Liquid-infused slippery anti-corrosion surface: From laboratory to marine environment assessments

• A liquid-infused slippery anti-corrosion surface with continuous PFPE liquid film was fabricated. • The surface exhibits exceptional liquid repellency and anti-fouling performance. • Real marine exposure tests reveal zone-dependent anti-corrosion behaviors. • Lubricant retention of liquid-infused SS is a critical challenge in dynamic marine environments. As a promising alternative to address the instability of the air layer in superhydrophobic anti-corrosion materials, the corrosion resistance of bioinspired liquid-infused slippery surface (SS) has been demonstrated. However, evaluations have been largely confined to laboratory testing, which fails to accurately predict their performance in real-world service environments. In this paper, we constructed a liquid-infused SS by infusing perfluoropolyether (PFPE) into an epoxy resin/fluorinated TiO 2 (EP/F-TiO 2 ) superhydrophobic coating (SC). Analyses of surface wettability, morphology, roughness, and chemical composition confirmed the formation of a continuous PFPE liquid film, which successfully replaced the trapped air layer within the structural interstices of EP/F-TiO 2 SC. This resulted in a surface with slippery and low surface energy properties, effectively repelling liquids across a wide range of surface tensions from water (72.8 mN·m -1 ) to peanut oil (34.5 mN·m -1 ). Laboratory tests verified the excellent anti-fouling and anti-corrosion capabilities of the prepared EP/F-TiO 2 /PFPE SS, with its low-frequency impedance modulus and charge transfer resistance showing a six-order-of-magnitude increase over bare Q235 carbon steel. More importantly, we evaluated the real-world marine anti-corrosion performance of the EP/F-TiO 2 /PFPE SS by exposing samples to four distinct corrosion zones. The results revealed that the EP/F-TiO 2 /PFPE SS exhibited superior long-term anti-corrosion performance in the atmospheric and splash zones. However, in the tidal and submerged zones, the gradual depletion of PFPE under dynamic seawater conditions led to a decline in surface slippery property and eventual biofouling during long-term exposure. This study, integrating both laboratory experiments and field assessments in marine environments, underscores the significant challenges associated with transitioning liquid-infused slippery materials from laboratory to practical applications. In particular, the long-term retention of lubricant within surface structures remains a paramount concern requiring further investigation.