KR20190071149A - Method of coating for nanofiber using reduction of metalic salts and method for manufacturing transparent electrode - Google Patents

Abstract

Provided by an embodiment of the present invention is a nanofiber electroless plating method which is able to simplify a nanofiber manufacturing process and reduce manufacturing costs by reducing an electroless plating process on nanofibers. The nanofiber electroless plating method using a silver reducing effect according to an embodiment of the present invention includes: a step i) of producing spinning solution by mixing an organic reducing solvent, metal salt, and a carbon fiber precursor; a step ii) of aging the spinning solution at an aging temperature; a step iii) of electrospinning the spinning solution and forming nanofibers; a step iv) of injecting the nanofibers into electroless copper plating solution and performing a copper plating on the nanofibers; and a step v) of drying the plated nanofibers at a drying temperature.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a nanofiber metal coating method using a metal salt reducing effect and a method for manufacturing a transparent electrode,

The present invention relates to a nanofiber metal coating method and a transparent electrode manufacturing method using the metal salt reducing effect, and more particularly, to a nanofiber metal coating method and a transparent electrode manufacturing method that reduce a metal coating process on a nanofiber, simplify a nanofiber manufacturing process, And a method of manufacturing a transparent electrode using the same.

Nanofibers are ultrafine fibers having a very small diameter of about 1 μm or less and have many applications such as medical materials, filters, MEMS, and nano devices. Nanofibers have a very large surface area per unit mass, are flexible, have many micro spaces, and have a large number of fibers per unit area, so that they can be blended with other materials and exhibit a large dispersion in external stress.

One of the manufacturing methods of nanofibers is electrospinning. The electrospinning device used in the electrospinning method is composed of a spinning tip from which the solution comes out, a high voltage device, and a collector which collects the nanofibers. A high voltage is applied to the spinning tip to charge the droplets discharged from the discharging portion to jet the stream from the droplet by electrostatic repulsion, thereby forming nanofibers on the collecting plate. Nanofibers can also be fabricated using microfluidic techniques. A device consisting of an injection tube and a collection tube is used. When the middle fluid and the outer fluid are different and are pushed to the external pressure, the core shell structure ≪ / RTI >

The plated nanofibers can be used for various purposes by performing plating on the nanofibers as described above.

In the prior art, a heat treatment process for carbonization of nanofibers is required to perform electroplating on nanofibers. Or to perform plating on nanofibers, a catalytic process for nanofibers, and an activation treatment process.

However, when the above process is performed, the entire process is complicated and the manufacturing cost increases.

Korean Patent No. 10-1079775 (entitled Electrospinning Electrolytic Nanofiber Fabrication Method Through Electrolytic Plating), a) an electrospinning solution containing a polymer capable of forming a fiber and an electroless plating catalyst, Producing; b) electrospinning the electrospinning liquid to produce nanofibers having a diameter of 10 nm to 5 탆 in size; and c) electroless plating the nanofibers. The method of manufacturing the metal-coated nanofibers of the present invention includes the steps of:

Korean Patent No. 10-1079775

In order to solve the above problems, an object of the present invention is to provide a method for preparing an electrospinning solution, which comprises adding a metal salt to induce a reducing effect in a solution, forming nanoparticles in a solution through an aging process, Can be continuously and uniformly performed simultaneously with the electrospinning so that the metal coating process can be performed.

An object of the present invention is to produce a transparent electrode with high efficiency by forming copper-plated nanofibers on a transparent substrate.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

According to an aspect of the present invention, there is provided a method of manufacturing a spinning solution, comprising: i) preparing a spinning solution by mixing an organic reducing solvent, a metal salt, and a carbon fiber precursor; ii) aging the spinning solution at an aging temperature; iii) electrospinning the spinning solution to form nanofibers; iv) injecting the nanofibers into an electroless copper plating solution to perform copper plating on the nanofibers; And v) drying the plated nanofibers at a drying temperature.

In the embodiment of the present invention, in the step iii), the metal may be precipitated on the surface of the nanofiber by the reducing effect of the solvent.

In an embodiment of the present invention, the carbon fiber precursor may be polyacrylonitrile (PAN).

In an embodiment of the present invention, the carbon fiber precursor may be 5 to 20% by weight based on 100% by weight of the spinning solution.

In an embodiment of the present invention, the metal salt may be 1 to 80% by weight based on 100% by weight of the spinning solution.

In an embodiment of the present invention, the aging temperature may be lower than the boiling point of the organic reducing solvent.

In the embodiment of the present invention, in the step ii), the spinning solution is radiated to a target cathode, and the cathode may be a roll, a plate, or a needle type.

 In an embodiment of the present invention, the rotation speed of the roller may be 1000 to 2000 rpm.

In the embodiment of the present invention, in the step ii), the spinning liquid may be radiated to a cathode electrode formed of a conductive material.

In an embodiment of the present invention, the drying temperature may be 10 to 100 degrees Celsius.

In the embodiment of the present invention, the step iv) may be performed by injecting the nanofibers into the electroless copper plating solution at a concentration of 0.05 to 0.5 g / L and stirring the nanofibers.

According to an aspect of the present invention, there is provided a method of manufacturing a spinning solution, comprising: i) preparing a spinning solution by mixing an organic reducing solvent, a metal salt, and a carbon fiber precursor; ii) aging the spinning solution at an aging temperature; iii) electrospinning the spinning solution on a substrate to form nanofibers; iv) dipping the substrate on which the nanofibers are formed in an electroless copper plating solution to perform copper plating on the nanofibers; And v) drying the substrate at a drying temperature.

In an embodiment of the present invention, the substrate may be formed of a transparent material.

The effect of the present invention according to the above structure is to reduce the metal coating process on the nanofibers to simplify the nanofiber manufacturing process and reduce the manufacturing cost.

The effect of the present invention is that the process of immersing the nanofibers in a solution is omitted so that the multifunctional multi-layer nanofibers (a combination of metal-coated nanofibers or non-metal-coated nanofibers) can be formed, It is possible to form a metal coated nanofiber by a simple process which is capable of metal coating after transfer and can be used for a large area continuous process and which does not require heat treatment or vacuum process.

Further, the effect of the present invention is that a transparent electrode can be produced by forming the plated nanofibers on a transparent substrate, and having a low sheet resistance and generating a high heat even with a small electric power.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a state change of a nanofiber according to an embodiment of the present invention. FIG.
2 is an FIB image of plated nanofibers according to one embodiment of the present invention.
3 is an FIB image of plated nanofibers according to one embodiment of the present invention.
4 is an SEM image of a nanofiber according to an embodiment of the present invention.
5 is a SEM image of nanofibers according to an embodiment of the present invention.
6 is an SEM image of nanofibers according to an embodiment of the present invention.
7 is an SEM image of nanofibers according to an embodiment of the present invention.
8 is a TEM image of nanofibers according to another embodiment of the present invention.
9 is an SEM image of nanofibers after being electrospun in accordance with another embodiment of the present invention.
10 is an SEM image of a copper-plated nanofiber according to another embodiment of the present invention.
11 is a graph showing transmittance of a transparent electrode using nanofibers according to another embodiment of the present invention.
12 is a graph illustrating sheet resistance of a transparent electrode using nanofibers according to another embodiment of the present invention.
13 is a graph showing sheet resistance of a transparent electrode using nanofibers according to another embodiment of the present invention.
14 is a graph illustrating heating of a transparent electrode using nanofibers according to another embodiment of the present invention.
15 is a graph showing changes in sheet resistance with respect to folding of a transparent electrode using nanofibers according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" (connected, connected, coupled) with another part, it is not only the case where it is "directly connected" "Is included. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a state change of a nanofiber according to an embodiment of the present invention. FIG. FIG. 1 (a) shows a nanofiber formed by electrospinning. FIG. 1 (b) shows a state where silver is precipitated on the surface of the nanofiber. FIG. 1 (c) .

As shown in FIG. 1, the nanofiber metal coating method of the present invention can be performed in the following steps.

In the first step, a spinning solution can be prepared by mixing an organic reducing solvent, a metal salt, and a carbon fiber precursor.

Here, the organic reducing solvent may be formed of dimethylformamide (DMF). In addition, the metal salt may be silver nitrate (AgNO ₃ ).

And, the carbon fiber precursor may be polyacrylonitrile (PAN).

At this time, the carbon fiber precursor may be 5 to 20% by weight based on 100% by weight of the spinning solution.

When the carbon fiber precursor is less than 5% by weight based on 100% by weight of the spinning solution, the concentration of the carbon fiber precursor in the spinning solution can not be sufficiently formed and the formation rate of nanofibers due to electrospinning may be lowered.

When the carbon fiber precursor is more than 20% by weight based on 100% by weight of the spinning solution, the thickness variation of the nanofibers formed by electrospinning increases and the proportion of the carbon fibers having diameters of 1 탆 or more increases, The formation ratio of the nanofibers may be lowered.

Further, the metal salt may be 1 to 80% by weight based on 100% by weight of the spinning solution.

When the silver nitrate (AgNO ₃ ) content is less than 1% by weight based on 100% by weight of the spinning solution, the concentration of silver (Ag ⁺ ) in the spinning solution can not be sufficiently formed and the amount of silver particles precipitated on the surface of the nanofiber And the proportion of nanofibers without silver particles may increase.

When silver nitrate (AgNO ₃ ) is contained in an amount of more than 80% by weight based on 100% by weight of the spinning solution, the concentration of silver (Ag ⁺ ) in the spinning solution is excessive and silver particles precipitated on the surface of the nanofiber It is not evenly distributed in the nanofibers, and a phenomenon that a part of the particles are precipitated out may be generated.

In the second step, the spinning solution can be aged at the aging temperature.

Here, the aging temperature may be lower than the boiling point of the organic reducing solvent.

When the aging temperature is higher than the boiling point of the organic reducing solvent, nanoparticles formed by the carbon fiber precursor may not be uniformly generated and distributed in the solvent.

In the third step, the spinning solution can be electrospun to form nanofibers.

Here, the metal by the metal salt may be precipitated on the surface of the nanofiber by the reducing effect of the solvent. Here, the metal by the metal salt may be silver (Ag).

The silver nanoparticles produced by the reduction effect of the solvent can be adjusted according to the aging time and temperature, and the nanoparticles can be used as a catalyst when electroless plating the nanofibers after electrospinning the spinning solution.

That is, depending on the aging time and temperature of the silver nanoparticles, the amount or size (surface area per particle) of silver nanoparticles deposited on the surface of the nanofibers can be controlled.

Herein, the spinning liquid is radiated to the target cathode, and the cathode may be roll, plate or needle type.

Here, when the target is a roll type, the rotation speed of the roll may be 1000 to 2000 rpm.

The angle at which the spinning liquid is radiated to the roll is referred to as an orientation angle. When the rotation speed of the roll is 1000 to 2000 rpm, the orientation angle is maintained and the nanofibers can be formed. Namely, when the rotation speed of the roll is less than 1000 rpm or exceeds 2000 rpm, the nanofiber is generated in a state in which the orientation angle is not constant and the diameter of the nanofiber is not uniformly formed, When a voltage is applied after forming a network, electricity may not be conducted.

Alternatively, the spinning solution may be radiated to a cathode electrode formed of a conductive material.

When the spinning solution is radiated to the cathode electrode, the spinning solution may be radiated toward the cathode electrode while changing the position or the spraying angle of the syringe for spraying the spinning solution.

In the fourth step, the nanofibers can be injected into the electroless copper plating solution to perform copper plating on the nanofibers.

Here, the nanofibers can be injected into the electroless copper plating solution at 0.05 to 0.5 g / L and stirred.

In the embodiment of the present invention, nanofibers are injected into the electroless copper plating solution and then stirred. However, nanofibers may be injected into the electroless copper plating solution without stirring.

When nanofibers are injected into the electroless copper plating solution in an amount of less than 0.5 g / L or more than 0.5 g / L, copper plating may not be performed on some nanofibers.

There is a known technique for the production of the electroless copper plating solution, and thus a detailed description thereof will be omitted.

In the fifth step, the plated nanofibers can be dried at the drying temperature.

In this case, the drying temperature may be 10 to 100 degrees Celsius.

If the drying temperature is less than 10 degrees, drying on the plated nanofibers may not be performed properly.

If the drying temperature exceeds 100 ° C., the plated copper may peel off due to rapid drying.

In the case of using the conventional electroless plating method of nanofibers, the nanofibers may be frequently broken due to the surface tension during immersing the nanofibers in the solution for the catalyst treatment. Accordingly, there is a problem in that it is difficult to commercialize a product using nanofibers because it is difficult to mass-produce a product using nanofibers or other additional processes.

However, in the case of using the nanofiber metal coating method of the present invention, the process of immersing the nanofibers in a solution is omitted, thereby making it possible to manufacture large-sized products using the nanofibers.

The nanofiber composite material having copper-plated nanofibers can be prepared using the nanofiber metal coating method of the present invention.

Hereinafter, embodiments of the nanofiber metal coating method of the present invention will be described.

[Example 1]

The carbon fiber precursor, polyacrylonitrile (PAN), was dissolved in a solvent composed of dimethylformamide (DMF) in an amount of 10% by weight, silver nitrate (AgNO ₃ ) was dissolved in 10% by weight, Respectively.

Aging was carried out for 30 minutes at room temperature (RT, 25 캜) with respect to the spinning solution.

Thereafter, the spinning solution was electrospun with a roller rotating at 1500 rpm in an electric field of 20 kV to form nanofibers.

Next, copper plating was performed by injecting nanofibers into commercialized electroless copper plating solution (Macdermid M185A) in an amount of 0.3 g / L, and then electroless copper plating solution injected with nanofibers was filtered to form plated nano- The fibers were obtained and dried on plated nanofibers at room temperature (RT, 25 캜).

Thus, copper-plated nanofibers were prepared.

2 and 3 are FIB images of plated nanofibers according to [Example 1] of the present invention.

2 (a) is an image of a plated nanofiber dried at room temperature (RT) for 10 seconds at a magnification x 25000 and x 1750 of an FIB (ion microscope), and Fig. 2 (b) RT) at a magnification of x 2500 and x 250 of FIB (ion microscope) for plated nanofibers dried for 1 minute.

3 (a) is an image of a plated nanofiber dried at room temperature (RT) for 5 minutes at a magnification x10000 and x2500 of FIB (ion microscope), and Fig. 3 (b) ) With a magnification of x12500 and x2500 of FIB (ion microscope) for plated nanofibers dried for 10 minutes.

As shown in FIGS. 2 and 3, it is possible to uniformly disperse and manufacture nanofibers containing a catalyst by electrospinning.

4 to 7 are SEM images of nanofibers according to [Example 1] of the present invention.

4 (a) is an image of a nanofiber formed with a pre-copper plating diameter of 0.964 to 1.1 micrometers (탆), image taken at a magnification x50000 of an SEM (electron microscope), and Fig. 4 (b) Is an image picked up at a magnification x50000 of an SEM (electron microscope) on a nanofiber formed with a diameter of 1.2 to 1.6 micrometers (mu m) after copper plating. It can be confirmed that the thickness of the copper metal layer is formed to 0.1 to 0.5 micrometer (mu m) by comparing the diameter of the pre-plating nanofiber of FIG. 4 (a) and the diameter of the post-plating nanofiber of FIG. 4 (b).

5 (a) is an image of a nanofiber formed with a copper pre-plating diameter of 0.696 to 0.916 micrometers (탆), image taken at SEM (electron microscope) magnification x50000, and FIG. 5 And an image picked up at a magnification x50000 of an SEM (electron microscope) on a nanofiber formed with a diameter of 1.1 to 1.16 micrometers (mu m) after copper plating. It can be confirmed that the thickness of the copper metal layer is formed in the range of 0.4 to 0.65 micrometer (mu m) by comparing the pre-plating nanofiber diameter in Fig. 5 (a) and the post-plating nanofiber diameter in Fig. 5 (b).

6 (a) is an image of a nanofiber formed with a pre-copper plating diameter of 0.778 to 1.03 micrometer (占 퐉) at a magnification x25000 of an SEM (electron microscope), and Fig. 6 The image was taken at a magnification x50000 of an SEM (electron microscope) on a nanofiber formed with a diameter of 1.53 micrometers (탆) after copper plating. It can be confirmed that the thickness of the copper metal layer is formed to be 0.5 to 0.76 micrometer (mu m) by comparing the diameter of the pre-plating nanofiber of FIG. 6 (a) with that of the post-plating nanofiber of FIG. 6 (b).

7 (a) is an image taken at a magnification x50000 of an SEM (electron microscope) for a nanofiber formed with a copper pre-plating diameter of 0.827 to 1.26 micrometers (占 퐉), and FIG. Is an image of a nanofiber formed with a diameter of 1.32 to 1.56 micrometers (占 퐉) after copper plating at a magnification x 25000 of an SEM (electron microscope). It can be confirmed that the thickness of the copper metal layer is formed to 0.3 to 0.5 micrometer (mu m) by comparing the diameter of the pre-plating nanofiber of Fig. 7 (a) with that of the post-plating nanofiber of Fig. 7 (b).

As shown in FIGS. 4 to 7, in the plated nanofiber, the copper metal layer may be formed to a thickness of 0.1 to 0.76 micrometers (占 퐉).

As described above, by using the nanofiber metal coating method of the present invention, it is possible to reduce the metal coating process on the nanofibers, simplify the nanofiber manufacturing process, and reduce the manufacturing cost.

By omitting the process of immersing the nanofibers in a solution, it is possible to form multifunctional multi-layer nanofibers (a combination of metal-coated nanofibers or non-metal-coated nanofibers), transfer the nanofibers to the substrate, And it is possible to form a metal coated nanofiber by a simple process which does not require a heat treatment or a vacuum process.

In addition, a metal electrode plated nanofiber can be formed on a transparent substrate to produce a transparent electrode that has low sheet resistance and generates high heat even at low electric power.

As another embodiment of the present invention, a transparent electrode having copper-plated nanofibers can be manufactured using the nanofiber metal coating method of the present invention.

Hereinafter, a method of manufacturing a transparent electrode according to the present invention will be described.

In the first step, a spinning solution can be prepared by mixing a solvent, a metal salt, and a carbon fiber precursor formed of an organic reducing solvent.

In the second step, the spinning solution can be aged at the aging temperature.

In the third step, the spinning solution can be electrospun onto the substrate to form nanofibers.

Here, the substrate may be formed of a transparent material. Specifically, the substrate may be formed of synthetic resin, glass, and silicon. In the embodiments of the present invention, the substrate is formed of the above-described material, but the present invention is not limited thereto.

In the fourth step, the substrate on which the nanofibers are formed can be immersed in an electroless copper plating solution to perform copper plating on the nanofibers.

In a fifth step, the substrate can be dried at the drying temperature.

The transparent electrode manufacturing method of the present invention is characterized in that unlike the above-described nanofiber metal coating method of the present invention, electrospinning is performed on a substrate as a target without using a roller as a target, It can be immersed in a copper plating solution to perform copper plating on the nanofibers. The remaining matters may be the same as those of the nanofiber metal coating method of the present invention described above.

[Example 2]

Polyacrylonitrile (PAN), a carbon fiber precursor, was dissolved in a solvent composed of dimethylformamide (DMF) in an amount of 8% by weight, dissolved in 10% by weight of silver nitrate (AgNO ₃ ) Followed by stirring to prepare a spinning solution.

Aging was carried out for 60 minutes at room temperature (RT, 25 캜) with respect to the spinning solution.

Thereafter, the spinning solution was subjected to electrospinning for 10 seconds on a 2.5 cm x ^2.5 cm ² PC film (PolyCabonate film) to form nanofibers on the PC film.

Next, a PC film on which a nanofiber was formed on a commercially available electroless copper plating solution (Macdermid M185A) was immersed for 2 hours to perform copper plating, followed by drying on the plated nanofibers at room temperature (RT, 25 ° C) Respectively.

Thus, a transparent electrode having copper-plated nanofibers was produced.

[Example 3]

Polyacrylonitrile (PAN), a carbon fiber precursor, was dissolved in a solvent composed of dimethylformamide (DMF) in an amount of 8% by weight, dissolved in 10% by weight of silver nitrate (AgNO ₃ ) Followed by stirring to prepare a spinning solution.

Aging was carried out for 60 minutes at room temperature (RT, 25 캜) with respect to the spinning solution.

Then, the spinning solution by electrospinning 30 seconds target the PC film (PolyCabonate film) of 2.5X2.5cm ^2, thereby forming the nanofibers on a PC film.

Next, a PC film on which a nanofiber was formed on a commercially available electroless copper plating solution (Macdermid M185A) was immersed for 2 hours to perform copper plating, followed by drying on the plated nanofibers at room temperature (RT, 25 ° C) Respectively.

Thus, a transparent electrode having copper-plated nanofibers was produced.

[Example 4]

Polyacrylonitrile (PAN), a carbon fiber precursor, was dissolved in a solvent composed of dimethylformamide (DMF) in an amount of 8% by weight, dissolved in 10% by weight of silver nitrate (AgNO ₃ ) Followed by stirring to prepare a spinning solution.

Aging was carried out for 60 minutes at room temperature (RT, 25 캜) with respect to the spinning solution.

Thereafter, the spinning solution was electrospun for 60 seconds to a 2.5 cm x ^2.5 cm ² PC film (polyCabonate film) to form nanofibers on the PC film.

Next, a PC film on which a nanofiber was formed on a commercially available electroless copper plating solution (Macdermid M185A) was immersed for 2 hours to perform copper plating, followed by drying on the plated nanofibers at room temperature (RT, 25 ° C) Respectively.

Thus, a transparent electrode having copper-plated nanofibers was produced.

FIG. 8 is a TEM image of nanofibers according to another embodiment of the present invention, and FIG. 9 is an SEM image of nanofibers after electrospun according to another embodiment of the present invention. 10 is an SEM image of copper-plated nanofibers according to another embodiment of the present invention.

Figs. 8 to 10 are images of the transparent electrode of [Example 2]. Fig.

8 (a) is an image taken in 100 nanometers (nm), and FIG. 8 (b) is an image taken in 20 nanometers (nm).

As shown in FIG. 8, nanoparticles of 2.35 to 3.05 nanometers (nm) were generated, and it was confirmed that silver (Ag) particles were well dispersed on the surface of the nanofibers during electrospinning. Such silver (Ag) particles can be used as a catalyst for copper electroless plating.

9 (a) is an image taken at a magnification x20000 of an SEM with respect to nanofibers after electrospinning, and Fig. 9 (b) is an image obtained at a magnification x100000 of an SEM with respect to nanofibers after electrospinning.

As shown in FIG. 9, the nanofiber formed on the PC film according to Example 2 has a diameter of 350 to 400 nanometers (nm).

10 (a) is an image taken at a magnification x20000 of an SEM for a copper-plated nanofiber, and Fig. 10 (b) is an image at a magnification x100000 of an SEM for a copper-plated nanofiber.

As shown in FIG. 10, it can be confirmed that the transparent electrode of [Example 2] has copper-plated nanofibers having a diameter of 800 to 910 nanometers (nm).

9 and 10, it can be seen that the diameter of the copper-plated nanofibers increases by at least two times the diameter of the pre-copper-coated nanofibers, and thus the silver (Ag ) Particles are remarkably catalytic.

11 is a graph showing transmittance of a transparent electrode using nanofibers according to another embodiment of the present invention. Specifically, it is a graph showing the transmittance with respect to the wavelength of light in each of the transparent electrodes of [Example 2] - [Example 4].

11, a graph is a graph showing the transparent electrode transmittance of [Example 2], a graph b is a graph showing the transparent electrode transmittance of [Example 3], and a graph c is a transparent electrode transmittance of [Example 4] Fig.

As shown in FIG. 11, the transparent electrode transmittance of [Example 2] was formed to be 94% on average, the transparent electrode transmittance of [Example 3] was formed to be 70% on average, The electrode transmittance may be formed to be 58%.

That is, by decreasing the capacity of the polyacrylonitrile (PAN) as the carbon fiber precursor in the spinning solution, the spinning liquid is spun on the transparent PC film to form the nanofiber on the PC film, and the PC film on which the nanofiber is formed, When a PC film having copper-plated nanofibers is obtained by dipping in a plating solution, a transparent electrode having excellent transmittance can be formed.

FIG. 12 is a graph showing sheet resistance of a transparent electrode using nanofibers according to another embodiment of the present invention, and FIG. 13 is a graph illustrating sheet resistance of a transparent electrode using nanofibers according to another embodiment of the present invention. Here, FIG. 12 is for a transparent electrode of [Example 3], and FIG. 13 is for a transparent electrode of [Example 4].

Here, the calculation of the sheet resistance measurement by the graph is well known and will not be described here. The unit of sheet resistance is AVRRES Ω / sq.

As shown in the graph of Fig. 12, the sheet resistance of the transparent electrode of [Example 3] can be measured to be 2.61 AVRRES? / Sq. As shown in the graph of Fig. 13, the sheet resistance of the transparent electrode of [Example 4] can be measured at 1AVRRES? / Sq.

14 is a graph illustrating heating of the transparent electrode using nanofibers according to another embodiment of the present invention.

In Fig. 14, a graph a shows the transparent electrode temperature (temperature) of Example 4 according to time (sec) when a voltage of 1 V is applied to the transparent electrode of Example 4, and the graph b shows [ (Temperature) of [Example 4] according to time (sec) when a voltage of 1.5 V is applied to the transparent electrode of Example 4.

14, when a voltage of 1 V was applied to the transparent electrode of Example 4, the temperature of the transparent electrode of Example 4 rose to about 60 degrees (C) within 25 seconds, When a voltage of 1 V is maintained for about 200 seconds, it can be confirmed that the temperature of the transparent electrode of [Example 4] is maintained at about 60 degrees (C).

14, when a voltage of 1.5 V was applied to the transparent electrode of Example 4, the temperature of the transparent electrode of Example 4 rose to about 121 degrees (C) within 25 seconds , And when the voltage of 1.5 V is maintained for about 75 seconds, it can be confirmed that the temperature of the transparent electrode of [Example 4] is maintained at about 121 degrees (C).

The above-mentioned heating experiment was carried out by shortening the time required for the characteristics of the substrate formed of the PC film. When the substrate is formed of glass (quartz glass), the heating time can be increased and the experiment can be performed at a considerably high temperature have.

As shown in FIGS. 12 to 14, the transparent electrode according to another embodiment of the present invention can obtain a transparent electrode which is excellent in heating performance and low in sheet resistance, so that a high-performance heating can be performed even with a small amount of electric power.

The transparent electrode of the present invention can be applied to a place where transparency and heating are required, in particular, a windshield for a vehicle, and the like.

15 is a graph showing changes in sheet resistance with respect to folding of a transparent electrode using nanofibers according to another embodiment of the present invention.

In FIG. 15, a graph a shows the change in sheet resistance (ΔR / R) versus the number of times the transparent electrode of Example 3 was folded (bending cycle) The change in sheet resistance (ΔR / R) with respect to the bending cycle of a conventional transparent electrode, which is a PC film, is shown.

As shown in FIG. 15, in the case of the transparent electrode of [Example 3], the change of the sheet resistance is maintained at a constant level even when the number of times of folding is increased. In the case of the conventional transparent electrode, , Respectively.

As can be seen from the above, the transparent electrode of the present invention can be applied to wearable devices because the change in sheet resistance is maintained at a constant level even when the shape changes.

Specifically, the transparent electrode of the present invention is provided on the clothes, so that clothes that are heated even at a low electric power can be manufactured.

It can also be attached to an object of complex shape.

As a result, it is possible to uniformly disperse the nanofibers containing the catalyst by electrospinning. This can solve the problem that when the catalyst for electroless plating is large, the nanofibers weakly break when the catalyst is treated due to the weak strength of the nanofibers.

Previously, it was difficult to apply nanosize for large area electroless processing, and in the case of nanofibers, loss of transparency largely occurred, making it difficult to apply it as a transparent electrode.

According to the embodiment of the present invention, it is possible to manufacture a nanofiber transparent electrode having a high transmittance and a low sheet resistance, by preparing a nanofiber including a catalyst uniformly dispersed at one time during electrospinning.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. 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, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (14)

i) preparing a spinning solution by mixing an organic reducing solvent, a metal salt and a carbon fiber precursor;
ii) aging the spinning solution at an aging temperature;
iii) electrospinning the spinning solution to form nanofibers;
iv) injecting the nanofibers into an electroless copper plating solution to perform copper plating on the nanofibers; And
and v) drying the plated nanofibers at a drying temperature. The method of coating a nanofiber metal using the metal salt reducing effect.
The method according to claim 1,
Wherein the metal salt is precipitated on the surface of the nanofiber by the reducing effect of the solvent in the step iii).
The method according to claim 1,
Wherein the carbon fiber precursor is polyacrylonitrile (PAN). ≪ RTI ID = 0.0 > 8. < / RTI >
The method of claim 3,
Wherein the carbon fiber precursor is 5 to 20 wt% based on 100 wt% of the spinning solution.
The method according to claim 1,
Wherein the metal salt is used in an amount of 1 to 80% by weight based on 100% by weight of the spinning solution.
The method according to claim 1,
Wherein the aging temperature is lower than the boiling point of the organic reducing solvent.
The method according to claim 1,
Wherein the spinning solution is radiated to a target negative electrode in the step ii), and the negative electrode is a roll, a plate, or a needle type.
Claim 7
Wherein the rotating speed of the roll is 1000 to 2000 rpm.
The method according to claim 1,
Wherein the spinning liquid is radiated to a cathode electrode formed of a conductive material in the step ii).
The method according to claim 1,
Wherein the drying temperature is in the range of 10 to 100 degrees Celsius.
The method according to claim 1,
Wherein the step iv) is performed by injecting the nanofibers into the electroless copper plating solution at a rate of 0.05 to 0.5 g / L and stirring the metal nanofibers.
A nanofiber composite comprising copper-plated nanofibers produced by any one of claims 1 to 11.
i) preparing a spinning solution by mixing an organic reducing solvent, a metal salt and a carbon fiber precursor;
ii) aging the spinning solution at an aging temperature;
iii) electrospinning the spinning solution on a substrate to form nanofibers;
iv) dipping the substrate on which the nanofibers are formed in an electroless copper plating solution to perform copper plating on the nanofibers; And
and v) drying the substrate at a drying temperature.
14. The method of claim 13,
Wherein the substrate is made of a transparent material.

Images