The definition of silica gel refers to a highly active adsorbent material, which is an amorphous material and its chemical formula is mSiO2·nH2O; it does not react with any substances other than strong alkali and hydrofluoric acid, is insoluble in water and any solvent, and is non-toxic. Odorless, chemically stable. For more details of the industry, the following is the definition and classification of silicone industry by Xiao Bian.
Various types of silica gel form different microporous structures due to their different manufacturing methods. The chemical composition and physical structure of silica gel determine that it has many other similar materials that are difficult to substitute: high adsorption performance, good thermal stability, chemical stability, and high mechanical strength. According to the size of its pore size, silica gel is divided into: large pore silica gel, coarse pore silica gel, B-type silica gel, and fine-pored silica gel.