The thickness of 33 microns, can shield 99%incident electromagnetic waves
My scientific research team has developed high -performance electromagnetic shielding materials
Reporter Li He
In daily life and work, electromagnetic radiation will be generated when the electronic equipment is running, which may have adverse effects on people’s health. Electromagnetic interference between equipment will also seriously affect the performance of electronic equipment and its normal operation.Therefore, the development of new electromagnetic shielding materials, especially high -performance electromagnetic shielding materials, is the key to solving electromagnetic pollution.
Today, more and more electronic devices are applied to people’s lives and work, but electronic equipment will produce electromagnetic radiation during operation, which may have adverse effects on people’s health. Electromagnetic interference between equipment may also be on.It will cause signal being intercepted, data loss, etc., which seriously affects the performance of electronic equipment and its normal operation.Especially with the development of the Internet of Things, autonomous driving, and wearable equipment, electronic equipment is becoming more and more complicated, the volume is smaller and the accuracy requirements are getting higher and higher. It is necessaryDriving shielding is important.
The development of new electromagnetic shielding materials is the key to solving electromagnetic pollution, especially high -performance electromagnetic shielding materials with super thin, lightweight, and excellent mechanical strength and reliability.A few days ago, Hengli Ping team, a researcher at the School of Chemistry, Beijing University of Aeronautics and Astronautics, developed a heterogeneous layer-shaped nano-composite material with a super-lubricated interface.Electromagnetic shielding.Related research results were published in the international academic journal "American Chemistry Society · Nano".
Use graphene to develop high -performance flexible electromagnetic shielding materials
Electromagnetic shielding materials are functional materials that can decay electromagnetic wave energy by absorbing, reflected, etc. to effectively inhibit electromagnetic interference and pollution.
People hope that when electronic equipment is working, it is neither disturbed by the external electromagnetic waves, nor radiating electromagnetic waves to interfere with other equipment or harm human health. Therefore, when the electronic equipment is running, the electromagnetic waves generated by themselves need to be absorbed, and the electromagnetic waves of the outside world needReflection or absorption.Metals such as copper and aluminum are commonly used electromagnetic shielding materials, but they are easily corroded, density, and heavy weight. It is mainly reflecting electromagnetic waves, which will cause secondary electromagnetic pollution.In particular, traditional metal materials do not have flexibility, and it is difficult to be applied in the field of flexible electromagnetic shielding.
The cymbal liquid metal (LM) is currently the most widely used material in flexible electronics manufacturing, which is mainly due to its physical characteristics such as low melting points, low viscosity, high -electricity conductivity and thermal conductivity.Heng Liping said that with the gradual deepening of the research on the research on metal and cymbal alloy liquid metal materials with room temperature, it has shown considerable potential in the field of flexible electromagnetic shielding materials.
However, the existing cymbal liquid metal electromagnetic shielding material generally needs to mix with the polymer substrate that is insulating to obtain an electromagnetic shielding material with a certain mechanical strength and practical application.The better the conductivity and magnetic conductivity of the material, the higher the shielding performance of the electromagnetic, and the mixing of the pyrine -based liquid metal electromagnetic shielding material and the polymer substrate of the insulation, which will lose the conductive performance of the cymbal liquid metal and make the electromagnetic shieldPerformance cannot reach the best level.The use of a substrate with an ultra -high -conductive rate itself to build a liquid metal flexible composite material, which has become the key to improving the performance of liquid metal flexible electromagnetic shielding composite materials.As a result, the graphene entered the sight of the Hengli Ping team.
Graphene has excellent optics, electrical, and mechanical characteristics, and it can maintain good conductivity in itself.The oxide graphene (GO) also plays a good bridge effect on the cymbal liquid metal. Therefore, within the S-Rgo/LM material, a continuous and complete conductive network can be formed.The thickness of the material is only 33 microns, which can shield 99%of the incident electromagnetic waves, and the electromagnetic shielding efficiency of the X -band is high.
Can be used as a functional material for freezing and ice removal
Polymidal siliconxane (PDMS) has heat resistance, cold resistance, waterproof, thermal conductivity, and good chemical stability. The electrical insulation and hydration performance can be used for a long time at -50 ° C ° C for a long time.At present, PDMS has been widely used in insulation lubrication, shockproof, oil -proof dust and heat carriers.
The team first dipped the S-RGO/LM material in the diluted PDMS solution, and then rotated silicone oil to obtain the super lubrication characteristics.Heng Liping said that thanks to the stability of the material itself and the coordinated protection of the ultra-lubricating interface, the S-RGO/LM material can still maintain good electromagnetic shielding capabilities after severe mechanical wear.
In addition to excellent electromagnetic shielding performance, S-RGO/LM materials also have excellent thermal management performance.Experiments show that under a sunlight power (100 mile/square centimeter), the surface temperature of the S-RGO/LM material can reach 47.5 ° C within 40 seconds.This shows that in low temperature areas, S-RGO/LM can also be used as materials with anti-freezing and ice removal function.(Technology Daily)
Source: Science and Technology Daily
