膨胀石墨含量对竹炭/膨胀石墨复合材料电磁屏蔽性能的影响

Effect of Expanded Graphite Content on Electromagnetic Interference Shielding Performance of Expanded Graphite Composite with Bamboo Charcoal Powder Incorporated

采用高速粉碎法制备竹炭粉末,使用高温插层氧化的方式制备了膨胀石墨,研究了竹炭、膨胀石墨及竹炭/膨胀石墨复合材料的电磁屏蔽效能。结果表明:竹炭粉末在300kHz^30MHz频段的屏蔽效能最高达21.82dB,而在200~3000MHz范围的屏蔽效能约为5dB;竹炭/膨胀石墨复合材料的屏蔽效能随膨胀石墨含量的增加而提高,低频段,膨胀石墨质量百分含量从0提升到40%时,复合材料的屏蔽效能变化不大;而高频段,复合材料的屏蔽效能随膨胀石墨增加而快速提升,最高可达53.47dB。

Bamboo charcoal powder was prepared with high-speed smash, and expanded graphite(EG) was made by high temperature intercalating oxidation. The electromagnetic interference(EMI) shielding performance of bamboo charcoal, expanded graphite and bamboo charcoal/EG composite were investigated. The results show that the EMI shielding effectiveness of bamboo charcoal reaches 21.82 dB at the frequencies from 300 kHz to 30 MHz, while it is about 5 dB in the range of 200 MHz to 3.0 GHz. The EMI shielding effectiveness of bamboo/expanded graphite composite material improves with the increasing amount of EG. When the content of EG is raised from zero to 40 wt%, and the EMI shielding effectiveness remains nearly constant In low frequency band, while the EMI shielding effectiveness of the composite material rises rapidly with the increase of EG content in high frequency band. The maximum value of the EMI shielding performance reaches 53.47 dB.