Wei Qinwei, Pei Songfeng, Qian Xitang, Liu Haopeng, Liu Zhibo, Zhang Weimin, Zhou Tianya, Zhang Zhangcai, Zhang Xuefeng, Cheng Hui-Ming, Ren Wencai
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China.
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, P. R. China.
Adv Mater. 2020 Apr;32(14):e1907411. doi: 10.1002/adma.201907411. Epub 2020 Feb 24.
Ultrathin, lightweight, high-strength, and thermally conductive electromagnetic interference (EMI) shielding materials with high shielding effectiveness (SE) are highly desired for next-generation portable and wearable electronics. Pristine graphene (PG) has a great potential to meet all the above requirements, but the poor processability of PG nanosheets hinders its applications. Here, efficient synthesis of highly aligned laminated PG films and nacre-like PG/polymer composites with a superhigh PG loading up to 90 wt% by a scanning centrifugal casting method is reported. Due to the PG-nanosheets-alignment-induced high electrical conductivity and multiple internal reflections, such films show superhigh EMI SE comparable to the reported best synthetic material, MXene films, at an ultralow thickness. An EMI SE of 93 dB is obtained for the PG film at a thickness of ≈100 µm, and 63 dB is achieved for the PG/polyimide composite film at a thickness of ≈60 µm. Furthermore, such PG-nanosheets-based films show much higher mechanical strength (up to 145 MPa) and thermal conductivity (up to 190 W m K ) than those of their MXene counterparts. These excellent comprehensive properties, along with ease of mass production, pave the way for practical applications of PG nanosheets in EMI shielding.
具有高屏蔽效能（SE）的超薄、轻质、高强度和导热的电磁干扰（EMI）屏蔽材料是下一代便携式和可穿戴电子产品所迫切需要的。原始石墨烯（PG）具有满足上述所有要求的巨大潜力，但PG纳米片的加工性能差阻碍了其应用。在此，报道了通过扫描离心铸造法高效合成高度取向的层状PG薄膜和具有高达90 wt%超高PG负载量的类珍珠母PG/聚合物复合材料。由于PG纳米片的取向诱导了高电导率和多次内部反射，此类薄膜在超低厚度下表现出与报道的最佳合成材料MXene薄膜相当的超高EMI SE。PG薄膜在厚度约为100 µm时获得了93 dB的EMI SE，PG/聚酰亚胺复合薄膜在厚度约为60 µm时实现了63 dB的EMI SE。此外，此类基于PG纳米片的薄膜显示出比其MXene对应物更高的机械强度（高达145 MPa）和热导率（高达190 W m⁻¹ K⁻¹）。这些优异的综合性能以及易于大规模生产，为PG纳米片在EMI屏蔽中的实际应用铺平了道路。
