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[Terminology] Surfactant / Surface active agent

Time:2014-12-04 21:11:06; Reading: 20

[Terminology] Surfactant / Surface active agent

Also known as interface active agent.

Definition: the substance having the following properties: strongly reduce surface tension or interfacial tension of the system; at certain concentration can form organized molecular assembly; change surface state or interface state of the system, and further bring a series of abilities, such as: cleansing, emulsifying, dispersing, wetting, foaming, antifoaming, demulsifying, flocculating, solubilizing abilities.

This is a traditional definition of surfactant. The definition mainly describes the role of surface tension or interface tension.

Parts of substances (such as: polyelectrolytes) do not strongly reduce surface tension or interfacial tension of the system; however, can strongly change surface state or interface state of the system.

Therefore, surfactants can be understood: the substance acting on the interface and significantly changing the interface state.

Surfactant is amphiphilic molecule. It includes two structural units: hydrophilic unit and lipophilic unit.

Depending on distinction of charge, surfactant can be divided into four categories:

(1), anionic surfactant, such as: soap.

(2), cationic surfactant, such as: quaternary ammonium salt.

(3), zwitterionic surfactant, such as: betaine.

(4), non-ionic surfactant, such as: fatty alcohol polyoxyethylene ether.

Usually, special surfactant be classified separately. Such as:

(1), fluorine surfactant;

(2), silicon surfactant;

(3), polymer surfactant.

Surfactant

gamma-Oryzanol

Diflucortolone valerate

Betamethasone valerate

Megestrol acetate

Betamethasone acetate

Standard

Test methods of surfactants, catalog, Chinese national standards

Surfactants, catalog, Chinese national standards

Test methods of materials, catalog, Chinese national standards

Basic standards of materials, catalog, Chinese national standards

Test methods of textile auxiliaries, catalog, Chinese national standards