Electromagnetic Response of Multistage‐Helical Nano‐Micro Conducting Polymer Structures and their Enhanced Attenuation Mechanism of Multiscale‐Chiral Synergistic Effect

Abstract

Among these strategies, chiral materials with helical structure emerge outstanding electromagnetic wave loss capability owing to special electromagnetic cross polarization and further impedance optimization. [18][19][20] Moreover, chiral MAMs can induce magnetic loss to certain extent without adding extra magnetic lossy medium, contributing to lightweight design and environmental preparation. [21,22] Recently, helical nanocarbon nanotubes/fibers, chiral conductive polymers, and the corresponding composites have all been proven to possess good microwave absorption. The corresponding loss mechanism mainly comes from the additional magnetic loss caused by cross polarization, interface polarization loss, conductance loss, and so on.However, in spite chiral MAMs begin to attract more and more attention recently, many studies just focus on simple material preparation and performance characterization. There are still some problems remaining to solve for chiral MAMs, especially in performance modulation and chiral absorption mechanism. Most available construction strategy could hardly precisely control the ordering of chiral/ helical morphology and even helical parameters. Furthermore, the restriction and cooperation relationship between chiral/ helical structure and electromagnetic characteristics is still fuzzy and it lacks guidelines and explanations for how helical parameters influence MA properties. As a result, it is laborious to make it clear how helical structure would affect properties by experimental design, even not to mention the high-performance MA. Therefore, more challenges are deserved to overcome in order to promote the developments chiral MAMs.To handle the above-mentioned problems, a designable strategy was herein proposed to construct multistage-superhelical nano-microstructures with superhelical polypyrrole (PPy) nanofibers and chiral polyaniline (PANi) nanoarrays via in situ polymerization. Then, optimizing chiral structure and exploring new mechanism of enhanced attenuation were further applied. It was found that the ratio of chiral doped acids and Ani monomers could influence steric hindrance effect during induction process and then resulted in transforming growth pattern of chiral PANi. Therefore, breaking balance relationship of Nowadays, the rapidly development of advanced antidetection technology raises stringent requirements for microwave absorption materials (MAMs) to focus more attention on wider bandwidth, thinner thickness, and lower density. Adding magnetic medium to realize broadband absorption may usually result in the decline of service performance and accelerating corrosion of MAMs. Chiral MAMs can produce extra magnetic loss without adding magnetic medium due to the unique electromagnetic cross polarization effect. However, more efforts should be taken to furtherly promote efficient bandwidth of chiral MAMs and reveal attenuation mode and modulation method of chiral structure. Herein, a novel superhelical nano-microstructure based on chiral polyaniline and helical polypyrrole is suc...

Kinetics-mediated assembly assisted precise synthesis of magnetic ordered mesoporous carbon nanospheres for ultra-efficient electromagnetic wave absorption

“…In an actual application, the maximum value of reection loss (RL max ), effective absorption bandwidth (EAB, the bandwidth of RL # −10 dB), thickness, and ller loading are four primary indicators for evaluating the comprehensive EMWA performance. 36,37 In other words, high-performance EMWAMs need to simultaneously meet the requirements of a strong RL intensity, wide EAB, thin thickness and low ller loading. Fig.…”

“…[29][30][31][32][33][34][35] It is widely acknowledged that highperformance EMWAMs with thin thickness, light weight, strong absorption and a broad absorption bandwidth require both good impedance matching and sufficient electromagnetic wave dissipation capability. [36][37][38] However, there is still a longstanding challenge to develop EMWAMs that simultaneously satisfy the above four standards.…”

Structure–Activity Relationship in Microstructure Design for Electromagnetic Wave Absorption Applications

“…Reproduced with permission. [ 143 ] Copyright 2023, John Wiley and Sons. h) Microwave absorption mechanisms for CSA‐RGO AMs and PANI@RGO AMs.…”

“…Reproduced with permission. [ 143 ] Copyright 2023, John Wiley and Sons. m–p) Schematic illustrations of electronic transport mechanism of MWCNTs.…”

“…The magnetic field simulation results at 13.36 GHz of l 1 ) single helical structure, l 2 ) multihelical structure. Reproduced with permission [143]. Copyright 2023, John Wiley and Sons.…”