Multifunctional heterostructured composite foam with tunable electromagnetic interference shielding

Multifunctional composite materials with adjustable electromagnetic interference (EMI) shielding properties hold significant promise in the emerging field of combating electromagnetic radiation pollution. Herein, we construct a heterostructured composite foam with tunable EMI shielding performance by adjusting the thickness and spatial distribution of Ag conductive network in the porous sponge, coupled with the incorporation of CNTs/WPU aerogel. The remarkable conductivity of 3D Ag network within the composite foam enables it possesses excellent shielding performance at X-band (47.1 dB), fast sensing response time (∼0.2 s), and high temperature of 101.8 °C through efficient joule heating even at a low voltage of 3 V. Importantly, controllable tuning of EMI shielding effectiveness (from 25.0 to 40.1 dB), are successfully achieved by changing the position of the Ag layer or compression strain of the composite foam. These achievements underscore the substantial potential of this material for creating electromagnetic shielding solutions with adaptable characteristics.