高导电性PVDF/MWCNTs-AgNWs@MXene双层三维网络的电磁屏蔽复合薄膜的构建

Construction of high conductive PVDF/MWCNTs-AgNWs@MXene bilayer 3D networks electromagnetic shielding composite films

随着通信网络、无线设备及航空航天的快速发展,电磁波危害日益加剧,因而亟需电磁屏蔽性能更优异的复合材料。本文采用MXene(Ti_(3)C_(2)Tx)、银纳米线(AgNWs)和多壁碳纳米管(MWCNTs)构建了双层的高导电三维(导电率最高为1.4×10^(4)S·m^(-1))网络电磁屏蔽复合薄膜(Ti_(3)C_(2)TxMXene基功能复合薄膜)。特别是采取真空辅助抽滤法(VAF)将10 mL AgNWs及15 mL Ti_(3)C_(2)TxMXene的水溶液吸附于聚偏氟乙烯(PVDF)/MWCNTs复合薄膜之上,制备出的Ti_(3)C_(2)TxMXene基功能复合薄膜的总电磁干扰屏蔽效能(EMI SET)高达69.0 dB,比商用标准(20 dB)高出245%,其中吸收损耗效能(SEA)占比85.1%。说明Ti_(3)C_(2)TxMXene基功能复合薄膜主要的电磁损耗机制为吸收损耗,比电磁屏蔽效能(SSE/t)最高可达2719.8 dB/(cm^(-2)·g)。这项工作为新型MXene材料在电磁屏蔽复合材料中的应用提供了结构设计和研究思路。

With the development of communication networks,wireless devices and aerospace industries.Electromagnetic wave hazards become prevalent.Therefore,it is essential to develop composites with better electromagnetic shielding properties.In this paper,highly conductive three-dimensional(conductivity up to 1.4×10^(4)S·m^(-1))networked electromagnetic shielding composite films(Ti_(3)C_(2)Tx MXene-based functional composite films)were constructed using MXene(Ti_(3)C_(2)Tx),silver nanowires(AgNWs)and multi-walled carbon nanotubes(MWCNTs)in a bilayer.In particular,the aqueous solutions of 10 mL AgNWs and 15 mL Ti_(3)C_(2)Tx MXene were adsorbed on top of poly(vinylidene fluoride)(PVDF)/MWCNTs composite films by vacuum-assisted filtration(VAF),and the total electromagnetic interference shielding effectiveness(EMI SET)of the Ti_(3)C_(2)Tx MXene-based functional composite film was as high as 69.0 dB,which was 245%higher than that of the commercial standard(20 dB),of which the absorption loss effectiveness(SEA)accounted for 85.1%.It is shown that the main electromagnetic loss mechanism of Ti_(3)C_(2)Tx MXene-based functional composite films is absorption loss,with a specific electromagnetic shielding effectiveness(SSE/t)of up to 2719.8 dB/(cm^(-2)·g).This work provides structural design and research ideas for the application of novel MXene materials in electromagnetic shielding composites.