CONCENTRATION OF VARIOUS FORMS OF WATER IN SILICA PRECIPITATED FROM A HYDROTHERMAL SOLUTION

Abstract

The physicochemical properties of the surface of silica precipitated from a hydrothermal solution have been studied. The concentration of physically adsorbed water, and the net concentration of surface and bulk (internal) hydroxyl groups have been found by low-temperature adsorption of nitrogen and thermogravimetric data. The concentration of internal silicone (internal water) under different temperatures of the silica specimens under study has been estimated from the difference between the net concentration and the Zhuravlev physicochemical constants. The type of noncrystalline silica containing substantial amounts of internal water has been identified. The difference in mechanisms involved in internal and surface water extraction has been established.