Sustainable cellulose-based multifunctional material for electromagnetic shielding, flame retardancy and antibacterial

Biomass-based multifunctional electromagnetic shielding materials have attracted extensive interest in academia and industry due to the sustainability of biomass and the environmental adaptability of multifunctional mate-rials. After removing lignin and hemicellulose wood become a porous substrate with aligned cellulose, which is a good platform for building cellulose-based materials. In this work, a cellulose composite with sandwich-like structure was constructed by in-situ polymerization of aniline on delignified wood and coating a PDMS/CNT layer. Benefiting from the natural porous hierarchical structure and the constructed multilayer continuous conductive network, the PDMS/CNT/PANI WA exhibits excellent electrical conductivity (18.6 S/m) and elec-tromagnetic shielding performance (shielding efficiency value of 26 dB at the X band (8.2-12.4 GHz)). The synergistic effect of PANI and CNT endowed the material with excellent flame retardancy (HRR, THR and HRC decreased by 84 %, 53.4 % and 83.3 %) and significant antibacterial activity. Moreover, PDMS imparts a water contact angle of 105 degrees to the material, which acts as a protective layer, further improves the durability of the material. This work provides a new strategy for developing sustainable and multifunctional electromagnetic shielding materials.