Wettability of striped patterned mono-and multilayer graphene supported on platinum

Wettability of water nanodroplet on graphene and graphene-coated metals in recent years have been the subject of interest. In the present work, the wettability of mono and three-layer graphene supported on underlying platinum was investigated using molecular dynamics simulation. Furthermore, the striped patterns were generated on the substrates by parallel grooves with different widths and depths. Wetting results showed that the Cassie-Baxter state converts into the Wenzel state by increasing the width of the grooves, which was confirmed by free energy results that obtained from free energy perturbation and potential of mean force methods. A chain of water molecules forms at interface by increasing the width of the grooves, which leads to higher hydrogen bond lifetime. Water-platinum interaction in the grooves and nanodroplet pinning cause anisotropy in the wetting and nanodroplet shape. This suggests that such artificial surfaces with anisotropic wetting properties can mimic water anisotropic behavior on some natural structures, which lead water to move in a specific direction.