Transparent, robust, water-resistant and high-barrier self-healing elastomers reinforced with dynamic supramolecular nanosheets with switchable interfacial connections

Self-healing elastomers are usually confronted with poor mechanical properties, high humidity vulnerability and gas permeability. To address these issues, we develop a bottom-up strategy to reinforce self-healing elastomers with in situ assembled supramolecular nanosheets with switchable interfacial covalent bonds. Both the interfacial covalent bonds and supramolecular nanosheets are dynamic in response to temperature. Under ambient conditions, the 5 nm-thick supramolecular nanosheets act as rigid layered-nanofillers with strong interfacial covalent bonds, significantly improving the mechanical properties and water/gas barrier performances of the elastomers. At high temperature, the interfacial covalent bonds are dissociated and the supramolecular nanosheets are disintegrated, leading to increased molecular mobility, which remarkably facilitates the self-healing process. Consequently, the elastomers simultaneously possess outstanding mechanical properties, humidity resistance, gas impermeability, self-healing efficiency and transparency, despite the fact that these properties are mutually exclusive in most self-healing polymers.