The properties and antifouling performance of anion exchange membranes modified by polydopamine and poly (sodium 4-styrenesulfonate)

Abstract

Fouling of anion exchange membranes (AEMs) is the bottleneck restricting electrodialysis technology, and surface modification is an effective way to solve this problem. This paper investigated the effects of different components such as single poly (sodium 4-styrene sulfonate) (PSS), single polydopamine (PDA) and mixed polydopamine and poly (sodium 4-styrene sulfonate) (PDA@PSS) used as the modifier, respectively, on the surface properties and antifouling performance of AEMs. Comparing the surface properties of different modified AEMs, it was found that the surface hydrophilicity and negative charge density of PDA@PSS modified AEM (PDA@PSS-M) were obviously improved due to the combined action of PDA and PSS. The desalination rate, surface morphology and relative content of surface S element of different AEMs after the fouling experiments were also analyzed. The results indicated that PDA@PSS-M presented the greatest antifouling performance among three modified AEMs. The effect of PDA@PSS co-deposited layer on its desalination performance was negligible and the modification layer had relatively good stability.