Mössbauer investigations of Nafion membranes

2014 Mössbauer experiments have been performed on Nafion ion exchange membranes neutralized with iron chloride. The recoilless fraction falls to zero at a temperature which depends on the water content, showing that the rigidity of the local ion environment is greatly influenced by the amount of water retained in these membranes. Two different iron sites are defined, whose relative intensities vary with water content. One of the doublets is attributed to a (Fe2+, H2O complex whose hyperfine parameters are essentially independent of the quantity of water. The second doublet is attributed to a less hydrated species. No evidence of magnetic hyperfine structure is found, even at 4.2 K. Revue Phys. Appl. 15 (1980) JUIN 1980, PAGE 1179 Classification Physics Abstracts 61.40K 76.80