Polystyrene (PSt) was grafted on the surface of silica gel particles in the manner of "grafting from'' in a solution polymerization system, and grafting particles PSt/SiO2 was obtained. The chloromethylation reaction of the grafted polystyrene was performed using a novel chloromethylation reagent, 1,4-bis(chloromethyoxy) butane which is un-carcinogenic, and grafting particles CMPS/SiO2 was gained. Subsequently, grafted CMPS was quaternized (denoted as QPS) using tertiary amine, and finally functional composite-type particles QPS/SiO2, on which quaternary ammonium groups were immobilized, were prepared. The catalysis activity of the particle QPS/SiO2 as a triphase catalyst in phase-transfer catalysis systems and its antibacterial activity as a water-insoluble antibacterial material were studied preliminarily. The experimental results show that the particle QPS/SiO2 exhibits higher catalysis activity as a triphase catalyst for the reaction between benzyl chloride in organic phase and sodium acetate in aqueous phase to form benzyl acetate, and under a mild condition of 60 degrees C for 7 h of reaction time a conversion of 66% for benzyl chloride can be obtained. The particle QPS/SiO2 has high antibacterial activity as a water-insoluble antibacterial material against Escherichia coli (E. coli). (C) 2008 Elsevier B.V. All rights reserved.