High Pressure Studies of Hydrated Nafion Membranes: Dielectric Relaxation and Deuteron NMR
Abstract
Audio frequency electrical conductivity/dielectric relaxation and nuclear magnetic resonance studies of Nafion-117 have been carried out at pressures up to 0.3 GPa (3 kbar). For some samples, the electrical conductivity exhibits dispersion typical of hopping conductivity in an amorphous material, sigma=sigma o omega m. The values of m are sample dependent and vary from about 0.55 to 0.75. In addition, the values of m are not strongly pressure sensitive. At a given frequency, the electrical conductivity tends to decrease as pressure increases and yield activation volumes on the order of 5 to 10 cu. cm/mol. The activation volume determined from the NMR spin-lattice relaxation time measurements are also sample dependent. The data shown correspond to an activation volume of about 8.6 cu.cm/mol.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 16, 1993
- Accession Number
- ADA263511
Entities
People
- J. P. Jayakody
- John J. Fontanella
- M. C. Wintersgill
- M. G. Mclin
- R. S. Chen
- S. G. Greenbaum
Organizations
- United States Naval Academy