The world’s whitest paint—seen in this year’s edition of Guinness World Records and “The Late Show With Stephen Colbert”—keeps surfaces so cool that it could reduce the need for air conditioning. Now the Purdue University researchers who created the paint have developed a new formulation that is thinner and lighter—ideal for radiating heat away from cars, trains and airplanes.
October 3, 2022
The world’s whitest paint—seen in this year’s edition of Guinness World Records and “The Late Show With Stephen Colbert”—keeps surfaces so cool that it could reduce the need for air conditioning. Now the Purdue University researchers who created the paint have developed a new formulation that is thinner and lighter—ideal for radiating heat away from cars, trains and airplanes.
“I’ve been contacted by everyone from spacecraft manufacturers to architects to companies that make clothes and shoes,” said Xiulin Ruan, a Purdue professor of mechanical engineering and developer of the paint. “They mostly had two questions: Where can I buy it, and can you make it thinner?”
The original world’s whitest paint used nanoparticles of barium sulfate to reflect 98.1% of sunlight, cooling outdoor surfaces more than 4.5°C below ambient temperature. Cover your roof in that paint, and you could essentially cool your home with much less air conditioning. But there’s a problem.
“To achieve this level of radiative cooling below the ambient temperature, we had to apply a layer of paint at least 400 microns thick,” Ruan said. “That’s fine if you’re painting a robust stationary structure, like the roof of a building.
