Mechanical properties of carbon nanotubes Mechanical properties of carbon nanotubes The mechanical properties of carbon nanotubes reveal them as one of the strongest materials in nature. Carbon nanotubes (CNTs) are long hollow cylinders of graphene. Although graphene sheets have 2D symmetry, carbon nanotubes by geometry have different properties in axial and radial directions. It has been shown that CNTs are very strong in the axial direction. Young's modulus on the order of and tensile strength of were obtained. Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp bonds
Carbon–carbon bond bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond. Carbon is one of the few elements that can form long chains of its own atoms, a property called catenation. This coupled with the strength of the carbon–carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements