Study of Hydrated Structures on the Surface of Mesoporous Silicas and Carbosils by <SUP>1</SUP>H NMR Spectroscopy of Adsorbed Water

¹H NMR spectroscopy of adsorbed water was used to study mesoporous silica 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 freezing in an aqueous medium in mesopores. This phenomenon may be explained 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 mesopore silica gel surface leads to formation of carbon layers which are denser than those on a nonporous silica and the main types of water adsorption sites on the surface are basic graphite planes of carbon and oxygen-containing groups on the carbon part of the carbosil surface.