend on size of nanoparticles. The static 

and dynamic structural properties have been calculated for 

four nanoparticles with different sizes and then structural 

transitions have been investigated in detail. The initial 

configurations of spherical nanoparticles, with 

nanoparticles diameter 4, 6, 8, 10 nm, are extracted from a 

large BCC crystal structure of spherical cutoff centered at a 

core of cubes. All of the atoms are located on their lattice 

positions. The stable structure at 0 °K is obtained through 

the initial configurations annealed fully at T=300 °K and 

then cooled to T=0 °K at a cooling rate 0.5 K/ps. In order to 

get an energy-optimized structure during heating at a given 

temperature for bulk systems, molecular dynamics 

calculations under constant temperature and constant 

pressure conditions (NPT) with periodic boundary 

conditions have been performed. For the nanoparticles, we 

used the constant volume and constant temperature (NVT) 

molecular dynamics without the periodic boundary 

conditions. The temperature is controlled by Nose-Hoover 

thermostat. Newtonian equations of motion are integrated 

using the Leapfrog Verlet method with a time step 2 fs. For 

bulk and nanoparticles, system is subjected to heating 

process consisting of a series of MD simulations with 

temperature increments T=50 °K and relaxing time 100ps. 

However, for a temperature near the melting region, we 

have used smaller temperature increment, T=10 °K, wh ile 

keeping the relaxation time as 100 ps. 

For the investigation of melting evolution and 

distinctive surface properties, two spherical shell regions 

with the same thickness of a 0 are divided and labeled as A, 

B, starting fromthe outmost shell, and the remaining core is 

labeled as C analyzed respectively as shown in Figure 1. 

T =300 °K T =900 °K T =1200 °K T =1800 °K 

Figure 1. x-y coordinate snapshot views of the MD sample with 

N=9577 (D=6nm) at a series of temperatures during heating with 

layers A, B, C(core) yellow, brown and red respectively. 

To conclude, we have investigated the melting evolution 

of iron nanoparticles from molecular dynamics simulations 

using a modified analytic embedded-atom potential. The 

evolution of atomic configuration and energy with 

temperature reveals that the melting process of iron 

nanoparticles can be described in two stages, the stepwise 

premelting from the outmost surface and the sudden 

melting in the inner core. The thickness of the liquid skin 

resulting from the surface premelting is discrepant for 

particles with different diameters. Owing to the two stages 

melting, the heat of melting for nanoparticles should 

involve two parts. As the particle size decreases, the heat of 

melt decreases correspondingly. The atomic diffusion in 

nanoparticles is mainly localized to the surface layers 

before the melting temperature and increases with the 

reduction of particle size at the same temperature. 

* Corresponding author: dserap@yahoo.com 

[1] Huber D L Small 1, 482 (2005) 

[2] Hoang V. V, Nanotechnology, 20, 295703 (2009). 

[3] Postnikov A V, Entel P and Soler J M, Eur. Phys. J. D 25 

261 (2003) 

[4] Rollmann G, GrunerM E, Hucht A, Meyer R, Entel P, 

Tiago M L and Chelikowsky J R, Phys. Rev. Lett. 99 083402 

(2007) 

[5] Shibuta Y and Suzuki T, Chem. Phys. Lett. 445 265 (2008) 

[6] 0TZhang J, Wen Y, Xu K, Central European Journal of 

Physics, 4, 481 (2006) 




Computational studies for free energies of solvation of additives in polymeric nanostructures 

Tuba Arzu Özal* 

Kadir Has University 

Abstract- Computational studies for free energies of solvation of additives in polymeric nanostructures are not trivial when there is 

no naturally occuring free volumes available in the system of a material matrix. In such system matrices, a new methodolgy should be 

applied. Solvation free energy calculations for several additive molecules (such as DMSO, propane and chloroform) based on a softcore 

reference state in a Bisphenol-A- Polycarbonate (BPA-PC) polimer matrix was performed. The applicability and usefulness of 

the methodology was discussed via comparison with some other basic and recent free-energy calculation methodologies. The 

numerical results obtained via these various methodologies which makes use of Molecular Dynamic simulation procedures at the 

atomic scale were compared and they are found to be in agreement quite well. 

Solubility is a crucial property in material science and in 

many other fields, and its thermodynamic correspondence 

solvation free energy and its individual thermodynamic terms 

had been our research interest thinking in terms of 

computational efforts at atomic scales. We had performed 

studies initially on solvation of small gas molecules such as 

methane in binary mixtures of liquids, and the 

thermodynamic terms, enthalpy and entropy was investigated 

deep into details leading to some critical questions about the 

terminology. [1] However, further studies on the solvation 

free energy computations based on molecular dynamic 

simulation techniques enhance the fact that there must be an 

already available free volumes for the methods such as 

Widom’s test particle insertion (TPI) to be applied. [2] When 

there is no such available volume, then some other methods 

should be applied by using the thermodynamic cycle 

properties. For example, solvation of additive molecules in 

polymer matrices this is generally the case. 

The methodology that we make use of the thermodynamic 

cycle in this work was introducing an intermediate soft-core 

spherical cavity and then performing the perturbation. By this 

means, our aim was first creating the volume to make the 

insertion possible and then performing the TPI. [3] 

In Figure 1, the soft-core reference state used as an 

intermediate state for the insertion in the thermodynamic 

cycle was depicted and the results compared with the ones 

obtained by Fast-Growth Thermodynamic Integration method 

was given in the table 1. [4] 

Table 1. Free energy changes computed for BPA-PC by FEP and 

TI, with long runs of 10ns and 1ns at each , respectively for these 

two methods. Data for various reference states are given for 

comparison and the criteria for a good choice of a reference state is 

discussed in the chapter. Errors (obtained by block averaging) are 

given in parentheses. [3] 

This study was supported by Max Planck Institute for 

Polymer Research Center. 

*Corresponding author: tugba.ozal@khas.edu.tr 

[1] Özal,T.A.; van der Vegt, N.F.A.,2006, “Confusing cause and 

effect: Energy-entropy compensation in preferential solvation of 

a nonpolar solute in DMSO/water mixtures”, Journal of 

Physical Chemistry B 110, 12104 

[2] Peter, C.; van der Vegt, N.F.A., 2007, “Solvent 

reorganization contributions in solute transfer thermodynamics: 

Inferences from the solvent equation of state.”, Journal of Physical 

Chemistry B. 111(27), 7836-7842 

[3] Özal, T.A.; Peter, C.; Hess, B.; van der Vegt, N.F.A.,2008, 

“Modeling Solubilities of Additives in Polymer Microstructures: 

Single Step Perturbation Method based on a Soft Cavity Reference 

State”, Macromolecules 41, 5055 

[4] Hess, B.; Peter, C.; Ozal, T.; van der Vegt, N.F.A., 2008, 

“Fast growth thermodynamic integration: solubilities of additive 

molecules in polymer microstructures”, Macromolecules 41, 2283. 

Figure 1. Snap-shot presenting a Soft-core Reference state 

(yellow transparent) in BPA_PC polymer matrix at 480 K 

used for the free energy calculation based on a new 

combinatory method of Thermodynamic Integration (TI) and 

Free Energy Perturbation (FEP). [3] 




Size effect on melting of ternary CuTiZr nanoparticles : a molecular dynamics study 

Serap Senturk Dalgic 1 * and Oguz Gulseren 2 

1 Departmen of Physics, Trakya University, Edirne, 22030, Turkey 

2 Department of Physics, Bilkent University, Ankara, 06800, Turkey 

Abstract-In the present study, the melting process of spherical CuTiZr ternary nanoparticles with the diameters around 3–9nm has been 

simulated by the tight binding second moment approximation (TB-SMA) model potential. Size depending melting properties of CuTiZr 

nanop articles are investigated with the composition Cu 50 Ti 25 Zr 25 . We find that the melting temperatures of CuTiZr nanoparticles are lower 

than that of the bulk. The size dependent melting temperature, surface energy and cohesive energy for corresponding ternary nanop articles 

have been predicted. 

The melting of nanomaterials is under considerable 

investigation because of the broad scientific and 

technological interest for possible applications. It is 

important and necessary to understand and predict the 

thermodynamics of nanomaterials for fabricating the 

materials for practical applications. 

In recent years, the ternary Cu-Ti-Zr system has attracted 

increasing interest because of its good glass forming ability 

[1]. Even though many atomistic simulation studies have 

been performed in order to investigate the atomic scale 

materials phenomena of bulk metallic glassy alloys [2], 

such as CuTiZr [3, 4], none has been done for nanoscale of 

this material. This is mostly because of the difficulty in 

developing the interatomic potentials for ternary systems 

which can be used successfully in molecular dynamics 

(MD) calculations. 

The objective of the present work is to determine the size 

dependent melting properties of ternary spherical 

nanoparticles CuTiZr for the selected alloy composition. 

For this purpose, we have studied the melting evolution of 

Cu 50 Ti 25 Zr 25 nanoparticles using molecular dynamics 

without the periodic boundary conditions. The temperature 

is controlled by Nose-Hoover thermostat. Newtonian 

equations of motion are integrated using the Leapfrog 

Verlet method with a time step 2 fs. For bulk and 

nanoparticles, system was subjected to heating process 

consisting of a series of MD simulations with temperature 

increments T=50 °K and relaxing time 50 ps. However, 

for a temperature near the melting region, we used smaller 

temperature increment, T=10 °K while keeping the 

relaxation time as 50 ps. 

calculations with the TB-SMA many body potential [5]. 

The potential parameters can deal with all the different 

elements, Cu, Ti, Zr proposed by Cleri and Rosato and 

alloys systems composed of those elements using common 

mathematical formalism developed in Ref. [4]. 

In order to validate the TB potential, we first simulate the 

melting process of bulk Cu 50Ti 25 Zr 25 alloys and check our 

results with those presented in the literatures. The 

simulation method was as follows: first of all, all spherical 

nanoparticles started with geometries constructed from a 

large cubic FCC crystal structure using a series of spherical 

cutoff centered at a core of cubes. The stable structure at 0 

K is obtained through the initial configurations annealed 

fully at T=300 °K and then cooled to T=0 °K at a cooling 

rate 1 K/ps. In order to get an energy-optimized structure 

during heating at a given temperature for bulk systems, 

molecular dynamics under constant temperature and 

constant pressure conditions (NPT) with periodic boundary 

conditions has been performed. For the nanoparticles, we 

used the constant volume and constant temperature (NVT) 

molecular 

dynamics 

Cu 50 Ti 25 Zr 25 . The structural properties of nanoparticles 

were also studied via radial distribution function, mean 

atomic distances and coordination number. The size 

dependence diffusion have been established, the diffusion 

mechanism for ternary nanoparticles is dominated at 

surface diffusion. Surface energies for different 

nanoparticles have also been calculated. In summary, the 

presented study has been established to describe the size 

dependences of melting properties of ternary 

nanoparticles. The presented results will be verified by the 

experimental and other theoretical models developed for 

ternary nanoparticles in future studies. 

*Corresponding author: dserap@yahoo.com 

T=0 °K T =700 °K T=1100 °K 

Figure 1. Snapshot views of the MD sample with N=32085 

(D=9nm) at a series of temperatures during heating. 

It is established experimentally that the melting begins 

preferentially at the surface in the melting process of 

nanoparticles and nanorods [6-8]. It has been shown in 

Figure 1 that the surface atoms much more active than the 

other atoms. The relations between the mean atomic 

energy and temperature for different size of nanoparticles 

and bulk have been obtained. The melting temperatures of 

ternary Cu50Ti25Zr25 nanoparticles show clear 

dependence of particle diameters. The heat of melting for 

the nanoparticles is lower than that of the bulk 

[1] S. Pauly, J. Das, N. Mattern, D.H. Kim, J. Eckert, 

Intermetallics, 17, 453 (2009). 

[2] A. Inoue, W. Zhang, T. Zhang, K. Kurosaka, Acta. Mater. 49, 

2645 (2001). 

[3] X. J. Han and H. Teichler Physical Review E 75, 061501 

(2007) 

[4] S. S. Dalgic and M. Celtek (unpublished results). 

[5] F. Cleri and V. Rosato Phys. Rev. B48, 22 (1993). 

[6] O Gulseren, F. Ercolessi ve E. Tosatti ; Phys. Rev B51,7377 

(1995). 

[7] Z.L. Wang et al. Phys. Rev. B 67, 193403 (2003). 

[8] W. Hu, S. Xiao, J. Yang and Z. Zhang, Eur. Phys. J. B 45, 

547 (2005). 




Fundame ntal Prope rties of Carbon Onions Correlated with Tribologi cal Performance 

Raed Alduhaileb 1 *, Virg inia Ayres 1 , Benjamin Jacobs 1 , Xudong Fan 1 , Kaylee McElroy 1 , Martin Crimp 1 and Atsushi Hirata 2 

1 College of Engineering, Michigan State University, East Lansing, MI, 48824, USA 

2 Graduate School of Mechanical Sciences, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, Japan 

Abstract-A fundamental characterization of carbon onion films is performed using high-resolution transmission electron miscoscopy and 

electron energy loss spectroscopy for strucutres, scanning electron microscopy for film stalbility and force volume imaging by atomic force 

msicoscopy for mechanical perperties. The results are correlated with actual tribiolgical performance of carbon onion films in air and vacuum 

environments. We find that carbon onoin films show great promise as a nano-property enabled solid lubricant. 

Multi-shell fullerenes, or carbon onions, are under 

investigation as a nano-property enabled solid lubricant. The 

potential applications for a carbon onion-based lubricant range 

from an environmentally benign option for wind power to a 

vacuum lubricant for solar panel deployment in space. These 

uses of carbon onions depend on both their individual 

properties such as mechanical strength and elasticity, and their 

interaction properties with a wear surface and with each other. 

When carbon onions are applied as a thin lubricating film, 

their stiction, rolling, and sliding interactions, with each other 

and with the wear surfaces govern their ultimate usefulness, in 

addition to their individual mechanical load-bearing 

characteristics. 

Carbon onion physical structures are known to vary with 

synthesis temperature. Several authors have reported the 

structural evolution from spherical to polyhedral multi-shells 

as a function of increasing synthesis temperature [1]. It has 

been generally assumed that the structural evolution is 

accompanied by a change in the sp 3 /sp 2 ratio, since a reduction 

in potential sp 3 defect sites, which are visible as broken shells 

in high-resolution electron microscopy (HRTEM) images, is 

observed. However, broken shells may also terminate in 

amorphous carbon networks that are more sp 2 than sp 3 ,and 

individual sp 3 point defects could be very hard to detect based 

on HRTEM images alone. Accurate knowledge of a systematic 

evolution of the sp 3 /sp 2 ratio is important for the synthesis of 

carbon onions for an optimum lubricating film, especially at 

the nano-scale, since sp 2 carbons interact principally through 

-electron overlap, while sp 3 defect sites exhibit local dangling 

bonds. 

In this work, we investigate the fundamental tribological 

(frictional) and stability characteristics of the carbon onions in 

air and vacuum due to their distinctive structure (Figure 1 a 

and b) and frictional performance in different surroundings. 

HRTEM is used to investigate structural evolution from 

spherical to polyhedral multi-shells as a function of increasing 

synthesis temperature. Electron energy loss spectroscopy 

(EELS) is used to quantitatively investigate the sp 

3 /sp 2 ratio [2 

MRS]. EELS is also used along with energy filtered TEM 

(EFTEM) to investigate the possible development of oxygen 

functionalities at defect sites during wear. Scanning electron 

microscopy is used to characterize film uniformity and force 

volume imaging by atomic force microscopy is used to 

provide information about film mechanical properties. The 

fundamental properties are correlated with tribological results 

obtained by ball-on-disk measurements [3, 4]. 

Figure 1. HRTEM images of carbon onions prepared by heat 

treatment of nano-crystalline diamonds at (a) 1700 °C and 

(b) 2300 °C. 

The fundamental characteristics and performance of the 

additional nano-carbons, C 60 and single-walled carbon 

nanotubes are also considered. We find that carbon onions 

may exhibit a combination of electronic and mechanical 

properties that result in the optimum tribological performance 

and film stability. 

*Corresponding author: alduhail@msu.edu 

[1] S. Osswald et al., J. Am. Chem. Soc. 128, 11635-11642 (2006). 

[2] R. Alduhaileb et al., Mater. Res. Soc. (2010). 

[3] A. Hirata et al., Tribo. Inter. 37, 893-898 (2004). 

[4] A. Hirata et al., Tribo. Inter. 37, 899-905 (2004). 




Preparation of MoSi 2 -MoC Nano-composite Powder by Mechanical Alloying 

H. Ramezanalizadeh 

1 and Saeed Heshmati-Manesh 1 * 

1 School of Metallurgy and Materials Engineering, University of Tehran, Tehran, PO Box 14395-553, Iran 

Abstract- In this study, MoSi 2 -MoC nano-composite powder was prepared by mechanochemical synthesis. MoO 3 powder and various amounts 

of Si and C were mixed together and subjected to severe mechanical activation using a high energy planetary ball mill. The milling operation 

resulted in carbosilicothermic reduction of MoO 3 and simultaneous formation of an ultra fine MoSi 2 -MoC powder. The synthesized p roduct 

was characterized by SEM and X-ray diffraction. XRD analysis indicated that in a typical mixture of reactants, MoSi 2 is obtained after 25 h 

milling. The final products after 60 h milling were -MoSi 2 -MoSi 2 and MoC and their mean crystallite sizes were calculated to be 22.5, 22.1 

and 9 nm, respectively. 

R 

Molybdenum disiliside is an attractive material for high 

MoO3+Si 2 +SiO 2 298 = -293 kJ/mol (4) 

temperature applications. It is an intermetallic compound and 

has tetragonal C11b 

value in which case, it was expected to have SiO2 in the XRD 

pattern. But it could not be detected because of occurrence of 

1900 o C and hexagonal C40 structure (high temperature phase reaction (5) in the milling condition, the product of which is in 

o C and its melting point. MoSi 2 has excellent gaseous state: 

oxidation resistance and average density (6.24 gr/cm 3 ). 

However, its performance is limited by weak toughness at low SiO 2 +Si (5) 

temperatures and high creep rate at elevated temperatures. For 

these reasons, numerous efforts have been focused on During the next reduction step, MoO 2 can be reduced by Si 

designing and fabricating of MoSi 2 based composites for and C. Comparing the XRD patterns of the samples in similar 

applications in oxidizing and aggressive environments [1]. milling times, it was found that the rate of decrease in 

Various methods have been introduced for synthesis of intensity of MoO 2 peaks was faster in the sample with higher 

MoSi2 and its composites including arc melting, powder C content, which means that C is the effective reducing agent 

metallurgy, hot pressing, combustion synthesis, mechanical at this step. Also, the overall reduction rate was observed to 

alloying, chemical vapor deposition and shock synthesis [1]. increase in samples with higher C/Si mo le ratio in the starting 

Mechanical alloying (MA) has also been experienced on material. However, C acts as a lubricant which retard the 

various reactants to synthesize MoSi 2 and its composites with formation of MoSi 2 as more MoSi 2 was obtained when more 

different second phases [2,3]. MA has been extensively Si was added to the powder mixture. 

exploited as a powerful technique to produce a variety of Typical XRD results obtained from a sample containing 

stable and/or metastable crystallines, nanocrystallines and 10 mol% of excess C and 30 mol% of excess Si, indicated that 

amorphous structured materials including alloys, intermetallic -MoSi2 -MoSi 2 phases appeared after 25 

compounds, ceramics, etc [4]. 

hours of milling. When the sample was milled for 42 h, more 

In this investigation, MoO3 powder was used as Mo starting intense peaks of - -MoSi 2 were appeared. At the same 

material together with Si and C as reducing agents to prepare time, peak intensities of MoO 2 decreases and a peak related to 

MoSi 2 -MoC nano-composite by MA which combines both MoC was detected. Increasing milling time to 60 hours 

reduction and alloying into one single milling step. 

resulted in complete reduction of MoO 2 . The final products of 

Powders of MoO3, C and Si with commercially purity were -MoSi 2 -MoSi 2 and MoC and their 

precisely weighed according to reaction 1 and milled by a mean crystallite sizes were calculated to be 22.5, 22.1 and 9 

planetary ball under pure argon atmosphere. 

nm, respectively. 

In summary, MoSi2 was synthesized successfully by MA. 

MoO 3 +2Si+1.5C 2 +1.5CO 2 (1) MoSi 2 -MoC nano-composite powder was formed by 

mechanical activation of MoO 3 , Si and C powder mixtures. 

Other samples containing excess C and Si powders over The rate of MoO 3 reduction reaction and formation of MoSi 2 

stoichiometric ratios were also prepared to evaluate their was shown to be influenced by the Si and C contents in the 

effect on the process. 

initial powder mixture. 

Phase composition and morphology of the samples were The financial support of this work by the Iranian 

evaluated by XRD and SEM, respectively. The mean Nanotechnology Initiative is gratefully acknowledged. 

crystallite size of the milled powders was calculated by 

Scherrer method from the line broadening of the diffraction *Corresponding author: 1Tsheshmat@ut.ac.ir 

lines [5]. 

XRD results showed peak broadening in patterns of the [1] Yao, J. Stiglich, and T.S. Sudarshan, ASM International, 

milled samp les which was indicative of the crystallite size JMEPEG, 8, 291 (1999). 

[2] S.C. Deevi and S. Deevi, Scr. Metall. Mater. 33, 415 (1995). 

reduction and accumulation of micro strains in the crystal 

[3] M. Sannia, R. Orru, J.E. Garay, G. Cao and Z.A. Munir, Mater. 

lattices. 

Sci. Eng. A, 345, 270 (2003). 

During the milling operation on all samples, MoO 3 was first [4] C. Suryanarayana, Prog. Mater. Sci. 46, 1 (2001). 

reduced to MoO 2 . This step is believed to occur through either [5] B.D. Cullity, Elements of X-Ray Diffraction, 2nd edn. Addisonesley 

reaction 3 or reaction 4. 

Publishing, (1977). 

MoO 3 +C 2 +CO 2 298 = -122.3 kJ/mol (3) 




Synthesis of Cobalt Fe rrite Nano-particles by Sol-gel Method 

A. Ataie 1 *, H. R. Emamian 2 , A. Yourdkhani 3 , A. Honarbakhsh- raouf 2 

1 School of Metallurgy and Materials Engineering, University of Tehran, Tehran, Iran 

2 Department of Materials, Faculty of Engineering, University of Semnan, Semnan, Iran 

3 Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, USA 

Abstract-In this study, cobalt ferrite nano-particles were synthesized by a facile sol-gel method based on polyesterification reaction between 

citric acid, benzoic acid and ethylene glycol without pH adjusting of solution and aging of gel. Thermal behavior, phase evolution and magnet ic 

properties of the products were evaluated using DTA, XRD and VSM techniques. SEM and TEM were employed to study t he powder particle 

morphology. A pure spinel cobalt ferrite was formed after heat treatment at 750 °C for 1 h. 

Synthesis and characterization of spinel ferrites have been 

intensively studied because of fundamental understanding as 

well as their applicability in a variety of areas such as highdensity 

information storage system [1], ferro fluid technology 

[2], biological and clinical applications [3] and gas sensors [4]. 

Among spinel ferrites, cobalt ferrite, CoFe 2 O 4, has attracted 

considerable attention due to its large magneto-crystalline 

anisotropy, high coercivity, moderate saturation 

magnetization, large magneto-strictive coefficient, chemical 

stability and mechanical hardness. 

Several chemical methods like sol-gel, micro-emulsion, 

citrate gel, co-precipitation, auto-combustion synthesis and 

hydrothermal process have been reported to synthesize cobalt 

ferrite nano-particles. Recently, polymerized complex (PC) 

which is a Pechini type sol-gel method, in which a solution of 

ethylene glycol, citric acid and metal ions is polymerized to a 

polyester network, has been employed to process nano size 

ceramic powders at a relatively low temperatures. 

In this research, nano particles of cobalt ferrite were 

prepared by a PC method. The effects of the synthesis 

parameters on the powder particle characteristics were also 

investigated. 

Iron citrate, cobalt nitrate, citric acid, ethylene glycol and 

benzoic acid all of analytical grade were used as starting 

materials. A mixed solution with 4.61C 6 H 8 O 7 : 

13.84(CH 2 OH) 2: 0.7C 6 H 5 COOH: 2FeC 6 H 7 O 7 : 1Co 

(NO 3 ).6H 2 O: 300H 2 O molar ratio was used to prepare Co-Fe 

complex solution. First, citric acid was dissolved in water at 

60 °C followed by addition of iron citrate and cobalt nitrate to 

the solution under stirring until a bright brownish homogenous 

solution achieved. Then ethylene glycol and benzoic acid were 

added to the solution. The pH of solution was 1.4 in the 

process. Then stirring was being continued, without pH 

adjusting, at 80°C for 1.5 hour to obtain a dark brownish 

viscose gel. The obtained gel was dried at 150 °C for 24 hours. 

Annealing process was carried out at 550, 650, 750 and 850 

°C for 1 hour by a heating rate of 10 °C/min. 

Phase composition and morphology of the samples were 

evaluated by XRD and SEM/TEM, respectively. The thermal 

behavior of the gel was examined by DTA technique in air 

with the heating rate of 10 °C/min. The magnetic properties 

were analyzed by VSM. 

DTA trace showed one endothermic and two exothermic 

distinct peaks which appear at about 110, 320 and 510 °C, 

respectively. Endothermic reaction is related to the 

dehydration of sample. An exothermic reaction around 320 °C 

is due to de-esterification and de-carboxilation of COOH 

groups, while the second exothermic reaction at around 510 

°C is due to the formation of cobalt ferrite. 

XRD results revealed the coexistence of cobalt ferrite and - 

Fe R 

R2 ROR3 (maghemite) in the samples annealed at 550 °C and 

650 °C. By increasing the annealing temperature to 750 °C, 

cobalt ferrite single phase was formed with sharp 

characteristic peaks related to the high degree of its 

crystallinity. 

Both SEM and TEM images of the annealed powder at 

850 °C for 1 houre showed spherical shape particles with a 

uniform particle size distribution. The mean particle size was 

measured as 40 nm from the TEM images. The coercivity of 

sample annealed at 550 °C was small as 567.2 Oe. However, 

the highest coersivity of 1353.7 Oe was obtained in the sample 

annealed at 650 °C. The saturation magnetization of the 

samples increased by increasing the annealing temperature and 

reached to a maximum value of 79.4 emu/g in the sample 

annealed at 850 °C. 

In summary, cobalt ferrite nano-particles were successfully 

synthesized by a facile sol-gel route based on 

polyesterification reaction between citric acid, benzoic acid 

and ethylene glycol under strong acidic condition of achieved 

complex solution, without pH adjusting of solution and aging 

of gel. 

The financial support of this work by the Iranian 

Nanotechnology Initiative is gratefully acknowledged. 

*Corresponding author: 1Taataie@ut.ac.ir1T 

[1] Giri, A.K., K. Pellerin, W. Pongsaksawad, M. Sorescu and S. 

Majetich, IEEE Trans. M agn. 36, 3029 (2000). 

[2] Raj, K., B. Moskowitz and R. Casciari, J. Magn. Magn. Mater. 

149, 174 (1995). 

[3] Baldi, G., D. Bonacchi, C Innocenti, G. Lorenzi and C. 

Sangregorio, J. Magn. Magn. Mater. 311, 10 (2007). 

[4] Gopal Reddy, C.V., S.V. Manorama and V.J. Rao, J. Mater. Sci. 

Lett. 19, 775(2000). 




Evol ution of Nano-crys talline NiTi and Amorphous Structures in Mechanical Alloyi ng o f Ni and Ti 

A. Rabiezadeh 1 and S. F. Kashani Bozorg 1 * 

1 School of Metallurgy and Materials Engineering, University of Tehran, Tehran, P.O. Box: 14395-553, Iran 

Abstract-Mechanical alloying of Ni and Ti was conducted in a planetary ball mill using a powder mixture with equiatomic stoichiometry for 

various times. The milled products were found to decrease in size as a function of milling time as evidenced by scanning electron microscopy. 

X-ray diffractometry of the milled products exhibited peak broadening and the formation of amorphous structure which became dominant after 

25h of milling. Transmission electron microscopy using bright field imaging and electron diffraction pattern modes revealed that the 25h milled 

product was consisted of mixture of nano-crystalline NiTi (20-40nm size) and an amorphous phase. 

NiTi has unique properties that could be very useful in 

surgical applications [1]. Conventionally, Ni-Ti alloys are 

produced by arc or induction melting. Melting methods have 

shortcomings due to gas absorption, elemental vaporization, 

segregation formation, and crucible contamination absorption. 

Thus, throughout the last decade solid state processing routes 

have gained considerable interest for NiTi fabricat ion [2-5]. 

In this study, the mechanical alloying (MA) process of 

elemental Ni and Ti with equiatomic ratio was carried out. The 

morphology, phase composition of the milled products for 

different durations were investigated. MA of the powder 

mixture was conducted in a planetary ball mill at room 

temperature in a stainless steel vial with chromium steel balls 

under an argon atmosphere. The milling speed and the ball to 

powder charge ratio were 450 rpm and 15:1, respectively. The 

maximum milling time was 25 h. 

During the preliminarily stage of milling (until 4h), the 

specific size of powders increases which corresponds to the 

formation of coarse multiphase particles. With further milling, 

the mean particle size decreased; this can be related to work 

hardening and/or formation of new brittle phase(s). After 10h 

of milling, substantial powder was crushed and flattened by 

the collisions between the powder and the milling media. No 

significant change in particle size of the powders can be 

observed after 10 h of milling. With further milling, the milled 

products become more homogeneous while keeping its 

granular morphology. The particle size was found to be 

smaller than 10 h of milling. 

In a first period of milling up to 6h, the intensity of the X- 

ray diffraction peaks of the milled product decreases and 

broadens simultaneously. The broadening of the peaks is 

commonly attributed to the structural change in the samples, 

such as formation of amorphous phases, large lattice strains in 

grains, decrease of crystallite size, or embedding of very small 

crystals in an amorphous matrix. X-ray diffraction 

examination studies showed that the milled products contained 

nano-crystallites of disordered NiTi (with a mean crystallite 

size of ~30nm) and an amorphous phase (Figure 1a). A new 

broad diffuse scattering halo at abo -44° can be 

observed after 10h of milling, which implies that the milled 

product becomes partially amourphized. It is found that further 

milling enhances the formation of the amorphous phase. The 

diffraction lines corresponding to fcc nickel (111) become 

broad and shift towards low angles with increasing milling 

time; this is attributed to increasing the lattice parameter of 

nickel fcc structure with increasing the milling times. 

In order to evaluate the crystallite size of the powders, the 

powders are further examined by TEM. Bright-field image 

with corresponding electron diffraction pattern for the 25h 

milled product is shown in Fig. 1b. It can be seen that the 

approximate grain size of the milled product are 20-40 nm. 

The corresponding diffraction pattern using smallest selected 

area aperture showed several even and broad rings. The rings 

were found to be consistent with NiTi nano-crystalline 

structure. Also, the first wide ring may be indicative of 

coexistence of substantial amorphous phase. 

Figure 1. (a) X-ray pattern of the milled product for 25h. (b) TEM 

bright field and corresponding selected area diffraction pattern 

micrographs of 25h milled product. The key of the diffraction pattern 

is shown at the top left. 

In summary, nano-crystalline NiTi-based powder was 

achieved using mechanical alloying of elemental Ni and Ti 

powder mixtures. NiTi mean crystallite size after 25h of 

milling was found to be ~30 nm. In addition, an amorphous 

NiTi phase was detected. 

*corresponding author fkashani@ut.ac.ir 

[1] A. Kapanen, J. Ilvesaro, A. Danilov, J. Ryhanen, P. Lehenkari and 

J. Tuunkkanen, Biomaterials, 23, 645 (2002). 

[2] B. Y. Li, L. J. Rong, Y. Y. Li and V. E. Gjunter, Scripta Mater, 

44, 823 (2001). 

[3] A. Kapanen, J. Ilvesaro, A. Danilov, J. Ryhanen, P. Lehenkari and 

J. Tuukkanen, Biomaterials, 23, 645 (2002). 

[4] D. S. Grummon, J. A. Shaw and A. Gremillet, Applied Physics 

Letters, 82, 2727 (2003). 

[5] A. Takasaki, Physica Status Solidi A, 169, 183 (1998). 




Oxidation Behaviour of Sol-Gel Derive d Alumina/Silicon Carbide Nanocompos ite Powde rs 

Yilmaz Firat Birtane 1 ,Cem Kahruman 1 and Suat Yilmaz 1 * 

1 Department of Metallurgical and Materials Engineering, Istanbul University, Avcilar, 34320 Istanbul Turkey 

Abstract-In this study, the properties of Al 2 O 3 /SiC nanocomposite powders which were obtained by sol-gel method were examined. Firstly, 

boehmitic sol was prepared via sol-gel route and than 5wt% -SiC (



Nano TiO 2 Doped Hydroxyapatite Composites 

Azade Yelten 

1 , Suat Yilmaz 1 *, S. Agathopoulos, 2 and Faik Nuzhet Oktar, 3-4 

1 Department of Metallurgical and Materials Engineering, Istanbul University, 34320, Avcilar, Istanbul, Turkey 

2 Materials Science and Engineering Department, Ioannina University, Greece 

3 Department of Radiology, School of Health Related Professions , Marmara University, Istanbul, Turkey 

4 Nanotechnology and Biomaterials Application and Research Centre, Marmara University, Istanbul 34722, Turkey 

Abstract-We predict here that nano-dopants in correct amounts could be very useful to prepare hydroxyapatite (HA) composites, which were 

not be used at load-barrier conditions. Here show that nano dopants could be effective if correct amounts in the HA matrix will used. 

The number of treated skeletal deficiencies steadily 

increases in a global scale. Effective ways for bone 

replacements and enhancement of bone formation together 

with research directed to find ideal biomaterials for grafting 

purposes, which will feature biocompatibility and production 

simplicity and economy, are required. Hydroxyapatite (HA, 

Ca 10 (PO 4 ) 6 (OH) 2 ), the main mineral component of bones and 

teeth, is among the leading biomaterials satisfying these 

requirements. Nevertheless, pure HA features low mechanical 

strength and fracture toughness, which limit their use in loadbearing 

applications [1]. The applications of pure HA are 

restricted to non load-bearing implants due to the poor 

mechanical properties of HA. Doping with (biocompatible or 

even better bioactive) oxides may result in strong HA 

composites [2]. There are lots of studies using various oxides, 

whiskers in the literature but they are almost nothing about 

adding nano-dopants into HA matrix in the recent literature. 

The aim of this study is to produce stronger HA composites 

adding nano-dopands than regular composites. 

Calcined (at 850 °C) HA powder was produced from fresh 

bovine femoral bones (BHA). The nano-dopant TiO2 was 

obtained from Sigma Aldrich TiO with

P 



Screening of Antioxidant Activity and Phenolic Content of Selected Food Items Cited in the Holly 

Quran 

1 

1 

1 

USafaa Y. QustiUP P*, Ahmed N. Abo-khatwaP Pand Mona A. Bin LahwaP 

1 

PDepartment of Biochemistry- King Abdulaziz University- Jeddah, SA. 

Abstract-Antioxidants are vital substances, which possess the ability to protect the body from damages caused by free radical-induced 

oxidative stress. A variety of free radical scavenging antioxidants is found in a number of dietary sources. The main objective of this study 

was to assess the antioxidant activity of a number of fruits, vegetables and grains. Therefore, (16) edible plant materials cited in the Holly 

Quran were selected to determine their antioxidant properties. The antioxidant capacity of these extracts were investigated based on their 

ability to scavenge (DPPH) stable free radical. Phenolic content of the extracts was determined using Folin-Ciocalteau reagent. Results of the 

antioxidant capacity were classified in three categories; (1) Fruits possessing extremely high free radical scavenging activity or antioxidant 

activity (ICR50R



Preparation and Characterization of Nanostructured ZnS Thin Films Grown on Glass and 

Monocrystalline Si Substrates 

R. Sahraei 1* , G. Nabiyouni 2 and A. Daneshfar 1 

1 Department of Chemistry, University of Ilam, Ilam P.O. Box: 65315-516, Iran 

2 Department of Physics, University of Arak, Arak, Iran 

Abstract— Nanocrystalline zinc sulfide thin films were prepared by a new chemical bath deposition technique onto glass and 

silicon (111) substrates. Deposition takes place at a temperature of 70 ºC and a pH of 6.0, from an aqueous solution containing 

zinc acetate, thioacetamide, and ethylenediamine. Microstructure analysis using atomic force microscopy shows that the films 

deposited on glass substrates contain 28-30 nm clusters, whereas much larger clusters (around 80-120 nm) comprise the films 

deposited on silicon (111) substrate. X-ray diffraction analysis indicates that both the ZnS films deposited on glass and Si 

substrates have cubic zincblende structure. Direct band gap energy for these samples was measured to be in the range of 3.97- 

4.00 eV. 

Recently, the II-VI compounds semiconductor thin films 

have received an intensive attention due to their application in 

thin film solar cells [1]. Among these metal chalcogenides, 

ZnS is an important semiconductor material because of its 

broad direct band gap energy (~3.6 eV) at room temperature 

[2]. Various techniques have been employed to fabricate ZnS 

thin films, such as, electrodeposition, pulsed-laser deposition, 

chemical vapor deposition (CVD), and chemical bath 

deposition (CBD) [3, 4]. 

In this work, we report deposition of nanocrystalline zinc 

sulfide thin films on the glass and mono-crystalline Si 

substrates using a weak acidic bath in which ethylenediamine 

acts as a complexing agent and thioacetamide acts as a source 

of sulfide ions. Atomic force microscopy (AFM), X-ray 

diffraction (XRD), and UV-Vis spectrophotometery are used 

to investigate the surface morphology, structural, and optical 

properties of the nanostructured ZnS thin films. We show how 

the morphology and surface roughness of the ZnS thin films 

depend on the substrate type. 

Figure 1. AFM images (two- dimensional (2D)) of CBD ZnS thin films 

on (a) Si and glass substrate (b). 

X-ray diffraction patterns of the ZnS film grown on glass 

and monocrystalline Si substrate show three distinguished 

peaks at the angles of 28.6º, 47.7º and 56.5º reveal a cubic 

lattice structure and can be assigned to the (111), (220), and 

(311) plans, respectively. Broadening of diffraction peaks in 

the XRD pattern of the ZnS film is attributed to the 

nanometer-sized crystallites. The calculated average size of 

nanocrystallites, using Scherrer equation is found to be about 

4.5 and 8 nm for the ZnS films deposited on glass and single 

crystal Si substrates, respectively. 

The average transmittance of ZnS films is calculated to be 

84%, 78%, 74% and 71%, respectively, in the visible 

wavelength region. As it is clear from spectra the films have a 

steep optical absorption feature, indicating good homogeneity 

in the shape and size of the nanocrystallites and low defect 

density near the band edge [5]. The band gap energy (E g ) was 

determined to be in the range of 3.97-4.00 eV for the ZnS 

films with deposition times varying from 4 to 16 hours. These 

values are rather larger than the literature value for the bulk 

ZnS (~ 3.6 eV). The result could be attributed to the quantum 

size effects as expected from the nanocrystalline nature of the 

ZnS thin films [6, 7]. 

Figure 1 (a) and (b) illustrates two-dimensional AFM 

images of the ZnS thin films deposited on monocrystalline Si 

and commercial glass slide substrates, respectively. The thin 

film deposited on Si substrate is made of aggregates (clusters) 

with a square-like surface morphology, whereas much finer 

aggregates with an isosceles triangular surface morphology 

comprise the film deposited on glass substrate. As can be seen, 

the films deposited on the glass substrate contain smaller 

clusters (average grain size of around 28-30 nm in diameter) 

and have more surface aggregates than those deposited on Si 

substrate (average grain size of around 80-120 nm in 

diameter). 

In summary, we have successfully deposited the 

nanocrystalline ZnS thin films onto glass and monocrystalline 

Si substrates, from a chemical bath at temperature of 70 °C, 

and using ethylenediamin as a complexing agent. The XRD 

measurements indicate that the structure of the ZnS thin films 

is cubic. In our experiment, based on the optical transmission 

measurements, the band gap energies are calculated to be 

between 3.97-4.00 eV for the ZnS films with different 

thicknesses. Morphology and optical properties of the ZnS 

films were characterized using AFM and UV-Visible 

spectroscopy. 

*Corresponding author: reza_sahrai@yahoo.com 

[1] M. Bär, A. Ennaoui, J. Klaer, R. Sáez-Araoz, T. Kropp, L. Weinhardt, C. 

Heske, H.-W. Schock, Ch.-H. Fischer, M.C. Lux-Steiner, Chem. Phys. Lett. 

433, 71 (2006). 

[2] J. Mu, Y. Zhang, Appl. Surf. Sci. 252, 7826 (2006). 

[3] R.S. Mane, and C.D. Lokhande, Mater. Chem. Phys. 65, 1 (2000). 

[4] A. Goudarzi, G. Motedayen Aval, S. S. Park, . Choi, R. Sahraei, M.Habib 

Ullah, A. Avane, and C. S. Ha, Chemistry of Materials 21, 2375 (2009). 

[5] C. Hubert, N. Naghavi, B. Canava, A. Etcheberry, and D. Lincot, Thin 

Solid Films 515, 6032 (2007). 

[6] R. Sahraei, G. Motedayen Aval, A. Baghizadeh, M. Lamehi-Rachti, A. 

Goudarzi, M. H. Majles Ara, Materials Letters 62, 4345 (2008). 

[7] K. Yamaguchi, T. Yoshida, D. Lincot, H. Minoura, J. Phys. Chem. B 107, 

387 (2003). 




Nanos tructured GaN on Silicon Fabricated by Electrochemical and Laser-induced Etching 

Asmiet Ramizy 1 , Z. Hassan 1 *and Khalid Omar 1 

1 Neon-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang, Malaysia 

Abstract-Nanostructured GaN layers have been fabricated by electrochemical and laser-induced etching (LIE) processes. The etched samples 

exhibited dramatic increase in photoluminescence intensity as compared to the as-grown samples. The Raman spectra also displayed stronger 

intensity peaks which were shifted and broadened as a function of etching parameters. 

Wide-gap III–V nitride semiconductors such as GaN are 

most promising for blue or ultraviolet (UV)-emitting 

devices. For the fabrication of GaN nanostructures-based 

devices, it is important to control the size of nanocrystals as 

well as to develop a reliable means of monitoring the size 

distributions of the nanocrystallites in these luminescent 

materials. In recent years, processing techniques for III– V 

nitrides nanostructures have been successfully established, 

especially for crystal growth, while the most suitable etching 

method is not still concrete because of the excellent chemical 

stability and high hardness of these compounds. Plasma 

etching [1] and reactive ion etching (RIE) [2, 3] have mainly 

been applied so far to etching of III–V nitride crystals. With 

these processes, however, damage by ion or plasma 

bombardment is a serious problem. 

In this work, the fabrication of nanostructured porous GaN 

by electrochemical etching (Figure 1) and laser-induced 

etching (Figure 2) have been attempted. Laser processing 

has the advantages of not causing damage or contamination, 

as well as of special selectivity with high resolution and high 

efficiency; however, there are few reports on the laser 

processing of III–V nitride crystals. The studies on the 

fundamental properties of these nanostructures are very 

important due to their unique structural and optical 

properties relative to the bulk form of the corresponding 

materia l. 

Figure 1. The electrochemical etching set-up 

GaN thin films were grown on n-type Si (111) substrate 

using Veeco model Gen II molecular beam epitaxy (MBE) 

system. The GaN samples with (0001) orientation, carrier 

concentration of 2.1 10 19 cm -3 , and thickness of 0.47 um 

were placed in an electrolyte solution with ethanol 99.999%: 

HF40% (4:1), and applied with current density of 75mA/cm 2 

for the electrochemical etching, and for the laser-induced 

etching, power density of 12 W/cm 2 fro m a laser diode 

(=635 nm, 1.90 eV) was applied. The etching duration was 

12 min. 

The as-grown samp les exh ibited relatively surface 

morphology. Electrochemical etching resulted in the 

formation of pores structures with different sizes and shape. 

The etched surface became hexagonal, and pores structures 

are confined to smaller size. In addition, the pores walls were 

very thin with some short thin tips at the top. On the other 

hand, the surface morphology of the sample obtained after 

laser induced etching process shows deep and extremely thin 

pores. 

Photoluminescence (PL) spectra showed blue shift 

luminescence relative to the as-grown sample. The band 

edge emission wavelength shifted from 362.0 to 335.0 nm 

for the electrochemically etched sample, and to 346.5 for the 

laser-induced etched sample. The average diameter of the 

GaN crystallites was about 7-10 n m, as determined fro m the 

PL data. The Raman spectra for the etched samples revealed 

shifted and broadened peaks relative to the as grown GaN 

which can be attributed to the quantum confinement effects 

on electronic wave function of the GaN nanocrystals. 

In summary, GaN nanostrutures have been fabricated by 

two different etching techniques. The quantum confinement 

effects are considered to control the mechanism of the 

lu minescence in the nanocrystallites. 

This study was supported by FRGS grant and Universiti 

Sains Malaysia. 

*Corresponding author: zai@usm.my 

[1] S.A. Smith, C.A. Wolden, M.D. Bremser, A.D. Hanser, R.F. 

Davis, W.V. Lampert. Appl. Phys. Lett. 71, 3631 (1997) 

[2] D. Basak, M. Verdú, M.T. Montojo, M.A. Sánchez-Garcia, F.J. 

Sánchez, E. Munõz, E. Calleja. Semicond. Sci. Technol. 12, 1654 

(1997) 

[3] J. B. Fedison, T. P. Chow, H. Lu, I. B. Bhat, J. Electrochem. 

Soc. 144, L221 (1997) 

Figure 2. The laser-induced etching set-up 




Effect of Porosity on the Characteristics of GaN Grown on Sapphire 

A. Mahmood 1,2 , Z. Hassan 1 *,F.K. Yam 1 S.K. , Mohd Bakhori 1 and L.S. Chuah 3 

1 Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia 

2 Department of Applied Sciences, Universiti Teknologi MARA, 13500 Permatang Pauh, Penang, Malaysia 

3 Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia 

Abstract-We investigated the structural and optical characteristics of porous GaN obtained by UV assisted electrochemical etching. SEM 

micrographs indicated that the average pore size for samples was around 0.16 . Photoluminescence (PL) measurements revealed 

that the near band edge peak of all the porous samples were red-shifted. Raman spectra exhibited the shift of E 2 (high) to the lower frequency for 

porous samples. 

The preparation of porous semiconductors has attracted a 

great deal of research interest in recent years, primarily due to 

the potential for intentional engineering of properties not 

readily obtained in the corresponding crystalline precursors as 

well as the potential applications in optoelectronics, chemical 

and biochemical sensing [1-4]. When porosity is formed, these 

materials exhibit various special optical features, for instance, 

the shift of bandgap [5], luminescence intensity enhancement 

[6], as well as photoresponse improvement [7]. To date, 

porous silicon (Si) receives enormous attention and has been 

investigated most intensively; however the instability of 

physical properties has prevented it from large scale 

applications [8]. Thus, this leads to the development of other 

porous semiconductors, for instance, the wide bandgap 

materials such as GaN [2]. 

In this work, porous GaN layers were prepared by ultraviolet 

(UV) assisted electrochemical etching method using 

unintentionally doped (UID) n-type GaN films grown on 

sapphire (0001) substrate with GaN thickness of 

Platinum (Pt) wire was used as a cathode electrode. The wafer 

was cleaved into few pieces and subsequently dipped into 2 % 

concentration of KOH electrolyte under illumination of 500 W 

UV lamp for various anodization duration and applied 

voltages. Table 1 shows the anodization conditions for 

preparation of porous GaN samples. 

Table 1. Anodization condition for the samples 

Sample 

KOH 

Voltage Duration 

concent rat ion 

wt . % (V) (min) 

SU1 2 15 15 

SU2 2 20 20 

SU3 2 20 30 

SU4 2 30 20 

SU5 2 30 30 

Scanning electron microscopy (SEM) images of the porous 

GaN samples generated under different conditions were shown 

in Figure 1. From the SEM micrographs, the pore size of all 

the samples was found to be varied widely, and different 

shapes could be observed. For the SU1 and SU2 samples, the 

etching was in the initial stage; pores started to form, and the 

size of the pores were relatively small, therefore mostly 

circular shaped structures were observed. For SU3, SU4 and 

SU5 samples, the surface became relatively rough. SEM 

images revealed that the average pore size for samples were 

around 0.16 34 

samples was found to be influenced significantly by the 

anodization duration and the change of applied voltage. The 

size of the pores increased with the increase of the anodization 

duration. Furthermore, it can be observed that the pores are 

not distributed uniformly. On the other hand, it is interesting 

to note that the porous GaN prepared by the electrochemical 

etching method does not always produce similar surface 

morphology. 

(a) 

(b) 

(c) 

(e) 

Figure 1. SEM images of different samples. (a) as grown, (b) SU1, 

(c) SU2, (d) SU3, (e) SU4 and (f) SU5. 

Photoluminescence (PL) measurements revealed that the 

near band edge peak of all the porous samples were redshifted; 

moreover, the PL intensity enhancement was observed 

in the porous samples. The red shift was also ascribed to the 

relaxation of the compressive stress in the porous samples. 

Raman spectra exhibited the shift of E 2 (high) to the lower 

frequency for porous samples. In contrast, the forbidden 

modes, A 1 transverse optical (TO) and E 1 (TO) phonon modes 

were present in Raman spectra only for SU3, SU4 and SU5. 

In summary, the studies showed that porosity could 

influence the structural and optical properties of the GaN. 

Support from FRGS, USM Postgraduate Grant and 

Universiti Teknologi MARA is gratefully acknowledged. 

*Corresponding author: zai@usm.my 

[1] H.Sohn, S. Letant, M.J. Sailor, W.C. Trogler, J. Am. Chem. Soc. 

122, 5399 (2000) 

[2] V.S.Y. Lin, K. Motesharei, K.P.S. Dancil, M.J. Sailor, M.R. 

Ghadiri, Science 278, 840 (1997) 

[3] L.T. Canham, Appl. Phys. Lett. 57, 1046 (1990) 

[4] A.G. Cullis, L.T. Canham, P. D.J. Calcott, J. Appl. Phys. 82, 909 

(1997) 

[5] X. Li, Y.-W. Kim, P.W. Bohn and I. Adesida, Appl. Phys. Lett. 

20, 980 (2002) 

[6] M.A. Steven-Kaleeff, I.M. Tiginyanu, S. Langa, H. Foll and H.L. 

Hartnagel, J. Appl. Phys. 89, 2560 (2001) 

[7] M. Mynbaeva, N. Bazhenov, K. Mynbaev, E. Evstropov, S.E. 

Saddow, Y. Koshka and Y. Melnik, Phys. Status Solidi B 228, 589 

(2001) 

[8] P.M. Fauchet, L. Tsybeskov, C. Peng, S.P. Duttagupta, J. Von 

Behren, Y. Kostoulas, J.M.V. Vandyshev and K.D. Hirschman, IEEE 

J. Sel. Top. Quantum Electron. 1, 1126 (1995) 

(d) 

(f) 


P –12 



Computing Closed Walks of Nanostar Dendrimers 

G. H. Fath-Tabar 1 * andA. R. Ashrafi 2 

1 Department of Mathematics, Faculty of Science, University of Kashan, Kashan 87317-51167, I. R. Iran 

2 Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran 

Abstract-Suppose G = (V, E) is a simple graph. The sequence of vertices v 0 v 1 …v t v 0 is called a closed walk if v i v i+1 are in E(G). In this paper, 

the number of closed walks (CW(G, k)), k = 1,2,…, 10 and k = 11, 13, 15, … for three types of nanostar dendrimers are presented. 

Dendrimers are highly branched macromolecules. They are 

being investigated for possible uses in nanotechnology, gene 

therapy, and other fields. The nanostar dendrimer is part of a 

new group of macromolecules that appear to be photon 

funnels just like artificial antennas. The topological study of 

these macromolecules is the aim of this article. 

In this paper, the word graph refers to a finite, undirected 

graph without loops and multiple edges. Let G be a graph and 

{v 1 , ..., v n } be the set of all vertices of G. The adjacency 

matrix of G is a 01 matrix A(G) = [a ij ], where a ij is the 

number of edges connecting v i and v j . The spectrum of a 

graph G is the set of eigenvalues of A(G), together with their 

multiplicities. Throughout this paper our notation is standard 

and taken mainly from the standard book of graph theory. A 

walk is a sequence of graph vertices and graph edges such that 

the graph vertices and graph edges are adjacent. A closed walk 

is a walk in which the first and the last vertices are the same. 

A closed walk has backtracking if, in the closed walk, an edge 

appears twice in immediate succession. For more information 

1-3 

about these concept you can see referencesP 

P. 

n+2 

Cl ( NS1[ 

n], 

2k 

1) 

0, Cl ( NS [ n], 

2) 21.2 - 30, 

n+2 

Cl ( NS1[ 

n], 

4) 48.2 1230. 

1 

 

*Corresponding author: ashrafi@kashanu.ac.ir 

[1] G. H. Fath-Tabar, M. J. Nadjafi-Arani, M. Mogharrab and A. R. 

Ashrafi, MATCH Commun. Math. Comput. 63 (2010) 145. 

[2] I. Gutman, Graph Theory Notes of New York 27, 9 (1994). 

[3] P.V. Khadikar and S. Karmarkar, J. Chem. Inf. Comput. Sci. 41, 

934 (2001). 

Figure 1. The Nanostar Dendrimer NSR2R[2]. 

We now consider the nanostar dendrimer NS[n], Figures 1. 

Using a simple calculation, one can show that |V(NS[n])| = 

n+1 

n+1 

18.2P and |E(NS[n])| = 21.2P 

P-15. We prove that: 

The number of closed walks of the nanostar dendrimer 

NS[n ] are co mputed as follows: 




Synthesis and Structural Study of L1 0 - FePt Nanoparticles 

M. Farahmandjou 1 * 

1 Islamic Azad University, Varamin -Pishva Branch, Varamin, Iran 

Abstract 

A comparison of the synthesis and structural properties of magnetic FePt nanostructures is presented. The FePt nanop article system is an 

excellent candidate for ultrahigh-density magnetic recording. Monodisperse FePt nanoparticles were synthesized by superhydride method. The 

composition of nanocrystals was determined by EDS. Transmission electron microscopy (TEM) images show monosize FePt nanoparticles with a 

diameter of 3.5 nm. The average distance between the monodispesre particles is nearly 2 nm. In order to determine the stability of nanoparticles 

colloidal solution, a measure of stability is defined via spectrophotometery analysis. The magnetic measurement shows that as-made FePt is first 

superparemagnetism at room temperature and after annealing at 600 o C for 4 hours, the nanoparticles can ability to do phase transition to L1 0 - 

FePt and coersivity of nanocrystals is raised to 6.5 kOe. 

*Corresponding author: Farahmand_ph@yahoo.com 




TEM study of Al-SiC nanocomposite powders 

Taha Rostamzadeh, 1,2 * and Hamid Reza Shahverdi 2 

1 Department of Electronic Engineering, Faculty of Engineering, Islamic Azad University, Garmsar Branch, Garmsar, Iran 

2 Department of Nano-Material Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran 

Abstract-In this study Al-5%SiCp nanocomposite powders has been successfully synthesized by high-energy planetary milling of Al and SiC. 

The nanocomposite powders microstructure have been investigated by transmission electron microscopy (TEM), scanning electron microscopy 

(SEM), and X-ray diffraction (XRD) analyses. The results show that after 25 h of milling, nanocomposite powders composed of near-spherical 

particles were obtained. 

Incorporation of ceramic particulates into the metallic matrix 

can be accomplished by several techniques, such as moltenmetal 

routes or solid-state processing [1-3]. It should be noted 

that Al-SiC composites are difficult to obtain by conventional 

melting-based methods due to the poor wettability between 

molten Al and the SiC. The mechanical alloying process 

involves repeated welding and fracturing of a mixture of 

powder particles to produce an extremely fine microstructure 

of Al-SiC nanocomposite [4-6]. As the morphology of 

nanocomposite powder has considerable effect on the 

properties of mechanically milled powder, this study was 

designed and undertaken to consider the microstructure of 

nanocomposite powder. 

In this work, Aluminum and SiC powders were mixed to 

give a nominal composition of Al-5%SiC. The preparation of 

the nanocomposite powders by mechanical milling of the 

mixed powder was carried out using a high-energy planetary 

ball mill in an argon atmosphere. A rotational speed of 

300 rpm and a ball-to-powder weight ratio of 15:1 were 

employed. To avoid agglomeration and the cold welding of 

powder particles, stearic acid amounting to 1.5 wt% of the 

total powder charge was used as a process control agent. 

parallel appearance probably related to severe deformation 

come by mechanical alloying process. 

Figure 2. SEM morphologies of Al–5% SiC after 25h of MA 

Figure 3. (a) Bright-field image (BFI) and (b) selected-area 

diffraction pattern SADP) of Al-5%SiC milled powders for 25h 

Figure 1. X-ray diffraction pattern of Al-5%SiC milled powders for 

25h 

Figure 1 shows the XRD patterns of the nanocomposite 

powder. The final product consists of Al and SiC mixture and 

there is no formation of any other phase such as Al 4 C 3 and Si. 

Fig. 2 shows the SEM image of the agglomerated spherical 

nanocomposite powder obtained after 25 h of MA. 

Figs. 3 (a) and (b) show a bright-field image (BFI) and a 

selected-area diffraction pattern (SADP), respectively, of the 

nanocomposite powder obtained after 25 h of ball-milling. The 

bright-field image indicates that there are some nearly 

spherical nanoparticles, approximately 5–20 nm in diameter, 

and some layered structures of greater size (Fig. 3 (a)). The 

SADP shows a quite sharp ringspot pattern characteristic of 

diffracting polycrystalline co mponents. EDS analysis proved 

the existence of Al and SiC components. Fig. 4 shows BFI 

image of powders in high magnification. There are some 

nearly parallel lines in that. As the distance between this lines 

are more than the space of crystallite p lanes, theses nearly 

Figure 4. Bright-field image of nanocomposite powders in high 

magnification 

In summary, by using high energy ball milling of the 

mixture of powders, SiC nanometer sized particle reinforced 

Al–SiC composite powder can be obtained. The TEM analysis 

and morphological study has revealed that the agglomerated 

powders consist of many layers and that they contain 

embedded spherical nanoparticles. In addition it seems that 

MA process induces severe plastic deformation in the 

composite. 

*Corresponding author: shahverdi@modares.ac.ir 

[1] D. B Miracle, Composites Science and Techno logy 65, 2526– 

2540 (2005) 

[2] M. Sherif El-Eskandarany, Journal of Alloys and Compounds 

279:263-271(1998) 

[3] K.B. Lee, H.S Sim, J. Matter. Sci 36:3179 – 3188 (2001) 

[4] C Suryanarayana, Progress in Materials Science 46:1-184 (2001) 

[5] D.L. Zhang, Progress in Materials Science 49:537–560 (2004) 

[6] S.M Zebarjad, S.A Sajjadi Materials and Design 27:684–688 

(2006) 







Abstract—Nucleation and growth mechanism during formation of poly(AA) films on gold substrates was intestigated. 

Repeated potential cycling by using cyclic voltammetry and potential controlled electrolysis techniques have been performed 

to synthesize poly(AA) thin films on gold working electrodes in the solution containing 0.1 mM AA and 0.1 M phosphate 

solution (pH:6.2). Chronoamperometry, STM (Scanning Tunneling Microscopy), AFM (Atomic Force Microscopy), and UVvis. 

absorption spectroscopy techniques were applied for the characterization of prepared polymeric films. 






















. 


The redox behaviour of dyes has been under study for 

nearly 65 years [3-7]. Chen et al. [6] prepared poly(AA) films 

in different pH’s and found that the optimum pH of the 




In this study, we have investigated nucleation and 

growth mechanism during the formation of poly(AA) films on 

gold substrates. Repeated potential cycling by using cyclic 













two cases are 

2 




2 

3 


J prog 

Figure 2. Experimental current-time transients for different 

electrooxidation potential values. The non-faradaic charging currents 

in the absense of AA have been subtracted from these data 

STM (Scanning Tunneling Microscopy), and AFM 

(Atomic Force Microscopy) techniques was applied to 

investigate poly(AA) film surface structure. We have also 

studied the optical properties of the prepared polymeric films 

by using UV-vis. absorption spectroscopy. 





[2] G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science 

270, 1789 (1995) 


[4] A. A. Karyakin, A. K. Strakhova, E. E. Karyakina, S. D. 

Varfolomeyev, A. K. Yatsimirsky, Bioelectrochem. Bioenergetics 32, 

35 (1993) 




[8] A. Bewick, M. Fleiscmann, H. R. Thirsk, H. R. Trans Faraday 

Soc. 58, 2200 (1962) 





Oxidation and Hot Corrosion Resistance of Atmospheric Plasma Sprayed Conventional and 

Nanostructured Zirconia Coatings 

Ahmad Keyvani 1 *, Mohsen Saremi 1 and Mahmoud Heydarzadeh Sohi 1 

1 School of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran. P. O. Box 11365-4563, Tehran, Iran 

Abstract-Conventional and nanostructured zirconia coatings were deposited on In-738 Ni supper alloy by atmospheric plasma spray technique. 

The oxidation was measured at 1100 °C and hot corrosion resistance of the coatings were measured at 1050 °C using an atmospheric electrical 

furnace and a fused mixture of vanadium pent oxide and sodium sulfate respectively. According to the experimental results nanostructured 

coatings showed a better oxidation and hot corrosion resistance than conventional ones. The improved oxidation resistance could be explained by 

the change of structure to a dense and more packed structure in the nanocoating. The improvement in hot corrosion resistance was not as good as 

the oxidation but much better than conventional coating. 

Hydrogen Plasma sprayed thermal barrier coatings based on 

yttrium stabilized zirconia YSZ, have been applied to hot 

section components of gas turbine engine to increase the inlet 

temperature of the combustion chamber [1-3]. Due to low 

density, high hardness, good stiffness, strength and 

refractoriness, zirconia based ceramics are considered as a 

good selection to be used in thermal and wear applications [4]. 

The coatings sprayed onto cylinder liners and turbine work 

pieces could enhance the thermal efficiency of internal 

combustion aerial and gas turbines engines [5]. 

The TBC coatings are subject to the harsh atmosphere of the 

combating chamber and facing thermal shock, oxidation and 

hot corrosion phenomena. Many reports revealed that 

resistance against: thermal shock, oxidation and hot corrosion 

resistances of TBC coatings depended mainly on the coating 

microstructure as well as to the heating conditions. Therefore 

by controlling the microstructure it would be possible to 

control the durability of the TBC coatings. It could be 

improved by use of controlled porosity, segmentation, microcracking, 

residual stress control and post-spray thermal 

treatment [6-11]. In recent years, nanostructured zirconia 

coatings deposited by atmospheric plasma spraying have 

attracted some research interest because of some superior 

properties than that of traditional zirconia coatings [12, 13]. 

Some investigators have reported that nanostructured coatings 

are expected to improve mechanical properties, show better 

thermal resistance, and reduce thermal conductivity compared 

to their coarse-grained coatings [14-18]. Few articles were 

reported on thermal shock resistance of the nanostructured 

zirconia coatings but rarely their oxidation and hot corrosion 

resistances were investigated. Many methods can be used to 

apply nanostructured TBC such as thermal spary methods, gascondensation 

process, electron beam vaporization, EBPVD, 

magnetron sputtering, and electrochemical deposition [19, 20]. 

Recently, thermal spraying has also been used to prepare 

nanoscale layers [21, 24]. Therefore, this work aims to 

investigate and compare the oxidation and hot corrosion 

resistances of nanostructured zirconia coating applied by the 

plasma sprayed with conventional ones. 

In the present study Nickel based super alloy (Inconel 738) 

was used as substrate. All specimens were in the shape of a 

disk (Ø25×10mm). The specimen’s surfaces were shot-blasted 

with alumina grit in the range of 50-80 mesh and under a 

pressure of 40-50psi. The surface oxides were removed using 

methyl ethyl kethon cleaner, and degreasing was performed by 

trichloro ethylene vapor. After washing they were preheated at 

150-200°F and finally the following coatings were applied 

over specimens. Argon was used as primary plasma gas whilst 

hydrogen was the secondary gas. 

Amdry 962 trade mark NiCrAlY micro-powders, micro-sized 

Metco 204NS-G trade mark YSZ conventional zirconia 

powders were used. The nanosize yttria stabilized zirconia 

powders were prepared via chemical co-precipitation process, 

with particle sizes of



Mechanical Properties of Graphite and Nano Tubes 

1 * 

1 r University, Faculty of Engineering, Bornova-,35100,Turkey 

Abstract- Graphite is one of the special form of carbon. Carbon nanotubes can be thought of as a sheet of graphite (a hexagonal lattice of 

carbon) rolled into a cylinder. These tubes exhibit important mechanical properties: the Young's modulus is over 10 12 Pascal. Hardness of 

graphite is quite anisotropic. Graphite is very soft in c-axis direction, but it is very hard in the directions inside the hexagonal-planes. Young 

Modulus of graphite along a-axis is 103x10 10 N/m 2 but along c-axis is about 3.61x10 10 N/m 2 . So in basal plane bonds are 30 times 

stronger, that means binding forces among the atoms in hexagonal basal planes are very strong. This property of graphite in some nano-dy es 

or coating is used to protect the object against corrosion and scratches. 

In HCP crystal, c/a ratios are quite important for atomic 

binding forces. In Dy (1.574) and Mg (1.624) c/a ratio is 

very close to ideal value (1.633), therefore elastic 

properties nearly isotropic. But in Zn (1.86)and graphite 

( 2.31), we have a large anisotropy. Especially in graphite 

this is quite clear. 

Young Modulus along a-axis is 103x10 

10 N/m 2 and 

along c-axis is 3.61x10 10 N/m 2 in graphite (Figure.1). 

Therefore Young’s modulus along a-axis is 30 times 

greater than that of in c-axis. Longitudinal sound velocity 

in a-axis is 21 km/s ,4 km/s in c-direction. These 

calculations show that binding forces between the atoms in 

basal plane of the graphite are very strong, these forces 

are quite weak in the c-direction. The weakness of the 

bond explain why graphite is so soft even though its 

melting point is so high. 

Soft materials are easily compressed. Therefore if 

compressibility has high value that material can easily 

compressed or deformed. this means that the atomic 

binding forces are weak in that special direction in the 

substance. 

Ultrasonic velocity is very high in the direction in which 

the binding forces are quite large. Longitudinal wave 

velocity in the basal plane is 21610 m/s but in the c-axis is 

about 4010 m/s in graphite. 

Table 1. Elastic constants of some hexagonal crystals, 

Cij , ( 10 10 N/m 2 ) 

C11 C12 C13 C33 C44 

c/a 

 

Dy 7.31 2.53 2.23 7.81 2.40 1.574 

Mg 5.97 2.62 2.17 6.17 1.64 1.624 

Zn 16.10 3.42 5.01 6.10 3.83 1.856 

Cd 12.10 4.81 4.42 5.13 1.85 1.886 

Grafit 106.0 18.0 1.5 3.65 0.4 2.310 

Table. 2. Ultrasonic velocities at different directions in Dy, Zn, 

Mg, Cd ve graphite 

Velocities Dy Zn Mg Cd Graphite 

(10 3 m/s ) 

vL-c-axis 3.02 2.91 5.87 2.43 4.01 

vS-c-axis 1.67 2.31 3.02 1.46 1.32 

vL-a axis 2.92 4.73 5.77 3.74 21.61 

vS-a axis 1.67 2.31 3.02 1.46 1.33 

Table.3 Young’s modulus and compressibility’s of some 

Hexagon al crystals 

Mg Zn Cd Graphite 

Young’s Modulus 

in a-axis (10 10 N/m 2 ) 

in c-axis (10 10 N/m 2 ) 

4.5 

5.0 

12.0 

3.5 

8.1 

2.8 

103.0 

3.6 

Linear compressibility 

In a- axis (10 -12 m 2 /N) 

In c-axis (10 -12 m 2 /N) 

9.2 

9.7 

1.58 

13.7 

1.5 

16.9 

0.5 

27.0 

Volume compresibility 28.1 16.9 19.9 28.0 

(10 -12 m 2 /N) 

Ayasse ,J.B. , et al, (1979), On the Softening of the Elastic 

Constant C44 in Graphite, Solid State Com. , 5, 659-662. 

 

Magnetic Phases in Dy, J. Physics F: Metal Physics, 8, 247 

Hexagonal Kristallerin Esneklik 

Özellikleri, Y.L. Tezi 

C., e-dergi-http:/joy.yasar.edu.tr,J.of Yasar University, 

Vol:1,No:4, 1-6 (2006) 

Figure 1.Young’s modulus of graphite in a-c plane(10 10 N/m 2 ) 

Carbon nanotubes are the strongest and stiffest materials 

yet discovered in terms of 1Ttensile strength . Multiwalled 

carbon nanotube was tested to have a tensile 

strength of 63 giga pascals (GPa). This means it has the 

ability to endure tension of 6,3 ton on a cable with crosssection 

of 1 mm 2 . Since carbon nanotubes have a low 

density for a solid of 1.3 to 1.4 g·cm , its specific strength 

of up to 48,000 kN·m/kg is the best of known materials, 

compared to high-carbon steel's 154 kN·m/kg. The cables 

made of nano tubes are suggested to be used for spaceelevators 

in near future. These cables may be as long as 

35 000 km and carry space-elevators from the earth to a 

space-ship or to a space-city. 




Synthesis and Modification of Multi-walled Carbon Nano-tubes (MWCNT) for Water Treatment 

Applications 

Mohammed Baghat 1 *, Ahmed Farghali 2 , Mohamed Khedr 2 , 

1 CMRDI, Egypt 

2 

Banii-Sue f university 

Abstract-Fe-Co/CaCO 3 catalyst/support prepared by wet impregnation method is used for preparation of MWCNTs by chemical vapor 

deposition (CVD) of acetylene. CaCO 3 was found to be a good support as a high selective material for deposition of CNTs with high purity. 

Catalyst/support phases were identified by using XRD. The effect of growing time and temperature on carbon yield was studied. The 

structure and purity of CNTs was examined by TEM. The prepared CNTs were purified using chemical oxidation method and the effect of 

acid treatment on CNTs surface was studied by TEM and SEM. The functional groups produced at CNTs surface were examined by using 

FTIR spectroscopy. The funcationalzed CNTs were used for adsorption of some heavy metals and for removal of some organic dyes from 

water. 

*Corresponding author: m_bahgat70@yahoo.com 




Fabrication and Band Gap Engineering of Te rnary Nanofilms by Electroche mical Co-depos ition 

1 *and Ümit Demir 2 

1 Bingöl University, Sciences and Arts Faculty, Department of Chemistry, 12000, Bingöl-Turkey 

2 Atatürk University, Sciences Faculty, Department of Chemistry, 25240, Erzurum-Turkey 

Abstract-We report on the preparation of ternary compound (Bi x Sb 1-x ) 2 Te 3 nanofilms on single crystal Au (1 1 1) using a practical 

electrochemical method, based on the simultaneous underpotential deposition (UPD) of Bi, Sb and Te from the same. Nanofilms are 

characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and reflection absorption- 

FTIR (RA-FTIR). Nanofilms of bismuth-antimony-telluride with various compositions are highly crystalline and have a kinetically preferred 

orientation at (0 1 5) for hexagonal crystal structure. AFM studies show uniform morphology with hexagonal-shaped crystals deposited over the 

entire gold substrate. The compositional and structural analyses reveal that the films are pure phase with corresponding atomic ratios. The 

absorbance studies show that the band gap of nanofilms could be tuned as a function of composition. 

The binary and ternary compound semiconductors such as 

Bi2Te 3 , Sb 2 Te 3 and (Bi x Sb 1-x ) 2 Te 3 have also attracted 

considerable interest due to the requirements of environment 

protection and military applications [1]. Particularly for 

optoelectronic applications, it is important to be able to tune 

the band gap of the material [2]. 

In recent years, extensive attention has been devoted to tune 

the band gap of the binary compound semiconductors through 

the quantum confinement effect [3]. However, progress in this 

field has so far only allowed generating films with thickness 

of a limited range, in which the quantum confinement effect is 

prominent. The superior success of compound semiconductors 

in optoelectronics, integrated circuits and thermoelectric 

applications is largely attributed to the capability of energyband 

gap engineering through composition modulation of 

ternary compound semiconductors [4]. Most of the difficulties 

experienced in research on alloy films lie in devising a 

synthetic scheme to produce the desired ternary homogeneous 

structure. To achieve homogeneous ternary compounds, the 

growth rates of the two constituent materials (Bi2Te 3 and 

Sb 2 Te 3 ) must be equal and the conditions necessary for the 

growth of one constituent cannot impede the growth of the 

other. Furthermore, the structure and bonding of the two 

materials must be sufficiently similar to allow their facile 

mixing; otherwise, the formation of segregated structures such 

as two different binary compounds may occur [5]. 

Various methods have been used to synthesize ternary 

(BixSb 1-x ) 2 Te 3 films. In these studies, ternary compounds 

with only several x values were prepared. No comprehensive 

study has yet been conducted on (Bi x Sb 1-x ) 2 Te 3 compound in 

which x displays a broad variation. Here, we report on the 

electrochemical synthesis of homogeneous ternary films in all 

proportions. 

Recently, we have developed a simple and convenient way 

for electrochemical deposition of compound semiconductor 

materials on the basis of a combination of co-deposition and 

the UPD [6]. We have shown that this method could be used 

to grow highly crystalline binary thin films [7,8]. 

In this study, we report on the synthesis of homogeneous 

ternary nanofilms with various compositions. Nanofilms of 

bismuth-antimony-telluride with various compositions are 

highly crystalline preferred orientation at (0 1 5) for hexagonal 

crystal structure. Studies show uniform morphology with 

hexagonal-shaped nanocrystals. The films are pure phase with 

corresponding atomic ratios. The band gap of nanofilms could 

be tuned as a function of composition. 

(a) 

Figure 1. (a) Absorbance of (Bi x Sb 1-x ) 2 Te 3 nanofilms for different 

compositions, (b) Plot of shifting of XRD peak positions for 

nanofilms, with different compositions. 

In summary, bismuth-antimony-telluride nanofilms could 

be deposited underpotentially by an electrochemical codeposition 

method at room temperature. The prepared 

nanofilms with various compositions were homogeneous and 

in highly crystalline structure. The dependence of the band 

gap on the alloy composition is found to be linear and the 

band gap could be tuned from 0.17 eV to 0.29 eV by changing 

the concentration ratio of (Bi+Sb) solutions during 

electrochemical deposition. These results indicate that ternary 

compound semiconductor thin films could be successfully 

prepared by UPD-based electrochemical co-deposition 

technique. Atatürk University is gratefully acknowledged for 

the financial support of this work. 

*Corresponding author : 2Tiern@mynet.com 

[1] J. Yang, W. Zhu, X. Gao, S. Bao, X. Fan, X. Duan, J. Hou, J. 

Phys. Chem. B 110, 4599 (2006). 

[2] J.B. Chaudhari, N.G. Deshpande, Y.G. Gudage, A. Ghosh, V.B. 

Huse, R. Sharma, Appl. Surf. Sci. 254, 6810 (2008). 

[3] Langmuir, 22, 4415 (2006). 

[4] Y. Liang, L. Zhai, X. Zhao, D. Xu, J. Phys. Chem. B 109, 7120 

(2005). 

[5] R.E. Bailey, S.M. Nie, J. Am. Chem. Soc. 125, 7100 (2003). 

[6] Chem Mater, 17, 

935 (2005). 

[7 

517, 5419 (2009). 

 

(b) 


C 

C 



Synthesis of Multiwalled Carbon Nanotube/Polyphosphazene Nanocomposites 

Elif Okutan 1* , Gülah Ozan 1 , Ferda Hacveliolu 1 , Saadet Kayiran Beyaz 2 , Serkan Yeilot 1 , Adem Klç 1 

1 Kocaeli University, Faculty of Science and Arts, Department of Chemistry, 41380 Izmit- TURKEY. 

2 Gebze Institute of Technology, Department of Chemistry, 41400 Gebze Kocaeli-TURKEY 

Abstract— For improving the solubility of carbon nanotubes (CNTs) through chemical grafting both academic and commercial 

organs have focused on. For this purpose remarkable effort has been devoted to the attachment of polymers to the nanotube surface, as 

macromolecules can be much more effective in modifiying nanotube solubility properties than small molecules. This report demonstrates 

simple and highly effective non-covalent method for the preparation of soluble MWCNT/poly-(4-pyridineoxy)(phenoxy)- 

polyphosphazene nanocomposites. 

Since their discovery the area of research focused on the 

properties and the applications of CNTs [1]. However for the 

wide applications of CNTs in industry the major problem is 

still their poor wettability and dispersibility because of their 

dewetting surface which waters down their great potential [2]. 

Coat them with a polymer through covalent or noncovalent 

surface modification is a general strategy to overcome this 

difficulty [3]. Interestingly CNT/polymer composites could be 

tougher and more stratch-resistant than any other materials [4]. 

Polyphosphazenes (PDCP) have a flexible backbone of 

alternating phosphorus and nitrogen atoms [5]. These 

molecules can have wide range of physicochemical properties 

and also their hydrophobic and hydrophilic balance can be 

controlled by variation of side groups. 

Our research area concerns the synthesis of carbon 

nanotubes by CVD (chemical vapour deposition) method and 

their organic or inorganic functionalization. Synthesis of 

polyphosphazene derivatives and the synthesis of 

nanotube/polyphosphazene (MWCNT/PZS) nanocomposites 

in order to enhance dispersibility of the molecules in solvents 

present also the goal of our researches. 

In this study carbon nanotubes were synthesized by CVD 

method and carboxylic acid functionalized MWCNTs (f- 

MWCNTs) have been obtained by treatment of concentrated 

H 2 SO 4 /HNO 3 (v:v, 3:1). PDCP has been synthesized via ring 

opening polymerization of hexachlorocyclotriphosphazene. 

Pyridineoxy and phenoxy substituted polyphosphazene (PZS) 

has been obtained by the reaction of sodium salts of 4- 

hydroxypyridinoxy and phenoxy with PDCP. A simple 

pathway has been applied for the non-covalent side-wall 

modification of f-MWCNTs using PZSs (Figure 1). The 

MWCNT/PZS nanocomposite was characterized by FTIR, 

Raman, SEM, HRTEM, 31 P NMR, 1 H NMR and TGA 

methods. 

Cl 

P Cl 

250 

N N 

o C 

Cl Cl 

P P 

Cl N 

Cl 

O 

P N 

O n 

Cl 

P N 

Cl 

f-MWCNT, TEA 

ultrasonication 

n 

OH 

NaH, THF 

N Cl 

H 

Figure 1. Schematic formation mechanism of the f MWCNT/PZS 

, 

OH 

N 

O 

P N 

O 

N 

n 

HO 

O 

HO 

O C 

: 

OH 

OH 

O C 

O 

P N 

O 

N 

H 

OH 

O 

C O C O 

: f - MWCNT 

OH 

Cl 

n 

The core shell structures of f-MWCNT/PZS nanocomposites 

were visible by HRTEM. As shown in Figure 2(A,B), the PZS 

shell and the f-MWCNT graphite sheet structures are clearly 

observed. The MWCNT diameter is measured as xxxxnm, and 

the internal diameter is about xxx nm. Typical PZSs were 

covered the MWCNT surface uniformly with shell thickness 

in the range of 3.3-4.7 nm and the lengths of several 

micrometers. 

Figure2. Typical HR-TEM images of f-MWCNT/PZS nanocomposite at a 

scale of 50 nm (A), and 5 nm (B) 

Other characterization methods have demonstrated that the 

MWCNTs are well functionalized without deterioration of 

structure. The structure of the composite material is clarified 

by the NMR measurements. 

In conclusion, we have succeeded in evenly coating lineer 

type polyphosphazene derivative onto the f-MWCNT surface. 

This strategy is expected to beat a path to functionalizing 

CNTs and prepearing new MWCNT-PZS nanocomposites. 

The polyphosphazene having aromatic moieties and 

quaternary nitrogen atoms in pyridine ring made f-MWNTs 

soluble in solvents. Synthetic advantages of PZSs make them a 

promising candidate for an advanced dispersing agent of 

carbon nanotubes. 


Grant No. 106T502 109T619. 

*Corresponding Author: eokutan@gyte.edu.tr 

A 

[1] Iijima, S. , Nature 354, 56–58 (1991). 

[2] Gao, C., He, H., Zhou, L., Zheng, X., Zhang, Y., Chem Mater. 21, 360-370 

(2009) 

[3] D. Tasis, N. Tagmatarchis, A. Bianco and M. Prato, Chem. Rev. 106, 1105 

(2006) 

[4] Ajayan, P. M., Zhou, O. Z., Top. Appl. Phys. 80, 391 (2001) 

[5] Allcock H. R. Chemistry and Applications of Ployphosphazenes (John 

Wiley&Sons. Hoboken, NJ, 2003 

B 




Investigating the Temperature Effect on Velocity Profile in Electroosmotics Driven Nano-Channel 

Mehdi Mostofi 1 *, Davood D. Ganji 2 and Mofid Gorji-Bandpy 2 

1 Islamic Azad University, East Tehran Branch, Tehran, Iran. 

2 Department of Mechanical Engineering, Noshiravani University of Technology, Babol, Iran 

Abstract-In this paper, an electroosmotic flow of an electrolyte in a 15 nm radius nano-channe l will be investigated. This study will be with 

existence of the Electric Double Layer (EDL) with large zeta potentials. In large amounts of zeta potential, numerical study should be employed 

in order to investigate the flow field. Governing equations for electroosmotic phenomena are Poisson-Boltzmann, Navier-Stokes, species and 

mass conservation equations. In most of the literature surveyed works, all physical properties are assumed to be constant, but in this paper, 

temperature will be variable and consequently, some of the fluid properties such as dielectric constant and dynamic viscosity are not constant as 

well. After modeling the variations of the fluid properties through temperature, velocity is investigated in some typical temperatures. 

Nano-channel term is referred to channels with hydraulic 

diameter less than 100 nanometers [1]. 

Concentrating surface loads in liquid – solid interface makes 

the EDL to be existed in electroosmotic phenomena. If the 

loads are concentrated in the end of nano-channels, a potential 

difference will be generated that forces the ions in the nanochannel. 

However, induced electric field 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 the 

problem based on the curvilinear coordinates system. Also, all 

of them studied the problem with existence of the pressure 

gradient while in the modern applications, the pressure 

gradient can be eliminated and consequently, solving the 

problem considering this fact is necessary. In this paper, 

velocity profiles for large zeta potentials without pressure 

gradient will be studied based on the curvilinear coordinates in 

a capillary tube. 

Governing equations in electroosmotic phenomena are 

species and mass conservation, Navier-Stokes and Poisson- 

Boltzmann equations [5]. By some simplifications, set of 

nonlinear differential equations will be identified for bulk 

flu id: 

1 

 

r 

X p 

X m 

 

2 

(1) 

r r 

r 

 

1 u 

 

e 

E0 

RT 

r 

 

X 

p 

X 

m 

 

2 

(2) 

r r 

r 

F U 

0 

According to [5], we can explore the following assumption for 

nano-tube bulk fluid: 

1 

sinh 

 

 

r 

 

2 

(3) 

r r 

r 

 

In small amount of zeta potential, we can assume sinh 

and consequently, problem will be solved analytically, but in 

this paper, this assumption is no longer valid. As a result, 

numerical simulation has been employed. By using finite 

difference method powered by Newton-Raphson algorithm, 

flow and velocity fields have been obtained through nanotube. 

Next, the main part of the paper contribution starts. 

Temperature assumed to be variable in the range of liquid 

water (0 to 100 o C). in this case, some of the electrolyte 

(water) properties will be variable such as viscosity and 

dielectric constant . in addition, zeta potential is affected by 

e 

temperature variations. In this paper, we use the exact 

definition or interpolation for temperature effect on zeta 

potential, dynamic viscosity and dielectric constant according 

to data shown in [5,6,7] respectively. 

Figures (a) and (b) show the effect of temperature variation 

on velocity and potential fields. 

In summary, by considering curvilinear coordinates and using 

finite difference method powered by Newton-Raphson 

algorithm for Poisson-Boltzmann equation with large zeta 

potentials, velocity and potential fields have been investigated. 

In addition, by comparison of figures (a) and (b), it is clear 

that, temperature variations has significantly stronger effect on 

velocity filed rather than potential one. 

Figure 1. Potential distribution over nano-tube in different 

temperatures 

Figure 2. Velocity distribution over nano-tube in different 

temperatures. 

* Corresponding author: 1Tmehdi_mostofi@yahoo.com 

[1] S. Kandlikar, et. al, Heat Transfer and Fluid Flow in 

Minichannels and Microchannels. Elsevier Limited, Oxford (2006). 

[2] C.L. Rice, and R. Whitehead, 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] Z. Zheng: Electrokinetic Flow in Micro- and Nano- Fluidic 

Components. Ohio State University, (2003). 

[6] V.L. Wylie and E.B. Streeter: Fluid Mechanics: First SI Metric 

Edition, Mc-Graw Hill, (1983). 

[7] M. Uematsu, and E.U. Franck, J Phys. Chem. Ref. Data, 9 (4), 

1291-1306 (1980). 




Multiwalled carbon nanotube modified with 5-Br-PADAP for stripping voltammetric 

determination of Pb(II) 

Ashraf Salmanipour, 1 Mohammad Ali Taher 1 and Alireza Mohadesi 2* 

1 

Department of Chemistry, Shahid Bahonar University of Kerman, P.O. Box 76175-133, Kerman, Iran 

2 

Department of Chemistry, Payame Noor University (PNU), P.O. Box 76175-559, Kerman, Iran 

Abstract— In this work, we have demonstrated that glassy carbon electrode (GCE) modified with multiwalled carbon 

nanotube (MWNT) functionalized with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) as a ligand can be 

used for the stripping voltammetry of lead(II). The ability of the 5-Br-PADAP to extract Pb(II) into the electrode surface leads 

to an electrochemical sensor that is precise and accurate for determination of lead(II) in water samples. 

Adsorptive stripping voltammetry generally applies an 

accumulation step prior to the voltammetric scan in order to 

develop analysis methods with higher levels of sensitivity. In 

this step, analyte (metal ion) is adsorbed from sample solution 

to electrode surface based on complexation between metal ion 

and ligand immobilized on the electrode surface. In this sense, 

owing to the strong sorption properties of carbon nanotubes 

and their advantages in electrochemical measurements, this 

nanostructured material has allowed some novel methods of 

stripping analysis to be developed [1-4]. 

In this work, the MWNT functionalized with a complex 

reagent (5-Br-PADAP) was prepared and coated on a GCE. 

This modified electrode was used successfully for anodic 

stripping determination of lead(II) in some real samples. 

Before use, the MWNTs were purified and pretreated to 

remove graphitic nanoparticles, amorphous carbon, and 

catalyst impurities, and then functionalized with carboxylic 

acid groups according to the literature [5]. After these 

procedures, the carboxylic acid groups were introduced onto 

the cross sections of the MWNTs. For preparation of 5-Br- 

PADAP-functionalized MWNT, the 5-Br-PADAP dissolved 

in ethanol was added to 1 g of pretreated MWNT, step by step 

and the solution was stirred for 24 hour till the solution 

became colorless. Then the modified MWNTs were filtered 

and washed with doubly distilled water and got dried at room 

temperature. Then ultrasonication agitation for 20 min was 

applied to disperse 0.5 mg 5-Br-PADAP/MWNT into 1 ml of 

double distilled water to give 0.5 mg/ml suspension. Before 

coating, the GCE was polished with a nano-Al 2 O 3 powder on a 

polishing pad rinsed thoroughly with doubly distilled water, 

then sonicated in aceton for 2 min. Finally, the GCE was 

coated with 10 μL of 0.5 mg/ml 5-Br-PADAP/MWNT 

suspension and the water allowed evaporating at room 

temperature in the air. The bare electrode was prepared by the 

same procedure just with unfunctionalized MWNTs. 

For differential pulse anodic (DPA) or cyclic stripping 

voltammetric experiments, the 5-Br-PADAP/MWNT/GCE 

was immersed in a 25 ml of sample solution (0.1 M acetate 

buffer pH 5.58) containing a known amount of Pb(II) and the 

solution was stirred for 15 min. This was followed by medium 

exchange to a 0.1 M stripping solution (0.1 M KNO 3 , 0.1 M 

acetate buffer pH 4.23), where the DPA or cyclic 

voltammograms were recorded from -1.0 to -0.2 V. 

Figure 1a shows typical cyclic voltammogram for the 

detection of Pb 2+ following open-circuit accumulation onto 5- 

Br-PADAP/MWNT film. An anodic peak at -0.55 V can be 

observed, which is related to the oxidation of accumulated 

lead(II). To prove further the importance of 5-Br-PADAP as a 

chelator reagent in the electrode surface, GC electrode 

modified with MWNT without 5-Br-PADAP were prepared, 

and used for the accumulation and stripping of Pb 2+ . Figure 1c 

shows no significant peak, as expected, in the case of 

unmodified MWNT. These results show the importance of 

modification of MWNT with 5-Br-PADAP for the 

preconcentration of Pb 2+ . 

From the above observations, under the conditions of the 

experiments, the possible pathways for the analysis cycle, 

from modification of MWNT to stripping voltammetry, are 

postulated below ("sol", or "surf" subscript means compound 

is in solution or electrode surface): 

Modification of pretreated-MWNT with 5-Br-PADAP: 

reflux 

MWNT + 5 − Br − PADAP( sol ) 

⎯⎯⎯ 

→ 5 − Br − PADAP / MWNT 

Accumulation of Pb 2+ from acetate buffer solution: 

Pb 

2+ 

( 

sol 

) 

+ 

open circuit 2+ 

[ 5 − Br − PADAP / MWNT ]( 

surf ) 

⎯⎯ ⎯⎯→ 

[ Pb / 5 − Br − PADAP / MWNT ]( 

surf 

Reduction of accumulated Pb 2+ in clean acetate buffer: 

2+ 

in more negative than −0.7V 

0 

[ Pb / 5 − Br − PADAP / MWNT] 

( surf ) 

+ 2e 

⎯⎯⎯⎯⎯⎯⎯⎯→ 

Pb( 

surf ) 

+ [5 − Br − PADAP / MWNT] 

( surf 

Stripping of reduced lead in clean acetate buffer: 

Pb 

⎯⎯⎯⎯⎯⎯⎯→Pb 

0 Scan from −1.0 

to −0.2V 

2+ 

( surf ) 

( surf ) 

Figure 1. Cyclic (50 mV/s) voltammograms in acetate buffer pH 4.23 after 

open circuit accumulation (15 min) in acetate buffer pH 5.58: (a) 5-Br- 

PADAP/MWNT/GCE, with 100 μg L -1 Pb(II) in accumulation medium, (b) 5- 

Br-PADAP/MWNT/GCE, no Pb(II) in accumulation medium, (c) 

MWNT/GCE, with 100 μg L -1 Pb(II) in accumulation medium and (d) 

MWNT/GCE, no Pb(II) in accumulation medium. 

*Corresponding author: mohadesi_a@yahoo.com 

[1] G.H. Hwang et al., Talanta 76 301–308 (2008) 

[2] K. Wu et al., Anal. Chim. Acta 489 215–221 (2003) 

[3] H. Xu et al., Electroanalysis 20 2655 – 2662 (2008) 

[4] L. Zhu et al., Electroanalysis 20 527 – 533 (2008) 

[5] X. Tan et al., Anal. Biochem. 337 111 (2005) 

) 

) 




An electrochemical sensor for stripping voltammetric determination of cadmium (II) based on 

multiwalled carbon nanotube functionalized with 1-(2-pyridylazo)-2-naphthol 

Alireza Mohadesi, 1* Zahra Motallebi 1 and Ashraf Salmanipour 2 

1 

Department of Chemistry, Payame Noor University (PNU), P.O. Box 76175-559, Kerman, Iran 

2 

Department of Chemistry, Shahid Bahonar University of Kerman, P.O. Box 76175-133, Kerman, Iran 

Abstract— The present work has focused on the modification of multiwalled carbon nanotube with a ligand, 1-(2-pyridylazo)- 

2-naphthol (PAN), and its potential application for the development of a new, simple and selective modified glassy carbon 

electrode for stripping voltammetric determination of Cd(II). this method demonstrates the powerful application of carbon 

nanotubes in the field of mercury-free electrodes in voltammetric stripping analysis. 

Traditional working electrodes for voltammetric 

determination were generally based on a hanging drop 

mercury electrode and a mercury film electrode. However, the 

toxicity of the Hg and its precursors make these materials 

undesirable for disposable in situ sensing applications. 

Therefore, various chemically modified electrodes as mercuryfree 

electrodes are applied for adsorptive stripping 

voltammetry of heavy metal ions [1-3]. Adsorptive stripping 

voltammetry generally applies an accumulation step prior to 

the voltammetric scan in order to develop analysis methods 

with higher levels of sensitivity. In this step, analyte (metal 

ion) is adsorbed from sample solution to electrode surface 

based on complexation between metal ion and ligand 

immobilized on the electrode surface. In this sense, owing to 

the strong sorption properties of carbon nanotubes and their 

advantages in electrochemical measurements, this 

nanostructured material has allowed some novel methods of 

stripping analysis to be developed [1-6]. 

In this work, the multiwalled carbon nanotube (MWNT) 

functionalized with a complex reagent (PAN) was prepared 

and coated on a glassy carbon electrode (GCE). This modified 

electrode was used successfully for anodic stripping 

determination of Cd(II) in some real samples. 

Before use, the MWNTs were purified and pretreated to 

remove graphitic nanoparticles, amorphous carbon, and 

catalyst impurities, and then functionalized with carboxylic 

acid groups according to the literature [7]. After these 

procedures, the carboxylic acid groups were introduced onto 

the cross sections of the MWNTs. For preparation of PANfunctionalized 

MWNT, the PAN dissolved in ethanol was 

added to 1g of pretreated MWNT, step by step and the 

solution was stirred for 12 hour till the solution became 

colorless. Then the modified MWNTs were filtered and 

washed with doubly distilled water and got dried at room 

temperature. Then ultrasonication agitation for 30 min was 

applied to disperse 2.0 mg PAN/MWNT into 1 ml of double 

distilled water to give 2.0 mg/ml suspension. Before coating, 

the GCE was polished with a nano-Al 2 O 3 powder (Fluka) on a 

polishing pad (Metrohm) rinsed thoroughly with doubly 

distilled water, then sonicated in aceton for 2 min. Finally, the 

GCE was coated with 5 μL of 2.0 mg/ml PAN/MWNT 

suspension and the water allowed evaporating at room 

temperature in the air. The bare electrode was prepared by the 

same procedure just with unfunctionalized MWNTs. 

For differential pulse anodic (DPA) stripping voltammetric 

experiments, the modified GCE was immersed in a 25 ml 

solution of 0.1 M oxalate buffer pH 3.0 containing a known 

amount of Cd(II) and a potential of -1.0 V was then applied 

for 100 seconds (while stirrer was on, 600 rpm). Finally the 

DPA stripping voltammogram was recorded (with 20 mV s−1 

scan rate, 100 mV pulse amplitude, and 4 ms pulse period). 

The scan was terminated at -0.4 V. All measurements were 

carried out at room temperature (22 ± 1 °C). 

Figure 1a shows typical DPA for the detection of Cd 2+ 

following closed-circuit accumulation onto PAN/MWNT film. 

An anodic peak at -0.59 V can be observed, which is related to 

the oxidation of accumulated and reduced Cadmium(II). To 

prove further the importance of PAN as a chelator reagent in 

the electrode surface, GCE modified with MWNT without 

PAN were prepared, and used for the accumulation and 

stripping of Cd 2+ . Figure 1c shows no significant peak, as 

expected, in the case of unmodified MWNT. These results 

show the importance of modification of MWNT with PAN for 

the preconcentration of Cd 2+ . 

Figure 1: DPA (20 mV/s) voltammograms in oxalate buffer pH 3.0 after 

closed circuit accumulation (150 s at -0.9 V): (a) PAN/MWNT/GCE, with 50 

μg L -1 Cd(II) in solution, (b) PAN/MWNT/GCE, no Cd(II) in solution, (c) 

MWNT/GCE, with 50 μg L -1 Cd(II) in solution and (d) MWNT/GCE, no 

Cd(II) in solution. 

*Corresponding author: mohadesi_a@yahoo.com 

[1] D. Sun et al, J Appl Electrochem 381223–1227 (2008) 

[2] W. Yantasee et al., Environ. Health Perspect. 115 1683-1690 (2007) 

[3] G.H. Hwang et al., Talanta 76 301–308 (2008) 

[4] K. Wu et al., Anal. Chim. Acta 489 215–221 (2003) 

[5] H. Xu et al., Electroanalysis 20 2655 – 2662 (2008) 

[6] L. Zhu et al., Electroanalysis 20 527 – 533 (2008) 

[7] X. Tan et al., Anal. Biochem. 337 111 (2005) 




Formation of Thermoelectric Nanos tructures by2T Electroche mical Atom-by-atom Codeposition 

Ümit Demir 1 * 

1 Department of Chemistry, Atatürk University, Erzurum 25240, Turkey 

Abstract-Nanostructures of Bi 2 Te 3 , Sb 2 Te 3 and PbS were electrodeposited using a novel and p ractical electrochemical method, based on 

simultaneous underpotential deposition of precursors of target compound from the same solution at a constant potential. These nanostructures 

are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and reflection 

absorption-FTIR (RA-FTIR) to determine structure, morphology, composition and optic properties. 

Synthesis of nanomaterials with controlled size, shape and 

crystalographic orientation has become an important issue in 

material science research. Since the properties of 

semiconductor nanocrystals, which possess many novel 

properties that differ considerably from those of the bulk [1,2], 

depend both on dimension and superlattice structure. 

Therefore, the development of synthetic methods that enable 

their precise control is expected to have a significant impact 

on progress. Bi2Te 3 and Sb 2 Te 3 with a narrow band gap and 

other V-VI group semiconductors are best-known materials 

for TE applications at room temperature and are widely used 

for thermoelectric (TE), biomedical and optoelectronic 

applications as heat pumps, power generations, solid state 

refrigeration, cooling IC chips, biochips, infrared sensors, 

optoelectronic sensors, photo detectors, and so on. Recently, 

we have developed a new electrochemical process, based on 

co-deposition from the same solution at the upd of the 

precursors of the target compound, which have been used for 

the electrochemical deposition of PbS, PbTe, ZnS, and CdS in 

the single crystal form [3-6]. The appropriate 

electrodeposition potentials based on the underpotential 

deposition potentials (upd) of precursors have been 

determined by the cyclic voltammetric measurements. In the 

present study, we illustrated the detailed growth process of 

Bi 2 Te 3 and Sb 2 Te 3 [7] nano films and Bi 2 Te 3 nanorodstructured 

films on single crystalline Au(111) electrodes by 

using Atomic Force Microscopy (AFM), X-ray Diffraction 

(XRD), Electron Dispersive Spectroscopy (EDS), and UV-v is- 

NIR Spectroscopy techniques. We found out that that the 

growth direction (orientation) and thickness of nanostructured 

Bi 2 TeR 3 can be readily controlled by pH, composition of the 

solution, and the time of the electrodeposition. 

The morphological investigation of Bi2Te 3 nanostructures 

revealed that the film growth follows 3D and 2D nucleation 

and growth mechanism in acidic and basic solutions, resulting 

in nanofilms and nanowires, respectively. XRD results show 

that single crystalline nanostructures of Bi2Te 3 are highly 

preferentially orientated along the (015) for nanofilms and 

(110) for nanowires. The growth of Sb 2 Te 3 nanofilms follows 

the nucleation and three-dimensional (3D) growth mechanism 

resulting in high crystalline films of Sb 2 Te 3 (110) in 

hexagonal structure, which were grown at a kinetically 

preferred orientation at (110) on Au (111). Highly strong 

quantum confinement effect, for both Sb 2 Te 3 and Bi 2 Te 3 

nanostructures, was observed. 

Figure 1. Bi 2 Te 3 nanostructures; (a) nanofilm, (b) nanowires 

Figure 2. Nanostructures of Sb 2 Te 3 (a) and PbS (b) 

Moreover, we applied a new modified electrochemical 

method [8] to deposit nanostructure of PbS on a thiol modified 

Au(111) surfaces. Electrochemical deposition was carried out 

after the stripping of thiol from the surface at different 

potential pulses. We showed that the size of the PbS 

nanostructures could be controlled by the electrochemical 

deposition time and pulse width. 

In summary, structural and morphological studies indicate 

that growth of these nanostructures follows atom by atom 

growth mechanism resulting in highly crystalline 

nanostructures grown at a kinetically preferred orientation. 

Absorption measurements as a function of thicknesses 

indicated that the band gap of the nanostructures increase as 

the thickness decreases. 

This study was supported by Atatürk University 

[1] E. Ronsencher, A. Fiore, B. Vinter, V. Berger, P.Bois, J. Nagle, 

Science 271, 168 (1996). 

[2] S.Yanagida, M.Yooshiya, T.Shiragami, C. Pac, H. Mori, H. 

Fujita, J. Phys. Chem. 94, 3104 (1990). 

[3] T. Öznülüer, Ü. Demir, Chem. M ater. 17, 

935 (2005). 

Langmuir 22, 4415 (2006). 

[5] M. Ü. Demir, J. Phys. Chem. C 111, 

2670 (2007). 

[6] T. Öznülüer, F. Bülbül, Ü. Demir, Thin Solid Films 

517, 5419 (2009). 

J. Electroanal. Chem. 633, 253 (2009). 

 

54, 6554 (2009). 




Mechanical Transfer of Epitaxially Grown Graphene Layers from SiC to SiO x 

Mahmut Tosun, Cem Çelebi, Görkem Soyumer, Anıl Günay, Cenk Yanık, İsmet İ. Kaya 

Faculty of Engineering and Natural Sciences, Sabanci University, İstanbul 34956, Turkey 

Abstract – We study the epitaxial graphene production process from SiC to understand the effects of the parameters such as 

pressure and temperature as well as the duration of growth. Furthermore, we investigate the efficiency of transferring the 

graphene layers from SiC to other substrates by means of mechanical cleavage technique. 

Graphene, a recently discovered two dimensional 

material has been taking immense attraction in 

research since it presents novel physics and offers a 

new era in high frequency electronic devices [1]. 

Although graphene can be produced by many 

different methods, epitaxial growth on SiC seems 

to be the most promising way of producing 

graphene for large scale integration [2]. AFM 

measurements of the graphene films show that they 

conform to the substrate that they stack. Therefore, 

in order to have higher mobilities, having a 

smoother surface is essential [3]. Moreover, the 

interaction of the graphene layers with the 

underlying substrate is another key parameter in the 

quality of the graphene films. Therefore an efficient 

means of transferring the epitaxially grown 

graphene on to other substrates could improve 

garphene device fabrication processes [4]. 

In this work, we analyzed the yield of graphene 

production process by epitaxial growth from SiC. 

Furthermore, we study the efficiency of 

transferring the produced graphene layers from SiC 

to SiO x . Epitaxial growth of graphene from SiC is 

done under high vacuum and high temperatures [5]. 

Direct current heating is applied to n-type, H 2 

etched 4H-SiC samples. Carbon face of the SiC 

samples is chosen for the epitaxial growth due to 

having rotational stacking on this particular face 

which results in producing undoped single layer 

graphene on the top most layer in multilayer films 

which ranges from 3 layers to 60 layers [6]. The 

growth pressure is varied between 10 -5 mbar to 10 -7 

mbar, the duration is varied between 10 minutes to 

60 minutes and the temperature is varied between 

1350C˚ and 1600C˚. 

Characterization of the graphene on SiC samples is 

done with Raman spectroscopy, atomic force 

microscopy (AFM) low energy electron diffraction 

(LEED) and auger electron spectroscopy (AES). 

Transfer of the graphene layers from SiC to SiO x is 

performed both at ambient pressure and under 

vacuum by mechanical cleavage technique. After 

the transfer, characterization steps are repeated to 

check the efficiency of the transfer. 

This work was supported by TUBITAK under 

Grant No. TBAG-107T855. 

[1] Geim, A.K. Graphene Status and Prospects. 

Science 324, 19 June 2009. 

[2] Geim, A.K. Novoselov K. S. Rise of Graphene. 

Nature Materials 6, March 2007. 

[3] Jernigan, [Glenn. Comparison of Epitaxial 

Graphene on Si-face and C-face 4H SiC Formed by 

Ultrahigh Vacuum and RF Furnace Production. 

Nanoletters 9, May 2009. 

[4] Caldwell, Joshua. Technique for the Dry 

Transfer of Epitaxial Graphene onto Arbitrary 

Substrates. ACSNano 4, 2010. 

[5]Heer, Walt de. Epitaxial Graphene. Solid State 

Communication 143, 2007. 

[6]Hass, J. The growth and morphology of epitaxial 

multilayer graphene. Journal of Physics: 

Condensed Matter 20, 2008. 

b. 




Synthesis and characte rization of TiO 2 nanotubes filed with NiFe 2 O 4 nanocrystals 

A.A. Fargali 

1 , M . H. Khedr 1 , M. Bahagat 2 * and A. F. Moustafa 1 

1 Chemistry Dep. Fac. of Sci. Beni-Sueif Univ., Beni-Sueif , Egypt 

2 CMRDI, Egypt 

Abstrac t-TiO 2 NTs is the most attractive catalyst in many fields of application, as semiconductors, 

photocatalyst, gas sensor. There are many method for preparation of TiO 2 NTs, anodization, Templates 

assistance, and thermal method. In this work TiO x nanotubes was prepared from anatase phase of TiO 2 

powder with crystal size 90 nm via hydrothermal treatment in 10M NaOH at different time and 

temperature flowed by ion exchange reaction. The samples prepared at higher temperature and longer 

reaction time shows high quantity and good c rystallinity than those prepared at lower temperature and 

shorter reaction time. TiO x Nanotubes was treated in oxygen at 500 o C for 2 h to obtain anatase phase of 

TiO 2 nanot ube s (TiO 2 NTs). The filling process of TiO 2 NTs with NiFe 2 O 4 occurs by immersing 

TiO 2 NTs in mixed solution of iron nitrate and nickel nitrate with adjusted molar ratio. The percentage of 

filling process depends strongly on the concentration of mixed solution and the immersing time. The 

empty and filled TiO 2 NTs was characterized using XRD, TEM, and SEM. 

The filled NTs was reduced at different temperatures to obtain Ni-Fe nanoalloy inside NTs, we found that 

the optimum temperature for complete reduction of filled NTs is 600 

o C, which produced Ni-Fe nanoa lloy 

and saving geometry of nanotube s. The photocatalytic activity of as prepared, heated, empty, filled and 

reduced NTs was studied for the degradation of Brobopyrogallol red (Bb red) and adsorption of some 

heavy metals. 

*Corresponding author: m_bahgat70@yahoo.com 




Structural and electrical properties of spray deposited pure and Sb doped tin oxide 

* Güven Turgut, Demet Tatar, Serdar Aydın, Erdal Sönmez and Bahattin Düzgün 

K. K. Education Faculty, Department of Physics, Ataturk University, Erzurum 25240, Turkey 

Abstract— Pure and 2wt. % Sb doped tin oxide (SnO 2 :Sb) thin films were prepared by spray pyrolysis onto glass substrates at 420 0 C. X-ray 

diffraction (XRD) analysis showed that all films are polycrystalline and Sb doping increased crystallinity. The films are prefentially oriented 

along the (110) direction. Atomic force microscopy (AFM) studies showed that roughness (RMS) of 22.52 nm for undoped films has been 

slightly reduced to 15.56 nm on Sb doping films. Hall effect studies have been performed on SnO 2 (TO) and SnO 2 :Sb(ATO) films coated on glass 

substrates.The electrical study reveals that the films are degenerate and exhibit n-type electrical conductivityand also Sb doping increased carrier 

concentrarion(n), decreased sheet resistance(Rs) and resistivity(ρ). 

Among transparent and conducting oxides (TCOs), tin 

oxide (TO) is widely used in solar cells, display devices, 

hybrid microelectronics, stable resistors, touch-sensitive 

switches digital displays [1], electro-chromic displays and gas 

sensors [2] etc. due to theirs low electrical resistivity, high 

optical transmittance in visible region, high optical reflectance 

in infrared region, chemically inert and mechanically hard [3]. 

Many researchers focused on doping TO, because electrical, 

structural and optical properties of TO can be changed by 

doping with F or Sb [1-8]. 

In this study, pure and 2 wt.% Sb doped SnO 2 thin films 

onto glass substrates at 420 ο C were deposited by spray 

pyrolysis technique. The spray pyrolysis technique is an 

attractive method to obtain thin films because of its simple and 

inexpensive experimental arrangement [9], ease of adding 

doping materials, reproducibility [3], high growth rate and 

mass production capability for uniform large area coatings [7]. 

We investigated structural, morphological and electrical 

properties of pure and Sb doped SnO 2 thin films. 

The structural characterization of the films was carried out 

by X-ray diffraction (XRD) measurements using a Rigaku 

D/Max-IIIC diffractometer (λ=1.5418Å for CuKα radiation) at 

30 kV, 10 mA. Surface morphology was examined by atomic 

force microscopy (AFM, which was produced by 

Nanomagnetics- Instrument). The electrical measurements 

were carried out by Hall measurements in van der Pauw 

configuration. 

(a) 

(b) 

Fig. 2. AFM images of (a) pure tin oxide (SnO 2 ) and (b) 2wt.% Sb 

doped tin oxide (SnO 2 :Sb) 

The AFM study reveals nanostructural growth of the film. 

AFM analysis showed that, Sb doping decreased RMS value 

for TO, thus Sb doping improved the film morphologies. 

The negative sign of Hall coefficient confirmed that the 

films are n-type. As seen from Table 1, Sb doping decreased 

sheet resistance (Rs), resistivity(ρ) and increased carrier 

concentration(n) and Hall mobility(μ). 

Table 1. Electrical properties of SnO 2 and 2wt.% Sb doped 

tin oxide ( SnO 2 :Sb) 

Sample Rs 

(Ωcm -2 ) 

ρ 

(x10 -4 Ωcm) 

n 

(x10 18 cm -3 ) 

μ 

(cm 2 /V s) 

SnO 2 728,3 64,1 0,215 452 

SnO 2 :Sb 114,9 6,4 1,7 560 

In summary, undoped and Sb doped SnO 2 thin films have 

successfully been via a simple and cost-effective spray 

pyrolysis technique. Structural analyses showed that the Sb 

doping increased crystallinity and improved surface 

morphology. Electrical studies revealed that Sb doping 

decreased resistivity of tin oxide film and increased carrier 

concentration. 

Fig. 1. XRD patterns of SnO 2 (TO) and SnO 2 :Sb (ATO) 

XRD images showed that the films are polycrystalline and 

are prefentially oriented along (110) direction. Other peaks 

observed are (101), (200) and (211). Further, the crystallinity 

was seen to be increasing, since peak intensities increased as 

Sb doping. 

*Corresponding author: guventurgut@atauni.edu.tr 

[1] K. Ravichandran, et al. Journal of Ovonic Research. 5, 93-69 (2009). 

[2] E. Elangovan et al. Journal of Crystal Growth. 276, 215-221 (2005). 

[3] B. Thangaraju, Thin Solid Films. 402, 71-78 (2002). 

[4] S. Lee, B. Park, Thin Solid Films. 510, 154-158 (2006). 

[5] K. Ravichandran, P. Philominethan, Materials Letters. 62, 2980-2983 

(2008). 

[6] E. Elangovan, K. Ramamurthi, Applied Surface Science. 249, 183-196 

(2005). 

[7] K. Ravichandran, G. Muruganantham, Physica B. 404, 4299-4302 (2009). 

[8] E. Elangovan, K. Ramamurthi, Cryst. Res. Technol. 38, 779-784 (2003). 

[9] R.R. Kasar et al. Physica B. 403, 3724-3729 (2008). 




Resonant donor states in quantum well 

Arnold Abramov 1 * 

1 Department of Applied Mathematics, Donbass State Engineering, Academy, Kramatorsk 84313, Ukraine 

Abstract-A method of calculation of donor impurity states in quantum well is developed. The used techniques have made it possible to find the 

binding energy both of ground and excited impurity states attached to each QW subband. The positions of resonant states in 2D continuum are 

determined as poles of corresponding wave functions. As result of such approach the identification of resonant states in 2D continuum is 

avoided without introducing special criterions. The calculated dependences of binding energies versus impurity position are presented for 

various width of Si/Si1-xGex quantum. 

It is known, that the incorporation of small amounts of 

impurities in semiconductor led to occurrence of additional 

(impurity) states in band structure. In case of a complex band 

structure consisting of several subbands impurity states arise 

under each of them. For the lower subband they are in the 

forbidden gap and are localized. Impurity states for overlying 

subbands are on a background of a continuum, and become 

quasilocal. The existence of such states was experimentally 

confirmed in bulk and nanostructures. To describe them 

theoretically it is necessary to solve Shredinger equation for 

multiband model. To solve this problem a method of 

expansion the unknown electron wave function (WF) on plane 

waves basis has been developed in [1]. Then the problem is 

reduced to a task of determination of eigen vectors (envelope 

functions) and eigen values (binding energy) for rather large 

matrixes. For characteristic sizes of the matrix >1000 (more 

than thousand) most of the solutions are in the continuum. 

And it is necessary to introduce special criterion to identificate 

(resonant) impurity states among the obtained set of solutions. 

As such one the peaks on energy dependence of wave function 

were used. However, in vicinity of RS the wave function has a 

pole and use of explicit energy dependence of WF is not 

correct. 

Thus, the main difficulties of the calculations are in need of 

processing large matrices, as well as the correct and easy 

identification of RS. Our method allow to overcome these 

problems. WF of impurity states (both localized and resonant) 

are determined from set of coupled integral equations, which 

first were introduced in [2]. Proposed techniqes consist in 

replacement the integrals by the finite sums and followed 

conversion from set of integral equations to the equation in 

matrix form. Unlike the works [1,3] energy here are not 

eigenvalue of matrix, but is parameter on which matrix 

elements depends. The positions of resonant impurity states 

correspond to poles of WF, which are defined by equating a 

determinant of the matrix to zero. Our method allows easy to 

include in calculations external fields - electric, magnetic. 

Other advantages include no necessity for explicit knowledge 

of the band structure, and also the absence of Coulombs 

divergence problem. 

The efficiency of the method is demonstrated on the analysis 

of the impurity state depending on the position of the impurity 

center: at the moving impurity atom away the middle of the 

QW impurity state can be transformed from a resonant state to 

localized. This fact is of interest for further theoretical study, 

and may also have practical applications in the creating an 

optical device based on intracenter transitions. Besides, 

resonant impurity states can play a determining role in 

creation of a so-called inverted distributions, which can lead to 

novel optical devices in the far-infrared (or terahertz) range. 

Therefore efficient and correct calculation of RS, in addition 

to theoretical, also has a practical importance for the analysis 

and development of a theory of the experimentally observed 

lasing effect. 

This work was partially supported by by Ukranian Ministry 

of Education and Science. We thank Dr. H.Najafov for fruitful 

discussions. 

*Corresponding author: qulaser@gmail.com 

[1] A. Blom, M. A. Odnoblyudov, I. N. Yassievich, K.-A. Chao, 

Phys. Rev. B 68, 165338 (2003) 

[2] B.Vinter, Phys.Rev. B 26, 6808 (1982) 

[3] A.A.Abramov, C.-H. Lin, C.W. Liu, Int. J. of Nanoscience 7, 

No. 4/5, 181 (2008) 




Electrical, structural and optical properties of spray deposited SnO 2 and SnO 2 :F thin films 

Demet Tatar 1* , Güven Turgut 1 , Erdal Sönmez 1 , Bahattin Düzgün 1 , and Mehmet Ertugrul 2 

,1 K. K. Education Faculty, Department of Physics, Ataturk University, Erzurum 25240, Turkey 

2 Engineering Faculty, Department of Electric-Electronic, Ataturk University, Erzurum 25240, Turkey 

Abstract—The undoped and fluorine doped thin films are synthesized by using cost-effective spray pyrolysis technique. The dependence optical 

structural and electrical properties of SnO 2 films, on the concentration of fluorine is reported. Optical absorption, X-ray diffraction, scanning 

electron microscope (SEM) and Hall effect studies have been performed on SnO 2 :F (FTO) films coated on glass substrates.X-ray diffraction 

pattern reveals the presence of cassiterite structure with (200) preferential orientation for FTO films. The roughness of the films changed from 

22,52 to 15,52 nm. Atomic force microscopy (AFM) study reveals the surface of FTO to be made of nanocrystalline particles. The electrical 

study reveals that the films exhibit n-type electrical conductivity. The 20 wt% F doped film has a minimum resistivity of 1,29.10 -4 Ωcm, carrier 

density of 8,48.10 18 cm -3 and mobility of 568 cm 2 V -1 s -1 . The sprayed FTO film having minimum resistance of 12,46 Ω/cm 2 and a good 

transparency in the visible, these films are useful as conducting layers in electrochromic and photovoltaic devices and also as the passive counter 

electrode. 

The undoped stoichiometric SnO 2 films have very high 

electrical resistivity because of their low intrinsic carrier 

density and mobility [1]. Therefore the challenge is to prepare 

non-stoichiometric doped thin films. The conductivity of 

weakly nonstoichiometric tin oxide films is supposed to be due 

to doubly ionized vacancies serving as donors [2]. Dopants as 

antimony, Sb, indium, In, and fluorine, F, are frequently used. 

The fluorine-doped tin oxide (FTO), being an n-type, wide 

band gap semiconductor (≥3 eV) with special properties, high 

transmittance in the visible range and high reflectance in the 

infrared, excellent electrical conductivity, greater carrier 

mobility and good mechanical stability are used in different 

devices like solar cells as transparent, protective electrodes 

[3], flat panel collectors as spectral selective windows, sensors 

for detection of gases, sodium lamps, gas sensors, and 

varistors [4–6]. FTO films have been prepared by various 

techniques, such as chemical vapour deposition, metalorganic 

deposition, rf sputtering, sol–gel, and spray pyrolysis [7–9]. 

Spray pyrolysis is used to prepare films because of its 

simplicity and commercial viability [10,11]. Moreover, the 

spray pyrolysis technique is well suited for the preparation of 

doped tin oxide thin films because of it is ease to adding 

various doping materials, controlling the texture via various 

deposition temperatures and mass production capability for 

uniform large area coatings. 

The prime aim of this work is to produce low thickness with 

high transmission, low resistance and highly conducting F 

doped tin oxide thin films with higher figure of merit by costeffective 

chemical spray pyrolysis technique and study their 

optical, structural, electrical and optoelectrical properties. 

and X-ray rocking curve with CuK α radiation. The surface 

morphology of the FTO thin films were observed by an atomic 

force microscopy (AFM) (by products nanomagnetic-inst). 

The electrical studies were carried out by Hall measurements 

in van der Pauw configuration. The visible transmission 

spectra of FTO films were measured using UV– spectrometer . 

(a) 

(b) 

Figure 2. AFM images of samples, a) SnO 2 (TO), b) SnO 2:F (FTO) 

The physical properties of the spray pyrolyzed tin oxide and 

FTO thin film deposited at 420˚C from SnCl 2 .2H 2 O precursor 

have been presented. The transmittance enhancement of these 

films is due to the well-crystallized film and the pinhole free 

surface. X-ray diffraction pattern reveals the presence of 

cassiterite structure with (200) preferential orientation for 

FTO film. The roughness of the films changed from 22,52 to 

15,52 nm. The AFM analysis showed that improved 

morphological structural of the films. The FTO film deposited 

on 420°C revealed the minimum resistivity of about 1,29.10 −4 

Ω.cm and high transmittance in the visible band. This high 

conductivity and transparency of FTO film suggest that these 

films are likely to be useful as electrical contacts in various 

electronic and energy harvest applications. 

*Corresponding author: demettatar@atauni.edu.tr 

Figure 1. X-ray diffraction pattern of samples 

Figure 1. shows the X-ray difraction (XRD) patterns of the 

FTO films. XRD studies were made with a X-ray diffraction 

[1] A.V. Moholkar, et. al. Applied Surface Science 255, 9358–9364 (2009). 

[2] Z.M. Jarzebski, J.P. Marton, J. Electrochem. Soc. 123, 2 (2000). 

[3] S. Colen, Thin Solid Films 77, 127 (1981). 

[4] P.S. Patil, et. al. Thin Solid Films 437, 34 (2003). 

[5] A. Dima, et. al. Thin Solid Films 427, 427 (2003). 

[6] D.S. Lee, et. al. Thin Solid Films 416, 271 (2002). 

[7] J. Kane, H.P. Schweizer, J. Electrochem. Soc. 123, 270 (1976). 

[8] T.N. Blanton, M. Lelental, Mater. Res. Bull. 29, 537 (1994). 

[9] K.Y. Rajpure, et. al. Mater. Chem. Phys. 64, 184 (2000). 

[10] P.S. Patil, Mater Chem Phys. 59, 158 (1999). 

[11] E. Elangovan, K. Ramamurthi, J. Optoelect. Adv. Mater. 5, 45 (2003). 




Temperature and thickness dependence of the grain boundary s cattering of the Ni-Si Silicide Films 

Formed at 500 C by Rapid Thermal Annealing of the Ni/Si Films 

G. Utlu 1 *, N.Artunç 1 S.Selvi 1 

1 Department of Physics, Ege University, 00, Turkey 

Abstract-In this study, Ni-Si silicide films with 18-290 nm thicknesses are studied as a function of temperature and film thickness over the 

temperature range of 100-900 °K. The most striking behavior is that the variation of the resistivity of the Ni-Si silicide films with temperature 

exhibits an unusual temperature-dependent behavior with respect to those of the transition and un-transition metals. We have also shown t hat in 

the temperature range of (100-Tm) °K paralel-resistor formula is reduced to Matthiessen’s rule and D Debye temperature is independent of the 

temperature for a given thickness range, whereas at high temperatures it increases slightly with thickness. We have found that for the 

temperature range of (100-Tm) °K, lineer variation of the resistivity of the Ni-Si silicide films with temperature is caused from both the grainboundary 

scattering and electron-phonon scattering and resistivity data could be analyzed very well in terms of the Mayadas-Schatzkes (M-S) 

model. 

In recent years silicides, intermetallic co mpounds of silicon 

and transition metals, have received much attention because of 

their wide application in very large-scale integrated circuits 

(VLSI) and ultra large-scale integrated circuits (ULSI) [1-3]. 

Because they show metallic behavior with low electrical 

resistivity, high electro-migration resistance, high thermal 

stability and resistance to acids [1, 4]. Due to these properties, 

they have been proposed as candidates for replacing aluminum 

alloys for applications in microelectronics [3-5].Metal silicides 

can be synthesized by various techniques, e.g. solid-state 

reaction of thin metal films deposited on Si wafer, explosive 

silicidation, react ive deposition, and ion implantation [6-9] 

In this study, the first aim is to deposit Ni thin films, with 

thicknesses of 7.0 –89 nm, onto n-type Si(100) substrate by 

thermal evaporation technique, and then to anneal these Ni /Si 

bilayers by rapid thermal annealing (RTA) process for 60 s at 

500 C, so as to synthesize NiSi (n ickel mono-silicide) silicide 

films by solid-state reaction technique. The second aim is to 

investigate the temperature dependence of the electrical 

resistivity of Ni-Si silicides over the temperature range 100- 

900 °K. And the final aim is to analyze the resistivity data of 

Ni-Si silicides in terms of the M-S grain boundary scattering 

model, and calculate the R reflection coefficient of the films. 

The correlation of Ni–Si silicide formation with its electrical 

and morphological properties is also established. 

The temperature-dependent resistivity measurements of our 

Ni-Si silicide films with thickness of 18-290 nm are studied as 

a function of temperature and film thickness over the 

temperature range of 100-900 °K. The most striking behavior 

is that the variation of the resistivity of the Ni-Si silicide films 

with temperature exhibits an unusual temperature-dependent 

behavior with respect to those of the transition and untransition 

metals. Our measurements show that the total 

resistivity of the Ni-Si silicide films increases linearly with 

temperature up to a Tm temperature, at which resistivity 

reaches a maximum, thereafter Tm it decreases rapidly and 

finally is zero at 800 °K. Moreover, in this study, Tm 

temperature is found to decreases with both decreasing film 

thickness and annealing temperature / or Si concentration and 

to shift from 610 °K to 490 °K with decreasing film thickness 

from 290 to 18 nm, corresponding to increased concentration 

of Si in the lattice. 

Paralel–rezistör formula uses for analysing of the 

temperature dependent resistivity datas for several thin film 

and metal silicid film in a wide temperature range (4-1000) °K 

[10-13]. We have shown that in the temperature range of 

(100-Tm) °K paralel-resistor formula is reduced to 

Matthiessen’s rule and D Debye temperature is independent 

of the temperature for a given thickness range, whereas at high 

temperatures it increases slightly with thickness. D Debye 

temperature are found to be about 400-430 K for all the Ni-Si 

films. 

We have also shown that for the temperature range of (100- 

Tm) °K, lineer variation of the resistivity of the Ni-Si silicide 

films with temperature is caused from both the grain-boundary 

scattering and electron-phonon scattering and resistivity data 

could be analyzed very well in terms of the Mayadas- 

Schatzkes(M-S)model. Theoretical and experimental values of 

Reflection coefficients are calculated by analyzing resistivity 

data using M-S model and f.d =f(d) plots respectively. 

According to our analysis, for a given temperature R increases 

with decreasing film thickness, whereas it is almost constant 

over a thickness range of 200-67 nm and 47-18 nm, for which 

silicide films have almost same phases. For room temperature 

(T=295 °K) the average values of theoretical and experimental 

reflection coefficient are calculated to be R th = 0.44, R th = 0.66 

and R exp = 0.46, R exp = 0.67 by taking an average over the 

thickness ranges of 200-67 nm and 47-18 nm respectively. 

According to our XRD, RBS and SEM measurements for the 

thickness of 200-67 n m Ni, Ni 3 Si and NiSi silicide phases 

coexist, while NiSi and Si-rich silicide phases are present over 

the range of 47-18 nm. This phase transformation with 

decreasing film thickness should be responsible for the 

increase observed in the values of both R reflection coefficient 

(or the grain boundary resistivity) and total resistivity of all 

the Ni-Si silicide films. 

Corresponding author: gokhan.utlu@ege.edu.tr 

[1] S.P.Murarka, Silicides for VLSI Application, Academic, NewYork,(1983). 

[2] M.A. Nicolet, S.S.Lau, in: N.G. Einspruch (Ed.), 

VLSI Electronic Microstructures Science,6,Academic pres, New York,(1983). 

[3] Y. Hu and S. P. Tay, J. Vac. Sci. Technol. A 16, 1820 (1998). 

[4] A.H. Reader et al, Rep.Prog. Phys. 56 1397 (1992). 

[5] J.P. Gambino, E.G. Colgan, Mater. Chem. Phys. 52, 99 (1998). 

[6] B.A. Julies et al, Thin Solid Films, 347,201 (1999). 

[7] S. Abhaya et al, Appl. Surf. Sci. 253,3799 (2007). 

[8] L.A Clevenger, C.V. Thomson, K.N. Tu, J. Appl. Phys. 67 (1990) 2894. 

[9] Gi Bum Kim et al, J. Vac. Sci. Technol.B 21, 1319 (2003). 

[10] M. Gurvitch, Physical Review B, 24, 7404 (1981). 

[11] M.Milewits et al, Physical Review B, 13, 5199 (1976). 

[12] F. Nava and K.N. Tu, Journal of Applied Physics, 61, 1085 (1987). 

[13] F. Nava, K.N. Tu, O. Thomas, J.P. Senateur, R. Madar, A. Borghesi, G. 

Guizzetti and O. BiSi, Materials Science Reports, 9, 141 (1993). 




Fabrication of Alumina Borate Nanofibe r by Electros pinning Technique 

Mehtap Ozdemir 1 *, Aslihan Suslu 1 , Umit Cöcen 1 and Erdal Celik 1 

1 Department of Metallurgical and Materials Engineering, Dokuz Eylul University, 35160, Izmir, Turkey 

Abstract-Alumina borate (Al 18 B 4 O 33 ) nanofibers have been successfully fabricated by electrospinning method using a solution that contains 

poly (vinyl alcohol) (PVA) and Aluminium acetate stabilizied with boric acid. The effect of viscosity and temperature were investigated. 

DTA/TG analyses were done to determine the heat treatment regime. Morphology of the fibers was investigated by SEM analyses and phase 

structure of fibers was obtained using XRD and chemical bonding structure was determined by FTIR. 

One-dimensional materials, such as nanowires, 

nanorods, nanowhiskers and nanofibers, have stimulated 

great interest due to their importance in basic scientific 

research and potential technology applications. They are 

expected to play an important role as both interconnects 

and functional components in the fabrication of nanoscale 

devices. Many unique properties have already been 

proposed or demonstrated for this class of materials, such 

as high elastic modulus and tensile strength, chemical 

inertness, excellent resistance to oxidation/corrosion, low 

thermal expansion coefficient, high thermal conductivity, 

stability at high temperature and low-cost production [1-5]. 

Of these properties, aluminium borate is one of the most 

common materials for a variety of applications such as 

high temperature structure components, nonlinear optical 

and tribological materials, electronic ceramics and 

reinforced composites materials [2, 6]. 

Electrospinning is a most preferred technique to produce 

fibers with a diameter of 20-1000 nm. The diameter of the 

fibers depends on process parameters; including viscosity 

of the solution, applied electric field, distance between the 

collector and needle and feeding rate of the solution [7]. 

In this study, we attempt to form alumina borate 

nanofibers and investigate the effect of viscosity during the 

electrospinning process on nanofiber morphology and 

spinability. 

We first prepared PVA solutions at different 

concentrations. Then aluminium acetate stabilized with 

boric acid (CH 3 CO 2 Al(OH) 2 .1/3H 3 BO 3 ) added to PVA 

solution and stirring was continued until transparent and 

homogeneous solution was obtained. Viscosity of 

solutions was determined by CVO 100 Digital Rheometer. 

The alumina borate/PVA fibers were heat treated at 800- 

1200 o C for 2 h in air. The prepared solution used in the 

electrospinning was dried at 100 °C for 1 h and the 

obtained powder subjected to thermogravimetric 

differential thermal analysis (DTA/TG) to define the 

reaction type of intermediate temperature products and to 

use suitable process regime. The chemical bonding 

structures of fibers before and after heat treatment were 

determined by Fourier Transform Infrared Spectroscopy 

(FTIR). The X-ray diffraction (XRD) measurements were 

performed for crystal phase identification (Rigaku D/Max- 

2200/ 

average fiber diameter of nanofibers was characterized by 

scanning electron microscope (SEM). 

Solution viscosity plays a major role for producing 

uniform nanofiber. At low viscosity, it is common to find 

beads along the fibers. When the viscosity increases, there 

is a gradual change in the shape of the fibers until smooth 

fibers are obtained [8]. For spinability viscosity must be 

neither very dense nor dilute. Viscosity of the prepared 

solutions at different concentrations are determined in the 

range of 0.17- 2.34 Pa.s. After the heat treatment of 

electrospun fibers at 800 

o C and 1200 o C, crystalline 

Al 4 B 2 O 9 and Al 18 B 4 O 33 fibers were obtained respectively. 

As a result of high temperature, fiber diameters reduced 

from 922 nm to 523 nm. 

In conclusion, the electrospinning technique was used to 

produce alumina borate/PVA composite nanofibers. The 

effect of viscosity on spinability and the morphology of 

alumina borate/PVA nanofibers were investigated. After 

heat treatment at 1200 

o C, alumina borate (Al 18 B 4 O 33 ) 

fibers were produced. It has been found that viscosity of 

the prepared solution affects the fiber morphology. 

Increasing the viscosity as a result of increasing solution 

concentration thicker fibers are obtained and furthermore 

spinability of solution become more difficult because 

dense solution leads to clogging of needle tip. 

This work was supported by BOREN (National Boron 

Research Institute) and TUBITAK (Scientific and 

Technical Research Council of Turkey) project number 

105M363. Also, authors M.O and A.S acknowledge the 

support from TUBITAK, in the framework of the National 

Scholarship Programmes for PhD Students. 

*Corresponding author: 

0Tmehtap.ozdemir@ogr.deu.edu.tr 

[1] Jian Wang, Guiling Ning , Xuefeng Yang, Zhihong Gan, 

Hongyu Liu, Yuan Lin, Materials Letters 62 1208 (2008). 

[2] Haisheng Song, Junjie Luo, Miaodan Zhou, 

Elawadmihammed Elssfah, Jun Zhang, Jing Lin, Sujing Liu, 

Yang Huang, Xiaoxia Ding, Jianming Gao, and Chengcun Tang, 

Crystal Growth & Design, 7, 576 (2007). 

[3] Hongqin Dai, Jian Gong, HakyongKim and Doukrae Lee, 

Nanotechnology 13 674 (2002). 

[4] Elawad Elssfah and Chengcun Tang, J. Phys. Chem. C, 111, 

8176 (2007). 

[5] C C Tang, EMElssfah, J Zhang and D F Chen, 

Nanotechnology 17,2362 (2006). 

[6] Jun Wang , Jian Sha , Qing Yang , Youwen Wang , Deren 

Yang, Materials Research Bulletin 40, 1551 (2005). 

[7] Dan Li and Younan Xia, Adv. Mater. 14, 16(2004). 

[8] RAMAKRISHNA S., Fujihara K., Teo W-E., Lim T-C., Ma 

Z., “An Introduction to Electrospinning and Nanofibers”, World 

Scientific Publishing Company, United States of America, 

(2005). 




Preparat ion of Ag doped HAP/PHBV Nanocompos ite Fibers via Electrospinning Technique 

Aslihan Suslu 1 *, Aylin Ziylan Albayrak 1 and Umit Cocen 1 

1 Department of Metallurgical and Materials Engineering, Dokuz Eylul University, 35160, Izmir, Turkey 

Abstract- Silver doped hydroxyapatites were produced by coprecipitation method and Ag doped HAP-PHBV nanocomposite suspensions 

were prepared with the aid of the surfactant, 12-hydroxysteric acid (HSA). Nanocomposite fibers prepared from Ag doped HAP-PHBV 

suspensions were produced via electrospinning. Surface morphology of the fibers analyzed by SEM and HAP dispersion on the fiber surface 

was investigated by EDS analysis via Ca, P and Ag quantity determination. XRD was used in order to see whether the crystal structure of 

HAP is maintained or not. 

An ideal tissue scaffold should be mechanically stable, 

bio-compatible and capable of functioning biologically in 

the implant site. Biologic functioning is regulated by 

biologic signals from growth factors, extracellular matrix 

(ECM), and the surrounding cells. ECM molecules 

surround cells to provide mechanical support and regulate 

cell activities [1].To mimic natural ECM, many research 

groups have tried to produce nanofibrous tissue scaffolds 

using electro-spinning method [2]. Electrospinning is an 

actively investigated technique recently, as well as the 

simplicity of the process; it offers ultrafine polymer fibers, 

high specific surface area, highly porous structure and the 

possibility of various modifications [3-5]. In tissue 

engineering applications in particular, ultrafine nanofibers 

have been fabricated from biodegradable and 

biocompatible natural or synthetic polymers such as 

collagen, fibrinogen, poly(glycolic acid) (PGA), poly(L- 

Lactic acid) (PLA), poly(lactic acid-co-glycolic acid) 

(PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 

(PHBV) [6]. 

The target of our study is to produce polymer based 

tissue scaffold that can be used in the field of tissue 

engineering. As the main matrix, PHBV as a 

biodegradable and a biocompatible polymer was chosen. 

Together with the cheapness, PHBV has longer 

degradation time than PLA and PLGA polymers, which 

means that the scaffold can maintain its mechanical 

integrity until there is sufficient tissue formation [6]. To 

increase the mechanical strength of the main matrix and 

also to improve cell adhesion hydroxyapatite (HAP) is 

used. In addition, as the cation exchange rate of HAP is 

very high, HAP is doped with minor amount of Ag ions in 

this way tissue scaffold will gain antibacterial function as 

well as the osteoconductive function. [7-9]. Due to its 

nontoxic and cell-friendly nature HSA is a safely used 

chemical in biomedical applications as a surfactant [10]. In 

this study, HSA was used to disperse Ag doped HAP in 

the PHBV matrix in a homogenous manner. Also, 

organosoluble salt benzyl triethylammonium chloride 

(BTEAC) was used to increase the conductivity of solution 

and to obtain uniform fibers. 

Ag doped (2 wt %) hydroxyapatite powder was 

produced by coprecipitation method using AgNO 3 , H 3 PO 4 

and Ca(OH) 2 as starting materials. Ag doped HAP 

powders were characterized by XRD and SEM/EDS. As 

the Ag content of the powders was very low, no difference 

between the XRD patterns of HAP and Ag dopped HAP 

was observed. Nanocomposite fibers were successfully 

fabricated by using the Ag doped HAP-PHBV suspensions 

via electrospinning. Optimum parameters were defined as 

follows: Voltage supply, 20 kV; distance between the 

needle and the collector, 15 cm; flow rate, 0,3 ml/h. SEM 

and EDS analyses showed Ag doped HAP was 

successfully incorporated and homogenously dispersed on 

the PHBV fibers. In order to reduce the fiber diameter and 

get better spinability BTEA C salt (2-5 wt %) was used. 

In conclusion Ag doped HAP powder was synthesized 

successfully by coprecipitation method. Ag doped HAP- 

PHBV nanocomposite suspensions prepared. The innate 

dispersion and agglomerate problems associated within 

hydrophilic bioceramic powder within hydrophobic 

biopolymers were solved by using a surfactant. 

Nanocomposite fibers successfully produced from the 

prepared Ag doped HAP-PHBV suspensions via 

electrospinning technique. Author A.S acknowledges the 

support from TUBITAK, in the framework of the National 

Scholarship Programmes for PhD Students. 

* Corresponding author: 0Taslihan.suslu@deu.edu.tr 

[1] W. J. Li, C. T. Laurencin, E. J. Caterson, R. S. Tuan, F. K. 

Ko, Journal of Biomedical Materials Research, 60, 613-621, 

(2002). 

[2] Y., Ito, H., Hasuda, M. Kamitakahara, C. Ohtsuki, M. 

Tanihara, I. K. Kang, O. H. Kwon, Journal of Bioscience and 

Bioengineering, 100, 1, 43-49.,(2005). 

[3] D. Li , Y. Xia, Advanced Materials, 16, 1151-1170, (2004). 

[4]. M. Sawickak, P. Gouma, Journal of Nanoparticle Research, 

8, 769-781, (2006). 

[5] O. H .Kwon, I. K. Lee, Y. G. Ko, W. Meng, K. H. Jung, I. K. 

Kang, Y. , Biomedical Materials, 2, S52-S58, (2007). 

[6] N. Sultana, M. Wang, J. Mater Sci: Mater Med, 19, 2555-256 

(2008). 

[7] N. Sanpo , M. L. Tan, P. Cheang, K. A. Khor,, Journal of 

Thermal Spray Technology, 18, 1, 10-15, (2009). 

[8] N. Rameshbabu, T.S. Sampath Kumar, T.G. Prabhakar, V.S. 

Sastry, K.V.G.K. Murty, K. Prasad Rao, , Journal of Biomedical 

Materials Research Part A, 581-591, ( 2006). 

[9] W. Chen, Y. Liu, H. S. Courtney, M. Bettenga, C. M. 

Agrawal, J. D. Bumgardner, J. L. Ong, Biomaterials, 27, 5512- 

5517, (2006). 

[10] H. W. Kim, H. H. Lee, J. C. Knowles, J. Biomed Mater 

Res, 79A, 643-649, (2006). 




Surface Chemical Conversion of 3-glycidoxypropyldimethylethoxysilane on Hydroxylated Silicon 

Surfaces: Contact Angle, FT-IR and Ellipsometry 

Serkan Demirci, 1* Tuncer Çaykara 2 

1 Department of Chemistry, Ahi Evran University, Kırşehir 40200, Turkey 

2 Department of Chemistry, Gazi University, Ankara 06500, Turkey 

Abstract — The chemical conversion of the top surface of 3-glycidoxypropyl dimethylethoxysilane (GPDMES) selfassembled 

monolayer on hyroxylated silicon surface has been studied as a function of reaction time. A multiple-step procedure 

was applied in this study. At first, GPDMES molecules were self-assembled on the hydroxylated silicon surface. The second 

step is the modification of epoxy groups with 3,3’-iminodipropionitrile (IDPN) and the last step is the amidoximation reaction 

of nitrile groups. Existence of the GPDMES, GPDMES-CN and GPDMES-(NH 2 )C=NOH layers covalently attached to silicon 

surfaces were revealed by X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR). 

Modification and conversion of surfaces were followed by contact angle, FT-IR and ellipsometry analysis. 

The self-assembled monolayers (SAMs) of organosilanes 

have been successfully used to tailor material surfaces to 

obtain control over the molecular composition and the 

resulting integral properties of the surfaces [1]. Several SAMs 

systems have been explored and reviewed [2]. There is a 

growing interest in covalently attached functional-terminated 

monolayers. However, alkoxysilane monolayers terminated 

with functional group cannot be directly prepared from 

functional-alkoxysilane due to the reactivity of functional 

groups with hydroxylated silicon, which competes with the 

preferred reaction alkoxysilane groups and the substrate [3]. 

As a consequence, the chemical diversity of these monolayers 

have been limited, especially when compared with SAMs on 

solid surfaces. 

SAMs have been analyzed by a variety of techniques 

including spectroscopic [4], electrochemical, microscopic [5] 

and wetting (contact angle) measurements [6]. Due to the high 

sensitivity and simplicity of operation, contact angle 

measurements have been widely used to study carboxylic acid 

monolayers on gold, such as to monitor the formation process, 

and to follow the step-by-step modification. FT-IR 

spectroscopy has been proved to be a powerful tool to study 

the chain conformation and orientation [7], to determine the 

coverage and parking, and to monitor the surface chemistry 

[8] of organic SAMs formed on different surfaces. As 

mentioned before, FT-IR spectroscopy has been frequently 

used for the characterization analysis of the original silicon 

and modified silicon surfaces. 

In this work, the use of three-step procedure for the 

introduction of functional groups in SAMs on hydroxylated 

surfaces is described. Reaction time has been studied and can 

also be used to control product structure. This procedure is a 

useful route to covalently attached monolayers with a variety 

of controllable structure. This comprehensive report describes 

our XPS, FT-IR, ellipsometry analysis and contact angle 

studies of the surfaces. We report detailed ellipsometry 

analysis, contact angle and FT-IR studies of GPDMES, 

GPDMES-CN and GPDMES-(NH 2 )C=NOH surfaces as a 

reaction time. 

In this study, a new route was developed for the 

preparation of amidoxime-terminated silioxane monolayers 

covalently attached to silicon wafer surfaces. GPDMES, 

GPDMES-CN and GPDMES-(NH 2 )C=NOH layer covalently 

attached to silicon surface was characterized by XPS, FT-IR, 

ellipsometry and contact angle measurements. Modification 

and conversion of surfaces were followed by contact angle, 

FT-IR and ellipsometry analysis. All the experimental results 

show that direct control over the density of the –CN or 

amidoxime groups on the surface can be obtained with 

reaction time. 

Figure: A model that explains GPDMES-CN or GPDMES- 

(NH 2)C=NOH layers coverage on GPDMES or GPDMES-CN surface as 

a function of reaction time. 

* sdemirci@ahievran.edu.tr 

[1] A. Shida, et al., Surf. Coat. Tech. 169-170, 686 (2003). 

[2] A. Ulman, Chem. Rev. 96, 1533 (1996). 

[3] S. Demirci, T. Caykara, Surf. Sci.,604, 649 (2010). 

[4] L. Sun, R.M. Crooks, Langmuir 9, 1775 (1993) 

[5] H.Y. Nie, et al., Thin Solid Films 517, 814 (2008). 

[6] S.E. Creager, J. Clarke, Langmuir 10, 3675 (1994). 

[7] A.B. Sieval, et al., Langmuir 17, 7554 (2001). 

[8] S.S. Cheng, et al., Langmuir 11, 1190 (1985). 




Synthesis of ZnO nanorods by a simple Hydrothermal method 

Leili Motevalizadeh * 1 ; Zahra Heidary * 1 ; Nasser Shahtahmassebi 2 

1 Department of Physics, Faculty of Sciences, Islamic Azad University, Mashhad branch, Mashhad, Iran 

2 Department of Physics, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran 

Abstract- ZnO nanorods have been synthesized in low temperature by a novel simple hydrothermal method without using any substrates, 

catalysts and autoclave. The samples have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD 

patterns confirm that the prepared ZnO powders with different time reaction have the single-phase Wurtzite structure. SEM images show that the 

sample was in the form of ZnO nanorods, with the average lengths of 2-3 μm and diameters of 200-400 nm. 

In recent years studies on one-dimensional (1-D) 

nanostructures such as nanotubes, nanowires, and nanorods 

have received increasing attention because of their great 

potential applications in the fields of scanning microscopes 

and sensors [1], field emission devices [2], biological probes 

[3] , and nanoelectronics [4]. 

ZnO is one of the most important materials due to its 

large band gap energy of 3.37 eV and large exciton binding 

energy of 60 meV at room temperature [5]. One-dimensional 

ZnO nanostructures have attracted considerable interest 

because of their promising applications in nanoscale 

optoelectronic devices [6]. For preparation of 1-D ZnO 

nanostructures various approach such as chemical vapor 

deposition (CVD) [7], thermal evaporation [8], and pulsed 

laser deposition (PLD) [9] have been reported. Recently, 

Ashfold reported the preparation of 1-D ZnO nanostructures 

via hydrothermal method [10, 11]. 

In this paper we reported the synthesis of ZnO nanorods 

via the hydrothermal method at low temperature (90 ºC) 

without using autoclave, catalysts, and templates. Aqueous 

solution of deionized water, zinc chloride and ammonia (25%) 

were prepared. The mixture solution transferred into closed 

balloon in presence of nitrogen gas. the balloon was Sealed 

and heated in an oil bath at 90°C for (a) 5 h, (b) 10 h, (c) 15 h, 

respectively. After this stage, the balloon was cooled down to 

room temperature. Following carefully washing with 

deionized water and drying at 40°C under air atmosphere, the 

white precipitates were collected, and kept for advance 

characterization. 

Figure 1 shows X-ray diffraction patterns from final 

products with different reaction time. It is observed that all of 

the diffraction peaks match the hexagonal ZnO structure with 

lattice constants of a=b=3.249 Å and c=5.206 Å. 

Figure 2 shows the SEM images of the products. A 

comparison between SEM images reveals that with the 

increase of reaction time initial nanoclusters (Fig. 2-a) divide 

into uniform nanorods. By analysis of SEM images (Fig. 2-b, 

Fig. 2-c) it is found that the average diameter of fabricated 

ZnO nanorods is around 250 nm and their length is around 2.5 

μm. 

In summary, we synthesized ZnO nanorods via a simple 

hydrothermal method without using autoclave. XRD analysis 

confirmed the formation of hexagonal ZnO structure. SEM 

images showed that the length and diameter of nanorods were 

2-3 m and 200-400 nm, respectively. Meanwhile, had 

synthesized ZnO nanorods with a diameter of 70 nm using 

Intensity (a.u.) 



0.8 

0.6 

0.4 

0.2 

1 

0.8 

0.6 

0.4 

0.2 

0 

1 

0.8 

0.6 

0.4 

0.2 

0 

1 

0 

(a) 

20 30 40 50 60 

2 0 

(b) 

20 30 40 50 60 70 80 

2 0 

(c) 

20 30 40 50 60 70 80 

2 0 

Fig. 1: X-ray diffraction patterns from 

final products with different reaction 

time, (a) 5h, (b) 10h, (c) 15h. 

autoclave [12]. The difference between our nanorods diameter 

and that of Ref. [12] is due to different ambient pressure in the 

two synthesis processes. 

*Corresponding authors: lmotevali@mshdiau.ac.ir, z.heidary.62@gmail.com 

[1] R. Service, Science 281 (1998) 940. 

[2] S. Fan et al; Science 283 (1999) 512. 

[3] G.I. Dovbeshko et al; Chem. Phys. Lett. 372 (2003) 432. 

[4] S.J. Tans, R.M. Verschueren, C. Dekker, Nature 393 (1998) 49. 

[5] M. Willander et al; Superlattices and Microstructures, 43 (2008) 352. 

[6] C.R. Gorla et al; J.Appl. Phys. 85 (1999) 2595. 

[7] J.J.Wu, S.C. Liu, Adv. Mater. 14 (2002) 215. 

[8] X. Kong et al; Materials Chemistry and Physics; 82 (2003) 997. 

[9] Ye. Sun et al; Chemical Physics Letters; 396, (2004) 21. 

[10] M.N.R. Ashfold et al; Chem. Phys. Lett. 431 (2006) 352. 

[11] M.N.R. Ashfold et al; Adv. Mater. 17 (2005) 2477. 

[12] J. H. Yang et al; Cryst. Res.Technol. 44 (2009) 87. 

(a) 

(b) 

(c) 

Fig. 2: SEM images of ZnO 

nanorods prepared with 

different reaction time, (a) 5h, 

(b) 10h, (c) 15h. 




Photoluminescence enhancement from Silicon/Germanium quantum structures 

1 . Kalem, 2 P. Werner, 3 V. Talalaev, 4 Ö. Arthursson 

TUBITAK-UEKAE National Research Institute of Electronics and Cryptology, Gebze-Kocaeli, Turkey 

2 Max-Planck-Institute, Department of Experimental Physics, Halle(Saale), Germany 

3 ZIK "SiLi-nano" Martin-Luther-Universität (Halle), Karl-Freiherr-von-Fritsch-Str. 3 D - 06120 Halle, Germany 

4 Microtechnology and Nanosciences Department., Chalmers University of Technology, Göteborg, Sweden 

Abstract— This work describes the results of an investigation of optical and electronic properties of Si/Ge quantum 

heterostructures grown by molecular beam epitaxy on Silicon wafers. 

During the last decade, the group IV 

semiconductor nano structures has been at the focus 

of intense research for promising applications in the 

field of information storage, optoelectronic devices, 

communications and sensors. Focusing on the Si 

and Ge based quantum structures concerns the 

development of nano memories, novel 

electroluminescent devices, fabrication of new light 

harvesting layers for the next generation of solar 

cells, biosensors, development of new information 

processing devices, etc. Basic scientific research 

activity on the light emission of these Group IV 

nano structures has particular reasons for 

understanding microscopic mechanisms behind the 

related effect [1-4]. Knowledge generated from 

these activities can pave the way to manufacturing 

where, for example, CMOS compatible electronic 

and photonic components can be integrated with a 

lower cost while enhancing performance values for 

processors. 

In order to realize above mentioned 

applications, the fundamental mechanism of the 

excitation process, optical and electronic properties, 

the charge trapping in Si and Ge based quantum 

structures (nano wires, nano clusters, superlattices) 

are to be explored in greater extent. In this work, an 

investigation of optical, electronic and structural 

properties was carried out on Si/Ge multilayer nano 

wires grown by molecular beam epitaxy on Si 

wafers. The layers were treated by acid based 

vapors in an attempt to induce efficient carrier 

confinement in the Ge dots and wells. 

A significant enhancement in infrared 

photoluminescence at room temperature was 

observed from Si/Ge quantum structures 

(multilayers, nano wires, dots) as shown in Figure 

for a variety of quantum structures exposed to HF 

based acid vapors. The emission (>1200 nm) 

originates mainly from Ge dots and the band edge 

emission from Si at 1100nm (Si TO ) with possible 

contribution from dislocations. The results are 

correlated with Raman, ellipsometry and TEM 

analysis in an attempt to clarify the origin of the 

emission enhancement from Si/Ge nanostructures. 

PL intensity, a.u. 

Ge dots 804d 

Si(9)/Ge(2)x9ML 

3x10 5 

2x10 5 Si(100)/Ge(80)-060425 

1x10 5 

0 

. Si(200)/Ge(100)-070614 . 

800 1000 1200 1400 1600 

Wavelength, nm 

Figure : Room temperature photoluminescence from Si/Ge 

multilayers as compared to a reference Ge dot. 

Controlling light emission in tele 

communication wavelengths from Si/Ge quantum 

structures has a great potential for novel LED 

device fabrication particularly for applications 

ranging from biology to interconnects in 

nanoelectronics. 

This work was supported by TUBITAK-BMBF 

programme under contract No: TBAG-107T624. 

*Corresponding author: s.kalem@uekae.tubitak.gov.tr 

[1] D. Grützmacher et al., Materials Science and Engineering 

C 27, 947 (2007) 

[2] Talalaev et al., Physica Status Solidi A 198, R4- R6 

(2003). 

[3] N.D. Zakharov et al., Appl. Phys. Lett. 83, 3084- 3086 

(2003). 

[4] G.E. Cirlin et al, phys.stat.sol. (b) 232, R1-R3 (2002). 




Synthesis of anatase TiO 2 nanotubes at high temperature by sol-gel template method 

Elaheh Ghorbani 1, * , Leili Motevalizadeh 1, * , Nasser Shahtahmassebi 2 , Ebrahim Attaran 2 

1 Department of physics, Faculty of science, Islamic Azad university, Mashhad branch, Mashhad, Iran. 

2 Department of physics, Ferdowsi university of Mashhad, Mashhad, Iran. 

Abstract—The anatase phase of TiO 2 nanotubes have been synthesized by sol-gel template method using alumina membrane 

as a template after annealing at 800°C for 2 hours. Transmission electron microscopy (TEM) and X-ray diffraction were used 

to investigate the structure and morphology of the TiO 2 nanotubes. TEM image showed that the obtained TiO 2 nanotubes were 

highly ordered and uniform. The diameter and length of the obtained nanotubes were determined by the pore size and the 

thickness of AAO template. XRD results showed that the TiO 2 nanotubes were crystallized in anatase phase after annealing at 

800°C for 2 hours. 

TiO 2 is one of the semiconductor materials that are widely 

investigated due to important applications in many fields such 

as gas sensors, solar cells and photocatalysts [1, 2]. Most of 

these applications are a consequence of its chemical stability, 

high photocatalytic activity and surface reactivity [3, 4]. 

Recently, much effort has been devoted to preparation of TiO 2 

nanotubes that have larger surface area compared to TiO 2 

nanoparticles and bulks. These structures should enhance 

surface related properties such as catalytic activity and surface 

adsorption [5]. 

One of the most important methods for synthesis TiO 2 

nanotubes is the template assisted method due to controlling 

the morphology and arrangement (1D) nanostructures in 

which the diameter, length and aspect ratio of the obtained 

structures are fully controlled by the templates used [6]. This 

method combines the sol-gel processing and template-based 

growth. In this manner, the template is dipped directly into 

TiO 2 -sol solution with an appropriate deposition time, sol 

particles can fill channels of template and form structures with 

high aspect ratio. The final product will be obtained after a 

thermal treatment to remove the gel [7]. 

In this paper the TiO 2 -sol is formed by mixing of 

titanium tetra isopropoxide and 2-propanol at molar ratios of 

1:20. The mixture was then stirred for 3 h at the room 

temperature. 

For the synthesis of nanotubes, the porous anodic 

alumina membranes (Whatman Anodisc 25) were used as the 

template. The average thickness, and pore size of these 

templates were 60 μm and 150–200 nm, respectively. The 

alumina template membranes were dipped into sol solution for 

5 min, then the samples were dried in air at room temperature 

for 30 min. For thermal treatment, the prepared specimens 

were placed in a furnace (in air) and the samples warm up to 

200°C in less than 5 min, then they were heated up at a rate of 

2°C/min in 800°C and were held in this temperature for 2 h. 

Finally, the furnace was shut down and the samples were 

cooled down to room temperature. The fig 1 shows the XRD 

patterns of samples annealed at 800°C for 2 h. we have to 

notice that these samples are include of AAO membrane and 

polycrystalline TiO 2 nanotubes. The peak positions and their 

relative intensities are consistent with the standard powder 

diffraction pattern of anatase TiO 2 . Sadeghzade Attar et al. 

reported the formation of anatase TiO 2 in annealing 

temperature between 400 to 600°C and in 800°C the phase of 

TiO 2 was reported rutile[8]. But in this work the phase of TiO 2 

has been changed from rutile to anatase in this annealing 

temperature. 

Fig. 2 shows TEM images of obtained TiO 2 nanotubes. 

They have a wall thickness about 10 nm and a diameter of 

around 200 nm, which correspond exactly with the pore size 

of the AAO membrane. This indicates that the diameter of the 

nanotube synthesized is controlled by the pore size of 

aluminum oxide membrane. 

Fig. 1 XRD pattern of sample that include TiO 2 nanotubes and AAO 

template. 

200 nm 500 nm 

Fig. 2 TEM images of TiO2 nanotubes 

In this study, TiO 2 nanotubes have been synthesized by 

sol-gel chemical method within the pores of AAO template 

membrane. The results of XRD showed that the obtained TiO 2 

nanotubes are polycrystalline with anatase phase after 

annealing at 800ºC for 2h. The TEM images showed the 

average diameter of nanotubes were about 200 nm in diameter 

with several micrometers in length. It was shown that the 

dimension of nanotubes depends on the pore size of the 

template. 

*Corresponding author: lmotevali@mshdiau.ac.ir, e.ghorbani80@gmail.com 

[1] E. Palomares, R. Vilar, J.R. Durrant, Chem. Commun. 4 (2004) 362. 

[2] B. O , Regan, M. Gratzel, Nature (1991) 353. 

[3] A-W. Xu, Y. Gao, H-Q. Liu, J Catal 207(2002)151. 

doi:10.1006/jeat.2002.3539. 

[4] M. Keshmiri, M. Mohseni, T. Troczynski, Appl Catal Environ 

53(2004)209. doi: 10.1016/j.apcatb.2004.05.016 

[5] E. Comini, C. Baratto, G. Fglia, M. Ferroni, A. Vomiero, G. Sberveglieri, 

Progress in material science 54 (2009) 1. 

[6] John C. Hulteen and Charles R. Martin, J. Mater. Chem. 7 (1997) 1075. 

[7] B.B. Lakshmi, C.J. Patrissi, C.R. Martin, Chem. Mater. 9 (1997) 2544. 

[8] A. Sadeghzadeh Attar, M. Sasani, F. Hajiesmaeilbaigi, Sh. Mirdamadi, 

K.Katagiri, K. Koumoto; J Mater Sci 43 (2008) 5924. 



Preperat ion CdS thin films for optoe lectronic applications 

S. Morkoç 1 *, F. N. Tuzluca 1 , A. E. Ekinc 1 E. Büyükkasap 2 3 

1 Erzincan University, Science Faculty, Department of Physics, Erzincan 

2 Ataturk University, Education Faculty, Department of Physics, Erzurum, 

3 Ataturk University, Engineering Faculty, Department of Electric&Electronics, Erzurum 


Abstract- Cadmium sulfide (CdS) thin films were prepared by Chemical Spray Pyrolysis Deposition (CPD) technique onto microscope glass 

substrates at 200, 250 °C, using aqueous solution of cadmium chloride and thiourea salts. The crystalline quality and the surface morphology of 

the deposited CdS thin film were characterized using X-ray diffraction and Atomic Force Microscopy, respectively. The optical properties of 

the prepared films were analyzed by UV-Visible . After all investitagions, it is concluded that 200, 250 °C substrate temperature is suitable for 

producing CdS thin with (CPD) technique. 

II-IV compound semiconductors have hexagonal type 

structure, they have wide energy gap (1,7-13,4 eV) [1]. CdS 

is one of the most vital and classical II-IV group 

semiconductors with a direct band gap of 2.4 eV at room 

temperature[2]. CdS thin films are also widely used as n 

type window layers in thin film solar cells [3] because of 

suitable band gap, optical absorption, and good stability of 

the used materials[4]. Spray pyrolysis method is best suited 

for CdS thin film deposition because of simplicity, 

convenience, least expenses[5]. 

In the present work, the spray solutions were prepared 

using a mixture of solutions of CdCl 2 (source of cadmium 

ions) and (NH 2 ) CS (source of sulfur ions); water was added 

in order to obtain a concentration of 0.01 M. The schematic 

representation of the CPD apparatus is shown in Figure 1. 

Microscope glass was used as substrates. First, they were 

cleaned with acetone for ten minutes and then thoroughly 

washed in deionizer water for 15 minutes. The substrates 

were then dried in a drying oven. The temperature of the 

substrate was measured as 200 °C and 250 ±5 °C by a noncontact 

IR thermometer and a K type thermo couple. 

Figure 3. AFM results of CdS thin film prepared at a) 200 °C b) 

250 °C 

The optical properties of CdS thin film was measured by 

UV-Vis spectrometer. Figure 4a-b shows the transmittance 

spectra of CdS film as grown by Chemical Spray pyrolysis 

technique were observed in the wavelenght range 500-850 

nm. According to results, CdS thin film exhibits high 

transparency (fro m 85 to 98 % ) in the visible region fro m 

530 to 850 nm, making them possible to be used as window 

layers in solar cells for as deposited CdS thin film at 250 °C 

[5]. However, CdS thin film exhibits transparency from 40 

to 60 % in the visible region from 530 to 850 nm for as 

deposited CdS thin film at 200 °C. 

100 

55 

Transmission % 

50 

45 

Transmission % 

95 

90 

40 

85 

Figure 1. Spray Pyrolysis System 

450 500 550 600 650 700 750 800 850 900 


450 500 550 600 650 700 750 800 850 900 


In this work , it is expected hexagonal (wurtzite ) phase 

for as- deposited CdS thin films at 200 °C and 250 °C by 

Chemical Spray Pyrolysis Technique . It is observed from 

figure 2a-b, the highest reflection peak intensity that for asdeposited 

thin film at 200 °C and 250 °C is (002) hexagonal 

plane. However, Other peaks are observed that are very 

low intensity for 250 °C but they are very high intensity for 

200 °C. The morphologies of as-deposited CdS thin film 

characterized by two-dimensional AFM scans of the sample 

surface after deposition are shown in Figure 3a-b. The 

images were obtained in tapping mode. From the 

micrograph it is seen grains of CdS thin films. 

Intensity(A.U.) 

(002) 

900 

(101) 

800 

 

700 

600 

 

(110) (103) (112) 

500 (100) 

 

(102) 

 

400 

300 

200 

20 30 40 50 60 

2(degrees) 

intensity(a.u.) 

850 

(002) 

800 

750 

700 

650 

600 

550 

500 

450 

(101) 

400 

(103) 

350 

300 

250 

200 

150 

100 

50 

0 

20 25 30 35 40 45 50 55 60 65 

2(degrees) 

Figure 4. UV-Vis results of CdS thin film prepared at a)200 °C b) 

250 °C 

*Corresponding author: morkocsibel@gmail.com 

[1] Deokjoon Cha,Sunmi Kim,N.K. Huang, Material Science and 

Engineering B, 106(2004)63-68 

[2] Fei Li ,Wentuan Bi, Tao Kong, ChuanjinWang, Zhen Li, 

Xintang Huang Journal of Alloys and Compounds 479 (2009) 707– 

710 

[3] Hui Zhang,Xiangyang Ma, Deren Yang, Materials Letters 58 

(2003) 5-9 

[4] V.Bilgin,S. Kose,F.Atay,I Akyuz, Material Chemistry and 

Physics 94(2005) 103-108 

[5] J.Hiie, T.Dedova, V.Valdna, K.Muska Thin Solid Films 511- 

512 (2006) 443-447 

Figure 2. Xrd results of CdS thin film prepared at a)200 °C 

b) 250 °C 




Electroc hemical inve stigations of the interac tion of Albumin with Cibac ron Blue F3GA 

chemically immobilized on a modified glas sy carbon electrode as a nanofilm 

Sümeyra Akkaya 1 * , Mustafa Uçar 1 ,Remziye Güzel 2 , 3 , 4 and Ali Osman Solak 4 

1 Afyon Kocatepe University, Faculty of Arts and Sciences, Dept. Of Chemistry, Afyonkarahisar, Turkey 

2 

3 mistry, Kütahya, Turkey 

4 Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey 

Abstract- Benzoic acid modified glassy carbon electrode was prepared at a glassy carbon surface by the electrochemical reduction of 

diazobenzoic acid tetrafluoroborate salt. Subsequently, albumin from an albumin suspension was attached to the benzoic acid modified 

surface to prepare a benzoic acid-albumin nano composite film. Onto the nanocomposite film, Cibacron Blue F3GA molecules were 

deposited by self-assembling technique to form GC-BA/Alb/CB-Dye surfaces. These surfaces were characterized by cyclic voltammetry, 

electrochemical impedance spectroscopy , X-ray photoelectron spectroscopy, reflectance-absorption infrared spectroscopy in each step during 

the fabrication process. 

Human serum albumin (HSA) consists of a single 

polypeptide chain containing 585 amino acid residues and is 

the major soluble protein component in serum. It has many 

physiological functions which contributes to colloid osmotic 

blood pressure and aids in the transport, distribution, and 

metabolism of many endogenous and exogenous substances 

[1,2]. Cibacron Blue F3GA is a monochlorotriazine dye and 

has the group specificity for albumin, dehydrogenase and 

lysozyme [3]. Via the nucleophilic reaction between chloride 

of its triazine ring and reactive groups of the supports 

including hydroxyl or amino, Cibacron Blue F3GA can be 

immobilized onto the supports for protein affinity adsorption 

[4]. 

In this study the glassy carbon electrode surfaces were 

modified with the electrochemical reduction of diazonium 

salt of benzoic acid by cyclic voltammetry (CV) in the 

potential range of +0.2 V and -0.8 V at a scan rate of 200 

mVs -1 for ten cycles vs. Ag/AgNO 3 electrode in acetonitrile 

containing 0.1 M tetrabutylammoniumtetraflouro-borate 

(TBATFB). 

Modification voltammogram recorded is very characteristic 

for the reduction of diazonium salt, in which an irreversible 

reduction CV wave of diazonium salt is indicative of the loss 

of N and the formation of a diazobenzoic acid radical 

2 

followed by covalent binding to the carbon surface [5-6]. 

Modified electrodes were characterized electrochemically 

using redox probes of ferricyanide, dopamine and ferrocene 

by CV and electrochemical impedence spectrpscopy (EIS). 

In BA modified GC electrodes, carboxylic acid groups of the 

BA film were further activated by covering the GC surface 

with 10 μL of 4 mM EDC/ 1 mM NHS in 10 mM PBS (pH 

7.6) and incubated at room temperature for 1 h, followed by a 

rinse with deionized water. After that, 4 μL of albumin in BR 

buffer solution was placed on the BA-GC electrode surface as 

dropping with micropipettes and dried at 4 ºC overnight. The 

albumin-BA modified GC electrode was then rinsed 

throughly with 10 mM PBS (pH 7.6) to remove the weakly 

adsorbed protein. 

Electrochemical impedance spectroscopy were used to 

investigate the formation of GC-BA, GC-BA/Alb and GC- 

BA/Alb/Cibacron Blue F3GA. Here, EIS was used to 

monitor the fabrication process of the benzoic acid surface 

modification of GC, the albumin attachment and self 

assembling of organic dye layers to modified surfaces. To 

investigate the interaction between albumin and dye, the 

Nyquist plots of bare GC, GC-BA, GC-BA/Alb and GC- 

BA/Alb/CB-Dye surfaces were recorded for the redox couple 

of 1 mM Fe(CN) 3-/4- 6 mixture prepared in BR buffer of pH 2 

and 6,7. 

NH 

O 

C 

CB-Dye 

O NH 

C 

Figure 1. Schematic figure of nanofilm product. 

I would like to thank Prof. Dr. Ali Osman SOLAK who 

presenting us his research laboratory for our experiments. 

*Corresponding author: sakkaya@aku.edu.tr 

[1] Tietz, N.W., 1976. Fundamentals of clinical chemistry, 

Saunders,Philadelphia. 

[2] He, X-M., Carter, D-C., 1992. Atomic structure and 

chemistry of huma serum albumin. Nature, 358: 209. 

[3] Yu, Y-H., Xue, B. Sun, Y. 2001. Dye-ligand poly( GMA- 

TAIC-DVB) affinity adsorbent for protein adsorption. Bioprocess 

and Biosystem Engineering, 24: 25-31. 

[4] Suen, S-Y., Lin, S-Y., Chiu, H-C., 2000. Effects of spacer 

 

using regenerated cellulose membrane discs. Ind. Eng. Chem. 

Res., 39(2): 478-487. 

[5] Liu, G., Liu, J., Böcking, T.,Eggers, P-K., Gooding, J-J., 

2005. The modification of glassy carbon and gold electrodes with 

aryl diaznium salt: The impact of the electrode materials on the 

rate of heterogenous electron transfer. Chemical Physics, 319: 

136-146. 

[6] Ustundag, Z., Solak, A-O. 2009. EDTA modified galssy 

carbon electrode: preparation and characterization. Electrochimica 

Acta, 54: 6426-6432. 




Continuum Buckling Analysis of Double-Walled Carbon Nanotubes with Different Inner and Outer 

Boundary Conditions 

Seckin Filiz 1 , Metin Aydogdu 2 * 

1 Graduate School of Natural and Applied Sciences, Trakya University, Edirne, Turkey 

2 Department of Mechanical Engineering, Trakya University, Edirne, 22180, Turkey 

Abstract- Buckling of in-plane loaded doublewalled carbon nanotubes is studied by using continuum Euler-Bernoulli beam theory. Different 

boundary conditions are assumed for inner and outer carbon nanotubes. A finite difference method is proposed for the solution of governing 

equations. 

In recent years, small scale engineering members have been 

used in many scientific and industrial applications. Carbon 

nanotubes are one of these small elements which are used due 

to their extraordinary mechanical, electrical, low weight and 

optical properties [1-4]. 

Mechanical properties of CNTs were studied by some 

researchers in the last two decades. Buckling is one of the 

problems which occur due to external loads. Studies related 

with static and dynamic analysis of CNTs can be divided in to 

two parts: molecular dynamic simulations [5-7] and 

continuum mechanics models [8-10]. In the previous studies it 

was shown that molecular dynamic simulations are limited 

with small number of atoms and short time intervals. Due to 

this fact continuum beam and shell models were used in the 

previous analysis [8-10]. It is important to mention that 

previous studies are limited to simply supported boundary 

conditions or same boundary conditions for all nested carbon 

nanotubes. In the real engineering applications it is possible to 

have different boundary conditions for nested CNTs. Actually 

it is not possible to have a classical boundary conditions for 

inner tubes other then free one. This important issue is not 

considered in the previous studies. 

In the present study, a finite difference continuum beam 

model based on classical Euler-Bernoulli beam theory is 

proposed to analyze buckling of multiwalled CNTs. After 

general formulation, buckling of double walled carbon 

nanotubes is studied using classical Euler-Bernoulli beam 

model. Different boundary conditions are assumed for inner 

and outer CNTs. It is believed that using different boundary 

conditions for nested tubes is more realistic when compared 

with previous studies. 

In the present study, the deflections of the nested tubes are 

coupled through the van der Waals intertube interaction 

pressure. Nondimensional critical buckling loads will be given 

for different boundary conditions and mode numbers. The 

proposed finite difference formulation of multiwalled CNT 

can also be used for other dynamic and static analysis of CNT 

related problems. 

[8] J. Yoon, C.Q. Ru, A. Mioduchowski, Compos. Part B-Eng. 35, 

87(2004). 

[9] M. Aydogdu, M.C. Ece, Turkish J. Eng. Env. Sci. 31, 305 (2007). 

[10] M. Aydogdu, Physica E. 41, 1651 (2009). 

*Corresponding author: metina@trakya.edu.tr 

[1] S. Iijima, Nature (London) 354, 56 (1991). 

[2] P. Kim and C.M. Lieber, Science 286, 2148 (1999). 

[3] J. Kong, Science 287, 622 (2000). 

[4] E.T. Thostenson, Z. Ren and T.W. Chou, Comp.Sci. Techno l. 61, 

1899 ( 2001). 

[5] B.I. Yakobson, C.J. Brabec and J.Bernholc, Phys. Rev.Lett. 76, 

19 

71 (1996). 

[6] B.I. Yakobson and R.E. Smalley, Am.Sci., 85, 324 (1997). 

[7] Y.G. Hu, K.M. Liew, Q. Wang, X.Q. He, B.I. Yakobson, J. Mech. 

Phys. Solids 56, 3475 (2008). 




Mechanical Properties in Multiwalled Carbon nanotubes/ PAM composites 

1 * 1 , Önder Pekcan 2 

1 Department of Physics, , 34469, Turkey 

2 

0, Turkey 

Abstract- The mechanical properties of multiwall carbon nanotubes (MWNTs)/polyacrylamide (PAM) composites were studied as a function of 

nanotube content. Multiwalled carbon nanotube (MWNT) composites with polyacrylamide (PAM) were prepared via free radical crosslinking 

copolymerisation with different amounts of MWNTs varying in the range between 0.1 and 50 wt%. The PAM-MWNT composite gels were 

characterized by tensile testing machine. A small content of doped nanotubes dramatically changed Young modulus and toughness, respectively. 

Carbon nanotubes (CNTs) have been one of the hottest 

research topics since the discovery [1] because of their special 

properties and wide potential applications [2]. 

The mechanical properties of hydrogels with nano materials 

are best understood using the theories of rubber elasticity and 

viscoelasticity. To derive relationships between the network 

characteristics and the mechanical stress- strain behavior, 

classical and statistical thermodynamics have been used to 

develop an equation of state for rubber elasticity. It is known 

the entropic model. From classical thermodynamics, the 

equation of state for rubber elasticity may be expressed as [3] 

f 

U 

f 

 

T 

 

L 

T, 

V T 

L, 

V 

(1) 

where f is the refractive force of the elastomer in response to a 

tensile force, U is the internal energy, L is the length, V is the 

volume, and T is the temperature. For ideal rubber elastic 

behavior, the first term in equation 1 is zero. The refractive 

force and entropy are related through the following Maxwell 

equation 

S 

f 

 

 

L 

T, 

V T 

L, 

V 

(2) 

Stress- strain analysis of the energetic and entropic 

contributions to the refractive force (Equation 1) indicates that 

entropy accounts for more than 90% of the stress. After some 

statistical analysis, shear modulus can be defined by 

G 

(3) 

 

where , the force per unit area and is the extension ratio. 

While the thermodynamic and statistical thermodynamic 

approaches describe observed rubber-elastic behavior at low 

extensions quite well, the equation is invalid higher 

elongations [3] 

Composite gels were prepared via free radical crosslinking 

copolymerization with different amounts of MWNTs varying 

in the range between 0.1 and 50 wt%. Compression module of 

PAM- MWNTs composite gels at 25°C was determined by 

means of a Hounsfield H5K-S model tensile testing machine. 

Any loss of water and changing in temperature during the 

measurements was not observed because of the compression 

period being less than 1 min. 

Figure 1(a) and (b) show that young modulus and toughness 

depend on the content of MWNTs in PAM, respectively. 

Young modulus increases progressively until 3 wt. % 

MWNT with increasing nanotube content. At contents above 

Young modulus(MPa) 

Toughness(kPa) 

0,12 

0,10 

0,08 

0,06 

0,04 

0,02 

2 

1 

0 

0,0 10,0 20,0 30,0 40,0 50,0 60,0 

0,0 10,0 20,0 30,0 40,0 50,0 60,0 

%MWNT 

(a) 

1.trial 

2.trial 

(b) 

1.trial 

2.trial 

Figure 1. (a) Young modulus and (b) Toughness dependence 

on the MWNTs content in composite gels. 

3wt. %MWNTs, the young modulus is decreased marginally 

with increasing MWNTs content in Figure 1(a). On the other 

hand, at lower content(3 wt.%), the toughness decreases from 

the neat composite of 1.3kPa, only exceeding it when the 

MWNT content is above 20 wt. % (Figure 1(b)), and then 

increases further as the MWNTs content is raised[4]. 

This work explores the mechanical properties of PAM- 

MWNTs composite gels characterized by tensile testing 

machine. Our results show that a decrease in length brings 

about an increase in entropy because of changes in the end to 

end distances of the network chains of PAM-MWNTs 

composite gels, thermodynamically. Thus, the entropic model 

for composite elasticity is a reasonable approximation. 

We thank Argun Talat 

measure ments. 

*Corresponding author: evingur@itu.edu.tr 

Gökçeören for tensile test 

[1] S. Lijima, Nature 354, 56, (1991). 

[2] P. J. F. Harris, Int. Mat.Rev. 49, 31, (2004). 

[3] K. S. Anseth, C. N. Bowman, L. B. Peppas, Biomaterials 17, 

1647, (1996). 

[4] R. Andrews, D. Jacques, D. Qian, T. Rantell, Acc. Chem. Res.35, 

1008, (2002). 




Preparat ion and characterization of CdSe, ZnSe, CuSe, thin films depos ited by t he successive ionic 

layer adsorption and reaction (SILAR) method 

B. Gü zeld ir 1 *, A. A 1 and M. S 1 

1 Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum, Turkey 

Abstract-In this study, the CdSe, ZnSe,CuSe thin films have been directly formed on n- type Si by means of Succesive Ionic Layer Adsorption 

and Reaction (SILAR) method at room temperature. The films characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) 

and energy dispersive X-ray analysis (EDAX). The SEM and XRD studies showed that films are covered well with glass and n-type Si substrates 

and exhibit polycrystalline characterization. The EDAX spectra showed that the expected elements exist in the thin films.Some of the thin film 

with equal distribution of grains, mostly falling in nanometer regime, was clearly seen. According to the optical characterization, in the future, it 

can be used solar-cell studies, rectifying contacts, integrated circuits, the other electronic devices and so on. 

Thin films can be deposited with different methods onto 

semiconductor substrates. The one of these method is 

succesive ionic layer adsorption and reaction (SILAR) 

method. Relatively simple, quick, economical and suitable for 

large area deposition of any configuration, the SILAR method 

was reported in mid-1980s [1]. It does not require 

sophisticated instruments, the substrate need not be conductive 

and have a high melting point [2]. It applies the same soft 

growth conditions as cehmical bath deposition (CBD). The 

difference between CBD and SILAR is that in SILAR the 

growth is performed layer by layer by dipping the substrate 

sequentially into stable percursor solutions and rinsing in 

between the unadsorbed ions from the surface [3]. Single 

SILAR deposition cycle involves the immersion of the 

substrate alternately in cationic and anionic precursor 

solutions and rinsing between every two consecutive 

immersions with deionized water to avoid homogeneous 

precipitation in the solution, so that only the tightly adsorbed 

layer stays on the substrate. The adsorption is a surface 

phenomenon occurring due to attractive force between ions 

and surface of substrate. This attractive force is of Van der 

Waals type that basically orig inates due to the residual or 

unbalanced force present in the substrate. Thus, ad-atoms can 

be holding on the surface of the substrate by that residual force 

[4, 5]. 

In this study, the SILAR method was used to deposition of 

CdSe, ZnSe, CuSe thin films on n- type Si. These films were 

investigated by XRD, SEM and EDAX measurement 

techniques. One SILAR cycle contained four steps: (i) the 

substrate was immersed into first reaction containing the 

aqueous cotion precusor, (ii) rinsed with water, (iii) immersed 

into the anion solution, and (iv) rinsed with water. Repeated 

these cycles, a solid solution CdSe, ZnSe, CuSe thin films 

with desired thickness and composition were grown. 

The X-ray diffraction patterns are analysed to obtain the 

structual information of thin film. The spectrophotometer is 

used to carry out the optical absorption and transmission 

studies of the film in the wavelength range. It was seen fro m 

the XRD patterns that the CdSe, ZnSe, CuSe films were 

polycrystalline with orientation along diffrent planes and 

phases. The thin film on Si substrate shows improvement in 

crystallinty. Such increase in crystallinty for Si substrate is 

attributed to the single crystalline nature of Si substrate. 

Scanning electron microscopy is well- known the surface 

studying morphology of metals in thin film form. It was 

observed that the as-deposited CdSe, ZnSe, CuSe thin films 

were well coverages without cracks or pinholes to the 

substrates. 

One of the important applications of the SEM is the 

analiztaion of the elemental composition of a material. This 

microanalization mode of SEM replied upon the monitoring 

X-rays emitted by surface of the sample under electron 

irradiation. These X-rays are collected and analyzed to give 

information on the elemental compounds present in the 

sample. This technique is called as EDAX and can be used to 

detect elements of the periodic table with an atomic number 

greater than eleven. The EDAX spectras show that the 

expected elements detected in the thin films. The elemental 

analysis was carried out only for Cd, Zn, Cu, Se and the 

average atomic percentages were found. Also, small 

percentage of the other elements were present in the thin films. 

It is thought that these elements may probably result from Si 

used as substrate. 

In summary, the SILAR method was used to deposit CdSe, 

ZnSe, CuSe thin films on Si subsrate. Structural properties of 

these thin film were investigated by XRD, SEM and EDAX 

methods. The films were found to have polycrystalline, 

homogeneous and covered the substrates well. The 

quantitative analysis of the films were carried out by using 

EDAX technique and it was determined that expected 

elements were present in the thin films. .Some of the thin film 

with equal distribution of grains, mostly falling in nanometer 

regime, was clearly seen We would also like to acknowledge 

under Grant No. 

TBAG-108T500. 

*Corresponding author: 1Tbguzeldir84@gmail.com 

[1] M. Ristov, G. J. Saindinovski, I. Grazdanov, Thin Solid Films 123 

63. (1985) 

[2] Y. F. Nicolau, Appl. Surf. Sci., 22 1061. (1985) 

[3] J. Puiso, S. Tamulevicius, G. Laukaitis, S. Linross, M. Leskela, V. 

Snitka, Thin Solid Films, 403 457. (2002) 

[4] R. S. Patil, C. D. Lokhande, R. S. Mane, H. M. Pathan, Oh-Shim 

Joo, Sung-Hwan Han, M aterials Science and Eng. B, 129 227 (2006) 

[5] Biswajit Ghosh, Madhumita Das, Pushan Banerjee and Subrata 

Das, Semiconductor Science And Techonolgy, 23 1250123 (2008) 




Investigation of Potential Use of Carbon Nanotube Membranes in Desalination 

Pinar Baltaci 1 , Leyla Ozgur 1 , Deniz Rende 1,2 , Rahmi Ozisik 3 and Nihat Baysal 1* 

1 Department of Chemical Engineering, Yeditepe University, Istanbul 34755, Turkey 

2 Department of Chemical Engineering, Bogazici University, Istanbul 34342, Turkey 

3 Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA 

Abstract– The potential use of carbon nanotube membranes in water desalination was evaluated in the present study. 

Water transport by reverse osmosis through hexagonally packed carbon nanotube (CNT) membranes was studied with 

Molecular Dynamics simulations. Our results showed that due to the osmotic gradient, the distance between CNT 

membranes decreased until steady state conditions were reached. The flow rate of water during its transportation 

indicates high degree of desalination. 

Reduction of potable water sources is one of the primary 

environmental issues of the last two decades. This deficiency 

causes a decrease in the human lifetime expectancy, an 

increase in disease epidemics, and therefore, is a political 

issue [1]. In addition, desalination of soil and underground 

water is an important issue in regions that have very low 

precipitation. [2]. As a result, treatment of available water 

sources receives global attention and is a promising research 

area. 

Carbon nanotubes (CNTs), which are rolled up sheets of 

sp 2 -bonded graphite [3], are suggested as efficient membrane 

materials for desalination processes [4]. The current study 

focuses on the potential use of CNT membranes in the 

desalination processes to make desalination cheaper and fresh 

water more widely available [5]. 

Due to the importance of this subject in terms of 

environmental and health impact, the current study aims to 

study the separation of a NaCl solution from H 2 O by reverse 

osmosis. The system contains two (6,6) single walled carbon 

nanotube (SWNT) membranes separating NaCl solution and 

H 2 O (Figure 1). The simulation was carried out at 300 K and 

1 atm for 60 ns via molecular dynamics (MD) simulations 

with a time step of 1 fs. Polymer Consistent Force Field 

(PCFF) was chosen as the governing force field and periodic 

boundary conditions were applied in all spatial directions. 

Initially, the distances between the two SWNT membranes 

was set to 2 nm across both compartments, and the 

concentration of salt compartment (Na + and Cl - ) was set to 

5.4 M. All the systems were energy minimized prior to MD 

simulations. 

The periodically replicated simulation cell contains eight 

SWNTs each containing 144 sp 2 carbon atoms, 545 

transferable intermolecular potential (TIP) water molecules 

and 25 pairs of Na + and Cl - ions. SWNTs were held together 

with van der Waals forces and solvent induced hydrophobic 

interactions. 

In this study, the flow of water molecules through openended 

SWNT membranes under an osmotic gradient was 

performed. The distance between membranes decreases 

continuously but not monotonically. Due to the high 

transportation rate of water molecules through the SWNTs, it 

can be concluded that SWNTs are promising desalination 

membrane materials. 

Computer resources supplied by Yeditepe University are 

gratefully acknowledged. Pinar Baltaci is an undergraduate 

student at Yeditepe University. 

*Corresponding author: nbaysal@yeditepe.edu.tr 

[1] Cygan, R.T., Liao, J-D., 2008. A molecular basis for 

advanced materials in water treatment, MRS Bulletin, V33-1: 42- 

47. 

[2] Kotzer, E., 2005. Artificial kidneys for the soil – Solving the 

problem of salinization of the soil and underground water, 

Desalinization, V185: 71-77. 

[3] Robertson, J., 2004. Realistic applications of CNTs, 

Materials Today, V7-10: 46-52. 

[4] Kalra, A.S., Garde, S., Hummer, G., 2003. Osmotic water 

transport through carbon nanotube membranes, PNAS, V100-18: 

10175-10180. 

[5] Wang, L., Zhao, J., Li, F.,Fang, H., Lu, J.P., 2009. First 

principles study of water chains encapsulated in singlewalled 

carbon nanotube, J. Phys. Chem. C, V113-14: 5368- 

5375. 

NaCl 

Solution 

CNT 

Membrane 

H 2O 

CNT 

Membrane 

NaCl 

Solution 

Figure 1. The H 2 O compartment at the center is separated from 

the NaCl-solution compartment (left and right) by two water 

permeable membranes of hexagonally packed CNTs. 




Green Reactive Extrusion Technology of Functional 

Copolymer–Polyolefin–Modified Organic Silicate Nanofilms 

Eren Altungöz, * Ernur Söylemez, Zakir M. O. Rzayev and Erdoğan Alper 

Department of Chemical Engineering, Hacettepe University, Ankara 06800, Turkey 

Abstract—This work is an approach to develop a green technological process for the preparation of polyolefin biaxially 

oriented nanofilms without utilization of toxic and volatile monomers as grafting agents. Novel polymer nanosystems were 

prepared by an one step twin-screw extrusion in situ processing using poly(α-olefin-alt-maleic anhydride)s as reactive 

compatibilizers, functionalized organoclays as reactive nano-fillers and plasma surface treated powder polyolefins as matrix 

polymers. 

Polymer/layered organoclay nanosystems and nanocomposites 

with large quantity of interfacial area offer significant 

potential to develop the high performance engineering 

materials for a wide range of numerous applications. In the 

last decade, the attention of many academic and industrial 

researchers was focused on development of green technology 

of production and processing of thermoplastic polymer silicate 

layered nanomaterials using various type of reactive extrusion 

systems. This reactive polymer melt intercalation/exfoliation 

method is one of the mostly used processes because of its 

versatibility, and compatibility with current polymer 

processing techniques, controllability of the chemical and 

physical interfacial interactions, and its environmentally green 

character [1-7]. Most known technological methods are based 

on two step extrusion processes: (1) grafting of toxic and 

volatile functional monomers onto thermoplastic polymer 

chains and (2) melt compounding polymer/graft copolymercompatibilizer/organoclay 

mixtures. 

In this report, we discuss the results of (a) designing and 

utilizing the green technological line including Rondol twinscrew 

extruder (21 mm) supported by plasma surface 

treatment unit (Lab. Plasmatron), unit for morphology control 

of melt blending process by polarized microscopy, (b) 

granulation-milling system and biaxially oriented filmforming 

unit (blowing method) for the preparation of 

nanofilms (Scheme 1), (c) investigation of extruder 

parameters–nanofilm properties relations and evaluation of 

optimum technological parameters for the formation of 

nanostructures with higher interfacial interaction area and 

degree of exfoliation of polymer chains between silicate 

galleries, (d) investigation of nanofilm composition–physical 

and chemical structure–surface morphology relationships. 

Scheme 1: Schematic representation of melt intercalation green 

technology for preparation of polymer thin nanofilms. 

Functional alternating copolymers of α-olefins (C 6-18 ) with 

maleic anhydride (MA) were synthesized by complex-radical 

copolymerization method. Polyolefins (PO) such as isotactic 

polypropylene (i-PP) and ethylene-propylene (EP) copolymer 

were supported from PETKIM Inc. (Izmir, Turkey). Reactive 

and non-reactive organoclays (Aldrich) were used without any 

purification. Modification of organoclays was carried out by in 

situ intercalation of functional copolymer chains between 

silicate galleries through amidization and complex-formation 

reactions. Hybrid nanofilms with different compositions were 

prepared by Rondol twin-screw extrusion system supported 

plasmatron and biaxially oriented film-forming unit according 

to technology line presented in Scheme 1. The results of FTIR 

and XRD analysis of chemical and physical structures of 

functional copolymer/organoclay composites indicated that the 

pre-intercalation of functional copolymer between silicate 

layers proceeds via complex-formation and amidolysis 

reactions of anhydride units with ammonium cation and 

primary amine groups of organoclays, respectively. DMA and 

DSC analysis of prepared hybrid films show that long alkyl 

groups of functional copolymer-compatibilizer also play a 

role internal plastification in the processing and formation of 

nanofilms. Obtained mechanical properties, thermal behaviors, 

MFI, XRD patterns and SEM images of nanofilms showed 

that these important characteristics strongly depend on the 

technological and operational parameters designed technology 

system, composition of reactive polymer blends and chemical 

structure of surfactants of organoclays and length of branched 

alkyl linkages of functional copolymers. 

In summary, this work presents design and utilization of a 

novel technological line, including reactive extrusion system, 

plasmatron, biaxially oriented film-forming unit and melt 

blending morphology control unit and granulation-milling 

system, for the melt intercalation/exfoliation in situ processing 

and preparing PO/functional copolymer pre-intercalated 

organoclay hybrid nanofilms with higher exfoliation degree of 

polymer chains and physico-mechanical properties as 

compared with conversional POs and known PO/organoclay/ 

compatibilizer films. 

*Corresponding author: altungoz@uniturk.net 

[1] M. Alexandre, P. Dubois, Mater. Sci. Eng. R. 28, 1 (2000). 

[2] S.S. Ray, M. Okamoto, Prog. Polym. Sci. 28 1538 (2003). 

[3] L.A. Goettler, K.Y. Lee, H. Thakkar, Polym. Reviews, 47, 291 (2007). 

[5] Z.M.O. Rzayev, A. Yilmazbayhan, E. Alper, Adv. Polym. Technol. 26, 41 

(2007). 

[6]. L.S. Schadleret et al., MRS Bulletin 32, 340 (2007). 

[7]. Rzayev ZMO. Polyolefin nanocomposites by reactive extrusion. In: 

Advances in Polyolefin Nanocomposites, Chapter 4, Taylor & Francis 

Groups: New York, 2010. 




OPTICAL CHEMICAL SENSOR BASED ON POLYMER NANOFIBERS FOR 

SILVER(I) ION DETECTION 

Sibel Kaçmaz 1* , Kadriye Ertekin 1 , Yavuz Ergün 1 , Mehtap Özdemir 2 , Ümit Cöcen 2 

1 University of Dokuz Eylul, Faculty of Arts and Sciences, Department of Chemistry, 35160, Izmir,Turkey 

2 University of Dokuz Eylul, Faculty Engineering, Department of Metallurgical and Materials Engineering, 35160, Izmir,Turkey 

Abstract- In this work, Ag + sensing nanofibers were produced by electrospinning of composites containing Y-5 

(4(dimethylamino)benzaldehyde2-[[4(dimethylamino)phenyl]methylene]hydrazone) dye, ethyl cellulose (EC) and/or polymethyl-methacrylate 

(PMMA). The fluorescence spectra of the embedded dyes in fiber and thin film form were recorded. 

Presence of ionic liquid in the matrix material enhanced electrospinning process providing ionic conductivity. 

Results of the studies performed in liquid phase 

provide valuable information for researchers; 

however, they remain far from applications in sensor 

technology at this stage. The integration of liquid 

components with solid state optics is not practical and 

molecule-based solid state approaches employing 

polymeric media should be developed. 

In this context, recently, a number of ultrasensitive 

fluorescent optical sensors for a variety of analytes 

have been demonstrated; new strategies are still being 

developed [1-3]. 

Electrospinning is a relatively simple and versatile 

method for creating high-surface-area polymeric 

fibrous membranes. In a typical process, a large static 

voltage is applied to a polymer solution to generate 

fine jets of solution that dry into an interconnected 

membrane like web of small fibers [4]. Electrospun 

fibres can be functionalized by the use of proper 

indicator and auxiliary additives for desired purposes. 

In this work, we reported the use of electrospun 

polymer fibers as highly responsive fluorescent 

optical sensors for Ag+ ions. 

A series of Ag + sensitive nanofibers with various 

compositions of poly-methyl-methacrylate (PMMA), 

ethyl cellulose (EC), plasticizer and ionic liquid (1- 

ethyl-3-methylimidazolium tetrafluoroborate) were 

produced and characterized by Scanning Electron 

Microscopy (SEM). The Ag + sensitive dye Y-5 

4(dimethylamin)benzaldehyde2[[4(dimethylamino)ph 

enyl]methylene]hydrazone dyes has been used as 

sensing agent. (See Fig.1). 

The fiber diameters were measured between 480- 

680 nm for 40% DOP, 10% IL and 50% EC 

containing composites and 1.72-2.43 μm for 25% 

DOP, 25% IL and 50% PMMA containing 

composites. 

Upon exposure to Ag + ions the Y-5 dye exhibited 

fluorescence quenching based response at 580 nm. 

Fig. 3 reveals response of the sensing agent to Ag+ 

ions in the concentration range of 3.51×10 -07 - 

1.43×10 -02 M. 

Figure 2. Scanning electron microscopy (SEM) images of 

EC (40% DOP, 10% IL) based nanofiber. 

300 

250 

200 

150 

100 

50 

g 

ı 

h 

c 

d 

e 

f 

a 

b 

g 

h 

ı 

c 

d 

e 

f 

a 

b 

0 

400 500 600 700 


H 3 C 

C 

H 3 

N 

N 

N 

Figure 1. Chemical structure of Y-5 dye 

N 

CH 3 

CH 3 

Electrospinning was performed at 25 kV voltage 

and at 0.3 mL/h flow rate. SEM micrograph of EC 

based nanofibers were shown in Fig. 2. 

Figure 3. Response of EC based sensing nanofibers to Ag+ 

ions. 

*Corresponding author: sibel.kacmaz@ogr.deu.edu.tr 

[1]. J. S. Yang, and T. M. Swager, J. Am. Chem. Soc., 120, 

11864-11873(1998). 

[2] L. H. Chen, D. W. Mcbranch, H. L. Wang, R. Helgeson, 

F. Wudl, and D. G. Whitten, Proc. Natl. Acad. Sci., 96, 

12287-12292 (1999). 

[3] C. Fan, K. W. Plaxco, A. J. Heeger, J. Am. Chem. Soc., 

124, 5642-5643 (2002). 

[4] D. H. Reneker, and I. Chun, Nanotechnology, 7, 215 

(1996). 




Growth and luminescence properties of Zinc Oxide nanowires 

S.H. Mousavi 1,* , H. Haratizadeh 1 

1 Department of Physics Shahrood University of Technology, 3619995161, Shahrood, Iran 

Abstract— In this work, 1-D nanostructures were synthesized in a horizontal tube furnace by chemical vapour deposition 

method. The effect of substrate, evaporation temperature, gas flow flux and vacuum conditions are investigated on the 

structural and morphological studies by means of the field emission SEM, EDX, XRD and Photoluminescence (PL) studies. 

Zinc oxide (ZnO) is an exclusive material that exhibits 

optical and semiconducting properties such as wide band gap 

(3.37 eV) and large binding energy (60 meV). Recently, onedimensional 

structures of ZnO attract great attention due to 

sensing, optoelectronic applications and nanodevices [1, 2]. 

In this work, 1-D nanostructures were synthesized in a 

horizontal tube furnace by chemical vapour deposition 

method. The effect of substrate, evaporation temperature, gas 

flow flux and vacuum conditions are investigated on the 

structural and morphological studies by means of the field 

emission SEM, EDX and XRD. Photoluminescence (PL) 

spectroscopy has been used for the optical studies and PL 

spectra show green and green-blue wavelength strong 

emissions at RT. The synthesized nanowires with the average 

width 70 nm are shown in Fig.(1-a). The EDX measurement 

indicates the volume ratio 1:5 of oxygen:zinc components 

respectively (Fig. (1-b)). 

purpose, the variations of PL spectra for different 

morphologies are investigated and the high intensity light 

emitting is detected for visible wavelengths that are great 

interest for light emitting devices at room temperature (RT) 

[3-5]. 

Intensity (a. u.) 

PL spectrum of ZnO nanowires at RT 

400 500 600 700 800 


Figure 2: PL spectrum of ZnO nanowires at room temperature 

*Corresponding author: hadi_mousavi@yahoo.com 

(a) 

[1] X.W. Sun, J.Z. Huang, J.X. Wang and Z. Xu, Nano Lett. 8, 1219 (2008). 

[2] A. Khan and M.E. Kordesch, Mater. Res. Soc. Symp. Proc. 872, J 18.16.1 

(2005). 

[3] Yong Qin, Rusen Yang, and Zhong Lin Wang J. Phys. Chem. C, 112, 48, 

18734-18736 (2008) 

[4] Yaguang Wei, Yong Ding, Cheng Li,Sheng Xu,Jae-Hyun Ryo, Russell 

Dupuis, Ashok K.Sood, Dennis L.Polla, and Zhong Lin Wang, J. Phys. 

Chem., 112 , 48, 18935-18937 (2008) . 

[5] R.S. Yang and Z.L. Wang Philos. Mag., 87, 2097-2014 (2007). 

(b) 

Figure 1: (a) SEM image, (b) EDX analysis of ZnO nanowires. 

PL spectrum of the same sample exhibits two peaks, a sharp 

peak at 390 nm and a strong broad peak at 487 nm (Fig. 2). As 

a direct band gap semiconductor, the near band-edge emission 

appears at 390 nm, while vacancy oxygen defects lead to 

visible emission at mentioned wavelengths. As another 




SPECTROFLUORIMETRIC DETECTION OF DISSOLVED CARBON DIOXIDE BY 

ELECTROSPUN POLYMER NANOFIBERS 

Sibel Aydoğdu 1* , Kadriye Ertekin 1 , Mustafa Göçmentürk 1 , Yavuz Ergün 1 , Aslıhan Süslü 2 , Ümit Cöcen 2 

1 University of Dokuz Eylul, Faculty of Arts and Sciences, Department of Chemistry, 35160, Izmir,Turkey 

2 University of Dokuz Eylul, Faculty Engineering, Department of Metallurgical and Materials Engineering, 35160, Izmir,Turkey 

Abstract- In this work CO 2 sensing nanofibers were produced. Fluorescence sensing agent and auxiliary additives were doped 

into PMMA and EC matrices. Presence of ionic liquid in the matrix material enhanced electrospinning process and provided 

higher analytical signal. 

Electrospun fibers find applications in the making 

of functional fiber composites, electronic and optical 

devices, and as biotechnological materials [1]. 

Electrospinning is an effective method by which 

polymer nanofibers (with submicron scale diameters) 

can be formed by accelerating a charged polymer jet 

under a high voltage electric field [2]. As this droplet 

flows in air, the solvent evaporates leaving behind a 

fiber that can be electrically oriented on a substrate. 

Electrospun fibres can be functionalized by the use of 

proper indicator and auxiliary additives for desired 

purposes. 

Most of the optical CO 2 sensor designs utilize 

indicator dyes with pKa values between 7.4 and 10.0, 

which are doped into the polymer matrices. In such 

designs, mainly absorption or emission based 

measurements were performed on thin film surface or 

dip-coated fiber optics. In this work quenching-based 

optical chemical sensors were produced by the 

electrospinning technique. A series of dissolved CO 2 

sensitive nanofibers with various compositions of 

poly-methyl-methacrylate (PMMA), ethyl cellulose 

(EC), plasticizer and ionic liquid (1-ethyl-3- 

methylimidazolium tetrafluoroborate) were produced 

and characterized by Scanning Electron Microscopy 

(SEM). 

The CO 2 sensitive dye N’-[(1Z)-(9-methyl-9Hcarbazol-3-yl)methylene]isonicotinohyrazide 

(MY9) 

has been used as sensing agent. (See Fig.1). Polymer 

solutions were prepared by mixing 240 mg of ethyl 

cellulose, 1 mg MY9 dye, equivalent amount of phase 

transfer agent, varying amounts of plasticizer (DOP) 

and ionic liquid in 1.5mL of tetrahydofuran (THF). 

PMMA based solutions were prepared by a similar 

protocol. 

Figure 1. Chemical structure of MY9 dye 

Electrospinning was performed at 25 kV voltage and 

at 0.3 mL/h flow rate (See Fig.2) SEM micrographs 

of EC based nanofibers were shown in Fig. 3. Upon 

exposure to dissolved CO 2 the MY9 dye exhibited an 

emission based signal change at 440 nm in direction 

of signal decrease. Photo-characterization, 

electrospinning fabrication, and sensing capability of 

PMMA and EC based fibers are discussed. The fiber 

diameters were measured between 322-688 nm for 

40% DOP, 10% IL and 50% ethyl cellulose 

containing composites. 

Figure 2. An SEM micrograph EC based nanofiber 

Figure 3. A simplified schematic of the electrospinning 

process. 

This study was supported by TUBITAK Münir Birsel 

National Graduate Scholarship Programme and 

TUBITAK project-104M268. 

*Corresponding author: sibel.aydogdu@ogr.deu.edu.tr 

[1]. V. Gunaranjan, M. Saravanababu, P. Victor, N. 

Omkaram, A. M., Pulickel and L. J. Robert, 

Biomacromolecules., 7, 415-418 (2006). 

[2] S. Piperno, L. Lozzi a , R. Rastelli, M. Passacantando and 

S. Santucci, Applied Surface Science, 15, 252, 5583-5586 

(2006). 




The effect of transition metals on electronical properties of nanocrystalline indium oxide films by 

experimental and theoretical approaches 

Hossein Asghar Rahnamaye Aliabad, 1* Seyed Mohammad Hosseini 2 and Mohammad-Mehdi Bagheri-Mohagheghi 3 

1 Department of Physics, Sabzevar Tarbiat Moallem University, Sabzevar, Iran 

2 Department of Physics, Ferdowsi University of Mashhad, Mashhad, Iran 

3 Department of Physics, Damghan University of Basic Sciences, Damghan, Iran 

Abstract— Electronical properties of pure nanocrystalline indium oxide films and its alloys with Y and La have been investigated 

using experimental and theoretical methods. The Full Potential Linearized Augmented Plane Wave (FP-LAPW)approach was used 

with the Local Density Approximation plus Hubbard potential (LDA+U). Theoretical calculations have indicated that there are two 

band gaps for pure Indium Oxide. The band gap is increased with Y dopant while decreases with La dopant. These impurities 

increase the value of the electron effective mass in the bottom of the conduction band. We have also prepared samples by spray 

pyrolysis method at 500 degree centigrade as thin films. The obtained optical band gap for pure indium oxide sample is 4.1 eV. It 

was found that adding Y and La impurities increases and decreases the band gap, respectively. Increasing and decreasing 

procedure of the band gap is conformed to both theoretical and experimental methods and also is in good agreement with others. 

Over the last two decades there has been an attracted 

increasing attention in both fundamental research and 

industrial applications of transparent conducting oxides 

(TCOs). These materials have many applications in numerous 

devices such as flat panel displays, solar cells, gas sensors and 

low-emissive windows [1, 2]. Among various transparent 

oxides the indium tin oxide (ITO), indium oxide (In 2 O 3 ), tin 

oxide (SnO 2 ), and zinc oxide (ZnO) are the dominant TCOs. 

Tin-doped indium oxide (ITO), with a typical electrical 

conductivity and transparency in the visible region is usually 

used in thin coating form. Also the developments of 

polycrystalline and amorphous transparent conducting oxide 

semiconductors, used for practical thin-film transparent 

electrode applications, have been under discussion in the 

literature during the last few years [3, 4]. 

In this work, We have studied, the effect of Y and La on 

electronical properties of In 2 O 3 nanostructure by using two 

methods spray pyrolysis metod and Local density 

approximation (LDA+U) based on the density functional 

theory (DFT). Indium oxide can exist in three different phases 

[5] characterized by space group symmetries I2 1 3, Ia 3 and 

R 3 . In 2 O 3 with space group Ia 3 and the band gap of 

Eg =3.7 eV is similar to many trivalent rare-earth oxides, such 

as Yb 2 O 3 and Dy 2 O 3 . This phase of indium oxide has two nonequivalent 

six-fold coordinated cation sites. The two cation 

sites are referred to as equipoints “b” and “d”. The sites of the 

cations are coordinated to six oxygen anions at three different 

distances, which lie near the corners of a distorted cube with 

two empty ions along one face diagonal. The unit cell contains 

80 atoms and crystallized in cubic bixbyite structure. We 

substituted the impurities in b positions, since at low 

temperatures the impurities prefer to sit at b positions [6]. 

The Y an La -doped In 2 O 3 thin films have been deposited on 

glass substrates at 500 °C with 250 nm thickness. For 

deposition of In 2 O 3 films, we used the technique of spray 

pyrolysis. The carrier gas used in all the experiments was N 2 . 

These films have been prepared by sol–gel technique that is a 

suitable chemical method for the preparation of 

nanostructures. Initial solution composed of 

In(NO 3 ).4H 2 O(0.08 wt%), H 2 O(0.44 wt%), HNO 3 (0.04 wt%) 

and CH 3 CH 2 OH(0.44 wt%). For doping of Y and La, we have 

used an aqueous ethanol solution consisting of Y(NO 3 ).5H 2 O 

and N 3 O 9 La.6H 2 O with various doping levels from 0 to 25 

and 33 wt% in solution. 

The optical absorption and transmission spectra of films were 

recorded using a UV visible Spectrophotometer and X-ray 

diffraction was used to characterize the crystal structure of the 

films. 

The optical absorption edge for undoped In 2 O 3 film by spray 

pyrolysis lies at 4.1 eV. This result is good agreement with 

others [7].The effect of Y(In 1.85 Y 0.15 O 3 ) and La (In 1.85 Y 0.15 O 3 ) 

with 15 wt% increases and decreses optical band gap to 4.3 eV 

and 4.05 eV respetively. 

Obtained band gap for In 2 O 3 by density functional theory 

(DFT) is 1.43 eV. This result is good agreement with others 

[5]. The effect of Y (In 1.5 Y 0.5 O 3 ) and La (In 1.5 La 0.5 O 3 ) 

increases and decreses band gap to 1.88 eV and 1.24 eV 

respetively. The experimental and theoretical results are good 

agreement with each other. 

*Corresponding author: h_rahnamay@yahoo.com 

[1] T. J. Coutts, J. D. Perkins, D. S. Ginley and T. O. Mason,, Presented at the 

195th Meeting of the Electrochemical Society, Seattle, Washington May 2-6, 

(1999). 

[2] D. S. Ginley and C. Bright (Guest Editors), "Transparent Conducting 

Oxides" MRS Bulletin, 15-18, August (2000). 

[3] T. Minami, , Semicond. Sci. Technol., 20 ,S35-S44 (2005) 

[4] N. G. Lewis and D. C. Paine, , MRS Bulletin- Materials Research Society, 

Vol. 25; Part 8,22-27 (2000). 

[5]S. Zh. Karazhanov, P. Ravindran, P. Vajeeston, A. Ulyashin, T. G. Finstad 

and H. Fjellvåg, , Phys. Rev. B 76, 075129(1-13) (2007). 

[6]J. E. Medvedeva, Phys. Rev. Lett. 97, 086401(1-4) (2006). 

[7] Prathap, P., Subbaiah ,Y.P.V., Devika ,M.and Ramakrishna Reddy, K.T., 

Materials Chemistry and Physics 100, pp. 375–379(2006). 

Figure: Non-equivalent cation sites and anion vacancies in In 2 O 3 . 




Morphological and electronic properties of Moiré patterns on graphene 

and graphitic layers on HOPG 

1 , Tansu Ersoy 1 and 1 * 

1 stanbul Technical University, Department of Physics, Maslak, 34469, stanbul, Turkey 

Abstract - Super periodicities can be observed upon shifting of similar periodic structures on each other. Such structures are named as Moiré 

patterns. When a graphene layer composing the highly oriented pyrolytic graphite (HOPG) crystal is slightly moved from its original position 

hexagonal or linear super periodicities form. We investigate the ways to produce these patterns on HOPG crystals and study their physical 

properties using scanning tunneling microscopy and spectroscopy. 

Graphite is a widely used and taken for guaranteed 

material in daily life as solid lubricant or as pencil. Its 

derivatives (such as highly oriented pyrolytic graphite 

(HOPG)) are also used extensively in advanced scientific 

studies such as calibration samples for scanning 

tunneling microscopy (STM) systems or also as inert 

substrates for investigation of nano scale structures. It is 

so much popular in surface science because it has quite a 

smooth surface. HOPG is composed of stacked two 

dimensional hexagonal lattices with carbon atoms, 

popularly named as graphene layers (figure.1). However, 

this property may disturb that almost perfect smoothness. 

(a) 

(b) 

(a) 

(b) 

Figure 2. (a) Moire pattern due to two slightly rotated, 2D 

hexagonal lattices. (b) STM image of a graphene flake on HOPG 

surface showing Moire pattern (I=0.8nA, V=1.3V, size 91 nm x 

91 nm). 

Figure 1. (a) HOPG crystal model showing graphene layers. (b) 

STM image of HOPG (I=0.7nA, V=60mV, size 3.2 nmx 3.2 nm). 

Atoms in the graphene layers are strongly bonded but the 

layers are not bonded so strongly with each other. That is why 

it is easy to exfoliate one atom thick graphene layer from the 

HOPG surface even with sticky tape. Additionally, the layers 

can shift on each other creating local Moiré patterns. 

When a graphene layer is placed on a regular HOPG surface 

with a slight shift/rotation from its expected position or some 

broken graphene layer is replaced on the HOPG surface, 

Moiré patterns due to the hexagonal lattice may form 

(figure.2a) [1,2]. These patterns on HOPG surfaces can be 

observed using scanning tunneling microscopy (STM). 

We use scanning tunneling microscopy and spectroscopy 

(STM and STS) to observe morphological and electronic 

properties of graphene Moiré patterns on HOPG. There are 

several methods mentioned in the literature for producing 

these patterns on HOPG surfaces but the methodology is not 

well established. Moreover, in our study we investigate the 

types of the patterns (with respect to their periodicities and 

shapes (hexagonal or linear)) and look for certain selection 

rules as there are infinitely many possibilit ies for the 

periodicities. Also the correlation between the patterns and the 

procedures applied to attain those patterns are looked upon. 

Furthermore, we investigate the effect of these patterns on the 

local electronic structure due to the change in the surface 

periodicities. 

*Corresponding author: 2Tgurlu@itu.edu.tr 

[1] . BWing-Tat Pong and Colm Durkan (2005), J. Phys. D: Appl. 

Phys. 38 R329–R355. 

[2] Yongfeng Wang, Yingchun Ye and Kai Wu (2006) , Surface 

Science 600 pp.729–734. 




The Hydrogen Sensing Properties of Pd Nanowires 

ennik 1 *, Necmettin K 1 and Zafer Ziya Öztürk 1, 2 

1 Gebze Institute of Technology, Science Faculty, Department of Physics, Kocaeli 41400, Turkey 

2 TUBITAK Marmara Research Centre, P.O. Box 21, 41470 Gebze Kocaeli, Turkey 

Abstract- In this study, Pd nanowires are successfully fabricated directly on Highly Oriented Pyrolytic Graphite (HOPG) depending on time 

using palladium nitrate solution at room temperature and then the hydrogen sensing properties of the fabricated these structures are investigated 

in the various concentrations of H 2 . Nanowires with diameters approximately 100 nm are obtained by electrodeposition onto the step edges on 

the surface of a ZYH quality of HOPG. The sensitivity is observed approximately 2 % for 1000 ppm H2 at room temperature. 

Hydrogen has numerous applications in industry, such as 

chemical production, fuel cell technology, and rocket engines 

[1]. However, the flammable and explosive properties of 

hydrogen gas make its detection an important issue [2]. That’s 

why nanotechnology has been used and become more vogues 

day by day. Nanostructures such as nanotubes [3] and 

nanowires [4] have been fabricated for H 2 gas sensing. 

Pd plating solutions were used: aqueous 2 mM Pd(NO3) 2 , 

0.1 M HClO 4 . These solutions were prepared using nanopure 

water (r ~ 

experiment. The surface of highly oriented pyrolytic graphite 

(HOPG) crystal was cleaved using adhesive tape immediately 

prior to use. The growth of metal nanowires was carried out 

using the 3 - pulse potential program. 

The values for the oxidation potential, E 

ox 

, the nucleation 

potential, E nuc 

, and the growth potential, E grow 

are 0.8 V, - 

0.8 V and 0.3 V, respectively. The oxidation potential was 5 s 

for activating the electrodeposition. The nucleation potential 

was chosen for 0.01 s and this potential determined the 

forming of nanowires through growth potential and growth 

time that are called deposition potential and deposition time, 

respectively. Following deposition, the graphite was removed 

from the plating solution, rinsed with water, and air dried prior 

to characterization using SEM. 

sensor were purged with 200 sccm high purity N 2 . As shown 

in Figure 2, the resistance of the sensor was increased by the 

increasing concentrations of H 2 . 

Figure 2. The resistance versus the concentrations of hydrogen for the 

Pd nanowire sensor [4] 

In conclusion, electrochemical step edge decoration (ESED) 

is very general method for preparing nanowires that are size 

and shape uniformity. Pd nanowires fabricated on HOPG were 

used as H 2 gas sensor. The results of gas sensing 

measurements have shown that Pd nanowires sensor is 

abundant at room temperature. 

This work was supported by TUBITAK under Grant No. 

TBAG106T546. 

*Corresponding author: zozturk@gyte.edu.tr 

Figure 1. Pd Nanowires Electrodeposition for 600 s (scale: 2 [4] 

Pd nanowires were fabricated on HOPG for 600 s. These 

nanowires were approximately 100 nm in diameter, as seen in 

figure 1 [4]. After the fabrication of Pd nanowires, they were 

transferred fro m the HOPG surface to a glass slide droped 

with cyanoacrylate. The cyanoacrylate film was hardened for 

8 hours, and then an array of gold (Au) electrode was coated 

by the evaporation using a mask. The device was prepared for 

H 2The gas sensing. 

device was exposed to various concentrations of H 2 in a 

home made measurement cell. After reaching saturation the 

[1] Bevenot X, Trouillet A, Veillas C, Gagnaire H, Clement M. 

Hydrogen leak detection using an optical fibre sensor for aerospace 

applications. Sensors and Actuators B: Chemical 2000;67:57–67. 

[2] Yazdi N, Ayazi F, Najafi K. Micromachined inertial sensors. 

Proceedings of the IEEE 1998;86:1640–59. 

[3] Erdem Sennik, Zeliha Colak, 

Ozturk, Synthesis of highly-ordered TiO 2 nanotubes for a hydrogen 

sensor, International Journal of Hydrogen Energy 

(doi:10.1016/j.ijhydene.2010.01.100) 2010. 

 

dependent H2 gas sensing properties of fabricated Pd nanowires 

using HOPG submitted to International Journal of Hydrogen Energy 




A study o n The Microstructure and Optical Charactarization of Nanocrystalline NiO Film 

D. Duygu Dogan 1 , Yasemin Caglar 1 *, Saliha I 1 and Mujdat Caglar 1 

1 Department of Physics, Anadolu University, Eskisehir 26470, Turkey 

Abstract-The nanosrystalline structure NiO film deposited onto ITO substrates by the sol gel method using spin coating technique. The 

structural, morphological and op tical properties of the film were performed by XRD, FESEM and UV-VIS spectra measurements. XRD 

measurement shows that the film is crystallized in the cubic phase and presents a (111) preferential orientation. The optical band gap, Urbach 

energy and optical constants of the nanocrystalline NiO film were determined. 

Metal oxides have long been a subject of various 

investigations due to its unique physical properties and 

applications in commercial devices [1-4]. Among these 

materials, Nickel oxide (NiO) film has a p-type conductivity 

and wide band gap semiconductor (>3.5eV). So, NiO film 

becomes an attractive material due to its superior chemical and 

electrical stability as well as optical, electrical and magnetic 

properties. The NiO films have been applied in different 

fields, including electrochromic display devices, 

electrochemical supercapacitors, gas sensors, fuel cell 

electrodes. NiO films have been prepared by various methods 

such as sputtering, evaporation, spray pyrolysis and sol gel [5- 

7]. The sol gel method has several advantages due to its 

simplicity, easy control of the film composition, safety, low 

cost of the apparatus and raw materials. 

In this study, NiO film was prepared by sol gel process 

using a spin coating technique onto ITO substrates. To obtain 

the sol, the precursor nickel (II) nitrate hexahyrate (NiN) was 

first dissolved into 2-methoxyethanol as a solvent and by 

adding monoethanolamine (MEA), which acts as the 

stabilizer. Molar ratio of MEA to NiN was maintained at 1:1 

and the concentrations of these sols were 0.5M. The obtained 

mixture was stirred at at room temperature 2 h to yield a clear 

and homogeneous solution. The cleaned substrate was placed 

on the sample holder and was rotated at a speed of 3000rpm 

for 30s. Immediate drying after successive coating was done at 

300 o C for 10min. The film was finally annealed at 500 o C for 

1h in air for crystallization and phase formation. 

Surface morphology and crystalline structure of the film 

have been investigated by field emission scanning electron 

microscopy (FESEM) and X-ray diffractometer (XRD), 

respectively. Figure 1 shows FESEM image of the 

nanostructure NiO film. It was observed that the surface 

morphology of the film is almost uniform nanoparticle size 

distribution. NiO film has polycrystalline structure (single 

Bunsenite phase) with (111) preferential orientation. The 

informat ion on strain and crystallite size was obtained from 

the fullwidths-at-half-maximu m (FWHM) of the diffraction 

peaks. The FWHM () can be expressed as a linear 

combination of the contributions from the strain () and 

crystallites size (L) through Nelson-Riley function (NRF). 

Texture coefficient (TC) and lattice constant were also 

calculated. 

The optical transmittance and diffuse reflectance 

measurements were recorded with a spectrophotometer with 

an integrating sphere in the wavelength range 190–900 nm. 

The optical band gap, Urbach energy and optical constants of 

the nanocrystalline NiO film were determined using 

transmittance and reflectance spectra. 

Figure 1. FESEM image for the nanocrystalline NiO film. 

This work was supported by Anadolu University 

Commission of Scientific Research Projects under Grant No: 

061039 and 081029. 

*Corresponding author: yasemincaglar@anadolu.edu.tr 

[1] Caglar M., Wu J., Li K., Caglar Y., Ilican S., Xue D., 2010. 

Mg x Zn 1_x O (x = 0–1) films fabricated by sol–gel spin coating, Mater. 

Res. Bull., 45: 284-287. 

[2] Ilican S., Caglar Y., Caglar M., Kundakci M., Ates A., 2009. 

Photovoltaic solar cell properties of CdxZn1-xO films prepared by 

sol–gel method, Int. J. Hydrogen Energ., 34: 5201-5207. 

[3] Caglar M. ,Ilican S., Caglar Y., Yakuphanoglu F., 2009. Electrical 

conductivity and optical properties of ZnO nanostructured thin film, 

Appl. Surf. Sci., 255:4491-4496. 

[4] Fu Y.-S., Sun J., Xie Y., Liu J., Wang H.-L., Du X.-W., 2010. 

ZnO hierarchical nanostructures and application on high-efficiency 

dye-sensitized solar cells, Mat. Sci. Eng. B., 166:196-202. 

[5] Ai L., Fang G., Yuan L., Liu N., Wang M., Li C., Zhang Q., Li J., 

Zhao X., 2008. Influence of substrate temperature on electrical and 

optical properties of p-type semitransparent conductive nickel oxide 

thin films deposited by radio frequency sputtering, Appl. Surf. Sci., 

254:2401-2405 

[6] Romero R., Martin F., Ramos-Barrado J.R., Leinen D., 2009. 

Synthesis and characterization of nanostructured nickel oxide thin 

films prepared with chemical spray pyrolysis, Thin Solid Films in 

pres. 

[7] Al-Ghamdi A.A., Mahmoud Waleed E., Yaghmour S.J., Al- 

Marzouki F.M., 2009. Structure and optical properties of 

nanocrystalline NiO thin film synthesized by sol–gel spin-coating 

method, J. Alloy. Compd., 486:9-13. 




Synthesis and Characterization of Peptidic One-Dimensiona l Inorganic Nanofibers for Functional 

Materials 

Handan Acar 1 , Mustafa Özgür Güler 1 * 

1 UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey 

Abstract— A new bottom-up approach including self-assembly of both organic and inorganic molecules was studied to obtain unique onedimensiona 

l inorganic nanotubes. 

Molecular programming enables molecules to form welldefined 

nanoscale structures. Self-assembly process exploits 

non-covalent interactions such as hydrogen bonding, 

hydrophobic, electrostatic, metal-ligand, - and van der 

Waals interactions [1]. Through the bottom-up approach 

technique, it is possible to form functional nanostructures 

through biomineralization [2]. Biomineralization is the process 

by which living organisms produce minerals, often to harden 

or stiffen existing tissues. Biomineralization encompasses 

mineral-containing tissues formed by organisms to fulfil a 

variety of different functions in shells, skeleton, teeth and the 

like. There are examples of using biomineralization of selfassembled 

nanostructures forming organic-inorganic hybrid 

nanostrucutures [3-4]. 

functionalized peptide molecules to enhance their affinity for 

metal ions. The amine groups were used on the peptide 

scaffold to accumulate the metal ions on the self-assembled 

peptidic nanofibers. 

We designed the peptide molecule to mimic the amyloid 

fibrils to form self-assembled peptide nanofibers. The peptide 

molecules form alcogel containing 3-D network of nanofibers 

with diameters ca. 10 nm and micrometers in length. The 

amine groups on the periphery of the nanofibers were 

exploited to act as seeds for accumulation of metal ions for 

template directed synthesis of organic-inorganic hybrid 

nanostructures. As a hard base, amine group has affinity to 

hard acid minerals [5]. We used hard acid metal ions for 

mineralization process. Titanium, silver, and gold ions are 

some of the metal ions we are currently working. The solution 

of mineral salts in ethanol were added into the alcogel and 

studied mineralization process. 

In summary, we showed a new bottom-up approach to 

generate inorganic nanotubes from different minerals. This 

new approach includes self-assembly of peptide molecules 

forming organic nanofibers as templates. The formation of 

metal layer around the peptide nanofibers occurs due to the 

metal binding groups on the periphery of the peptide 

nanofibers. 

This work is partially supported by T 

*Corresponding author: moguler@unam.bilkent.edu.tr 

Figure 1. The functinalized peptide molecule, (a) self-assembly 

of peptide into 1-D nanofibers in ethanol, (b) mineralization of 

peptide nanofibers in the presence of metal ions in ethanol, (c) 

elimination of peptide, and obtaining inorganic 1-D nanotube 

[1]Lehn, J.-M., Supramolecular chemistry : concepts and 

perspectives. A personal account built upon the George Fisher Baker 

lectures in Chemistry at Cornell University ; Lezioni Lincee, 

Accademia Nazionale dei Lincei, Roma. 1995, Weinheim [u.a.]: 

VCH. 

[2]Hartgerink, J.D., E. Beniash, and S.I. Stupp, Self-Assembly and 

Mineralization o f Peptide-Amphiphile Nanofibers. Science, 2001. 

294 (5547): p. 1684-1688. 

[3]Zubarev, E.R., et al., Self-Assembly of Dendron Rodcoil Molecules 

into Nanoribbons. Journal of the American Chemical Society, 2001. 

123 (17): p. 4105-4106. 

[4]Yuwono, V.M. and J.D. Hartgerink, Peptide Amphiphile 

Nanofibers Template and Catalyze Silica Nanotube Formation. 

Langmuir, 2007. 23 (9): p. 5033-5038. 

[5]Pearson, R.G., Hard and Soft Acids and Bases. Journal of the 

American Chemical Society, 1963. 85 (22): p. 3533-3539. 

Figure 2. The Scanning Electron M icroscope image of inor ganic 

Titania nanotubes. 

In this work, we studied the biomineralization of self 

assembled peptidic nanostructures. We synthesized and 




IONIC LIQUID DOPED ELECTROSPUN POLYMER COMPOSITE NANOFIBERS 

FOR COPPER(II) SENSING 

Merve Zeyrek a* , Kadriye Ertekin a , Mustafa Göçmentürk a , Yavuz Ergün a , Mehtap Özdemir b , Erdal Çelik b,c 

a 

University of Dokuz Eylul, Faculty of Arts and Sciences, Department of Chemistry, 35160, Izmir, Turkey 

b 

University of Dokuz Eylul, Faculty Engineering, Department of Metallurgical and Materials Engineering, 35160, Izmir, Turkey 

c University of Dokuz Eylul, Center for Fabrication and Application of Electronic Materials (EMUM), 35160, Izmir, Turkey 

Abstract- In this work Copper(II) sensing nanofibers were produced. Fluorescence sensing agent and auxiliary additives were 

doped into PMMA and EC matrices. Presence of ionic liquid in the matrix material enhanced electrospinning process and 

provided higher analytical signal. 

Recently electrospinning has gained much 

attention as a simple and reliable process to produce 

polymer and composite nanofibers, which have small 

diameter and high aspect ratio and have different 

types of applications including tissue engineering, 

biocompatible materials, filters, optical sensor design 

and drug delivery. For a typical electrospinning setup 

as shown in Fig. 1, a high voltage, usually more than 

5 kV, is applied to the polymer based composite in a 

spinneret so that free charges accumulate at the 

liquid-air interface of the capillary. At a critical 

voltage, the repulsive force within the charged 

polymer solution is larger than the surface tension and 

a jet erupts from the tip of the spinneret. As the jet 

travels through the air, it solidifies leaving behind a 

polymer fiber to be collected on an electrically 

grounded support [1]. Electrospun fibers can be 

functionalized by the use of proper indicator and 

auxiliary additives for desired purposes. 

amount of phase transfer agent and varying amounts 

of plasticizer (DOP) and ionic liquid in 1.5mL of 

EtOH/CH 3 Cl (v/v 3/1). EC based solutions were 

prepared by a similar protocol. 

Figure 2. Chemical structure of MY10 dye 

Electrospinning was performed at 25 kV voltage 

and at 0.3 mL/h flow rate. SEM micrographs of 

PMMA based nanofibers were shown in Fig. 3. Upon 

exposure to Cu 2+ the MY10 dye exhibited an 

emission based signal change at 530 nm in direction 

of signal decrease. The fiber diameters were 

measured between 634-823 nm for 25% DOP, 25% 

IL and 50% PMMA containing composites. Photocharacterization, 

electrospinning fabrication, and 

sensing capability of PMMA and EC based fibers are 

discussed. 

Figure 1. A simplified schematic of the electrospinning 

process. 

Copper is the third most abundant element in the 

human body and is essential in several biological 

pathways including electron transport, O 2 metabolism 

and enzymatic catalysis. Oter et al. that offered sensor 

exhibited remarkable fluorescence intensity 

quenching upon exposure to Cu 2+ ions at pH 4.0 in 

the concentration range of 1.0×10 −9 to 3.0×10 −4 M 

[Cu 2+ ] [2]. In this work the Cu 2+ sensitive dye; N’-3- 

(4(dimethylamino)phenyl)allylidene)isonicotinohydra 

zide) (MY10) has been used as sensing agent (See 

Fig.2). The MY10 dye was doped into poly-methylmethacrylate 

together with ionic liquid and other 

additives. Composite fibers were fabricated by 

electrospinning and characterized by Scanning 

Electron Microscopy (SEM). Polymer solutions were 

prepared by mixing 240 mg of poly(methyl 

methacrylate), 1 mg of MY10 dye, equivalent 

Figure 3. An SEM micrograph PMMA based nanofiber 

The preliminary results show that these sensing 

agents have an order of magnitude higher sensitivity 

to the Cu 2+ than sensor slides formed from continuous 

thin films. This is believed to be due to the higher 

surface area to volume ratio of the electrospun 

nanofibrous materials. 

* Corresponding author: mervezeyrek@gmail.com 

[1] K. Tong, C. Xu, Q. Wang, B. Gu, K. Zheng, L. Ye and 

X. Li, Chin.Phys.Lett. 25, 4453 (2008). 

[2] O. Oter, K. Ertekin, C. Kırılmıs and M. Koca, Analytica 

Chimica Acta 584, 308–314 (2007). 




What determines the easy-axis in magnetic nanowire arrays 

1 *, Giray Kartopu 1, 2 , K.-L. Choy 2 , Ramazan Topkaya 3 

1 

2 Mechanical, Materials and Manufacturing Engineering, University of Nottingham, Nottingham NG7 2RD, UK 

3 Department of Physics, Gebze Institute of Technology, 41400 Gebze, Kocaeli, Turkey 

Abstract- Magnetic behaviour of nanowire (NW) arrays produced by an electrodeposition method has been investigated by ferromagnetic 

resonance (FMR) and vibration sample magnetometer (VSM) techniques at room temperature. FMR spectra, their resonance field values as well 

as magnetic hysteresis curves indicate that the easy-axis shows changes as a function of the nanowires’ geometrical factors, namely the packing 

density and aspect ratio. 

The magnetic nanowires are expected to have potential 

applications in a broad range of topical areas, including 

magneto-electronic devices, data storage media, 

magneto/nano-optics, nanosensors, and molecular electronics 

[1-3]. The magnetic properties of NWs have been investigated 

by using a variety of techniques [4-7]. Magnetic behavior of 

nickel (Co) NWs have been reported by electrodeposition 

techniques on alumina (AAO) templates [8]. Some magnetic 

NWs have also become very important for their magnetic and 

microwave absorbing properties [9]. The magnetic properties 

of NWs with the easy axis along the perpendicular direction 

have not been studied in detail, e.g. with varying packing 

density and aspect ratio. 

The experimental and theoretical coordinate systems for 

NWs sample geometry; dc, magnetic field, and relative 

orientation of the equilibrium magnetization are shown in 

Figure 1. 

Figure 2. Experimental (open /closed symbols) and calculated (full 

red lines) resonance fields for NWs. 

Magnetic NWs exhibit uniaxial anisotropy, usually with the 

easy axis along the wire length in small diameters (open 

symbols in fig. 2) or aligned perpendicular to the wire axis as 

in thicker diameters (closed symbols in fig. 2). The support of 

the Scientific and Technological Research Council of Turkey 

gratefully acknowledged. 

*Corresponding author: yalcin@nigde.edu.tr 

Figure 1. (a) Sketch of the sample geometry (b) Sample parameters 

used in calculating the packing factors (P). (c) Schematic 

representation of a hexagonal nanowire array exhibiting seven wires. 

The dashed lines point out the six-fold symmetry. 

In this work, we have studied dense arrays of NWs by 

vibrating sample magnetometry (VSM) and techniques 

ferromagnetic resonance (FMR) as functions of different 

geometric factors (e.g. packing factor, P, and 

and applied field direction at the room temperature (RT) [10]. 

The FMR technique has proved to be a very powerful 

technique which can provide information on the 

magnetization, magnetic anisotropy, g-value and relaxation 

times, as well as the damping in magnetization dynamics 

[11-12]. 

In the frame of relevant theories FMR results, its magnetic 

resonance fields and magnetic hysteresis were investigated in 

detail. The magnetic resonance field, coercive field, 

magnetization values, magnetic anisotropies and relaxation 

time of wires are presented and discussed in the context of 

geometrical factors. 

[1] Fabrication and Applications of 

Metal Nanowire Arrays Electrodeposited in Ordered Porous 

Templates, in Nanowires, Ed. A. Lazinica, In-Tech, Vienna (2010). 

[2] 2T, 

Tuominen, “FMR Studies of Co Nanowire Arrays”, Nanostructures 

Magnetic Materials and Their Applications, Kluwer Academic 

Publisher. Nato Science Series. Mathematics, Physics and Chemistry. 

Volume: 143. Page:347–356, (2004). 

[3] G. Kartopu, M. Es-Souni, A.V. Sapelkin, and D. Dunstan, Phys. 

Stat. Solidi (a), 203 (10) (2006) R82; J. Nanosci. Nanotech. 8 (2008) 

931 

[4] -souni J. 

Magn. Magn. Mater. 321 (2009) 1142, and references therein. 

[5] P. M. Paulus, F. Luis, M. Kröll, G. Schmid, L. J. De Jongh, J. 

Magn. Magn. Mater. 224 (2001) 180. 

[6] K. Niels, et al., J. Magn. Magn. Mater. 249 (2002) 234. 

[7] 

Bal, M.T. Touminen. J. Magn. Magn. Mater. 272-276 (2004) 1684. 

[8] - 

Phys. 103 (2008) 093915. 

[9] M. Vazquez, M. Hernández-Vélez, K. Pirota, A. Asenjo, D. 

Navas, J. Velázquez, P. Vargas and C. Ramos. Eur. J. Phys. B 40 

(2004) 489 

[10] -L. Choy, R. Topkaya, S. Kazan and 

-axis in Ni nanowires” prepared (2010) 

[11] öz, F. Yildiz, Y. Yerli and B. 

 

[12] 

Stat. Solid (a) 203 (2006) 1539. 




MD Simulations of the Tensile Strength of (20,0) Single Walled Carbon Nanotubes 

Gülay Dereli, * Necati Vardar and 

Department of Physics, Yildiz Technical University, 34210, Turkey 

Abstract— We have performed a computer experiment to examine the stability of (20,0) Single Walled Carbon Nanotubes (SWCNTs) with the 

application of uniaxial strain. A (20,0) single-walled carbon nanotube consisting of 400 atoms with 20 layers is simulated under tensile loading 

using our developed O(N) parallel tight-binding molecular-dynamics algorithms. It is observed that the simulated carbon nanotube is able to carry 

the strain up to 118 % of the relaxed tube length in elongation. In this study, the elastic limit, Poisson ratio, Young’s modulus and tensile strength 

of (20,0) SWCNTs are calculated. 

There has been increasing attention given to Single-Walled 

Carbon Nanotubes (SWCNTs) since they are the most durable 

material against stretching and heating. SWCNTs properties 

are mostly determined by the chirality of the tubes. Depending 

on their chirality, carbon nanotubes could be metal or 

semiconductor. Durability of the nanotubes are examined in 

terms of the uniaxial compressive or tensile deformations. 

Single Walled Carbon Nanotubes are specified by chiral 

 

vector Ch 

( n, m) 

.The Zigzag SWCNTs that are represented 

as (n,0) are metallic, if n is a multiple of 3 and all other are 

semiconducting in unstrained condition. 

In this study, we have performed a computer experiment to 

examine structural stability and mechanical properties of 

(20,0) SWCNT under tensile loading. Deformations due to 

uniaxial strain are studied using a parallel, Order (N) tightbinding 

molecular dynamics (O(N) TBMD) simulation code. 

Parallel O(N) (TBMD) simulation code is designed by 

G.Dereli et al.[1-3] and applied successfully to SWCNTs 

simulations[4-7]. 

A semiconducting (20,0) SWCNT consisting of 400 atoms 

with 20 layers is simulated. Periodic boundary condition is 

applied along the tube axis. Velocity Verlet algorithms along 

with the canonical ensemble molecular dynamics (NVT) is 

used. In our simulation procedure (20,0) SWCNT is simulated 

at a specified temperature for a 3000 MD steps of run with a 

time step of 1 fs. This eliminates the possibility of the system 

to be trapped in a metastable state. We wait for the total 

energy per atom to reach the equilibrium state. Next, uniaxial 

strain is applied to the SWCNT. We further simulate the 

deformed tube structure under uniaxial strain for another 2000 

MD steps. In our study, while the nanotube is axially 

elongated or contracted, reduction or enlargement of the radial 

dimension is observed. Strain is obtained from ( LL0)/ 

L0 

where L 

0 

and L are the tube lengths before and after the 

strain, respectively. We applied the elongation and calculated 

the average total energy per atom. Following this procedure, 

we examined the structural stability, total energy per atom, 

stress-strain curves, elastic limit, Young’s modulus, tensile 

strength, and Poisson ratio of (20,0) SWCNT. Deformations 

affect the physical properties of SWCNTs. 

We calculated the total energy of (20,0) SWCNTs as -8.29582 

eV at zero strain. Figure 1, shows the total energy per atom of 

(20,0) SWCNT as a function of simulation time. On 

application of uniaxial strain, the total energy values have 

changed. Figure 2, gives the total energy values for various 

strain values. 

Our studies show that (20,0) SWCNT is stable until 18% 

uniaxial strain value. Figure 3 indicates that the tube can not 

sustain its structural stability at 23% strain. Beyond these 

strain values, bond breakings between the carbon atoms are 

observed and the tube is no longer stable. Stability of (20,0) 

SWCNT is compared with the same number of atom but 

smaller diameter SWCNTs during the study. 

E (eV/atom) 

-8,27 

-8,28 

-8,29 

-8,30 

-8,31 

-8,32 

-8,33 

-8,34 

0 500 1000 1500 2000 2500 3000 

MD Step 

Figure 1: Total energy of (20,0) SWCNT as a function of simulation 

time 

E (eV/atom) 

-6,8 

-7,2 

-7,6 

-8,0 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

12 

15 

18 

21 

23 

(20,0) 

-8,4 

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 

MD Step 

Figure 2: The effect of strain on the total energies of (20,0) SWCNTs 

as a function of simulation time. 

Figure 3: Simulation picture of (20,0) SWCNT under % 23 uniaxial 

strain 

The research reported here is supported through the Yildiz 

Technical University Research Fund Project No: 24-01-01-04. 

The simulations are performed at the Carbon Nanotubes 

Simulation Laboratory at the Department of Physics, Yildiz 

Technical University, Istanbul, Turkey. 

*Corresponding author: gdereli@yildiz.edu.tr 

148, 188 

(2002). 

[2] G. Dereli and C. Özdogan, Phys. Rev. B 67, 035416 (2003). 


[4] G. Dereli and B. Süngü, Phys. Rev. B 75, 184104 (2007). 

[5] G. Dereli, B. Süngü and C. Özdogan, Nanotechnology 18, 24570 (2007). 

20 , 

075707 ( 2009) 

 

171 (2010). 

(20,0) 




Electrochemical Deposition of Lead on Conducting 4-Nitrothiophenol Covered Gold Surfaces 

Adem Kara, Züleyha Kuda, Ali Yeilda and Duygu Ekinci * 

Department of Chemistry, Faculty of Science, Atatürk University, 25240 Erzurum, Turkey 

Abstract— In this study, the electrochemical deposition of lead on Au surfaces covered by self-assembled monolayers of 

electroactive 4-nitrothiophenol (4-NTP) was investigated by using cyclic voltammetry and chronoamperometry. The resulting 

structures were characterized by X-ray photoelectron spectroscopy (XPS) and the surface properties of the films were studied using 

scanning tunneling microscopy (STM). 

In recent years, self-assembled monolayers (SAMs) of 

organosulfur compounds such as thiols and disulfides on metal 

surfaces have proven to be a popular method for the 

fabrication of well ordered and defined interfaces [1]. Among 

SAMs, the organized monolayers of aromatic thiols are of 

great interest due to their high electrical conductivities and 

strong - stacking interactions, although most of the studies 

addressed the assembly process of alkanethiols [2,3]. The 

surface properties of thiol monolayers for various purposes 

can be easily tailored by changing the chemical nature of the 

terminal groups attached to the other end of aromatic rings [4]. 

In this sense, the modification of the metal surface with 

molecules containing redox active groups has provided an 

elegant way for the construction of molecular electronic 

devices. In the fabrication of molecular electronics consisting 

of metal substrate/organic thin film/metal top contact 

sandwich structure, the formation of metal on top of the SAM 

can be achieved by three different methods: i- the deposition 

of the metal onto functionalized thiol SAMs from the vapor 

phase [5], ii- electroless metal deposition from solution [6], 

and iii- electrochemical deposition [7]. Compared to vacuum 

deposition, electrochemical deposition commonly offers since 

the amount of the deposit and the kinetics of the deposition 

process can be controlled [8]. 

In this study, the electrochemical deposition of lead on Au 

surfaces covered by self-assembled monolayers of 4- 

nitrothiophenol (4-NTP) was investigated. 4-NTP has a thiol 

group that covalently binds to gold surface and a reactive nitro 

group that undergoes electrochemical reduction. 

NO 2 

S 

Au 

PbClO 4 /HClO 4 

e - 

S 

Au 

Pb 

NHOH 

Previous studies have shown that the terminal –NO 2 group 

of the 4-NTP SAM can be irreversibly reduced to an 

electrochemically active terminal group (-NHOH) which 

exhibits a reversible redox behavior with –NO (Figure 1A) [9]. 

If such a reduction process of 4-NTP SAM is performed in 

aqueous solution containing Pb 2+ ions, we believe that the 

electrocrystallization of metals on the modified Au electrode 

can be achieved, and it can be used as an effective pathway for 

the creation of multilayer structures. 

Figures 1B and 1C show the cyclic voltammograms for 

the deposition of Pb at bare Au and 4-NTP modified Au 

electrodes. 

600 

50 µA 

400 

200 

0 

Potential/mV 

-200 

(A) 

(B) 

(C) 

-400 

Figure 1. Cyclic voltammograms for (A) 4-NTP modified Au electrode in 0.1 

M HClO 4 solution, (B) bare Au electrode in 1 mM PbClO 4+0.1 M HClO 4 

solution and (C) 4-NTP modified Au electrode in 1 mM PbClO 4+0.1 M 

HClO 4 solution. 

The resulting metallic lead layers on modified Au surfaces 

were also characterized by X-ray photoelectron spectroscopy 

(XPS) and scanning tunneling microscopy (STM). 

*Corresponding author dekin@atauni.edu.tr 

[1] R. G. Nuzzo, D. L. Allara, J. Am. Chem. Soc. 105, 4481 

(1983). 

[2] R. F. Dou, X. Ma, L. Xi, H. L. Yip, K. Y. Wong, W. M. Lau, J. 

Jia, Q. Xue, W. Yang, H. Ma, A. K. Jen Langmuir, 22, 3049 

(2006). 

[3] Y. Kazzi, H. Awada, M. David, M. Nardin, Surf. and Interface 

Analys. 39, 691 (2007). 

[4] C. D. Bain, E. B. Troughton, Y. T. Tao, J. Evall, G. M. 

Whitesides, R. G. Nuzzo, J. Am. Chem. Soc. 111, 321 (1989). 

[5] M. J. Tarlov, Langmuir 8, 80 (1992). 

[6] W. J. Dressick, C. S. Dulcey, J. H. Gregor, G.S. Calabrese, J. 

M. Calvert, J. Electrochem. Soc. 141, 210 (1994). 

[7] J. A. M. Sondag-Huethorst, L. G. Fokkink, Langmuir 11, 4823 

(1995). 

[8] H. Hagenstrm, M. J. Esplandi, D. M. Kolb Langmuir, 17, 839 

(2001). 

[9] J. U. Nielsen, M. J. Esplandi, D. M. Kolb Langmuir, 17, 3454 

(2001). 




The Effect of Vacancies on the Mechanical Properties of (10,10) Single Walled Carbon Nanotubes 

Gülay Dereli*, Banu Süngü* and Önder Eyeciolu 

Department of Physics, Yildiz Technical University, stanbul 34210, Turkey 

Abstract— In this work, we aimed to show the effect of vacancies on the structural stability, tensile strength and Young modulus of (10,10) 

Single Walled Carbon Nanotubes (SWCNTs). We used O(N) tight-binding molecular dynamics (TBMD) simulation method. We studied at 300K 

to except the effect of temperature and to study with the brittle SWCNTs. We have concluded the results with respect to the defect free and single 

vacancy defect results of (10,10) SWCNTs. 

Soon after their discovery, carbon nanotubes become 

most promising materials due to their extremely small 

dimensions, mechanical strength, as well as, elasticity and 

adjustible electronic properties. These remarkable 

characteristics lead to many important applications in 

nanotechnology. In our previous works, we have shown that 

temperature has significant effects on the thermal stability and 

mechanical properties of nanotubes [1-3]. On the other hand, 

the recent high-resolution transmission electron microscopy 

(HR-TEM) studies and computational simulation results point 

out that the structural defects play a crucial role on the 

electronic, optical and mechanical properties of carbon 

nanotubes [4-13]. These studies show variety of results 

according to the methods and the defects. Several kinds of 

defects may occur on carbon nanotubes. Here we examined 

the vacancy defects on the atomic structure. We used a parallel 

O(N) TBMD code designed by Dereli et al [14-16]. We 

studied at 300K to except the effect of temperature and to 

study with the brittle SWCNTs. 

During our simulations, we first optimized a pristine 

(10,10) SWCNT using the “thermal equilibrium” method as 

described in [1]. Then multiple amount of vacancies are 

generated on the tube structure and the tensile loading is 

applied to the defected tube. Using this procedure, we 

investigated the structural stability and the bond breaking 

strain values of the (10,10) SWCNT. The stress-strain curve of 

the nanotube is obtained and the mechanical parameters such 

as the tensile strength, elastic limit, Young modulus are 

calculated. In our work of [17], we investigated the effect of 

single vacancy defect on the tensile properties of (10,10) 

SWCNTs and we compared the results with the pristine tube 

[2]. In the study, we have shown that a single vacancy defect 

decreased the bond breaking strain from 23% to 16%. The 

elastic limit maintained its value as 10%. A single vacancy 

defect did not represent a significant effect on the Young’s 

modulus of SWCNTs, which is calculated as a decrease of 

1.5%. However it is shown that a single vacancy defect is 

observed to reduce the tensile strength from 83.23 GPa to 

64.14 GPa which corresponds to 23% decrease. 

Here we reach one step ahead from these studies to 

clarify the decreasing ratios of tensile strength and mechanical 

parameters with respect to the certain amount of vacancies. 

Figure 1(a), shows the difference between the total energy 

values of pristine (10,10) tube and the (10,10) tube with 4 - 

vacancies. Last 2000MD Step in Figure 1(b), (c) and (d) show 

the total energy results of (10,10) tube under 5%, 10% and 

15% strain, respectively. Figure 1 and the corresponding 

simulation pictures of Figure 2, show that the simulated 

carbon nanotube with 4 - vacancies can not carry the strain 

when it is stretched to 10 -15% of its original length. This 

work will set lights to the applications of carbon nanotubes 

with vacancy defects which is very common during their 

formation. Careful study on the bond breaking values of these 

SWCNTs during stretching will be done. Effect of 4-vacancies 

on the structural stability, tensile strength and Young modulus 

will be reported. 

Total energy (eV/atom) 

Total energy (eV/atom) 

-7,8 

-8,0 

-8,2 

-8,20 

-8,24 

-8,28 

-8,32 

(a) 

0 2000 4000 6000 

MD Step 

10% 

-8,15 

-8,20 

-8,25 

-8,30 

(b) 

-8,35 

0 2000 4000 6000 8000 

MD Step 

-7,6 

15% 

-7,8 

(c) 

(d) 

-8,4 

-8,4 

0 2000 4000 6000 8000 0 2000 4000 6000 8000 

MD Step 

MD Step 

Figure:1 Total energy per atom results of (10,10) SWCNT (a) with 4 –vacancies; 

(b) under 5% strain; (c) under 10% strain; (d) under 15% strain. 

-8,0 

-8,2 

Figure:2 Simulation pictures of (10,10) tube (a) with 4 –vacancies; 

(b) under 5% strain; (c) under 10% strain; (d) under 15% strain. 






(http://www.yildiz/edu/tr/~gdereli/lab_homepage/index.html) 


5% 




Amyloid-like peptidic template-directed synthesis of inorganic nanomaterials 

Ruslan Garifullin, Mustafa Özgür Güler* 

UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey 

Abstract— We have designed amyloid like peptides self-assembling into nano-sized fibrilar structures. These assemblies are 

further exploited as a universal nano-template for synthesis of inorganic materials through the mineralization process. Our 

method of using mineralization process to produce inorganic nanostructures is unique as it realizes “bottom-up” molecular 

design concept. 

Self-assembly is an important technique for materials design 

using non-covalent interactions including hydrogen bonding, 

hydrophobic, electrostatic, metal-ligand, - and van der 

Waals interactions. 1 Nanostructures inspired from biological 

systems have been investigated for use in electronics 5-7 , 

optics 8 and regenerative medicine 9 , among other 

HO 

O 

O 

NH 

O 

functional group 

H 

N 

R 1 

O 

N 

H 

R 2 

O 

O R 

H 

4 

O 

H 

N 

N 

N 

R H 

OH 

3 O 

O NH 2 

beta-sheet forming peptide 

functional 

group 

Figure 1. Representation of self-assembling peptidic unit. 

Cobalt (II) oxide is not the only inorganic material that we 

succeeded to synthesize. We also had positive results with 

copper (II) oxide, zinc oxide, titanium (II) oxide and many 

other metals. The ability to realize in practice this number of 

inorganic compounds truly testifies that designed template is 

universal and at the same time proves our concept of templatedirected 

synthesis. 

In summary, having shown feasibility of the method we 

propose to employ soft-materials templating approach to 

create one-dimensional nanostructures. Novel supramolecular 

architectures will be built molecule-by-molecule, thus 

realizing “bottom-up” approach. By using non-covalent 

intermolecular forces, it will be possible to construct dynamic 

self-assembled systems. Highly tailorable small molecules 

facilitate incorporation of multifunctional groups for 

controlled morphology, chemical and physical characteristics, 

and surface chemistry. Controlled formation of shape at 

nanoscale will enable researchers to investigate novel 

multifunctional nanodevices. 

Acknowledgement. This work is supported by TUBITAK. 

*Corresponding author: moguler@unam.bilkent.edu.tr 

Figure 2. TEM image of peptide nanofibers (left) and template 

directed synthesis of Cobalt(II) oxide nanotubes(right). 

applications. 10-13 Supramolecular chemistry opens interesting 

opportunities for new technology by directing the structure 

and function of materials at 1-100 nm scale, a length-scale 

which is difficult to access through conventional covalent 

2, 14-16 

chemistry. 

In this work, we explored the idea of forming nanofibers by 

means of self-assembly of amyloid-like peptides and found 

that self-assembly is achieved by specially designed short 

peptide sequences that can form sheet-like hydrogen bonded 

structures. Moreover, functional groups can be relatively 

easily introduced to the peptidic molecules and it is possible to 

control nanostructure surface morphology by affecting the 

hydrogen bonding orientation. These results suggest that 

obtained nanofibers can further be used as a template in 

synthesis of inorganic nanomaterials. 

We studied formation of several metal oxides and metal 

sulfides through mineralization process. Metal salts were 

deposited on the surface of the preformed template, and the 

template was removed by calcination process. We found that 

this method is, indeed, feasible. For instance, cobalt (II) oxide 

formed nanotubes. Structure of nanotubes was verified and 

characterized by SEM-EDAX and TEM. 

1. Hoeben, F. J. M.; Jonkheijm, P.; Meijer, E. W.; Schenning, A. Chem. 

Rev. 2005, 105, 1491-1546. 

2. Stupp, S. I.; LeBonheur, V.; Walker, K.; Li, L. S.; Huggins, K. E.; 

Keser, M.; Amstutz, A. Science 1997, 276, 384-389. 

3. Jolliffe, K. A.; Timmerman, P.; Reinhoudt, D. N. Angew. Chem., Int. 

Ed. 1999, 38, 933-937. 

4. Thurmond, K. B.; Kowalewski, T.; Wooley, K. L. J. Am. Chem. Soc. 

1997, 119, 6656-6665. 

5. Nguyen, S. T.; Gin, D. L.; Hupp, J. T.; Zhang, X. Proc. Natl. Acad. Sci. 

U. S. A. 2001, 98, 11849-11850. 

6. Forrest, S. R. Nature 2004, 428, 911-918. 

7. Scheibel, T.; Parthasarathy, R.; Sawicki, G.; Lin, X.-M.; Jaeger, H.; 

Lindquist, S. L. Proc. Natl. Acad. Sci. U. S. A. 2003, 100, 4527-4532. 

8. Sanchez, C.; Arribart, H.; Guille, M. M. G. Nature Materials 2005, 4, 

277-288. 

9. Stupp, S. I. MRS Bull 2005, 30, 546-553. 

10. 10.Hwang, J. J.; Iyer, S. N.; Li, L.-S.; Claussen, R.; Harrington, D. A.; 

Stupp, S. I. Proc. Natl. Acad. Sci. U. S. A. 2002, 99, 9662-9667. 

11. 11.Silva, G. A.; Czeisler, C.; Niece, K. L.; Beniash, E.; Harrington, D. 

A.; Kessler, J. A.; Stupp, S. I. Science 2004, 303, 1352-1355. 

12. Metzke, M.; O'Connor, N.; Maiti, S.; Nelson, E.; Guan, Z. 

Angewandte Chemie International Edition 2005, 44, 6529-6533. 

13. Lee, K. Y.; Alsberg, E.; Hsiong, S.; Comisar, W.; Linderman, J.; Ziff, 

R.; Mooney, D. Nano Letters 2004, 4, 1501-1506. 

14. Whitesides, G. M.; Simanek, E. E.; Mathias, J. P.; Seto, C. T.; Chin, 

D. N.; Mammen, M.; Gordon, D. M. Acc. Chem. Res. 1995, 28, 37-44. 

15. Frechet, J. M. J. Journal of Polymer Science Part a-Polymer 

Chemistry 2003, 41, 3713-3725. 

16. Mirkin, C. A. Small 2005, 1, 14-16. 




Electronic Structure of Single Wall Carbon Nanot ubes With Vacancy Defect 

Gülay Dereli 1 *, 1 , Necati Vardar 1 

1 Department of Physics, Yildiz Technical University, 34210, Turkey 

Abstract-Electronic structure of (12,0) and (14,0) single wall carbon nanotubes (SWCNT) with vacancy defect are studied using Order (N) Tight 

Binding Molecular Dynamics simulation method (O(N) TBMD) [1-3]. We have obtained the total energy per atom and Fermi energy levels of 

(12,0) and (14,0) SWCNTs with vacancy defect. The effect of vacancy defects on the electronic band gap is investigated in real space. Change of 

the electronic band gap values are discussed. 

An important property of carbon nanotubes is that SWCNT 

can be either metallic or semiconducting depending on the 

geometrical structure. Geometrical structure of SWCNT is 

given by the chiral vector ( ). The armchair 

SWCNTs ( ) are metallic, and the zigzag SWCNTS 

( ) are only metallic when n is a mu ltiple of 3. 

SWCNTs may have various kinds of defects such as vacancy, 

either during their growth or when they are part of an 

electronic circuit. Defects may influence the physical 

properties of SWCNTs. Theoretical calculations have shown 

that vacancy defects in SWCNTs can substantially modify their 

electronic properties [4-12]. 

In this study, energetic and electronic structures of (12,0) and 

(14,0) SWCNTs with multi-vacancy defects are studied using 

order (N) tight binding molecular dynamic (O(N) TBMD) 

simulation code designed by Dereli et al [1-3] and applied to 

nanotube simulations successfully [13-16]. We simulated 

(12,0) metallic and (14,0) semiconducting SWCNTs with multi 

vacancy defect . We calculated the total energy per atom and 

the Fermi energy levels during the simulation . 

(a) 

eDOS 

1,0 

nvac=0 

(12,0) 

0,8 

0,6 

0,4 

0,2 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

1,0 

0,8 

0,6 

0,4 

0,2 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

1,0 

0,8 

0,6 

0,4 

0,2 

nvac=0+1 

nvac=0+2 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

Energy (eV) 

DOS 

1,0 

0,8 

0,6 

0,4 

0,2 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

1,0 

0,8 

0,6 

0,4 

0,2 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

1,0 

0,8 

0,6 

0,4 

0,2 

nvac=0 (14,0) 

nvac=1 

nvac=4 

0,0 

-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 

Energy (eV) 

Figure 2. Electronic density of states of (12,0) and (14,0) SWCNTs 

with vacancies. 

Our studies have shown that the vacancy defects can 

effectively change the energetics and hence the electronic 

structure of SWCNTs. 







(b) 

Figure 1. a) (12,0) b) (14,0) SWCNTs with vacancy defect 

We showed that the total energy values increase with the 

number of vacancies and the Fermi energy levels decrease. 

The effects of multi vacancy defects on the electronic band gap 

are given in figure2. Band gap is obtained in real space through 

the behavior of electronic density of states (eDOS) near the 

Fermi level . The band gap of (12,0) SWCNT increases from 

0.01 eV (perfect CNT) to 0.07eV for one vacancy and 0.13 

eV for two vacancies. For (14,0) SWCNT, band gap rapidly 

decreases from 0.55eV to 0.09 eV for one vacancy and 

semiconductor-metal transition occurs. 

148, 

188 (2002). 



[4] L. Chico, L. X. Benedict, S. G. Louie, and M. L. Cohen, Phys. 

Rev. B 54, 2600 (1996) 

[5] A. J. Lu and B. C. Pan, Phys. Rev. Lett. 92,10,105504 (2004). 

[6] L-G Tien, C-H,T F-Y Li, and M-H Lee, Phys. Rev. B 72, 245417 

(2005). 

[7] W. Orellana , P. Fuentealba, Surface Science 600, 4305–4309 

(2006). 

[8] Seun g-Hoon Jhi, Carbon 45, 2031–2036 (2007). 

[9] Susumu Okada, Chemical Physics Letters 447, 263–267 (2007) . 

[10] H. Ishii, N. Kobayashi, K. Hirose, Surface Science 601, 5266– 

5269 (2007). 

[11] A. R. Rocha, J. E. Padilha, A. Fazzio, and A. J. R. da Silva, Phys. 

Rev. B 77, 153406 (2008). 

[12] S. Berber and A. Oshiyama, Phys. Rev. B 77, 165405 (2008). 

[13] G. Dereli and B. Süngü, Phys. Rev. B 75, 184104 (2007). 

[14] G. Dereli, B. Süngü and C. Özdogan, Nanotechnology 18, 24570 

(2007). 

[15 

201T , 075707 ( 2009) 

[16 

181023 , 171 (2010). 




The Effect of Annealing Temperature on the Microstructure of TiO 2 Thin Films 

Deniz Gu ltekin 

1 *, Mehmet Oguz Guler 1 , Ozgur Cevher 1 and Hatem Akbulut 1 

1 Department of Metallurgical & Materials Engineering, Sakarya University,Sakarya 54187, Turkey 

Abstract-Titanium dioxide (TiO 2 ) thin films have been prepared on soda lime glass substrates by the sol-gel process. The preparation of covering 

solution is investigated with the method of orthogonal experimental design, and the heat treatment temperature and time, which influenced on the 

films properties are discussed. And the TiO 2 thin films had been studied by the means of fourier transform infrared (FTIR), X-ray diffraction 

(XRD), scanning electron microscopy (SEM) and four probe electrical resistivity tests. 

Titanium oxide (TiO2) is one of the most extensively studied 

transition metal oxide. TiO 2 films have excellent 

photocatalytic properties as well as the high transparency, 

excellent mechanical and chemical durability of in the visible 

and near-infrared region of the spectrum [1]. These TiO 2 films 

carried out for the different applications as in opto-electronic 

devices, sensors, dye-sensitized photo-voltaic cells, electro 

chromic displays, planner wave guides, photo-catalysts, etc [2, 

3]. The preparation of TiO 2 thin films has received great 

attention during the past several decades because of its 

remarkable optical, photo-catalytical and electronic properties 

[4]. An important aspect in the preparation of TiO 2 

photocatalysts for environmental applications is the 

development of nanostructured TiO 2 powders with a number 

of favorable properties such as small particle size, high surface 

area, controlled porosity, and tailor-designed pore size 

distribution. In particular, a number of recent literatures have 

focused on the preparation of mesoporous TiO 2 materials with 

high surface area and tailored framework structure using 

surfactant template. Owing to their high surface-to-volume 

ratio and offering more easily accessible surface active sites, a 

further enhancement in the catalytic activity and process 

efficiency is expected [5]. TiO 2 films can be synthesized by 

various thin film deposition techniques, such as thermal 

evaporation, chemical vapor deposition (CVD), metal organic 

chemical vapor deposition pulsed laser deposition and sol–gel 

process [4]. 

In this study, nanostructured mesoporous TiO2 coatings 

were prepared by the sol–gel route using Titanium 

tetrachloride as a precursor. Titanium tetrachloride was first 

dissolved in a solution composed of ethanol and de-ionized 

water (volume ratio is 1:1). Then TiCl 4 was added to the 

solution with the dispersant of polyethylene glycol and stirred 

for 20 min at 80 °C. After 48 h of aging in the air, de-ionized 

water and ethanol was applied to remove chloride ions. The 

gel was dried in an oven at 60 °C for 4 h to remove moisture. 

We have demonstrated the fabrication and characterization 

of nanostructured mesoporous TiO2 coatings by the sol–gel 

dip-coating technique onto soda-lime glass. The preparation 

method is based on a sol-gel technique using Titanium 

tetrachloride as precursors. The effects of sol-gel parameters 

and annealing temparatures on the film properties were 

investigated. The prepared TiO 2 thin films were characterized 

using Transmission Electron Microscopy (SEM), X-ray 

Diffraction (XRD), Fourier Transform Infrared (FTIR) and 

Four Probe Electrical Resistivity. 

We have mainly focused on the effect of annealing 

temperature on the physical properties of TiO2 films. Postannealing 

treatment is necessary to convert the deposited 

amorphous film into titanium oxide (TiO 2 ) crystalline 

(anatase) phase [4]. In order to investigate the effect of the 

annealing temperature on the properties of TiO 2 coating, the 

dried gel was sintered for d ifferent temperatures in a furnace. 

These films have been characterized using transmission 

electron microscopy (SEM), X-ray diffraction (XRD), fourier 

transmission (FTIR) and four probe electrical resistivity. 

*Corresponding author: dkurt@sakarya.edu.tr 

[1] M. Sasani Ghamsari, A.R. Bahramian, Materials Letters 62 

(2008) 361–364 

[2] M. Flischer, H. Meixner, Sens. Actuators B 4 (1991) 437. 

[3] Y.Q. Li, S.Y. Fu, G. Yang, M. Lee, J. Non-Cryst. Solids 352 

(2006) 3339. 

[4] S. K. Sharma, M. Vishwas, K. N. Raoa, S. Mohana, D. S. 

Reddyb, K.V.A. Gowda, Journal of Alloys and Compounds 471 

(2009) 244–247. 

[5] J. Zhu, J. Yang , Z. Bian, J. Ren, Y. Liu , Y. Cao, H. Li, H. He, K. 

Fan, Applied Catalysis B: Environmental 76 (2007) 82–91. 




Synthesis of ZnO Nanowires and Nanorods 

Sadullah Öztürk 1 , 1 , 1, Zafer Ziya Öztürk 1 * 

1 Gebze Institute of Technology, Science Faculty, Department of Physics, Kocaeli 41400, Turkey 

Abstract-In this study, fabrication of ZnO nanostructures such as nanowires and nanorods will be explained in details. ZnO nanowires were 

grown by cathodically induced sol-gel deposition using an anodic aluminum oxide (AAO) template which is approximately 70 nm diameter and 

10 μm length. So vertically aligned ZnO nanowires were grown in AAO template by applying cathodic voltage in aqueous Zinc Nitrate solution 

at 23 ºC. For electrochemical deposition, three-electrode system was used. The ZnO nanowires are approximately 65 nm diameter and 10 μm 

lengths. For fabrication of ZnO nanorods hydrothermal technique was used. Firstly sol-gel ZnO solution was coated on glass substrate by spin 

coating for seed layer. Then ZnO nanorods were grown in Zinc nitrate and HMTA aqueous solution at 90 ºC about 3h. The ZnO nanorods are 

approximately 40 nm diameter. The vertical nanowires and nanorods were characterized by scanning electron microscope (SEM). 

ZnO nanostructures are attractive material in last decade 

because of their n-type semiconducting behavior with large 

exciton binding energy (60 meV) and a large band gap (3.37 

eV). ZnO nanostructures can be used in novel devices, such as 

photonic devices and very sensitive chemical sensors etc. In 

literature, there are many techniques for fabricating of ZnO 

nanowires such as electrochemical and chemical vapor 

deposition, and also for fabrication ZnO nanorods such as 

hydrothermal, sonochemical and chemical vapor deposition 

technique [1,2]. In this study, ZnO nanowires were grown in 

an AAO template with 75 nm diameter and m in length by 

electrochemical deposition techniques. The AAO template 

was grown on Al foil with two anodization techniques and the 

details were given [1]. ZnO nanowires were electrodeposited 

in this template with applying -1.5V at room temperature 

about 2h. Then AAO template was etched in NaOH aqueous 

solution. So ZnO nanowires was obtained with 70 nm 

ZnO nanowires was shown in 

figure 1. 

On the other hand for preparing ZnO nanorods, ZnO seed 

layer solution was deposited on glass with spin coating at 

2500 rpm about 30s. Then the coated glass was dried in an 

oven at 130°C for 5min. and this step was repeated 5 times. 

Finally, ZnO seed layer glass was annealed 300 °C 

approximately 1h. The ZnO nanorods were grown in 

Zn(NO 3 ) 2 .6H 2 O and HMTA equmolar aqueous solution at 

90 °C about 3h on ZnO seed layer coated glass. For preparing 

of nanorods, cleavable laboratory bottle was used. ZnO seed 

layer coated glass was put in vertically. ZnO nanorods were 

40nm diameter and 800nm length. ZnO nanorods were shown 

in Figure 2 

It is clearly seen from figure1 that, ZnO nanowires were 

deposited in AAO template. Because the aspect ratio was very 

high so the nanowires were come together. 

Figure 2. Top view of ZnO nanorods 

It is clearly seen fron fig. 2 that ZnO nanorods were 

completely covered surface of the ZnO seed layer coated 

glass. 

In summary, in this study, two different types of ZnO 

nanostructures were synthesized by using different techniques. 

If these two techniques were compared, a hydrothermal 

technique was easier. In our future works, these nanostructures 

will be used as gas sensor such as NO2, CO, H2 and volatile 

organic compound. 

*Corresponding author: zozturk@gyte.edu.tr 

[1] N. Tüüzer, Z. Z. Öztürk, 95, 781- 

787, 2009 

[2] S. Öüzer, Z.Z. Öztürk, 

Fabrication of ZnO nanowires at room temperature by cathodically 

induced sol–gel method in press, DOI: 10.1007/s00339-009-5504-8 

[3] Z.L. Wang, J. Phys: Cond. Matt. 16, R829 (2004). 

[4] L. Schmidt-Mende, J. MacManus-Driscoll, Materials Today, 10, 

40 (2007). 

Figure 1. Top view of the free standing of ZnO nanowire 




The Effect of Annealing Temperature of the Electrical Properties of Tin (IV) Oxide Films Synthesized 

by Sol-Gel Methods 

Deniz Gu ltekin 1 *, Mehmet Oguz Guler 1 , Ozgur Cevher 1 , Mustafa Basaran 1 , Hatem Akbulut 1 


Abstract-Semiconducting thin films with tin dioxide have been deposited on soda lime glass substrates from tin (II) chloride dihydrate 

(SnCl 2 2H 2 O) precursor using the dip-coating sol-gel method. They are prepared from a powder obtained from chlorides directly in our 

laboratory: 8.37 g of SnCl 2 2H 2 Oare dissolved in 100 ml of absolute ethanol. Finally, sintering was done in a furnace with a heating rate 

(2 o C/min) to 500 o C and kept for 2 hours). 

Transparent conductive oxides (TCOs) are very important in 

modern electronic industry and have been used as plastic 

liquid crystal display devices, touch sensitive overlays, 

transparent electromagnetic shielding materials, front 

electrodes of solar cells, energy efficient windows, etc. 

Numerous works have been performed on SnO2 thin films for 

improvement of their electrical conductivity to utilize it as a 

TCO material in transparent electrode applications [1–6]. 

SnO2 films are low cost, chemically and environmentally 

more stable than other TCOs such as ZnO, and Sn-doped 

In 2 O 3 (ITO) [7,8]. Tin oxide films have been widely 

fabricated by several workers using a variety of techniques 

such as chemical vapor deposition [9], metal-organic 

deposition [10], dc and rf-sputtering, etc. [11,12], among 

which sol-gel lies in the fact that the doping level, solution 

concentration and homogeneity can be controlled easily 

without using expensive and complicated equipment. 

The Sol-Gel Dip-Coating (SGDC) method is more and more 

used for the deposition of various thin films on different 

substrates. This low temperature soft process presents major 

advantages and the possibility of h igh purity starting materials, 

an easy coating of large and complex-shaped substrates, 

almost no perturbations of devices in the case of deposition on 

top, an easy technology and most of the time a low cost. 

In the present work the mechanism of formation of a SnO 2 

film prepared by the sol-gel method from an ethanolic solution 

of SnCl 2 .2H 2 O precursor onto soda-lime glass. The precursor 

salt -SnCl 2 .2H 2 O (Merck)- was dissolved in ethanol and a 

0.05M stock solution was made. The gel-like film was 

prepared onto soda-lime glass (size 4 cm x 2 cm, thickness 2 

mm). Before starting the processes, sodium silicate glass 

substrates were cleaned using distilled water, ammon ia and 

hydrogen peroxide (5:1:1 by volume) and then rinsed carefully 

using methanol, acetone and distilled water, respectively The 

coating was made by applying the precursor salt solution (after 

a 10-fold dilution with ethanol) drop by drop onto the support 

and removing the solvent by hot air (60°C). This procedure 

was continued until a relatively thickness of 400-800 nm layer 

was deposited. 

Scanning electron microscopy (SEM) and X-ray diffraction 

(XRD) us 

microstructural data. The crystallinity of each film was 

calculated fro m XRD spectra by Scherrer’s formula. Chemical 

composition of the synthesized thin films was analyzed by 

Fourier transform infrared spectra. The surface topography of 

the thin films were observed by scanning electron microscopy 

(SEM). The effect of different annealing temperature on the 

electrical resistivity of the thin films were also analyzed by 

using four probe resistivity techniques. 

[1] H.J. Kim, J.W. Bae, J.S. Kim, Y.C. Jang, G.Y. Yeom, N.E. Lee, 

Surf. Coat. Technol. 131 (2000) 201. 

[2] Y.K. Fang, J.J. Lee, Thin Solid Films 169 (1989) 52. 

[3] W.A. Badway, H.H. Afifi, E.M. Elgair, J. Electrochem. Soc. 137 

(1990) 1592. 

[4] J.C. Mannifacier, L. Szepessy, J.F. Bresse, M. Perotin, R. Stuck, 

Mater. Res. Bull. 14 (1979) 163. 

[5] E. Shanthi, V. Dutta, A. Banerkee, K.L. Chopra, J. Appl. Phys. 51 

(1980) 6243. 

[6] I.H. Kim, J.H. Ko, D. Kim, K.S. Lee, T.S. Lee, J.-h. Jeong, B. 

Cheong, Y.-J. Baik, W.M. Kim, Thin Solid Films 515 (2006) 2475. 

[7] T. Minami, S. Takata, H. Sato, J. Vac. Sci. Technol. 13 (1995) 

1095. 

[8] B. Thangaraju, Thin Solid Films 402 (2002) 71. 

[9] J. Kane, H.P. Schwiezer, J. Electrochem. Soc. 123 (1976) 270. 

[10] T.N. Blanton, M. Lelental, Mater. Res. Bull. 29 (1994) 537. 

[11] R.S. Dale, C.S. Rastomjee, F.H. Potter, R.G. Egdell, Appl. Surf. 

Sci. 70/71 (1993) 359. 

[12] A. Martel, F. C-Briones, J. Fandino, R. C-Rodriguez, P. B-Perez, 

A. Z-Navarro, M. ZTorres, J.L. Pena, Surf. Coat. Technol. 122 

(1999) 136. 





Influence of Spin Speed on the Structural and Morpholog ical Properties of Sol Gel Derived 

Nanocrystalline Structure ZnO Films 

Seval Aksoy 1 *, Yasemin Caglar 1 , Saliha Ilican 1 , Mujdat Caglar 1 

1 

Department of Physics, Anadolu University, Eskisehir 26470, Turkey 

Abstract-The nanocrystalline structure ZnO films were deposited onto p-Si substrates by the sol gel method using spin coating technique. The 

effect of spin speed on the structural and morphological properties of the ZnO films was investigated. X-ray diffraction showed that the films 

were polycrystalline and had a wurtzite structure. The crystallites are preferentially oriented with (0 0 2) planes parallel to the substrate surface. 

The nanostructured zinc oxide (ZnO) exhibits a variety of 

properties such as: semiconducting (II–VI), photoconducting, 

piezoelectricity, acousto-optical, transparency in the visibleinfrared 

region, and opto-electrical properties. So, 

nanostructure ZnO has been studying by many research 

groups [1-6]. 

In this study, Zinc acetate dihydrate (ZnAc), 2- 

methoxyethanol and monoethanolamine (MEA) were used as 

a starting material, solvent and stabilizer, respectively. The 

mo lar ratios of ZnAc to MEA were maintained at 1:1. The sol 

was stirred at 60 o C 2 h to yield a clear and homogeneous 

solution. The spin speed was maintained at 1000 (S1), 3000 

(S3), 4000 (S4), 5000 (S5) rpm for 30 s. After each coating, 

the coated film was dried at 300°C for 10 min. The coating– 

drying cycles were repeated ten times. The films were finally 

annealed at 500 °C for 1 h. 

The crystalline structure of the films was investigated by the 

X-ray diffraction (XRD) method with a diffracto meter using 

CuK radiation (=1.5406Å). The deposited films at high spin 

speed were uniform, smooth and have a good adherence to the 

substrates. Figure 1 shows XRD pattern of the nanostructure 

ZnO films. It is observed that the film deposited at 4000rpm 

(S4 film) has the best crystalline structure. Texture coefficient 

(TC), crystalline size and lattice constants of the films were 

also calculated. 

Surface morphology of the S4 film has been investigated by 

field emission scanning electron microscopy (FESEM). Figure 

1 shows FESEM image of the nanocrystalline structure ZnO 

films. It was observed that the surface morphology of the S4 

film is almost uniform nanoparticle size distribution. The film 

exhibits a nanostructure and the spherical crystalline part icle 

size is approximately 50 nm. 

Figure 2. FESEM image of the S4 film. 

This work was supported by Anadolu University 

Commission of Scientific Research Projects under Grant No: 

061039 and 081029. 

*Corresponding author: 2Tsevala@anadolu.edu.tr 

Figure 1. XRD patterns of the nanocrystalline structure ZnO films 

( :p-Si substrate). 

[1] http://www.semiconductorslab.com 

[2] http://www.webjam.com/dfxue 

[3] http://www.nanoscience.gatech.edu/zlwang/index.htm 

[4] http://www.science24.com/paper/3870 

[5]Wang ZG, Wang MQ, Lin ZH, Xue YH, Huang G, Yao X, 2009. 

Growth and interconversion of ZnO nanostructure films on different 

substrates, Appl Surf Sci, 255:4705-4710. 

[6]Takai O., Futsuhara M., Shimizu G., Lungu C.P., Nozue J., 1998. 

Nanostructure of ZnO thin films prepared by reactive rf magnetron 

Sputtering, Thin Solid Films, 318:117–119. 




The Effect of Annealing Temperature on the Formation of ZnO Thin Films 

Deniz Gu ltekin 1 *, Mehmet Oguz Guler 1 , Ozgur Cevher 1 , Fatih Kuzak 1 , Hatem Akbulut 1 


Abstract-Thin films of ZnO grown by sol-gel dip coating method onto soda lime glass substrates under different annealing temperatures using 

zinc acetate precursors. The physical and chemical properties of the deposited thin films were investigated via SEM, XRD, FTIR and 4-probe 

electrical resistivity techniques. 

ZnO is one of the compounds studied actively in various 

fields due to its significant physical and chemical properties. 

For example, ZnO has much attention as a host material for 

transparent conducting films because impurity- doped ZnO 

films show high transparency above 90% in the visible region 

and low electrical resistivity around 5 x 10 -4 -3]. In a 

chemical field ZnO is well known as a photocatalyst with high 

chemical activity. Under irradiation of photons having higher 

energy than the optical band gap of ZnO, oxidation reactions 

are promoted on the ZnO surface. 

There are many techniques to prepare ZnO thin films, 

including sputtering [4], molecular beam epitaxy [5], chemical 

vapor deposition [6], spray pyrolysis [7] and sol-gel technique 

[8], etc. Compared with the others, sol-gel technique is simple, 

less expensive and has an advantage of large area deposition 

and the facility of the doping. Owing to the requirement of the 

commercial process, the sol-gel technique is selected to 

prepare high-quality ZnO thin films. It is known that the 

properties of ZnO thin films prepared by sol-gel technique are 

affected by the precursor materials and the postanneal 

technique. Especially, the post-anneal technique is a very 

important factor for the preparation of ZnO thin films. In this 

work, dried gel films deposited by sol-gel technique were 

respectively annealed under nitrogen atmosphere and at 

different temperatures (300 

ZnO thin films were deposited by sol-gel technique. Zinc 

acetate [Zn(CH 3 CO 2 ) 2·2H 2 O] and pure ethyl alcohol were 

used as the precursor material and the solvent, respectively. 

Diluted lactic acid solution (molar ratio CH 3 CH(OH)COOH: 

H 2 O = 1:2) was used as the solvent and stabilizer, which 

controlled the pH value of the solution to avoid turbidity and 

precipitate [9]. Zinc acetate was dissolved in pure ethyl 

alcohol by the molar ratio of 1:85. After stirring the solution 

with reflu x at 40 °C for 2 h, the lactic acid solution was slowly 

added drop wise into the dissolved zinc acetate solution to 

yield a clear and homogeneous solution. Subsequently, the 

solution was placed in an oven at 65°C for 2 h and used as the 

coating solution after being cooled to room temperature. Two 

days after the solution was prepared, the coating was made to 

increase the viscosity of the solution. 

To understand the change of the organic composition, the 

[1] M. Ohyama, H. Kozuka, T. Yoko, S. Sakka, J. Ceram. Soc. Jpn. 

104 (1996) 296. 

[2] D. Bao, H. Gu, A. Kuang, Thin Solid Films 312 (1998) 37. 

[3] Z.K. Tang, G.K.L. Wong, P. Yu, M. Kawasaki, A. Ohtomo, H. 

Koinuma, Y. Segawa, Appl. Phys. Lett. 72 (1998) 3270. 

[4] T. Minami, H. Nanto, S. Takata, J. Appl. Phys. Lett. 14 (1982) 

958. 

[5] K. Emilar, R. Schieck, S. Fiechter, Appl. Surf. Sci. 70 (1993) 707. 

[6] F.S. Mahmood, R.D. Gould, M.H. Salih, Thin Solid Films 270 

(1995) 376. 

[7] M. Futsuhara, Y. Ishida, R. Baba, A. Fujishima, J. Oil Colour 

Chem. Assoc. 75 (1992) 236. 

films annealed under different conditions were analyzed by 

Fourier t ransform infrared spectra. The crystallinity of the 

ZnO thin films was identified with a DMax/2200 X-ray 

diffraction instrument (XRD, Cu K 

The Sherrer equation and the Bragg law were used to calculate 

the grain size and the lattice constants, respectively. The 

surface topography was observed by scanning electron 

microscopy (SEM). All the above measurements were 

completed at room temperature. 





An alternative approach to graphene and graphitic flake preparation and their morphology on Au 

and SiO substrates 

Merve Altay 1 , Ahme 2 2 , * 1 

1 stanbul Technical University, Department of Physics, l, Turkey 

2 National University of Singapore, Department of Physics, 2 Science Drive 3, 117542, Singapore 

Abstract-We are working on alternative methods for graphene production based on the known methods, especially on the HOPG exfoliation 

with scotch tape technique, which is a rather inefficient one. Our method involves the preparation of a solution with graphite and graphene 

flakes. We place our graphitic flakes on clean Au and SiO substrates and investigate their optical properties as well as their morphological 

properties using Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM). We compare our samples to the morphologies 

of the known graphene samples. 

There is an explosive interest on the graphene research in 

the past few years [1,2]. Graphene is a single layer of graphite 

with exotic properties [1,2,3]. Much of the research on 

graphene has been oriented in the exploration of its electronic 

properties; however the structural properties of this twodimensional 

model system are also of great interest [4]. Also 

and efficient method for the preparation of reliable graphene 

samples is required. 

Graphene is generally prepared by four different methods: 

Epitaxial growth by chemical vapour deposition (CVD); the 

mechanical exfoliation of highly oriented pyrolytic graphite 

(HOPG) using scotch tape (the most popular method); 

epitaxial growth on insulating (or semiconductor) surfaces 

(like SiC); and the formation of colloidal suspensions 

(graphene oxide) [5]. 

We prepare solutions using scotch tape with graphite on 

them. By means of drop casting the solution on Au on glass or 

Au on mica substrates; or on SiO wafers, we investigate their 

optical and morphological properties. In our studies we use 

reference graphene samples on SiO prepared by means of 

mechanical exfoliation technique with lithographic Au 

contacts on them. We especially studied the reference samples 

by STM such that we were able to get local ato mic resolution 

on the graphene structures [6]. 

(a) (b) (c) 

(a) (b) (c) 

Figure 2. STM images of our reference sample.(a)STM image of Au 

contact on Graphene on SiO 

(size:112nmx112nm,V=50mV,I=0.5nA).(b) STM image of Graphene 

(size:128nmx128nm,V=50mV, I=1nA).(c)Atomic resolution on 

Graphene (size:6.09nmx6.09nm,V=50mV, I=1nA). 

Our initial results on the samples we have prepared using 

our graphene production recipe hints at the possible successful 

graphene flakes with considerably large sizes, even visible to 

the naked eye. Their optical microscopy images compare to 

those of the reference samples (figure.3). We are investigating 

the properties of our flakes using raman scattering, AFM and 

STM measurements. 

(a) (b) (c) 

Figure 1. Our reference sample.(a)Microscopy image of graphene 

on SiO with Au contacts, image size: 650umx650um. (b) zoom on to 

the graphene, image size:65umx65 um. Graphene is35.36umx 12um. 

(c)AFM image of the same graphene with Au contact (image 

size:4.00umx4.00um) 

We can clearly identify the graphene samples using AFM. 

The typical step height of graphene samples on SiO is about 

2.6nm. This indicates the existence of a rough surface 

underneath (Figure 1c). We can also aim at the graphene 

samples as well as the lithographic Au contacts using the STM 

tip. The Au contacts and the graphene sections of the samples 

are imaged and we can get atomic resolution on the graphene 

under ambient conditions (Figure 2). 

Figure 3. Optical microscopy images of our samples. (a)Image of 

our sample casted on Au, scale bar (red):10um., image size: 

60umx60um. (b)Image of another sample of ours on SiO wafer, scale 

bar: 200 um. , image size: 1000 um x 1000 um. (c) Zoom on to (b) 

scale bar: 50um., image size: 300 um x 300 um. 

*Corresponding author: gurlu@itu.edu.tr 

[1]Novoselov,K.S.;Geim,A.K.;Morozov,S.V.;Jiang,D.;Zhang,Y.;Dub 

onos, S.V.;Grigorieva,I.V.;Firsov,A.A.,Science, 306,666-669 (2004). 

[2] Novoselov,K.S.;Jiang,D.;Schedin,F.;Booth,T.J.;Khotkevich,V.V.; 

Morozov,S.V.;Geim,A.K.,Proc.Natl.Acad.Sci.U.S.A.,102,10451- 

10453 (2005). 

[3] Ishigami,M.;Chen,J.H.;Cullen,W.G.;Fuhrer,M.S.;Williams,E.D., 

Nanoletters, No.6, 1643-1648 (2007). 

[4] Lui,C.H.;Liu,L.; Mak,K.F.;Flynn,G.W.;Heinz,T.F., 

Nature,Vol.462, 08569 (2009). 

[5] Park, S.; Ruoff, R.S., Nature Nanotechnology, 58, (2009) 

[6] Ozyilmaz, B.; Jarillo-Herrero, P.; Efetov, D.; Kim, P., APL, 97, 

192107 (2007). 


P Torr. 

pressure 

P 

pressure 

P and 

P 

pressure. 



Characteristics of TiOR2R Thin Films Produced by Using the Pulsed Laser Deposition Method 

1 

1 

1 

1 

UMesure Mutlu SanliUP P*, Erhan AkmanP P, Elif KacarP P, Arif DemirP 

1 

PUniversity of Kocaeli, Laser Technologies Research and Application Centre, 41380 Umuttepe, Kocaeli 

Abstract- In this study, TiOR2R (titania) thin films were obtained using the third harmonic (355 nm) of pulsed Nd:YAG laser. Optical 

characteristics of the thin films deposited on microscopic glass slides were investigated as deposition time (film thickness), OR2R 

Deposition process carried out at vacuum ambient with oxygen existence and at room temperature. Microscopic, spectroscopic and ellipsometric 

investigations were done to get the optical properties. 

TiOR2 R(titania) is a material that has been studied many times 

because of its excellent properties. Hardness, high chemical 

stability, high physical resistance, high refractive indices make 

it requested material for many applications. The transparency 

feasibility from UV to IR region makes it important for optical 

coating applications. There are many different studies made by 

TiOR2R as a functional material, electrochromic, photocatalytic 

[1-2], solar cells, and gas sensors. Deposition of thin films for 

various applications by using pulsed laser deposition method 

gives opportunity to control and form desired film structure. 

Detailed studies were described in literature [3, 4]. The 

technological developments have provided significant 

improvements in this method. The recent studies [5] indicate 

that if the ambient OR2R and post annealing temperature 

increased the anatase phase turn into rutile phase. 

In this study TiOR2R thin films have been obtained using the 

third harmonic (355 nm) of pulsed Nd:YAG laser, frequency was 

-3 

10Hz. Thin films have been grown on glass slides at 9x10P 

-1 

Torr vacuum then the OR2R was applied at 5x10P 

0 

5x10P Target material is Ti metal which is rotated 16 

rpm (revolutions per minute) to avoid of drilling. Ablation 

processes were continued during 30 min and 45 min. Laser 

beam was focused using 150mm lens. 

The thicknesses of the obtained TiOR2R thin films were 

measured by ellipsometre. The absorption coefficient, , of the 

deposited thin film was determined by [6]: 

Transmittance (%) 

100 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

ln(1/ T ) 

(1) 

d 

250 450 650 850 

lambda (nm) 

 

1/2 

h C h 

E gap 

( ) 

(2) 

2 

The plot of (h)P P-h is given in Figure 2. From the 

intersection of the photon energy axis gives the band gap of 

the titania film. 

(abs*photon energy)1/2 

0,0018 

0,0016 

0,0014 

0,0012 

0,001 

0,0008 

0,0006 

0,0004 

0,0002 

0 

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 

Photon Energy (eV) 

Figure 2. Optical Transmittance spectra of TiOR2R thin film on glass 

slide. 

*Corresponding author: mesuremutlu@kocaeli.edu.tr 

[1] S.C. Jung, S.J. Kim, N. Imaishi, Y.I. Chod, Applied Catalysis B: 

Environmental 55 (2005) 253–257. 

[2] B.S. Richards, J.E. Cotter, C.B. Honsberg, Appl. Phys. Lett. 80 

(2002) 1123–1125. 

[3] D.B.Chrisey, G.K.Hubler (ed), John Wiley & Sons Inc. 1994 

[4] R.Eason (ed), John Wiley & Sons Inc. 2007 

[5] G. Shukla, P. K. Mishra, A. Khare, Journal of Alloys and 

Compounds 489 (2010) 246–251 

[6] Aarik J, Aidla A, Kiisller A A, Uustare T and Sammelselg V 

1997 Thin Solid Films 305 270 

[7] Tauc J and Menth A 1972 J. Non-Cryst. Solids 8–9 569 

Figure 1. Optical Transmittance spectra of TiOR2R thin film on glass 

slide. 

Film thickness, d, and the transmittance spectra, T, was 

derived to calculate the absorption coefficient, . The optical 

energy band gap, ERgapR, for the TiOR2R films on glass was 

determined from the transmission spectra (Figure 1) using 

Tauc relation [7]. 




Indium Tin Oxide (ITO) 

Transparent Conductive Thin Films Elaborated by Sol-Gel Routes 

M. Tümerkan Kesim, Hakan Yavaş and Caner Durucan* 

Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06531, Turkey 

Abstract—Commercial grade ITO thin films are widely produced by sputtering. On the other hand, aqueous based coating 

techniques such as sol-gel, which is simple and easily applicable in the economic sense, has the potential for developing ITO 

thin films. In this study, sols prepared from indium and tin salts are employed to form ITO thin films on soda lime silica float 

glass. The effects of processing parameters such as film deposition parameters, the number of coating layers and heat treatment 

on the morphological, electrical, and optical properties of ITO coatings are reported. 

Indium tin oxide (ITO) thin films have been used in many 

optoelectronic applications such as display panels, solar cells, 

touch screens and electrochromic devices. Among different 

processing methods, sol-gel approaches offer several 

advantages for preparation of ITO films. These include 

feasibility in coating large area substrates, low equipment cost 

and ease in controlling chemical homogeneity and tin-dopant 

incorporation [1-3]. Sol-gel derived ITO films can be prepared 

by using organic metal alkoxide precursors or inorganic metal 

salts. Organic based routes offer higher chemical homogeneity 

and are also advantageous in achieving desired film thickness 

(in the order of 200-250 nm) by single coating operation. But, 

the need for highly expensive starting chemicals and poor 

storage stabilities of organic sols limit industrial scale 

production. 

In this study, sol-gel processing routes for developing ITO 

thin films utilizing inorganic precursors has been established. 

The sols were prepared from InCl 3 .4H 2 O and SnCl 4 . The 

solvents were ethanol (EtOH) and acetylacetone (AcAc) 

which may also serve as chelating agent [4]. ITO sol 

preparation was achieved by dissolving 8.00 g of InCl 3 4H 2 O 

in 45 mL AcAc at 25 C followed by refluxing at 60 C for 3 h. 

Meanwhile, 0.33 mL SnCl 4 were mixed with 4.50 mL ethanol 

at 25 C. After complete homogenization of In-solution, two 

solutions were mixed under stirring. Final coating sols were 

aged for at least 2 days prior to coating and then were 

deposited on precleaned glass substrates by spinning. In case 

of multiple coating operations 10 min 150 C air drying was 

performed in between the subsequent operations. Finished 

samples were heat treated in air for 1h at 600 C. 

The characterization of the films was performed by X-ray 

diffraction (XRD) and scanning electron microscopy (SEM) 

examinations. The performance assessments were achieved by 

UV-Vis spectroscopy for examining the optical properties and 

by four-probe conductivity measurements. 

XRD analyses revealed that tin-incorporated indium oxide 

films were obtained after heat treatment at 600 C. The SEM 

micrographs in Figure 1 exhibit the effect of post coating heat 

treatments on film formation behavior. The films exposed to 

open air cooling were severely cracked as shown in Figure 1a. 

However, a firm film build up can be achieved for coatings 

formed by furnace cooling. The micrograph in Figure 1b 

shows the representative detailed microstructure of the sol-gel 

derived ITO films imaged from pristine region of a 4-layered 

film heat treated at 600 C followed by furnace cooling. The 

ITO crystals vary in size (10-40 nm) with an average size of 

around 20±5 nm. 

(a) 

5 m 250 nm 

Figure 1. (a) SEM micrographs of microcracked ITO coating (4- 

layered) heat treated at 600 C for 1h followed by air cooling, and (b) 

the details of the microstructure of furnace cooled coating with 

similar processing history. 

Figure 2a shows that as the film thickness increases from a 

single layer to 10 layers, the resistance decreases 2 orders of 

magnitude, reaching to value of several thousands ohms/sq. 

This value is comparable with the resistance reported for 

commercial quality sputtered ITO films. However, the film 

thickness also greatly changes the transmittance. As shown in 

Figure 2b, the transmittance of the films produced by 1-, 4- 

and 7-step coating operations are comparable and are in the 

range of 90±5%, and there is only slight reduction in visible 

light transmittance with increasing film thickness. However, 

the transmittance remarkably decreases for the film produced 

by 10 coating operation, reaching to a value of 70%. 

Figure 2. (a) Variation in sheet resistance and (b) the visible spectral 

transmittance of ITO coatings as a function of number of coating 

operations. 

In summary, ITO films were prepared by sol-gel using lowcost 

non-alkoxide precursors. A comparison of resistivity and 

transparency has been performed for the films obtained by 

multiple spin coating operations. The properties of the films 

are promising and potentially applicable for coating of large 

area substrates. 

This work is supported by METU-BAP-03-08-2010-04. 

*corresponding author: cdurucan@metu.edu.tr 

[1] R. B. Hadj Tahar et al., J. Appl. Phys. 82, 15 (1997). 

[2] Y. Djaoued et al., Thin Solid Films 293, 108 (1997). 

[3] S. R. Ramanan et al., Thin Solid Films 389, 207 (2001). 

[4] H. Uchihashi et al., J. Ceram. Soc. Jpn. 97, 396 (1989). 

(b) 




Graphene and Single Walled Carbon Nanotubes As High Performance Thin Film Semiconductors 

Coskun Kocabas 1 * 

1 Department of Physics, Bilkent University, Ankara 06800, Turkey 

Abstract-Recent advances of the growth and assembly of low dimensional carbon provides promises for thin film electronic applications. 

Chemical vapor deposition of single walled carbon nanotube (SWNT) arrays on quartz substrates provides a scalable approach for carbon 

nanotube based electronics. Similar growth process of graphene on metallic substrates could also provide possibilities to fabricate large area thin 

film transistors. This presentation will provide a brief summary of the chemical vapor deposition of SWNT arrays and graphene on single crystal 

quartz and metallic substrates. Furthermore, we will provide some of the recent results on the experimental and theoretical study of high 

frequency performance of these devices. 

This material is based upon work supported by the TUBITAK under the Grant No. 109T259 and FP7 under the Grant No. 

0T256458 (GrapheneRF) 

. 


+ 

P 

= 



1 

Coated Multi-Walled Carbon Nanotubes with Ceria Nanoparticles 

1 

Evgeniya Koval’s’kaP 

PO.O. Chuiko Institute of Surface Chemistry, Nat. Acad. f Sci. of Ukraine; 17, Gen. Naumov Str., Kyiv 03164, Ukraine 

Abstract-The composites have been received by sedimentation of oxides on surface multi-wall carbon nanotubes (MWNTs). The 

nanocomposites of were identified by transmission electronic microscope. The crystalline structure was verified by electron diffraction pattern 

and X-ray spectroscopy. Also XPS spectra were performed on the MWNT samples. 

The combination of carbon nanotubes (CNTs) with other 

nanocrystals is expected to be useful for applications in 

catalysts, sensors, nanoelectronic devices, polymer or ceramic 

reinforcement. In the paper [1], the authors highlight 

opportunities for decorating CNTs with a broad range of 

functional metal oxides including CeR2ROR3R and/or CeOR2R, AlR2ROR3R, 

LaR2ROR3R, in SC COR2R modified with ethanol. For example, the 

nanocomposites of CNTs and cerium are very interesting for 

further studies on their physical and chemical properties. 

In this paper, the composites have been received by 

sedimentation of oxides on surface multi-wall carbon 

nanotubes (MWNTs) from solutions by a reaction: 

4Ce(NOR3R) R3R 12NaOH + OR2R 4CeOR2R + 12NaNOR3 R+ 6HR2RO 

. 

A certificated catalytic MWNTs (Nanothinx S. A.) having 

12–31 nm diameters, 15–35 walls and 97 % purity (about 2 % 

is iron catalyst and less 1 % is pyrolytic carbon) was used. The 

nanocomposites of CeRxRORyR/MWNTs were identified by 

transmission electronic microscope (TEM), and their 

crystalline structure was verified by the selected area electron 

diffraction (SAED) pattern and X-ray spectroscopy. 

Figure 1 shows the MWNTs. TEM images of modified 

MWNTs show the ceria nanoparticles on the MWNTs surface. 

The size of the particles is 6-10 nm. SAED indicates the rings 

pattern of nanoparticles can be indexed using the facecentered 

cubic polycrystalline structure of cerium oxides. 

MWNT bundles were functionalized with hydroxyl and 

carbonyl. The deposition of ceria particles on the MWNT 

bundles depended on the surface state of the MWNT bundles. 

We believe that the methodology described here expands the 


Intensity (a. u.) 

20000 

15000 

10000 

5000 

Ce3d 

O1s 

1000 800 600 400 200 0 

Binding energy (eV) 

C1s 

MWNTs 

a 

Ce x O y (5.2%)/MWNTs 

Ce x O y (31%)/MWNTs 


8000 

6000 

4000 

2000 

C-O 

C-C 

C=O 

O-C=O 

0 

280 284 288 292 296 300 


12000 C-C 

c 

8000 

C-C 

d 

9000 

6000 

6000 

4000 

3000 C-O C=O 

O-C=O 2000 

C-O 

0 

280 284 288 292 296 300 

0 

280 284 288 292 296 300 




C=O O-C=O 

s (c). 

(d). 

Figure 2. Total XPS spectra of the purified MWNTs, 

CeRxRORyR(5.2%)/MWNTs and CeRxRORyR(31%)/MWNTs (a). XPS 

spectrum of carbon (C1s) in the purified MWNTs (b). XPS 

spectrum of carbon (C1s) in the CeRxRORyR(5.2%)/MWNTs (c). 

XPS spectrum of carbon (C1s) in the CeRxRORyR(31%)/MWNTs 

b 

functionality chemistry of CNTs and opens up a new avenue 

for coating one-dimensional nanostructures with various metal 

oxides and construction of designed nanoarchitectures. 

Figure 1. TEM images of MWNTs (a), modified MWNTs by 

ceria (5.2 %, b) and modified MWNTs by ceria (31 %, c). 

To further investigate the surface state of the MWNTs and 

the mechanism of ceria coating on the MWNTs, XPS spectra 

were performed on the MWNT samples. Figure 2 shows the 

XPS spectra of the purified MWNTs and the ceria-coated 

CeRxRORyR(5.2%)/MWNTs and CeRxRORyR(31%)/MWNTs, respecttively. 

The atomic ratio of Ce/O/C in the sample 

CeRxRORyR(5.2%)/MWNTs calculated from the XPS spectrum is 

about 1.1 : 1 : 18 and in the sample CeRxRORyR(31%)/MWNTs is 

about 1.1 : 1 : 3.6 which indicates that there are still large 

amount of functional groups on the surface of the MWNTs 

after the deposit process. 

Ceria nanoparticles with diameter of about 6–10 nm were 

successfully deposited on the MWNT bundles by a chemical 

reaction of Ce(NOR3R)R3R with NaOH solution. The synthesis was 

done in the aqueous solution at room temperature that reduces 

cost of the preparation procedure of nanosized ceria. The 

*Corresponding author: evgeniya1209@ukr.net 

[1] Z. Sun, X. Zhang, B. Han, Y. Wu, G. An, Z. Liu, S. Miao, Z. 

Miao, Carbon 45, 2589 (2007). 




Cerium-doped yttrium iron ga rnet thin films with nano s ize regions prepared by s ol-gel process 

Yavuz Öztürk* 1 , Mustafa Erol 2 ,Erdal Celik 2 1 

1 Ege University Electrical and E lectronics Department, 35100 Bornova, Izmir-TURKEY. 

2 Dokuz Eylul -TURKEY. 

Abstract- Cerium doped yttrium iron garnet (Ce x Y 3-x Fe 5 O 12 ; Ce-YIG) magneto-optical thin films were fabricated on Si (100) substrates by 

using sol-gel method for magneto-optical applications. Ce doped YIG films with nano size regions fabricated with dip coating from solutions 

prepared from Ce, Y and Fe-based precursors, solvent and chelating agent at low temperature using a sol-gel technique. Coated thin films 

annealed at the temperature range of 800 and 1000 o C for 2 h in air. Morphological, structural and magnetic properties were investigated by 

scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). 

New technological applications such as magnetic sensor, 

optical wave-guides, magneto-optical modulator and 

integrated magneto-optic devices are required improved 

sensitivity, smaller size and compatibility with electronic 

systems. Ce substituted yttrium iron garnet (Ce x Y 3-x Fe 5 O 12 ; 

Ce-YIG) have appeal for these kind of applications due to 

their magnetic and magneto-optic properties [1,2]. Sol-gel 

processing offers considerable advantages such as better 

mixing of the starting materials and excellent chemical 

homogeneity in the final product [3]. The available Ce-YIG 

material research has mainly on a single crystals and thin 

films [4,5]. Polycrystalline Ce-YIG, produced by using solgel 

method, has rarely been investigated. In this study, we 

have presented garnet films synthesized by using sol-gel 

method. 

Ce, Y and Fe based precursor materials dissolved in 

methanol and glacial acetic acid (GAA) were used as a 

solvent for the synthesis of materials. Si(100) were used as 

substrates. Different solutions prepared with different GAA 

ratios and constant molarities. The pH values of 3.5 ml 

Ce:YIG gel solutions with 1.5 ml, 1ml, and 0.5 GAA were 

3.6, 3.05 and 2.5, respectively. Higher GAA concentration 

leads to poor wetting and lower one leads to unsolved 

precursors. So we used solution with 1 ml GAA. Ce-YIG gel 

films were dip-coated on the substrates at room temperature. 

This process was followed by heat treatment by annealing 

films between 800-1000 °C for 2 hours in air. 

(a) 

c) d) 

Figure 2. SEM and AFM result of Ce:YIG prepared at 1000 °C 

The magnetization curve of Ce-YIG phase observed with 

VSM at room temperature. As can be seen from Fig. 3 

measured saturation magnetization value of Ce-YIG is lower 

than bulk YIG (136 emu/cc) [5]. 

Magnetization (emu/cc) 

60 

40 

20 

0 

-20 

CEYIG1000EH 

(b) 

-40 

Intensity (a.u) 

CEYIG1000EH 

 

 

 

 

CEYIG900EH 

 

 

CEYIG800EH 

 

 

 

 

 

20 30 40 

2 

50 60 

 

 

: Y 3 

Fe 5 

O 12 

(Kübik) 

: Unknown 

Figure 1. XRD patterns of Ce-YIG films coated on Si(100) 

annealed at 800 °C, 900 and 1000 °C for 2 h. 

Figure 1 shows XRD patterns of selected samples. All 

produced samples contains cubic YIG phase. However, there 

is unknown phase which is reducing at higher annealing 

temperatures. It is interesting to note that other intermediate 

phases FeYO3 or/and Fe2O3 were not observed. Fig.2 shows 

the SEM and AFM results of Ce:YIG annealed at 1000°C. 

Darker regions have less Si content compared to the lighter 

regions according to the EDS results. So there is interaction 

between substrate and garnet phase which leads to nucleation. 

Roughness of darker regions measured with AFM and as can 

be seen from Figure 3 nearly smooth surface obtained. 

-60 

-1500 -1000 -500 0 500 1000 1500 

Applied Field (Oe) 

Figure 3. VSM result of Ce:YIG prepared at 1000 °C 

As conclusion, cerium-doped Y3Fe5O12 garnet films were 

prepared on Si(100) by sol-gel method using alkoxides of 

respective elements. Ce:YIG thin films were obtained with 

cubic YIG phase and good the surface quality. By 

considering measured hysteresis loop, desired magnetization 

values were obtained. We believe that sol-gel technique with 

alkoxide route is the promising method to prepare thin garnet 

films. 

This work has been supported by The Scientific and 

Technological Research Council of Turkey (TUBITAK). 

*Corresponding author: yavuz.ozturk@ege.edu.tr 

[1] T. Shintaku, T. Uno, Jpn. J. Appl. Phys. 35 (1996) 4689–4691 

[2] A. Tate, T. Uno, S. Mino, A. Shibukawa, T. Shintaku, Jpn. J. 

Appl. Phys. 35 (1996) 3419–3425 

[3] L.L Hench, J.K. West, Principles of Electronic Ceramics. John 

Wiley & Sons, New York (1990) 

[4] N. Inoue, K. Yamasawa: Elect. Eng. In Jpn. 117 (1996) 1 

[5] X. Zhou, W. Cheng, F. Lin, X. Ma, W. Shi, Applied Surface 

Science 253 (2006) 2108–2112 

[6] B. Lax, K.J. Buton, Microwave Ferrites and Ferrimagnetics, 

McGraw-Hill, NY, (1962) 




Hollow Cathode Type Glow Discharge for Starch Modification 

Ritchie Eanes* and Sümeyra Bayır 

Department of Chemistry, Izmir Institute of Technology, Izmir 35430, Turkey 

Abstract— A home-built hollow cathode type dc glow discharge instrument modified with a special glass holder is 

used to effect possible surface and bulk modification of starch films. Specifically built for the study of the cross-linking of 

starch by plasma treatment, this device makes use of a hollow cathode arrangement towards enhanced plasma interactions. 

There is much interest in biodegradable polymers and in 

this regard much work has focused on the cross-linking of 

starch [see 1 and the references therein]. Although probably 

more often considered as a part of food science, starch, in its 

crosslinked or modified form, has found uses in non-food 

applications including those in the biomedical, 

pharmaceutical, and wastewater fields as mentioned by Ayoub 

and Rizvi in their review [2]. There are several methods 

available for the modification of starch; however, some of 

these methods require the use of rather exotic or potentially 

harmful crosslinking reagents [see 3 and references therein]. 

Zou et al. have described their modification of starch 

using a glow discharge plasma [3]. In their design, a starch 

slurry sample was placed in the positive column of their glow 

discharge device, between the anode and cathode. They 

concluded that a highly crosslinked starch could be obtained 

by using the glow discharge plasma in place of a more 

traditional chemical crosslinking reagent [3]. More recently, 

Bastos et al. have described the production of hydrophobic 

starch films by plasma treatment where the sample was placed 

directly on the cathode of a radio-frequency (rf) glow 

discharge apparatus [4]. 

The glow discharge is a useful medium for sputterdeposition 

[5] as well as analytical spectroscopies [6]. Under 

vacuum, gas is introduced into the region between an anode 

and cathode. This gas can be of the relatively "non-reactive" 

or "reactive" variety. Quite often argon, helium, or a 

combination of these two gases is used, especially for 

analytical glow discharge applications. More traditionally, 

both the anode and cathode are flat. However, especially for 

analytical glow discharge spectroscopy, the hollow-cathode 

design has gained interest due to the increased electron density 

of this electrode geometry. Also present in the plasma are 

ions of the discharge gas as well as the cathode. However, 

depending on the cathode material, the degree of sputtering of 

the cathode can be kept to a minimum [6]. 

In our dc glow discharge configuration, the cathode is large 

enough to contain a small sample that is immersed in the 

plasma by means of a glass L-shaped holder. By using 

holders of varying lengths, the sample can be placed at 

different positions within the glow discharge. Likewise, the 

cathode is attached to a probe that also allows adjustment in 

the position of the hollow cathode. This movable probe 

design is a modified form of the pin-type analytical glow 

discharge direct insertion probe of Duckworth and Marcus [7]. 

Other adjustable parameters include discharge voltage, 

discharge gas type, and pressure. By modifying these 

parameters, the shape and contents of the plasma can be varied 

as well as their degree of interaction with the sample. 

This work was partially supported by IYTE BAP project 

2003 IYTE 02. N.R.E. is gratefully acknowledged for 

financial support. We thank Polat Bulanık for his glass 

blowing expertise and Prof. Dr. Tamerkan Özgen for the high 

voltage power supply and vacuum pump. 

Figure 1. Simple schematic of the hollow cathode glow discharge arrangement 

with the glass L-shaped sample holder immersed in the plasma. 

Figure 2. View through the UV transparent window of the inside of the hollow 

cathode glow discharge in operation without the glass sample holder in place. 

*Corresponding author: ritchieeanes@iyte.edu.tr 

[1] N. Reddy and Y. Yang. Food Chemistry. 118, 702-711 (2010). 

[2] A. S. Ayoub and S.S.H. Rizvi. J. Plastic Film & Sheeting. 25, 25-45 

(2009). 

[3] J.-J. Zou, C-J. Liu, and B. Eliasson. Carbohydrate Polymers. 55, 23-26 

(2004). 

[4] D.C. Bastos, A.E.F. Santos, M.L.V.J. da Silva, and R.A. Simão. 

Ultramicroscopy. 109, 1089-1093 (2009). 

[5] B. Chapman. Glow Discharge Processes. John Wiley & Sons, New York: 

1980. 

[6] R. K. Marcus and J.A.C. Broekaert, Eds. Glow Discharge Plasmas in 

Analytical Spectroscopy. John Wiley & Sons, Chichester: 2003. 

[7] R. K. Marcus, Ed. Glow Discharge Spectroscopies. Plenum Press, New 

York: 1993, p. 309. 


P 

P Mustafa 



Deposition and Characterization of ZnS Thin Films by Thermionic Vacuum Arc (TVA) Technique 

1 

1 

1 

1 

1 

UMehmet OzkanUP P* Naci EkemP Zafer BalbagP P, Suat PatP P, Sadan KorkmazP 

1 

PDepartment of Physics, Eskisehir Osmangazi University,Eskisehir 26480, Turkey 

Abstract-ZnS thin films have been deposited on a glass slide as substrate by thermionic vacuum arc technique from 3-6mm pieces of ZnS slugs. 

The deposited ZnS thin films were characterized for determining of the structural, morphological, and optical properties. Thickness and 

transparency of ZnS thin films were measured using optical method. Refractive index and band gap energies were calculated by Swanepoel 

method. AFM, SEM images and EDS analyses were realized to determine for surface morphology of produced ZnS thin films. According to 

obtained data deposited of ZnS thin film are in high purity and nano scaled. Band gap of the deposited ZnS thin films is approximately 3.7 eV 

ZnS is an important II–VI compound semiconductors with a 

large band gap of 3.67 eV in bulk material. It is used as a key 

material for light-emitting diodes, cathode-ray tubes, thin film 

electroluminescence, and window layers in photovoltaic cells. 

Semiconductor nanocrystals have received much attention in 

recent years because of their potential for use in fabrication of 

optoelectronic devices [1,2]. Preparations of thin films of 

these compounds are most often uses vacuum evaporation, 

chemical vapor deposition, sputtering, spray pyrolysis method 

and molecular beam epitaxy. Additionally, chemical bath 

deposition and photochemical are using the deposits ZnS thin 

film. [3, 4]. However, TVA was used firstly in ZnS thin film 

deposition. 

Thermionic vacuum arc (TVA) is a new technology for thin 

film deposition [5-8]. This technology has been supplied great 

advantages to deposited thin films like compact, low 

roughness, nanostructures, homogeneities, adhesive, high 

deposition rate etc [6]. A lot of materials were used for thin 

films production and characterization in this technique. TVA 

technique is gives ability to deposited pure thin films and 

alloys thin films. One of the biggest applications of TVA is 

thin films of high melting point materials like C, W, Mo, Nb, 

Ta, Re, B etc. Also, TVA cans ability to growth 

semiconductor thin films for photo voltaic applications and 

optoelectronic materials devices. Additionally, pure 

compounds thin films (two and more atoms) are enable for 

this technology like AlOR3R, ZnO, ZnTe, ZnS, SiOR2R, ZrOR2R etc 

from our research group [7]. 

Figure 1. Drawing of the TVA vacuum chamber and electrodes 

arrangements 

Thermionic vacuum arc materials plasma can be ignited in 

high or ultra high vacuum conditions between a heated 

cathode (special design for produced focused electron beam) 

and anode materials. Anode materials are consisting of the 

crucible and deposited materials. Due to the electron 

bombardment of the anode by the accelerated (with high 

voltage) and focused thermo-electrodes from the electron gun, 

the anode materials first melts and afterwards starts to 

evaporates in the inter electrodic space in vacuum chamber. 

Table 1. EDS analysis results for deposited ZnS thin films 

Elt. Line Intensity 

(c/s) 

Error 

2-sig 

Conc 

Units 

O Ka 21.33 2.920 2.769 wt.% 

Si Ka 533.14 14.602 15.837 wt.% 

S Ka 1,282.63 22.648 34.931 wt.% 

Zn Ka 487.83 13.967 46.463 wt.% 

100.000 wt.% Total 

Optical properties of deposited ZnS thin films are good 

harmony in literatures. A transmittance spectrum of deposited 

ZnS thin film is proper for Swanepoel method. Calculated 

refractive index value is 2.2. Band gap energy of it is 

approximately 3.7 eV. These results are also good harmony in 

literature and supported our results. Other measurement and 

analyses techniques show that surface of the deposited thin 

films are smooth, low roughness, compact. Additionally 

impurities of the structures were very small (4%). This 

impurities data were collect from glass slides. Because of 

deposited layer was 300 nm. 

*Corresponding author: mozkan@ogu.edu.tr 

[1] P. Roy, J. R. Ota, S. K. Srivastava, Thin Solid Films, 515 (2006) 

1912-1917 

[2] H. J. Lee, S. I. Lee, Current Applied Physics 7 (2007) 193-197 

[3] M. Innocenti, G. Pezzatini, F. Forni, M.L. Foresti, J. Electrochem. 

Soc. 148 (2001) C357. 

[4] J. H. Fendler, Nanoparticles and Nanostructured Films, Wiley- 

VCH, Weinheim. 1998 

[5] N. Ekem, G. Musa, S.Pat, Z.Balbag, I. Cenik , R. Vladoiu, J. Opt. 

and Adv. Mater, Vol. 10, No. 3, March 2008, p. 672 – 674 

[6] C.Surdu-Bob, I.Mustata, C.Iacob, Journal of Optoelectronics and 

Advanced Materials, Vol9 No9,2007,2932-2934 

[7] G.Musa, I.Mustata, V.Ciupina, R.Vladoiu, G.Prodan, E.Vasile, 

H.Ehrich , Diamond and Related Materials 13 (2004) 1398–1401 

[8] HBalbag MZH, HPat SH, HCenik MIH. , HAkan TH, HEkem NH, HMusa GH, 

Journal of Optoelectronics and Advanced Materials, Vol. 9 No: 

4, 2007,p. Pages: 858-861 




Production of Ceramic Nanofibers with Negative Coefficient of Thermal Expansion 

Nasser Khazeni* ,1 , Irem Vural 1 , Bora Mavis 2 , Güngör Gündüz 1 and Üner Çolak 3 

1 Department of Chemical Engineering, Middle East Technical University, Ankara 06531, Turkey 

2 Department of Mechanical Engineering, Hacettepe University, Ankara 06800, Turkey 

3 Department of Nuclear Engineering, Hacettepe University, Ankara 06800, Turkey 

Abstract—Zirconium tungstate (ZrW 2 O 8 ) is a ceramic that shows negative coefficient of thermal expansion (NCTE) over a 

wide range of temperature from 0.3 to 1443K. In this study, by adopting new low temperature synthesis and micro-emulsion 

synthesis approaches, phase pure nano particles of ZrW 2 O 8 were prepared. After a series of size distribution homogenization 

and filtering processes, recovered nanoparticles were used in an electrospinning process for production of nanofibers with 

diameters around 300nm. 

Thermal mismatch between different components of a 

system can often be sources of problems like residual stress 

induced cracking, thermal fatigue or even optical 

misalignment in certain high technology applications. Use of 

materials with tailored thermal expansion coefficient is a 

counter-measure to overcome such problems. With its 

negative thermal expansion coefficient (NCTE), ZrW 2 O 8 is a 

candidate component to be used in synthesis of composites 

with controlled coefficient of thermal expansion (CTE). 

Tuning of the thermal expansion property is expected to 

compensate such thermal mismatch problems. 

Production of composites could be achieved by blending 

negatively and positively expanding materials in different 

forms. While blending the respective components in particle 

form is the first obvious choice, different process or 

application constraints can dictate the production of 

components in core-shell structures or in the form of fibers. 

The aims of this study are; i) synthesis of zirconium tungstate 

nanoparticles by a new low temperature approach using 

shorter aging times and, ii) applying an electrospinning 

process to produce ZrW 2 O 8 nanofibers. 

Cubic ZrW 2 O 8 can be synthesized by a variety of 

methods. Solid state methods have been traditionally used to 

produce ZrW 2 O 8 [1]. Other strategies involve sol-gel, non 

hydrolytic sol-gel [2], hydrothermal [2], co-precipitation [3], 

combustion synthesis [2] and low temperature synthesis [4]. In 

sol-gel technique, long aging times (1-3 weeks) are used to 

produce ZrW 2 O 8 . To shorten aging times, hydrothermal 

ageing can be applied. Although different compounds have 

been used as tungsten sources in the reported sol-gel and 

hydrothermal methods, the low cost tungstic acid (TA) that 

can readily be produced in Turkey has never been considered 

as a possible source. A modified low temperature method by 

using TA and ZrOCl 2 as starting materials was chosen to 

synthesize the ZrW 2 O 8 precursor. The production technique is 

given in Figure 1. By using this procedure, ZrW 2 O 8 is 

produced in shorter aging times and without the use of a 

hydrothermal ageing condition over 100 o C. 

After obtaining ZrW 2 O 8 precursor, the product was 

calcined at 600 o C for 10 hours. Obtained particles had sizes in 

the range of 300nm-1μm. It was determined that, for the 

preservation of integrity of nanofibers, particle sizes should be 

smaller than 100nm. In order to decrease the particle sizes 

further, a microemulsion (ME) technique was developed 

taking the baseline recipe from the procedure given in figure1. 

For ME, oleylamine (OAm) and hexane system was used. 

XRD patterns of produced particles can be seen in figure 2. 

Figure 1. Experimental flowchart 

Figure 2. XRD pattern of produced ZrW 2 O 8 . 

In order to produce nanofibers, produced particles were 

dispersed in isopropyl alcohol (IPA) and, simple decantation 

and filtering processes were applied to obtain 10-100 nm 

diameter particles. Then spin dope containing PVP, IPA and 

nanoparticles were prepared. The dope was spun by a syringe 

pump at a rate of 2ml/hr. Typically applied voltage was 10kV 

to the tip-target distance of 10cm. The spun mat was burnt for 

8hr at 325 o C and then for 10hr at 600 o C. Produced fibers have 

diameters around 300nm. SEM image of burnt fibers has been 

depicted in figure 3. This work is supported by 

TÜBTAK under Grant No. MAG–107M006. 

Figure 3. SEM images of fibers. 

*Corresponding author: khazeni.n@gmail.com 

[1] Graham, J., Wadsley, A. D., Weymouth, J. H. and Williams, L. S. 

Journal of American Ceramic Society 42, 570 (1959). 

[2] Kameswari, U., Sleight, A. W. and Evans, J. S. O. International 

Journal of Inorganic Materials 2, 333-337 (2000). 

[3] Sun, X. J., Yang, J., Liu, Q. and Cheng, X. N. Wuji Huaxue 

Xuebao 21, 1412-1416 (2005). 

[4] Closmann, C., Sleight, A. W. and Haygarth, J. C. Journal of Solid 

State Chemistry 139, 424 (1998). 




The Fabrication of YBa 2 Cu 3 O 7- Superconducting Thin Film on SrTiO 3 Buffered Si Substrate by PED 

Z. Mutlu 1 *, M. Yilmaz 1 , Y. G. Mutlu 1 , O. Dogan 1 

1 Department of Physics, Selcuk University, A. K. Education Faculty, Konya 42090 Turkey 

Abstract- A superconducting YBa 2 Cu 3 O 7- (YBCO) thin film has been produced by pulsed electron deposition (PED) which is an essential and 

low-cost physical deposition technique of high quality superconducting films. The crystalline structure, surface morphology and microstructure 

of thin films have been characterized with x-ray diffractometer (XRD), atomic force microscope (AFM) and scanning electron microscope 

(SEM). 

The method of pulsed electron deposition (PED) has 

recently become an alternative to PLD as a means for 

producing thin films. PED shares some of the same 

advantages that characterize PLD for vacuum deposition. 

Among these are modest requirements for vacuum, easy 

control of film thickness, easy set-up, multicomponent film 

stoichiometry nearly identical to target material, and a 

relatively high deposition rate with low consumption of target 

materials. In addition, PED works for UV-transparent 

materials where PLD might fail [1]. Moreover, PED has a 

significant cost advantage over PLD because of the much 

lower cost of the electron source compared to the cost of the 

excimer laser typically used in PLD. 

The aim of this study is to determine some properties of 

YBCO thin film and STO buffer layer deposited by PED 

process. We have reported a detailed study of the 

superconducting layer of YBCO on STO buffered Si substrate 

and the buffer layer of STO on Si substrate. 

Using PED, several research groups have successfully 

grown YBCO thin films on STO [4], LaAlO 3 [2] and Ni-W [3] 

substrates. However, a study of the deposition of YBCO 

on STO buffered Si substrate by PED has not yet been 

realised. Our research has thus been focused on the possibility 

of fabricating the YBCO thin film on STO buffered Si 

substrate by PED. 

PED electron beam source from Neocera Inc. (PEBS–20 

Model) was used to fabricate YBCO superconducting lms on 

STO buffered substrates. Deposition conditions are the 

following: the base pressure of 5x10 –6 Torr, 13 kV 

accelerating voltage, 5000 total shots and 5 Hz electron 

repetition rate. The distance between target and substrate was 

10 cm. STO thin film was first deposited on Si at substrate 

temparature of 890 o C in O 2 pressure of 16 mTorr. Then 

YBCO thin film was deposited on the top of STO thin film at 

substrate temparature of 890 o C in O 2 pressure of 15 mTorr. 

After deposition, deposited films were cooled to room 

temparature in ambient of high oxygen pressure. 

The surface structure and surface morphology of the film 

was investigated by AFM. Fig.1 shows typical 3-dimensional 

AFM image of the YBCO film on STO buffered Si substrate. 

The values of root-mean-square (Rms) and average (Ra) 

surface roughness have been measured ~ 27 nm and ~ 22 nm, 

respectively. The droplets were observed on the film surface. 

The droplets sizes were measured directly from AFM scans of 

the film. The average size of the droplets is about 0,098 μm in 

diameters. 

Figure 1. Typical 3-dimensional atomic force microscope image of 

the surface of an YBCO film at deposited 890 o C (scan area: 1.0x1.0 

μm 2 ). 

We observed the film surface is dense and free of cracks. 

Surface particulates across the entire film were observed. The 

size of these particulates is typically 1–3 μm in diameters. The 

particulates might be secondary phases which are observed in 

XRD. The presence of particulates on the surface of film 

grown by PED is well known [3, 5]. 

The crystal structures of STO/Si and YBCO/STO/Si thin 

films were characterized by XRD. The XRD results indicated 

that YBCO was formed with complete c-axis orientation. 

There are also two peaks of (110) and (003) of STO and the 

peaks from Si of the substrate materials. The weak XRD peak 

intensities show poor crystallinity of the YBCO thin film. The 

crystallinity and superconductivity of YBCO film could be 

hampered by the intermediate layer formed at the YBCO/STO 

interface. 

In summary, from the -2 XRD analysis of YBCO films, 

(00l) diffraction peaks are obtained indicating they have a 

poor c-axis oriented structure. SEM analysis show that the 

films surfaces are crack-free but they have some particulates. 

On AFM images, the droplets are clearly observed leading to a 

rough surface. The measured experimental results are 

compared with the results of other studies. 

*Corresponding author: 0Hzmutlu@selcuk.edu.tr 

[1] Mathis J.E., Christen H.M., Physica C: Superconductivity, 

Vol:459, Iss:1-2 (2007), 47-51. 

[2] Zhai H.Y., Christen H.M., Feenstra R., List F.A., Goyal A., 

Leonard K.J., Xu Y., Christen D.K., Venkataraman K., Maroni A., 

Mat. Res. Soc. Symp. Proc. Vol. EXS–3 (2004), USA. 

[3] Gilioli E., Baldini M., Bindi M., Bissoli F., Calestani D., Patini 

F., Rampino S., Rocca M., Zannella S., Woerdenweber R., J. of 

Physics: Conference Series 97 (2008). 

[4] Jiang Q.D., Matacotta F.C., Konijnenberg M.C., Mueller G., and 

Schultheiss C., Thin Solid Films, 241:100 (1994). 

[5] Kovaleski S.D., Gilgenbach R.M., Ang L.K., Lau Y.Y., J. of 

Appl. Phys., Vol. 86, No. 12 (1999), 7129–7137. 



THE RANDIC INDEX OF DENDRIMER NANOSTARS 

A. Madanshekaf and M. Ghaneei 

Dept. of Mathematics, Faculty of Sciences, 

Semnan University, Semnan, Iran 


Abstract 

Among the numerous topological indices considered in chemical graph theory, only a few have been found noteworthy in practical 

application, Randic index is one of them. The dendrimer nanostars is a synthesized molecule built up from branched unit called monomers. In 

this article, we compute the Randic index of two types of polymer dendrimers and fullerene and G3 dendrimers. 1-3 

Keywords: Randic index, dendrimer nanostars. 

1. Introduction 

denotes the degree of the vertex i. Randic introduce the 

Randic index as 

, where i-j ranging 

over all pairs of adjacent vertices of G. This index has been 

successfully correlated with physico-chemical properties of 

organic molecules. Indeed if G is the molecular graph of a 

saturated hydrocarbon then there is a strong correlation 

to all properties of dendrimers nanostars, but general 

topological indices are considered in our present work. 

Figure 2. Fullerene dendrimer 

2. Results and discussion 

denote the number of edges of G connecting vertices of 

. 12-13 

The aim of this section is to compute the Randic 

index of these dendrimer nanostars. 

Theorem 1. The Randic index of polymer 

References 

Figure 3. G 3 dendrimer 

[1] Jevpraesesphant, R. et al., "The influence of surface 

modification on the cytotoxicity of PAMAM 

dendrimers", Int. J. Pharm., 252, 263266, 2003. 

[2] Rissing, C.; Son, D. Y. "The Thiol-ene Reaction for the 

Synthesis of Multifunctional Branched Organosilanes", 

Organometallics 2008, 27, 5394-5397. 

[3] "The application of the Diels-Alder reaction to polymer 

syntheses based on furan / maleimide reversible couplings". 

Polymeros vol. 15 no. 2 slo carlos April / June 2005. 

Theorem 2. The Randic index of 

dendrimer is computed as follows: 

fullerene 

6th Nanoscience and Nanotechnology Conference, İzmir, 2010 416-1

Photonic crystals in biology

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