Accession Number:

ADA263511

Title:

High Pressure Studies of Hydrated Nafion Membranes: Dielectric Relaxation and Deuteron NMR

Descriptive Note:

Interim technical rept. Mar 1992-Apr 1993

Corporate Author:

NAVAL ACADEMY ANNAPOLIS MD DEPT OF PHYSICS

Report Date:

1993-04-16

Pagination or Media Count:

16.0

Abstract:

Audio frequency electrical conductivitydielectric 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, sigmasigma 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. cmmol. 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.cmmol.

Subject Categories:

  • Inorganic Chemistry
  • Physical Chemistry
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE