Comb-shaped guanidinium functionalized poly(ether sulfone)s for anion exchange membranes: Effects of the spacer types and lengths

Abstract

A series of poly(ether sulfone)‐based anion exchange membranes (AEMs), tethering with guanidinium side chains with different spacers, were synthesized via azide‐alkyne cycloaddition, deprotection, and the subsequent ion exchange reactions. The designed polymer structures were verified by the 1H NMR spectra. Because of the appropriate water uptake and formation of interconnected ionic clusters, the GPES‐3C with propyl spacer showed higher conductivity than the GPES‐1C and GPES‐9C, with methylene and nonyl spacers, respectively. Comparatively, the GPES‐EO AEM with two ethylene oxide (EO) spacers exhibited even higher conductivity, these can be interpreted by interconnectivity of ionic channels and hydrophilicity nature of the EO spacer. Additionally, although the GPES membranes displayed sufficient thermal stability, the chemical stability of as‐prepared materials needs to be much improved for fuel cell applications. Overall, these results demonstrated that the properties of “pendent‐type” AEM can be tuned facilely by the spacer types and lengths. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1313–1321

Advances in alkaline stable guanidinium based anion exchange membranes

“…伯胺易得且种类丰富, 因此容易 对五取代胍的结构进行设计和调节, 进而得到不同 结构的胍盐离子. 此外, 还可以通过仲胺与Vilsmeier 盐反应直接得到胍盐离子 [21,22] [18,23,24] ; (2) 制备含有伯胺或仲胺的聚合物, 通过聚合物上的胺基与Vilsmeier盐反应, 实现胍盐 与聚合物骨架结构的共价相连 [25] ; (3) 通过对位吸电 子基团活化的氟代苯与四烷基胍进行亲核取代反应, 将胍盐引入到聚合物骨架中 [26~28] ; (4) 利用含有特征 基团的卤代烷烃与五烷基胍进行反应得到含有胍盐 结构的功能化单体, 随后利用功能化单体将胍盐引 入到聚合物骨架结构中 [29,30] ; (5) 通过盐酸胍与二胺 进行缩聚反应直接制备主链型胍盐聚电解质 [31] . 研 究人员采用以上几种方法设计制备了不同结构的胍 盐AEMs, 根据己报道的胍盐结构中取代基种类的不 同将胍盐AEMs分为以下几类.…”

“…最近, 丁运生课题组 [30] 制备了含有叠氮基团的 聚醚砜(APES), 随后利用不同结构的含胍炔类单体 与APES进行点击反应成功将胍盐结构引入聚合物骨 架中, 最后进行脱保护、离子交换等过程制备得到了 一 系 列 侧 链 型 胍 盐 类 的 聚 醚 砜 阴 离 子 交 换 膜 材 料 GPES(图6). 研究发现, 由于具有适宜的吸水率以及 图 4 含有六烷基胍盐的聚芳醚砜阴离子交换膜材料PES-GOH的制备过程 [25] Figure 4 Synthesis of poly(aryl ether sulfone) containing hexaalkylguanidinium groups (PES-G-OH) [25] 图 5 (网络版彩色)聚半倍硅氧烷胍盐复合膜材料BG-BPS/PTFE的制备过程 [29] Figure 5 (Color online) Fabrication strategy for the BG-BPS/PTFE membrane [29] 图 6 GPES-nCs以及GPES-EO的合成路线 [30] Figure 6 Synthetic routes of GPES-nCs and GPES-EO [30] 进 展 Figure 7 Synthesis of phenyl-guanidinium-functionalized poly(arylene ether sulfone) [26] 聚体的碱性阴离子交换膜燃料电池在80℃…”

Progress of polymer chain structure regulation of alkaline anion-exchange membranes for fuel cells

“…课题组 [24] 和本课题组 [25] 的双接枝, 刘庆林课题组 [26] 与白如科课题组 [27] 的三接枝, 徐铜文课题组 [28] 的多 接枝, 均在低的GD下获得高的离子交换容量(IEC), 从而在较低的溶胀度下实现膜电导率的大幅提高. [32] 在疏水的聚砜主链上 接枝亲水的聚二醇侧链和季铵基团构建了5~10 nm的 离子通道; 李南文课题组 [33,34] 、刘庆林课题组 [35] 、Kim 课题组 [36] 与丁运生课题组 [37] 等分别制备了"梳形"的 AAEMs, 通过调节GD和疏水链段长度实现离子簇尺 寸从5到33 nm的增大; 庄林课题组 [38] 在未接枝季铵 基团的位点引入烷基链构建了高速离子传输通道, 将AAEMs的离子电导率提高到100 mS cm −1 (80℃); 除 了 烷 基 链 的 长 度 和 季 铵 基 团 的 GD, Dang 和 Jannasch [39] 发现烷基链与季铵基团的组合方式影响 膜微观结构与性能, 通过引入疏水烷基链与阳离子 基团多接枝制备的AAEMs其离子电导率在80℃达到 221 mS cm −1 [14] ; Lee课题组 [40] 发现通过端基3个乙炔 基的交联可以增大亲水区域的尺寸. 本课题组 [41] [26,42~53] .…”

Highly conductive and stable anion‐exchange membranes based on crosslinked poly(arylene ether sulfone)‐block‐poly(phenylene oxide) Networks

“…Quaternary guanidinium groups, imidazolium cations, cobaltocenium cation, piperidinium, quaternary phosphonium groups, and metal‐complex cation have been reported as conducting groups . Partially high‐density function group polyelectrolyte, graft polyelectrolyte, and multiblock polyelectrolyte are applied successively to AEMs . However, compared to PEMs, the AEMs have to face the low conductivity due to the fact that ion mobility of OH − and H + are 20.64 × 10 −8 and 36.23 × 10 −8 m 2 s −1 v −1 in water at 298.15 K, respectively …”