With the rapid development and popularization of smart, portable, and wearable flexible electronic devices, urgent demands have been raised for flexible electromagnetic interference (EMI) shielding films to solve related electromagnetic pollution problems. With polyvinyl alcohol (PVA) as polymer matrix, the sandwich-structured EMI shielding nanocomposite films are prepared via electrospinning-laying-hot pressing technology, where Fe₃O₄/PVA composite electrospun nanofibers in the top and bottom layers and Ti₃C₂T_x/PVA composite electrospun nanofibers in the middle layer. Owing to the electrospinning process and the successful construction of the sandwich structure, when the amounts of Ti₃C₂T_x and Fe₃O₄ are respectively only 13.3 and 26.7 wt%, the EMI shielding effectiveness (EMI SE) of the sandwich-structured EMI shielding nanocomposite films reach 40 dB with the thickness of 75 µm, higher than that of (Fe₃O₄/Ti₃C₂T_x)/PVA EMI shielding nanocomposite films (21 dB) prepared based on blending-electrospinning-hot pressing process under the same amounts of fillers. Furthermore, the prepared sandwich-structured EMI shielding nanocomposite films possess excellent thermal conductivities and mechanical properties. This novel kind of flexible sandwich-structured EMI shielding nanocomposite films with excellent EMI shielding performances, thermal conductivities, and mechanical properties presents broad application prospects in the fields of EMI shielding and protection for high-power, portable, and wearable flexible electronic devices.

中文翻译：

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具有优异导热性的柔性夹层结构电磁干扰屏蔽纳米复合薄膜

随着智能、便携、可穿戴柔性电子设备的快速发展和普及，迫切需要柔性电磁干扰（EMI）屏蔽膜来解决相关的电磁污染问题。以聚乙烯醇（PVA）为聚合物基体，通过静电纺丝-铺设-热压技术制备了夹层结构的EMI屏蔽纳米复合薄膜，其中顶层和底层为Fe ₃ O ₄ /PVA复合电纺纳米纤维，Ti ₃ C ₂ T _x /PVA 复合电纺纳米纤维在中间层。由于静电纺丝工艺和夹层结构的成功构建，当 Ti ₃C ₂ T _x和Fe ₃ O ₄分别仅为13.3和26.7 wt%，夹层结构EMI屏蔽纳米复合膜的EMI屏蔽效率（EMI SE）达到40 dB，厚度为75 μm，高于（ Fe ₃ O ₄ /Ti ₃ C ₂ T _x)/PVA EMI 屏蔽纳米复合薄膜 (21 dB) 基于共混-静电纺丝-热压工艺制备，填料用量相同。此外，所制备的夹层结构的 EMI 屏蔽纳米复合薄膜具有优异的导热性和机械性能。这种新型柔性夹层结构EMI屏蔽纳米复合薄膜具有优异的EMI屏蔽性能、导热性和机械性能，在大功率、便携、可穿戴柔性电子设备的EMI屏蔽和保护领域具有广阔的应用前景。