Absorption Properties of Porous Carbon Doped with Nitrogen Derived by Polyaniline

In this study, polyaniline-derived carbon doped with nitrogen was synthesized through in-situ polymerization and high-temperature carbonization, using aniline as the raw material and ammonium persulfate as the initiator. The phase, morphology, and composition of polyaniline-derived carbon at different carbonization temperatures were characterized by thermogravimetric, transmission electron microscopy, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman, and Brunauer–Emmertt–Teller. The electromagnetic parameters of polyaniline-derived carbon with a filler content of 20 wt % were measured by a vector network analyzer, and the electromagnetic wave absorption performance was calculated using the transmission line method. The results showed that the samples had a porous morphology, and the specific surface area of polyaniline-derived carbon-650 and polyaniline-derived carbon-700 was up to 12 times greater than that of polyaniline. Furthermore, polyaniline-derived carbon-700 exhibited excellent electromagnetic wave absorption performance, with the best reflection loss at a thickness of 2.5 mm being –44.35 dB. The effective absorption bandwidth was 3.23 GHz (8.56–11.79 GHz). The effective absorption of C, X, and Ku band electromagnetic waves could be achieved by adjusting the coating thickness. The hybridization of N atoms and C atoms in polyaniline-derived carbon induced magnetism, and the synergistic effect with enhanced dielectric loss improved the electromagnetic loss capacity of the material, optimized impedance matching, and enhanced the electromagnetic wave absorption performance of polyaniline-derived carbon. The electromagnetic wave dissipation mechanism of polyaniline-derived carbon material mainly included dipole polarization, interface polarization, conductivity loss, and magnetic loss caused by N doping. The synthesized polyaniline-derived carbon is a potential electromagnetic wave absorbing material.