Dependence of Young’s modulus of vertically aligned carbon nanotubes on their aspect ratio

Abstract

The experimental studies of the dependence of Young’s modulus of vertically aligned carbon nanotubes (CNTs) on their aspect ratio were carried out. It was shown that the Young’s modulus of the individual CNTs increased from 1.63 to 1.83 TPa with an increase in their aspect ratio from 8 to 15.8. This dependence is probably due to the fact that the relative number of the structure defects in the CNT decreases with increasing its aspect ratio. The Young’s modulus of the CNT bundles also increased with the growth of the aspect ratio of CNTs. However, the calculated values of the Young’s modulus of the CNT bundles with a large aspect ratio were smaller than ones of the individual CNTs with a smaller aspect ratio. It is due to the fact that CNTs that form the bundles are in strained state initially. A smaller strain is required to form a given deformation in CNT bundle than that of individual nanotube. The obtained results can be used to develop and create nanoelectronics devices based on vertically aligned CNTs, in particular adhesion coatings and nonvolatile memory elements.