Krafft temperature (rus. критическая температура мицеллообразования otherwise Температура Крафта) — the temperature above which the solubility of a surfactant increases sharply and the critical micelle concentration can be reached.

Description

The Krafft temperature (Krafft point) is the minimum temperature at which ionic surfactants, such as sodium lauryl sulphate (a component of household detergents), form micells. It depends on the nature of hydrophobic groups and ionic composition of the detergent. On the contrary, the solubility of nonionic surfactants decreases with increasing temperature. They are characterised by the cloud point, i.e. the maximum temperature at which nonionic surfactants form micelles and above which the mixture starts to phase separately in the surfactant- solvent , thus changes in its optical properties occur.

Illustrations

Solubility-temperature ratio of a typical ion surfactant.
Solubility-temperature ratio of a typical ion surfactant.

Author

  • Shirinsky Vladimir P.

Sources

  1. IUPAC. Compendium of Chemical Terminology. 2nd ed. (the «Gold Book»), 1997. Compiled by A.D. McNaught, A. Wilkinson. — Oxford: Blackwell Scientific Publications, 1997. — http://www.goldbook.iupac.org (reference date: 12.12.2011).
  2. Myers D. Surfactant Science and Technology. 3d ed. — N.Y.: Wiley–Interscience, 2006. — 380 p.

Contact us