Determination of critical micelle concentration by hyper-Rayleigh scattering

Determination of the critical micelle concentration (CMC) of several surfactants that contain an NLO chromophore, either at the hydrocarbon tail, or at the hydrophilic headgroup, or even as a counterion, was done by hyper-Rayleigh scattering (HRS). The CMC is detected by an unprecedented drop in the HRS signal, which is believed to be due to the formation of smaller pre-micellar aggregates whose effective beta value is higher than that of the micellar aggregates.