High-speed shearing process as a novel strategy toward tailoring ultra-short carbon nanotubes

Ultra-short carbon nanotubes (CNTs) have many unique features but cutting CNTs to below 100 nm is still challenging. Herein, we explore a new high-speed shearing process based on the shearing force-assisted compressing force process to cut CNTs, which is different from the conventional mechanical process based on compressing force. The optimal balance of CNTs length (47.2 +/- 22.3 nm) and structural integrity was achieved after the high-speed shearing process at 1500 rpm for 15 min, after that, the length reduction of CNTs was not obvious but the structure was damaged significantly. The molecular dynamics simulation shows that shearing force is more beneficial to fracture CNTs into several segments along their axial direction and assists compressing force to cut CNTs by reducing the critical compressing force and energy consumption. The cutting length of CNTs by high-speed ball milling was above 100 nm because the compressing force tends to compact CNTs clusters and squash the CNTs along their radial direction rather than cutting CNTs along their axis direction. Our work provides a new perspective for the scalable manufacturing of ultra-short CNTs below 100 nm for various specific applications.

Automated summary

A new high-speed shearing process based on shearing force-assisted compressing force has been developed to cut carbon nanotubes (CNTs) below 100 nm. This process achieves an optimal balance between CNTs length and structural integrity. Molecular dynamics simulation shows that shearing force fractures CNTs into segments along their axial direction and assists compressing force in cutting CNTs by reducing force and energy consumption.