Micelle
A spherical aggregate of surfactant molecules that forms in solution above a characteristic concentration.
Unit
mol/L
In depth
Surfactant molecules have a polar head and a non-polar tail. Above the critical micelle concentration they cluster with tails inward and heads outward, creating a hydrophobic interior that can dissolve oily material in an aqueous medium. This is precisely how detergents clean.
Examples in the real world
Soap micelles trapping grease so it rinses away; bile salts emulsifying dietary fats for digestion.