A novel atmospheric dielectric barrier discharge (DBD) plasma graft-filling technique to fabricate the composite membranes for pervaporation of aromatic/aliphatic hydrocarbons

A double-plasma grafting strategy for the fabrication of the “pore-filling” composite membranes was proposed herein. By means of atmospheric dielectric barrier discharge (DBD) plasma, the graft copolymer was covalently anchored in the sublayer pores and onto the surface of the asymmetric polyacrylonitrile (PAN) ultrafiltration (UF) membrane through the combination of syn-irradiation grafting and postirradiation grafting of macromonomer poly(ethylene glycol) methacrylate (PEO526OHMA), consequently, a “pore-filling” composite membrane for pervaporation of aromatic/aliphatic hydrocarbons was obtained. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements (WCA), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) were utilized to characterize the composite membrane. The effects of DBD irradiation time, DBD input voltage, macromonomer concentration on the degree of grafting and pervaporation performance of composite membrane for the toluene/n-heptane mixtures (1:4 in mass) at 80 °C were investigated. Separation factor αtoluene/n-heptane up to 7.8 and permeate flux up to 1.62 kg/m2 h were achieved.