Double-Walled Carbon Nanotubes with Dynamic Strength of over 90 GPa Enhanced by Intershell Friction.

Low-dimensional ultra-strong nanomaterials have attracted great anticipation for applications under extreme dynamic conditions. A photocatalytic method is developed to selectively cut off the outer shell of double-walled carbon nanotubes (DWCNTs), achieving non-contact measurement of intershell friction with both high temporal and spatial resolutions at high sliding velocities under optical microscope. The intershell friction linearly increases with the sliding velocity, with a slope related to intershell distance and chirality of DWCNTs.

Toughening and Crack Healing Mechanisms in Nanotwinned Diamond Composites with Various Polytypes.

As an emerging ceramic material, recently synthesized nanotwinned diamond composites with various polytypes embedded in nanoscale twins exhibit unprecedented fracture toughness without sacrificing hardness. However, the toughening and crack healing mechanisms at the atomic scale and the associated crack propagation process of nanotwinned diamond composites remain mysterious. Here, we perform large-scale atomistic simulations of crack propagation in nanotwinned diamond composites to explore the underlying toughening and crack healing mechanisms in nanotwinned diamond composites.