LIQUID-VAPOR COEXISTENCE IN THE SCREENED COULOMB (YUKAWA) HARD-SPHEREBINARY MIXTURE IN DISORDERED POROUS-MEDIA - THE MEAN SPHERICAL APPROXIMATION

The thermodynamics of a two-component fluid with a hard core interacti on and screened Coulomb (Yukawa) interaction between particles, simila r to the primitive model of an electrolyte solution, adsorbed in a dis ordered matrix of hard spheres, is studied by using replica Ornstein-Z ernike integral equations and the mean spherical approximation (MSA). The gas-liquid transition is localized. The coexistence curve is inves tigated dependent on the range of interaction between fluid species, o n matrix density, and on fluid-matrix attraction. We have observed shr inking of the coexistence envelope with increasing matrix density. The critical temperature of adsorbed mixture decreases with increasing ma trix density. The critical density is less affected; however, it also decreases slightly. The critical temperature is sensitive to the fluid species-matrix attraction and depends nonmonotonously on their streng th. For a given matrix microporosity, it increases slightly and then d ecreases with augmenting strength of fluid-matrix attraction. The crit ical density is less affected by this attraction. However, it decrease s for the model with a sufficiently long-range tail of fluid-matrix at traction, (C) 1998 Academic Press.