A Highly Ionic Conductive, Healable, and Adhesive Polysiloxane‐Supported Ionogel

Abstract

A new kind of polysiloxane‐supported ionogel is successfully designed via locking ionic liquids (ILs), 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]), into poly(aminopropyl‐methylsiloxane) (PAPMS) grafted with [2‐(methacryloyloxy)ethyl] trimethylammonium chloride (METAC) in the presence of tannic acid (TA). The novel ionogel exhibits good mechanical and recovery properties, as well as high ionic conductivity (1.19 mS cm−1) at 25 °C. In addition, the totally physical dual‐crosslinked network based on ionic aggregates among METAC and the hydrogen bonds between PAPMS and TA provides excellent self‐healing ability, which allows the damaged ionogel to almost completely heal (≈83%) in 12 h at room temperature. Interestingly, the obtained ionogel also shows satisfactory adhesive behavior to various solid materials. Moreover, this novel ionogel can maintain its high ionic conductivity and recovery property even at subzero temperatures. Therefore, this polysiloxane‐supported ionogel is anticipated to be advantageous in flexible electronic devices such as sensors and supercapacitors, even at low temperatures.

Elastic and Thermoreversible Iongels by Supramolecular PVA/Phenol Interactions

“…Despite the ability of polyphenols to form supramolecular interactions such as hydrogen bonding, metal–ligand coordination, and π–π staking, they have not yet been deeply studied for the formation of iongels. [ 38–40 ] Herein, and to the best of our knowledge, we report for the first time the assisted formation of thermoreversible and elastic iongels with plant‐derived polyphenol compounds (PhCs) of low molecular weight. In this new type of conductive soft materials, polyphenol supramolecular chemistry is used to induce the gelation of a biocompatible hydroxyl‐rich polymer, in the presence of imidazolium‐based ILs.…”

Substrate‐Independent, Reversible, and Easy‐Release Ionogel Adhesives with High Bonding Strength

“…Gecko‐inspired reversible adhesives have been developed by utilizing the deliberately designed micro/nano fibril structures to enhance the van der Waals interactions with the substrate. [ 5–7 ] Reversible and stimuli‐responsive adhesives can also be fabricated based on stimuli‐responsive polymers or polymer systems involving reversible and dynamic molecular interactions, such as the introduction of temperature or light isomerization groups, [ 8–10 ] dynamic covalent bonds [ 11,12 ] (e.g., Diels–Alder reaction, disulfide bonds) and reversible noncovalent interactions [ 13–20 ] (e.g., hydrogen bonds, metal‐ligand and host–gust interactions). However, these adhesives were mostly reported to exhibit high‐performance bonding with high‐surface‐energy substrates, such as glass and metal.…”

Recent progress in self-healable ion gels

“…The use of reversible non-covalent or dynamic covalent interactions in self-healing materials has received significant attention [76][77][78][79][80][81][82][83][84][85]. Although still in its early stages, studies into self-healing ion gels based on supramolecular and dynamic covalent chemistries have gradually increased in number in recent years [86][87][88][89][90]. For example, self-healing ion gels that exploit hydrogen bonding between hydrophilic ILs and biopolymers, such as guar gum [86] and functionalized agarose [87], have been reported.…”