KR101467303B1 - Continuous dispersion device of carbon nanotube - Google Patents

Abstract

The present invention relates to a continuous dispersion apparatus for carbon nanotubes, and more particularly, to a continuous dispersion apparatus for carbon nanotubes using a particle separation apparatus for a carbon nanotube aggregate using a magnetic field.

Description

TECHNICAL FIELD [0001] The present invention relates to a continuous dispersion apparatus for carbon nanotubes (hereinafter, referred to as " CONTINUOUS DISPERSION DEVICE OF CARBON NANOTUBE "

The present invention relates to a continuous dispersion device for carbon nanotubes, and more particularly, to a continuous dispersion device for carbon nanotubes using a particle separation device for a carbon nanotube aggregate using a magnetic field.

Carbon nanotubes (CNTs) are carbon nanotubes that combine with hexagonal honeycomb patterns to form a cylindrical structure. Carbon nanotubes (CNTs) have unique properties that are difficult to find in conventional materials because carbon atoms form sp ² bonds. Therefore, various application techniques have been developed to utilize excellent physical properties such as electrical characteristics, strength, stability, and thermal conductivity in connection with such carbon nanotubes.

However, since single-walled carbon nanotubes generally have surface atoms, aggregation due to van der Waals force between carbon nanotubes tends to occur, and a bundle or an agglomerate structure composed of a plurality of carbon nanotubes And the multi-walled carbon nanotubes are also generally agglomerated in a net-like manner.

Conventionally, as a method of dispersing carbon nanotubes in a solution, a physical dispersion treatment method such as ultrasonic treatment has been proposed. This physical dispersion treatment method is a method of dispersing the carbon nanotubes in acetone, N -methyl-pyrrolidone (NMP), or methyl-ethyl ketone (MEK) by introducing a single walled carbon nanotube aggregate into acetone and subjecting the aggregated carbon nanotube to ultrasonic treatment ; Alternatively, in addition to the ultrasonic treatment, a method of increasing the hydrophilicity of the carbon nanotubes by adding a substance such as a surfactant to the solvent. Korean Patent Publication No. 2010-0051927 discloses an integrated grinding and dispersing system capable of dispersing carbon nanotubes. However, such a conventional method of dispersing carbon nanotubes has a small effect of dispersing carbon nanotubes and may cause external damage to the carbon nanotubes.

In addition, the technology for recovering and separating specific carbon nanotubes using a conventional magnetic field is not intended to recover carbon nanotubes dispersed from carbon nanotube agglomerates but to separate carbon nanotubes from which metal impurities have been removed using a magnetic field Or selectively separating only semiconductive or metallic carbon nanotubes that react with a magnetic field.

In order to produce a composite of carbon nanotubes with high potential marketability, it is necessary to use a minimum carbon material to ensure excellent mechanical properties or electrical conductivity. At this time, the degree of dispersion of the material is an important point. The high-efficiency dispersion technology of carbon nanotubes is also expected to be able to create higher added value by being applied to other kinds of conductive polymer, conductive electronic paint (e-paint), electromagnetic wave absorbing material, tennis ball or racing bicycle .

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 continuous dispersion apparatus for carbon nanotubes.

However, the problems to be solved by the present invention are not limited to the problems described above, and other problems not described can be clearly understood by those skilled in the art from the following description.

The present invention relates to a dispersion unit for dispersing and dispersing an aggregate mixture of carbon nanotubes having magnetic particles attached thereto, A dispersing electromagnet for dispersing the carbon nanotube aggregate mixture by applying a magnetic field to the disperser; A particle separator provided with an electromagnet for particle size separation into which a carbon nanotube mixture liquid dispersed by a magnetic field flows in the dispersing unit; A peristaltic pump for separating and obtaining a solution containing the dispersed carbon nanotubes recovered from the particle size separator; And a peristaltic pump connected to the dispersing unit, the peristaltic pump transferring the mixed liquid including the carbon nanotubes recovered from the particle separation unit.

According to an aspect of the present invention, there is provided a continuous dispersion apparatus for carbon nanotubes capable of dispersing a large amount of carbon nanotubes with high efficiency by implementing a continuous circulation process using a magnetic field. In particular, the present invention relates to a process for mixing carbon nanotubes entangled with each other in a shape of a polymer in a polymer or a solvent and attaching magnetic particles physically reacting to the magnetic field, and a process of dispersing the carbon nanotubes This method can be applied to the development of large-scale dispersion technology of entangled carbon nanotubes which can not be achieved by conventional dispersion techniques. Industrialization of the continuous dispersing apparatus of the present application is economically advantageous because it allows a continuous and stable separation without input of manpower as a very simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a continuous dispersing apparatus according to one embodiment of the present invention.
2 is a photograph showing an actual arrangement of a continuous dispersion apparatus according to an embodiment of the present invention.

Hereinafter, 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 carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

As used herein, the term "carbon nanotube aggregates " refers to aggregates of one or more carbon nanotubes in the form of bundles or agglomerates. The carbon nanotubes may be dispersed according to the method for dispersing carbon nanotubes And may include all necessary aggregated carbon nanotubes.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

The present invention provides a continuous dispersion device for carbon nanotubes comprising:

A dispersing unit for dispersing and mixing an aggregate mixture of carbon nanotubes having magnetic particles attached thereto; A dispersing electromagnet for dispersing the carbon nanotube aggregate mixture by applying a magnetic field to the disperser; A particle separator provided with an electromagnet for particle size separation into which a carbon nanotube mixture liquid dispersed by a magnetic field flows in the dispersing unit; A peristaltic pump for separating and obtaining a solution containing the dispersed carbon nanotubes recovered from the particle size separator; And a peristaltic pump connected to the dispersing unit, the peristaltic pump transferring the mixed liquid including the carbon nanotubes recovered from the particle separation unit.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a continuous dispersion apparatus according to one embodiment of the present invention.

First, a mixture of carbon nanotubes aggregates, magnetic particles, a dispersant, and the like are mixed to form a mixed solution of carbon nanotubes aggregated with magnetic particles on the surface of the aggregated carbon nanotubes, and then injected into the dispersing unit 100, And the dispersing process is performed using the dispersing electromagnet 300 in the unit 100. At this time, the dispersing electromagnet 300 is for dispersing the mixed carbon nanotube aggregate mixture with magnetic particles into individual carbon nanotubes through a magnetic force. When the carbon nanotubes mixed with the dispersed carbon nanotubes are applied to the particle separator 200 and the magnetic field is repeatedly applied, the carbon nanotubes are dispersed to a small particle size and finally dispersed into individual carbon nanotubes do. At this time, the solution containing the dispersed carbon nanotubes must be recovered separately, and the mixed solution containing the carbon nanotubes still having large particle size is continuously exposed to the magnetic field to induce dispersion.

According to an embodiment of the present invention, a temperature controller for adjusting the internal temperature of the dispersion unit or the particle size separation unit may be additionally included, but the present invention is not limited thereto. The dispersion process performed in the dispersion unit 100 or the particle size separation unit 200 may be performed at a temperature of about 10 ° C to about 200 ° C, but is not limited thereto.

According to one embodiment of the present disclosure, the particle size separator 200 may include, but is not limited to,

A container that is not affected by a magnetic field; An injecting unit disposed above the vessel for introducing the dispersed carbon nanotube mixture; A first collecting part disposed at a lower portion of the vessel opposite to the charging part to separate and obtain a solution containing the dispersed carbon nanotubes; A second collecting unit disposed at a lower portion of the vessel opposite to the injecting unit and collecting the mixed liquid including the carbon nanotubes; And the electromagnet for separating the particle size disposed on one side outer wall surface of the container.

According to one embodiment of the present application, the container may be made of a metal-containing material other than glass, quartz, metal oxide, ceramic, polymer, polymer composite material, carbon material, rock or metal magnetized in a magnetic field , But may not be limited thereto. The container can be used without limitation as long as it is made of a material which is not affected by the magnetic field.

According to an embodiment of the present invention, the first collecting unit 220 may be disposed to face the electromagnet 240 for separating the particle size separating member, but the present invention is not limited thereto. When the dispersed carbon nanotube mixture formed in the dispersing unit flows into the particle separator 200 through the input unit 210 disposed on the upper part of the vessel, And dispersed into individual carbon nanotubes. At this time, the solution containing the dispersed carbon nanotubes dispersed in individual carbon nanotubes is hardly influenced by the magnetic field due to its viscosity and drag. Therefore, the solution containing the dispersed carbon nanotubes, which is dispersed in the individual carbon nanotubes, And may be discharged through the first recovery unit 220, but may not be limited thereto.

According to an embodiment of the present invention, the particle size separator 200 may include, but is not limited to, one or more containers that are not affected by the magnetic field. First, a solution containing the dispersed carbon nanotubes, which is recovered through the first collecting part 220 in the particle separator vessel 250, is introduced into another particle separator vessel When the carbon nanotubes are introduced, the carbon nanotubes are dispersed again by the electromagnet, and the mixed liquid containing the carbon nanotubes, which may flow into the carbon nanotubes, may be attracted to the magnetic field to collect only the individual carbon nanotubes having higher purity . At this time, the mixed liquid containing the carbon nanotubes drawn to the magnetic field may be discharged through the second collecting part 230 of the container.

According to an embodiment of the present invention, a magnetic field applying device for applying a magnetic field to the dispersing electromagnet and the electromagnet for separation of particles may be additionally included, but the present invention is not limited thereto. The magnetic field applying device 360 of the dispersing electromagnet is connected to the dispersing portion 100; The magnetic field application device 350 of the magneto-splitting electromagnet applies a magnetic field of a constant intensity to the particle size separator 200 to apply the magnetic field of the carbon nano- The tube aggregate mixture solution or the carbon nanotube mixture solution in which the dispersion is performed functions to have a certain shear stress.

According to an embodiment of the present invention, the dispersing electromagnet and the particle separating electromagnet may include two or more electromagnets, but the present invention is not limited thereto.

According to an embodiment of the present invention, the dispersing electromagnet and the particle separating electromagnet may include, but are not limited to, alternately applying a magnetic field to each of two or more electromagnets. In the dispersing unit, the dispersed electromagnet 300 having two or more dispersed particles can uniformly disperse the carbon nanotube aggregate mixed liquid and the additional dispersing agent, which are contained in the mixed liquid, to which the magnetic particles are attached. When two or more of the electromagnets 240 for separating granules are arranged in the particle separator, alternately a magnetic field is alternately applied thereto, the carbon nanotube mixture having a large particle size is first separated by one magnetic field of the upper electromagnet When the magnetic field disappears, the magnetic field is applied. Then, the magnetic field is applied and then the magnet moves to the electromagnet and sinks. Therefore, further dispersion can be progressed as many as the number of disposed electromagnets to be dispersed to smaller particle sizes, and eventually dispersed in individual carbon nanotubes.

According to an embodiment of the present invention, the magnetic field applying apparatus may further include a power supplying unit that supplies power to the magnetic field applying apparatus, but the present invention is not limited thereto.

According to an embodiment of the present invention, the intensity of the magnetic field applied in the magnetic field applying device may be about 0.05 T to about 20 T, but the present invention is not limited thereto. The intensity of the magnetic field applied to the particle size separator is not particularly limited and may be sufficient if the magnetic particles are aligned in the direction of the magnetic field to generate a shear stress sufficient to disperse the carbon nanotube mixture . For example, the intensity of the magnetic field may be from about 0.05 T to about 20 T, from about 0.1 T to about 20 T, from about 0.5 T to about 20 T, from about 1 T to about 20 T, from about 5 T to about 20 T, About 10 T to about 20 T, about 15 T to about 20 T, about 0.05 T to about 15 T, about 0.05 T to about 10 T, about 0.05 T to about 5 T, about 0.05 T to about 1 T, To about 0.5 T, from about 0.05 T to about 0.1 T, or from about 1 T to about 10 T, for example. At this time, when the magnetic field strength of the electromagnet 300 for dispersing carbon nanotube agglomerates is less than about 0.05 T, there is a fear that the influence of the magnetic field applied to the magnetic particles contained in the mixture is weak, If it exceeds 20 T, carbon nanotubes may be damaged due to abrupt movement of magnetic particles. The application time of the magnetic field may be as long as a magnetic field is applied for a period of time sufficient to disperse the carbon nanotube aggregates by aligning the magnetic particles in the direction of the magnetic field in accordance with the purpose of the present invention, and the range may not be particularly limited.

According to an embodiment of the present invention, a collection unit 600 for collecting the solution containing the dispersed carbon nanotubes may be additionally included, but the present invention is not limited thereto. The carbon nanotubes dispersed in the dispersed carbon nanotubes are transported by the peristaltic pump 500 for separating and obtaining the solution containing the dispersed carbon nanotubes, (600).

According to an embodiment of the present invention, the mixed liquid containing the carbon nanotubes may be reintroduced into the dispersion unit, but the present invention is not limited thereto. 1, when the continuous dispersing apparatus of the present invention includes two particle separator vessels 250, the carbon nanotubes recovered through the second collecting unit 230 of the first particle separator vessel And the carbon nanotube aggregate recovered through the second collecting unit of the second particle separator vessel connected to the first particle separator vessel may be reintroduced into the dispersing unit 100 , But may not be limited thereto. When a magnetic field is applied to the electromagnet 240 for separating granularity provided in the granularity separator 200, the mixed liquid containing the carbon nanotubes adheres to the wall surface on which the electromagnets are disposed by attraction action of the magnetic field, It can be directly discharged and discharged to the second recovery section. At this time, the mixed liquid including the carbon nanotubes discharged may be transferred to the dispersing unit 400 by the peristaltic pump 400 for transferring the mixed liquid including the carbon nanotubes, and may be continuously dispersed again. However, .

According to one embodiment of the present invention, the magnetic particles may include, but are not limited to, a transition metal or a transition metal oxide. The magnetic particles may include a magnetic transition metal or a transition metal oxide, and may include any material that can be aligned in a direction in which a magnetic field is generated in response to a magnetic field. For example, the transition metal may be iron, cobalt, nickel, Chromium, and combinations thereof. The term " chromium " As the magnetic particles, various types of ferrite known in the art can be used. Specifically, ferrite including iron oxide, cobalt, nickel, chromium oxide or the like may be used, but not limited thereto .

According to an embodiment of the present invention, the carbon nanotube aggregation mixture may include about 0.1 part by weight to about 20 parts by weight of the magnetic particles, relative to about 1 part by weight of the carbon nanotube aggregates. However, But may not be limited thereto. For example, the carbon nanotube aggregate mixture may contain about 0.1 to about 20 parts by weight, about 0.5 to about 20 parts by weight of the magnetic particles, about 1 to about 20 parts by weight, About 20 parts by weight, about 2 parts by weight to about 20 parts by weight, about 5 parts by weight to about 20 parts by weight, about 10 parts by weight to about 20 parts by weight, about 0.1 to about 10 parts by weight, To about 5 parts by weight, from about 0.1 parts by weight to about 2 parts by weight, from about 0.1 parts by weight to about 1 part by weight, from about 0.1 parts by weight to about 0.5 parts by weight, or from about 2 parts by weight to about 5 parts by weight But may not be limited thereto.

According to an embodiment of the present invention, the aggregate mixture of the carbon nanotubes to which the magnetic particles are added may further include at least one dispersant, but the present invention is not limited thereto. The dispersant is mixed with the carbon nanotube agglomerate and the magnetic particles to disperse the carbon nanotube agglomerates through shear stress generated when the magnetic particles are aligned in the direction of the magnetic field according to application of the magnetic field . The dispersant may be any material that can be used as a dispersant having a predetermined viscosity to disperse the carbon nanotube aggregates. The dispersant may be a solvent such as water or alcohol, an organic solvent, a polymer resin capable of controlling viscosity, and a plasticizer. For example, the dispersant may be at least one selected from the group consisting of water, an organic solvent, an epoxy resin, a urea resin, a melamine resin, a phenol resin, a urethane resin, an amide resin, an acrylic resin, a silicone resin, a natural oil, a phthalic acid ester, But are not limited to, those selected from the group consisting of trimellitic acid esters, phosphoric acid esters, polyesters, and combinations thereof. The dispersant may be, for example, water; Methanol, ethanol, propanol, butanol, dimethylformamide (DMF), acetone, N -methyl-pyrrolidone (NMP), and methyl-ethyl ketone (MEK); Epoxy resin; Urea resin; Melamine resin; Phenolic resin; Urethane resin; Amide resin; Acrylic resin; Silicone resin; Triglyceride; Di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), dihexyl phthalate (DHP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP); Dioctyl malate; Dioctyl adipate; Triethylhexyl trimellitate (TOTM), triisononyl trimellitate (TINTM), triisodecyl trimellitate (TID TM); Phosphoric esters of aliphatic alcohols or aromatic alcohols; Chlorinated polyester; ≪ / RTI > and combinations thereof.

According to one embodiment of the present invention, the dispersant may further include a viscosity adjusting agent such as water, alcohol, ketone, and aromatic hydrocarbon, and may be adjusted to an easily dispersible viscosity. For example, when the water-soluble polymer is used as the dispersing agent, a viscosity controlling agent such as water or alcohol may be added. When a general polymer is used as the dispersing agent, a viscosity controlling agent such as an aromatic hydrocarbon or a ketone may be added. But may not be limited thereto. The viscosity controlling agent serves to control the viscosity of the mixed liquid to such a degree that the magnetic particles mixed in the dispersing agent can move in response to the magnetic field application.

The content of the dispersant is not particularly limited. For example, about 1 part by weight of the aggregate of carbon nanotubes may contain about 10 parts by weight to about 1,000 parts by weight, about 15 parts by weight to about 1,000 parts by weight, 20 parts by weight to about 1,000 parts by weight, about 30 parts by weight to about 1,000 parts by weight, about 40 parts by weight to about 1,000 parts by weight, about 50 parts by weight to about 1,000 parts by weight, about 100 parts by weight to about 1,000 parts by weight, About 500 parts by weight to about 1,000 parts by weight, about 800 parts by weight to about 1,000 parts by weight, about 10 parts by weight to about 800 parts by weight, about 10 parts by weight to about 500 parts by weight, about 300 parts by weight to about 1,000 parts by weight, about 500 parts by weight to about 1,000 parts by weight, From about 10 parts by weight to about 30 parts by weight, from about 10 parts by weight to about 30 parts by weight, from about 10 parts by weight to about 300 parts by weight, from about 10 parts by weight to about 100 parts by weight, from about 10 parts by weight to about 50 parts by weight, 10 parts by weight to about 20 parts by weight, about 10 parts by weight to about 15 parts by weight , Or about 20 may be contained in an amount of parts by weight to about 50 parts by weight.

Hereinafter, the present invention will be described in more detail with reference to examples and drawings, but the present invention is not limited thereto.

[ Example ]

2 is an actual arrangement photograph of the continuous dispersion apparatus according to the present embodiment. As shown in FIG. 2, the continuous dispersing apparatus was installed and carbon nanotube dispersion experiments were performed as described below.

Adhesion between carbon nanotubes and magnetic particles was performed by the radical initiator attachment method of Stoffelbach et al. (MWNTs) were prepared by adding magnetite magnetic particles to 100 mL of distilled water containing 1.5 g of 4,4'-azobis (4-cyanovaleric acid) [4,4'-azobis (4-cyanovaleric acid) And the magnetic particles were attached to the surface of the carbon nanotubes by injecting nitrogen gas at 80 ° C for 10 hours. NMP (N-methyl-pyrrolidone), a solvent, was added to a carbon nanotube-magnetite complex having carbon nanotube aggregates and magnetic particles at a weight ratio of 1: 3 at a weight ratio of 10 times the weight of the carbon nanotube aggregates Then, the dispersion liquid was dispersed in the dispersion unit 100, and the mixed carbon nanotube-magnetite complex mixture was transferred to the particle separation unit. A magnetic field of 1 T was applied to the particle separator through which the mixed solution was transferred for 8 hours at intervals of 2 seconds to disperse the carbon nanotubes and recover the solution containing the dispersed carbon nanotubes as a collecting part.

[ Experimental Example ]

The solution containing the dispersed carbon nanotubes obtained in the examples was sprayed onto a glass substrate, and then SEM images were taken to confirm the degree of dispersion of the carbon nanotubes. That As a result, it was confirmed that the carbon nanotube aggregates were well dispersed.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative and non-restrictive in every respect. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

100: dispersion part
200: particle size separator
210: input portion of the container
220: First container of the container
230: second vessel of vessel
240: electromagnet for particle size separation
250: container body
300: Dispersing electromagnet
350: magnetic field applying device of electromagnet for particle size separation
360: magnetic field applying device of dispersing electromagnet
400: Peristaltic pump for transporting mixed liquid containing carbon nanotubes
500: peristaltic pump for separation and preparation of a solution containing dispersed carbon nanotubes
600: collection part

Claims (2)

A dispersing unit for dispersing and mixing an aggregate mixture of carbon nanotubes having magnetic particles attached thereto;
A dispersing electromagnet for dispersing the carbon nanotube aggregate mixture by applying a magnetic field to the disperser;
A particle separator provided with an electromagnet for particle size separation into which a carbon nanotube mixture liquid dispersed by a magnetic field flows in the dispersing unit;
A peristaltic pump for separating and obtaining a solution containing the dispersed carbon nanotubes recovered from the particle size separator; And
And a peristaltic pump connected to the dispersing unit and transferring the mixed liquid including the carbon nanotubes recovered from the particle separator,
Wherein the dispersing electromagnet and the particle separating electromagnet each include two or more electromagnets,
Continuous dispersion device of carbon nanotubes.
The method according to claim 1,
Wherein the dispersing electromagnet and the particle separating electromagnet each include a magnetic field alternately applied to each of two or more electromagnets.

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