A new model for thermal diffusion: kinetic approach.
We present a new model for thermal diffusion, and we compare its results for both simple and real systems. This model is derived from a kinetic approach with explicit mass and chemical contributions. It involves self-diffusion activation free energies, following Prigogine's original approach. We performed, furthermore, both equilibrium and nonequilibrium molecular dynamics evaluations in order to compute respectively the self-diffusion activation free enthalpies and the Soret coefficient when no experimental data were available. Our model is in very good agreement with simulation data on Lennard-Jones mixtures, and a good behavior is noted for the water-ethanol mixture, where the composition dependence at which the Soret coefficient changes its sign is predicted very accurately. Finally, we propose a new water-ethanol experiment at higher temperature in order to check the validity of our model.
Artola
Pierre-Arnaud
PA
Laboratoire de Chimie Physique, UMR 8000, Université Paris-Sud 11, Orsay, France.
Rousseau
Bernard
B
Galliéro
Guillaume
G
D003198:Computer Simulation; D004058:Diffusion; D000431:Ethanol / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D014867:Water; D000431:Ethanol