The formation of silica gels from the silica sols prepared by the ion-exchange method

The methods of the sorption of water and tetrachloromethane vapors are appl ied to study the texture of silica gel formed from silica sol (prepared by the ion-exchange method) as a result of its flocculation by cetyl pyridiniu m chloride. Depending on the concentration of the latter and the type of ad sorbate used, the sorption isotherms of types I and IV are identified, and a different character of changing the sorption properties of samples is obs erved. It is shown that the main feature of the effect of cetyl pyridinium chloride is the transformation of the microporous structure of silica gel, in which the adsorption of vapor is described by the isotherm of type I, in to the mesoporous one, the latter being responsible for the condensation of vapors and hysteresis of either H4 or mixed (H4 + H2) forms.