Photonic crystals in biology

More documents

Recommendations

Info

Poster Session, Tuesday, June 15 Theme A1 - B702 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. 6th Nanoscience and Nanotechnology Conference, zmir, 2010 290
Poster Session, Tuesday, June 15 Theme A1 - B702 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). 6th Nanoscience and Nanotechnology Conference, zmir, 2010 291
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: 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 83: Poster Session, Tuesday, June 15 Th
Page 103 and 104: P P P and Poster Session, Tuesday,
Page 125 and 126: Poster Session, Tuesday, June 15 Hy
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
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?