Electrostatic Tailoring of Freestanding Polymeric Films for Multifunctional Thermoelectrics, Hydrogels, and Actuators

Organic conducting polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has garnered enormous attention in organic electronics due to its low-cost solution processability, highly tunable conductivity, superior mechanical flexibility, and good biocompatibility together with excellent atmospheric stability. Nevertheless, limited electrical properties and unfavorable water instability of pristine PEDOT:PSS film impede its further implementation in a broad spectrum of practical applications. In this work, the successful tailoring of the intrinsic electrostatic interaction within PEDOT:PSS and consequent optimized electrical properties are enabled by a simple yet effective ionic salt post-treatment strategy. The choice of zinc di[bis(trifluoromethylsulfonyl)imide] (Zn(TFSI)