Micellar solution

In colloidal chemistry, a micellar solution consists of a dispersion of micelles (small particles) in a solvent (most usually water). Micelles are made of molecules that are attracted to both water and oily solvents, known as amphiphiles. Micellar solutions form when the concentration of amphiphile moleculus exceeds the critical micelle concentration (CMC), which is when the tails aggregate inward to minimize contact with water, while the heads face outward, creating spherical or other-shaped micelles.

Although micelles are often depicted as being spherical, they can be cylindrical or oblate depending on the chemical structure of the amphiphile. Because surfactant molecules and micelles are randomly oriented and distributed throughout the solvent, the solution has a homogeneous, transparent appearance. At higher surfactant concentrations or under specific conditions (e.g. temperature), micellar solutions can transition into lyotropic liquid crystalline phases with anisotropic properties, such as hexagonal or lamellar arrangements.