Thermodynamics of Viscous Flow in Ethane-1,2-diol+Water Binary Mixtures

Abstract

Kinematic viscosities (v) of pure ethane-1,2-diol (component 1) and of nine mixtures with water (component 2) were measured at 19 temperatures ranging from -10 to +80°C, and for binary compositions covering the whole miscibility field expressed by the relation 0 ≤ X₁ ≤ 1. The property fitted some empirical equations in terms of the dependences v = v(T) and v(X₁), where T is the thermodynamic temperature and X₁ is the mole fraction of ethane-1,2-diol. Furthermore, the excess function (v^E) and the excess Gibbs energy of activation of viscous flow (∆G*^E) have been investigated. The trend of v^E against binary composition of the mixtures shows negative deviations from ideal behaviour, while the contrary is true for ∆G*^E The results indicate specific molecular interactions between the components, and an overview is given on the basis of the molecular dynamics of the pure species.