Gelification of liquid-polymer systems: a valid approach for the development of various types of polymer electrolyte membranes

Large interest is presently devoted to the development of gel membranes and to their use in advanced-design, plastic-like electrochemical devices. In our laboratory, we have demonstrated the validity of this approach for the case of lithium ion conducting membranes, e.g., membranes formed by the imm obilization of mixed organic solutions of lithium salts in a polymer matrix (PM). Relevant examples are membranes formed by the gelification of a LiPF 6 ethylene carbonate-dimethyl carbonate (EC-DMC) solution into a poly(acryl onitrile) (PAN) matrix. In this paper, in addition to reporting the charact eristics of some selected examples of lithium membranes, we demonstrate tha t the gel approach can be extended to other ion-conducting membranes. In pa rticular, we report the properties of new types of protonic membranes forme d by the inclusion of mixed solvent solution of an organic acid in a poly(m ethylmetacrylate) (Ph IMA) matrix. The results confirm that the gel-forming procedure, so far mainly addressed to the fabrication of lithium-conductin g membranes, may indeed be extended to other ionic polymer systems. (C) 200 0 Elsevier Science S.A. All rights resented.