抄録
Membranes having acrylic acid or sulfonate fixed charges were prepared by plasma polymerization. Acrylic acid-grafted membranes were prepared by gas phase polymerization in a plasma reactor with outer electrodes and a conjugate liquid vessel, followed by post-polymerization in the liquid phase on the microporous film of polypropylene (CG) or polyethylene (HP) as a base film. Fluorosulfonate charged-membranes were prepared by gas phase polymerization of both surfaces of the base film in a bell-jar type plasma reactor with inner electrodes, using trifluoromethane sulfonate and hexafluoropropylene. The effects of the operational conditions of plasma pressure, the RF power and the polymerization period, on the properties of a changed-membrane, grafting degree, the ion-exchange capacity, the membrane conductivity and the cation transference number, were examined experimentally. Acrylic acid-grafted membranes had high water content, and showed the high membrane conductivity. The transference number of cations of the membrane grafted on the CG film was higher than that of the membrane on the HP film. Fluorosulfonate-grafted membranes showed the resistivity lower than that of Nafion-117 membrane, and had the ion-exchange capacity competitive to that of Nafion and the high transference number of cations.
