Synthesis and Characterization of Regioregular Water-Soluble 3,4-Propylenedioxythiophene Derivative and Its Application in the Fabrication of High-Contrast Solid-State Electrochromic Devices

Abstract

Water-soluble sulfonated monomer based on 3,4-propylenedioxythiophene (ProDOT-sultone) was synthesized and characterized for the first time via the O-alkylation of the corresponding unreactive β,β-disubstituted hydroxyl group with propane sultone in the presence of a catalytic amount of 1,4-diazabicyclo[2.2.2]octane (DABCO). This new monomer was oxidatively polymerized to produce regioregular water-soluble conjugated anionic polyelectrolyte, which was then used for the fabrication of solid-state electrochromic devices using the layer-by-layer (LbL) deposition method. These solid-state devices were found to exhibit better electrochromic properties in terms of color contrast, switching time, coloration efficiency (CE), surface control electroactivity, and conductivity in thin films compared with the corresponding water-soluble regiorandom 3,4-ethylenedioxythiophene (EDOT) derivative. For the 40 and 80 bilayer solid-state electrochromic devices, the electrochemical contrast was observed to be 31 and 40% at 5...