Shock-Wave Resistance of WS2 Nanotubes

The shock-wave resistance of WS2 nanotubes has been studied and compared to that of carbon nanotubes. Detailed structural features of post-shock samples were investigated using HRTEM, XRD, and Raman spectroscopy. WS2 nanotubes are capable of withstanding shear stress caused by shock waves of up to 21 GPa, although some nanotube tips and nanoparticles containing multiple structural defects in the bending regions are destroyed. Small WS2 species, consisting of only a few layers, are extruded from the nanotubes. Well-crystallized tube bodies were found to exhibit significant stability under shock, indicating high tensile strength. XRD and Raman analyses have confirmed this structural stability. Under similar shock conditions, WS2 tubes are more stable than carbon nanotubes, the latter being transformed into a diamond phase. WS2 nanotubes containing small concentrations of defects possess significantly higher mechanical strength, and, as a consequence, hollow WS2 nanoparticles are expected to act as excellent lubricants under much higher loading than was previously thought.