FLUID-FLUID EQUILIBRIUM OF A MIXTURE OF NONPOLAR AND DIPOLAR HARD-SPHERES IN AN APPLIED-FIELD

The influence of an external static electric field on the high-pressur e fluid-fluid equilibrium of a mixture of non-polar and dipolar hard-s phere molecules has been investigated by a generalization of the therm odynamic perturbation theory of mixtures of polar fluids. The effect o f the field was considered via the held-dependent relative permittivit y. It was found that the critical temperature at a fixed pressure incr eases with the held strength. This increase is more rapid at lower pre ssures. At low pressures the coexisting phases are richer in the dipol ar component and therefore the effect of the field is stronger. The be haviour of the critical loci changes in the presence of the field.