Covalently Merging Ionic Liquids and Conjugated Polymers: A Molecular Design Strategy for Green Solvent-Processable Mixed Ion-Electron Conductors Toward High-Performing Chemical Sensors

Abstract

Polymeric mixed ionic？electronic conductors hold great potential for advancing high-performance organic electronics due to their exceptional electrical conductivity achieved through ion？electron coupling. However, the widespread adoption of these conductors faces obstacles due to their reliance on environmentally harmful solvents during processing and the potential performance degradation under various conditions. In this study, a practical solution to these challenges is proposed by incorporating monomers with ionic liquid-behaving pendant groups into conjugated polymers. The copolymerization of these charged monomers not only improves solubility in environmentally friendly solvents but also imparts long-term stability against humidity, high temperatures, and mechanical deformation. The immobilized ion species foster highly selective interactions of these polymers with nitrogen dioxide, paving the way for the development of stretchable sensing devices capable of functioning at exceptionally high temperatures.