Simon Rondeau-Gagne1
University of Windsor1
To further develop current electronics for the Internet of Things, in which smart and conformable devices and sensors embedded ubiquitously collect and exchange data, materials require a good charge transport and processability. They also need to be mechanically robust and stable to many different environments. In recent years, important efforts have been devoted to push the boundaries between chemical engineering and chemistry towards materials with excellent charge transport. Among the semiconductors developed in the last decade, π-conjugated semiconducting polymers possess particularly outstanding properties as these materials have good charge transport properties, tunable mechanical properties, and high biocompatibility/low toxicity. However, despite having unique qualities for the fabrication of emerging electronics, current semiconducting polymers lack important features for their application at large scale. These include high Young’s moduli and limited mechanical properties, poor solubility in polar solvents, and low resistance to complex patterning techniques<br/><br/>Among others, the incorporation of non-covalent interactions in conjugated polymers has been an emerging strategy to control the electronic and thermophysical properties of organic semiconductor. Recent examples of materials incorporating moieties capable of generating intermolecular and intramolecular hydrogen bonds, as well as coordinating ligands, have been reported. The careful characterization of these materials confirmed that supramolecular chemistry can be an efficient strategy toward a well-defined solid-state morphology and molecular self-assembly. Building from this new knowledge, our group utilizes various types of dynamic covalent and non-covalent bonds to generate adaptable semiconducting polymer networks. By using this strategy with different semiconducting polymer systems, we found that not only are these bonds dynamic, but that they also disrupt chain packing in the solid-state, resulting in materials that are more amorphous (softer). Some particularly interesting properties, including autonomous self-healing, was also accessed through this rational materials design, opening new avenues to create soft electronics.<br/><br/>This presentation will cover our strategy to rationally design new functional semicrystalline polymers through the utilization of supramolecular interactions and dynamic covalent bonds. Results from a detailed multimodal characterization of the solid-state morphology of the new materials in thin films will be introduced, as well as the new structure-property relationships unveiled during our investigation. Application of the materials as active materials in organic field-effect transistors (OFETs) and flexible sensors will also be discussed.