The development and characterisation of polyaniline—single walled carbon nanotube composite fibres using 2-acrylamido-2 methyl-1-propane sulfonic acid (AMPSA) through one step wet spinning process

Abstract

High strength, flexible and conductive polyaniline (PANi)–carbon nanotube (SWNT) composite fibres have been produced using wet spinning. The use of dichloroacetic acid (DCAA) containing 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPSA) has been shown to act as an excellent dispersing medium for carbon nanotubes and for dissolution of polyaniline. The viscosity of DCAA–AMPSA solution undergoes a transition from Newtonian to non-Newtonian viscoelastic behaviour upon addition of carbon nanotubes. The ultimate tensile strength and elastic modulus of PANi–AMPSA fibres were increased by 50 and 120%, respectively, upon addition of 0.76% (w/w) carbon nanotubes. The elongation at break decreased from 11 to 4% upon addition of carbon nanotubes, however, reasonable flexibility was retained. An electronic conductivity percolation threshold of ∼0.3% (w/w) carbon nanotubes was determined with fibres possessing electronic conductivity up to ∼750Scm−1. Raman spectroscopic evidence confirmed the presence of carbon nanotubes in the polyaniline and also the interaction of the quinoid ring with the nanotubes to provide a doping effect.