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The Hague, Netherlands

Mozir A.,University of Ljubljana | Strlic M.,University College London | Trafela T.,University of Ljubljana | Cigic I.K.,University of Ljubljana | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2011

Historic parchment is an extremely complex material, not only due to the various methods of production used and various past environmental histories of objects, but also due to its inhomogeneous structure. Many traditional methods of characterisation are empirical, but useful since they have gained recognition by the end-users. In this paper, we investigated the shrinkage temperature of collagen and the influence of lipids contained in parchment on the measurements. While the content of lipids does not seem to significantly affect shrinkage temperature measurements themselves, it strongly affects the decrease of shrinkage temperature of collagen during degradation, and thus its thermomechanical properties. This confirms the high importance of lipid peroxidation during degradation of parchment. While shrinkage temperature determination is a micro-destructive method, we also demonstrated that it is possible to determine this property using near infrared (NIR) spectroscopy based on partial least squares calibration. The root-mean square error of validation (RMSEV), obtained on a set of variously delipidised and degraded samples, was 7°C, so the method could be used for condition assessment or classification of historic objects. Using a set of 185 historic objects dating from 1200-1800, we also developed a method for non-destructive dating of parchment based on NIR spectroscopy using partial least squares regression (RMSEV=72 years), and successfully determined the correct age of a historic charter from the collection of Nationaal Archief, The Netherlands. © 2010 Springer-Verlag.

Strlic M.,University College London | Menart E.,University of Ljubljana | Cigic I.K.,University of Ljubljana | Kolar J.,Morana RTD D.o.o. | And 2 more authors.
Polymer Degradation and Stability | Year: 2010

Iron gall inks are characterised by high contents of acids and transition metals, promoting degradation of cellulose due to hydrolysis and oxidation, respectively. Their chemical interaction with the environment is not well understood, especially in view of emissions of degradation products which could lead to spread of degradation processes. In order to study the emissions, we employed gas chromatography/mass spectrometry following headspace micro-extraction, and liquid chromatography following hydroxyl radical scavenging with appropriate probes. We also studied chemiluminescence of cellulose affected by ink degradation. We show that while the emissions of organic volatile degradation compounds by inks are less intense than those of surrounding paper, ink does promote the degradation of cellulose across big distances (from object to object). We were able to link this to emission of reactive oxygen species, probably hydrogen peroxide. Its emission from ink is considerably more intensive than from paper. © 2009 Elsevier Ltd. All rights reserved.

Strlic M.,University College London | Kralj Cigic I.,University of Ljubljana | Mozir A.,University of Ljubljana | De Bruin G.,Nationaal Archief | And 2 more authors.
Polymer Degradation and Stability | Year: 2011

The possible effects of volatile organic compounds (VOCs) and of hypoxic conditions on the durability of library and archival collections have been investigated. There is growing evidence that particularly in micro-environments, there may be an important contribution of these indoor-generated pollutants to the degradation of paper. However, since the principal source of VOCs in repositories is the collections themselves, there are also significant possibilities for less stable papers, which are net VOC emitters, to promote the degradation of more stable papers, which may be net VOC absorbers. Using a range of model and real historic papers, the influence of acetic acid, formic acid, furfural, toluene, 1,4-diethylbenzene, iso-butylbenzol, 2-pentylfuran, paraformaldehyde, hexanal and vanillin was evaluated by adding them to samples degraded in closed vessels at elevated temperature. Possible protective effects of the use of activated charcoal cloth, oxygen removal, and of various chemisorbents were also investigated. The results strongly suggest that particularly VOCs with acidic or oxidisable functions can have a strong effect on degradation of cellulose. This is less pronounced in lignin-containing and acidic papers and more pronounced in papers with a small alkaline reserve. The removal of VOCs from the immediate environment can have a pronounced beneficial effect on papers emitting VOCs more intensively, in fact, the lifetime expectancy can be doubled. The results have immediate implications for storage of paper-based heritage in enclosures, but also for initiation of long-term VOC monitoring programmes in libraries and archives, where significant development is still needed. © 2011 Elsevier Ltd. All rights reserved.

Willemsen E.,B Cat B.V. | Luyten R.,B Cat B.V. | Castelijns W.,Army Museum Delft | Beentjes G.,Nationaal Archief
Restaurator | Year: 2011

Low-oxygen technology - ZerOx technology, offers new opportunities for museums, libraries and archives in protecting, preserving and treatment of biological infested objects. The ZerOx technology can be applied in any of the following areas: fire prevention, through permanent oxygen reduction; conservation, through active climate control of rooms or anoxic show cases; treatment of infested objects with the advantage of avoiding their contamination with chemicals. The contribution provides an overview of the working principle, the technology behind it, application possibilities, limitations and case studies. © 2011 De Gruyter Saur.

Menart E.,University College London | de Bruin G.,Nationaal Archief | Strlic M.,University College London
Cellulose | Year: 2014

This research investigates degradation of historic paper in polluted environments during long-term dark storage. In an innovative experiment, degradation rates at realistic pollution levels are compared with degradation rates in the absence of pollution, using a set of real historic papers. The most abundant pollutants in repositories in post-industrial environments are taken into account: acetic acid and nitrogen dioxide. Their action was assessed in terms of reduction of 'handling' (as defined by decrease in degree of polymerisation) and 'display' (as defined by discolouration) lifetimes. Extrapolations to room conditions enabled lifetime predictions in conditions that are comparable to a real archival or library repository environments while prediction uncertainties were analytically evaluated to assess the significance of conclusions. While 10 ppb of NO2 does reduce the handling lifetime of almost all types of paper, their predicted lifetimes were still assessed to be several millennia, with the exception of acidic paper. Acetic acid at concentrations that are typical for archival and library repositories (<100 ppb) has significantly less effect than NO2 while it does not affect display lifetimes. From a conservation management perspective, it needs to be addressed whether the predicted reductions in otherwise significant handling lifetimes are of real concern and whether air filtration in archival and library repositories is justified. © 2014 The Author(s).

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