Gradient structured UHMWPE/graphene composites for integrated electromagnetic shielding, thermal management and controllable joule heating

Room-temperature gravity-driven preparation of gradient UHMWPE/graphene composite. • This method enables scalable 22 cm sample fabrication with good repeatability. • Double-sided gradient samples deliver max 85.9 dB X-band EMI SE at 2 mm thickness. • The composite exhibits high thermal conductivity and tunable Joule heating. Active antenna units for terrestrial and space communications require large-area processable materials with ultrathin thickness, low surface density, flexibility, electromagnetic interference (EMI) shielding and heat dissipation properties. Existing composite materials struggle to balance simple fabrication processes, large-scale production and efficient multifunctional integration. In this work, we innovatively propose a room-temperature multi-sided drying strategy for gravity-driven assembly of gradient-structured lightweight multifunctional UHMWPE/graphene composites. This strategy requires no complex equipment or processes, and can stably fabricate 22 cm large-size gradient structure materials with good process repeatability while ensuring excellent overall performance of the products. The results show that the sample with double-layer graphene-enriched layers exhibits the best comprehensive performance, with a density of 0.947 g/cm 3 and a maximum tensile strength of 8.05 MPa; at a stacked thickness of 2 mm, it achieves a maximum total shielding effectiveness (SE T ) of 85.9 dB in the X-band (literature average: 30–80 dB), an in-plane thermal conductivity of 15.82 W/(m·K) (literature average: 1–13 W/(m·K)), and its Joule heating temperature reaches 82.4 °C at an applied voltage of 5  V . This work provides a novel approach for the controllable fabrication of lightweight multifunctional composite materials.