4/30/2023 0 Comments Last wood requirements![]() ![]() ![]() The role these factors play in the selection of appropriate consolidants and drying methods for the conservation of waterlogged archaeological wooden objects is also investigated. Here, the effect these differences in structuration have on the coating of the wood cells and the biological and thermal stability of the wood are examined, as well as the role of the environment in the formation of specific structures. The method of drying reveals a significant difference in the morphology of these biopolymers both ex situ and within the wood cells. 100,000 g/mol) and cellulose nanocrystals (CNCs)-are investigated in relation to their drying behaviour. 60,000 g/mol), medium-molar-mass alginate (Mw ca. Three polysaccharides-low-molar-mass (Mw) chitosan (Mw ca. ![]() ![]() Recently, there has been great interest in the replacement of the standard, but limited, polyethylene glycol with biopolymers for wood conservation however, their behaviour and action within the wood is not completely understood. Drying of an object is commonly carried out in one of three ways: (i) air-drying with controlled temperature and relative humidity, (ii) drying-out of a non-aqueous solvent or (iii) freeze-drying. Any mechanical instability caused during drying can induce warping or cracking of the wood cells, leading to irreparable damage of the object. The removal of water from archaeological wooden objects for display or storage is of great importance to their long-term conservation. We are obliged to protect it, save from oblivion and preserve it for future generations. We need to remember that wooden cultural heritage is an integral part of our culture and history that define our humanity. It contains both review and research papers to give the readers a broader picture of the problems and issues related to the conservation of wooden historical objects and structures. The articles present the new methods for conservation of various historical wooden artefacts, reliable modern techniques for characterisation of the wood structure, properties and degree of degradation, and discusses problems and doubts related to all aspects of conservation and re-conservation of wooden cultural heritage. This is a selection of manuscripts devoted to the conservation and preservation of wooden cultural heritage. This book is a printed edition of the Special Issue Historical Wood: Structure, Properties and Conservation that was published in Forests. It is shown that crystalline cellulose particles usually flocculate when used to treat archaeological wood but that they may be treated with surfactants in order to improve penetration of archaeological finds. The materials and the procedures used in testing are described. Crystalline cellulose is interesting in conservation as the individual particles are resistant to acid and not as hygroscopic as the amorphous part of cellulose. Chitosan is made from modified chitin (primarily from shrimp and crabs) and may be dissolved in acidic solutions. Tests on biomimetic cellulose and chitosan have begun and the initial evaluation of these materials is given. It may be possible to construct a frame using bio-inspired materials (possibly an ‘artificial lignin’ mixed with other compounds optimise strength and flexibility) or through biomineralisation (an inorganic ‘skeleton’). Special attention is given to the field of biomimetics–the discipline of constructing materials inspired by existing natural designs. Such particles may help stabilise pH inside the wood by neutralising any acid generated inside treated artefacts. This might be accomplished by foaming a polymer, or by combining nanoparticles with a polymer ‘spider web’ network to keep them in place. It is proposed that an important requirement for a future stabilising agent is to leave an airy structure in order to allow retreatment in the future. Since new consolidants would be advantageous, it is discussed what the requirements of such consolidants are and how material sciences may help procure them. Melamine-formaldehyde (Kauramin) has also been used and while it is fairly stable, it may also fill the wood and turn it into a ‘block’ of plastic. Poly(oxy ethylene) (POE or Polyethylene glycol ) is widely used as a consolidant today but this material degrades over time and thus cannot support the finds for a very long time. A few of the more common examples are: Alum salt, KAl(SO4)2♱2H2O, which was used for treatment earlier but does not penetrate well and leaves the wood very acidic. While numerous polymers have been previously tested, most do not stabilise the wood sufficiently, penetrate far enough, or remain stable without producing toxic fumes. Given the perilous state of the Oseberg find from Norway, the Museum of Cultural History and the Department of Chemistry both at the University of Oslo, are looking into new methods for treating archaeological wood. ![]()
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