Self-Healing Structured Graphene Surface with Reversible Wettability for Oil–Water Separation

Stable functional surfaces with reversibly switchable wettability have recently been developed for the continuous separation of oil–water mixtures. This article proposes a facile method to fabricate superhydrophobic surfaces on copper meshes by combining poly(dimethylsiloxane) and graphene. The superhydrophobic surface can dramatically switch to a superhydrophilic state under O2 plasma etching and recover to a superhydrophobic state after laser etching to achieve unidirectional transport of oil or water. The surface had a high separation efficiency and favorable reusability in oil–water separation. In addition, the superhydrophobic surfaces demonstrated not only outstanding stability, including an anticorrosion ability, anti-UV exposure ability, oil contamination resistance, and abrasion resistance, but also an excellent self-healing ability after flame treatment. This research opens a novel avenue for the design of stable materials with reversible wettability that may have promising potential applications in microfluidics, wastewater purification, oil-spill cleanup, and quick, low-cost realization of self-healing materials in situ using operations that can be easily scaled and automated.