A rapid one-step preparation method of the repairable three-dimensional antifouling superhydrophobic 2.5EPZF coating on magnesium alloys

Although three-dimensional (3D) superhydrophobic coating has been gradually prepared on the surface of metal substrate for anticorrosion and antifouling, their complex preparation steps and equipment requirements limit their practical application. Herein, by a rapid one-step spray preparation method the fabricating 3D superhydrophobic 2.5EPZF (2.5 g epoxy resin/polycaprolactone (PCL)/zinc oxide/perfluorodecyltriethoxysilane) coating is prepared. This method utilizes a certain degree of directional arrangement of macromolecular long chain polymers (PCL) as solvent evaporation during the spraying process to form a filamentous structure to construct the 3D coating. This preparation mechanism provides us a novel theoretical guidance method for preparing 3D coating. Further, the silk thickness and mesh density of the 3D mesh structure is controlled by adding epoxy resin. When the amount of epoxy resin is 2.5 g, the surface of 2.5EPZF coating is with about 1–3 μm thick branch frame and 0.1–0.4 μm thin treetop. And the water-contact angle (CA) of 2.5EPZF is 156.6 ± 1.5° and the sliding angle (SA) is < 10° . The 2.5EPZF coating exhibits durable antifouling, strong mechanical&chemical durability, and corrosion resistance. The corrosion current of the 2.5EPZF coating for 0 day's immersion and 35 days’ immersion in NaCl solution is 1.043 × 10−12 A•cm−2 and 1.1703 × 10−11 A•cm−2, respectively. Under solar irradiation and at 50 °C for 30 min, the 2.5EPZF coating is with scratching recovering. Additionally, the composite coating can be prepared by a large area. It is expected that this method is readily used and shows great application potentials.