Viscosity calculations with the Eyring-Patel-Teja model for liquid mixtures

The Patel-Teja equation of state was incorporated with Eyring's theory to f orm the Eyring-Patel-Teja viscosity model, in which both the excess activat ion free energy of flow and the density of a liquid mixture were calculated with the aid of the equation of state. The model correlated viscosities to a grand average absolute deviation of 2.1% for 60 nonaqueous binaries, whe n the one-parameter van der Waals one-fluid mixing rules were used for the equation constants of such mixtures. With the two-parameter Redlich-Kister type mixing rule of a(m), the Eyring-Patel-Teja model correlated viscositie s to a grand average absolute deviation of 4.5% for 15 aqueous binaries. Th is new model is applicable to elevated pressures and, with the binary inter action parameters as determined from binary mixtures, also successfully pre dicted ternary viscosities. The binary interaction parameters could be esti mated from a rather limited data source of mixture viscosities (one data po int for a nonaqueous system and two data points for an aqueous system).