Synthesis of carbon nanotube fiber via direct spinning for conducting wires

Abstract

The commercial conducting materials (Cu, Ag, Al etc.) have achieved their saturation due to their high density andJoule’s heating effect in terms of efficiency. In this outlook, carbon nanotubes (CNTs) are the most versatile, light weightand high electrically conducting material for advance generation. But it is difficult to weave them for commercialization.For the growth of 3-D CNT assemblies such as CNT fiber, CNT sheet, CNT rope and CNT ribbon, direct spinning is themost suitable technique because of its simplicity for continuous growth of CNT fiber. In the present work, different growthparameters were analysed for the growth of CNT fibers. The growth of CNT fibres has been carried out through directspinning of as-synthesised CNT aerogel. CNT fibers were grown successfully via optimizing different processingparameters like temperature, pressure and argon to hydrogen ratio. The morphology of as-spun fibers was investigated viamicroscopic techniques such as optical microscopy, SEM and TEM. Moreover, the defects and metallicity of as-spun fibershave been analysed using Raman spectroscopy. The change in resistance with change in temperature was also measured forquality of as-made CNT fiber which shows metallic behavior as CNT fiber has positive temperature coefficient. Above151K, conducting CNTs are dominating and below this temperature, semiconducting CNTs are showing their nature inR v/s T curve. Furthermore, the measured electrical conductivity of as-made fiber is 3.9×10³ S/m. These as-spun metallicfibers can outperform the currently used Cu wire. Hence, as-synthesized conductive CNT fibers have great potentialas conducting wires.