Disjoining properties of Ne and Ar on graphite surface

The disjoining properties of the thin films of Ne and Ar, respectively, absorbed on graphite basal plane are presented. These properties are resolved down to a molecular scale by using molecular dynamics simulation (MD). First, it is first shown that there are a subtle difference between the disjoining pressure and the disjoining potential multiplied by the bulk liquid density. It is due to the difference between the normal pressure of the thin film and the pressure at the saturated state. As the film thickness decreases, the disjoining pressure in all cases increases exponentially and has only the positive values with no sign-change in curvature. The disjoining potential has negative values that decreases exponentially as the thickness decreases, and this trend corresponds to the state of complete wetting. Finally, the disjoining-pressure results obtained by MID are compared with those obtained front the Mean Field Theory. Significant discrepancies are shown for both the neon and argon cases when the effective film thickness decreases below about 10 molecular diameters. (c) 2008 Elsevier B.V. All rights reserved.