Synthesis of composite latex particles filled with silica

Encapsulation of silica nanoparticles was performed by dispersion polymeriz ation of styrene, butyl acrylate and butyl methacrylate in aqueous alcoholi c media. Following previous works(1-3)), the silica beads were first modifi ed by reacting on their surface the 3-trimethoxysilyl propyl methacrylate c oupling agent (MPS). In every case, the silica beads are all surrounded by polymer giving composite latex particles filled with silica. Each composite particle contains from one to a great number of silica beads. Changing the size or the concentration of the silica beads, and the experimental condit ions for the synthesis of the polymer particles enables to control this num ber. One can take benefit of this to synthesize model composite particles w ith controlled compositions.