NMR, DCS, TMA, and High Pressure Electrical Conductivity Studies in Solid, Crosslinked Dimethylsiloxane-Ethylene Oxide Copolymer Networks Containing Sodium.
Abstract
Audio frequency electrical conductivity and 23Na NMR studies have been carried out on solid, crosslinked dimethylsiloxane-ethylene oxide copolymer networks containing sodium. The electrical measurements have been carried out in vacuum over the temperature range 5-380K and at pressures up to 0.65 GPa over the temperature range 230-380K. The electrical conductivity exhibits VTF or WLF behavior. From a VTF analysis, Ea is found to be about 0.11 eV and T sub 0 is found to be about 45 C below the central glass transition temperature as determined by both DSC and TMA. Also T sub O is found to increase about 50 K/GP and Ea increases significantly with pressure. In addition, the high pressure studies show that the activation volume associated with the electrical conductivity decreases from 44 to 23 cu cm/mol over the temperature range 262-323K. The 23Na NMR measurements reveal the presence of both bound and mobile sodium species, the relative concentrations of which change by about a factor of 10 over the temperature range -100 to +100 C. Broadening of the bound 23Na line above room temperature suggests the possible presence of ion pairs or higher aggregates in the complex. Keywords: Solid electrolytes; Polymer electrolytes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1986
- Accession Number
- ADA172339
Entities
People
- John J. Fontanella
- Mary C. Wintersgill
Organizations
- United States Naval Academy