Scientists have created a super white paint, which is the yin to the yang of the Vantablock.
Although ultra black materials today can absorb more than 99.96 percent of sunlight, this new super white coat can reflect 95.5 percent of the photons.
Instead of being heated in direct light, objects painted with this new acrylic material can remain cooler than the temperature under the sun, allowing an energy-efficient new way to control the temperature inside buildings.
The other “heat-repellent paints” we currently have can only reflect 80 to 90 percent of the sunlight, and cannot achieve temperatures below atmospheric.
“Developing a bottom-up ambient radiative cooling solution that provides single-layer particle-matrix paint form and high reliability is an ongoing task.” Says Siulin Ruwan, Mechanical Engineer, Purdue University, Indiana.
This is crucial for the widespread application of radiative cooling and mitigation of the effects of global warming.
In the summer, many modern buildings rely on air conditioning units, which dissipate heat from the inside of a building. This contributes to the transformation of cities with the additional heat generated by the intense through-energy needed to achieve cooling. “Hot Islands“Global warming is getting worse.
Radiative cooling It is a passive technology that reflects heat from a building into space, but it is much harder to achieve than radiant heating.
Since the 1970s, scientists have been trying to figure out how to adequately reflect sunlight, so passive cooling is more effective than an active air conditioner.
Recently, some people have tried to put together ‘reverse solar panels’ that can capture some of the outgoing heat and convert it into energy, even at night.
But for now these are still just ideas, and it is not clear whether such tools will simply work outside of a simulation.
Painting residential and commercial buildings in super white would be a more practical approach, at least in the near future.
The new acrylic paint is made using calcium carbonate fillers of high particle density and wide size, which effectively diffuses all wavelengths of the solar spectrum.
The paint matrix has a peak of vibrational resonance, which ensures that a large amount of heat is reflected out – at a much higher rate than other cooling paints can achieve.
In two days of field tests at different locations and in different climates, the researchers tested the paint’s radiative cooling capabilities, which found that it had a 95.5 percent chance of scattering sunlight, 10 degrees Celsius above night and 1.7 degrees Celsius above room temperature.
Compared with surfaces coated with the same thickness of commercial white paint, materials coated with calcium carbonate paint retain significantly lower temperatures in infrared footage.
What’s more, this paint is brushed and dried in the same way, it is abrasion resistant, waterproof, and can withstand at least three weeks of doodor weather, although more testing is underway.
“Our paint is compatible with the manufacturing process of commercial paint, and the cost may be comparable or less.” Says Ruwan.
“It’s important to ensure the reliability of the paint, so it can be enabled in long – term dot door applications.”
Authors Say Their paint is “the best radiative cooling performance ever reported”, yet another team published a review of their results. Paper Cooling paint should contain a high band gap particle density.
They also suggest the inclusion of fluorocarbon based polymers that are highly resistant to weathering.
“Many traditional white paints, while designed for durability, have a decrease in solar reflectance over time,” said another recent paper. Explaining.
“Materials such as fluoropolymer based binders increase the reflectivity and thereby reduce the average cost per year.”
Creating a single layer of paint that can reflect heat directly into space without the need for energy input would be a huge success for the climate crisis, as cooling is usually provided by fossil fuels. Affecting global warming as a whole.
The new paint still has some tests to do, but the patents have already been filed. The name has not yet been revealed.
The study was published Cell Reports Physical Science.