Supramolecular Polymer‐Based Ionogels Enable Large‐Scale Fabrication of Stable Smart Windows with Room‐Temperature Closed‐Loop Recyclability and Self‐Healing Capability

Abstract

AbstractCurrent self‐healing ionogels are unable to undergo closed‐loop recycling and are unsuitable for large‐scale fabrication, which increases their manufacturing costs and limits their practical applications. In this study, self‐healing thermochromic ionogels with room‐temperature closed‐loop recyclability and self‐healing capability are large‐scale prepared by the in situ synthesis of imine bond cross‐linked supramolecular polymers in binary ionic liquids. The resulting ionogels show excellent mechanical and environmental stability, high solar modulation capability, and long service life, which can provide spontaneous solar modulation for buildings and vehicles to reduce cooling‐related energy consumption. The temperature‐responsive hydrogen bonding between supramolecular polymers and ionic liquids influences the dissolution state of the supramolecular polymers, allowing the self‐healing thermochromic ionogels to switch between transparent and opaque states through reversible agglomeration of ILs inside the ionogels. Dynamic imine bonds enable the ionogels to spontaneously heal themselves at room temperature and to be depolymerized into monomers in an extremely high yield and purity under hydrochloric acid catalysis at room temperature. The recovered monomers can be used to re‐manufacture self‐healing thermochromic ionogels without losing their original mechanical properties or thermochromic capability. This study provides a new route for developing functional self‐healing ionogels that can be large‐scale fabricated and closed‐loop recycled.