Smog Busting Paint Breaks Down Noxious Gasses

jlechem writes "New Scientist is reporting a story about a new paint that can absorb noxious gas. According to the article the new paint is called Ecopaint. The substance is designed to reduce levels of the nitrogen oxides, collectively known as the NOx gases, which cause respiratory problems and trigger smog production. The paint's base is polysiloxane, a silicon-based polymer. Embedded in it are spherical nanoparticles of titanium dioxide and calcium carbonate 30 nanometres wide. Because the particles are so small, the paint is clear, but pigment can be added. The first paint to go on sale will of course be white."

Comments

Saturated?

[dolo666]

Sure this sounds like great news. Here comes the science...

What happens when the paint is saturated? Sure it works to a point, but will additional coats of paint over revitalize production, or are we looking at a long term problem when the paint fails and begins soaking up noxious chemicals that could leak and cause a really nasty effect on the environment? Furthermore, did anyone read this sentence in the article and become slightly shocked? "The acid is then either washed away in rain, or neutralised by the alkaline calcium carbonate particles, producing harmless quantities of carbon dioxide, water and calcium nitrate, which will also wash away."

So it either causes acid rain, or it cleans the environment? :-)

Re:Saturated?

[rasafras]

I don't think it could possibly do more harm than is present. After all, if the NOxes aren't in the paint, they're in the environment around it. It may concentrate them more, but I would imagine that it shouldn't be a problem. If I recall correctly, soil actually has micro-organisms capable of breaking down these chemicals. It sounds like a good plan to me, but like many others, I fear that it won't get enough of a push to catch on in the mainstream.

Re:Saturated?

[gcaseye6677]

Why the hell does everyone focus on SUVs as the only vehicles that pollute a lot? How about mini-vans, full size vans, pickup trucks, RVs, semi trucks, delivery trucks, and people who just drive a lot? Don't they pollute as well?

People who hate SUVs hate the typical 'SUV lifestyle' more than they hate pollution itself. Some SUVs are actually more fuel efficient than some cars.

Besides, would these people really want the government deciding what size vehicle they get to drive?

Re:Saturated?

[realdpk]

The reason people are upset about SUVs is that the folks who buy SUVs are using them to do activities that would be better done in higher fuel-economy cars, most of the time. That is, going to the grocery store, going to/from work, etc. It's incredibly wasteful.

They're not complaining about delivery trucks and etc is because very few people drive those. They're a smaller problem, relative to the benefits their drivers receive.

Re:Saturated?

[Chainsaw Messiah]

Yeap, SUVs are a political issue not an enviromental one. Apparently the standard of living in the US is such that people no longer have to worry about their own lives, they can now spend all their time telling other people what they should be doing.

Re:Saturated?

[Dashing Leech]

Aren't trucks and buses responsible for most of the particulate emissions

That might be true on a per vehicle basis, but not likely on a total pollution output. Still, it's missing the point. It's not like the bus drivers and truck drivers can do the same thing with a fuel-efficient car. The size and carrying capacity of those vehicles are required to do the things they are doing, and indeed improvements in fuel efficiency for buses and trucks is desirable even by those who use them. The thing stopping these users from being less polluting is (a) technology is just making such options available now, and (b) more efficiency is expensive (for them). So they may pollute, but there is reasonable justification.

SUV's on the other hand, are entirely unnecessary for most of what they're used for (commuting, groceries, etc.). These things are better done in more fuel-efficient cars, which are actually cheaper. This is the opposite of the bus/truck problem, economics should drive SUV drivers to cheaper, more fuel-efficient cars. It's mainly status symbol, machismo, whatever, that generally keeps them from getting "better" vehicles. The difference with SUVs is that there is no reasonable justification of why they are necessary in most cases. (Yes, sometimes they are necessary and justifiable, but that usually involves living in rural and snowy areas.)

I'm no anti-SUV zealot, but there is clear reasoning why (most) SUVs are bad and unnecessary. Some SUV owners use the "stop telling people how to run their lives" argument, which is basically equivalent to saying "I should be allowed to blow cigarette smoke in your face if I want to, it's a free country". Pollution, health, and effects on environment are everybody's concern.

Could this be used on pollution sources?

[catscan2000]

Could this paint also be applied directly on pollution sources, such as on the inside of car tail pipes or the inside surface of smoke stacks?

That would seem like a more logical place to apply this paint, though applying it to roads and other surfaces probably doesn't hurt, either.

What about noxious gasses in production?

[Fex303]

I'd be interested to know if this paint can neutralise as much pollutant as is generated in its production.

I seem to recall TO2 being a fairly nasty chemical to produce, using lots of Chlorine in production, etc. (Of course, high-school chem was a while back...) Is using the paint a net benefit to the environment? If not, what's the point?

It doesn't get saturated

[Dark Lord Seth]

In a typical 0.3-millimetre layer, there will be enough calcium carbonate to last five years in a heavily polluted city, says Robert McIntyre of the British company Millennium Chemicals, based in Grimsby, Lincolnshire, which developed the paint. When the carbonate has been exhausted, the titanium dioxide will continue to break down NOx, but the acid this produces will discolour the paint,

If you read the article you'll see a nice and practically useless image where it shows that NOx is broken down to harmless stuff like water and oxygen. Don't ask me HOW exactly. Anyways, once the calcium carbonate runs out, the nitric acid will not be nuetralized. ( good read up on a chem textbook regarding bases ( like calcium carbonate ) and acids, especially how they affect eachother ) Having a whole load of acid building up inside your paint isnt a good thing but according to the article it will just discolour the paint. While the Titanium Oxide will happily continue to absorb more NOx and thus create more acid.

So basically, nowadays you have to paint once every 5 years because the smog attacks the paint. Now you have to paint once every 5 years because the paint attacks the smog.

Re:Paint that *causes* corrosion?

[Night Goat]

Naturally, you wouldn't use this paint on things that it would corrode. I don't think this is something to lose sleep over- the paint would have its recommended uses and warnings on the label of the paint can.

I agree with some of the other posts before me though: is the benefit of reduced nitrous oxide in the air outweighed by the other possible environmental dangers? I hope this goes through a lot of testing by independent groups before it hits the market.

Re:Paint that *causes* corrosion?

[JoeBuck]

They mix in calcium carbonate to neutralize the acid. But the article says that the calcium carbonate runs out in about five years, and then the acid discolors the paint (and presumably corrodes whatever is under it).

The calcium nitrate will eventually run off into the nearest body of water, and excess nitrates in water cause algal blooms and can kill off fish. However, I doubt if the amount of nitrates from this source will be significant compared to the large amount of fertilizer runoff.

Re:And allegedly...

[EvilTwinSkippy]

And don't forget Aluminum wiring. Works great... until the aluminum oxide builds up on the electrical connections.

Hey, and that crap they threw into gasoline, yup that was safe.

Asbestos was a really nice fire retardent material. Too bad it had a tendency to create dust that causes lung cancer.

And to cap it all off, let's have 3 cheers for air bags and anti-lock brakes. If you are a small-fry like my wife and myself, you too can be killed in a 10mph impact by a piece of safety equipment! Anti-Lock brakes, they actually increase breaking distance and if you pump them (like anyone over the age of 26 was trained to do) you are screwed.

You really start to understand why people in ages past were so resistant to change.

Environmental Problems

[yintercept]

The fact that the paint is trying to address environmental problems will probably make people have even greater worries about what chemicals it puts into the ground water etc..

People should realize that all paints and coatings end up in the environment.

I admit this is intriguing science. The most interesting thing about pollution reducing coatings to work, there will need to be a unique formula for each city. I live in a city where the worst pollution days happen in the dead of winter with temperature around 30 degrees farenheit. Other cities get bad during the heat.

It is an interesting science, but not a one size fits all science.

Re:crazy

[tupshin]

RTFA...the substance actually breaks down the NOx molecules, converting them into a relatively harmless form:

The polysiloxane base is porous enough to allow NOx to diffuse though it and adhere to the titanium dioxide particles. The particles absorb ultraviolet radiation in sunlight and use this energy to convert NOx to nitric acid.

The acid is then either washed away in rain, or neutralised by the alkaline calcium carbonate particles, producing harmless quantities of carbon dioxide, water and calcium nitrate, which will also wash away.

-Tupshin