The Effects of Processing Conditions upon the Yield of Carbon Nanotubes:Abstract – This research investigates the optimal process
conditions to make multi-wall nano-tubes (MWNTs) and to
achieve high yielding. This study applies Arc Discharge Method
(ADM) to synthesize multi-wall nanotubes (MWNTs) and hollow
carbon nanocapsules (HCNCs). The morphology and
micro-structure of carbon nanotubes (CNTs) were observed by
Transmission Electron Microscope (TEM) and Field Emission
Scanning Electron Microscope (FE-SEM). The experimental
result shows that the optimal process conditions for high yield of
CNTs are 3.0 l/min of inert gas（Ar）flow rate, 70A of the
discharged current, and 20V of the discharged voltage. In
addition, the lower the cooling temperature is, the higher the yield
of CNTs. The diameter of carbon nanotubes range from 10 to 20
nm and the aspect ratio of CNTs are between 100 and 600.
Finally, the smaller the diameter of carbon rod is, the lower the
discharged current and the yield of CNTs.
Keywords: multi-wall carbon nanotubes（MWNTs）、hollow
carbon nanocapsules（HCNCs）、Arc discharged method（ADM）、aspect ratio