膨润土基水凝胶黏合剂的可控构筑及其对砂岩质文物的长效保护应用研究

Hydrogels present broad application prospects in the field of conservation of cultural heritage due to their strong adhesion, high transparency, high flexibility and controllable mechanical strength. In this study, a novel bentonite-based hydrogel (AR-gel) material for efficient adhesive conservation of the damaged and fractured sandstone-based cultural heritage was fabricated via introducing functionalized bentonite into the acrylamidebased hydrogel, and the components, forming temperature and time were optimized. The bentonite-based hydrogel improved the compatibility with sandstones, and presented excellent adhesion without any obvious trace at the adhesion joints. While, the adhesive on sandstones kept primary state without white or discoloration, which (Figure Presented) further indicated its non-destructive bonding protection. In addition, the overflow during the bonding process can be easily removed with water without any trace. The morphology and properties of the repaired sandstone can keep consistent with primary sandstones, which avoid the secondary damage to the sandstones during the adhesion process. The high-durability conservation of AR-gel material on sandstone was verified by severe freezing and thawing aging cycle and salt crystallization-wet/heat cycle aging test, and the high-durability conservation mechanism was deeply analyzed: sandstone and AR-gel were firmly bonded by strong hydrogen bond, Si－O－Si bond, Si－O－M bond, protonation and ionic bond, mechanical bite, and so on. Besides, AR-gel presented excellent bonding properties for various types of cultural relics, such as glass, metal, sandstone, ceramics, and pottery. The development of this work was expected to provide a durable cultural relic bonding conservation material with wide application prospects.