KR20110049278A - Method for manufacturing nanotubes with nanoparticles and depositing nanoparticles on nanopores - Google Patents

Abstract

PURPOSE: A method for manufacturing nanotubes containing nanoparticles and a method for attaching the nanoparticles to nanopores are provided to uniformly attach the nanoparticles to the nanopores using block copolymer micelle with metal salt. CONSTITUTION: A method for manufacturing nanotubes(50) containing nanoparticles includes the following: A porous nano-template is prepared. A block copolymer micelle solution is prepared. Metal salt is added to the block copolymer micelle solution to obtain metal salt-containing block copolymer micelle solution. The metal salt-containing block copolymer micelle is injected into the pores of the porous nano-template. The porous nano-template is eliminated.

Description

Methods for manufacturing nanotubes containing nanoparticles and attaching nanoparticles to nanopores {Method For Manufacturing Nanotubes With Nanoparticles And Depositing Nanoparticles On Nanopores}

The present invention relates to a method for manufacturing nanotubes containing nanoparticles and a method for attaching nanoparticles to nanopores, and more particularly, nanoparticles containing nanoparticles using a block copolymer polymer micelle to which a metal salt is added. A method of making a tube and a method of attaching nanoparticles to nanopores.

Anodized aluminum oxides (AAO) are manufactured by electrochemically oxidizing aluminum, and are one of the newly emerging materials in the nanotechnology field. In the case of using such anodized aluminum as a template, since nanostructures such as nanopores, nanorods, and nanotubes can be easily manufactured using a desired material, there is a growing interest in this.

In particular, the production of nanotubes is not easy to control their size (length or thickness). In the case of using anodized aluminum as a template, nanotubes can be controlled in various sizes by varying the diameter and arrangement of the pores, and researches for producing nanotubes using anodized aluminum are actively conducted. For example, the nanotubes are filled with pores formed in the anodized aluminum template, and the anodized aluminum is removed by an acid such as hydrogen fluoride (HF) or a basic material such as sodium hydroxide (NaOH). Methods of preparing the have been introduced in various publications. In addition, recently, in order to improve the surface properties of nanotubes, using an aminosilane-modified anodized aluminum template (filling pores formed in the template with a metal colloidal solution and then removing the anodized aluminum ), A method of manufacturing nanotubes containing metal nanoparticles has been introduced.

Meanwhile, in order to improve the surface properties of porous nanomaterials, researches using anodized aluminum have also been actively conducted. For example, a method of fabricating a porous nanomaterial to which metal nanoparticles are attached by attaching metal nanoparticles to nanopores formed in anodized aluminum by ultra-layer-by-layer deposition has been introduced. .

However, according to these methods, there is a problem that metal nanoparticles tend to form ropes or bundles, that is, it is not easy to prevent aggregation of metal nanoparticles. Aggregation of these metal nanoparticles has resulted in an increase in surface area, which causes deterioration of various properties of nanotubes or porous nanomaterials.

In order to prevent the aggregation of the metal nanoparticles, a technique for introducing an aggregation inhibitor such as capping agents has been proposed. However, such an aggregation inhibitor had a limitation of limiting the function of the metal nanoparticle as a catalyst.

It is an object of the present invention to provide a method for producing nanotubes in which metal nanoparticles are uniformly distributed by using a block copolymer polymer micelle to which a metal salt is added.

Another object of the present invention is to provide a method for uniformly attaching metal nanoparticles to nanopores by using a block copolymer polymer micelle to which a metal salt is added.

It is also an object of the present invention to provide nanotubes and porous nanomaterials with improved surface properties.

In order to achieve the above object, a nanotube manufacturing method comprising a nanoparticle according to an embodiment of the present invention comprises the steps of preparing a porous nano-template; Preparing a block copolymer micelle solution; Preparing a metal salt block copolymer micelle solution by adding a metal salt to the block copolymer micelle solution; Injecting the metal salt block copolymer micelle solution into the pores of the porous nano-template; And removing the porous nano template.

In addition, the method for attaching nanoparticles to nanopores according to another embodiment of the present invention comprises the steps of preparing a block copolymer micelle solution; Preparing a metal salt block copolymer micelle solution by adding a metal salt to the block copolymer micelle solution; Injecting the metal salt block copolymer micelle solution into the pores of the porous nano-template; And removing the block copolymer.

The block copolymer may be polystyrene-polyvinylpyridine.

The porous nano template may be composed of aluminum oxide.

The metal salt added to the block copolymer micelle solution may be at least one of HAuCl ₄ , AgNO ₃ , CoCl ₂ , ZnCl ₂ , FeCl ₃ .

The concentration of the block copolymer of the block copolymer micelle solution may be in the range of 0.1 to 30 wt%.

The size of the nanopores of the porous nano-template may be in the range of 40 to 400 nm.

The block copolymer micelle solution may be injected into the pores of the porous nano-template using at least one of dipping or spin coating.

The porous nano template may be removed using at least one of an acid or a base solution.

The block copolymer may be removed using an oxygen plasma.

According to the present invention, by using a block copolymer polymer micelle to which a metal salt is added, there is an effect that a nanotube in which metal nanoparticles are uniformly distributed can be produced.

In addition, according to the present invention, by using the block copolymer polymer micelle to which the metal salt is added, there is an effect that the metal nanoparticles can be uniformly attached to the nanopores. In addition, according to the present invention, there is an effect that can provide a nanotube and a porous nanomaterial with improved surface properties.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. In the drawings, like reference numerals refer to the same or similar functions throughout the several aspects, and length, area, thickness, and the like may be exaggerated for convenience.

DETAILED DESCRIPTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

First, the present invention is characterized by manufacturing nanotubes containing nanoparticles using a block copolymer micelle solution and attaching nanoparticles to nanopores. Here, the nanoparticles refer to particles having a size in the range of 0.1 to 1,000 nm including clusters at the molecular level.

A block copolymer is a block copolymer in which two or more polymer chains are connected by covalent bonds. Unlike general polymer mixtures that show macrophase separation of several microns, each block is limited by the covalent bond between two blocks. It has the property of phase separation into domains of. Because of the spontaneous phase separation, nanostructures having a size of about 10 nm to 100 nm can be formed, and block copolymers capable of using blocks having various chemical structures can realize materials having desired physical properties. Various nanostructures formed by such block copolymers have properties that can be applied to the synthesis of nanoparticles such as metals, semiconductors, and oxides. In particular, the size of the particles within the nanostructure of the block copolymer is limited to the size of nanometers, and the arrangement of the particles is also limited by the size and spacing of the nanostructure, it is possible to control the size and arrangement of the particles. In other words, the use of block copolymer not only enables the control of nanoparticle size, position, and arrangement in the nanometer range, but also maintains the properties of polymer materials such as flexibility, transparency, ease of manufacture, and low cost. There is an advantage. On the other hand, the amphoteric double block copolymer composed of a hydrophobic block and a hydrophilic block has a hydrophobic block (core block) of each molecule in water, and a hydrophilic block (corona block) has two. It has a structure called micelles. If the precursor of nanoparticles is introduced into the core block of the block copolymer micelle structure, the micelles are properly post-treated to enable nanoparticle synthesis of a desired material.

Accordingly, the present inventors, when adding a metal salt to the block copolymer micelle solution and introducing it into the porous nano-template, it will be possible to prepare a nanotube including the metal nanoparticles and a porous nanomaterial to which the metal nanoparticles are attached. Attention was drawn to the present invention.

1 to 4 are diagrams showing a method of manufacturing a nanotube 50 including metal nanoparticles 52 according to an embodiment of the present invention.

First, referring to FIG. 1, a porous nano template 10 is prepared. As such, manufacturing the nanotubes 50 using the porous nano template 10 controls the size (length and diameter) of the pores 12 of the porous nano template 10, and thus, sizes of the nanotubes 50. Because it is easy to adjust. At this time, the size of the pores 12 of the porous nano template 10 is preferably in the range of 40 to 400 nm. In addition, the porous nano-template 10 is preferably composed of anodized aluminum oxide which is simple to manufacture and can form a lot of pores (12).

In the present embodiment, anodized aluminum template 10 is prepared by selecting anodized aluminum as the porous nano template 10 and performing a two-step anodization. First, the pure aluminum sheet was electrochemically polished and anodized at 0 ° C. for 15 hours after applying 160 V in an aqueous solution of about 0.01 M phosphoric acid. Thereafter, the aluminum oxide layer produced as a result of the anodic oxidation was removed at 60 ° C. for 10 hours using an aqueous solution in which 1.8 wt% of chromic acid and 6.0 wt% of phosphoric acid were dissolved. After the anodization again in the same manner to prepare an anodized aluminum template 10 in which a plurality of pores 12 of about 250nm diameter was formed. Since the technique of manufacturing the anodized aluminum template 10 is well known in the art, further description will be omitted.

Next, referring to Figure 2, to prepare a block copolymer micelle 30 solution. First, the block copolymer 20 used in the embodiment of the present invention is characterized in that the polystyrene (polystyrene; 22) -polyvinylpyridine (b-polyvinylprydine; 24). Here, the block copolymer 20 refers to a block copolymer capable of forming micelles in an organic solvent or water and having an amphoteric property in a specific organic solvent or water, that is, having hydrophilicity and lipophilic property. The block copolymer 20 is manufactured using an anion polymerization method or living radical polymerization method. Since the anion polymerization method or the living radical polymerization method is a known technique, detailed description thereof will be omitted.

 Next, when a solubility such as toluene is added to the block copolymer 20, the block copolymer 20 generates a self-reaction and the inner core portion is made of a polyvinylpyridine 24 component. The outer shell portion is reconstituted with a solution of block copolymer micelle 30 composed of polystyrene 22 components. At this time, the concentration of the block copolymer micelle 30 solution is preferably in the range of 0.05 wt% to 30 wt%, more preferably in the range of 0.2 wt% to 5 wt%.

In this embodiment, two types of polystyrene-polyvinylpyridine block copolymers 20 were prepared. First, polystyrene having number average molecular weights of about 47600 g mol ⁻¹ (hereinafter PS [48]; [48] means having a number average molecular weight of about 48000 g mol ⁻¹ ) and 20900 Polyvinylpyridine (PVP [21]) having a number average molecular weight of g mol ^-1 was synthesized to prepare PS [48] -PVP [21], and the polydispersity index of the polymer material was about 1.14. Was measured. Next, polystyrene (hereinafter referred to as PS [32]) having a number average molecular weight of 31900 g mol ⁻¹ and polyvinylpyridine (hereinafter referred to as PVP [13]) having a number average molecular weight of 13200 g mol ⁻¹ were synthesized to form PS [32] -PVP [ 13], the polydispersity index of the polymer material was measured to be about 1.08. The two types of block copolymers 20 thus prepared are dissolved in a toluene solution at a concentration of about 0.5 wt%, stirred at room temperature for about 2 hours, and then stirred at about 80 ° C. for about 8 hours. A micelle 30 solution was prepared.

Next, referring further to FIG. 2, a metal salt block copolymer micelle 40 solution is prepared. As shown in FIG. 2, the metal salt powder is added to the block copolymer micelle 30 solution to form a metal salt block copolymer micelle 40 solution. At this time, the metal salt powder is formed by combining a substituent having the properties of an anion with a metal component, including a metal chloride, metal nitrate, metal acetate, such as transition metal or heavy metal on the periodic table. These metal salt powders are HAuCl ₄ , AgNO ₃ , CoCl ₂ , ZnCl ₂ , FeCl ₃ It may include at least one of the. In the present embodiment, the metal salt block copolymer micelle 40 is selected by adding gold pylori chloride (HAuCl ₄ ) as a metal salt component and adding 1.0% by weight of vinylpyridine monomer to the block copolymer micelle 40 solution. The solution was prepared.

Next, referring to FIG. 3, the metal salt block copolymer micelle 40 solution is injected into the pores 12 of the porous nano template 10. In this case, as the injection method, an immersion method for dipping and injecting the porous nano template 10 into a solution contained in a storage container or a spin coating method for dropping and injecting a solution onto the porous nano template 10 rotating at high speed may be used. In the present embodiment, the immersion method was used, and the metal salt block copolymer micelle 40 solution was easily injected into the pores 12 of the porous nano-template 10 by capillary action.

Next, the metal salt is reduced in the solution of the metal salt block copolymer micelle 40 injected into the pores 12 of the porous nano template 10. To this end, an immersion method of dipping the porous nano template 10 in a solution containing a reducing agent for reducing metal salts may be used. In this embodiment, the porous nano template 10 was immersed in sodium borohydride (NaBH ₄ ) of about 1.0 wt% concentration, the immersion time was about 30 seconds.

 Next, the porous nano template 10 is removed. At this time, as a method of removing the porous nano-template 10, an immersion method of dipping the porous nano-template 10 in an acid or base solution may be used. When the porous nano template 10 is immersed in an acid or base solution for a predetermined time, the templates 10 are all dissolved and removed, while the nanotubes composed of the block copolymer micelles 30 are not dissolved in the acid or base solution. Therefore, the porous nano template 10 can be easily removed. In this embodiment, a method of immersing the porous nano-template 10 composed of anodized aluminum in a sodium hydroxide (NaOH) base solution of about 5.0 wt% concentration was used.

Through all the above-described process, as shown in FIG. 4, the nanotubes 50 including the metal nanoparticles 52 and the block copolymer micelles 30 can be manufactured.

Figure 5 is a photograph showing the appearance of the block copolymer micelle nanotubes prepared according to an embodiment of the present invention. 5 (a) is a photograph taken with the nanotubes by the field emission scanning electron microscope (FE-SEM), (b) is a photograph taken by the transmission electron microscope (TEM). As shown in (a) and (b) of Figure 5, it was confirmed that the nanotube having a diameter of about 250nm was prepared. By controlling the weight of the block copolymer or the diameter of the pores formed in the porous nanomaterial, the size of the nanotube to be manufactured may be appropriately controlled.

Figure 6 is a close-up photograph of the appearance of a nanotube including a metal nanoparticles prepared according to an embodiment of the present invention. 6 (a) is a photograph taken with a transmission electron microscope of a nanotube composed of PS [48] -PVP [21], and (b) shows a transmission electron nanotube composed of PS [32] -PVP [13]. The picture was taken with a microscope. As shown in (a) and (b) of FIG. 6, gold (Au) nanoparticles were uniformly distributed in the two types of nanotubes without aggregation. The average diameter of these gold nanoparticles was measured to be about 6 nm. By controlling the degree of reduction of the metal salt, the area where the metal nanoparticles included in the nanotubes are distributed, the number and diameter of the metal nanoparticles, etc. may be appropriately adjusted.

On the other hand, Figure 7 is a view showing the metal nanoparticles (14a) attached to the pores (12a) of the porous nano-template (10a) according to another embodiment of the present invention.

In the present embodiment, the porous nano template 10 and the metal salt block copolymer micelle 40 are prepared as in the previous embodiment, and the metal salt block copolymer micelle 40 is formed in the pores 12a of the porous nano template 10. The process of injecting the solution is the same.

However, the process of reducing the metal salt in the injected metal salt block copolymer micelle solution 40 is not included, and the process of removing the block copolymer 20 instead of removing the porous nano template 10 is included. That is, since the end purpose is to attach the metal nanoparticles 14a to the pores 12a of the porous nano template 10a, all the polymer components other than the metal nanoparticles 14a are removed from the metal salt block copolymer micelle 40. It's a step. In the present embodiment, the polymer component was removed using an oxygen plasma while maintaining a vacuum at a power of 100 W at a pressure of 2.0 × 10 ⁻² Torr. The treatment time was about 10 minutes.

As a result, as shown in FIG. 7, the metal nanoparticles 14a may be attached to the pores 12a of the porous nano template 10a.

8 is a photograph showing the appearance of the metal nanoparticles attached according to the method for attaching the metal nanoparticles to the nanopores according to an embodiment of the present invention. Figure 8 (a) is a photograph taken with the field emission scanning electron microscope image of the gold nanoparticles attached using PS [48] -PVP [21], (b) is PS [32] -PVP [13 ] Is a photograph of the gold nanoparticles attached using a field emission scanning electron microscope. As shown in (a) and (b) of FIG. 8, it was confirmed that the gold nanoparticles were uniformly attached to the pores of the anodized aluminum without aggregation. In addition, the diameter of gold nanoparticles deposited using PV (48) -PVP (21) was measured to be about 29 nm, and the diameter of gold nanoparticles deposited using PV (32) -PVP (13) was about 18 nm. Was measured. As can be seen from these results, as the weight of the block copolymer 20 is adjusted, the diameter of the metal nanoparticles attached to the pores may be appropriately adjusted.

On the other hand, although not shown in Figure 8, ferric chloride (FeCl ₃₎ to select a metal component results of the experiment in the same manner as in the above embodiment, the iron oxide having a diameter of about 24nm (Fe ₂ O ₃₎ particles on the nanoporous It was confirmed that it could be attached uniformly. The iron oxide particles thus attached may help to improve the surface properties, particularly the magnetic properties, of the porous nanomaterial.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. Variations and changes are possible. Such modifications and variations are intended to fall within the scope of the invention and the appended claims.

1 to 4 is a view showing a method for manufacturing a nanotube containing nanoparticles according to an embodiment of the present invention.

Figure 5 is a photograph showing the appearance of the block copolymer micelle nanotubes prepared according to an embodiment of the present invention.

Figure 6 is a close-up photograph of the appearance of a nanotube including a metal nanoparticles prepared according to an embodiment of the present invention.

7 is a view showing a metal nanoparticles attached to the pores of the porous nano-template in accordance with another embodiment of the present invention.

8 is a photograph showing the appearance of the metal nanoparticles attached according to the method for attaching the metal nanoparticles to the nanopores according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10, 10a: porous nano template

12: pore

14a: nanoparticles

20: block copolymer

22: polystyrene block

24: poly (vinyl pyridine) block

30: block copolymer micelles

40: metal salt block copolymer micelle

50: nanotube

52: nanoparticles

Claims (10)

Preparing a porous nano template; Preparing a block copolymer micelle solution; Preparing a metal salt block copolymer micelle solution by adding a metal salt to the block copolymer micelle solution; Injecting the metal salt block copolymer micelle solution into the pores of the porous nano-template; And Removing the porous nano template Nanotube manufacturing method comprising a nanoparticle comprising a. Preparing a porous nano template; Preparing a block copolymer micelle solution; Preparing a metal salt block copolymer micelle solution by adding a metal salt to the block copolymer micelle solution; Injecting the metal salt block copolymer micelle solution into the pores of the porous nano-template; And Removing the block copolymer Method of attaching nanoparticles to nanopores, characterized in that it comprises a. The method according to claim 1 or 2, The block copolymer is characterized in that the polystyrene-polyvinylpyridine. The method according to claim 1 or 2, The porous nano template is characterized in that it comprises aluminum oxide. The method according to claim 1 or 2, The metal salt is at least one of HAuCl ₄ , AgNO ₃ , CoCl ₂ , ZnCl ₂ , FeCl ₃ . The method according to claim 1 or 2, The concentration of the block copolymer is characterized in that in the range of 0.1 to 30 wt%. The method according to claim 1 or 2, The pore size of the porous nano template is characterized in that in the range of 40 to 400 nm. The method according to claim 1 or 2, And injecting the block copolymer micelle solution into the pores of the porous nano-template using at least one of dipping or spin coating. The method of claim 1, The porous nano template is removed using at least one of an acid or a base solution. The method of claim 2, The block copolymer is removed using an oxygen plasma.

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