Superhydrophobic Anodized Metals and Method of Making Same

A method for producing a superhydrophobic anodized surface, the method comprising:

• anodizing a surface of a substrate in an anodization acid to form a plurality of pores,
• wherein the plurality of pores have an average diameter of from 1 to 10,000 nm, and
• wherein the plurality of pores are spaced from each other by an average distance of from about 10 to about 1500 nm;
• etching the surface with an etchant to widen an edge of each of the plurality of pores;
• repeatedly anodizing the surface in the anodization acid and etching the surface with the etchant until the edges of the plurality of pores overlap to form a plurality of nano-sharp ridges,
• wherein the plurality of nano-sharp ridges each have a width, a length, and a height of from 1 to 500 nm;
• and
• coating the surface with a hydrophobic polymer to render the surface superhydrophobic, such that the surface exhibits a contact angle of at least 150 degrees with a drop of water.