For any artist, seeing their artwork fade away is their worst nightmare. However, a research team led by Prof. Costas Galiotis has claimed that some atoms layer of graphene produced by chemical vapor deposition can prevent up to 70% of color fading.
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The research is the product of a collaboration between the University of Patras, the University of Florence, and the Foundation for Research and Technology Hellas in Greece, demonstrating a reversible transparent layer of graphene that can protect art objects. It can also be removed using a rubber without damaging the artwork (Kotsidi, et al., 2021). The research was published in the journal Nature Nanotechnology on 1 July 2021.
Over time, art materials have endured irreversible color changes upon exposure to light and oxidizing agents. As a result, dark and crack lines are visible across the canvas. Although it has always been a well-known problem, the solution was not so straightforward. World-famous artists, such as Vincent van Gogh, Pierre-Auguste Renoir, and James Ensor heavily used pigments in their work, which later visibly suffered from pigment degradation. However, it was van Gogh’s well-known bright yellow sunflowers artwork that caught scientists’ considerable attention after it turned greenish-brown over time (Metcalfe, 2021).
The Problem with Artwork
After studying pigment degradation on van Gogh’s canvases, scientists have found insufficient adhesion to be the main reason behind it. This means that paint peels away from the surface when exposed to ultraviolet light. It is understood that van Gogh's canvas hung on a wall receiving direct sunlight, with color fading being even during his lifetime (Everts, 2016).
Karimi et al. (2020) stated that the painting is mainly affected by photodegradation, which involves altering paint properties due to the absorption of photons from the sunlight. Although UV radiation represents only 8 % of total sunlight, its high energy is believed to be the primary cause of this degradation, causing irreversible effects on paint properties, such as a change in molecular weight and loss of color.
Using graphene as a solution, Prof. Galiotis has claimed that graphene in large thin sheets can block ultraviolet light and is impermeable to oxygen, moisture, and corrosive agents.
Since its discovery in 2004 by Nobel Prize winner scientists Andre Geim and Konstantin Novoselov, graphene’s remarkable optical, electrical, and mechanical properties have drawn much interest from the research community (Chhantyal, 2020).
As a result, numerous graphene-based devices have been developed from this material's versatile properties, including fast carrier mobility, high optical transparency, unique mechanical flexibility, and strength. Due to its previous reputation in the field of optical devices, scientists have explored this material as a conventional light stabilizer.
With time, huge progress in research and cost-effective manufacturing of graphene has made it an easy choice to be experimented on for many industries (Karimi, et al., 2020).
How Invisible Graphene Protects Artwork
One of the fascinating features of graphene is its broad absorption peak between 230–320 nm with a maximum of around 280 nm. As a result, UV radiation is prevented from reaching polymer chains.
Graphene is also believed to demonstrate the quenching effect, which means it interacts with excited state molecules and converts them into nonreactive species by accepting their energy (Kasry, et al., 2012). Another team (Qiu, et al., 2014) has studied the antioxidant effect of graphene, the quality that protects the artwork against oxidation and traps free radicals when exposed to sunlight
Still, due to its large specific surface area, graphene act as a physical barrier against the diffusion of oxygen into artwork, slowing down the photodegradation rate enormously. In this review (Karimi, et al., 2020), the presence of graphene has been seen acting as a nucleating agent that leads to an increased crystallinity. Photodegradation is understood to occur in the amorphous phase, which can be avoided by improving the material's crystallinity
These extraordinary qualities of graphene have convinced Prof. Costas and his team to consider the material for their research, who commented on the material's ability to absorb ultraviolet light while being an excellent barrier to oxygen and moisture.
The team's technique consists of growing thin graphene lattices on a copper foil substrate with a chemical vapor deposition, transferring it onto an adhesive film, and removing the copper substrate. This film is then appropriately aligned on the painting. Examination of the art painting with and without the graphene veil followed.
After 1000 hours, colors at the unprotected half had faded significantly, whereas those under the graphene veil remained at a strong intensity (Metcalfe, 2021).
Future of Graphene in Protecting Artwork
Although Prof. Galiotis and his team's discovery has achieved a magnificent milestone in considering graphene to protect artworks, experts still believe more knowledge and behavior of materials on artwork is needed to optimize the technique. However, the proof of concept in graphene's application in protecting artwork has already stunned scientists and artists, showing great potential in preserving them forever.
References and Further Reading
Kotsidi, M., et al. (2021) Preventing colour fading in artworks with graphene veils. Nature Nanotechnology. Available at: https://doi.org/10.1038/s41565-021-00934-z (Accessed on August 2021).
Everts, S. (2016) Van Gogh's Fading Colors Inspire Scientific Inquiry. [Online] c&en. Available at: https://cen.acs.org/articles/94/i5/Van-Goghs-Fading-Colors-Inspire.html (Accessed on August 2021).
Karimi, S., et al. (2020) A Review on Graphene's Light Stabilizing Effects for Reduced Photodegradation of Polymers. Crystals. Available at: https://doi.org/10.3390/cryst11010003 (Accessed on August 2021).
Kasry, A., et al. (2012) Highly Efficient Fluorescence Quenching with Graphene. J. Phys. Chem. C. Available at: https://doi.org/10.1021/jp207972f (Accessed on August 2021).
Metcalfe, T. (2021) Invisible graphene veil protects paintings from fading. [Online] Chemisty World. Available at: https://www.chemistryworld.com/news/invisible-graphene-veil-protects-paintings-from-fading/4013992.article (Accessed on August 2021).
Qiu, Y., et al. (2014) Antioxidant chemistry of graphene-based materials and its role in oxidation protection technology. Nanoscale. Available at: https://doi.org/10.1039/C4NR03275F (Accessed on August 2021).
Chhantyal, P. (2020) Antibacterial Applications of Graphene-Based Nanomaterials. [Online] AzoNano. Available at: https://www.azonano.com/article.aspx?ArticleID=5481 (Accessed on August 2021).