The unique properties of surfactants stem from their special molecular structure. Surfactants are generally linear molecules containing both hydrophilic polar groups and lipophilic non-polar hydrophobic groups. Hydrophobic groups can have many different structures, such as direct, branched, cyclic, etc., the common ones are hydrocarbon chains, which can be alkanes, alkenes, cycloalkanes, aromatic hydrocarbons, and the number of carbon atoms is mostly in the range of 8 to 20. . Other hydrophobic groups include aliphatic alcohols, alkylphenols, atomic groups containing fluorine or silicon and other elements. Hydrophilic groups include anionic, cationic, zwitterionic, nonionic and other types. Among them, the ionic type can be electrolyzed in water to be charged, and the non-ionic type cannot be ionized in water, but has polarity and water solubility.