Coal-based carbon composite with excellent electromagnetic-shielding properties prepared from modification of coal with D-A reaction

A novel method has been developed to synthesize fine coal-based carbon composite particles containing rich nitrogen-doped microcrystalline structure with superior electromagnetic-shielding (EMI) performances using anthracite as raw material for the first time. Carbon composite was observed after reacting with furanmethylamine (FMA), followed by ball-milling and a high-temperature (1000 °C) thermal anneal. Carbon structure was assessed before and after reacting FMA with X-ray diffraction (XRD), Raman, Fourier transform infrared spectroscopy (FT-IR), temperature-programmed oxidation (TPO), and X-ray photoelectron spectroscopy (XPS). All data are consistent with the occurrence of Diels–Alder (D-A) reaction, providing D-A reaction occurred between coal and FMA for the first time. Because the D-A reaction changes the three-dimensional structure of coal and weakens the cross-linking of the coal structure, ball-milling modified coal reduces the size of coal particles without deepening the disorder of coal, and heat treatment caused the reverse reaction of D-A reaction, which improved the structural integrity of the carbon networks. The final product called “Coal-FBT” shows a maximum attenuation of 62.2 dB, which qualifies as excellent electromagnetic shielding as 50wt% mixed with paraffin. Graphical abstract The modified coal (Coal-FBT) showed a max SE T of 62.2 dB, which is much higher than the pristine coal (8.81 dB).