| Summary: | 碩士 === 逢甲大學 === 材料科學所 === 98 === Poly(vinyl alcohol)(PVA) membranes have been sulfonized and cross-linked with sulfuric acid and glutaraldehyde to increase the ion conductivity and chemical stability. The PVA membranes were used in proton exchange membrane fuel cells. Since catalyst loss plays an important role in electrochemical reactions of fuel cells, the catalysts adhesion to PVA membranes were studied as a function of the degree of related functional groups on the sulfonization. In addition, polytetrafluoroethene (PTFE) was sputtered to grow C-F PVA membranes to improve the adhesion of catalyst to the membrane. The properties of PVA membrane were also investigated, including surface morphology, structure, water uptake, chemical stability, proton conductivity, and electrochemical performances. The results showed that increased sulfonization of the PVA membranes, elevated the proton conductivity, but the water uptake, catalyst adhesion and electrochemical performances degrade due to the increased cross-linking effect. After growing of C-F functional groups, the adhesion of catalysts to membrane surface was improved due to the strong electronegativity of C-F bonds on the membrane surface.
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