Organic Mixed Ionic-Electronic Conductors Based on Tunable and Functional Poly(3,4-ethylenedioxythiophene) Copolymers

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrochemistry

Background:

• Organic mixed ionic-electronic conductors (OMIECs) are crucial for bioelectronics, biosensors, and optoelectronics.
• Conjugated polymers in OMIECs enable coupled ionic and electronic transport but often face limitations in either ion conduction or synthetic modification.
• Previous research has primarily focused on optimizing individual OMIEC properties, hindering the development of materials excelling in both.

Purpose of the Study:

• To develop novel OMIECs based on functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) copolymers.
• To achieve efficient ion/electron transport combined with versatile post-functionalization capabilities.
• To create OMIECs with tunable properties for advanced applications, particularly in bioelectronics.

Main Methods:

• Electrochemical copolymerization of EDOT monomers bearing sulfonic (EDOTS) and carboxylic acid (EDOTCOOH) groups.
• Utilized oxygen plasma treatment on conductive substrates to enable synthesis of high EDOTS ratio copolymers.
• Post-functionalization of EDOTCOOH groups on the synthesized copolymers.

Main Results:

• Successfully synthesized functionalized PEDOT copolymers with tunable conductivity (2-0.0019 S/cm) and ion/electron transport (122-11 F/cm³).
• Oxygen plasma treatment facilitated the incorporation of high EDOTS ratios (up to 68%), overcoming limitations of untreated substrates.
• Demonstrated successful post-functionalization of EDOTCOOH without compromising ionic and electronic transport properties.

Conclusions:

• Developed a new class of OMIECs with enhanced ion/electron transport and synthetic flexibility.
• The developed OMIECs offer tunable properties, making them suitable for diverse applications, especially in bioelectronics.
• Post-functionalization capability opens new avenues for tailoring OMIEC properties for specific technological demands.