Polymeric Micro- and Nanosystems for Wood Artifacts Preservation

The complex methods of diagnosis investigation of the wood artifacts state and proper materials for their protection against decay are very important goals in cultural heritage. This chapter focuses on the recent trends in micro- and nanostructured polymer systems for application in cultural heritage and on wood preservation, especially. The synthesis, properties, and applications, as well as the relevant analysis techniques to reveal the structures and properties of polymer systems, are discussed, too. To overcome the specific problems that exist for wood artifacts, some aspects should be treated: effects of the environmental factors, as moisture and pollutant absorption into the wood fibers, over-exposure effect of sun or artificial light sources, biological attack of different microorganisms, and the effects of the protective and decorative coatings

Poly(3-HydroxyButyrate-co-3-HydroxyValerate) based Inorganic Consolidate for Firwood Preservation

The aim of this study was to address one of the major challenges of the conservation state of wooden artifacts or artworks namely, the preservation and restoration of wood surfaces. The factors involved in the deterioration of wood are mainly the external factors such as fire, low temperature and microbiological agents, which induce some degradation processes in wood, identified by discoloration, fragility and unsightly appearance. In this study, biodegradable materials based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) and composites based on PHBHV and particles (zinc oxide (ZnO), carbonated hydroxyapatite (CHAp) and its metallic derivatives with silver (AgCHAp) and strontium (SrCHAp) were applied on firwood specimens in order to investigate their consolidation capacity. Colorimetric measurements have confirmed that the chosen treatments did not change the colour of the natural wood. The hardness test revealed that the consolidation system increases the mechanical properties of the samples. The used treatments confer a strong hydrophobic character which prevents exfoliation of the wood samples, as confirmed by the performed water absorption test

Investigation of Chromatic Parameters of Some Samples from Constanta Casino

Cultural monuments are subject to a degrading phenomenon induced by several factors, such [...

Nanomaterials Used in Conservation and Restoration of Cultural Heritage: An Up-to-Date Overview

In the last few years, the preservation of cultural heritage has become an important issue globally, due to the fact that artifacts and monuments are continually threatened by degradation. It is thus very important to find adequate consolidators that are capable of saving and maintaining the natural aspect of these objects. This study aims to provide an updated survey of the main nanomaterials used for the conservation and restoration of cultural heritage. In the last few years, besides the classic nanomaterials used in this field, such as metal nanoparticles (copper and silver) and metal oxides (zinc and aluminum), hydroxyapatite and carbonated derivatives, tubular nanomaterials (such as carbon nanotubes) have been used as a potential consolidate material of cultural heritage. Tubular nanomaterials have attracted attention for use in different fields due to their structures, as well as their ability to present multiple walls. These nanotubes have the necessary properties in preserving cultural heritage, such as superior mechanical and elastic strength (even higher than steel), high hydrophobicity (with a contact angle up to 140°), optical properties (high photodegradation protection), large specific surface area (from 50 to 1315 m2/g, depending on the number of walls) for absorption of other nanomaterials and relatively good biocompatibility

Chemical Synthesis of Multi-Walled Carbon Nanotubes and Their Functionalization with Carboxylated Groups

Carbon nanotubes (CNTs) have attracted attention, due to their structures as well as their ability to present multiple walls. [...

Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery

Currently, approximately 70% of paintings in museum collections are affected by the presence of metallic soaps, evidenced by spherical globules visible on the surface of the paintings. They are responsible for altering the paintings’ surface through processes such as exfoliation and cracking, or even in the form of surface “skins” that appear in the pictorial layers. The objective of this study is the investigation of the icon paintings from Saint Mary Monastery, Techirghiol, Romania, which underwent some restoration procedures. This study is so important/significant, due to the presence of efflorescence that is correlated with the conversion of some fatty acids, as palmitic acid, stearic acid and azelaic acid, in the so-called metallic soaps through the reaction of the metals contained in the pigments from the painting layer and the binder. The investigated paintings are strongly affected by zinc carboxylate aggregation, and for this, the sample was embedded in polyester resin and the obtained cross-section, after polishing, was investigated by microscopic techniques (optical microscopy (OM), stereomicroscopy, and scanning electron microscopy with electronic dispersion spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and gas-chromatography with mass spectrometry (GC-MS) in good agreement with data from the literature. The potential result of this study is the identification and quantification of the metallic soap generated as a white deposit (probably salts, a kind of white efflorescence), from the binding medium of the metal carboxylate ionomer, by the crystallization of saturated fatty acids, through polymerization in oil. Six pigments (calcite, lithopone, carbon black, red ochre, vermilion, and ultramarine), present in the sublayers of the samples were identified

Waste Electrical and Electronic Equipment Processing as Thermoplastic Composites

In the last decades, the waste electric and electronic equipment (WEEE) has increased substantially due to an accelerated development of the economy and the lifetime of electronics

Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery

Currently, approximately 70% of paintings in museum collections are affected by the presence of metallic soaps, evidenced by spherical globules visible on the surface of the paintings. They are responsible for altering the paintings’ surface through processes such as exfoliation and cracking, or even in the form of surface “skins” that appear in the pictorial layers. The objective of this study is the investigation of the icon paintings from Saint Mary Monastery, Techirghiol, Romania, which underwent some restoration procedures. This study is so important/significant, due to the presence of efflorescence that is correlated with the conversion of some fatty acids, as palmitic acid, stearic acid and azelaic acid, in the so-called metallic soaps through the reaction of the metals contained in the pigments from the painting layer and the binder. The investigated paintings are strongly affected by zinc carboxylate aggregation, and for this, the sample was embedded in polyester resin and the obtained cross-section, after polishing, was investigated by microscopic techniques (optical microscopy (OM), stereomicroscopy, and scanning electron microscopy with electronic dispersion spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and gas-chromatography with mass spectrometry (GC-MS) in good agreement with data from the literature. The potential result of this study is the identification and quantification of the metallic soap generated as a white deposit (probably salts, a kind of white efflorescence), from the binding medium of the metal carboxylate ionomer, by the crystallization of saturated fatty acids, through polymerization in oil. Six pigments (calcite, lithopone, carbon black, red ochre, vermilion, and ultramarine), present in the sublayers of the samples were identified

Morphological and Mechanical Properties of Book Cellulose-Based Paper (XX^th Century) Treated with Hydroxyapatite Nanoparticles

Paper aging and protection processes play an essential function in the preservation of library collections and archives. In this study, some physical-mechanical properties of paper samples from XXth century books (private collections), such as pH acidity, tensile strength, and modulus of elasticity, as well as optical properties, such as absolute change in yellowness, were examined before and after treating them with hydroxyapatite nanoparticles (HAp). Accelerated light aging was also evaluated and discussed. The treatment with HAp nanoparticles increased the paper’s pH to slightly alkaline values (approximately pH 8). Washing and treating the paper improved its mechanical properties compared to untreated paper; the tear length increased by 35% and the modulus of elasticity increased by 56%. That the treated and aged samples are more elastic than the original samples demonstrates that HAp nanoparticles consolidated the cellulose fibers. Additionally, particle morphology, size, composition and size distribution were assessed via image analysis using scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), and the ImageJ processing program

Wood Surface Modification with Hybrid Materials Based on Multi-Walled Carbon Nanotubes

In this work, new treatments based on multi-walled carbon nanotubes (MWCNTs), MWCNTs decorated with zinc oxide (ZnO), MWCNTs decorated with hydroxyapatite (HAp) and MWCNTs decorated with silver (Ag) nanoparticles dispersed in PHBHV solution are proposed for improving sound oak wood properties. We hypothesize that the solutions containing decorated MWCNTs will be more efficient as wood consolidants, not only because of the improved mechanical properties of the treated wood but also because of the hydrophobic layer created on the wood surface. In order to test these hypotheses, the treatments’ potential was investigated by a number of complex methods, such as colorimetric parameter measurements, water absorption tests, mechanical tests, artificial aging and antifungal tests. The data confirm that the treated wood materials have moderate stability, and the color differences are not perceived with the naked eye. A significant improvement of the treated samples was observed by water absorption, humidity and mechanical tests compared to untreated wood. The best results were obtained for samples treated by brushing with solutions based on decorated CNTs, which confirms that a uniform and thicker layer is needed on the surface to ensure better protection. The wood behavior with accelerated aging revealed that the control sample degraded faster compared to the other treated samples. Antifungal tests showed that higher growth inhibition was obtained for samples treated with 0.2% MWCNTs_ZnO + PHBHV. Considering all of the obtained results, it can be concluded that the most effective treatment was MWCNTs_ZnO + PHBHV at a nanocomposite concentration of 0.2%, applied by brushing. Thus, wood protection against mold and fungi will be achieved, simultaneously ensuring improved mechanical strength and water barrier properties and therefore maintaining the structural integrity of sound oak wood over time