Editing Krafft temperature (section)

{{short description|Temperature above which micelles form in a solution of dissolved surfactants}}

In [[colloidal chemistry]], the  '''Krafft temperature''' (or '''Krafft point''', after German chemist [[Friedrich Krafft]]) is defined as the minimum [[temperature]] at which the formation of [[micelle]]s occurs in a [[Solution (chemistry)|solution]] of dissolved [[surfactant]]. It has been found that [[solubility]] at the Krafft point is nearly equal to [[critical micelle concentration]] (CMC). Below the Krafft temperature, the maximum solubility of the surfactant will be lower than the critical micelle concentration, meaning micelles will not form.  The Krafft temperature is a point of [[Phase transition|phase change]] below which the surfactant remains in [[crystalline]] form, even in an aqueous solution. Visually the effect of going below the Krafft point is similar to that of going above the [[cloud point]], with the solution becoming cloudy or opaque due to the surfactant molecules undergoing [[flocculation]].

Surfactants in such a crystalline state will only solubilize and form micelles if another surfactant assists it in overcoming the forces that keep it crystallized, or if the temperature increases, thus causing entropy to increase and encouraging the crystalline structure to break apart.