Development of polyvinyl alcohol (PVA) supported zirconium tungstate (ZrW/PVA) composite ion-exchange membrane

Abstract

A polyvinyl alcohol supported zirconium tungstate (ZrW/PVA) composite ion exchange membrane has been synthesized by the sol-gel technique. The membrane was prepared by blending zirconium tungstate sol into polyvinyl alcohol gel which was cross-linked with glutaraldehyde (GA). The prepared membrane was analyzed by FT-IR, optical microscopy, SEM, XRD & EDS. The membrane was found to be devoid of any cracks and defects. Electrochemical properties which include transport number, ion exchange capacity (IEC), and proton conductivity were also measured. An IEC count of 0.92 meq.g−1 and transport number of 0.88, thus obtained, were indicators of good electrochemical properties that shows its potential to be used in the direct methanol fuel cell. Moreover, water uptake, methanol uptake and chemical resistivity in the acidic and basic medium of the prepared membrane have also been assessed. Synthesized membrane showed high water holding capacity as compared to Nafion-117. The water uptake of ZrW/PVA composite membrane was found to be 114% which is much higher than that of Nafion-117 (29.2%) [18]. The final weight loss of the ZrW/PVA composite membrane in acidic medium was 10%. Oxidative stability of the membrane was evaluated by using Fenton's reagent. The weight loss in the reagent after 24 h was 17% without disruption.