▎ 摘　　要

The evaluation of the wetting stability of supported graphene in ambient environment is important for its practical applications. Herein, it is shown by experiments that a monolayer graphene coating can alter the water contact angles of various substrates to a converged value around 80-85 degrees in ambient environment, almost independent of substrate materials, graphene layer numbers as well as long-term air exposure up to 14 months. First-principles calculations and van der Waals modeling indicate that a monolayer graphene is sufficient to alter both short-range and long-range interactions of a water molecule with various substrates to a converged state. The stable wettability of graphene would facilitate its practical applications, ranging from functional coatings, liquid gated electronic devices, and other areas requiring its exposure to water.