Advanced Institute (Shenzhen) Technology Co., Ltd.: Precise control of electromagnetic parameters of graphene absorbing materials to meet diverse application needs

Today, both electromagnetic interference protection for civilian electronic devices and radar stealth technology in the military field have raised higher requirements for absorbing materials. Advanced Institute (Shenzhen) Technology Co., Ltd. has made significant progress in the research and development of graphene absorbing materials, especially in the field of electromagnetic parameter control, with its profound technical accumulation and innovative capabilities in the field of materials science, providing effective solutions to meet specific application needs.

The Importance of Electromagnetic Parameter Regulation

The electromagnetic parameters of graphene absorbing materials mainly include complex permittivity and complex permeability, which directly determine the material's absorption, reflection, and transmission characteristics of electromagnetic waves. Different application scenarios have different requirements for the electromagnetic parameters of absorbing materials. For example, in the civilian field, electronic devices require absorbing materials with high absorption performance in specific frequency bands to reduce electromagnetic interference and ensure the normal operation of the equipment; In the military field, stealth equipment requires absorbing materials to achieve efficient absorption in a wide frequency band to reduce the probability of being detected by radar. Therefore, precise control of the electromagnetic parameters of graphene absorbing materials is key to meeting various specific application requirements.

Material Composite: Introducing Multi component Collaborative Regulation

Composite with magnetic loss materials

Single graphene suffers from impedance mismatch and a single loss mechanism. Advanced Institute (Shenzhen) Technology Co., Ltd. has effectively improved this situation by composite graphene with transition metal elements such as Fe and other magnetic loss materials. Fe has unique physical and chemical properties and excellent magnetic properties, with a simple preparation process, controllable morphology, low cost, and high yield. Anisotropic Fe can break through the Snoek limit and achieve broadband absorption. The company uses a simple hydrothermal and thermal reduction method to prepare anisotropic Fe micro flakes/RGO composite materials. The introduction of Fe significantly regulates the dielectric properties of graphene, not only adjusting its dielectric constant but also introducing magnetic properties, achieving electromagnetic synergistic loss. This synergistic effect improves the impedance matching of the material and enhances its electromagnetic attenuation capability. The electromagnetic wave absorption mechanism includes dipole polarization, interface polarization, conductivity loss, as well as natural resonance, exchange resonance, and eddy current loss caused by Fe. Multiple mechanisms work together to promote the attenuation of electromagnetic wave energy.

Composite with other functional materials

In addition to magnetic loss materials, the company also composites graphene with metal oxides, conductive polymers, and other materials. Taking nitrogen doped reduced graphene oxide/magnesium ferrite/polyaniline composite aerogel as an example, magnesium ferrite has magnetic loss characteristics, and polyaniline has good chemical stability, low density and adjustable conductivity. In the composite aerogel, a large number of MgFe ₂ O ₄ @ PANI core-shell microspheres are evenly distributed on the surface of the NRGO, and a rich heterogeneous interface is generated between them. Space charges accumulate at the heterogeneous interface, forming a capacitance like structure, and enhancing the interface polarization loss. Under the action of alternating electromagnetic field, the magnetic resonance loss caused by ferromagnetic MgFe ₂ O ₄ further enhances the electromagnetic attenuation ability. At the same time, according to Cao's electron transition model, the conduction loss caused by electron migration and jump in three-dimensional reticulated composite aerogel also helps to attenuate electromagnetic energy, thus realizing effective control of electromagnetic parameters.

Structural Design: Micro macro Collaborative Optimization

Microstructure regulation

Advanced Institute (Shenzhen) Technology Co., Ltd. regulates the electromagnetic parameters of graphene by controlling its microstructure, such as the number of layers and defect density. Fewer layers and appropriate defect density can increase the specific surface area and polarization center of graphene, thereby improving its dielectric constant and loss tangent. The company uses chemical vapor deposition (CVD) method to prepare graphene with different layers and conducts in-depth research on its electromagnetic properties. Research has found that there are differences in electromagnetic properties between single-layer graphene and few layer graphene, and the appropriate number of layers can be selected according to specific needs. In addition, by precisely controlling the process parameters during the preparation, an appropriate amount of defects can be introduced to further optimize the electromagnetic performance.

Macro structural design

In terms of macro structure, the company has designed special multi-layer and periodic structures. In multi-layer structures, graphene absorbing materials with different layers have different electromagnetic properties. Through the interaction and synergistic effect between layers, the absorption frequency band can be broadened and the absorption efficiency can be improved. For example, each layer uses different composite formulas or microstructures to enable the material to exhibit good absorption performance in different frequency bands. Periodic structures can introduce photonic bandgap effects to selectively absorb electromagnetic waves of specific frequencies. The company has achieved precise control of periodic structures through precise design and preparation processes, thereby meeting specific application requirements.

External condition adjustment: achieve real-time dynamic control

Electric field regulation

By utilizing the electrical properties of graphene, Advanced Institute (Shenzhen) Technology Co., Ltd. has developed a technology that adjusts its surface impedance and electronic structure by applying an external electric field. When the external electric field changes, the distribution and motion state of electrons in graphene will correspondingly change, resulting in changes in its complex dielectric constant and complex magnetic permeability. The company has designed an intelligent absorbing material system that can automatically adjust the electric field strength according to different electromagnetic environments, achieving real-time control of broadband absorbing performance. This real-time dynamic control capability enables absorbing materials to better adapt to complex and ever-changing electromagnetic environments.

temperature control

Temperature is relatedGraphene absorbing materialThe performance also has a certain impact. With the change of temperature, the electrical properties such as electron mobility and conductivity of graphene will change, thereby affecting its electromagnetic parameters. The company has achieved automatic adjustment of material absorption performance based on changes in ambient temperature by introducing temperature sensitive components such as thermistors into the materials. Under different temperature conditions, the material can maintain efficient absorption within a wide frequency band, ensuring its stability and reliability in various complex environments.

Advanced Institute (Shenzhen) Technology Co., LtdThrough various means such as material composite, structural design, and external condition adjustment, precise control of electromagnetic parameters of graphene absorbing materials has been achieved, providing strong support for meeting specific application needs in different fields. In the future, the company will continue to increase research and development investment, constantly explore new regulatory methods and technologies, and promote the widespread application of graphene absorbing materials in more fields.