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 methods determined the physical and chemical characteristics of nanosized SiO₂ samples. By choosing the pore size of the ultrafiltration membranes at the sol concentration stage, one can control the ratio of the SiO₂ content to the total salt content and provide a zeta potential of nanoparticles sufficient for the stability of the sols. It was shown that by varying the temperature at the polycondensation stage from 20 to 90 °С at pH = 8.5–9.3, it is possible to control the final average diameter of SiO₂ particles in the range from 5 to 100 nm, respectively. The specific surface area of particles are 50–500 m²/g, the average diameter of the mesoporous powders in the range of 2–15 nm; the fraction of the area (<4%) and volume (<0.25%) of micropores are low.

进行实验以基于水热介质获得SiO ₂溶胶，凝胶和中孔纳米粉末。为了实现这一目标，在一定的pH和温度下原硅酸（OSA）进行了缩聚反应，并进行了超滤膜浓度，溶胶-凝胶转变和冷冻化学真空升华。动态光散射，扫描和隧道电子显微镜，低温氮吸附以及其他方法确定了纳米SiO ₂样品的物理和化学特性。通过选择溶胶浓缩阶段超滤膜的孔径，可以控制SiO ₂的比例含量相对于总盐含量而言，并提供足以使溶胶稳定的纳米粒子的ζ电位。结果表明，通过在pH = 8.5–9.3的条件下，将缩聚阶段的温度从20°C更改为90°C，可以将SiO ₂颗粒的最终平均直径分别控制在5至100 nm之间。颗粒的比表面积为50–500 m ² / g，中孔粉末的平均直径为2–15 nm。微孔的面积分数（<4％）和体积（<0.25％）低。