Strength and breaking mechanism of multiwalled carbon nanotubes under tensile load
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.
Yu
MF
Department of Physics, Washington University in St. Louis, CB 1105, St. Louis, MO 63130, USA. Zyvex LLC, Suite 200, 1321 North Plano Road, Richardson, TX 75081, USA. Department of Materials Science and Engineering, University of Wisconsin, 1509 Uni.
Lourie
O
Dyer
MJ
Moloni
K
Kelly
TF
Ruoff
RS