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https://newatlas.com/materials/ultra-white-ceramic-cools-buildings-record-high-reflectivity/>
"Scientists in Hong Kong have demonstrated a new ultra-white ceramic material
that can drastically cool buildings by reflecting sunlight and heat at record
highs. The beetle-inspired material gets its ability from its nanostructure,
stays tough to the elements and should be relatively easy to scale up for
production.
When our homes get too hot, the first solution for many people is to crank the
air conditioning. It may be effective, but it’s not very energy efficient, as
heating and cooling buildings accounts for a huge percentage of energy costs.
So, scientists are investigating ways to passively manage interior
temperatures, and one of the simplest is to just paint buildings and rooftops
white.
Basic physics dictates that lighter colors absorb less light than darker ones,
and therefore remain cooler. In recent years new ultra-white paints have been
developed that reflect over 95% of the sunlight that hits them, doing a decent
job of cooling buildings. But these coatings have their issues, including
durability.
For the new study, scientists at City University of Hong Kong (CityU) developed
a new cooling ceramic material that performs better than others. Rather than
just being a very white paint, the material gets its high reflectivity from its
nanostructure, which efficiently scatters almost the entire spectrum of
sunlight – just like the Cyphochilus beetle which inspired it. This results in
a solar reflectivity of 99.6%, which is a record high, along with an infrared
thermal emission of 96.5%.
The material is made of alumina, which not only reduces solar absorption, but
the team says it makes the cooling ceramic more durable in the face of weather.
It resists degradation from UV light exposure, which is a weakness of other
passive cooling materials and coatings, and boosts the rate of water
evaporation from the surface, which adds the bonus effect of evaporative
cooling. It even boasts fire resistance by withstanding temperatures of over
1,000 °C (1,832 °F)."
Via Diane A.
Share and enjoy,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
