Liquid-vapor interface of square-well fluids of variable interaction range.
Properties of the liquid-vapor interface of square-well fluids with ranges of interaction lambda=1.5, 2.0, and 3.0 are obtained by Monte Carlo simulations and from square-gradient theories that combine the Carnahan-Starling equation of state for hard spheres with the second and third virial coefficients. The predicted surface tensions show good agreement with the simulation results for lambda=2 and for lambda=3 in a temperature range reasonably close to the critical point, 0.8</=T/T(c)</=0.95. As expected, the surface tension increases with the range of interaction and decreases monotonically with temperature. A comparison between theory and simulation results is also given for the width of the interface and for the coexistence curves for the different interaction ranges.
Orea
Pedro
P
Ingeniería Molecular, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, 07730 México D.F., México.
Duda
Yurko
Y
Weiss
Volker C
VC
Schröer
Wolffram
W
Alejandre
José
J