Well-designed mono- and di-functionalized comb-shaped poly(2,6-dimethylphenylene oxide) based alkaline stable anion exchange membrane for fuel cells

Abstract

To mitigate the membrane stabilities (dimensional and mechanical) and ionic properties, we report well functionalized hydrophilic and hydrophobic (responsible for stabilities) phase separated quaternized anion exchange membrane (AEM). The N,N,N,N-Tetramethyl-1,3-propanediamine quaternized AEM spliced with alkyl chain (DQCP-36) formed self-amassed morphology with larger ionic clusters. The most suitable optimized AEM (DQCP-36) demonstrated enhanced hydroxide ion conductivity (4.66 × 10−2 S cm−1), ion-exchange capacity (1.35 meq./g) and lower activation energy (11.52 kJ/mol). These AEMs showed self-amassed morphology (well balanced hydrophilic and hydrophobic domain) and excellent stabilities (thermal, alkaline and dimensional). Under harsh alkaline medium (2 M NaOH) at 60 °C, DQCP-36 AEM showed about 9% reduction in conductivity after 700 h treatment, and assessment to be a suitable candidate for alkaline fuel cells.