critical micelle concentration
abbr.,
CMC
(rus. критическая концентрация мицеллообразования abbr., ККМ)
—
concentration of a surfactant in a solution, above which stable micelles form.
Description
At low concentrations surface-active agents (surfactants) form true solutions. When the surfactant concentration is increased at some point it reaches CMC, i.e. a concentration of surfactant at which the surfactant starts aggregating into micelles, which are in thermodynamic equilibrium with the non-associated surfactant molecules. When the solution is diluted the micelles break up, and when the surfactant concentration is increased they re-emerge. Above the CMC all the excess surfactant is in the form of micelles. Very high concentrations of surfactants in a system lead to the formation of liquid crystals or gels.
Author
- Shirinsky Vladimir P.
Sources
- Micelle concentration // Chemical encyclopedia (in Russian). V. 2. — Moscow.: The Great Soviet Encyclopedia, 1992. pp. 95–96.
- Shchukin E.D., Pertsov A.V., Amelina E.A. Colloid and Surface Chemistry(in Russian). — Moscow.: Vysshaja shkola, 2006. — 444 pp.