Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
J Colloid Interface Sci. 2017 Jul 1;497:333-342. doi: 10.1016/j.jcis.2017.03.033. Epub 2017 Mar 6.
Two N3-substituted imidazoles 1,2-dimethylimidazole and 1-butyl-2-methylimidazole were chosen to functionalize poly(aryl ether ketone), respectively. The generated imidazolium cations could electrostatically react with sulfonate ions of the sulfonated poly(ether ether ketone) forming the ionic crosslinking structure of the membranes. The changes in crosslinking degree and the alkyl chain-length on N3 site of the imidazoliums could highly affect the properties of the anion exchange membranes (AEMs). The AEMs functionalized by 1-butyl-2-methylimidazole exhibited superior properties compared to those functionalized by 1,2-dimethylimidazole according to the tolerance tests of the AEMs towards hot alkaline solutions. After exposed to 1M KOH at 80°C for 200h, the 1-butyl-2-methylimidazole modified AEMs maintained the ion exchange capacity of above 85%, the conductivity of about 70%, and the tensile stress at break of around 80%, respectively. The hydrophile-lipophile balance of the polymer membranes was calculated and proposed to better understand the correlation between structures and properties of the AEMs. The degradation of the imidazolium functional groups of the AEMs under the attack of hydroxide ions was evidenced by FT-IR analysis.
选择了两种 N3 取代的咪唑 1,2-二甲基咪唑和 1-丁基-2-甲基咪唑，分别对聚芳醚酮进行功能化。生成的咪唑阳离子可以与磺化聚（醚醚酮）的磺酸根离子静电反应，形成膜的离子交联结构。咪唑中 N3 位的交联度和烷基链长度的变化会高度影响阴离子交换膜（AEM）的性能。根据 AEM 对热碱性溶液的耐受性测试，1-丁基-2-甲基咪唑功能化的 AEM 表现出优于 1,2-二甲基咪唑功能化的 AEM 的性能。在 80°C 的 1M KOH 中暴露 200h 后，1-丁基-2-甲基咪唑改性的 AEM 仍保持 85%以上的离子交换容量、约 70%的电导率和约 80%的断裂拉伸应力。计算了聚合物膜的亲水-亲脂平衡值，并提出了该值以更好地理解 AEM 结构与性能之间的关系。通过 FT-IR 分析证实了 AEM 中咪唑官能团在氢氧根离子攻击下的降解。
