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

Re:Not much of a story

[Indras]

Actually, this is quite a story. Here's a quote that might interest you:

"Because it's the only carbon material that exhibits this ignition property."

Carbon doesn't normally do this. In the right circumstances, it is flammable, sure, but never explosive.

quantum efficiency

[avandesande]

This is significant because most photochemical reactions have poor quantum yield. This may lead to some highly efficient solar cells, photo catylists or sensors.

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: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.

give this kid a reward!

[Banner]

Buy trying to take the picture in the lab, this kid found out something more important then all the researchers developing this. And may have saved us from some nasty things.
Can you imagine if this was found out -after- this stuff was rolled out into general use?

Re:Weapons and more...

[Kailden]

I *love* human nature. Every time we make a scientific discovery, the thought process is

1) Wow. hummph. neat. cool!
2) I wonder if i can make any money off this.
3) How could we make this into a weapon?

aieeee.

-K.