What Is Critical Micelle Concentration?

The lowest concentration of surfactant molecules associated with micelles to form micelles is the critical micelle concentration cmc. The surfactant's surface activity originates from the amphiphilic structure of the molecule. The water-repellent group tries to prevent it from dissolving in water and migrates from the inside to the outside, and has a tendency to escape the water phase. As a result of these two tendencies to balance, the surfactant is enriched on the surface of the water, with the hydrophilic groups extending into the water and the hydrophobic groups extending into the air. The surface tension decreases.

Critical micelle concentration

1. Surface tension ^[1]

1.Using the concept of critical micelle concentration, we can cleverly design the solution above the critical micelle concentration of the main surfactant used, so that it forms a bilayer, that is, the first surfactant molecule during use. The hydrophobic group is attached to the solid surface, and the hydrophilic group extends to the outside. The hydrophilic group of the second layer of surfactant is attached to the hydrophilic group of the first layer, and the hydrophobic group extends to the outside, thereby forming a unique lipophilic surface.

2. The substance has its solubility saturation in a certain liquid. After reaching the saturation, the substance will no longer dissolve, but we can use the principle of critical micelle concentration to design the surfactant above the critical micelle concentration, which can greatly increase the solubility of the substance. .