Ultrathin flexible reduced graphene oxide/cellulose nanofiber composite films with strongly anisotropic thermal conductivity and efficient electromagnetic interference shielding
Ultrathin flexible reduced graphene oxide/cellulose nanofiber composite films with strongly anisotropic thermal conductivity and efficient electromagnetic interference shielding
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具有强各向异性导热性和高效电磁干扰屏蔽的超薄柔性还原氧化石墨烯/纤维素纳米纤维复合薄膜
DOI：
10.1039/c7tc00400a
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发表时间：
2017-04-21
影响因子：
6.4
通讯作者：
Fu, Qiang
中科院分区：
文献类型：
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作者：
Yang, Weixing;Zhao, Zedong;Fu, Qiang
随着便携式和可穿戴电子设备的广泛使用，人们对具有良好热管理性能的超薄电磁干扰(EMI)屏蔽材料的需求越来越高。本研究采用真空辅助过滤和氢碘酸还原的方法制备了具有良好电磁屏蔽性能和热导率各向异性的超薄高取向氧化石墨烯(RGO)/纤维素纳米纤维(CNF)复合膜。制备的50wt%RGO/CNF复合薄膜的电导率约为4057.3 S m(-1)，电磁屏蔽效能约为26.2dB，这是由于RGO的均匀分散和自对准形成的层状结构所致。另外，RGO含量为50wt%的RGO/CNF复合薄膜具有很高的面内热导率(K约为7.3Wm(-1)K-1)和很低的跨面热导率(K垂直约为0.13Wm(-1)K-1)，导致热导率的各向异性很强(K/K垂直约为56)。因此，这些超薄的RGO/CNF复合薄膜作为有效的轻质电磁微波和热屏蔽材料具有很大的应用潜力，特别是在柔性便携式电子设备和可穿戴设备中。
With the extensive use of portable and wearable electronic devices, ultrathin electromagnetic interference (EMI) shielding materials with excellent thermal management are increasingly desirable. In this study, ultrathin and highly aligned reduced graphene oxide (RGO)/cellulose nanofiber (CNF) composite films with excellent EMI shielding performance and strong anisotropy of thermal conductivity were fabricated by vacuum-assisted filtration followed by hydroiodic acid (HI) reduction. The obtained 50 wt% RGO/CNF composite films, which are only approximate to 23 mm in thickness, possess the remarkable electrical conductivity of approximate to 4057.3 S m(-1) and outstanding EMI shielding effectiveness (SE) of approximate to 26.2 dB owning to the uniform dispersion and self-alignment into the layered structure of RGO. In addition, the RGO/CNF composite films with 50 wt% RGO loadings possess high in-plane thermal conductivity (K approximate to 7.3 W m(-1) K-1) and, unexpectedly, very low cross-plane thermal conductivity (K-perpendicular to approximate to 0.13 W m(-1) K-1), resulting in strong anisotropy of the thermal conductivity (K/K-perpendicular to approximate to 56). Thus, these ultrathin RGO/CNF composite films have great application potential as effective lightweight shielding materials against electromagnetic microwaves and heat, especially in flexible portable electronic devices and wearable devices.