Alginate–Nanosilver Hydrogels: A Self-Dissolving System\nfor Comprehensive\nPreservation of Waterlogged Wooden Artifacts

The utilization of biomass-based hydrogels represents\na versatile\napproach toward the conservation of waterlogged wooden artifacts,\nshowcasing the potential of sustainable technologies in mild and long-term\ncultural relic treatments while simplifying preservation procedures\nto minimize environmental impact. Alginate/polyacrylamide hydrogels\noffer promising potential as substrate materials for conserving waterlogged\nwooden artifacts. Their robust mechanical properties and flexible\nfunctionality address specific preservation requirements, such as\nantimicrobial, moisturizing, and deacidifying needs, thereby enhancing\nthe effectiveness and adaptability of conservation efforts. Herein,\na self-dissolving hydrogel with antibacterial and deacidifying effects\nwas prepared using silver nanoparticles (AgNPs) embedded in alginate/polyacrylamide\nhydrogels and used for the conservation of waterlogged archeological\nwood obtained from Nanhai No. 1, an 800-year-old shipwreck salvaged\nfrom the South China Sea. Its self-dissolving characteristics can\neffectively avoid damage to the wood when removing the hydrogel. The\nembedded AgNPs were found to provide a good preservation effect on\nwooden cultural relics in terms of solubility, stretchability, and\nantibacterial properties due to their tunable interaction with the\npolymer chains, which was characterized through scanning electron\nmicroscopy (SEM), gel permeation chromatography (GPC), mechanical\ntesting, antibacterial experiments, etc. The gels can be stretched\nto 20 times their initial length and demonstrate a 99% reduction in\nbacterial presence. This innovative hydrogel effectively neutralizes\nthe acid generated by bacteria metabolism and notably possesses self-dissolution\nbehavior that avoids the damage caused by peeling off the hydrogel\nfrom the wood surface. These characteristics provide a distinct advantage\nfor the timely protection and multipurpose preservation of wooden\nartifacts and offer potential in other comparable scenarios.