Monte Carlo simulations of argon adsorption in nanoscopic linear channels

We have studied, using grand canonical Monte Carlo simulations, the adsorption of Ar at 85 and 128 K inside nanoscopic open channels of different cross-section shapes on an Al surface. We studied, in particular, the filling phenomenology in linear channels whose cross sections are shaped like a cusp, wedge, parabola, and square well. The influence of the channel geometry on the adsorption behavior is analyzed by computing the adsorption isotherms. Different growth regimes are found as the adsorption proceeds, which are compared with existing model calculations and experimental data. Our simulations show, in particular, the occurrence, in square-well channels, of a nanoscale version of the so-called "Moses transition," in agreement with the predictions of model calculations and with recent experimental results.