Effects of temperature, size of water droplets, and surface roughness on nanowetting properties investigated using molecular dynamics simulation

The wetting properties of water nanodroplets on a gold substrate are studied using molecular dynamics (MD) simulations. The effects of temperature, droplet size, and surface roughness are evaluated in terms of molecular trajectories, internal energy, dynamic contact angle, and the radial distribution function. The simulation results show that the wetting ability and spreading speed of water greatly increases with increasing temperature. The dynamic contact angle of water on the gold substrate decreases with increasing temperature and decreasing droplet size and surface roughness, which leads to an increase in wetting ability. The compactness of a water droplet increases with decreasing temperature and droplet size, and slightly increases with degree of roughness. The internal energy of a water droplet decreases with increasing surface roughness, indicating that droplets form more stably on a rough surface.