Graphene, which is composed of a single layer made up of carbon atoms arranged in a hexagonal structure, is the thinnest known material. This structure offers graphene many unique properties that are promising for real-world applications, including batteries, super capacitors and antennas. It also has water filters, transistors and solar cells. According to Nature Nanotechnology, this material may be able to fix the problem of artistic masterpieces' colors fading.
Costas Galiotis (a chemical engineer at University of Patras, Greece) said that all art establishments concern themselves with the discoloration of paintings after exhibition and storage. "Hazard factors like sunlight, moisture and certain volatile organic compound (VOCs), accelerate the degradation." There are many references to endangered artworks such as Van Gogh's The Bedroom and Sunflowers or Munch's The Scream.
There are many factors that contribute to the degrading of fine art. Many of Georgia O'Keeffe's oil painting have suffered from tiny, pin-sized blisters that look almost exactly like acne for decades. Conservators have seen similar signs in oil-based masterpieces from all periods and even Rembrandt's works. We've reported previously that scholars and conservationists initially thought they were grains trapped in the paint. The protrusions began to grow and spread and eventually started flaking.
The blisters were found to be metal carboxylate soaps by chemists. This is a chemical reaction between the metal ions in lead and zinc pigments and the binding medium that was used in paint. The soaps clump together and eventually migrate through the paint film. About 70% of oil paintings show signs of deterioration due to soaps made from metal carboxylate.
Van Gogh's Sunflower Series has been showing signs of fading in recent years due to its constant exposure to sunlight. The culprit appears to be the lead-chromate dyes that he used. An analysis of chrome yellow Van Gogh used found that it reacts strongly to other compounds such as barium and sulfur, when exposed to sunlight. The sulfates are responsible for UV-induced degradation, according to a 2016 study.
Advertisement
Scientists took swabs of Renaissance and Renaissance-style pieces last March and found that there were "oxidase-positive" microbes living on painted wood and canvas surfaces. These microbes eat paint, glue and cellulose compounds, which can be found in wood, paper, and canvas. As byproducts, this produces water and hydrogen peroxide. These byproducts can influence the appearance of mold and the rate at which artworks deteriorate.
Even modern art materials can be affected by irreversible color changes due to exposure to light and oxidizing agent, among other hazards. Recent research has focused on nanomaterials as a means of conserving artworks. Galiotis says graphene is attractive for art conservation purposes because of its many properties. The transparent material, which is one atom thick, can adhere to many substrates and acts as an excellent barrier against oxygen and other gases (corrosive and otherwise). It is also highly hydrophobic, and absorbs UV light well.
Galiotis explained to Ars that graphene seemed like the ideal solution to protect colors against photodegradation. Our approach is unique because graphene sticks to clean surfaces and can be easily removed. This contrasts with current polymeric coatings. It has a competitive advantage over all other protective materials and substances that protect artworks against color fading.
Matina Stavropoulou
M. Kotsidi et al., 2021
M. Kotsidi et al., 2021
M. Kotsidi et al., 2021
Galiotis developed a roll to roll method that allows you to transfer a thin layer graphene onto a piece of art. This eliminates the need to use solvents or any other chemicals that could damage the art. They first synthesized a graphene monolayer veil onto copper foil by chemical vapor deposition. Then they cleaned the material with nitrogen gas to remove dirt, dust and water molecules. They attached graphene to the one-side of a commercial silicon/polymer adhesive membrane using a roll-to–roll machine.
Advertisement
How could they obtain original paintings to prove the safety and effectiveness? The work would also be destroyed. Galiotis says that the group had a large network of European and Greek painters, but many were reluctant to see their paintings destroyed. Matina Stavropoulou was an artist who was so fascinated by the group's techniques that she donated three of her most recent paintings. They were all made using Indian inks and glossy paper, which is placed on top of a canvas support. Galiotis said, "We are very thankful to her for this."
Art is suffering
Stavropoulou’s Resistance, Triton and Nereid each measured 20x20cm2, were used in the characterization of aging experiments. The team used the roll-to-roll method of applying graphene veil to protect half the artwork. The paintings were artificially aged in an indoor chamber. One portion of the artwork was covered to serve as a reference. Triton, Nereid and Resistance were exposed to three neon lamps over 16 weeks. Triton was then exposed to seven white lights for 1,050hrs. After the aging process, there were no cracks or wrinkles in graphene layers of both cases.
Biplane, Handley Page H.P., is the third painting. 42 was used to evaluate how easily and safely the graphene layers could have been removed from the painting's surface. The graphene layer was applied as usual, and then the team used a soft rubber eraser. To test the process, researchers made paper mockups from cardboard with pink ink. The graphene layer was applied to the samples and they were artificially aged under white lights for 70 hours. After that, the graphene was removed using a soft rubber eraser.
This promising proof of principle is in graphene veils protecting art from harmful agents. It's especially important for artworks made on gloss paper, cardboard, or canvas. The authors warn that this method might not work for artworks with very rough surfaces or embossed designs. The authors have developed a method to deposit graphene onto museum framing glasses for additional protection.
DOI: Nature Nanotechnology 2021. 10.1038/s41565-021-00934-z (About DOIs).
