KR101890348B1 - Manufacturing method of metal-nano complex powder using spray dryer - Google Patents

Abstract

Disclosed is a method for manufacturing metal-nano composite powder using spray-drying, obtaining metal-nano composite powder in a completely dried state in quantity in a short period of time by using pray-drying in which a metal mixture solution is dried by spraying a fine aerosol to the same and heating the same. According to the present invention, the method comprises the following steps of: (a) forming a metal mixture solution by mixing a solvent with a capping agent and a metal precursor; and (b) obtaining metal-nano composite powder by spray-drying the metal mixture solution.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a metal nanocomposite powder by a spray drying method,

More particularly, the present invention relates to a method for producing a metal nanocomposite powder, and more particularly, to a method for producing a metal nanocomposite powder by a spray drying method in which a metal mixed solution is sprayed with a very fine aerosol, The present invention relates to a method for producing a metal nanocomposite powder using a spray drying method capable of obtaining a powder.

In recent years, as the development of industrial technology has progressed, nanotechnology has also developed, making it easier to manufacture a large number of nanoparticles of inorganic or metallic particles. Nanoparticles of inorganic or metallic nanoparticles have been reported to exhibit properties that are different from those of the bulk phase as well as being able to realize better physical and chemical properties due to the maximized surface area and quantum effect, .

As such, nanoparticles exhibit nearly equal or even better effects than bulk materials, even when used in very small quantities. In addition, since nanoparticles are used only in very small amounts, they show little toxicity to humans and the environment. Therefore, they are regarded as being environmentally friendly and beneficial to human and natural environment, and nanoparticles are attracting attention as new materials, .

Among these nanoparticles, silver has been known as a metal having excellent conductivity following gold and has a complex performance such as antibacterial, sterilizing, antifungal, deodorizing, far infrared ray emission, and antistatic.

Such silver is cheaper than other noble metals but is still a precious noble metal with respect to other materials. Therefore, in order to economically utilize silver's conductivity, antibacterial property, deodorization property, or the like, Supported, or coated or plated.

Nano-sized microparticles of silver nanoparticles are expected to exhibit more superior properties than silver in bulk, and there have been numerous studies on nanotechnology to produce silver nanoparticles in powder or solution form.

However, such silver nanoparticles are not only difficult to produce with a uniform particle size, but are also chemically and physically unstable, making long-term storage difficult.

A related prior art is Korean Patent Laid-Open Publication No. 10-2004-0023039 (published on Mar. 18, 2004), which discloses ceramic powder slurry for spray-drying and a method for producing the same.

An object of the present invention is to provide a metal nano composite powder which is capable of obtaining powdery metal nano composite powders that are completely dried in a short time in a short time by using a spray drying method in which heat is applied and dried while spraying a metal mixed solution with a very fine aerosol, And a method for producing the composite powder.

According to an aspect of the present invention, there is provided a method for preparing a metal nanocomposite powder using a spray drying method, comprising the steps of: (a) forming a metal mixed solution by mixing a reducing agent, a capping agent, ; And (b) spray drying the metal mixed solution to obtain a metal nanocomposite powder.

The step (a) may further include the steps of adding a reducing agent and a capping agent to the solvent and stirring the mixture at a rate of 200 to 1,000 rpm for 10 to 60 minutes, and adding a reducing agent and a surface- adding a metal precursor to a mixed solution of a capping agent and secondary stirring at a speed of 500 to 3,000 rpm.

The reducing agent may include at least one selected from the group consisting of polyvinylpyrrolidone (PVP), trisodium citrate, sodium borohydride, and ascorbic acid, May include at least one selected from polyvinylpyrrolidone (PVP), trisodium citrate, cetyl trimethylammonium bromide (CTAB), and polysorbate, and the metal precursor may be at least one selected from the group consisting of acetate, Nitrates, chlorides, hydroxides, carbonates, and oxides of at least one selected from the group consisting of nitrates, nitrates, carbonates, and oxides.

Here, the metal precursor preferably has a concentration of 0.7 to 1.75M. Particularly, it is preferable that the reducing agent and the capping agent are polyvinylpyrrolidone (PVP) capable of simultaneously performing two functions, and the metal precursor is silver nitrate (AgNO ₃ ).

Also, in the step (b), the metal nanocomposite powder is obtained at a rate of 8.0 to 25.0 g / hour.

The step (b) may further include the steps of: (b-1) injecting the metal mixed solution into the heat treatment chamber and performing heat treatment; and (b-2) (B-3) spraying and drying the metal mixed solution in an aerosol state in a drying chamber, and then collecting the metal mixed powder in a collection chamber connected to the drying chamber; and (b-4) And filtering the metal mixed powder in an external filter connected to the collecting chamber to obtain a metal nanocomposite powder.

In the step (b-1), the heat treatment is preferably performed at 100 to 400 ° C., and in the step (b-2), the metal mixed solution is sprayed at a rate of 1.0 to 5.0 mL / min .

The step (b) may further include: (b-5) discharging the drying gas to the outside through a discharge pipe communicating with the transfer pipe connecting the drying chamber, the collecting chamber and the external filter have.

Here, the metal nanocomposite powder has an average particle diameter of 200 nm or less and has a monodisperse shape.

In addition, the metal nanocomposite powder can be reversibly dissolved in a solvent.

The method for preparing metal nanocomposite powder using the spray drying method according to the present invention is characterized in that the metal nanocomposite powder is produced at a very high speed of 8.0 to 25.0 g / hour by using a spray drying method in which heat is applied and dried while spraying the metal mixed solution with very fine aerosol It may be possible to mass-produce the powder.

As a result, it is possible to obtain a metal nanocomposite powder having an average particle size of 200 nm or less and having a monodisperse shape by the spray drying method according to the present invention.

In addition, since the method for preparing a metal nanocomposite powder using the spray drying method according to the present invention can obtain a powder of a metal nanocomposite having a completely dried powder form, it has excellent long-term storage property and, at the same time, It is easy to add application because of its excellent acidity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process flow diagram illustrating a method of preparing a metal nanocomposite powder using a spray drying method according to an embodiment of the present invention; FIG.
FIG. 2 is a schematic view illustrating a process for producing a metal nanocomposite powder using the spray drying method according to an embodiment of the present invention. FIG.
FIG. 3 is a graph showing the results of measurement of the Ag-PVP composite powder prepared according to Example 2 with a zetaizer. FIG.
4 is a photograph showing the state of the Ag-PVP composite powder prepared according to Example 3 and the Ag-PVP composite powder dissolved in water.
FIG. 5 is a graph showing the results of measurement of a composite powder in which Ag-PVP composite powder prepared in Example 3 is dissolved in water, by ultraviolet-visible light spectroscopy.
6 is a graph showing the XRD measurement results of the Ag-PVP composite powder produced according to Example 3. Fig.
7 is a SEM photograph of the Ag-PVP composite powder prepared according to Example 3. Fig.
8 is a graph showing XRD measurement results according to the concentration of AgNO ₃ .
9 is a graph showing the results of XRD measurement according to PVP concentration.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a method of manufacturing a metal nanocomposite powder using the spray drying method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a process flow diagram illustrating a method for manufacturing a metal nanocomposite powder using the spray drying method according to an embodiment of the present invention. FIG. 2 is a view for explaining a method for manufacturing a metal nanocomposite powder using the spray drying method according to an embodiment of the present invention. Fig.

Referring to FIGS. 1 and 2, the method for preparing a metal nanocomposite powder using the spray drying method according to an embodiment of the present invention includes a mixing step (S110) and a spray drying step (S120).

mix

In the mixing step (S110), a reducing agent, a surface protecting agent, and a metal precursor are mixed with the solvent to form a metal mixed solution.

The solvent may be any solvent that can be used in the spray drying process. For example, as the solvent, at least one selected from pure water, distilled water, alcohol and the like may be used, and pure water is preferably used among them.

The reducing agent and the capping agent may be a material capable of protecting the surface of the metal precursor and the chemical reducing power.

The reducing agent may include at least one selected from the group consisting of polyvinylpyrrolidone (PVP), trisodium citrate, sodium borohydride, and ascorbic acid, and a capping agent And may include at least one selected from polyvinylpyrrolidone (PVP), trisodium citrate, cetyl trimethylammonium bromide (CTAB), and polysorbate.

Particularly, it is more preferable to use at least one selected from polyvinylpyrrolidone (PVP) and trisodium citrate which can simultaneously act as a reducing agent and a capping agent.

The metal precursor may include at least one selected from the group consisting of acetate, nitrate, chloride, hydroxide, carbonate, and oxide containing a metal. At least one selected from Ag, Sn, Ti, Fe, Co, Li, Ni, Mn, W, Zn, Cu, Cr, Zr, Al, Ce, Y, Pd, Among them, Au, Ag and Pt are more preferably used.

It is preferable to use such a metal precursor having a concentration of 0.7 to 1.75M, more preferably a concentration of 0.75 to 1.70M. If the concentration of the metal precursor is less than 0.7 M, the efficiency of obtaining metal particles may be lowered due to an excessively low concentration. On the other hand, if the concentration of the metal precursor is more than 1.75M, the surface of the metal particles may not be sufficiently protected by the surface protective agent, resulting in increase of the particle size and the uniformity of the particles may be lowered.

Here, it is most preferable to use PVP (polyvinylpyrrolidone) as the reducing agent and capping agent, and silver nitrate (AgNO ₃ ) as the metal precursor. When polyvinylpyrrolidone (PVP) is used as the reducing agent and the surface protective agent, it is preferable to use a polyvinylpyrrolidone (PVP) having a concentration of 0.02 to 0.05 g / mL.

It is more preferable that the mixing step (S110) is subdivided into a first mixing step and a second mixing step.

In the first mixing step, a reducing agent and a capping agent are added to the solvent and stirred at a rate of 200 to 1,000 rpm for 10 to 60 minutes to sufficiently dissolve the reagent. At this time, if stirring is not sufficient, uniform mixing between the reducing agent and the capping agent may not be performed.

In the second mixing process, the metal precursor is added to the mixed solvent of the reducing agent and the capping agent, and the mixture is stirred at a rate of 500 to 3,000 rpm for the second time. At this time, if the secondary agitation is not sufficiently performed, uniform particles may not be generated.

Spray drying

In the spray drying step (S120), the metal mixed solution is spray-dried to obtain a metal nanocomposite powder.

This spray drying is the basic principle that the metal mixed solution is sprayed in a very fine aerosol state and dried by heat. The general spray drying method does not involve chemical changes, but spray drying in the present invention involves chemical changes, which maximizes the local concentration of the reducing agent and the metal precursor by drying the solvent, As a result of maximization of the reduction power by

For this, the spray drying step (S120) can be subdivided into a heat treatment process, an injection process, a collection process, and a filtering process. In addition, the spray drying step (S120) may further include a drying gas discharging step.

In the heat treatment process, the metal mixed solution is injected into the heat treatment chamber 120 and heat-treated. Here, the metal mixed solution is introduced into the heat treatment chamber 120 through the material inlet 110.

At this time, the heat treatment is preferably performed at 100 to 400 ° C. If the heat treatment temperature is less than 100 ° C, the metal precursor in the metal mixed solution may not be sufficiently decomposed. On the other hand, if the heat treatment temperature exceeds 400 ° C, it can be a factor that raises the manufacturing cost without further increase in the effect, which is not economical.

In the spraying process, the heat-treated metal mixed solution is sprayed in an aerosol state using the spray nozzle 130.

Here, the metal mixed solution is preferably sprayed at a rate of 1.0 to 5.0 mL / min. If the injection speed is less than 1.0 mL / min, the injection nozzle 130 may be clogged. On the contrary, when the injection speed exceeds 5.0 mL / min, it may be difficult to obtain monodispersed nanocomposite particles.

In the collecting process, the metal mixed solution in an aerosol state is spray dried in the drying chamber 140, and then the metal mixed powder is collected in the collecting chamber 150 connected to the drying chamber 140.

As described above, the metal precursor sprayed in an aerosol state during spray drying in the drying chamber 140 forms a local concentration instantaneously, thereby enabling the metal precursor to be sufficiently reduced to metal particles As a result, it is possible to collect a large amount of the metal mixed powder.

In the filtering process, the metal mixed powder is filtered in an external filter 160 connected to the collecting chamber 150 to obtain a metal nanocomposite powder. As a result, the metal nanocomposite powder produced by the method according to the embodiment of the present invention can be mass-produced at a considerably high speed of 8.0 to 25 g / hour by using the powder drying method.

The drying gas is discharged to the outside through the discharge pipe 180 which communicates with the transfer pipe 170 connecting the drying chamber 140, the collecting chamber 150 and the external filter 160.

The metal nanocomposite powder prepared by the method for preparing a metal nanocomposite powder by the spray drying method according to the embodiment of the present invention has an average particle diameter of 200 nm or less and has a monodisperse shape.

As a result, the metal nanocomposite powder produced by the method according to the present invention can be sprayed with a very fine aerosol while spraying the metal mixed solution with heat to dry it, whereby a very high speed of 8.0 to 25.0 g / hour It is possible to mass-produce them.

In addition, since the metal nanocomposite powder produced by the method according to the embodiment of the present invention has a completely dried powder form, it has excellent long-term storage property and is excellent in dispersibility when reversibly dissolved in a solvent, .

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

One. Ag - PVP  Composite Powder Production

Example  One

15 g of PVP (polyvinylpyrrolidone), which is simultaneously used as a reducing agent and a capping agent, was added to 300 g of DI water, stirred at 500 rpm for 30 minutes, and then 50 g of 0.7 M silver nitrate (AgNO ₃ ) was added The mixture was stirred at a speed of 700 rpm for 5 minutes to prepare a metal mixed solution.

Next, the metal mixed solution was injected into the heat treatment chamber and heat-treated at 200 ° C., and the heat-treated metal mixed solution was sprayed at 3.37 mL / min in an aerosol state using an injection nozzle.

Next, a metal mixed solution in an aerosol state was spray-dried in a drying chamber, and then the metal mixed powder was collected in a collecting chamber connected to the drying chamber.

Next, the metal mixed powder was filtered in an external filter connected to the collection chamber to obtain an Ag-PVP composite powder.

Example  2

The Ag-PVP composite powder was obtained in the same manner as in Example 1, except that the heat-treated metal mixed solution was sprayed at 3.95 mL / min in an aerosol state using an injection nozzle.

Example  3

The Ag-PVP composite powder was obtained in the same manner as in Example 1, except that the heat-treated metal mixed solution was sprayed at a rate of 4.51 mL / min in an aerosol state using an injection nozzle.

2. Property evaluation

Table 1 shows the average particle sizes of the Ag-PVP composite powders prepared according to Examples 1 to 3, and FIG. 3 shows the results of measurement of the Ag-PVP composite powders prepared according to Example 2 with zeta sis Fig.

[Table 1]

As shown in Table 1, it was confirmed that the Ag-PVP composite powders prepared according to Examples 1 to 3 had a monodispersed form and all the average particle diameters were 200 nm or less.

Also, as shown in FIG. 3, the Ag-PVP composite powder prepared according to Example 2 was observed to have monodispersed particles when measured using a Zatasizer.

FIG. 4 is a photograph showing a state where the Ag-PVP composite powder prepared according to Example 3 and the Ag-PVP composite powder are dissolved in water, FIG. 5 is a photograph showing the state where the Ag- Of the composite powder in a state of being dissolved in an ultraviolet-visible light spectrophotometer.

As shown in FIG. 4, in the case of silver nano-particles in solution, the contents were often denatured during long-term storage, but it was confirmed that the Ag-PVP composite powder prepared according to Example 3 had a completely dried powder form . Thus, the Ag-PVP composite powder prepared according to Example 3 is a completely dried powder, which is easy to store for a long period of time.

As a result, it can be confirmed that the Ag-PVP composite powder prepared according to Example 3 can be reversibly dissolved in water. As described above, the Ag-PVP composite powder is easily dispersed in the solvent during the additional operation, and thus is easy to apply.

On the other hand, as shown in FIG. 5, the result of UV-vis spectrum measurement shows that the Ag-PVP composite powder prepared according to Example 3 exhibits a strong peak in the region of 410 nm. In this case, in the case of Example 3, it is judged that the peak is due to silver nanoparticle, considering that the input raw material is only PVP and silver nitrate (AgNO ₃ ).

FIG. 6 is a graph showing the XRD measurement results of the Ag-PVP composite powder prepared according to Example 3. FIG. 7 is a SEM image of the Ag-PVP composite powder prepared according to Example 3. FIG.

As shown in FIGS. 6 and 7, in the case of the Ag-PVP composite powder prepared according to Example 3, AgNP peaks were detected and it was confirmed that the AgNP peaks were uniformly dispersed in a monodispersed form.

8 is a graph showing XRD measurement results according to the concentration of AgNO ₃ , and FIG. 9 is a graph showing XRD measurement results according to PVP concentration.

As shown in FIG. 8, when the reference concentration (Ag 1X) of AgNO ₃ was increased to 1.75 M (Ag 2.5X) which is 2.5 times as much as 0.7 M, residual AgNO ₃ was present after the powder drying reaction.

On the other hand, as shown in FIG. 9, when the concentration of PVP is reduced to 0.01 g / mL (PVP 0.2X) or less, which is 0.2 times the existing concentration of 0.05 g / mL, residual AgNO ₃ Respectively.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

S110: mixing step
S120: spray drying step

Claims (14)

(a) mixing a solvent with a reducing agent, a surface protecting agent, and a metal precursor to form a metal mixed solution; And
(b) spray-drying the metal mixed solution to obtain a metal nanocomposite powder,
The metal precursor has a concentration of 0.7 to 1.75 M,
The step (b) includes the steps of: (b-1) injecting the metal mixed solution into the heat treatment chamber and performing heat treatment; and (b-2) spraying the heat-treated metal mixed solution into an aerosol state (B-3) spraying and drying the metal mixed solution in an aerosol state in a drying chamber, and collecting the metal mixed powder in a collection chamber connected to the drying chamber; and (b-4) And filtering the mixed powder in an external filter connected to the collection chamber to obtain a metal nanocomposite powder,
In the step (b-2), the metal mixed solution is sprayed at a rate of 1.0 to 5.0 mL / min,
Wherein the metal nanocomposite powder has an average particle diameter of 200 nm or less and is obtained at a rate of 8.0 to 25.0 g / hour in the step (b).
The method according to claim 1,
The step (a)
Adding a reducing agent and a capping agent to the solvent and stirring the mixture at a speed of 200 to 1,000 rpm for 10 to 60 minutes,
A metal precursor is added to a solution containing a reducing agent and a capping agent, and the solution is stirred at a speed of 500 to 3,000 rpm for a second time to prepare a metal nanocomposite powder.
The method according to claim 1,
The reducing agent includes at least one selected from the group consisting of polyvinylpyrrolidone (PVP), trisodium citrate, sodium borohydride, and ascorbic acid,
Wherein the capping agent comprises at least one selected from the group consisting of PVP (polyvinylpyrrolidone), trisodium citrate, CTAB (cetyl trimethylammonium bromide) and polysorbate. (Method for producing metal nanocomposite powder).
The method according to claim 1,
The metal precursor
A method of producing a metal-containing metal by a spray drying method, which comprises at least one selected from the group consisting of acetate, nitrate, chloride, hydroxide, carbonate and oxide containing a metal. (Method for producing nanocomposite powder).
delete The method according to claim 1,
Each of the reducing agent and the capping agent is PVP (polyvinylpyrrolidone)
Wherein the metal precursor is silver nitrate (AgNO ₃ ).
delete delete The method according to claim 1,
In the step (b-1)
The heat treatment
100 to 400 < 0 > C.
delete delete delete The method according to claim 1,
The metal nanocomposite powder
Wherein the metal nanocomposite powder is monodispersed.
The method according to claim 1,
The metal nanocomposite powder
Wherein the metal nanocomposite powder is reversibly dissolved in a solvent.

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