Our project leader, Santiago Pozo Antonio assisted the 10th International Conference on Metrology for Archaeology and Cultural Heritage #MetroArcheo2024 (7-9 October) held at the University of Malta in Valleta Campus.
Within the topic “Non-invasive methods for analysis and diagnostic in the field of cultural heritage” he presented the oral communication, entitled “Monitoring of thermal and colorimetric changes in outdoor ex-posed acrylic and alkyd paints: influence of environment, paint composition and wall orientation”. This contribution presents the initial phases of the SmArt project (CINTECX Challenge2024 project: Sustainable strategies for urban art conservation), which aims to develop a simulation system for the sustainable conservation of contemporary murals. The project focuses on creating a Machine Learning model to determine temperature distributions on paint mock-ups outdoor exposed and their relationship with their colorimetric changes, assessing murals’ sensitivity in different locations. More in detail, key objectives include: (1) influence of the paint composition (alkyd and acrylic paints) on the deterioration level produced after exposure; (2) influence of the orientation of the wall on the deterioration level; (3) determining surface temperatures of murals through ML models and relating these to deterioration, and (4) evaluating the effectiveness of a commercial UV protective coating on painting murals. Understanding atmospheric impacts on murals will inform decisions on wall selection and maintenance strategies, helping prevent deterioration and optimize resources for preserving these artworks.
To this end, a series of mock-ups with different paints (acrylic and alkyd paints, green and pink colours) were coated with a colour protector, with the aim of monitoring certain properties over time, such as their surface temperature and colour variation, considering parameters like orientation and the environment to which these materials would be exposed. More specifically, two acrylic and two alkyd paints were selected, along with a UV protector. During exposure, surface temperature was measured using T-type surface thermocouples attached to each surface, allowing for the continuous registration of the surface temperature. Moreover, colorimetric changes, mainly colour difference (ΔE* ab ), were measured with a spectrophotometer every 45 days, considering the color of the unprotected mock-up as reference. The impact of the protector on the samples was also evaluated through the ΔE* ab . After exposure, references and exposed samples were characterized using stereomicroscopy, hyperspectral imaging and Fourier-transform infrared spectroscopy (FTIR) for physical and chemical characterization. Three locations were chosen for samples placement: (1) coastal area, sea level (2) coastal area, 400 m altitude and (3) countryside, 400 m altitude. Samples were placed in each selected location with varying orientations, typically north and south (locations 1 and 3) and west (location 2).
All the information about the research and the rest of the contrition is the Book of Abstract: https://www.metroarcheo.com/
At the closing ceremony, awards were presented for the best poster and the best oral communication. Our contribution was awarded the Best Conference paper Award. Our team was proud to receive this award. We would like to thank the scientific committee of the congress for this award.
Acknowledgements: This study is part of the Safeguarding the urban murals: cleaning and protection (CNS2022-135645) research project funded by MICIU/AEI/10.13039/501100011033 and, by “European Union NextGenerationEU/PRTR” and by the CINTECX Challenge2024 project: Estrategias sostenibles para la conservación del arte urbano. J.S. Pozo-Antonio was supported by the RYC2020-028902-I project funded by MICIU/AEI/10.13039/501100011033 and, by “ESF Investing in your future”. For more information: https://sosmurals.webs.uvigo.es/
