(128c) Broadband Dielectric Spectroscopy Characterization of Chemical Degradation in Nafion®/Silicate Nanocomposite Membranes

Nafion/silicate nanocomposite membranes were generated by means of in situ sol-gel processes catalyzed by dibutyltin dilaurate. The results of the use of broadband dielectric spectroscopy to examine the molecular motions in such hybrid membranes that were degraded in Fenton's reagent at room temperature will be presented. Spectral shifts in the β-relaxation (glass transition) temperature-frequency region for untreated samples that were caused by degradation will be discussed. Relaxation parameters extracted from fitting experimental data to the Havriliak-Negami and Vogel-Fulcher-Tammann-Hesse equations quantitatively characterize chemical degradation. These parameters reflect long range perfluorocarbon chain dynamics, local molecular environment and molecular weight distribution as affected by degradation. The results of other dynamic characterization methods, such as dynamic mechanical analysis, stress relaxation and creep will be presented and correlated to the dielectric spectroscopic results.