Simultaneous improvements in conversion and properties of molecularly controlled CNT fibres

Abstract

Fibres of ultralong and aligned carbon nanotubes (CNT) have axial properties above reference engineering materials, proving to be exceptional materials for application in structural composites, energy storage and other devices. For CNT fibres produced by direct spinning from floating catalyst chemical vapor deposition (FCCVD), a scaled-up method, the challenge is to simultaneously achieve high process conversion and high-performance properties. This work presents a parametric study of the CNT fibre spinning process by establishing the relation between synthesis conditions, molecular composition (i.e. CNT type), fibre mechanical and electrical properties, and conversion. It demonstrates tensile properties (strength 2.1 N/tex, modulus 107 N/tex) above some carbon fibres, combined with carbon conversion about 5%, significantly above literature on similar materials. The combined improvement in conversion and properties is obtained by conducing the reaction at high temperature (1300 °C), using toluene as a carbon source, and through adjustment of the promotor to carbon ratio (S/C) to favor formation of few-layer, collapsed CNTs that maximize packing at relatively high conversions. Lower S/C ratios produce low-defect single-wall CNT, but weaker fibres. An increase in electrical conductivity to 3 x 10^5 S/m is also observed, with the data suggesting a correlation with longitudinal modulus.

arXiv comment19 pages, 8 figures, 1 table

References in corpus (5)

• A Perspective on High-performance CNT fibres for Structural Composites
• Tensile properties of carbon nanotube fibres described by the fibrillar crystallite model
• Understanding cooperative loading in carbon nanotube fibres through in-situ structural studies during stretching
• A Route to High-Toughness Battery Electrodes
• Molecular characterization of macroscopic aerogels of single-walled carbon nanotubes

Cited by in corpus (3)

• Simultaneously Enhanced Tenacity, Rupture Work, and Thermal Conductivity of Carbon Nanotubes Fibers by Increasing the Effective Tube Contribution
• Gas-to-nanotextile: high-performance materials from floating 1D nanoparticles
• Identification of Collapsed Carbon Nanotubes in High-Strength Fibres Spun from Compositionally Polydisperse Aerogels