X-Band Microwave Absorbing Properties of Epoxy Resin Composites Containing Magnetized PANI-Coated Magnetite

Magnetized (PANI-coated Fe3O4) epoxy resin was synthesized to produce X-band microwave absorbing structures (MASs) with tuning thickness and fillers ratio. The structure and crystallinity of materials were checked by SEM and X-ray diffraction. It was found that the thickness, amount, and ratio of magnetized PANI-coated Fe3O4 affect the microwave absorption properties. Single layer MAS with 3 mm showed a reflection loss (RL) of -54 dB at 8.73 GHz and -41 dB at 9.52 GHz. However, a double-layer absorber based on 0.9 mm of the matching layer of PANI and the absorbing layer of magnetized (PANI-coated Fe3O4) epoxy resin composite with a thickness of 1.8 mm show a minimum RL value of -38 dB at 9.82 GHz and an absorption bandwidth of about 3.55 GHz with RL below -10 dB. In addition, by rising thicknesses the RL peak shift to lower frequency. A materials prepared with thin double-layer structure have a high absorption performances and broader bandwidth in X-band.