Mimicking lotus leaf: Development of micro-nanostructured biomimetic superhydrophobic polymeric surfaces by ultrafine powder coating technology

This study demonstrates the development of polymeric superhydrophobic surfaces by a solvent-free ultrafine powder coating (UPC) technique for the first time. The developed surfaces exhibit lotus effect with water contact angles (CAs) of over 160° and sliding angle (SA) of less than 5°. It is evident that the higher CA and lower SA of the low-energy surfaces are attributed to the appropriate surface textures of micro- and/or nano-scales. AFM and SEM images revealed the unique double-scale hierarchical (micro- and nano) structures on the developed superhydrophobic surfaces. As an additional advantage, these superhydrophobic UPC technology eliminates the use of toxic solvents that are responsible for the hazardous emissions of VOCs. Therefore, fabrication of polymeric superhydrophobic surfaces by solvent-free PC technique has enormous opportunities for a revolutionary expansion in coating industry to save the surfaces from the intervention of moisture.