Lightweight Composite Microwave Absorbing Materials Based on Graphene Aerogels with Honeycomb Structure

Abstract

Porous graphene-based composites offer immense potential for microwave absorption because of their light weight and high performance. In this work, a honeycomb structure filled with porous graphene is demonstrated with excellent radar-absorbing properties. This graphene-based composite reaches the maximum reflection loss (RL) of À15 dB at 8.8 GHz with only a thickness of 4.0 mm and an areal density of 0.26 kg m À2 . Raman spectroscopy confirms the existence of graphene and scanning electron microscopy images reveal how these large graphene flakes are arranged to a three-dimensional porous structure. In addition, a monolithic porous graphene aerogel, without the honeycomb core, and a RL simulation of it are also investigated for comparison, which reveals antipodal properties. This work shows that the insulated honeycomb structure increases the surface characteristic impedance of the whole composite material, which mainly contributes to the reduction of total reflection from the interface. Various structural influence factors have been analyzed, the results provide a new idea for exploring high-performance microwave absorbers of graphene-based materials.

Hierarchical Porosities Strategy to Enhance the Absorbing Performance of Graphene Aerogels

“…As revealed in Figure 9c,d and Table 1 , compared to the reported graphene‐based absorbers, the RL min and EAB values of S3 in this work are higher than that reported absorbing materials with absorbent content higher than 5 wt%. [ 32–39 ] This indicates that S3 has broad application prospects in the field of the lightweight and efficient EM absorption field.…”

Polysilazane hybrid phenolic resin ceramic aerogels with excellent electromagnetic wave absorption performance

“…One of the possible ways toward this goal is to utilize special microstructures (i.e., porous, layered, and three‐dimensional [3D] network structures) by providing rich heterogeneous interfaces to achieve excellent EMW absorption performance 20–22 . For example, multifunctional aerogels with unique porous structures and adjustable microstructure have been widely documented, which could be used for boosting EMW absorption 23–27 .…”

“…[15][16][17][18][19] One of the possible ways toward this goal is to utilize special microstructures (i.e., porous, layered, and three-dimensional [3D] network structures) by providing rich heterogeneous interfaces to achieve excellent EMW absorption performance. [20][21][22] For example, multifunctional aerogels with unique porous structures and adjustable microstructure have been widely documented, which could be used for boosting EMW absorption. [23][24][25][26][27] Moreover, ceramic aerogel is an ideal EMW absorbing material relying on the 3D nanonetwork structure and excellent high-temperature resistance performances, which could achieve effective dissipation and absorption of electromagnetic waves.…”

Lightweight and Compression-Resistant Carbon-Based Sandwich Honeycomb Absorber with Excellent Electromagnetic Wave Absorption

“…Moreover, to realize the lightweight broadband microwave-absorption structural absorbers, it is necessary to use a structure with a low weight ratio, such as the SHC structure [ 13 , 14 , 15 ]. Kou et al [ 16 ] used an HC structure filled with porous graphene as a radar absorbing material, and the experiment proved that it had good radar absorption performance. At 8.8 GHz, the RL min of this graphene-based composite was −15 dB, thickness only 4.0 mm, and area density 0.26 kg/m 2 .…”