Dielectric studies of molecular mobility in hydrogels

Pissis, P; Kyritsis, A; Konsta, AA; Daoukaki, D

dc.contributor.author	Pissis, P	en
dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Konsta, AA	en
dc.contributor.author	Daoukaki, D	en
dc.date.accessioned	2014-03-01T01:14:31Z
dc.date.available	2014-03-01T01:14:31Z
dc.date.issued	1999	en
dc.identifier.issn	0022-2860	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13120
dc.subject	Dielectric relaxation spectroscopy	en
dc.subject	Hydrogels	en
dc.subject	Organization of water	en
dc.subject	Polymer-water interactions	en
dc.subject	Thermally stimulated depolarization currents	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	article	en
dc.subject.other	cross linking	en
dc.subject.other	depolarization	en
dc.subject.other	dielectric constant	en
dc.subject.other	hydration	en
dc.subject.other	hydrogel	en
dc.subject.other	implantation	en
dc.subject.other	molecular dynamics	en
dc.title	Dielectric studies of molecular mobility in hydrogels	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0022-2860(98)00867-9	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0022-2860(98)00867-9	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	We report on polymer-water interactions and on the organization of water in two hydrogel systems, investigated by dielectric relaxation spectroscopy (DRS) measurements. The hydrogels are based on poly(hydroxyethyl acrylate) (PHEA) and on polyacrylamide (PAM), respectively. The water content was systematically varied up to 0.46 g water/g dry material in the PHEA hydrogels and up to 1.5 g/g in the PAM hydrogels. The measuring techniques include broadband DRS in the 5 Hz to 20 GHz frequency range and thermally stimulated depolarization currents (TSDC) techniques in the 77-300 K temperature range. Information on specific polymer-water interactions and on the organization of water in a separate water phase in the pores of the hydrogels is obtained by systematically investigating the effects induced by water on the secondary and main dielectric relaxation mechanisms and on DC conductivity and by looking at the reorientation of water molecules themselves. The PHEA hydrogels were studied extensively, whereas only preliminary results are reported for the PAM hydrogels. (C) 1999 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Journal of Molecular Structure	en
dc.identifier.doi	10.1016/S0022-2860(98)00867-9	en
dc.identifier.isi	ISI:000079357000006	en
dc.identifier.volume	479	en
dc.identifier.issue	2-3	en
dc.identifier.spage	163	en
dc.identifier.epage	175	en