Sustainable solutions for removing aged wax-based coatings from cultural heritage. Exploiting hydrophobic deep eutectic solvents (DESs)

This study describes the investigation on the use of hydrophobic Deep Eutectic Solvents (DESs) for the removal of nonpolar coatings from works of art to replace toxic solvents. Beeswax and two microcrystalline waxes (R21 and Renaissances) have been selected as reference nonpolar coatings since they are commonly present in their aged state on metal and stone artifacts. The interaction between the DESs and three waxes has been evaluated through contact angle measurements, solubility tests, and cleaning tests carried out by implementing a method that is ordinarily used by restorers. Tests have been conducted on mockups consisting of microscope glass slides covered by wax. The effective removal of the wax-based coating from the mockups has been assessed through spectrocolorimetry and multispectral imaging under visible (VIS) and ultraviolet light (UV) at 365 nm by loading the waxes with a fluorescent marker (Rhodamine 6G). Fourier Transform Infrared (FT-IR) spectroscopy in the Attenuated Total Reflectance (ATR) mode was performed to assess the presence of both the wax and the solvent on the swabs used for the cleaning tests, confirming the actual interaction among the solvent and the solute. The experimental process proved DESs’ potential of being used as green solvents for cleaning treatments on Cultural Heritage

Mattel’s Barbie: Investigation of a Symbol—Analysis of Polymeric Matrices and Degradation Phenomena for Sixteen Dolls from 1959 to 1976

Mattel’s Barbie dolls are the most famous and iconic dolls since 1959. Today, they are being collected by individuals and often conserved in museum environments due to their cultural and historical significance reflecting everyday life and historical events. However, just like most museum objects made of plastics, both historical and more recent Barbies show evident degradation phenomena. Firstly, Barbies were made of plasticized polyvinyl chloride (PVC), affected by the migration of additives—mostly the plasticizers—from the bulk phase to the outermost layer, appearing as a tacky and glossy exudate. Over the years, Barbies’ polymeric constituents were replaced with more stable ones, whose additives migration is limited compared to PVC, even though still occurring. Multispectral photography in visible (VIS) and ultraviolet (UV) light, microscopical observations in VIS and UV light, and Fourier Transform Infrared spectroscopy in the Attenuated Total Reflectance mode (FT-IR ATR) were performed to characterize the constituent materials of 15 Barbies produced between 1959 and 1976, bridging the information gap on their processing over the years. The micro-invasive multi-analytical approach also allowed for the characterization of the degradation products, permitting the reference of the exudated compound to the specific bulk polymer

Preserving Intangible Heritage through Tangible Finds: The “Skull with Ears”—St. Luciella ai Librai’s Church (Naples, Italy)

The present study reports the conservative first aid concerning the human cranium known as the “Skull with Ears”, which is conserved in the crypt of Santa Luciella ai Librai’s church in Naples, Italy. These remains have historically been worshipped by devotees within the cult of the “abandoned souls”. The skulls were “adopted” by the Neapolitan population and treated with particular care in exchange for divine favors. The critical preservation status of the “Skull with ears” required a multidisciplinary approach aimed at defining the taphonomy and anthropological features of the cranium, while determining the state of its conservation by using a multi-analytical approach. Multispectral imaging, 3D modeling, X-ray imaging, microscopical observations, and microbiological tests enabled the documentation of the cranium while assessing this state of conservation. Electron scanning microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR) in the attenuated total reflectance (ATR) mode, and radiocarbon dating allowed for essential data to be obtained on the cranium’s history and constituent components. The results that were obtained from both the analysis of the cranium and the environmental monitoring of the crypt showed the advanced degradation of the bones due to a significant bacterial attack, which was facilitated by the inadequate environmental conditions at the site of conservation. The acquired data enabled the definition of the most suitable conservation strategy and the securing of the cranium