An emulsion swelling route to surface-wrinkled polystyrene-silica colloidal nanocomposite particles

Abstract

There is increasing interest in the fabrication of surface-wrinkled colloidal particles. This paper reports a facile emulsion swelling route to prepare surface-wrinkled polymer-silica core-shell nanocomposite particles. Submicrometer-sized polystyrene-silica (PS–SiO 2 ) nanocomposite particles were first prepared by emulsion polymerization of styrene using glycerol-functionalized ultrafine aqueous silica sols, and then surface-wrinkled PS−SiO 2 particles were obtained by swelling the PS−SiO 2 particles with a toluene/water emulsion and subsequent drying. The key to success is simply the use of the PS-SiO 2 core-shell nanocomposite particles prepared by emulsion polymerization, in which the SiO 2 shell was composed of individual and discrete ultrafine SiO 2 sols. The influence of various swelling parameters including toluene/particle ratio, surfactant concentration, swelling temperature and swelling time on the formation of the wrinkled nanocomposite particles was studied. Furthermore, hollow wrinkled silica thin shells composed of silica nanoparticles could be obtained by calcination of the wrinkled nanocomposite particles. This method represents a new paradigm in the preparation of surface-wrinkled polymer colloids. This paper reports a facile route to prepare surface-wrinkled polymer-silica nanocomposite particles with a thin silica shell through the judicious combination of emulsion polymerization and emulsion swelling. • A facile emulsion swelling route to prepare surface-wrinkled polymer-silica core-shell nanocomposite particles is reported. • The protocol involves judicious combination of emulsion polymerization and emulsion swelling. • Hollow wrinkled silica thin shells composed of silica nanoparticles could be obtained by calcination. • This method represents a new paradigm in the preparation of surface-wrinkled polymer colloids.