J. Luettmerstrathmann et Jv. Sengers, THE TRANSPORT-PROPERTIES OF FLUID MIXTURES NEAR THE VAPOR-LIQUID CRITICAL LINE, The Journal of chemical physics, 104(8), 1996, pp. 3026-3047
We apply the mode-coupling theory for the dynamics of critical fluctua
tions to binary fluid mixtures near the vapor-liquid critical line and
derive a set of coupled equations for the mode-coupling contributions
to the diffusion coefficients of the relevant hydrodynamic modes. An
approximate solution of the mode-coupling integrals yields representat
ive equations for the effects of the critical fluctuations on the ther
mal conductivity, the viscosity, the mutual diffusivity and the therma
l-diffusion coefficient, which are valid not only in the asymptotic cr
itical region but also describe the crossover to regular behavior far
away from the critical line. The ''crossover'' functions depend on the
thermodynamic properties of the mixtures, background values of all th
e transport coefficients and two concentration-dependent cutoff wave n
umbers. We compare the proposed crossover model with experimental ther
mal-conductivity data for mixtures of carbon dioxide and ethane in the
critical region and find good agreement between theory and experiment
. (C) 1996 American Institute of Physics.