Synthesis and microwave electromagnetic characteristics of bamboo charcoal/polyaniline composites in 2–40 GHz

Bamboo charcoal coated with polyaniline was synthesized by in situ polymerization at different bamboo charcoal/aniline weight ratio (BC/Ani = 1/1, 1/2, 1/3) and introduced into epoxy resin to be a microwave absorber. The spectroscopic characterizations of the formation processes of bamboo charcoal/polyaniline composites were studied using Fourier transform infrared, ultraviolet–visible spectrophotometer, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron spin resonance. Microwave absorbing properties were investigated by measuring complex permittivity, complex permeability and reflection loss in the 2–18 and 18–40 GHz microwave frequency range using the free space method. The results showed that a wider absorption frequency range could be obtained by adding different polyaniline contents in bamboo charcoal.