| 초록 |
Perfluorinated sulfonic acid polymer membranes widely used in polymer electrolytes membrane fuel cells have some critical problems such as poor conductivity at high temperature region, low dimensional stability and limited industrial production. To obtain high temperature membranes, we prepared composite ionomer membranes based on poly(vinylidene fluoride) matrix and sulfo-phenylated solid proton conductors. Sulphophenyl phosphonic acid(SPP) was synthesized from phenylphosphate and sulphur trioxide in the absence of any solvents. At the end of purification, zirconium sulphophenyl phosphonic acid(ZrSPP) was formed by the addition of HF and ZrOCl2 into an aqueous SPP. ZrSPP slurry was ultrasonfically mixed with PVdF dissolved in dimethylacetamide, and then composite ionomer membrane was obtained by casting the mixture onto a glass substrate in a convection oven. FTIR spectroscopy and X-ray diffraction were employed to characterize the crystalline of ZrSPP. AC impedance spectroscopy was used to determine proton conductivity at different temperature. It was found that ZrSPP/PVdF composite membranes showed much better dimensional stability and their conductivities reached ca. 10-2 S/cm at ambient condition.
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