Fluffy Polyfluoroalkoxy Layer Produced by Air Plasma Spraying Based on “Grapeshot” Effect

Fluoropolymers with low surface energies are widely used in friction reduction, anti-corrosion, and anti-ice coatings. The fabrication of hierarchical micro- and nanostructures with fluoropolymers is beneficial for industrial application. In this study, a superhydrophobic composite coating was prepared by an improved air plasma spraying technique using feedstocks of Cr and polyfluoroalkoxy (PFA). A fluffy structure was found on the surface of the coating. A similar structure could not be found on the surface when the Fe and PFA powders were used as the feedstocks under the same condition. The characterization results suggest that the fluffy layer was derived from PFA. The formation of such a fluffy structure was attributed to the evaporation of Cr during spraying and their interaction with PFA droplets. This spraying method provides a new route for preparing hierarchical polymers, which have potential applicability in functional coatings.