Template-free electrodeposition of ultra-high adhesive superhydrophobic Zn/Zn stearate coating with ordered hierarchical structure from deep eutectic solvent

The adhesion of superhydrophobic surface is closely correlated with its surface structures. As a new class of high-efficient green solvents, deep eutectic solvents are widely used to deposit superhydrophobic materials. However, there are still no reports of the electrodeposition of high-adhesive superhydrophobic materials from deep eutectic solvent. Herein, a simple method (free-template) is developed to fabricate an ordered hierarchical structured superhydrophobic Zn/Zn stearate coating with superior corrosion resistance from deep eutectic solvent. The Zn/Zn stearate-4 coating is composed of numerous orderly arranged pure Zn micro-slices and tens of thousands of Zn stearate nano-concaves. The unique structures show excellent superhydrophobic (164.8 +/- 0.6 degrees) and high adhesive performances due to the synergetic effect of strong capillary adsorption effect, large van der Waals' forces and quasi-continuous three-phase contact lines. The maximum value of water droplet that can be pinned on the overturned Zn/Zn stearate-4 surface is 30 mu L. This work provides a new strategy to fabricate ultra-high adhesive superhydrophobic metal coating, which is promising for the application in microfluidic devices.