Comment on Ultra-white ceramic cools buildings with record-high 99.6% reflectivity
echo64@lemmy.world 10 months ago
NightAHawkinLight on youtube has been working on something similar. same kind of snow-like nanostructure to reflect light away, but with the added benefit of a paint that emits light in a wavelength that travels through the atmosphere without interacting with any of it.
so if you point a painted tile at the sky it will actually cool below ambient temperature, it’s pretty wild www.youtube.com/watch?v=N3bJnKmeNJY
Thorry84@feddit.nl 10 months ago
Tech Ingredients did a video about it as well. www.youtube.com/watch?v=dNs_kNilSjk
The biggest problem with making stuff white and using fancy materials is the amount of crap they get exposed to.
Moisture is one issue, both in the form of water vapor / condensation as well as rain. But there’s also smallish animals, like birds and cats that crawl around on roofs. Not to mention all the insects. Then there is the normal sand and dust in the air, plus all the pollution. Depending on where you live, white stuff gets really dirty within weeks or months.
I work in a white office building and they have it cleaned with pressure washers twice a year, it takes a whole climbing team a good two weeks to clean the whole thing and it looks dirty again after a few months. And that’s just a white form of plastic (HPL) you can blast away on, without causing damage. With these fancy meta materials often they are really fragile and any damage undoes the special properties.
EatYouWell@lemmy.world 10 months ago
They could just put a layer of something like Teflon over it. That’s why crosswalk stripes feel so slick.
Thorry84@feddit.nl 10 months ago
If you put something over it, it loses it’s reflective properties. Something is only as reflective as it’s upper most layer. Unless you use something transparent, but even things we would commonly think of as transparent usually are only transparent at specific wavelength. And even then it’s probably not really transparent, more like translucent. Not to mention things like internal reflections and wavelength lengthening.
schmidtster@lemmy.world 10 months ago
Those are slick from the added glass powder for reflectivity.
Who’s putting Teflon on road stripes…?
EatYouWell@lemmy.world 10 months ago
Huh, I stand corrected. I could have sworn I read an article linked in a discussion about solar panel roads that said Teflon was mixed in the paint to keep the stripes from getting dirty super fast.