1,721,696 research outputs found
New Methodologies for the Conservation of Cultural Heritage: Micellar Solutions, Microemulsions, and Hydroxide Nanoparticles
No full textModern civilization’s inherited artworks have a powerful impact on society, from political, sociological, and anthropological points of view, so the conservation of our Cultural Heritage is fundamental for conveying to future generations our culture, traditions, and ways of thinking and behaving. In the conservation of cultural artifacts, scientists intervene in the degradation of often unique handcrafts, resulting from a delicate balance of aging, unpredicted events, environmental conditions, and sometimes incorrect previous restoration treatments, the details of which are often not precisely known.
Nanoscience and nanotechnology are revolutionizing materials science in a pervasive way, in a manner similar to polymer chemistry’s revolution of materials science over the preceding century. The continuous development of novel nanoparticle-based materials and the study of physicochemical phenomena at the nanoscale are creating new approaches to conservation science, leading to new methodologies that can “revert” the degradation processes of the works of art, in most cases “restoring” them to their original magnificent appearance.
Until recently, serendipity and experiment have been the most frequent design principles of formulations for either cleaning or consolidation of works of art. Accordingly, the past has witnessed a number of actively detrimental treatments, such as the application of acrylic and vinyl resins to wall paintings, which can irreversibly jeopardize the appearance (or even the continued existence) of irreplaceable works of art. Current research activity in conservation science is largely based on the paradigm that compatibility of materials is the most important prerequisite for obtaining excellent and durable results.
The most advanced current methodologies are (i) the use of water-based micelles and microemulsions (neat or combined with gels) for the removal of accidental contaminants and polymers used in past restorations and (ii) the application of calcium hydroxide nanoparticles for the consolidation of works of art. In this Account, we highlight how conservation science can benefit from the conceptual and the methodological background derived from both soft (micro- emulsions and micelles for cleaning) and hard (nanoparticles for consolidation) nanoscience.
A combination of different nanotechnologies allows today’s conservators to provide, in each restoration step, interventions respectful of the physicochemical characteristics of the materials used by artists. The “palette” of methods provided by nanoscience is continuously enriching the field, and the development of novel nanomaterials and the study of nanoscale physicochemical phenomena will further improve the performance of restoration formulations and our comprehension of degradation mechanism
Coupling non invasive and fast sampling of proteins from work of art surfaces to surface plasmon resonance biosensing: Differential and simultaneous detection of egg components for cultural heritage diagnosis and conservation
No full textDespite the wide application of surface plasmon resonance (SPR) to a broad area of interests, from en- vironment to food analysis, from drug discovery to diagnostics, its exploitation in cultural heritage conservation is still unexplored. Water-based highly viscous polymeric dispersions (HVPD) composed by partially hydrolyzed polyvinyl acetate (PVA), borax, and water, were recently developed and successfully applied for the selective removal of surface degradation patinas (i.e. protein materials, natural resins etc.) from paintings of historical and artistic interest. This approach is here coupled for the first time to a SPR biosensor to simultaneously recognize albumen, yolk, or their mixtures in HVPD extracts. Ovalbumin and immunoglobulin Y are selected as analytes for egg white and yolk recognition, respectively. The bio- sensor was first characterized on standard analytes within the range 0–400 mg L 1 and then on fresh and dried egg albumen and yolk down to 2 10^4 and 1 10^5 dilution factors, respectively. Once optimized, the biosensor was combined to the HVPD application on simulated and real art samples for the eva- luation of hen egg presence in the extract, i.e. albumen, yolk, or their co-presence in the matrix. For a contemporary ‘sacred icon’, realized by the traditional egg tempera procedure described by Cennino Cennini, the biosensor successfully distinguished different uses of egg components for the realization of painted and gilded areas, i.e. yolk and albumen, respectively. Finally, a XVIII century italian painting whose the realization technique is unknown, was tested confirming its egg tempera-based realization technique
Nanostructured Surfactant-Based Systems for the Removal of Polymers from Wall Paintings: A Small-Angle Neutron Scattering Study
No full textNanostructured soft matter systems represent effective and long-lasting solutions with respect to traditional and often obsolete methodologies for the conservation of works of art. In particular, complex fluids such as micelles and microemulsions are the most performing media for the removal of organic materials from porous supports, like wall paintings or stones. In this Article, we report on the characterization of two systems, EAPC and XYL, which have shown good to optimal performances in the removal of organic polymers from wall paintings. EAPC is a five-components fluid composed of water, sodium dodecylsulfate (SDS), 1-pentanol (PeOH), propylene carbonate (PC), and ethyl acetate (EA), while XYL is a “classical” o/w microemulsion, where p-xylene droplets are stabilized in water by SDS and PeOH. Small-angle neutron scattering (SANS) with contrast variation is used to infer a detailed picture of the structure of these complex fluids, with a particular focus on the partition of the components between the bulk phase and the nanocompartments. We found that, differently from XYL, the EAPC system is neither a microemulsion nor a simple micellar solution, with the cosolvents partitioned between the dispersing phase and the disperse droplets. These different structural features play a key role in defining the cleaning effectiveness and specifically the kinetics of interaction between the nanofluid and the polymeric coating to be removed, which is of paramount importance for the application in the field. Both of these nanofluids are effective in polymer removal, but EAPC is considerably more efficient and versatile. The composition and the structure at the nanoscale determine the capability of removing a broad range of different polymer coatings from porous materials. A representative case study is here described, addressing a particularly challenging conservative issue, which is the removal of a multilayered aged coating that was irreversibly damaging the pictorial layer of the Annunciation Basilica in Nazareth
Nanofluids and chemical highly retentive hydrogels for controlled and selective removal of overpaintings and undesired graffiti from street art
Full text linkOne of the main problems connected to the conservation of street art is the selective removal of overlying undesired
graffiti, i.e., drawings and tags. Unfortunately, selective and controlled removal of graffiti and overpaintings from street
art is almost unachievable using traditional methodologies. Recently, the use of nanofluids confined in highly retentive
pHEMA/PVP semi-interpenetrated polymer networks was proposed. Here, we report on the selective removal of acrylic
overpaintings from a layer of acrylic paint on mortar mockups in laboratory tests. The results of the cleaning tests were
characterized by visual and photographic observation, optical microscopy, and FT-IR microreflectance investigation. It was
shown that this methodology represents a major advancement with respect to the use of nonconfined neat solvent
Chapitre : On the Nature of the Pigments of the General History of the Things of New Spain: The Florentine Codex
No full textBaglioni, Piero Giorgi, Rodorico Arroyo, Marcia Carolina Chelazzi, David Ridi, Francesca Magaloni Kerpel, Diana Baglioni, Piero ; Giorgi, Rodorico ; Arroyo, Marcia Carolina ; Chelazzi, David ; Ridi, Francesca ; Magaloni Kerpel, Diana, "On the Nature of the Pigments of the General History of the Things of New Spain: The Florentine Codex», en Colors between Two Worlds. The Florentine Codex of Bernardino de Sahagún", dans Wolf, Gerhard (éd.) ; Connors, Joseph (éd.) ; Waldman, Louis A. (éd..
Smart cleaning of cultural heritage: a new challenge for soft nanoscience
No full textThe search for innovative, smart and performing cleaning agents is one of the main issues of modern
conservation science. Nanosciences do not only provide solutions to this scientific field in terms of new
materials but also change radically the approach to problems and challenges. In this feature article we
review the most innovative nanostructured systems developed in the last decade for the cleaning of
artworks together with some noteworthy case studies. Micelles, microemulsions, thickened complex
fluids, and responsive gels that constitute the new ‘‘cleaning palette’’ for modern conservators are here
presented and critically analyzed. The development of these smart nanostructured systems requires the
comprehension of their behavior and interactions with other materials down to the nanoscale. In the
last section of this manuscript we report on the most recent results from a study about the mechanism of
polymer removal from porous artifacts using nanofluids, such as micelles or microemulsions. The rules
of classical detergency do not fully address the polymer removal mechanism and a schematic model of
the process is proposed
Chapter 13 Soft Hybrid Nanostructures Composed of Phospholipid Liposomes Decorated with Oligonucleotides
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