Paint, a part of humankind’s attempt to recreate colors and images in the natural world, has been used for tens of thousands of years in different shapes and forms. In the current day and age, the word ‘paint’ might bring to mind acrylics, oils, or even the image of a famous work like Starry Night. But a recent breakthrough from a nanoscience lab at the University of Central Florida, led by Professor Debashis Chanda, has invented a new paint based on structural color, which means for significant improvements in unexpected areas.
Unlike the colors in Starry Night, those we see in nature are examples of structural color, produced by the diffraction of light on surfaces like a monarch’s wings, for example. Longer-lasting and pigment-free, they are vastly different from typical pigment-based paints that can be bought from stores, which have a multitude of shortcomings. Traditional paint can only last so long on surfaces depending on its exposure to light and the elements, and is often toxic to the environment as well, due to ingredients such as cobalt. Chanda’s team has successfully produced the world’s first example of a structural paint, offering coloring with a single coat and having a surface density of 0.4 g/m2, qualifying it as the lightest paint in the world, as published in a paper on ScienceAdvances. The paint itself is made of tiny aluminum flakes covered with aluminum nanoparticles, which means it does not hold heat from sunlight exposure in the way traditional paints do. Actually, preliminary lab experiments have shown its cooling features, keeping surfaces 20-30 degrees Fahrenheit cooler than conventional paints, making it a conceivable solution to the “urban heat island effect,” the excruciatingly hot temperatures generated from urban architecture and activities.
When it comes to colors available, it depends on the size of the nanoparticle clumps present on the aluminum flakes, which Chanda refers to as “nanoislands.” Changing the dimension of these nanoislands allows for light to be oscillated at different wavelengths, which translates to different colors being perceived by the human eye. So virtually, there’s no limit as to the colors that can be created with this new paint.
According to an article from Wired, a Boeing 747 requires approximately 500 kilograms of paint and needs to be repainted every four years. Chanda estimates that only 1.3 kilograms of paint would cover the same surface area since only a single layer is needed and the material is much less dense. What that equates to is more than a 1,000 pound decrease off of every plane which would save significant amounts of fuel for every journey. To further put into perspective how drastic this would be, in 2021 American Airlines switched to a mica-free paint, making each plane only 62 pounds lighter. This was projected to save nearly 300,000 gallons of fuel annually and reduce carbon emissions by 9,525 metric tons per year. A new paint might not have initially seem like a huge advancement in modern science, but Chanda’s discovery holds promise in helping cool cities, and decrease both carbon emissions and fuel consumption in commercial airlines.
