Dehydration and in situ consolidation of waterlogged archeological wood via laccase catalyzing eugenol nanoemulsion

Lignin-like materials share chemical similarities with wood and exhibit excellent mechanical properties along with resistance to aging and microbial degradation. This study focuses on eugenol as a target lignin-like monomer. Three eugenol nanoemulsions with concentrations of 10%, 20%, and 30% were prepared using surfactant Pesticide Emulsifier 1602 and co-surfactant diethylene glycol mono butyl ether (DEGBE). Laccase facilitated the in-situ polymerization of eugenol on the cell walls of waterlogged archeological wood (WAW) from the Nanhai No.1 shipwreck at temperatures of 35 °C °C, 45 °C, and 55 °C for dehydration and consolidation purposes. The 30 wt% eugenol emulsion at 45 °C showed the best consolidation effectiveness, with a minimal shrinkage rate of 3.62% and a 400–1000% increase in bending strength compared to controls. The polymer reinforced the decayed wood while preserving cellular lumens, offering an innovative, environmentally sustainable conservation method for WAW.