Other than picking that perfect color for the outside of your home or inside of your favorite room, you probably don’t give paint much thought.
But Purdue University researchers do. And you’d be surprised just how much technology goes into the paint coming out of West Lafayette – and how much it can impact your air conditioning bill and possibly even global warming. I know, that’s pretty ambitious for a can of paint.
After a six-year-long research project, a group of Purdue University engineers insists they’ve created white paint that can lower the temperature in a room as well as any air conditioner and have a positive impact on the earth’s environment by taking the heat from a surface or room and sending it into outer space.
As weird as the idea sounds, the group from Purdue says the paint it has developed can keep surfaces 18 degrees Fahrenheit cooler than their surroundings – without consuming any energy.
Is this too good to be true? Xiulin Ruan, Purdue professor of mechanical engineering who headed up the project, says no.
“It’s very counterintuitive for a surface in direct sunlight to be cooler than the temperature your local weather station reports for that area, but we’ve shown this to be possible,” Ruan says.
“This not only saves money, but it reduces energy usage, which in turn reduces greenhouse gas emissions,” he adds. “And unlike other cooling methods, this paint radiates all the heat into deep space, which also directly cools down our planet. It’s pretty amazing that a paint can do all that.”
Purdue’s research, which was built on attempts dating back to the 1970s, was supported by Purdue’s Cooling Technologies Research Center and the Air Force Office of Scientific Research through the Defense University Research Instrumentation Program. This research was supported by the National Science Foundation and a National Science Foundation Graduate Research Fellowship grant.
The ultra-reflective paint made this year’s edition of Guinness World Records as the world’s whitest paint.
Now, Ruan says, he and his team have put their paint on a diet and made it even better.
Ruan said since the paint debuted a little over a year ago, people from around the world have contacted him wanting to know where they could buy the paint – and if he could make it thinner.
But why thinner?
“To achieve this level of radiative cooling below the ambient temperature, we had to apply a layer of paint at least 400 microns thick,” explains Ruan, who previously worked for the Air Force Research Laboratory in Dayton, Ohio. “That’s fine if you’re painting a robust stationary structure, like the roof of a building. But in applications that have precise size and weight requirements, the paint needs to be thinner and lighter.”
So Purdue researchers who created the paint developed a new formulation that is thinner and lighter – ideal for radiating heat away from moving objects such as cars, trains, airplanes and even spacecraft. The new paint – which was unveiled this month – is as much as 80% lighter than the previous formula.
If you want to dive into the technical aspects of the paint, Purdue’s research was published this month in Cell Reports Physical Science.
All universities have put a premium on commercializing their research, and Purdue – under the leadership of its president, Mitch Daniels, is one of the leading forces in this effort.
“We are in discussions right now to commercialize (the paint),” Ruan explains. “There are still a few issues that need to be addressed, but progress is being made.”
Patent applications for the paint have been filed through the Purdue Research Foundation Office of Technology Commercialization.
Anthony Schoettle is the director of communications for the Indiana Chamber. He started with the Chamber in 2021 after a long career in journalism. He’s won multiple awards for his storytelling ability on a wide range of business topics.
