With the growing demand for flexible electronic systems, requirements for electromagnetic interference (EMI) shielding materials are also increasing. These materials must not only be lightweight and deformable but also provide excellent shielding performance. However, traditional shielding materials often face challenges: it is difficult to balance shielding effectiveness, flexibility, and weight. To address these challenges, this study designed a multilayer cobalt–nickel alloy (CoNi)/transition-metal carbide/nitride (MXene)/CoNi/MXene/thermoplastic polyurethane (TPU) nanocomposite film employing an “absorption–reflection–reabsorption” electromagnetic attenuation strategy, which was fabricated through processes including electrospinning, vacuum-assisted filtration, and interfacial bonding. Its structure consists of a surface magnetic absorption layer composed of CoNi nanoparticles anchored within electrospun TPU nanofibers; an intermediate magnetoelectric transition layer in which CoNi nanoparticles are grown in situ on two-dimensional MXene nanosheets to form MXene/CoNi nanoheterostructures; and a bottom conductive reflective layer consisting of a continuous MXene nanosheet network deposited on a TPU fiber membrane. The hierarchical nanoheterostructures at each interface enable synergistic magnetic loss, conductive loss, and interfacial polarization loss, yielding an absorption-dominant shielding mechanism. Experimental results demonstrate that the composite film achieves an overall electromagnetic interference shielding effectiveness (EMI SE) of 30.89 dB with an absorption coefficient (A) of 0.56 at an ultrathin thickness of just 0.27 mm, exhibiting a highly efficient shielding mechanism dominated by absorption. The nanorough surface architecture also imparts outstanding hydrophobicity. Durability tests confirm that the film retains EMI SE above the commercial threshold after 15 days of aqueous immersion, 15 days of thermal oxidation at 50 °C, and 200 cyclic tensile deformations, demonstrating acceptable functional durability for practical flexible and wearable electromagnetic shielding applications.
Wu et al. (Wed,) studied this question.