Natural superhydrophobic coatings templated from protein aggregation: Multipurpose liquid repellence and application across virtually arbitrary substrates

The integration of promising packaging techniques with biomimetic materials emerges as a novel strategy to attenuate food waste, contamination and corrosion. Inspired by the superhydrophobic surfaces of lotus leaves, a natural superhydrophobic material that can be applied to virtually arbitrary substrates is developed via the bilayer deposition of bovine serum albumin (BSA) aggregates and blended wax (wax@BSA). The wax@BSA-based superhydrophobic coating exhibits high water contact angle (WCA>150°) and a low sliding angle (SA<10°). Surface-anchored abundant functional groups in the BSA aggregates can combine with wax through non-covalent interaction, promoting the formation of a stable superhydrophobic surface to resist the adsorption of water, beverages, blood and highly-viscous liquids. The wax and BSA aggregates endow the substrate with surface roughness and low surface energy, imparting excellent stability as the coating maintains its superhydrophobicity after the treatment under various extreme conditions. The wax@BSA-coated paper exhibits remarkable water repellence and self-cleaning behavior without sacrificing its mechanical properties and printability. This coating on the various types of textiles significantly resists wetting by edible liquids and blood after washing cycles. In addition, wax@BSA-coated tinplate exhibits the corrosion potential (Ecorr) of −0.17 V, the corresponding corrosion current density (Icorr) of 3.52 × 10 −7 A/cm 2 and a Z ´ ´ of 8. 7 × 10 4 Ωcm 2 , demonstrating superior anti-corrosion properties under humid as well as ambient atmospheres. This work provides a sustainable and universal strategy for the fabrication of all-natural and superhydrophobic materials, which opens up a significant prospect for the practical application in corrosion resistance and food packaging.