Purdue's record-setting white paint now thinner, could be available commercially

Purdue University photo/Andrea Felicelli

Purdue University researchers have created a new formula for the world's whitest paint, making it thinner and lighter. The previous iteration (left) required a layer 0.4 millimeters thick to achieve sub-ambient radiant cooling. The new formulation can achieve similar cooling with a layer just 0.15 millimeters thick. This is thin and light enough for its radiant cooling effects to be applied to vehicles like cars, trains and airplanes.

By: Michelle Kaufman

WEST LAFAYETTE — Purdue University is continuing to work on the world's whitest paint.

The Guinness World Record holding paint is now thinner, lighter and could soon be available for purchase.

"We are in discussions right now to commercialize it,” said Xiulin Ruan, a Purdue professor of mechanical engineering and developer of the paint. "There are still a few issues that need to be addressed, but progress is being made.”

Purdue says the paint keeps surfaces so cool that it could reduce the need for air conditioning. Since its creation, Ruan says the two questions they've gotten are where it can be purchased and can it be thinner.

The original paint could cool outdoor surfaces by 4.5°C, but the amount of layers required for the paint could be too much for items that have size and weight requirements.

The original paint needed to be in a layer that was at least 400 microns thick. The new formula only needs one 150-micron layer and weighs 80% less while providing nearly the same amount of solar reflectance.

“This light weight opens the doors to all kinds of applications,” said George Chiu, a Purdue professor of mechanical engineering and an expert in inkjet printing. “Now this paint has the potential to cool the exteriors of airplanes, cars or trains. An airplane sitting on the tarmac on a hot summer day won’t have to run its air conditioning as hard to cool the inside, saving large amounts of energy. Spacecraft also have to be as light as possible, and this paint can be a part of that.”

Patent applications have been filed for the paint formulation.