Физико-химические и структурно-поверхностные свойства диоксида кремния, получаемого из минерального сырья

Abstract

Samples of amorphous silicon dioxide (SiO2) were obtained by acid decomposition of mineral raw materials (nepheline). Their physico-chemical, acid-base and structural-surface properties have been studied by methods of chemical analysis, Parks, BET, BJH, etc. It was found that in terms of the content of impurities, the pH of the aqueous extract, the pH values of the isoionic point and the zero charge point, the SiO2 samples obtained are almost identical to pyrogenic amorphous silicon dioxide obtained from reactive raw materials (pharmaceutical preparation “Polysorb PM”) and have an increased specific external surface compared to “Polysorb PM” (in 1.1 – 1.9 times) and specific pore volume (1.4 times). Based on the obtained values of the specific capacity of the adsorption monolayer of the surface of SiO2 samples and the change in Gibbs energy (ΔG0) during sorption, it is concluded that the method of their preparation does not significantly affect the physicochemical properties of their surfaces and the mechanism of nitrogen sorption. Based on the results obtained, an assumption is made about the prospects of using silicon dioxide, obtained on the basis of acid processing of mineral raw materials, as an enterosorbent in therapeutic practice.