It has fixed hydrophilic and lipophilic groups and is oriented in the surface energy of solution. The molecular structure of surfactant is amphoteric: one end is hydrophilic group and the other end is hydrophobic group.
Hydrophilic groups are often polar groups, such as carboxylic acids, sulfonic acids, sulfuric acids, amino groups or amino groups and their salts, as well as hydroxyl groups, amide groups, ether bonds and so on. Can also be used as a polar hydrophilic group; While hydrophobic groups are generally nonpolar hydrocarbon chains, such as hydrocarbon chains with more than 8 carbon atoms.
Surfactants are divided into ionic surfactants (including cationic surfactants and anionic surfactants), nonionic surfactants, amphoteric surfactants, composite surfactants and other surfactants.
Application of surfactants
Surfactant plays an important role as detergent, wetting agent, dispersant, emulsifier, foaming agent and defoamer in many practical applications and products, including detergent, fabric softener, engine oil, emulsion, soap, paint, adhesive, ink, antifogging agent, ski wax, snowboard wax, deinking, flotation, washing and enzymatic treatment of recycled paper.
There are also agricultural chemicals, such as herbicides (some), pesticides, biocides (disinfectants) and spermicide (nonoxynol -9). Personal care products, such as cosmetics, shampoo, shower gel, conditioner and toothpaste. Surfactants are used in fire fighting and pipelines (liquid drag reducer). Alkaline surfactant polymers are used to make oil in oil wells flow.
Above content reference: Baidu Encyclopedia-Surfactants