Abstract To explore the alkaline stability of cationic groups, several investigations have been reported via small molecule model compounds, theoretical calculations or grafting cations to the benzylic positions of the polymer backbones. In this work, anion exchange membranes (AEMs) with various head groups of trimethylammonium (TMA), 1-methylpyrrolidinium (MPY), 1-methylpiperidinium (MPRD), 1-methylimidazolium (Im1) and 1,2-dimethylimidazolium (Im1,2)) flexibly linked to poly(ether sulfone) (PES) backbones are prepared to explore the effect of pendent functional groups. The AEMs tethering MPRD groups are found to exhibit the highest Br− conductivity of 60.4 ± 2.1 mS cm−1 at 80 °C. PES-MPY exhibits the best relative stability and maintains 90.7% and 83.1% of the original ionic exchange capacity (IEC) and conductivity, respectively, after immersed into 2 M NaOH at 60 °C for 672 h. Meanwhile, the alkaline stability is in the order of PES-MPY > PES-MPRD > PES-TMA > PES-Im1,2 > PES-Im1. The maximum power density of a H2/O2 fuel cell using PES-MPRD (109.0 mW cm−2) and PES-MPY (106.5 mW cm−2) is larger than that using PES-Im1 (65.1 mW cm−2). The results provide a guidance for designing high-performance AEMs.

中文翻译：

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具有发达导电通道的阴离子交换膜：官能团的影响

摘要 为了探索阳离子基团的碱性稳定性，已经通过小分子模型化合物、理论计算或将阳离子接枝到聚合物骨架的苄基位置进行了多项研究。在这项工作中，阴离子交换膜 (AEM) 具有三甲基铵 (TMA)、1-甲基吡咯烷 (MPY)、1-甲基哌啶 (MPRD)、1-甲基咪唑 (Im1) 和 1,2-二甲基咪唑 (Im1,2 )) 灵活连接到聚（醚砜）（PES）主链，以探索悬垂官能团的影响。发现束缚 MPRD 基团的 AEM 在 80 °C 下表现出最高的 Br− 电导率 60.4 ± 2.1 mS cm−1。PES-MPY 表现出最好的相对稳定性，分别保持原始离子交换容量 (IEC) 和电导率的 90.7% 和 83.1%，在 60 °C 下浸入 2 M NaOH 672 小时后。同时，碱稳定性的顺序为 PES-MPY > PES-MPRD > PES-TMA > PES-Im1,2 > PES-Im1。使用 PES-MPRD (109.0 mW cm-2) 和 PES-MPY (106.5 mW cm-2) 的 H2/O2 燃料电池的最大功率密度大于使用 PES-Im1 (65.1 mW cm-2) 的最大功率密度。结果为设计高性能 AEM 提供了指导。