Acrylic polymer/silica hybrids were prepared by emulsifier-free emulsion polymerization and the sol-gel process. Acrylic polymer emulsions containing triethoxysilyl groups were synthesized by emulsifier-free batch emulsion polymerization. The acrylic polymer/silica hybrid films prepared from the acrylic polymer emulsions and tetraethoxysilane (TEOS) were transparent and solvent-resistant. Atomic force microscopy studies of the hybrid film surface suggested that the hybrid films did not contain large (e.g., micrometer-size) silica particles, which could be formed because of the organic-inorganic phase separation. The Si-O-Si bond formed by the cocondensation of TEOS and the triethoxysilyl groups on the acrylic polymer increased the miscibility between the acrylic polymer component and the silica component in the hybrid films, in which the nanometer-size silica domains (particles) were dispersed homogeneously in the acrylic polymer component. (c) 2005 Wiley Periodicals, Inc.