Site-Selective Modification of Conductive Materials By Bipolar Electropolymerization

Electrooxidative coupling polymerization of aromatic monomers affords π-conjugated polymers. Conducting polymers are generally insoluble in solvents and are thus deposited on the surface of an anode during polymerization. This film formation is one advantage of electropolymerization because the chemical oxidative polymerization of aromatic monomers using chemical oxidants affords only insoluble powder or bulk of the corresponding polymers. This advantage is potentially useful for wide variety of applications, such as in electronics and sensors.Recently, bipolar electrodes (BPEs) are available as wireless electrodes that undergo anodic and cathodic reactions at their terminals. When electropolymerization of aromatic monomers is conducted on a BPE, which is known as bipolar electropolymerization, this results in the wireless and site-selective formation of conducting polymer films or clusters at one terminal of the BPE. The alternating current (AC) bipolar electropolymerization of 3,4-ethylenedioxythiophene (EDOT) successfully provides microfibers of the corresponding polymer, poly (3,4-ethylenedioxythiophene) (PEDOT), grown from both terminals of the BPE. In this context, the bipolar method is next-generation electropolymerization that can site-selectively modify wireless electrodes with conducting polymers to afford novel hybrid materials. Herein, the concept of bipolar electropolymerization and recent examples are described.