title: Enhanced Microwave Absorption Performance of Coated Carbon Nanotubes by Optimizing the Fe3O4Nanocoating Structure.
abstract: It is well accepted that the microwave absorption performance (MAP) of carbon nanotubes (CNTs) can be enhanced via coating magnetic nanoparticles on their surfaces. However, it is still unclear if the magnetic coating structure has a significant influence on the microwave absorption behavior. In this work, nano-Fe3O4compact-coated CNTs (FCCs) and Fe3O4loose-coated CNTs (FLCs) are prepared using a simple solvothermal method. The MAP of the Fe3O4-coated CNTs is shown to be adjustable via controlling the Fe3O4nanocoating structure. The results reveal that the overall MAP of coated CNTs strongly depends on the magnetic coating structure. In addition, the FCCs show a much better MAP than the FLCs. It is shown that the microwave absorption difference between the FLCs and FCCs is due to the disparate complementarities between the dielectric loss and the magnetic loss, which are related to the coverage density of Fe3O4nanoparticles on the surfaces of CNTs. For FCCs, the mass ratio of CNTs to Fe3+is then optimized to maximize the effective complementarities between the dielectric loss and the magnetic loss. Finally, a comparison is made with the literature on Fe3O4-carbon-based composites. The FCCs at the optimized CNT to Fe3+ratio in the present work show the most effective specific RLmin(28.7 dB·mm-1) and the widest effective bandwidth (RL < -10 dB) (8.3 GHz). The excellent MAP of the as-prepared FCC sample is demonstrated to result from the consequent dielectric relaxation process and the improved magnetic loss. Consequently, the structure-property relationship revealed is significant for the design and preparation of CNT-based materials with effective microwave absorption.
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Gui-Wen
authors.initials: GW
authors.lastname: Huang
authors.affiliation: College of Aerospace Engineering, Chongqing University , Chongqing 400044, China.
authors.forename: Yuan-Qing
authors.identifier: http://orcid.org/0000-0002-0478-0177
authors.initials: YQ
authors.lastname: Li
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Xiao
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Qing-Ping
authors.initials: QP
authors.lastname: Feng
authors.affiliation: College of Aerospace Engineering, Chongqing University , Chongqing 400044, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Hu
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.|College of Aerospace Engineering, Chongqing University , Chongqing 400044, China.
authors.forename: Shao-Yun
authors.identifier: http://orcid.org/0000-0002-3067-9582
authors.initials: SY
authors.lastname: Fu
keywords: carbon nanotube; coating structure; impedance matching; iron oxide; microwave absorption; reflection loss