Carlos, Luís D.Sá Ferreira, Rute A.De Zea Bermudez, VerónicaRibeiro, Sidney José Lima [UNESP]2014-05-272014-05-272001-04-01Advanced Funtional Materials, v. 11, n. 2, p. 111-115, 2001.1616-301Xhttp://hdl.handle.net/11449/66482Sol-gel derived hybrids that contain OCH2CH2 (polyethylene glycol, PEG) repeat units grafted onto a siliceous backbone by urea, -NHC(=O)NH-, or urethane, -NHC(=O)O-, bridges have been prepared. It is demonstrated that the white light PL of these materials results from an unusual convolution of a longer lived emission that originates in the NH groups of the urea/urethane bridges with shorter lived electron-hole recombinations occurring in the nanometer-sized siliceous domains. The PL efficiencies reported here (maximum quantum yields at room temperature of ≈ 0.20 ± 0.02 at a 400 nm excitation wavelength) are in the same range as those for tetramethoxysilane-formic acid, and APTES-acetic acid, sol-gel derived phosphors. The high quantum yields combined with the possibility of tuning the emission to colors across the chromaticity diagram present a wide range of potential applications for these hybrid materials.111-115engAminesCrosslinkingElectronsGrafting (chemical)Molecular weightOrganic acidsPhotoluminescencePolyethylene glycolsQuantum theorySol-gelsUreaChromaticityElectron-hole recombinationFormic acidQuantum yieldTetramethoxysilaneUrethanePhosphorsArtigo10.1002/1616-3028(200104)11:2<111::AID-ADFM111>3.0.CO;2-VWOS:000169587200004Acesso restrito2-s2.0-003531439964460474630346540000-0003-3286-9440