Thiophene- and selenophene-based conjugated polymeric mixed ionic/electronic conductors

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrochemistry

Background:

• Mixed ionic/electronic conductors (MIECs) are crucial for advanced electronics and energy storage.
• Polymeric MIECs offer tunable structures and mechanical robustness.
• Conjugated polymers based on thiophene and selenophene are promising candidates.

Purpose of the Study:

• To synthesize and investigate conjugated copolymers containing thiophene and selenophene repeat units.
• To evaluate the ionic and electronic conductivity of these novel copolymers.
• To explore the impact of copolymerization and heavy atom incorporation on MIEC properties.

Main Methods:

• Synthesis of conjugated copolymers with thiophene and selenophene units, including side chain functionalization (triethylene glycol).
• Polymerization and copolymerization techniques to create blocky copolymers.
• Ionic doping for Li-ion conductivity measurements.
• Oxidative doping for electronic conductivity measurements.

Main Results:

• Synthesized blocky copolymers containing sulfur (S) or selenium (Se).
• Ionic conductivity of doped copolymers (P3DDT-s-P3(EG3)T and P3DDS-s-P3(EG3)T) was 3-4 times higher than the homopolymer P3(EG3)T.
• Electronic conductivity of oxidatively doped copolymers significantly surpassed the homopolymer, with P3DDS-s-P3(EG3)T reaching ~7 S/cm.

Conclusions:

• Copolymerization and incorporation of heavy atom heterocycles (like Se) enhance MIEC performance.
• These findings offer a pathway for designing next-generation polymeric MIECs.
• The developed materials show potential for applications in electronic devices and energy storage.