Optimizing Sodium Alginate/PVA Polymer Electrolyte Membrane with Montmorillonite for Enhanced Architectural Features and Performance in DMFC Application

Nafion, a widely utilized commercial membrane in direct methanol fuel cells (DMFC), presents significant limitations due to its cost and susceptibility to high methanol crossover. This study explores alternative membranes, focusing on Sodium Alginate/Poly (Vinyl Alcohol) (SA/PVA) blends with montmorillonite (MMT) modification as an inorganic filler. The MMT content in the SA/PVA membrane was varied from 2 to 20 wt% using the solvent casting method. Optimally, 10 wt% MMT content demonstrated the highest proton conductivity (9.38 mScm −1 ) and the lowest methanol uptake (89.28%) at ambient temperature. The SA/PVA-MMT membrane exhibited superior thermal stability, optimal water absorption, and reduced methanol uptake, attributed to the electrostatic attraction within the sodium alginate and PVA polymer matrices interacting with H + , H 3 O + , and –OH ions. The homogeneous dispersion of 10 wt% MMT, along with its hydrophilic properties, facilitated an efficient proton transport channel in SA/PVA-MMT membranes. Increasing MMT content enhanced membrane hydrophilicity, indicating that 10 wt% MMT loading is crucial for adequate water intake to activate proton transfer. This study suggests that the developed membrane holds great potential as a cost-effective alternative with competent performance for future applications.