Wang Junhua, Gu Shuang, Xiong Ruichang, Zhang Bingzi, Xu Bingjun, Yan Yushan
Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA.
ChemSusChem. 2015 Dec 21;8(24):4229-34. doi: 10.1002/cssc.201501035. Epub 2015 Dec 2.
A series of poly(2,4-dimethyl-1,4-phenylene oxide) hydroxide-exchange membranes (HEMs) with cation strings containing a well-defined number of cations (CS-n) and similar, high ion-exchange capacities are synthesized to investigate the effect of cation distribution on key HEM properties. As the number of cations on each string grows, the size of the ionic clusters increases from 10 to 55 nm. Well-connected ion pathways and a hydrophobic framework are observed for n≥4. The enhanced phase segregation increases the hydroxide conductivity from CS-1 to CS-6 (30 to 65 mS cm(-1) ) and suppresses the water uptake (from 143 % to 62 %). Moreover, molar hydroxide conductivities for CS-n membranes show two distinctive stages as n increases: ∼23 S cm(2) mol(-1) for n≤3; and ∼34 cm(2) mol(-1) for n≥4.
合成了一系列具有明确阳离子数量的阳离子串（CS-n）且离子交换容量相近的聚（2,4-二甲基-1,4-苯撑氧化物）氢氧化物交换膜（HEM），以研究阳离子分布对关键HEM性能的影响。随着每条串上阳离子数量的增加，离子簇的尺寸从10纳米增大到55纳米。当n≥4时，观察到离子通道连接良好且有疏水骨架。增强的相分离使氢氧化物电导率从CS-1提高到CS-6（从30毫西门子/厘米提高到65毫西门子/厘米），并抑制了吸水率（从143%降至62%）。此外，随着n的增加，CS-n膜的摩尔氢氧化物电导率呈现两个不同阶段：n≤3时约为23西门子·厘米²/摩尔；n≥4时约为34厘米²/摩尔。
