Effect of Carbon Precursors on the Structure and Properties of Continuously Spun Carbon Nanotube Fibers

摘要

Synthesis of pristine carbon nanotubes (CNTs) by chemical vapor deposition (CVD) and their direct assembly into macroscopic entities, such as fibers and films, is desirable for a wide range of applications. Here, we present our attempts to directly synthesize high-quality pristine CNT fibers from a floating catalyst CVD reactor built in-house. We explored the effects of using various carbon precursors (methane, methanol, ethanol, n-propanol, n-butanol, and n-pentanol) as CVD reactants in combination with ferrocene (the iron catalyst precursor) and thiophene (the sulfur promoter precursor) on the composition and the properties of the fibers obtained. At optimal conditions, the methanefferrocene/thiophene and the n-butanol/ferrocene/thiophene feedstock produced fibers with minimal extraneous materials, which exhibited better tensile properties and electrical conductivities than the impure fibers obtained from the other carbon precursors. The purity of the fibers spun from methane and n-butanol is attributed to the favorable combinatorial pyrolysis chemistries of the feedstock components.