Stabilizer (chemistry)
In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym to a catalyst. The term can also refer to a chemical that inhibits separation of suspensions, emulsions, and foams.
Some kinds of stabilizers are:
- antioxidants, preventing unwanted oxidation of materials
- sequestrants, forming chelate complexes and inactivating traces of metal ions that would otherwise act as catalysts
- emulsifiers and surfactants, for stabilization of emulsions
- ultraviolet stabilizers, protecting materials, especially plastics, from harmful effects of ultraviolet radiation
- UV absorbers, chemicals absorbing ultraviolet radiation and preventing it from penetrating the materials; principally the same as sunscreens
- quenchers, dissipating the radiation energy as heat instead of letting it break chemical bonds; often organic nickel salts, e.g. nickel phenolates
- scavengers, eliminating the free radicals formed by ultraviolet radiation; often hindered amine light stabilizers (HALS)
See also