Surfactants

Classification

Surfactants are compounds with hydrophilic "heads" and hydrophobic "tails." The "heads" of surfactants are polar and may or may not carry an electrical charge. The "tails" of most surfactants are fairly similar, often consisting of a hydrocarbon chain (linear or branched) and may comprise aromatic units. Most commonly, surfactants are classified according to the polarity of their head group: A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative, charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic, or amphoteric.