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• BC/ZnO nanocomposite strengthens paper and improves aging resistance. • The nanocomposite imparts antifungal properties to paper. • The nanocomposite helps in deacidification of paper. Paper, commonly used as an information carrier, can become acidified and brittle over time. In this study, 0.3 % bacterial cellulose (BC) composite with 1.0% zinc oxide (ZnO) nanoparticles was prepared and used to coat brittle book paper for deacidification and consolidation. The BC/ZnO nanocomposite was characterized using zeta potential, micro morphology, elemental mapping, X-ray photoelectron spectra, Fourier transform infrared, and thermogravimetric analyses. The results indicated that the composite exhibited good stability. ZnO nanoparticles were bonded to the hydroxyl groups on BC, enhancing the thermal stability of BC. The composite was uniformly sprayed on the paper surface, and the mechanical properties, color difference, readability, pH, and micromorphology of the paper samples were examined before and after the treatment. The BC/ZnO nanocomposite exhibited good deacidification and consolidation effects on paper samples with low impact on the original paper appearance. Moreover, the BC/ZnO nanocomposite showed a good inhibitory effect on fungi growth on paper. [ABSTRACT FROM AUTHOR]

Improving the strength decrease caused by fungal metabolites is still an arduous task in the field of paper materials protection. A set of damaged Kangxi Dictionary from Qing Dynasty was chosen as samples in this work. The main goal of this work is to develop high-efficiency and eco-friendly media with the characteristics of antifungal and reinforcement, to preserve paper materials and continue the historical and scientific research value of cultural heritage. PHMG as an efficient antifungal was used in this work. For better behavior, the epoxy group of KH560 can be induced by the amino group in PHMG by ring opening reaction to form PHMG-KH560 colloidal complex. Spraying PHMG-KH560 on paper could establish Si-O-C bonding and increased the hydrogen bond between polymeric material and paper fibers, which simultaneously inhibited fungi and improved mechanical strength of the original paper, even after the artificial aging. PHMG-KH560 had certain antifungal activity against five fungi, such as Aspergillus versicolor, and Aspergillus Niger , and had better inhibitory effect on Cladosporium herbarum, Trichoderma viride , and Penicillium expansum. The ancient writing ink on the paper sprayed with PHMG-KH560 did not affect its visual beauty, which also indicated that the complex reagent was expected to be applied to the antifungal and reinforcement of paper materials. [ABSTRACT FROM AUTHOR]

• Artificial light radiation is a viable tool for paper documents bleaching. • Artificial light bleaching does not produce any physico-chemical change in paper. • Artificial light bleaching reduces the yellowing of paper in short and long term. • Paper is physico-chemical and optically deteriorated by hydrogen peroxide. This study offers a new tool to restorers to bleach paper documents: artificial light radiation (ALR). It is a controlled method that is an alternative to other highly aggressive procedures that have been applied to cellulose based media. Its main novelty is its intrinsic lighting characteristics which guarantee uniformity and avoid heating the paper. The results of testing this new tool were compared to those of bleaching with hydrogen peroxide (H 2 O 2). Each of the two methods was applied to five different types of widely used paper: Arches and Somerset (brands serving for engraving and digital printing), Ingres (drawing), press-type (magazines and newspapers) and Bible-type (historical documents). Once characterised by physico-mechanical, chemical and optical parameters (grammage, thickness, specular gloss, optical properties, air permeance, tensile properties, determining the pH of both surface and aqueous extracts), the different papers were bleached by the two methods according to pre-established criteria. Finally, to determine the evolution and effects of the two treatments, the papers were subjected to accelerated ageing. [ABSTRACT FROM AUTHOR]

Lining of canvases and paper artworks is a diffused conservation methodology developed to ensure the safe and long-term preservation of weakened supports. Lining systems are generally constituted by a new supporting material or a package of new materials glued to the original artefact. This paper reports on the study of the mechanical behaviour of four multi-layered paper and canvas composites, proposed as lining systems for a large drawing on paper: the "School of Athens" by Raffaello Sanzio, dated 1508. This masterpiece is the 1:1 preparatory cartoon for the wall-painting in the Vatican rooms. Uniaxial tensile testing has been employed in this study to characterize both the single layer materials and the overall mechanical behaviour of the composites. The mechanical tests have been performed before and after artificial ageing with high humidity regime. The complex testing protocol allowed selecting the best performing composite for the final lining, and to assess a safety threshold in terms of stress value for the framing and display of the restored artwork in the new showcase. The results constitute a quantitative evaluation of the different systems, and therefore they can effectively support the conservators' activity and methodological choices. [ABSTRACT FROM AUTHOR]

Abstract Books, prints, drawings, watercolours, engravings, as well as all other works of art based on paper, are very susceptible to fungal development. The excreted substances and the fungal structures themselves are often coloured and interfere with the readability of the artefacts, diminishing their artistic and monetary value. In order to direct cleaning methods for specific fungal stains on paper, the colourants (molecules) responsible for those stains need to be assessed. However, the literature regarding fungal stains on paper and colourants produced by those fungi is very dispersed and scarce. Therefore, the main objectives of this work were surveying the most common stains on paper, the colourants present on those stains and the main fungi responsible for these colourants' production. To achieve these goals, two different but complementary literature reviews were made: one on paper conservation literature, where fungal stains observed on paper cultural heritage are reported; and another survey on the chemical/food/pharmaceutical fields where colourants' molecules produced by fungi, that can colonise paper cultural heritage, are identified and studied in greater detail. This paper presents the first literature review on this subject. The results show that the fungal genera more frequently related with fungal stains on paper cultural heritage are Aspergillus (29%) and Penicillium (13%). The most common colour of the stains is brown (54%), caused by foxing in most of the cases. However, in the paper conservation literature, no consistent correlation has been observed between stain colour on paper/specific fungal species and colourants/chemical compounds. On the literature review regarding the use of fungal colourants for industrial/commercial purposes, the referred colourants can be mostly classified chemically as carotenoids and polyketides. Biosynthetically, most colourants produced by fungi are polyketide-based and representative classes may include chemical structures such as azaphilones, anthraquinones, hydroxyanthraquinones, naphthoquinones and other structures. From a total of 80 different colourants, the ones mostly produced by paper colonising fungi were polyketide quinones, namely the hydroxyanthraquinoid (HAQN) colourants. This review showed that the most commonly studied colours are yellow and red, followed by orange. The production of these colourants is often associated with the genera Aspergillus sp. and Penicillium sp. which are frequently found on stained paper. Overall, there is no doubt that colourants producing fungi are a serious problem to paper conservators, since there is a great variety of colourants produced by different species of fungi colonising paper. This review catalogues the fungal genera, species and excreted colourants mentioned in the literature as being responsible for staining paper cultural heritage. [ABSTRACT FROM AUTHOR]

The research aim was to determine the effectiveness of disinfection methods: thyme essential oil microatmosphere (TEO), silver nanoparticles misting (AgNPs), and low temperature plasma (LTP) by culture-dependent method and RNA analysis. In addition, we examined the influence of disinfection on mechanical and optical properties of paper from historical books with different levels of microbial contamination. All disinfection methods were generally bacteriostatic and fungistatic. The AgNPs misting method was more effective for bacterial inhibition ( R = 60–100%), than LTP ( R = 25–100%) and TEO ( R = 12–100%); all tested methods were less effective for fungi ( R = 0–99.8%). TEO exhibits a broader spectrum of fungicidal activity compared to AgNPs and LTP. The antimicrobial effectiveness depended on the area from where the microorganisms were isolated and their sensitivity to the active agent. A higher disinfection effectiveness was observed for books with higher levels of microbial contamination. RNA concentration was a good marker of antimicrobial activity of disinfection. RNA amount decreased by 95–100% after disinfection with LTP and TEO, and by 29–89% after AgNPs disinfection. Disinfection of paper from historical books with LTP, AgNPs and TEO did not significantly influence or have a positive effect on the mechanical and optical properties of paper from tested historical books. We show that LTP, TEO, and AgNPs can be used as microbiostatics, alternatively to the currently available methods. [ABSTRACT FROM AUTHOR]

Clotrimazole is a well-known antimycotic agent, listed in the World Health Organization List of essential medicines, with minimal health side effects acknowledged throughout a long certification period. In this study, clotrimazole in isopropanol was tested as a potential antifungal treatment for paper objects. The antifungal properties of this azole compound were evaluated against five of the most common fungal species affecting paper collections. The addition of a deacidifying agent, calcium hydroxide nanoparticles, resulted in a multipurpose formulation also aimed at neutralizing the deleterious effects of acids excreted by fungi. Clotrimazole showed antifungal activity against all tested fungal species and its effectiveness followed the ascending order: Chaetomium globosum < Cladosporium cladosporioides < Penicillium chrysogenum < Aspergillus niger < Penicillium corylophilum . The best relationship between minimal concentration and fungal inhibition was achieved for 0.05% clotrimazole. The impact of the tested formulation on paper preservation was evaluated in terms of pH, colour and folding endurance, using moist heat artificial ageing. Clotrimazole and calcium hydroxide nanoparticles protected the paper from acidification and loss of folding endurance in the long term, thus representing a non-aqueous alternative treatment for paper affected by fungi. [ABSTRACT FROM AUTHOR]

Historic works on paper, illuminated (painted) or unpainted manuscripts, and textiles are fragile and nearly impossible to sample. Non-invasive techniques such as visible microscopy, X-ray fluorescence, Raman, and reflectance spectroscopy are commonly used to determine the artist material present. Recently, nonlinear optical ultrafast pump-probe microscopy was shown to provide non-invasive, high-resolution mapping of pigments in historic paintings to investigate paint stratigraphy. In this paper, we combine our pump-probe contrast with nonlinear fluorescence and second-harmonic generation contrasts exhibited by fibrous supports composed of natural bio-materials (cellulose, collagen, or lignin). Hence, our multi-modal nonlinear microscope is able to simultaneously investigate pigments in conjunction with their support in three dimensions with micrometer-scale spatial resolution. Here we examine the utility of nonlinear pump-probe microscopy by studying a series of mock-up samples, including indigo-dyed cotton cloth, ultramarine blue painted on various types of paper, and papers painted with mixtures and layers of the two pigments. In each case we find that we can combine pump-probe pigment contrast with nonlinear optical fiber contrast to obtain spatial information that is otherwise unavailable to the conservator. [ABSTRACT FROM AUTHOR]

Cellulose oxidative and hydrolytical degradation is one of the greatest problems for the conservation of paper supports. To contrast these degradation processes, both deacidification and reduction of the oxidized functions are needed. Dealing with original documents, it is often impossible to perform the two mentioned treatments in aqueous solutions and in a distinct subsequent way, because of the fragility of the artifacts. After studying, in a separate way, an effective deacidifier (calcium propionate) soluble in ethyl alcohol and many reducers (boron complexes), able to act in different non-aqueous solvents, it was decided to test a simultaneous method of deacidification and reduction in ethanol. This paper presents the chemical-physical results obtained by applying simple deacidification and simultaneous deacidification-reduction on laboratory paper samples that were artificially aged and then re-measured after 10 and 15 years of natural aging. Results show that all alcoholic treatments are very effective: papers are stable also after a long period of both artificial and natural aging. [ABSTRACT FROM AUTHOR]

A severe decay process, catalyzed by acidity and metal ions, affects cellulose in historical manuscripts and books that contain iron gall inks. The inhibition of this process can be achieved by alkaline-earth nanoparticles dispersions in alcohols, which create a neutral environment in which both oxidation and depolymerization of cellulose are hindered. As a result of the degradation process, paper in historical manuscripts and books is fragile and very difficult to handle. A reinforcement intervention with gelatin and Japanese tissue could be used for the strengthening of historical manuscripts, even if this method could not prevent paper degradation due to iron gall inks. Therefore, a new method, combining a deacidification treatment based on calcium hydroxide nanoparticles and a reinforcement process using Japanese tissue has been developed and tested on mockups containing iron gall inks. The protective action arising from the combined treatment was evaluated by performing cellulose viscosimetric degree of polymerization (DPv) and pH measurements on artificially aged systems. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDX) was used for the evaluation of calcium distribution from the deacidification agent within samples cross section. Determinations of DPv clearly showed that the degradation of untreated inked paper was significantly slowed down by the combined treatment. The method was also tested on original manuscripts from 16th and 18th century. SEM-EDX maps showed that the applied treatment, which raised the pH to an appropriate value, is homogenously distributed over the treated surfaces. [ABSTRACT FROM AUTHOR]

In this paper, members of three research teams, namely the Turfan Project of the Berlin Brandenburg Academy of Sciences and Humanities, the Berlin-based research project on pigments in Central Asian paper manuscripts, and the Hamburg-based project on the history and typology of Central Asian paper manuscripts, present some of the results of their cooperation. The investigated manuscripts belong to the Berlin Turfan Collection. On the basis of different examples the contribution of scientific methods to philological scholarship within a multidisciplinary approach is demonstrated. [ABSTRACT FROM AUTHOR]

Ground wood cellulose paper exhibits a practicable cleaning laser fluence window during middle-UV radiation processing. In this case, a minimum dose volume density should be applied. However, cleaning of bleached cellulose paper is accompanied by strong yellowing and destruction. The presence of charcoal graphite particulates shows substantial influence on the yellowing with increasing coverage. [ABSTRACT FROM AUTHOR]

This research evaluates the use of microblasting technique with powdered cellulose as a new tool for dry cleaning documents. Different cleaning tests were conducted on three documents with different properties following this new approach and the results were compared to those obtained with traditional dry cleaning with erasers. In order to assess changes caused to the supports, the treated documents were examined both before and after cleaning with optical and 3D stereomicroscopy, SEM-EDS and spectrophotometry. The results allow the conclusion that microblasting with powdered cellulose is a feasible technique to remove surface dirt or grime on paper documents. This research proves that the new use of the technique does not entail changes to the surface properties of the treated supports. Moreover, powdered cellulose is chemically stable and compatible with paper documents, preventing negative long-term effects derived from the presence of rubber residues that may remain in paper fibres when using erasers in dry cleaning treatments. [ABSTRACT FROM AUTHOR]

Abstract: Zinc oxide nanoparticles were prepared and used for surface treatment of oil paintings painted on paper supports. The prepared coating mixture containing 2% of ZnO nanoparticles showed excellent transparency. The effect of coating on protecting the paper support and paintings against microbial attack by Trichoderma reesei and Aspergillus niger, dirt accumulation, and UV aging was studied. Coatings containing ZnO nanoparticles enhanced the durability of linseed oil-based paintings toward UV aging regarding the change in color. Coatings containing ZnO nanoparticles improved resistance to microbial attack when subjected to inoculums containing T. reesei or A. niger fungi. In addition, coatings containing ZnO nanoparticles reduced accumulation of dirt on oil paintings when left in open air for 6 months; cleaning of paintings was quite easy compared to the non-coated paintings or those coated with the varnish without ZnO nanoparticles. [Copyright &y& Elsevier]

Abstract: With the acidification of paper and paper-containing relics becoming increasingly serious, a convenient, effective and harmless method for deacidification has become an urgent necessity in the protection of paper relics. In this research, a novel method for reducing the acidity of paper by plasma technology is presented, which can be used simply at room temperature and atmospheric pressure. The pH of the paper rises to alkalescence rapidly after treatment and remains stable with no color change, with a slight accompanying increase in the mechanical properties of the paper. [Copyright &y& Elsevier]

Abstract: Selecting an appropriate paper deacidification agent is very important for the deacidification of paper. The use of three deacidification agents (i.e., iso-butylamine, calcium propionate, and borax) is studied for the deacidification of paper using the immersion treatment by investigating the paper surface pH, alkaline residue, paper whiteness, strength, and other performance indicators. Results show the deacidification by borax solution not only results in the promotion of a proper pH range, high level of alkali reserves, and ignorable influence to paper appearance, but also to the enhancement of the mechanical intensities of paper even after artificial aging. Supercritical carbon dioxide (CO2SCF), as a solvent system, is used in the deacidification of acidic papers using the borax solution of water and alcohol. CO2SCF improved the deacidification process by significantly improving the pH value and the base residual value. The borax in supercritical fluids can be better combined with cellulose hydroxyl to improve the mechanical properties of paper substantially. The treatment of borax in CO2SCF could be an alternative for acidic papers. Aside from improving the pH and depositing a sufficient alkaline residual, CO2SCF also strengthens the mechanical properties of treated papers. [Copyright &y& Elsevier]

Abstract: Library materials are susceptible to fungal deterioration. The paper constituents of archival materials are subjected to harmful physical and chemical processes as they are slowly consumed by fungi. Remediation of fungal contamination can be costly and risk further damage to fragile or previously degraded materials. Early detection of fungal growth would permit the use of relatively noninvasive treatments to remediate fungal contamination of artifacts before visible or lasting damage has occurred. Current methods used for the detection of microbial biomass, such as colony counts, microscopic biovolume estimation, and ergosterol analysis are expensive, time consuming, or are inappropriate for use with fungi. Beta-N-acetylhexosaminidase (EC 3.2.1.52) activity provides a rapid and reliable means of fungal detection on a variety of cultural heritage materials. Adapted for use on archival materials, fluorogenic 4-Methylumbelliferyl (MUF) labeled substrate N-acetyl-Beta-D-glucosamine (NAG) was used to detect fungal beta-N-acetylhexosaminidase activity. The fluorescence generated by minute quantities of fungi was quickly detected at an early stage of growth. The sensitivity of the assay was comparable to other biochemical techniques. The fluorometric assay was well-suited for early detection of fungal biomass on paper and assessment of the effectiveness of common remediation practices. [Copyright &y& Elsevier]

Abstract: A simple transfer function has been used to predict indoor temperature and humidity from outdoor climate. Using downscaled output from the Hadley Model (HadCM3) changes in indoor climate through to 2100 were predicted for an idealised unheated room at a number of European sites. The potential threats to paper and the risk of salt damage were predicted using damage functions. Although paper faces an increased risk in some temperate locations, salt weathering can increase or decrease dependent on location. Many future indoor climates may already exist at other locations, so communication throughout the heritage sector offers examples for the management of future challenges. Climate change is relatively slow so there is ample time for the adoption of good practices at these locations. [Copyright &y& Elsevier]

Abstract: The goal of preventive conservation is to provide the correct maintenance of our cultural heritage in order to enrich our future. The Canadian Museum of Nature developed a risk model for preventive conservation that has proven useful in application to a Portuguese archive. This work applies this model to compare the magnitudes of specific risks estimated for this same archive collection when located in either of two pairs of storage rooms. These rooms are in two different parts of this building: two are in an older part and two are in a recent addition. It was, therefore, necessary to assess the building itself, both structurally and environmentally, as well as analyse its common human practices. In terms of the overall risk magnitude, the best room was found to be in the recent building and the worst in the older building. However, risks related to water problems were found to be higher in the new building. In this work cost-free measures and easy to implement recommendations are given in order to improve the quality of the storage rooms. A final comment on the method itself is also given. [Copyright &y& Elsevier]

Abstract: The damage to historical documents and books caused by the acidic character of paper is often manifested as a complete loss of their mechanical properties. Deacidification and restoration of archived paper objects require knowledge of the long-term behaviour of paper before and after repair actions. Our study was focused on the investigation of mechanical properties (tensile strength, stretch, tensile index, zero-span tensile strength, folding endurance) of original papers (one alkaline and three different acidic samples) exposed to five methods of dry-heat and moist-heat accelerated ageing. The degree of paper deterioration upon ageing was significantly influenced by the temperature and relative humidity, along with the intrinsic chemistry of the individual paper samples. The correlation matrix evaluated at a 95% confidence level for tensile strength, stretch, tensile index and zero-span showed linear correlations between these mechanical properties for all the paper samples. However, a linear dependence of folding endurance on zero-span tensile strength was found only for alkaline paper, which revealed the highest resistance to the accelerated ageing tests. In addition, the concentration of paramagnetic semiquinone species in the acidic lignin-containing paper samples was monitored by Electron paramagnetic resonance spectroscopy. [Copyright &y& Elsevier]

Abstract: A new process using aminoalkylalkoxysilanes (AAAS) was developed recently for paper and book mass deacidification. This process is entirely novel in that, besides deacidifying, it also improves the mechanical properties of paper. In the present article, the properties of inhibition of fungal growth of the treated papers are investigated. It was found that the AAAS tested acted as surface-active antifungal agents when introduced in the paper, significantly reducing the growth of Aspergillus niger and Paecilomyces variotii, two fungal species commonly found in storage areas of libraries and archives. The AAAS which seemed the most efficient in preventing the fungal development was 3-aminopropylmethyldimethoxysilane (AMDES), functionalised with a primary amine. The effect was significant in the different papers tested which demonstrated the protection against the proliferation of filamentous fungi in vitro for papers treated with AMDES. The higher concentration of AMDES inside the paper proved to be the most effective. The highest efficiency was reached for AAAS uptakes around 6%. At this concentration the sporulation of the two strains was inhibited and the development of A. niger mycelia was highly reduced. [Copyright &y& Elsevier]

Abstract: The brownish spots known as foxing, commonly found on old paper artefacts contain sometimes structures, which look like filamentous fungi. Attempts to grow these structures in vitro have been always unsuccessful so far. In order to study the role of these biological elements in paper decay, it is essential to identify them. This study is aimed at the identification of isolates from these brownish areas by culture-independent approaches using molecular biology techniques. The two Internal Transcribed Spacers and the 5.8 S gene (ITS1-5.8S-ITS2) from the nuclear ribosomal DNA were amplified, cloned and sequenced. Following a preliminary treatment with cellulase from Trichoderma reesei, DNA extractions were successfully achieved directly from paper samples. From 22 selected stained spots from a book dating from the 19th century, 8 extracts of genomic DNA were entirely analysed, which yielded 145 sequenced clones. No DNA could be sampled in unstained areas. Multiple alignment of the ITS sequences and comparison with reference sequences published in the NCBI database allowed to identify 14 groups of fungi belonging mainly to the following genera: Aspergillus, Bjerkandera, Chaetomium, Gloeotinia, Penicillium, Polyporus, Saccharicola, Trichoderma and Ulocladium. Some of these fungi are cellulolytic species but are not commonly found as indoor contaminant in storage rooms of graphic documents. The majority of the foxing spots exhibited sequences identified as Penicillium minioluteum. Gloeotinia temulenta occurred also frequently. Few isolates such as Aspergillus japonicus, Aspergillus oryzae, Chaetomium globosum, Penicillium citrinum, Trichoderma citrinoviride, Ulocladium chartarum and Ulocladium cucurbitae were present in only 1 or 2 clones. One of the foxing spots produced only one type of sequence similar to both Cordyceps sinensis and Fusarium lateritium, which have identical sequences in this rDNA region. This molecular approach, simple and rapid, could provide additional data for further discussion on the origin of the phenomenon of biological foxing. [Copyright &y& Elsevier]

Abstract: The efficiency of a recently described non-aqueous method for paper deacidification using Ca(OH)2 nanoparticles in isopropanol was evaluated by pH and colorimetric measurements and by the analysis of the degree of polymerization (DP). Samples of plain paper and paper with iron gall ink were tested. The results were compared with non treated samples and samples submitted to the traditional treatment with saturated aqueous Ca(OH)2 solution. By comparing the two conservation methods, the aqueous one shows higher neutralization reaction kinetics than the non-aqueous one. The iron gall ink samples maintain their coloration closer to the original after the non-aqueous Ca(OH)2 nanoparticles treatment, in contrary to the aqueous treatment that changes the ink aesthetics considerably. Artificial aging tests revealed a general increase in the aging stability of deacidified paper samples. The Ca(OH)2 nanoparticles treatment can be an alternative for papers who can not be treated by the classical aqueous treatment, e.g. papers with water soluble components. [Copyright &y& Elsevier]

Abstract: An optimised headspace-solid-phase microextraction (HS-SPME) coupled with a gas chromatography/mass spectrometry (GC/MS) method has been applied to the analysis of volatile organic compounds (VOCs) emitted from a groundwood pulp book naturally and artificially aged. In order to assess the potentiality of HS-SPME for accessing the compounds produced during the degradation of paper, two different accelerated ageing treatments were applied on an early 20th century book. First, a dry heat ageing was used. Then, the humidity level was increased to take into consideration the role of the hydrolysis reactions in the degradation of paper. The influence of these parameters (temperature and relative humidity) on the reaction products characterized was evaluated separately and discussed. This HS-SPME/GC/MS method associated with accelerated ageing enabled the characterisation of 36 VOCs of which four—furfural, 5-methyl furfural, vanillin and guaiacol—can be considered as relevant carbohydrates and lignin degradation compounds. Their relative abundance has been followed during ageing treatments in order to evaluate their potential role as lignocellulosic degradation markers. HS-SPME/GC/MS appears to be a suitable method for investigating volatile compounds emitted by an old book, and for distinguishing some relevant degradation compounds. Moreover, the method allowed us to monitor their relative abundance. It would now be worthwhile trying to detect these four relevant compounds in naturally aged books using a non-destructive microextraction method and, likewise to suggest a new approach to evaluate the state of deterioration of old books. [Copyright &y& Elsevier]

Abstract: A novel modified “sol–gel” method based on the carboxylate-alumoxanes has been developed for the fabrication of coatings for the protection of degradation of paper. Two types of paper chosen for study: the filter paper (Whatman) and particulate matter from the several pages of ancient manuscript at Lithuanian National M. Mazvydas Library. All paper samples used in this study were coated by hexanato-alumoxane. The obtained hexanato-alumoxane was dissolved in CHCl3, and paper specimens were treated in hexanato-alumoxane solution. The filter paper samples were artificially aged at different conditions. All the filter paper samples (untreated, impregnated with hexanato-alumoxane and treated-uncoated) were examined by SEM. The hexanato-alumoxane treated and treated-uncoated paper samples were visually indistinguishable from their untreated equivalents. Analytical characterization of hexanato-alumoxane coated and treated-uncoated of particulate matter from the ancient manuscript showed no degradation of its cellulosic substrate. [Copyright &y& Elsevier]

A new portable nuclear magnetic resonance (NMR) device allows in situ non-invasive investigation of paper in order to examine some aspects of the microscopic healthy state of documents of historical and artistic interest. The apparatus has a NMR surface probe, which permits to perform most of the NMR relaxometric measurements on objects of almost every size and shape. It uses non-ionizing radio frequency electromagnetic waves and is easily transportable without hazard for people or environment. Some results obtained with this device on the pages of the Codex Major, a manuscript musical anthology that belongs to the Collectio Altaempsiana (1600–1610) of Palazzo Altaemps in Rome, are here presented. The NMR results provide indications about the spread of the deterioration process of the paper and of the corrosion effect caused by the iron-gall ink. [Copyright &y& Elsevier]

Q-switched Nd:YAG lasers operating at 1064 nm have often been held responsible for the yellowing of various substrates during cleaning. Possible causes are the presence of an underlying yellow layer, residues, light scattering and substrate damage, or combinations of these. This article reviews the existing evidence on this subject, and suggests venues for future practice and research. [Copyright &y& Elsevier]

The historical paper samples from XIII–XIX c. are characterised by means of techniques of the optical spectroscopy. The influence of pulsed laser cleaning by means of the Q-switched Nd:YAG laser at 532 nm on the spectra and also cleaning results of stained paper documents are reported and considered. In the absorption spectra, the minima around 280 and 370 nm are identified and luminescence reveals a characteristic band centred around 430 nm. The laser cleaning diagnosed by the recording of the LIF spectra with 266 nm excitation shows a profile of increasing intensity and preserved structure. The LIPS spectra reveal sharp emission lines recorded at 612.5, 644.2, 646.5, 671, 714.9, 720.2 nm (Ca I), 589.4, 616.4, 780 nm (Na I), and 766.5: 769.9 nm (Mg I) which are ascribed to the surface contaminations. The intensity decrease of these peaks is in accordance with successive laser pulses and monitors the cleaning progress of the stained paper. [Copyright &y& Elsevier]

The paper reports on immediate effects of pulsed laser operating at 532 nm and fluences below 2.5 J cm–2 on soiled cellulose. The degree of polymerisation was determined viscometrically, while diffuse reflectance FTIR was used to gain insight into the changes in the chemical composition. Although no detectable immediate changes were observed after treatment of paper with laser beam at 532 nm, the irradiation of paper containing carbonaceous dirt resulted in significant discoloration of the treated substrate. The possible reasons for the extensive formation of yellow chromophores are discussed. [Copyright &y& Elsevier]