Sustainable wood-based composites for microwave absorption and electromagnetic interference shielding

With the continuous deterioration of the electromagnetic environment, there is an urgent need for exploring highly efficient and widely applicable electromagnetic interference shielding and microwave absorption materials. In current years, wood-based composites have been vastly investigated with low cost, light weight, sustainability, and an inherent porous and hierarchical structure. However, imperfect interfacial compatibility and electrical conductivity of wood are the main factors, which result in inferior electromagnetic interference shielding and microwave absorption performances. Meanwhile, the intrinsic defects of wood such as rotting and flammability also limit their practical applications. To overcome these shortcomings, improving the combination of each phase unit in micro-nano size and exploiting multi-functional composites are feasible solutions to optimize the electromagnetic properties of wood-based materials. In this review, the basic principles and mechanisms of electromagnetic interference shielding and microwave absorption are introduced comprehensively. Meanwhile, various wood-based electromagnetic interference shielding, microwave absorption composites, and their fabrication methods are discussed in detail. Furthermore, the perspectives and challenges in this field are put forth as well.