Synergistic Enhancement of Thermal Conductivity and Electromagnetic Shielding via Dual Cu···π and Cu–O Bond-Bridged Graphene/MXene Interfaces

Polymer-based thermally conductive films face significant challenges related to interfacial thermal resistance, especially when required to deliver both efficient heat dissipation and electromagnetic interference (EMI) shielding in advanced electronic applications. In this study, we present a multifunctional composite system by incorporating copper-decorated hydroxylated graphene (Cu-GOH) and MXene (Ti 3 C 2 T X ) into a poly(vinylidene fluoride) (PVDF) matrix. The hybrid filler network is engineered through dual interfacial interactions: Cu···π bonding with the graphene framework and Cu–O coordination with the MXene surface, establishing continuous thermal and electrical transport pathways. At an optimized filler loading (22.5 wt % Cu-GOH and 2.5 wt % MXene), the composite achieves: (i) a through-plane thermal conductivity of 3.64 W·m –1 ·K –1, representing a 19.22-fold enhancement over pristine PVDF; (ii) an in-plane electrical conductivity of 6.44 × 10 –4 S·cm –1; and (iii) robust X-band EMI shielding effectiveness (≥25 dB across 8–12 GHz), exceeding military-grade requirements. Additionally, the hierarchically organized filler architecture enhances mechanical integrity, addressing the common trade-offs between functionality and durability in polymer composites. These findings demonstrate the potential of Cu-GOH/MXene/PVDF composites for integration into high-performance thermal management and EMI shielding components in aerospace systems, satellite communications, and next-generation renewable energy technologies.