In situ polymerisation of isoeugenol as a green consolidation method for waterlogged archaeological wood

This paper reviews the degradation, preservation and conservation of waterlogged archaeological wood. Degradation due to bacteria in anoxic and soft-rot fungi and bacteria in oxic waterlogged conditions is discussed with consideration of the effect on the chemical composition of wood, as well as the deposition of sulphur and iron within the structure. The effects on physical properties are also considered. The paper then discusses the role of consolidants in preserving waterlogged archaeological wood after it is excavated as well as issues to be considered when reburial is used as a means of preservation. The use of alum and polyethylene glycol (PEG) as consolidants is presented along with various case studies with particular emphasis on marine artefacts. The properties of consolidated wood are examined, especially with respect to the degradation of the wood post-conservation. Different consolidants are reviewed along with their use and properties. The merits and risks of reburial and in situ preservation are considered as an alternative to conservation.

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Even Visually Intact Cell Walls in Waterlogged Archaeological Wood Are Chemically Deteriorated and Mechanically Fragile: A Case of a 170 Year-Old Shipwreck

Molecules ◽

10.3390/molecules25051113 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1113 ◽

Cited By ~ 1

Author(s):

Liuyang Han ◽

Xingling Tian ◽

Tobias Keplinger ◽

Haibin Zhou ◽

Ren Li ◽

...

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Intact Cell ◽

Nitrogen Adsorption ◽

Wet Chemistry ◽

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

X Ray Scattering ◽

Crystallite Structure ◽

Cell Wall Mechanics

Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.

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An in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged archaeological wood

Holzforschung ◽

10.1515/hf-2019-0238 ◽

2020 ◽

Vol 74 (11) ◽

pp. 1043-1051

Author(s):

Åke Henrik-Klemens ◽

Katarina Abrahamsson ◽

Charlotte Björdal ◽

Alexandra Walsh

Keyword(s):

Polyethylene Glycol ◽

Spectroscopic Method ◽

Calibration Model ◽

Efficient Treatment ◽

Raman Spectroscopic ◽

Archaeological Wood ◽

Validation Set ◽

Impregnation Period ◽

Polymer Impregnation

AbstractThe weakened microstructure of archaeological wood (AW) objects from waterlogged environments necessitates consolidation to avoid anisotropic shrinkage upon drying. Polymer impregnation through submergence or spraying treatments is commonly applied, and for larger and thicker objects, the impregnation period can stretch over decades. Thus, for efficient treatment, continuous monitoring of the impregnation status is required. Today, such monitoring is often destructive and expensive, requiring segments for extraction and chromatographic quantification. This study proposes an in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged AW. A calibration model was built on standards of PEG, cellulose powder, and milled wood lignin using orthogonal partial least squares (OPLS). The OPLS model had a strong linear relationship, and the PEG content in wood of varying degrees of degradation could be determined. However, the accuracy of the model was low with a root mean square error of prediction of 11 wt%. The low accuracy was traced to the heterogeneity in the calibration and validation set samples with regard to the small probing volume of the confocal instrumental setup.

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New trials in the consolidation of waterlogged archaeological wood with different acetone-carried products

Journal of Archaeological Science ◽

10.1016/j.jas.2011.06.012 ◽

2011 ◽

Vol 38 (11) ◽

pp. 2957-2967 ◽

Cited By ~ 28

Author(s):

Gianna Giachi ◽

Chiara Capretti ◽

Ines D. Donato ◽

Nicola Macchioni ◽

Benedetto Pizzo

Keyword(s):

Archaeological Wood ◽

Waterlogged Archaeological Wood

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Identification of Bacteria from Waterlogged Archaeological Wood

Heritage Microbiology and Science ◽

10.1039/9781847558633-00151 ◽

2008 ◽

pp. 151-155

Keyword(s):

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

Identification Of Bacteria

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Essential Oils as Alternative Biocides for the Preservation of Waterlogged Archaeological Wood

Microorganisms ◽

10.3390/microorganisms8122015 ◽

2020 ◽

Vol 8 (12) ◽

pp. 2015

Author(s):

Federica Antonelli ◽

Marco Bartolini ◽

Marie-Laure Plissonnier ◽

Alfonso Esposito ◽

Giulia Galotta ◽

...

Keyword(s):

Essential Oils ◽

Inhibitory Concentration ◽

Treated Wood ◽

Biological Degradation ◽

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

Materials Used ◽

And Storage ◽

Generation Sequencing

Waterlogged archaeological wood is exposed to a high risk of biological degradation during the post-excavation phases of storage and restoration. For this reason, often biocides must be used to preserve wooden remains. In the present work three essential oils (cinnamon, wild thyme, and common thyme) were tested as possible alternative biocides to use in the preservation of waterlogged archaeological wood. The oils were first tested in vitro to establish the minimum inhibitory concentration (MIC) and to evaluate the biocidal activity on selected fungal strains. Then, the established MIC was applied on waterlogged archaeological wood samples and during an actual restoration treatment. The effectiveness of the oils was evaluated through cultural analyses, ATP quantification, and next-generation sequencing. The results showed that the oils caused a significant decrease in the vitality of fungal mycelia grown in vitro and of the microbiota present in treated wood and storage water. Furthermore, an influence on the composition of the bacterial communities of treated wood samples was observed. Although further tests are needed to evaluate interferences with the materials used during restoration procedures, essential oils could be considered as a possible alternative to the currently used biocide.

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