Sapphire provides the ideal surface for templated growth of nanotubes
Ordered nanotubes have been formed in the wake of a catalyst acting as their creator as it moves across an ordered surface.
Ernesto Joselevich’s team at the Weizmann Institute of Science, Israel, was investigating the possibility of electric fields influencing carbon nanotube growth on different surfaces.
The researchers discovered that, contrary to their instincts, the electric field had no influence. However, they did find that a stepped sapphire surface could be decorated perfectly by a layer of nanotubes grown parallel to the direction of the steps, as if each tube were a very thin carpet.
Until now, nanotubes have lined-up alongside the steps and not parallel to their direction when they have been grown on atomic-scale steps. In this case, however, an iron nanoparticle was used as a catalyst and the carbon nanotubes grew behind the catalyst as it passed over the steps.
Possibilities of scaling-up nanotechnology are constantly being sought, says Joselevich, and he is optimistic that now they are aware that nanotubes can be grown in such an ordered way over a templated surface, other shapes might also be able to act as templates.
This latest work could be a nanostep in the right direction to making scale-up a more realistic prospect.
A Ismach et al, Angew. Chem. Int. Ed., 2004, 43, 6140