Improvement the hydroxide conductivity and alkaline stability simultaneously of anion exchange membranes by changing quaternary ammonium and imidazole contents
Kai Yang, Hongzhe Ni, Xinming Du, Tianen Shui, Hongcheng Shen, Jingmei Xu, Yao Liu, Chenyang Li, Yepeng Gao, Zhe Wang
Abstract
A series of cross-linked anion exchange membranes (AEMs) base on poly (aryl ether ketone)s (PAEKS) with different contents of trimethylamine and 1-vinylimidazole by brominating and grafting was prepared. The designed structures of PAEKS and AEMs were demonstrated by the 1H-NMR and FT-IR spectrum, respectively. TEM pictures confirmed that there are obvious microphase-separated morphologies in CImTPAEKS membranes, which provided a mass of efficient ionic transport channels. The OH− conductivity of the CImTPAEKS membranes had 0.070 to 0.083 S/cm at 80°C. The 1-vinylimidazole played a cross-linked role in AEMs, improving the dimensional stability and alkaline stability of AEMs. The OH− conductivity of the CImTPAEKS membranes still had 0.051 to 0.058 S/cm after the alkaline test (2 M NaOH at 80°C for 15 days). Moreover, the cross-linked membrane had prominent thermal stability. Based on these results, we are reasonable to believe that ClmTPAEKS membranes with excellent hydroxide conductivity and alkaline stability will be of great significance for the development of alkaline fuel cells.