Silica gel is a transparent or milky white granular solid. It has an open porous structure, strong adsorption, and can adsorb a variety of substances. Add dilute sulfuric acid (or hydrochloric acid) to the aqueous solution of water glass and let it stand to form a hydrous silicic acid gel and solidify. Wash with water to remove the electrolyte Na catalyst dissolved in it. If cobalt chloride is added, it will be blue when dry, and red after absorbing water. It can be used repeatedly.

The main component of silica gel is silica, which is chemically stable and does not burn. It has a strong adsorption capacity and can have a drying effect on human skin.

Organic silica gel is an organosilicon compound, which refers to a compound that contains Si-C bonds and at least one organic group is directly connected to a silicon atom. It is customary to use oxygen, sulfur, nitrogen, etc. to make the organic group and silicon Compounds with connected atoms are also regarded as organosilicon compounds.

Inorganic silica gel is a highly active adsorption material, which is usually prepared by reacting sodium silicate and sulfuric acid and undergoing a series of post-treatment processes such as aging and acid foaming.