Effect of Surface Nano-Texturing on Wetting Properties: Molecular Dynamics Study

Molecular dynamics simulations describing the equilibrium shape of a nanodroplet located on the solid substrate are presented for the cases of a “cylindrical water droplet” on silicon substrates. Several examples of the structuration of the solid substrate surface are simulated, i.e.: atomistic flat substrate and substrates with ordered nanopillars and nanopores. The adhesives forces between molecules of the substrate and the fluid are modified to change the wettability. Three wetting configurations are considered in this work for the smooth surface: (i) hydrophilic (0 = 30∘), (ii) hydrophobic (0 = 136∘), and (iii) an intermediate regime (0 = 80∘). Further, the dependence of the wetting angle as a function of the surface state is studied in details for the above-mentioned configurations.