Hydrodynamics at the moving contact line

By removing the smearing effect of capillary waves in molecular dynamics simulations we are able to provide a microscopic picture of the region around the moving contact line (MCL) at an unprecedented resolution. On this basis, we show that the continuum character of the velocity field is unaffected by molecular layering down to below the molecular scale. The solution of the continuum Stokes problem with MCL and Navier-slip matches very well the molecular dynamics data and is consistent with a slip-length of 42 Å and small contact line dissipation. This is consistent with observations of the local force balance near the liquid-solid interface