Production of CNT yarns for use as filaments in incandescent bulb: effect of carbon source and state of catalyst on production of CNT

Abstract

Presence of highly aligned carbon nanotubes (CNTs) bundles is a prerequisite to producing good quality CNTs that will retain their original good electrical and mechanical properties when spun into yarn. In this study, effects of carbon source and state of catalyst on the CNT yield and quality during the production of CNTs were investigated. CNTs were produced in a Swirled Continuous CVD reactor using acetylene and methane as carbon sources and ferrocene as a catalyst to investigate the effect of carbon source and the production was carried out with the state of the catalyst altered to investigate effect of state of catalyst on the yield and quality of the CNTs. The quality and purity of the produced CNTs were checked with Raman and Scanning electron microscopy (SEM) provides information on the morphology of the produced CNTs. SEM images of the produced CNTs using acetylene gas reveal the presence of more nanoballs than those produced using methane under the similar conditions. However, amount of CNTs produced using methane is very low compared to the amount obtained when acetylene was used. The CNT yield from methane was enhanced when ferrocene (catalyst) was dissolved in cyclopentane. Results from SEM and Raman Spectroscopy indicates CNT bundles with longer lengths and reduced number of nanoballs when methane was used together with ferrocene dissolved in cyclopentane as compared to using ferrocene in a solid state.