Rheology of concentrated suspensions

Abstract

Abstract The dependence of the viscosities of highly concentrated suspensions on solids concentrations and particle size distributions is investigated by using an orifice viscometer. Based on the extensive amount of data on pertinent systems, an empirical equation which correlates the relative viscosities of suspensions (or relative moduli of filled polymeric materials) as a function of solids concentrations and particle size distributions is proposed. The equation has a constant which characterizes size distributions of spherical particles and can be determined experimentally without measuring viscosities. For uniform‐size spherical particles, it reduces to the well‐known Einstein equation at dilute solids concentrations.