Self-healing nanocomposite hydrogels via Janus nanosheets: Multiple effects of metal–coordination and host–guest interactions

Abstract Recently years, hydrogels have received increased attention due to their promising applications in wound dressing, tissue engineering, biosensors and human-machine interfaces. However, designing hydrogels with good mechanical strength and self-healing ability remains a challenge. As a novel strategy, functional Janus nanosheets (JNs) were used as reinforcement to develop self-healing nanocomposite hydrogels. Herein, the silica Janus hollow spheres were prepared by a sol-gel process, modified with poly(2-(acryloyloxy)ethyl ferrocenecarboxylate)(PMAEFc)/polydopamine(PDA) to the internal/external surfaces and then crushed to fabricate the SiO2@PMAEFc/PDA JNs. The SiO2@PMAEFc/PDA JNs were then used as robust reinforcement to design self-healing nanocomposite hydrogels. Based on multiple effects of metal–coordination and host–guest interactions, the mechanical strengths and self-healing properties of hydrogels were both enhanced. Specially, after introducing JNs, the rupture stress of hydrogels increased from 1.27 MPa to 2.23 MPa, and the self-healing efficiency improved from 66.7% to 92.4%. These results demonstrate that JNs can be used as robust reinforcement to fabricate self-healing nanocomposite hydrogels, which enriches the design of self-healing hydrogels and broadens the application prospects of Janus nanomaterials.