Conventional batch processing in terms of unzipping multiwalled
carbon nanotubes (MWCNTs) suffers from discontinuity, safety and environmental
issues, reproducibility, and limited scalability. We have established
a continuous-flow, scalable, and safe process for unzipping MWCNTs,
achieving a yield of 75% under flow conditions, without the need for
any auxiliary reagents. This involves using a mild oxidant, aqueous
hydrogen peroxide, and harnessing the mechanical energy in a vortex
fluidic device (VFD) while operating at ambient temperature. The physical
properties of the fabricated unzipping MWCNTs were investigated by
scanning electron microscopy, transmission electron microscopy, thermogravimetric
analysis, X-ray photoelectron spectroscopy, powder X-ray diffraction,
and Raman spectroscopy. This scalable, continuous-flow VFD-enabled
fabrication method for unzipping MWCNTs unveils the power of a fluidic
vortex confined in a thin film of liquid for nanocarbon structural
re-formation and functionalization.