Simultaneous improvements in conversion and properties of molecularly controlled CNT fibres

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