Facile Fabrication of Hybrid Hollow Microspheres via in Situ Pickering Miniemulsion Polymerization

Hybrid hollow microspheres have been fabricated successfully via miniemulsion polymerization using the in situ formed and modified nanosilica particles as Pickering emulsifier. The hydrolysis and condensation reactions of tetraethoxysilane (TEOS) take place to form nanosilica particles which are then partially modified by oil-soluble 3-(trimethoxysilyl)propyl methacrylate (MPS) at the oil/water interface under basic conditions. After the miniemulsification process, Pickering miniemulsions were stabilized by the in situ nanosilica particles. Hybrid hollow microspheres are obtained with silica nanoparticles closely packed on the surface of polymer microspheres. The results showed that both the weight ratios of TEOS/styrene and MPS/TEOS have great effects on the production of stable Pickering emulsion and then the morphologies of the obtained hybrid microspheres.