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

[Anonymous Coward]

Well I guess hopes for a space elevator are shot now, since the first time someone took a photo of it would cause the whole thing to explode.

text is here

[Carbon Unit 549]

Nanotubes go flash bang wallop
19:00 25 April 02 NewScientist.com news service

Taking a snapshot of carbon nanotubes using an ordinary camera flash can cause them to emit a loud pop and then suddenly burst into flame.

Scientists say this unique explosive phenomenon may lead to new means of manufacturing nanoscale carbon materials and even remote-control devices for small explosive charges.

Pulickel Ajayan and his team at Rensselaer Polytechnic Institute, New York, have been at work since one of his students accidentally sparked a tiny explosion by photographing a bundle of single-walled carbon nanotubes. "It was a complete accident," Ajayan told New Scientist.

Researchers around the world are exploring the potential that carbon nanotubes could have for a wide range of super-strong materials and nanoscale circuits. Ganapathiraman Ramanath, also at Rensselaer Polytechnic, says that the latest discovery "will serve as a starting point for developing nanotube-based actuators and sensors that rely on remote activation and triggering."

Ultra-absorbent

Ajayan says the explosion occurs because the black carbon nanotubes absorb light so efficiently that, when it is converted into heat, the heat cannot dissipate quickly enough across bunched-up tubes. However, only the single-walled variety of nanotubes catch fire. Those with multiple walls do not explode - the researchers are unsure why.

Video of flashlit nanotube explosion (744kB download)

The initial popping noise is generated by the heating of the oxygen inside and between the tubes, which causes a shock wave. And when the temperature of carbon reaches between 600C and 700C it oxidises sparking combustion.

When the researchers tried the experiment in the absence of oxygen they found that the tubes were transformed into different nanoscopic shapes, some reminiscent of cone-shaped "nanohorns".

"It's a very nice surprise," says Angel Rubio, an expert in carbon nanotubes at the University of the Basque Country in Spain. "Because it's the only carbon material that exhibits this ignition property."

Journal Reference: Science (vol 296, p 705)

Will Knight

Ouch, hope NASA knows this

[Indras]

Last I heard NASA was making serious plans for a space elevator (slashdot story) using nanotubes. That may have to seriously reconsider this if it means tourists with cameras or solar flares can bring the whole thing toppling down.

I wonder what kind of shielding or heat-dissipation they would need for a 22,000 mile long cable of nanotubes? Might be more effor than it's worth after all.

Alternative uses

[sydneyfong]

Imagine the possibilities!!

Scenario:

Reporter: Mr. famous_person *camera flashes* would you comment on your relationship *camera flashes* with Miss XXX?

Mr. famous_person: Sorry but I have no *camera flashes* comment *camera flashes* at this stage. (tries to get away)

Reporter: Do you believe *camera flashes* that this relationship will have an impact on *camera flashes* your career?

Mr. famous_person: I have a nanotube in my pocket!!!

Re:so much for my futuristic rave

[robolemon]

Just use a Beowulf nano-cluster and you could make the explosions part of the show.

Just make sure at least one remains at the end...

"This song's blowing up the charts!"