- Chemicals that change the properties of surfaces with which they come in contact. In construction, surfactants are used as wetting or spreading agents and to facilitate the mixture of normally incompatible substances. They also affect the emulsification characteristics and alter the behavior (the dispersion, suspension, or precipitation) of pesticides in water. In environmental remediation, a surfactant is used to solubilize contaminants and mobilize the highly contaminated fines material. See also anionic surfactant and non-ionic surfactant.
- noun a substance in the alveoli of the lungs which keeps the surfaces of the lungs wet and prevents lung collapse