Conservation process of archaeological waterlogged wood studied by spectroscopy and gradient NMR methods

Abstract

The properties of methyltrimethoxysilane-treated, waterlogged archeological elm wood were studied by magnetic resonance imaging and nuclear magnetic resonance (NMR) methods. The spatially resolved proton density images, spin-spin relaxation profiles, proton NMR spectra, and self-diffusion coefficients of the preservative agents were measured during drying. The resolution of the data allowed for the differentiation between the early and late wood areas of the elm wood and determination of the shrinkage of the sample in the tangential and radial directions, and it showed the different dynamics of methyltrimethoxysilane (MTMS) in the lumen cells of both early and late woods. The NMR spectra indicated that the MTMS, after rapid evaporation of ethanol, is bound to the wood. Identical measurements were also taken for the archeological elm wood treated with polyethylene glycol (PEG) and for an untreated wood sample. From the results, it can be concluded that MTMS showed significantly higher stability against shrinkage when compared to PEG. Therefore, it may be considered as an alternative preservative for archeological wood.

High‐resolution multiparametric MRI of contemporary and waterlogged archaeological wood

“…For this purpose, it is possible to monitor by MRI the flow of chemical agents that replace the water in the wood and investigate their interaction with the wood structures. [10,11] In this paper, we show that high-resolution MRI can be a useful tool for the identification of waterlogged wood species and to assess their condition and conservation.…”

“…This involves the exchange of the water that fills the wood tissue for an appropriate chemical that will strengthen the wood structure and prevent its distortion, but unlike water, it will not evaporate from the wood when exposed to air. [10] Therefore, studies on conservation agents that meet such requirements are desirable in order to better preserve the wooden remains. For this purpose, it is possible to monitor by MRI the flow of chemical agents that replace the water in the wood and investigate their interaction with the wood structures.…”

Pickering Emulsions Stabilized by Halloysite Nanotubes: From General Aspects to Technological Applications

“…[191] For instance, the interactions between PEGs polymeric chains and sulfate or iron compounds in the woods are responsible for the production of acidic species which increase the acidity inside the wooden structures, thus enhancing the degradation in the long term. [192] The damage of Vasa, a Swedish warship from the 17th century, is the most popular example. [193] Other methods dealing with the use of biopolymers, ethers, sugars, epoxy resins, or inorganic species are also critical due to the need for high amounts of either organic solvents or acids or they alter the aspects of the artworks in the long term.…”

Structural Monitoring of a Large Archaeological Wooden Structure in Real Time, Post PEG Treatment

“…In anaerobic conditions, wood can survive for thousands of years due to limited degradation because of the reduced development of decay fungi [11]. Once extracted, however, these structures need to be dried, which, if not performed properly, can lead to cracking due to the shrinkage associated with the removal of water, and the voids created by degradation [12].…”