HOW long is a carbon nanotube? Until recently, the answer was no more than a few micrometres. But the creation of the world’s longest nanotube suggests there is no fundamental length limit.
Nanotubes will grow only with the help of a catalyst such as a particle of iron, which encourages carbon to crystallise into tubes. But the tubes tend to bump into surfaces, preventing them from growing beyond a few micrometres. Now Yuntian Zhu and colleagues at Los Alamos National Laboratory in New Mexico have overcome this problem (Nature Materials, DOI: 10.1038/nmat1216). When they suspended an iron particle in a…
