石墨烯增强FeSiAl-MoS_(2)/PLA复合材料吸波性能

Graphene-enhanced electromagnetic wave absorbing properties of FeSiAl-MoS_(2)/PLA composites

多元材料复合是制备轻质、宽频和强吸收吸波材料的有效方法。以聚乳酸(PLA)为基体,FeSiAl、MoS_(2)和石墨烯(GN)为填料,通过球磨和熔融挤出两步法制备了可用于熔融沉积成形(FDM)的FeSiAl-MoS_(2)-GN/PLA复合材料。采用XRD、拉曼光谱、SEM和矢量网络分析仪分别对复合材料的物相结构、微观形貌和电磁特性进行了表征,并研究了石墨烯含量对复合材料吸波性能的影响。研究表明:石墨烯、FeSiAl和MoS_(2)随机分散在PLA基体中,形成了复杂的导电网络;多元材料复合构筑了丰富的介电/磁异质界面,有利于促进界面极化;当石墨烯含量增加时,复合材料的吸波性能随之增强,当石墨烯含量为5wt%时,复合材料的吸波性能最佳,在厚度为1.7 mm时最小反射损耗为-27.90 dB,在厚度为1.9 mm时有效吸收带宽为4.96 GHz(12.64~17.60 GHz)。其优异的吸波性能归因于良好的阻抗匹配及介电损耗和磁损耗之间的协同作用。

Multi-material composite is an effective method to prepare light-weight,broadband and strong absorbing materials.In this paper,polylactic acid(PLA)was used as the matrix material,and FeSiAl,MoS_(2)and graphene(GN)were used as fillers.FeSiAl-MoS_(2)-GN/PLA composites,which were used for fused deposition modeling(FDM),prepared by the two-step process of ball milling and melt extrusion.The phase structure,microscopic morphology and electromagnetic properties of composites were characterized by XRD,Raman spectroscopy,SEM and vector network analyzer,respectively.And the effect of graphene content on the electromagnetic wave absorbing properties of composites was also investigated.The research shows that graphene,FeSiAl and MoS_(2) are randomly dispersed in the PLA matrix and form a complex conductive network;Multi-material composites build rich dielectric/magnetic heterointerfaces,which are beneficial to promote interface polarization;The higher the graphene content,the stronger the electromagnetic wave absorbing properties of composites;When the graphene content is 5wt%,the minimum reflection loss is-27.90 dB at a thickness of 1.7 mm,and the effective absorption bandwidth is 4.96 GHz(12.64-17.60 GHz)at a thickness of 1.9 mm.Its excellent absorbing properties are attributed to the perfect impedance matching and the synergy between dielectric and magnetic losses.