Effect of Poly(diallyldimethylammonium chloride) on the Properties of Chitosan/poly(vinyl alcohol) Anion Exchange Membranes for Fuel Cells

Anion exchange membranes (AEMs) have received significant attention as cost-effective electrolytes for alkaline fuel cells due to their potential to enhance electrochemical performance while replacing expensive proton exchange membranes. In this work, composite AEMs were fabricated from chitosan (CS), poly(vinyl alcohol) (PVA), and poly(diallyldimethylammonium chloride) (PDDA) through a solution casting method followed by chemical crosslinking using glutaraldehyde as a crosslinking agent. Chitosan served as the main biopolymer matrix, PVA improved film-forming ability and mechanical strength, while PDDA introduced quaternary ammonium groups that facilitated hydroxide ions transport. The prepared membranes were characterized by water uptake (WU), and hydroxide ion conductivity (σ). FTIR and SEM analyses confirmed the successful incorporation of PDDA and strong intermolecular interactions among polymer components, resulting in a dense and homogeneous structure. Increasing PDDA concentration led to enhanced ionic transport, with the CPP–0.20 membrane achieving the highest hydroxide conductivity of 21 mS cm−1 at room temperature.