- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
Nanotubes Show Flash of Talent
26 April 2002 (All day)
A simple flash of light sets high-tech carbon fibers alight, a young researcher has found. The effect adds to the list of the fibers' remarkable properties and could have applications in fields ranging from rocket science to nanotechnology.
With a little coaxing, carbon atoms can arrange themselves in tubes resembling atomic-scale cylinders of chicken wire. Such single-walled carbon nanotubes are among the strongest materials known, can carry electricity like the metals in wires and the semiconductors in silicon chips, and can even be made to conduct electricity with no resistance. Such properties could someday allow nanotechnologists to fashion tiny electrical circuits and mechanical devices out of nanotubes. Now, single-walled carbon nanotubes have displayed another novel property: They catch fire when exposed to a simple flash of light.
The discovery was made by undergraduate Andres de la Guardia while working with Pulickel Ajayan, a materials scientist at Rensselaer Polytechnic Institute in Troy, New York. De la Guardia was supposed to take close-up photographs of tangles of freshly made nanotubes, but he found that the flash from his camera ignited the fluffy masses. The researchers and their colleagues repeated the process with the tubes in a vacuum or surrounded by helium or argon gas. In those experiments, the tubes could not burn for lack of oxygen, but the light still scrambled the arrangement of the carbon atoms, the team reports in the 26 April issue of Science. The changes suggest that light might be used to control the properties of single-walled nanotubes, Ajayan says.
The fire-from-light phenomenon could also have direct applications, says David Carroll, a physicist at Clemson University in South Carolina. For instance, it might be used to control the ignition of flammable materials. "I anticipate a potential use in solid propellants such as the space shuttle's solid rocket motors," Carroll says. Michael Sailor, a materials chemist at the University of California, San Diego, says that the light-sensitive nanotubes might be used to set off minuscule "nano-explosives" to perform tiny remote-controlled chemical experiments, kill tumors from the inside out, or even power microscopic robots.