Wettability of a surface engraved with the periodic nanoscale trenches: Effects of geometry and pressure

[Display omitted] •A surface with the nanotrenches studied by using molecular dynamics simulation.•Hydrophobicity of the entrenched surface was examined.•Metastable and transition states uncovered for the wetting transition of trenches.•A trapezoid trench remained dewetted from a liquid under pressure up to 105 atm. The hydrophobicity of a surface is greatly enhanced by engraving the nanoscale trenches on the surface. By using all-atom molecular dynamics simulation, we studied the thermally activated process of the (de)wetting of the trenches by a macroscopic liquid water. By varying the shape of the trench and pressure of the liquid, we unveiled the structures and free energies of the (meta) stable and transition states in the (de)wetting transition. As the trench varied from a rectangle to a trapezoid in shape, the surface became increasingly resistant to a liquid, remaining dewetted from an intruding liquid under pressure up to 105 atm. The present study provides molecular insights for designing the texture of a surface with an improved hydrophobicity.