In the development for alternative to the currently dominating ITO technology, organic transparent conductive films have been demonstrated for some successful. Especially, 3,4-ethylenedioxythiophene (EDOT) is the most intensively investigated monomer in the past decade due to the very high conductivity, transparency, and excellent environmental stability of its polymer (PEDOT). In this work, the author has demonstrated that the realization of direct electropolymerization of water-insoluble EDOT monomer in aqueous media using tandem acoustic emulsification without surfactants. In this demonstration, the tandem acoustic emulsification was conducted with sequential ultrasonic irradiation (20 kHzy → 1.6 MHz → 2.4 MHz), and this technique provided a clear solution containing a few tens nanometer droplets. In addition, electropolymerization in this solution afforded the PEDOT film composed of polymer spheres with a few tens nanometer size range. In addition, packing of these polymer spheres was found to be very high. Smaller size and higher packing of the PEDOT spheres were needed to construct the PEDOT film with high transparency and conductivity. From these results, it can be stated that tandem acoustic emulsification method is suited for development of the PEDOT film with high transparency and conductivity.
