title: Unlocking the observation of different proton populations in fluorinated polymers by solid-state1H and19F double resonance NMR spectroscopy.
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-state1H and19F double resonance nuclear magnetic resonance (NMR) spectroscopy using the recently revived multiple contact cross-polarization (MC-CP) pulse sequence along with double-quantum1H-1H 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 mobile1H and19F 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.
authors.affiliation: Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F Box 2461, B-3001 Leuven, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Goossens
authors.affiliation: Tectospin, Institut Lavoisier de Versailles, CNRS UMR8180, Université de Versailles Saint-Quentin en Yvelines, 45 Avenue des États-Unis, 78035 Versailles Cedex, France. Charlotte.Martineau@uvsq.fr Francis.Taulelle@uvsq.fr and CEMHTI, CNRS UPR3079, 1D Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France.
authors.forename: C
authors.initials: C
authors.lastname: Martineau-Corcos
authors.affiliation: Tectospin, Institut Lavoisier de Versailles, CNRS UMR8180, Université de Versailles Saint-Quentin en Yvelines, 45 Avenue des États-Unis, 78035 Versailles Cedex, France. Charlotte.Martineau@uvsq.fr Francis.Taulelle@uvsq.fr.
authors.forename: F
authors.initials: F
authors.lastname: Saïdi
authors.affiliation: Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F Box 2461, B-3001 Leuven, Belgium.
authors.forename: J A
authors.initials: JA
authors.lastname: Martens
authors.affiliation: Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F Box 2461, B-3001 Leuven, Belgium and Tectospin, Institut Lavoisier de Versailles, CNRS UMR8180, Université de Versailles Saint-Quentin en Yvelines, 45 Avenue des États-Unis, 78035 Versailles Cedex, France. Charlotte.Martineau@uvsq.fr Francis.Taulelle@uvsq.fr.
authors.forename: F
authors.initials: F
authors.lastname: Taulelle