Supramolecular hydrogels mediated by cucurbit[6]uril-modified Fe3O4 with self-healing, photothermal responsiveness and stretchability for flexible electronics

The development of supramolecular hydrogels with multifunction is in high demand. In this work, Fe3O4 hybrid supramolecular hydrogels were fabricated via dynamic host-guest interactions between the host molecule CB[6] and guest units. The "supramolecular crosslinker" formed by CB[6]-modified Fe3O4 (Fe3O4@CB[6]) nanoparticles, was used to generate a 3D network of supramolecular hydrogels. Results indicate that the tensile stress of the sample is 0.31 MPa, and the self-healing efficiency of the supramolecular hydrogels at room temperature is nearly 100% (fracture strain) after 48 h. The hydrogels exhibited a self-healing property without a loss of conductivity. Furthermore, these supramolecular hydrogels were used to detect the bending of human fingers and knees. The hybrid supramolecular hydrogels with photothermal responsiveness, self-healing, injectability, stretchability, conductive ability and biocompatibility, can find applications in flexible electronics.