The influence of carbon nanotubes on mechanical and electrical properties of polyaniline fibers

Two possible candidate materials investigated for conductive fibres are polyaniline (PANi) and carbon nanotubes (CNTs). This current research has produced composite fibres consisting of a PANi host reinforced by carbon nanotubes. Many challenges are inherent in the wet-spinning of carbon nanotube/PANi fibres, particularly the preparation of highly dispersed CNTs in the PANi solution and the control of the nature of the CNTs/PANi interface to ensure both charge transport and the transfer of mechanical load. Size distribution studies demonstrate that the quality of the dispersion can be improved by addition of PANi to CNTs in dimethyl propylene urea (DMPU). The mechanical and four probe electrical conductivity tests show a 150% increase in tensile stress and a 110% increase in young's modulus as well as a 30 times enhancement in electrical conductivity with the addition of 2% CNTs. SEM studies confirm the lower porosity of the composite fiber due to a higher viscosity of the composite spinning solution. In addition, Raman spectroscopy reveals specific π-π interactions between PANi (quinoid ring) and CNTs.