Krafft temperature

The Krafft point is a narrow range of temperature ( Krafft temperature ), above which the solubility of anionic and cationic surfactants increases sharply due to micelle formation. It is a triple point, at which the surfactants are present as monomers, micelles, and as hydrated solids. It is named after Friedrich Krafft, who developed the theory of emulsion.

The determination of the Krafft point is made by turbidity measurement in accordance with DIN 53918th case of soaps is meant by the Krafft point, the temperature at which a hot, transparent soap solution becomes turbid on cooling.

Since a weak function of the total surfactant concentration is in the system, one also speaks of Krafft boundary.