Evaluation of Solid or Liquid Phase Conducting Polymers Within a Flexible Textile Electrochromic Device

Conducting polymers, in both their solid or liquid states, have been successfully employed within a novel flexible 4-layer electrochromic prototype device. The device consists of the polymer combined with a flexible PET textile spacer, sandwiched between two electrodes - one of which is applied on a flexible textile substrate. The electrochromic materials that have been employed are polyaniline and substituted polythiophene polymers. Two methods of preparation have been used. Aniline was chemically polymerized to the surface of the PET textile substrate, in its solid state, prior to application within the device. Conversely, substituted thiophene monomers, in the solution phase, were suspended within the textile spacer and electrochemically polymerized in situ within the device. The application of an electrical voltage ( ±3 V) effects a reversible color change for both solid and liquid phase systems, providing a flexible communicative textile with applications for protection and safety purposes, or for added fashion. This paper outlines the preparation and characterization of each of the solid and liquid electrochromic display systems and discusses the benefits and drawbacks of each.