Nanotube length and density dependences of electrical and mechanical properties of carbon nanotube fibres made by wet spinning

Abstract Fibres composed of carbon nanotubes (CNT) can be used to make lightweight materials with high mechanical strength and electrical conductivity. However, the reported properties have been much poorer than those of the individual CNT. To address this discrepancy, it is necessary to elucidate the relationship between the fibres' structure and their properties. Here, we systematically investigated the CNT length and fibre density dependences of the electrical and the mechanical properties of CNT fibres produced by the wet-spinning method. The obtained specific conductivities of the fibres were almost proportional to the effective CNT lengths, whereas such correlations were less apparent for the fracture strengths and Young's moduli.