Self‐Healing Micellar Ion Gels Based on Multiple Hydrogen Bonding

• Published in: Advanced materials (Weinheim) Vol. 30; no. 36; pp. e1802792 - n/a
• Main Authors: Tamate, Ryota, Hashimoto, Kei, Horii, Tatsuhiro, Hirasawa, Manabu, Li, Xiang, Shibayama, Mitsuhiro, Watanabe, Masayoshi
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 06.09.2018
• Subjects: Block copolymers; Electronic devices; Gels; Healing; High temperature; Hydrogels; Hydrogen bonding; Hydrogen bonds; ion gels; Ionic liquids; Ions; Materials science; Molten salt electrolytes; self‐healing; Solid electrolytes; block copolymers; ion gels; ionic liquids; hydrogen bonds; self-healing
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.201802792

Ion gels, composed of macromolecular networks filled by ionic liquids (ILs), are promising candidate soft solid electrolytes for use in wearable/flexible electronic devices. In this context, the introduction of a self‐healing function would significantly improve the long‐term durability of ion gels subject to mechanical loading. Nevertheless, compared to hydrogels and organogels, the self‐healing of ion gels has barely investigated been because of there being insufficient understanding of the interactions between polymers and ILs. Herein, a new class of supramolecular micellar ion gel composed of a diblock copolymer and a hydrophobic IL, which exhibits self‐healing at room temperature, is presented. The diblock copolymer has an IL‐phobic block and a hydrogen‐bonding block with hydrogen‐bond‐accepting and donating units. By combining the IL and the diblock copolymer, micellar ion gels are prepared in which the IL phobic blocks form a jammed micelle core, whereas coronal chains interact with each other via multiple hydrogen bonds. These hydrogen bonds between the coronal chains in the IL endow the ion gel with a high level of mechanical strength as well as rapid self‐healing at room temperature without the need for any external stimuli such as light or elevated temperatures. Room‐temperature self‐healable micellar ion gels are developed. The ion gel is composed of an ionic liquid and jammed micelles consisting of a diblock copolymer with an ionic‐liquid‐phobic block and a hydrogen‐bonding block. The ion gel exhibits high toughness and rapid self‐healing behavior at ambient temperature due to the multiple hydrogen bonding between the coronal chains.