An integrated approach for developing a durable and superhydrophobic anti-corrosion coating inspired by biomimetic starfish surface structures

Abstract

Applying superhydrophobic coatings with excellent anti-corrosion, anti-fouling, self-cleaning, antibacterial, and wear-resistant properties is a promising approach to protect metal surfaces. This study presents a novel and cost-effective approach, inspired by the biomimetic structure of starfish, to develop a durable and superhydrophobic coating. Unlike traditional methods, we introduce a meticulously engineered tetrapodal ZnO@SiO2-fluorosilane composite that forms a unique hierarchical micro-nano core-shell structure, reducing surface energy and exceptional performance. The formulation combines perfluorooctyl triethoxysilane (FOTS)-modified SiO2, silicone polyester, and tetrapodal ZnO (T-ZnO) in thermoplastic polyurethane (TPU), resulting in a first-of-its-kind T-ZnO@SiO2-FOTS (ZSF) coating with superhydrophobic properties, demonstrated by a water contact angle of 160°, a sliding angle of 3°, and the lowest surface free energy of 14.50 mN/m, contributing to excellent anti-corrosion properties (corrosion rate of 1.44 × 10−6 mm/year) and a corrosion inhibition efficiency of 99.87 %. In addition, the coating exhibits remarkable mechanical durability, adhesion enhancement, and stability against harsh environmental agents, including salt spray, HCl, and NaOH. Our biomimetic approach leverages the starfish-inspired surface design and highly crosslinked interface to enhance resilience, making this coating more robust under real-world conditions. These results provide a promising pathway for the development of multifunctional coating materials suitable for various solid surfaces.