Mechanical Properties of Individual WS2 Nanotubes

Abstract

The Young’s modulus of WS2 nanotubes is an important property for various applications. Measurements of the mechanical properties of individual nanotubes are challenging because of the small size of the tubes. Lately, measurements of the Young’s modulus by buckling of an individual nanotube using an atomic force microscope resulted in an average value of 171GPa. Further study of the buckling behavior is performed here using the scanning electron microscope and some preliminary results are shown. Furthermore, tensile tests of individual WS2 nanotubes were performed experimentally (again using a scanning electron microscope) and simulated tensile tests of MoS2 nanotubes were performed by means of a density‐functional tight‐binding (DFTB) based molecular dynamics (MD) scheme. Preliminary results for WS2 nanotubes show Young’s modulus value of ca.137GPa, tensile strength value of ca. 11 GPa and average elongation of ca. 12%. MD simulations resulted in elongation of 19% for zigzag and 17% for armchair MoS2 single wall nanotubes. Since MoS2 and WS2 nanotubes have similar structures the same behavior is expected for both, hence there is a good agreement regarding the elongation of WS2 nanotubes between experiment and simulation.