Mechanical and wave absorption properties of Fe₃O₄‐deposited Buckypaper reinforcing epoxy resin composites

Abstract

There are increasing need for the development of electromagnetic wave‐absorbing materials since the growing concern about electromagnetic interference. However, materials with integrated structure and function are difficult to attain due to the high content of functional fillers. In this paper, carbon nanotubes (CNTs) were formed into a three‐dimensional porous framework, known as Buckypaper (BP), which was subsequently in situ deposited with iron tetraoxide (Fe3O4) through the sol–gel method and incorporated into epoxy resin to create Fe3O4/BP/EP composites by hot pressing. The three‐dimensional porous structure of Fe3O4/BP facilitates the high‐content incorporation and uniform dispersion of CNTs and Fe3O4 nanoparticles. The results indicate that the 33%Fe3O4/BP/EP composite achieved an optimal reflection loss of −38.41 dB and an absorption bandwidth of 3.28 GHz at the optimal matching thickness of 1.5 mm. This performance primarily stems from Fe3O4 adjusting the impedance matching of BP and enhancing the magnetic loss capability of CNTs. Furthermore, the deposition of Fe3O4 on BP improves the mechanical strength of BP/EP, The 17% Fe3O4/BP/EP composite achieves a tensile strength of 35.09 MPa, which is 46.27% higher than that of BP/EP and 92.38% higher than pure EP.Highlights Fe3O4/BP was prepared by deposition of Fe3O4 onto surfaces of the CNTs framework. Fe3O4/BP/EP composites with different Fe3O4/BP were fabricated. Fe3O4 adjusts impedance matching of BP, and forms heterogeneous interfaces. Fe3O4/BP/EP composites exhibit excellent wave absorption performance. Fe3O4/BP/EP composites possess improved mechanical properties.