Prospects of poly (vinyl alcohol)/Chitosan/poly (styrene sulfonic acid) and montmorillonite Cloisite®30B clay composite membrane for direct methanol fuel cells

Abstract

A proton conducting polymer electrolyte nanocomposite membrane has been fabricated by using poly (vinyl alcohol) (PVA), Chitosan, and poly (styrene sulfonic acid) (PSSA) polymers and montmorillonite Cloisite®30B clay with the objective of its application in direct methanol fuel cells. Comparative studies of a PVA/PSSA/Chitosan/Cloisite30B clay composite membrane with a base PVA/PSSA membrane has been carried out by using thermal gravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, X-ray diffraction, methanol permeability and proton conductivity measurements. Properties of the membrane have been compared with Nafion®117 at identical test conditions. Methanol permeability of the PVA/PSSA/Chitosan/Cloisite30B clay composite membrane has been found to be superior to that of PVA/PSSA as well as Nafion117 membranes. Water uptake of the membrane is much higher compared to the Nafion117 membrane. Proton conductivity of the membrane has been found in the range of 10-2 S cm-1 at room temperature and 70% relative humidity. Selectivity of the membrane is in the range of 104S s cm-3, which is better than that of Nafion117.