Ionically Self-Assembled Polyelectrolyte-Based Carbon Nanotube Fibers

We present a process for synthesizing ionically self-assembled polyelectrolyte-complex-based carbon nanotube fibers using a simple noncovalent stabilization of carbon nanotube aqueous dispersions where no surface functionalizations of the nanotubes were necessary. The polyelectrolyte-carbon nanotube composite fibers have mechanical, electrical and chemical properties which make them a choice of materials in applications such as biosensors, chemical electrodes or flexible electronics. The fibers showed reasonable strength and conductivity as high as 45 S/cm for single-walled carbon nanotubes and 80—90 S/cm for multiwalled carbon nanotubes, due to the presence of an interconnected network of carbon nanotubes embedded inside the fibers. Fiber formation was demonstrated for a variety of strong polyelectrolyte combinations, including a conductive fiber matrix consisting of poly (ethylenedioxythiophene) (PEDOT), with the presence of nanotubes causing a 2 orders of magnitude increase in the conductivity of the base polymer. The self-assembled polyelectrolyte-carbon nanotube fibers have potential applications in biosensing and flexible electronics.