Camera Flashes Kill Nanotubes

Fnordmonger writes "New Scientist is running a story claiming that flash photography can cause nanotubes to explode. Basically , the carbon absorbs heat, which cannot be dissipated. Instead, the energy is released in an explosion. There is a cool video there of the stuff going off."

Comments

Space Elevator?

[Matey-O]

So we've build this elevator to space....but nobody can take a picture of it. :P

new ignition source?

[Lumpy]

This could be a cool way to make a simple sealed emergency fire starting device for survival equipment companies...

Think about it.. get a pile of wood and twigs, set device in middle press button, get away..

Oh wait... a bic lighter might be a better idea...

nevermind

Not as bad as it sounds

[Athyra]

This is a more positive development than the headline implies. First, since double-layer nanotubes won't break, they now know how to keep them working if needed, and second, this now allows them to have a trigger action to set things in motion during complex sequences.

Personally, I'd like to see Milton Bradley take advantage of this and update Mousetrap. Turning the crank woud now release the ball, causing the little man to land on the flash button, breaking the nanotube and releasing the mousetrap. Of course, setup would just suck. :-)

Obligatory Simpsons

[Anonymous Coward]

This isn't news. Bart found this out when he visited Itchy and Scratchy Land and fought robots powered by nanotubes

Dexters Labratory

[Odinson]

"Dee Dee, what did I tell you about comming in here?"

"Look Dexter, I got a new camera, isn't it cooooool??"

*-FLASH-*

"Dee Dee, You are a geeeniuuuuss!"

Circa 2030

[Kibo]

AMD's C4 Featuring a new nanotube superconducting core.

Extream case mods have graduated from hobby to a high risk sport lauded in Mountain Dew commercials.

Read the article, thanks!

[manual_overide]

Firstly, only the single sided tubes exhibit this behavior. So building things out of multiple sided tubes is still viable. Next, they absorb the light of the flash because they are black, but can't dissipate the heat out fast enough when there are a number of them bunched together because the heat from one nanotube gets absorbed by another, and so on. Think of it like dissipation interference.

Re:Read the article, thanks!

[caesar-auf-nihil]

After reading the article, there is still a lot of questions regarding the mechanism of nanotube degradation.

One question that comes to mind is the wavelength of the light produced by the flash. Some materials are stable to some wavelengths, but fall apart under others. The wavelength of that light may have been just right to exite the electrons in the bonds of the nanotube and cause them to break.

I think we need to look at the structure of the nanotube itself. The single-wall nanotubes have a huge amount of bond strain, and therefore, are somewhat unstable already. What lends support to the heat dissipation arguement is the structure similiarity between the carbon nanotubes (high strain) and graphite (low-strain). Graphite and carbon nanotubes both conduct electricity well, but both are thermal insulators. Graphite however, has no bond strain or instablity, and glows upon heating (releasing the excess energy as light). What I think happens with the single wall nanotubes is not just heat dissipation.

Since the nanotubes have a lot of bond strain due to their structure, they have a lot of energy built into the structure. However, those strained bonds can be easily broken by putting in enough energy to break them. Once the bonds break, they release bond strain, and therefore, the energy built into the structure. So, its not just heat dissipation, I think what we're seeing here is that intense light is powerful enough to break the bonds in the carbon nanotube, and once that happens, the bond strain energy is released catastrophically, thus causing the explosion/ignition. So each nanotube explodes at the same time, not one leading to another.

All that being said, this may be the first example of a light-detonated organic chemical degradation. Most are heat generate or shock generated (kinetic energy). Light is almost unheard of. Very interesting result.

Re:Can't dissipate heat?

[MarkusQ]

If you heat an issolated something uniformly it doesn't matter how well it conducts heat; heat only flows if there's a gradient (in this case, that implies someplace else (that wasn't flashed) to dump the heat).

-- MarkusQ

Re:What's that?

[rusty0101]

A nano-tube is what you get when you start with a bucky ball, split it in half, add carbon atoms between the hemispheres to build a cylinder with a hemisphere at each end. that would be a Bucky-tube. Taking the hemisphere's off then end will make an open Bucky-tube.

You could also take a one atom thick sheet of carbon atoms (graphite is multiple layers of these sheets) and roll it so that one edge bonds to the other edge. This would give you a tube of arbitrary radius. An open Bucky-tube is a special case.

Further trivia, a bucky ball is a sphere of 60 carbon atoms formed in a shape similar to a socker ball.

-Rusty

Re:What's that?

[moreati]

Quick: A Carbon Nanotube is a molecule of Carbon in the shape of a tube, a few nanometrea across and possibly infinitely long.

Helpful: Carbon Nanotubes are a varient of buckminsterfullerene. Molecules of which are made of 60 carbon atoms in a sephircal arrangement (like a british (soccar) football). Their exetremely tough, and have great potential for drug delivery and lubricant applications. Carbon Nanotubes split the fullerene molecule in half and extend it with a cylinder of carbon atoms. Another way to think of them is by imagining a rolled up sheet of grphite and capping the ends. Some pictures might make things clearer.

Nano is the next step from micro, current microchips are in the 0.1 micrometre range, this is the same as 100 nanometres. Carbon nanotubes are only a few (ie less than 10) nanometres across.

The article discusses single walled nanotubes, the other varient is multiwalled nanotubes, which are simply many nanotubes wrpped in layers - like a telescopic radio ariel. The potential of carbon nanotubes lies in making lots of them long and all in the same orientation, then we have a rope stronger than diamond (think space elevator strong). Also they might be used in nano scale electronics.

Hope that helps

Alex

photovoltaic?

[sammy baby]

Here's a thought: if the nanotubes are so efficient at absorbing light, is there a way to build them such that the heat could be effeciently drawn out of them in order to provide power for a turbine?

Or, in English, could you use these things to make ultra-powerful solar panels?

Re:photovoltaic?

[bugg]

For the sake of being correct, this is nowhere near how photovoltaic cells work. It is based on the photoelectric effect, which states that when an electron of an atom is bombarded with a photon of a certain energy (equal to the atom's work function) the electron becomes free. In solar cells, this same thing happens with two dissimilar semiconducting materials to easily create a usable voltage.

What's happening here is the energy absorbed by the nanotubes cannot dissipate fast enough and cause an explosion. In a photoelectric/photovoltaic system all heat is definitely wasted. So your answer is no, because carbon is not particularly useful in a photovoltaic cell and carbon nanotubes certainly wouldn't be, because their internal resistance is *way* too high.

Mirror of the MPEG here

[Otto]

Mirror of the MPEG is here: flash.mpeg

No photos, please!

[Hoi Polloi]

I can see it now...

"Welcome to the Daytona Airshow! The newest, most advanced fighter in the world, with the first carbon nanotube body!"

"Wooo! Quick, take a photo!"

*FLASH*
*FIZZLE*
*CRASH*

"Oh shit..."

No more funny business

[brer_rabbit]

Hey mods: don't you think this article has enough comments marked *funny*? The signal to noise ratio -- even for slashdot -- is in the crapper. Maybe consider not modding stuff down that really isn't funny or better yet find something with real content to mod up.