'Whitest ever' paint reflects 98% of sunlight
bbc.com
bbc.com
The reason I want this is because we seem to be swimming in innovation, but nobody to aggregate and make sense of it all, and `join-the-dots` of all this tech so we can make even bigger leaps with it. Also: A lot of these articles are great, but too quickly shoved into people's bookmarks and forgotten about, without any real action taken on them. Put simply: we are addicted to innovation, but with little action taken on this innovation!!
For instance,I've been subscribing to materialdistrict.com for years and some materials they showcase are simply mind boggling.
Think what could have been had we joined those two dots in 2000BC instead of 17-1800 AD.
I should note that their train was of course pulled by slaves and not a locomotive.
It’s like asking “Why wasn’t there a chess engine as good as stockfish for the PDP-11?” It simply wasn’t possible with the technology in 1970.
But in this hypothetical timeline they would’ve hand-made the first leaky and inefficient engine if someone with some clout had the idea for a piston back then.
These people didn’t blink at moving mountains to build burial crypts, so it’s conceivable that they might’ve experimented with steam if that notion struck, say, the pharaoh.
But then I watch Clickspring recreating the Antikythera mechanism, and I wonder.
Yes, there is a big leap between what is effectively clockwork and, say, making a pressure boiler. But I wonder: if Francis Bacon had been a student of Euclid and derived the scientific method in 3rd century BC Alexandria, and Rome had been better governed, devoting more energy to science and less to war, speed-walking the tech tree 1500 years early isn't impossible to contemplate.
Fun to think about anyway!
Science = long-term benefit, military = survival right now.
I remember playing Master of Orion 2 with a pure science focus and getting my ass whipped every time.
Then I realised that a good long term strategy needs to work around a good short-term strategy which enjoys priority. I switched to population and production focused games, and suddenly the “Impossible” AI was too easy.
>You would need pure zink (obtained in ~1750)
https://en.wikipedia.org/wiki/Roman_metallurgy#Types_of_meta...
"By the height of the Roman Empire, metals in use included: silver, zinc, iron, mercury, arsenic, antimony, lead, gold, copper, tin"
>You would need copper wire to implement telegraph
copper is very pliable, so it is easy to make wires.
I am not that sure about vinegar as a medium. I beleive it will lead to low voltage and weak power, rendering the pile useless for long distance transmission.
The same applies to copper wire. You need steel to draw copper to make wire, otherwise wires will be short, need to be soldered and become ineffective for long distance.
Also, telegraph lines are too easy to sabotage. Fire signals are much more reliable to rule ancient empire.
Contact info is in my profile if interested.
And from the article: > In the US, New York has recently coated more than 10 million sq ft of rooftops white. The state of California has already updated building codes to promote cool roofs.
Unfortunately, that's the whole point of this little discussion, right? GP is saying how many things like this, yes, seem like they have merit, but at the end of the day can't be produced practically outside of a lab.
Does the paint stick to the surface you want to paint, how is it applied, what is the coverage, is it durable, does it repel contaminants, can it withstand the environmental conditions, is it chemically compatible with the surface, it is chemically a concern for the other items/humans/animals that may come in contact with, can it be produced at scale, does it (and it's vehicle for application) meet regulatory standards? etc...
Many products drop by several % after a few years.
If you want a really smooth topcoat, you usually want to sand past what you can reasonably/economically/effectively do on the substrate. Some primers are formulated to sand nicely to a powder (as opposed to balling up in clumps on the paper). You'll see this spraying higher quality paint grade work. You have to have a decent surface before you prime, but the primer can really smooth it out for the topcoat.
If you're finishing pine with knots in it, you'll want a primer that will seal the knots, otherwise the pitch will eventually bleed through and discolor the topcoat. Shellac excels at this.
Shellac is also outstanding as a sanding sealer. You can use that in a couple of ways: to fill the pores in the wood so they don't get full of sanding dust (which can be key if you have inlay of strongly contrasting woods), or to stiffen the fibers of softer woods so you can get a better/smoother sanded surface for the next steps in the finishing schedule.
Shellac is also often used as a barrier coat between otherwise incompatible finishes or when you have a relatively fragile stain layer. If you're putting an oil based finish over an oil based stain, you run the risk of picking up the stain as you apply the topcoat, especially if you're brushing or wiping the topcoat. Because the solvent in shellac is alcohol, you can pretty freely brush it over oil or water based stains without risking a disaster.
And yes, I do use primers other than shellac from time to time if I have a specific need, but dewaxed shellac is compatible with basically everything, so I always have a can around.
N.B. I'm not a professional finisher. Don't take my word on any of this; test your prep and finishing schedule on scrap!
yes, i learned this the hard way, albeit on a simple set of wall shelves as cat stairs that i can easily fix eventually with shellac and another topcoat (when i get around to it).
i.e. electroplate > primer > base > mid pearl > clear
IMO, the stores could do better about offering basic information about this, about when one would need a primer, or just a topcoat, what kinds of paint bases are appropriate for what applications, what kinds of application methods are appropriate, etc. Instead, the response of the big box stores seems to be to skip the question entirely with combined products, e.g. "paint and primer in one".
oh, and yeah, paint and primer in one does neither job very well.
If you wanted to wait for this specific product, that's fine, but that's almost like waiting for 26% efficient solar panels instead of ~23% we already have (even though most production panels are 18% - 22%)...
And actually this is also one of those things that also helps beat Tesla Solar roof - get a white paint - THEN add bifacial solar panels. So the Tesla roof panels is actually worse for your overall cooling than regular panels now.
The white-painted object will heat less than when painted in another color, but it will heat anyway.
The white paints described in the paper and in the patent applications, which use either barium sulfate or calcium carbonate instead of the normal titanium white pigment, actually cool the painted object, even in strong solar light.
I think the catch is that if you really knew that... you'd be out making an insane amount of money as you'd be able to pick and choose winners / make them work ;)
I'm reminded of the old TV series "Connections" where lots of individual innovations are cobbled together over surprisingly long periods of time to really have an impact. Mostly... it seemed like a combo of inspiration and happenstance when someone strung them together.
In this particular case, thought, the article claims they won't be patent trolls and this paint should be cheaply available.
[1]: https://en.m.wikipedia.org/wiki/List_of_emerging_technologie...
I don't know of any compendium on the web, but if someone were looking to get started there is a field to dig into where people do this kind of work full time. It's essentially a two-sided market making process of curating useful innovations and building up a sales function to close deals.
https://www.sciencedaily.com/releases/2020/10/201021112358.h...
And they have an absurd number RSS feeds for every topic too:
There is. It's called "the market". Each one of those innovative ideas gets tested by their inventors and backers against real world use-cases. Nothing validates an idea or innovation more than someone writing a check to buy it.
On their own though, right? That's not what was being asked. They wanted someway to track things that would work really well together and bring bigger benefits than things could on their own.
Yeah. When I ran a startup, you look for customers, but you also look at partnerships all the time to complement whatever you're doing. Sometimes the partnership finds you, and sometimes you find the partnership. You attend tradeshows and conferences. Sometimes your customers will point you at another company you should work with. That's all part of the market. People behind innovative technologies (inventors, and investors) are constantly looking to find ways for their tech to gain traction.
>They wanted someway to track things that would work really well together and bring bigger benefits than things could on their own.
OP is advocating for a top-down system where they can get a list of innovative technologies and just put them together like lego. It doesn't work that way. It's why a top-down command economy with a central authority doesn't work. There's a lot of trial and error (and failure) that happens at the bottom level and from the top, you just don't know what ultimately is worth expanding effort on and what is a waste of time. Any decision you make about what should go with what is going to be wrong. That's why the market is so powerful for innovation.
If you see this then you can reach me (in profile)
Honey, it’s going to be -27°C (-16.6°F) tomorrow, can you turn the reflectivity to 0% after brewing the coffee?
Mixing them as-is would ruin the effect of Vantablack. Since carbon nanotubes are black you probably would get a boring grey color with a gloss surface due to barium sulfate.
I'm curious what the effect would be if you coated Vantablack with barium sulfate. A highly reflective surface with an extreme black paint underneath.
Flip from one side to the other to help maintain temperature by absorbing or reflecting sunlight.
https://en.wikipedia.org/wiki/Anti-flash_white
It was also used on interceptors like the Avro Arrow prototypes.
The Wikipedia page does say "The purpose of the colour was to reflect some of the thermal radiation from a nuclear explosion", as far as my experience goes polished metal can still get extremely hot.
A mirror would reflect light directionally, but white paint would seem to be diffuse.
Or said in another way, seeing a laser in a mirror might cause retinal damage, but on a white wall you would just see a dot. (although probably a speckly coherent dot)
For sale at: https://www.culturehustleusa.com/
WHY ARE THE COLOUR CRIMINALS BANNED?
Anish Kapoor & the creators of Vantablack for hoarding the material and for generally being rotters.
Dupont for the imprisonment of tech consultant Walter Liew for espionage, after he stole and sold blueprints for their secret titanium white process for over $30million.
T-Mobile & its parent company Deutsche Telekom for claiming magenta as their own and suing small businesses for using it.
Scientists at ISIS Neutron and Muon Source who are in the process of investigating polar bear fur, insect scales and fathers for industrial and commercial applications.
3M for their ownership of Canary Yellow.
Daniel Smith, for buying up the last reserves of quinacridone Gold pigment in the world, so that only they would be able to sell it to artists.
https://www.bloomberg.com/features/2016-stealing-dupont-whit...
https://sandrinemaugy.com/2018/04/30/the-final-batch-of-quin...
Bears are huge ferocious animals that typically live solitary lives and will kill you and your entire family while hardly breaking a sweat.
Keeping polar bears "like cows" sounds like some good comedy sketch material.
Also, injuries and even deaths from dogs are still quite common, and polar bears (and their hypothetical domesticated descendents) are a lot stronger.
https://www.dezeen.com/2017/07/07/anish-kapoor-banned-from-u...
> In response, UK-based artist Stuart Semple created a pigment that he claimed to be the world's "pinkest pink" and made it available to purchase on his website for "everyone but Anish Kapoor".
I love artists.
Q. Can I paint my car / bike etc...
A. NO - 3.0 is quite fragile and will just scratch off, it won’t weather well.
Q. Can I put a topcoat over it then?
A. NO that will destroy the matte effect, and many topcoats (including our COAT) will react with the paint and ruin the finish.
https://culturehustle.com/collections/black/products/black-3... (it's on the right hand side a few scrolls down the page)
I think I’ll end up removing the trim, masking the pieces I dont want to paint, and then hitting the chrome with Plastidip spray. It’s an aerosol can that contains a rubberized coating. It comes out looking like a matte finish paint but it can be peeled off of most surfaces so it’s not permanent.
The Culture Hustle blacks are also matte, which is very much a limiting factor (and part of the concept). I find if you're willing to accept highlights, super gloss black is way better at being super black everywhere that isn't a highlight. At that point you're trying to get the most localized highlight as possible, to get it out of the way so everywhere else can look blacker.
before: https://photos.app.goo.gl/usBMEYDRgykc2bni6
after: https://photos.app.goo.gl/89cyApVzncXWcHYt5 https://photos.app.goo.gl/zxnGMrcUrodM78Lq8
night (really just gone): https://photos.app.goo.gl/La1KNutxn3PhSEAg8
I'm not sure about the suggestion that people are going to paint their roofs with it. People already have the opportunity to paint their roofs with cheap white paint which would provide nearly all the benefits this would, and still choose not to do it.
> Commercially available white paints reflect between 80% and 90% of sunlight, according to lead researcher Prof Xiulin Ruan from Purdue, in West Lafayette, Indiana. "It's a big deal, because every 1% of reflectance you get translates to 10 watts per metre squared less heat from the Sun," he explained.
And yet it's hard enough even to do that.
do they get dirty fast in both humid and not humid climates? I would think in not humid, dry climates it might be more useful?
However you don’t need white to see significant benefit over a black roof, even just green helps.
Shovelling your roof with a flexible waterproof membrane can lead to gouges which defeat the impermeability. And one small leak can go unnoticed until it has seeped into the visible part of the house and rotted rafters and supporting timbers. Drainage on flat roofs get clogged and need to be cleaned or you end up with standing water.
A sloped metal roof will last for 30+ years without any maintenance. A flat roof of any type will require several maintenance operations a year and last half that unless you have a commercial tar and gravel roof which is heavy and imposes additional load bearing requirements on the structure.
One downside being that after a heavy rain, some fraction of the gravel makes its way down from the roof.
What looks great and what is not significantly affected by what are you used to see. In the place I've ground up galvanized steel roofing was common and I think it looks fine. But someone who used to dark roofs likely would tell that galvanized steel looks ugly.
That said, in the desert southwest and many places in the world, white roofs are common. I wish it were more common in the southeast...
In general I think a lot of energy savings can be realized by accommodating buildings to the prevailing climate, and using passive means of heating and cooling.
I'd never thought about ceiling height - that makes a lot of sense.
This is all known science but getting it cheap enough to be used as roofing is the trick.
In the summer, they shade the roof keeping it cooler.
In the winter, they provide an additional ventilation area that allows heat to escape without melting snow (thus mitigating risk of ice dams). Even a snow covered solar panel provides a benefit.
LMAO me I love living in the future. This sentence could’ve been lifted from the Hitchiker’s Guide to the Galaxy.
However maybe we could build a bunch of similar mirrors in the Earth-Sun L1 Lagrange point (reflecting light straight back at the Sun of course!)
But if you can grab the 20 million tons from asteroids, maybe it's achievable.
If you haven’t yet read Douglas Adams, I can highly recommend it.
[1] Golgafrincham: https://www.bbc.co.uk/cult/hitchhikers/guide/golgafrincham.s...
On another note, the building rooftop outside my office window was painted white, within 1.5 years its gone from from blinding white to a very dark gray, I am not sure this does much good over time.
Mirrors don't have to reflect very much, they have to reflect as a picture. That's why one-way mirrors work — people generally don't notice that the light mirrored is much less than 100%. White paint is free to reflect the photons in any direction, so that >98% is a harsher requirement on the share of incoming photons, but a laxer requirement on the photons' direction.
I'm talking about dielectric mirrors. Wikipedia suggests 99.999% or better reflectivity over a narrow range of wavelengths.
https://en.wikipedia.org/wiki/Specular_reflection
Paint reflects primarily with diffuse reflection. The rays of light are scattered in all directions:
What percent of the light does a mirror reflect in a specular way?
https://www.semrock.com/maxmirrors.aspx
Mirrors that are a cheaper coating on glass or metal can be in the 95% range without too much effort. If you don't care about actually forming an image with a mirror, it can be quite cheap, e.g., plain aluminum (with whatever oxide forms on its surface) or aluminized mylar film.
I’m sure there’s some good incremental improvements here but this is over the top marketing.
But.. the ultra-white paint, on a roof? Perhaps it will be ultra-white on the first few days. Rain, pollution, dust, smog, and a myriad of other particulates (esp. in an urban setting) will quickly render it off-white, and bring it on par with existing finishes.
Also, if this were that big a problem, it seems that solar panels would fail. It seems that rain often counteracts the pollution, dust, & smog items on your list, washing them off.
I'm not seeing a problem here that supports GP's implication that the new 98% reflective paint is somehow rendered useless vs existing extra-bright ~85% white paint, which already demonstrably works. It seems that the new paint would work better on any cleaning schedule, up to the point where the pollutants fully covered both surfaces. Am I missing something?
I imagine you can take a roof like that (say 80% albedo) vs a high-tech ultra-white (99.9% albedo), and the 80% roof won't degrade in reflectiveness because the sun naturally bleaches things to that level -- but the wear and tear of high-tech roof will bring it down to about the same.
Just musing here, no solid evidence to support this.
> “Our white is so white you can paint a chunka coal and you’d have to crack it open with a sledge hammer to prove it wasn’t white clear through.”
Of course, I'm not implying any connection to this 'whitest ever' paint, but the book is quite good.
So... Maxwell's demon?
Still, it's pretty cool.
The process of electromagnetic radiation is the inverse of electromagnetic absorption, and so what will happen here is that the sample will reach a state of thermal equilibrium with the walls of its container (or the 2.7K cosmic background radiation if we're in deep space) through the exchange of infra-red radiation. If it went to a lower temperature, we could create a perpetual motion machine by putting a thermocouple between the painted object and its container.
It is possible to cool some things with radiation, but that requires creating a state that is not in thermal equilibrium, which is not plausible for paint on a wall.
My uncle works at Tinker AFB in Oklahoma and always used to explain the different unique features of TACAMO [0] aircraft. Also, on a side note, he currently has his identical job he held in the air-force as a civilian and collects multiple pensions (albeit, he was always my "cool engineer uncle" who bought me my first soldering iron).
I've been following news about materials which reflect in this spectrum so much, that they effectively cool their surroundings, but I understand that this paint, while probably less effective, should be much cheaper.
Without that you can't really judge the news article.
If it does, it’ll only be really effective until the next cleaning... and then probably just as good as plain white paint.
What is novel is that they have discovered some new method for preparing the barium sulfate pigment and mixing it with the binder, which allows very small pigment particles, possibly having a certain form, and also a very large ratio between the quantities of pigment and binder in the paint.
https://arxiv.org/abs/2011.01161
The main points are:
1. The more common white pigment titanium white is not good for cooling something exposed to sun, because it strongly absorbs ultraviolet light. (Besides generating heat, this ultraviolet absorption also causes photo-chemical reactions that degrade in time the organic paint binders.)
2. So they have chosen barium sulfate, which reflects not only visible light, but also ultraviolet and near infrared.
3. Barium sulfate not only reflects solar light, but it also emits efficiently in the far infrared, which cools the painted surface.
4. Barium sulfate was traditionally considered a worse white pigment, because it has a lower refractive index than other pigments, like titanium white.
5. The Purdue University team has overcome this disadvantage of barium sulfate by designing a manufacturing process for the pigment that not only ensures a very small average pigment particle size but also a broad distribution of the particle sizes, which results in good reflection properties over the entire solar spectrum.
The notion of painting roofs white to increase albedo is an old one (look up "Whitecap", which I was familiar with about 30 years ago). And the practical limit is of behaviour in the environment: dirt, grime, damage (hail, wind, birds, insects, ultraviolet light, etc.). It's unlikely that a "whitest white" substance will also be optimised for those characteristics.
But a durable, easily-cleaned, reflective surfacing material could prove useful.
It's all but certain that the actual applications for this material won't be as roofing. At least not for standard construction.
The problem with such paints or coatings is that they don’t perform well over time outside of a clean room environment. On a roof this 98% would likely only exist for 1.2 microseconds. Dust, dirt, aging an bird shit will make sure of that.
Climate change? Oh please. Ridiculous.
It would be a waste of money on multiple fronts:
- Super-reflective materials and coatings already exist.
- They don't perform well at all outside of very well controlled environments.
- To repeat myself, the idea that reflective roofs are going to even represent a rounding error in the climate change equation is nothing short of delusional.
They might even cause more harm than good.
- And then there's the same set of questions that should be applied to every single magical climate change solution: How much CO2 will be produced making it? How much energy will it take? How many other pollutants are we going to generate and disperse? What is the resource equation for the entire life cycle, from manufacturing, through application, maintenance and eventual replacement?
"...only need to paint 1% of the Earth's surface..."
In the apartment I rent there's a huge 1.5x1.5m ceiling window for letting the sun in. In addition to huge 2m-high windows. The number of buildings not suitable for the present-day climate is astonishing.
https://news.railbusinessdaily.com/a-reflective-perspective-...
https://www.smithsonianmag.com/smart-news/first-blue-pigment...
Musou Black has a slight edge over Black 3.0.
https://www.ko-pro.black/2020/05/14/black-3-0-vs-musou-black...
I also wonder if some arrangement of perfect mirrors could act as a sort of light storage mechanism (battery)
From rockets, the reason white paint is often higher performance is that, while it has lower reflectivity than a mirrored surface, it has higher emissivity.
Between the performance, the lower cost of white paint as opposed to a mirror finish, and the curb appeal, I doubt more than a few people have clad their house in mirrors.
> I also wonder if some arrangement of perfect mirrors could act as a sort of light storage mechanism (battery)
I don't know, but I suspect that mirrors just aren't reflective enough for this to be practical.
Sure, using the energy for solar would be nice too, but that’s far more expensive per square meter, so paint is a fine solution that’s cheap.
By reflecting white light back through the atmosphere, rather than absorbing light and re-radiating heat (infrared) wavelengths, more energy can be transmitted back through and out of the atmosphere into space. Air, and specifically the CO2 and other greenhouse gasses in it, are relatively opaque to infrared light, so that is trapped.
In areas with high cooling loads, offsetting heat before it can enter into structures has benefits. This is reflective rather than insulative blocking, and is quite effective.
Solar panels are of course useful, though expensive compared with even specialty paints. They also convert most of the incident sunlight to heat (only about 10-20% is typically converted to electricity), which is re-radiated into surroundings. Again, typically this isn't a major factor, but it could well be worthwhile painting surfaces not covered with PV arrays white, especially in warm climates and high-solar-incidence regions.
I have my doubts whether this specific paint's characteristics are all that meaningful in a real world with dust, dirt, grime, and bird droppings. But the underlying idea is valid and has been used in similar technologies and deployments.
You know what's big, white and help with climate change ? The ice caps we're destroying. We won't replace them with paint
Painting 1% of the world in white paint is everything but that.
It's a cool gadget that will be experimented in a few niche places and quickly and quietly abandoned when real life kicks in.
How often will it need to be cleaned ? repainted ? How much will it cost to paint your building's roof, is you building roof even paintable in the first place ? What is the paint made of exactly ? Is it going to leak in the environment ? How much energy/resources are needed to make/transport it ? What impacts does it have on a multi storey building ?
Time will tell but I bet it's going to end up in the same bin as the "massive lithium battery breakthrough" news. /reminder 10 years
They've been talking about this since at least 2005 by the way. Good old hype cycle in effect:
https://www.osti.gov/servlets/purl/10172670
https://www.bbc.com/news/10333304
http://archive.iwlearn.net/unep.org/paint4planet/default.htm
https://www.theguardian.com/environment/2009/jan/16/white-pa...
Are double pane windows, solar panels, and insulation also gadgetry hype?
There are really no disadvantages of using this as a white paint.
Barium sulfate is abundant and the cost of a paint based on this pigment should be very similar to the cost of the current titanium white based paints, once the pigment is produced at industrial scale using the process developed by this team.
There are no environmental concerns, because barium sulfate is as inert as titanium dioxide. Actually there are various living beings which use barium sulfate as a bio-mineral, instead of the more frequently used calcium salts, like in our bones.
So both in cost and environmental properties and also in maintenance properties the proposed white paint should match the currently used titanium white paints, with the difference that it can ensure that any painted surface exposed to solar light is cooled instead of being heated.
Only this will certainly not be enough to save the world, but it will certainly be a useful product.