Significantly Enhanced Electromagnetic Interference Shielding Performances of Epoxy Nanocomposites with Long-Range Aligned Lamellar Structures

Abstract

High‑efficiency electromagnetic interference (EMI) shielding materials are of great importance for electronic equipment reliability, information security and human health. In this work, bidirectional aligned Ti3C2Tx@Fe3O4/CNF aerogels (BTFCA) were firstly assembled by bidirectional freezing and freeze-drying technique, and the BTFCA/epoxy nanocomposites with long-range aligned lamellar structures were then prepared by vacuum-assisted impregnation of epoxy resins. Benefitting from the successful construction of bidirectional aligned three-dimensional conductive networks and electromagnetic synergistic effect, when the mass fraction of Ti3C2Tx and Fe3O4 are 2.96 and 1.48 wt%, BTFCA/epoxy nanocomposites show outstanding EMI shielding effectiveness of 79 dB, about 10 times of that of blended Ti3C2Tx@Fe3O4/epoxy (8 dB) nanocomposites with the same loadings of Ti3C2Tx and Fe3O4. Meantime, the corresponding BTFCA/epoxy nanocomposites also present excellent thermal stability (Theat-resistance index of 198.7 °C) and mechanical properties (storage modulus of 9902.1 MPa, Young's modulus of 4.51 GPa and hardness of 0.34 GPa). Our fabricated BTFCA/epoxy nanocomposites would greatly expand the applications of MXene and epoxy resins in the fields of information security, aerospace and weapon manufacturing, etc.

Bioinspired Carbon Superstructures for Efficient Electromagnetic Shielding

“…As a result, the higher absorption losses for CTA-middle-1500 are mainly attributed to the carbon tube structure with a high graphite degree and a good conductive property, in which alternating induced currents occur and attenuate quickly in the resistive network, converting into Joule heat and leading to rapid decay of massive incident EM energies . Moreover, being attributed to the presence of a large number of micropores and channels, plenty of interfaces between air and the carbon matrix are produced, resulting in potential interfacial loss and multiscattering of the incident EM energies. , Furthermore, due to the curvature structural characteristics, oxygen-containing functional groups rich at the edges of graphite structures, inevitable defects in graphite structures, and dislocation or lattice deformation in the bonding region caused by graphite structure accumulation, higher absorption losses are caused by the dielectric relaxation–polarization, tunneling effect, and the interfacial polarization effect when the EMWs penetrate through an EM shielding material, resulting in an enhanced EM attenuation. − Thus, the obtained EMI shielding performance is mainly attributed to the synergy between the conductive loss and polarization loss, along with multiscattering and interfacial loss.…”

3D Printed Integrated Gradient-Conductive MXene/CNT/Polyimide Aerogel Frames for Electromagnetic Interference Shielding with Ultra-Low Reflection

“…To minimize the secondary electromagnetic radiation pollution, absorption-dominated EMI shielding polymer composites with low reflection are greatly desired for next-generation electronic devices. Yet, polymer-based EMI shielding materials with low conductivity would effectively reduce the reflection of electromagnetic waves, but inevitably reduces the EMI shielding efficiency (EMI SE ) due to weak absorption losses within the material [ 10 , 11 ]. Therefore, an improved understanding between structure and functionality of polymer-based EMI shielding material is critical for design and development of advanced EMI shielding materials with low reflection and high absorption.…”

Research Progress with Membrane Shielding Materials for Electromagnetic/Radiation Contamination

“…It was known that boron could absorb neutrons [ 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 ]. If a boron-containing coating material has sufficient thickness, most charged neutron particles will be absorbed, and boron-containing materials can prevent neutron migration.…”

“…Wang et al [ 149 ] used a Ti 3 C 2 T x @Fe 3 O 4 /CNF aerogel (BTFCA) to prepare BTFCA/epoxy nanocomposites with a long-distance layered structure ( Figure 19 a). Due to the introduction of Fe 3 O 4 , BTFCA is endowed with excellent magnetism.…”