title: Thermodiffusion, molecular diffusion and Soret coefficients of aromatic+n-alkane binary mixtures.
abstract: In the present work, we have measured the thermodiffusion coefficient of 51 binary liquid mixtures at 25oC. These mixtures correspond to the series of the aromatics toluene and 1-methylnaphthalene with n-alkanes nCi (i = 6, 8, 10, 12, and 14) at different mass fractions in the whole range. For that, we have used the thermogravitational technique. It is shown that the thermodiffusion coefficient is a linear function of the mass fraction in all the mixtures. Extrapolating the lines, we obtain the thermodiffusion coefficient in dilute solutions of n-alkanes for both toluene and 1-methylnaphthalene. These limiting values show a linear dependence with the inverse of the product of the molecular weights. In addition, we have measured the molecular diffusion coefficient of all the mixtures at 0.5 of mass fraction and at 25oC, by the sliding symmetric tubes technique. It is observed that the product of this coefficient with the viscosity at the same concentrations takes a constant value for each of the series considered. Finally, we have also determined the Soret coefficient of the equimass mixtures by the combination of the measurements of thermodiffusion and molecular diffusion coefficients.
authors: MGEP Mondragon Goi Eskola Politeknikoa, Mechanical and Industrial Manufacturing Department, Loramendi 4 Apdo. 23, Mondragon 20500, Spain.
authors: Miren
authors: M
authors: Larrañaga
authors: MGEP Mondragon Goi Eskola Politeknikoa, Mechanical and Industrial Manufacturing Department, Loramendi 4 Apdo. 23, Mondragon 20500, Spain.
authors: M Mounir
authors: MM
authors: Bou-Ali
authors: MGEP Mondragon Goi Eskola Politeknikoa, Mechanical and Industrial Manufacturing Department, Loramendi 4 Apdo. 23, Mondragon 20500, Spain.
authors: Estela
authors: E
authors: Lapeira
authors: MGEP Mondragon Goi Eskola Politeknikoa, Mechanical and Industrial Manufacturing Department, Loramendi 4 Apdo. 23, Mondragon 20500, Spain.
authors: Ion
authors: I
authors: Lizarraga
authors: Department of Applied Physics II, University of Basque Country, Apdo. 644, Bilbao 48080, Spain.
authors: Carlos
authors: C
authors: Santamaría