Reduced graphene oxide porous films containing SiC whiskers for constructing multilayer electromagnetic shields  

含碳化硅晶须的还原氧化石墨烯多孔电磁屏蔽薄膜及其多层结构

作　　者：LI Jing Qi Yi-quan ZHAO Shi-xiang QIU Han-xun YANG Jun-he YANG Guang-zhi 李静;祁奕铨;赵诗翔;邱汉迅;杨俊和;杨光智(上海理工大学材料与化学学院,上海200093)

机构地区：[1]School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China

出　　处：《新型炭材料（中英文）》2024年第6期1191-1201,共11页New Carbon Materials

摘　　要：Developing lightweight and flexible thin films for electromagnetic interference(EMI)shielding is of great importance.Porous thin films of reduced graphene oxide containing SiC whiskers(SiC@RGO)for EMI shielding were prepared by a two-step reduction of graphene oxide(GO),in which the two steps were chemical reduction by HI and the solid phase microwave irradiation.A significant increase of the film thickness from around 20 to 200μm was achieved due to the formation of a porous structure by gases released during the 3 s of solid phase microwave irradiation.The total shielding effectiveness(SET)and the reflective SE(SE_(R))of the SiC@RGO porous thin films depended on the GO/SiC mass ratio.The highest SET achieved was 35.6 dB while the SE_(R) was only 2.8 dB,when the GO/SiC mass ratio was 4∶1.The addition of SiC whiskers was critical for the multi-reflection,interfacial po-larization and dielectric attenuation of EM waves.A multilayer film with a gradient change of SE values was constructed using SiC@RGO porous films and multi-walled carbon nanotubes buckypapers.The highest SET of the multilayer films reached 75.1 dB with a SE_(R) of 2.7 dB for a film thickness of about 1.5 mm.These porous SiC@RGO thin films should find use in multilayer or sand-wich structures for EMI absorption in packaging or lining.轻质柔性的电磁屏蔽薄膜材料的开发具有重要的意义。本文报道了一种含碳化硅晶须的还原氧化石墨烯(SiC@RGO)多孔电磁屏蔽薄膜,其中氧化石墨烯的还原采用两步法,即HI化学还原,加固相微波处理。仅3s的固相微波处理便可高效还原氧化石墨烯,同时,快速释放的气体使薄膜厚度从约20μm增加至200μm,且薄膜获得多孔结构。当氧化石墨烯与碳化硅晶须的质量比为4∶1时,该薄膜的电磁屏蔽效能达到35.6 dB,其反射效能仅为2.8 dB。在薄膜中添加SiC晶须有利于电磁波的多次反射、界面极化和介电衰减。进一步,将SiC@RGO多孔薄膜按照透过层到反射层的顺序叠加,构建多层复合薄膜,并采用多壁碳纳米管纸作为反射层。当多层结构厚度为1.5 mm时,最高电磁屏蔽效能达到75.1 dB,其中反射效能仍保持在2.7 dB。该多孔状SiC@RGO薄膜可用于设计以吸收为主的电磁屏蔽多层封装材料或三明治结构的芯层。

关 键 词：GRAPHENE Thin films Silicon carbide whiskers Electromagnetic interference shielding 

分 类 号：TQ127.11[化学工程—无机化工]