The Preparation, Properties, and Application of Nanosilica Based on Hydrothermal Solutions

Abstract

Experiments on the preparation of sols and nanopowders of SiO2 based on hydrothermal solutions are performed. In order to achieve a result, processes of polycondensation of orthosilicic acid, ultrafiltration membrane concentration, and cryochemical vacuum sublimation are performed. The physicochemical characteristics of the sols and nanopowders of SiO2 are determined using a set of methods. In particular, it is shown that the diameters of the nanoparticles of SiO2 in the sols and nanopowders fall within the range of 5 to 100 nm. The possibility for the application of the obtained nanosilica as a modifying additive for the enhancement of the strength of concrete is justified.