NEWS & EVENTS 

The 2023 edition of TECHNART, the international conference, held in Lisbon on May 7-12 in Lisbon, just concluded. The conference had a mission to provide a scientific forum for scientists, conservators, and museum professionals to discuss and communicate the research and innovation related to analytical techniques in the field of art and cultural heritage, to foster contacts and exchange of experiences, making a bridge between science, art, and cultural heritage. The MOXY project team presented their preliminary results in two poster presentations: MOXY Project: a preliminary investigation of non-contact cleaning of some typical art materials using atomic oxygen“ and „A New Look into NASA’s Pioneering Atomic Oxygen Treatment Removing Lipstick Defacement from Andy Warhol’s “Bathtub” (1961)“.  ​ The first poster presented the results from a preliminary study, where 39 mock-ups were produced using a range of artistic supports and media (plaster, limestone, canvas, paper, acrylic, oil paint, and pastel). Mock-ups were exposed to atomic oxygen using the low Earth orbit oxygen environment simulator LEOX at the European Space Agency (ESA). The system operates at low-pressure and uses laser detonation to separate oxygen atoms and produce an effluent of atomic oxygen at 99%, which is directed to the sample holder. Mock-ups were investigated with an array of techniques to obtain an initial assessment of the effects of AO exposure: spectrocolorimetry and reflectance spectroscopy were used to assess color differences and changes in the spectral features; scanning electron microscopy (SEM) and confocal laser microprofilometry (CLM) to evaluate changes in the surface morphology; analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC-MS) to gain insights into molecular effects, and the results were presented in the poster. The results obtained from this preliminary study are very promising since contaminants are successfully removed from the substrates, in particular, soot was removed from plaster, sandstone, and acrylic paint. In this context, a crucial aspect revealed by this study is the fact that the assessment of the cleaning efficiency and the effect of AO on the substrate is not straightforward due to the contact-less and solvent-less nature of the cleaning method. In contact and solvent/gel-based methods, it is often necessary to evaluate the presence of residues on the artwork surface or the degree of diffusion of solvents used for cleaning. Differently from the contact methods, for the AO-cleaning, this is not necessary, as there are no residues, but the possible effects of atomic oxygen on the artwork itself need to be investigated in depth, which calls for new cleaning assessment protocols to be combined with traditional approaches.   ​ The second MOXY poster presented new insights into the origins of AO technology,  which, has its origins in a serendipitous invention, as it started with a defacing lipstick kiss on Andy Warhol’s painting Bathtub (1961) at The Andy Warhol Museum in Pittsburgh in 1997. Lipstick is designed for porous substrates, such as human skin, and may be extremely difficult to safely remove from delicate porous modern materials, such as the acrylic paints used by Andy Warhol. When a lipstick-wearing visitor kissed the Bathtub at an event in 1997, Ellen Baxter, the former chief conservator in charge of the treatment, noted that “Of all the paintings there for her to put her lips to, that was the worst one… I couldn’t use typical conservation methods to clean it… It was like trying to take a lipstick stain out of a piece of Kleenex”.  Conservators turned to NASA where Bruce Banks and Sharon Miller were investigating AO erosion on spacecraft materials and had already tested AO treatment under low pressure for fire-damaged paintings. The “Bathtub” required a targeted treatment without placing the painting in a low-pressure chamber, and Banks and Miller pioneered an atmospheric AO apparatus which was moved to the museum and used to remove the lipstick without physically touching the surface. The treatment made headlines in the 1990s but was never repeated until recently when MOXY researchers in collaboration with the European Space Agency (ESA) began experimenting with AO on typical cultural heritage materials using their low Earth orbit oxygen environment simulator, LEOX and to develop an innovative atmospheric AO technology in the MOXY project.  In the reconstruction of the NASA Warhol treatment, contemporary lipsticks were exposed to AO under low-pressure conditions, which made lipsticks appear lighter but did not remove them. Lipsticks contained red iron oxides, which are not affected by AO. However, the AO role was essential, as it converted organic compounds in the lipstick into volatile byproducts (CO, CO2, H2O vapor), leaving a dry powdery residuum on the surface. This enabled the dry removal of the residual powder using soft natural rubber in a second step, repeating NASA’s methodology. The colorimetric analysis confirmed highly effective recovery, and FTIR-ATR did not identify molecular changes in the substrate after cleaning. The issue of slow treatment (54.9 h) can be resolved by using atmospheric AO technology in development by the MOXY project, which reduces the treatment time from multiple hours to minutes and seconds.  See the poster and read more details on how exactly NASA saved Andy Warhol's painting. The results will be published in the post-prints of TECHNART2023.