Surfactant means that a small amount of substance can make a significant change in the interface state of the solution system. With a fixed hydrophilic lipophilic groups, the surface of the solution can be aligned. The molecular structure of the surfactant is amphipathic: hydrophilic groups at one end and hydrophobic groups at the other end. The hydrophilic groups are often polar groups such as carboxylic acid, sulfonic acid, sulfuric acid, amino group or amine group and Its salt, hydroxyl, amido, ether bond, etc. can also be used as polar hydrophilic groups; and hydrophobic groups often non-polar hydrocarbon chain, such as 8 carbon atoms or more hydrocarbon chain. Surfactants into ionic surfactants (including cationic surfactants and anionic surfactants), non-ionic surfactants, amphoteric surfactants, complex surfactants, other surfactants and so on.
