In-situ construction of modified layer on the surface of anion exchange membrane to improve antifouling performance

Abstract

A new strategy combining electrodeposition with co-deposition modification was proposed to in-situ construct a stable antifouling modified layer on the AEM surface without disassembling the membrane stack. Specifically, dopamine (DA) was introduced into the electrodeposition process of poly (sodium 4-styrene sulfonate) (PSS) to co-deposit onto the AEM surface, in which the polymerization reaction could promote by supporting electrolyte (NaCl). The formation of cross-linked structure and π-π stacking effect during in-situ modification could ensure the stability of the modified layer. The in-situ modified AEM had a negatively charged and more hydrophilic surface, significantly improving the antifouling performance against organic matter (sodium dodecylbenzene sulfonate) without affecting desalination performance. Moreover, it still had excellent antifouling properties after 96 h neutral rinsing. This work provided a novel approach for preventing organic fouling of AEM in ED process through surface modification.