Synthesis of carbon nanotube fiber via direct spinning for conducting wires

The commercial conducting materials (Cu, Ag, Al etc.) have achieved their saturation due to their high density and Joule’s heating effect in terms of efficiency. In this outlook, carbon nanotubes (CNTs) are the most versatile, light weight and 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 the most suitable technique because of its simplicity for continuous growth of CNT fiber. In the present work, different growth parameters were analysed for the growth of CNT fibers. The growth of CNT fibres has been carried out through direct spinning of as-synthesised CNT aerogel. CNT fibers were grown successfully via optimizing different processing parameters like temperature, pressure and argon to hydrogen ratio. The morphology of as-spun fibers was investigated via microscopic techniques such as optical microscopy, SEM and TEM. Moreover, the defects and metallicity of as-spun fibers have been analysed using Raman spectroscopy. The change in resistance with change in temperature was also measured for quality of as-made CNT fiber which shows metallic behavior as CNT fiber has positive temperature coefficient. Above 151K, conducting CNTs are dominating and below this temperature, semiconducting CNTs are showing their nature in R v/s T curve. Furthermore, the measured electrical conductivity of as-made fiber is 3.9×10³ S/m. These as-spun metallic fibers can outperform the currently used Cu wire. Hence, as-synthesized conductive CNT fibers have great potential as conducting wires.