Long-term preservation of sandstone-based cultural relics: multi-functional applications from modified hydroxyapatite-based mineralized hydrogels

The preservation of historical relics is necessary for the inheritance of human civilizations, but historical relics often suffer irreversible damage. It’s urgent for heritage conservation to provide a more efficient, environmentally friendly, and sustainable direction. Herein, a versatile mineralized hydrogels (PHA/Gel) was synthesized for the preventative and salvageable conservation of sandstone relics. PHA/Gel demonstrated a fast and efficient gel time (< 60 s) and adjustable adhesive strength (340–680 kPa). PHA/Gel maintained excellent long-term in-situ infiltration reinforcement and adhesive repair conservation performance and excellent fluorescence stability during the aging process. Furthermore, the PHA/Gel demonstrated universal adhesion to multi-material relics (glass, sandstone, pottery, porcelain, and metal). PHA/Gel also provided temporary protection to excavated water-saturated relics, reducing the risk of drying out and cracking due to rapid water loss. Overall, this study is expected to promote the upgrading of cultural relics conservation from passive restoration to active protection.