Tensile Loading of Double-Walled and Triple-Walled Carbon Nanotubes and their Mechanical Properties

Abstract

The mechanical response of individual double-walled and triple-walled carbon nanotubes (CNTs) and CNT ropes consisting of only two double-walled CNTs under tensile load was measured using nanomanipulators in a scanning electron microscope. The breaking strain and strength and Young’s modulus of individual CNTs were measured to be 1.5−4.9%, 13−46 GPa, and 0.73−1.33 TPa, respectively. The low breaking strain and strength are most likely caused by the defects presented in the measured CNTs synthesized by chemical vapor deposition. Carbon nanotube ropes exhibited one-step or stepwise breaks depending on the relative breaking strains of the two CNTs.