具有宽带微波吸收性能的MWCNTs/SiC纳米复合材料的点击化学法制备及性能研究

Preparation and properties of MWCNTs/SiC nanocomposites withbroadband microwave absorption properties by click reaction

多壁碳纳米管/碳化硅(MWCNTs/SiC)纳米复合材料,以电阻型微波吸收剂MWCNTs为基体材料,电介质型微波吸收剂碳化硅作为损耗介质通过点击反应制备。采用XRD,IR,XPS,TG,SEM,矢量网络分析仪进行该复合材料的结构表征和微波吸收性能测试。此外还探讨了不同投料比,对复合材料的微波吸收性能的影响。实验结果表明:MWCNTs/SiC二元纳米复合材料由点击法成功制备;当投料的质量比MWCNTs:SiC=1∶1时,MWCNTs/SiC二元纳米复合材料在2.0 mm的厚度下,其最小反射损耗(RLmin)达到了-44.96 dB,在1.5 mm的超薄厚度下有效吸收的最宽带宽(RL<-10 dB)达到5.04 GHz(从12.66~17.93 GHz,覆盖了Ku波段的87.8%);此外,MWCNTs/SiC二元纳米复合材料可以在整个X波段有效吸收电磁波,厚度范围为2.0~2.5 mm。并且,通过调整吸收层的厚度,几乎可以有效覆盖所有的C、X和Ku波段。MWCNTs和SiC之间通过点击反应以共价键连接,分子内部形成导电通道,产生足够的载流子,在外加电场的作用下产生感应电流,也可以衰减电磁波,从而增强对电磁波能量的消耗。

MWCNTs/SiC nanocomposites were prepared by click reaction using resistive microwave absorbent MWCNTs as the matrix material and dielectric microwave absorbent SiC as the loss medium.XRD,XPS,TG,SEM and vector network analyzer were used to characterize the structure and test the microwave absorption performance of the composite.In addition,the influence of different feeding ratio on the microwave absorption properties of the composites was also discussed.The experimental results show that the MWCNTs/SiC binary nanocomposites were successfully prepared by clicking method.When the ratio of MWCNTs to SiC is 1:1,the minimum reflection loss(RL min)of the MWCNTs/SiC binary nanocomposite at the thickness of 2.0 mm reaches-44.96 dB,and the minimum effective absorption bandwidth(RL min<-10 dB)up to 5.04 GHz(from 12.66-17.93 GHz,covering 87.8%of the Ku band).MWCNTs/SiC binary nanocomposites can effectively absorb electromagnetic waves in the whole X-band,and the thickness range is 2.0~2.5 mm.Moreover,by adjusting the thickness of the absorption layer,almost all the electromagnetic wave of C,X and Ku bands can be effectively covered.Therefore,the composite materials with covalent bond between MWCNTs and SiC prepared by click reaction is a new method to be used as efficient microwave absorbing materials.