Selective removal of dilute benzene from water by poly(methyl methacrylate)-graft-poly(dimethylsiloxane) membranes containing hydrophobic ionic liquid by pervaporation

This paper focuses on the addition of hydrophobic ionic liquid, 1-allyl-3-butylimidazilium bis (trifluoromethane sulfonyl) imide ([ABIM]TFSI) to poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) membranes, on the pervaporation characteristics for the removal of dilute benzene from an aqueous solution. When an aqueous solution of 0.05 wt% benzene was permeated through [ABIM]TFSI/PMMA-g-PDMS membranes, they showed high benzene permselectivity and permeability. Both the benzene/water selectivity and permeability of the membranes were enhanced with an increase of [ABIM]TFSI, because the affinities of [ABIM]TFSI/PMMA-g-PDMS membranes for benzene were increased by introducing [ABIM]TFSI into the membranes. The [ABIM]TFSI localized in the PMMA layer of the microphase separated PMMA-g-PDMS membrane plays an important role as an absorbent to selectively partition benzene from the aqueous benzene solution. (C) 2016 Elsevier B.V. All rights reserved.