Scientists have created a super white paint called Vantablack’s Young to Yin.
Ultra black metals can absorb more than 99.96 percent of sunlight today, but this new super white coat can reflect 95.5 percent of all photons hitting it.
Instead of warming under direct light, things painted with this new acrylic material can stay cool under the sun or even at ambient temperatures, giving the opportunity for a new energy-efficient approach to temperature control inside the building.
Other “heat-rejecting paints” currently only reflect 80 to 90 percent of our sunlight and cannot achieve lower temperatures than the atmosphere.
“Developing a bottom-up radiating cooling solution is an endless task that provides a convenient single-layer particle-matrix paint form and high reliability,” said Julien Ruan, a mechanical engineer at Indiana Purdue University.
“This is important for the broader application of radiation cooling and to reduce the effects of global warming.”
During the summer, many modern buildings rely on air-conditioning units that suppress heat from the inside of any building outside. It plays a role in transforming cities into “heat islands” with the extra heat generated by the intense energy needed to achieve cooling, and further intensifies global warming.
Radiative cooling is a passive technology that reflects heat from a building outside of space, but it is harder to achieve than radiant heating.
Since the seventies, scientists have been trying to figure out how to reflect enough sunlight so passive cooling is more effective than active air conditioners.
Recently, some have even tried to put together ‘retro solar panels’, which can capture some of that outgoing heat and convert it into energy even at night.
But at the moment these are just ideas and it is not clear whether such devices can work outside of mere simulations.
At least in the near future there may be more possible ways to depict residential and commercial buildings in Super White.
The new acrylic paint was created using a high particle density and calcium carbonate filler of various sizes, which can efficiently disperse all wavelengths in the solar spectrum.
The paint matrix has a vibrating resonance top, which ensures that a lot of heat is reflected outwards – at a much higher rate than what other cooling paints can achieve.
During a two-day field test at different locations and under different weather conditions, the researchers tested the paint’s radioactive cooling capabilities to show that it can scatter 95.5 percent of sunlight, which is 10 degrees Celsius at night below ambient temperature and at least 1.7 degrees Celsius below noon. .
Objects covered in calcium carbonate paint maintain significantly lower temperatures in infrared footage than surfaces coated with the same thickness of commercial white paint.
What’s more, this paint similarly brushes and dries, and is abrasion-resistant, waterproof, and can withstand outdoor weather for at least three weeks, although longer trials are currently underway.
“Our paint is compatible with the commercial paint production process and the cost can be comparable or even less,” Rouen said.
“The key is to ensure the reliability of the paint so that it is effective in long-term outdoor applications.”
The authors say their paint has “reported the best radioactive cooling performance”, although they acknowledge that while reviewing their results, another team published a paper suggesting that the cooling paint should include a high concentration of wide band gap particles.
They recommend the inclusion of fluorocarbon based polymers that show high resistance to weather.
“In many conventional white colors, engineered for durability, the experience of solar reflection decreases over time,” another recent study explained.
“Ingredients such as fluoropolymer-based binders can extend the lifetime of the reflector and result in lower year-round costs.”
Creating a single layer of paint that can reflect heat directly into the sky without the need for energy inputs would be a huge win for the climate crisis, as cooling is usually driven by fossil fuels and has an overall impact on global warming.
The new paint still needs to be tested, but the patent has already been filed. The name has not been released yet.
The study was published Cell Physical Science Report.