this post was submitted on 14 Nov 2023
508 points (99.0% liked)

Technology

58303 readers
21 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 1 year ago
MODERATORS
 

Ultra-white ceramic cools buildings with record-high 99.6% reflectivity::undefined

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 69 points 11 months ago (1 children)

Tech Ingredients did a video about it as well. https://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.

[–] [email protected] 4 points 11 months ago (2 children)

They could just put a layer of something like Teflon over it. That's why crosswalk stripes feel so slick.

[–] [email protected] 22 points 11 months ago* (last edited 11 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.

This is a super complex subject with many people all over the world working on it and lots of money being put into it. It likely everything people can think of has been thought of and we need some real effort to get to a workable solution. Since no commercial application has been found, it's not certain this is a fixable problem.

Too often we see innovative ideas and they are marketed as this is just the first version. We can work out the kinks, extrapolate and get to something real special. In reality this is often not the case, actual limitations apply and not all problems are fixable.

[–] [email protected] 8 points 11 months ago (1 children)

Those are slick from the added glass powder for reflectivity.

Who’s putting Teflon on road stripes…?

[–] [email protected] 3 points 11 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.