Delamination-free boron nitride/MXene multilayer films via triple-coordination interfacial bridging for thermal management and electromagnetic interference shielding

초록

Multifunctional films that simultaneously provide high thermal conduction, electromagnetic interference shielding, electrical insulation, and mechanical durability are increasingly required for compact and flexible electronics, yet multilayer architecture often suffers from interfacial delamination that disrupts transport pathways and compromises long-term reliability. Here, a delamination-free multilayer composite is developed through an Fe3+-cross-linked sodium alginate interfacial bridging strategy that integrates tannic acid-functionalized boron nitride/cellulose nanofiber outer layers with a Ti3C2Tx MXene/cellulose nanofiber shielding layer. The cross-linked interlayer functions as a molecular adhesive network, combining ionic coordination, hydrogen bonding, and nanofiber entanglement to suppress interlayer slippage while preserving continuous in-plane thermal and electromagnetic attenuation pathways. The optimized composite achieves an in-plane thermal conductivity of 24.2 W‧m−1‧K−1 and an electromagnetic interference shielding effectiveness of 39 dB, while retaining electrical insulation. Owing to the mechanically cohesive multilayer architecture, the film also exhibits a tensile strength of 115.2 MPa, a Young's modulus of 1.7 GPa, and a toughness of 4.4 MJ·m−3. More importantly, over 90% of both thermal conductivity and shielding performance is retained after 1500 bending cycles, demonstrating the critical role of interfacial bridging in durable multifunctional thermal-management films. © 2026 Elsevier B.V.

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