PVDF-HFP-Based Pioneering Anion Exchange Membranes for Advanced Sulfuric Acid Enrichment with Reduced Water Mobility

In the context of industrial effluent management, the application of electrodialysis (ED) for the recovery of sulfuric acid has attracted significant interest. Despite the technological promise, the employment of traditional anion exchange membranes (AEMs) is frequently marred by substantial proton leakage, a pervasive issue that markedly degrades the effectiveness of acid recovery. To address this challenge, we embarked on a novel approach utilizing a polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) substrate. This innovative method harnessed the inherent properties of fluorine-containing groups within PVDF-HFP to provide robust acid stability, while incorporating tertiary amine groups to minimize water uptake resulted in the creation of a proton-blocking AEM. A distinguishing feature of this AEM is its thermally cross-linked diene structure, which not only preserves acid concentration properties but also considerably reduces water migration. Moreover, our investigation undertakes an exhaustive examination of the recycling concentration and water transport within the acid recovery framework, alongside the intricate interplay with energy expenditure. This investigation could facilitate the adoption of industrial acid recovery methods utilizing AEMs designed for minimal water uptake and enhanced acid-blocking capabilities.