Unlocking the observation of different proton populations in fluorinated polymers by solid-state 1H and 19F double resonance NMR spectroscopy. Issue 41 (7th October 2016)

• Record Type: Journal Article
• Authors: Goossens, P.; Martineau-Corcos, C.; Saïdi, F.; Martens, J. A.; Taulelle, F.
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 41(2016)
• Page Start: 28726
• Page End: 28731
• Publication Date: 2016-10-07
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp04139f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : This new method for observing Nafion proton distributions holds potential for finally unraveling the mystery behind its phenomenal proton conduction. Abstract : Nafion proton exchange membranes (PEMs) for fuel cell applications are extensively studied and commercially applied, but their unique proton conduction capabilities are still somewhat unexplained. For studying proton dynamics in situ, molecular level spectroscopic techniques have been of limited utility so far. By solid-state 1 H and 19 F double resonance nuclear magnetic resonance (NMR) spectroscopy using the recently revived multiple contact cross-polarization (MC-CP) pulse sequence along with double-quantum 1 H– 1 H filtering, high resolution proton populations distinct from the dominant water resonance were observed in Nafion for the first time. This methodology quenches signal decay due to spin–lattice relaxation in the rotating frame and enables magnetization transfer between the relatively mobile 1 H and 19 F spin baths in Nafion. Further studies of these previously unrevealed proton populations will lead to a better understanding of the Nafion proton conduction mechanism and proton exchange processes in general.