Dielectric studies of molecular mobility in hydrated zeolites

Pissis, P; Daoukaki-Diamanti, D

dc.contributor.author	Pissis, P	en
dc.contributor.author	Daoukaki-Diamanti, D	en
dc.date.accessioned	2014-03-01T01:09:22Z
dc.date.available	2014-03-01T01:09:22Z
dc.date.issued	1993	en
dc.identifier.issn	0022-3697	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/10929
dc.subject	conductivity	en
dc.subject	depolarization currents	en
dc.subject	dielectric relaxation	en
dc.subject	water sorption	en
dc.subject	Zeolites	en
dc.subject.classification	Chemistry, Multidisciplinary	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	Crystal structure	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Electric current measurement	en
dc.subject.other	Hydration	en
dc.subject.other	Mass transfer	en
dc.subject.other	Porous materials	en
dc.subject.other	Spectroscopy	en
dc.subject.other	Dielectric polarization	en
dc.subject.other	Dielectric relaxation spectroscopy	en
dc.subject.other	Hydrated zeolites	en
dc.subject.other	Ion motion	en
dc.subject.other	Maxwell-Wagner effect	en
dc.subject.other	Thermally stimulated depolarization currents	en
dc.subject.other	Water molecule mobility	en
dc.subject.other	Zeolite supercages	en
dc.subject.other	Zeolites	en
dc.title	Dielectric studies of molecular mobility in hydrated zeolites	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/0022-3697(93)90130-J	en
heal.identifier.secondary	http://dx.doi.org/10.1016/0022-3697(93)90130-J	en
heal.language	English	en
heal.publicationDate	1993	en
heal.abstract	We report on detailed investigations of the dielectric relaxation mechanisms in a Na-13X zeolite by means of the method of thermally-stimulated depolarization currents (TSDC) over a wide range of temperatures, 77-300 K, and water content, 0.020-0.566 w w. Interest is mainly focused on quantitatively characterizing the effects of water on the motion of ions and the reduction of the mobility of water molecules in the confined pore geometry. Five distinct relaxation processes were identified. Three of them were attributed to motions of ions, namely, in the order of increasing temperature, local jumps of ions in the supercages, a Maxwell-Wagner effect and d.c. conductivity. The remaining two processes, present in the samples only for water content higher than a critical one for the completion of the first hydration layer, about 0.30, were ascribed to the reorientation of water molecules in the supercages and the small β-cages, respectively. The reduction of the mobility of water molecules was much stronger in the β-cages than in the supercages. © 1993.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Journal of Physics and Chemistry of Solids	en
dc.identifier.doi	10.1016/0022-3697(93)90130-J	en
dc.identifier.isi	ISI:A1993LG39000005	en
dc.identifier.volume	54	en
dc.identifier.issue	6	en
dc.identifier.spage	701	en
dc.identifier.epage	709	en