Proton blocking anion exchange membrane (AEMs) can be used to treat various of acidic wastewater (i.e., enrich the recovered acid from acidic wastewater). In this work, four AEMs based on aliphatic chain segment imbedding poly(arylene ether sulfone)s bearing salt-terminated side-chains have been prepared for acid enrichment by electrodialysis (ED). In particular, the length of flexible aliphatic chain segments (methylenes of –(CH₂)₃–), –(CH₂)₆–, –(CH₂)₉–, and –(CH₂)₁₂–) in aromatic poly(arylene ether sulfone) was tuned to tailor the micro-structure. Our investigation demonstrates that the AEM with aliphatic chain segments of –(CH₂)₁₂– shows the strongest surface hydrophobicity (water contact angle: 107°) and has the smallest ion clusters (0.75 nm, relative to the other three AEMs with 0.78 nm, 0.80 nm, and 0.81 nm). In ED process, at the current densities of 10 mA cm⁻², the maximum concentration of H⁺ enriched by the AEM is 2.06 M (initial concentration: 1.0 M). The investigations demonstrate that the optimized AEM with stronger hydrophobicity and smaller ion clusters shows the superior capacity of acid concentration relative to commercial AEM (AMX, Astom Japan). This work should be certain guiding significance for designing advanced proton blocking AEMs.

质子阻断阴离子交换膜（AEM）可用于处理各种酸性废水（即从酸性废水中富集回收的酸）。在这项工作中，已经制备了四种基于脂肪族链段嵌入带有盐封端侧链的聚（亚芳基醚砜）的 AEM，用于通过电渗析（ED）富集酸。特别是，芳族聚烯烃中柔性脂肪族链段（–(CH ₂ ) ₃ –)、–(CH ₂ ) ₆ –、–(CH ₂ ) ₉ – 和–(CH ₂ ) ₁₂ – 的亚甲基）的长度（亚芳基醚砜）被调整以定制微观结构。我们的研究表明，具有 -(CH₂ ) ₁₂ – 显示出最强的表面疏水性（水接触角：107°）并且具有最小的离子簇（0.75 nm，相对于其他三个 AEM 为 0.78 nm、0.80 nm 和 0.81 nm）。在ED过程中，在10 mA cm ^-2的电流密度下，AEM富集的H ⁺的最大浓度为2.06 M（初始浓度：1.0 M）。研究表明，与商业 AEM（AMX，Astom Japan）相比，具有更强疏水性和更小的离子簇的优化 AEM 显示出优异的酸浓度能力。这项工作对于设计先进的质子阻断AEMs应该具有一定的指导意义。