In an MD simulation of a hydrophobic brush layer on a pure metal surface one can investigate in direct comparison where water and other substances are distributed under the chosen conditions. The study of longer sequences allows to derive the thermodynamic equilibrium (mean preferred location) as well as the dynamics (diffusion: how fast are sites exchanged).
Hydrophobic coatings can be applied by hydrophobic substances, e.g. so called brush layers. Mostly they are bound chemically after they have been brought to the surface, such that wear of the molecular brushes is low. Those who never have seen such a simulation model by their own eyes, would be surprised by the quick motions, that quick that only little measuring methods could capture them at all.
A simple measure for the quality of the brush layer is the contact angle of an applied water droplet. The more it comes close to 180 degrees, the more hydrophobic the surface is.