Memory function for a colloidal liquid

Abstract

The reduced memory function has been measured for a dilute suspension of interacting colloidal particles as the ionic strength of the suspension was slowly decreased. Care was taken to minimize the effects of multiple scattering. In contrast to earlier measurements of Gruner and Lehman, the reduced memory function was found to increase in value with decreasing ionic strength over the experimentally accessible range of k space. The reduced memory function did not exhibit a universal character as the interaction between particles was increased, even to the point where the colloidal liquid was coexisting with the colloidal solid phase. Other features of the reduced memory function are also compared and contrasted with earlier measurements and theoretical models.