School of Mechanical Engineering, Southeast University, Nanjing211189, Jiangsu Province, PR China.
Engineering Research Center of New Light Sources Technology and Equipment of MOE, Southeast University, Nanjing211189, Jiangsu Province, PR China.
ACS Appl Mater Interfaces. 2023 Feb 1;15(4):5787-5797. doi: 10.1021/acsami.2c18759. Epub 2023 Jan 20.
Structure and material composition is crucial in realizing high electromagnetic interference (EMI) shielding effectiveness (SE). Herein, an ultrathin MXene@AgNW@MoS (MAM) composite film that resembles the structure of a pork belly and exhibits superior EMI shielding performance was fabricated via the vacuum-assisted suction filtration process and atomic layer deposition (ALD). The staggered AgNWs form skeletons and intersperse in MXene sheets to build a doped layer with three-dimensional network structures, which improves the electrical conductivity of the film. Based on the optimal dispersion concentration of Ag in doped and single layers, the MXene/AgNW doped layer and AgNW single layer are alternately vacuum-assisted-filtered to obtain laminated structures with multiple heterogeneous interfaces. These interfaces generate interface polarization and increase multiple reflection and scattering, resulting in the increased electromagnetic (EM) wave losses. On the other hand, MoS outer nanolayers fabricated precisely by ALD effectively increases the absorption proportion of electromagnetic waves, reduces the secondary reflection, and improves the stability of EMI shielding properties. Ultimately, an ultrathin MAM film (a thickness of 0.03 mm) with five alternating internal layers and MoS outer layers exhibits an excellent EMI SE of 86.3 dB in the X-band.
结构和材料组成对于实现高电磁干扰（EMI）屏蔽效能（SE）至关重要。本文通过真空辅助抽吸过滤工艺和原子层沉积（ALD）制备了一种超薄 MXene@AgNW@MoS（MAM）复合膜，其结构类似于五花肉，并具有优异的 EMI 屏蔽性能。交错的 AgNW 形成骨架并散布在 MXene 片层中，构建具有三维网络结构的掺杂层，从而提高了薄膜的导电性。基于掺杂层和单层中 Ag 的最佳分散浓度，将 MXene/AgNW 掺杂层和 AgNW 单层交替进行真空辅助过滤，以获得具有多个异质界面的层压结构。这些界面产生界面极化并增加多次反射和散射，导致电磁波损耗增加。另一方面，ALD 精确制备的 MoS 外层纳米层有效地增加了电磁波的吸收比例，减少了二次反射，并提高了 EMI 屏蔽性能的稳定性。最终，具有五层交替内部层和 MoS 外层的超薄 MAM 薄膜（厚度为 0.03 毫米）在 X 波段表现出优异的 EMI SE 为 86.3 dB。
