Rahmati Reza, Ashouri-Sanjani Mehran, Salehi Amirmehdi, Kheradmandkeysomi Mohamad, Omranpour Hosseinali, Park Chul B, Hamidinejad Mahdi
Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario, M5S 3G8, Canada.
Department of Mechanical Engineering, University of Alberta, 9211-116 Street NW, Edmonton, Alberta, T6G 1H9, Canada.
Small. 2025 Oct;21(39):e06670. doi: 10.1002/smll.202506670. Epub 2025 Sep 4.
Rapid strides in portable electronics and telecommunication technologies have sharply escalated the demand for high-performance electromagnetic interference (EMI) shielding materials that effectively suppress secondary electromagnetic pollution while simultaneously integrating thermal management. Here an innovative, lightweight, hierarchical triple-layer aerogel structure comprising nickel (Ni) foam (NiF), titanium carbonitride (TiCNT) MXene, and poly(vinyl alcohol) (PVA), fabricated via a facile, one-step bidirectional freeze-casting process is presented. This asymmetric aerogel architecture strategically employs an impedance-matching MXene/PVA top layer for optimized microwave entry, a NiF/MXene/PVA interlayer introducing magnetic loss and enhancing heat conduction, and a reflective, thermally foamed MXene bottom layer promoting internal reflection for superior energy absorption. With an ultralow density (240 mg cm) and robust mechanical stability supported by hydrogen bonding, the aerogels enable synergistic energy loss mechanisms, delivering outstanding EMI shielding effectiveness (91.7 dB) and absorptivity (88%) at 3.4 mm thickness. Tailored thermal management is achieved through contrasting thermal conductivities across layers; the insulating top layer (0.056 W m K) restricts vertical heat flow, whereas the conductive NiF-based interlayer (0.932 W m K) accommodates efficient lateral heat dissipation upon microwave absorption. This multifunctional, scalable material platform sets a benchmark for addressing EMI shielding challenges, holding great promise for future electronics and communication systems.
便携式电子设备和电信技术的飞速发展，急剧增加了对高性能电磁干扰（EMI）屏蔽材料的需求，这种材料能有效抑制二次电磁污染，同时兼具热管理功能。本文介绍了一种创新的、轻质的、具有分级结构的三层气凝胶结构，它由泡沫镍（NiF）、碳氮化钛（TiCNT）MXene和聚乙烯醇（PVA）组成，通过简便的一步双向冷冻铸造工艺制备而成。这种不对称气凝胶结构策略性地采用了阻抗匹配的MXene/PVA顶层，以优化微波入射；NiF/MXene/PVA中间层引入磁损耗并增强热传导；反射性的、热发泡的MXene底层促进内部反射，以实现卓越的能量吸收。该气凝胶密度超低（240 mg/cm），并通过氢键作用具备强大的机械稳定性，能实现协同能量损耗机制，在3.4毫米厚度时可提供出色的电磁干扰屏蔽效能（91.7 dB）和吸收率（88%）。通过各层不同的热导率实现了定制的热管理；绝缘的顶层（0.056 W/(m·K)）限制垂直热流，而基于NiF的导电中间层（0.932 W/(m·K)）在微波吸收时能实现高效的横向散热。这种多功能、可扩展的材料平台为应对电磁干扰屏蔽挑战树立了标杆，对未来的电子和通信系统具有巨大的潜力。
