Dynamics and scaling in hard-sphere colloidal suspensions

Results are described from dynamic light scattering studies on concentrated suspensions of 'hard-sphere' colloidal particles in their equilibrium and metastable fluid states. We have found that the time and wave vector dependencies of the diffusion coefficients and (consequently) the logarithms of the intermediate scattering functions can be factorized. This is demonstrated by a simple scaling procedure which collapses the diffusion coefficients and the measured intermediate scattering functions over a wide (but not complete) range of wave vectors onto single time-dependent master curves. An interpretation suggests that the relaxation of interparticle structure is related to self-diffusion.