Surfactants are compounds that reduce the surface tension
between two states of matter, i.e, between two liquids, between a
liquid and a solid, or between a gas and a liquid.
They may act as detergents, emulsifiers, dispersants, wetting
agents, and foaming agents.
Detergents when added to a liquid, increase its spreading and
wetting properties. They help a dye to penetrate a fabric
evenly.
In biology, pulmonary surfactant is secreted in lungs that
facilitate breathing by increasing total lung capacity. In
respiratory distress syndrome, patients are treated with artificial
surfactants that facilitate normal respiration, called surfactant
replacement therapy.
