二氧化锰改性膨胀石墨及其吸波性能研究

Study on the microwave absorbing properties ofmanganese dioxide modified expanded graphite composite

膨胀石墨具有优异的各向异性导电性和疏松多孔的蠕虫状结构特征,是极具潜力的新型吸波剂材料。基于此,选取膨胀石墨为基体材料,采用水热法制备了一系列MnO_(2)改性膨胀石墨吸波剂,并对其微观结构和吸波性能进行研究。结果表明,MnO_(2)层改善了膨胀石墨的阻抗匹配,有助于介电损耗和磁损耗能力的提升。其中,150℃水热温度下制备的改性膨胀石墨具有最佳的吸波性能,其在厚度为1.14 mm时,最低反射损耗值为-50.01 dB;调整其厚度至1.86 mm时,最大有效吸收带宽可达5.12 GHz。

Expanded graphite is a promising absorber with excellent conductivity anisotropy and porous worm-like structure.Herein,a series of MnO_(2) modified expanded graphite composites are fabricated by hydrothermal method,and their microstructure and microwave absorption properties are systematically investigated.The results show that the MnO_(2) coating on the surface of the expanded graphite effectively enhances the impedance matching of the material,which improves the dielectric loss and magnetic loss capability.Specifically,the minimum reflection loss(RL)value of EG@MnO_(2)-150 is -50.01 dB at a thickness of 1.14 mm,and the optimal the modified expanded graphite prepared at 150℃ exhibits the best microwave absorption performance with the lowest reflection loss value of -50.01 dB at a thickness of 1.14 mm.And the effective absorption bandwidth reaches 5.12 GHz when its thickness is adjusted to 1.86 mm.