[Nano-Micro Letters] Lightweight, flexible cellulose-derived carbon aerogel@reduced graphene oxide/PDMS composites with outstanding EMI shielding performances and excellent thermally conductivities
作者：Ping Song#, Bei Liu#, Chaobo Liang, Kunpeng Ruan, Hua Qiu, Zhonglei Ma, Yongqiang Guo and Junwei Gu*
關鍵字：EMI Shielding
論文來源：期刊
具體來源：Nano-Micro Letters
發表時間：2021年
In order to ensure the operational reliability and information security of sophisticated electronic components and to protect human health, efficient electromagnetic interference (EMI) shielding materials are required to attenuate electromagnetic wave energy. In this work, the cellulose solution is obtained by dissolving cotton through hydrogen bond driving self-assembly using sodium hydroxide (NaOH)/urea solution, and cellulose aerogels (CA) are prepared by gelation and freeze-drying. Then, the cellulose carbon aerogel@reduced graphene oxide aerogels (CCA@rGO) are prepared by vacuum impregnation, freeze-drying followed by thermal annealing, and finally the CCA@rGO/polydimethylsiloxane (PDMS) EMI shielding composites are prepared by backfilling with PDMS. Owing to skin-core structure of CCA@rGO, the complete three-dimensional (3D) double-layer conductive network can be successfully constructed. When the loading of CCA@rGO is 3.05 wt%, CCA@rGO/PDMS EMI shielding composites have an excellent EMI shielding effectiveness (EMI SE) of 51 dB, which is 3.9 times higher than that of the co-blended CCA/rGO/PDMS EMI shielding composites (13 dB) with the same loading of fillers. At this time, the CCA@rGO/PDMS EMI shielding composites have excellent thermal stability (THRI of 178.3oC) and good thermal conductivity coefficient (λ of 0.65 W/mK). Excellent comprehensive performance make CCA@rGO/PDMS EMI shielding composites great prospect for applications in lightweight, flexible EMI shielding composites.
為了保障精密電子元器件的運行可靠性及信息安全性、保護人體健康，需使用高效的電磁屏蔽材料來衰減電磁波能量。本文采用氫氧化鈉/尿素溶液通過氫鍵驅動自組裝溶解棉花得到纖維素溶液，經凝膠化和冷凍干燥制備了纖維素氣凝膠（CA），進而采用真空浸漬-冷凍干燥-高溫碳化制備了具有“皮-芯”結構的纖維素碳氣凝膠@還原氧化石墨烯（CCA@rGO）氣凝膠，最后澆注回填聚二甲基硅氧烷（PDMS）制備CCA@rGO/PDMS電磁屏蔽復合材料。得益于CCA@rGO的“皮-芯”結構特征成功構建了完善的三維雙層導電網絡，當CCA@rGO的用量僅為3.05 wt%時，CCA@rGO/PDMS電磁屏蔽復合材料在3 mm厚度下具有51 dB的優異電磁屏蔽效能（EMI SE）值，是相同填料用量的共混（CCA/rGO）/PDMS電磁屏蔽復合材料EMI SE的3.9倍（13 dB）。此時CCA@rGO/PDMS電磁屏蔽復合材料具有優異的熱穩定性能（耐熱指數THRI為178.3oC）和良好的導熱性能（導熱系數λ達到0.65 W/mK）。優異的電磁屏蔽性能和熱穩定性能、以及良好的導熱性能使CCA@rGO/PDMS電磁屏蔽復合材料在輕質、柔性電磁屏蔽復合材料和便攜式、可穿戴電子設備等領域具有巨大的應用前景。