ScienceDaily (Feb. 22, 2007) — The process by which carbon nanotubes repair themselves has now been explained and modeled in detail. These tubes, sometimes only a nanometer or so in width but microns in length are among the toughest but also flexible materials known. And when they develop a tear, whether through irradiation or the application of extreme heat or strain, they are able to sew themselves back up without any leftover stitches or imperfections.

The way they do it, a new study conducted by scientists at Rice University shows, is through the propagation of a sort of sliding carbon-repair crew. The crew consists of a pentagon-heptagon phalanx of 10 carbon atoms moving along the tube, filling in the crack created by ejecting carbon atoms and rearranging local bondings as they go. The ejected carbons can either go away or they can be used in the repair work elsewhere.

Repair of other carbon-based material, such as proteins or DNA, is much more complicated and usually leaves behind stitches or other signs of the repair. But Rice engineer Boris Yakobson believes that the "5/7 machine" repair mechanism at work in carbon nanotubes might operate too in other 2-dimensional tilings, such as micelles (arrays of surface molecules deployed on a colloid) or microtubules.

Reference: Ding et al., Physical Review Letters, upcoming article

The microscopic behavior of a carbon nanotube with a tear resembles somewhat the motion of a ladybug. The rip in the nanotube fabric, caused by heating stressing the nanotube, is sewn up in a moving process in which carbon a pentagon-heptagon structure propagates along the tube. (Credit: Reported by Ding et al. in Physical Review Letters / Courtesy of American Institute of Physics)

Related Stories

Buckypapers Clarify Electrical, Optical Behavior Of Nanotubes (Oct. 20, 2008) — Using highly uniform samples of carbon nanotubes, materials scientists have made some of the most precise measurements yet of the concentrations at which delicate mats of nanotubes become ...  > read more

Tweezers Trap Nanotubes By Color (Sep. 29, 2008) — Singled-walled carbon nanotubes are graphene sheets wrapped into tubes, and are typically made up of various sizes and with different amounts of twist (also known as chiralities). Each type of ...  > read more

Structural Defects Introduced Into Carbon Nanotubes Could Lead The Way To Carbon Nanotube Circuits (Jan. 15, 2009) — Structural defects introduced into carbon nanotubes could lead the way to carbon nanotube circuits, new research ...  > read more

Nanotubes Act As 'Thermal Velcro' To Reduce Computer-chip Heating (May 2, 2006) — Engineers have created carpets made of tiny cylinders called carbon nanotubes to enhance the flow of heat at a critical point where computer chips connect to cooling devices called heat sinks, ...  > read more

Search ScienceDaily

Metal Rubber