Evaluation of cell wall reinforcement in feather keratin-treated waterlogged wood as imaged by synchrotron X-ray microtomography (μXRT) and TEM

Archaeological waterlogged woods (WLW) become considerably fragile over time because of chemical hydrolysis and the deterioration by microorganisms in the wet buried environment. The methods are sought for the dimensional stabilization of such woods. In the present article, the conservation of archaeological WLW of (Sieb. et Zucc.) Endl. by means of a commercially available feather keratin was in focus. The impregnation of an ancient wood from the 9th century A.D. was examined by the noninvasive synchrotron X-ray microtomography, which is well suited for imaging fragile samples. The thickness of the cell walls of keratin-treated wood was preserved and was comparable with that of recent wood. Notably, the middle lamella (ML) of keratin-treated wood appeared to be electron dense as indicated by transmission electron microscopy. Thus, it can be concluded that feather keratin is predominantly adsorbed on the ML and it prevents wood cell walls from collapsing and provides reinforcement.