A mechanical model for liquid nanolayers

Liquids in contact with solids are submitted to intermolecular forces making liquids heterogeneous and stress tensors are not any more spherical as in homogeneous bulks. The aim of this article is to show that a square-gradient functional representing liquid-vapor interface free energy corrected with a liquid density functional at solid surfaces is a well adapted model to study structures of very thin nanofilms near solid walls. This result makes it possible to study the motions of liquids in nanolayers and to generalize the approximation of lubrication in long wave hypothesis.