Influence of ratio of silicon complex and coagulant on silicon dioxide physicochemical characteristics

Abstract

It is known that the physicochemical characteristics of amorphous SiO2 are influenced by the raw material, process temperature, pH of the reaction medium, the ratio of reagents, the addition of coagulant, and modes of washing and drying. Previously, a waste-free technology for the production of biogenic silicon dioxide was described. However, there was a question of the ability to control the grain size of the final product. Therefore, the aim of our work was to study the effect of the ratio of mass concentrations of silicon-containing solution and coagulant (5:100; 5:500; 5:1000) on the physicochemical properties of the final product. The obtained samples of silicon dioxide were studied by various physicochemical methods. XRD pattern of the obtained silica showed that the 2-theta region between 5° and 80° at long collection times indicates no crystalline peaks. The FT-IR spectrum of the whole silica samples shows typical functional groups corresponding to pure silicon dioxide at 1074, 982, 800, and 457 cm?1. There are two distinct mass loss steps in thermograms (TGA). It was established that obtained samples had a specific surface area of 86.8, 318.3, and 310.2 m2/g and pore size of 3.3, 13.8, and 9.2 nm depending on coagulant concentration (100, 500, and 1000), respectively. The atomic force microscope method established that the 3D image clearly shows the pointed vertices of SiO2 tetrahedral for the whole gels and some powders depending on the ratio of silicon-containing solution and coagulant (5:100; 5:500; 5:1000). © 2023, King Abdulaziz City for Science and Technology.