Removal of benzene from an aqueous solution of dilute benzene by various cross-linked poly(dimethylsiloxane) membranes during pervaporation

This paper focuses on the effects of cross-linkers of the cross-linked poly(dimethylsiloxane) membranes derived from poly(dimethylsiloxane) dimethyl methacrylate macromonomer (PDMSDMMA), and divinyl compound, on the pervaporation characteristics of the removal of benzene from an aqueous solution of dilute benzene. When an aqueous solution of 0.05 wt % benzene was permeated through the cross-linked PDMSDMMA membranes, they showed high benzene permselectivity. Both the permeability and benzene permselectivity of the membranes were enhanced with increasing divinyl compound content as the cross-linker and were significantly influenced by the kind of divinyl compound. PDMSDMMA membranes cross-linked with divinylsiloxane (DVS) showed very high membrane performance during pervaporation. The best normalized permeation rate, separation factor for benzene permselectivity, and pervaporation separation index of a PDMSDMMA-DVS membrane were 1.96 x 10(-5) in kg/(m(2) h), 2886, and 5657, respectively. These pervaporation characteristics are discussed from the viewpoint of the chemical and physical structure of the cross-linked PDMSDMMA membranes.