A search for prewetting in a molecular dynamics simulation

A first-order wetting transition should be accompanied by a prewetting transition. Although many such wetting transitions have been reported, clear observations of prewetting are rare. We report on a search for prewetting in a wall-fluid system that has previously been shown to exhibit a first-order wetting transition. The fluid consists of a vapour phase whose density is increased towards the coexistence density while the coverage of the wall-vapour interface is monitored. This approach to coexistence is studied as a function of the interaction strength between the wall and the fluid. Although we do recognize the presence of a wetting transition in the adsorption curves, the more subtle effects associated with prewetting cannot be observed unambiguously.