Self‐Healing Micellar Ion Gels Based on Multiple Hydrogen Bonding

Abstract

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.

Toughening a Self‐Healable Supramolecular Polymer by Ionic Cluster‐Enhanced Iron‐Carboxylate Complexes

“…The quantitative self‐healing experiments were performed in water, and the mechanical tensile test showed a good healing efficiency (Figure E), in which the mechanical strength recovered 93.9 % of the original moduli and the breaking elongation fully recovered. The good self‐healing efficiency under water might be attributed to the presence of dynamic ionic bonds at the interfaces . To evaluate the water‐stability of the ionic‐cluster‐toughened network, soaking in water for several days led to no swelling or dissolution (Figure S22).…”

Flourishing Self‐Healing Surface Materials: Recent Progresses and Challenges

“…h) The relationship between healing time and fracture energy of hydrogel. f–h) Reproduced with permission . Copyright 2018, Wiley‐VCH Verlag GmbH & Co. KGaA.…”

“…Presently, the mechanically tough hydrogels with self‐healing property based on hydrogen bonds have been paid considerable attention. In a more recent study, a new ion gel, which composed of the diblock copolymer and hydrophobic ionic liquid (IL), was prepared . By applying the multiple hydrogen bonding interactions of coronal chains in the IL surface, the ion gel successfully achieved self‐healing without the external intervene.…”

Ionic Tactile Sensors for Emerging Human‐Interactive Technologies: A Review of Recent Progress

“…b) Schematic illustration and structures of self‐healing micellar ion gel. Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

“…Recently, Tamate et al demonstrated a new class of micellar ion gels composed of diblock copolymers with an IL‐phobic and a hydrogen‐bonding block with hydrogen bonds donating and accepting units (Figure b) . The diblock copolymer consisted of an IL‐phobic poly(styrene) (PS) block and a hydrogen bonding block composed of statistical copolymers of N,N ‐dimethylacrylamide (DMAAm) and acrylic acid (AAc) (i.e., PS‐ b ‐P(DMAAm‐r‐AAc)).…”