Broadening of the fluorescence spectra of hydrocarbons in ethylene-vinyl acetate copolymers and the dynamics of the glass transition

dc.creatorMartins, TD
dc.creatorYamaki, SB
dc.creatorPrado, EA
dc.creatorAtvars, TDZ
dc.date2003
dc.date43891
dc.date2014-11-15T00:34:36Z
dc.date2015-11-26T17:18:01Z
dc.date2014-11-15T00:34:36Z
dc.date2015-11-26T17:18:01Z
dc.date.accessioned2018-03-29T00:05:51Z
dc.date.available2018-03-29T00:05:51Z
dc.identifierJournal Of Photochemistry And Photobiology A-chemistry. Elsevier Science Sa, v. 156, n. 41699, n. 91, n. 103, 2003.
dc.identifier1010-6030
dc.identifierWOS:000181809900013
dc.identifier10.1016/S1010-6030(02)00401-X
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/63277
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/63277
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/63277
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1282585
dc.descriptionThe steady-state fluorescence of two fluorescent condensed aromatic hydrocarbons (anthracene and pyrene) with different fluorescence decay rates (a few nanoseconds and hundreds of nanoseconds, respectively) were employed to investigate the relaxation processes of several random ethylene-co-vinyl acetate copolymers (EVA). Copolymers with various comonomer compositions (EVA-9, EVA-18, EVA-25 and EVA-33) were studied. Data for the EVAs were compared with the same aromatic molecules in low-density polyethylene (LDPE), high-density polyethylene (HDPE) and poly(vinyl acetate) (PVAc) homopolymer models. The fluorescence rate constants were measured by single photon counting at room temperature. The wavelength dependence of the emission spectra (the edge-excitation red-shift (EERS)) were studied at room temperature and at 77 K and the data were interpreted based on the correlation of the differences of decay rates for both molecules and the time correlation of the polymer relaxation processes. The spectral broadenings (full-width at half-maximum (FWHM)) of the fluorescence spectra were studied from 20 to 400 K, which included temperature ranges above and below the glass transition, and these broadenings are compared. (C) 2003 Elsevier Science B.V. All rights reserved.
dc.description156
dc.description41699
dc.description91
dc.description103
dc.languageen
dc.publisherElsevier Science Sa
dc.publisherLausanne
dc.publisherSuíça
dc.relationJournal Of Photochemistry And Photobiology A-chemistry
dc.relationJ. Photochem. Photobiol. A-Chem.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectethylene-co-vinyl acetate copolymers
dc.subjectspectral broadening
dc.subjectrelaxation processes
dc.subjectfluorescence spectroscopy
dc.subjectanthracene and pyrene
dc.subjectLow-density Polyethylene
dc.subjectRed-edge Excitation
dc.subjectDielectric-relaxation
dc.subjectPoly(vinyl Acetate)
dc.subjectBeta-relaxation
dc.subjectSpectroscopy
dc.subjectPolymers
dc.subjectProbes
dc.subjectState
dc.subjectTranslocation
dc.titleBroadening of the fluorescence spectra of hydrocarbons in ethylene-vinyl acetate copolymers and the dynamics of the glass transition
dc.typeArtículos de revistas


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