연도 | 2010 |
---|---|
저널명 | Carbon |
쪽 |
Formation of the cone-shaped multi-walled carbon nanotube (MWCNT) bundles was
investigated with the consideration of the induced dipole moments of the MWCNTs
interaction under the ion irradiation which is accelerated by the applied sheath
electric field for the various argon, hydrogen, nitrogen, and oxygen plasmas.
Vertically grown MWCNTs were irradiated by energetic ion whose energy and dose
were controlled by the sheath formed on the MWCNT substrate. Plasma irradiation
was carried out in a downstream region separated from the plasma source region,
providing that the irradiated ion density and energy could be controlled
precisely with the sheath electric field. In argon and hydrogen plasmas, the
cone-shaped MWCNT bundle was not fabricated, while it was formed successfully in
nitrogen and oxygen plasmas. Especially, the oxygen plasma was the most
effective in the formation of the bundle. The mechanism of the bundle formation
could be explained by a model explaining the interaction between the induced
dipole moment of the MWCNT and the sheath electric field. For the nitrogen and
oxygen plasma irradiated MWCNT, the induced dipole moment could be enhanced by
C–N and C–O bonds so the size of the bundle is proportional to the ion
irradiation and the sheath electric field.