The effect of surface properties on film rupture: roughness, slip, and disjoining pressure.

Models of rupture in thin liquid films are usually developed under the assumption that the surface of the solid substrate is flat, chemically homogeneous, and that the no-slip condition is satisfied at the solid-liquid interface. Given that the rupturing film thickness is often in the sub-micron range, non-uniformities in surface properties, e.g. due to roughness or trapped nanoscale bubbles, can have a significant effect on the process. This is also confirmed by experimental data. We identify three independent mechanisms affecting the rupture dynamics: topographic features of the surface, variations in the slip length, and changes in the parameters that define the disjoining pressure. All mechanisms are included in a lubrication-type model which allows us to compute rupture time as a function of surface properties.