Dependence of the liquid-vapor surface tension on the range of interaction: a test of the law of corresponding states

TL;DR

This study investigates how the liquid-vapor surface tension of Lennard-Jones fluids varies with interaction range, using simulations and density functional theory, confirming Guggenheim's law of corresponding states across different conditions.

Contribution

It provides a comprehensive analysis of surface tension dependence on interaction range, validating the law of corresponding states through combined simulation and theoretical approaches.

Findings

Surface tension decreases with increasing interaction range.

Guggenheim's law accurately describes the surface tension behavior.

Theoretical results depend on the quality of the bulk equation of state.

Abstract

The planar surface tension of coexisting liquid and vapor phases of a fluid of Lennard-Jones atoms is studied as a function of the range of the potential using both Monte Carlo simulations and Density Functional Theory. The interaction range is varied from $r_c^* = 2.5$ to $r_c^* = 6$ and the surface tension is determined for temperatures ranging from $T^* = 0.7$ up to the critical temperature in each case. The results are shown to be consistent with previous studies. The simulation data are well-described by Guggenheim's law of corresponding states but the agreement of the theoretical results depends on the quality of the bulk equation of state.