The effects of plasticizer agent in mesoporous phosphotungstic acid modified chitosan membrane and its performances for direct methanol fuel cell application

Abstract

Chitosan (Cs) is an attractive material with outstanding properties such as excellent film-forming properties, biodegradability, and ease of chemical modification. The Cs membrane is usually applied as part of the proton exchange membrane (PEM) material in fuel cell applications. The drawbacks of the Cs membrane can be surmounted by applying the hydrophilic/plasticizer agent and combining the modified heteropoly acid filler. In this research, the Cs membrane was successfully fabricated using a solvent-evaporation method with the incorporation of mesoporous phosphotungstic acid (m-PTA) and glycerol (gly). The outstanding performances were obtained by the Cs/gly-1/m-PTA membrane, which had the first degradation temperature up to 200 ?C, chemical stability with the lowest weight loss at 18.33?0.762%, and the highest proton conductivity at 5.13 mS/cm. The other performances exchange capacity (IEC) at 2.949?0.022 mmol/g, and water and methanol uptake at 89.05?0.092% and 1.26?0.031%, respectively. In comparison to the pristine Cs membrane, which exhibits lower proton conductivity and higher methanol permeability at 2.40 mS/cm and 1.003?10?5 cm2 /s, respectively, the addition of m-PTA filler and gly as a plasticizer agent increases the performance of the chitosan properties used in direct methanol fuel cell membranes.