Stepwise Physicochemical Design of Antifouling Materials: Integrating Superamphiphobic Surfaces with Antibacterial Nanoparticles for Dual-Action Defense

The pursuit of durable and eco-friendly antifouling surfaces has become a critical challenge across engineered systems, ranging from architectural coatings to marine infrastructure. Herein, we propose an innovative stepwise physicochemical antifouling mechanism through the rational integration of hierarchical superamphiphobic architectures with bactericidal copper oxide nanoparticles. The designed coating operates via a sequential defense protocol: physical antiadhesion enabled by a superamphiphobic surface exhibiting ultralow surface energy, coupled with a chemical antibacterial effect through controlled Cu²⁺ ion release from embedded CuO nanoparticles. When the action time reaches 24 h, the coating shows excellent antibacterial effects against Gram-negative <i>Escherichia coli</i> (<i>E. coli</i>), <i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>), and Gram-positive <i>Staphylococcus aureus</i> (<i>S. aureus</i>). A scalable spray-coating technique was developed using 3-aminopropyltriethoxysilane (APTES)-functionalized CuO/SiO₂ nanocomposites with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) modification for the coating fabrication. Systematic characterization combining Cassie-Baxter modeling, X-ray Photoelectron Spectroscopy (XPS) analysis, and bacterial viability assays confirms the mechanistic coupling between topographical liquid repellency and chemical bactericidal activity. The contact angle (CA) value of CuO-SiO₂/APTES@PFDTES calculated by dynamic density functional theory (DDFT) is 165.5°. This work provides a promising strategy for the rational design of advanced superamphiphobic antifouling coatings through physicochemical antibacterial strategies.