Synthesis And Microwave Absorption Properties Of Ferric Oxide/graphene (Polyaniline) Composite Materials

Although Fe2O3 possesses various crystal form and high dielectric properties, the individual Fe2O3 microwave absorbent can not achieve impedance matching as well as satisfactory attenuation intensity.In this work, Fe2O3/MnO2/PANI, SnO2@a-Fe2O3@RGO and SnO2@a-Fe2O3@PANI composites were synthesized. The structure, micromorphology, magnetism and microwave absorption parameters of the composites were measured by X-ray diffractometry (XRD), infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA), respectively. Details are as follows:(1) The Fe2O3/MnO2 was prepared by solvothermal using KMnO4 and FeCl3·6H2O as raw materials, and then Fe2O3/MnO2/PANI composites were synthesized by emulsion polymerization. The effects of Fe2O3/MnO2 content on microwave absorption properties of composites were investigated. The results show that Fe2O3/MnO2/PANI exhibits excellent microwave absorption properties with the increase of the Fe2O3/MnO2 content to 10 wt%. It can be found that the maximum reflection loss is -43.22 dB at 9.6 GHz, and the bandwidth exceeds-10 dB (90% of electromagnetic wave absorption) is 3.44 GHz (8.4～11.44 GHz) with absorber thickness of 2.5 mm.(2) The SnO2@a-Fe2O3@RGO composites were synthesized by one-step hydrothermal method using SnCl4·5H2O, FeCl3·6H2O and GO as raw materials. The effects of molar ratio of Fe3+ to Sn4+ and the introduction of flaky RGO on microwave absorption properties of composites were investigated. The results show that RGO sheets provides the transport path of electromagnetic wave, and improve the dielectric loss of composites, thus enhances the microwave absorption properties. In the case of the molar ratio of Fe3+ to Sn4+ is 6:1 in composites, it can be found that the maximum reflection loss is -44.33 dB at 12.64 GHz, and the bandwidth exceeds -10 dB is 4.4 GHz (10.80～15.20 GHz) with absorber thickness of 2.0 mm.(3) The SnO2@α-Fe2O3 was prepared by hydrothermal using SnCl4·5H2O、 FeCl3·6H2O as raw materials, and then SnO2@α-Fe2O3@PANI composites were synthesized by emulsion polymerization. The effects of molar ratio of Fe3+ to Sn4+ and the introduction of PANI on microwave absorption properties of composites were investigated. The results show that the maximum reflection loss is-50.33 dB at 11.04 GHz, and the bandwidth exceeds-10 dB is 4.08 GHz (8.96～13.04 GHz) with absorber thickness of 2.5 mm in the case of the molar ratio of Fe3+ to Sn4+ is 2:1 in composites. Furthermore, in the case of the molar ratio of Fe3+ to Sn4+ is 10:1 in composites, it can be found that the maximum reflection loss is -50.31 dB at 17.6 GHz, and the bandwidth exceeds-10 dB is 2.88 GHz (15.12～18 GHz) with absorber thickness of 1.5 mm.