Oil-impregnated gel grafting onto UiO-66-NH2 coating engineered slippery lubricant-infused porous surface for durable corrosion protection

• A SLIPS is engineered by PFPE-impregnated PFDTES gel grafting onto UiO-66-NH 2 coating. • Covalent grafting of gel layer onto UiO-66-NH 2 enhances bonding strength for long-lasting stability. • Compatible polarity enables PFPE to anchor onto PFDTES gel surface for durable hydrophobicity. • PFDTES gel layer acts as a sustained reservoir of PFPE, maintaining the integrity of protective oil film. • The coating maintains stable hydrophobicity and high corrosion resistance under 12 weeks of salt spray. Slippery lubricant-infused porous surfaces (SLIPSs) have attracted much attention in recent years due to their significant potential for wide applications in surface engineering. However, the depletion of lubricants severely limits the long-term durability of SLIPSs. Herein, we fabricate a durable SLIPS by covalently grafting a perfluoropolyethers (PFPE)-impregnated perfluorodecyltriethoxysilane (PFDTES) gel onto a UiO-66-NH 2 metal-organic framework (MOF) membrane to create a robust lubricant reservoir. It is worth noting that a similar polarity of PFDTES gel and PFPE enables PFPE to anchor onto the gel surface and within the crosslinked gel network via intermolecular forces, facilitating durable hydrophobicity. Meanwhile, the covalent grafting of a gel layer onto UiO-66-NH 2 membrane enhances the bonding strength for long-lasting stability. The resultant UiO-66-NH 2 based SLIPS exhibits the water repellency with water contact angle of ∼121° and sliding angle of ∼4°, performing satisfactory anti-fouling, anti-icing, self-cleaning, salt-tolerance and acid-/alkali-resistance properties. Electrochemical tests reveal a significant increase in corrosion resistance after PFPE infusion. The coating maintains stable hydrophobicity and provides sustainable corrosion protection during immersion in 3.5 wt.% NaCl aqueous solution and even 5 wt.% NaCl salt spray tests for over 12 weeks. This work would offer valuable insights into the multi-functional development of MOF-based protective coatings.