Improvement of sulfonated polysulfone membrane for direct methanol fuel cell : effect of zeolite Y and sulfonated graphene oxide

Abstract

The proton exchange membranes (PEMs) are being developed intensively due to their great potential as a promising power source for transportation, residential, and portable applications. In this work, the novel PEMs consisting of inorganic fillers embedded in sulfonated polysulfone (S-PSF) were fabricated. The effect of zeolite Y and sulfonated graphene oxide (S-GO) was investigated on the thermal and mechanical stability, water uptake, proton conductivity, and methanol permeability. The proton conductivity of S-PSF/zeolite Y membrane increased with increasing zeolite Y content, in parallel with the methanol permeability. It was due to its water retention property. The highest proton conductivity was found at 3 % v/v of S-GO because of the increment of sulfonic acid groups by incorporating of S-GO. The S-GO particles positively affected for blocking water and methanol molecules, caused by the increasing of interfacial interaction between S-PSF and S-GO, leading to the decreases in the water uptake and methanol permeability. Besides, the hybrid membranes, which were S-PSF membrane mixing with both zeolite Y and S-GO, were investigated. They also showed better performance than the pristine S-PSF and Nafion 117 membrane. Therefore, all composite membranes are a potential candidate for being used in DMFC applications.