KR20110038430A - Production method of metal nano particles using electron beam and the metal nano particles - Google Patents

Abstract

PURPOSE: A method for manufacturing metal nano-particle using electron beam radiation and the metal nano-particle manufactured thereby are provided to uniform the distribution of particle size and reduce the diameter of a particle by directly radiating electron beam to a solution state sample in order to generate the metal nano-particle. CONSTITUTION: A metal precursor and a polymer compound are added in a solvent and are stirred. A mixture or a complex compound is generated. The mixture or the complex compound is introduced into a container. Electron beam is radiated to the container. The metal is selected from gold(Au), silver(Ag), the iron(Fe), cobalt(Co), nickel(Ni), chrome(Cr), manganese(Mn), barium(Ba), strontium(Sr), titanium(Ti), zirconium(Zr), platinum(Pt), palladium(Pd) and ruthenium(Ru). The polymer compound is natural surfactant. The solvent is one selected from a group including alcohol, glycol-based solvent, water, and the mixture of the same.

Description

TECHNICAL METHOD OF METAL NANO PARTICLES USING ELECTRON BEAM AND THE METAL NANO PARTICLES

The present invention relates to a method for producing metal nanoparticles using electron beam irradiation and to metal nanoparticles prepared by the above method, and more particularly, after the metal precursor and the surfactant are added to a solvent and stirred to form a mixture or a complex compound. The present invention relates to a method for producing metal nanoparticles by directly irradiating an electron beam in a solution state.

Nanoparticles are particles having at least one dimension of 100 nm or less. In other words, it is a particle belonging to the field of nanotechnology that manipulates molecules or atoms to make new materials, structures, machines, mechanisms, devices, and studies the structure. The materials in these states, despite their identical chemical composition, exhibit very different optical and electromagnetic properties from the bulk due to their rapidly increasing specific surface area and quantum mechanical effects.

Among the nanoparticles, especially metal nano powders, the application range is very wide as there are various types. Metal nanopowders are used in a bulk form or applied to the surface until now take up a large number of cases and if the nanocomposite technology is developed, the use of the nano-powder will be expanded to the dispersed form. Because of their unique optical, magnetic, electrical, and chemical properties, bulk metal nanoparticles are used in many industries, including catalysts, sensors, data recording media, abrasives, antimicrobials, photoresists for photographic films, paints, computer monitor coatings, and displays. In this case, particle performance is greatly influenced by particle size and distribution.

Examples of applications using the electrical properties of the metal nanopowder include nanocrystals applied to semiconductors, solar cells, and batteries by electron transport of quantum dots. Application fields using optical properties include light absorbers, optical filters, photocatalysts, ultraviolet sensors, and optical fibers. Applications using magnetic properties include components for switching mode power supplies of recording media and magnetic fluid nanostructured powder magnetic materials in computer communication devices, and applications of organic molecules, polymers, and biological materials can also be expected.

In the case of the metal nanopowder, if the size of the powder is continuously reduced, the powder becomes unstable due to an increase in surface energy due to an increase in specific surface area. Since the degree of activity varies depending on the type of metal, there is a difference in the limit size, but the size of spontaneous ignition is about 1 μm. Even if it is not spontaneously ignited, it is not stable because the surface is oxidized continuously when stored in the air. Therefore, various studies have been made regarding the method for producing metal nanoparticles.

Currently used methods for producing metal nanoparticles can be divided into physical manufacturing methods and chemical synthesis methods. In the case of physical manufacturing, there are gas condensation, which is produced through homogeneous nucleation and condensation in the gas phase, and mechanical grinding, in which the bulk metal is pulverized and nanoscaled. However, especially in the case of the mechanical grinding method, there is a limitation in the size of the particles to be crushed, and the biggest disadvantage is that the particle size distribution and the size of the particles are large. In addition, it requires a lot of energy and equipment cost to crush the particles, but the amount produced is very small.

In the case of chemical synthesis, the most commonly used method can be classified into gas phase reaction, liquid phase reaction, and solid phase reaction according to the reaction region. In the chemical reaction, the energy accompanying the reaction can be utilized, so that the synthesis is possible with a small amount of energy input, and the speed of the synthesis reaction can be controlled quickly and uniformly. However, despite these advantages, there is a problem that it is difficult to remove impurities. The largest impurity can be called a reducing agent. In the process of removing the reducing agent from the reduced nanoparticle solution, the reducing agent is not certainly removed, and the process is very complicated. In addition, it is necessary to disperse the nanoparticles again in the solvent after the removal of impurities, this process is also not complete, may cause precipitation phenomenon.

In order to solve the above problems, a metal nanoparticle manufacturing method using an electron beam has recently been used. In the case of using the electron beam, the electron beam itself may provide the reducing energy, and thus it is not necessary to use a separate reducing agent. Therefore, there is no impurities such as a reducing agent harmful to the human body can be an environmentally friendly manufacturing method.

A method of manufacturing a nanomaterial using an electron beam is disclosed in Korean Patent No. 10-0782133, which is a method of irradiating an electron beam to a sample in a solid state or powder state. However, there was a problem that the yield is small and the size and distribution of the produced particles are uneven. Before irradiating an electron beam, a process of purifying a compound in a solvent is required to make a powder, which makes the process complicated and cannot be easily mass-produced. In addition, in order to commercialize a sample in a solid state it is necessary to disperse in a solvent after the nanoparticles are generated by irradiation with an electron beam, due to technical difficulties there is a problem that the nanoparticles are not uniformly dispersed in the solvent because of the dispersion.

The present invention is to solve this conventional problem, a method for producing metal nanoparticles using electron beam irradiation that can obtain a large amount of metal nanoparticles in a short time by directly irradiating the electron beam in a state in which the powder is dispersed in a solvent and It is to provide a metal nanoparticles prepared by the manufacturing method.

According to an aspect of the present invention for achieving the above object, the step of adding a metal precursor and a polymer compound to the solvent and stirring, injecting the mixture or complex compound produced in the stirring step into the receiving container and receiving in the injection step Irradiating an electron beam to the mixture or complex compound injected into the container.

Preferably the metal precursor is a metal salt or a mixture of two or more metal salts, the metal is gold (Au), silver (Ag), iron (Fe), cobalt (Co), nickel (Ni), chromium (Cr), manganese (Mn), barium (Ba), strontium (Sr), titanium (Ti), zirconium (Zr), platinum (Pt), palladium (Pd), and ruthenium (Ru).

Preferably, the polymer compound may be a natural surfactant.

Preferably, the polymer compound is a hydrocarbon containing at least one functional group, and the hydrocarbon is a C1 to C20 alkane thiol, an alkanethiol derivative, and a di-thiol and tri-thiol compound including a mercapto group (-SH). At least one selected from the group consisting of one or more selected from a hydroxyl group (-OH), a benzyl group (-C6H5), a nitro group (-NO2), a carboxylic acid group (-COOH), and a phosphonic acid group (-H3PO4) It may be one selected from the group consisting of compounds containing an alkyl group of C1 to C20 having a substituent.

Preferably, the functional group is carbonyl group (-CO), ether group (-O-), ester group (-COO), nitro group (-NO ₂ ), amino group (-NH ₄ ), sulfonic acid group (-SO ₃ H) , Mercapto group (-SH), carboxylic acid group (-COOH), phosphonic acid group (-H ₃ PO ₄ ), hydroxy group (-OH), benzyl group (-C ₆ H ₅ ), and aldehyde group (- CHO).

Preferably the intensity of the electron beam is in the range of 0.1 ~ 100 MeV, the irradiation time of the electron beam may be 1 second to 2 hours.

Preferably, the molar ratio of the metal precursor and the polymer compound may range from 1: 0.1 to 1: 100.

Preferably the pH of the mixture or complex may be 3 to 11.

Preferably, the material of the container is plastic, the total thickness when the mixture or complex compound is contained in the container may be 0.1 ~ 40 cm.

Preferably, the solvent may be any one selected from alcohols, glycol solvents, water, and mixtures of two or more thereof.

According to another aspect of the present invention, it includes metal nanoparticles prepared according to the above-described manufacturing method.

Preferably, the metal nanoparticles may be 1 to 100 nm.

According to the present invention, by irradiating an electron beam in a state in which a sample is in a solvent instead of a powder state, the metal nanoparticles can be mass produced very simply and efficiently. In addition, since nanoparticles are produced directly in a solvent state, particles of a smaller size can be obtained as compared to the invention of irradiating an electron beam to a conventional powder state sample, and can be commercialized without a separate dispersion process.

Hereinafter will be described in detail according to a preferred embodiment of the present invention.

The present invention provides a method for producing metal nanoparticles using an electron beam. The manufacturing method consists of the following steps.

Adding a metal precursor and a polymer compound to a solvent and stirring the mixture (step 1);

Injecting the mixture or complex compound produced in the stirring step into a container (step 2); And

Irradiating an electron beam to the mixture or complex compound injected into the container in the injection step (step 3); It consists of A schematic diagram of this is shown in FIG. 1.

In the first step, the metal precursor and the polymer compound are added to the solvent and stirred to ionize the metal precursor in the solvent. As a result, mixtures or complexes are produced. The optimal pH and solvent selection are important here.

It is preferable that the pHs of a mixture and a complex compound are 3-11 normally, and it is more preferable that it is 5-9. This is because the reduction does not occur well when the pH is less than 3, and when the pH is higher than 11, the reduction rate is faster, making it difficult to obtain metal nanoparticles of a desired size.

The solvent is used for the purpose of ionizing the metal salt. As the solvent, at least one selected from alcohols, glycol solvents and water may be used, and two or more of these may be mixed and used. As alcohol in a solvent, methanol, ethanol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, ethylene glycol, etc. are preferable, and ethanol is especially preferable. However, when water is used as a solvent, there is almost no impurity, so the scope of application of the nanoparticles produced is very wide and it is an environmentally friendly solvent, so there is no concern for environmental pollution and it is harmless to the human body.

Surfactants may be used as the polymer compound and include natural surfactants. Preferably, natural surfactants can be used, including lecithin; Saponins extracted from soybean, rice, deodeok, bellflower, etc .; And ginsenosides in ginseng as special saponins; Etc. can be used. In particular, as ginsenosides, ginsenosides extracted from ginseng, red ginseng, or wild ginseng culture root are preferably used, and ginsenosides extracted from wild ginseng culture root are more preferable. The use of such environmentally friendly natural surfactant is more advantageous because it does not generate a harmful substance to the human body.

In addition, the polymer compound is a hydrocarbon containing at least one functional group, and the hydrocarbon is selected from the group consisting of C1 to C20 alkanethiol, alkanethiol derivatives, and di-thiol and tri-thiol compounds including a mercapto group (-SH). 1 or a substituent selected from hydroxy group (-OH), benzyl group (-C6H5), nitro group (-NO2), carboxylic acid group (-COOH), and phosphonic acid group (-H3PO4) It may be one selected from the group consisting of compounds containing an alkyl group of C1 to C20.

The functional group is carbonyl group (-CO), ether group (-O-), ester group (-COO), nitro group (-NO ₂ ), amino group (-NH ₄ ), sulfonic acid group (-SO ₃ H), mercap Earthenware (-SH), carboxylic acid group (-COOH), phosphonic acid group (-H ₃ PO ₄ ), hydroxy group (-OH), benzyl group (-C ₆ H ₅ ), and aldehyde group (-CHO), Can be selected from.

The polymer compound containing the functional group is surrounded by the nanomaterials generated by the electron beam irradiation to prevent the non-uniform agglomeration of nanoparticles by binding to each other between the nanoparticles.

The metal precursor is a metal salt or a mixture of two or more metal salts, wherein the metal is gold (Au), silver (Ag), iron (Fe), cobalt (Co), nickel (Ni), chromium (Cr), manganese (Mn), It is preferable to select from barium (Ba), strontium (Sr), titanium (Ti), zirconium (Zr), platinum (Pt), palladium (Pd), and ruthenium (Ru).

In one embodiment of the present invention, the metal is exemplified, but is not limited to the metal, of course, and includes metals that can be reduced to an electron beam to be generated as nanoparticles.

The molar ratio of the metal precursor and the polymer compound is preferably in the range of 1: 0.1 to 1: 100.

Step 2 is a step of injecting the mixture or complex compound obtained in step 1 into the receiving container. The container may be a bag made of a plastic material such as polypropylene (PE), polyethylene (PP). However, a container that can hold liquid is not limited to plastic and other materials such as aluminum may be used. The thickness of the container is preferably from 0.1 to 40 cm based on the total thickness when the mixture or complex compound is contained. More preferably, it may be 1-4 cm. This is because the depth at which the electron beam penetrates the liquid is limited.

If the solution stirred in step 1 is packed in 1kg or 2kg in the container through the step 2, only the step of irradiating the electron beam to the solution in the unit packaging from the subsequent step including the step 3 will be described later. Nanoparticles can be easily obtained.

Step 3 is a step of reducing the mixture or complex by irradiating an electron beam to the mixture or complex injected into the container. This may produce metal nanoparticles.

The energy intensity of the electron beam is mainly adjusted to 0.1 to 100 MeV, preferably 1 to 10 MeV. In addition, the irradiation time of the electron beam may be 1 second to 2 hours. As a result, the electron beam provides reducing energy, and thus, a separate reducing agent is not required, and nanoparticles can be obtained simply by irradiating the electron beam directly on a mixture or a complex compound in a solvent.

In order to achieve another object of the present invention looks at the metal nanoparticles prepared by the method for producing metal nanoparticles using the electron beam irradiation.

Metal nanoparticles obtained using the electron beam irradiation have an even particle size distribution and high electromagnetic characteristics because the particle size and distribution are uniform. In addition, since the particle size is about 1 to 2 nm, it is possible to obtain a much finer particle than the present invention (see FIG. 2 and FIG. 3 in which nanoparticles are manufactured using platinum). Because of this wider effect, the same effect can be achieved with a smaller amount, resulting in cost savings and faster reaction speed.

If the particle size distribution is even, metal nanoparticles can be used as electromagnetic, optical and medical functional elements. For example, in flat CRTs in the field of displays, electromagnetic shielding materials for transparent conductive films, electrical devices such as multilayer ceramic capacitors, single-electron transistors using metal nanoparticles of uniform size, or memory devices and resonance tunneling phenomena using the same It can be used in the transistor used, it can be used as a nonlinear optical material or an optical filter using an optical phenomenon of the metal nanoparticles, an indicator such as a fluorescent indicator reagent, electron microscope.

Example 1

1 L of water was used as a solvent and 1 g of platinum chloride was added for ionization. 1 g of ginsenoside, which is a wild ginseng cultured root extract, was added thereto, followed by sufficiently stirring the pH to 7 using NaOH. At this time, the minimum mass ratio of platinum chloride and ginsenoside is 1: 1, and depending on the situation, the mass of ginsenoside may be 2 g or more.

After completion of stirring, the resulting mixture or complex was packaged by pouring it into a polypropylene (PE) or polyethylene (PP) bag, which is a kind of plastic. The completed bag was irradiated with an electron beam. The energy intensity was 10 MeV and the irradiation time was 30 minutes. Since platinum nanoparticles are produced, black nanoparticles were produced in the case of platinum. In this case, the platinum nanoparticles produced are much more reactive than conventional methods because the particle size is only 1 to 2 nm as can be seen in the transmission electron microscope (TEM) images of FIGS. 2 and 3. This large particle generation was possible.

Example 2

1 g of water was used as a solvent, and 1 g of gold chloride was added thereto for ionization. 1 g of ginsenoside, which is a wild ginseng cultured root extract, was added thereto, followed by sufficiently stirring the pH to 7 using NaOH. At this time, the minimum mass ratio of gold chloride and ginsenoside is 1: 1, and depending on the situation, the mass of ginsenoside may be 2 g or more.

After completion of stirring, the resulting mixture or complex was packaged by pouring it into a polypropylene (PE) or polyethylene (PP) bag, which is a kind of plastic. The completed bag was irradiated with an electron beam. The energy intensity was 10 MeV and the irradiation time was 30 minutes. Afterwards, gold nanoparticles are produced, and in the case of gold, purple nanoparticles were produced with the naked eye. In the case of the gold nanoparticles produced at this time, since the particle size is only 1 to 2 nm, it was possible to generate particles that are much more reactive than the conventional manufacturing method.

As described above, according to the method for preparing metal nanoparticles using the electron beam irradiation, the manufacturing process is much simpler because the electron beam is irradiated when the sample is in a solution state instead of a powder state. In other words, when the nanoparticles are produced in a powder state, a process of dispersing them in a solvent is required. However, the present invention can be commercialized directly without dispersing because the nanoparticles are produced directly in a solution state.

As mentioned above, the metal nanoparticle using the electron beam irradiation which concerns on this invention, and its manufacturing method were demonstrated with reference to the preferable Example of this invention. However, the present invention is not limited to the embodiments and drawings described above, and various modifications and changes may be made by those skilled in the art within the scope of the claims.

1 is a schematic diagram showing a method of manufacturing metal nanoparticles according to the present invention.

2 is a transmission electron microscope (TEM) photograph of platinum nanoparticles synthesized according to an embodiment of the present invention.

3 is a partially enlarged view of FIG. 2.

Claims (12)

Adding a metal precursor and a polymer compound to the solvent to stir; Injecting the mixture or complex compound produced in the stirring step into a container; And Irradiating an electron beam on the mixture or complex compound injected into the container in the injection step; Metal nanoparticles manufacturing method comprising a. The method according to claim 1, The metal precursor is a metal salt or a mixture of two or more metal salts, wherein the metal is gold (Au), silver (Ag), iron (Fe), cobalt (Co), nickel (Ni), chromium (Cr), and manganese (Mn). , Barium (Ba), strontium (Sr), titanium (Ti), zirconium (Zr), platinum (Pt), palladium (Pd), and ruthenium (Ru) method for producing metal nanoparticles. The method according to claim 1, The polymer compound is a method for producing metal nanoparticles, characterized in that the natural surfactant. The method according to claim 1, The polymer compound is a hydrocarbon containing at least one functional group, and the hydrocarbon is a group consisting of C1 to C20 alkanethiol, alkanethiol derivatives, and di-thiol and tri-thiol compounds including a mercapto group (-SH). 1 or a substituent selected from hydroxy group (-OH), benzyl group (-C6H5), nitro group (-NO2), carboxylic acid group (-COOH), and phosphonic acid group (-H3PO4) Method for producing metal nanoparticles, characterized in that one selected from the group consisting of compounds containing C1 to C20 alkyl group. The method according to claim 4, The functional group is carbonyl group (-CO), ether group (-O-), ester group (-COO), nitro group (-NO ₂ ), amino group (-NH ₄ ), sulfonic acid group (-SO ₃ H), mercap Earthenware (-SH), carboxylic acid group (-COOH), phosphonic acid group (-H ₃ PO ₄ ), hydroxy group (-OH), benzyl group (-C ₆ H ₅ ), and aldehyde group (-CHO), Metal nanoparticles manufacturing method characterized in that selected from. The method according to claim 1, The intensity of the electron beam is in the range of 0.1 ~ 100 MeV, the irradiation time of the electron beam is a method of producing metal nanoparticles, characterized in that 1 second to 2 hours. The method according to claim 1, The molar ratio of the metal precursor and the polymer compound is a method of producing a metal nanoparticles, characterized in that the range of 1: 0.1 to 1: 100. The method according to claim 1, PH of the mixture or complex is a metal nanoparticle manufacturing method, characterized in that 3 to 11. The method according to claim 1, The material of the container is plastic, the total thickness when the mixture or the complex compound is contained in the container is characterized in that the metal nanoparticles manufacturing method characterized in that the 0.1 ~ 40 cm. The method according to claim 1, Wherein the solvent is any one selected from alcohol, glycol-based solvent, water, and a mixture of two or more thereof. Metal nanoparticles prepared by the method for producing metal nanoparticles according to any one of claims 1 to 10. The metal nanoparticle of claim 11, wherein the particle has a size of about 1 nm to about 100 nm.

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