By Jim Grant
Despite the fact that humans can be found on virtually every continent, two things remain universally true: we’re never comfortable with the temperature (ask a married couple if they’re both comfortable in the car, ever!), and we all want to spend less money remedying that issue.
One solution architects and painters alike have arrived at is the use of light and dark colors in specific regions to reduce heating or cooling bills. For example, painting a home in a bright color like white reflects a tremendous amount of solar heat that the home itself would otherwise absorb and thus need to be cooled.
Alternatively, homes in cooler regions benefit more from darker paints that help them absorb that same solar warmth to reduce heating costs.
But what about structures located in areas with a full range of seasons where the winters are cold and the summers are hot?
One intrepid group of scientists looked to the king of adaptive camouflage in the animal kingdom for a solution: the chameleon.
More information on this new breakthrough tech from the American Chemical Society:
“Inspired by the Namaqua chameleon, Fuqiang Wang and colleagues wanted to create a color-shifting coating that adapts as outside temperatures fluctuate.
To make the coating, researchers mixed thermochromic microcapsules, specialized microparticles and binders to form a suspension, which they sprayed or brushed onto a metal surface. When heated to 68 degrees Fahrenheit, the surface began to change from dark to light grey. Once it reached 86 degrees, the light-colored film reflected up to 93% of solar radiation.
Even when heated above 175 degrees for an entire day, the material showed no signs of damage. Next, the team tested it alongside three conventional coatings — regular white paint, a passive radiative cooling paint and blue steel tiles — in outdoor tests on miniature, doghouse-sized buildings throughout all four seasons.
In winter, the new coating was slightly warmer than the passive radiative cooling system, though both maintained similar temperatures in warmer conditions.
In summer, the new coating was significantly cooler than the white paint and steel tiles.
During spring and fall, the new coating was the only system that could adapt to the widely fluctuating temperatures changes, switching from heating to cooling throughout the day.
The researchers say that this color-changing system could save a considerable amount of energy for regions that experience multiple seasons, while still being inexpensive and easy to manufacture.”
If these claims turn out to be accurate, this new paint could revolutionize exterior coatings – especially on large commercial buildings. It could even open up certain areas of the planet deemed too inhospitable or too expensive to regulate via traditional HVAC systems thermally.
Another application not mentioned by ACS or Fuqiang Wang could be a warning device for outdoor swimming pools or children’s playgrounds. Swingsets or slides often reach temperatures over 150 degrees Fahrenheit, where children’s sensitive skin can easily be burned. A thermal-reactant paint that changes from green to red or blue to red could visually indicate a surface’s temperature.
Truly, the possibilities for such a coating are limitless, and I’m personally excited to see how the technology evolves and what uses its creators come up with.
