Development of fluorine-free superhydrophobic antibacterial and antifouling coatings: A multifunctional composite system for biomedical materials and metal protection

Bacterial infections—driven by the relentless rise of antimicrobial resistance constitute a critical global health burden, implicated in millions of fatalities annually. This escalating challenge has catalyzed intense research into advanced biomedical materials. Superhydrophobic antimicrobial coatings effectively reduce water adhesion and prevent microbial growth on substrate surfaces, making them one of the most effective strategies to combat microbial infections. Therefore, it is essential to develop an antimicrobial coating that combines both superhydrophobic and anticorrosive properties. In this study, a superhydrophobic antimicrobial coating was fabricated by a simple spraying technique, combining polyphenylene sulfide (PPS), Brazilian carnauba wax (CW), and zirconium-based MOF (UiO66) filled with nanosilver. Brazilian carnauba wax and PPS form a nanostructured layered structure, which imparts excellent water-repellent properties to the composite coating. Testing showed that the composite coating exhibited a water contact angle of 151 ± 1° and a rolling angle of less than 5 ± 1°. The molecular dynamics simulation of the hydrophobic properties of palm wax provides a theoretical basis for its hydrophobic characteristics at the microscopic level. Furthermore, the addition of UiO66@Ag nanoparticles imparts remarkable antimicrobial properties to the coating. The superhydrophobic properties effectively reduce bacterial adhesion to the coating in aqueous environments, the antibacterial properties of the coating effectively inhibit bacterial growth on its surface. Based on these characteristics, a dual antibacterial adhesion mechanism combining physical protection and chemical sterilization has been established. Moreover, the composite coating demonstrated excellent performance in antifouling, salt spray, electrochemical, and adhesion tests. Therefore, this multifunctional antimicrobial composite coating holds great potential for advancing the design and manufacturing of biomedical materials and the protection of metal substrates. • Natural palm wax forms a superhydrophobic surface. • MOF-loaded nanosilver exhibits efficient antibacterial properties. • The dual barrier resists microbial adhesion. • The coating demonstrates excellent corrosion resistance and mechanical stability.