Carbon Nanotubes (CNTs) - worth five times as much as gold - deal with the manipulation of individual atoms and molecules.

With its extraordinarily high elasticity and strength, it is hoped CNTs can be used to create machinery to manoeuvre individual atoms to enhance physical and chemical properties from their normal state.

However, the problem has been the lack of production of CNTs, in which only 200 grams can be produced per hour. Until now, that is.

Using a new approach they developed, a research team under the Tsinghua-Nafine Nano-powder Commercialization Engineering Centre claims they have succeeded in making multi-layer CNTs at a startling speed of 15 kilograms per hour.

According to Wei Fei, chief scientist of the research team and a professor with the Chemical Engineering Department of Tsinghua University, the price of CNTs - with purity of 90 per cent on the international market - is approximately US$60 per gram, or roughly five times that of gold. "So the technology for mass production of CNTs is crucial," said Wei. The purity of the CNTs created by the research team is 80 per cent on average, and the inner diameter of the CNTs ranges between 2 to 30 nanometres.

The method Wei and his colleagues invented, called Catalytic Chemical Vapour Deposition Method, relies on chemical reaction that allows the CNTs to "grow" into nano agglomerate on a large scale through a reactor they developed. "The key (of the method) is to create conditions for the hydrocarbon materials to develop into agglomerate of nano tubes rather than loose, larger structures or highly dense structures," Wei said, "otherwise, the produce of CNTs will be too low to be meaningful for industrial use."

However, he admitted there is still a long way to go before products based on CNTs are created. "We have raw materials now but the research and development of products with the CNTs are still in their infancy worldwide."

( November 23,2001)