Influences of ambient temperature, surface fluctuation and charge density on wettability properties of graphene film

Abstract

Some molecular dynamics simulations focusing on the interactions between graphene films and water droplets are carried out in this article to investigate the fluid–solid interfacial behavior of surface wettability. The wettability of an ideal graphene film is investigated at room temperature at the beginning of the simulations, then the influences of ambient temperature, surface fluctuation and charge density of the graphene film on the wetting behaviors of water droplets on the film are also discussed from three points of view, namely the interaction energy of the graphene and the water droplet, the mass density of water and the water contact angle on the graphene film. The simulation results indicate that the ideal graphene film is slightly hydrophobic and that both the ambient temperature and the fluctuation of the graphene film play a negative role during the wetting processes. The observations also show that, once charged, the wetting property of graphene changes massively, from slightly hydrophobic to super-hydrophilic.