Methods of synthesis, properties and application of silica-zols for obtaining composite materials Part I
Abstract
Methods of synthesis, properties and application of silica-zols for obtaining composite materials Part I
Incoming article date: 25.07.2018The article considers examples of obtaining silica sols by ion-exchange methods. An analysis was made of the factors of this method that affect the properties of the resulting sols. The principal technological scheme of an industrial plant for the production of silica-sol by an ion-exchange method were considered. The results of studies of the sol-gel transition in silica-sol obtained by the ion exchange method were presented. The growth kinetics of colloidal silica-sol particles, which were obtained from solutions of polysilicic acid, was investigated. The dependence of the growth kinetics of colloidal particles from solutions of polysilicic acid on the temperature and on the initial pH of the sol was shown. The dependence of the gel time on the dimensions of the colloidal particles in the ash, on temperature, concentration and pH, was shown. The effect of the composition of the liquid phase on the stability of silica sols was established. Influence of the charcoal characteristics on the properties of the xerogels obtained. The effect of silica powder on the properties of the xerogels obtained was analyzed. An analysis of the possibilities of the practical application of silica powder as a binder in the preparation of heat-resistant heat-shielding composite materials was carried out.
Keywords: silica-sol, ion exchange, sol-gel technology, stability of sols, xerogels, composite materials