Studies On Preparation And Microwave-absoring Properties Of PANI/Ferrits Composite Materials

The study of microwave absorbing materials applying to military stealth information and environment protection is an important item. The conducting polyaniline/ferrite nano-composites possess both dielectric losses and magnetic losses, so they have good application prospect in radar absorbing material.Conducting polymers as a kind of typical resistance absorbing properties, have become the heat research in this order, because PANI is a sort of raw materials easily getting, diverse structure, special blending mechanism, and excellent conductivity rate, processing possibility and envioronment stability, so far it has became one of the host conducting polymers.In this thesis, PANI/Li_0.45Zn_0.1Fe_0.45O₄, PANI/Co_0.7Zn_0.3Fe₂O₄,PANI/SrFe₁₂O₁₉ series composites are synthesized by Chemical Oxidation method for the very first time, and than adopt CIP,carbon fiber to blend it. The structures, microwave absorbing properties and one of PANI/ferrite composites have been studied by XRD FI-IR, TEM and Vector network analyzer. The main results are as follows:1. PANI/SrFe₁₂O₁₉ nano-composites with core-shell structure have been successfully prepared by us. The results show that there are chemical bonds between PANI and SrFe₁₂O₁₉,Li_0.45Zn_0.1Fe_2.45O₄ nano-composites. The influence of wt% on microwave absorbing properties was studied. When the PANI has doped by 15wt% ferrite, the composite show the best microwave absorbing properties.2. We have analyzed PANI which is packed by different kinds of ferrites for the very first time. The results show that the PAIN/Li_0.45Zn_0.1Fe_2.45O₄ composites show the best microwave absorbing properties. It is founded that the max reflectivity of-26dB and 5GHz of 8dB bandwidth and density decrease to 0.28g·cm^-2; At the same time, we have wrapped two kinds of ferrites in the PANI for the first time. The result show that quality percentage for 1:1 which is better microwave absorbing properties than that wrapping just one function ferrite, whose main crest moves toward the low frequency rate, we found the 1.8mm is the best thickness matching this compound microwave absorbing materials. 3. When blending CIP and carben fiber with PANI/ferrites compound absorbers, It widens the bandwidth of the compound microwave absorbing materials-8dB, up to 8.8GHz and improved the applications of this type of compound microwave absorbing materials effectively. The density of this sample beCome lower.According to the design of impedance-matching principle and adjusting this type of compound microwave absorbing material's electromagnetism, which has instructive signification for experiment and provides worthy experiment data and conclusion for opening the exhibition carben fiber and blending graphite slice to PANI/Ferrite compound absorbing materials further.Above all, the new conductive PANI/ferrites nano-composites show good microwave absorbing in range of (2-18)GHz, whose best bandwidth-8dB is 8.8GHz; density decrease to 0.28g·cm^-2. By further excellent blending, which can make high performance absorbing materials to meet practical requirements, and give further research of PANI compound microwave absorbing materials.