A targeted low-intervention stabilisation strategy for shell-degraded archaeological wood from arid burial environments

Archaeological wood from arid burial environments may show shell-like degradation, with severe deterioration concentrated near the surface while the interior remains comparatively preserved. Here, a bio-based carboxylated cellulose nanofiber/polyanionic cellulose/carboxymethyl chitosan (CCNC/PAC/CMCS) ternary system was evaluated as a targeted low-intervention treatment for severely degraded tomb-door wood. Guided by a previously established shell-like degradation model, the treatment aimed to stabilise the principal degraded outer zone rather than maximise penetration or uptake. Fuchsin tracing showed controlled liquid-phase migration, with longitudinal and transverse representative maximum distances of 4.74–8.23 and 2.13–2.35 mm, respectively. Despite low uptake (2.46%), radial and tangential apparent compressive strengths increased by 2.88- and 8.94-fold. The treatment caused limited colour change (Δ E 00 < 3), moderate air-permeability reduction (10.24%) and near-surface pore modification. Microscopy, FTIR and TGA supported local deposition and non-covalent network-assisted stabilisation.