Photonic crystals in biology

More documents

Recommendations

Info

Poster Session, Tuesday, June 15 Theme A1 - B702 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 3 Dropwise 4 - 40 4 Dropwise 4 + 40 5 Dropwise 2 + 40 6 Dropwise 4 - 70 7 Dropwise 2 - 70 8 Dropwise 4 + 70 9 Dropwise 2 + 70 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 6th Nanoscience and Nanotechnology Conference, zmir, 2010 323
Poster Session, Tuesday, June 15 Theme A1 - B702 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. 6th Nanoscience and Nanotechnology Conference, zmir, 2010 324
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: Poster Session, Tuesday, June 15 Th
Page 67 and 68: Poster Session, Tuesday, June 15 Sy
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 115: Poster Session, Tuesday, June 15 Th
Page 125 and 126: Poster Session, Tuesday, June 15 Hy
Page 167 and 168:
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

Create successful ePaper yourself

Delete template?

Save as template?