Morphological Heterogeneity by Diffusional Kurtosis NMR Spectroscopy in Perfluorosulfonic Acid/SiO2 Composite Proton-Exchange Membranesстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 9 ноября 2017 г.
Аннотация:Diffusional kurtosis is introduced to characterize the heterogeneity of the channel architecture for ionic transport in proton exchange membranes. Measuring the apparent kurtosis by a pulsed-field-gradient NMR spectroscopy technique may yield additional information about membrane morphology not available to the conventional water-diffusion method. Water diffusional kurtosis and the apparent diffusion coefficient are investigated for perfluorinated sulfonic acid (PFSA)/SiO2 nanocomposites. Diffusional kurtosis is anisotropic revealing higher channel heterogeneity in-plane of solution-cast films compared with the transverse direction. Diffusional kurtosis is related to the non-Gaussian character of the averaged diffusion propagator. A universal relationship is proposed for the root-mean-squared displacement.