Papers

ICMCTF2006 Session D3-1: Special Forum on Technology and Market of Carbon Nanotubes

Wednesday, May 3, 2006 1:30 PM in Room Sunset

Wednesday Afternoon

Start	Invited?	Item
1:30 PM		D3-1-1 Introduction to Special Forum S.R.P. Silva (University of Surrey, United Kingdom)
1:50 PM		D3-1-2 Selective Synthesis of Carbon Nanotubes in a Large Scale and their Applications M. Endo (Shinshu University, Japan) Nano-sized carbon nanotubes with hollow core were observed when hydrocarbon was decomposed in the existence of nano-sized catalyst such as iron at higher temperature¹. Up to now, this catalytic chemical vapor deposition (CVD) method² has been extensively studied as the most promising technique for the large-scale production of carbon nanotubes at relatively low cost. Through judicious selection of transient metal, support materials and synthetic conditions (temperature, duration), it is possible to control the number of shells of carbon nanotubes (e.g., multi-walled carbon nanotubes (MWNTs), double-walled carbon nanotubes (DWNTs) and single-walled carbon nanotubes (SWNTs)) selectively. The recent hot topic is the synthesis of DWNTs because these tubes are more thermally and chemically stable when compared to SWNTs; they also exhibiting the 1D character of a quantum wire. In addition, DWNTs could also be used in the fabrication of electron field emitter and nano-composites. We fabricated highly pure and clean DWNTs by a catalytic CVD method and subsequently optimized two-step purification procedures³. By pouring highly dispersed DWNTs solution into a filter, we obtained a dark and stable paper-like sheet, which is very flexible and mechanically stable (tough)³. Careful HRTEM observations revealed an extremely high-yield of DWNTs (more than 95%) arranged in bundles. In this study, we will describe the catalytic synthesis of various types of carbon nanotubes in terms of industrial view point, and their practical applications including medical apparatus⁴ will be presented. ¹A. Oberlin, M. Endo and T. Koyama, J. Crys. Gro., 32, 335 (1976). ²M. Endo, CHEMTECH, American Chemical Society, September, 568, (1988). ³M. Endo, et al. Nature, 433, 476 (2005). ⁴M. Endo, et al., Nano Lett. 5, 101 (2005).
2:30 PM		D3-1-4 The Nano-Carbon: Potential and Practical Applications with Business Models S. Katagiri (Mitsubishi Corporation, Japan); R.O.O. Loutfy (NMIC (a JV of Mitsubishi)) Since back in 1993, I have been working on various types of nano-carbons’ commercialization from mass production to applications. I will present the status of production, practical applications, business model and IP strategies, in addition more challenges shall be introduced, such as metal composites, rubber composites, resins, ceramics and so on with various types of carbon nanotubes. Regarding business models, the new venture company shall be introduced with its challenges, risk analysis, alternatives, goal etc shall be introduced from business aspects. For success, people, products, money and IP strategies must be well balanced, and how to expand network are to be discussed. I do hope my introduction focusing on nano carbon application development in ICMCTF 2006 rings your bell to come up with new ideas that leads us to contribute to our society.
3:10 PM		D3-1-6 A Flat-Panel Lamp Based on Carbon Nanotube Field Emission H.-J. Lai (Industrial Technology Research Institute, Taiwan) A high luminance, cold cathode flat lamp using screen-printed carbon nanotube (CNT) cathodes is studied. The carbon nanotube cathode plate of flat lamp was fabricated by thick film coating process. The microstructure of multi-walled carbon nanotube emitters and field emission properties of cathode plate are measured. From field emission results, the low threshold voltage and high luminance can be achieved. A prototype field emissive flat lamp with different spacing was made by size of 1 in Ã- 1 in, and a luminance brightness of this prototype flat lamp more than 10,000 cd/m² can be obtained. The cold cathode flat lamp is an innovative light source capable of displaying high uniform bright pictures. And a new CNT backlight device of 20 shows a potential application for the backlighting module of LCD-TV display, and this new CNT backlight unit is also mercury-free, continuously dimmable and has a high luminance capability.
3:50 PM		D3-1-8 Effect of Ar Neutral Beam Treatment of Carbon Nanotubes for Enhanced Field Emission S.J. Kyung, M. Voronko, B.J. Park, J.B. Park, J.H. Lee, G.Y. Yeom (Sungkyunkwan University, Korea) To use carbon nanotubes(CNTs) for field emission, special surface treatments of the CNTs are often required to achieve low-voltage emission characteristics and a high emission site density. Several surface treatment methods have been studied, such as focused ion beam irradiation, plasma exposure, and laser irradiation, etc. In this study, to improve the field emission properties of screen printed CNT films as one of the surface treatment technique, Ar neutral beam was used and its properties were investigated. Neutral beam plasma treatment has led to an enhancement in the emission properties of CNTs which showed a decrease in turn-on field and an increase in emission sites after the treatment. In addition, the increased defects produced by the neutral beam treatment appeared to make the CNT surfaces more active, thus emitting more electrons compared with other treatment methods. When the field emission properties were measured after the treatment, the turn on field was 0.8 V/µm and the emission field at 1mA/cm² was 1.35 V/µm.
4:10 PM		D3-1-9 Field Emission Characteristics of Chromium Carbide Capped Carbon Nanotip C.H. Hsu, C.-F. Chen (National Chiao Tung University, Taiwan) Chromium carbide capped carbon nanotip was synthesized by bias-assisted microwave plasma chemical vapor deposition. Such a unique structure consists of a solid graphite tip with crystalline chromium carbide on top of each tip. The material may grow to about 500nm in length and 50nm in diameter with good uniformity which may suitable for field emission applications. By selectively coating the catalyst, the material also showed good alignment in the gated structure. The I-V measurements showed a turn-on field of 5 V/µm could be obtained and a stable emission life-time was revealed. The chromium carbide contributed to the field emission stability due to resistance of ion bombardment. The microscopic field emission behavior was also discussed.
4:30 PM		D3-1-10 Magnetic Data Storage Devices Using Carbon Nanotubes E. Titus, N. Ali, G. Cabral, J.C. Madaleno (University of Aveiro, Portugal); D.S. Misra (Indian Institute of Technology, India); B.P. Ramesh, W.J. Blau (Trinity College, Ireland); J. Gracio (University of Aveiro, Portugal) The devices made of ferromagnetically contacted carbon nanotubes (CNTs) is expected to exhibit giant magneto-resistance (GM) and their magnetic properties are crucial for future spintronic applications .The field has expanded significantly since (1998) the discovery of the GM effect in magnetic multilayers and has been the main driving force leading to the development of the present generation of magnetic storage devices. We report the attachment of ferromagnetic transition metals onto multiwalled carbon nanotubes using a novel laser treatment technique. We have established the formation of stable contacts between CNT and transition metal and have confirmation from different analysis techniques.