Structure Design, Surface Modification, and Application of CNT Microwave‐Absorbing Composites

Abstract

Electromagnetic (EM) contamination has now become a non‐negligible problem. To solve the EM contamination problem, it is imperative to develop high‐efficiency absorption materials with thin thickness, light weight, strong absorption properties, and broad absorption bands. Carbon nanotubes (CNTs) have a special helical structure and chirality, which will lead to special EM effects and therefore can absorb EM microwaves through magnetic polarization attenuation such as hysteresis loss, domain wall resonance, and aftereffect loss. Moreover, they have the characteristics of light weight, good compatibility, wide absorption frequency band, and high electrical loss angle tangent. In this paper, the different structures of CNT microwave‐absorbing composites are reviewed and the effects of the composite structures on the microwave‐absorbing properties are systematically discussed. The methods and mechanisms of surface modification of CNT absorber composites and the effects of modification on the absorber properties are summarized in detail. The progress of two specific CNT microwave‐absorbing composites, namely flexible and high‐temperature microwave‐absorbing composites, is briefly described. The shortcomings and challenges in the application of CNT microwave‐absorbing composites are described and future research directions for CNT microwave‐absorbing composites are explored.

Review of Three-Dimensional Graphene and Related Composite Materials for Microwave Absorption

“…In recent years, with the continuous progress in scientific research and constant development of communication technology, electronic devices have infiltrated many aspects of everyday life; this is particularly notable in the industrial, commercial, and medical sectors. − However, while these electronic devices have improved the quality of human life, they also pose potential hazards . The use of a large number of electronic devices not only causes serious electromagnetic pollution but also seriously affects human health and the living environment. − In the military field, with the continuous improvement of radar detection technology, stealth technology utilized in weapons and equipment is increasingly important to their survival on the battlefield.…”

“…After years of development, various MAMs have been reported and practically utilized. Traditional MAMs include magnetic metal particles − and ferrites, − which primarily rely on magnetic loss, and metal oxides, ,, carbides, , and carbon-based materials, ,− which primarily rely on dielectric loss. In order to pursue better MA effects, researchers have successively developed cutting-edge materials in the field of MA, such as topological insulator MAMs, nanoporous metal organic framework (MOF) MAMs, two-dimensional transition metal sulfide composites, magneto-optical composites, and 3D carbon materials …”