Synthesis of silica–polystyrene core–shell nanoparticles via surface thiol-lactam initiated radical polymerization

This paper reports the synthesis of structurally well-defined silica–polystyrene (SiO2@PS) hybrid nanoparticles using a thiol-lactam-initiated, radical-polymerization technique. The surface of silica particles, 80 nm in size, were functionalized with (3-mercaptopropyl) trimethoxysilane and used as seeds in the polymerization of styrene in the presence of butyrolactam. 1H nuclear magnetic resonance and X-ray photoelectron spectroscopy showed that the thiol groups on the SiO2 surface could initiate polymerization with the aid of butyrolactam. Transmission electron microscopy showed that the hybrid particles had uniform core–shell morphologies. The molecular weight of grafted PS increased with increasing polymerization time.