| 초록 |
Sulfonated poly(vinyldene fluoride)(PVdF) has attracted much attention as a proton conducting polymer, especially for proton exchange membranes fuel cells. PVdF has good chemical resistance, mechanical properties and high fuel selectivity but it still shows poor proton conductivity. Thus several methods have been reported to improve proton conductivity of PVdF by copolymerization or grafting with ion-conducting polymers or by hybridization with inorganic heteropoly acids. In this study, we prepared Nafion/PVdF blend membrane incorporated with silicotungstic acids as a hygroscopic filler. The resultant composite film was immersed in strong base solution to make PVdF hydrophilic. Then finally boiled in H2SO4. AC impedance spectroscopy was used to determine proton conductivity at various temperatures. X-ray diffraction and IR spectroscopy were employed to characterize nano-hybrid membrane. Hydrophilic surface was determined by contact angle measurement. 25 cm2 single cell performance was tested using high purity H2/O2.Membrane electrode assemble was fabricated by hot-press method. Proton conductivity was remarkably increased at high temperature. Conductivity of Nafion® at 100 oC remained ca. 0.03 S/cm but that of composite membrane reached ca. 0.07 S/cm.
|
