Ti3C2TX MXene-Ferroferric Oxide/Carbon Nanotubes/Waterborne Polyurethane-Based Asymmetric Composite Aerogels for Absorption-Dominated Electromagnetic Interference Shielding

Absorption-dominated electromagnetic interference (EMI) shielding materials are more attractive to manage the increasing electromagnetic radiation pollution than conventional reflection-dominated counterparts due to their advantages of balancing the efficient EMI shielding performance while minimizing the secondary pollution of the reflected electromagnetic (EM) wave. Herein, we first fabricate ferroferric oxide/carbon nanotubes/waterborne polyurethane (Fe3O4/CNTs/WPU) aerogels and then coat Ti3C2Tx MXene at the bottom to construct an asymmetric structure. Moreover, the medium or transition layer is formed during the coating process of MXene-ferroferric oxide by the gravity and aerogel's capillary action. This delicate design makes them with obvious absorption, transition, and reflection layers according to the progressive modular design principle. The composite aerogels show an average EMI shielding effectiveness (SE) of 20.06 dB, low reflectivity of 0.396, and specific EMI SE of SSE/t of 332.60 dB cm2 g-1 in the X-band when the MXene content is only 2.35 vol %. Additionally, the resultant aerogels exhibit remarkable flexible and mechanical properties, which could even bear weights of about 4500 times their own weight. In sum, this work provides a promising absorption-dominated EMI shielding candidate with flexible and high strength features.