Preparation of polystyrene/SiO_2 microsphere via Pickering emulsion polymerization: Synergistic effect of SiO_2 concentrations and initiator sorts

摘要

In this paper, polystyrene (PS)/SiO_2 microspheres were successfully prepared via Pickering emulsion polymerization stabilized solely by ethacryloxypropyltrimethoxysilane (MPTMS) modified SiO_2 nanopar-ticles. The formation mechanisms of PS/SiO_2 microspheres with different morphology were investigated under various Pickering emulsion polymerization conditions. The results showed that SiO_2 concentrations and initiator sorts would synergistically impact on the morphology of products corresponding to distinct formation mechanisms. When SiO_2 concentrations was low and water-solute initiator potassium persulfate (KPS) was used, aqueous nucleation was dominant, which was deduced to the formation of dispersive microspheres sparsely anchored by SiO_2 particles. When SiO_2 concentrations was increased and oil-solute initiator azobisisobutyronitrile (AIBN) was applied, nucleation in oil phase prevailed which lead to the formation of microspheres densely packed by SiO_2 particles.