The historical development process of plasma low temperature plasma

• Categories:Technical Support
• Author:Plasma cleaning machine-CRF plasma plasma equipment-plasma surface treatment machine manufacturer-chengfeng intelligent manufacturing
• Origin:
• Time of issue:2022-01-01
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(Summary description)The historical development process of plasma low temperature plasma: Plasma was discovered in 1879 and called "plasma" in 1928. It is a microscopic system consisting of a large number of charged particles that interact but are still in an unbound state. They are the fourth material in addition to gas, liquid, and solid. state. Electron temperature and ion temperature can be used to respectively indicate plasma temperature. The ionization rate of plasma low-temperature plasma is low, and the ion temperature can even be almost the same as room temperature. Therefore, there are many scenarios in daily life that can use low-temperature plasma technology. In the process of plasma low-temperature plasma generation, a large number of active particles can also be produced. These particles have more types of reactions than general chemical reactions, more active, and simpler reactions when they come in contact with the surface of the material. Compared with traditional physical and chemical methods, plasma surface treatment has low cost, no waste, and no pollution to the environment. Therefore, the surface modification treatment of low-temperature plasma materials is very suitable. In addition, low-temperature plasma can also be used to prepare organic and Inorganic nanoparticles are used in sterilization and other fields. Low-temperature plasma can be generated by ultraviolet radiation, electromagnetic field excitation, high-temperature heating, and the application of X-rays. In the meantime, electromagnetic field excitation method, which is a relatively simple technology to manipulate gas release method, is used in laboratory research and industrial production. Much. Arc discharge is one of the plasmas produced by various gas discharges; it is difficult to produce sufficient active particles in the low-temperature plasma produced by corona discharge; DC glow discharge requires a low-pressure environment, so expensive vacuum systems are required. Therefore, it is difficult to achieve continuous production; the electrodes of the low-frequency AC discharge plasma are exposed to the outside and only pollute the plasma generated by simple pollution. Therefore, these gas discharge methods are not suitable for large-scale assembly line industries. Dielectric Barrier Discharge (DBD for short) refers to placing an insulating medium between two metal electrodes to obstruct the discharge channel across the air gap between the plates, so that the discharge in the air gap channel does not generate arcs, but Existing in the form of filament discharge, the plasma low-temperature plasma is dispersed in it. This method is easy to implement in the laboratory and is widely used in industrial production; and in the atmospheric pressure discharge mode, the plasma that occurs in this way The body can be evenly distributed in the entire discharge space. Therefore, atmospheric pressure glow discharge is also called dielectric obstructive discharge in uniform mode, but it is more difficult to achieve in the laboratory. In filament discharge mode, if it is improperly operated, it will become The dielectric obstructs the discharge. Therefore, dielectric barrier discharge is currently a plasma generation method suitable for industrial production. The basis of dielectric obstruction of discharge is to increase the insulating medium. If there is no insulating medium to hinder the discharge, the charged particles located in the air gap of the electrode plate will tend to attach to the two electrode plates at a very high migration speed, which makes it difficult for the airflow to blow out and become charged. The particles will reach the surface of the insulating medium after the two plates are covered with an insulating layer, instead of the surface of the plate. After applying the reverse voltage of the high-frequency AC power supply on the two plates, the low-temperature plasma of the plasma again undergoes avalanche ionization due to the action of the strong electric field in the gap between the two plates, and the current is immediately cut off, and the current curve shows a sharp pulse. At this time, there are still charged particles in the air, and they will continue to move to the two plates and continue to move. This kind of charged particles are plasma low-temperature plasma ions that occur after being ionized. Because they exist in the air gap between the plates in a suspended state, they can easily blow out the ionization zone.