高透光率MXene/CNTs复合薄膜的界面焊接机制及电磁屏蔽性能研究

透明电磁屏蔽薄膜在通讯设备、医疗器械、航空航天等领域具有广泛应用需求。然而，高透光率和高电磁屏蔽效率这一相互掣肘性能难以兼得。本项目提出基于强毛细作用力驱动下构建多尺度MXene/CNTs界面，进而分层构筑MXene/CNTs复合薄膜。研究MXene喷涂过程参数对界面微观结构的影响，确定最优界面增强方式，揭示界面焊接机制。结合微观结构表征及宏观性能测试，建立薄膜电导率与透光率之间以及电导率与电磁屏蔽效率之间的关联模型，揭示多尺度微观结构（一维CNTs、二维Ti3C2Tx及Ti3C2Tx/CNTs界面）对薄膜透光率和电磁屏蔽性能的影响机制。基于平面波屏蔽理论，调控空气层厚度及堆叠层数，实现透光率及电磁屏蔽效能的最优化(8-12GHz波段，SE>60dB,透光率>70%)，揭示复合薄膜电磁屏蔽机理。本项目实施可进一步丰富多尺度界面结构设计理论，为一维/二维结构的界面优化和性能优化提供理论依据。

Transparent electromagnetic shielding films are attracting expanding attention and showing great promise in scientific and engineering fields, especially in communication devices, medical equipment and aerospace fields. However, it is difficult to endow both high light transmittance and excellent electromagnetic shielding effectiveness. Herein, we proposed to build a multi-scale MXene/CNTs interface driven by strong capillary forces, and further construct a layered MXene/CNTs composite film. The effects of spray-coating parameters of MXene solution including (spray mechanical load, solvent type and solvent evaporating rate) on the morphology and structure of the interface are systematically studied, and the optimal interface strengthening method is analyzed. Then the soldering mechanism are put forwarded well-grounded. Furthermore, combined with microstructures characterization and performance testing, the correlation model between the conductivity and light transmittance along with the one between the conductivity and electromagnetic shielding effectiveness are both well-established properly. Specifically, the influence of multi-scale microstructures (1D CNTs, 2D MXene，MXene/CNTs interface) on the transmittance and electromagnetic shielding performance of as-constructed film was explored. Special focus is given to the relationship between the structural characteristics and transmission of light along with electromagnetic shielding effectiveness. Based on the planar wave shielding theory, the light transmittance and electromagnetic shielding effectiveness of the composite film is optimized by adjusting the thickness of the lamellar spacing and the number of stacked layers (8-12 GHz band, SE >60 dB, light transmittance >70%). Finally, the electromagnetic shielding mechanism was proposed legitimately. Consequently, the implementation of this project can further develop the theory for multi-scale interface design, and provide a theoretical basis for the interface structure optimization and properties optimization for one-dimensional/two-dimensional interface structures.