Tommaso Poli

Tailoring New Fluorinated Acrylic Copolymers as Protective Coatings for Marble

Abstract The protective performances of two new fluorinated acrylic copolymers (based on the monomers 1H,1H,2H,2H-perfluorodecyl methacrylate (XFDM) and 1,1,1,3,3,3-hexafluoroisopropyl methacrylate (HFIM) are evaluated and compared with Paraloid B72, a commercial copolymer ethyl methacrylate/methyl acrylate (EM/MA) and its partially fluorinated homologous 2,2,2-trifluoroethyl methacrylate/MA (TFEM/MA). The polymeric materials have been tested on Candoglia marble, a very low open porosity stone (

Materials and techniques in the pictorial oeuvre of Lucio Fontana

Abstract The painting materials used by Lucio Fontana were investigated through the analysis of 28 Spatial Concept works created between the early 1950s and the artists death in 1968. The pictorial media were analyzed by means of numerous techniques including Fourier transform infrared spectroscopy, pyrolysis-gas chromatography–mass spectrometry, scanning electron microscopy, and X-ray fluorescence. This study has provided a more complete understanding of the artists technique, as it was found that Lucio Fontana had already begun experimenting with new synthetic pictorial and binding media such as alkyds and polyvinyl acetates at the beginning of the 1950s, and polyesters during the early 1960s. Although he never abandoned the use of commercial oil paints, Fontanas application of these new materials continued in an infinitely varied search for innovative expressive effects. The characterization results explain the physical and mechanical properties of the paint layers, and may be correlated with the conservation state of the works analyzed. All the results have been compiled and are discussed together with the artists practices and their evolution over time.

Poly(vinylalcohol)-borate hydrogels with improved features for the cleaning of cultural heritage surfaces

Poly(vinylacohol) (PVA) is a versatile polymer capable of forming hydrogels useful in a wide range of applications. Hydrogels based on cross-linking of PVA with borax, and able to incorporate organic solvents, have been used in the field of cultural heritage as tool for cleaning the surfaces. Poly(ethylenoxide) (PEO) has been introduced in the formulations of PVA-borax, with the aim of increasing the gel compatibility with organic solvents and of improving the mechanical properties of the materials. The formulations were investigated with rheological characterization, solvent loss measurements and study of the free water through the determination of the Free Water Index. The PEO molecules do not participate in the formation of the network but have been found to be responsible for a decrement of the storage moduli, explained by a spacing between crosslinks and the partial disentanglement of the PVA chains. At the same time PEO produces in the gel an increase of the apparent relaxation time, thus stabilizing the dispersions and enhancing their ability to maintain the shape. Cleaning tests for removal of an acrylic coating on limestone have been also successfully performed. Graphical abstractPVA/borax hydrogels with acetone were studied with cleaning test and rheological measurements and hypothesis on network structure was proposed.

LEAF COMPRESSIONS FROM THE LATE MIOCENE SECTIONS OF NW ITALY:RESEARCH ON AN EFFICIENT, EASY AND QUICK CONSOLIDATION TREATMENT

Abstract Compressions of fossil leaves on marl blocks soaked with water are tricky palaeobotanic findings to deal with. In fact, this peculiarity makes the findings exposed to serious degradation: the evaporation of water causes shrinkage of the matrix and the leaf leading to fragmentation, delamination and exfoliation of the fossil, until its final disappearance. The aim of this research was to identify a consolidation method which satisfies museum needs and can be utilised for all conditions of hydration of the object. Following a survey of several natural science museums in Northern Italy, Paraloid™ B72 and PEG4000 along with other resins never previously used on this kind of fossil were tested. At the end of the research, two products gave adequate or good results, preserving the leaf from further degradation whatever the hydration condition of the object: the acrylic resin Paraloid™ B72 and a polyurethane resin.

Short Communication: THE PAINTING MATERIALS IN A WORK OF THE FUTURIST ARTIST GIACOMO BALLA

Abstract The 1915 Giacomo Balla painting Grido dimostrazione in piazza del Quirinale has been studied in detail to investigate the artists materials. Radiographic analysis revealed the presence of a previous work underneath and thus the existence of a complex stratification of paint layers that make the data interpretation both complex and interesting. Pigments and binders have been identified in an attempt to find correlations with the composition of common commercial paint products available in the first decades of the 20th century. A representative stratigraphy from a complex area of the painting revealed important information about the technical execution of the painting executed on top of the original. This study is intended to increase the knowledge of the painting materials used by Balla and other Futurist artists.

Protection Efficacy of Fluorinated Acrylic Copolymers Applied on Historical Italian Marbles.

Use of polymeric materials to protect stone started in the 1960’s but the study and knowledge of the complex and multiple interactions between stone and polymers has been carried out only recently. In a previous paper [1] the problems related to the efficacy of a stone treatment (film formation, deep penetration and coating behavior) has been addressed. In this paper performance after a thermal and a simulated solar UV ageing has been evaluated. In particular the issues related to stability and durability of two fluorinated acrylic copolymers applied on two different Italian marbles, Carrara and S. Giuliano, have been investigated. The specimens characterized and treated with two new partially fluorinated acrylic copolymers, 2, 2, 2-trifluoroethyl methacrylate / methyl acrylate (TFEMA / MA) and trifluoromethyl-2, 2, 2-trifluorethyl methacrylate / methyl acrylate (HFIMA / MA), have been artificially aged in two different ways: with a long simulated solar UV ageing of 1000h and a thermal one at the same temperature (about 50°C) usually reached in the UV chamber, in order to separate the two ageing contributions (photochemical and thermal). After the ageing most of the testing methodologies suggested by UNI-Normal Italian protocol for evaluation of stone protective coatings, including capillary water absorption, static contact angles and colour variation, have been carried out. Slightly better protective efficacy was found for the HFIMA/MA before and after the two ageing. The important contribution of the thermal component in the worsening of the shielding efficacy has been assessed.

Risk Assessment and Preservative Measures for Volatile Organic Compounds in Museum Showcases

ABSTRACT The first step in preservative measures for artworks in airtight showcases is the exclusion of outgassing from construction materials or, at least, limitation of the emissions to a minimum acceptable level if the volatile organic compounds (VOCs) generated may be qualified as harmless. Once it is ascertained that the objects in the showcases are responsible for VOC emissions, a step forward becomes necessary, implying showcase ventilation with air flowing through active sorbent materials. Solid phase micro-extraction (SPME) followed by GC separation and MS identification has been applied for checking the outgassing characteristics of different types of materials used for the construction of airtight showcases, and the method was found particularly attractive in terms of speed and sensitivity, suitable for measurements in presence of low-emitting materials. Sampling could also be done in the case interiors, thus making possible detection and recognition of emissions from art objects within a case. A comprehensive preventive conservation scheme has been further devised by means of active air circulation within the showcase and functional sorbent materials along the flow, for complete suppression of gaseous compounds. Control of the compounds in the air flow and of their filtration efficacy was achieved by direct sampling, also using SPME fibers. Continuous monitoring of the air quality in the showcases has been developed with insertion of a photoionization detector capable of detecting the VOCs in the air by inducing molecular ionization, and measuring the generated photocurrent. The system is not selective, but gives the total concentration, reaching ppb sensitivity with high-quality data. In addition it includes temperature and humidity sensors, making the whole a useful instrument for environment control.

Study on laser cleaning of Sculptures-Éponge by Yves Klein

Abstract Yves Kleins Sculptures-Éponge are natural sea sponges soaked in International Klein Blue (IKB), assembled on metal pedestals. This work examines the constituent materials, the execution technique and the deterioration problems of the sculptures which are covered by a friable matt paint, in order to define the guidelines for treatment and collections care. For the experimental work, samples were prepared in the laboratory with the same materials and techniques used by the artist. In order to solve problems relating to removal of dust deposits, many aspects were considered in the evaluation process, such as the presence of an organic and porous support, not discussion in the existing literature, the poor cohesion of the surface and Kleins specific recommendations for handling his Monochromes only with gloves, and removing dust while avoiding any contact with the painted layers. Photo-ablation using laser radiation was identified as a possible solution. Three Nd:YAG lasers with different pulse durations (short free-running (SFR), long Q-switched (LQS), and Q-switched (QS)) operating at 1064 nm were tested on two kinds of support (samples of sponges saturated of IKB and glass slides painted with the same color) and on two different types of dirt (one only deposited and another adhered to the support). The interaction of laser radiation with the support and with the paint layers, and the effectiveness of cleaning operations, was monitored with a stereo microscope and a scanning electron microscope (SEM). It was possible to define a method which was then applied for the removal of particulate dirt from a blue sponge stored in the Museum of Modern Art, Turin, Italy.