Glutenin phase transition as a method of fabricating primer for superhydrophobic and corrosion-resistant coating

Concerns over food safety arising from conventional plastic and resin-based corrosion barriers cannot be underestimated, particularly in light of the potential for plasticizer migration. We introduce an environmental-friendly and sustainable approach to develop superhydrophobic and anticorrosion coatings. This involved a unique process where glutenin, post-reduction with tris(2-carboxyethyl)phosphine, underwent a phase transition, naturally adhering to diverse surfaces to form a foundational primer. The core mechanism of this adhesion lied the β-sheet stacking configuration, confirmed by grazing-incidence wide-angle X-ray scattering. To further elevate the performance, carnauba wax was easily incorporated as a topcoat, forming a superhydrophobic coating that surpassed standalone wax coatings in durability against wear, impact, high temperature, and corrosion. This enhancement was derived from the intricate intermolecular interactions, including hydrogen bonding and hydrophobic interactions, established between the primer and carnauba wax. Notably, the phase-transited coating and superhydrophobic coating maintained a low-frequency impedance of 0.1 and 2.1 MΩ/cm², respectively, even after prolonged immersion in a 3.5 % NaCl solution for 21 days. The superhydrophobic coating was ideally applicated in an extensive range of canned food products, such as beverages, fruits, etc., that undergo pasteurization. Additionally, both the primer and the superhydrophobic coating exhibited outstanding biocompatibility, as evidenced by red blood cell hemolysis and cytotoxicity assessments. In summary, this research contributes significant knowledge to the development of superhydrophobic coatings and expand applications of protein-based assembly materials.