Critical micelle concentration (CMC)

Surfactants/amphiphilic molecules contain both hydrophilic and hydrophobic parts. The hydrophilic part of the molecule prefers to interact with water while the hydrophobic part is repelled from water.

Surface active molecules absorb at the air/water interface, decreasing surface tension. As the interface becomes saturated, the molecules start to form aggregates or micelles in the bulk of the liquid, with the surface tension remaining constant.

CMC is a key parameter for the optimization of surfactants in chemical formulations and home & beauty care products.

CMCeeker records surface tension for a serial dilution of a sample sample from the lowest to highest concentration (minimizing carry over), giving the concentration of the surfactant for CMC, critical micelle concentration.