Ti ₃ C ₂ T _<i>x</i> MXene-mediated sensitization-metallization enables sandwich-structured copper@aramid films for high-performance electromagnetic interference shielding

Optimizing the structural design of electromagnetic interference (EMI) shielding materials to enhance their effectiveness, mechanical properties, and thermal management remains a significant challenge. In this work, a sandwich-structured copper@aramid nanofiber/Ti₃C₂T_x MXene (Cu@ANF/MXene) composite film with high mechanical strength and thermal conductivity was achieved via a straightforward electroless deposition process. Crucially, Ti₃C₂T_x MXene serves dual roles: reinforcing the ANF matrix and sensitizing the formation of Ag seeds to facilitate subsequent Cu deposition, rather than merely acting as a conductive filler. The sandwich-structured film achieves an exceptional maximum EMI shielding effectiveness of 102.7 dB, while simultaneously integrating robust mechanical properties (149.7 MPa) and superior thermal conductivity (40.7 W m^‒1K^‒1). Remarkably, the sandwich-structured film exhibits a 34.5 dB enhancement in EMI shielding effectiveness compared to its non-sandwich counterpart under identical conditions, unequivocally demonstrating the critical importance of architectural optimization. This multifunctional performance underscores the significant potential of the metal@aramid composites for advanced EMI shielding applications.