KR101755795B1 - Making copper nano particle and nano ink by underwater discharge - Google Patents

Abstract

The present invention provides a method for producing an ink comprising nanoparticles and nanoparticles, comprising the steps of: (S1) preparing an aqueous solution of copper precursor; Synthesizing nanoparticles by using an underwater discharge in the prepared aqueous solution (S2); Recovering the copper nanoparticles produced by underwater discharge (S3); And dispersing the recovered nanoparticles in a digital printing ink composition containing a hydrophilic organic solvent and an aqueous dispersant to synthesize a nano ink (S4).

Description

TECHNICAL FIELD [0001] The present invention relates to a copper nanoparticle and a nano ink,

The present invention relates to a method for synthesizing nanoporous particles through plasma discharge in an aqueous solution containing a copper precursor, and a method for producing nanopowders using the synthesized particles.

Research on nanoceramic powder manufacturing technology has been carried out a lot, but nanometer metal powders have not been actively studied due to difficulty in treatment due to strong reactivity. Metal materials are unstable because the powder is unstable due to an increase in surface energy when the size of the powder is continuously decreased and the surface is continuously oxidized when stored in air.

In addition, printing electronic technology using metal nano ink is expected to lead the electronics industry by enabling the fabrication of wiring without using the existing semiconductor process and the production of electronic circuit on a flexible substrate.

Conventionally developed nanoparticle synthesis methods have focused on silver or gold. However, there is a problem that the raw material is expensive to be applied to a printing electron, and ion migration and aggregation occur. There have been reported methods of synthesizing copper nanoparticles to replace silver or gold nanoparticles. However, there are problems in that they are difficult to mass-produce because of problems of environmental pollution due to use of chemicals or high energy consumption.

On the other hand, underwater plasma discharge means a technique for generating plasma underwater by underwater electric discharge. Generally, such underwater plasma discharge is widely used for water quality improvement. It is used directly or indirectly, for example, in ship ballast water, ultrapure water production, and desalination.

The generation path of the underwater plasma varies. Underwater plasma generation due to the high voltage discharge in which the nearby electric field dissociates water molecules and ionization occurs due to the voltage applied to the electrodes inserted in the water is very large, and bubbles are formed between the two electrodes, A method of raising the temperature of the surface of the electrode up to the boiling point and forming a boundary layer (bubble) with water vapor on the surface of the electrode while discharging is performed in the bubble while flowing the electrolytic ions through the electrode in the electrolyte.

Such an underwater plasma discharge is expected to be applied to various fields of industry based on the potential of plasma, and to cope effectively in many fields.

The inventors have come to discover and discover new applications of underwater plasma discharge in accordance with the needs of this industry.

In order to solve the above problems, the present invention aims to synthesize copper nanoparticles using underwater discharge and to produce nano ink for printing electronics.

The present invention provides a method for preparing copper nanoparticles using energy generated by underwater discharge without using a chemical reducing agent in the aqueous solution with a metal precursor as a starting material.

It is an object of the present invention to mass-produce copper nanoparticles for printing electronics having a nano-size environmentally and economically at room temperature and atmospheric pressure, without using high energy such as chemicals, radiation, or electron beams.

In one aspect, the present invention provides a method comprising: preparing an aqueous solution comprising a copper precursor; And subjecting the aqueous solution to a plasma discharge.

In the plasma discharge,

A method of generating an underwater plasma in which a high voltage is applied to an electrode inserted in water to dissociate or ionize water molecules around the electrode;

A method of generating an underwater plasma in which bubbles are formed between two electrodes inserted in water and an electric field is generated to discharge the inside of bubbles;

A method of raising the temperature of the surface of the electrode inserted in the water up to the boiling point to form a bubble on the surface of the electrode and discharging the bubble;

- pulse underwater plasma discharge; or

- Includes capillary plasma discharge.

The plasma discharge method may be various methods using normal AC, direct current, pulse, RF, microwave, or the like.

The pulse in-water discharge or the capillary plasma discharge may be a method in which pulse power is supplied and discharged, and the pulse supply may be performed by an apparatus including, for example, a pulse generating unit and a pulse discharging unit.

As an example, the pulse generating unit may include: a first electrode; A second electrode surrounding the first electrode with the first electrode as a virtual center axis; Capacitors electrically connected to the first electrode and the second electrode at both ends thereof and arranged in parallel to each other in a circumferential direction radially with the first electrode as a center axis; An electrical supply connected to an input of the first electrode and configured to supply electrical energy to charge the capacitors; And a switch unit connected to the output terminal of the first electrode to discharge the pulse energy accumulated in the capacitors through the output terminal. In this unit, the capacitors are stacked in a plurality of rows along the longitudinal direction of the first electrode. The second electrode may be formed in a plurality of bars spaced radially with respect to the first electrode and connected to each of the capacitors.

Wherein the pulse discharge unit comprises: a metal tip electrically connected to an output terminal of the pulse generation unit; And a dielectric tube surrounding the metal tip. Alternatively, the pulse discharger may include a metal tip electrically connected to an output terminal of the pulse generator; And a dielectric tube surrounding the metal tip and protruding from the end of the metal tip by a predetermined length.

The material of the rapid tip of the electrode is tungsten, platinum or molybdenum, and the material of the dielectric tube is alumina or teflon.

The aqueous solution may comprise an organic solvent. The aqueous solution may be water alone or a mixture of water and an organic solvent. The organic solvent may include ethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol.

The copper precursor, cyan East (Cu (CN) _2), copper oxalate (Cu (COO) _2), copper acetate (CuCOOCu), copper carbonate (CuCO _3), cupric chloride (CuCl _2), chloride 1 copper (CuCl), copper sulfate (CuSO _4), and may be at least one selected from the group consisting of copper nitrate _{(Cu (NO 3) 2)} .

Copper is reduced from the copper precursor by the underwater plasma discharge, and the copper particles reduced by the effect of the discharge have a weak positive charge.

The aqueous solution includes an OH scavenger, and the antioxidant may be at least one selected from the group consisting of D-mannitol, N-acetyl-cysteine and N-methyl-2-pyrrolidone. The OH scavenger suppresses the oxidation of copper atoms due to OH radicals in the aqueous solution generated during the plasma discharge.

After the plasma discharge step, a metal or ion exchange filter is immersed in the aqueous solution to collect copper nanoparticles. Positively charged copper nanoparticles adsorb to the metal or ion exchange filter and become electrically neutral.

The plasma discharge is characterized by being capable of controlling the size of the copper nanoparticles by controlling the pulse width in the case of plasma in-pulse discharge. The pulse width can be increased to enlarge the size of the produced copper particles, and the width of the produced copper particles can be made smaller by narrowing the width.

In another aspect, the present invention provides a method of making an ink comprising nanoporous particles comprising immersing copper nanoparticles adsorbed on the metal or ion exchange filter into an ink composition. When metal or ion exchange filter adsorbing copper nanoparticles is immersed in the ink composition, nanoparticles are separated naturally and dispersed in the ink composition due to the dispersing power of the nanoparticles.

The ink composition includes an organic solvent for copper oxidation inhibition, a surfactant, and a dispersant to facilitate dispersion of the nanoparticles and to inhibit contact with oxygen.

The organic solvent may be at least one selected from the group consisting of an alcohol compound, an ether compound, and a ketone compound.

The alcohol compound may be at least one selected from the group consisting of water-soluble oligomers of methanol, ethanol, isopropanol, ternary butanol, trivalent amyl alcohol, mellicolector, butoxyethanol, methoxypropanol, methoxypropoxypropanol, ethylronglytol, ethylene glycol, And propylene glycol.

The ether compound may be at least one compound selected from ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, and glycerol ether.

The ketone compound may be at least one compound selected from acetone and methyl ethyl ketone dioxane.

The surfactant may be at least one selected from polyoxyethylene olefin amine ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleylpolyethylene glycol distearate.

The dispersing agent may be at least one selected from polydimethylsilane, alkylester polyol ester ammonium salt and alkyl acrylate alkyl ammonium salt.

According to another aspect of the present invention, there is provided a water treatment apparatus comprising: a first aqueous solution containing portion; A discharge unit fluidly connected to the first aqueous solution storage unit and having a width smaller than a width in the transverse direction of the first storage unit; A second aqueous solution accommodating portion fluidly connected to the discharge portion and located on the opposite side of the first accommodating portion and having a width larger than a width in the transverse direction of the discharge portion; An aqueous solution that sequentially flows through the first aqueous solution storage portion, the discharge portion, and the second aqueous solution storage portion and includes a copper precursor; And a pair of electrodes applied to two opposite surfaces of the discharge unit.

In another aspect, the present invention includes a venturi nozzle-type copper synthesis system in which at least two venturi nozzle-type copper synthesis apparatuses of claim 17 are connected in series in parallel to the flow direction of the aqueous solution.

The method for synthesizing copper nanoparticles of the present invention has an effect of not requiring a chemical reducing agent.

The present invention is to provide a new use of an underwater plasma method.

The present invention can mass-produce copper nanoparticles for printing electronics that are environmentally friendly and economically nano-sized at room temperature and atmospheric pressure, without using high energy such as chemicals, radiation, or electron beams.

Figure 1 is a flow chart illustrating the method of the present invention.
2 is a diagram illustrating a detailed configuration of a pulse circuit unit according to an embodiment of the present invention.
3 is a diagram showing a detailed configuration of a half-wave rectifying circuit unit 108 according to an embodiment of the present invention.
4 is a view showing a pulse discharge electrode 400 according to an embodiment of the present invention.
5 is a view showing a capillary discharge electrode 500 according to an embodiment of the present invention.
FIG. 6 is a photograph showing an aqueous solution of copper nanoparticles synthesized through the present invention. FIG.
7 is a photograph of copper nanoparticles synthesized using an underwater discharge.
FIG. 8 shows the EDX analysis results of the copper nanoparticles synthesized in FIG.
9 is a photograph showing an aqueous solution of copper nanoparticles synthesized through the present invention.
10 is a photograph showing the concentration of the copper nanoparticles synthesized by the discharge time.
11 is a TEM photograph of the synthesized copper nanoparticles.
12 is a view illustrating a venturi nozzle type copper synthesizing apparatus.
13 is a diagram illustrating a copper synthesis system in which a venturi nozzle type copper synthesis apparatus is connected in series.
14 is a configuration diagram showing a configuration of a pulse power supply unit according to an embodiment of the present invention.
15 is a plan view showing the arrangement of the capacitors of FIG.
FIG. 16 is a plan view showing another embodiment of the second electrode in FIG. 2. FIG.
17 is a configuration diagram showing a configuration of a pulse power supply apparatus according to an embodiment of the present invention.
FIG. 18 is a configuration diagram showing a configuration of a pulse power supply apparatus according to another embodiment of the second electrode of FIG. 4; FIG.
19 is a graph showing the particle size according to the pulse width.

Figure 1 is a flow chart illustrating the method of the present invention. A method of manufacturing an ink comprising nanoparticles and nanoparticles of the present invention comprises the steps of: (S1) preparing an aqueous solution of copper precursor; Synthesizing nanoparticles by using an underwater discharge in the prepared aqueous solution (S2); Recovering the copper nanoparticles produced by underwater discharge (S3); And dispersing the recovered nanoparticles in a digital printing ink composition containing a hydrophilic organic solvent and an aqueous dispersant to synthesize a nano ink (S4).

[Underwater plasma  Discharge System for Discharging]

The pulsed power supply system as one embodiment of the underwater plasma discharge of the present invention includes a power supply unit, a voltage amplification unit, a pulse circuit unit, and a pulse discharge unit. A detailed description of this is found in Korean Patent Application No. 10-2011-0056077, which is incorporated herein by reference in its entirety.

1. Half wave rectification Supplier

As an example, the underwater discharge electrode of the present invention, for example, a capillary electrode system, can be subjected to half wave rectification. The system includes a power supply, a voltage amplifying part, a half wave rectifying circuit part, and a capillary discharging part. A detailed description of this is found in Korean Patent Application No. 10-2011-0056077, which is incorporated herein by reference in its entirety.

3 is a diagram showing a detailed configuration of a half-wave rectifying circuit unit 108 according to an embodiment of the present invention. As shown, the half-wave rectifying circuit part 108 according to an embodiment of the present invention includes at least one half-wave rectifying circuit 300.

The half-wave rectifying circuit 300 includes two diodes D1 and D2 and two capacitors C1 and C2 as shown in FIG. 3. The half-wave rectifying circuit 300 rectifies the AC power amplified by the voltage amplifying unit 104 Wave half-wave rectification signal. In this case, it is preferable that the half-wave rectification signal is a negative half-wave rectification signal having a negative voltage. When the negative half-wave rectification signal is constituted in this manner, when a positive half-wave rectification signal or an un-rectified AC signal is supplied to a capillary discharge electrode The wear of the capillary discharge electrode can be minimized.

The structure of the half-wave rectifying circuit 300 is also an example, and the present invention is not limited thereto. Any circuit capable of generating the rectifying signal required by the present invention can be applied to the half-wave rectifying circuit 300 of the present invention, (300). ≪ / RTI >

2. Pulse power Generating unit 1

As an example of the pulse power generation of the present invention, the detailed configuration of the pulse circuit portion can be referred to Fig. As shown, the pulse circuit portion according to an embodiment of the present invention includes at least one high voltage pulse generating circuit 200. [ The number of such high voltage pulse generating circuits 200 is determined according to the number of pulse discharge electrodes provided in the pulse discharging portion.

Each of the high voltage pulse generating circuits 200 includes a capacitor C having one end connected to the first output terminal of the voltage amplifying section, a diode D having one end connected to the second output terminal of the voltage amplifying section 104, And a switch S connected to the other end of the capacitor C and the other end of the resistor R. The ground is connected to the other end of the capacitor C, Lt; / RTI >

The AC power input to the high voltage pulse generating circuit 200 through the first output terminal and the second output terminal is accumulated in the capacitor C and the charge accumulated in the capacitor C is stored in the capacitor C So that a pulse signal is generated. The switch S is formed by an air gap structure. The air gap maintains an insulation state at all times, and when the amount of charge accumulated in the capacitor C becomes a certain amount or more, the insulation state breaks and a high voltage pulse is output. With such a structure, since the charge accumulated in the capacitor C is concentrated and discharged within a short time (within about 90 nS), a large energy can be obtained in a short time. Also, when the switch S has an air gap structure, even if a plurality of high-voltage pulse generating circuits 200 are provided, the load can be prevented from being concentrated at one place, and an effective discharge can be generated.

The high-voltage pulse generation circuit 200 described above is an example, and the present invention is not limited thereto. Any circuit capable of generating a high-voltage pulse required by the present invention can be applied to the high- (200). ≪ / RTI >

3. Pulse power Supply 2

As another example of the pulse power supply system, FIGS. 14 and 15 are referred to. The pulse power supply system 1400 according to the embodiment of the present invention includes a first electrode 1410, a second electrode 1420, a capacitor 1430, a switch portion 1440, and an electric power source 1450 , Each of which is connected and connected via a transmission line.

The first electrode 1410 has a bar shape as an anode and is connected to the electricity source 1450 as an upper input terminal and the switch unit 1440 as an output terminal on the lower side.

The first electrode 1410 is positioned on the central axis of the second electrode 1420 and the capacitors 1430 as described later so that the pulse energy accumulated in the capacitors 1430 can be easily focused ).

The second electrode 1420 surrounds the first electrode 1410 with the first electrode 1410 as a virtual center axis as a cathode. In detail, the second electrode 1420 has a round tube shape having both ends opened and surrounding the first electrode 1410 with the first electrode 1410 as a center axis, as shown in the figure. However, in a preferred embodiment of the present invention, the second electrode 1420 includes a conical tube or a conical tube symmetrically connected to the conical tube in addition to the circular tube. It is possible to use various structures as long as they are arranged radially in the circumferential direction and connected to each other. Hereinafter, embodiments of the second electrode 1420 in the form of a biconical tube will be described later.

It is preferable that the grounding portion of the second electrode 1420 is connected to the power grounding portion 1451 of the electricity supply source 1450 in order to accelerate discharge.

The capacitor 1430 is located inside the second electrode 1420 and is electrically connected at both ends to the first electrode 1410 and the second electrode 1420. The first electrode 1410 Are arranged in parallel to each other along the circumferential direction in a radial direction with the center axis as a central axis.

Accordingly, since the pulse power supply unit 1400 has a parallel connection structure in which the sum of the capacitances of the capacitors 1430 is the total capacitance, a large amount of pulse energy can be obtained by the combination of the capacitors 1430 .

Further, the capacitors 1430a and 1430b are stacked in a plurality of rows along the longitudinal direction of the first electrode 1410, so that more capacity can be obtained. When the capacitors 1430a and 1430b are stacked in a plurality of rows as described above, the capacitors 1430 are connected to the capacitors 1430a and 1430b arranged in different columns so that the entire length of the capacitors 1430a and 1430b is reduced, It is preferable that they are arranged in a zigzag manner.

The switch unit 1440 is connected to the output terminal of the first electrode 1410 so that the pulse energy accumulated in the capacitor 1430 is discharged through the output terminal. Here, the switch unit 1440 may be a gas discharge type switch having a long lifetime withstanding high current and high voltage. However, the present invention is not limited to this, and other trigger spark gap switches, TVS (Triggered Vacuum Sw.), It is needless to say that various switches such as a Vacuum Rotary Arc Gap (VRAG), an Ignitron switch, and a Thyratron switch can be applied.

The electricity supply source 1450 is connected to the input terminal of the first electrode 1410 and the second electrode 1420 to supply electric energy for charging the capacitors 1430 from the outside. A known capacitor charging device capable of charging the capacitor 1430 can be applied to the electricity supply source 1450, and a detailed description thereof will be omitted.

The pulse power supply unit 1400 may further include a resistor (not shown) that limits the magnitude of a current input to the capacitor 1430. The pulse power supply unit 1400 may further include a resistor A configuration for allowing compression or molding to be performed, and the like.

In addition, the second electrode 1420 may include a cover detachably coupled to both open sides to protect the first electrode 1410 and the capacitors 1430 therein, and the cover and the second The attachment and detachment structure of the electrode 1420 may be various detachable coupling structures such as a snap type and a thread type.

16 illustrates another embodiment of the second electrode 1420a. Referring to FIG. 16, a plurality of the second electrodes 1420a are arranged in a bar shape so as to be radially spaced apart from the first electrode 1420a And is connected to each of the capacitors 1430a and 1430b. Although not shown in the drawing, a grounding portion of the second electrode 1420a is provided for each of the second electrodes 1420a. Similarly, a power grounding portion 1451 of the electric power source 1450 ).

As described above, the pulse power supply units 1400 and 1400b are arranged such that the capacitors 1430 are connected in parallel along the circumferential direction in a radial direction, and are connected to the center of the second electrodes 1420 and 1420a and the capacitors 1430 By disposing the first electrode 1410, a low inductance and a high capacitance of the capacitor 1430 can be obtained.

Hereinafter, a pulse power supply apparatus according to an embodiment of the present invention will be described.

17, a pulse power supply device 1500 according to an embodiment of the present invention includes a first capacitor bank 1510a, a switch unit 1440, an electricity supply source 1550, Capacitor bank 1510b.

14, the detailed description thereof will be omitted. In the configuration of FIG. 17, the same reference numerals as those of FIG. 14 denote the same components . Hereinafter, a description will be given focusing mainly on the configuration that is generally similar to that shown in FIG.

The first capacitor bank 1510a includes a first electrode 1410, a second electrode 1420 surrounding the first electrode 1410 with the first electrode 1410 as a virtual center axis, A capacitor electrically connected to the first electrode 1410 and the second electrode 1420 at both ends and arranged in parallel to each other along the circumferential direction in a radial direction about the first electrode 1410 1430).

The second capacitor bank 1510b includes a third electrode 1411 having an input terminal connected to the switch unit 1440 and an output terminal connected to a load, A fourth electrode 1421 surrounding the third electrode 1411 and having opposite ends electrically connected to the first electrode 1410 and the second electrode 1420, And the capacitors 1430 are disposed in parallel to each other along the circumferential direction in a radial direction about the center axis.

The third electrode 1411, the fourth electrode 1421 and the capacitors 1430 of the second capacitor bank 1510b are connected to the first electrode 1410, the second electrode 1420, And the capacitor 1430, detailed description thereof will be omitted.

In addition, although the first capacitor bank 1510a and the second capacitor bank 1510b have the same structure in the drawing, it is a preferred embodiment that various configurations such as a combination of the configurations of FIG. 1 and FIG. 3 Of course, can be applied.

In the pulse power supply device 1500, the first electrode 1410 and the third electrode 101 are preferably arranged in a coaxial type. This is because the first electrode 1410 and the third electrode 1411 must be arranged in a coaxial type so that focusing of pulsed power (plasma) in a load is easy.

Here, the first capacitor bank 1510a serves as a main capacitor, and the second capacitor bank 1510b serves as a peak capacity. If the first capacitor bank 1510a and the second capacitor bank 1510b have the same structure, the capacities of the first capacitor bank 1510a and the second capacitor bank 1510b are theoretically the same, The capacitance of the first capacitor bank 1510a may be equal to or greater than the capacitance of the second capacitor bank 1510a in consideration of the loss and speed.

Further, the pulse power supply device 1500 may include a pulse power supply unit 1400 including the first capacitor bank 1510a and the switch unit 1440 as one module, And can be variously configured.

FIG. 5 is a diagram showing a pulse power supply 1500b showing another embodiment of the second electrode 1420 and the fourth electrode 1421 in FIG. Referring to the drawing, the pulse power supply device 1500b includes a second electrode 1420a and a fourth electrode 1421a formed in a bar shape not in the shape of a circular cylinder, and has a first electrode 1410 and a third electrode 1411 In the radial direction. Here, the other structures except for the second electrode 1420a and the fourth electrode 1421a are substantially the same as those of the structure of FIG. 4, and a detailed description thereof will be omitted. Further, reference numerals 1400b denote pulse power supply units, and 1511a and 1511b denote a first capacitor bank and a second capacitor bank, respectively.

In the meantime, although the pulse power supply device 1500b has been described in the case where both the second electrode 1420a and the fourth electrode 1421a are formed into a bar shape in the drawing, The second electrode 1420a and the fourth electrode 1421a may be applied to both the cylindrical shape and the bar shape at the same time.

As described above, the pulse power supply devices 1500 and 1500b supply power from the electricity supply source 1450 to the main capacitor bank, charge the energy to the main capacitor, and supply the switch unit 1440 So that the peak energy can be supplied to the peak capacity and the electric energy can be charged to the peak capacity. The charged electric energy forms a rod and an RLC circuit so that electric energy stored in the peak capacitor is discharged to the load (Discharging). Therefore, the pulse power supply devices 1500 and 1500b do not need a separate switch for the peak capacity.

According to the above description, the pulse power supply devices 1500 and 1500b include two capacitor banks, and when various types of preionization (for example, uv generation , Inducing a dvd discharge arc discharge) is made on the rod, so that a uniform uniform discharge can be induced in the rod.

4. Discharge electrode

4 is a view showing a pulse discharge electrode 400 according to an embodiment of the present invention. In an embodiment of the present invention, the pulse discharge portion includes at least one pulse discharge electrode 400, and the pulse discharge electrode 400 includes a metal tip 402 and a dielectric tube 404.

The metal tip 402 is electrically connected to the output terminal of the pulse generation section, for example, the pulse output terminal of the high voltage pulse generation circuit 200 of FIG. 2 or the output terminal of the first electrode of FIG. 14, It can be made of tungsten material.

The dielectric tube 404 is configured to surround the metal tip 402. In the case of the pulse discharge electrode 400, since the voltage of the pulse to be emitted is high and the wear of the electrode is high, the dielectric tube 404 is preferably made of a material resistant to abrasion. For example, it may be made of Teflon have.

5 is a view showing a capillary discharge electrode 500 according to an embodiment of the present invention. In an embodiment of the present invention, the capillary discharge electrode 500 includes at least one capillary discharge electrode 500, and the capillary discharge electrode 500 includes a metal tip 502 and a dielectric tube 504.

The metal tip 502 is electrically connected to the power supply means, e.g., the output terminal of the pulse power supply or rectification system illustrated above, and may be constructed of a metal material, for example, a tungsten material.

The dielectric tube 504 is configured to surround the metal tip 502 and protrudes a predetermined length d from the end of the metal tip 502. That is, the end portion of the metal tip 502 in the capillary discharge electrode 500 is formed in the dielectric tube 504 by d. In the drawing, the d is 2 mm. However, the present invention is not limited thereto. The d may be appropriately determined in consideration of the micro bubbles formed in the dielectric tube 504 and the discharge effect generated in the micro bubbles . The dielectric tube 504 may be made of, for example, alumina.

The plasma discharge in the capillary discharge electrode 500 having the above-described configuration takes place as follows. As the voltage | Vp | supplied from the half-wave rectifying circuit 300 to the metal tip 502 increases, a micro-sized vapor phase bubble is generated in the inner space of the dielectric tube 504. When hydrogen gas is generated at the cathode by electrolysis and the voltage is further increased, water bubbles are formed as the liquid (water) evaporates due to the joule heat, and when the voltage is further increased, the size of the bubble increases. When the breakdown voltage is reached, an electric discharge is generated and an underwater power generation plasma is generated. As | Vp | increases, the size of the fine bubbles increases due to Joule heating and becomes equal to the inner diameter of the dielectric tube 504.

The intensity of the Joule heat due to the surface discharge inside the dielectric tube 504 is gradually increased due to the restricted current inside the dielectric tube 504 as the voltage Vp | Is pushed toward the inlet of the dielectric tube 504, and the shape of the fine bubble changes from circular to elliptical. Also, when the shape of the fine bubbles becomes elliptical, the contact area between the fine bubbles and the dielectric tube 504 becomes wider as shown in the figure, and thus the intensity of the joule heat that is received by the fine bubbles becomes stronger.

After that | Vp | continues to increase, the micro bubble bursts and breaks into several bubbles. When the fine bubbles are completely formed inside the dielectric tube 504, two water columns formed on both sides of the fine bubbles act as electrodes, causing electrical discharge inside the fine bubbles, and if | Vp | A plasma discharge occurs outside the dielectric tube 504.

350 ml of DI water was prepared in a water tank as shown in FIG. 6, and a solution of dissolved CuCl ₂ and CuCl was prepared. Ethanol was added to each water bath. This solution was initially a solution in which black and pale blue precipitates were not visually recognized, as can be seen in the before photograph of FIG. 6.

The pulse discharge system and the pulse electrode described above were prepared. The tip 502 of the electrode was tungsten, and the dielectric 504 surrounding the electrode tip was a quartz tube.

The solution was placed in a water bath so that the pulse electrode and the ground electrode were located inside, and a pulse voltage was applied to the solution. The discharge time was 10 minutes, and the applied voltage was 160 kV _{p- p} .

The sediment was confirmed as shown in the after photograph of FIG.

A metal plate was immersed in this solution to adsorb the precipitated particles, which was confirmed by SEM photographs, and it was confirmed that nanosized particles as shown in FIG. 7 were obtained. Also, as shown in FIG. 8, it is confirmed that the particles synthesized through EDX analysis are copper particles.

An aqueous solution containing CuCl dissolved in an organic solvent (ethanol) was prepared, and the aqueous solution was discharged underwater by using a pulse discharge system as in Experimental Example 1. As can be seen from the photograph of FIG. 9, the synthesis of copper nanoparticles was confirmed.

The concentration of the copper nanoparticles synthesized by the discharge time can be confirmed as shown in FIG.

The synthesized aqueous solution OH scavenger was added and the adsorption of copper nanoparticles was induced using a metal plate (iron plate). As shown in FIG. 11, copper nanoparticles synthesized through TEM analysis can be confirmed.

Experiments were conducted to confirm the change of particle size according to the pulse width. 350 ml of DI water was prepared in a water bath and CuCl ₂ was added to prepare a dissolved aqueous solution. The change in particle size was measured while varying the pulse width using the pulse apparatus of the present invention. The results are shown in Fig. It was confirmed that the particle size increases with increasing pulse width.

The present invention provides a copper synthesis apparatus and a copper synthesis system capable of performing efficient nanoporous synthesis through underwater discharge. The copper synthesis apparatus of the present invention has a venturi tube shape. 12 is referred to. The apparatus includes a first aqueous solution containing portion 101; A discharge unit (102) fluidly connected to the first aqueous solution storage unit and having a width smaller than a width in the transverse direction of the first storage unit; A second aqueous solution accommodating portion (103) fluidly connected to the discharge portion and positioned on the opposite side of the first accommodating portion and having a width larger than a width in the transverse direction of the discharge portion; And a voltage application device 200 for applying a voltage to a pair of electrodes and two electrodes which are applied to two opposite surfaces of the discharge part. The copper precursor aqueous solution is configured to sequentially flow through the first aqueous solution containing portion, the discharge portion, and the second aqueous solution containing portion.

When a voltage is applied to the electrodes located on two surfaces of the discharge unit from the voltage application device 200, the discharge energy is generated in the discharge unit to transfer energy to the flowing aqueous solution that is located in the discharge unit, and the aqueous solution is discharged underwater.

The first aqueous solution containing portion may be a cylindrical tube. And contains an aqueous solution containing a copper precursor therein. The aqueous solution is configured to flow into a discharging portion that is fluidly connected to one longitudinal side of the first aqueous solution accommodating portion.

The discharge part may be a cylindrical tube. And the discharge portion is connected to the first aqueous solution accommodating portion and the second aqueous solution accommodating portion so as to fluidly communicate with both sides in the longitudinal direction. And the discharger is configured to receive the aqueous solution from the first aqueous solution storage portion and to discharge the aqueous solution into the second aqueous solution storage portion. The discharge unit includes a pair of electrodes facing the side surface, and a voltage is applied to the two electrodes such that underwater discharge occurs in the discharge unit. 12 and 13, the longitudinal direction means the longitudinal direction of the cylinder and the flow direction of the aqueous solution, and the transverse direction means the vertical direction of the longitudinal direction.

The second aqueous solution receiving portion may be a cylindrical tube. And is connected at one side in the longitudinal direction of the discharge part and at the opposite side of the first aqueous solution containing part in fluid communication with the discharge part. The aqueous solution treated underwater is introduced into the second aqueous solution storage portion from the discharge portion and accommodates the synthesized nanoporous particles.

The present invention provides a venturi nozzle type copper synthesis system in which two or more venturi nozzle type copper synthesis apparatuses are connected in series in parallel to the flow direction of the aqueous solution, as illustrated in FIG.

It is possible to increase the efficiency of copper synthesis by constructing underwater discharge in a narrow space of the shape of a venturi tube, and it is possible to increase the efficiency of the synthesis by making the circulation process and the continuous process possible.

Claims (21)

delete A bar-shaped first electrode;
A cylindrical second electrode surrounding the first electrode with the first electrode as a virtual center axis;
Capacitors electrically connected to the outer surface of the first electrode and the inner surface of the second electrode at both ends thereof and arranged in parallel to each other along the circumferential direction radially with the first electrode as a center axis;
An electrical supply connected to an input of the first electrode and configured to supply electrical energy to charge the capacitors; And
And a switch unit connected to an output terminal of the first electrode to discharge pulse energy accumulated in the capacitors through the output terminal.
Pulsed power supply means for underwater pulsed copper discharge or copper nanoparticle underwater synthesis by capillary plasma discharge. 3. The method of claim 2,
Wherein the capacitors are stacked in a plurality of rows along the longitudinal direction of the first electrode,
Pulsed power supply means for underwater pulsed copper discharge or copper nanoparticle underwater synthesis by capillary plasma discharge. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A first aqueous solution containing portion;
A discharge unit fluidly connected to the first aqueous solution storage unit and having a width smaller than a width in a lateral direction of the first aqueous solution storage unit;
A second aqueous solution accommodating portion fluidly connected to the discharge portion and located on the opposite side of the first aqueous solution accommodating portion and having a width larger than a width in the transverse direction of the discharge portion;
An aqueous solution that sequentially flows through the first aqueous solution storage portion, the discharge portion, and the second aqueous solution storage portion and includes a copper precursor;
And a pair of electrodes which are applied to two opposing surfaces of the discharge portion,
Venturi Nozzle Copper Nanoparticles Underwater Synthesis Device delete

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