Preparation of cylinder-like polystyrene-silica composite particles

The cylinder-like shape is one of the most common shapes in geometry and polymer-silica composite particles have been one of the most commonly reported organic-inorganic composite particles, while cylinder-like polymer-silica composite particles are seldom reported in literature. In this work, we report a facile method to prepare cylinder-like polystyrene-silica (PS–SiO2) composite particles by judicious combination of PVP-involved dispersion polymerization and magnetic stirring. First, spherical PS-SiO2 composite particles were synthesized by dispersion polymerization of styrene in an ethanol/water mixture. Second, cylinder-like PS-SiO2 composite particles were prepared by stirring the spherical PS-SiO2 particles in a water medium in the presence of PVP. The effects of PVP molecular weight, PVP concentration, stirring rate, stirring time and stirring temperature on the morphology of the composite particles were investigated. Optimization of the stirring conditions allowed relatively high percentage (up to ~73%) of cylindrical particles to be achieved. This method is expected to expand the morphology library of polymer-silica composite particles.