KR100977711B1 - Atmospheric pressure plasma generator and surface treatment method using the same - Google Patents

Abstract

The present invention relates to an atmospheric pressure plasma generating apparatus and a surface treatment method using the same, comprising: a ground electrode having a gas injection hole provided on a sidewall, and having an empty interior; an inner electrode inserted into an inner space of the ground electrode; A dielectric tube formed to surround the inner electrode in an inner space, and a power supply device configured to apply power between the inner electrode and the ground electrode, and an end of the ground electrode discharged through the gas injection hole; A gas outlet is formed so that gas is blown out through the space formed between the ground electrode and the dielectric tube, and a discharge space is formed between the gas outlet and the internal electrode. According to the present invention, plasma can be stably generated at room temperature, can be easily carried, and can be surface treated without damaging the object.

Atmospheric pressure, room temperature, plasma, internal electrode, surface treatment, jet

Description

Atmospheric pressure plasma generating device and surface treatment method using the same {APPARATUS FOR GENERATING ATMOSPHERIC PRESSURE PLASMA AND SURFACE TREATMENT METHOD USING THE SAME}

The present invention relates to an atmospheric pressure plasma generating apparatus and a surface treatment method using the same, and more particularly, to an atmospheric pressure plasma generating apparatus and a surface treatment method using the same to generate plasma stably at room temperature.

Techniques for surface treatment of metals, polymers and the like using high reactivity in a plasma state are well known. The plasma may be generated in a vacuum or at atmospheric pressure, and according to the temperature, the plasma may be classified into a high temperature plasma having an average temperature of several tens of degrees and a high degree of ionization, and a low temperature plasma having an average temperature slightly higher than room temperature and having a low degree of ionization.

Industrially active in accordance with the necessity of miniaturization and low temperature process is mainly atmospheric pressure low temperature plasma, it is useful for etching and deposition in the semiconductor process, surface treatment of metals and polymers, synthesis of new materials.

However, in the case of low-temperature plasma is also higher than the room temperature in most cases, it was difficult to apply to the surface treatment of polymers that are very sensitive to heat, particularly in the biomedical field such as wound healing of skin tissues, such as human body composed of protein. In other words, in the surface treatment and biomedical fields of heat-sensitive polymers, so-called room temperature plasma is required in which temperature does not increase at room temperature.

Among the present inventors, Hong uses a cathode having a pupil, that is, a capillary electrode, and a stable high temperature argon by applying an AC high voltage as a power source, through Patent No. 10-0672230. It has been successful in generating plasma jets. However, since this is caused by a high voltage of 20 kW, there is a problem to be solved, which is not suitable as a portable device because it can give an electric shock to a human body or the like when used.

US Pat. Nos. 6,228,330 and 6,262,523 describe the use of detoxification, sterilization, surface etching, etc. of chemical biological agents by adding a small amount of oxygen to an RF (radio frequency) plasma to generate an atmospheric equilibrium plasma. However, since it uses a large amount of expensive helium as a plasma gas and uses a large amount of oxygen to increase the surface treatment effect, the efficiency is drastically reduced and the equipment is overheated by the transition from glow discharge to arc discharge.

U.S. Patent Nos. 5,387,842 and 5,414,324 also disclose the application of detoxification of biological agents by generating low temperature glow discharge plasmas close to room temperature. However, this may be structurally useful for large-area surface treatment, but it is not portable and can be used anytime and anywhere, and there are restrictions on the gas used.

In various fields, including biomedical, generating plasma that is effective for a variety of purposes is required not only to operate at room temperature and atmospheric pressure, but also to devices that do not arc or overheat during operation. In addition, there should be no restriction on the gas used so that it can be easily used anytime, anywhere and portability also needs to be improved.

The electron energy distribution function can be controlled so that the electrons have a high energy distribution in order to improve the chemical reaction of the plasma gas without increasing the temperature at room temperature. It is. However, this method is not only costly for the manufacturing cost of the power supply, but also the portability of the power supply becomes large due to the power supply pulse system, resulting in poor portability.

Therefore, the present invention can generate a stable plasma that does not increase the temperature at room temperature without an electric shock, and can be implemented in a structure that is easy to carry and easy to carry without restriction of the gas to be used anytime and anywhere easily And it aims to provide a surface treatment method using the same.

At least one atmospheric pressure plasma generator according to the present invention for achieving the above object is a gas injection hole is provided on the side wall, the inner empty electrode, the internal electrode inserted into the inner space of the ground electrode, and A dielectric tube formed to surround the inner electrode in the inner space of the ground electrode, and a power supply device configured to apply power between the inner electrode and the ground electrode, and an end of the ground electrode through the gas injection hole. The ejection opening is formed so that the injected discharge gas is ejected to the outside through the space formed between the ground electrode and the dielectric tube, characterized in that the discharge space is formed between the ejection opening and the internal electrode.

Preferably, the length of the ground electrode may be shorter than that of the internal electrode, and the length of the dielectric tube may be configured to be longer than the ground electrode.

Also preferably, the end portion of the dielectric tube may protrude longer than the end portion of the internal electrode in the discharge space, and more preferably, the protruding length may be in the range of 0.01 to 20 mm.

Also preferably, an end of the ground electrode may be extended to be formed, and an additional gas inlet for injecting additional gas may be formed at a side of the extended end, and an inside of the extended end may be provided to the plasma ejected from the outlet. The additional gas injected from the additional gas inlet may be formed so that the mixing space is mixed.

Another preferred embodiment of the atmospheric pressure plasma generator according to the present invention includes a ground electrode having an empty inside, an inner electrode inserted into an inner space of the ground electrode and having a spiral formed on an outer surface thereof, and an inner space of the ground electrode. And a power supply device for applying power between the inner electrode and the ground electrode, wherein the dielectric tube is formed to surround the inner electrode, and an end portion of the ground electrode is disposed between the inner electrode and the dielectric tube. The ejection opening is formed so that the discharge gas injected into the space formed by the spiral flows through the internal electrode and the dielectric tube to the outside, and a discharge space is formed between the ejection opening and the internal electrode.

In addition, at least two atmospheric pressure plasma generators may be provided in a bundle type, and each of the atmospheric pressure plasma generators may further include a gas distributor for distributing and injecting discharge gas. .

On the other hand, the surface treatment method using a plasma according to the present invention to achieve the above object, the step of generating a plasma jet using the atmospheric pressure plasma generating apparatus as described above, and contacting the generated plasma jet to the surface of the target object It comprises the step of.

Preferably, in the surface treatment, a monoatomic gas such as argon and helium or oxygen, nitrogen, air, carbon dioxide, or two or more mixed gases may be used as the discharge gas.

Also preferably, in the surface treatment, the object to be treated includes metal, polymer, glass, human, animal, plant surface, skin, cells, tissue.

In addition, the surface treatment may include at least one of hydrophilicity or hydrophobicity improvement, etching, cleaning, sterilization, and detoxification.

The atmospheric pressure plasma generator according to the present invention as described above is not limited to the use of gas, as well as inert gas such as argon, helium, as well as nitrogen, air, oxygen, carbon dioxide gas using the discharge gas at room temperature plasma jet It can be generated and portable and easy to manufacture, and in particular generates a stable room temperature plasma, it can be used for a variety of surface treatment in a variety of fields, including the biomedical field.

In other words, all areas of the industry that expect to improve adhesion through the surface treatment of small and small parts or materials consisting of metal, polymer, glass, and hydrophilic surface modification, detoxification of chemical biological agents on the surface of military equipment sensitive to heat and moisture It is effective in disinfecting epidermis and cells of human body, animal, plant, wound tissue and promoting tissue recovery, hemostasis through surface treatment after surgery, treatment of skin diseases such as atopy, sterilization and disinfection of oral bacteria. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a first embodiment of the atmospheric pressure plasma generating apparatus of the present invention.

Referring to Figure 1, the end of the inner electrode 10 of the wire or cylindrical shape may be formed in a round or pointed shape. The internal electrode 10 is preferably made of tungsten, molybdenum, stainless steel, copper and the like, and of course, may be made of other metal materials.

A dielectric tube 20 is formed to surround the inner electrode 10, and the dielectric tube 20 has an inner diameter that is the same as the outer diameter of the inner electrode 10, and is preferably made of a material such as quartz, tempered glass, or teflon. It may also be composed of other insulating materials.

The inner electrode 10 surrounded by the dielectric tube 20 is larger than the outer diameter of the dielectric tube 20 and has a space S1 through which the discharge gas 40 flowing into the gas inlet 12 can easily flow. It is installed inside the electrode 30.

The ground electrode 30 is made of a good wear resistance and conductive conductor, it is preferable that the end is formed to have the shape of a pencil or a cone. At the center of the end of the ground electrode 30, a jet port 31 through which a plasma is ejected is formed. The diameter of the jet port 31 is preferably in the range of several micrometers to several millimeters equal to the diameter of the internal electrode 10.

In addition, in order to prevent sparks between the ground electrode 30 and the internal electrode 10 in the portion where the gas injection hole 12 is formed, not the discharge space S2, the ground electrode 30 is better than the internal electrode 10. ) And the length of the dielectric tube 20 therebetween is made longer than the ground electrode 30.

 Here, the discharge space (S2) for generating a plasma is formed between the end of the internal electrode 10 and the ground electrode 30. In this case, the end of the dielectric tube 20 in the discharge space (S2) is longer than the end of the internal electrode 10, the plasma between the ground electrode 30 and the end of the internal electrode 10, that is, the discharge space (S2) To occur. In order to generate stable plasma from the discharge in the discharge space S2, the distance between the end of the dielectric tube 20 and the end of the internal electrode 10 is preferably set to 0.01 mm to 20 mm.

The power supply device 80 for supplying power to the internal electrode 10 and the ground electrode 30 is, for example, a conventional AC neon transformer is used and can be modified by connecting a current limiting resistor, a stability resistor (Ballast), etc. Do. In addition, the power supply device 80 may supply DC power or AC power. When AC power is supplied, the frequency is preferably 1 Hz to 5 GHz.

In the apparatus according to the present embodiment, for example, a monoatomic gas such as argon or helium, and nitrogen, oxygen, carbon dioxide, or a mixed gas thereof may be used as the discharge gas 40, and a gas injection port provided on the side of the ground electrode 30 may be used. Is injected through 12.

The electric field formed in the discharge space S2 formed between the internal electrode 10 and the end of the ground electrode 30 causes an insulation breakdown of the discharge gas 40 passing through the discharge space S2 to generate plasma. The generated plasma is ejected to the outside in a jet form through the ejection opening 31 at the end of the ground electrode 30. The diameter of the ejection opening 31 may be larger or smaller than the diameter of the internal electrode 10 and may be adjusted in the range of 0.01 to 20 mm to obtain a stable plasma jet.

According to the present invention, the discharge gas injected from the gas injection port 12 causes discharge in the fine discharge space S2, and at this time, the plasma generated in the discharge space S2 is quickly discharged into the fine discharge port 31 due to the high flow velocity of the injected gas. Since it is ejected, it becomes possible to obtain plasma at room temperature without becoming hot.

In addition, since the distance between the end of the internal electrode 10 and the ground electrode 30 in the discharge space (S2) is very short, the electric field intensity in the discharge space (S2) is sufficiently large, thereby generating plasma without limiting the use gas. It is possible to eject the plasma jet by the discharge gas injected at a high flow rate.

For example, an electric field of 30 kV / cm is required to turn air into a plasma, but an electric field of 3 kV / mm is required when the distance between electrodes is 1 mm. Therefore, even in the case of oxygen gas, which is difficult to produce a plasma at a minute distance between the electrodes, the plasma can be easily produced.

 In addition, since the plasma is jetted to a place where a strong electric field is formed, the jet is discharged to the outside, so the potential is very low or zero potential (zero potential), there is no electric shock.

FIG. 2 is a view showing a second embodiment of the atmospheric pressure plasma generating apparatus of the present invention. Here, the atmospheric pressure plasma generating apparatus having a handy type structure is shown.

Referring to FIG. 2, the Handy-type atmospheric plasma generator includes the same basic components of the atmospheric plasma generator shown in FIG. 1 and surrounds the entire length of the atmospheric plasma generator. 60 and a molding 50 filled in the exterior material 60 and made of an insulating epoxy.

According to the Handy type atmospheric plasma generator, the user can easily grip the plasma generator and use it for surface treatment, and it is easy to carry.

In this case, the internal electrode 10 and the ground electrode 30 are connected to a power supply device 80, and a power line 13 connected to the internal electrode 10 and a ground wire connected to the ground electrode 30. 33) is configured to penetrate the molding 50 and to be drawn out.

3 is a view showing a third embodiment of the atmospheric pressure plasma generating apparatus of the present invention. Here, an example in which the other gas is mixed with the ejected plasma is shown.

Referring to FIG. 3, the atmospheric pressure plasma generating apparatus according to the present embodiment includes all of the basic structures of FIG. 1 as described above, and an end portion of the ground electrode 30 is extended, and additional gas is provided on the side of the extension portion. An additional gas inlet 34 through which 70 can be injected is formed.

In addition, a mixing space S3 is formed in which the plasma ejected from the jet port 31 and the additional gas 70 injected through the additional gas injection port 34 may be mixed. As the additional gas 70, a monoatomic gas such as argon or helium and nitrogen, oxygen, carbon dioxide, or a mixed gas thereof may be used.

The plasma ejected from the ejection opening 31 makes a part of the additional gas 70 into the plasma in the mixing space S3, from which a plasma jet containing two or more gases is ejected to the outside.

Here, the mixing space S3 may be larger or smaller than the jet port 31 and its shape or size may be appropriately changed according to the object to be treated in the surface treatment.

4 is a view showing a fourth embodiment of the atmospheric pressure plasma generating apparatus of the present invention. Here, an example is shown in which a vortex is formed in the discharge gas to prevent the plasma from spreading, thereby extending the length of the plasma jet discharged to the outside.

Referring to FIG. 4, the same basic components as those of the atmospheric pressure plasma generator described with reference to FIG. 1 may be included, and a spiral may be formed on an outer surface of the internal electrode 10, and the discharge gas 40 may be disposed above the internal electrode 40. Is injected along the space (S4) of the spiral formed on the outer surface of the internal electrode (10).

Due to the configuration, the discharge gas 40 injected along the space (S4) of the spiral formed on the outer surface of the internal electrode 10 is rotated flow, due to the vortex of the discharge gas 40 due to the plasma The jet can be prevented from spreading, and the extended plasma jet is ejected to the outside.

≪ Example 1 >

5 and 6 are views showing a nitrogen plasma jet ejected into the air by the atmospheric pressure plasma generator of the present invention.

For this embodiment, the inner electrode was made of tungsten with an outer diameter of 1.6 mm, and the ground electrode was made of stainless steel. The diameter of the plasma jet port was 1 mm, and the flow rate of the nitrogen gas used as the discharge gas was 2 liters per minute.

Referring to FIG. 5, the length of the plasma jet 90 jetted into the air was about 10 cm, and the power consumption at this time was about 10 watts (W). The temperature of the plasma jet 90 was near room temperature, and the temperature of the plasma jet 90 may be controlled in the range of 25-3000 ° C. according to the type of the power supply 80 used.

6 shows a state in which the surface treatment is performed on the skin (hand) of the human body using the nitrogen plasma jet 90. Here, since the temperature of the plasma jet 90 is close to room temperature, there is no thermal damage due to the plasma, and the plasma potential is very low, and there is no damage due to electric shock.

Therefore, according to the surface treatment method using the atmospheric pressure plasma generating apparatus of this invention, not only metal and glass but also heat sensitive polymer, the skin of human body, the epidermis, the cell, etc. of a human body can be stably surface-treated.

In the surface treatment, improvement of hydrophilicity like water or hydrophobicity like water to the surface of the object to be treated, etching to scrape off the surface of the substance, cleaning to wash away foreign substances on the surface, viruses of the surface, bacteria It can be carried out including sterilization or detoxification that kills toxins.

The various surface treatments are possible by selecting a discharge gas that produces the effect. For example, in order to implement hydrophobicity, a gas or a hydrocarbon gas of a florin compound is generally mixed with a discharge gas such as argon or helium.

In addition, in order to implement sterilization and detoxification on the surface of humans, animals, plants, skin, cells, and tissues, oxygen gas may be mixed with a monoatomic discharge gas such as argon and helium.

<Example 2>

7 is a graph illustrating spectroscopic spectra of plasma species generated in plasma using air as a discharge gas.

Referring to FIG. 7, peaks appearing in the 300-400 nm range are related to nitrogen species, peaks appearing at 777.1 nm are oxygen atom species, and weakly 844 nm oxygen atom species were also identified. These oxygen plasma species not only improve the hydrophilicity and cleaning effect of the material, but also are very effective in detoxifying chemical biological agents and sterilizing skin diseases.

8 is a view showing a fifth embodiment of the atmospheric pressure plasma generating apparatus of the present invention, in which a plurality of atmospheric pressure room temperature plasma generating apparatuses as shown in FIG. 1 are arranged in a row to generate a large-area plasma. will be. Therefore, according to this embodiment, the effective surface treatment of the to-be-processed object which has a large area is also possible.

In this embodiment, reference numeral 100 denotes a gas distributor. The gas distributor 100 distributes the discharge gas in the same amount to be injected into the reaction gas inlet of each ground electrode 30.

In the present embodiment, the number of the atmospheric pressure plasma generators of FIG. 1 may be increased or decreased according to the area of the object to be treated, and although not shown, the atmospheric pressure plasma generation shown in FIGS. 2 to 4 instead of the atmospheric pressure plasma generator of FIG. You can also use the device.

In addition, depending on the object to be surface-treated the atmospheric pressure plasma generator, it can be used continuously or discontinuously connected, it may also be arranged in two or more rows or may be implemented in a bundle (Bundle) of various shapes such as circular. .

1 is a view showing a first embodiment of an atmospheric pressure plasma generating apparatus of the present invention.

2 is a view showing a second embodiment of the atmospheric pressure plasma generating apparatus of the present invention.

3 is a view showing a third embodiment of the atmospheric pressure plasma generating apparatus of the present invention.

Figure 4 shows a fourth embodiment of the atmospheric pressure plasma generating apparatus of the present invention.

5 is a view showing a nitrogen plasma jet ejected into the air by the atmospheric pressure plasma generator of the present invention.

6 is a view showing a surface treatment to the skin of the human body using the nitrogen plasma jet of the present invention.

FIG. 7 is a graph showing spectroscopic spectra of plasma species generated in plasma using air as a discharge gas. FIG.

8 shows a fifth embodiment of the atmospheric pressure plasma generating apparatus of the present invention.

* Description of the symbols for the main parts of the drawings *

10: internal electrode 20: dielectric tube

30: ground electrode 40: discharge gas

50: epoxy molding 60: exterior material

70: additional gas 80: power supply

90: plasma jet 100: gas distributor

Claims (17)

A ground electrode provided at a side wall of the gas inlet and having an empty interior; An internal electrode inserted into an internal space of the ground electrode; A dielectric tube formed to surround the inner electrode in an inner space of the ground electrode; And It comprises a power supply for applying power between the internal electrode and the ground electrode, A discharge port is formed at an end of the ground electrode such that discharge gas injected through the gas injection hole is blown out through a space formed between the ground electrode and the dielectric tube, and a discharge space is formed between the discharge hole and the internal electrode. Formed, And the length of the ground electrode is shorter than that of the inner electrode, and the length of the dielectric tube is longer than the ground electrode. delete The method of claim 1, And the end portion of the dielectric tube protrudes longer than the end portion of the internal electrode in the discharge space. The method of claim 3, wherein An end portion of the dielectric tube in the discharge space is characterized in that the atmospheric pressure plasma generator, characterized in that protruding longer than 0.01 ~ 20mm than the end of the internal electrode. The method according to any one of claims 1, 3 and 4, The discharge gas is an atmospheric pressure plasma generator, characterized in that the monoatomic gas, nitrogen, oxygen, carbon dioxide or a mixture thereof. The method of claim 1, An end of the ground electrode is formed to extend, and an additional gas inlet for injecting additional gas is formed in a side of the extended end, and an inside of the extended end is provided from the additional gas inlet to the plasma ejected from the outlet. Atmospheric pressure plasma generator characterized in that the mixing space is provided with the injected additional gas is mixed. The method of claim 6, The additional gas is a monoatomic gas, nitrogen, oxygen, carbon dioxide or a mixture of these gases, atmospheric pressure plasma generator. The method according to any one of claims 1, 3 and 4, An exterior material is formed surrounding the outer circumferential surface of the ground electrode, and an atmospheric pressure plasma generator, characterized in that a molding is formed between the ground electrode and the exterior material. A ground electrode with an empty interior; An inner electrode inserted into an inner space of the ground electrode and having a spiral formed on an outer surface thereof; A dielectric tube formed to surround the inner electrode in an inner space of the ground electrode; And It comprises a power supply for applying power between the internal electrode and the ground electrode, At the end of the ground electrode, a discharge port is formed between the inner electrode and the dielectric tube so that the discharge gas injected into the space formed by the spiral passes through the inner electrode and the dielectric tube and is discharged to the outside, And a discharge space is formed between the jet port and the internal electrode. The method of claim 9, An end of the ground electrode is formed to extend, and an additional gas inlet for injecting additional gas is formed on a side of the extended end, and the additional gas inlet is formed inside the extended end to the plasma ejected from the outlet. Atmospheric pressure plasma generating apparatus characterized in that the mixing space is provided is mixed with the additional gas injected from. The method according to any one of claims 1, 6 and 9, At least two atmospheric plasma generators are provided, characterized in that the bundle (Bundle) type atmospheric pressure plasma generating apparatus. The method of claim 11, And a gas distributor configured to distribute and inject discharge gas into each of the atmospheric pressure plasma generators. The method according to any one of claims 1, 3 and 4, The power supply device is an atmospheric pressure plasma generator, characterized in that for supplying direct current power or alternating current power. The method of claim 13, When the power supply device supplies an AC power, the AC power supply frequency, characterized in that the frequency of 1Hz ~ 5GHz. Generating a plasma jet using the atmospheric pressure plasma generator according to any one of claims 1, 3, 4, 6, 7, 7, 9 and 10; And Surface treatment method comprising the step of surface treatment by contacting the generated plasma jet to the surface of the workpiece. The method of claim 15, The treated material is a surface treatment method comprising a metal, a polymer, glass, humans, animals, plants, skin, cells, tissues. The method of claim 15, The surface treatment step, Surface treatment method comprising at least one of hydrophilicity or hydrophobicity improvement, etching, cleaning, sterilization, detoxification.

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