International Assessment of Carbon Nanotube Manufacturing and Applications

Abstract : This WTEC study focuses on the manufacturing and applications of carbon nanotubes "CNTs" to identify recent progress in understanding the commercial potential of CNTs as viewed by academic, industrial, and government research facilities around the world. CNT manufacturing methods and equipment, processing and separation techniques, characterization procedures, and opportunities for international collaboration are highlighted in this study. These issues are also discussed in the context of leading electronic, optical, and mechanical applications of CNTs ranging from transistors to structural composites. CNTs can be produced by many methods, and depending on the diameter, one can obtain either single-walled CNTs "SWCNTs" or multi-walled CNTs "MWCNTs". The current capacity for the production of MWCNTs far exceeds that of SWCNTs. SWCNTs are much more expensive and difficult to manufacture than MWCNTs, and there is not yet a distinct large-scale market for SWCNTs, which is needed to drive down the production cost. For both types of CNTs, Asia?s production capacity is two to three times higher than that estimated for North America and Europe combined; Japan is the prominent leader in the production of MWCNTs. Use of CNTs in lithium-ion battery electrodes is the current driving force of ton-scale MWCNT production in Japan. CNT-replacement products for indium tin oxide "ITO" and field emission devices "FEDs" are driving increased production of SWCNTs, whereas applications using transistors require precise control over CNT diameter and conductivity, which is farther from commercial realization. When the cost of bulk SWCNTs decreases significantly, applications in electromagnetic shielding "EMI" and electrostatic discharge "ESD" protection can be expected, and SWCNTs will replace MWCNTs in conductive plastics.