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

2011 ◽  
Vol 38 (11) ◽  
pp. 2957-2967 ◽  
Author(s):  
Gianna Giachi ◽  
Chiara Capretti ◽  
Ines D. Donato ◽  
Nicola Macchioni ◽  
Benedetto Pizzo
Keyword(s):  
Archaeological Wood ◽  
Waterlogged Archaeological Wood

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

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1113 ◽  
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.

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

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.

THE CHARACTERIZATION OF WATERLOGGED ARCHAEOLOGICAL WOOD: THE THREE ROMAN SHIPS FOUND IN NAPLES (ITALY)*

Archaeometry ◽  
2008 ◽  
Vol 50 (5) ◽  
pp. 855-876 ◽  
Author(s):  
C. CAPRETTI ◽  
N. MACCHIONI ◽  
B. PIZZO ◽  
G. GALOTTA ◽  
G. GIACHI ◽  
...  
Keyword(s):  
Archaeological Wood ◽  
Waterlogged Archaeological Wood

Bio-based consolidants for waterlogged archaeological wood: Assessment of the performance and optimization of the diagnostic protocol

2019 ◽  
Vol 40 ◽  
pp. 49-58
Author(s):  
Alessandra Papacchini ◽  
Simona Dominici ◽  
Giuseppina Di Giulio ◽  
Marco Fioravanti ◽  
Antonella Salvini
Keyword(s):  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
Diagnostic Protocol

scholarly journals Synthesis and characterisation of lignin-like oligomers as a bio-inspired consolidant for waterlogged archaeological wood

2016 ◽  
Vol 88 (10-11) ◽  
pp. 969-977 ◽  
Author(s):  
Emily McHale ◽  
Susan Braovac ◽  
Calin C. Steindal ◽  
Richard B. Gillis ◽  
Gary G. Adams ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ethyl Acetate ◽  
Cell Walls ◽  
Water Soluble ◽  
Wood Structure ◽  
New Materials ◽  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
Maximum Water ◽  
Maximum Water Content

AbstractThe development of new materials for the consolidation of waterlogged archaeological wood from sustainable sources is an important area of research, as the most widely used consolidant today is petroleum based. Ideally a new consolidant will interact with the existing wood structure, ensuring maximum compatibility. Lignin is often the major component remaining in archaeological wood, as it is less susceptible to degradation than holocellulose. Therefore, in order to maximise the potential for interaction with the wood cells, lignin-like oligomers have been synthesized from isoeugenol using a water soluble copper salen catalyst at pH 10, giving a weight average Mw of 1.6 kDa. Analysis by NMR spectroscopy has shown that the oligomers have a lignin-like structure with β-O-4′, β-β′ and β-5′ connections. A 10 w/w% solution of the oligomers in ethyl acetate was found to thoroughly penetrate 1 cm3 samples of waterlogged archaeological wood (density of 0.146 g/mL, maximum water content of 620%) after 14 days impregnation, as determined by FTIR spectroscopy. No impregnation material could be seen by SEM, suggesting that it coats the cell walls upon drying. This indicates that dehydrogenated polymers penetrate waterlogged archaeological wood well and have the potential to be developed into consolidants.

Towards improved understanding of PEG-impregnated waterlogged archaeological wood: A model study on recent oak

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Ingela Bjurhager ◽  
Jonas Ljungdahl ◽  
Lennart Wallström ◽  
E. Kristofer Gamstedt ◽  
Lars A. Berglund
Keyword(s):  
Mechanical Properties ◽  
Microfibril Angle ◽  
Mechanical Tests ◽  
Chemical Degradation ◽  
Cellulose Microfibrils ◽  
Radial Compression ◽  
Biological Degradation ◽  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
The Impact

Abstract To prevent deformation and cracking of waterlogged archaeological wood, polyethylene glycol (PEG) as a bulk impregnation agent is commonly applied. PEG maintains the wood in a swollen state during drying. However, swelling of wood can reduce its mechanical properties. In this study, the cellular structure of oak and cell wall swelling was characterized by scanning electron microscopy (SEM) of transverse cross-sections, and the microfibril angle of oak fibers was determined by wide angle X-ray scattering (WAXS). Samples of recent European oak (Quercus robur L) impregnated with PEG (molecular weight of 600) were tested in axial tension and radial compression. Mechanical tests showed that axial tensile modulus and strength were only slightly affected by PEG, whereas radial compressive modulus and yield strength were reduced by up to 50%. This behavior can be explained by the microstructure and deformation mechanisms of the material. Microfibril angles in tensile test samples were close to zero. This implies tensile loading of cellulose microfibrils within the fiber cell walls without almost any shear in the adjacent amorphous matrix. These results are important because they can help separate the impact of PEG on mechanical properties from that of chemical degradation in archaeological artifacts, which display only small to moderate biological degradation.

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