Effects of morphology, tension and vibration on wettability of graphene: A molecular dynamics study

In the present study, we investigated the effects of morphology, tension and vibration on the wettability of graphene by performing classical molecular dynamics simulations. The contact angle of water droplet on ideal graphene is calculated to be 88.27° using the density profile method, which is in good agreement with the experimental data. The wrinkled morphology slightly decreases the wettability of graphene in most cases, and the droplet contact line always prefers to stay at the crest of wrinkles. The wrinkled morphology also brings extra barrier energy which leads to the pinning effect and discretized wetting effect with the droplet contact angle fluctuating up and down when the droplet volume increases. Tension and vibration strongly influence the wettability of graphene. The droplet contact angle linearly increases with increasing of biaxial tensile strain when the stain is lower than 10%, then remains at about 110°. The graphene becomes more and more hydrophobic with increasing of vibrational amplitude and decreasing of vibrational period. The contact angle of droplet on vibrational graphene and corresponding vibrational energy of graphene can be described by a logarithmic function.