‘World’s whitest paint,’ developed at Purdue, wins big at SXSW

Purdue Professor Xiulin Ruan and his team have developed the paint, which reflects 98.1% of sunlight. (Purdue University Photo/John Underwood)

A product developed by researchers at Purdue University that was recognized by Guinness World Records as the world’s whitest paint has earned two major awards.

The paint was named the winner of the 2023 Innovation Award in the sustainability category at the South by Southwest conference in Austin, Texas, this week, just a few weeks after winning the 2023 Gizmodo Science Fair.

Purdue says the paint reflects 98.1% of solar heat away from its surface, compared to paints currently on the market that reflect only 80% to 90% of sunlight.

Emily Barber, who was part of the team that presented the paint at SXSW, told Inside INdiana Business it was “incredibly exciting” to win the award.

“Especially being in that space, which is a lot more startup-oriented, we were very excited to win this award and have people see the potential of what our paint could be and how it could help the environment,” Barber said.

The paint was developed by Xiulin Ruan, a professor of mechanical engineering at Purdue. He says because the paint absorbs less heat from the sun than it emits, a surface coated with the paint is cooled below the ambient temperature without consuming power.

For example, a 1,000-square-foot area of a roof coated in the paint could equal 10 kilowatts of cooling power, which the university said is more powerful than air conditioners used by most houses.

At SXSW, the team demonstrated the paint by using model barns, one painted with commercial paint and the other in Purdue’s paint, that were sitting under direct halogen lights. The barn painted with Purdue’s paint showed internal temperatures 8-10 degrees cooler than the other.

Andrea Felicelli, a PhD student at Purdue who is a main developer of the formulation of the thin, lightweight paint, said mostly composed as any commercial white paint but it’s the introduction of white nanoparticles that are added that give the paint its high reflective quality.

While the team is focusing on using the paint on buildings, Felicelli said there is potential to use it on other types of surfaces as wel,l given the nanoparticles used in the paint.

“That sort of composition can be changed for different applications,” she said. “Right now, the two formulations that we have published can be used quite well in any application from buildings, outdoor electronic systems, wearable technologies, planes, cars, so there’s a lot of versatility there.”
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Ruan’s team is currently working with the Office of Technology Commercialization, or OTC, at the Purdue Research Foundation to move the paint closer to commercialization.

Barber said the recent wins, particularly the one at SXSW, will help those efforts.

“We talked with tons of different people who had connections within the paint industry that were very interested about seeing how this could develop further at a commercial scale,” said Barber. “I think not only could it help it get to that piece faster, but I also think if the world’s already heard about it, they’re going to want to buy it, and they’re going to know it exists, and they’re going to get excited about it.”

Barber said the team is in talks with a company about potential commercialization, but work is continuing to understand how the paint works over time.

“We’re doing different sorts of weathering tests, and unfortunately, understanding how the paint works over time takes time,” she said. “So even though we can do some accelerated testing there, we’re just sort of trying to wrap that up and understand that these optical properties keep over time.”

The team is also working to optimize different properties of the paint for potential use in other applications.

Purdue says patent applications have been filed for the paint formulation through the OTC.