Construction of polydopamine functionalized porous carbon network structure in polymer composites for excellent mechanical and electromagnetic interference shielding properties

Structural and functional integrated lightweight polymer-based composites with excellent mechanical and electromagnetic interference (EMI) shielding properties are urgently demanded in the field of advanced aerospace field. Effective design to construct the interfacial porous microstructures is crucial yet remains highly challenging for maximum EMI shielding effectiveness (SE) while improving the strength of composites. Herein, novel interfacial continuous network structures are constructed based on the in-suit synthesis of porous carbon network on the carbon fibers and chemical functionalized with polydopamine (PDA) to achieve simultaneous improvement of mechanical properties and EMI SE. Results indicate that the construction of active porous carbon networks significantly improves the surface activity and wettability of carbon fibers, which is conducive to enhancing the interfacial strength of the composites. Owing to the synergistic effect of physical enhancement for porous carbon and chemical reinforcement for PDA, the bending strength of the modified composite reaches 138.9 MPa, and the wear rate decreases by 82.9 %, demonstrating excellent mechanical properties. It is worth noting that the EMI SE reaches more than 62 dB in the X-band when the thickness of the modified composite is only 0.4 mm, showing excellent EMI shielding performance. Most importantly, this study provides solid basic knowledge of the interfacial structure design of composites, which is favorable for obtaining expected mechanical and EMI shielding performances and offers strong potential for applications in structural components of the aerospace and electronic equipment field.