Mimicking rose petal wettability by chemical modification of graphene films

The wettability of a solid surface is a parameter that determines its compatibility within the environment. This property is controlled by the chemical composition of the surface and its roughness. Herein we report the tailoring of the wettability of graphene films by the covalent attachment of functional moieties. The wetting properties of functionalized graphene films have been characterized by static and dynamic contact angle measurements. The introduction of functional groups produces graphene platforms with contact angle values between ∼60° and 140°. These new platforms resemble naturally occurring surfaces such as a rose petal with low wettability and high water adhesion. Results can be explained based on the micro-nanoscale structure and the well-defined chemical composition of the dispersed graphene layers. This strategy provides a convenient tool for the production of graphene films with tunable wetting properties for applications in electrodes, sensors, intelligent coatings, and for the inclusion of graphene into composite materials.