Supplementary material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2004
Supplementary Information for:
Facile fabrication of polymer and carbon nanocapsules using polypyrrole
core/shell nanomaterials
Jyongsik Jang,* Xiang Li Li and Joon Hak Oh
Hyperstructured Organic Materials Research Center and School of Chemical Engineering,
Seoul National University, Shinlimdong 56-1, Seoul 151-742, Korea.
Synthesis of PPy nanocapsules: A variable amount of cationic surfactants such as
octyltrimethylammonium bromide (OTAB), decyltrimethylammonium bromide (DeTAB),
and cetyltrimethyl- ammonium bromide (CTAB) was magnetically stirred in 40 mL of
distilled water. 0.5 g (7.5 mmol) of pyrrole was added dropwise to the surfactant solution, and
0.5 g (3.8 mmol) of copper(II) chloride was put into the solution. Chemical polymerization
proceeded for 3 h at 25°C. Then, 1.0 g (14.9 mmol) of pyrrole was added dropwise into the
micellar solution. Iron(III) chloride (1.2 g, 7.4 mmol) was dissolved in a small amount of
distilled water and the solution was added to the reaction mixture. After the chemical
polymerization for 3 h at 25°C, the reaction product was moved to a separation funnel and
excess methyl alcohol was poured. After precipitation, the upper solution containing
surfactant, soluble PPy and residual oxidants was discarded and the PPy nanocapsule
precipitate was dried in a vacuum oven at room temperature. Fig. S1 represents the shell
thickness variation of PPy nanocapsules as a function of monomer amount.
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Supplementary material (ESI) for Chemical Communications
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Preparation of carbon nanocapsules: A small amount of the crosslinked PPy
nanocapsule was put into a quartz tube in an electric furnace under Ar flow (0.2 L min1). The
sample was heated up to carbonization temperature at a heating rate 3°C min1, held for 3 h,
and then naturally cooled to room temperature.
Instrumental Analysis: The TEM images and EDX data were taken using a JEOL JEM2000 EX II microscope and a Philips CM-20 microscope coupled with an EDX facility. The
high resolution TEM image was taken with a JEOL JEM-2010 F microscope. The SEM
images were obtained with a JEOL JSM-6700 F microscope. Elemental analysis was
conducted with an EA 1110 apparatus (CE Instruments). XRD measurement was performed
with a Rigaku DMAX-IIIA. Raman spectra were obtained using a Jobin-Yvon T64000
spectrometer equipped with an Ar-ion laser. Nitrogen adsorption/desorption isotherms were
recorded with a Micromeritics ASAP 2000.
XRD and Raman spectroscopy analyses of carbon nanocapcules: Fig. S2 shows XRD
pattern and Raman spectrum of PPy nanocapsules carbonized at 1000°C. The XRD pattern of
carbonized hollow nanospheres confirms the presence of graphite, as the characteristic 002
and 001 Bragg reflections of graphenes are clearly displayed. The graphite 002 reflection
became sharper with increasing the carbonization temperature. The 002 peak sharpening is
related to the widening and thickening of the graphite layers by heat treatment.1 The Raman
spectrum of carbon nanocapsules showed two main peaks at 1580 and 1360 cm1. The band at
1580 cm1 is assigned to the E2g vibration of graphitic carbon with an sp2 electronic
configuration. On the other hand, the peak at 1360 cm1 is attributable to the A1g mode of
diamond-like carbon with an sp3 configuration.2 When the carbonization temperature
increased from 1000°C to 1200°C, the area ratio of the two Raman bands (Asp2/Asp3)
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Supplementary material (ESI) for Chemical Communications
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increased from 0.47 to 0.58. This means that the degree of graphitization of the carbon
nanocapsules could be enhanced by carbonization at an elevated temperature.
References
1 G. T. Fey, Y. C. Kao, Mater. Chem. Phys. 2002, 73, 37.
2 a) F. Tuinstra, J. L. Koenig, J. Chem. Phys. 1970, 53, 1126. b) A. W. P. Fung, A. M. Rao, K.
Kuriyama, M. S. Dresselhaus, G. Dresselhaus, M. Endo, N. Shindo, J. Mater. Res. 1993, 8, 489.
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Supplementary material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2004
Shell thickness of PPy nanocapsules (nm)
16
14
12
10
8
6
4
0.2
0.4
0.6
0.8
1.0
1.2
Pyrrole concentration (mol L-1)
Fig. S1 The shell thickness change of PPy nanocapsules with increasing monomer amount.
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Supplementary material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2004
10
20
30
40
50
G110
F511
F440
F311
F110
G100
F024
Intensity
G002
(a)
60
70
80
90
2 (degrees)
(b)
SP3
Intensity
SP2
500
1000
1500
2000
Raman shift (cm-1)
Fig. S2 (a) Powder X-ray diffraction pattern (graphite, G; -Fe2O3, F) and (b) Raman
spectrum of carbon nanocapsules carbonized at 1000°C.
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