Molecular dynamics simulations of disjoining pressure effect in ultra-thin water film on a metal surface

Molecular dynamics (MD) simulations are used to examine the disjoining pressure effect of a water thin film adsorbed on a metal surface. The model was validated against experiments and verified against previous MD simulations. The variation of vapor pressure with film thickness was examined for a water thin film adsorbed on a gold surface. The results agree well with the classic disjoining pressure theory without surface charges and show that liquid layering does not affect disjoining pressure. However, surface charges of the gold substrate enhance the disjoining pressure of the water thin film, consistent with experimental evidences for polar liquids. (C) 2013 AIP Publishing LLC.