Continuous and Patterned Conducting Polymer Coatings on Diverse Substrates: Rapid Fabrication by Oxidant-Intermediated Surface Polymerization and Application in Flexible Devices

Conducting polymer coatings and patterns are the most important forms of these materials for many practical applications, but a simple and efficient approach to these forms remains challenging. Herein, we report a universal oxidant-intermediated surface polymerization (OISP) for the fabrication of conducting polymer coatings and patterns on various substrates. A coating or pattern composed of densely packed colloidal V2O5·nH2O nanowires is deposited on the substrate via spin coating, dip coating, or printing, which is converted into a conducting polymer one after in situ oxidation polymerization. The polymerization occurs selectively on the V2O5·nH2O coatings, and high-quality polypyrrole, polyaniline, and poly(3,4-ethylenedioxythiophene) coatings and patterns on planar and curved polymeric, metallic, and ceramic substrates are obtained in a fast reaction rate similar to the electrochemical polymerization. The mechanistic study reveals that the method relies on the excellent processability and formability of V2O5·nH2O nanowires, which is further explained by their large aspect ratio and surface activity. A flexible gas sensor array comprising three individual sensors made of different conducting polymers is fabricated using oxidant-intermediated surface polymerization, and it is successfully used to distinguish various analyte vapors. The method developed here will provide a powerful tool for the fabrication of conducting polymer-based devices.