Posted: June 15, 2006

Spinning of high strength fiber using single-walled carbon nanotubes

(Nanowerk News) A research team headed by Dr. Takeshi Saito from the Research Center for Advanced Carbon Materials of the National Institute for Advanced Industrial Science and Technology (AIST) in Japan has developed a novel synthesis method for SWNTs (single-walled carbon nanotubes) to be the core material for nanotechnologies.
This method modified from the DIPS (direct injection pyrolytic synthesis) method has dramatically improved an accurate control of the reaction conditions to achieve high purity and a high degree of graphitization. The purity of the nanotubes increased from 50% to 97.5%, and the structural defects in the nanotubes was reduced to one tenth of the previous level. As there is no need for purification processes, surface treatments or use of binder, these high quality SWNTs can be used directly as high strength threads (SWNT wire) or as SWNT mesh sheets for cell culture.
The results of the present research were presented at the "Advanced Nanocarbon Application Project Symposium" organized by the New Energy and Industrial Technology Development Organization (NEDO) on May 12, 2006 under the title "Research on Catalysis and Processes of Single-Walled Carbon Nanotubes"
SWNTs manufactured through conventional mass production technologies produce a large amount of impurities that require aftertreatments for purifying or modifying and become an obstacle to their use as an industrial material. Delivering SWNT in this form could be compared to delivering coal and asking the user to refine or modify it before using it, with the corresponding investment in time and effort. The refining process could be also detrimental to the quality and homogeneity of the SWNTs, creating problems from the point of view of quality control and hindering their use as an industrial material.
Under the direction of Sumio Iijima, the Research Center for Advanced Carbon Materials has been tackling two important topics: synthesis and application of SWNTs. Recently, Dr. Takeshi Saito et al. has concentrated efforts on developing a mass production technology for SWNTs using the DIPS method, identifying the main points that allow an accurate control of the reaction field during the synthesis of SWNTs, and enhancing the conventional production method to improve the quality and catalytic efficiency of manufactured SWNT.
Source: AIST