STUDY OF HYDRATED STRUCTURES ON THE SURFACE OF MESOPOROUS SILICAS ANDCARBOSILS BY H-1-NMR SPECTROSCOPY OF ADSORBED WATER

Citation
Vv. Turov et al., STUDY OF HYDRATED STRUCTURES ON THE SURFACE OF MESOPOROUS SILICAS ANDCARBOSILS BY H-1-NMR SPECTROSCOPY OF ADSORBED WATER, Langmuir, 13(5), 1997, pp. 1237-1244
Citations number
44
Categorie Soggetti
Chemistry Physical
Journal title
ISSN journal
07437463
Volume
13
Issue
5
Year of publication
1997
Pages
1237 - 1244
Database
ISI
SICI code
0743-7463(1997)13:5<1237:SOHSOT>2.0.ZU;2-A
Abstract
H-1 NMR spectroscopy of adsorbed water was used to study mesoporous si lica gel and carbosils synthesized with carbon in the range from 4 to 14.5% w/w in the surface layer. It has been revealed that both silica gel and carbosil are characterized by a rise in temperature of water f reezing in an aqueous medium in mesopores. This phenomenon may be expl ained by contact of water adsorbed in pores with a continuous aqueous medium. The changes in free energy of water in pores due to adsorption have been calculated. It has been shown that carbonization of the mes opore silica gel surface leads to formation of carbon layers which are denser than those on a nonporous silica and the main types of water a dsorption sites on the sui face are basic graphite planes of carbon an d oxygen-containing groups on the carbon part of the carbosil surface.