Carbon nanotube growth on carbon fibers

Carbon nanotubes (CNT) were synthesized on graphite fibers by thermal CVD. On the fiber surface, iron nanoparticles are coated and act as catalysts for CNT growth. The growth temperature ranges from 550 to 1000 degreesC at an ambient pressure. Methane and hydrogen gases with methane contents of 10-100% are used for the CNT synthesis. At high growth temperatures (>800 degreesC), the rapid inter-diffusion of the transition metal iron on the graphite surface results in a rough fiber surface with no CNT grown on the surface. When the growth temperature is relatively low (650-800 degreesC), CNT are fabricated on the graphite surface with catalytic particles on the nanotube top ends. Using micro Raman spectroscopy in the breath mode region, single-walled or multi-walled CNT can be determined, depending on methane concentrations. (C) 2003 Elsevier B.V. All rights reserved.