ION CONDUCTION IN POLY(CROWN ETHERS), POLYGLUCOSAN GELS AND MACROPOROUS POLYETHYLENE FILMS

Much work has been reported on ion conduction in solid solutions of salts dissolved in linear and comb-branched poly(ethylene oxide) analogues. There appears to be a limit to the conductivity levels achieved in such systems, and conductivity values rarely exceed sigma similar to 10(-4) Scm(-1) at room temperature. To overcome this there has been a move towards more mobile plasticized systems and polymer gel electrolytes are receiving some attention. Gels prepared from N-methyl-2-pyrrolidinone/LiCl and polyglucosans such as cellulose and amylose have been studied and show some promise with ambient sigma greater than or equal to 10(-4) Scm(-1). Macroporous polyethylene has also been used to support fluid polyethylene glycol/salt systems, but these only reached sigma greater than or equal to 10(-5) Scm(-1) at ambient temperature. Comb-branch polymers with crown ethers provide systems with respectable room temperature conductivities of between 10(-4) and 10(-5) Scm(-1), but these might be improved if the crown ethers could be arranged in regular channels. Ways to achieve this are briefly discussed.