KR101790282B1 - Graphite-conductive polymer composite and process for production thereof - Google Patents

Abstract

The present invention relates to a method for producing a graphite-conductive polymer monomer dispersion, which comprises dispersing graphite in a conductive polymer monomer to prepare a graphite-conductive polymer monomer dispersion solution; And a polymerization step of polymerizing the conductive polymer monomer to form a graphite-conductive polymer composite. The present invention relates to a method for producing a graphite-conductive polymer composite by polymerizing the conductive polymer monomer to form a graphite-conductive polymer composite, A graphite-conductive polymer composite excellent in electrical conductivity and excellent in electrical conductivity can be provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a graphite-conductive polymer composite and a method for manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a complex of graphene and a conductive polymer and a method for producing the same.

 Graphene, which is a two-dimensional monolayer of carbon atoms with sp2 bonds, has attracted much attention due to its excellent electrical conductivity, thermal conductivity, good mechanical strength, wide specific surface area and low manufacturing cost. Due to such excellent properties, it has been found to be used in various applications such as transparent electrodes, energy storage devices, sensors, and nanocomposite materials. Especially, the complex of graphene and polymer has attracted much interest in scientific and industrial fields due to the reinforcing effect of graphene.

 Basically, graphene (GO) or reduced graphene oxide (RGO) is used for the combination of graphene and polymer. However, GO has good dispersibility in water, but sp2 bond breaks down in oxidation process, resulting in deterioration of electrical properties. In the case of RGO, sp2 bond is restored by reduction, and electric properties are restored to some extent. Resulting in difficulty in complexing with the water-dispersible polymer.

In spite of these various industrial efforts, satisfactory results have not appeared to date.

1. U.S. Published Patent Application No. 2014-0367618 (published on Dec. 18, 2014) 2. European Patent No. 1,375,425 (Published on January 2, 2004)

An object of the present invention is to improve the water dispersibility and electrical conductivity of a graphite-conductive polymer composite by dispersing graphite in a conductive polymer monomer and then polymerizing it.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

As means for solving the above problem,

Disclosed is a method for producing a graphite-conductive polymer monomer dispersion, comprising: dispersing a graphite-conductive polymer monomer dispersion solution by dispersing graphite in a conductive polymer monomer; And a polymerization step of polymerizing the conductive polymer monomer to form a graphite-conductive polymer composite. The present invention also provides a method for producing a graphite-conductive polymer composite.

The conductive polymer monomer may include EDOT (3,4-ethylenedioxythiophene), and the graphite may be contained in an amount of 0.5 to 2.0 wt% based on 100 wt% of the conductive polymer monomer solid content.

In the method for producing a graphite-conductive polymer composite, graphite may be dispersed in the conductive polymer monomer by using an ultrasonic crusher in the dispersion step, and the graphite may be dispersed in the conductive polymer monomer for 1 hour and 30 minutes to 2 hours in the dispersion step .

In the method for producing a graphite-conductive polymer composite, an oxidizing agent may be added to the dispersion solution in the polymerization step for polymerization for 24 to 26 hours. In addition, the polymerization step may include adding a dopant to the dispersion solution to polymerize. When the dispersion solution is stored at room temperature for 48 hours, the graphite may not precipitate.

The present invention also provides a graphite-conductive polymer composite comprising a conductive polymer comprising a dopant and graphite, and a conductive polymer comprising the dopant surrounding the graphite surface.

When the graphite-conductive polymer composite is analyzed through X-ray photoelectron spectroscopy (XPS), a peak corresponding to a sulfur (S) element is determined as a reference , Wherein a peak area ratio of the conductive polymer to the dopant is 1: 1.5 to 2.5 ≪ / RTI > When the graphite-conductive polymer composite is analyzed through energy dispersive spectroscopy (EDS), the carbon (C) element is contained in an amount of 50 to 65 wt%, sulfur (S) Sulfur) element may be included in the range of 8 to 15% by weight.

When the water dispersibility of the graphite-conductive polymer composite is measured, it may be 0.8 to 1.2 times the water dispersibility of the conductive polymer in which the graphite is not complexed. Also, when the electrical conductivity of the coated film is measured using the graphite-conductive polymer composite, the electric conductivity may be 2.00 × 10 ² to 1.00 × 10 ⁴ S / m.

The present invention can produce a composite directly from an inexpensive graphite by forming a graphite-conductive polymer composite by polymerizing a conductive polymer monomer after dispersing the graphite in a conductive polymer monomer without using graphene flake to impart water dispersibility Can be provided.

The graphite-conductive polymer composite produced by the above method has excellent water-dispersibility compared to a single graphite and can provide improved electrical conductivity compared to a single conductive polymer.

Further, by combining with a thermally highly stable inorganic material (graphite), an improved thermal stability compared to a single conductive polymer can be expected.

Here, a single graphite and a single conductive polymer refer to a state in which graphite and a conductive polymer are not combined.

1 is a schematic view of a graphite-conductive polymer composite according to an embodiment of the present invention.
FIG. 2 shows FT-IR analysis results of a graphite-conductive polymer composite prepared according to an embodiment of the present invention.
FIG. 3 shows XPS analysis results of the graphite-conductive polymer composite prepared according to an embodiment of the present invention.
FIG. 4 is a graph showing a Raman spectrum analysis result of a graphite-conductive polymer composite prepared according to an embodiment of the present invention.
5 shows XRD results of a graphite-conductive polymer composite prepared according to an embodiment of the present invention.
6 shows SEM and EDS results of a graphite-conductive polymer composite prepared according to an embodiment of the present invention. (GP-RP) in which the free conductive polymer is removed from (a) graphite, (b) graphite-conductive polymer composite, and (c) graphite-conductive polymer composite.
7 shows the dispersibility of graphite to a solvent according to Experimental Example of the present invention.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout this specification and claims, the word "comprise", "comprises", "comprising" means including a stated article, step or group of articles, and steps, , Step, or group of objects, or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. Any feature that is specifically or advantageously indicated as being advantageous may be combined with any other feature or feature that is indicated as being preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

Conventional graphene-conductive polymer complexes have limitations in achieving compatibility between water dispersibility and excellent electrical conductivity. The present inventors have found that graphite is well dispersed in EDOT (3,4-ethylenedioxythiophene) solution which is a monomer of PEDOT (poly (3,4-ethylenedioxythiophene)) which is an aqueous conductive polymer and dispersion stability is almost same as NMP (NMethyl-pyrrolidone) And found that higher levels of complexes were developed by polymerizing EDOT in the presence of graphite dispersed in an EDOT solution. A detailed description will be given.

≪ Production method of graphite-conductive polymer composite >

 The method for producing a graphite-conductive polymer composite according to the present invention is a dispersion step of dispersing graphite in a conductive polymer monomer to prepare a dispersion solution of a graphite-conductive polymer monomer, forming a graphite-conductive polymer composite by polymerizing a conductive polymer monomer And a polymerization step. FIG. 1 is a schematic view of a graphite-conductive polymer composite prepared according to a method for producing a graphite-conductive polymer composite according to an embodiment of the present invention.

The dispersing step of the manufacturing method according to an embodiment of the present invention is a step of dispersing graphite in the conductive polymer monomer.

The graphite contained in the dispersion step is used in an amount of 0.5 to 2.0 wt% based on 100 wt% of the conductive polymer monomer solid content. If it is more than 2.0% by weight, the graphite can be precipitated without being dispersed in the conductive polymer monomer, and if it is less than 0.5% by weight, there is little difference in electric conductivity with the single conductive polymer. It is preferable to use 0.8 to 1.8% by weight, more preferably 1.0 to 1.5% by weight.

The conductive polymer monomer included in the dispersing step may be selected from the group consisting of thiophene series, pyrrol series and aniline series. Preferably, the conductive polymer monomer is selected from thiophene series. Preferably, EDOT (3,4-ethylenedioxythiophene) is used.

In the dispersing step, an ultrasonic crusher is used to disperse the graphite in the conductive polymer monomer and dispersed for 30 minutes to 4 hours. If it exceeds 4 hours, the conductive polymer monomer can be polymerized, and if it is less than 30 minutes, the graphite is not properly dispersed in the conductive polymer monomer and precipitates. Preferably 1 to 3 hours, and more preferably 1 to 30 minutes to 2 hours.

The dispersion solution of the graphite and the conductive polymer monomer prepared in the dispersion step does not precipitate graphite even when stored at room temperature for 48 hours. Therefore, the conductive polymer monomer can be used as a medium for dispersing graphite.

The polymerization step of the production method according to an embodiment of the present invention is a step of preparing a graphite-conductive polymer composite by adding an oxidizing agent to a dispersion solution of graphite and conductive polymer monomer prepared in the dispersion step to perform polymerization reaction. The polymerization may be carried out by further adding a dopant.

In the polymerization step, an oxidizing agent is added to the dispersion solution and polymerization is carried out for 16 to 40 hours. It is insignificant to lengthen the reaction time over 40 hours, and polymerization does not occur sufficiently if it is less than 16 hours. The polymerization is preferably carried out for 20 to 30 hours, more preferably 24 to 26 hours.

The polymerization step may be carried out in the presence of at least one selected from the group consisting of sodium persulfate, iron (III) sulfate hydrate, ammonium peroxydisulfate, 1,4-benzoquinone, benzaldehyde, benzoyl peroxide, tert- butylbenzenesulfinimidoyl chloride, tert- 3-chloroperoxybenzoic acid, 3-chloroperoxybenzoic acid, chromium trioxide, cumene hydroperoxide, hydrogen peroxide, iodobenzene dichloride, nitrosobenzene, peracetic acid, periodic acid, peroxy acids, phenyliodonium diacetate, phthaloyl peroxide, potassium ferricyanide, potassium peroxydisulfate, potassium peroxomonosulfate bromide, sodium chlorite, sodium dichloroiodate, sodium hypochlorite, sodium nitrite, sodium percarbonate, sodium peroxydisulfate, and 1,1,1-trifluoroacetone.

The oxidizing agent is necessary for the oxidative polymerization of the conductive polymer monomer, and 20 to 55% by weight of the total reactants is used. If it is less than 20% by weight, oxidation polymerization of the monomer can not be performed smoothly, and if it exceeds 55% by weight, it is difficult to control the polymerization reaction rate. Preferably 25 to 50% by weight, and more preferably 30 to 45% by weight.

The polymerization step may be a dopant that can be contained in addition to the conductive polymer monomer, for example, an anion of a polymeric carboxylic acid or a polymeric sulfonic acid. As the anion of the polymeric carboxylic acid, polyacrylic acid, polymethacrylic acid, polymaleic acid and the like can be used, and as the polymeric sulfonic acid, polystyrene sulfonic acid, polyvinylsulfonic acid and the like can be used. It is particularly preferable to use polystyrene sulfonic acid (PSS) as the dopant.

The dopant uses 30 to 60 wt% of the total reactants. If the dopant is more than 60% by weight, the electrical properties of the conductive polymer are deteriorated because the amount of the dopant is excessively large in the synthesized conductive polymer. If the dopant is less than 30% by weight, the doping is not sufficient and the electrical characteristics are deteriorated. It is preferable to use 40 to 50% by weight, more preferably 42 to 45% by weight.

The manufacturing method according to an embodiment of the present invention may further include a purification step after the polymerization step. In the purification step, the polymerized reactant in the polymerization step is filtered using a nylon membrane filter (pore size: 0.2 μm) and then washed. Through the purification step, a pure graphite-conductive polymer composite can be obtained.

In the production method according to one embodiment of the present invention, water or an aqueous alcohol solution is used as a solvent in both the dispersion step and the polymerization step.

<Graphite-Conducting Polymer Complex>

The graphite-conductive polymer composite having the structure as shown in FIG. 1 can be provided by the process for producing a graphite-conductive polymer composite according to an embodiment of the present invention. The graphite-conductive polymer composite according to the present invention is composed of a conductive polymer including a dopant and graphite, and has a structure in which a conductive polymer wraps around graphite.

The structure of the graphite-conductive polymer composite according to the present invention will be described in detail through XPS and EDS analysis. The structure of the specific graphite-conductive polymer composite can be confirmed by the following experimental examples (FT-IR, XPS, Raman spectrum, XRD, SEM, EDS analysis) and FIGS.

FIG. 3 shows the result of analyzing the graphite-conductive polymer composite according to the present invention through XPS analysis. The graphite-conductive polymer composite according to the present invention is composed of a conductive polymer including a dopant and graphite. The peak area ratio of the conductive polymer and the dopant is preferably 1: 1.5 to 2.5. When the area ratio falls within the above range, a ratio of a portion that actually exhibits conductivity to a dopant that provides water solubility is suitable, thereby providing a water-soluble and conductive polymer. If the proportion of the dopant in the above area ratio is less than 1.5, the content of the dopant is small and the conductive polymer is not dispersed in water. If the ratio of the dopant in the area ratio exceeds 2.5, the relative content of the conductive polymer to the dopant is small. It is preferably 1: 1.6 to 2.3, more preferably 1: 1.8 to 2.1.

The elemental analysis of the graphite-conductive polymer composite according to the present invention was performed through EDS elemental analysis, and the result is shown in FIG. The weight% of carbon (C) and sulfur (S) elements of the graphite-conductive polymer composite according to the present invention is 50 to 65% by weight of carbon (C) Is preferably 8 to 15% by weight. When the content of carbon (C) is less than 50% by weight, the conductive polymer is not complexed with graphite and the conductivity is lowered. When the content of C (carbon) is less than 65% by weight, the conductive polymer is not sufficiently synthesized on the graphite surface. If the content of S (sulfur, sulfur) element is less than 8% by weight, the content of the dopant is lowered, so that the water dispersibility is lowered. When the content of S (sulfur, sulfur) The relative content of the conductive polymer is smaller than that of the water-soluble dopant, and the conductivity is lowered. Preferably, the C (carbon) element is 55 to 62 wt%, the S (sulfur, sulfur) element is 9 to 14 wt%, more preferably the C (carbon) element is 58 to 61 wt% , And the sulfur (S) element is preferably 10 to 12 wt%.

The graphite-conductive polymer composite according to the present invention has excellent water dispersibility and electrical conductivity. The water dispersibility of the graphite-conductive polymer composite according to the present invention is measured by visual observation after being dispersed in water using an ultrasonic crusher for 24 hours. The water dispersibility of the graphite-conductive polymer composite according to the present invention is 0.8 to 1.2 times the water dispersibility of the single conductive polymer. Preferably 0.9 to 1.1 times, and more preferably has a water dispersibility equivalent to that of the single conductive polymer. The graphite-conductive polymer composite has a water-dispersibility equal to or higher than that of the single conductive polymer even in the presence of graphite by forming a complex of graphite and conductive polymer according to an embodiment of the present invention.

The graphite-conductive polymer composite according to an embodiment of the present invention is filtered and then dried at room temperature to measure a 4-point probe in the form of paper to obtain a resistance, and electric conductivity is calculated in consideration of the area and thickness of the sample. The electrical conductivity of the graphite-conductive polymer composite according to the present invention is 0.50 x 10 ² to 2.00 x 10 ⁴ S / m. Preferably, 1.00 x 10 &lt; ² &gt; 1.50 x 10 ⁴ S / m, and more preferably 5.00 x 10 ² to 1.00 x 10 ⁴ S / m.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following examples and experimental examples are given for the purpose of helping understanding of the present invention, and thus the scope of the present invention is not limited thereto.

&Lt; Process for producing graphite-conductive polymer composite >

&Lt; Example 1 >

(0.010 g) was dispersed in distilled 3,4-ethylenedioxythiophene (EDOT, 2.00 g, 14.06 mmol) according to the composition shown in Table 1 for 2 hours using an ultrasonic crusher and sodium persulfate (5.02 g, 21.09 mmol ) and iron (III) sulfate hydrate (0.028 g, 0.07 mmol) in 10 ml of distilled water were dissolved in 160 ml of distilled water and poly (styrene sulfonic acid) (PSS, 30% aqueous solution, 17.23 g, 28.12 mmol) And the mixture was stirred at room temperature. The reaction time was checked by TLC, and when the EDOT monomer and oligomer disappeared, the reaction was terminated for about 24 hours. The obtained reactants were filtered and washed with a nylon membrane filter (pore size: 0.2 μm) to prepare a pure graphite-PEDOT / PSS composite.

Example Graphite Conductive polymer monomer Oxidant Dopant Distilled water content  Kinds content  Kinds content  Kinds content content Example 1 0.018 g EDOT 2.00 g Sodium persulfate 5.02 g poly (styrene sulfonic acid) 17.23 g 170ml iron (Ⅲ) sulfate hydrate 0.028 g Example 2 0.010 g EDOT 2.00 g Sodium persulfate 5.02 g poly (styrene sulfonic acid) 17.23 g 170ml iron (Ⅲ) sulfate hydrate 0.028 g Example 3 0.040 g EDOT 2.00 g Sodium persulfate 5.02 g poly (styrene sulfonic acid) 17.23 g 170ml iron (Ⅲ) sulfate hydrate 0.028 g Comparative Example 1 0 EDOT 2.00 g Sodium persulfate 5.02 g poly (styrene sulfonic acid) 17.23 g 170ml iron (Ⅲ) sulfate hydrate 0.028 g Comparative Example 2 0.018 g EDOT 0 Sodium persulfate 5.02 g poly (styrene sulfonic acid) 17.23 g 170ml iron (Ⅲ) sulfate hydrate 0.028 g

&Lt; Example 2 >

A graphite-PEDOT / PSS composite was prepared in the same manner as in Example 1 except for the mixing condition of Example 2 in Table 1. [

&Lt; Example 3 >

Example 3 of Table 1 A graphite-PEDOT / PSS composite was prepared in the same manner as in Example 1 except for the mixing condition.

&Lt; Comparative Example 1 &

Comparative Example 1 of Table 1 PEDOT / PSS not combined with graphite was prepared under the mixing condition.

&Lt; Comparative Example 2 &

Comparative Example 2 in Table 1 Graphite having no conductive polymer complex was prepared under the mixing conditions.

&Lt; Evaluation test of manufactured graphene-conductive polymer composite >

&Lt; Experimental Example 1 > IR analysis

The FT-IR (Fourier transform infrared spectroscopy, Perkin Elmer FT-IR Spectrum Two) analysis was performed using the KBr method in order to analyze the chemical structure of the graphite-conductive polymer composite of Example 1 and Comparative Example 1.

As a result, in the IR of PEDOT / PSS of Comparative Example 1, COC (1200, 1134, 1086 cm ^-1 ), CC / C = C (1520, 1326 cm ^-1 ) 1620 cm ^-1 ) and SO ^3- (1050 cm ^-1 ). Almost identical peaks were also seen in the IR of the graphite-PEDOT / PSS complex of Example 1. From the IR analysis results, it can be seen that the polymerization of PEDOT / PSS was performed well even in the presence of graphite.

&Lt; Experimental Example 2 > XPS analysis

The chemical structures of the graphite-PEDOT / PSS complexes of Example 1 and Comparative Example 1 were analyzed by X-ray photoelectron spectroscopy (XPS).

To branch the sample, 0.45 mg of graphite-PEDOT / PSS complex was dispersed in 30 ml of distilled water for 2 hours using an ultrasonic crusher. After the dispersion was filtered under reduced pressure using an anodisc membrane filter (diameter 47 mm, pore size 0.22 μm), the resulting film-like composite was dried at 50 ° C. for 48 hours and then analyzed.

FIG. 3 shows a spectrum of PEDOT / PSS of Comparative Example 1 and XPS of the graphite-PEDOT / PSS complex of Example 1 and scanning S (Sulfur, Sulfur). In the PEDOT / PSS spectrum of Comparative Example 1, peaks corresponding to PEDOT were observed at 163.7 and 164.7 eV, peaks corresponding to PSS were observed at 167.7 and 168.9 eV, and PSS and PEDOT The corresponding peak has an area ratio of 2.3: 1. Similarly, the graphite-PEDOT / PSS complex of Example 1 showed peaks corresponding to PEDOT at 163.6 and 164.8 eV, peaks corresponding to PSS at 167.5 and 168.7 eV, and PSS and PEDOT peaks (peak) is 1.85: 1, which is similar to that of general PEDOT / PSS. In other words, PEDOT / PSS synthesis can be concluded when the binding energy of each peak and the area ratio of PEDOT and PSS peaks are considered.

&Lt; Experimental Example 3 > Raman spectrum analysis

The structure of the graphite-PEDOT / PSS complex of Example 1 and the PEDOT / PSS of Comparative Example 1 were analyzed through Raman spectrum. The results are shown in Fig.

To prepare the sample, 0.45 mg of the complex was dispersed in 30 ml of distilled water for 2 hours using an ultrasonic crusher. After the dispersion was filtered under reduced pressure using an anodisc membrane filter (diameter 47 mm, pore size 0.22 μm), the resulting film-like composite was dried at 50 ° C. for 48 hours and then analyzed.

When the graphite-PEDOT / PSS complex of Example 1 and the Raman spectrum of PEDOT / PSS of Comparative Example 1 were analyzed, the PEDOT / PSS results of Comparative Example 1 show that the peaks associated with the stretching vibration of a single CC bond, 1363 cm ^-1, an aromatic C = peak (peak) related to the symmetric stretching vibration of C bond of 1437 cm ^-1, thiophene ring C = C bond of 1536 cm ^-1 peak (peak) associated with asymmetric stretching vibration and 1565 cm ^- And the peaks related to PEDOT ¹ were confirmed. The results of the graphite-PEDOT / PSS complex of Example 1 also confirmed a specific peak appearing at a position similar to that of the PEDOT / PSS of Comparative Example 1. This shows that the PEDOT / PSS synthesis proceeded well. It was confirmed that the polymerization of the PEDOT / PSS of the graphite-PEDOT / PSS composite of Example 1 was well performed in the results of Experiments 1 to 2,

<Experimental Example 4> XRD analysis

PEDOT / PSS composite of Example 1, PEDOT / PSS of Comparative Example 1, graphite of Comparative Example 2, and PEDOT / PSS uncomplexed with graphite in a graphite-PEDOT / PSS composite , graphite-PEDOT / PSS removed PEDOT / PSS). GP-RP was prepared by the following method. The graphite-conductive polymer composite was subjected to ultrasonic disruption treatment for 24 hours, and the conductive polymer which was not complexed with the graphite was removed by centrifugation at 12,000 rpm for 30 minutes to 1 hour. The XRD results are shown in Fig.

The XRD results of the graphite-PEDOT / PSS composite in FIG. 5 are almost similar to PEDOT / PSS, but peaks appear at slightly larger angles than PEDOT / PSS due to the influence of graphite. The XRD results of the GP-RP show that the PEDOT / PSS peaks are accompanied by graphite peaks. Thus, it can be determined that graphite is present in the graphite-PEDOT / PSS composite of Example 1 and is well dispersed in the PEDOT / PSS matrix. Compared with XRD results of graphite, XRD results of graphite-PEDOT / PSS complex showed peaks at smaller angles, which suggests that fine plate changes in graphite during polymerization process. From the XRD results, it was confirmed that the synthesis of PEDOT / PSS, the presence of graphite, the fine plate change of the graphite during the polymerization process, and the graphite were well dispersed in the PEDOT / PSS matrix.

<Experimental Example 5> SEM and EDS analysis

Scanning Electron Microscope (SEM) and Energy Spectroscopy (Energy) analysis of GP-RP with PEDOT / PSS removed from the graphite of Comparative Example 2, the graphite-PEDOT / PSS composite of Example 1 and the graphite- Dispersive Spectroscopy (EDS) results are shown in FIG. 6 as (a) graphite, (b) graphite-PEDOT / PSS complex and (c) GP-RP, respectively. Several kinds of elements were additionally measured in EDS for reasons such as using Al as a substrate for sample preparation. However, since only C, O and S are existed basically, only these three kinds of elements are obtained and represented.

6 (a) and 6 (b) are different from the shape of FIG. 6 (a) because PEDOT / PSS is wrapped with graphite and PEDOT / PSS Existence was confirmed by EDS elemental analysis. 6 (b), 11.4 wt% of S (sulfur, sulfur) element not present in (a) can be confirmed, which is evidence that PEDOT / PSS exists on the graphite surface. On the other hand, FIG. 6 (c) shows that the carbon (C) element is increased from 59.4 wt% to 72.1 wt% and sulfur (S) is decreased from 11.4 wt% to 3.1 wt% Respectively. It is believed that a portion of the graphite was exposed as a part of the PEDOT / PSS wrapping the graphite was removed during the crushing process. The EDS results in FIG. 6 (c) show that the binding of graphite to PEDOT / PSS is not completely deteriorated because a small amount of sulfur (S) is present. That is, from the SEM image and the EDS results of FIG. 6, it can be seen that PEDOT / PSS wrapped graphite in the graphite-PEDOT / PSS composite, and strong physical bonds exist between PEDOT / PSS and graphite, It means that it was done successfully.

Experimental Example 6: Dispersion of graphite

Graphite was dispersed in 1.0% EDOT solution, which is a monomer of H ₂ O, MeOH, NMP, Acetone, MEK, Toluene and PEDOT, and the dispersion stability of each solvent with time was examined at room temperature. The results are shown in Fig. 7 (A) immediately after dispersing in the ultrasonic wave crusher for 24 hours can confirm that the dispersion is good in all the solvents. In FIG. 7 (B), which has elapsed 10 minutes after the dispersion, it can be clearly seen that the color of the dispersion is clearly changed in Acetone, MEK, and Toluene due to the complete precipitation of graphite. H ₂ O and MeOH are precipitated graphite slowly, It can be confirmed that the color is finely brighter. In the case of NMP and EDOT solution, dispersion similar to (A) was observed. In FIG. 7 (C), 48 hours after the dispersion, graphite was precipitated in all the solvents except NMP and EDOT solution, and thus the dispersion was also transparent. On the other hand, in the case of NMP and EDOT solutions, the dispersed state was maintained as in (A) immediately after dispersion. From these results, it can be confirmed that the graphite is stably dispersed in the EDOT solution and that the EDOT solution can be used as a medium for dispersing the graphite.

<Experimental Example 7> Dispersibility and electrical conductivity of graphite-conductive polymer composite

Table 2 shows the water dispersibility and electrical conductivity of the graphite-PEDOT / PSS composite of Example 1, the PEDOT / PSS of Comparative Example 1 and the graphite of Comparative Example 2.

The water dispersibility was visually confirmed after the samples prepared according to Examples and Comparative Examples were dispersed using an ultrasonic crusher for 24 hours.

The graphite-PEDOT / PSS dispersion prepared in accordance with an embodiment of the present invention was filtered using an Anodisc membrane (pore size 0.2 탆) and dried at room temperature to prepare paper Respectively. The electrical conductivity was obtained by measuring the resistance using a 4 point probe and converting it into conductivity by considering thickness and area.

Example Code Water-dispersibility Electrical Conductivity (S / m) Example 1 Graphite-PEDOT / PSS complex up to 1.5% 1.00 x 10 ³ Example 2 Graphite-PEDOT / PSS complex up to 1.5% 2.00 x 10 ² Example 3 Graphite-PEDOT / PSS complex up to 0.5% 4.30 × 10 ² Comparative Example 1 PEDOT / PSS up to 1.5% 1.00 x 10 ² Bar Teaching 2 Graphite Not distributed 2.50 x 10 ⁴

It was confirmed that the graphite-PEDOT / PSS composite of Examples 1 and 2 had superior water dispersibility comparable to that of PEDOT / PSS of Comparative Example 1. This is considered to be the result of the form in which PSS reacts with EDOT attached to graphite to synthesize PEDOT / PSS and wrapping graphite.

The electrical conductivity of the graphite-PEDOT / PSS composite of Example 1 is 1.00 x 10 ³ S / m, which is 10 times more than the conductivity of PEDOT / PSS, which is 1.00 x 10 ² S / m. It is presumed that graphite in the graphite-PEDOT / PSS complex is well dispersed in the PEDOT / PSS, contributing to the electron transport and thus contributing to the improvement of the electrical conductivity.

The features, structures, effects, and the like illustrated in the above-described embodiments can be combined and modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

Claims (13)

A dispersion step of dispersing the graphite in the conductive polymer monomer to prepare a dispersion solution of the graphite-conductive polymer monomer; And
And a polymerization step of polymerizing the conductive polymer monomer to form a graphite-conductive polymer composite,
The conductive polymer monomer includes EDOT (3,4-ethylenedioxythiophene)
The graphite is contained in an amount of 0.5 to 2.0 wt% based on 100 wt% of the solid content of the conductive polymer monomer,
Wherein the polymerization step is a step of adding a dopant to the dispersion solution to polymerize,
The water dispersibility of the graphite-conductive polymer composite is 0.8 to 1.2 times the water dispersibility of the conductive polymer in which the graphite is not complexed,
The graphite is polymerized in the range of 0.5 to 2.0 wt% based on 100 wt% of the solid polymer of the conductive polymer monomer, so that the plate of the graphite changes and is smaller in angle than the graphite intrinsic peak as a result of XRD measurement, And a peak is generated in the graphite-conductive polymer composite.
delete delete The method according to claim 1,
Wherein the dispersing step is a step of dispersing the graphite in the conductive polymer monomer using an ultrasonic crusher.
The method according to claim 1,
Wherein the step of dispersing the graphite in the dispersion step for 1 hour and 30 minutes to 2 hours is a step of dispersing the graphite in the conductive polymer monomer.
The method according to claim 1,
Wherein the polymerizing step comprises polymerizing the dispersion solution for 24 to 26 hours by adding an oxidizing agent to the dispersion solution.
delete The method according to claim 1,
Wherein the dispersion solution does not sediment the graphite when stored at room temperature for 48 hours.
9. A graphite-conductive polymer composite produced by the manufacturing method of any one of claims 1, 4, 6, and 8,
A conductive polymer including a dopant and graphite,
Wherein a conductive polymer including the dopant surrounds the graphite surface,
The water dispersibility of the graphite-conductive polymer composite is 0.8 to 1.2 times the water dispersibility of the conductive polymer in which the graphite is not complexed,
The graphite is polymerized in the range of 0.5 to 2.0 wt% based on 100 wt% of the solid polymer of the conductive polymer monomer, so that the plate of the graphite changes and is smaller in angle than the graphite intrinsic peak as a result of XRD measurement, Wherein a peak occurs in the graphite-conductive polymer composite.
10. The method of claim 9,
When the graphite-conductive polymer composite is analyzed by X-ray photoelectron spectroscopy (XPS), the peak of the conductive polymer and the peak of the dopant (peak ) Area ratio of the graphite-conductive polymer composite is 1: 1.5 to 2.5.
10. The method of claim 9,
When the graphite-conductive polymer composite was analyzed through Energy Dispersive Spectroscopy (EDS), 50 to 65% by weight of carbon (C), 8 to 15% by weight of sulfur (S) Lt; RTI ID = 0.0 &gt; (I). &Lt; / RTI &gt;
delete 10. The method of claim 9,
Wherein the graphite-conductive polymer composite has an electrical conductivity of 5.00 x 10 &lt; ² &gt; to 1.00 x 10 &lt; ⁴ &gt; S / m when electrical conductivity is measured after forming the coating film using the graphite-conductive polymer composite.

Images