Ionic conductivity in solid, crosslinked dimethylsiloxane-ethylene oxide copolymer networks containing sodium

The preparation of an ion-conducting elastomeric solid based on a dimethylsiloxane-ethylene oxide copolymer complexed with a sodium salt is described. 23Na nuclear magnetic resonance measurements reveal the presence of both bound and mobile sodium species throughout the temperature range −120 to 100 °C. Electrical conductivity measurements over a similar temperature range are found to be consistent with the configurational entropy model for transport, with a T0 parameter about 50 °C below the ‘‘central’’ glass transition temperature Tg.