Enhancing interfacial bonding and compositional synergy in ANF-PPy/Ag-MXene/ANF-PPy multilayer heterostructures for efficient electromagnetic interference shielding and infrared thermal camouflage
The proliferation of electronic devices and wireless communications has escalated the demand for materials that simultaneously provide electromagnetic interference (EMI) shielding and infrared (IR) thermal camouflage, a combination critical for military and civilian applications. Traditional metallic shields suffer from high density, poor processability, and cost, while polymer-based alternatives often lack sufficient shielding effectiveness and environmental stability. Here, we report a multilayer composite film fabricated via layer-by-layer vacuum filtration and hot-pressing, integrating modified aramid nanofibers (ANF) and MXene (Ti3C2Tx) nanosheets. The film architecture comprises ANF-polypyrrole (ANF-PPy) as the matrix and Ag-MXene as the functional filler, with in-situ grown Ag nanoparticles intercalating between MXene layers to enhance interlayer spacing and electromagnetic wave scattering. At a thickness of only 33 μm, the film achieves an average EMI shielding effectiveness (SE) of 66.75 dB and a specific shielding effectiveness (SSE/t) of 38432.54 dB cm2 g−1. The multilayer structure promotes multiple internal reflections and interfacial polarization losses, while the tight integration ensures high IR reflectivity. This work establishes a foundation for developing multifunctional protective materials with dual EMI shielding and IR camouflage capabilities, addressing the critical bottleneck of simultaneous performance in ultrathin, flexible formats.