title: Quantifying the structural changes of perfluorosulfonated acid ionomer upon reaction with hydroxyl radicals.
abstract: We report molecular-level quantification of chemical degradation of perfluorosulfonated acid (PFSA) ionomer membranes. This is made possible by determining the structure of Nafion 211 using calibrated (19)F magic angle spinning nuclear magnetic resonance spectroscopy upon exposure to hydroxyl radicals. Individual segments of the ionomer were monitored to show that the backbone is resistant to hydroxyl radical attack and that degradation occurs solely on the side chain, with the most significant attack occurring toward the end of the side chain. The method provides a means to evaluate changes in chemical structure of PFSA ionomers with a much higher degree of certainty than previously possible.
authors.affiliation: Department of Chemistry, Simon Fraser University , 8888 University Drive, Burnaby, British Columbia, Canada V5A1S6.
authors.forename: Lida
authors.initials: L
authors.lastname: Ghassemzadeh
authors.forename: Steven
authors.initials: S
authors.lastname: Holdcroft