Heterogeneous MXene-based films with graded electrical conductivity towards highly efficient EMI shielding and electrothermal heating  

作　　者：Yu Zhang Guangcheng Zhang Zhonglei Ma Jianbin Qin Xi Shen 

机构地区：[1]Department of Aeronautical and Aviation Engineering,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong,China [2]Shaanxi Key Laboratory of Macromolecular Science and Technology,School of Chemistry and Chemical Engineering,Northwestern Polytechnical University,Xi’an 710072,China [3]Research Institute for Sports Science and Technology,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong,China

出　　处：《Nano Research》2024年第8期7264-7274,共11页纳米研究（英文版）

基　　金：supported by the Young Scientists Fund of National Natural Science Foundation of China(No.52303106);Research Grants Council of Hong Kong SAR(No.16200720);Environment and Conservation Fund of Hong Kong SAR(No.21/2022);Research Institute of Sports Science and Technology(No.P0043535);Research Institute of Advanced Manufacturing(No.P0046125);the start-up fund for new recruits of PolyU(Nos.P0038855 and P0038858).

摘　　要：The increasing need for electromagnetic interference(EMI)shielding of electronics in cold environments such as those in aircraft,space exploration,and wearable heaters to avoid hazardous icing conditions or hypothermia requires the development of thin and lightweight EMI shielding materials preferably by absorbing rather than reflecting electromagnetic(EM)waves while also generating heat through energy-efficient electrothermal conversion.However,it is challenging to achieve absorption-dominant EMI shielding and energy-efficient electrothermal heating simultaneously in a thin and lightweight structure.Here,we develop a heterogeneous composite film comprising a porous multi-walled carbon nanotubes(MWCNTs)/bacterial cellulose(BC)film and an aligned MXene/Ag nanowires(NWs)backing via a sequential vacuum filtration process.The porous film contains random conductive networks of MWCNTs with moderate conductivity while the aligned MXene sheets atop Ag NWs network affords high conductivity in the backing,giving rise to graded electrical conductivity for absorption-dominant EMI shielding.The increasing Ag NW coverage leads to significantly increased electrical conductivity without increasing the EM wave reflection as well as the density and thickness of the film,yielding excellent specific EMI shielding effectiveness(>8500 dB/(g·cm^(2))),low driving voltage for energy-efficient electrothermal heating(163℃at 2.5 V),and fast response time(60 s)at a low areal density of 0.015 mg/cm^(2).Combining EMI shielding and electrothermal heating,the heterogeneous film developed here are promising contenders for the protection of electronic equipment in low-temperature environment.

关 键 词：heterogenous composite film MXene electromagnetic interference(EMI)shielding thermal management 

分 类 号：TB383[一般工业技术—材料科学与工程]