The white paint emits more infrared heat than it absorbs. The paint features various sizes of barium sulfate particles that scatter different wavelengths of solar radiation. This means it cools a surface below the surrounding temperature.
For example, previous experiments showed this paint cooling a surface by 8 degrees Fahrenheit versus the surroundings under noon sunlight. At night, the ultra-white material can keep things 19 degrees Fahrenheit cooler.
The Guinness World Records even recognized this substance as the "Whitest paint." The "This is Purdue" podcast also interviewed Ruan.
In 2022, the team developed a lighter version of the paint that can work on vehicles. It's not clear when this substance might appear on cars. Commercial applications are a year or more away.
Ruan is also working on barium-sulfate paints in different colors. They wouldn't be as effective as the white version but would still have improved reflectivity of solar radiation than existing solutions.