Studies of Water in Nafion Membranes: Dielectric Relaxation and Deuteron and Oxygen-17 NMR
Abstract
Dielectric relaxation and both deuteron and oxygen-17 nuclear magnetic resonance measurements on NAFION-117 membranes with variable water content (approx. 5 - 18 % by weight) are reported. Glassy behavior of the water domains at low T (below approx. 200 K) is evidenced by the specific nature of the observed dielectric loss peaks and 2 H NMR lineshapes. Activation energies extracted from 2 H spin-lattice relaxation data on the high T side of the T sub one minimum exhibit a steady increase with increasing water content. In spite of a high degree of water molecular mobility, angular-dependent spectra in both as- received and stretched samples reflect considerable anisotropy of the host polymer. A dielectric loss peak is observed which has previously been attributed to the glass transition of the aqueous domains.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 25, 1993
- Accession Number
- ADA261505
Entities
People
- Gaofeng Xu
- J. J. Fontanella
- J. R. Jayakody
- M. G. Mclin
- R. S. Chen
- S. G. Greenbaum
- Y. S. Pak
Organizations
- Hunter College