Synthesis and Characterization of Crystal‐Like Electroactive Conjugated Polymers
Ryo Kawakami, Sae Kohroki, Shigeki Nimori, Hiromasa GotoABSTRACT
In this study, electrochemical polymerization is successfully achieved within a spherulite crystal matrix. Poly(3,4‐ethylenedioxythiophene) and polythiophene thin films featuring a spherulitic optical texture are synthesized via electrochemical polymerization within a soft molecular crystal. Furthermore, electrochemical polymerization within the crystal is performed under a 28 T magnetic field. Molecular structural analysis confirms that the resulting polymer films are composed of pure polymers without any residual elements. The as‐synthesized polymer films exhibit the characteristic optical texture of spherulitic crystals, featuring radial bands that reflect a twisted lamellar structure imprinted by the spherulite matrix. Cyclic voltammetry analysis reveals the electrochemical activity of the as‐obtained crystal‐like polymers, indicating reproducible redox processes governed by electron transfer. Ultraviolet–visible absorption measurements reveal the electrochromic activity of the polymers, demonstrating a clear decrease in the intensity of the absorption corresponding to the π–π* transition and a concomitant increase in the intensity of those associated with polarons and bipolarons induced by electrochemical doping. The proposed method provides a simple and effective approach for the preparation of electroactive conjugated polymer films featuring spherulitic morphological ordering.