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Titolo:
Diffuse reflectance UV-Visible spectroscopy for the qualitative and quantitative study of chromophores adsorbed or grafted on silica
Autore:
Lacombe, S; Cardy, H; Soggiu, N; Blanc, S; Habib-Jiwan, JL; Soumillion, JP;
Indirizzi:
Univ Pau, UMR CnRS 5624, CNRS, F-64013 Pau, France Univ Pau Pau France F-64013 au, UMR CnRS 5624, CNRS, F-64013 Pau, France Univ Catholique Louvain, Unite Chim Mat, CMAT, B-1348 Louvain, Belgium Univ Catholique Louvain Louvain Belgium B-1348 , B-1348 Louvain, Belgium
Titolo Testata:
MICROPOROUS AND MESOPOROUS MATERIALS
fascicolo: 2-3, volume: 46, anno: 2001,
pagine: 311 - 325
SICI:
1387-1811(200108)46:2-3<311:DRUSFT>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
LINE ACTIVITY MEASUREMENTS; CHROMIUM-OXIDE CATALYSTS; X-RAY PHOTOELECTRON; MICROCRYSTALLINE CELLULOSE; AMINO-GROUPS; PORE-SIZE; SURFACES; LUMINESCENCE; GEL; SPECTROMETRY;
Keywords:
silica; adsorption; grafting; diffuse reflectance UV-Visible spectroscopy;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Lacombe, S Univ Pau, UMR CnRS 5624, CNRS, BP1155, F-64013 Pau, France UnivPau BP1155 Pau France F-64013 BP1155, F-64013 Pau, France
Citazione:
S. Lacombe et al., "Diffuse reflectance UV-Visible spectroscopy for the qualitative and quantitative study of chromophores adsorbed or grafted on silica", MICROP M M, 46(2-3), 2001, pp. 311-325

Abstract

Diffuse reflectance UV-Visible spectroscopy (DRUV) is used to study the adsorption and grafting of the pyrene derivative 1 on different types of silicas. For the adsorbed silicas, the formation of dimeric aggregates is evidenced both by DRUV and by fluorescence spectroscopy. The processing of the UV spectrophotometric data allows, as in solution. the determination of apparent equilibrium constants and of the spectra of the dimer. From these results, two sets of silicas are distinguished according to the amount of dimerformed and to its UV spectrum. Lower amounts of dimeric species are found on silica with either large pore size or low particle size. The spectrum inthis case is only slightly redshifted relative to that of the monomeric compound. When the pore size decreases, dimer formation is more significant and its spectrum is more characteristic. The results obtained for adsorbed silicas were quantitatively treated and the Kubelka-Munk function, F(R), plotted against the concentration. Attempts to estimate the loading of silicasgrafted with 1 were undertaken. It appears that small particle size silicagives rise to the highest loading and to the best quality DRUV spectra as a consequence of a minor amount of fluorescent dimer. On the other hand, itis shown that the loading of grafted silica is difficult to control by theused grafting process and that milder conditions are required. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 08:44:14