Electrospun mats for the cleaning of paints in Cultural Heritage

Traditional methods of cleaning of paints involve the use of abrasive techniques or chemical agents, such as solvents, which can pose risks to the underlying materials. These methods can lead to undesired changes in surface texture, to degradation of the original layers, or the introduction of harmful residues. This highlights the need for alternative, non-invasive cleaning techniques that can be precisely controlled and tailored to the specific needs of cultural artifacts [1-2]. This study investigates the potential of electrospun mats made from Agarose/PEO and PVA for the removal of repaints and the cleaning of paints, focusing on the use of benzyl alcohol as a solvent. The electrospinning technique, a versatile and efficient method for producing nanofibrous materials, was employed to fabricate the mats characterized by their high surface area, porosity, and fine structure, making them ideal for delicate cleaning tasks [3]. The mats' morphology and mechanical properties were thoroughly examined using Scanning Electron Microscopy (SEM) and mechanical testing to ensure their suitability for conservation purposes. Electrospun mats were tested in laboratory conditions to assess their stability in benzyl alcohol, a solvent commonly used in conservation to remove repaints. Swelling and deswelling behaviors were first analyzed on two model surfaces: a worthless painted canvas and a glass slide coated with a pigment layer. Then, mats were tested in situ on an ancient wooden paint undergoing restoration at the Soprintendenza Archeologia Belle Arti e Paesaggio per la città metropolitana di Genova e la provincia di La Spezia. The cleaning process was monitored through macro photography and cross-sectional imaging to assess the mats' efficiency in removing repaints and varnish without damaging the underlying original paint layer. Furthermore, SEM-EDS analysis was conducted on the used mats to understand the cleaning mechanism and examine the material removed from the artwork layers. The results suggest that electrospun mats offer a promising solution for the non-abrasive, targeted cleaning of cultural heritage, effectively removing repaints and dirty varnish without compromising the integrity of the original artwork. This method addresses key challenges in the field of conservation, including precision, no residues, and the preservation of fragile materials, presenting a valuable tool for the restoration of cultural heritage.