Fluorosilane-modified MIL-53(Al) with enhanced hydrophobic performance for stone heritage conservation

Applying protective coatings to the surface of stone heritage is one of the most common methods for its preservation. To enhance the weathering resistance of the limestone heritages, MIL-53@FS, a hydrophobic metal-organic framework (MOF) composite, was prepared through fluorosilane modification of MIL-53-OH synthesized via a solvothermal method. Characterization analyses were conducted using SEM, XRD, TGA, and FTIR techniques. The results indicated that MIL-53@FS maintained its well-ordered framework structure and certain porosity, while forming a continuous and uniform hydrophobic coating, leading to a significant increase of water contact angle to 127.14° and enhanced thermal stability. It exhibited excellent corrosion resistance, anti-icing performance, and color compatibility in the application tests, holding a promising outlook for protecting limestone-based heritages.