Water self-diffusion anisotropy and electrical conductivity of perfluorosulfonic acid/SiO2 composite proton exchange membranes

Autor:	Dan E. Demco, Carmen Filipoi, Martin Möller, Radu Fechete, R. A. Vinokur, Oliver Conradi, Xiaomin Zhu
Rok vydání:	2012
Předmět:	Self-diffusion Membrane Proton Chemistry Electrical resistivity and conductivity Diffusion Analytical chemistry General Physics and Astronomy Relative humidity Physical and Theoretical Chemistry Conductivity Anisotropy Physics::Atmospheric and Oceanic Physics
Zdroj:	Chemical Physics Letters. 554:143-149
ISSN:	0009-2614
DOI:	10.1016/j.cplett.2012.10.031
Popis:	Water self-diffusion anisotropy in perfluorosulfonic acid (PFSA)/SiO2 composite membranes was investigated by pulsed gradient spin-echo NMR as a function of diffusion time, temperature and relative humidity. The anisotropy of water diffusion that is related to the ion channel orientation decreases with the increase of silica content, diffusion time and relative humidity. Activation energies of water diffusion and proton conductivity were evaluated for the temperature range of 313–363 K. Empirical dependences for proton conductivity and proton diffusion coefficient as a function of water uptake were established and correlated with the silica content of membranes. The effect of in situ grown sulfonated silica nanoparticles on the orientation of water channels is also discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::9aff1b0a3494224841b5724241d10630 https://doi.org/10.1016/j.cplett.2012.10.031 Zobrazit plný text záznamu Full Text from ScienceDirect