Process for the production of mechanically stable, superhydrophobic surfaces

Water repellent coatings developed in this work showed that two superimposed rough structures are required to generate superhydrophoby with WCA >150 degrees. A micro rough surface overcoated with a submicro or nano rough hydrophobic material behave similar to the hierarchical structures found on leafs of some plants which generate the highly mobile Cassie/Baxter droplets. Coatings of inorganic and organic materials were performed by thermal spraying (inorganic materials) and spraycoating (organic materials) on sandblasted metal, mainly stainless steel, surfaces. Hierarchical roughness structures were developed by thermal treatment of pure and composite fluoropolymeric layers. Such hierarchical superhydrophobic coating systems showed water contact angles between 160 degrees and 170 degrees. The coatings have good mechanical stability and can be applied in numerous technical applications.