The world’s whitest paint has been created by researchers at Purdue University. This special paint reflects so much sunlight that it can actually help cool buildings, making it useful in the fight against climate change.
Professor Xiulin Ruan created this exclusive paint along with his team . In 2020, they made a version that reflected 95.5% of sunlight.
Following additional research, they enhanced the paint to reflect 98.1% of sunlight, which led to it being recognized by Guinness World Records as the whitest paint ever created.
Professor Ruan explained that their goal wasn’t just to break records. They were trying to find a way to cool down buildings and reduce the need for air conditioning which uses a lot of energy and contributes to global warming.
The paint looks like normal white paint but it works much better. Most regular white paints reflect 80% to 90% of sunlight, which means some heat is still absorbed. The new ultra-white paint reflects nearly all sunlight and also releases heat, keeping surfaces cooler than the air around them.
In real-world tests, surfaces painted with this ultra-white paint stayed about 8 degrees Fahrenheit cooler than the surrounding air during the day and up to 19 degrees cooler at night. This cooling effect can help reduce the “urban heat island” problem, where cities get hotter because buildings and roads absorb more heat than natural areas.
The first version of the paint was made using calcium carbonate, the same material found in chalk. The newer version incorporates barium sulfate, a substance commonly found in photo paper and cosmetics. This material helps the paint reflect even more light. However using too much barium sulfate can make the paint crack so the team had to find the right balance.
Even though white paint has been used for years on buildings in hot areas to reflect heat, this new paint is far more effective. It could reduce the need for air conditioning by as much as 40%, saving energy and lowering emissions.
Still, to make a big difference in the Earth’s temperature, a large area would need to be painted with this ultra-white paint about one to two percent of the planet’s surface or more than half the size of the Sahara Desert.
Many industries are interested in the paint, from building designers to car makers and even clothing companies. People want to know when they can buy it and if it can be made thinner for other uses. The original version needed a thick coat (0.4 millimeters), but the team has since created a thinner version (0.15 millimeters) that works just as well.
The paint isn’t available to the public yet, but a commercial version is being developed. The team is also working on making it more durable and resistant to dirt, and even exploring other colors that use the same reflective technology.
In short, this paint could help cool buildings, save energy and fight climate change without using electricity.
