Perchloric acid doped fluorinated polymer membranes for fuel cell applications

Solid proton conducting polymer electrolytes of high ionic conductivity were prepared using Poly (vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) and Perchloric acid (HClO4) by solvent casting technique. PVdF-co-HFP has high dielectric constant and possesses good mechanical strength. Perchloric acid is an interesting supporting electrolyte for methanol oxidation and gives perfect plasticizing effect for polymer electrolytes. These films were dry, free standing and dimensionally stable. The prepared electrolytes were characterized by X-ray diffraction (XRD), Infra-red spectroscopy (FTIR), Ac impedance spectroscopy and contact angle measurements .The X-ray diffraction analysis confirms the polymer - HClO4 complex formation. FTIR spectra analysis reveals the interaction between the proton and the polymer matrix. The Contact angle measurement explains that hydrophobic or hydrophilic and super hydrophobic nature of the polymer electrolyte membranes. Conductivity study of these polymer electrolytes systems were carried out in the temperature range 308-373K. The log vs. 1/T plot shows Arrhenius behaviour.