多孔羰基铁/CoFe2O4/聚苯胺复合材料的制备及吸波机理

通过金属点蚀技术制备了表面多孔形貌的羰基铁粉（PCIP），并采用共沉淀及原位聚合方法，将CoFe₂O₄与聚苯胺（PANI）负载于多孔羰基铁表面，得到具有电磁吸收性能的PCIP/CoFe₂O₄/PANI复合材料.通过扫描电子显微镜（SEM）、X射线衍射仪（XRD）、傅里叶变换红外光谱仪（FTIR）、热重分析仪（TGA）及矢量网络分析仪（VNA）等对复合材料的形貌、成分和吸波性能进行了研究.结果表明，CoFe₂O₄/PANI团聚于PCIP表面，显著提升了复合材料电损耗能力，促进了低频电磁波的1/4波长干涉相消.当苯胺添加量为0.5 mL，复合材料在频率为5.7 GHz时，反射损耗达到-22.9 dB，低频吸波性能得到大幅提升.利用1/4波长干涉相消理论及电磁波界面反射模型对复合材料低频吸波性能提升的内在原因进行了分析.

Fabrication and Microwave Absorption Mechanism of PCIP/CoFe2O4/PANI Composites

Porous carbonyl iron powder(PCIP) was obtained by pitting etching technique. CoFe₂O₄ and polyaniline(PANI) were loaded on the surface of porous carbonyl iron by coprecipitation and in-situ polymerization to obtain PCIP/CoFe₂O₄/PANI composites with electromagnetic absorption properties. The morphology, composition and microwave absorption properties of the composites were studied by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared(FTIR), thermogravimetric analyzer(TGA) and vector network analyzer(VNA). The results showed that CoFe₂O₄/PANI agglomerated on the surface of PCIP, which significantly improved the electrical loss ability of the composites, and promoted the interference cancellation of 1/4 wavelength of low frequency electromagnetic wave. When the content of aniline was 0.5 mL, the reflection loss of the composites reaches -22.9 dB at 5.7 GHz, and the absorbing property was greatly improved in low frequency. The internal reasons for the improvement of low frequency absorbing properties of composites were analyzed by using the electromagnetic wave interface reflection model and the 1/4 wavelength interference cancellation theory.