Facile synthesis of highly conductive and dispersible PEDOT particles

Abstract

Poly(3,4-ethylene dioxythiophene) (PEDOT) is widely used in electronics for its excellent conducting property. However, it is challenging to synthesize PEDOT nanoparticles with high conductivity and high dispersibility in various organic solvents. We introduce a novel strategy for synthesizing highly conductive, dispersible PEDOT particles in a binary organic solvent system. The synthesis strategy is based on a standard chemical oxidation procedure, which uses ferric chloride (FeCl 3 ) as the oxidant without any post-doping process in a mixed solvent of dichloromethane and acetonitrile (CH 2 Cl 2 and CH 3 CN). By optimizing the synthesis process, high-quality colloidal PEDOT nanoparticles (average diameter is around 50 nm) are obtained with a high yield of over 75%. These nanoparticles show a maximum electrical conductivity of 220 S/cm, which is close to the highest electrical conductivity of the current solid PEDOT powder. Moreover, these particles can be dispersed in various organic solvents and water without a surfactant and maintain stable conductivity for over one month. This outstanding processability and conductivity could reinforce thermoplastic polyurethane resins as conductive composites. Prototyped applications of the PEDOT nanoparticles as supercapacitor materials are demonstrated. The PEDOT nanoparticles show a high specific capacitance of 280 F/g, comparable to other reported PEDOT materials prepared using various templates. • Colloidal PEDOT nanoparticles with a conductivity of 220 S/cm are obtained. • These particles are dispersible in various organic solvents or water. • These particles are potentially for supercapacitor and conductive additives.