Preparation of wheat flour-derived carbon/multi-walled carbon nanotubes/nickel composite by kneading method for electromagnetic wave absorption

Abstract

Wheat flour-derived carbon/multi-wall carbon nanotubes/Nickel magnetic particles (WFC/MWCNT/Ni) composite electromagnetic wave (EMW) absorber had been made by traditional kneading technology. Compared to conventional hard template biomass materials, kneading dough can disperse multi-wall carbon nanotubes (MWCNT) and nickel salts more uniformly. The introduction of MWCNT can tune the dielectric constant of Wheat flour-derived carbon (WFC) to achieve stronger dielectric loss. The Ni magnetic particles encapsulated in the carbon matrix not only provide the composite with magnetic loss capability, likewise also improve the impedance match conditions of the material. In addition, the ternary structure of WFC/MWCNT/Ni endows the EMW absorber with more polarization losses. The results show that at a matched thickness of 1.38 mm, the sample achieves minima reflect loss (RLmin) of − 74.03 dB and an effective absorption bandwidth (EABW, RL≤−10 dB) of 4.72 GHz. Benefitting from broadband absorption under relatively thin thickness, simple preparation process and easy availability of raw materials, it possesses enormous potential to become an efficient EMW absorption material.