Monte Carlo simulation of liquid–liquid benzene–water interface

Abstract

A Monte Carlo simulation of liquid–liquid benzene–water interface is reported. Molecular pair potentials obtained from quantum mechanical calculations have been used. The two phases remain stable over 70 000 configurations/molecule and the interior of each phase is shown to have bulk properties. The intrinsic interface is molecularly sharp, but the interfacial region is broadened by capillary waves. The preferential water–benzene orientation at the interface is similar to that in a dilute aqueous solution of benzene. There is no longitudinal water ordering induced by the interface. The presence of the nonpolar phase gives an alignment of water dipoles parallel to the surface and a reduced probability of parallel orientation of adjacent dipoles. The hydrogen bonds between water neighbors are reinforced at the interface.