Robust Superamphiphobic Nanoscale Copper Sheet Surfaces Produced by a Simple and Environmentally Friendly Technique

In this study, robust nanoscale superamphiphobic (SAP) copper (Cu) sheet surfaces are obtained with an exceptionally simple and environmentally friendly technique. Copper oxide nanostructures are imparted onto the Cu sheet surface by a facile treatment of the surfaces with hot de‐ionized water (≈80 °C) for different time periods. A morphological transformation starting from cube‐like nanostructures associated with Cu2O to leaf‐like nanostructures of CuO with the progress in treatment time is observed. Scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy‐dispersive X‐ray spectroscopy (EDS), and laser scanning microscopy (LSM) analysis confirm the formation of copper oxide nanostructures. Consequently, the wetting properties of the treated Cu sheet surfaces toward water and organic liquids is varied after the surface energy reduction of the nanostructures with long chain fluorocarbon molecules of 1H, 1H, 2H, 2H‐perfluorodecyltrichlorosilane (PFDCS). The leaf‐like nanostructured CuO surfaces demonstrate SAP properties with a water contact angle (CA) as high as 160° and organic liquid CAs of around 150°. The robustness of the obtained SAP Cu sheet surface is confirmed after being exposed to a stream of both water and organic liquids, annealed under various temperatures in ambient environment, and ultra‐sonicated in acetone for various time periods. A novel, simple, and environmentally friendly technique of hot water treatment is used to introduce copper oxide nanostructures onto copper sheet surfaces. Analysis reveals that nanostructures are made of either cube‐like Cu2O or leaf‐like CuO. After surface energy reduction, superamphiphobic nanoscale copper sheet surfaces are obtained. The surfaces also show a high physical and chemical robustness.