Production of carbon nanotube yarn from swirled floating catalyst chemical vapour deposition: a preliminary study

Oluseyi Aberefa, Kabir Bedasie, Shaakirah Madhi, Michael O Daramola and Sunny E Iyuke

Abstract

Production of yarn made of high purity carbon nanotubes (CNTs) is essential to novel macro-scale applications in the making of bulletproof vests, electrically conductive wire, antennas and mechanical actuators. In this study, which serves as a preliminary investigation towards optimization and scaling-up of production of high purity yarn using direct spinning of CNT bundles in a swirled floating catalyst chemical vapour deposition (SFCCVD), yarn was produced through direct spinning of CNT bundles. CNT bundles were synthesized in the SFCCVD reactor using acetylene as the carbon source and ferrocene as the catalyst. Effect of feed flow rate and reaction temperature on the production was investigated. Morphology, degree of defect and electrical conductivity of the as-produced yarn were checked using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), Raman spectroscopy and four-probe method, respectively. CNT yarn was successfully obtained at a reactor temperature of 1000 °C and at acetylene flow rate of 135 ml min⁻¹. SEM micrographs of the fibrous structure show high degree of alignment parallel to the fibre direction with good consistency. Results from the four-probe method test show a typical linear ohmic behaviour indicating that the samples are electrically conductive. Higher reactor temperature favours the production of CNT yarn with a higher electrical conductivity and less crystalline defects