Vintage Artwork Fading? Add a Layer of Carbon Atoms for Protection

(Inside Science) -- Flash photography, meet your match: graphene.

“No Flash Photography” signs adorn museums and art galleries across the globe because excessive light can damage or destroy artwork. A team of European scientists has developed a way to use a layer of carbon atoms to protect colors in artworks from fading, and European museums are already showing interest in this new technique.

The fading cadmium yellows in Van Gogh’s “Flowers in a Blue Vase” and Munch’s “The Scream” that are degrading into white are a famous example of how color can disappear from paintings. It’s a well-studied problem, said Francesca Gherardi, a materials scientist at Historic England, a government organization that conserves, protects and supports England’s cultural heritage. Because light and moisture primarily cause the fading, a museum’s environment needs to be perfectly controlled, both for display and storage. Some artists choose to add a layer of varnish atop their paintings, or museums cover artworks with protective glass, but they don’t always do that, Gherardi said.

Costas Galiotis, a nanomaterial researcher at the University of Patras in Greece, knew all about graphene’s wonderous properties. It can be as thin as one atom and, importantly, transparent. It absorbs ultraviolet light. And it can work as a barrier between an object and gas molecules such as oxygen and water vapor. That is why Galiotis, one of the authors of the study published in the journal Nature Nanotechnology in July, thought he could use graphene to protect artwork.

Lifting a small layer of graphene from graphite can be simple -- you can peel it off with tape. But placing a large layer of carbon atoms on top of artwork was not an easy task, Galiotis wrote in an email to Inside Science. Directly depositing graphene on a surface can require an extremely high temperature of 1,000 degrees Celsius and extremely low pressure of one ten-thousandth atmospheric pressure. Fragile artwork can’t withstand these conditions, so Galiotis and his co-workers had to devise a multistep process to get the graphene on the art. In this process, a graphene layer is deposited onto a sheet of copper foil, then transferred onto an adhesive film, and then finally rolled onto the artwork from the adhesive like a transfer sticker.

When the protective layer of graphene was tested with mock-up artworks, the graphene successfully slowed the fading of the colors. The technique protected smoother surfaces such as glossy photographs better than canvas works.

Galiotis wanted to test the technique on actual artworks, so he solicited them through his networks. But many artists were reluctant to donate, as participating in the experiment would mean that their work would be exposed to intense light for a long time, which would destroy it. “Fortunately for us, an Athenian painter, Ms. Matina Stavropoulou, became fascinated by our technique and donated to us a number of her latest works for research purposes,” Galiotis wrote. And the results seen in mock-ups also held up when tested on real artworks. When half of Stavropoulou’s piece “Triton and Nereid” was covered by a layer of graphene and the other half was not, the pinks and blues of the protected half were 27.5% and 38.5% less faded than the other half, respectively, when subjected to intense white light for 1,050 hours, equivalent to over 200 years in an exhibition setting.

One final advantage of this new technique is removability. The graphene layer can be easily removed using a rubber eraser. However, Gherardi, who was not involved in the new research, said using an eraser on a work of art is not always ideal. To that, Galiotis said cautious artists or museums could choose to apply the graphene to protective picture framing glass instead.

Galiotis said he envisions his technique being used globally; several museums and art conservators have already expressed interest. And Gherardi said she could easily imagine the new technique being used widely for storage and transportation. A lot can go wrong when artworks are being transferred from one museum to another, especially when exposed to not-so-ideal temperature and humidity. “The properties [of graphene] are really remarkable, and they can make a difference,” Gherardi said.