1. International Conference on Sustainable Built Environment
NANCO AND UNIVERSITY OF MELBOURNE JOINT RESEARCH SESSION ON NANOTECHNOLOGY AND SUSTAINABLE BUILT ENVIRONMENT
13-14 December, 2010 at Earls Regency, Kandy, Sri Lanka

2. Space Elevator Possible
Sri Lankan Graphite
making the
Space Elevator Possible

3. A metal catalyst free, low cost process of
Abstract
A metal catalyst free, low cost process of
manufacturing carbon nanotubes (CNT) using Sri Lankan
graphite as anode and cathode, in the absence of
external cooling, in an inert gas atmosphere is presented.
The in-situ CNT yield has been analyzed using High Resolution
Transmission Electron Microscopy (HRTEM),
Scanning Electron Microscopy(SEM) and Raman spectroscopy.
Authors
B. G. L. T. Samaranayake1, S. Gunasekera2, A. K. R. Kumarasinghe1, N. S. Kottegoda1 and V. V. Karunaratne3
1Senior Scientist, 2Technical Services Manager, 3Science Team Leader, NANCO (Pvt.) Ltd.,

4. Graphite Resources in Sri Lanka
Reference: Dissanayake , 1981, The Origin of graphite of Sri Lanka, Organic Geochemistry, vol. 3, pp. 1-7

5. Natural Graphite types
Vein
Flake
Component
Amorphous
Vein Crystalline
Flake Crystalline
Carbon (%)
Sulphur (%)
True Density (g/cm3)
Graphite content
d-spacing(002)(A0)
Ash true density (g/cm3)
Resistivity (ohm-cm)
Morphology
81.00
0.10
2.31
28.00
3.361
2.68
0.091
Granular
96.70
0.70
2.26
100.00
3.354
2.89
0.029
Plates, Needles, Granular
90.00
2.29
99.90
3.355
2.91
0.031
Flaky

6. Carbon NanoTubes (CNTs)
Types
1 Single-walled nanotubes (SWCNT)
2 Double-walled carbon nanotubes (DWCNT)
3 Multi-walled nanotubes (MWCNT)
Production methods
1 Arc discharge Method- (yield up to 30%)
2 Laser ablation Method- (yield up to 70%)
3 Chemical vapor deposition (CVD)

7. Properties of Carbon Nanotubes
Reference: Wong E. W. et al., , 1997 “Nanobeam mechanics: elasticity, strength, and toughness of nanorods and nanotubes,” Science, vol. 277, pp. 1971–1975

8. CNT Market Sector Growth
Global CNT market by  US $ 700 million
Market price of 1g CNT  US $
Market price of one Mt of Graphite  US $ 1500

9. Laboratory scale CNT production
Operation
Block diagram
Before igniting
Conditions: Pressure = 1 atm,
Cooling = Natural, Environment = Inert (Ar)
Arc initiation
During Arc

10. Results: RAMAN spectroscopy
Radial Breathing Mode
G band
peak
D band
peak
G (1580cm-1)/D (1300cm-1) band ratio is used to determine the proportion of
SWCNT to MWCNT in a sample
ωRBM(cm-1)= 248 cm-1/ dt

11. Results: HRTEM image of SWCNT
By courtesy of Institute Nano Scale Physics (INFN), Elettra, Trieste, Italy

12. Results: By products MWCNT Nano Onions (precursors)
By courtesy of Institute Nano Scale Physics (INFN), Elettra, Trieste, Italy

13. Catalyst Free CNT Growth process

14. Quality control of CNT Parameter Property Arcing current
Directly proportional to the length of CNT
Directly proportional to the yield
But too high current can evaporate the electrodes without forming the CNT
Inversely proportional to the diameter
Arcing time
Directly proportional to the yield. But too long time can destroy the yield.
Gap between Anode & Cathode
Inversely proportional to the yield. But too short gap can reduce the aspect ratio.

15. References
[1] S. Ijima, “Helical Microtubules of Graphitic Carbon”, Nature, vol. 354, pp 55 – 58, Nov [2] H. Wang, K. Ghosh, Z. Li, T. Maruyama, S. Inoue, Y. Ando, “Direct Growth of Single-Walled Carbon Nanotube Films and Their Optoelectric Properties”, Journal of American Chemical Society, vol. 113,pp 12079–12084, Nov [3] W. Zhou, L. Ding, J. Liu, “Role of Catalysts in the Surface Synthesis of Single-Walled Carbon Nanotubes”, Review Article, Nano Research, vol. 2, pp 593 – 598, June [4] D. N. Borisenko, N. N. Kolesnikov, M. P. Kulakov, V. V. Kveder, “Growth of Carbon Nano-Tubes (CNT) in Electric-Arc Discharge in Argon”, Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region, Russia. [5] Z. H. Li, X. F. Shang, S. Qu, Y. B. Xu, M. Wang, “A Novel Method to Produce Large Amount Single-Walled Carbon Nanotubes by Arc Discharging”, Journal of Inorganic Materials, vol. 45, No. 5, pp. 495–497, Nov [6] T. Charinpanitkul, W. Tanthapanichakoon, N. Sano, “Carbon nanostructures synthesized by arc discharge between carbon and iron electrodes in liquid nitrogen”, Journal of Current Applied Physics, vol. 9, pp 629–632, [7] M. Endo, T. Hayashi, Y. A. Kim, H. Muramatsu, “Development and Application of Carbon Nanotubes”, Japanese Journal of Applied Physics, vol. 45, No. 6A, pp 4883 – 4892, Feb [8] M. S. Dresselhaus, G. Dresselhaus, R. Saito, A, Jorio, “Raman Spectroscopy of Carbon Nanotubes”, Physics Reports, Oct