As a unique form of carbon allotropes, carbon nanotubes are well known for their extraordinary electrical properties, thermal conductivity, and mechanical strength. Considered as the strongest materials, a question naturally rises: how can you break carbon nanotubes?

A recent study carried out by Pulickel M. Ajayan, Rice University, Houston, TX, USA, and colleagues may answer the question. The researchers subjected carbon nanotubes in the form of spherical pellets to impact on an aluminum target at a speed of 6.9 km/s. Accompanied by significant defect formation and rapid atom evaporation, the process eventually led to the unzipping of carbon nanotubes along the tube axis, which was highly dependent on the impact angle.

This research yields valuable insights into the mechanisms for mechanical deformation and fracture of carbon nanotubes. Moreover, it provides an alternative approach to mechanically produced graphene carbonribbons without introducing any chemical contaminant.

• Unzipping Carbon Nanotubes at High Impact,
  S. Ozden, P. A. S. Autreto, C. S. Tiwary, S. Khatiwada, L. Machado , D. S. Galvao, R. Vajtai, E. V. Barrera, P. M. Ajayan
  Nano Lett. 2014.
  DOI: 10.1021/nl501753n