Aggregation number

An aggregation number is a description of the number of molecules present in a micelle once the critical micelle concentration (cmc) has been reached.

A typical experiment to determine the mean aggregation number would involve the use of a luminescent probe, quencher and a known concentration of surfactant. If the concentration of the quencher is varied, and the cmc of the surfactant known, the mean aggregation number can be calculated.