A scientific team led by chemists from Nipsea Group has developed a practical way to produce ultra black coatings for luxury vehicles. The innovation was designed primarily for the Chinese market, where the color of the car has become a key selling point, but it is not difficult to see a future in which such colors will be globally popular. The new technology, detailed in a paper published in the journal Matter & Light, combines carbon black pigments and carbon nanotubes, and the result is a deep, extremely dark black color that meets the strict standards of the automotive industry.
A long development process
The search for such a solution began back in 2019, when a BMW concept car was painted with a series of vertically aligned carbon nanotubes. This started a new race for the “blackest black” color in the automotive industry. The goal was to create coatings that absorb almost all light, creating a “black hole” effect. Previous approaches relied exclusively on soot pigments and dispersion of light rays, which limited the achievement of the maximum level of blackness, while the new approach brings a significant turn towards structural absorption.
In this case, the scientists created a stable nanometer-sized composite of carbon black pigments and carbon nanotubes, which they then integrated into the coating’s binder and sprayed on the car model. Within this material, a specific structure is formed that connects the components with strong interactions. Thanks to the dual effect of high internal efficiency and a light-trapping structure, this coating manages to absorb an average of 99.9% of visible light wavelengths. In addition, the film demonstrated excellent long-term stability and adhesion properties even during demanding water and moisture exposure tests.
It’s not ready for the road yet
Although the technological design of the production process has been successfully proven at the concept level, the ultra black cars will not hit the roads immediately. Scientists note that there is still room for improvement with this technology. Namely, a higher proportion of nanotubes in the mixture could further increase the light absorption capacity, but this would also bring new difficulties in processing on an industrial level.
In the future, scientists plan to develop a multi-layer ultra black coating with a gradient refractive index, which would reduce reflection and further improve light absorption efficiency for an even darker appearance. By the way, the record for the “blackest black” color in the world is held by engineers from MIT. They have created a carbon nanotube material that absorbs as much as 99.995% of visible light, making it considerably darker than the previous record holder, the famous Vantablack (which absorbs 99.965%).