Extracting subnanometer single shells from ultralong multiwalled carbon nanotubes.
We report a simple but powerful method for engineering multi-walled carbon nanotubes (MWNTs) by using manipulation by an atomic-force microscope. The successive shell-by-shell extraction process of ultralong MWNTs allows the exposure of the innermost single-walled carbon nanotubes (SWNTs), which have diameters as small as approximately 0.4 nm. The inner-shell extraction process changes the electrical characteristics of the MWNTs. Whereas the outer hollowed-out nanotubes show either metallic or semiconducting character, the innermost SWNTs of small diameter exhibit predominantly metallic transport properties.
Hong
Byung Hee
BH
Nanoscale Science and Engineering Center, Columbia University, New York, NY 10027, USA.
Small
Joshua P
JP
Purewal
Meninder S
MS
Mullokandov
Asher
A
Sfeir
Matthew Y
MY
Wang
Feng
F
Lee
Ju Young
JY
Heinz
Tony F
TF
Brus
Louis E
LE
Kim
Philip
P
Kim
Kwang S
KS