Highly Processable Ionogels with Mechanical Robustness

• Published in: Advanced functional materials 2023-08, Vol.33 (31), p.n/a
• Main Authors: Ma, Chuao, Wei, Jun, Zhang, Yuqiang, Chen, Xingchao, Liu, Chan, Diao, Shen, Gao, Yuan, Matyjaszewski, Krzysztof, Liu, Hongliang
• Format: Article
• Language: English
• Subjects: 3-D printers; 3D printing; Block copolymers; Entanglement; Flexible components; Inkjet printing; Ionic liquids; ionogels; Materials science; Polymerization; Prepolymers; Robustness; Self-assembly; spray coatings; strain sensors; Three dimensional printing
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202211771

Currently, the increasing needs of conductive ionogels with intricate shapes and high processability by individual requirements of next‐generation flexible electronics constitute significant challenges. Here, the design of highly processable ionogels is reported with mechanical robustness by self‐assembly of a common triblock copolymer into a precursor in functional mixed ionic liquids (ILs) containing conductivity‐enhancing and polymerizable strength‐enhancing components. The subsequent in situ polymerization of the precursor forms physical‐co‐chemical cross‐linked networks, in which the entanglement between physical and chemical cross‐linked networks and microphase separation give rise to mechanical robustness of as‐fabricated ionogel. The viscosity of the self‐assembled precursor can be rationally tuned, which makes the fabrication process compatible with diverse technologies including inkjet printing, spray coating, and 3D printing. By virtue of highly processable capability of the designed ionogels, an auxetic‐structured ionogel can be easily generated using 3D printing, which exhibits greatly improved sensitivity and thus is able to monitor tiny deformations. This study that relies on designing functional mixed ILs as the dispersion phase rather than focusing on synthesizing new‐type polymers establishes a new route for versatile and programmable fabrication of high‐performance ionogels for broader applications. Conductive ionogels with high processability and mechanical robustness are fabricated by self‐assembly of a triblock copolymer, PS‐PEO‐PS, in mixed ionic liquids, [VBBIm]NTf2, and [EMIm]NTf2, and subsequent in situ chemical cross‐linking of [VBBIm]NTf2. This fabrication route is compatible with inkjet printing, spray coating and 3D printing, which will broaden the applications of ionogels.