THE THERMAL-DIFFUSION FACTOR OF THE VAN-DER-WAALS BINARY MIXTURE

The explicit dependence of the thermal diffusion factor with respect t o composition and interaction parameters for the van der Waals binary mixture is obtained in the framework of die mean-field kinetic variati onal theory and in the scheme of Scott and van Konynenburg. Here, we p resent a numerical study where tile global behavior of the thermal dif fusion factor is described in terms elf molecular masses, sizes, and i nteraction parameters, along the phase diagram of this model mixture. This numerical study allows us to understand what molecular parameters modify the sign of the thermal diffusion factor. In addition a compar ison is made between the thermal diffusion factor coming from the van der Waals mixture and from the hard-sphere mixture. (C) 1997 American Institute of Physics.