ABSTRACT
Carbon nanotubes (CNTs) can behave like metals or semiconductors, can conduct electricity better than copper, can transmit heat better than diamond and they rank among the strongest materials known. CNTs produced using the chemical vapour deposition (CVD) method may have more structural defects compared to nanotubes produced by arc-discharge or laser vaporization. However, a perfect CNT structure is not important for many applications. By the end of the 1990s, applications of CNTs and nanofibres were attracting extensive interest. CNTs have proven to be good field emitters. The first CNTs identified by S. Iijima in 1991 were synthesized using a carbon arc-discharge. CNTs were found to grow on the negative end of the carbon electrode, plentifully on only certain regions of the electrode. CNTs and nanofibres can be synthesized efficiently by the catalytic decomposition of a reactant gas that contains carbon, when made to flow over a transition metal catalyst, CVD.
