Bio-inspired self-healing flexible films with pomegranate-shaped nanosphere loaded graphene for electromagnetic interference shielding and superhydrophobicity performances

Abstract

A self-healing strategy is an urgent requirement for extending the service life of the electromagnetic interference (EMI) shielding films. In this study, the multi-stimuli self-healing flexible films with EMI shielding and self-cleaning properties were prepared by using bionic pomegranate-shaped magnetic nanosphere loaded graphene sheets (PMNs-FG) and pyrene-grafted multi-branched polyurethane (MPU). Due to the unique structure of PMNs-FG, the fabricated PMNs-FG/MPU composite film exhibits excellent EMI shielding effectiveness and self-cleaning ability. Interestingly, inspired by geckos' feet, the pyrene groups of MPU can stick to the surface of graphene via π–π interaction, which allows the damaged film to completely self-heal. The repaired film can recover its initial EMI shielding efficiency and superhydrophobicity. Moreover, owing to the great photothermal and electrothermal properties, the self-healing process can be triggered by solar irradiation or electricity except for the direct heating, broadening the application prospects of self-healing materials and providing a novel approach for the fabrication of durable functional films.