Photonic crystals in biology - NanoTR-VI

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