At CMC the surfactant molecules
As we learned in concept
Associated Colloids (Micelles) -
There are some substances which at low concentrations behave as normal strong electrolytes, but at higher concentration exhibit colloidal behaviour due to the formation of aggregates. The aggregate molecule thus formed are called micelles.
At lower concentrations, the surfactants behave as normal strong electrolytes but once the concentration crosses critical micelle concentration, the surfactant molecules start associating to form aggregates and each aggregate molecule is called a micelle.