Conjugated polymers exhibit electrically driven volume changes when included in electrochemical devices via the exchange of ions and solvent. So far, this volumetric change is limited to 40% and 100% for reversible and irreversible systems, respectively, thus restricting potential applications of this technology. A conjugated polymer that reversibly expands by about 300% upon addressing, relative to its previous contracted state, while the first irreversible actuation can achieve values ranging from 1000–10 000%, depending on the voltage applied is reported. From experimental and theoretical studies, it is found that this large and reversible volumetric switching is due to reorganization of the polymer during swelling as it transforms between a solid-state phase and a gel, while maintaining percolation for conductivity. The polymer is utilized as an electroactive cladding to reduce the void sizes of a porous carbon filter electrode by 85%.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: J.G. and E.S. contributed equally to this work. M.B. and E.S. conceived the project. J.G. and E.S. performed the experiments and analyzed all data. S.G. and I.Z. performed and analyzed MD calculations. A.G. and M.M. synthesized materials. E.S., M.B., I.Z., and J.G. wrote the manuscript with input from all authors. E.S., M.B., I.Z., and I.M. supervised the project. This work was supported by Knut and Alice Wallenberg Foundation, The Wallenberg Wood Science Center (KAW 2018.0452), the Swedish Research Council (VR), and the Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU No. 2009-00971). The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at NSC and HPC2N. A.G. and I.M. acknowledge funding from the Engineering and Physical Sciences Research Council (EP/G037515/1) and (EP/N509486/1).