Surfactant refers to a substance that can obviously change the interface state of its solution system by adding a small amount. It has fixed hydrophilic and lipophilic groups and is oriented in the surface energy of solution.

Surfactants are divided into anionic surfactants according to the dissociation properties of polar groups: stearic acid and sodium dodecyl benzene sulfonate; Cationic surfactant: quaternary ammonium compound; Zwitterionic surfactants: lecithin, amino acid type and betaine type; Nonionic surfactant: alkyl glycoside, fatty acid glyceride, fatty acid sorbitan, polysorbate.

Surfactants have a series of physical and chemical functions, such as wetting or anti-sticking, emulsification or demulsification, foaming or defoaming, solubilization, dispersion, washing, anticorrosion and antistatic.

Extended data:

Principle of surfactant

According to the affinity of different parts of molecules to two phases, the two phases are regarded as the components of the phase, and the molecules are arranged between the two phases, so that the surfaces of the two phases are equivalent to being transferred into the molecules. Thereby reducing the surface tension.

Because both phases regard it as a component of this phase, it means that there is no interface between the two phases and surfactant molecules, which means that the interface between the two phases is partially eliminated in this way, and the surface tension and surface free energy are reduced.

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