石墨烯/聚苯胺复合材料的电磁屏蔽性能

采用直流电弧放电法制备高结晶性石墨烯, 利用乙醇助溶分散法得到石墨烯/聚苯胺电磁屏蔽复合材料, 研究不同掺杂比例的石墨烯/聚苯胺复合材料的电磁屏蔽性能。拉曼光谱分析表明: 由于石墨烯与聚苯胺之间的相互作用, 复合材料中聚苯胺特征峰比纯聚苯胺特征峰稍弱或向低频方向移动。复合物的电导率随石墨烯掺杂量的增加而增大, 当掺杂质量分数为25%时, 其电导率达到19.4 S/cm, 接近纯石墨烯电导率(20.1 S/cm)。频率为2~18 GHz时, 复合材料的电磁屏蔽效能随着石墨烯掺杂量和频率的增大而增强; 当石墨烯掺杂质量分数为25%时, 总屏蔽效能在2~18 GHz范围内由19.8 dB增至34.2 dB, 增加了约42%, 其中吸收部分占总屏蔽效能的比例为66%~81%, 这表明石墨烯/聚苯胺复合材料的电磁屏蔽性质是以电磁波吸收为主; 同时也说明了拥有特殊结构与特性的石墨烯是一种较好的聚苯胺填料, 在微波屏蔽与微波吸收领域将会有广阔的应用前景。

Graphene sheets/polyaniline composite for electromagnetic interference shielding

The electromagnetic interference(EMI) shielding effectiveness(SE) of the graphene sheets/polyaniline (GSs/PANI) composite in different contents of GSs was investigated. The high crystalline GSs were prepared by DC arc-discharge method. The GSs/PANI composites were synthesized by an alcohol-assisted dispersion and pressing process. Compared with the pure PANI materials’ Raman spectra, the GSs/PANI composites show the decrease of the characteristic peak intensity or a red shift of the peak, which is induced by the interaction between the GSs and PANI. The electrical conductivity of GSs/PANI composite increases with the increase of the GSs doping quantity and reaches to 19.4 S/cm at the mass fraction of 25%, which almost equals to that of pure GSs (20.1 S/cm). The EMI SE increases with the frequency and the GSs doping quantity. When the mass fraction of GSs is 25%, the EMI SE increases about 42%, from 19.8 dB to 34.2 dB in the range of 2~18 GHz. Besides, the absorption proportion increases from 66% to 81%, which indicates that the GSs/PANI composite is the absorption-dominated EMI shielding material. These also prove that GSs are excellent filler of the PANI because of their special structure and properties. There will be a wide application prospects in the field of EMI shielding and microwave absorption.