Synthesis of poly(3,4-ethylenedioxythiophene) nanoparticles via chemical oxidation polymerization

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles were synthesized via chemical oxidation polymerization using 3,4-ethylenedioxythiophene as the starting monomer and ammonium peroxydisulfate (APS) as the oxidant. The effects of APS concentration, surfactant concentration and type of surfactant, namely dodecylbenzenesulfonic acid and sodium dodecylsulfate, were investigated. Distinct particle shapes were obtained: irregular, raspberry agglomerate, coralliform, orange-peel, globular and plum shapes. The particle sizes and the electrical conductivity are in the ranges 60 to 900 nm and <1 to 153 S cm−1, respectively, depending on the polymerization conditions. PEDOT synthesis in the absence of a surfactant yields a smaller particle size because a larger amount of initiator induces lower molecular weights and smaller PEDOT particles. The smaller PEDOT particles correspond to higher electrical conductivity because of the larger surface areas for electron transfer and a smaller amount of obstructing surfactant aliphatic segments. Moreover, particle size and shape can be varied, depending on surfactant type and concentration which dictate the micellar shapes in the polymerization reaction. This work is focused on the tailor-made PEDOT shape and property relationship under synthesis conditions where several shapes have not been previously seen. © 2013 Society of Chemical Industry