KR102398273B1 - Method for manufacturing modified conductive polymer thin films, and modified conductive polymer thin films using the same - Google Patents

Abstract

The present application relates to a method for manufacturing a modified conductive polymer thin film comprising a protonated ionic liquid and a conductive polymer, and to a modified conductive polymer thin film manufactured using the same.

Description

Method for manufacturing a modified conductive polymer thin film and modified conductive polymer thin film manufactured using the same

The present application relates to a method for manufacturing a modified conductive polymer thin film using a protonated ionic liquid and a conductive polymer, and to a modified conductive polymer thin film manufactured using the same.

Currently, transparent electrodes are widely used in flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic light-emitting diodes (OLEDs), touch screens, and thin-film solar cells. is being used extensively. The most representative transparent electrode uses indium tin oxide (ITO), which exhibits excellent optical and electrical performance. However, when the ITO film is thickened, the conductivity is increased but the transparency is decreased, and when the film is thinned, the transparency is increased but the conductivity is decreased. In addition, since the ITO is difficult to use in the field of next-generation flexible devices due to its fragile properties, there is a limit in manufacturing a transparent electrode. Also, ITO is most commonly deposited on the surface by a range of electron beam deposition, vapor deposition, and sputtering techniques, which are transparent to replace ITO because of the high cost, limited resources of indium, brittle nature, and also the high vacuum required for layer deposition. Although many studies have been conducted on carbon nanotubes, graphene, silver nanowires, metal oxides, etc. as electrodes, the plastic transparent electrodes developed so far have the disadvantage of remarkably low conductivity.

PEDOT:PSS [poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)] is a kind of representative conductive polymer to replace ITO. The PEDOT:PSS is one of the most widely used materials because it has high conductivity among conductive plastic materials, good transmittance in the visible light region, and can be environmentally friendly solution process because it is dissolved in water. The PEDOT:PSS induces 3,4-ethylenedioxythiophene (EDOT) to be dispersed in an aqueous solution using polystyrenesulfonate (PSS) as a template. The PEDOT:PSS particles are not separated from each other and can be well dispersed in an aqueous solution because the PEDOT has a very strong ionic bond to the PSS polymer chain. With these properties, the PEDOT:PSS has properties suitable for solution process and printing process. do.

Korean Patent Registration Publication No. KR 10-1022208

An object of the present application is to provide a method for manufacturing a modified conductive polymer thin film using a protonated ionic liquid and a conductive polymer, and a modified conductive polymer thin film manufactured using the same.

A first aspect of the present application comprises mixing a protonated ionic liquid represented by the following Chemical Formula 1 and a conductive polymer to obtain a modified conductive polymer thin film composition, and thinning the modified conductive polymer thin film composition, A method for preparing a modified conductive polymer thin film is provided:

[Formula 1]

;

;

In Formula 1,

R ₁ is selected from hydrogen, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and a tert-butyl group,

A ^- is a halogen ion, hexafluorophosphate, imidazolate, dicyanamide, 4,5-dicyanoimidazolate, bis(trifluoromethane)sulfonimide, tetracynovorate, and ferric It is chosen from anide.

A second aspect of the present application is a modified conductive polymer thin film composition comprising a protonated ionic liquid and a conductive polymer, wherein the conductive polymer is a mixture of a polar polymer and a non-polar polymer, the modified conductive polymer thin film A composition is provided.

A third aspect of the present application provides a modified conductive polymer thin film prepared according to the manufacturing method according to the first aspect.

According to the embodiments of the present application, the elasticity of the modified conductive polymer thin film (PEDOT:PSS/HMIM:TCB, etc.) using the protonated ionic liquid is improved by the existing conductive polymer thin film (PEDOT) that does not use the protonated ionic liquid. : It has an improved effect than the elasticity of PSS thin film).

According to the embodiments of the present application, the crystallinity of the modified conductive polymer thin film using the protonated ionic liquid is improved compared to the crystallinity of the conventional conductive polymer thin film not using the protonated ionic liquid.

According to the embodiments of the present application, the roughness of the modified conductive polymer thin film using the protonated ionic liquid is increased compared to the roughness of the conventional conductive polymer thin film not using the protonated ionic liquid.

According to the embodiments of the present application, the conductivity of the modified conductive polymer thin film after the water washing process is improved compared to before the water washing process.

FIG. 1 a shows the chemical structure of the protonated ionic liquid and the chemical structure of the ionic liquid to which an alkyl group is bonded, according to an embodiment of the present application.
FIG. 1 b shows a sample state of an ionic liquid protonated at room temperature (RT), 50° C. and 70° C. and a sample state of an ionic liquid to which an alkyl group is bonded, according to an embodiment of the present application.
2 is a graph showing the electrical conductivity of a modified conductive polymer thin film prepared using RMIM:TCB or RMIM:TFSI (RMIM: HMIM, MMIM, EMIM, PMIM or BMIM) in an embodiment of the present application.
3 is, in one embodiment of the present application, HMIM: a conventional conductive polymer thin film without using TCB (PEDOT: PSS thin film) and a modified conductive polymer thin film using HMIM: TCB (PEDOT: PSS/HMIM: TCB) This is a picture showing the elasticity comparison.
4 is a graph showing the roughness of the modified conductive polymer thin film according to the number of alkyl groups, according to an embodiment of the present application;
5 is a graph showing the crystal length (Lc) of the modified conductive polymer thin film according to the alkyl group, prepared using HMIM:TCB or HMIM:TFSI according to an embodiment of the present application.
6 is a graph showing a comparison of the electrical conductivity of the modified conductive polymer thin film (PEDOT:PSS/HMIM:TCB) before and after the distilled water washing process in one embodiment of the present application.
7 is a graph showing the electrical conductivity of a modified conductive polymer thin film that has undergone a water washing process using distilled water, acetonitrile (ACN), respectively, and both, in an embodiment of the present application.
8A is, in one embodiment of the present application, absorption according to the wavelength of the initial conductive polymer thin film (PEDOT: PSS thin film) without using the protonated ionic liquid and the wavelength of the conductive polymer thin film that has been washed with distilled water It is a graph showing the spectrum (190 nm to 300 nm: wavelength of PSS; 480 nm to 3,200 nm: wavelength of PEDOT).
FIG. 8 b shows the initial wavelength of the conductive polymer thin film (PEDOT:PSS/HMIM:TCB thin film) using the protonated ionic liquid and the wavelength of the conductive polymer thin film that has been washed with distilled water in an embodiment of the present application. It is a graph showing the absorption spectrum according to (190 nm to 300 nm: wavelength of PSS; 480 nm to 3,200 nm: wavelength of PEDOT).
Figure 9a, in an embodiment of the present application, PEDOT:PSS, HMIM:TCB, the conductive polymer thin film before the water washing process (PEDOT:PSS+ HMIM:TCB thin film) and the conductive polymer thin film after the water washing process (PEDOT:PSS+ after the distilled water washing process) It is a graph showing XPS results of HMIM:TCB thin film, PEDOT:PSS+ HMIM:TCB thin film after ACN washing process, and PEDOT:PSS+ HMIM:TCB thin film after ACN/distilled water washing process).
9B is a graph showing XPS results for the removal of boron, which is enlarged after a fine scan of FIG. 9A in an embodiment of the present application.
9c is a graph showing the XPS results for the reduction of PSS by the protonated ionic liquid [the left peak (166 eV in FIG. 9c) to 170 eV): PSS; right peak (163 eV to 166 eV): PEDOT].
FIG. 10 shows AFM images of the pure PEDOT:PSS thin film before the water washing process and the PEDOT:PSS thin film to which the ionic liquid is added after the distilled water washing process according to an embodiment of the present application.
11, in one embodiment of the present application, the pure PEDOT:PSS thin film before the water washing process, the PEDOT:PSS thin film to which the ionic liquid is added after the distilled water washing process, and the protonated ionic liquid after the ACN/distilled water washing process A TEM image of the added PEDOT:PSS thin film is shown.
Figure 12, in an embodiment of the present application, a pure PEDOT: PSS thin film, and an ionic liquid is added PEDOT: shows the 2D GI-WAXD pattern analysis results of the PSS thin film.
13a is, in one embodiment of the present application, pure PEDOT:PSS, PEDOT:PSS HMIM:TCB subjected to distilled water washing process, ACN/distilled water washing process PEDOT:PSS HMIM:TCB, distilled water washing process 2D GI-WAXD pattern line profile of PEDOT:PSS MMIM:TCB, and PEDOT:PSS EMIM:TCB subjected to distilled water washing process is shown.
13 b is, in one embodiment of the present application, pure PEDOT:PSS, PEDOT:PSS HMIM:TFSI subjected to distilled water washing process, PEDOT:PSS MMIM:TFSI subjected to distilled water washing process, PEDOT:PSS subjected to distilled water washing process 2D GI-WAXD pattern line profiles of EMIM:TFSI, PEDOT:PSS PMIM:TFSI subjected to a distilled water washing process, and PEDOT:PSS BMIM:TFSI subjected to a distilled water washing process are shown.
14 is a schematic diagram showing a manufacturing mechanism of a modified conductive polymer thin film (PEDOT: PSS/IL thin film) in one embodiment of the present application.

Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present application pertains can easily carry out. However, the present application may be implemented in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present application in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout this specification, when a part is “connected” with another part, it includes not only the case of “directly connected” but also the case of “electrically connected” with another element interposed therebetween. do.

Throughout this specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. As used throughout this specification, the terms “about”, “substantially”, etc. are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to enhance the understanding of the present application. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure. As used throughout this specification, the term “step of (to)” or “step of” does not mean “step for”.

Throughout this specification, the term “combination(s)” included in the expression of the Markush form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the Markush form, It means to include one or more selected from the group consisting of the above components.

Throughout this specification, reference to “A and/or B” means “A or B, or A and B”.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings. However, the present application may not be limited to these embodiments and examples and drawings.

A first aspect of the present application comprises mixing a protonated ionic liquid represented by the following Chemical Formula 1 and a conductive polymer to obtain a modified conductive polymer thin film composition, and thinning the modified conductive polymer thin film composition, A method for preparing a modified conductive polymer thin film is provided:

[Formula 1]

;

;

In Formula 1,

R ₁ is selected from hydrogen, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and a tert-butyl group,

A ^- is a halogen ion, hexafluorophosphate, imidazolate, dicyanamide, 4,5-dicyanoimidazolate, bis(trifluoromethane)sulfonimide, tetracynovorate, and ferric It is chosen from anide.

In one embodiment of the present application, Formula 1 may include one selected from the following compounds:

및

.

and

.

In one embodiment of the present application, the conductive polymer may be a mixture of a non-polar polymer and a polar polymer.

In one embodiment of the present application, the non-polar polymer may be a conjugated polymer, and the polar polymer may be a surfactant and a dopant.

로 표시되는 화합물로서, Ar₁ 및 Ar₂는 각각 독립적으로 하기 화합물들 중에서 선택되는 것을 포함할 수 있다:In one embodiment of the present application, the conjugated polymer is

As a compound represented by , Ar ₁ and Ar ₂ may each independently include one selected from the following compounds:

,

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.

In one embodiment of the present application, the non-polar polymer is polythiophene-based, polyaniline-based, polyacetylene-based, poly(3,4-ethylenedioxythiophene)-based, poly(para-phenylene)-based, or poly(para) -phenylenevinylene), and the polar polymer may include a compound represented by the following Chemical Formula 2, the following Chemical Formula 3, or the following Chemical Formula 4:

[Formula 2]

;

;

[Formula 3]

;

;

[Formula 4]

;

;

In Formula 2, Formula 3, and Formula 4, R ₂ , R ₃ , and R ₄ are each independently, a linear or non-linear C _1-50 alkyl group, a linear or non-linear C _1-50 heteroalkyl group, A linear or non-linear C _5-50 aryl group, a linear or non-linear C _2-50 heteroaryl group, a linear or non-linear C _1-30 alkyl ester group, a linear or non-linear C _1-30 alkyl carbonate group , or a linear or non-linear C _1-30 carbonyl group, Z ⁺ is selected from H ⁺ , Li ⁺ , Rb ⁺ , Cs ⁺ , NH ₄ ⁺ , K ⁺ or Na ⁺ , and n is 1 it is more than

In one embodiment of the present application, Formula 2 may include one selected from the following compounds:

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In one embodiment of the present application, Formula 3 may include one selected from the following compounds:

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In one embodiment of the present application, Formula 4 may include one selected from the following compounds:

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In one embodiment of the present application, the non-polar polymer may be poly-(3,4-ethylenedioxythiophene), and the polar polymer may include polystyrene sulfonate. Since the poly-(3,4-ethylenedioxythiophene) is additionally mixed well with water, alcohol, or a solvent having a high dielectric constant, it can be easily coated by diluting it with the solvent. It can exhibit excellent transparency compared to the polypyrrole series and the like.

In one embodiment of the present application, after mixing the protonated ionic liquid and the conductive polymer, a water washing process may be further included.

In one embodiment of the present application, the water washing process uses at least one selected from distilled water, acetonitrile, methanol, ethanol, propanol, isopropanol, isopropyl alcohol, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran and acetone. it could be

A second aspect of the present application is a modified conductive polymer thin film composition comprising a protonated ionic liquid and a conductive polymer, wherein the conductive polymer is a mixture of a polar polymer and a non-polar polymer, the modified conductive polymer thin film A composition is provided.

In one embodiment of the present application, the content of the protonated ionic liquid may be about 1 part by weight to about 1,000 parts by weight based on 100 parts by weight of the conductive polymer. Specifically, the content of the protonated ionic liquid is about 1 part by weight to about 1,000 parts by weight, about 1 part by weight to about 900 parts by weight, about 1 part by weight to about 800 parts by weight based on 100 parts by weight of the conductive polymer. , about 1 part by weight to about 700 parts by weight, about 1 part by weight to about 600 parts by weight, about 1 part by weight to about 500 parts by weight, about 10 parts by weight to about 1,000 parts by weight, about 10 parts by weight to about 900 parts by weight , about 10 parts by weight to about 800 parts by weight, about 10 parts by weight to about 700 parts by weight, about 10 parts by weight to about 600 parts by weight, or about 10 parts by weight to about 500 parts by weight, but is not limited thereto.

In one embodiment of the present application, the mass ratio of the non-polar polymer to the polar polymer in the modified conductive polymer thin film composition may be about 1:0.1 to 1:10. Specifically, in the modified conductive polymer thin film composition, the mass ratio of the non-polar polymer: the polar polymer is about 1:0.1 to 1:10, about 1: 0.1 to about 1:8, about 1: 0.1 to about 1:6, about 1: 0.1 to about 1:4, about 1: 0.1 to about 1:2, about 1: 0.4 to about 1:2, or about 1: 0.6 to about 1:2, but is not limited thereto.

In one embodiment of the present application, the protonated ionic liquid may separate a portion of the polar polymer from the non-polar polymer.

A third aspect of the present application provides a modified conductive polymer thin film prepared according to the manufacturing method according to the first aspect.

In one embodiment of the present application, the elasticity of the modified conductive polymer thin film (PEDOT:PSS/HMIM:TCB) using the protonated ionic liquid is improved by the existing conductive polymer thin film (PEDOT: It has an improved effect than the elasticity of PSS thin film).

In one embodiment of the present application, the tensile strain of the modified conductive polymer thin film stretchability may be about 70% or more, but is not limited thereto. Specifically, the tensile strain of the modified conductive polymer thin film stretchability may be about 70% or more, about 72% or more, about 74% or more, about 76% or more, about 78% or more, or about 80% or more, but is limited thereto. it is not going to be

In one embodiment of the present application, the crystallinity of the modified conductive polymer thin film using the protonated ionic liquid is improved compared to the crystallinity of the conventional conductive polymer thin film not using the protonated ionic liquid.

In one embodiment of the present application, the crystal size of the modified conductive polymer thin film may be about 35 Å or more, but is not limited thereto. Specifically, the crystal size of the modified conductive polymer thin film may be about 35 Å or more, about 36 Å or more, about 37 Å or more, or about 38 Å or more, but is not limited thereto.

In one embodiment of the present application, the conductivity of the modified conductive polymer thin film before the water washing process may be about 100 s/cm or more, but is not limited thereto. Specifically, the conductivity of the modified conductive polymer thin film is about 100 s/cm or more, about 150 s/cm or more, about 200 s/cm or more, about 250 s/cm or more, about 300 s/cm or more, about 350 s /cm or more, about 400 s/cm or more, about 450 s/cm or more, about 500 s/cm or more, about 550 s/cm or more, about 600 s/cm or more, about 650 s/cm or more, about 700 s/ cm or more, about 750 s/cm or more, about 800 s/cm or more, about 850 s/cm or more, about 900 s/cm or more, about 950 s/cm or more, or about 1,000 s/cm or more. However, the present invention is not limited thereto.

In one embodiment of the present application, the conductivity of the modified conductive polymer thin film after the water washing process is improved than that of the modified conductive polymer thin film before the water washing process.

In one embodiment of the present application, the conductivity of the modified conductive polymer thin film after the water washing process may be about 2,000 s/cm or more, but is not limited thereto. Specifically, the conductivity of the modified conductive polymer thin film after the water washing process is about 2,000 s/cm or more, about 2,050 s/cm or more, about 2,100 s/cm or more, about 2,150 s/cm or more, about 2,200 s/cm or more, About 2,250 s/cm or more, about 2,300 s/cm or more, about 2,350 s/cm or more, about 2,400 s/cm or more, about 2,450 s/cm or more, about 2,500 s/cm or more, about 2,550 s/cm or more, about 2,600 s/cm or more, about 2,650 s/cm or more, about 2,700 s/cm or more, about 2,750 s/cm or more, about 2,800 s/cm or more, about 2,850 s/cm or more, about 2,900 s/cm or more, about 2,950 It may be s/cm or more, or about 3,000 s/cm or more, but is not limited thereto.

In one embodiment of the present application, the roughness of the modified conductive polymer thin film using the protonated ionic liquid is increased compared to the roughness of the conventional conductive polymer thin film not using the protonated ionic liquid.

In one embodiment of the present application, the surface roughness root mean square (RMS) of the modified conductive polymer thin film may be about 0.1 nm or more, but is not limited thereto. Specifically, the surface roughness root mean square (RMS) of the modified conductive polymer thin film is about 0.1 nm or more, about 0.2 nm or more, about 0.3 nm or more, about 0.4 nm or more, about 0.5 nm or more, about 0.6 nm or more, about 0.7 or more, about 0.8 nm or more, or about 0.9 nm or more, but is not limited thereto.

Hereinafter, the present invention will be described in more detail through examples of the present application, but the following examples are merely illustrative to aid understanding of the present application, and the content of the present application is not limited to the following examples.

[Example]

Example 1. Synthesis method

1. Synthesis method of protonated ionic liquid using 1-methylimidazole

Synthesis of HMIM:Br

[Formula 1]

1 equivalent of hydrogen bromide was slowly added dropwise to a mixed solution of 1-Methylimidazole (the compound 1) (1.00 g, 0.012 mol) added to 20 mL of tetrahydrofuran (THF; tetrahydrofuran) The mixture was stirred at room temperature for 24 hours. After the reaction was completed, the solvent was removed using a rotary evaporator. Then, the mixture was dissolved in distilled water and ethyl acetate, added to a separatory funnel, and stirred. After separating the water layer, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain HMIM:Br (93% yield).

Synthesis of HMIM:TFSI

[Formula 2]

The obtained HMIM:Br (1.00 g 0.0061 mol) was dissolved in 5 mL of distilled water. 1 equivalent of bis(trifluoromethane)sulfonimide lithium salt [Bis(trifluoromethane)sulfonimide lithium salt] was added to the mixed solution, and the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the mixture was dissolved in distilled water and dichloromethane, added to a separatory funnel, and stirred. After extracting the organic layer, MgSO ₄ was added to remove moisture. The organic solvent was distilled off under reduced pressure using a rotary evaporator to obtain HMIM:TFSI (81% yield).

Synthesis of HMIM:TCB

[Formula 3]

1 equivalent of tetracyano borate salt was added to a mixed solution of the obtained HMIM:Br (1.00 g 0.0061 mol) added to 2 mL of distilled water, and the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the mixture was dissolved in distilled water and dichloromethane, added to a separatory funnel, and stirred to separate the layers. Thereafter, the organic layer was separated and water was removed by adding MgSO ₄ . The organic solvent was distilled off under reduced pressure using a rotary evaporator to obtain HMIM:TCB (87% yield).

Chemical formulas and appearances of the prepared materials (HMIM:TFSI and HMIM:TCB) were confirmed ( FIG. 1 ). 1(b), it was confirmed that the HMIM:TFSI(H:F) sample was in a gel (G) state at room temperature and 50°C, and maintained in a liquid state at 70°C to make a protonated ionic liquid. did In addition, the HMIM:TCB(H:B) sample was in a powder (P) state at room temperature, and maintained a powder state even at 50°C and 70°C, confirming that it was an ionic liquid having different physical properties from that of HMIM:TFSI. On the other hand, other ionic liquids except MMIM:TCB (M:B) are liquid at room temperature, 50 °C and 70 °C, and the MMIM:TCB is in a gel state at room temperature, and changes to a liquid state at 50 °C and 70 °C. It was confirmed that it was an ionic liquid.

2. Synthesis method of protonated ionic liquid using 1-ethylimidazole

Synthesis of HEIM:Br

[Formula 4]

1 equivalent of hydrobromic acid was slowly added dropwise to a mixed solution of 1-ethylimidazole (the compound 2) (1.00 g, 0.010 mol) added to 20 mL of THF, followed by stirring at room temperature for 24 hours. After the reaction was completed, the solvent was removed using a rotary evaporator. Then, the mixture was dissolved in distilled water and ethyl acetate, added to a separatory funnel, and stirred. After separating the water layer, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain HEIM:Br (91% yield).

Synthesis of HEIM:TFSI

[Formula 5]

The obtained HEIM-Br (1.00 g 0.0056 mol) was dissolved in 5 mL of distilled water. To the mixed solution, 1 equivalent of bis(trifluoromethane)sulfonimide lithium salt was added, and the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the mixture was dissolved in distilled water and dichloromethane, added to a separatory funnel, and stirred. After extracting the organic layer, MgSO ₄ was added to remove moisture. The organic solvent was distilled off under reduced pressure using a rotary evaporator to obtain HEIM:TFSI (95% yield).

Synthesis of HEIM:TCB

[Formula 6]

1 equivalent of tetracyano borate salt was added to a mixed solution of the obtained HEIM-Br (1.00 g 0.0056 mol) added to 2 mL of water, and the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the mixture was dissolved in distilled water and dichloromethane, added to a separatory funnel, and stirred to separate the layers. Thereafter, the organic layer was separated and water was removed by adding MgSO ₄ . The organic solvent was distilled off under reduced pressure using a rotary evaporator to obtain HEIM:TCB (90% yield).

Example 2. Synthesis of modified conductive polymer thin film composition [PEDOT:PSS-protonated ionic liquid (PEDOT:PSS/IL)]

After diluting the protonated ionic liquid (HMIM:TFSI, HMIM:TCB, HEIM:TFSI or HEIM:TCB) synthesized in Example 1 with distilled water, a conductive polymer (PEDOT:PSS) (Clevios PH1000, Heraeus) was added. Then, a modified conductive polymer thin film composition (PEDOT:PSS/IL composition) solution was prepared by mixing with vortex for 2 hours or more. The thin film composition solution was applied on a SiO ₂ substrate treated with UV-ozone (AC-6, AHTECH) and spin-coated, followed by heat treatment at 150° C. for 5 minutes to obtain a modified conductive polymer thin film (without water washing process) ). On the other hand, after spin coating and heat treatment of the composition solution, the surface of the SiO ₂ substrate coated with the modified conductive polymer thin film composition solution is washed with distilled water / ACN and then vacuum dried in a desiccator, protonated ionic liquid A modified conductive polymer thin film (PEDOT: PSS/IL thin film) was obtained using

[Experimental example]

I. Characterization of the modified conductive polymer thin film (without water washing process)

1. Electrical Conductivity Measurement and Characterization

In order to measure the thin film conductivity of the modified conductive polymer thin film (PEDOT: PSS/IL thin film), the obtained modified conductive polymer thin film was After measuring the sheet resistance of the thin film using a four-point probe system (=4 needle method, or 4pp) (Ossila) equipment, atomic force microscopy of the thin film The thickness was measured and the conductivity was calculated ( FIG. 2 ).

The sheet resistance of the modified conductive polymer thin film is shown in Table 1 below.

[Table 1]

The thickness of the modified conductive polymer thin film is shown in Table 2 below.

[Table 2]

2, in the modified conductive polymer thin film prepared using RMIM:TFSI (▲), as the length of the alkyl group attached to the cation becomes shorter, the electrical conductivity of the modified conductive polymer thin film increases linearly (BMIM < PMIM<EMIM<MMIM order), it was confirmed that the electrical conductivity of the modified conductive polymer thin film (PEDOT: PSS/IL thin film) added with a protonated ionic liquid (HMIM) substituted with a hydrogen atom instead of the alkyl group increased rapidly. can Similarly, in the modified conductive polymer thin film prepared using RMIM:TCB(■), as the length of the alkyl group attached to the cation becomes shorter, the electrical conductivity of the modified conductive polymer thin film increases linearly (EMIM<MMIM order) , it can be seen that the electrical conductivity of the modified conductive polymer thin film (PEDOT: PSS/IL thin film) to which a protonated ionic liquid (HMIM) substituted with a hydrogen atom instead of the alkyl group is added is rapidly increased.

2. Elasticity measurement and characterization

In order to compare the thin film stretchability of the modified conductive polymer thin film (PEDOT: PSS/IL thin film), a sample was prepared in the same manner as in Example 2. After diluting the protonated ionic liquid (HMIM:TFSI, HMIM:TCB, HEIM:TFSI, or HEIM:TCB) with distilled water, a conductive polymer (PEDOT:PSS) (Clevios PH1000, Heraeus) was added, followed by 2 vortex A modified conductive polymer thin film composition (PEDOT:PSS/IL composition) solution was prepared by mixing for more than an hour. Styrene Ethylene Butylene Styrene (SEBS; Styrene Ethylene Butylene Styrene) (SEBS/Toluene: 300 mg/mL) was spin-coated on a glass substrate and then heat treated at 70° C. for 30 minutes. The thin film composition solution was applied on the SEBS surface-treated with UV-ozone (AC-6, AHTECH) treatment equipment and spin-coated, followed by heat treatment at 70° C. for 10 minutes. The SEBS substrate coated with the modified conductive polymer thin film composition solution was fixed to a stretch test equipment and then stretched and measured under a microscope (FIG. 3).

3, the conventional conductive polymer thin film (PEDOT: PSS thin film) that does not use HMIM:TCB cracks and tears when stretched by 30% or more, whereas HMIM, which is a protonated ionic liquid : Since the modified conductive polymer thin film (PEDOT:PSS/HMIM:TCB thin film) using TCB does not crack and stretches well even when stretched to 70%, it can be confirmed that the elasticity is greatly improved when the protonated ionic liquid is added. can

3. Surface roughness analysis

A topographic image was obtained using an atomic force microscope (AFM5100N, Hitachi), and the surface of the modified conductive polymer thin film was analyzed by confirming the surface roughness (FIG. 4).

4, the roughness of the modified conductive polymer thin film prepared using HMIM:TFSI or HMIM:TCB is increased compared to the roughness of the conventional conductive polymer thin film (initial PEDOT:PSS thin film) that does not use a protonated ionic liquid. it can be seen that Specifically, it can be seen that the shorter the alkyl group of the protonated ionic liquid used in HMIM:TFSI and HMIM:TCB, the surface roughness of the modified conductive polymer thin film (PEDOT:PSS/IL thin film) increases. However, in the ionic liquid in which TFSI was used, the roughness was rather increased from the carbon number of the alkyl group exceeding 2, which is considered to be the result of phase separation between PEDOT:PSS and the ionic liquid.

4. Crystallinity Analysis

The crystallinity of the modified conductive polymer thin film using HMIM:TCB or HMIM:TFSI was analyzed (FIG. 5).

5, when the ionic liquid is RMIM:TCB (black circle) and RMIM:TFSI (red circle), it can be seen that the shorter the alkyl group, the better the crystallinity, and when H is synthesized instead of the alkyl group, the crystallinity is more It can be seen that there is a significant improvement. This is considered to be due to aggregation of the material. On the other hand, the electrical conductivity decreases because the isolated cohesion increases the resistance. Here, Lc is calculated using the (010) peak corresponding to the in-plane (q _xy ) π-π stacking peak. Accordingly, the improvement of the electrical conductivity of the modified conductive polymer thin film (PEDOT: PSS/IL thin film) can be seen as the main cause of the increase in crystallinity due to the improvement of π-π stacking.

II. Characterization of the modified conductive polymer thin film (including washing process)

1. Electrical Conductivity Measurement and Characterization

In order to compare the electrical conductivity of the modified conductive polymer thin film (PEDOT:PSS/IL thin film) with or without post-treatment, the modified conductive polymer thin film was prepared. Assuming that the concentration of the conductive polymer (PEDOT:PSS) in the modified conductive polymer thin film composition (PEDOT:PSS/IL composition) aqueous solution is 1.3 wt% (based on PEDOT:PSS 100), the protonated ionicity compared to the solid content of the conductive polymer The electrical conductivity of the modified conductive polymer thin film was measured before and after washing with distilled water by changing the mass ratio (HMIM:TCB 0 wt% to 200 Swt%) of the liquid (HMIM:TCB) (FIG. 6).

After the distilled water washing process, the conductive polymer thin film (PEDOT:PSS/HMIM:TCB) had the highest electrical conductivity at 150 wt%. It can be seen that the electrical conductivity decreases. In addition, it can be seen that the PEDOT:PSS/HMIM:TCB thin film (red circle) after the distilled water washing process showed higher electrical conductivity than the PEDOT:PSS/HMIM:TCB thin film (white circle) before the distilled water washing process. This is because, as the non-conductive PSS is washed away through the process of washing the prepared modified conductive polymer thin film (PEDOT: PSS/IL thin film) with water with a polar solvent such as water, the electrical conductivity is improved.

In addition, the electrical conductivity of the modified conductive polymer thin film subjected to a water washing process using distilled water, ACN (acetonitrile), and both was measured (FIG. 7). Specifically, referring to FIG. 7 , it can be seen that the electrical conductivity increases in the order of ACN washing<distilled water washing<ACN/distilled water washing.

The granular conductive polymer (PEDOT:PSS) is a nanoparticle in which polar PSS (water-soluble, non-conductive, non-conductive) surrounds non-polar PEDOT (lipid-soluble, conductive, conductor) and dispersed in aqueous solution. As a result, the electrical conductivity is very low, about 1 S/cm, due to PSS, which is an insulator. That is, when a protonated ionic liquid is added and mixed with a conductive polymer, a charge-separated state is formed, which can be interpreted as a result of removing excess PSS in this process (involved in PEDOT doping) PSS without; only minimal amount of PSS remains).

2. Water resistance measurement and characterization

A sample was prepared in the same manner as in Example 2 to measure the water resistance of the modified conductive polymer thin film (PEDOT: PSS/IL thin film). The absorption of the modified conductive polymer thin film (PEDOT: PSS/IL thin film) was measured using a UV-Vis-NIR spectrophotometer (V-770, Jasco) (FIG. 8).

Referring to FIG. 8(a), if you look at the wavelength (blue line) of the conductive polymer thin film that has been washed with distilled water, there are no PSS and PEDOT remaining, whereas in FIG. 8(b), HMIM:TCB is used On the other hand, if you look at the conductive polymer thin film (blue line) that has undergone the distilled water washing process, it can be seen that only a part of PSS that is not bound to PEDOT is washed away, and there is no change in absorption in the near-infrared region corresponding to PEDOT. In this case, some of the polar PSS is removed by a protonated ionic liquid such as HMIM:TCB, and thus the modified conductive polymer thin film is no longer soluble in water.

In order to show the XPS results, in the same manner as in Example 2, after diluting the protonated ionic liquid with distilled water, a conductive polymer (PEDOT:PSS) (Clevios PH1000, Heraeus) was added, and then mixed with vortex for 2 hours or more. Thus, a modified conductive polymer thin film composition solution was prepared. The modified conductive polymer thin film composition solution was applied to a Si substrate and spin-coated, followed by heat treatment at 150° C. for 5 minutes. The surface of the Si substrate coated with the modified conductive polymer thin film composition solution was washed with distilled water and ACN and dried. The surface spectrum of the modified conductive polymer thin film (PEDOT:PSS/IL thin film) was analyzed using a photoelectron spectrometer K-alpha+ (Thermo scientific) (FIG. 9).

Looking at the XPS results of FIG. 9(b), PEDOT:PSS+HMIM:TCB after the distilled water washing process, PEDOT:PSS+HMIM:TCB after the ACN washing process, and PEDOT:PSS+HMIM:TCB after the distilled water/ACN washing process It can be seen that boron (B) is washed out, indicating that the protonated ionic liquid is removed in the water washing process in a polar solvent such as water, where no element corresponding to the anion is found. there is.

Looking at the XPS results of FIG. 9(c), compared to the conventional PEDOT:PSS, PEDOT:PSS/HMIM:TCB after the distilled water washing process, PEDOT:PSS/HMIM:TCB after the ACN washing process, and PEDOT after the distilled water/ACN washing process: It can be seen that PSS, which is an insulator in PSS/HMIM:TCB, is decreased [left peak in Fig. 9(c): PSS; right peak: PEDOT].

3. Crystallinity and Morphology Analysis

i. AFM image analysis

Topographic images were obtained using an atomic force microscope (AFM5100N, Hitachi), and the surface roughness of the modified conductive polymer thin film and the surface roughness of the modified conductive polymer thin film washed with distilled water were analyzed (FIG. 10).

Looking at the AFM images of the pure PEDOT:PSS thin film before the water washing process of FIG. 10 and the PEDOT:PSS thin film with the ionic liquid added after the distilled water washing process, compared to the conductive polymer thin film synthesized with an alkyl group, the protonated ionic liquid It can be seen that the surface roughness of the modified conductive polymer thin film prepared using However, in the case of PMIM:TFSI and BMIM:TFSI, it can be seen that the surface roughness increases due to aggregation, but the electrical conductivity decreases (see FIG. 6 ).

ii. TEM image analysis

A sample was prepared to examine the TEM image according to the protonated ionic liquid. In the same manner as the electrical conductivity sample, a modified conductive polymer thin film was prepared, and the prepared thin film was washed with distilled water and then vacuum dried in a desiccator. The thin film was chopped and floated on distilled water, and then transferred to a TEM grid to prepare a sample. The internal morphology of the thin film was confirmed using a transmission electron microscopy (JEM-ARM200F, Cold FEG, JEOL Ltd, Japan) (FIG. 11).

Looking at the TEM images of the pure PEDOT:PSS thin film before the water washing process of FIG. 11 and the PEDOT:PSS thin film added with the ionic liquid after the distilled water washing process, the conductive polymer thin film containing the alkyl group is added after the distilled water washing process. In contrast, the TEM images of the conductive polymer thin film to which the protonated ionic liquid was added after the distilled water washing process showed less white (PSS) and a more dense image. In particular, the TEM image of the conductive polymer thin film after the ACN/distilled water washing process showed a cleaner fiber structure.

Specifically, the modified conductive polymer thin film to which the protonated ionic liquid is not added is a simple connection of nanoparticles in the form of granules without a distinct shape, whereas the protonated ionic liquid and the conductive polymer are simply connected. When the polymer is mixed, a morphological transformation into a fibrillary form occurs. Accordingly, it can be seen that the electron flow through the fibrils is smoothed and the electrical conductivity is improved, and it can be seen that the mechanical elasticity is excellent due to the entanglement between the fibrils.

iii. 2D GI-WAXD pattern analysis

In order to show the crystallinity of the modified conductive polymer thin film to which the protonated ionic liquid is added, two-dimensional grazing incidence-wide angle X-ray diffusion (2D GI-WAXD; 2-dimensional grazing incidence-wide angle X-ray) diffraction) samples were prepared and measured. A modified conductive polymer thin film composition (PEDOT:PSS/IL composition) solution was prepared, and it was spin-coated on a Si substrate to prepare a thin film, and heat-treated at 150° C. for 5 minutes. The surface of the Si substrate coated with the modified conductive polymer thin film composition solution was washed with distilled water or ACN and dried. The crystallinity of the thin film was analyzed using the beamline of the Pohang Accelerator Research Institute ( FIGS. 12 and 13 ).

Looking at the 2D GI-WAXD pattern of FIG. 12 , it can be seen that a pattern shape occurs, which indicates that there is a repeating unit and indicates that crystallinity exists. Specifically, it can be seen that the pattern in a specific direction occurs more clearly in the modified conductive polymer thin film to which a protonated ionic liquid is added compared to the modified conductive polymer thin film to which the ionic liquid of the alkyl group is added, It can be predicted that the crystallinity increases further.

In addition, referring to FIGS. 13 (a) and 13 (b), the crystallinity and crystal direction of the film can be seen, and in the peak for the in-plane (q _xy ) (010) direction, the peak after washing with water is You can see it's sharper. This indicates further improved determinism for edge-on configuration.

Inference, through the comparative experiment of the conductive polymer thin film to which the ionic liquid was added, the electrical conductivity, elasticity, and water resistance of the conductive polymer thin film to which the protonated ionic liquids (HMIM:TFSI and HMIM:TCB) synthesized herein were added In terms of performance, it was confirmed that the performance was the best.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present application.

Claims (12)

To obtain a modified conductive polymer thin film composition by mixing the protonated ionic liquid represented by the following Chemical Formula 1, and a conductive polymer,
Thinning the modified conductive polymer thin film composition
A method for producing a modified conductive polymer thin film comprising:
[Formula 1]

;
In Formula 1,
R ₁ is selected from hydrogen, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and a tert-butyl group,
A ^- is selected from hexafluorophosphate, imidazolate, dicyanamide, 4,5-dicyanoimidazolate, bis(trifluoromethane)sulfonimide, tetracynovorate, and ferricyanide it is
The method of claim 1,
The conductive polymer is a mixture of a non-polar polymer and a polar polymer,
A method for manufacturing a modified conductive polymer thin film.
3. The method of claim 2,
The non-polar polymer is a conjugated polymer,
The polar polymer is a surfactant and a dopant (dopant) will, the method for producing a modified conductive polymer thin film.
3. The method of claim 2,
The non-polar polymer is polythiophene-based, polyaniline-based, polyacetylene-based, poly(3,4-ethylenedioxythiophene)-based, poly(para-phenylene)-based, or poly(para-phenylenevinylene)-based It is to include one or more selected,
The polar polymer is a method for producing a modified conductive polymer thin film comprising a compound represented by the following Chemical Formula 2, the following Chemical Formula 3, or the following Chemical Formula 4:
[Formula 2]

;
[Formula 3]

;
[Formula 4]

;
In Formula 2, Formula 3 and Formula 4,
R ₂ , R ₃ , and R ₄ are each independently a linear or non-linear C _1-50 alkyl group, a linear or non-linear C _1-50 heteroalkyl group, a linear or non-linear C _6-50 aryl group, linear Or a non-linear C _2-50 heteroaryl group, a linear or non-linear C _1-30 alkyl ester group, a linear or non-linear C _1-30 alkyl carbonate group, or a linear or non-linear C _1-30 carbonyl group is selected from
Z ⁺ is selected from H ⁺ , Li ⁺ , Rb ⁺ , Cs ⁺ , NH ₄ ⁺ , K ⁺ or Na ⁺ ,
n is greater than or equal to 1.
3. The method of claim 2,
The non-polar polymer is poly- (3,4-ethylenedioxythiophene),
The method for producing a modified conductive polymer thin film, wherein the polar polymer comprises polystyrene sulfonate:
The method of claim 1,
After mixing the protonated ionic liquid and the conductive polymer, the method of manufacturing a modified conductive polymer thin film further comprising a water washing process.
7. The method of claim 6,
The water washing process uses at least one selected from distilled water, acetonitrile, methanol, ethanol, propanol, isopropanol, isopropyl alcohol, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran and acetone, a modified conductive polymer thin film manufacturing method.
A modified conductive polymer thin film composition comprising a protonated ionic liquid represented by the following Chemical Formula 1 and a conductive polymer,
The conductive polymer is a mixture (mixture) of a polar polymer and a non-polar polymer,
Modified conductive polymer thin film composition:
[Formula 1]

;
In Formula 1,
R ₁ is selected from hydrogen, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and a tert-butyl group,
A ^- is selected from hexafluorophosphate, imidazolate, dicyanamide, 4,5-dicyanoimidazolate, bis(trifluoromethane)sulfonimide, tetracynovorate, and ferricyanide it is
9. The method of claim 8,
The content of the protonated ionic liquid is 1 part by weight to 1,000 parts by weight based on 100 parts by weight of the conductive polymer, the modified conductive polymer thin film composition.
9. The method of claim 8,
The mass ratio of the non-polar polymer: the polar polymer is 1:0.1 to 1:10, the modified conductive polymer thin film composition.
9. The method of claim 8,
The protonated ionic liquid separates a portion of the polar polymer from the non-polar polymer, the conductive polymer thin film composition.
A modified conductive polymer thin film prepared according to the manufacturing method of any one of claims 1 to 7.

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