LASER-INDUCED TRANSIENT ELECTRIC BIREFRINGENCE AND LIGHT-SCATTERING IN AEROSOL-OT/CCL4 REVERSE MICELLES

Simultaneous transient turbidity and electric birefringence (optical Kerr effect) are induced in Aerosol-OT/CCl4 reverse micelles by single, 300 mu s long, linearly polarized step pulses of a Nd:YAG laser. No effect is observed with 50 ns Q-switched pulses. A method of extracting the birefringence component from the turbidity-dominated signal is described. The birefringence is a consequence of the creation of induced micellar dipoles in the direction of the optical electric field, E, and the turbidity is the result of clustering of micelles. The reequilibration process following the laser E-jump consists of two relaxations, both in the 10(2) mu s range. The faster relaxation is attributed to the collapse of anisotropic structures and the slower one to the disintegration of the clusters. The effects of surfactant concentration, water content, and temperature on the relaxation rate and amplitude of cluster decay are reported. The mechanisms of induced polarization in dry and wet reverse micelles are discussed.