核壳型Fe3O4-聚吡咯电磁屏蔽填料的制备与表征

采用一步刻蚀法制备了核壳Fe₃O₄-聚吡咯(Fe₃O₄-PPy)复合微球,并采用FT-IR、XRD、TG和矢量网络分析仪对其结构和电磁参数进行了表征。结果表明:盐酸刻蚀产生的Fe ³⁺引发了吡咯在Fe₃O₄微球表面的聚合。扫描电镜与透射电镜证实了其核壳结构;FT-IR谱图证明了聚吡咯的生成;XRD谱图证明了在反应过程中核的晶型没有变化。热重曲线与磁滞回线表明:随着反应时间的延长,Fe₃O₄的含量减少而聚吡咯的含量增加。当反应时间为5 min时,该样品的吸波性能最优,最低反射损耗为-41.9 dB,有效吸收带宽达到6 GHz。Fe₃O₄-PPy基电磁屏蔽涂层在30 MHz~1 GHz的电磁屏蔽效能≥36 dB。

Preparation and Characterization of Core Shell Fe3O4-Polypyrrole Microsphere Filler for Electromagnetic Shielding

Core shell Fe₃O₄-polypyrrole composite microspheres were prepared by one-step etching method, and their structures and electromagnetic parameters were characterized by FT-IR, XRD, TG and vector network analyzer. The results showed that the Fe ³⁺ produced by hydrochloric acid etching initiated the polymerization of pyrrole on the surface of Fe₃O₄ microspheres. The core-shell structure was confirmed by scanning electron microscopy and transmission electron microscopy. The formation of polypyrrole was confirmed by FT-IR spectra. The XRD spectra showed that the crystal shape of the nuclei did not change during the reaction. The thermo-gravimetric curve and hysteresis regression lines showed that the content of Fe₃O₄ decreased and the content of polypyrrole increased with the increase of reaction time. When the reaction time was 5 minutes, the sample had the best microwave absorbing performance, the lowest reflection loss was -41.9 dB, and the effective absorption bandwidth was 6 GHz.The electromagnetic shielding effectiveness of Fe₃O₄-polypyrrole based coating was ≥36 dB in the 30 MH~1 GHz band.