This "microreactor" is where the single-walled carbon nanotubes grow.
T1 - High quality single-walled carbon nanotube synthesis using remote plasma CVD
KW - Single-walled carbon nanotubes
If the growth process could be understood and optimized, the incredible properties of carbon nanotubes could be applied for a multitude of high-volume applications.
Meindl, "Design and Performance Modeling for Single-walled Carbon Nanotubes as Local, Semiglobal, and Global Interconnects in Gigascale Integrated Systems," IEEE Trans.
Achiba, "Optical Properties of Singlewall Carbon Nanotubes," Synth.
Single-walled carbon nanotube (SWNT) forest synthesis using antenna-type remote plasma chemical vapor deposition (ARPCVD) is presented. A series of synthesis using carbon monoxide gas as carbon feedstock reveals that the remote conditions, in other words, distance between an antenna and a substrate affects the quality of nanotube significantly. That is, far distance geometry on ARPCVD creates high-quality SWNTs. It motivates us to use same methodology for the synthesis using CH 4/H 2 previously proven to make long SWNT forests. Finally, along the methodology, we achieve to make SWNT forest with high-quality and small diameter successfully. This study offers an important suggestion to embody SWNT forests with both length and quality using remote plasma CVD.
This technique involves biasing a sharp carbon rod to many thousand volts. The voltage is then discharged from the rod, rapidly heating the rod and vaporizing some of the carbon. This carbon vapor is allowed to cool, and as it does CNTs are produced. The arc discharge method generally involves the use of a vacuum chamber and an inert gas supply. Even single-walled nanotubes can be produced if the proper metal ions are introduced. When optimized, this method can turn roughly 30% of the carbon into carbon nanotubes.
McEuen, "Single-wall Carbon Nanotubes," Phys.
A variant of CVD developed by scientists at the NASA Glenn Research Center, and embodied by the Nanotech Innovations SSP354 reactor involves injecting a liquid precursor that already contains both the carbon and catalyst atoms in it into a two temperature zone reactor tube. The first zone vaporizes the liquid and the iron and carbon atoms are swept into a second, higher temperature zone where the growth occurs. The iron atoms from the vapor congregate into nanoparticle islands and the CNT growth takes place from those. This allows for the entire inside of the hot zone of the reactor tube to be used as a growth surface, both simplifying the process and greatly increasing yield. Since this technique eliminates the need for pre-patterned catalyst deposition prior to carbon atom injection by using a single compound that contains both atoms it is often called a “single source precursor” method. It saves both time and money when making multi-walled nanotubes. At present the single source precursor method is used to produce only multi-walled tubes. Work is underway to extend the technique to include growth of single-walled nanotubes.
The most popular and simplest way to grow carbon nanotubes in the laboratory is to use chemical vapor deposition (CVD). A CVD system for CNT growth injects a vaporized hydrocarbon compound (methane or ethane are common) into a high temperature zone in a furnace. The hot zone contains a substrate on which has been pre-deposited a thin film of iron, nickel or cobalt that has either separated or been pre-patterned into nanoscale islands of the metal. These nanoscale islands catalyze the growth of the carbon nanotubes. The catalyst is the key to the whole process and careful attention must be given to its deposition. Both single and multi-walled CNTs can be produced via CVD.
Lu, "Elastic Properties of Carbon Nanotubes and Nanoropes," Phys.
Zuppiroli, "Mechanical Properties of Carbon Nanotubes," Appl.
Beyers, "Cobalt-catalysed Growth of Carbon Nanotubes with Single-atomic-layer Walls," Nature, 363 605-7 (1993).
Treacy, "Young's Modulus of Single-walled Nanotubes," Phys.
Unger, "How do Carbon Nanotubes Fit into the Semiconductor Roadmap?," Appl.
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Haddon, "Chemistry of Singlewalled Carbon Nanotubes," Acc.
Based on the achievements of a NEDO project, Zeon Corporation (ZEON) has completed and begun operation of the world’s first mass production plant for carbon nanotubes (CNTs) using the Super-growth (SG) method developed by the National Institute of Advanced Industrial Science and Technology.
The SG method enables high speed, large quantity synthesis, and CNTs made with the SG method have high aspect ratio, high purity, and large surface area compared with conventional CNTs. They bear high expectations for application in new functional materials and next generation devices with as of yet unseen functions and characteristics. Increasing demand is expected, as they can be applied to innovative materials and devices, including high-performance capacitors, highly functional rubber materials, and high-heat conductive materials.
Zeon Corporation began mass production in November, 2015.
Lieber, "Diameter Controlled Synthesis of Carbon Nanotubes," J.
Carbon nanotubes were discovered by Dr. Sumio Iijima of Japan, and Japan currently leads the world in researching this material. Its light weight, high strength, and high electrical and thermal conductivity lend to great expectations for its use in a variety of applications.
In the NEDO project “Nanocarbon Application Product Creation Project” (FY2003 to FY2005), the National Institute of Advanced Industrial Science and Technology (AIST) developed the base technology of the Super-growth method (SG method), an innovative CNT synthesis method found by Dr. Kenji Hata of AIST in 2004. In the “Carbon Nanotube Capacitor Development Project” (FY2006 to FY2010), AIST and ZEON advanced development of carbon nanotube (CNT) mass production technology. Additionally, AIST and ZEON started construction of a mass-production demonstration plant through the FY2009 Ministry of Economy, Trade, and Industry supplementary budget project, and since 2011 have promoted technology dissemination activities by providing samples.
Recently, ZEON has used technology derived from the AIST mass production demonstration plant to complete the world’s first mass production plant for high quality CNTs produced with the SG method (SGCNTs).
Because SGCNTs display such traits as high aspect ratio, high purity, and large surface area compared with other CNTs, this material bears expectations for application to new functional materials and next generation devices with as of yet unseen functions and characteristics. This suggests the possibility of innovative materials and devices, including high-performance capacitors, highly functional rubber materials, and high-heat conductive materials, and demand is also expected to expand greatly. In order to meet the demand in the market for these applied products, ZEON began mass production of SGCNTs from November, 2015.
Carbon nanotube synthesis - Nanoscience Instruments
 Development of SGCNT mass production base technology
In the NEDO project, AIST and ZEON have built inexpensive catalyst deposition technology, large-area synthesis technology, and continuous synthesis technology, which are especially important within the SG method. Figure 1 shows the SG method. The SG method is an excellent CNT synthesis method that greatly improves the activity and life span of a catalyst, and maintains high growth efficiency by adding a small amount of moisture to the gas-phase synthesis furnace atmosphere. Compared with conventional CNT synthesis, synthesized SGCNTs show hundreds of times the growth efficiency and can be easily separated from the substrate, therefore SGCNTs with a carbon purity of over 99 % can easily be collected, allowing for a significant reduction in catalytic usage and manufacturing cost.
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