Biomass-derived porous carbon for electromagnetic interference shielding

Carbon-based porous materials showing low density, excellent mechanical properties, good durability, and controllable electromagnetic interference (EMI) shie lding effectiveness (SE) are promising for high-performance EMI shields. Particularly, abundant pores introduced in the carbon-based shields significantly reduce the weight, and efficiently introduce numerous interfaces between the voids and cell walls, which can increase the multiple reflections or scatterings of incident electromagnetic waves. Combined with the intrinsic electromagnetic wave loss ability derived from the charge carriers in the carbon phase, the carbon-based porous architectures have high EMI SE values. Compared with the porous architectures constructed dominantly from carbon nanomaterials, such as graphene layers or CNTs, the carbon foams can be prepared effortlessly by the carbonization treatment of cost-efficient materials such as polymer foams or sponges. The polymer-derived porous carbon architectures can also be loaded with other additives such as metal or magnetic particles for achieving the high-performance EMI-shielding applications. Particularly, replacing the synthetic or petrochemical polymers with sustainable, renewable biomass as raw materials to prepare high-performance porous carbon-based EMI-shielding materials is highly desirable for practical applications. In this chapter, we have discussed the biomass-derived porous carbon-based EMI-shielding architectures based on the “bottom-up” and “top-down” preparation strategies.