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. Tensile tests of individual WS₂ nanotubes were performed experimentally 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. The results which were obtained for WS₂ nanotubes show Young’s modulus value of ca.150GPa, tensile strength value of ca. 15GPa and average elongation of ca. 12%. DFTB-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 the experiment and the simulation. The combination of studies shows that the nanotubes are both ultra-strong and flexible distinguishing them from other known materials.

Schematic view of a Buckminster Fullerene molecule