Effect of Thermophyisical Properties and Morphology of the Molecules on Thermodiffusion Coefficient of Binary Mixtures

In this article, new experimental data of the thermal diffusion coefficient (DT) of 20 binary mixtures of hexane-hexadecane, decane-hexadecane, toluene-hexadecane and 1-metilnaphtalene-hexadecane at several different compositions and at 298K and atmospheric pressure, are reported. Thermal diffusion coefficients were measured in a thermogravitational column with rectangular configuration. The results obtained show that the mass fraction dependence of thermodiffusion coefficients of the mixture is linear in all the cases. The studied mixtures have a common component, hexadecane, and they can be classified into two groups according to their mass and to the morphology of their components. We also show that the thermal diffusion coefficient and mixture viscosity are related in a different way for mixtures of n-alkanes and for mixtures of aromatic rings.