Preparation and Application of Graphene-Based Composites for Electromagnetic and Thermal Management
We report the structural design and functional integration of graphene frameworks, and explore their applications in microwave absorption, flexible electromagnetic interference (EMI) shielding, and high thermal conductivity films. In situ grown magnetic iron nanoparticles are introduced to suppress sheet restacking, and the synergistic effect of dielectric loss and magnetic loss enhances electromagnetic wave attenuation, achieving a minimum reflection loss (RLₘᵢₙ) down to −54.6 dB. When incorporated into silicone rubber, the resulting composite sheet delivers a minimum reflection loss of −50 dB and an effective absorption bandwidth of 5 GHz at a thickness of 1.32 mm.
We also demonstrate an effective strategy to reinforce graphene frameworks using bacterial cellulose networks, constructing continuous and interconnected layered structures that facilitate efficient phonon and charge transport. The as-fabricated composite film exhibits a tensile strength of 18.9 MPa, a thermal conductivity of 105 W m⁻¹ K⁻¹, and an electrical conductivity of 4 × 10⁴ S m⁻¹, along with an EMI shielding effectiveness (SE) as high as 110 dB. When deployed as a thermal interface material, it achieves an out-of-plane thermal conductivity of 50 W m⁻¹ K⁻¹. Further optimization of the solid–liquid synergistic transport network via liquid metal yields composite films with a tensile strength of 24.6 MPa, an in-plane thermal conductivity of 111 W m⁻¹ K⁻¹, and an electrical conductivity of 5.3 × 10⁴ S m⁻¹. The films retain stable EMI shielding performance after 1000 bending cycles. This work provides new insights and methodologies for rationally tuning the electromagnetic response, heat transport, and mechanical properties of graphene-based composites, advancing their applications in high-performance microwave absorption, flexible EMI shielding, and advanced functional thermal management.
