Sun Rui, Elabd Yossef A
Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States.
ACS Macro Lett. 2019 May 21;8(5):540-545. doi: 10.1021/acsmacrolett.9b00039. Epub 2019 Apr 29.
Herein, we present the synthesis of five styrene-based poly(ionic liquids) (PILs) containing (covalently linked) saturated -heterocyclic cations with various ring sizes (i.e., methylpyrrolidinium, methylpiperidinium, methylazepanium, methylazocanium, and methylazonanium). High alkaline chemical stability was confirmed by H NMR spectroscopy after 4 weeks in 40 mol equiv of KOH (1.0 M KOH in DO) at 80 °C for PILs with 5-, 6-, 7-, and 8-membered ring cations; a requirement for polymer electrolyte separators in long-lasting alkaline fuel cells. Additionally, ion conductivity of PILs increased by 4 orders of magnitude with increasing water content, where a master percolation power law curve was observed, that is, similar conductivity versus water volume fraction for all PILs, regardless of cation size.
在此，我们展示了五种基于苯乙烯的聚离子液体（PILs）的合成，这些聚离子液体包含（共价连接）具有不同环大小的饱和杂环阳离子（即甲基吡咯烷鎓、甲基哌啶鎓、甲基氮杂环庚烷鎓、甲基氮杂环辛烷鎓和甲基氮杂环壬烷鎓）。对于具有5元、6元、7元和8元环阳离子的PILs，在80°C下于40摩尔当量的KOH（在D₂O中的1.0 M KOH）中放置4周后，通过¹H NMR光谱证实了其高碱性化学稳定性；这是长效碱性燃料电池中聚合物电解质隔膜的一个要求。此外，随着水含量的增加，PILs的离子电导率增加了4个数量级，在此观察到一条主渗流幂律曲线，也就是说，所有PILs的电导率与水体积分数相似，与阳离子大小无关。
