KR20240023815A - Composite fiber and method for manufacturing the same - Google Patents

Abstract

The composite fiber according to the present invention can maximize mechanical properties, mechanical stability, and oxidation stability by including a substrate containing a polymer and having the shape of a fiber, and MXene distributed inside the substrate at an appropriate content.

Description

Composite fiber and method for manufacturing the same {COMPOSITE FIBER AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to composite fibers and methods for producing the same.

MXene is a new two-dimensional material with high electrical conductivity and electrochemical properties similar to metals. It shows excellent performance in many fields such as electrochemical energy storage devices, electrodes, gas and moisture sensors, and conductive fillers.

Additionally, MXene has excellent dispersibility due to the hydrophilic functional groups on its surface. Therefore, highly dispersed MXene solutions can also be produced by fiberization. However, compared to the excellent performance of a single MXene sheet, fibers made as a structure have weak mechanical properties and very poor oxidation stability. Therefore, in order to use MXene as an electric wire, electrical and heating material, and wearable electronic material, further improved chemical stabilization and mechanical properties must be secured.

Republic of Korea Patent Publication No. 10-2020-0176009

The present invention is intended to solve the above problems, and its purpose is to provide a composite fiber with improved mechanical properties by mixing MXene and a polymer and filling the voids inside the MXene with the polymer.

The object of the present invention is not limited to the objects mentioned above. The object of the present invention will become clearer from the following description and may be realized by means and combinations thereof as set forth in the claims.

The composite fiber according to the present invention includes a substrate containing a polymer and having the shape of a fiber; and Mxene distributed inside the substrate, and may include Mxene in an amount of 10% by weight to 40% by weight.

The polymer may include polyacrylonitrile (PAN).

The MXene may be a stack of a plurality of nanosheets, and the polymer may be filled between the nanosheets.

The polymer and the MXene may be combined by electrostatic interaction.

The composite fiber may have a circular, oval, hollow, or flat cross-sectional shape.

The composite fiber may have an electrical conductivity of 10 S/cm to 200 S/cm.

The composite fiber may have a tensile strength of 10 MPa to 200 MPa.

The composite fiber may have a density of 1.0 g/cm to 2.5 g/cm.

The method for producing composite fibers according to the present invention includes preparing a first dispersion containing Mxene and a first solvent; Preparing a second dispersion containing a polymer and a second solvent; Obtaining a mixed solution containing the first dispersion and the second dispersion; and wet spinning the mixed solution to obtain composite fibers, wherein the composite fibers include a base material containing a polymer and having the shape of a fiber; and Mxene distributed inside the substrate, and may include Mxene in an amount of 10% by weight to 40% by weight.

The first solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , dimethyl sulfoxide (DMSO), and combinations thereof.

The first dispersion may have a MXene concentration of 10 mg/mL to 45 mg/mL.

The second solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , dimethyl sulfoxide (DMSO), and combinations thereof.

The second dispersion may have a polymer concentration of 50 mg/mL to 500 mg/mL.

The mixed solution may contain 10% to 60% by weight of MXene.

In the step of obtaining the composite fiber, the composite fiber can be obtained by wet spinning the mixed solution into the coagulation solution.

The coagulating liquid is water, acetone, methanol, ethyl alcohol, isopropyl alcohol, methyl acetate, ethyl acetate, and propyl acetate. (Propyl acetate), Acetic acid, Acetonitrile, 1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone (NMP), dimethylformamide (N, N- It may include one or more selected from the group consisting of Dimethylformamide (DMF), Dimethylacetamide (DMAc), Dimethyl Sulfoxide (DMSO), Tetrahydrofuran (THF), and combinations thereof. .

The temperature of the coagulating liquid may be 20°C to 60°C.

The wet spinning can use a spinneret with a diameter of 10 μm to 1500 μm.

It may further include heat treating the composite fiber at a temperature of 400°C to 600°C in an inert gas atmosphere.

The composite fiber according to the present invention has greatly improved mechanical properties and oxidation stability, and can simultaneously improve electrical conductivity and mechanical properties through additional heat treatment.

The effects of the present invention are not limited to the effects mentioned above. The effects of the present invention should be understood to include all effects that can be inferred from the following description.

1 is a flowchart briefly showing the method for manufacturing composite fibers according to the present invention.
Figure 2 is a cross-sectional photograph of the composite fiber according to Preparation Example 1 of the present invention.
Figure 3 is a cross-sectional photograph of the composite fiber according to Preparation Example 5 of the present invention.
Figure 4 is a cross-sectional photograph of the composite fiber according to Preparation Example 6 of the present invention.
Figure 5 shows the measured tensile strength of composite fibers according to Preparation Examples 1, 7, and 8 of the present invention.
Figure 6 is a cross-sectional photograph of the composite fiber according to Preparation Example 7 of the present invention.
Figure 7 is a cross-sectional photograph of the composite fiber according to Preparation Example 8 of the present invention.
Figure 9 is a cross-sectional photograph of the composite fiber according to Preparation Example 1 of the present invention.
Figure 10 is a cross-sectional photograph of the composite fiber according to Preparation Example 2 of the present invention.
Figure 11 is a cross-sectional photograph of the composite fiber according to Preparation Example 3 of the present invention.
Figure 12 is a cross-sectional photograph of the composite fiber according to Preparation Example 4 of the present invention.
Figure 13 is a cross-sectional photograph of the composite fiber according to Preparation Example 9 of the present invention.
Figure 14 is a cross-sectional photograph of the composite fiber according to Preparation Example 10 of the present invention.
Figure 15 is a cross-sectional photograph of the composite fiber according to Preparation Example 11 of the present invention.
Figure 16 is a cross-sectional photograph of the composite fiber according to Preparation Example 12 of the present invention.
Figure 17 shows the measured tensile strength of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention.
Figure 18 shows measurements of the toughness of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention.
Figure 19 shows the electrical conductivity of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention.
Figure 20 shows the density of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention.

The above objects, other objects, features and advantages of the present invention will be easily understood through the following preferred embodiments related to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete and so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art.

While describing each drawing, similar reference numerals are used for similar components. In the attached drawings, the dimensions of the structures are enlarged from the actual size for clarity of the present invention. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” another part, this includes not only being “directly above” the other part, but also cases where there is another part in between. Conversely, when a part of a layer, membrane, region, plate, etc. is said to be "underneath" another part, this includes not only being "immediately below" the other part, but also cases where there is another part in between.

Unless otherwise specified, all numbers, values, and/or expressions used herein expressing quantities of components, reaction conditions, polymer compositions, and formulations are intended to represent, among other things, how such numbers inherently occur in obtaining such values. Since they are approximations reflecting the various uncertainties of measurement, they should be understood in all cases as being qualified by the term "approximately". Additionally, where a numerical range is disclosed herein, such range is continuous and, unless otherwise indicated, includes all values from the minimum to the maximum of such range inclusively. Furthermore, when such range refers to an integer, all integers from the minimum value up to and including the maximum value are included, unless otherwise indicated.

The composite fiber according to the present invention includes a substrate containing a polymer and having the shape of a fiber; And it may include; Mxene distributed inside the substrate.

Mxene is a new two-dimensional material with high electrical conductivity and electrochemical properties similar to metals. Due to the hydrophilic surface and negatively charged functional groups (OH, O, F), it has excellent dispersibility and is easy to assemble into structures. Additionally, because it does not require post-processing like graphene oxide, the expected cost of the process is low. In the case of fibers manufactured as structures, electrical and mechanical properties are greatly reduced. The reason why these physical properties are weak is because the MXene is made of a plurality of nanosheets stacked, and the bonding force is low due to the pores between the nanosheets inside the MXene.

Therefore, in order to solve the weak physical properties of MXene as described above, the present invention can have improved physical properties by mixing MXene and a polymer and filling the pores between the nanosheets with the polymer.

The content of MXene may be 10% to 40% by weight. If the content of MXene is less than 10% by weight, electrical conductivity may be reduced due to high resistance, and if it exceeds 40% by weight, MXene may act as an impurity and cause radioactivity problems such as fiber breakage when forming a fiber structure.

The polymer may include monomers having a C≡N functional group and all polymers polymerized with monomers having a C≡N functional group. For example, it may be polyacrylonitrile (PAN).

The polymer and the MXene may be combined by electrostatic interaction.

The dispersibility of the composite fiber can be increased by combining -OH, -O, the functional groups of the MXene, and -C≡N-, the functional group of the polymer, through electrostatic interaction.

The composite fiber may have a circular, oval, hollow, or flat cross-sectional shape.

Specifically, in the present invention, the circular and flat types have an aspect ratio of 1 to 30.

The composite fiber may have an electrical conductivity of 10 S/cm to 200 S/cm.

The composite fiber may have a tensile strength of 10 MPa to 200 MPa.

The composite fiber may have a density of 1.0 g/cm to 2.5 g/cm.

Hereinafter, the method for producing composite fibers according to the present invention will be described in detail. In the above manufacturing method, the composition of the polymer-containing base material and MXene is the same as that described above for the composite fiber, so detailed description is omitted.

1 is a flowchart briefly showing the method for manufacturing composite fibers according to the present invention. Referring to FIG. 1, the method for producing composite fibers according to the present invention includes preparing a first dispersion containing Mxene and a first solvent (S10); Preparing a second dispersion containing a polymer and a second solvent (S20); Obtaining a mixed solution containing the first dispersion and the second dispersion (S30); and wet spinning the mixed solution to obtain composite fibers (S40), wherein the composite fibers include a base material containing a polymer and having the shape of a fiber; and Mxene distributed inside the substrate, and may include Mxene in an amount of 10% by weight to 40% by weight.

First, S10 is a step of preparing a first dispersion containing Mxene and a first solvent.

The first dispersion may have a MXene concentration of 10 mg/mL to 45 mg/mL. If the concentration of MXene is less than 10 mg/mL, when mixed with polymer, a mixed solution with low viscosity may be produced and radioactivity may be reduced. If it exceeds 45 mg/mL, aggregation of MXene and polymer occurs, and the viscosity is very high, making radioactivity less likely. It may fall.

The first solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , dimethyl sulfoxide (DMSO), and combinations thereof.

MXene has excellent dispersibility in water because it has hydrophilic functional groups on the surface. However, MXene dispersed in water is difficult to use practically when produced in high concentration. The reason is that it is difficult to redisperse in water. In addition, it is difficult to prepare a uniform dispersion because the nanosheets in MXene tend to agglomerate with each other. Therefore, in the present invention, an organic solvent can be used as the first solvent.

Next, S20 is a step of preparing a second dispersion containing a polymer and a second solvent.

The second dispersion may have a polymer concentration of 50 mg/mL to 500 mg/mL. If the concentration of the polymer is less than 50 mg/mL, the mixed solution may not solidify, and if it exceeds 500 mg/mL, uniform radiation may not be achieved due to the high conductivity of the mixed solution.

The second solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , dimethyl sulfoxide (DMSO), and combinations thereof.

As described above, the polymer may include polyacrylonitrile (PAN), and since polyacrylonitrile is not dispersed in moisture, an organic solvent may be used as the second solvent as described above.

Next, S30 is a step of obtaining a mixed solution containing the first dispersion and the second dispersion.

When an organic solvent is used as a solvent for both the MXene and the first and second dispersions, they are stable at high concentrations, so a uniform mixed solution can be obtained without agglomeration of the MXene. In addition, MXene dispersed in an organic solvent shows high affinity with polyacrylonitrile solution due to its surface functional group, so a stable mixed solution can be obtained. That is, solution stability is excellent, a high concentration spinning solution can be prepared, and a mixed solution with high oxidation stability can be obtained.

The mixed solution may contain 10% to 60% by weight of MXene. For example, it may be included in 10% by weight to 50% by weight, or 20% by weight to 60% by weight. If the content of MXene is less than 10% by weight, conductivity may decrease due to increased electrical resistance, and if it exceeds 60% by weight, formation of a gel capable of spinning fiber may not be possible and spinning may not be possible.

Finally, S40 is the step of wet spinning the mixed solution to obtain composite fibers.

In S40, composite fibers can be obtained by wet spinning the mixed solution into a coagulating solution.

Specifically, in the present invention, wet spinning, for example, applies pressure to the mixed solution and spins it through a spinneret (nozzle) into a coagulating liquid where the fibers are solidified, and solidification proceeds by diffusion of the solvent into the coagulating liquid, resulting in leaching. This is a method in which fibers are formed as the process progresses.

The mixed solution may be spun at a rate of 0.1 mL/h to 35 mL/h. If the spinning speed exceeds 35 mL/h, there may be a problem in that non-uniform fibers are spun due to lack of constant shear stress in the mixed solution.

The coagulating liquid is water, acetone, methanol, ethyl alcohol, isopropyl alcohol, methyl acetate, ethyl acetate, and propyl acetate. (Propyl acetate), Acetic acid, Acetonitrile, 1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone (NMP), dimethylformamide (N, N- It may include one or more selected from the group consisting of Dimethylformamide (DMF), Dimethylacetamide (DMAc), Dimethyl Sulfoxide (DMSO), Tetrahydrofuran (THF), and combinations thereof. . For example, the coagulating liquid may include water and ethanol in a volume ratio of 3:7 to 7:3.

The temperature of the coagulating liquid may be 20°C to 60°C. If the temperature of the coagulating liquid is less than 20 ℃, the coagulation speed is slow, and irregular shrinkage may occur during the drying process of the remaining solvent, which may deteriorate the physical properties. If it exceeds 60 ℃, the solvent diffusion rate increases and the solvent on the surface of the fiber quickly escapes. As it solidifies, the solvent inside the fiber may remain, which may deteriorate its physical properties.

The wet spinning can use a spinneret with a diameter of 10 μm to 1500 μm. For example, it may be 100 μm to 1000 μm, or 100 μm to 500 μm, preferably 100 μm to 410 μm. If the diameter of the spinneret is less than 10 μm, a problem may occur in which spinning through the nozzle does not proceed, and if it exceeds 1500 μm, the orientation and density of the fibers may decrease due to insufficient shear stress, which may deteriorate mechanical properties.

The composite fiber may be stretched 1 to 20 times. Through the stretching, the degree to which the nanosheets and polymers in the MXene are aligned along the axial direction of the fiber, that is, the degree of orientation, can be improved.

It may further include heat treating the composite fiber in an inert gas atmosphere.

Through the heat treatment, polyacrylonitrile can undergo a cyclization reaction and carbonization, thereby strengthening its mechanical properties. In addition, as some of the surface functional groups of MXene are removed, the stability of oxidation due to moisture is improved and the gap between nanosheets is narrowed. As a result, the distance over which electrons can hop is reduced, thereby improving electrical properties. Additionally, since the gap between sheets narrows and becomes denser, density increases and mechanical properties can be improved.

The heat treatment may be performed at a temperature of 400°C to 600°C. If the temperature of the heat treatment is less than 400°C, cyclization of PAN does not proceed, which may cause problems with deterioration of electrical conductivity and mechanical properties. If it exceeds 600°C, normal cyclization reaction results cannot be obtained due to carbonization of PAN. It can happen.

The inert gas may include Ar (argon), N (nitrogen), etc.

The heat treatment may be performed for 30 minutes to 2 hours at a temperature increase rate of 1°C/min to 10°C/min.

The composite fiber is not limited in its field of use, but can be applied to wearable textile materials, electric wires, and heating wires. Additionally, it can be applied to the automotive field, aviation field, and various cable and electric heating product fields.

Hereinafter, the present invention will be described in detail with reference to the following production examples. However, the technical idea of the present invention is not limited or restricted thereby.

Mixed solution preparation examples 1 to 4

A first dispersion containing MXene and dimethyl sulfoxide at a concentration of 9.09 mg/mL was mixed with a second dispersion containing polyacrylonitrile and dimethyl sulfoxide at a concentration of 100 mg/mL, each having different MXene contents. Mixed solution preparation examples 1 to 4 were prepared.

Mixed solution preparation example MXene content in mixed solution Mixed solution preparation example 1 10wt% Mixed solution preparation example 2 20wt% Mixed solution preparation example 3 30wt% Mixed solution preparation example 4 40wt%

Composite fiber production examples 1 to 4

Each mixed solution obtained from Mixed Solution Preparation Examples 1 to 4 was placed in a plastic syringe equipped with a spinneret with a diameter of 100 μm, and spun into a coagulation bath at a rate of 15 mL/h using an injection pump to obtain composite fibers. At this time, the temperature of the coagulating liquid in the coagulating tank was 20°C, and it was a mixed liquid of water and ethanol in a volume ratio of 3:7. The obtained composite fibers Preparation Examples 1 to 4 were dried through a drying heater at 60°C and further dried at 80°C for heat fixation.

Composite fiber manufacturing example Example of mixed solution preparation MXene content in mixed solution Composite fiber manufacturing example 1 Mixed solution preparation example 1 10wt% Composite fiber production example 2 Mixed solution preparation example 2 20wt% Composite fiber production example 3 Mixed solution preparation example 3 30wt% Composite fiber production example 4 Mixed solution preparation example 4 40wt%

Composite fiber production examples 5 to 6

It was prepared in the same manner as in Composite Fiber Preparation Example 1, except that a spinneret with a different diameter from the composite fiber Preparation Example 1 was used.

Composite fiber manufacturing example Example of mixed solution preparation spinneret diameter Composite fiber manufacturing example 1 Mixed solution preparation example 1 100μm Composite fiber production example 5 Mixed solution preparation example 1 250μm Composite fiber production example 6 Mixed liquid preparation example 1 410μm

Composite fiber production examples 7 to 8

It was prepared in the same manner as in Composite Fiber Preparation Example 1, except that a coagulating solution having a different temperature from that in Preparation Example 1 of the composite fiber was used.

Composite fiber manufacturing example Example of mixed solution preparation coagulant temperature Composite fiber manufacturing example 1 Mixed solution preparation example 1 20℃ Composite fiber production example 7 Mixed solution preparation example 1 40℃ Composite fiber production example 8 Mixed solution preparation example 1 60℃

Composite fiber production examples 9 to 12

Each mixed solution obtained from Mixed Solution Preparation Examples 1 to 4 was placed in a plastic syringe equipped with a spinneret with a diameter of 100 μm, and spun into a coagulation bath at a rate of 15 mL/h using an injection pump to obtain composite fibers. At this time, the temperature of the coagulating liquid in the coagulating tank was 20°C, and it was a mixed liquid of water and ethanol in a volume ratio of 3:7. The obtained composite fibers Preparation Examples 5 to 8 were heat treated in an argon atmosphere at a temperature of 500°C for 1 hour at a temperature increase rate of 5°C/min while preventing shrinkage while fixing both ends of the fiber.

Composite fiber manufacturing example Example of mixed solution preparation MXene content in mixed solution Composite fiber production example 9 Mixed solution preparation example 1 10wt% Composite fiber production example 10 Mixed solution preparation example 2 20wt% Composite fiber production example 11 Mixed liquid preparation example 3 30wt% Composite fiber production example 12 Mixed solution preparation example 4 40wt%

Experimental Example 1: Morphological changes in physical properties and cross-section of composite fibers depending on the diameter of the spinneret

Morphological changes in physical properties and cross sections of composite fiber preparation examples 1, 5, and 6 were observed. The results are shown in Table 6 below and Figures 2 to 4.

Composite fiber manufacturing example spinneret diameter tensile strength Composite fiber production example 1 100μm 105MPa Composite fiber production example 5 250μm 95MPa Composite fiber production example 6 410μm 92MPa

Figures 2 to 4 are cross-sectional photographs of composite fibers according to Preparation Examples 1, 5, and 6 of the present invention. Referring to Table 6 and Figures 2 to 4, it can be seen that the shear stress increases with the diameter of the spinneret regardless of the change in shape, and that as the shear stress increases, the orientation and density of the fibers can be adjusted. there is.

Experimental Example 2: Morphological changes in physical properties and cross-section of composite fibers depending on the temperature of the coagulating liquid

Morphological changes in physical properties and cross sections of composite fiber preparation examples 1, 7, and 8 were observed. The results are shown in Figures 5 to 7.

Figure 5 shows the measured tensile strength, which is a physical property of composite fibers according to Preparation Examples 1, 7, and 8 of the present invention. Figures 6 and 7 are cross-sectional photographs of composite fibers according to Preparation Examples 7 and 8 of the present invention. Referring to Figures 5 to 7, it can be seen that as the temperature of the coagulation bath is increased, solvent exchange within the gel fiber is accelerated, resulting in a non-uniform structure in the fiber, thereby deteriorating the mechanical properties.

Experimental Example 3: Morphological changes in physical properties and cross-section of composite fibers depending on heat treatment

Morphological changes in physical properties and cross sections of composite fiber preparation examples 1 to 4 and 9 to 12 were observed. The results are shown in Figures 9 to 20.

9 to 16 are cross-sectional photographs of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention. Figures 17 to 20 show the measured physical properties of composite fibers according to Preparation Examples 1 to 4 and 9 to 12 of the present invention. Referring to Figures 9 to 16, it can be seen that the mechanical and electrical properties of the fiber can be improved by inducing cyclization and dehydrogenation of PAN through the heat treatment process.

Additionally, referring to Figures 17 to 20, it can be seen that Preparation Examples 9 to 12 subjected to heat treatment are all superior in tensile strength, toughness, electrical conductivity and density to Preparation Examples 1 to 4 without heat treatment.

That is, through this, it can be seen that the mechanical properties of the polymer become stronger due to heat treatment, and some of the functional groups on the surface of MXene are removed, and the gap between nanosheets narrows and becomes denser, so the density increases and the mechanical properties become stronger.

Therefore, the composite fiber according to the present invention can maximize mechanical properties, mechanical stability, and oxidation stability by including a substrate containing a polymer and having the shape of a fiber and an appropriate content of MXene distributed inside the substrate. .

Although the manufacturing example of the present invention has been described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. . Therefore, the manufacturing examples described above should be understood in all respects as illustrative and not restrictive.

Claims (20)

A substrate containing a polymer and having the shape of a fiber; and
It includes; Mxene distributed inside the substrate,
A composite fiber containing 10% to 40% by weight of Mxene. According to paragraph 1,
The polymer is a composite fiber containing polyacrylonitrile (PAN). According to paragraph 1,
The MXene is a composite fiber in which a plurality of nanosheets are stacked, and the polymer is filled between the nanosheets. According to paragraph 1,
A composite fiber in which the polymer and the MXene are combined by electrostatic interaction. According to paragraph 1,
The composite fiber is a composite fiber whose cross-sectional shape is circular, oval, hollow, or flat. According to paragraph 1,
Electrical conductivity is 10 S/cm to 200 S/cm,
The tensile strength is 10 MPa to 200 MPa,
Composite fibers with a density of 1.0 g/cm to 2.5 g/cm. Preparing a first dispersion containing Mxene and a first solvent;
Preparing a second dispersion containing a polymer and a second solvent;
Obtaining a mixed solution containing the first dispersion and the second dispersion; and
It includes the step of wet spinning the mixed solution to obtain composite fibers,
The composite fiber includes a substrate containing a polymer and having the shape of a fiber; And Mxene distributed inside the substrate; A method of producing a composite fiber comprising 10% to 40% by weight of Mxene. In clause 7,
The first solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , Dimethyl Sulfoxide (DMSO), and a method of producing a composite fiber containing at least one selected from the group consisting of combinations thereof. In clause 7,
The first dispersion is a method of producing composite fibers wherein the MXene concentration is 10 mg/mL to 45 mg/mL. In clause 7,
The second solvent is methylpyrrolidone (1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone, NMP), dimethylformamide (N, N-Dimethylformamide, DMF), and dimethylacetamide (DMAc). , Dimethyl Sulfoxide (DMSO), and a method of producing a composite fiber containing at least one selected from the group consisting of combinations thereof. In clause 7,
The second dispersion is a method of producing composite fibers in which the polymer concentration is 50 mg/mL to 500 mg/mL. In clause 7,
The mixed solution is a method of producing a composite fiber containing 10% to 60% by weight of MXene. In clause 7,
In the step of obtaining the composite fiber, the mixed solution is wet-spun into the coagulating solution to obtain the composite fiber,
The coagulating liquid is water, acetone, methanol, ethyl alcohol, isopropyl alcohol, methyl acetate, ethyl acetate, and propyl acetate. (Propyl acetate), Acetic acid, Acetonitrile, 1-Methyl-2-pyrrolidinone-N-Methyl-2-pyrrolidone (NMP), dimethylformamide (N, N- Composite fibers containing one or more selected from the group consisting of Dimethylformamide (DMF), Dimethylacetamide (DMAc), Dimethyl Sulfoxide (DMSO), Tetrahydrofuran (THF), and combinations thereof Manufacturing method. According to clause 13,
A method for producing composite fibers wherein the temperature of the coagulating liquid is 20°C to 60°C. In clause 7,
The wet spinning is a method of producing composite fibers using a spinneret with a diameter of 10 μm to 1500 μm. In clause 7,
A method of producing a composite fiber further comprising heat-treating the composite fiber at a temperature of 400°C to 600°C in an inert gas atmosphere. In clause 7,
The polymer is a method of producing a composite fiber containing polyacrylonitrile (PAN). In clause 7,
The MXene is a stack of a plurality of nanosheets, and the polymer is filled between the nanosheets. In clause 7,
A method of producing a composite fiber in which the polymer and the MXene are combined by electrostatic interaction. In clause 7,
The composite fiber has a circular, oval, hollow or flat cross-sectional shape,
Electrical conductivity is 10S/cm to 200S/cm,
The tensile strength is 10 MPa to 200 MPa,
Method for producing composite fibers having a density of 1.0 g/cm to 2.5 g/cm.