Modeling of the Viscosity Behavior in the Interface Area of Two Miscible Liquids

The paper presents the results of the share viscosity (η) investigations performed for binary mixtures composed of the liquids of extremely different viscosities: a high-viscous α-tocopherol acetate (η ≈ 10 Pa s) is mixed with 4-n-propylcyclohexyl-4′-n-pentylphenyl (η ≈ 10 mPa s) and mesitilene (η ≈ 1 mPa s), the two low-viscous solvents composed of the non-polar molecules of an essentially different shape. It was found that the viscosities of the mixtures, disregarding the molecular shape of the non-polar admixture, exhibit a strong nonlinear dependence on tocopherol mole fraction and, at a given temperature, the dependence can be described with an exponential function. For a constant tocopherol concentration in the mixtures, the viscosity temperature dependences are well described with the Vogel–Fulcher–Tammann relation. The results can be considered as a model of the viscosity behavior related to the laminar flow of miscible liquids of a different viscosity being in contact to each other.