Direct method of tracing the wetting states on nanocomposite surfaces.

Identifying the two distinctive wetting states on a nanostructured surface remains an open challenge. We report here a direct method of tracing the Wenzel and Cassie states by using Ag nanoparticles as tracing agents. The method provides an answer to the long-standing question of whether there is a transition from the Wenzel to Cassie state in the sliding angle drop on superhydrophobic nanocomposite thin films containing multiwalled carbon nanotubes.