Scientists from the University of Sheffield are on the brink of developing a new type of white paint made from recycled plastic – a breakthrough discovery made by researching a bug. Sounds strange? The connection is not as out of place as it seems. See, the Cyphochilus beetle’s scales are one of the brightest whites in nature and so researchers decided to analyze the insect to understand exactly what it is that makes it like that. Turns out, the color is created by the nanostructure of the beetles’ scales, not by pigments and dyes.
The researchers used a technique called X-ray tomography (similar to a CT scan but on a minuscule scale) to measure the tiny individual beetle scales. The intense X-ray source at the European Synchrotron Radiation Facility (ESRF) meant whole intact scales could be measured. The research has been published in Nature Communications Chemistry.
Dr. Stephanie Burg, a Ph.D. researcher at the University of Sheffield said:
This research answers long-standing questions about how the structure inside these scales actually form and we hope these lessons from nature will help inform the future of sustainable manufacturing for paint.
The researchers then went to replicate the ultra-white beetles’ scale structure in the lab using plastic with hopes that it could pave the way for sustainable, ultra-white paints made from recycled plastic waste. Such paints would have a much lower carbon footprint and help tackle the challenge of recycling single-use plastics.
Using low-cost materials, they have been able to successfully recreate and even improve on the nanostructure in the lab. The technique is something that could be used as a sustainable alternative to titanium dioxide in white paint. It’s the foamy structure of the beetles’ scales that has the right proportion of empty spaces, optimizing the scattering of light—creating the ultra-white coloring.
Dr. Andrew Parnell, from the University of Sheffield’s Department of Physics and Astronomy, who led the research, explained:
In the natural world, whiteness is usually created by a foamy, Swiss cheese-like structure made of a solid interconnected network and air. Until now, how these structures form and develop and how they have evolved light-scattering properties has remained a mystery.
Having understood these structures we were able to take plastic and structure it in the same way. Ideally, we could recycle plastic waste that would normally be burnt or sent to landfill, structure it just like the beetle scale and then use it to make super white paint. This would make paint with a much lower carbon footprint and help tackle the challenge of recycling single-use plastics.
In conventional white paint, it’s nanoparticles of titanium dioxide that do the job of scattering light so strongly that the color appears as white. Unfortunately, the use of titanium dioxide is harmful to the environment. It contributes to nearly 75% of the carbon footprint of each tin of paint that is produced. Therefore, if titanium dioxide didn’t have to be used it would be a total game-changer for sure!
