Graphitized multi-walled carbon nanotubes

Multi-walled carbon nanotubes are concentrically aligned single-walled carbon nanotubes assemblies with different diameters. The distance between adjacent shells is about 0.34 nanometers. Multi-walled carbon nanotubes differ from single-walled carbon nanotubes not only in their dimensions, but also in their corresponding properties. Various techniques have been developed to produce carbon nanotubes in sizable quantity, high yield, and purity, while maintaining a reasonable cost. Well-developed techniques include arc discharge, laser ablation, and chemical vapor deposition, and most processes involve costly vacuum conditions. Novel chemical, electrical, and mechanical properties absent in other materials have been discovered in carbon nanotubes. Pristine carbon nanotubes are inert to most chemicals and need to be grafted with surface functional groups to increase their chemical reactivity and add new properties. Along the longitude directions, carbon nanotubes show superior mechanical strength, with the highest known tensile strength and elastic modulus among known materials. Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China