Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff Lauren Vogel bomb Here at noon on a sunny summer day, the temperature of a conventional dark colored flat roof can reach a hundred and fifty degrees fahrenheit that's sixty five degrees celsius, according to the U. S Department of Energy, and that heat will warm the inside of the building or home as well, making it more likely that the occupants will turn to air conditioning, an
energy expenditure that often requires burning fossil fuels at electrical power plants, whose emissions contribute to the progression of climate change. It's a bedeviling problem that might easily be solved if we only had roofs that reflected solar energy back into the sky instead of absorbing it. It's a deviling problem that might be easily solved if we could only have roofs that reflected solar energy back into the sky instead
of absorbing it. That's why researchers development of the whitest paint ever created an ultra white formulation that reflects up to nine point one percent of sunlight could turn out to be a really big deal in the effort to reduce energy consumption and combat the warming of our planet.
The breakthrough is detailed in April issue of Applied Materials and Interfaces, an American Chemical Society journal, and not only does the paint absorb very little energy from sunlight, but it also emits thermal energy in the infrared range back into the atmosphere so that it travels out and away from Earth before the article. This episode is based on how Stuff Works. Spoke by email with Zen You Lee,
the paper's first author. He's a postdoctoral researcher at the Massachusetts Institute of Technology who worked on the project while in graduate school at Purdue. He said this paint not only reflects the majority of the sunlight to avoid overheating, but also cools itself down colder than the air surrounding it even under direct sunlight. In some way, it's effectively
an air conditioner without consuming any electricity. Researchers have been trying to make paints that could be used in passive cooling since the nineteen seventies, but most of them have absorbed too much sunlight, so they don't provide any cooling effect in the daytime. Lee explained, in recent years, scientists have also been exploring exotic technologies for creating light reflecting surfaces, such as multi layered nanostructured films, but those solutions tend
to be expensive and not easily scalable to buildings. That brought this team of researchers back to thinking that the best approach might be a particle polymer composite similar to commercial paint. Ordinary white paint isn't quite white enough to help much with passive cooling. It only reflects eight of sunlight and actually gets warmer from absorbing ultraviolet light, and so the task became finding a way to make white paint even whiter, and that turned out to be a challenge.
Alice said. We first tried multiple materials with high electron band gap to avoid solar absorption. However, the paints often appeared semi transparent at low thickness due to the lack of ability to reflect sunlight. During our previous studies on commercial paints and theoretical modeling, we identified that both high
concentration and broad particle size distribution were beneficial. As we implemented these two approaches, we saw the paint solution appere wider compared to previous attempts, they landed on burying sulfate as a way to make the paint very reflective and thus very white. You may have heard of burying sulfate before.
It's the stuff that medical patients take in drink or tablet form to code the esophagus, stomach, and intestines when they're getting an X ray exam or CT scan, so the doctors can see diseased or damaged areas more clearly. As a paint ingrediently notes it's already widely available safe for humans and the environment. The researchers used a variety of sizes of barry and sulfate particles in the paint, which enabled the paint to scatter more of the spectrum.
They also had to make sure that the paint would last long enough outside to be suitable for painting rooftops. Lee explained, we tested the abrasion resistance, three week outdoor weathering, and a water rinse test. All three showed promising results as initial durability tests. We also tested the viscosity and the paints can be brushed and dried very similar to commercial paint. It can also be fabricated in a similar way.
In this work, we not only achieved a paint that's superior to the commercial paint, but also do not need specialized equipment or materials to fabricate, transport, or apply the paint. The ultra white paint looks pretty similar to regular white paint because the difference in reflectivity, while significant in terms
of cooling, is imperceptible to humanize. The next step in the research is to optimize the paint for long term durability under different sorts of weather conditions, but there isn't yet a target date for it to be market ready, so don't search for it at your local hardware store just yet. Today's episode is based on the article the whitest paint Ever produced could save energy climate change on how stuff works dot com, written by Patrick J. Keiger.
Brain Stuff is production of I Heart Radio in partnership with how stuff works dot com, and it is produced by Tyler clang. Or more podcasts my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.