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, e17665. 10.1002/adfm.202517665. 2024IF= 19.0. （1区材料科学类Top期刊）.

DOI: 10.1002/adfm.202517665

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 |Z_in/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.