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.

Poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) was synthesized by oxidative polymerization and pH dependence of structure and electrical conductivity of the cast films were investigated by means of UV-vis-NIR, XRD, AFM analyses, and four-point technique. It was found that the neutralization of PEDOT/PSS with NaOH decreased the absorption of bipolarons representing the PEDOT in the highly doped state and disrupted the π-π stacking of the PEDOT crystalline structure, which lowered the electrical conductivity by six orders of magnitude with increasing the pH from 1.7 to 13.

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The correlation between the hierarchical structure and electrical conductivity of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) was investigated by means of X-ray photoelectron spectroscopy, wide-angle X-ray diffraction, conductive atomic force microscopy and the temperature dependence of the electrical conductivity. Upon adding 3% ethylene glycol (EG), the electrical conductivity at room temperature significantly increased from 3 to 175 S cm − 1 , while a further increase in EG up to 20% resulted in a decrease in the electrical conductivity to 117 S cm − 1 . It was found that the improvement in the electrical conductivity could be explained from the changes in the hierarchical structure; a decrease in the insulating PSS shell, crystallization of the PEDOT and aggregation of the PEDOT/PSS particles, which affect both the intra-and interparticle transport of charge carriers.