Preparation And Properties Of Ferrite, Graphite And Polyaniline Wave-absorbing Composites

Because electromagnetic wave radiation from electrical and communication equipments is getting more and more serious, electromagnetic wave absorbing materials emerged in this environment. Mg0.5Zn0.5Fe2O4(MZFO) and Mg0.5Co0.5Fe2O4(MCFO) ferrites with spinel structure, graphite and PANI are all electromagnetic wave absorbing materials, but there are some limitations when these materials are applied alone. In order to prepare composite materials with better wave absorbing properties, three kinds of composite materials were prepared, and the influence of composition and ratio on the properties of the composites is studied in this paper.MZFO, MCFO, MZFO/graphite(MZFO/G) and MCFO/graphite(MCFO/G) composites were prepared by hydrothermal method. The results of X-ray diffraction analysis(XRD) measurement show that all the samples have been successfully prepared. The observation results of scanning electron microscope(SEM) show that the granular ferrite and flake graphite are combined well in MCFO/G and MZFO/G. The results of vibrating sample magnetometer(VSM) measurement show that the saturation magnetization of the composites decreases with the increase of the non-magnetic graphite. The results of Vector network analyzer measurement show that the absorbing wave properties of MCFO and MCFO/G is better than those of MZFO and MZFO/G; the maximum reflection loss peaks of MZFO/G are similar to that of MZFO, just move to high-frequency; the maximum reflection loss peaks of MCFO/G are not only greater than that of MCFO, but also move to high-frequency, at the same time, with the increase of content of graphite, the maximum absorption intensity is unchanged but slightly moves to high-frequency.PANI and MCFO/G/PANI composites were prepared by in situ polymerization method. The results of XRD measurement show that all the samples have been successfully prepared. The observation results of SEM show that with the change of material composition, the morphology of the material changes, when the content of PANI in the MCFO/G/PANI composite is large, the PANI exists in the sheet besides covering on the surface of the MCFO/G. The results of fourier transform infrared spectroscopy(FTIR) measurement show that the characteristic bands of PANI have different degrees of movement toward the high wave number when the MCFO/G/PANI composites are compared with the PANI. Vector network analyzer measurement results show that the maximum reflection loss peaks of MCFO/G/PANI composites are significantly greater than that of MCFO/G and move to low-frequency, the frequency range with the reflection loss value less than-10 dB is up to 4 GHz, and with the increase of content of PANI in the MCFO/G/PANI composites, the absorption intensity increases.