Highly electrically conductive poly(3,4-ethylenedioxythiophene) prepared via high-concentration emulsion polymerization

Poly(3,4-ethylenedioxythiophene) (PEDOTh) with high electrical conductivity was prepared by oxidative polymerization of 3,4-ethylenedioxythiophene under high-concentration emulsion conditions in the presence of 2-naphthalenesulfonic acid sodium salt acting as an emulsifier and a doping agent and Fe2(SO4)3 as an oxidant. PEDOTh with electrical conductivity as high as 165 S cm−1 was obtained with good yield. XRD analysis indicated that the PEDOTh had a face-to-face stacking distance of 3.3 Å between the polythiophene planes in the solid. The SEM image revealed that the PEDOTh particles formed a layered structure. The packing structure, morphology, and electrical conductivity of the obtained PEDOTh were compared with those of PEDOTh synthesized via a usual emulsion polymerization.