Core–Multishell Heterostructure with Excellent Heat Dissipation for Electromagnetic Interference Shielding

Abstract

Herein, we report high electromagnetic interference (EMI) shielding effectiveness of -40 dB in the K-band (for a 600 μm thick film) through a unique core-shell heterostructure consisting of a ferritic core (FeO) and a conducting shell (multiwalled carbon nanotubes, MWCNTs) supported onto a dielectric spacer (here SiO). In recent times, materials with good flexibility, heat dissipation ability, and sustainability together with efficient EMI shielding at minimal thickness are highly desirable, especially if they can be easily processed into thin films. The resulting composites here shielded EM radiation mostly through absorption driven by multiple interfaces provided by the heterostructure. The shielding value obtained here is fairly superior among the different polymer nanocomposite-based EMI shielding materials. In addition to EMI shielding capability, this composite material exhibits outstanding heat dissipation ability (72 °C to room temperature in less than 90 s) as well as high heat sustainability. The composite material retained its EMI shielding property even after repeated heat cycles, thereby opening new avenues in the design of lightweight, flexible, and sustainable EMI shielding materials.

Multifunctional Organic–Inorganic Hybrid Aerogel for Self‐Cleaning, Heat‐Insulating, and Highly Efficient Microwave Absorbing Material

“…Among various microwave absorbing materials, CNTs represent one of the most promising candidates due to its light weight, high stability, and remarkable mechanical and electronic properties . Many studies have combined CNTs with magnetic nanoparticles (NPs) to produce composite absorbers that possess both dielectric loss and magnetic loss, such as CNT‐Fe 3 O 4 and CNT‐Co . Despite their strong microwave absorption, these composites are difficult to have versatility to satisfy other functional requirements for some special application environments.…”

Thermal Conductivity and Electromagnetic Interference (EMI) Absorbing Properties of Composite Sheets Composed of Dry Processed Core–Shell Structured Fillers and Silicone Polymers

“…It is considered that the close-packed structure of DFSs consisting of bimodal CSSFs shows high density and therefore low transmission. In the process of evaluating a single performance, it is possible to confirm the results that are superior to each evaluation item, but in the case of [ 25 , 26 ] a core-shell structure, to show a maximum of 2.2 W m −1 K −1 of TC and −23~−40 dB of shielding effectiveness [ 27 ].…”

MnO2‐Magnetic Core‐Shell Structured Polyaniline Dependent Enhanced EMI Shielding Effectiveness: A Study of VRH Conduction

“…When the electromagnetic waves interact with magnetic particles, the magnetic domains or the spins starts to align along the direction of applied magnetic field or in a particular direction. This leads to increase magnetic losses in the shielding materials and hence attenuated the electromagnetic waves . Thus, the high conductivity of the prepared samples determines the dielectric loss and high permeability governs the magnetic loss along with structural heterogeneity, which collectively improves the shielding effectiveness through absorption, as can be depicted from equation (16).…”