Synthesis of conductive polymer alloys by electrochemical polymerization in chiral liquid crystal

Abstract

Synthesis of conjugated polymer alloys with chirality was developed. Optically active polymer alloys were prepared by electrochemical polymerization in cholesteric liquid crystal. First, we prepared polymer alloys with 2,2′-bithiophene (BT) and bis-(3,4-ethylenedioxythiophene) as monomers. By mixing the amounts of the two types of monomers, surface structure and optical texture were tuned. Next, we prepared polymer alloys with the monomers by electrochemical polymerization. The electrochemical redox function was present in all the polymer alloys. The absorption bands derived from electrochemical doping and dedoping were observed in an oxidized and reduced state. Circular dichroism (CD) of the polymer alloys was controllable with electrochemical redox tuning. The CD bands in the near-IR range were assigned to the doping band as a form of polarons (radical cations). This research examined electrochemical control of charge carrier “chiralions.” Synchrotron XRD measurement confirmed the molecular form imprinting of the polymer alloys from the host cholesteric liquid crystal.