Dual hydrophobic modifications toward anion exchange membranes with both high ion conductivity and excellent dimensional stability
Dual hydrophobic modifications toward anion exchange membranes with both high ion conductivity and excellent dimensional stability
复制标题
对阴离子交换膜进行双重疏水改性，使其兼具高离子电导率和优异的尺寸稳定性
DOI：
10.1016/j.memsci.2019.117521
复制
发表时间：
2020-02-01
影响因子：
9.5
通讯作者：
Liu, Qinglin
中科院分区：
文献类型：
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作者：
Hu, Chuan;Zhang, Qiugen;Liu, Qinglin
阴离子交换膜(AEMS)作为一种重要的功能材料，在燃料电池、电渗析、水处理等领域有着广泛的应用。然而，合成的AEMS通常会受到有害的取舍：高离子导电性的AEMS缺乏尺寸稳定性，反之亦然。在这里，我们展示了一种通用的策略，通过疏水交联和引入疏水链来制备既具有高离子电导率又具有优异尺寸稳定性(即低溶胀比)的AEMS。交联剂的疏水长度对AEMS中构建高效离子通道有很大影响。令人惊讶的是，由1，8-二氨基辛烷交联的亲水性聚苯醚分子膜具有最高的氢氧化物电导率，通过引入疏水的聚苯醚主链，在80℃下进一步提高到157.2 ms cm(-1)(增加10%)，低溶胀率为12.9%。这种AEM不仅克服了交联型AEMS的离子导电性和尺寸稳定性之间的权衡，而且打破了离子导电性和吸水率之间的上限。新开发的疏水双改性策略有望成为开发高性能AEMS的有效途径。
Anion exchange membrane (AEMs) as a kind of important functional material are widely used in many fields including fuel cell, electrodialysis and water treatment. However, synthetic AEMs generally suffer a pernicious trade-off: high ion-conductive AEMs lack dimensional stability and vice versa. Herein we demonstrate a versatile strategy to prepare the AEMs with both high ion conductivity and excellent dimensional stability (i.e., low swelling ratio) via hydrophobic crosslinking and introducing hydrophobic chains. The hydrophobic length of crosslinkers has great influence on construction of highly efficient ion channels in the AEMs. Amazingly, the hydrophilic poly (phenylene oxide) (PPO) AEM crosslinked by 1,8-diaminooctane has the highest hydroxide conductivity that is further improved to 157.2 mS cm(-1) (10% increases) with a low swelling ratio of 12.9% at 80 degrees C by introducing hydrophobic PPO backbone. This AEM not only overcomes the trade-off between the ion conductivity and the dimensional stability of crosslinked AEMs, but also breaks the upper bound between the ion conductivity and the water uptake. The newly developed strategy of hydrophobic dual-modifications promises to be an effective approach to develop the high-performance AEMs.