1H nuclear magnetic resonance study of low-temperature water dynamics in a water-soaked perfluorosulfonic acid ionomer Nafion film. (January 2017)

• Record Type: Journal Article
• Authors: Han, Jun Hee; Lee, Kyu Won; Lee, Cheol Eui
• Is Part Of: Solid state communications. Volume 250(2017)
• Page Start: 28
• Page End: 30
• Publication Date: 2017-01
• Subjects: A. Water-soaked Nafion film -- D. Non-freezing water dynamics -- E. Proton nuclear magnetic resonance spectroscopy; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2016.11.005
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We have employed proton nuclear magnetic resonance (NMR) spectroscopy in order to study the low-temperature water dynamics in a water-soaked perfluorosulfonic acid ionomer Nafion (NR-211) film. According to the recent models, Nafion may comprise water strongly bound to the sulfonic acid group, hydration water, and condensed water species. In this work, three separate NMR peaks from the water species revealing distinct behaviors were identified. A significant portion of the "bound" water remained unfrozen down to 200 K, whereas a slow-to-fast motional limit transition was observed at T M =220 K from the relaxation measurements. Abstract : Highlights: Proton NMR to study the low-temperature water dynamics in a water-soaked Nafion film. Three distinct water species were well separated revealing distinct behaviors. "Bound" water remained unfrozen showing a slow-to-fast motional limit transition at 220 K.