Publication: EXAFS, SAXS and Eu3+ luminescence spectroscopy of sol-gel derived siloxane-polyethyleneoxide hybrids
Loading...
Date
Advisor
Coadvisor
Graduate program
Undergraduate course
Journal Title
Journal ISSN
Volume Title
Publisher
Kluwer Academic Publ
Type
Article
Access right
Acesso restrito
Abstract
Hybrid Eu3+-doped silica-poliethyleneoxide (PEO) nanocomposites with covalent bonds between the inorganic (siloxane) and organic (PEO) phases have been obtained by sol-gel process. These materials are transparent, flexible and present high Eu3+ luminescence output. Their luminescence properties, local environment around europium ions and structure have been investigated as a function of europium content. EXAFS measurements indicate that the increase in Eu-doping induces a decrease in Eu3+ coordination number. An increase in symmetry degree around the metal ion is also observed for increasing Eu3+ concentration, while non radiative decay paths from the D-5(0) excited state become more important. SAXS results suggest the preferential interaction of europium ions with ether-type oxygens of the polymer chains. However, the existence of interactions between the cations and the carbonyl groups from urea bridges located at the siloxane-PEO interface can not be excluded.
Description
Keywords
hybrids, luminescence, SAXS, EXAFS
Language
English
Citation
Journal of Sol-gel Science and Technology. Dordrecht: Kluwer Academic Publ, v. 19, n. 1-3, p. 615-620, 2000.
