Filling Uniformity of AgNPs in EMI Shielding Patch Regulated by Surface Morphology

en Silver nanoparticles (AgNPs) are extensively employed for electromagnetic interference (EMI) shielding owing to their remarkable conductivity, and are commonly incorporated into polymer matrices. Therefore, the uniformity of the AgNP distribution within the polymer matrix is a crucial factor that affects the EMI shielding performance. This study demonstrates the impact of the surface morphology of AgNPs on the uniformity of the filling in electromagnetic interference shielding patches. The AgNPs were synthesized through a liquid-phase reduction process, regulating the surface shape by thermal treatment at varying temperatures. The morphology transitioned from a flower-spherical shape to a coarse-strip shape when the heat treatment temperature increased from 20°C to 250°C. The morphological alteration of the AgNPs was ascribed to the interplay between their surface effects and sintering kinetics. The results indicated that after heat treatment at 100°C, AgNPs with a spherical surface morphology demonstrated remarkably superior filling uniformity. The EMI patch containing AgNPs subjected to heat treatment at 100°C demonstrated superior EMI shielding efficacy. Its efficacy was further validated in practical electronic equipment by applying surface electromagnetic radiation scanning techniques. These findings offer significant insights into the practical design of EMI shielding patches for real-world applications using the morphology-regulated filling uniformity method. 摘要 zh 银纳米颗粒因其优异的导电性能已被广泛应用于电磁屏蔽领域,并且通常需要与高分子基体混合后使用。其中,作为填充剂的银纳米颗粒在基体中的分布均匀性是调控电磁屏蔽性能的关键影响因素之一。本研究通过液相还原法制备了银纳米颗粒,采用不同温度的热处理工艺调控其表面形貌,并系统分析了银纳米颗粒表面形貌对电磁屏蔽贴片中填充均匀性的影响。实验表明,当热处理温度从20°C升至250°C时,银纳米颗粒的表面形貌从花状球形逐渐转变为粗糙条状,这种表面形貌变化源于其表面效应与烧结动力学的相互作用。在经过100°C热处理后的银纳米颗粒具有球形表面形貌,并且展现出最优异的填充均匀性,因此,采用100°C热处理银纳米颗粒的电磁屏蔽贴片呈现出优异的电磁屏蔽性能,并进一步通过表面电磁辐射扫描法在电子设备中验证了其在实际应用中的优异性能。该研究结果为实际应用中通过形貌调控填充均匀性设计高性能电磁屏蔽贴片提供了重要参考依据。