DYNAMICAL LIGHT-SCATTERING STUDY OF ABNORMALLY FLUID SEMIDILUTE SOLUTIONS OF WORM-LIKE MICELLES

Light scattering experiments were carried out on aqueous micellar solu tions of cetylpyridinium chlorate (CPClO3) in the presence of sodium c hlorate (NaClO3) as a function of surfactant concentration. The time a utocorrelation function of the scattered field is found to be bimodal. The slow relaxation time, that is assumed to be the terminal time of the stress relaxation, is a decreasing function of the surfactant conc entration. The behaviour of the plateau modulus obtained by combining measurements of the slow relaxation time and of the zero-shear viscosi ty suggests the presence of entanglements in these highly fluid micell ar systems.