POLYCONDENSATION KINETICS OF ORTHOSILICIC ACID IN HYDROTHERMAL SOLUTIONS

摘要

The polycondensation kinetics of orthosilicic acid in hydrothermal solutions were studied experimentally at different temperatures, pH, and ionic strengths. As a result of the mathematical processing of experimental data, equations approximating the time dependence of the polycondensation process and the dependence of the polycondensation rate constant on the solution ionic strength were obtained. Experimental data on the kinetics of the reverse process of dissolving colloidal silica were obtained for different temperatures and pH. Experimental data on polycondensation kinetics were compared with the results of numerical simulation.