Published online by Cambridge University Press: 01 February 2011
Polymer encapsulation of inorganic silica nanoparticles was performed through emulsion polymerization of styrene and methyl methacrylate monomers. Two different approaches are described. In a first one, the hydrophilic silica was modified by reacting the coupling agent, 3-trimethoxysilyl propyl methacrylate, which was involved further in propagation reactions. In a second approach, we used the 2–2'- azobis (2-amidinopropane) dihydrochloride cationic initiator to promote interactions of the positively charged growing polymer with the negatively charged silica surface. We demonstrate, using transmission electron microscopy, that the silica beads are successfully encapsulated by the two techniques giving silica/polymer nanoparticles with different morphologies. The influence of some parameters, such as the nature of the surfactant and the monomer concentration, on the efficiency of the encapsulation reaction and the morphology of the encapsulated products are reported.