Siloxane‐Schiff Base Dual‐Crosslinking Enable Damage‐Free Consolidation of Fragile Waterlogged Ivory From the Sanxingdui Site

ABSTRACT

The conservation of decayed waterlogged ivory from the Sanxingdui site faces a dual challenge: structural collapse upon dehydration caused by capillary forces and microcracking during consolidation due to internal stress from conventional consolidants. Here, we report a novel dual‐crosslinking consolidant (APG) based on (3‐aminopropyl)trimethoxysilane (APTMS) and glyoxal for damage‐free consolidation of decayed waterlogged ivory. The APG employs mildly hydrolyzed APTMS to form a permeable, weakly bonded Si–O–Si network with minimal shrinkage stress, enabling safe infiltration and consolidation. Glyoxal dynamically crosslinks with APTMS via Schiff base chemistry, creating a reinforcing imine network that enhances mechanical strength. Upon penetrating the ivory's porous hydroxyapatite skeleton, the APG consolidant reinforces the structure through pore‐filling (reducing total pore volume by 39%), anchoring, and interfacial bonding, while maintaining color variations within acceptable limits (ΔE = 3.46). By adjusting glyoxal content, curing kinetics and storage stability can be finely controlled to suit conservation requirements. This study offers a rational siloxane‐Schiff base dual‐crosslinking strategy for the effective consolidation of waterlogged ivory and other fragile archaeological materials.