Silica gel is an amorphous substance, and its chemical formula is mSiO2. nH2O. It is insoluble in water and any solvents, non-toxic, tasteless, chemically stable, and does not react with any substances except strong alkalis and hydrofluoric acid. Various types of silica gel form different microporous structures due to their different manufacturing methods.
The silica gel is household used as a desiccant, humidity conditioner, deodorant, etc.; is industrially used as oil hydrocarbon decolorizer, catalyst carrier, pressure swing adsorbent, etc.; separation and purification agent for fine chemical industry, beer stabilizer, paint thickener, toothpaste friction agent, matting agent, etc. According to the size of its pore size, silica gel is divided into: macroporous silica gel, coarse pore silica gel, type B silica gel, and fine pore silica gel.