S. Iatsevitch et F. Forstmann, DENSITY PROFILES AT LIQUID-VAPOR AND LIQUID-LIQUID INTERFACES - AN INTEGRAL-EQUATION STUDY, The Journal of chemical physics, 107(17), 1997, pp. 6925-6935
The structure of liquid-vapor and liquid-liquid interfaces in Lennard-
Jones (LJ) fluids and mixtures is studied using integral equations. To
obtain density distributions at interfaces between coexisting fluid p
hases we solve the Lovett-Mon-Buff-Wertheim equation. In this equation
we approximate the direct correlation functions of the inhomogeneous
fluid via interpolation between the direct correlation functions of th
e bulk phases. In the homogeneous bulk phases the system of the Ornste
in-Zernike equation with the reference-hypernetted-chain closure is so
lved to obtain the direct correlation functions at coexisting densitie
s. Density distributions and other interfacial properties are studied
for a liquid-vapor interface in a pure LJ fluid, in an Ar-Kr mixture a
nd for a liquid-liquid interface between two immiscible LJ fluids. The
results are in good agreement with simulations and other theories. At
low temperatures the liquid-vapor and liquid-liquid density profiles
exhibit oscillating structures with periods near the diameters of the
LJ spheres. Being quite weak at liquid-vapor interfaces these oscillat
ions become very pronounced at a liquid-liquid interface between immis
cible fluids. (C) 1997 American Institute of Physics. [S0021-9606(97)5
2341-5].