Dielectric studies of glass transition in confined propylene glycol

Pissis, P; Kyritsis, A; Daoukaki, D; Barut, G; Pelster, R; Nimtz, G

dc.contributor.author	Pissis, P	en
dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Daoukaki, D	en
dc.contributor.author	Barut, G	en
dc.contributor.author	Pelster, R	en
dc.contributor.author	Nimtz, G	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	0953-8984	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12656
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	FORMING LIQUIDS	en
dc.subject.other	POLYMER-FILMS	en
dc.subject.other	MOLECULAR LIQUIDS	en
dc.subject.other	ALPHA-RELAXATION	en
dc.subject.other	POROUS-GLASS	en
dc.subject.other	DYNAMICS	en
dc.subject.other	TEMPERATURE	en
dc.subject.other	SIZE	en
dc.subject.other	METHACRYLATE)	en
dc.subject.other	COOPERATIVITY	en
dc.title	Dielectric studies of glass transition in confined propylene glycol	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/0953-8984/10/28/004	en
heal.identifier.secondary	http://dx.doi.org/10.1088/0953-8984/10/28/004	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	The dynamical behaviour of the glass transition of propylene glycol confined in droplets in butyl rubber (three-dimensional confinement, mean droplet diameter d = 8-11 nm) and in pores in controlled porous glasses (two-dimensional confinement, mean pore diameter d = 2.5-7.5 nm) has been studied in detail by means of broadband dielectric spectroscopy (5 Hz-2 GHz) and of thermally stimulated depolarization current measurements. Effective medium theory corrections of the data are discussed. The results indicate the existence of a relatively immobile interfacial layer close to the wall. For the volume liquid the dynamics of the glass transition becomes faster and the glass transition temperature T-g decreases compared to the bulk liquid. The shifts Delta T-g increase with decreasing d, are larger in butyl rubber than in controlled porous glasses (three-dimensional versus two-dimensional confinement) and vanish for d approximate to 10-12 nm. These results are discussed in relation to those obtained with polymers confined in thin polymeric films (one-dimensional confinement) and in semicrystalline polymeric samples and are explained on the basis of the cooperativity concept and the model of Adam and Gibbs. The cooperativity length xi at T-g is determined to be xi less than or equal to 5-6 nm in both butyl rubber and controlled porous glasses. Interesting effects of confinement are observed on the shape of the dielectric response of the process associated with the glass transition.	en
heal.publisher	IOP PUBLISHING LTD	en
heal.journalName	Journal of Physics Condensed Matter	en
dc.identifier.doi	10.1088/0953-8984/10/28/004	en
dc.identifier.isi	ISI:000075047000004	en
dc.identifier.volume	10	en
dc.identifier.issue	28	en
dc.identifier.spage	6205	en
dc.identifier.epage	6227	en