Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes Under Tensile Load

Abstract

The tensile strengths of individual multiwalled carbon nanotubes (MWCNTs) were measured with a "nanostressing stage" located within a scanning electron microscope. The tensile-loading experiment was prepared and observed entirely within the microscope and was recorded on video. The MWCNTs broke in the outermost layer ("sword-in-sheath" failure), and the tensile strength of this layer ranged from 11 to 63 gigapascals for the set of 19 MWCNTs that were loaded. Analysis of the stress-strain curves for individual MWCNTs indicated that the Young's modulus E of the outermost layer varied from 270 to 950 gigapascals. Transmission electron microscopic examination of the broken nanotube fragments revealed a variety of structures, such as a nanotube ribbon, a wave pattern, and partial radial collapse.

Carbon nanotube thin film strain sensors: comparison between experimental tests and numerical simulations

“…Treacy et al [12] estimated the Young's moduli of 11 different isolated MWCNTs to be between 0.40 to 4.15 TPa, with an average value of 1.8 TPa. On the other hand, Yu et al [13] found that the tensile strength of MWCNTs can be as high as 63 GPa. Furthermore, the electrical properties of CNTs respond to applied mechanical stimuli.…”

Monitoring a Micromechanical Process in Macroscale Carbon Nanotube Films and Fibers

“…Theoretical and experimental work on the mechanical properties of individual or bundles of CNTs proceeded well at the end of the last century. [1][2][3] It is now widely held that the modulus and strength of a typical single-walled carbon nanotube (SWNT) can reach 640 and 37 GPa, respectively, which surpass those of all existing materials. [4] However, because of weak intertube interactions, it is still a great challenge to acquire such super mechanical properties when CNTs are assembled as macroarchitectures (such as fibers and films).…”

Buckling of peapods, fullerenes and nanotubes

“…Experimental [3][4][5] and theoretical works [6,7] indicate that the axial stiffness and strength of CNTs are of the order of 1 TPa and 50 GPa, respectively, both in agreement with those for in-plane graphite [8] and graphene [9]. The interaction between walls in CNTs and the self-interaction of CNTs in bundles, mostly governed by van der Waals forces, is also similar to the interaction between graphene layers in graphite and results in a low shear strength between adjacent graphene layers that facilitates CNTs sliding [10].…”