In-situ cross-linked porous anion exchange membranes with high performance for efficient acid recovery

Diffusion dialysis (DD) has high economic competitiveness for acid recovery; however, the fabrication of highly acid-permeable and salt-rejecting anion exchange membranes (AEMs) for DD is still a grand challenge. This paper presents in-situ cross-linked porous AEMs with tunable microstructures and high DD performance. The AEMs were fabricated based on chloromethyl polyethersulfone substrate using N, N, N ', N '', N ''-pentamethyldiethylenetriamine as a bifunctional agent for cross-linking and quaternization. The prepared porous AEMs showed significantly superior DD performance over conventional dense AEMs due to the high free volume and cross-linked networks within our membranes. The acid dialysis coefficient (UH+) and acid/salt separation factor (S) of the optimal AEM were 2.6 and 255.4 times as high as those of the commercial DF-120 AEM, respectively. Therefore, our low-cost, high-performance in-situ cross-linked porous AEMs may pave the way for large-scale acid recovery applications.

Automated summary

This study presents in-situ cross-linked porous anion exchange membranes (AEMs) with tunable microstructures and high diffusion dialysis (DD) performance for acid recovery. The prepared AEMs exhibit significantly superior DD performance due to the high free volume and cross-linked networks within the membranes. The optimized AEM shows 2.6 times higher acid dialysis coefficient (UH+) and 255.4 times higher acid/salt separation factor (S) compared to the commercial DF-120 AEM. Therefore, these low-cost, high-performance in-situ cross-linked porous AEMs can potentially contribute to large-scale acid recovery applications.