Synthesis and electrochromic properties of polyacrylate functionalized poly(3,4-ethylenedioxythiophene) network films

Abstract

A novel acrylate modified 3,4-ethylenedioxythiophene (EDOT-AA) was synthesized, and its free radical polymerization and electrochemical polymerization led to the formation of corresponding precursor polymer polyacrylate (PAA) functionalized with 3,4-ethylenedioxythiophene (EDOT-PAA) and uniform electrodeposition of acrylate modified poly(3,4-ethylenedioxythiophene) (PEDOT-AA) and polyacrylate modified poly(3,4-ethylenedioxythiophene) (PEDOT-PAA), respectively. The structure, electrochemical, optical, thermal properties and morphology of as-formed polymers were systematically investigated by FT-IR, cyclic voltammetry, UV–vis, thermogravimetry (TG) and scanning electron microscopy (SEM). Cyclic voltammetry and spectroelectrochemistry studies demonstrated that PEDOT-AA and PEDOT-PAA can be reversibly oxidized and reduced accompanied by obvious color changes from dark brown to transmissive blue for PEDOT-AA, and from magenta to blue for PEDOT-PAA. The introduction of the acrylate group significantly improves the electrochromic properties of PEDOT and results in high contrast ratios (ΔT% = 50.9 % at 620 nm for PEDOT-AA) and coloration efficiencies (339 cm² C⁻¹ for PEDOT-AA and 211 cm² C⁻¹ for PEDOT-PAA), low switching voltages and fast response time (1.4 s for PEDOT-AA and 0.9 s for PEDOT-PAA).