电纺碳纳米纤维/石墨烯气凝胶薄膜的可控制备与电磁屏蔽性能研究

Controllable Preparation of Electrospun Carbon Fibers/Graphene Films and Their Electromagnetic Interference Shielding

随着信息技术的迅猛发展,高功率电子设备包括卫星通信、宽带雷达、无线网络和便携式数字硬件等在医疗卫生、电子安全和国防安全领域广泛应用,电磁干扰、辐射污染以及信息泄露等问题则随之产生。目前,如何制备具有优异力学性能、电导率和电磁屏蔽性能的石墨烯基薄膜材料仍然是一个巨大的挑战。因此,本工作以氧化石墨烯(Graphene oxide, GO)水溶液和电纺碱处理聚丙烯腈(Alkali-treated polyacrylonitrile, aPAN)纳米纤维为原料,通过水热还原和冷冻干燥得到气凝胶,进一步通过预氧化和高温退火处理获得碳纳米纤维增强的石墨烯气凝胶(GCA),并通过液压机压制得到石墨烯基气凝胶薄膜,系统研究了薄膜的电导率、电磁屏蔽和光热转化性能。结果表明,在加入碳纳米纤维后,GCA膜的电导率可以提升至20.5 S/cm。对于电磁屏蔽性能,可从73.7 dB(GA)增加到78.8 dB(GCA-10),且气凝胶膜的整体屏蔽效果可以达到99.999 995%以上。此外,该气凝胶膜还呈现出优异的光热转化性能,有望应用于光吸收和原油传输等领域。

With the rapid development of information technology,high-power electronic equipment including satellite communications,broadband radar,wireless networks and portable digital hardware are widely used in medical,health,electronic security and national defense security,the electromagnetic interference,radiation pollution and information leakage problems have followed.At present,how to prepare graphene-based thin film materials with excellent mechanical properties,electrical conductivity and electromagnetic shielding properties is still a huge challenge.In this work,we adopted a facile and effective method by annealing the alkali-treated polyacrylonitrile(aPAN)nanofibers reinforced graphene oxide(GO)composite films to obtain carbon nanofiber-reinforced graphene aerogel(GCA).The conductivity,electromagnetic shielding and photothermal conversion properties of the thin film were systematically studied.The results show that after the addition of carbon nanofibers,the conductivity of the GCA membrane can be increased to 20.5 S/cm.For electromagnetic shielding performance,it can be increased from 73.7 dB(GA)to 78.8 dB(GCA-10),and the overall shielding effectiveness(SE)of aerogel film can reach more than 99.999995%.In addition,the aerogel film also exhibits excellent photothermal conversion properties,which is expected to be applied to the fields such as light absorption and crude oil transmission.