tocs3 8 hours ago

I do not have any polyvinylidene fluoride-co-hexafluoropropene (PVDF-HFP) but I wonder if there is a similar DIY option. It sounds like it uses little bubbles in the paint to reflect the sunlight. I would really like something like this here in Texas. It is getting dryer and I worry about our well.

bell-cot 9 hours ago

> Researchers at the University of Sydney and commercial start-up Dewpoint Innovations have created a nano-engineered polymer coating that not only reflects up to 97% of the sun's rays, but also passively collects water. In tests, it was able to keep indoors up to 6 °C (~11 °F) cooler than the air outside.

So "blocks" is a poor word choice - tarpaper will block 97%+ of light.

I see nothing about the cost / durability / toxicity of the new paint-ish coating. Hopefully that's "low" / "very" / "non-".

  • allears 9 hours ago

    They did say that the material didn't degrade over the course of their testing, but of course that's only a year or so.

    • bell-cot 9 hours ago

      > the coating withstood the challenging test of the harsh Australian sun, and showed no signs of degradation over the six months.

      Real-world optimal would be 25+ years - in environments with acid rain, bat/bird droppings, hailstones, heavy smog, ice dams, 65° C summers, and several other sorts of hazards.

      (Yes, that's a ridiculously big ask. OTOH, the planet we're stuck on is starting to char. And workable Planet B's are looking extremely scarce):