How to heal nanotubes
doi:10.1038/nindia.2010.120 Published online 31 August 2010
Researchers have shown that carbon ion beams can simultaneously generate and heal defects in carbon nanotubes (CNTs). This phenomenon may allow CNTs to be tailored for specific applications or provide a method of repairing CNTs used in environmental conditions brimming with energetic charged particles, such as space.
It is widely believed that irradiating a material with energetic ions or electrons induces disorder. However, recent experiments involving ion irradiation of carbon-based nanostructures have shown striking evidence of material reordering on illumination.
To find out the material effects of irradiation on CNTs, the researchers irradiated multiwalled and single-walled CNTs with a 55 MeV carbon ion beam. The researchers found that when carbon ions hit a CNT, they form vacancies or dangling bonds in the system by ejecting some of the carbon atoms out and away from the surface. The displaced carbon atoms can then be adsorbed on the inner and outer walls of the CNT.
Vacancy formation occurs in the extremely high temperature core region formed around the ion track. The area surrounding this core has a lower temperature than the outside, therefore providing optimum conditions for the reconstruction of the atomic network by saturating the dangling bonds of the defected hexagonal atomic network.
The researchers say that the simultaneous generation and healing of defects may open up new possibilities for manipulating and designing new CNT-based structures.
The authors of this work are from: Department of Physics, Panjab University, Biomolecular Electronic and Nanotechnology Division, Central Scientific Instruments Organization, Chandigarh, and Materials Science Group, Inter University Accelerator Centre, New Delhi, India.
- Jeet, K. et al. Damaged carbon nanotubes get healed by ion irradiation. J. Appl. Phys. 108, 034302 (2010) | Article |