Nanotube Dermatology

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 (see figure at Physics News Graphics).

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 (713-348-3572, biy@rice.edu) 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.

Ding et al., Physical Review Letters, upcoming article
Contact Boris Yakobson
Rice University
Tel: 713-348-3572
biy@rice.edu
Also see the Rice University press release