| Description |
Organic mixed ionic electronic conductors (OMIECs) are conjugated polymers that conduct both ions and electrons. These materials are promising for applications in healthcare and energy technologies, including biosensors and batteries. An obstacle for using these materials in next-generation technologies is a lack of understanding of the fundamental principles that underlie operation, particularly the coupled ion motion, electron transport, and structural dynamics. This work presents both the electropolymerization and characterization of thiophene-based p-type polymers and copolymers as well as the influences of post-processing treatments on n-type organic mixed conductors. One advantage of electropolymerized materials is that they do not require bulky side chains to dissolve in organic solvents, allowing them to hold more charge per volume. Using electropolymerization, we synthesize several polythiophenes with different side chain chemistries. We investigate ion injection kinetics in these materials using spectroelectrochemistry and find that injection kinetics depend on the identity of the electrolyte. We also characterize their morphology with grazing incidence wide angle x-ray scattering (GIWAXS) and scanning electron microscopy (SEM). Compared to their p-type counterparts, n-type OMIECs exhibit poorer performance. This work focuses on how thermal annealing, ion identity, and pH impact electrochemical doping of the n-type OMIEC p(gNDI-gT2). Through the use of electrochemical quartz crystal microbalance (EQCM) and spectroelectrochemistry, we find that electrolyte identity and pH, as well as annealing temperature, have a significant impact on the electronic species formed in thin films of p(gNDI-gT2) upon electrochemical doping. |
