Here, we report the covalent coupling of poly (styrene-co-maleic anhydride) onto γ-alumina to develop high-performance organic solvent nanofiltration (OSN) membranes. A high molecular weight (M w ) alternating copolymer of maleic anhydride (MA) and styrene (St) was synthesized and directly grafted to the γ-alumina membrane, while commercially available low M w random copolymers of St and MA were also investigated. We show that solute rejection and membrane permeability strongly depend on the nature of the applied copolymer. In particular, the M w of the copolymer applied is potentially the key for improving the membrane performance. When a high M w copolymer was applied, the grafted layer covered the surface of the membrane. This results in membranes with significantly improved rejection, while maintaining a high permeability. In contrast, we observed pore grafting by applying low M w copolymers, which resulted in membranes with slightly higher rejection and dramatically lower permeability compared to unmodified membrane. The best results were obtained by grafting γ-alumina with a high M w alternating copolymer. These membranes showed a solute rejection of 98% for Sudan Black B (457 g mol −1 ) in toluene, while the permeability remained high at 2.9 L m −2 h −1 bar −1 .

Original languageEnglish
Pages (from-to)298-306
JournalJournal of Membrane Science
Volume582
DOIs
Publication statusPublished - 2019

    Research areas

  • Alumina membrane, Copolymer grafting, Molecular separation, Pore modification, Surface modification

ID: 53483304