Carbon fiber electromagnetic shielding composite material is a lightweight and high-strength material with good conductivity and shielding effectiveness. The shielding efficiency of carbon fiber composite materials can reach over 70dB, and they have good corrosion resistance and fatigue resistance. However, their cost is high, and they are usually prepared together with shielding fillers to form carbon fiber electromagnetic shielding composite materials. According to the different types of fillers, they can be divided into metal based fillers, intrinsic conductive polymer based fillers, and carbon based fillers.
Carbon based fillers have become a research hotspot in electromagnetic shielding and absorbing materials due to their lightweight, corrosion resistance, and good conductivity, mainly including carbon black, graphite, nanocarbon fibers, carbon nanotubes, and graphene.
Carbon black
Carbon black is a black powdery substance mainly composed of carbon elements. It has good conductivity and thermal conductivity, which can effectively shield electromagnetic waves.
The following are some characteristics and applications of electromagnetic shielding filler carbon black:
1. Electromagnetic shielding performance: Carbon black has a high conductivity and can effectively reflect and absorb electromagnetic waves, thereby achieving the effect of electromagnetic shielding.
2. Thermal conductivity: Carbon black has a high thermal conductivity, which can quickly transfer heat to the surrounding environment, thereby reducing the temperature of electronic devices.
3. Stability: Carbon black has good chemical and thermal stability, is not easily reactive with other substances, and can be used for a long time in harsh environments.
4. Filling performance: Carbon black has a smaller particle size and can be filled into polymer materials to improve their conductivity and electromagnetic properties
5. Application field: Electromagnetic shielding filler carbon black is widely used in electronics, communication, aerospace, military and other fields, such as electromagnetic shielding of electronic devices such as mobile phones, computers, flat screen televisions, radars, satellites, etc.
Graphene
Compared with traditional electromagnetic shielding materials such as copper, graphene has the following advantages:
1. Good chemical stability: Graphene has a special two-dimensional layered structure, which gives it good chemical stability and is not easily corroded.
2. High shielding efficiency: Graphene with staggered layers in the coating has a larger specific surface area. By using only honeycomb porous graphene material, the shielding efficiency can reach about 40dB. After stacking into multiple layers, the electromagnetic shielding performance can reach over 60dB, which can attenuate more than 99% of the incoming electromagnetic waves.
Carbon nanotubes are a tubular structure material composed of carbon atoms, which have excellent conductivity, thermal conductivity, and mechanical properties. Its diameter usually ranges from a few nanometers to tens of nanometers, and its length can reach several micrometers or even several millimeters. The special structure and properties of carbon nanotubes make them an ideal electromagnetic shielding material.
Carbon nanotubes
Some characteristics and applications of carbon nanotubes as electromagnetic shielding materials:
1. Excellent conductivity: Carbon nanotubes have extremely high conductivity and can effectively reflect and absorb electromagnetic waves.
2. Lightweight and high-strength: Carbon nanotubes have a low density but high strength, which can improve the structural strength without increasing weight.
3. Good corrosion resistance: Carbon nanotubes have good corrosion resistance and can be used for a long time in harsh environments.
4. Good processing performance: Carbon nanotubes can be processed into various shapes through weaving, winding, and other methods, suitable for different application scenarios.
The application of carbon nanotubes as electromagnetic shielding materials mainly includes the following aspects:
1. Electronic devices: Carbon nanotubes can be used for components such as casings and circuit boards of electronic devices, effectively reducing the radiation of electromagnetic waves.
2. Communication field: Carbon nanotubes can be used in communication base stations, antennas and other equipment to improve communication quality.
3. Medical field: Carbon nanotubes can be used in medical equipment, such as X-ray machines, CT machines, etc., to reduce the impact of electromagnetic waves on the human body.
4. In the aerospace field, carbon nanotubes can be used in aircraft, satellites and other equipment to improve their reliability and anti-interference ability.
Carbon nanotubes, as a new type of electromagnetic shielding material, have excellent conductivity, lightweight and high strength, good corrosion resistance, and good processing performance. They have a wide range of application prospects in electronic equipment, communication, medical, and aerospace fields.