A facile method for fabrication of superhydrophobic surface with controllable water adhesion and its applications

In this work, a simple alkaline etching method was presented to fabricate superhydrophobic surfaces. X-Ray Diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and atomic force microscope (AFM) were utilized to characterize the surfaces. The morphology of superhydrophobic surfaces shows hierarchical structures and the corresponding water contact angles (WCA) are more than 155 inverted perpendicular. The adhesion force between the water droplets and the surfaces were discussed in detail, the specimen etching for 40 min in NaOH solution shows the lowest adhesion. The applications of these superhydrophobic surfaces were exploited. For instance, the superhydrophobic surface with high adhesion can be used in drug delivery. In addition, the self-cleaning property of the superhydrophobic surface with low adhesion was also tested by applying nano-silica powder as dust on the surfaces. Importantly, the superhydrophobic surfaces show excellent anti-corrosion performance with an extremely low corrosion current density of 2.748 x 10(-9) A/cm(2), and the anti-corrosion mechanism was discussed comprehensively. The present method can also be used to fabricate large-scaled superhydrophobic surfaces and expand applications of metal materials. (C) 2017 Elsevier B.V. All rights reserved.