PVP对石墨烯/Fe3O4复合吸波材料形貌及吸波性能的影响

目的研究分散剂PVP对Fe_3O_4在石墨烯表面分散性的影响,以获得吸波性能良好的吸波材料。方法采用溶剂热法制备石墨烯/Fe_3O_4复合吸波材料,通过扫描电子显微镜、X射线衍射分析仪、X射线光电子能谱、矢量网络分析仪等对石墨烯/Fe_3O_4复合吸波材料进行表征,并研究了PVP添加与否在石墨烯/Fe_3O_4复合吸波材料形貌及吸波性能的影响。结果添加PVP后的石墨烯/Fe_3O_4复合吸波材料与未添加PVP的相比,Fe_3O_4在石墨烯表面的团聚现象明显减少,尺寸显著减小。通过计算机模拟反射率,未添加PVP的石墨烯/Fe_3O_4复合吸波材料在匹配厚度d=2.00 mm时,在16.25 GHz处达到最大反射损耗-18.79 dB,复合材料反射损耗小于-10 dB的频带宽度可达4.1 GHz。添加PVP的复合材料在匹配厚度d=2.00 mm时,在16.25 GHz处达到最大反射损耗-25.88 dB,复合材料反射损耗小于-10 dB的频带宽度可达4.5 GHz,相比未添加PVP的复合吸波材料,反射损耗小于-10 dB的频带宽度增加0.4 GHz,最大反射损耗提高7.09 dB。结论 PVP能提高Fe_3O_4在石墨烯表面的分散性,并在石墨烯表面形成良好的导电网络,使复合材料的吸波性能明显提升。

Effect of PVP on Morphology and Microwave-absorbing Properties of Graphene/Fe3O4 Composite Absorbing Materials

The work aims to study the effect of PVP on the dispersion of Fe3O4 on the surface of graphene to obtain the absorbing material with good absorbing properties. The graphene/Fe3O4 composite absorbing materials were prepared by solvothermal method. The graphene/Fe3O4 composite absorbing materials were characterized by scanning electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy and vector network analyzer. Effects of PVP (dispersant) whether added or not on the morphology and absorbing properties of graphene/Fe3O4 composite absorbing materials were studied. On graphene/Fe3O4 composite absorbing materials added with PVP, the agglomeration of Fe3O4 significantly decreased and the size was significantly reduced, compared with that not added with PVP. Through the reflectivity simulated by computer, the maximum reflection loss of graphene/Fe3O4 composite absorbing materials without PVP reached -18.79 dB at 16.25 GHz at a matching thickness of d=2.00 mm and the frequency bandwidth of composite materials with reflection loss less than -10 dB could reach 4.1 GHz. The composite materials with PVP could reach the maximum reflection loss of -25.88 dB at 16.25 GHz when the matching thickness was d=2.00 mm, and the frequency bandwidth of the composite materials with the reflection loss less than -10 dB could reach 4.5 GHz. Compared with the composite absorbing materials without PVP, the frequency bandwidth of materials with reflection loss less than -10 dB increased by 0.4 GHz and the maximum reflection loss increased by 7.09 dB. PVP can improve the dispersion of Fe3O4 on the surface of graphene and form a good conductive network, and the microwave absorption performance is obviously improved.