Porous network carbon nanotubes/chitosan 3D printed composites based on ball milling for electromagnetic shielding

Abstract Carbon nanotubes (CNTs) are easy to agglomerate, which results in poor structure reproducibility, and seriously restricts the improvement of conductivity and electromagnetic interference (EMI) shielding properties of CNTs composites. In this study, CNTs were evenly dispersed in the chitosan (CS) matrix by a high energy mechanical ball milling method, and three-dimensional (3D) printing ink of CNTs/CS was obtained. The CNTs/CS composites with porous network structures are prepared by the 3D printing technology. The results show that the 3D porous network CNTs/CS composites can effectively absorb electromagnetic waves. The 3D printed CNTs/CS composites with porous networks show an exceptional EMI shielding effectiveness of 25.07 dB at a low density of 72 mg/cm3. According to the square hole grid structure of 3D printed products, the influence of pore size and conductivity of the composites on the EMI shielding performance is simulated and analyzed, which are consistent with the experimental results. For non-magnetic materials, conductivity has a greater influence on the EMI shielding performance than that of pore size. This study provides a new idea and method for the rapid and accurate preparation of polymer matrix composites with excellent EMI shielding properties as surface of electronic components.