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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."
Parent isnt exactly offtopic, he is trying to state that his digestion problems produce a noxious gas.
According to the article, after the carbonate runs out after about 5 years in a heavily polluted city, "the titanium dioxide will continue to break down NOx, but the acid this produces will discolour the paint."
Doesn't sound very good.
HCG 50a = 2MASX J11170638+5455016
11h17m06.4s +54d55m02s
In goes noxious gas (pun intended) and out comes a weak acid. Put a ring of limestone gravel or pavers around the base of the building and even that would be neutralized.
Of course the bigger question is if this paint and other materials like it are cheaper then catching the gasses closer at their sources, or at least ensuring those sources aren't so close to folk's lungs and other living creatures not appreciative of such.
I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
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? No. Would you rather breathe toxic chemicals or have them in wash into the ocean?
:-)
It won't cause acid rain because the acid will be washed into the sewers and flow out into to the ocean, or enter the soil. The problem with acid rain is that the acid frees the aluminum into the soil, causing it to wash into lakes which kills all of the fish in the lake. However none of the acid that isn't neutralized will do much damage since this will be used in already polluted areas. Again, most of the acid will end up in the oceans.
So it either causes acid rain, or it cleans the environment?
Bottom layer is an acid-sensitive primer, top layer is Ecopaint. When the buffering capacity of the Ecopaint is exhausted, the acid works its way down to the primer, which de-bonds. When the Ecopaint is peeling, it's time to power-wash and put on a new coat.
Time is Nature's way of keeping everything from happening at once... the bitch.
> What happens when the paint is saturated?
...and the stuff that gets produced isn't stuck in the paint (and so can be washed away).
it doesn't become saturated. it seems it can wear out, however.
the article states:
The particles absorb ultraviolet radiation
in sunlight and use this energy to convert
NOx to nitric acid.
which means that the titanium dioxide particles must do some sort of combining with the NOx. there's a finite number of particles, and so the paint would have a lifetime, estimated in the article to be about 5 years for a "typical 0.3-millimetre layer".
> "The acid is then either washed away in rain,
and yes, that sounds worrisome. washed away to where?
Time is Nature's way of keeping everything from happening at once... the bitch.
The Titaninum oxide is a catalyst, so it is not consumed. The calcium carbonate is just there to neutralize the acid that is produced on the catalyst. So, the paint will never get sauruated with acids. I'll bet that they catalyst will keep working without the calcium carbonate & that the resulting nitric acid will just wash off, probably into some nearby concrete, which aso has a lot of calcium carbonate to neutralize the nitric acid. Besides, a little nitric acid isn't all that bad as a pollutant... you can safely wash it down the drain.
Think global, act loco
Well, you could start by RTFA. The titanium breaks down the gasses into nitric acid that is converted to harmless carbon dioxide, water and calcium nitrate by carbonate particles. These are then washed away by the rain. When the carbonate particles break down (five years in heavily polluted areas), the paint will keep converting the gas to nitric acid that still washes away.
Sounds like a great idea to me.
The titanium dioxide is a catalyst. It catalyzes a reaction between NO2 and water to produce nitric acid, HNO3. This reacts with calcium carbonate, CaCO3 (basically chalk) in the paint to produce water, carbon dioxide, and calcium nitrate:
CaCO3 + 2HNO3 -> H2O + CO2 + Ca(NO3)2.
The titanium dioxide is not consumed in the reaction, but the chalk is, and when it runs out, your paint fills up with nitric acid, which is not good. However, the reaction that causes the formation of nitric acid happens at a slower rate on its own, it is one source of acid rain.
Calcium nitrate is not noxious; it's basically fertilizer. However, too much nitrate runoff will cause problems with excessive algae growth in water, which can drop the oxygen level low enough to kill fish. Just the same, there's a lot more nitrate runoff from farmers and lawns than you're likely to get from this stuff.
Just for the record, calcium carbonate (yes, it's the same stuff Tums is made of) is actually a buffer, not a base. Go grab yourself a litmus strip and several Tums. Crush the Tums up and dissolve them in a cup of water. Play with the litmus enough to convince yourself that your solution has a pH of 7.
But, yes, it does neutralize acids. Bases, too.
Yes, and monkeys fly out of my but. Are you listening to Bush's scientists?
Hey, I even provided you a couple of links to check out to verify the claim.
Don't be so lazy. The information is out there.
And you should learn to separate politics from science. The two don't mix.
No, it doesn't literally absorb gas.. It breaks NOx down with solar power and releases it as "carbon dioxide, water and calcium nitrate, which will also wash away."
I'll go point by point for your list, starting with cars and trucks (which are identical to SUVs in the eyes of the Govt), then going down your list:
cars: increased safety requirements (full passenger cage), increased CAFE (Corporate Average Fuel Economy) restrictions
Trucks: lesser safety requirements (no passenger cage, body is a rigid steel frame with an engine and wheels), decreased CAFE restrictions to be leniant to the numerous companies that use them for work-related activities (which is fine by me).
SUVs: same as trucks, many are built off the same frames and do not offer the same protection as cars, but are "safer" because they are larger.
mini-vans: newer than 1996 falls under same safety and CAFE statndards as cars.
full size vans: same restriction as trucks due to business usage, also built on truck frames.
RVs: Recreational vehicle, same as trucks and actually have lesser safety restrictions. Higher ad valorem taxes due to pleasure usage only.
semi trucks: higher safety standards than trucks (regulation on license, stringent inspections, etcetera), CAFE standards are more lenient due to commercial usage
buses: same as semi trucks, except school buses which are actually inspected as little as feasible on many occasions due to county control and wavers.
Hammer of Truth
Please, do not spread this FUD.
.au only deploy above 60km/h because they expect the seatbelt to be doing it's job keeping the occupant in the seat in minor impacts. Airbags in the US deploy a lot slower because they can't predict whether someone is using a belt or not. Anyway, airbags only deploy so far into the cabin - make sure you're not hurtling unrestrained towards the windshield and you'll be fine (if a bit shaken / bruised).
;-)
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!
Wear your damn seatbelt. Airbags in
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.
Antilock brakes allow you to steer your way out of (and possibly avoid) an impending accident. Most people's reflexes are to keep pressing that brake pedal until you stop. Train yourself away from pumping the pedal - ABS can pump that pedal a lot faster than you can. They are also multi-channel, and can yield considerably more braking effort from each wheel than you, eg two wheels off the edge of the road on dirt. So unless you have four brake pedals in your car, you , by yourself, have very little chance of getting a shorter braking distance than your antilock brakes can. (Yes, special circumstances apply).
I would buy the car with ABS and airbags, because those two technologies would significantly improve my chances of survival in day-to-day driving.
And here ends my little rant for the day
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
It's interesting to note that an experimental technology involving the use of very fine titanium dioxide powder has been selected to purify water. The water is recirculated in a fountain so that it is exposed to lots of light- ultraviolet catalyzes the decomposition of select contaminants in the presence of the otherwise inert titanium dioxide, producing non-toxic byproducts. It's CHEAP, safe, and effective- but nobody wants to do it, since the technology is still in the experimental phase. Company XYZ isn't willing to pay $millions to try it when there are proven (if more expensive) techniques for doing essentially the same thing.
And I'm a firefighter, too. And a chemist. Too many hats to wear these days.
it in some way offers an alternate reaction path that is more favorable. Some catalysts work by providing a surface to which the reactants stick. I suspect that is what is happening here since making microbeads of titanium dioxide would maximize the surface area and thus the potential catalytic effect. By definition catalysts are not used up in the reaction that they catalyse.
My only political goal is to see to it that no political party achieves its goals.
Well...titanium dioxide is widely used in paints already...it certainly beats lead, though it can be considered a mild health hazard:
titanium dioxide
Calcium carbonate, even in large quantities in dust form is not considered more hazardous:
calcium carbonate
-Tupshin
1. The titanium oxide is just a catalyst as many other d-group metal oxides do (e.g. vanadium (V) oxide).
It combines with the NOx molecules in the start of the reaction (as well as other reactants, e.g. H2O), the NOx molecules then combines with the H2O to form nitric acid. When the reaction completes, the titanium oxide molecule detachs itself from the nitric acid and is ready for the next reaction.
In theory, the oxide shouldn't get consumed in the reaction, it just serves as a reaction site for the reactants.
What is finite in the paint is the calcium carbonate. When it is completely consumed, instead of emitting carbon dioxide and the like, nitric acid will be washed away from the paint layer.
2. The acid will be washed away into the soil and the ocean.
The paint doesn't harm the environment this way tho, since NOx gases in the atmosphere will eventually combine with water in the air to form nitric and nitrous acids anyway. Which will also end up in the soil and in the ocean.
Ironically this process is essential in Earth's nitrogen cycle. The problem is we're having too much of it now.
The smog that most people care about is ozone: ozone is formed from a cycle involved NOx, VOCs, (volatile organic carbons), light, and the hydroxyl radical (OH radical).
NO2 + hv -> NO + O
O + O2 -> O3
NO + O3 -> NO2 + O2
which would be a closed cycle, except you can skip the last step by doing:
NO + RO2(rad) -> NO2 + RO(rad)
where RO2(rad) is a result of the reaction of VOCs and OH(rad).
So taking NO2 out of the cycle will be great for reducing ozone production.
And yeah, the problem is not only that it is easy to make NOx with combustion, but that the more efficient your engine (in terms of burning less fuel for the same energy) the more NOx it produces (usually).
-Marcus
The paint converts NOx to nitric acid (HNO3), rather than simply adsorbing it (which would quickly make the paint "full" and leave it useless). This conversion depends, as the article says, on ultraviolet light, water, and oxygen (it's an oxidation reaction, there's gotta be somewhere for electrons to go). Now, I dunno about you, but there's not much UV light in my lungs, so it's not likely the particles would work too well inside me.
This is aside from the fact that the particles themselves may well be active enough to trigger an immune response or mechanically abrade lung tissue. Plus there's all those wonderful paint vapors, as you pointed out.
Maybe instead you should look for a shirt with fiber that entrains/encapsulates similar particles - might work nicely as long as you wear it in the sunshine.