CN114082935B - Device and method for screening nano metal particle size - Google Patents

Abstract

The invention relates to the technical field of nano-metal particle production, in particular to a size screening device and method for nano-metal particles. A nanometer metal particle size screening device, including an electric spark ablation device and a screening device; the electric spark ablation device includes an inert gas source, an ablation reaction vessel, a high-voltage electrostatic generator and two electrodes, and the two electrodes The two electrodes are oppositely arranged on the inner wall of the ablation reaction container, and the two electrodes are respectively electrically connected to the high-voltage electrostatic generator, and the ablation reaction container is communicated with the inert gas source. The nano-metal particle size screening device can screen out nano-metal particles with uniform particle size, can realize precise screening of nano-metal particle size, has high screening accuracy, effectively improves production efficiency and output, and solves the problem of existing nano-metal particle size screening. The size screening device has low screening accuracy and poor screening effect.

Description

A kind of nanometer metal particle size screening device and method

technical field

The invention relates to the technical field of nano-metal particle production, in particular to a size screening device and method for nano-metal particles.

Background technique

The commonly used preparation methods of nano-metal particles include chemical reduction method, vapor deposition method, hydrothermal synthesis method, sol-gel method, photochemical method, microemulsion method, template method, phase transfer method, ultrasonic method and radiation method. During the preparation process, it is easy to be affected by the reaction conditions, and the reaction process is difficult to control accurately, so these methods are difficult to obtain nano-metal particles with uniform particle size. If it is necessary to improve the preparation method of nano-metal particles to prepare large quantities It is very difficult to control the nanoparticles with good monodispersity. In the current size screening technology for nanoparticles, there are screening channels of different sizes to screen nanoparticles of different sizes, but the device’s The screening accuracy is low and the screening effect is poor.

Contents of the invention

For the problems raised by the background technology, the purpose of the present invention is to propose a nano-metal particle size screening device, which can screen out nano-metal particles with uniform particle size, can realize precise screening of nano-metal particle size, and has high screening accuracy. Solve the problem of low screening accuracy and poor screening effect of the existing nano metal particle size screening device;

Another object of the present invention is to propose a method for screening the size of nano-metal particles, using the method of electric spark ablation to prepare nano-metal particles, the equipment is simple, the raw materials are easy to obtain, the cost is low, and the preparation conditions are easy to control. By using multiple electrode plates And the screening pipeline realizes the size screening of nano metal particles, the screening accuracy is high, the screening efficiency is high, and the production efficiency and output are effectively improved.

For reaching this purpose, the present invention adopts following technical scheme:

A nanometer metal particle size screening device, including an electric spark ablation device and a screening device;

The electric spark ablation device includes an inert gas source, an ablation reaction vessel, a high-voltage electrostatic generator and two electrodes, the two electrodes are oppositely arranged on the inner wall of the ablation reaction vessel, and the two electrodes are respectively electrically connected to the high-voltage electrostatic generator, and the ablation reaction vessel is connected to the inert gas source;

The screening device includes a screening pipeline and a plurality of electrode plates, the electrode plates are provided with through holes, and the screening pipeline passes through the through holes of the plurality of electrode plates in sequence;

A plurality of the electrode plates are arranged in the screening pipeline in a straight line from left to right, and the screening pipeline is respectively provided with a particle deposition collection platform on the left side of the plurality of electrode plates; the plurality of electrode plates are respectively Independently connected to power supplies of different voltages, and the voltage increases sequentially from left to right according to the direction of movement of the nano-metal particles, the nano-metal particles and the electrode plate have the same charge;

The inert gas source, the ablation reaction vessel and the screening pipeline are connected sequentially from left to right.

To further illustrate, the screening device further includes a collection box, the collection box communicates with the right end of the screening pipeline, and a particle deposition collection platform is arranged in the collection box.

To further illustrate, the electric spark ablation device also includes an air intake pipeline, one end of the air intake pipeline communicates with the gas outlet end of the inert gas source, and the other end of the air intake pipeline communicates with the ablation reaction vessel The air intake end is connected, and the air intake line is provided with a one-way valve.

To further illustrate, the cross-sectional shape of the screening pipeline is circular, the shape of the through hole of the electrode plate is circular, and the outer wall of the screening pipeline is in contact with the hole wall of the through hole of the electrode plate.

A nano-metal particle size screening method, using the nano-metal particle size screening device, comprising the following steps:

Use a high-voltage electrostatic generator to apply high-voltage static electricity of the same polarity to the two electrodes, and apply a pulse potential difference to the two electrodes, so that the two electrodes generate spark discharge, and the nano-metal particles are produced in the ablation reaction container, and the nano-metal The surface of the particle is charged with the same polarity as the high voltage electrostatic;

Use an inert gas source to feed an inert gas into the ablation reaction container, and the prepared nano-metal particles enter the screening pipeline under the airflow of the inert gas, and adjust the voltage of each electrode plate so that the nano-metal particles of different sizes are collected in the Individual particle deposition collection platforms.

To further illustrate, the voltage setting of the electrode plate satisfies the following relationship:

其中k为比例系数，k＝0.5～2，U₀为两个电极之间的电压，C为电火花烧蚀装置的等效电容，S为两个电极端面的横截面积。Wherein ρ is the density of nano metal particles, V is the flow velocity of the inert gas in the nano metal particle size screening device, R is the nano metal particle size, K is the surface charge density of the charged nano metal particles, and the expression of K is

Where k is the proportionality coefficient, k=0.5~2, U ₀ is the voltage between the two electrodes, C is the equivalent capacitance of the spark ablation device, and S is the cross-sectional area of the end faces of the two electrodes.

To further illustrate, the high-voltage static electricity applied to the two electrodes by using the high-voltage static electricity generator is positive or negative.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

The present invention proposes a nano-metal particle size screening device, which can screen out nano-metal particles with a uniform particle size, and can realize precise screening of the nano-metal particle size through the relationship between the kinetic energy and the potential energy of the nano-metal particles in the screening channel. The screening accuracy is high, which solves the problems of low screening accuracy and poor screening effect of the existing nano metal particle size screening device;

Further propose a nano-metal particle size screening method using a nano-metal particle size screening device, using the method of electric spark ablation to prepare nano-metal particles, the equipment is simple, the raw materials are easy to obtain, the cost is low, and the preparation conditions are easy to control. By using multiple electrode plates And the screening pipeline realizes the size screening of nano-metal particles, with high screening accuracy and high screening efficiency, effectively improving production efficiency and output, especially suitable for industrial fields, and has good industrialization prospects.

Description of drawings

Fig. 1 is the structural representation of the nanometer metal particle size screening device of an embodiment of the present invention;

Among them: EDM ablation device 1, inert gas source 11, ablation reaction vessel 12, high-voltage electrostatic generator 13, electrode 14, intake pipeline 15, one-way valve 151, screening device 2, screening pipeline 21, electrode plate 22 , through hole 221, particle deposition collection platform 23, collection box 24.

Detailed ways

In describing the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", " The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than Nothing indicating or implying that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation should therefore not be construed as limiting the invention.

As shown in Figure 1, a nanometer metal particle size screening device includes an electric spark ablation device 1 and a screening device 2;

The electric spark ablation device 1 includes an inert gas source 11, an ablation reaction vessel 12, a high-voltage electrostatic generator 13 and two electrodes 14, and the two electrodes 14 are oppositely arranged on the inner wall of the ablation reaction vessel 12 , and the two electrodes 14 are respectively electrically connected to the high-voltage electrostatic generator 13, and the ablation reaction vessel 12 is connected to the inert gas source 11;

The screening device 2 includes a screening pipeline 21 and a plurality of electrode plates 22, the electrode plates 22 are provided with through holes 221, and the screening pipeline 21 passes through the through holes 221 of the plurality of electrode plates 22 in sequence;

A plurality of the electrode plates 22 are arranged in the screening pipeline 21 in a straight line from left to right, and the screening pipeline 21 is respectively provided with a particle deposition collection platform 23 on the left side of the plurality of electrode plates 22; The electrode plates 22 are independently connected to power sources of different voltages, and the voltages increase sequentially from left to right according to the direction of movement of the nano-metal particles, and the nano-metal particles and the electrode plates 22 have the same charge;

The inert gas source 11 , the ablation reaction vessel 12 and the screening pipeline 21 are sequentially connected from left to right.

By setting the electric spark ablation device 1 and the screening device 2, the electric spark ablation device 1 is used to prepare nano-metal particles, specifically, a high-voltage electrostatic generator 13 is used to apply the same polarity to the two electrodes 14 High-voltage static electricity (positive or negative electricity), on the basis of static electricity, a pulse potential difference is further applied to the two electrodes, so that the two electrodes 14 generate spark discharge, and nano-metal particles are produced in the ablation reaction vessel 12. Due to the two The electrode 14 has static electricity, so that the surface of the nano-metal particles has the same charge as the high-voltage static electricity polarity;

By setting the inert gas source 11, the inert gas source 11 is used to feed an inert gas into the ablation reaction vessel 12, and the prepared nano-metal particles enter the screening pipeline 21 under the push of the inert gas flow Among them, since the electrode plate 22 is provided with a through hole 221, the screening pipeline 21 passes through a plurality of through holes 221 of the electrode plate 22 in sequence, and by nesting the electrode plate 22 in the screening pipeline 21, The structure of the device is simple, the installation is convenient, and it is convenient to realize the position adjustment of the electrode plates 22 in the device. By arranging a plurality of the electrode plates 22 in a linear array from left to right on the screening pipeline 21, a plurality of the electrode plates 22 The electrode plates 22 are respectively connected to power supplies of different voltages, and the nano-metal particles and the electrode plates 22 have the same charge, so there is a repulsive force between the nano-metal particles and the electrode plates 22, when the kinetic energy of the nano-metal particles When it is greater than the potential energy between it and the electrode plate, the nano-metal particle can pass through the electrode plate, and when the kinetic energy of the nano-metal particle is less than the potential energy between it and the electrode plate 22, the nano-metal particle cannot pass through the electrode plate 22. The electrode plate 22 is deposited and collected on the particle deposition collection platform 23 on the left side of the electrode plate 22. Since the kinetic energy of the nano-metal particles is proportional to the cube of the radius of the nano-metal particles, and a plurality of the electrodes The plate 22 is supplied with small to large voltages from left to right along the movement direction of the nano metal particles in the screening pipeline 21, so the smaller the radius of the nano metal particles, the earlier they will be deposited on the left electrode plate 22 The corresponding particle deposition and collection platform 23, the nano metal particles with larger radius will be deposited on the particle deposition and collection platform 23 corresponding to the electrode plate 22 on the right, by adjusting the voltage of each electrode plate 22, the nano metal particles of different sizes The particles are collected at each particle deposition collection platform 23 .

The nano-metal particle size screening device can screen out nano-metal particles with uniform particle size, and through the relationship between the kinetic energy and electric potential energy of the nano-metal particles in the screening channel 21, the precise screening of the size of the nano-metal particles can be realized, and the screening is accurate. The accuracy is high, which solves the problems of low screening accuracy and poor screening effect of the existing nanometer metal particle size screening device.

To further illustrate, the screening device 2 further includes a collection box 24 which communicates with the right end of the screening pipeline 21 , and a particle deposition collection platform 23 is arranged in the collection box 24 .

By setting the collection box 24, the particle deposition collection platform 23 in the collection box 24 can collect nano metal particles that are not deposited on a plurality of particle deposition collection platforms 23 provided by the electrode plate array of the screening pipeline 21, thereby completing the nano metal The screening and collection of particles with different sizes ensures that the size screening of all nano metal particles produced by the electric spark ablation device 1 is completed.

To further illustrate, the electric spark ablation device 1 also includes an air intake pipeline 15, one end of the air intake pipeline 15 communicates with the gas outlet end of the inert gas source 11, and the other end of the air intake pipeline 15 communicates with the gas outlet of the inert gas source 11. The inlet end of the ablation reaction vessel 12 is connected, and the inlet pipeline 15 is provided with a one-way valve 151 .

By setting the inlet pipeline 15, the ablation reaction vessel 12 communicates with the inert gas source 11 through the inlet pipeline 15, so that the inert gas discharged from the inert gas source 11 can be conducted to the In the ablation reaction vessel 12, in addition, by setting the one-way valve 151 in the inlet pipeline 15, the one-way valve 151 is used to control the flow rate of the inert gas. Specifically, the inert gas is any one of helium, nitrogen and argon, and the inert gas source may be a steel cylinder storing the inert gas.

Preferably, the cross-sectional shape of the screening pipeline 21 is circular, the shape of the through hole of the electrode plate 22 is circular, and the outer wall of the screening pipeline 21 is in contact with the wall of the through hole 221 of the electrode plate 22. fit together.

By setting the cross-sectional shape of the screening duct 21 as a circle, the nano-metal particles can move more smoothly in the screening duct 21 under the action of the air flow of the inert gas, ensuring the accuracy of size screening, and matching the screening duct 21, the shape of the through hole 221 of the electrode plate 22 is circular, so that the installation is convenient, and the outer wall of the screening pipeline 21 fits with the hole wall of the through hole 221 of the electrode plate 22, improving Installation stability.

A nano-metal particle size screening method, using the nano-metal particle size screening device, comprising the following steps:

Use a high-voltage electrostatic generator 13 to apply high-voltage static electricity of the same polarity to the two electrodes 14, and apply a pulse potential difference to the two electrodes 14, so that the two electrodes 14 generate spark discharge, and nano-metal particles are produced in the ablation reaction vessel 12 , the surface of the nano-metal particles has the same charge as the high-voltage electrostatic polarity;

Use the inert gas source 11 to feed the inert gas into the ablation reaction vessel 12, and the prepared nano-metal particles enter the screening pipeline 21 under the airflow of the inert gas, and adjust the voltage of each electrode plate 22 to make the nano-metal particles of different sizes The metal particles are collected at each particle deposition collection platform 23 .

Nano metal particles are prepared by electric spark ablation, the equipment is simple, the raw materials are easy to obtain, the cost is low, and the preparation conditions are easy to control. The size screening of nano metal particles is realized by using multiple electrode plates 22 and screening pipelines 21, and the screening accuracy is high. , high screening efficiency, effectively improving production efficiency and output, especially suitable for industrial fields, and has good industrialization prospects.

To further illustrate, the voltage setting of the electrode plate 22 satisfies the following relational expression:

其中k为比例系数，k＝0.5～2，U₀为两个电极之间的电压，C为电火花烧蚀装置的等效电容，S为两个电极端面的横截面积。Wherein ρ is the density of nano metal particles, V is the flow velocity of the inert gas in the nano metal particle size screening device, R is the nano metal particle size, K is the surface charge density of the charged nano metal particles, and the expression of K is

Where k is the proportionality coefficient, k=0.5~2, U ₀ is the voltage between the two electrodes, C is the equivalent capacitance of the spark ablation device, and S is the cross-sectional area of the end faces of the two electrodes.

Since the nano-metal particles and the electrode plate 22 have the same charge, there is a repulsive force between the nano-metal particles and the electrode plate 22. When the electric potential energy is high, the nano-metal particles can pass through the electrode plate 22, and when the kinetic energy of the nano-metal particles is less than the potential energy between it and the electrode plate 22, the nano-metal particles cannot pass through the electrode plate 22, The deposition is collected on the particle deposition collection platform 23 on the left side of the electrode plate 22, because the kinetic energy of the nano-metal particles is proportional to the cube of the radius of the nano-metal particles, and a plurality of the electrode plates 22 along the nano-metal particles The direction of motion in the screening pipeline 21 is sequentially passed with voltages from small to large, so the nano metal particles with smaller radius will be deposited on the particle deposition collection platform 23 corresponding to the electrode plate 22 on the left, and the larger the radius The nano-metal particles will be deposited on the particle deposition collection platform 23 corresponding to the electrode plate 22 on the right; by setting the voltage of the electrode plate 22 to satisfy this relational expression, the nano-metal particles with a radius smaller than R can be collected by the electrode The particle deposition collection platform 23 on the left side of the plate 22 is collected.

Specifically, the high-voltage static electricity applied to the two electrodes 14 by using the high-voltage static electricity generator 13 is positive or negative.

By using the high-voltage electrostatic generator 13 to apply high-voltage static electricity of the same polarity to the two electrodes 14, the high-voltage static electricity is positive or negative. Charges with the same polarity as the high-voltage static electricity, a plurality of the electrode plates 22 are respectively connected to power supplies of different voltages, and the nano-metal particles and the electrode plates 22 are controlled to have the same charge, so that the nano-metal particles and the electrode plates There is a repulsive force between 22 to complete the size screening of nano metal particles.

In order to facilitate the understanding of the present invention, a more complete description of the present invention follows. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Example 1

A method for screening the size of nano metal particles, comprising the following steps:

Use a high-voltage electrostatic generator 13 to apply positive high-voltage static electricity to the two electrodes 14, and the two electrodes 14 are charged with positive electricity at the same time, and a pulse potential difference is applied to the two electrodes 14, so that the two electrodes 14 generate spark discharge, and the ablation Nano-metal particles are prepared in the reaction vessel 12, and the prepared nano-metal particles are positively charged, and the surface charge density of the charges on the nano-metal particles is K;

的纳米金属颗粒就会沉积在第一个电极板22左方的颗粒沉积收集平台23上，半径为/>

的纳米金属颗粒就会沉积在第二个电极板22左方的颗粒沉积收集平台23，半径为/>

的纳米金属颗粒就会沉积在第三个电极板22左方的颗粒沉积收集平台23，半径为/>

的纳米金属颗粒就会沉积在第四个电极板22左方的颗粒沉积收集平台23，以此类推，半径为/>

的纳米金属颗粒便会收集沉积在收集箱24的颗粒沉积收集平台23上。Use inert gas source 11 to feed inert gas into ablation reaction vessel 12, the flow velocity _V of inert gas is 1m/s, the nanometer metal particle that makes enters in the screening pipeline 21 under the airflow of inert gas, adjusts setting N The voltage value of each electrode plate 22, wherein U ₁ =5V, U ₂ =10V, U ₃ =15V, U ₄ =20V... U _N =X ₁ V, so that the electrode plate array and the nano-metal particles have N potential differences, Therefore the radius is

The nano metal particles will be deposited on the particle deposition collection platform 23 on the left side of the first electrode plate 22, with a radius of

The nano metal particles will be deposited on the particle deposition collection platform 23 on the left side of the second electrode plate 22, with a radius of

The nanometer metal particles will be deposited on the particle deposition collection platform 23 on the left side of the third electrode plate 22, with a radius of

The nano metal particles will be deposited on the particle deposition collection platform 23 on the left side of the fourth electrode plate 22, and so on, the radius is

The nano metal particles will be collected and deposited on the particle deposition collection platform 23 of the collection box 24.

Example 2

A method for screening the size of nano metal particles, comprising the following steps:

Use a high-voltage electrostatic generator 13 to apply positive high-voltage static electricity to the two electrodes 14, and the two electrodes 14 are charged with positive electricity at the same time, and a pulse potential difference is applied to the two electrodes 14, so that the two electrodes 14 generate spark discharge, and the ablation Nano-metal particles are prepared in the reaction vessel 12, and the prepared nano-metal particles are positively charged, and the surface charge density of the charges on the nano-metal particles is K;

的纳米金属颗粒就会沉积在第一个电极板22左方的颗粒沉积收集平台23上，半径为/>

的纳米金属颗粒就会沉积在第二个电极板22左方的颗粒沉积收集平台23，半径为/>

的纳米金属颗粒就会沉积在第三个电极板22左方的颗粒沉积收集平台23，半径为/>

的纳米金属颗粒就会沉积在第四个电极板22左方的颗粒沉积收集平台23，以此类推，半径为/>

的纳米金属颗粒便会收集沉积在收集箱24的颗粒沉积收集平台23上。Use inert gas source 11 to feed inert gas in ablation reaction vessel 12, the flow velocity V of inert gas ₂ is 2m/s, the nanometer metal particle that makes enters in the screening pipeline 21 under the airflow of inert gas, adjusts setting N The voltage value of each electrode plate 22, wherein U ₁ =10V, U ₂ =20V, U ₃ =30V, U ₄ =40V... U _N =X ₂ V, so that the electrode plate array and the nano-metal particles have N potential differences, Therefore the radius is

The nano metal particles will be deposited on the particle deposition collection platform 23 on the left side of the first electrode plate 22, with a radius of

The nanometer metal particles will be deposited on the particle deposition collection platform 23 on the left side of the second electrode plate 22, with a radius of

The nanometer metal particles will be deposited on the particle deposition collection platform 23 on the left side of the third electrode plate 22, with a radius of

The nano metal particles will be deposited on the particle deposition collection platform 23 on the left side of the fourth electrode plate 22, and so on, the radius is

The nano metal particles will be collected and deposited on the particle deposition collection platform 23 of the collection box 24.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (6)

1. A nanometer metal particle size screening device is characterized in that, comprising an electric spark ablation device and a screening device; The electric spark ablation device includes an inert gas source, an ablation reaction vessel, a high-voltage electrostatic generator and two electrodes, the two electrodes are oppositely arranged on the inner wall of the ablation reaction vessel, and the two electrodes are respectively electrically connected to the high-voltage electrostatic generator, and the ablation reaction vessel is connected to the inert gas source; The screening device includes a screening pipeline and a plurality of electrode plates, the electrode plates are provided with through holes, and the screening pipeline passes through the through holes of the plurality of electrode plates in sequence; A plurality of the electrode plates are arranged in the screening pipeline in a straight line from left to right, and the screening pipeline is respectively provided with a particle deposition collection platform on the left side of the plurality of electrode plates; the plurality of electrode plates are respectively Independently connected to power supplies of different voltages, and the voltage increases sequentially from left to right according to the direction of movement of the nano-metal particles, the nano-metal particles and the electrode plate have the same charge; The inert gas source, the ablation reaction vessel and the screening pipeline are connected sequentially from left to right. 2. The nano metal particle size screening device according to claim 1, characterized in that, the screening device also includes a collection box, the collection box communicates with the right end of the screening pipeline, and the collection box is provided with There is a particle deposition collection platform. 3. The nanometer metal particle size screening device according to claim 1, wherein the electric spark ablation device also includes an air inlet pipeline, and one end of the air inlet pipeline communicates with the gas outlet end of the inert gas source , the other end of the air intake pipeline communicates with the air intake end of the ablation reaction vessel, and the air intake pipeline is provided with a one-way valve. 4. The nano metal particle size screening device according to claim 1, wherein the cross-sectional shape of the screening pipeline is circular, the shape of the through hole of the electrode plate is circular, and the shape of the screening pipeline is circular. The outer wall is attached to the hole wall of the through hole of the electrode plate. 5. A nano-metal particle size screening method, characterized in that, adopting the nano-metal particle size screening device as claimed in any one of claims 1 to 4, comprising the following steps: Use a high-voltage electrostatic generator to apply high-voltage static electricity of the same polarity to the two electrodes, and apply a pulse potential difference to the two electrodes, so that the two electrodes generate spark discharge, and the nano-metal particles are produced in the ablation reaction container, and the nano-metal The surface of the particle is charged with the same polarity as the high voltage electrostatic; Use an inert gas source to feed an inert gas into the ablation reaction container, and the prepared nano-metal particles enter the screening pipeline under the airflow of the inert gas, and adjust the voltage of each electrode plate so that the nano-metal particles of different sizes are collected in the Individual particle deposition collection platforms. 6. The nano-metal particle size screening method according to claim 5, characterized in that, the high-voltage static electricity applied to the two electrodes by using the high-voltage static electricity generator is positive or negative.

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