(335aq) Coupling Between Diffusion And Orientation Relaxation In A Cromolyn Aqueous Solution

The isotropic-to-nematic pretransitional fluctuations of the aqueous solution of disodium cromoglycate (cromolyn) have been studied by dynamic light scattering. Cromolyn is a representative of lyotropic chromonic liquid crystals with building units being elongated rods formed by aggregates of disc-like molecules. We have obtained the relaxation time of the orientational order-parameter fluctuations and the diffusion relaxation time as functions of temperature and wave numbers of light scattering. A coupling between the diffusion and the orientation relaxation is revealed through the dependence of the observed effective dynamic modes on the wave number.