Preparation of a biomass-derived electromagnetic wave absorber with potential EM shielding application in interior decoration surface coating

Abstract

Novel functional materials with electromagnetic energy attenuation ability are gradually considered in home decoration due to the increasing attention to the excess electromagnetic radiation pollution. A series of heterostructure carbon materials is prepared by surface modification of cellulose-derived graphite-like sheets with lignin-derived carbon particles through one-step pyrolysis of bamboo-derived lignin/cellulose mixture with varied mass ratios. Among the candidates, BC-8 shows a strong EMW absorption performance with a RLmin value of −49.4 dB, and an effective absorption band of 14.4 GHz. When the corresponding coating is applied to the flattened bamboo surface, the obtained decorative surface exhibits a maximum SET value of 30.1 dB (indicating more than 90% EM energy can be attenuated) with enhanced surface hydrophobicity while maintaining the original mechanical properties, implying its potential application in EM-attenuation involved biomass-based home decoration. The absorption attenuation loss is proved to be dominant in the shielding behavior. Such excellent EM energy attenuation performance is proved to be attributed to attributed to the good impedance matching due to the relatively large dielectric properties and strong dipolar polarization effect, the good energy conversion efficiency caused by dielectric loss and conductive loss behavior, and the elongated EMW propagation path among the graphitized lamellar structures.