Photonic crystals in biology

More documents

Recommendations

Info

Poster Session, Tuesday, June 15 Theme A1 - B702 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. 6th Nanoscience and Nanotechnology Conference, zmir, 2010 325
Poster Session, Tuesday, June 15 Theme A1 - B702 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) 6th Nanoscience and Nanotechnology Conference, zmir, 2010 326
Page 1 and 2:
Poster Presentations 1st Day 2nd Da
Page 3 and 4:
Poster Session, Tuesday, June 15 Th
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68: Poster Session, Tuesday, June 15 Sy
Page 69 and 70: Poster Session, Tuesday, June 15 Th
Page 73 and 74: P Poster Session, Tuesday, June 15
Page 79 and 80: P P P,P Poster Session, Tuesday, Ju
Page 103 and 104: P P P and Poster Session, Tuesday,
Page 117: Poster Session, Tuesday, June 15 Th
Page 125 and 126: Poster Session, Tuesday, June 15 Hy
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Poster Session, Tuesday, June 15 Pr
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
P Torr. pressure P pressure P and P
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
P P Mustafa Poster Session, Tuesday
Page 209 and 210:
show all

Photonic crystals in biology

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?