(129h) Counter-Ion Condensation on Doped ?-Conjugated Polymer Chains
AIChE Annual Meeting
Monday, November 14, 2022 - 2:30pm to 2:45pm
Here, we apply Manningâs âcounterion condensation theoryâ to characterize the molecular-level interactions in dilute liquid solutions between charge carriers on polythiophene derivatives and charge-compensating counterions. This theory offers a framework for understanding the degree of counterion-charge carrier interaction in terms of the Bjerrum length, i.e., the characteristic distance at which electrostatic energy is comparable in magnitude to the thermal energy. While this theory has been successfully used to interpret experimental data for non-conjugated polyelectrolytes, it has yet to be applied to systems with delocalized charge carriers in Ï-conjugated polymers. We have characterized variably doped poly(3-oligoethoxythiophenes) in exogenous electrolyte solutions using refractometry, NMR spectroscopy, and isothermal titration calorimetry. These efforts furnish fundamental insights into the charge carrier-counterion correlations that limit electronic conduction in doped polymer systems, which may lead to new molecular designs for improved mixed conductor performance.