|Title||Molecular separation using poly (styrene-co-maleic anhydride) grafted to γ-alumina : Surface versus pore modification|
|Author(s)||Amirilargani, Mohammad; Merlet, Renaud B.; Chu, Liangyong; Nijmeijer, Arian; Winnubst, Louis; Smet, Louis C.P.M. de; Sudhölter, Ernst J.R.|
|Source||Journal of Membrane Science 582 (2019). - ISSN 0376-7388 - p. 298 - 306.|
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Alumina membrane - Copolymer grafting - Molecular separation - Pore modification - Surface modification|
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 .