Structure-Transport Properties Governing the Interplay in Humidity-Dependent Mixed Ionic and Electronic Conduction of Conjugated Polyelectrolytes.

Autor: Grocke GL; Pritzker School of Molecular Engineering, University of Chicago, Illinois 60637, United States., Dong BX; Pritzker School of Molecular Engineering, University of Chicago, Illinois 60637, United States., Taggart AD; Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.; Advanced Materials for Energy-Water Systems Energy Frontier Research Center, Argonne National Laboratory, Lemont, Illinois 60439, United States., Martinson ABF; Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.; Advanced Materials for Energy-Water Systems Energy Frontier Research Center, Argonne National Laboratory, Lemont, Illinois 60439, United States., Niklas J; Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States., Poluektov OG; Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States., Strzalka JW; X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States., Patel SN; Pritzker School of Molecular Engineering, University of Chicago, Illinois 60637, United States.
Jazyk: angličtina
Zdroj: ACS polymers Au [ACS Polym Au] 2022 Apr 11; Vol. 2 (4), pp. 275-286. Date of Electronic Publication: 2022 Apr 11 (Print Publication: 2022).
DOI: 10.1021/acspolymersau.2c00005
Abstrakt: Polymeric mixed ionic-electronic conductors (MIECs) are of broad interest in the field of energy storage and conversion, optoelectronics, and bioelectronics. A class of polymeric MIECs are conjugated polyelectrolytes (CPEs), which possess a π-conjugated backbone imparting electronic transport characteristics along with side chains composed of a pendant ionic group to allow for ionic transport. Here, our study focuses on the humidity-dependent structure-transport properties of poly[3-(potassium- n -alkanoate) thiophene-2,5-diyl] (P3K n T) CPEs with varied side-chain lengths of n = 4-7. UV-vis spectroscopy along with electronic paramagnetic resonance (EPR) spectroscopy reveals that the infiltration of water leads to a hydrated, self-doped state that allows for electronic transport. The resulting humidity-dependent ionic conductivity (σ i ) of the thin films shows a monotonic increase with relative humidity (RH) while electronic conductivity (σ e ) follows a non-monotonic profile. The values of σ e continue to rise with increasing RH reaching a local maximum after which σ e begins to decrease. P3K n Ts with higher n values demonstrate greater resiliency to increasing RH before suffering a decrease in σ e . This drop in σ e is attributed to two factors. First, disruption of the locally ordered π-stacked domains observed through in situ humidity-dependent grazing incidence wide-angle X-ray scattering (GIWAXS) experiments can account for some of the decrease in σ e . A second and more dominant factor is attributed to the swelling of the amorphous domains where electronic transport pathways connecting ordered domains are impeded. P3K7T is most resilient to swelling (based on ellipsometry and water uptake measurements) where sufficient hydration allows for high σ i (1.0 × 10 -1 S/cm at 95% RH) while not substantially disrupting σ e (1.7 × 10 -2 S/cm at 85% RH and 8.0 × 10 -3 S/cm at 95% RH). Overall, our study highlights the complexity of balancing electronic and ionic transport in hydrated CPEs.
Competing Interests: The authors declare no competing financial interest.
(© 2022 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
Externí odkaz: