KR20110107034A - Al-peg composite nanopowders and method for manufacturing thereof - Google Patents

Abstract

Aluminum-polyethylene glycol (PEG) composite nano powder according to the present invention for achieving the above object is composed of an aluminum nano powder, and oxidation-resistant polyethylene glycol (PEG) coated on the outside of the aluminum nano powder. In addition, according to the present invention, a method for preparing an aluminum-polyethylene glycol (PEG) composite nanopowder includes a material preparation step of preparing AlCl ₃ as an aluminum precursor, LiAlH ₄ and an ethylene glycol solvent, and AlCl ₃ and LiAlH ₄ as ethylene glycol A material input step of dissolving by adding to a solvent, a composite powder manufacturing step of preparing a composite nano-powder coated with polyethylene glycol on the outer surface of aluminum nanopowder by heating and stirring the ethylene glycol solvent, and by-products formed in the composite powder manufacturing step Characterized in that the washing step to remove the phosphorus LiCl. There is an advantage that the production of composite nano powder having oxidation resistance by a simple process.

Description

Al-PEG composite nanopowders and method for manufacturing thereof

The present invention relates to an aluminum-polyethylene glycol (PEG) composite nano powder and a method for manufacturing the same that can be used as a solid material without carbon generation and electrode material, which is a key component of environmentally friendly products such as solar cells and OLEDs. Aluminum precursors AlCl ₃ and Lithium Aluminum Hydroxide (LAH: LiAlH ₄ ) were reacted in an ethylene glycol solvent to prepare aluminum nanopowders, and the heat of reaction produced induced ethylene glycol polymerization to produce polyethylene glycol (PEG) on the surface of aluminum nanopowders. The present invention relates to an aluminum-PEG composite nanopowder and a method of manufacturing the same.

Recently, due to the increasing interest in eco-friendly products, the spread of high-tech green industry products such as solar cells and OLEDs is rapidly spreading. Accordingly, research on the development of products with high productivity while improving the efficiency of such products is being conducted. There is a lot going on.

In addition, global efforts to reduce carbon generation have been conducted in a variety of ways, and metal solid fuels that control metal powder to nanometer size have little carbon generation, and research is being actively conducted.

Among them, aluminum is very low in price and has good electrical characteristics, so it is very useful as an electrode material for green energy products such as solar cells and OLEDs. In particular, due to its low work function, it is used as a Cathode material for OLEDs and organic solar cells.

In addition, aluminum has a very high oxidation characteristics, it can be said that the material has the advantage that can effectively utilize the heat energy generated during the oxidative exothermic reaction.

However, while aluminum has such an advantage, it is very easily oxidized, and an oxide film having a thickness of several tens of nm is always formed on the surface of the aluminum powder, and thus has a problem in that electrical properties are poor when used as an electrode material.

In addition, when an oxide film having a thickness of about 4 nm is formed on the surface of an aluminum powder having a size of about 50-100 nm, the mass of the oxide film is 30-40% of the total weight of the aluminum powder. Thermal energy loss occurs.

Therefore, in order to solve this problem, it can be said that a technique for effectively controlling the oxide film formed on the aluminum surface is necessary.

In order to solve the above problems, various technologies have been developed worldwide.

Powder Technology 164 (2006) 111-115

“Aluminum nanopowders produced by electrical explosion of wires and passivated by non-innert coatings: characterization and reactivity with air and water” discloses the formation of Oleic acid and Steric acid films on aluminum nanopowders by electroexplosion.

However, this technique has a disadvantage in that oxygen in the air easily penetrates the surface organic film, resulting in poor long-term oxidation stability.

Chemistry of materials 17 (11) (2005) 2987-2996

"Surface passivation of Bare Aluminum Nanoparticles using perfluoroalkyl carboxylic acids" discloses a technique for forming a perfluoroalkyl carboxylic acid film on the surface of an aluminum nanopowder prepared by a chemical wet process.

However, this technique has the advantage of high oxidation stability, but there is a disadvantage that the process for forming the organic material film is relatively complicated.

An object of the present invention is to solve the problems of the prior art as described above and to produce an aluminum nanopowder surrounded by an organic material excellent in oxidation resistance by a simple method, having a reducing power in a chemical wet process for the synthesis of aluminum nanopowder glycol (Ehtylene glycol) for use as a solvent to facilitate the aluminum precursor of AlCl ₃ is the reduction of the Al ^{3 +} ions be present dissolved in the solvent and thereby easily in a very short time only so that the aluminum nanopowder synthesis done Rather, the present invention provides an aluminum-PEG composite nanopowder and a method for preparing the same, which can be manufactured in a simple process by applying polyethylene glycol to the aluminum nanopowder outer surface by utilizing the heat of reaction generated during the synthesis of the powder in a polymerization reaction.

Aluminum-polyethylene glycol (PEG) composite nano powder according to the present invention for achieving the above object, characterized in that comprises an aluminum nano-powder, and oxidation-resistant polyethylene glycol (PEG) coated on the outside of the aluminum nano-powder. It is done.

The polyethylene glycol is characterized in that the ethylene glycol used as a solvent is formed by a polymerization reaction by the reaction heat generated when the aluminum nanoparticles are formed.

In the method for preparing an aluminum-polyethylene glycol (PEG) composite nanopowder according to the present invention, a material preparation step of preparing AlCl ₃ as an aluminum precursor, LiAlH ₄ and an ethylene glycol solvent, and the AlCl ₃ and LiAlH ₄ in an ethylene glycol solvent Injecting and dissolving the material, the composite powder manufacturing step of producing a composite nano-powder coated with polyethylene glycol on the outer surface of the aluminum nanopowder by heating and stirring the ethylene glycol solvent, LiCl which is a by-product formed in the composite powder manufacturing step Characterized in that the washing step to remove the.

In the material input step, the AlCl ₃ and LiAlH ₄ is characterized in that it is added to ethylene glycol in a molar ratio of 1: 3.

The composite powder production step, the reduction process of Al ^{3 +} ions dissolved in ethylene glycol during the material injection step, the nano-powder formation process of forming aluminum nano-powder by the polyol process, and the polymerization reaction of the ethylene glycol It characterized by consisting of a composite powder forming process of forming polyethylene glycol on the outer surface of the aluminum nanopowder.

In the composite powder preparation step, the ethylene glycol solvent in which AlCl ₃ and LiAlH ₄ is dissolved is heated to 120 to 140 ℃.

It is characterized in that the process of selectively removing LiCl using water or alcohol.

The washing step is characterized in that the process of separating the aluminum-polyethylene glycol (PEG) composite nano powder and LiCl using a centrifugal force.

The washing step is characterized in that the process of separating by rotating at a speed of 12000 to 20000 RPM.

As described above, in the present invention, the solvent necessary for synthesizing the aluminum nanopowder was used to induce the aluminum nanopowder synthesis reaction in a very short time by using ethylene glycol having reducing power, and the thermal energy generated during the reaction was utilized in the polyethylene glycol polymerization reaction. .

Therefore, by coating polyethylene glycol outside the aluminum nanopowder in a single process, it is possible to manufacture aluminum-polyethylene glycol (PEG) composite nanopowder, thereby improving the productivity.

In addition, since the oxidation resistance of the aluminum composite nanopowder is improved due to the PEG wrapping the aluminum nanopowder surface, there is an advantage that can exhibit high electrical characteristics and combustion characteristics when used as an electrode material or a solid metal fuel.

In addition, the process time is significantly reduced as compared with the conventional technique, which is performed by performing a separate step of coating a specific organic material on the surface of the aluminum powder after the aluminum powder is manufactured, and it does not cause trouble for material preparation. Production has an advantage.

In addition, since the ethylene glycol used as the solvent is utilized as a polyethylene glycol polymerization precursor surrounding the surface of the aluminum powder, it is possible to manufacture the composite nanopowder in a single process, and there is no additional cost.

In addition, the aluminum-polyethylene glycol composite nano powder can be used as an electrode material for green energy industries such as solar cells and OLEDs, and can also be used as aluminum solid fuel with controlled oxide film formation to maximize combustion efficiency of metal solid fuel. There is a possible advantage.

1 is an electron micrograph of an aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention.
2 is a process flow chart showing a method for producing an aluminum-polyethylene glycol (PEG) composite nano powder according to the present invention.
Figure 3 is a process flow chart showing in detail a composite powder manufacturing step of one step in the manufacturing method of aluminum-polyethylene glycol (PEG) composite nano powder according to the present invention.
Figure 4 is a high magnification electron micrograph of aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention.
5 is an X-ray diffraction analysis photograph of aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention.
Figure 6 is a graph showing the results of the FTIR analysis of aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention.
7 is a graph showing the results of GPC analysis of aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention.

Hereinafter, with reference to the accompanying Figure 1 looks at the configuration of the aluminum-polyethylene glycol composite nano powder (hereinafter referred to as "composite nano powder").

1 is an electron micrograph of an aluminum-polyethylene glycol (PEG) composite nanopowder prepared according to a preferred embodiment of the present invention.

As shown in the drawing, the composite nanopowder 100 includes aluminum nanopowder 120 and polyethylene glycol (PEG) 140 coated on the outside of the aluminum nanopowder 120.

The aluminum nano-powder 120 is a reducing reaction and the polyol process at the time of post-heating In the precursor of AlCl ₃ with LiAlH ₄ in ethylene glycol is conducted in sequence will formed from AlCl ₃ with LiAlH _4, wherein the polyethylene glycol is ethylene glycol It is formed by this polymerization reaction and is formed to be surrounded by the outer side of the aluminum nanopowder 120.

Therefore, as shown in FIG. 1, the composite nanopowder 100 has a shape in which a plurality of aluminum nanopowders 120 are accommodated in polyethylene glycol.

Hereinafter, a method of manufacturing the composite nanopowder will be described with reference to FIGS. 2 and 3.

2 is a process flow chart showing a method for producing an aluminum-polyethylene glycol (PEG) composite nano powder according to the present invention, Figure 3 is a step in the method for producing an aluminum- polyethylene glycol (PEG) composite nano powder according to the present invention. Process flow chart showing in detail the composite powder manufacturing step (S300).

First, as shown in FIG. 2, the process of preparing the composite nanopowder includes preparing an AlCl ₃ , an Al precursor, LiAlH _4, and an ethylene glycol solvent (S100), and AlCl ₃ and LiAlH ₄ in an ethylene glycol solvent. Material injection step (S200) to dissolve in, and the composite powder to prepare a composite nano-powder 100 coated with polyethylene glycol 140 on the outer surface of the aluminum nano-powder 120 by heating and stirring the ethylene glycol solvent. Step (S300), and the washing step (S400) for removing the by-product LiCl formed in the composite powder manufacturing step.

AlCl ₃ in the material preparation step (S100) And LiAlH ₄ are precursors, and LiAlH ₄ simultaneously serves as a reducing agent.

In addition, the ethylene glycol is to be able to manufacture the composite nanopowder 100 in a short time, not only has a reducing power itself, but also a polymerization precursor of polyethylene glycol 140 formed on the outer surface of the aluminum nanopowder 120 It will play a role at the same time.

After the material preparation step (S100), a material input step (S200) is performed. The material input step (S200) is a mole ratio of AlCl ₃ with LiAlH _4, 1: a step of melting and then put in ethylene glycol to control 3, the AlCl ₃ and LiAlH of ₄ aluminum is an Al ^{3 +} ions reduced It becomes easy.

After the material input step (S200), the composite powder manufacturing step (S300) is carried out. The composite powder manufacturing step (S300), by heating the ethylene glycol solvent in which AlCl ₃ and LiAlH ₄ is dissolved to prepare the aluminum nanopowder 120 and at the same time the polyethylene glycol 140 is formed on the outside of the aluminum nanopowder. It is a process.

That is, the composite nano powder manufacturing step is carried out for a very short time by the following reaction scheme.

AlCl ₃ + 3LiAlH ₄ → 4AlH ₃ + 3LiCl → 4Al + 3LiCl + 6H ₂ --- (Scheme)

Looking at the composite nano powder manufacturing step (S300) in more detail with reference to Figure 3, the composite powder manufacturing step (S300), Al ^{3 +} ions dissolved in ethylene glycol during the material input step (S200) is reduced Reduction process (S320), the nano-powder forming process (S340) is formed by the polyol process aluminum nanoparticles (120) and the polyethylene glycol (140) on the outer surface of the aluminum nanopowder (120) by the polymerization reaction of the ethylene glycol It consists of a composite powder forming process (S360) to form a.

The reducing process of the glycol solvent include Al ^{3 +} ions in (S320) is heated to 120 to 140 ℃, this time is brought into engagement with the Al ^{3 +} ion of hydrogen, 2 to 5 seconds rapid exothermic reaction occurs. At the same time, by-product LiCl is produced.

Since the aluminum combined with hydrogen forms the aluminum nanopowder 120 by a polyol process (nano powder formation process (S340)), the aluminum nanopowder 120 by the polymerization precursor of heat and ethylene glycol generated in the reduction process On the outer surface of the polyethylene glycol 140 is attached (composite powder forming process (S360).

When using a solvent other than ethylene glycol in the embodiment of the present invention takes a reaction time of at least 1 hour at a low temperature, when using ethylene glycol, the reaction time for the synthesis of aluminum nanopowder is very short within 5 seconds.

That is, the reaction scheme is completed within 5 seconds and high heat energy is generated, and the heat energy generated at this time enables ethylene glycol used as a solvent to form polyethylene glycol by a polymerization reaction.

Therefore, in the embodiment of the present invention, ethylene glycol is preferably applied.

On the other hand, the aluminum nano-powder surrounded by the polyethylene glycol is present with the byproduct LiCl.

Therefore, the LiCl is washed in step S400 to remove the aluminum-polyethylene glycol composite nanopowders.

The washing step (S400) is possible by dissolving LiCl and aluminum-polyethylene glycol composite nanopowder 100 in water or alcohol.

That is, since the composite nanopowder 100 is coated with polyethylene glycol 140 on its outer surface, it does not react with water or alcohol, but LiCl is not coated with polyethylene glycol, so it reacts with water or alcohol to oxidize or hydroxide. This will be made.

Therefore, after dissolving only LiCl in the composite nanopowder 100 using water or alcohol and centrifuging at a rotational speed of 12000 to 20000rpm, Al-PEG nanopowder is precipitated to the bottom of the centrifuge by centrifugal force and LiCl is It is possible to collect pure Al-PEG composite nano powder by separating and dissolving the dissolved upper solution. The suitability of this method can be confirmed that the crystal structure corresponding to LiCl does not appear in the XRD analysis of the powder after the alcohol washing of FIG.

Composite nano powder prepared according to the above process as shown in Figure 4, the spherical and polygonal aluminum nanopowder 120 has a shape accommodated inside the material that is assumed to be polyethylene glycol 140, aluminum nano The size of the powder has a size of 70 nm.

5 is attached with an X-ray diffraction analysis photograph of the aluminum-polyethylene glycol (PEG) composite nanopowder 100 prepared according to the preferred embodiment of the present invention.

As shown in the figure, it can be seen that the material contained in the composite nanopowder 100 is aluminum.

In addition, it was confirmed that the material outside the aluminum nanopowder is polyethylene glycol through FIGS. 6 and 7.

That is, Figure 6 is a graph showing the results of the FTIR analysis of the aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention, FTIR analysis results for the material present between the particles 2400 characteristics of polyethylene glycol It was confirmed that the peak corresponding to the OH band appears between -3000 cm ^-1 .

The peak corresponding to the OH band may also appear in ethylene glycol, which is a solvent before PEG polymerization, and it cannot be said that PEG surrounds the surface of Al powder only by the FTIR results. The same result was obtained.

7 is a graph showing the results of GPC analysis of the aluminum-polyethylene glycol (PEG) composite nano powder prepared according to a preferred embodiment of the present invention, the molecular weight of the material surrounding the Al powder surface as a result of the molecular weight range is small It can be seen that the maximum from 2000g / mol to 100g / mol, the number average molecular weight was 253g / mol, it can be seen that the PEG having an average number of six (CH ₂ -O-CH ₂ ) chains are formed. .

The scope of the present invention is not limited to the above-described embodiments, and many other modifications based on the present invention will be possible to those skilled in the art within the scope of the present invention.

100. Aluminum-Polyethylene Glycol (PEG) Composite Nanopowder
120. Aluminum Nano Powder
140. Polyethylene glycol
S100. Material preparation step S200. Material input step
S300. Composite powder production step S320. Reduction Process
S340. Nano powder formation process S360. Compound powder formation process
S400. Washing steps

Claims (9)

With aluminum nano powder,
Aluminum nano-polyethylene glycol (PEG) composite nano powder, characterized in that it comprises an oxidation-resistant polyethylene glycol (PEG) coated on the outside of the aluminum nano powder. The aluminum-polyethylene glycol (PEG) composite nanopowder according to claim 1, wherein the polyethylene glycol is formed by polymerization of ethylene glycol, which is used as a solvent, by reaction heat generated when aluminum nanoparticles are formed. A material preparation step of preparing AlCl ₃ which is an aluminum precursor, LiAlH ₄ and an ethylene glycol solvent,
A material input step of dissolving AlCl ₃ and LiAlH ₄ in an ethylene glycol solvent;
A composite powder manufacturing step of preparing a composite nanopowder coated with polyethylene glycol on the outer surface of the aluminum nanopowder by heating and stirring the ethylene glycol solvent;
Method for producing an aluminum-polyethylene glycol (PEG) composite nano powder, characterized in that consisting of a washing step for removing the by-product LiCl formed in the composite powder manufacturing step. [4] The method of claim 3, wherein the AlCl ₃ and LiAlH ₄ are added to ethylene glycol in a molar ratio of 1: 3 in the material input step. According to claim 4, The composite powder manufacturing step,
Reduction process of the Al ^{3 +} ions dissolved in the ethylene glycol in the material feed reduction step and,
Nano-powder formation process in which the aluminum nano-powder is formed by a polyol process,
Method for producing an aluminum-polyethylene glycol (PEG) composite nano-powder, characterized in that the composite powder forming process of forming polyethylene glycol on the outer surface of the aluminum nano-powder by the polymerization reaction of the ethylene glycol. The method of claim 4, wherein in the composite powder preparation step, the ethylene glycol solvent in which AlCl ₃ and LiAlH ₄ are dissolved is heated to 120 to 140 ° C. . The method of claim 3, wherein the washing step is a process of selectively removing LiCl using water or alcohol. The method of claim 3, wherein the washing step is a process of separating the aluminum-polyethylene glycol (PEG) composite nano powder and LiCl using a centrifugal force. 9. The method of claim 8, wherein the washing step is a process of separating by rotating at a speed of 12000 to 20000 RPM.

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