Interfacial tension in confined molecularly-thin films

The grand-canonical ensemble Monte Carlo method has been used to study the interfacial tension in a rare-gas film confined to a slit pore whose plane- parallel walls comprise rigidly fixed similar rare-gas atoms. In narrow pores, where both walls strongly influence the whole film, the interfacial tension is shown to be a highly complex function of pore width and transverse alignment of the walls. Oscillations in the tension are correlated with the addition of new fluid layers, the most highly structured layers corresponding to maxima in the tension. Separate interlayer and intralayer contributions to the tension are defined and shown to be useful in explaining the physics of the change in the interfacial tension with the addition of new layers to the film.