Obtaining sols, gels and mesoporous nanopowders of hydrothermal nanosilica

Experiments were performed to obtain SiO2 sols, gels, and mesoporous nanopowders based on hydrothermal medium. To achieve this, polycondensation of orthosilicic acid (OSA) at certain pH and temperature, as well as ultrafiltration membrane concentration, sol–gel transition, and cryochemical vacuum sublimation were done. The dynamic light scattering, scanning and tunneling electron microscopy, low-temperature nitrogen adsorption, and others...