Surfactant (surface active agent)


An organic chemical that, when added to a liquid, changes the properties of that liquid at a surface.

This is a basic function for products serving as detergents and as wetting, foaming, dispersing, emulsifying, and penetrating agents.  Surface active agent is commonly shortened to surfactant.  Surfactants are classified by whether or not they ionize in solution and by the nature of their ionic or electrical charges.  Categories of charges are called anionic, nonionic, cationic, or amphoteric.  The anionic and nonionic surfactant types (for example, LAS, ethoxylated alcohol , alkyl sulfate , alpha olefin sulfonate, and soap ) possess good cleaning properties and are important ingredients in household soaps and detergents.  In most detergent products designed for washing clothes and dishes, the surfactant is a basic ingredient. Soap is basic to most body-washing products.  All surfactants and soaps perform the important function of lowering waters surface tension, commonly known as making water "wetter."  This enables the cleaning solution more quickly to wet out the surface being cleaned so that soil can be readily loosened and removed (usually with the aid of mechanical action).  Surfactants are also instrumental in removing soils, both fatty and particulate, and in keeping them emulsified, suspended, and dispersed so that settling back on the surface is minimized.  In addition to their leading role in laundry and light duty formulations, surfactants are used to some degree in most other household cleaning and washing products.  They are the base of most liquid hard surface cleaners.  Relatively small amounts of surfactant are usually included in powdered hard surface cleaners, cleansers , and automatic dishwasher detergents.  Specialized surfactant applications include the use of cationic ( quaternary ammonium compounds ) to provide deodorizing and disinfecting action, while nonionic wetting agents are available for adding to the last rinse in automatic dishwashing to provide better draining of rinse water.