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

Space Elevator Possible Sri Lankan Graphite making the Space Elevator Possible

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.,

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

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

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)

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

CNT Market Sector Growth Global CNT market by 2010  US $ 700 million Market price of 1g CNT  US $ 25-2000 Market price of one Mt of Graphite  US $ 1500

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

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

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

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

Catalyst Free CNT Growth process

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.

References [1] S. Ijima, “Helical Microtubules of Graphitic Carbon”, Nature, vol. 354, pp 55 – 58, Nov. 1991. [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. 2009. [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 2009. [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, 142432 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. 2009. [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, 2009. [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. 2006 [8] M. S. Dresselhaus, G. Dresselhaus, R. Saito, A, Jorio, “Raman Spectroscopy of Carbon Nanotubes”, Physics Reports, Oct. 2004.