Electric birefringence of AOT/water solutions

The variation of the Kerr constant versus surfactant concentration in a solution of AOT in water was studied. The observed behavior shows changes when aggregates begin to form. allowing to measure the critical micelle concentration, with results coincident with those obtained through static light scattering and electric conductivity measurements. For concentrations higher than the critical micellar concentration the birefringence decreases proportional to the aggregates concentration The micelle contribution to birefringence is estimated to be negative.