SYNTHESIS OF FUNCTIONALIZED NANOPARTICLES VIA COPOLYMERIZATION IN MICROEMULSIONS AND SURFACE-REACTIONS

Oil-in-water microemulsions of mixtures of styrene and comonomer are e asily prepared using titration methods in the presence of nonionic (NP n) or anionic (SDS) surfactants. Functionalized nanoparticles in the 2 0-30-nm diameter range bearing chloromethyl, active-ester, acid or pyr idyl surface end-groups are prepared by polymerization of microemulsio ns containing mixture of styrene (St) and, respectively, vinylbenzylch loride (VBC), N-acryloyloxysuccinimide (NHA), methacrylic acid (MA) or vinylpyridine (VP). Reactions of nucleophiles on particles bearing ei ther chloromethyl or active-eater surface end-groups, performed direct ly in the aqueous suspensions, give rise to a wide range of nanopartic les with various functionalities. The main role of the surfactant on s uch surface reactions is demonstrated and used to improve the reaction yields.