Multifunctional attributes of carbon nanotubes (CNTs) have attracted the focus of industrial and academic communities alike. Translating the properties of individual CNTs into their macroscopic ensembles – fibres, yarns or films – is envisaged to uncover a vista of applications. The performance of the ensembles relies on their internal structures which are in turn governed by the structural characteristics of the nanotubes i.e the number of walls, aspect ratio and chirality distributions. Ideally, materials of (near) homogeneous composition are preferred. While, CNT production by chemical vapour deposition (CVD) is advantageous with its potential of scalability, the products are, in general, heterogeneous, requiring post-production purification and sorting. We present a novel CVD-based approach resulting in the large-scale continuous production of pristine CNT macroscopic-assemblies, composed of principally single or double or multi-walled CNTs, with well-defined structural characteristics. The synthesis was further optimised to directly produce metallic single-walled nanotube fibres, with a significant (near) armchair-CNT content. The duplex role of sulphur as a promoter and as a tool for catalyst-size control, in addition to the influence of orchestrated carbon, catalyst and sulphur-precursor pyrolysis, towards obtaining fibres comprising CNTs of selective morphologies and the resulting fibre- properties will be presented.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2012: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: June 18, 2012
Pages: 310 - 313
Industry sector: Advanced Materials & Manufacturing
Topic: Carbon Nano Structures & Devices