Mechanism of surface nanostructure changing wettability: A molecular dynamics simulation

Molecular dynamics simulation is performed to simulate the wetting behavior of nano water droplets on flat and pillar surfaces. The result shows that the contact angle of the water droplet on the flat surface becomes smaller with the increase of the surface characteristic energy parameter epsilon. At the same energy parameter epsilon, the hydrophobicity is enhanced on the pillar surface compared to the flat surface. For nanostructured surfaces with different geometrical features, the sparser the surface pillars, the larger the contact angle. What's more, we propose an equivalent potential well method, which can effectively reveal the mechanism of nanostructures changing surface wettability. The deeper the equivalent potential well, the smaller the contact angle.