Fabrication of cellulose acetate‐based radiation grafted anion exchange membranes for fuel cell application

Abstract

AbstractNovel cellulose acetate‐based anion exchange membranes (CA‐AEM) are successfully synthesized via gamma radiation grafting as a possible renewable alternative to commercial AEMs. Using CA film precursors with degree of acetylation of 2.5, the synthesized AEM shows a high ion exchange capacity of 2.15 mmol g−1 obtained at high degree of grafting of 45%. It was determined using thermogravimetric analysis that the radiation‐grafted CA‐AEM has stable amine functional groups under oxygen environment within the normal operating temperature range of alkaline fuel cells. The CA‐AEM also exhibits appreciable performance over a range of temperatures, with a highest ionic conductivity of up to 0.163 S cm−1 depending on the synthesis parameters. Results revealed that membranes prepared using gamma radiation dose of 31 kGy and above are susceptible to mechanical and dimensional instability due to increased water uptake and degree of swelling. Further study should consider the balance between grafting parameters and the desired hydrophysical properties.