APTES-Modified RE2O3:Eu3+ Luminescent Beads: Structure and Properties
| Autor: | Serge Mazeres, Jeannette Dexpert-Ghys, Robert Mauricot, Marc Verelst, Sidney José Lima Ribeiro, Peter Hammer, H. Dexpert, José Maurício Almeida Caiut, Séverine Lechevallier |
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| Rok vydání: | 2012 |
| Předmět: |
Lanthanide
LUMINESCÊNCIA Luminescence Materials science Propylamines Analytical chemistry Oxide Surfaces and Interfaces Silanes Condensed Matter Physics Lanthanoid Series Elements chemistry.chemical_compound Europium X-ray photoelectron spectroscopy chemistry Spectroscopy Fourier Transform Infrared Electrochemistry Surface modification General Materials Science Amine gas treating Titration Fourier transform infrared spectroscopy Spectroscopy Nuclear chemistry |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la204469f |
| Popis: | Europium-doped lanthanide oxide RE(2)O(3):Eu(3+) (RE = Y or Gd) luminescent beads, with a spherical shape and a diameter of 150 ± 15 nm, have been modified by reaction with 3-aminopropyltriethoxysilane (APTES), in order to introduce reactive amine groups at their surfaces. The direct silanation has resulted in the formation of a nanometric layer at the surface of the beads, with an optimum grafting rate of 0.055 ± 0.005 mol APTES/mol RE(2)O(3). Fourier transform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopies confirmed the condensation of an organosilane layer, made of cross-linked -O-Si-O-Si- and of groups -O-Si-R (with R = (CH(2))(3)NH(2) or O-Et). Titration of the accessible amine groups has been performed by simultaneously measuring the luminescence of grafted fluorescein isothiocyanate and that of core particles: there are about 2.3 × 10(4) (2.8 × 10(4)) -NH(2) per Y(2)O(3):Eu(3+) (Gd(2)O(3):Eu(3+)) bead. The isoelectronic point was shifted by one pH unit after APTES modification. The surface modification by APTES at least preserved (for Gd(2)O(3):Eu(3+)) or improved (for Y(2)O(3):Eu(3+)) the red emission of the beads. |
| Databáze: | OpenAIRE |
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