Self-healing, conductive and magnetic ZnFe2O4/MCNT/PPy ternary composite hydrogels

Highlights: • A self-healing composite hydrogel with conductivity was prepared by PVA-borax and ZnFe₂O₄/Multiwalled Carbon Nanotube (MCNT)/ polypyrrole (PPy). • The fractured hydrogel could be healed for 10 min. • The composite hydrogel could serve as a conductor to lighten a bulb in a closed loop and a self-healing process had no effect on electrical performance. • The maximum saturation magnetization of composite hydrogel could be up to 4.10 emu/g. • Even after being made into various shapes, the composite hydrogel still maintains great stretchability up tp 800%. -- Abstract: Self-healing hydrogel has become a hot spot for various practical applications such as biomedical materials and electron devices. However, developing composite hydrogels with self-healing, conductive, magnetic and other properties still remains a serious challenge. In this paper, we developed self-healing, conductive and magnetic ZnFe₂O₄/MCNT/PPy ternary composite hydrogels based on PVA. The composite hydrogels possessed several features including a high stretchability (about 800%), good electrical conductivity (0.3465 S m⁻¹) and nice magnetism (4.10 emu g⁻¹). Furthermore, the composite hydrogels exhibited excellent self-healing property owed to the dynamic interactions (boric acid ester bonds and hydrogen bonds). Due to the conductivity, magnetism, self-healing and other properties, the novel composite hydrogels were expected to be a promising material in many advanced applications, such as electronic skins, drug delivery carriers and electromagnetic interference shielding. In addition, we have reason to believe that the biocompatibility and easy-remolding property of the composite hydrogels would make them a great candidate for 3D printing technique of human organs.