KR20140111086A - Fabrication of conducting polymer nanoparticle from oxidative polymerization method in aqueous medium - Google Patents

Abstract

The present invention relates to a manufacturing method of conductive polymer nanoparticles, comprising the steps of mixing oil phase including conductive polymer monomer, a secondary emulsion agent, and non-polar organic solvents with aqueous phase including an emulsion agent containing a negative ion surfactant and then emulsifying the same; putting a first oxidizing agent; and putting a second oxidizing agent and performing oxygen polymerization.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for preparing a conductive polymer nanoparticle,

The present invention relates to a method for producing conductive polymer nanoparticles using an oxidative polymerization method, and more particularly, to a method for producing conductive polymer nanoparticles using a nonpolar organic solvent, in which a nonpolar organic solvent and a conductive polymer are dispersed in a nano- Reactors, and then oxidatively polymerizing the nano-reactors to produce conductive polymer nanoparticles.

The conventional process for synthesizing polythiophene nanoparticles uses a method of polymerizing an excess amount of an oxidizing agent in an organic solvent. In this method, a step of removing an oxidizing agent is further required, and since it is synthesized in an organic solvent, there is a problem in that it is harmful from the viewpoint of environment.

In order to overcome the above problem, a process for synthesizing polythiophene nanoparticles in an aqueous phase instead of an organic solvent phase has been proposed. In the process of synthesizing the polythiophene nanoparticles in the aqueous phase, instead of using an excessive amount of an oxidizing agent, two kinds of oxidizing agents are introduced, and the polythiophene nanoparticles are produced using a recycling process through oxidation and reduction of metal ions Respectively. An example of such a technique is Korean Registered Patent No. 10-0684913 (prior art document 1).

However, since the polythiophene nanoparticles prepared by the above method are insoluble in an organic solvent, they have a problem in workability and are difficult to apply to a light emitting layer such as an OLED or a PLED.

1. Korean Patent No. 10-0684913

The present invention relates to a method for producing conductive polymer nanoparticles using an oxidative polymerization method and has excellent processability and can be used for electronic materials, optical materials, toners and inks, An object of the present invention is to provide conductive polymer nanoparticles which can be applied to an EL material, an energy storage material, a pattern manufacturing material, and a printing ink material.

In the present invention, the oily phase containing the auxiliary emulsifier, the conductive polymer monomer and the nonpolar organic solvent,

A step of mixing and emulsifying the aqueous phase containing an emulsifier containing an anionic surfactant, adding a first oxidizing agent, and then introducing a second oxidizing agent and performing an oxidative polymerization.

Also, the present invention provides the conductive polymer nanoparticles prepared by the above-mentioned method.

The conductive polymer nanoparticles produced by the production method according to the present invention have excellent processability and can be used for electronic materials, optical materials, toners and inks and the like because they emit luminescent colors different from those in an aqueous phase. Further, A storage material, a pattern manufacturing material, and a printing ink material. In addition, the conductive polymer nano-particles to be produced have a property of being soluble in an organic solvent such as THF or CHCl ₃ .

FIG. 1 is a schematic diagram showing a process of synthesizing conductive polymer nanoparticles.
2 is a schematic diagram showing a nano-reactor state.
FIG. 3 is a view showing the chemical mechanism of the poly (octylthiophene nano-particles) prepared according to one embodiment of the present invention.
4 is an electron micrograph of the poly (octylthiophene nano-particles) prepared in Example 1 of the present invention.
5 is a photograph showing the degree of light emission of water (a) and the poly (octylthiophene) (b) prepared in Example 1 of the present invention.

The present invention relates to an oily phase containing a conductive polymer monomer, a secondary emulsifier and a nonpolar organic solvent,

Mixing an aqueous emulsion containing an anionic surfactant and emulsifying the emulsion, adding a first oxidizing agent, and then introducing a second oxidizing agent to oxidize and polymerize the conductive polymer nanoparticles.

Hereinafter, a method for producing the conductive polymer nanoparticles according to the present invention will be described in more detail.

In the present invention, the oil phase includes a conductive polymer monomer, a secondary emulsifier, and a nonpolar organic solvent.

The conductive polymer monomer contained in this oil phase is polymerized into the conductive polymer nanoparticles through the production process according to the present invention.

The kind of the conductive polymer monomer is not particularly limited and may include a water-soluble conductive polymer. The water-soluble conductive polymer may include thiophene, pyrrole, aniline or derivatives thereof. Specifically, the thiophene derivative may be an alkylthiophene (for example, methylthiophene, hexylthiophene, octylthiophene, etc.) Alkylene dioxythiophene, 3,4-dialkylthiophene, 3,4-dialkoxythiophene, and 3,4-cycloalkylthiophene, , The pyrrole derivative may include a polymer in which a substituent group such as a hydroxyl group, a carboxyl group or an alkyl group is substituted in the pyrrole skeleton, and the aniline derivative includes a polymer in which an aniline skeleton is substituted with a substituent such as an alkyl group, a cyano group, can do.

In the present invention, more specifically, thiophene or a derivative thereof may be used as the conductive polymer monomer, and octylthiophene is preferably used.

In the present invention, the auxiliary emulsifier included in the oil phase is used for stabilizing the mixture of oil phase and water phase. Specifically, a nano-reactor is formed when oil and water are emulsified using a high-speed homogenizer or the like, and the nano-reactor becomes mechanically unstable after a certain time, resulting in Ostwald ripening. By using the auxiliary emulsifier in the present invention, it is possible to prevent aging of the Ostwald and obtain an emulsified mixture in a dynamically stable state.

The kind of the auxiliary emulsifier is not particularly limited as long as it is a hydrophobic substance and may include hexadecane, cetyl alcohol, n-propanol, butanol, octanol, nonanol or a mixture thereof. The content of the auxiliary emulsifier is not particularly limited and may be 5 to 10 parts by weight, specifically 6 to 9 parts by weight, based on 100 parts by weight of the conductive polymer monomer. A nano-reactor having a dynamically stable state in the above content range can be produced.

In the present invention, the organic solvent contained in the oil phase is a nonpolar organic solvent. The organic solvent dissolves the conductive polymer monomer, and when emulsifying the aqueous phase, the organic solvent is present in a droplet state together with the conductive polymer monomer. The droplets of the organic solvent and the conductive polymer monomer form a nano-reactor surrounded by the emulsifier, and the polymerization of the conductive polymer monomer is carried out in the organic solvent droplet. In the conventional method for producing conductive polymer nano-particles, the organic solvent is not used. In this case, the conductive polymer monomer itself becomes a liquid droplet, and polymerization takes place in the form of an emulsion in which the emulsifier surrounds the droplet. In this case, there is a fear that the growth may be stopped in the course of the monomer becoming a polymer and sink into a low-molecular form.

Particularly, in the present invention, a nonpolar organic solvent is used as the organic solvent, and the nonpolar organic solvent enables the production of the conductive polymer nanoparticle having a high polymerization degree. The kind of the nonpolar organic solvent is not particularly limited, and may specifically include chloroform, toluene, chlorobenzene, or a mixture thereof.

Distributed element Dipole element Hydrogen bonding element Crolofil 8.65 1.5 2.8 toluene 8.82 0.7 1.0 Chlorobenzene 9.3 2.1 1.0 DMSO (polar organic solvent) 9 8 5

Table 1 shows the physical properties of the nonpolar organic solvent and the polar organic solvent (DMSO) used in the present invention. The above properties were referred to Polymer Handbook 4 ^th edition P.688 ~ 694.

As shown in the above table, DMSO inhibits the synthesis of conductive polymer nanoparticles because the dipole element is much higher than other nonpolar organic solvents. This is because the hydrogen bonding factor value of DMSO is higher than that of other nonpolar organic solvents, thereby inhibiting the propulsion of metal cations of the metal oxidizing agent used as an initiator of the polymerization reaction to the surface of the solvent droplet.

Specifically, first, DMSO plays a role of capturing metal cations present in the water phase due to a high dipole moment, so that the absolute amount of metal cations necessary for polymerization becomes insufficient. Therefore, the polymerization degree is lowered.

Second, since DMSO has a high dispersion element value, it can not stably stay on the monomer droplet and has a property of diffusing into the whole phase. Therefore, when the conductive polymeric monomer is grown into a polymer, the monomer is precipitated in a low molecular state before it is grown in the solvent droplet, which is in conflict with the purpose of introducing the solvent. Therefore, the polymerization degree is lowered.

The content of the organic solvent, specifically, the nonpolar organic solvent is not particularly limited and may be 50 to 200 parts by weight, specifically 70 to 150 parts by weight, based on 100 parts by weight of the conductive polymer monomer. The conductive polymeric monomer can be easily grown into the polymer in the above-mentioned content range.

Further, in the present invention, the water phase contains an emulsifier, and the emulsifier contains an anionic surfactant.

Such anionic surfactant is a hydrophilic substance and can impart safety to the produced nanoparticles. The kind of the anionic surfactant is not particularly limited, and sodium lauryl cell fade (SLS), alkyl sulfide (AS), alkyl ether sulfonate (AES), or a mixture thereof can be used.

The content of the emulsifier is not particularly limited and may be 3 to 5 parts by weight, specifically 3.5 to 4.5 parts by weight based on 100 parts by weight of the conductive polymer monomer. It is possible to manufacture safe nanoparticles within the above range of content.

In the present invention, the solvent contained in the water phase may be distilled water or the like.

Also, in the present invention, the first oxidizing agent serves to reduce the second oxidizing agent while oxidizing itself. Thereby, the second oxidizing agent has an oxidizing power which is higher than the inherent oxidizing power.

The kind of the first oxidizing agent is not particularly limited as long as it has a relatively higher oxidizing power than the second oxidizing agent, and peroxides, oxygen acids or a mixture thereof can be used. Specific examples of the peroxides include hydrogen peroxide, ammonium peroxide or a mixture thereof. As the oxygen acid, permanganic acid, nitric acid, perchloric acid or a mixture thereof may be used.

The content of the first oxidizing agent is not particularly limited and may be 50 to 1000 parts by weight, specifically 100 to 500 parts by weight based on 100 parts by weight of the conductive polymer monomer. It is possible to increase the oxidizing power of the second oxidizing agent in the above content range.

In the present invention, the second oxidant serves to oxidize the conductive polymer monomer. The type of the second oxidizing agent is not particularly limited, iron (Ⅲ), it may be an iron salt (Ⅱ) or oxide of a metal containing copper chloride (Ⅱ), Specifically, FeCl _3, CuCl _2, FeCl ₃ / H _{2 O 2, FeCl 3 / O 2} , FeCl 3 / HMnO 4, FeCl 3 / F 2, FeCl 2 / H 2 O 2, FeCl 2 / O 2, FeCl 2 / HMnO 4, FeCl 2 / F 2, CuCl 2 / H ₂ O ₂ , CuCl ₂ / HMnO _{4 , and the} like.

The content of the second oxidizing agent is not particularly limited and may be 0.1 to 20 parts by weight, specifically 1 to 10 parts by weight, based on 100 parts by weight of the conductive polymer monomer. When the content is less than 0.1 part by weight, the polymerization reaction rate can be significantly slowed. When the content is more than 10 parts by weight, the polymerization reaction rate is increased. However, since the polymer does not sufficiently grow, And the light intensity and the emission intensity can be reduced.

Meanwhile, a method for producing the conductive polymer nanoparticles according to the present invention having the above-described structure is as follows.

In the present invention, the conductive polymer nanoparticles can be polymerized through an oxidative polymerization method. At this time, since the nanoparticles are polymerized by oxidizing the monomers in the droplets of the non-polar organic solvent, the nanoparticles can be generally referred to as the nano-reactor oxidative polymerization method.

Generally, the method for producing the conductive polymer nanoparticles includes an emulsification process including a general emulsion polymerization process, for example, a radical initiation method using a persulfate-based or azobisisocyanate based on a starting method for a monomer, A method of starting oxidation using a metal-based oxidizing agent of the present invention, a method of initiating oxidation by using bis-sulfate / iron, bisulfate / silver and copper / thiosulfate can be used. However, the conductive polymer monomer used in the present invention requires high oxidizing power In order to minimize the influence of the dislocation metal on the physical properties of the polymer produced after the polymerization, an oxidation polymerization method using a second oxidizing agent according to the present invention, specifically a metal-based oxidizing agent, can be used specifically as an oxidation initiator.

Specifically, the production method according to the present invention includes a step of mixing and emulsifying the oil phase and water phase, introducing the first oxidant, adding the second oxidant, and oxidizing and polymerizing.

FIG. 1 is a schematic view showing a method for producing a conductive polymer nanoparticle according to the present invention. In FIG. 1, octylthiophene is used as a conductive polymer monomer. As shown in FIG. 1, the conductive polymer nanoparticles are prepared by mixing a solvent (nonpolar organic solvent), a conductive polymer, an emulsifier, and the like, and emulsifying the mixture at high speed, and then adding a first oxidizing agent to prepare a nano- And then oxidized and polymerized by injecting a quaternary oxidant to prepare emulsion particles, followed by drying to finally produce nanoparticles.

Further, FIG. 3 shows the chemical mechanism of the poly (octylthiophene nano-particles) when octylthiophene is used as the conductive polymer monomer. As shown in FIG. 3, the octylthiophene monomer is polymerized by polymerizing by oxidative polymerization with an oxidizing agent.

In the production process according to the present invention, the emulsification of the mixture of oil phase and water phase can be carried out using a high-speed homogenizer. At this time, the emulsification can be carried out at a speed of 1000 to 10,000 rpm, specifically 1000 to 5000 rpm for 10 minutes to 20 minutes, specifically about 10 minutes.

When the emulsification is complete, the first oxidant is added to the emulsified mixture and stabilized, at which time the mixture is present as a nano-reactor. As shown in FIG. 2, the nano-reactor refers to a state in which a nonpolar organic solvent and a conductive polymer monomer are surrounded by an emulsifier in a droplet state. In the nano-reactor state, polymerization of the polymer monomer can be easily performed. At this time, the stabilization can be performed for about 10 minutes.

The second oxidant is then added to the mixture in the nano-reactor state. The second oxidant acts as an initiator. The second oxidant may be introduced using a syringe, for example.

The reaction temperature during the oxidation polymerization may be 40 to 80 ° C, specifically 45 to 55 ° C, and the reaction time may be 12 to 24 hours, specifically, 15 to 20 hours. The oxidation polymerization reaction can be easily performed at the above temperature and time.

By the oxidation polymerization, the conductive polymer monomer is polymerized into the polymer in the droplet of the nonpolar organic solvent. In the present invention, the step of drying the reaction product after the oxidation polymerization reaction (drying step) is further performed to obtain the conductive polymer nanoparticles in powder form.

Further, in the present invention, it is possible to further carry out a step of reacting the oxidative polymerization reaction with a basic solution before performing the drying step. The reaction may be carried out at room temperature, specifically at 18 to 25 ° C, and the conductive polymer nanoparticles may be dedoped by the reaction to increase optical characteristics. Here, the basic solution used may be a commonly used basic solution, and specifically, potassium hydroxide, sodium hydroxide, or a mixture thereof may be used.

The present invention also relates to conductive polymer nanoparticles produced by the above-mentioned production method.

The average particle size of the conductive polymer nanoparticles may be 30 nm to 10 탆, specifically 100 to 250 nm.

The conductive polymer nanoparticles have excellent processability and can be used for electronic materials, optical materials, toners, inks and the like because they emit light in different colors from the aqueous phase. Further, they can be used for organic EL materials, energy storage materials, , Printing ink materials, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and is defined only by the scope of the claims of the invention.

[Example]

≪ Example 1 >

0.25 g of SLS as an emulsifier was added to 65 g of deionized water at 25 캜 and stirred to prepare a water phase.

Then, 0.5 g of octylthiophene monomer, 0.045 g of cetyl alcohol as a secondary emulsifier and 0.5 g of chloroform were dissolved to prepare an oily phase.

The mixture was then prepared by mixing the water phase with the oil phase and emulsifying with a high speed homogenizer at 8000 RPM for 5 minutes and then the mixture was placed in a reactor and stabilized by stirring for 30 minutes. Next, 0.866 g of 50% hydrogen peroxide as a first oxidizing agent was added to the mixture, and then 0.207 g of FeCl ₃ , which is a second oxidizing agent, was dissolved in 5 g of deionized water as an initiator, and the mixture was reacted. At this time, the reaction temperature was set to 50 ° C and the reaction was carried out for 24 hours to prepare an aqueous dispersion of poly (octylthiophene nano-particles).

Then, the poly-octylthiophene nano-particle water dispersion thus prepared was dried in a vacuum oven at a temperature of 70 ° C to obtain a poly-octylthiophene nano-particle powder.

≪ Example 2 >

The polythiothiophene nanoparticle powder was prepared in the same manner as in Example 1 except that 0.5 g of SLS was used.

≪ Example 3 >

The procedure of Example 1 was repeated except that 1.4434 g (5 eq) of hydrogen peroxide, which is the first oxidizing agent, was used to prepare a polyoxytriaphone nano-particle powder.

≪ Comparative Example 1 &

The procedure of Example 1 was repeated except that DMSO was used instead of chloroform, but no synthesis of poly (octylthiophene nano-particles) was carried out. ,.

Table 2 shows conversion ratios and average particle sizes of the poly (octylthiophene nano particles) prepared by the above Examples and Comparative Examples.

The conversion was measured using the gravimetric method and the average particle size was measured using Dynamic Light Scattering (DLS).

Example 1 Example 2 Example 3 Comparative Example 1 Conversion Rate (%) 95 96 95 20-35 Average particle size (nm) 148 105-150 179-210 -

In the case of Comparative Example 1, the synthesis of polyoctylthiophene nanoparticles was not achieved by a low conversion rate.

As shown in Table 2, the poly (octylthiophene nanoparticles) prepared by the process according to the present invention had an excellent conversion and an average particle size of 100 to 250 nm.

In the present invention, Fig. 4 is an electron micrograph (in net transmission electron microscope) of the poly (octylthiophene nano-particle) prepared in Example 1. Fig. The poly (octylthiophene) nanoparticles prepared are excellent in dispersibility in aqueous phase and have an average particle size within 200 nm.

5 is a photograph of a UV lamp irradiated to determine the degree of light emission when the poly (octylthiophene nano-particles) prepared in Example 1 is dispersed in water. Specifically, (a) is water used as a control group and (b) is a photograph of poly octylthiophene nanoparticles dispersed in water as an experimental group.

As shown in FIG. 5, when the poly (octylthiophene) nanoparticles are dispersed in water, it can be confirmed that orange light emission occurs on a UV lamp. It can be seen that the intrinsic color of octylthiophene can be controlled by adjusting the concentration of water.

Claims (17)

An oily phase containing a conductive polymer monomer, a secondary emulsifier and a nonpolar organic solvent,
Mixing an aqueous emulsion containing an anionic surfactant and emulsifying the emulsion, adding a first oxidizing agent, and then introducing a second oxidizing agent to oxidize and polymerize the aqueous polymer nanoparticles.
The method according to claim 1,
Wherein the conductive polymer monomer is a water-soluble conductive polymer.
3. The method of claim 2,
Wherein the water-soluble conductive polymer is thiophene, pyrrole, aniline or a derivative thereof.
The method according to claim 1,
Wherein the auxiliary emulsifier is hexadecane, cetyl alcohol, n-propanol, butanol, octanol, nonanol or mixtures thereof.
The method according to claim 1,
Wherein the content of the auxiliary emulsifier is 5 to 10 parts by weight based on the weight of the conductive polymer monomer.
The method according to claim 1,
Wherein the nonpolar organic solvent is chloroform, toluene, chlorobenzene or a mixture thereof.
The method according to claim 1,
Wherein the content of the non-polar organic solvent is 50 to 200 parts by weight based on the weight of the conductive polymer monomer.
The method according to claim 1,
Wherein the anionic surfactant is sodium lauryl cell fade, alkyl sulfide, alkyl ether sulfonate or a mixture thereof.
The method according to claim 1,
Wherein the content of the emulsifier is 3 to 5 parts by weight based on the weight of the conductive polymer monomer.
The method according to claim 1,
Wherein the first oxidizing agent is a peroxide, an oxygen acid, or a mixture thereof.
The method according to claim 1,
Wherein the content of the first oxidizing agent is 50 to 1000 parts by weight based on the weight of the conductive polymer monomer.
The method according to claim 1,
Wherein the second oxidant is an oxide of a metal containing iron (III), iron (II) chloride or copper (II) chloride.
The method according to claim 1,
Wherein the content of the second oxidizing agent is 0.1 to 10 parts by weight based on the weight of the conductive polymer monomer.
The method according to claim 1,
Wherein the oxidative polymerization is carried out at 40 to 80 캜 and for 12 to 24 hours.
The method according to claim 1,
And then conducting an oxidation polymerization and then reacting with a basic solution.
A conductive polymer nanoparticle produced by the manufacturing method according to claim 1.
17. The method of claim 16,
The average particle size of the conductive polymer nanoparticles is 30 nm to 10 탆.

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