PHASE COEXISTENCE AND INTERFACE STRUCTURE OF A LENNARD-JONES FLUID INPOROUS-MEDIA - APPLICATION OF BORN-GREEN-YVON EQUATION

The Born-Green-Yvon (BGY) equation with Fischer-Methfessel. (FM) appro ximation is used to calculate the density profiles of the planar liqui d-vapor interface of Lennard-Jones fluid in a hard-sphere disordered r igid matrix. The density profiles an compared with the results of cano nical ensemble Monte Carlo simulations. Both theory and simulation sho w that the thickness of the interface increases in the presence of dis ordered media. The phase diagrams for two different matrix densities h ave been evaluated and compared with the predictions of mean field and optimized cluster theories. Comparison with Monte Carlo data for low matrix densities indicates that the BGY-FM theory works reasonably wel l. Possible extensions of the theory are also discussed. (C) 1998 Amer ican Institute of Physics.