ENGINEERING TECHNOLOGY

The “pomegranate” structure has made a great contribution! New composite material for effective “wave absorption”


With the rapid development of electronic information technology, the problem of electromagnetic interference is becoming increasingly serious. Effective wave-absorbing materials, especially electromagnetic waves in the GHz band, are important for areas such as electronics security and healthcare.

Recently, Sun Chenglin, researcher of Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Gu Bin, associate researcher, and Professor Duan Yuping of Dalian University of Technology have cooperated to make new progress in constructing high-efficiency composite absorbing materials. The team designed and prepared a magnetic resin-derived carbon composite absorbing material with a “pomegranate” structure, and introduced multiple electromagnetic wave loss mechanisms through component control and microstructure design, so that the composite showed excellent absorption performance. The results were published in Composites Part B: Engineering.

“Pomegranate-like” structure. Photo courtesy of Dalian Chemical Properties

In general, absorbing materials can be divided into magnetic loss type and dielectric loss type according to the absorption mechanism. Among them, a single magnetic loss absorbing material has the disadvantages of easy corrosion, easy aggregation and high density, while a single dielectric loss material also has the problems of impedance mismatch and single loss mechanism.

In order to solve the above problems, the researchers proposed two solution strategies: component regulation and microstructure design. The synthetic resin with controllable molecular structure and physicochemical properties was used as the carbon source, coupled with the magnetic loss components, and effective multi-component regulation was carried out to form a multiple loss mechanism to achieve effective adjustment of electromagnetic parameters and absorption performance. In addition, the researchers designed and regulated the microstructure to construct a Fe3C@GC/AC composite with a pomegranate-like structure, which solved the problems of uneven size distribution of magnetic particles and easy aggregation of existing wave-absorbing materials.

The results show that the unique pomegranate-like structure optimizes impedance matching, and improves the interface polarization loss and magnetic loss. Under the combined action of reflection loss, interfacial polarization, dipole polarization, conductivity loss, and magnetic loss, the composite absorbing material prepared by this work achieves a reflection loss value of -96.3dB (99.99999%) at a thickness of 2.08mm, and at the same time, the effective absorption bandwidth is 6.38GHz. When the simulated thickness is modulated between 1.0 and 5.0 mm, 88% of the test bands achieve effective absorption. (Source: Sun Danning, China Science News)

Related paper information:https://doi.org/10.1016/j.compositesb.2023.110767



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