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Titolo:
Why an apparent surface dimension of silica gels may be abnormally high
Autore:
Okunev, AG; Aristov, YI;
Indirizzi:
Boreskov Inst Catalysis, Fed Sci Ctr, Novosibirsk 630090, Russia Boreskov Inst Catalysis Novosibirsk Russia 630090 sibirsk 630090, Russia
Titolo Testata:
LANGMUIR
fascicolo: 15, volume: 15, anno: 1999,
pagine: 5068 - 5072
SICI:
0743-7463(19990720)15:15<5068:WAASDO>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
FRACTAL DIMENSION; ALIPHATIC-ALCOHOLS; ADSORPTION; CHEMISTRY; ACETONE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
16
Recensione:
Indirizzi per estratti:
Indirizzo: Okunev, AG Boreskov Inst Catalysis, Fed Sci Ctr, Novosibirsk 630090, Russia Boreskov Inst Catalysis Novosibirsk Russia 630090 090, Russia
Citazione:
A.G. Okunev e Y.I. Aristov, "Why an apparent surface dimension of silica gels may be abnormally high", LANGMUIR, 15(15), 1999, pp. 5068-5072

Abstract

In the present paper, some problems of the "surface resolution analysis" to characterize silica gels are addressed. We measured the adsorption of organic adsorbates (fatty acids, aliphatic alcohols, and ketones) from CCl4 solution on mesoporous silicas of various porosity. A simple linear relationship is found between the monolayer thickness and the monolayer volume, which is valid even for the adsorbates of different homology series. A simple model to describe adsorption experiments quantitatively has been developed. The model shows that the curvature of silica mesopores may influence the packing of test molecules in the monolayer, and leads to a decrease in the adsorbate monolayer capacity for large molecules, so that measured surface area is underestimated. The effect increases when the ratio of adsorbed layerthickness h to pore radius R increases and may reach some tens of percent. The model explains why the apparent values of silica surface dimension maybe abnormally high (D-s > 3).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/04/20 alle ore 10:48:46