Supplemental Material (Methods and Figures) for
Structure of multi-wall carbon nanotubes: AA’ stacked
graphene helices
Jae-Kap Lee1,a), Sohyung Lee1, 2, Yong-Il Kim3, Jin-Gyu Kim4, Kyung-Il Lee5, JaePyoung Ahn6, Bong-Ki Min7, Chung-Jong Yu8, Keun Hwa Chae6, and Phillip John9
1
Surface Control Research Center, Korea Institute of Science and Technology, Seoul,
130-650, Korea
2
Department of Semiconductor Science, Dongguk University, Seoul, 100-715, Korea
3
Division of Metrology for quality of life, Korea Research Institute of Standards and
Science, Daejeon, 305-600, Korea
4
Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon
305-340, Korea
5
Nano-bio Division, Nuri Vista Co.LTD, Incheon, 406-840, Korea
6
Analysis Center, Korea Institute of Science and Technology, Seoul, 130-650, Korea.
7
Instrumental Analysis Center, Yeungnam University, Daegu, 712-749, Korea
8
Division of Science and Technology, Pohang University, Pohang, 790-784, Korea
9
School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh,
EH14 4AS, UK
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1. METHODS
We examined two types of commercial multi-wall carbon nanotubes (MWNTs) (Hanwha
nanotech) prepared by the vapor phase catalytic chemical vapor deposition (VCCVD)
technique (CM-95, 95 wt% purity) and an arc-discharge technique (AMI-20H, 20 wt%
purity).
The diameters and lengths of the samples were 10-20 nm and 3-20 ㎛,
respectively (See Fig.S1). The structures of the samples were studied by a highresolution transmission electron microscopy (HRTEM) (JEM-2100F) operating at 200
kV. Purified VCCVD- and arc-MWNTs were used for X-ray diffraction pattern analysis
using CuKα (λ=1.541 Å) source. The simulation for the oriented AA’ graphite was
performed using the modified March-Dollas function in the RIETAN-FP program.32
Surface morphology of a VCCVD tubule was probed by an atomic force microscopy
(AFM) (non-contact-mode) using a commercial cantilever with a tip radius of curvature
< 10 nm.
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2. FIGURES
FIG. S1. TEM morphologies of the commercial MWNTs analysed in this study. (a) A
low magnification TEM image of VCCVD-MWNTs, which are mostly curved. (a’) A TEM
image of a VCCVD-MWNT. (a”) An ED pattern obtained from a VCCVD-tubule,
showing the polycrystalline feature. (b) A low magnification TEM image of arc-MWNTs,
which are rare but straight. (b’) A TEM image of an arc-MWNT. Typical ED patterns of
arc-MWNTs are represented in Fig. 4.
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FIG. S2. Crystal structures of AB and AA’ graphite. (a) AB graphite (hexagonal, space
group p63/mmc #194, a = b = 2.46 Å, c = 6.70 Å). (b) AA’ graphite (orthorhombic,
Fmmm #69, a = 2.46 Å, b = 4.26 Å, c = 6.88 Å). In the orthorhombic AA’ structure, two
sets of (100) and (110) planes of AB hexagonal graphite (dotted blue lines), which are
equivalent to (220) and (260) planes respectively, latently exist (b).
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FIG. S3. Schematic diagrams showing typical turbostratic structures of MWNTs with
uniform chirality and their expected ED patterns. (a) A zigzag based turbostratic MWNT
and its expected ED pattern. (b) A chiral (θ~10°) MWNT and its expected ED pattern.
The (020) spots should appear within 30° to the vertical axis. (c) An armchair-based
MWNT and its expected ED pattern.
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FIG. S4. Schematic diagrams showing possible structures and expected ED patterns of
MWNTs. (a, b) A zigzag and an armchair models based on the AA’ stacked graphene
helices (right-handed). One outstanding difference between the two models is the
angle of <200> with respect to the tubule axis; the angle of the zigzag model is 30°,
whereas that of the armchair model is 60°. “F” and “B” represent the front side and the
back side of a tubule, respectively. Schematic of the AB stacking (c) is also shown for
comparison.
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FIG. S5. AFM analysis of VCCVD-MWNTs. (a) A SEM image showing the VCCVDMWNT sample where the diameter was confirmed to be ≈20 nm. (a’) A low
magnification SEM image showing the VCCVD-MWNT samples prepared on a silicon
substrate where metal indicators at 5 ㎛ intervals are marked. (b, c) Non-contact-mode
AFM images of the tubule probed by a commercial cantilever with a tip radius of
curvature < 10 nm. The tubule appeared to be broadened (≈110 nm in width) in the
AFM images.
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