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1.
The aim of this study is to develop a laboratory technique to simulate a natural ageing of canvas paintings adopting artificial ageing methods in air (thermal oxidation), in the absence of light. Four models of canvas paintings aged up to 315 years are considered. Paintings are constituted of oil film on oil ground layer, oil film on tempera ground layer, tempera film on tempera ground layer or by tempera film on oil ground layer. Surface strength and the colour of the paintings and the degree of polymerization (DP) of linen canvas were evaluated at different steps of ageing. The degradative result was estimated as the DP of linen canvas after prefixed times of microbial attack.  相似文献   

2.
The susceptibility to weathering of eleven carbonate and evaporitic Spanish building rocks was studied by means of dissolution experiments. Mineralogy, petrology, geochemistry and porosity of the rocks were also characterized in order to determine the potential relationships between these properties of the rocks and their dissolution rates. Rock slabs were submerged in a 0.1 M HCl acid solution for 72 h and the amounts of Ca, Mg and S released were measured, as well as the weight loss of the samples during the acid attack. Alabasters, which presented very low porosity, were dissolved to a lesser extent than limestones and dolostones in the time of the experiment. A significant positive correlation was found for connected with the weight loss of the rocks during dissolution and with the kinetic rate of Ca dissolution. Overall, the results highlight the influence of the porous network in the degradability of building stones by controlling their rate of dissolution. There is a positive correlation for all the rocks between weight loss along acidic attack and connected porosity, but no relationship between mineralogical and petrographical composition and susceptibility to dissolution.  相似文献   

3.
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4.
The damage to historical documents and books caused by the acidic character of paper is often manifested as a complete loss of their mechanical properties.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.  相似文献   

5.
Titanium dioxide (TiO2) can be used to realize transparent self-cleaning coatings on stone surfaces as an active and preventive protection system, limiting cleaning and maintenance actions, reducing their costs in Architectural Heritage. This self-cleaning ability is due to photo-induced hydrophilicity on treated surfaces. The aim of this investigation is to analyze this effect, since it could bring to a greater water absorption, a potential source of damage for stone surfaces. Titania sol, obtained by sol-gel and hydrothermal processes, was deposited on travertine by spray coating, in two different ways. Water absorption by capillarity, static contact angle and a specific surface water absorption analysis were assessed before and after the TiO2 treatments. The effects of deposited amount of titania on the characteristics of treated surfaces were evaluated. It was shown that there were no evident changes in the substrate reactivity without ultraviolet (UV) light exposure, while it seems that hydrophilicity due to UV light does not lead to higher water absorption, thus encouraging the use of TiO2 coatings in the field of Architectural Heritage. However, before widely applying this conservative treatment, some further researches are recommended in order to better assess its durability and sustainability.  相似文献   

6.
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7.
Due to sensitivity of historic papers and their conservation importance, it is necessary to produce appropriate environment condition for preservation purposes. TiO2 nanoparticles have been evaluated for multiple applications in the conservation of paper because of TiO2 nanoparticles special characteristics for UV filtration, decomposing of air pollutants and their antifungal and antibacterial properties. Firstly, TiO2 nanoparticles synthesized in sol-gel process, and then have been coated on glass surface with spray-pyrolysis method. Then, coated glass used for preparing display box for protecting paper-art-works. Also, non-coated glass was used as a blank sample and assessments have been done on the filter paper (Whatman®) as a standard for paper-art-works. Temperature, humidity and light accelerated aging were done on samples in both coated and uncoated boxes. Results showed more tension strength and lower oxidation of paper and also, lower growth of fungi and bacteria in coated glassy box. Furthermore, madder dyed papers into coated box showed lower fading after UV exposure.  相似文献   

8.
Limestone and marble, still frequently used as building materials are especially vulnerable to the destructive effects of efflorescence. The effect of interaction between five different calcareous stones and corrosive atmospheres has been investigated. A novel technique of stone degradation analysis has been used where thin sections of fresh stone materials were exposed in a corrosion chamber under controlled conditions (temperature, relative humidity (RH), SO2 and NO2 concentration). Following 1-week’s exposure; observations of the initial crystallisation were studied by light microscopy, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). The results obtained from the surface analysis clearly showed sulphation of the samples and formation of gypsum. Observations of the initial corrosion indicated differences in the location of efflorescence and its shape among and within the samples. The mineralogy, grain shape and size, mineral defects and existence of cracks and pores, all influenced the substrate’s reactivity. The most vulnerable areas and the places where the corrosion started on the calcitic stones were the triple grain junctions followed by grain boundaries, and on the dolomitic marble cracks and pores.  相似文献   

9.
Albert Namatjira (1902–1959), Emily Kame Kngwarreye (c1910–1996) and Rover (Julama) Thomas (c1926–1998) are three of Australia’s best-known Indigenous artists. Each is known for one style of painting—Namatjira for watercolor on paper, Kngwarreye for acrylic (synthetic polymer) on canvas and Thomas for natural earth pigments on canvas. We estimate a sample selectivity model using data from the Australian Art Sales Digest to study the determinants of sales and the hammer price of artworks offered at auction from these artists. The results show that pre-sale information on the artwork and auction effects are significant and that the three artists studied are very different from each other. Thus, data should not be pooled when estimating these models.  相似文献   

10.
Fibre Optics Reflectance Spectroscopy (FORS) is a well-established technique, widely used in the conservation field for in situ investigations and non-invasive diagnostics on traditional artworks. Nevertheless, there is little knowledge on the use of this technique for investigating modern artists materials used in contemporary artworks. The present study, carried out within the wider framework of the EC funded Project “POPART” (Preservation of Plastic ARTefacts in museum collections”), was aimed at investigating the possibility of extending the applications of FORS to synthetic polymers, and proposing this technique as new non-invasive analytical tool for diagnostics on plastic artworks in museum collections. Thus, a real case was selected from the permanent collection of the Conteporary Art Centre “Luigi Pecci” (Prato, Italy). The artwork, created in 1990 by the artist Stefano Arienti, was entirely constituted of expanded polystyrene (EPS) and it showed diffused signs of degradation. The need of singling out the main causes of deterioration in order to prevent further damages was evident. An in situ FORS measurements campaign was performed with the aim of gaining in-depth information about its conservation state and identifying the main agents responsible for the observed degradation. Thanks to the non-invasivity of the technique an extensive spectroscopic characterisation of different areas of the EPS surface could be performed and the spectral data were exploited to build a map of the degraded areas of the artwork. Data acquired in field were compared with those obtained from laboratory test performed on artificially aged EPS samples. These results helped in ascertaining the detrimental actions of the light sources used to back illuminate the artwork. In particular, in this case FORS proved to be effective in detecting EPS alterations before the chromatic effects became visually evident. These results suggested that FORS may be considered as a good candidate to be used for non-invasive investigations also on some modern materials and contemporary artworks. The research was completed with an interview to the artist Stefano Arienti, whose point of view was constructively integrated with the scientific results obtained. This emphasized the importance of an interdisciplinary approach to the solution of conservative problem in the field of contemporary art.  相似文献   

11.
To prevent the deterioration of artwork on stretched canvas in a museum, it is often necessary to neutralize the transmission of vibrations from sources such as the wall or the floor. An anti-vibratory system easily optimizes vibrations that are transmitted from the floor because the artwork's motion occurs in vertical translation. Hanging artwork, which receives vibrations from the wall, presents a more complex case because the motion consists of a translation and a rotation. This paper presents a model to determine a cutting frequency above which vibrations transmitted to the artwork are lowered. A procedure to obtain the parameters of this model is also presented. Experiments in a laboratory and in the Louvre Museum validate the predicted cutting frequency given by the model. A downloadable spreadsheet is available to apply this method to specific artwork.  相似文献   

12.
Almost all defects of earthen buildings such as roughening, erosion, volume reduction, cracking as well as crazing, etc., have been witnessed in the ancient city of Jiaohe, an earthen architectural heritage in northwest China. In this paper, their long-term durability and deterioration due to prolonged exposure to environmental factors were studied, based on the basis of field investigation and laboratory analysis. The results indicated that the deterioration of building materials should be attributed to their basic properties, including density, particle size distribution, soluble salts, mineral, mechanical strength, etc., and interaction with environmental factors. And then, four main deterioration modes can be identified, namely: wind-related deterioration, water-related deterioration, temperature-related deterioration and chemical related deterioration. It can be concluded that the greatest deterioration was wind-related deterioration on west-north facing façades, and chemical related deterioration on the surface of building materials.  相似文献   

13.
Brazilwood was used in this work to dye wool mordanted with different amounts of copper(II) sulfate, alum and iron(II) sulfate. Two different dyeing methods were used: premordanting (MD) and simultaneous mordanting (M+D) procedures. In order to evaluate the influence of the mordant ion in the brazilein chromophore photodegradation, samples were subjected to artificial light ageing. Color measurements were made and, for the first time, LC-DAD-ESI-MS was used for chromophore analysis of the dyed fibers before and after light exposure. Mordant ion quantification was done after fiber acid digestion, by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Mordant metal ion, mordant bath concentration and dyeing procedure were found to have strong influence in the wool fiber hues. Color variation was more pronounced in the alum dyed samples. Overall, mordant quantification showed that the amount of metal ions found in the fibers is very small when compared to the original concentrations of the dyeing bath, being Cu the ion with greater affinity for the wool fibers. MD dyeing procedure yielded fibers with larger amounts of mordant metal ions and higher chromophore peak areas. Higher amounts of brazilein were extracted from wool mordanted with copper(II) sulfate. Finally, chromatographic analysis of the brazilwood dyed samples before and after light exposure resulted in the detection of Type C compound as an outcome of the photodegradation process.  相似文献   

14.
The present paper reports a new method for converting ettringite and thaumasite in non-expansible and insoluble phases, for its application in the restoration of concrete artefacts subjected to deterioration through sulphate attack. The salts were synthesized by different processes and, after characterization by means of XRD, FT-IR and optical microscopy, were treated with a series of chemicals in order to induce their decomposition. In particular, different solutions containing barium nitrate, barium hydroxide and ammonium oxalate were used to achieve the complete transformation of both phases in barite, witherite, scarbroite and whewellite. Barium hydroxide seemed to be the most appropriate reactant because the others could give rise to efflorescence within the pores of the mortars by leaving free nitrate or sulphate ions inside the materials. The experimental technique was also tested on two concrete samples collected from the bell-tower of St. Nicholas’ Cathedral in Nicosia (Sicily) with encouraging results.  相似文献   

15.
During the past two decades, thanks to the rapid development of solid-state-based sensor technology, digital imaging emerged as one of the most attractive research areas for the noninvasive investigation of paintings and flat artworks. In particular, the commercial availability of high-performance digital cameras opened up new perspectives to transmitted imaging techniques, such as trans-illumination and trans-irradiation, which are based on the acquisition of the visible (Vis) and near infrared (NIR) radiation, respectively, transmitted through the object. Until recently, these techniques were indeed considered to be unsuitable for applications on artefacts, because of the risks of overheating and overexposure to the light of the object under analysis. Nowadays, with the new-generation digital cameras, transmitted imaging can be reconsidered as a possible tool for noninvasive diagnostics on paintings on canvas. These techniques have been proven to be effective for the examination of hidden details, such as underlying drawing, for a study of the pictorial style or the executive techniques, as well as for assessing the state of conservation of the supports. Both trans-illumination and trans-irradiation can be easily implemented by means of professional photographic digital cameras, and therefore offer a valuable alternative to the more expensive well-established methodologies, such as X-ray radiography. In some cases, they are found to be complementary to the conventional techniques in revealing details of the underlying paint layers. Potentials and limits of transmitted imaging techniques are discussed in this paper, starting from three case studies of oil-paintings on canvas that belong to the permanent collection of the Gallery of modern art at the Pitti Palace in Florence.  相似文献   

16.
The Benedictine monastic community at New Norcia, Western Australia needed an assessment of their historic textile collection as a preliminary step in gaining financial support to preserve the garments. The textiles were grouped according to functional use with sampling controlled by random number generation of the registers. The highest significance and conservation rankings were rated at 5 and the lowest in the categories was given values of one. The numbers in each category fell logarithmically as the significance values increased. The number of hours of work required to stabilise the objects increased logarithmically as the conservation ranking increased from 1 to 5. Analysis of the conservation needs indicated that nearly 84% of the collection, the sum of the level 1 and level 2 textiles can be stabilised with simple preventive conservation methods practised by trained volunteers, leaving the most significant items in the care of experienced conservators. Multiplication of the conservation and the significance values provides a treatment priority score to guide collection managers in determining which objects are treated by conservators. Data is also provided on the impact of light exposure on the deterioration of the coloured fabrics of the vestments.  相似文献   

17.
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.  相似文献   

18.
The state of conservation of the frescoes at Qusayr Amra was investigated by integrated physico-chemical measurements, particularly optical and scanning electron microscopy, μ-infrared spectroscopy, mass spectrometry and X-ray powder diffraction.The frescoes appear darkened and severely damaged owing to the deterioration of surface treatments and to the widespread presence of different salts. These caused significant detachments of the painting layers.The materials used in the painting and preparation layers and in the wall plaster were characterized in order to clarify the painting technique. Different pigments have been identified on the pictorial layers: the original ones correspond to green earth, yellow and red ochre, realgar, bone black and lapis lazuli and others, such as titanium white and cobalt blue, ascribed to recent restoration works. Proteinaceous materials (egg or yolk) have been identified as binders for the pigments, indicating a tempera painting technique.Three different products, belonging to restoration interventions, have been also identified: the natural product shellac, ascribable to next-to-last restoration and scarcely removed during last restoration also because of its insolubility, the synthetic vinyl acetate and acrylic polymers. Particularly the latter one indicates an on-going degradation of the applied fixatives.The extensive deterioration of the surfaces is also due to the widespread presence of salts, such as chloride, nitrate and sulphate clearly identified by XRD measurements.The obtained results give a comprehensive overview on the employed painting technique and its state of preservation and on the causes of the painting deterioration. Therefore, they are a fundamental tool to develop durable and compatible materials and methodologies for a future conservation strategy of this site.  相似文献   

19.
Magnetic tapes contain information that are an important part of our cultural heritage and must be preserved for further generations. However, they are unfortunately threatened due to the chemical deterioration of the magnetic layer. In order to develop a tool to assess the tape collection condition, 300 U-matic videotapes from the Institut National de l’Audiovisuel (INA) collection dated from 1975 to 1995 were analysed by different analytical techniques. The authors were attempting to constitute a group of 29 reference tapes representative of the INA collection using various analytical testing. The focus of this study was on hydrolytic tape stability using binder polymer identification and ageing tests. It was found that PET based polyester–polyurethane binders demonstrated a higher hydrolytic stability than binders made of poly(butyleneadipate)/polyurethane, which are more susceptible to fast deterioration. The authors examined the role of adipic acid in the hydrolytic degradation process. For such tape binders, a deterioration assessment method could be based on monitoring the adipic acid concentration and adipic acid rich oligomeric fragments in the binders. A method for measuring the amount of polymeric fragments in the low molecular weight region is proposed.  相似文献   

20.
The artist Jordi Teixidor is one of the leading exponents of twentieth century Spanish abstract art. In recent years, he has used a synthetic polymer as a support for his art work, namely polypropylene. The behaviour of this material in combination with layers of oil paint has not been studied until now. One of the objectives of this study was to chemically characterise the material present in Jordi Teixidor's work, using FT-IR spectroscopy, in order to be able to examine the behaviour of this set of materials after undergoing cycles of accelerated aging. After subjecting the samples to temperature and relative humidity cycles and ultraviolet radiation, their physico-mechanical behaviour was determined via tensile and bend tests, with the results being processed further by means of spectroscopic techniques and colour measurements. It was found that the possible migration of the additives present in the PP support and the gradual degradation of the materials could affect the adherence between the paint layers in the future.  相似文献   

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