Preparation and microwave absorption performance of a flexible Fe3O4/nanocarbon hybrid buckypaper and its application in composite materials

Graphene oxide (GO) and carbon nanotubes are promising microwave-absorbing materials. Herein, ferroferric oxide (Fe3O4)/multiwall carbon nanotube (MWCNT) and Fe3O4/GO hybrid buckypapers with excellent flexibility and manoeuvrability were coated on the surface of an epoxy substrate to fabricate microwave-absorbing composites. Fe3O4/GO buckypapers show a unique layered structure that differs from the complex network structure of Fe3O4/MWCNT buckypapers. Therefore, the Fe3O4/GO buckypapers exhibit lower tensile strength and toughness than the Fe3O4/MWCNT buckypapers, and the minimum electromagnetic reflection loss of Fe3O4/GO buckypapers is higher than that of Fe3O4/MWCNT buckypapers. Further, Fe3O4/GO buckypapers have a wider effective absorption-frequency band than Fe3O4/MWCNT buckypapers at 2.0–18.0 GHz. Although the mechanical properties of epoxy resin composites coated with Fe3O4/MWCNT or Fe3O4/GO buckypapers show a slight deterioration in comparison with those of the epoxy resin substrate, both buckypapers exhibit improved microwave-absorption performance compared with the epoxy resin substrate.