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Nanotech Coating Prevents Fogging
MilSF1 writes "MIT scientists have applied for a patent on a coating process that reduces or eliminates fogging on glass surfaces (car windshields, eyeglasses, etc). The new coating was described today at the 230th national meeting of the American Chemical Society."
Ever wanted a shave in the shower but your hand-held mirror fogs up? Rather than buying this patented glass you can resort to a low-tech solution: Rub a little shaving foam over the glass and the wash the excess off so you have a thin, clear, greasy film on the glass.You'll find that the mirror no longer steams up.
The reason this works is because the greasy film causes much larger drops to coalesce on the mirror than you would normally get. These larger drops don't refract the light nearly and as a result are essentially transparent. This simple trick allows me to insure my sideburns are the same length even when under the most horrendous time presure.
See, who says that Physics can't be useful in everyday situations?
Simon
XP + Nanotech coating = Transparent Windows! Probly explains the long delay in releasing LongHorn...
If you keep throwing chairs, one day you'll break windows....
And want a cheaper solution for keeping your bathroom mirror fog free, before you get in the shower/bath/whatever, rub some shaving foam into the glass. not alot - about a cm^2 blob. then rub with a very damp cloth so it dissapears and u can see your reflection.
Have the shower!
Get out, go to shave, and voila! No foggy window!
This nanotech gaff will definately work wonders in the car. Hey, it will mean I wont have to bust my gut when I get in having to clean every window of fog while my gf drives. now that I mention it, I should really learn to drive...
I won't believe any of this until there is a Podcast released on it.
The people who make rain-x, which works rather well itself to deflect rain, also make fog-x, which I've tested on a steamy bathroom mirror, and it works perfectly.
According to TFA (not that I expect people to actually read the thing):
So far, the coating is more durable on glass than plastic surfaces, but Rubner and his associates are currently working on processes to optimize the effectiveness of the coating for all surfaces. More testing is needed, they say.
It was a joke! When you give me that look it was a joke.
MIT scientists have applied for a patent on a coating process that reduces or eliminates fogging on glass surfaces. The new coating consists of a highly acidic chemical that melts the glass into a thick green goo. While the glass (now known as green goo) possesses none of its original qualities including transparency, it has also been shown to provide a 5% or greater resistance to fog.
I'm a big tall mofo.
...they simply spit in their masks to prevent fogging.
One of the worst things about wearing glasses up north is the fogging.. being outside in -25c temperatures for even a few minutes and glasses get cold enough that they fog up when paying for gas, or shovelling snow, etc.. pain in the ass. I welcome this new technology :)
May be this will finally replace the old method of spit and rinse, because all those special glasses on the scuba masks had no effect until now. For those who don't know, if you want your scuba mask to be perfectly clean of fog, you have to spit inside it when it is dry, then rinse very fast with sea water (just to make the glass clear enough but probably without rinsing all the substances in the saliva from the glass) then put it on the face and dive immediately. For those who forgot doing this, even the best tempered glass became foggy in a few minutes in cold water.
"My crew chief applied a coating of Drene Shampoo to the windshield. For some unknown reason it worked as an effective antifrost device, and we continued using it even after the government purchased a special chemical that cost eighteen bucks a bottle."
Basically, they take a glass/plastic mix of microscopic particles, coat the glass and then subject it to high heat, making a glass sponge (Very simplified explination).
I always think of nanotech as something more novel. If this were thousands of billions of tiny squeegee bulldozers one micron across moving the water to the edge of the glass, then I'd consider it nanotech.
The simple truth is that interstellar distances will not fit into the human imagination
- Douglas Adams
I guess not.
Humidity is still there - just not in the form of little droplets.
gtkaml.org
Because most of the light that does not pass through the glass is not "absorbed" inside the the glass but instead reflected at the air/glass and glass/air boundary layers.
Coating glass with stuff to minimize the reflection is a really old thing. Ever wonder why the lenses of (good) binoculars seem have a bluish or reddish tint to them ? Because they're coated to increase light transmission.
Their claim is valid. Anytime light passes through an abrupt change in the index of refraction (e.g., from air to glass), a percentage of the light it reflected back. That's why you see a ghost image of yourself in even "transparent" pieces of glass. On ordinary glass, about 4% of the light is reflected (removed) by each air-to-glass or glass-to-air interface (8% for each pane).
Adding a anti-reflective coating that has an intermediate index of refraction can reduce this. Nonlinearities in the reflection process mean that two interfaces of lesser change reflect far less than one big change. Camera lens makers do this all the time because many lens have 6 to 20 pieces of glass and thus a dozen or more interfaces that each would to attenuate light and create multiple internal reflections between the lens elements.
It may not be much, but that antifog coating probably lets a couple extra percent of the light through.
Two wrongs don't make a right, but three lefts do.
I'm not a raging anti-patent looney screaming about the need for a free utopioan society, but if funding for this was provided by the public, surely the results belong to the public and the methods belong in the public domain rather than to MIT for the next 17-34 years.
woof.
Why spend money on a coating for the glasses when there are several solutions readily at hand? 1) Don't eat junk food. 2) Wash your nasty hands. 3) Wear gloves.
-William Brendel
Just the other week I was nearly driven crazy by a layer of fog that had snuck in-between the two lenses of my ski goggles. It took several days of sitting them next to a heater before the problem was fixed. Presumably this couldn't happen with totally fog-free lenses.
It's not just glass that fogs up though. Despite the /. story suggesting that this coating is only for glass, TFA says that this coating can be applied to "virtually any surface", which is great news for motorcyclists with plastic visors that always fog up on cold/wet days. Normally when it is raining, I have three choices,
1. Closed visor, it fogs up within minutes - Can't see a thing.
2. Visor fully open (nothing to fog), subjected to a face full of fast moving water droplets - can't see a thing.
3. Visor open slightly, air can circulate, visor doesn't fog, but water droplets form on the inside of the visor, which severely reduce visibility.
Which reminds me: we need a coating for monitors that prevents greasy smudges from morons pointing at the screen. A thin metallic film with a 10 kV feed would be good.
So did MIT do their background research before starting this patents application?
Those products appear to be using (a) an attachable "sticker" or (b) a spray. Neither of which I would call particularly permanent. Anti-fog coatings (in general) have been around for years. The concept of applying them at manufacturing time using the particular process detailed in TFA is presumably the novel basis on which they are applying for a patent. If not, one would hope the Patents office will deny them the patent.
From TFA:
"The team has developed a unique polymer coating - made of silica nanoparticles - that they say can create surfaces that never fog."
"Some stores carry special anti-fog sprays that help reduce fogging on the inside of car windows, but the sprays must be constantly reapplied to remain effective."
So yes, I'm guessing they did do their background research. Did you, before posting? For example, by reading TFA?
I don't know why they're bandying the term "nanotechnology" around, because it's not. It's a silica coating that prevents fogging. In fact, the only reason this made it to slashdot is because the term "nanotechnology" was used in the title of the original press release. You'd think the people at MIT and the ACS would know better.
This does not meet those criteria.
What is humor if not pain tempered by time?
And if you wish for a slightly higher tech solution, your local auto parts store sells a product called Fog-X which when applied to glass, prevents fogging.
An engineer named Richard Hartman developed antifog glasses for whitewater kayaking based on this concept several years ago. He developed a hydrophillic coating that was baked onto the lenses, and which prevented the formation of fog droplets. He even offered them for sale for a time--send him your prescription and he would send back a pair of glasses. I don't think he does that anymore.
Here is a recent post describing his work.
Here is a post from 2001 answering some questions about the glasses.
Here is a search on the Boatertalk forum for most posts about it.
Build a man a fire, he's warm for one night. Set him on fire, and he's warm for the rest of his life.
Rain-X is quite destructve on the plastic visor ... and it is not made for anti-fogging. Says so right there on the bottle.
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is it that bad seein a hot chick again? if i see a hot chick walkin down the hall i dont say "repost"
Speaking as an MIT student working on this project, yes it lets more light through- a lot. Uncoated silica reflects about 8% of incident light, as was posted elsewhere. With our coating, this drops below one percent through most of the visible spectrum, and below .2% at a peak wavelength dependent on the number of coating layers (around 550nm for a 14-bilayer coating). It's a pretty nice improvement- you can place a half-coated slide against white paper and the untreated side looks dirty by comparison. I can try to dig up the spectrophotometer measurements I took a few weeks ago, if anyone cares that much.
/.ed. Party in lab today!
Also: Whoa, Rubner got
http://www.cyclegadgets.com/Products/product.asp?I tem=FC
These things are sweet. They don't fog, period, and if you get the UV reactive one, it darkens in sunlight so you don't need to carry two shields. It's not quite as dark a real reflective shield, but it's dark enough.
They make an anti-fog product sold under the Rain-X brand (in a black bottle, generally). It doesn't work very well on glass, and is just as safe on plastic as steel wool. :)
FWIW, my full-face helmet has a little vent on the front below the mask, and a shield over my nose that keeps me from breathing right on it. The combination seems to work fairly well as long as I'm moving. It's a Bell Sprint, and I'm fairly happy with it (in combination with a mirrored face shield, for occasionally riding off into the sunset). Their website sucks - as you can't link directly to a product, it uses Flash, and they don't even list that they have different face shields - but most any non-Harley "powersports" shop I've been in carries their stuff.
I have a product called FogX that I've been putting on the inside of my car windshield for years. No fog, no hassle, low cost. I've also been applying it to bathroom mirrors and such. Am I completely missing something, or is this not exactly a breakthrough?
This is great news for slashdotters. Now when you're making out with your girlfriend in the backseat of the car ... oh, wait. Never mind!
Firemen and HAZMAT workers have to open a 'de-fogging' vent on their SCBA's to dissipate fog from their facemasks, wasting air. This coating could add minutes to a workers time on scene.
It seems to me that people have all kinds of solutions to keep surfaces from fogging or to make the water that does condense on the surface to remain clear. However there are two things that seem to be difficult to do with any of these solutions.
They are to make the solution permanent and durable and...
To make the solution of a material that will not distort your vision when looking through the surface of the material.
So yes, you could apply rain-X every month or wipe shaving cream on your surface or even make sure the surface is vented or heat the surface. However having a permanent coating on it that prevents fogging and makes it easy to see through is the best solution.