Graphene Reinforced Binary Resin-Based Carbon Foam Composites for Mechanical and Electromagnetic Interference Shielding Applications

Lightweight carbon foam composites (CPF) with excellent mechanical properties and electromagnetic interference (EMI) shielding efficiency were prepared, using binary resin (phenolic and epoxy resin) as carbon source, hollow microspheres as the dispersed phase and graphene (GR) as reinforcement. The effects of GR content on the morphology, mechanics, and EMI shielding properties of carbon foams were investigated, respectively. The results showed that a certain content of GR-induced dispersive stress in the composites led to improved mechanical strength. The composites with 6 wt.% GR (6% CPF) exhibited the best performance, with the specific compressive strength of 57.1 MPa·cm³·g⁻¹, 52.7% higher than that of pure carbon foam (0% CPF). Carbon foam composites also presented excellent EMI performance. Their specific electromagnetic shielding (SSE) reached the maximum of as high as 228.0 dB·cm³·g⁻¹ for 8% CPF, 193.8 % higher than that of 0% CPF. GR’s high surface area provided better electromagnetic wave absorption activity and increased more conductive paths to improve the EMI efficiency. It suggested that carbon foam composites had broad application prospects in the aerospace field as ultralight, efficient EMI shielding materials with excellent mechanical strength.