Continuous production of aligned carbon nanotubes: a step closer to commercial realization

High-purity aligned multi-walled carbon nanotubes (MWNTs) were synthesized through the catalytic decomposition of a ferrocene-xylene mixture at similar to 675 degrees C in a quartz tube reactor and over quartz substrates, with a conversion of similar to 25% of the total hydrocarbon feedstock. Under the experimental conditions used, scanning electron microscope images reveal that the MWNT array grows perpendicular to the quartz substrates at an average growth rate of similar to 25 mu m/h. A process of this nature which does not require preformed substrates, and which operates at atmospheric pressure and moderate temperatures, could be scaled up for continuous or semi-continuous production of MWNTs. (C) 1999 Elsevier Science B.V. All rights reserved.