Geometrical and chemical modification of silica matrices at high pressures of reagents
Анотація
The effect of temperature and composition of modifying mixture, as well as mode of carrying out the process of hydrothermal (with water and with the mixture of water and some organic substances) modification of silica gels and silica in the form of hydrogel-xerogel, on the parameters of the pristine adsorbents have been studied. The peculiarities of interaction between some organic substances and dispersed silica at high pressures and high temperatures were considered. These investigations were performed by IR spectroscopy, differential thermal analysis, and the porous structure characterization of the modified silicas. It was shown that depending on the nature of the compound used for modification such organic substances can promote the process of silica mass transfer. During this process, the possibility occurs of the occlusion of the modifying reagent inside silica globules, changes in the parameters of the porous structure, physical or chemical bonding of the modifier molecules with the silica surface. Possible mechanism of geometrical and chemical modification of silica adsorbents is discussed.
Посилання
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