Dielectric properties of hydrated Nafion-(SO3K) membranes: Thermally stimulated depolarization currents

Tsonos, C; Apekis, L; Pissis, P

dc.contributor.author	Tsonos, C	en
dc.contributor.author	Apekis, L	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:13:41Z
dc.date.available	2014-03-01T01:13:41Z
dc.date.issued	1998	en
dc.identifier.issn	0022-2461	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12654
dc.subject	Activation Energy	en
dc.subject	Dielectric Properties	en
dc.subject	Potassium	en
dc.subject	Structural Change	en
dc.subject	Water Content	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.other	Activation energy	en
dc.subject.other	Anelastic relaxation	en
dc.subject.other	Dielectric properties of solids	en
dc.subject.other	Dispersions	en
dc.subject.other	Electrodes	en
dc.subject.other	Fluorine containing polymers	en
dc.subject.other	Hydration	en
dc.subject.other	Potassium compounds	en
dc.subject.other	Thermally stimulated depolarization current (TSDC) techniques	en
dc.subject.other	Polymeric membranes	en
dc.title	Dielectric properties of hydrated Nafion-(SO3K) membranes: Thermally stimulated depolarization currents	en
heal.type	journalArticle	en
heal.identifier.primary	10.1023/A:1004300109874	en
heal.identifier.secondary	http://dx.doi.org/10.1023/A:1004300109874	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	Dielectric studies have been carried out on hydrated perfluorosulfonate polymer membranes in potassium salt form, 1190 g equivalent(-1) by means of thermally stimulated depolarization current (TSDC) techniques in the temperature range 77-300K. Three dispersions I-III, are observed in a TSDC thermogram, and their positions depend upon the water content. We employ thermal sampling (TS) to analyse the three relaxation process experimentally, into approximately single responses and to determine the spectra of activation energy, E(T), on a sample with a water content of 0.9 H2O/SO3K. Dispersion I is analogous to the gamma-relaxation mechanism, which was observed in mechanical relaxation studies, with an activation energy between 0.55 and 0.68 eV. Measurements with different electrode configuration reveal different aspects of the dynamics of the relaxation mechanism and allow distinction between dipolar and interfacial polarization contributions of Dispersion II. Dispersion II is analogous to the beta-relaxation mechanism that was observed in mechanical relaxation studies on hydrated membranes. Dispersion III may be due to a phase or structural change of the material in this temperature range. However, a contribution to this peak from electrochemical effects at the electrodes cannot be excluded. (C) 1998 Chapman & Hall.	en
heal.publisher	KLUWER ACADEMIC PUBL	en
heal.journalName	Journal of Materials Science	en
dc.identifier.doi	10.1023/A:1004300109874	en
dc.identifier.isi	ISI:000073101400033	en
dc.identifier.volume	33	en
dc.identifier.issue	8	en
dc.identifier.spage	2221	en
dc.identifier.epage	2226	en