Viscosities of binary liquid mixtures

Abstract

Viscosities at 25°C have been measured at different molar concentrations for fourteen binary liquid systems representing different types and degrees of interaction between unlike components. Excess viscosities tend to become less negative and then increasingly positive as the strength of the interaction between unlike molecules increases and the excess viscosity is approximately proportional to the strength of the interaction. Some expressions describing viscosities of binary liquid mixtures in terms of those of the components and a parameter attributed to interaction between them are examined. The parameter d in the expression ln η=x₁ ln η₁+x₂ ln η₂+x₁x₂d appears to be a useful measure of the strength of the interaction.