Effects of Cationic Pendant Groups on Ionic Conductivity for Anion Exchange Membranes: Structure−Conductivity Relationships

Anion exchange membranes(AEMs) have attracted increasing interests due to their various applications, especially for Fuel cells. Previous proton exchange membranes(PEMs), such as Nafions® have better conductivity than AEMs so far. However, technical limitations such as slow electrode kinetics, carbon monoxide (CO) poisoning of metal catalysts, high methanol crossover and high cost of Pt-based catalyst deterred further usages. AEMs have advantages to supplement its drawbacks. In this work, we synthesized PS-PAGE (polystyrene-b-poly allyl glycidyl ether) block copolymer as backbone by anionic polymerization. And then we obtain various AEMs with different ratio of cationic groups by post modification. We also control nanostructures such as domain spacing, morphology by differentiating the block ratio. Hydroxide conductivity is measured using AC impedance analyzer and small angle x-ray scattering is employed to study nanostructures. Systematically investigated structure-conductivity relationships provide a foundation for further researches on AEMs with better performance.