Scalable Mass-Production of Purer SWNTs Feasible.

Researchers at Japan's National Institute of Advanced Industrial Science and Technology (AIST) have announced a new mass-production process for single-wall carbon nanotubes (SWNTs) with much higher purity than has been previously possible by other synthetic processes.

Currently Raymor Industries Inc. in Canada is the only company embarking on mass-production of SWNTs. The company recently announced its plan for 2006 SWNT production levels which are set at 2 to 3 tons/year primarily targeted for the nanocomposites market. Raymor's product is around 60% purity and is produced by a proprietary, environmentally-friendly, plasma torch-based process using methane feedstock which yields hydrogen as the only byproduct. The AIST group is headed by Sumio Iijima who originally discovered CNTs in 1991 while working as a researcher at NEC's laboratories in Japan. In this latest development Iijima's team at AIST, led by Takeshi Saito, have refined a conventional synthetic method called direct injection pyrolytic synthesis (DIPS). This process involves spray injection of toluene as the carbon feedstock, and a nanocolloid dispersion of metal catalyst, such as cobalt, into a furnace at 1200o Celsius.

In these latest refinements ...