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 super hydrophobic surface can dramatically switch to a superhydrophilic state under O-2 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 super hydrophobic 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.