Complex Impedance Studies Of Proton-Conducting Membranes
Abstract
Complex impedance studies have been carried out on Dow 800, Dow 1000 and Nafion 117 membranes at various water contents and a variety of temperatures and pressures. At room temperature and pressure a gradual decrease in electrical conductivity with decreasing water content is observed. Apparent activation volumes as large as 54 cm3/mol are obtained. In addition, there is a tendency for smaller equivalent weights (same side chains) or larger side chains to have larger activation volumes. Additionally, ambient-pressure, variable-temperature 2H T1 and linewidth measurements imply a heterogeneous environment of the water molecules. Proton pulsed field gradient NMR studies in saturated Dow membranes verify the expectation that ionic conductivity is determined primarily by diffusion of water molecules.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1999
- Accession Number
- ADA365266
Entities
People
- C. A. Edmondson
- John J. Fontanella
- M. C. Wintersgill
- M. E. Chapman
- P. E. Stallworth
Organizations
- United States Naval Academy