Surface tension at the liquid-vapor interface of screened ionic mixtures

Abstract

The liquid-vapor interface of binary mixtures of charged particles is studied usingmolecular dynamics (MD) simulations. The interaction between parti- cles is given by a short-range repulsive potential plus an attractive/repulsive Yukawa term, which models screened electrostatic interactions. To obtain the components of the pressure tensor two methods were used: a hybrid MD method which combines the hard sphere and continuous forces and a standard continuous MD method where the hard sphere was replaced by a soft interaction. We show that both models give essentially the same results. As the range of interaction decreases, the critical temperature and surface tension increase. The comparison with the restricted primitivemod- el of ionic fluids is discussed.