SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP*

Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graftpolymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles throughcondensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated bythis surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silicananoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence ofATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases withpolymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation ofpolymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.