AgCl/poly(methyl methacrylate) (PMMA) organicinorganic hybrid membrane has been synthesized by reverse microemulsion polymerization using triblock copolymer polyoxyethylenepolyoxypropylenepolyoxyethylene as surfactant and MMA as oil phase. The results by ultravioletvisible spectrum, transmission electron microscopy, and scanning electron microscopy showed that small AgCl nanoparticles distributed well in the F127 microemulsions and hybrid membranes at low reactant concentration. AgCl nanoparticles in the microemulsion became smaller with increasing reactant concentration. However, AgCl nanoparticles aggregated obviously in hybrid membranes, when reactant concentration was more than 0.15 mol L-1. The performance of different hybrid membranes for separation of the benzene and cyclohexane was measured. The results indicated that the separation performance of membrane was promoted obviously due to presence of more well-dispersed AgCl particles in hybrid membranes. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012