Water Absorption and Conductivity in Poly(Ethylene Oxide)-Lithium Tetrafluoroborate Films.
Abstract
Water-vapor absorption and conductivity in spin-cast poly(ethylene oxide)- lithium tetrafluoroborate films were investigated near 21 deg C by in situ near-infrared spectroscopy and ac conductance measurements. The film conductivity was less than or = .0002 ohhms/cm until the water content exceeded that corresponding to LiBF4.3H2O. It increased with additional water, reaching .003 ohms/cm at the composition equivalent to LiBF4.20H2O. Most of the water above the trihydrate level was unstably absorbed, however, and began to escape from the film within a few minutes. This syneresis was attributed to spontaneous restructuring or crystallization of the polymer. The conductivity data were interpreted on the basis of a two-phase model in which one portion of the salt remained in a nonconductive solid region, while the other portion dissolved in a more fluid conductive polymer-water region.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1984
- Accession Number
- ADA147969
Entities
People
- M. M. Nicholson
- T. P. Weismuller