PFDTS/SiO2 dual-modified hierarchical TiO2 nanostructures for sandstone cultural relics preservation coatings with enhanced weathering resistance

Water-induced degradation threatens sandstone cultural relics, highlighting the need for effective protection. This study applies a nano-coating of PFDTS-modified TiO 2 /SiO 2 to sandstone, optimizing PFDTS concentration, coating penetration depth, and hydrophobicity. A TiO 2 -to-SiO 2 ratio of 75:25 with 80 μL of PFDTS achieved high water and oil contact angles of 152.7° and 145.7°, respectively. After 210 h of UV exposure, contact angles showed minimal reduction, confirming the coating's durability. Additionally, air permeability is preserved to maintain sandstone breathability. These findings provide valuable insights for safeguarding sandstone heritage sites against weathering.