Surface-active substances

The Surface-active Substances (SAS) — chemical compounds which, concentrating on interfaces of phases, cause decrease in surface tension.

Surfactant is the main quantitative characteristic superficial activity — ability of substance to reduce surface tension on the interphase boundary is derivative of surface tension on concentration surfactant at aspiration With to zero. However, surfactant has solubility limit (so-called critical concentration of mitselloobrazovaniye or KKM) with which achievement at addition surfactant in solution concentration on the interphase boundary remains to constant, but at the same time there is self-organization of molecules surfactants in volume solution (mitselloobrazovaniye or aggregation). As a result of such aggregation so-called micelles are formed. The mitselloobrazovaniya characterizes surfactant solution opacification. The surfactants aqueous solutions, at mitselloobrazovaniye also get bluish shade (jellylike shade) due to light refraction by micelles.