[Advanced Functional Materials] Multifunctional Flexible WPU Composite Aerogels with Sandwich Structure for Dual-Sided Low-Reflection Electromagnetic Interference Shielding
writer：Xiaofeng Hu, Yali Zhang, Hua Guo, Mukun He, Hua Qiu, Xuetao Shi, Lei Wang*, Junwei Gu*
keywords：electromagnetic interference shielding, flexibility, heterogeneous structure, infrared camouflage, low reflection
source：期刊
Issue time：2025年
Xiaofeng Hu, Yali Zhang, Hua Guo, Mukun He, Hua Qiu, Xuetao Shi, Lei Wang*, Junwei Gu*. Multifunctional Flexible WPU Composite Aerogels with Sandwich Structure for Dual-Sided Low-Reflection Electromagnetic Interference Shielding, Advanced Functional Materials, 2025, 10.1002/adfm.202517665. 2024IF=19.0. （1區材料科學Top期刊）
Abstract
With the increasingly severe electromagnetic pollution, the demand for low-reflection electromagnetic interference shielding (EMI) materials has become progressively urgent. Based on the layered design, the (MXene@CoFe2O4/waterborne polyurethane (WPU))-(MXene/WPU)-(MXene@CoFe2O4/WPU) composite aerogels with sandwich structure (SWCA) are prepared by layer freezing and freeze-drying method, using WPU as the matrix and heterostructure MXene@CoFe2O4 prepared by solvothermal reduction as electromagnetic filler. When the mass ratio of MXene to CoFe2O4 is 1:6, MXene@CoFe2O4 exhibits optimal impedance matching (with the value of |Zin/Z0| closer to 1). Due to the synergistic effect between the absorbing layer of MXene@CoFe2O4/WPU aerogels and the reflecting layer of MXene/WPU aerogels, SWCA assembled with 80 wt.% MXene/WPU aerogels and 40 wt.% MXene@CoFe2O4-3/WPU aerogels achieve high EMI shielding effectiveness (77 dB) and low reflection (0.14) in the X band. Besides, SWCA demonstrates dual-sided low-reflection EMI shielding performance, to the extent that in practical applications, they are no longer restricted to specific installation directions. Moreover, SWCA shows high compressive stress (maximum compressive stress of 264.0 kPa at 50% compressive strain), compressive resilience (88% resilience after 100 cycles of compression), excellent thermal insulation (thermal conductivity between 0.0843 and 0.0941 W·(m·K)-1) and infrared camouflage performance. The multifunctional flexible EMI shielding aerogels with low reflection and high performance holds great promise for application prospect in next-generation electronic devices.
隨著電磁污染日益嚴峻，開發具有低反射特性的電磁屏蔽（EMI）復合材料的需求日趨迫切。本文基于分層模塊設計理念，以水性聚氨酯（WPU）為基體，溶劑熱法制備的異質結構MXene@CoFe2O4為功能填料，經逐層冷凍干燥技術制備三明治結構(MXene@CoFe2O4/WPU)-(MXene/WPU)-(MXene@CoFe2O4/WPU)氣凝膠（SWCA）。當MXene@CoFe2O4中MXene與CoFe2O4質量比為1：6（MXene@CoFe2O4-3）時，MXene@CoFe2O4具有良好的阻抗匹配特性（|Zin/Z0|的值更接近于1）。得益于吸收層MXene@CoFe2O4/WPU氣凝膠與反射層MXene/WPU氣凝膠的協同作用，當MXene@CoFe2O4-3/WPU氣凝膠中MXene@CoFe2O4-3質量分數為40 wt%、MXene/WPU氣凝膠中MXene質量分數為80 wt%時，SWCA誘導入射電磁波經歷“吸收-反射-再吸收”過程，在X波段的電磁屏蔽性能可達77 dB，平均反射系數僅為0.14。該氣凝膠更突破性地展現出雙面低反射EMI屏蔽性能，在實際應用中無需受限于特定安裝方向。此外，SWCA還兼具高壓縮應力（50%壓縮應變下的最大壓應力為264.0 kPa）、壓縮回彈特性（循環壓縮100次氣凝膠的回彈率達88%）、優異隔熱性能（導熱系數處于0.0843-0.0941 W/(m·K)之間）以及紅外偽裝的功能。這種兼具低反射、高性能、多功能的柔性電磁屏蔽氣凝膠在下一代電子器件中具有廣闊的應用前景。