KR20220072335A - Carbon dispersive solution and method of dispersing carbon in carbon dispersive solution - Google Patents

Abstract

The present invention provides a carbon dispersion solution and a dispersion method thereof. According to one embodiment of the present invention, the carbon dispersion solution, more than 0% by volume to 4% by volume of carbon particles; and the remainder being water; wherein the carbon particles have a surface potential of negative charge and are dispersed in the water.

Description

Carbon dispersive solution and method of dispersing carbon in carbon dispersive solution

The technical idea of the present invention relates to a carbon dispersion solution and a dispersion method thereof.

Carbon has allotropes such as graphite, diamond, carbon nanotube, fullerene, graphene, etc., and has different names and different properties depending on the bond and structure. The carbon material has the same basic atom bonding, so the chemical properties are similar, but the mechanical properties and physical properties may change depending on the stacked structure and the end of the two-dimensional plane of the base plane, which is a hexagonal structure. As such, carbon has a chemical structure that cannot easily form a substitution bond with a heterogeneous element. However, since the electron layer is thin and has a structure in which nuclear force can be strongly expressed, physical adsorption can be strongly implemented. In other words, carbon material can be physically adsorbed and desorbed with small energy, so it is a core material that enables charging and discharging by removing contaminants or adsorbing and desorbing ionic materials of cathode active materials such as lithium in secondary batteries. can be used a lot. In order to increase the amount of carbon adsorbed, it is necessary to increase the specific surface area, and for this purpose, it is essential to prevent aggregation of activated carbon.

Korean Patent Application No. 10-2006-0105648

The technical problem to be achieved by the technical idea of the present invention is to provide a carbon dispersion solution and a dispersion method thereof.

However, these tasks are exemplary, and the technical spirit of the present invention is not limited thereto.

According to one aspect of the present invention, there is provided a carbon dispersion solution and a dispersion method thereof.

According to one embodiment of the present invention, the carbon dispersion solution, more than 0% by volume to 4% by volume of carbon particles; and the remainder being water; the carbon particles may have a surface potential of negative charge and be dispersed in the water.

According to an embodiment of the present invention, the carbon particles may be charged at the surface potential of -30 mV to -60 mV.

According to an embodiment of the present invention, the carbon particles may include at least one of graphite, carbon nanotubes, fullerene, and graphene.

According to an embodiment of the present invention, the carbon particles may have a particle size in the range of 0.01 μm to 10 μm.

According to an embodiment of the present invention, the carbon dispersion solution, more than 0% by volume to 10% by volume of a functional group in the range; may further include.

According to an embodiment of the present invention, the functional group is one selected from the group consisting of hydrocarbon, halogen, oxygen-containing functional group, nitrogen-containing functional group, sulfur-containing functional group, phosphorus-containing functional group, boron-containing functional group, and metal-containing functional group. may include more than one.

According to an embodiment of the present invention, the carbon dispersion solution, the non-conductive material in the range of more than 0% by volume to 10% by volume; may further include.

According to an embodiment of the present invention, the non-conductive material may include any one of glass, quartz, plastic, ceramic, and metal oxide.

According to an embodiment of the present invention, the carbon dispersion solution may be accommodated and stored in a non-conductive container including any one of glass, quartz, plastic, ceramic, and metal oxide.

According to an embodiment of the present invention, the dispersion method of the carbon dispersion solution comprises the steps of: adding carbon particles in the range of more than 0% by volume to 4% by volume in a solvent to form a carbon dispersion solution; applying plasma to the carbon dispersion solution to charge the carbon particles with a surface potential of a negative charge; and accommodating and storing the carbon dispersion solution in a non-conductive container.

According to an embodiment of the present invention, the plasma may be provided under conditions of a voltage in the range of 1 kV to 2 kV, a current in the range of 10 A to 20 A, DC pulse power, and 1 kHz to 100 kHz.

According to an embodiment of the present invention, the non-conductive container may include any one of glass, quartz, plastic, ceramic, and metal oxide.

According to the technical idea of the present invention, in order to effectively disperse a non-conductive solute such as carbon particles in a solvent such as water, a negative charge was applied to the solute using plasma to form a carbon dispersion solution. When the carbon dispersion solution was stored in a container made of a non-conductive material, the dispersion of the solute was maintained even for several days. This carbon dispersion solution may be applied to activated carbon for removing contaminants, or may be applied to an electrode structure capable of adsorbing and desorbing an ionic material of a cathode active material such as lithium of a secondary battery.

The above-described effects of the present invention have been described by way of example, and the scope of the present invention is not limited by these effects.

1 is a flowchart illustrating a method of dispersing a carbon dispersion solution according to an embodiment of the present invention.
2 is a photograph showing a carbon dispersion solution according to an embodiment of the present invention.
3 is a graph showing a discharge spectrum of a carbon dispersion solution according to an embodiment of the present invention.
4 is an exposure image of a discharge spectrum of a carbon dispersion solution according to an embodiment of the present invention.
5 is a surface potential graph and table of a carbon dispersion solution according to an embodiment of the present invention.
6 is a graph showing the degree of precipitation of a carbon dispersion solution according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the technical idea of the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, The scope of the technical idea is not limited to the following examples. Rather, these embodiments are provided so as to more fully and complete the present disclosure, and to fully convey the technical spirit of the present invention to those skilled in the art. In this specification, the same reference numerals refer to the same elements throughout. Furthermore, various elements and regions in the drawings are schematically drawn. Accordingly, the technical spirit of the present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

Carbon has element symbol number 6, and has an electronic structure of 1S ² 2S ² 2P ² and has four outermost electrons, so it is an atom capable of single to triple covalent bonds depending on the number of electrons of the bonding target atom. Accordingly, carbon can be classified into graphite having a simple hexagonal structure and diamond having a face centered diamond cubic structure, etc., due to the number of atoms, electron bonds, and structure, and these are It is a representative allotropy with completely different properties. Among them, the carbon allotrope having a diamond structure has high mechanical strength, low reactivity, and transparent properties, so it is used as a jewel. On the other hand, carbon allotrope having a hexagonal close packing is brittle and opaque, and unlike diamond, it has the characteristic of forming carbon monoxide and carbon dioxide by combustion reaction with oxygen at a relatively low ignition temperature.

Carbon atoms in the graphite structure have a hexagonal structure, and two single bonds and one double bond are crossed to form a covalent bond in a two-dimensional plane. The form in which these two-dimensional planes are layered is "graphite", the most basic material of carbon materials. In addition, a material having a structure in which the two-dimensional plane is rolled as a covalent bond to form a cylinder is a carbon nano-tube. In addition, a material having a spherical structure with 60 carbon atoms as a unit is fullerene. In addition, a sheet in which the two-dimensional plane is spread only in a cross section is graphene. As such, carbon has different names and different properties depending on the bond and structure, and it is analyzed that it is formed based on graphene, which is covalently bonded in a two-dimensional plane.

The carbon material based on the graphite structure may have different mechanical properties and physical properties depending on the end portion of the two-dimensional plane of the base plane, which is a hexagonal structure, and the stacked structure. However, since the bonds of the basic atoms are the same, the chemical properties are similar. Based on graphene, which is the simplest structure, fullerene in which the basal surface is continuously bonded in a ball shape, carbon nanotubes in a cylindrical shape with both ends of the basal surface bonded together, and in a form in which the basal surface is stacked in the vertical direction Graphite is the outermost electron capable of covalent bonding, and exists in a state in which four electrons are bonded parallel to the basal plane. This means that there is a strong covalent bond with only carbon, which is a key factor in realizing mechanical/electrical properties in interatomic bonding. That is, when only carbon atoms without defects are bonded, the carbon has a chemical structure that cannot easily form a substitution bond with a heterogeneous element. However, since the electron layer is thin and has a structure in which nuclear force can be strongly expressed, physical adsorption such as dipole-dipole interaction or induced dipole can be strongly implemented.

Carbon materials based on graphite structure can physically adsorb various heterogeneous materials rather than chemical bonding, and conversely, desorption with small energy is possible. It can be widely used as a core material that enables charging and discharging by adsorbing or desorbing substances.

Among these carbon structures, a heterogeneous element material may be physically adsorbed on a surface perpendicular to the base surface. However, since the adsorption is not based on a strong bond between electrons, adsorption proceeds only on carbon atoms exposed to the surface. Therefore, the structure is deformed by bonding to a surface atom, such as an ionic bond or a covalent bond, and the surface area is increased by the deformation, so that a repetitive phenomenon in which another bond proceeds does not occur. That is, the amount of heterogeneous material adsorbable to the initial surface area of the activated carbon structure is approximately determined as a limit amount. Since all carbon atoms constituting the activated carbon do not have a surface area capable of adsorbing to foreign substances, it is necessary to increase the surface area in order to increase the adsorption amount. Such a surface area is called a specific surface area (unit [m ² /kg]), and means the surface area per unit mass of a certain particle.

The most common method for increasing the specific surface area is to reduce the particle size, thereby reducing the number of constituent atoms of the material inside the surface area. As a method of composing particles with a molecular size, which is the smallest unit that expresses the properties of an extremely material, it is common to reduce the size of the particles down to a length unit of nanometer (nano meter, 10 ^-9 m). However, activated carbon has a characteristic of being able to form a basal surface structure due to the characteristic that the molecular bonding structure has a hexagonal structure with the outermost four electrons that other elements do not have. Therefore, it is necessary to fill the internal elements inevitably because other elements maintain a three-dimensional structure.

However, carbon can maximize the surface area only by the configuration of the basal surface. For example, in the case of graphene, since it consists only of a base surface, the upper and lower surfaces of the graphene surface become the surface area. In addition, carbon nanotubes having a cylindrical structure may also have adsorption areas on the inner and outer surfaces, similar to graphene. Therefore, the most suitable structures for increasing the specific surface area of activated carbon are graphene and carbon nanotubes.

Since activated carbon has two-dimensional molecular bonds, it can easily increase the specific surface area unlike other elements. However, the biggest problem to be solved in order to utilize this is to construct a unit structure. In the case of graphene, it is the vertical length of the base plane, and the basic constituent material unit is a pico meter (10 ^-10 m), which is the size of a carbon atom. The units are all nanoscale work. In particular, in the case of graphene, since the structure on which the base surface is laminated is graphite, it also tends to easily form graphite bonds, so it is not easy to maintain the structure only on the base surface. Therefore, since the final destination of the adsorption structure using activated carbon is a graphene structure that can maximize the specific surface area by having a structure on the basal surface, a method for maintaining the structure only on the basal surface is required to utilize graphene.

As a suboptimal solution, nano-sized graphite and carbon nanotubes can be used. In order to utilize activated carbon based on the base surface of carbon as an adsorption material, a structure suitable for each application, such as a filter to filter out contaminants or a shelf for storing the cathode active material, must be constructed. The most basic approach for fabricating such a structure can be roughly divided into two.

The first is a method of producing and raising graphene, nano-carbon, and carbon nanotubes after manufacturing a structure for industrial application. However, in the method of making the industrial structure first and generating the activated carbon body, it is necessary to establish a production process according to each required structure, and there is a difficulty in mass production in which reliability is secured.

Second, after manufacturing each activated carbon material, it is to form a structure for application to industry. Both approaches have their own problems. However, in the method of manufacturing the activated carbon and then applying it to industry, the size of the manufactured activated carbon is atomic, so it is difficult to manufacture it in the form required by each industrial product.

As a solution to the two methods, technology research/development is continuously being carried out, but in the technical idea of this patent, the second method, a method for manufacturing activated carbon and then applying it to industry, is presented.

The most problematic reason in the case of industrial application after producing activated carbon is due to aggregation between activated carbons. For mass production, it is common to proceed with a wet method for industrial applications, including the case of wet (production in solution) when generating activated carbon for mass production. will come together As such, since the aggregation between the activated carbons significantly reduces the specific surface area as a result, the prevention of aggregation between the activated carbons is a problem that must be solved for mass production.

As such, in order to prevent agglomeration of activated carbon steel, there are largely a physical dispersion method and a chemical dispersion method.

The physical dispersion method is a method of dropping a particle boundary using vibration, and a representative ultrasonic dispersion method is used. Although it can be easily applied with advances in ultrasonic technology, there is a disadvantage in that activated carbon is destroyed when the amount of energy applied for dispersion increases, and over time, there is a problem in that sedimentation by gravity and re-agglomeration by manpower occur. .

Another physical dispersion method is the principle of preventing sedimentation by gravity by crushing particles and reducing their size to maximize Brownian motion. However, the crushing method to reduce particles has a high possibility of losing its function as the shape of the original dispersed material is changed, so it cannot be applied if it is not independent of the size of the dispersed material.

The chemical dispersion method utilizes a polar or non-polar dispersion stabilizer as a method of using a polar material for dispersion in a solution. In addition, it can be easily applied with advances in dispersion stabilizer technology and has a strong dispersion effect. However, even after drying and forming a structure for industrial product application, the dispersion stabilizer remains and acts as an impurity, and furthermore, it has strong adsorption on the activated carbon surface Because of this, there is a problem that an additional process to remove it is required.

The technical idea of the present invention is a dispersion technology for utilizing activated carbon in a wet process, in order to form a repulsive force between activated carbons, ① electrostatic charging effect and ② wet plasma process and conditions for functional group bonding for polar dispersion of aqueous solution. will do

First, electrostatic charging will be described. Static electricity generally refers to a state of static charge (electricity, charging) in which the distribution of charges generated on the surface of an insulator does not change with time. At this time, the elements that form an electric force on the surface of the insulator are positive and negative charges. Double positive charge is generated by protons constituting the nucleus of an atom, and it corresponds to atoms and molecules having fewer electrons than protons due to ionization. Negative charges are generated by electrons, and similarly, atoms and molecules with more electrons than protons due to ionization correspond to this. In addition, electrons that generate current also generate negative charges.

Static electricity is a phenomenon in which the amount of electric charge does not change with time in a charged material and refers to the absence of current flow. This means that there is no current flow that causes the dissipation of charge in the material system. Therefore, the basic electrostatic charging condition of the dispersed material can be easily applied to the case of an insulator, and all components must use an insulator to preserve the loss of electric charge.

In order to maintain the electrostatic charging effect of a dispersion such as a dispersion solution, it is preferable to basically include a non-conductive material. For example, the non-conductive material may include glass, quartz, plastic, ceramic, metal oxide, etc., and refers to a material used as an electrical resistor.

However, when an electrically conductive metal material is attempted in a situation in which the material used as the dispersion cannot be limited to only a non-conductor, the specific surface area of the charged object is a physical method to increase the amount of electric charge on the surface. There is a way to increase the particle size, and for this purpose, the particles can be nanosized. As a method to nanosize particles, a top-down method that reduces particle size from bulk size to mechanical/physical crushing and a bottom-up method that grows precursors existing as solute and solvent by chemical reduction method There is a bottom-up method. That is, all materials can increase dispersion stability in solution as the size is reduced.

When explaining the surface potential (zeta-potential), all immersed solutes that are not dissolved through polar ionization in solution have an electrical double layer on the surface due to the polarity of the solute and the solution, which is called the surface potential. do. This means the charge capacity stored on the surface, and C/m ² is used as a unit.

A method of measuring the surface potential is typically electrophoresis. The measurement principle is to calculate the voltage value of the electric double layer formed on the surface of the solute by measuring the mobility and speed of the solute obtained by electric force by applying an arbitrary pulsed electric field to the solute dispersed in the solution. Most of the solute dispersed in a general solvent has a surface potential of ±20 mV or less depending on conditions such as the size and polarity of the solute particle, and the polarity and temperature of the solvent.

Table 1 shows the approximate dispersion stability behavior of the dispersion solute according to the surface potential.

Surface potential (mV) Dispersion stability behavior of solutes 0 to ±5 Immediate precipitation and coagulation ±10 to ±30 Instability ±30 to ±40 moderate stability ±40 to ±60 good stability ±61 or more excellent stability

In the existing dispersion method, a method of increasing the surface potential by using a chemical bond has been used, but when the solvent is evaporated and solidified for product application, it remains as an impurity, and thus the product's performance may be deteriorated.

According to the technical idea of the present invention, it is possible to secure the dispersion stability by charging the surface of the dispersion material with negative charges, thereby causing electrical repulsion between the negative charges. As shown in Table 1, it is necessary to have a surface potential of +30 mV or more or -30 mV or less for stable dispersion. Since the present invention uses charging by electrons, a dispersion solution having a surface potential of -30 mV or less is provided. That is, it is charged with a negative value, and the absolute value is 30 or more. Preferably, the surface potential may range from -30 mV to -60 mV.

In general, chemical dispersion stabilizers are characterized by polarity control by chemical binding and charging by negative charge. That is, in a solute dispersed using a chemical dispersion stabilizer, the polarity of the surface potential depends on the properties of the dispersion stabilizer, and the magnitude of the surface potential is proportional to the number bound to the solute surface. In addition, a relatively stable bond is formed in the bond.

According to the technical idea of the present invention, the dispersion solute is negatively charged by electrons, and when an uncharged material is added to a limitedly charged system or grounded with a conductive material, a discharge occurs due to the movement of the charge and the surface potential is lowered. can In order to prevent such a decrease in surface potential, it is necessary to add a non-conductive material to the charged dispersion solution or to store it in a non-conductive container made of a non-conductive material. The non-conductive material to be added may include glass, quartz, plastic, ceramic, metal oxide, and the like. In addition, the non-conductive container includes glass, quartz, plastic, ceramic, metal oxide, and the like.

In order to charge a negative charge to a solute dispersed in a solution, a plasma is used in a manner that provides a plurality of negative charges. Plasma is a state referred to as the fourth state of matter, and as energy is applied to a material in a solid state, the distance between atoms or molecules is relaxed, and thus transitions between a liquid and a solid state. When more energy is applied in the gaseous state, electrons are excited in atoms and molecules.

According to the technical idea of the present invention, a plasma that generates electrons in a solution to charge a solute is used. In this case, generation of ions rather than generation of electrons may be increased by the heat source generated by high power when the discharge is generated. This negatively affects the charging effect by electrons, and as the charging effect is also reduced by the additionally generated heat, the condition for generating a non-equilibrium plasma in the solution can be a major condition for increasing the charging effect of the dispersed solute.

Table 2 exemplarily shows conditions for generating non-equilibrium plasma.

division Appropriate range reason power
Condition power
Volume Voltage 1 kV to 2 kV - Minimize discharge start voltage
- Electrode shape and cooling optimization electric current 10 A to 20 A - Minimize electrode heat
- Surface treatment speed power
category shape DC pulse
(uni-bipolar) - Minimize electrode heat
- Surface treatment speed pulse frequency ~ 100 kHz pulse duti 3 ± 2 μs electrode
Condition addition
Circuit low pass
filter circuit R _{filter part} 50Ω,
R _{discharge part} 100Ω,
C 2nF - Discharge stabilization
- Increased power efficiency machine
part electrode shape Interchangeable for copper, carbon, etc.
(Water cooling electrode) - Minimize discharge start voltage
- Minimize electrode damage power electrode
Channel Connection by power capacity
Series/Parallel selection - Discharge stabilization
- Optimization of total power capacity addition
Condition solution resistivity 10 ³ to 10 ⁶ Ωcm - Optimization of discharge start voltage
- Optimized total power capacity

The following substances may be added to the carbon dispersion solution in order to assist the polarity dispersion effect, which may be insufficient only with the negative charge charging effect by the plasma. In addition, the following substances can be used as a solvent for the carbon dispersion solution. Such materials may be referred to as functional group assited.

The functional group may include one or more selected from the group consisting of hydrocarbons, halogens, oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, phosphorus-containing functional groups, boron-containing functional groups, and metal-containing functional groups.

The hydrocarbon may include, for example, at least one of Alkane, Alkene, Alkyne, and Benzene derivative.

The halogen may include, for example, at least one of Haloalkane, Fluoroalkane, Chloroalkane, Bromoalkane, and Iodoalkane.

The oxygen-containing functional group is, for example, Alcohol, Ketone, Aldehyde, Acyl halide, Carbonate, Carboxylate, Carboxylic acid, Easter, Methodxy, Hydroperoxide, Peroxide, Ether, Hemiacetal, Hemiketal, Acetal, Ketal, Orthpeaster, Heterocycle, Orthocarbonate easter, And it may include at least one of organic acid anhydride.

The nitrogen-containing functional group may include, for example, at least one of Amide, Amine, Imine, Imid, Azide, Azo compound, Cyanates, Nirile, Nitrite, Nitro compound, Nitroso compound, Oxime, Pyridine derivative, and Carbamate easter. have.

The sulfur-containing functional group includes, for example, at least one of Thiol, Su;fide, Disulfide, Sulfoxide, Sulfone, Sulfinic acid, Sulfonic acid, Sulfonate ester, Thiocyanate, Thioketone, Thial, Thiocarboxylic acid, Thioester, and Dithiocarboxylic acid can do.

The phosphorus-containing functional group may include, for example, at least one of Phosphine, Phosphonic acid, Phosphate, and Phosphodiester.

The boron-containing functional group may include, for example, at least one of boronic acid, boronic ester, borinic acid, and borinic ester.

The metal-containing functional group may include, for example, at least one of Alkylitium, Alkylmagnesium haldie, Alkylaluminum, and Sily ether.

1 is a flowchart illustrating a method of dispersing a carbon dispersion solution according to an embodiment of the present invention.

Referring to Figure 1, the dispersion method of the carbon dispersion solution, the step of forming a carbon dispersion solution by adding carbon particles in the range of more than 0% by volume to 4% by volume in a solvent (S110); applying plasma to the carbon dispersion solution to charge the carbon particles with a surface potential of a negative charge (S120); and storing the carbon dispersion solution in a non-conductive container (S130).

The solvent may include, for example, water. Alternatively, the solvent may include a polar solution or a non-polar solution that exists as a liquid at room temperature (0°C to 40°C).

The plasma may be provided under conditions of, for example, a voltage in a range of 1 kV to 2 kV, a current in a range of 10 A to 20 A, DC pulse power, and 1 kHz to 100 kHz.

The non-conductive container may include any one of glass, quartz, plastic, ceramic, and metal oxide.

A carbon dispersion solution is formed by using the dispersion method of the carbon dispersion solution described above.

The carbon dispersion solution, for example, more than 0% by volume to 4% by volume of carbon particles; and the balance may include water.

The carbon particles may have a negatively charged surface potential and be dispersed in the water.

The carbon particles may be charged to the surface potential of, for example, -30 mV to -60 mV.

The carbon particles may include at least one of graphite, carbon nanotubes, fullerene, and graphene.

The carbon particles may have, for example, a particle size in the range of 0.01 μm to 10 μm.

The carbon dispersion solution may further include, for example, more than 0% by volume to 10% by volume of a functional group.

The functional group may include one or more selected from the group consisting of hydrocarbon, halogen, oxygen-containing functional group, nitrogen-containing functional group, sulfur-containing functional group, phosphorus-containing functional group, boron-containing functional group, and metal-containing functional group.

The carbon dispersion solution may further include, for example, a non-conductive material in a range of more than 0% by volume to 10% by volume.

The non-conductive material may include any one of glass, quartz, plastic, ceramic, and metal oxide.

The carbon dispersion solution may be accommodated and stored in a non-conductive container including any one of glass, quartz, plastic, ceramic, and metal oxide.

Experimental example

Hereinafter, preferred experimental examples are presented to help the understanding of the present invention. However, the following experimental examples are only for helping understanding of the present invention, and the present invention is not limited by the following experimental examples.

2 is a photograph showing a carbon dispersion solution according to an embodiment of the present invention.

2, it is an aqueous solution-based carbon dispersion solution prepared using the dispersion method of the carbon dispersion solution of an embodiment of the present invention, and the carbon content is 1% by volume (vol%), 2% by volume, 3% by volume, and 4 It is dispersed in % by volume.

3 is a graph showing a discharge spectrum of a carbon dispersion solution according to an embodiment of the present invention.

4 is an exposure image of a discharge spectrum of a carbon dispersion solution according to an embodiment of the present invention.

3 and 4 , in the discharge spectrum of the aqueous solution-based carbon dispersion solution, main atoms generating electrons are analyzed as hydrogen atoms and oxygen atoms. On the other hand, in other solution conditions, the main material generating electrons may be different depending on the material it contains. Basically, it is easier to increase the amount of electrons generated by using a solution with relatively weak binding force, such as aqueous solution and ethanol, rather than a solution having molecules with strong binding.

5 is a surface potential graph and table of a carbon dispersion solution according to an embodiment of the present invention.

Referring to FIG. 5 , it is a result of measurement after 6 days have elapsed after negative charge was applied to the carbon dispersion solution based on an aqueous solution of 4% by volume. The average surface potential is -50.75 mV, and it has a very high level of negative charge even after 6 days, so it is analyzed that the carbon particles are effectively dispersed in the solution.

6 is a graph showing the degree of precipitation of a carbon dispersion solution according to an embodiment of the present invention.

Referring to FIG. 6 , in all cases, the degree of precipitation (Delta BST) increased with the lapse of time, and the degree of precipitation increased as the volume ratio increased. In the case of the maximum volume of 4% by volume, it can be seen that the degree of precipitation up to 6 days is 1.2% or less. In the case of other volume ratios, it showed a low degree of precipitation compared to 1.2%.

The technical spirit of the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is the technical spirit of the present invention that various substitutions, modifications and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in the art to which this belongs.

Claims (12)

carbon particles in the range of greater than 0% to 4% by volume; and
The balance includes water;
wherein the carbon particles have a negatively charged surface potential and are dispersed in the water;
carbon dispersion solution. The method of claim 1,
The carbon particles are
charged to the surface potential of -30 mV to - 60 mV,
carbon dispersion solution. The method of claim 1,
The carbon particles are
At least one of graphite, carbon nanotube, fullerene, and graphene,
carbon dispersion solution. The method of claim 1,
The carbon particles are
having a particle size ranging from 0.01 μm to 10 μm,
carbon dispersion solution. The method of claim 1,
The carbon dispersion solution,
More than 0% by volume to a functional group in the range of 10% by volume; further comprising,
carbon dispersion solution. 6. The method of claim 5,
The functional group,
Containing one or more selected from the group consisting of hydrocarbons, halogens, oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, phosphorus-containing functional groups, boron-containing functional groups, and metal-containing functional groups,
carbon dispersion solution. The method of claim 1,
The carbon dispersion solution,
Non-conductive material in the range of greater than 0% by volume to 10% by volume; further comprising,
carbon dispersion solution. 8. The method of claim 7,
The non-conductive material is
glass, quartz, plastic, ceramic, and any one of metal oxides,
carbon dispersion solution. The method of claim 1,
The carbon dispersion solution,
Glass, quartz, plastic, ceramic, and stored in a non-conductive container containing any one of metal oxide,
carbon dispersion solution. Forming a carbon dispersion solution by adding carbon particles in the range of more than 0% by volume to 4% by volume in a solvent;
applying plasma to the carbon dispersion solution to charge a surface potential of negative charges to the carbon particles; and
Containing; storing the carbon dispersion solution in a non-conductive container
Dispersion method of carbon dispersion solution. 11. The method of claim 10,
The plasma is
Provided under conditions of voltages ranging from 1 kV to 2 kV, currents ranging from 10 A to 20 A, DC pulse power, and 1 kHz to 100 kHz,
Dispersion method of carbon dispersion solution. 11. The method of claim 10,
The non-conductive container,
comprised of any one of glass, quartz, plastic, ceramic, and metal oxide;
Dispersion method of carbon dispersion solution.

Images