Hairy particles were prepared by immobilization of poly(ethylene glycol) (PEG) on the surface of poly(styrene-co-maleic anhydride) (poly(S-co-MA)) spheres. It was found that the carbonyl groups on the poly(S-co-MA) surface can be conveniently esterified with the hydroxyl groups of PEG. Chemical and morphological changes were analyzed by FT-IR, TEM, and water contact angle. Results revealed that, with the immobilization of PEG, the morphology of poly(S-co-MA) turned from a smooth surface to a hairy-like structure and the hydrophilicity of the polymer particles improved. In addition, berry-like polymer/silica particles can be obtained by using the hairy particles as template. The PEG hairy chains show steric repulsion during the deposition of silica nanoparticles by in situ sol-gel process. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013