Abstract
Nowadays,carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference(EMI)shielding due to their renewability and affordability.However,it is critical and challenging to achieve effective regulation of shielding effectiveness(SE)as well as weaken the strong EM reflection of highly conductive biomass-based carbon materials.Herein,commercial cotton pads with oriented structure were selected as carbonaceous precursor to fabricate aligned carbon net-works by pyrolysis,and the EMI SE of the samples with increased temperature of 800-1000℃can be accurately controlled in the effective range of～21.7-29.1,～27.7-37.1 and～32.7-43.3 dB with high reflec-tion coefficient of＞0.8 by changing the cross-angle between the electric-field direction of incident EM waves and the fiber-orientation direction due to the occurrence of opposite internal electric field.More-over,the further construction of Salisbury absorber-liked double-layer structure could result in an ultra-low reflection coefficient of only～0.06 but enhanced SE variation range up to～38.7-49.3 dB during the adjustment of cross-angle,possibly due to the destructive interference of EM waves in the double-layer carbon networks.This work would provide a simple and effective way for constructing high-performance biomass carbon materials with adjustable EMI shielding and ultra-low reflectivity.
基金项目
Natural Science Foundation of Ningbo(202003N4026)
S&T Innovation 2025 Major Special Programme of Ningbo(2018B10054)
National Natural Science Foundation of China(62001065)
National Natural Science Foundation of China(51603218)
NETL
NSTL
维普
万方数据