Abstract
Microwave absorption(MA)materials have been captured extensive attentions due to the serious elec-tromagnetic(EM)pollution.Numerous interests focus on the MA performances of core-shell structural composites with magnetic constituents as cores and dielectric constituents as shells,which inevitably suppressed the magnetic coupling causing the decrease of magnetic loss to some extent.Herein,the core-shell structural carbon(C)microsphere/magnetic metal composites were fabricated through the combi-nation of an electrostatic assembly approach and subsequent in-situ reduction reaction.The complex per-mittivity and permeability of core-shell C@magnetic metal composite system can be effective adjusted by the constituent and microstructure of shells.Thanks to the distinct magnetic coupling from the subtle designed structures and the promotion of the magnetic-dielectric synergy,the C@magnetic metal com-posite exhibited enhanced MA properties.The optimal reflection loss(RL)of C@Ni composite was-54.1 dB with a thickness of 3.4 mm,meanwhile the effective absorbing band could reach over 5.5 GHz at only a 1.8 mm thickness.Broad absorption bandwidth with RL below-10 dB could achieve 6.0 GHz and 6.7 GHz for C@Co and C@NiCo composites with a thin 2.1 mm thickness,respectively.Our exciting findings might lead a guide on the novel structure design for the functional core-shell structural composites used for microwave absorption.
基金项目
国家自然科学基金(51725101)
国家自然科学基金(11727807)
国家自然科学基金(51672050)
国家自然科学基金(61790581)
Ministry of Science and Tech-nology of China973 Project(2018YFA0209102)
Science Foun-dation for the Excellent Youth Scholars of Henan Province(212300410089)
Support Program for Scientific and Tech-nological Innovation Talents of Higher Education in Henan Province(21HASTIT004)
China Postdoctoral Science Founda-tion(2019M661352)