Abstract: SiO₂ nanoparticles were obtained by means of Stober method, and the surfaces of the particles were modified. The monodisperse nanocomposite SiO₂/PSt particles were prepared by emulsion polymerization, and the size of the composite particles can be controlled successfully. The morphology, size and structure of the particles were characterized by TEM and particle size analysis. The effects of the quantities of SiO₂ nanoparticles, emulsifier and the proportion of medium etc on the composite nano particles have been discussed.

Key words: SiO₂/PSt, nanocomposite particle, monodisperse, preparation 