Electrodeposition of conductive poly(3-methoxythiophene) in ionic liquid microemulsions

The electrosyntheses of poly(3-methoxythiophene) (PMOT) by direct anodic oxidation of MOT in novel ionic liquid microemulsions, BmimPF6/Tween 20/H2O, have been investigated. Among water-in-BmimPF6 (W/IL), bicontinuous (BC), and BmimPF6-in-water (IL/W) sub-regions, IL/W was found to be the most suitable medium for the electropolymerization of MOT. The use of IL/W microemulsions remarkably reduces the amount of IL, which is really expensive as electrolyte. BmimPF6 serves both as the core of IL/W microemulsions and as the supporting electrolyte and thus presents a novel microenvironment for the electropolymerization of MOT. Thus, MOT microdroplets were assembled on a bare ITO electrode and polymerized into PMOT microcups. In addition, the oxidation onset potential of MOT in IL/W microemulsions was lower than that in micellar aqueous solutions or conventional organic solvents. As-formed PMOT films obtained in IL/W microemulsions had an electrical conductivity of 3.8 S/cm and could be dissolved in many conventional organic solvents, including dichloromethane, chloroform, acetonitrile, and dimethyl sulfoxide with green-light emitting property.