Synthesis and characterization of positively charged, alumina-coated silica/polystyrene hybrid nanoparticles via pickering miniemulsion polymerization

摘要

Positively charged, raspberry-like hybrid nanoparticles, consisting of a polystyrene core and an alumina-coated silica shell were successfully prepared in a surfactant free system via the radical copolymerization of styrene (St) and different comonomers (acrylic acid, methacrylic acid, and acrylamide) by using a cationic silica sol as the sole emulsifier in Pickering miniemulsion polymerization. The influence of different parameters like pH of the dispersion, comonomer content, and the amount and size of silica nanoparticles on the colloidal stability of the systems, prepared with different comonomers, was examined. The particles' morphology was observed via high-resolution scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The removal of free silica particles via centrifugation was proved by TEM and SEM, and the content of free and adsorbed silica was quantified via thermogravimetric analysis (TGA). ? 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 Positively charged, silica-armored polymer nanoparticles were prepared by miniemulsion copolymerization of styrene and hydrophilic comonomers. Investigations of the reaction parameters on the colloidal characteristics give insight into the interactions between the silica particles and the polymer surface. Those positively charged hybrid particles are highly intriguing for cellular uptake experiments.