Sustainable synthesis of high-performance anion exchange membranes for electrodialysis desalination via photopolymerization

Abstract

Sustainable chemistry principles underscore the pivotal role of solvent-free processes in the fabrication of anion exchange membranes (AEMs). This study presents an eco-friendly, solvent-free approach for AEM preparation via photopolymerization, utilizing 4-vinylpyridine as the monomer and divinylbenzene as the crosslinking agent. The polymerization, conducted at ambient temperature and completed within 20 min, was followed by post-polymerization N-alkylation with ethyl bromide to introduce pyridinium groups. The precise modulation of crosslinking and N-alkylation levels enabled meticulous control over the membranes' intrinsic chemical properties and their functional effectiveness in electrodialysis desalination. The optimal membrane's area resistance was recorded at 1.09 Ω cm², while its transport number reached 0.965, outperforming the commercial AMV AEM in desalination efficacy. This work underscores the promise of solvent-free photopolymerization as a sustainable, high-performance strategy for fabricating AEMs, providing substantial advancements in both environmental sustainability and electrodialysis desalination performance.