Surfactant Surfactant Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants. The term "surfactant" is a blend of "surface active agent". In the United States National Library of Medicine's Medical Subject Headings (MeSH) vocabulary, "surfactant" is reserved for the meaning pulmonary surfactant. For the more general meaning, "surface active agent/s" is the heading. Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their "tails") and hydrophilic
Surface tension a water droplet increases with decreasing radius. For not very small drops the effect is subtle, but the pressure difference becomes enormous when the drop sizes approach the molecular size. (In the limit of a single molecule the concept becomes meaningless.) When an object is placed on a liquid, its weight depresses the surface, and if surface tension and downward force becomes equal than is balanced by the surface tension forces on either side , which are each parallel to the water's surface at the points where it contacts the object. Notice that small movement in the body may cause