What is a micelle?

A micelle is the cluster or aggregated particles formed by associated colloids (substances which, at high concentration, behave as colloidal solutions due to formation of micelles) in solution. Micelle formation takes place above a certain concentration called Critical Micellization Concentration (CMC) and above a particular temperature called Kraft Temperature. Every micelle system has a particular value of CMC. Micelles are primarily responsible for the cleansing action of soaps. A micelle consists of a hydrophobic hydrocarbon-like central core. The cleansing action of soap is due to the fact that soap molecules form micelle around the oil droplet in such a way that hydrophobic part of the stearate ions is in the oil droplet and hydrophilic part projects out of the grease droplet like the bristles. This oil droplet surrounded by stearate ions is now pulled in water and removed from the dirty surface.