A mechanically durable slippery liquid-infused porous surface based on distinctive ‘jaboticaba-like’ TiO2/sepiolite nanocomposites with superior hot water repellency and anti-corrosion for protecting various substrates

Abstract

Slippery liquid infused porous surfaces (SLIPS) are widely utilized due to their omniphobicity and distinctive slippery properties. Fragile mechanical properties and unstable lubricant layer of SLIPS have a substantial impact on its long-term application performance. Herein, a pre-oil-infused mechanically robust organic/inorganic composite superhydrophobic surface (SC) for SLIPS with hierarchical roughness was obtained by in-situ growing a significant amount TiO2 nanospheres on the surface of sepiolite (SEP) fiber structures via hydrogen bonding, Ti-O-Si covalent bonding, and electrostatic power, resulting in a unique bionic “jaboticaba-like” structure on SC. Through hydrogen bonding, the hydroxyl groups on the TiO2 surface can also interact with the cross-linked polymer PVDF-HFP (polyethylene fluoride hexafluoropropylene). In the presence of multiple interactions, SC could resist 300 cycles of a rigorous Taber rubbing test with a 500 g weight and yet retain superhydrophobicity. The prepared SLIPS have exceptional hot water (boiling water) resistance, strong shear stability (8000 rpm/min), and water jetting resistance (40 kPa). Corrosion current density of SLIPS and SC was decreased by roughly 4 orders of magnitude and 3 orders of magnitude, respectively, after exposure to 3.5 wt% NaCl solution as compared to bare aluminum substrate. SLIPS have higher long-term corrosion resistance compared to SC. Owing to the “jaboticaba-like” hierarchical structure, SLIPS have great oil-locking capabilities, as well as good mechanical stability and long-term corrosion resistance. This article offers recommendations for developing tough SLIPS for future engineering applications.