Surface properties and conductivity of bis(2-ethylhexyl) sulfosuccinate-containing polypyrrole

Abstract

Polypyrrole (PPy) was chemically synthesized by oxidative polymerization of pyrrole in aqueous solution containing an oxidant, ferric chloride, and an anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The results of elemental analysis confirmed that the surfactant is incorporated into the PPy structure. The presence of the anionic surfactant AOT in polymerization mixture influences the properties of chemically prepared polypyrrole due to bonding the anionic part of the surfactant molecule to the PPy chains as proved by X-ray photoelectron spectroscopy (XPS) analysis. Scanning electron microscopy study showed that the presence of the AOT affects the morphology of the product. A more compact powder morphology and reduced size of the PPy globules were revealed. The addition of AOT to the reaction mixture results in a significantly increased conductivity: PPy synthesized in polymerization solution containing molar ratio [pyrrole]/[AOT] = 7 reached conductivity as high as 27 S cm −1, while the same experiment performed in the absence of AOT yielded a polymer with conductivity of 3.9 S cm −1 only.