Scientists Have Created The “white” Paint: How They Did It, And What Are Its Properties

Scientists from the US Purdue University have developed a paint that is significantly “whiter than the whitest paint currently available.” It absorbs 98% of sunlight and can help fight global warming, writes the BBC.

Painting rooftops white is an energy-efficient approach that is already being adopted in some major cities.

Commercially available white paints reflect 80% to 90% of sunlight. “This is important because every 1% of the reflectivity you get means more solar heat reflection – 10 watts per square meter,” says Professor Xiulin Ruan.

“So, if you were to use our paint to cover a roof of about 93 square meters, we estimate you could get 10 kilowatts of cooling capacity. This is more powerful than the AHUs used in most homes,” he said. …

In New York, more than a thousand square meters of roofs were recently covered with white paint. The state of California has already updated building codes to promote cool roofs.

Their benefits are still being studied, but research has shown that they can reduce energy consumption and lower ambient temperatures. This has the added benefit of reducing the amount of water used for irrigation in cities.

“We made a very rough calculation. And we assume that we will need to paint only 1% of the Earth’s surface with this paint – perhaps an area where there are no people, which is covered with rocks – and this can help combat the climate change trend,” said the professor Rouen.

The new paint contains a compound called barium sulfate, which is also used in photographic paper and cosmetics.

“We used a very high concentration of constituent particles. And we use many different particle sizes because sunlight has different colors at different wavelengths,” the professor explained.

How much each particle scatters light depends on its size, “so we deliberately used different sized particles to scatter each wave,” he said.

Researchers are now in talks with the company to manufacture and sell their paint, which they say should be comparable in cost to the paints currently available.

Professor Rouen says he has received a request from a museum that wants to place his whitest paint next to the blackest.

This refers to the Vantablack material developed by scientists in 2014. This material is not available to everyone. The sculptor Anish Kapoor bought the exclusive rights to “use it as an art material”.

In response, British artist Stuart Semple created what he says is “the pinkest pigment in the world” and made it available for purchase on his website “to everyone but Anish Kapoor.”

Professor Rouen says it will depend on the manufacturing company, but he hopes his “ultra-white” paint will be available to the general public.