Tsukuba, Japan—Conductive polymers possess various properties in addition to conductivity, with applications in light-emitting devices, electromagnetic wave shielding, and anticorrosion materials. One of their properties is the generation of polarons, which are virtual particles responsible for electrical conduction and are formed during doping via electrochemical oxidation in conductive polymers. These polarons considerably influence optical and magnetic properties. Herein, researchers focused on the "Faraday rotation" phenomenon, in which optically inactive substances exhibit optical rotation when linearly polarized light passes parallel to a magnetic field.
The research group has previously synthesized various optically active conductive polymers in liquid crystals. Herein, the researchers synthesized optically inactive polythiophenes and modulated their polarons by electrochemically oxidizing and reducing (doping and dedoping) them in a magnetic field under a Faraday configuration at a constant low voltage of <1.5 V. Thus, a combination of magnetic modulation and electrochemistry endows conducting polymers with electrochemical control of optical rotation. They developed a method for controlling the optical rotation of achiral polythiophenes. This method has promising applications in magnetic field sensors and optical communication devices.
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This research was supported by the Japan Society for the Promotion of Science under Grants-in-Aid for Scientific Research (No. 20K05626) and JST, the establishment of university fellowships towards the creation of science technology innovation, Grant Number JPMJFS2106.
Title of original paper:
Electrochemical Faraday Effect of a Conductive Polymer
Journal:
Molecular Crystals and Liquid Crystals
DOI:
10.1080/15421406.2025.2548702
Associate Professor GOTO, Hiromasa
Institute of Pure and Applied Sciences, University of Tsukuba
MIYASHITA, Ryo
Doctoral Program in Engineering Sciences, Degree Programs in Pure and Applied Sciences, Graduate School of Science and Technology, University of Tsukuba
Institute of Pure and Applied Sciences
Molecular Crystals and Liquid Crystals
Electrochemical Faraday effect of a conductive polymer
26-Aug-2025