KR101583593B1 - Nano Porous Films Composed Carbon Nano Structure-Metal Composite or Carbon Nano Structure-Metal Oxide Composite and a process for preparing the same - Google Patents

Abstract

The present invention relates to a porous film formed of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite that does not include a support and a method of manufacturing the same. Since the porous film does not include a support, By using nano-sized metal, it is possible to reduce the process cost through low temperature heat treatment. In addition, the porous membrane can be applied to various filter products such as biochemical fields such as purification of chemicals and protein separation.

Description

[0001] The present invention relates to a nanoporous film composed of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite and a method for manufacturing the same.

The present invention relates to a nanoporous membrane composed of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite not containing a support, a method for producing the same, and a filter product including the same.

Recently, with the advancement of the industry, porous membrane technology with high purity has been recognized as a very important field. Chemical industry, food industry, medicine industry, medical, biochemical and environmental fields. Especially in the field of environment, technical demands for air purification, water treatment purification, waste solvent treatment, microbial separation and oil purification increase However, as a method to solve this problem, a technique using a porous membrane has attracted much attention.

Most of these porous films are made of polymer, but recently, a method of using a carbon nanostructure as a new material for manufacturing a nanoporous film has started to be developed. Recent carbon nanostructures can be divided into carbon nanotubes, carbon nano horns, carbon nanofibers, and graphenes depending on the type of carbon nanostructure. In particular, carbon nanotubes can be applied to various fields such as energy, environment and electronic materials due to excellent mechanical strength, thermal conductivity, electrical conductivity and chemical stability.

As an example of a technique for fabricating a porous film composed of a carbon nanostructure, there is a method of synthesizing a nanostructure by direct growth of carbon nanotubes in a micron metal fiber filter. 45, No. 3, June, 2007, pp. 264-268 (2007), which is a result of direct synthesis and growth of carbon nanotubes on the surface of a micron metal fiber filter (Nature materials, Vol. 3, September, 2004, pp. 610-614), in which carbon nanotubes are directly grown in a quartz tube and a tube-shaped carbon nanotube module is fabricated .

However, the structure of the porous membrane composed of the carbon nanostructure is a level that complements the performance of a support by forming a carbon nanostructure on a commonly used fiber or ceramic filter support, and due to the double structure, There may be limits in scope. In order to produce a porous membrane using only a carbon nanostructure, a method of growing carbon nanotubes or the like on a support is used. This is disadvantageous in that it is inferior in manufacturing problems and economical efficiency, and since the carbon nanostructure is made of carbon, There is a problem in that there is no bonding force between the nanostructures.

Korean Patent No. 0558966 Korean Patent No. 1095840 Korean Patent Application No. 2008-0049464

Korean Chem. Eng. Res., Vol. 45, No. 3, June, 2007, pp. 264-268 Nature materials, Vol. 3, September, 2004, pp. 610-614

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a porous film formed of a metal nanostructure-metal composite or a carbon nanostructure-

In one embodiment, the present invention provides a porous membrane formed from a carbon nanostructure-metal complex or carbon nanostructure-metal oxide complex that does not include a support.

In yet another embodiment, with the method of providing the porous membrane,

Applying a dispersion of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite onto a support, and then decompressing the dispersion; And

And removing the support.

Further, a filter product using the porous membrane according to the present invention is provided.

Since the porous film according to the present invention does not include a support, it can be lightened and the cost of the process through low temperature heat treatment can be reduced by using nano-sized metal. In addition, the porous membrane may be variously applied to a biochemical field such as purification of chemicals and protein separation. For example, a filter for air purifier, an air conditioner filter, a water treatment filter, a filter for treating waste solvent, a porous membrane for separating microorganisms, a filter for oil purification, a field emission display, a hydrogen storage device combination, And can be applied to various fields such as a car or a lightweight high-strength application product.

1 is a scanning electron microscope (SEM) photograph of the carbon nanotube-silver composite prepared in Preparation Example.
FIG. 2 is a photograph of a carbon nanotube-silver nanoporous film in the form of a bucky paper produced in the embodiment. FIG.
FIG. 3 is a graph showing a flow rate measurement result according to the pressure of the nanoporous membrane manufactured in the embodiment.

Recently, a new material formed of a carbon nanostructure-metal complex has recently been developed. The carbon nanotube is chemically bonded to a carbon nanotube by inducing a functional group and reacting a metal (cobalt, copper, nickel, silver, etc.) with the functional group. Due to the metal components contained in the composite material of the carbon nanostructure-metal complex, a structure such as a field emission display, a hydrogen storage device assembly, an electrode, a super capacitor, an electromagnetic wave assembly, a lightweight high- It has excellent characteristics in molding production.

Materials for such carbon nanostructure-metal complexes are disclosed in Korean Patent No. 0558966, Korean Patent No. 1095840, and Korean Patent Application No. 2008-0049464.

The present invention can be applied to the case where the above-mentioned new material is used and a porous film formed of a "carbon nanostructure-metal composite or carbon nanostructure-metal oxide composite" (hereinafter referred to as "carbon nanostructure- Quot;), a porous membrane having a single structure, which is not a conventional double structure, and a method for manufacturing the same are provided by removing the support in the form of a carbon nanostructure-metal or metal oxide composite coated on the surface of the support .

For example, a carbon nanostructure-metal porous film in which a microporous membrane is formed on a carbon nanotube array, such as a buckypaper having excellent thermal and mechanical properties, can be provided.

In the porous membrane, the carbon nanostructure may include at least one selected from the group consisting of single wall carbon nanotubes, double wall carbon nanotubes, multiwall carbon nanotubes, carbon nanofines, carbon nanofibers, and graphenes.

The pore size of the carbon nanostructure-metal porous membrane according to the present invention can be controlled according to the kind of the carbon nanostructure. For example, the size of the carbon nanostructure varies depending on the kind of the carbon nanostructure, and as a result, the pore size of the porous membrane can be controlled by controlling the diameter of the porous membrane composed of the carbon nanostructure.

The porous membrane according to the present invention has pores between the carbon nanostructures and may have a size of 1 to 500 nm. For example, 10 to 500 nm, 50 to 300 nm, 30 to 150 nm, or 30 to 80 nm. By forming the pore size of the porous membrane within the above range, purification efficiency against impurities can be increased. When the pore size is smaller than the above range, the flowability of the fluid is lowered. When the pore size is too large, the nanoparticles can not be filtered.

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In the porous film, the metal may be at least one selected from the group consisting of Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, At least one selected from the group consisting of Pd, Ag, Cd, In, Sn, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Hf, Ir, Pt, can do. Specifically, the metal may be silver (Ag). Or an oxide of the above metal may be used.

In one example, the porous membrane can form a network structure. Specifically, a form in which the metal or metal oxide forming the porous film and the carbon nanostructure are connected can form a network structure. The network structure is a structure in a net shape, and is a structure that does not disturb the flow of the fluid, and is effective for filtering out impurities.

The present invention also provides a method for producing the above-described porous membrane.

As one example, the porous film manufacturing method includes:

Applying a dispersion of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite onto a support, and then decompressing the dispersion; And

And removing the support.

As an example, the porous film may be further subjected to heat treatment before or after the step of removing the support. The order of the heat treatment step is not particularly limited, and the degree of bonding of the porous membrane can be increased. In particular, since the nano-sized metal or metal oxide is used in the present invention, it is possible to perform the heat treatment at a relatively low temperature.

The heat treatment may be performed at a low temperature of 80 to 350 ° C, for example, 80 to 200 ° C, 80 to 170 ° C, 100 to 300 ° C, 100 to 200 ° C, or 120 to 250 ° C. For example, when the metal is silver (Ag), heat treatment is possible at 100 to 300 ° C. Specifically, the metal nanoparticles may be melted by the heat treatment to connect the carbon nanostructure-metal complexes to form a network structure. Further, since the process of manufacturing the porous film is performed at a relatively low temperature, the process cost can be reduced. Specifically, the principle of bonding the carbon nanostructure-metal complex to the support will be described as follows. The carbon nanostructure itself has no binding force. However, the carbon nanostructure-metal complex can be connected to each other while being heat-treated to form a porous film of a network structure. In particular, the metal or metal oxide used in the present invention has a characteristic of melting at a relatively low temperature because it has a nanometer range diameter.

The metal or metal oxide of the porous film may be nano-sized and may be particles having a diameter in the range of 1 to 500 nm, 10 to 500 nm, 100 to 500 nm, 10 to 300 nm, or 100 to 250 nm have. The melting point may be lowered due to the metal size of the nano unit, so that even when the heat treatment is performed at a low temperature, the metal is melted or sintered to connect the carbon nanostructure-metal complex to the network structure well. Thus, a nano-porous film in the form of a bucky paper having a single structure can be formed without a supporting layer.

The content of the metal or metal oxide may be 3 to 80 parts by weight based on 100 parts by weight of the carbon nanostructure. For example, the content of the metal or metal oxide may be 3 to 70 parts by weight, 3 to 50 parts by weight, 10 to 40 parts by weight, 10 to 60 parts by weight, 30 to 50 parts by weight, or 10 to 70 parts by weight. When the content of the metal is less than 3 parts by weight, it is possible to form an incomplete network form upon melting. If the content of the metal exceeds 80 parts by weight, the flow of the fluid may not be smooth because the metal particles block the nano pores. Can fall.

The dispersion of the carbon nanostructure-metal complex or the carbon nanostructure-metal oxide complex in the above production method may further include a dispersant. For example, the dispersing agent may be selected from the group consisting of Nafion, Sodium Dodecylbenzenesulfonate, Perfluorooctanate, Perfluorooctansulfonate, Sodium lauryl ether sulfate, sulfonate, alkyl benzene sulphonate, cetyltrimethylammonium bromide, cetylpyridinium chloride, benzalkonium chloride, benzethonium chloride, alkylpolyethylene Alkyl polyethylene oxide, Alkyl phenol polyethylene oxide, Alkyl polyglucoside, Cetyl alcohol, Oleyl alcohol, Cocamide-MEA, , Cocamide-DEA, dodecyl methylamine oxid e), polyacrylic acid, poly (ethyleneimine), poly (allylamine), poly (4-styrenesulfonic acid), poly It is also possible to use polyacrylic acid such as polymethacrylic acid, polyphosphonate, polyacrylamide, polyvinyl alcohol, polyvinyl acetate, cellulose nitrate and glycogen Glycogen), but the present invention is not limited thereto.

The support may be selected from the group consisting of polycarbonate, polyethylene terephthalate (PET), polyamides, cellulose ester, regenerated cellulose, nylon, polypropylene, poly And at least one of polyacrylonitrile, polysulfone, polyethersulfone, polyvinylidene fluoride, silica, alumina, and zirconia. Polymer; A ceramic filter, and a ceramic filter. For example, a ceramic filter containing alumina as a support may be used.

As an example, the step of applying the dispersion of the carbon nanostructure-metal composite or the carbon nanostructure-metal oxide composite dispersion to a support and then reducing the pressure may be performed by screen printing, doctor blade, spin coating ), Dip coating, spray coating, electrophoretic deposition, off-set printing, vacuum filtration, and normal casting. ≪ RTI ID = 0.0 > and / or < / RTI > For example, a vacuum filtration method can be used, and the carbon nanostructure-metal can be formed on the support through the above process.

In one embodiment, the step of removing the support may be performed through an etching or dissolution process.

Specifically, the step of removing the support may be performed through an etching process, and the etching process may be performed by plasma etching. For example, the plasma etching includes a process of etching a plasma by fluorine or chlorine gas using neutral radical diffusion, and various types of etching using plasma can be applied.

In addition, the step of removing the support may be performed through a dissolving process. Alternatively, the support may be removed by dissolving only the support in a solvent using a spraying method, a solvent levitation method, or a steam exposure method using an acidic or basic solvent have. For example, a basic solvent can be used, and as the basic solvent, sodium hydroxide (NaOH) can be used.

The carbon nanostructure-metal porous membrane according to the present invention can be applied to various filter products. For example, it can be used for a membrane filter such as an air purification filter, an air conditioner filter, a vacuum cleaner filter, a water treatment separator, a microbial separation membrane and an oil refining filter. It can also be used in electronic fields such as electric motors, light-weight high-strength applications.

Hereinafter, the present invention will be described in more detail by way of examples. The following examples are intended to illustrate the invention and are not intended to limit the scope of the invention.

Manufacturing example : Carbon Nanotube-Silver Composite Manufacturing

0.3 g of thin multi-wall carbon nanotube (Nanotek, Thin Multi-wall CNT grade) and 280 ml of ethylene glycol (EG) were added to a 500 ml round flask. The mixture was stirred for 30 minutes using an agitator, and then reacted for 3 hours using an ultrasonic washing machine. Then, the carbon nanotubes were dispersed on the surface of ethylene glycol, and the temperature inside the flask was maintained at about 50 캜. After the ultrasonic treatment, 1.68 g of polyvinylpyrrolidone (manufacturer: Fluka), 5.6 ml of oleylamine and 1.102 g of silver nitrate (AgNO ₃ ) were further mixed while stirring again. At this time, the air inside the round flask was removed by using a vacuum pump, and the flow of oxygen was prevented by flowing nitrogen into the flask through the inside of the flask. Further, a mantle was installed at the lower part of the flask, the temperature inside the reactor was raised to 200 DEG C over 40 minutes, and the reaction was carried out for 1 hour. After the reduction reaction was completed, the reactor temperature was gradually lowered over 3 hours. The synthesized carbon nanotube-silver complex was filtered using a filter paper and washed several times with ethyl acetate and hexane to obtain a carbon nanotube-silver complex. The carbon nanotube-silver complex was photographed using a scanning electron microscope (SEM), and the photograph of the photograph was shown in FIG. From the SEM photograph, it was confirmed that the silver particles were spherical and uniformly dispersed in a uniform size.

Example : Carbon Nanotubes - Silver Composite Nano Porous membrane  Produce

0.01 g of a carbon nanotube-silver nanocomposite (Bioneer, cat. No. T7031) and sodium dodecyl sulfate (Sigma-Aldrich) used as a surfactant were added to a 500 ml round- 100 g of the aqueous solution containing 1 g was mixed, and ultrasonication was performed by applying ultrasonic wave (Ultrasonicator: JEIOTECH UC-10) at 40 kHz and 45 W for 60 minutes. As a result, a 0.01 wt% carbon nanotube-silver composite dispersion aqueous solution which maintained a stable dispersion state was prepared.

A bucky paper type carbon nanotube - Alumina membrane (Whatman, Cat. No.: 6809-5012) having a pore diameter of 0.1 μm was used as a support to prepare a nanoporous membrane.

The carbon nanotube-silver nanocomposite film was fixed to the membrane using a vacuum filtration apparatus, and 100 ml of the aqueous solution of the carbon nanotube-complex dispersion was filtered using a vacuum filtration apparatus (filtration area: 10.7 cm 2).

In this case, the vacuum filtration apparatus is equipped with an alumina membrane (pore diameter: 0.1 μm) as a support, through which the solvent excluding the carbon nanotube-silver complex is filtered through the pores, A film of the carbon nanotube-silver complex was formed on the surface of the alumina membrane support. Thereafter, the carbon nanotube-silver composite film thus formed was washed with a sufficient amount of water.

The nanocomposite film was floated on a 3 M sodium hydroxide (NaOH) solution interface for 1 hour to remove the alumina membrane as a support in the carbon nanotube-silver composite film fixed to the membrane so that the support was dissolved in the basic solution A pure bucky paper type carbon nanotube-silver nanoporous film was obtained. The dried nanoporous film of the bucky paper type was dried and then heat treated at 200 ° C for 2 hours using an oven to melt the nanotubes to immobilize the carbon nanotube strands. Through this, a carbon nanotube-silver nanoporous film in the form of a bucky paper was produced, and a photograph of the nanoporous film is shown in FIG.

Experimental Example : Flow measurement

The flow rate measurement of the nanoporous film of the carbon nanotube-silver nanoporous film of the bucky paper type prepared in Example 1 was performed.

The nanoporous membrane was fixed on GF (GF / D; Whatman, Cat. No. 1823 047) having a pore size of 2.5 μm and then immersed in a filter holder (ADVANTEC, KS-47) (Water pump; WILO, PWN-351M), and then water was passed through to measure the flow rate. When measuring the flow rate, the time was fixed at 60 seconds, the pressure was controlled by a valve, and each pressure condition was measured at 1, 1.9, and 2.6 bar. The measurement results are shown in Fig. FIG. 3 shows that the flow of the fluid through the nanoporous membrane according to the present invention is smooth. Specifically, when the pressure was 1 to 2.6 bar, it was confirmed that the flow rate was in the range of 0.03 to 0.07 L / cm ² · min.

Claims (17)

A metal or metal oxide and a network structure in which a carbon nanostructure is connected,
Does not include a support,
When the pressure is 1 to 2.6 bar, the flow rate is 0.03 to 0.07 L / cm ² .min. The method according to claim 1,
The carbon nanostructure includes at least one selected from the group consisting of a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, a carbon nanohorn, a carbon nanofiber, and a graphene. The method according to claim 1,
Wherein the pore size is controlled by the size of the carbon nanostructure. The method according to claim 1,
Wherein the pore size is 1 to 500 nm. The method according to claim 1,
The metal may be selected from the group consisting of Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Mo, Ru, Rh, At least one selected from the group consisting of Cd, In, Sn, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Hf, Ir, Pt, Tl, Pb and Bi. 6. The method of claim 5,
And the metal is silver (Ag). delete Applying a dispersion of a carbon nanostructure-metal composite or a carbon nanostructure-metal oxide composite onto a support, and then decompressing the dispersion;
Removing the support; And
Treating the porous film at a temperature of 80 to 350 DEG C before or after the step of removing the support,
The porous film produced by the above method has a flow rate of 0.03 to 0.07 L / cm ² .min when the pressure is 1 to 2.6 bar. delete delete 9. The method of claim 8,
Wherein the metal or metal oxide has a size of 1 to 500 nm. 9. The method of claim 8,
Wherein the content of the metal or metal oxide is 3 to 80 parts by weight based on 100 parts by weight of the carbon nanostructure. 9. The method of claim 8,
The carbon nanostructure-metal composite or carbon nanostructure-metal oxide composite dispersion further comprises a dispersant. delete 9. The method of claim 8,
The step of applying the dispersion of the carbon nanostructure-metal composite or the carbon nanostructure-metal oxide composite dispersion to the support and then reducing the pressure comprises:
Wherein the method is carried out by one or more methods selected from the group consisting of screen printing, doctor blade, spin coating, dip coating, spray coating, electrophoretic deposition, offset printing, vacuum filtration and normal casting. 9. The method of claim 8,
The step of removing the support comprises:
Wherein the etching is carried out through an etching or dissolution process. A filter product using the porous membrane according to any one of claims 1 to 6.

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