KR102303927B1 - Manufacture method of micellar polymer protective layer using block copolymer and quantum dot used thereby - Google Patents

Abstract

The present invention relates to a method for producing a micelle polymer protective film formed of a block copolymer, and to quantum dots surrounded by a micelle polymer protective film prepared thereby, preparing the quantum dots, and a first repeating unit of a block copolymer comprising the quantum dots; Comprising the step of forming block copolymer micellar particles with the interaction difference of the second repeating unit composition to prepare the block copolymer micellar polymer protective film surrounding the quantum dots, the step of preparing the block copolymer micellar polymer protective film After dissolving the first repeating unit and the second repeating unit and the quantum dots using a first solvent, the solvent composition of the first repeating unit and the second repeating unit is changed using a second solvent to surround the quantum dots. is characterized in that it prepares a block copolymer micelle polymer protective film.

Description

Method for producing a micelle polymer protective film formed of a block copolymer and quantum dots surrounded by a micelle polymer protective film prepared thereby

The present invention relates to a method for producing a micelle polymer protective film formed of a block copolymer, and quantum dots surrounded by a micelle polymer protective film prepared thereby, and more particularly, to a block copolymer through a solvent change using polymers having different properties. It relates to a technology in which a micelle polymer protective film is formed, and a block copolymer micelle polymer protective film protects quantum dots in the process.

Quantum dots (QDs) are semiconductor materials and are composed of semiconductor nanocrystals with a size of several nanometers. This small size causes an effect called quantum confinement from quantum dots.

These quantum dots are materials with high color purity capable of emitting light of various emission wavelengths according to crystal size and material composition. In addition, quantum dots have a theoretical quantum yield of 100%, enabling high color reproducibility and improved luminous efficiency. Therefore, research for applying quantum dots to various display devices has been actively conducted in the prior art.

Since quantum dots are small in size, an organic ligand is attached to the surface of the quantum dots for crystal stability. In addition, a core and a shell structure are used for additional protection, and the stability of the quantum dots is secured by final encapsulation in the display device.

As the latest research trend, heavy metal-based quantum dots with excellent optical/electrical properties are used as materials for quantum dots. The heavy metal-based quantum dot maintains stability even in the display process, and thus is used as a main material.

However, since the conventional quantum dot material uses a heavy metal such as cadmium, it is necessary to secure technology for a heavy metal-free nano material. That is, in the prior art, a technology capable of ensuring excellent luminous efficiency and process stability of quantum dots was required without using heavy metal materials.

An object of the present invention is to provide a manufacturing method in which quantum dots are included in a block copolymer micelle polymer protective film in order to secure process stability of quantum dots having excellent luminous efficiency.

In the method for producing a micelle polymer protective film surrounding quantum dots (Quantum Dot, QD) through the use of a block copolymer according to an embodiment of the present invention, the step of preparing the quantum dots, the first repeating unit and the second of the block copolymer Forming a block copolymer micellar polymer protective film using block copolymer micellar particles formed due to the interaction difference of the repeating unit composition and the first repeating unit and the second repeating unit and the quantum dots using a first solvent after dissolving, changing the solvent composition of the first repeating unit and the second repeating unit using a second solvent to prepare a block copolymer micelle polymer protective film surrounding the quantum dots.

In the step of forming the block copolymer micelle polymer protective film, the first solvent and the second solvent interact with each other by changing the tendency of the solvent to dissolve the composition of the first repeating unit and the second repeating unit of the block copolymer. Due to the difference, the block copolymer micellar particles may be formed, and the block copolymer micellar polymer protective film may be formed through a solvent change using the block copolymer micelles.

The first repeating unit may include a functional group including a double bond or a triple bond at the terminal thereof.

The first repeating unit may include any one selected from vinylbenzene, a nitrile group (-CN), and derivatives thereof at the terminal thereof.

The second repeating unit may include a functional group including a hetero atom selected from O, N, P and S to be chemically bonded to the quantum dot.

The second repeating unit may include any one selected from pyridine, bipyridine, and derivatives thereof.

The first repeating unit may have a longer length than the second repeating unit, and may interact with a hydrophobic organic ligand of the quantum dot due to its hydrophobicity.

The second repeating unit may have a shorter length than the first repeating unit, and may have less interaction with the quantum dots due to hydrophilicity.

In the step of preparing the block copolymer micelle polymer protective film, both the first repeating unit and the second repeating unit and the quantum dots are dissolved using the first solvent, and then the first repeating unit is used using the second solvent. and changing the solvent composition for any one of the second repeating units to prepare the block copolymer micelle polymer protective film surrounding the quantum dots.

The quantum dots may be solvated in the first solvent, but aggregated in the second solvent and located in the block copolymer micelle polymer protective film.

The first solvent may be chloroform, and the second solvent may be dimethylformamide (DMF).

In the quantum dots (Quantum Dot, QD) surrounded by a micelle polymer protective film formed of a block copolymer according to an embodiment of the present invention, an organic formed to surround a core that emits light and a shell that promotes a quantum confinement effect It is located in the protective film of the block copolymer micelles formed by changing the ligand and the solvent of the polymer having different properties.

The block copolymer may include a first repeating unit and a second repeating unit.

The block copolymer micelle polymer protective film may be formed by changing a solvent using a polymer having different characteristics of the first repeating unit and the second repeating unit.

The block copolymer micellar polymer protective film is formed by dissolving the first repeating unit and the second repeating unit and the quantum dots through a first solvent of chloroform, and then through a second solvent of dimethylformamide (DMF). Any one of the first repeating unit and the second repeating unit may be formed by changing a solvent in which it dissolves.

The quantum dots may be solvated in the chloroform, but aggregated in the dimethylformamide (DMF) and positioned in the block copolymer micelle polymer protective film.

The quantum dots may include the core of indium phosphide (InP) and the shell of zinc sulfide (ZnS), and may be formed of the organic ligand formed to surround the core and the shell.

According to an embodiment of the present invention, by forming a block copolymer micelle polymer protective film surrounding quantum dots by utilizing block copolymer micelles containing quantum dots, it is possible to maximize the luminous efficiency of quantum dots and secure process stability. .

1 is a flowchart illustrating a method for manufacturing a micelle polymer protective film including quantum dots according to an embodiment of the present invention.
Figure 2 shows a structural example of a quantum dot according to an embodiment of the present invention.
3 is a diagram illustrating a change in a quantum dot according to a solvent change according to an embodiment of the present invention.
4 and 5 show images of block copolymer micelles according to an embodiment of the present invention.
6A and 6B are graphs and images showing changes in light emission after heat treatment of quantum dots and quantum dots surrounded by a protective film of a block copolymer micelle polymer prepared according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the examples. In addition, like reference numerals in each figure denote like members.

In addition, the terms used in this specification are terms used to properly express a preferred embodiment of the present invention, which may vary depending on the intention of a viewer or operator, or a custom in the field to which the present invention belongs. Accordingly, definitions of these terms should be made based on the content throughout this specification.

In the embodiments of the present invention, a block copolymer micelle polymer protective film is formed by utilizing the block copolymer micellar particles, and quantum dots are located in the block copolymer micelle polymer protective film in the process.

In particular, the present invention forms a block copolymer micelle polymer protective film through a solvent change using the first repeating unit and the second repeating unit of the block copolymer having different properties, and in the process, the block copolymer protects the quantum dots. suggest how to

The present invention will be described with reference to FIGS. 1 to 6B as follows.

1 is a flowchart illustrating a method for manufacturing a micelle polymer protective film including quantum dots according to an embodiment of the present invention.

Referring to FIG. 1 , in step 110, quantum dots are prepared.

Quantum dots are nano-sized semiconductor particles having a diameter of 5 nm to 100 nm, and emit light as electrons in an unstable state descend from the conduction band to the valence band. As the particles of the quantum dots are smaller, light of a shorter wavelength is generated, and as the particles are larger, light of a longer wavelength is generated. Therefore, various colors can be realized by controlling the size of the quantum dots. In addition, quantum dots have high luminous efficiency and high color purity, so that they can be applied to various fields such as a light emitting device for lighting, a light source of a liquid crystal display, and a display device.

Specifically, the quantum dot includes a core, a shell formed to surround the core, and an organic ligand formed to surround the shell. At this time, the core is a part that substantially emits light, and the shell promotes the quantum confinement effect and secures the stability of the quantum dots. In addition, the organic ligand serves to help the quantum dots to be well dispersed in the solvent.

The quantum dots are not particularly limited in structure, but may have a single structure consisting of only a core, a core consisting of a core and a single-layered shell, a core-single-shell structure, or a core and a multi-layered shell, a multi-shell structure.

A quantum dot according to an embodiment of the present invention includes a core of indium phosphide (InP) and a shell of zinc sulfide (ZnS) formed to surround the core, and is formed of an organic ligand formed to surround the core and the shell. characterized by being According to an embodiment, the core may be composed of group II-VI or group III-V on the periodic table, for example, cadmium selenide (CdSe), cadmium sulfide (CdTe), zinc selenide (ZnSe), zinc tele It may be made of a compound selected from lide (ZnTe), zinc sulfide (ZnS), mercury telelide (HgTe), and the like. In addition, the shell may be formed of a material selected from inorganic compounds including coral, such as silicon oxide (SiO), titanium oxide (TiO), zinc oxide (ZnO), silica (Silica), magnesium oxide (MgO), etc. have.

In step 120, the block copolymer micellar polymer protective film is formed by utilizing the block copolymer micellar particles formed due to the interaction difference between the first repeating unit and the second repeating unit of the block copolymer.

Specifically, in step 120, the first and second repeating units of the block copolymer have different propensities for dissolving the constituents of the first repeating unit and the second repeating unit, so that the difference in interaction between the first solvent and the second solvent causes block copolymer colloids (colloids). colloids) can be formed. At this time, the micelles have a pattern in which the particles are uniformly spread and float in the 'solvent', and the preferred solvent of the first repeating unit and the second repeating unit of the block copolymer is different. Accordingly, in step 120, the first repeating unit and the second repeating unit are uniformly spread and float in the solvent due to the difference in interaction with the solvent by varying the tendency of the solvent to dissolve the constituents of the first repeating unit and the second repeating unit It is possible to form block copolymer micelles representing Based on the above, step 120 may form a block copolymer micellar polymer protective film through a solvent change using the block copolymer micelles.

In an embodiment of the present invention, the block copolymer (block copolymer, BCP) is a diblock copolymer, a triblock copolymer, a multiblock copolymer comprising a first repeating unit and a second repeating unit represented by the formula Combinations may be included.

The first repeating unit may have a functional group including a double bond or a triple bond at the terminal, and more specifically, may include any one selected from vinylbenzene, a nitrile group (-CN), and derivatives thereof at the terminal. These functional groups are intended to have a high x value, indicating hydrophobicity.

The second repeating unit may have a functional group including a hetero atom selected from O, N, P and S to be chemically bonded to the quantum dot, and more specifically, the functional group including the hetero atom is a thiol group (-SH) , a carbonyl group (-COOH), thiophene, which is an aromatic hetero molecule, pyridine, imidazole, bipyridine, and derivatives thereof may be included. These functional groups may exhibit polarity by the lone pair included in N, O, P or S, and exhibit hydrophilicity.

In this case, the first repeating unit has a length longer than that of the second repeating unit, and may interact with the hydrophobic organic ligand of the quantum dot due to its hydrophobicity. In addition, the second repeating unit may have a shorter length than the first repeating unit, and may have less interaction with quantum dots due to hydrophilicity. Accordingly, preferred solvents of the first repeating unit and the second repeating unit may be different from each other.

The block copolymer can be synthesized in various ways including chain polymerization and step-growth polymerization, but is not limited thereto. As the chain polymerization method, RAFT (Reversible addition-fragmentation chain transfer), NMP (Nitroxide-mediated polymerization), ATRP (Atomic transfer radical polymerization), cation (cationic polymerization) and anionic polymerization method (Anionic polymerization), radical polymerization (Radical polymerization) polymerization) and the like, and as the step polymerization method, there may be a dehydration condensation reaction (Condensation).

In step 130, a block surrounding the quantum dots by dissolving the first repeating unit and the second repeating unit and the quantum dots using the first solvent, and then changing the solvent composition of the first repeating unit and the second repeating unit using the second solvent A copolymer micelle polymer protective film is prepared.

To describe in more detail step 130 of the method for producing a micelle polymer protective film including quantum dots according to an embodiment of the present invention, step 130 is a first solvent in which both the first repeating unit and the second repeating unit and the quantum dots are dissolved. Then, by changing the solvent composition of any one of the first repeating unit and the second repeating unit by using the second solvent, a block copolymer micelle polymer protective film surrounding the quantum dots may be prepared. At this time, the quantum dots are solvated in the first solvent, but aggregated in the second solvent to be positioned in the block copolymer micelle polymer protective film.

In an embodiment of the present invention, the first solvent may be chloroform, and the second solvent may be dimethylformamide (DMF).

For example, in step 130, both the first and second repeating units and quantum dots are dissolved using chloroform, and only one of the first and second repeating units of the block copolymer is dissolved in dimethyl formamide as a solvent. By changing the composition, aggregation of quantum dots due to a change in solvent can produce a block copolymer micelle polymer protective film including quantum dots.

Figure 2 shows an example of the structure of the quantum dot according to the embodiment of the present invention, Figure 3 is a diagram to explain the change of the quantum dot according to the solvent change according to the embodiment of the present invention.

Referring to FIG. 2 , the quantum dot 10 includes a core of indium phosphide (InP), a shell of zinc sulfide (ZnS) formed to surround the core, and oleic acid ( It is characterized in that it is formed as an organic ligand of Oleic Acid).

At this time, the core may be composed of group II-VI or group III-V on the periodic table, for example, cadmium selenide (CdSe), cadmium sulfide (CdTe), zinc selenide (ZnSe), zinc telelide ( ZnTe), zinc sulfide (ZnS), and a compound selected from mercury telelide (HgTe). In addition, the shell can be formed of a material selected from inorganic compounds including coral, such as silicon oxide (SiO), titanium oxide (TiO), zinc oxide (ZnO), silica (Silica), magnesium oxide (MgO), etc. have. In addition, the organic ligand may be formed of an organic material selected from trioctylphosphine (TOP), trioctylphosphine oxide (TOPO), oleic acid, amine, and the like.

As shown in FIG. 2 , the quantum dots 10 may be nano-sized semiconductor particles including a core having a diameter of 3.31 nm and a shell having a diameter of 5 nm. However, the diameter of the quantum dot 10 is not limited thereto, and the structure of the quantum dot 10 is also a single structure consisting of only a core, or a core consisting of a core and a single-layered shell - a single shell structure or a core consisting of a core and a multilayered shell - It may be any one of a multi-shell structure.

According to an embodiment, the quantum dots 10 are CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, CuInS2, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, PbSe, PbS, ZnSeS, ZnSeTe, ZnSTe, HgSeTe, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, AlN, GaZnAs, HgZnAs, HgZnSe, AlN, HgSTe, GaN HgSTe, GaN HgSTe, At least one selected from the group consisting of InN, InP, InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP, GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs It is preferable to be, but it is not necessarily limited thereto, and any element can be used as long as it can be used in the art.

Referring to FIG. 3 , in the method for manufacturing a micelle polymer protective film including quantum dots according to an embodiment of the present invention, in step (a), a first repetition of the block copolymer 20 through a first solvent of chloroform (Chloroform) It is possible to dissolve both the unit and the second repeating unit and the quantum dots 10, and in step (b), using a second solvent of chloroform rich and dimethylformamide (DMF), the block copolymer ( 20), only one of the first repeating unit and the second repeating unit may be dissolved. Thereafter, in the enriched dimethyl formide (DMF rich) of step (c), the quantum dots 10 may be aggregated and located in the block copolymer micelle polymer protective film.

4 and 5 show images of block copolymer micelles according to an embodiment of the present invention.

In more detail, FIG. 4 shows an image of the block copolymer micelles according to an embodiment of the present invention observed with a scanning electron microscope (SEM), and FIG. 5 is an embodiment of the present invention. It shows an image of the block copolymer micelles including quantum dots observed with a transmission electron microscope (TEM).

4 and 5, the block copolymer micelles of PS-b-P4VP formed by the method for producing a micelle polymer protective film containing quantum dots according to an embodiment of the present invention have excellent luminous efficiency, and block air It can be seen that quantum dots are stably included in the micelle polymer protective film formed by the use of the coalesced micellar particles.

6A and 6B are graphs and images showing changes in light emission after heat treatment of quantum dots and quantum dots surrounded by a protective film of a block copolymer micelle polymer prepared according to an embodiment of the present invention.

In more detail, FIG. 6A is a graph and an image showing changes in luminescence after heat treatment of quantum dots including a core of indium phosphide (InP) and a shell of zinc sulfide (ZnS), and FIG. 6b is a graph and an image showing the change in luminescence after heat treatment of quantum dots including a core of indium phosphide (InP) and a shell of zinc sulfide (ZnS) contained in the block copolymer micellar polymer protective film. will be.

6A and 6B , in the case of the quantum dots included in the block copolymer micelle polymer protective film according to an embodiment of the present invention, it can be confirmed that the quantum dots are preserved even after heat treatment. Accordingly, it can be seen that the block copolymer micelle polymer protective film protects the quantum dots, thereby maximizing the luminous efficiency of the quantum dots.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible for those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (17)

In the method of manufacturing a micelle polymer protective film surrounding quantum dots (QD) through the use of a block copolymer,
preparing quantum dots;
forming a block copolymer micelle polymer protective film using block copolymer micelles formed due to a difference in interaction between the first repeating unit and the second repeating unit of the block copolymer; and
After dissolving the first repeating unit and the second repeating unit and the quantum dots using a first solvent, the solvent composition of the first repeating unit and the second repeating unit is changed using a second solvent to surround the quantum dots. comprises the step of preparing a block copolymer micelle polymer protective film,
the first repeating unit is longer than the second repeating unit, and hydrophobically interacts with a hydrophobic organic ligand of the quantum dot, and the second repeating unit is shorter than the first repeating unit; Characterized in that the first repeating unit and the second repeating unit have different preferred solvents because they are hydrophilic and have little interaction with the quantum dots,
The step of preparing the block copolymer micellar polymer protective film is
a first step of dissolving both the first repeating unit and the second repeating unit of the block copolymer and the quantum dots through the first solvent of chloroform;
A second step of dissolving any one of the first repeating unit and the second repeating unit of the block copolymer using the second solvent of chloroform rich and dimethylformamide (DMF); and
A third step of preparing the block copolymer micellar polymer protective film surrounding the quantum dots by aggregation of the quantum dots in dimethyl formamide (DMF rich) enriched
A method for producing a micelle polymer protective film comprising quantum dots comprising a. According to claim 1,
The step of forming the block copolymer micellar polymer protective film is
By varying the tendency of a solvent to dissolve the composition of the first repeating unit and the second repeating unit of the block copolymer, the block copolymer micellar particles are formed due to a difference in interaction between the first solvent and the second solvent, , A method for producing a micelle polymer protective film comprising quantum dots, wherein the block copolymer micellar polymer protective film is formed through a solvent change using the block copolymer micellar particles. 3. The method of claim 2,
The first repeating unit is
A method for producing a micelle polymer protective film comprising quantum dots, characterized in that it comprises a functional group including a double bond or a triple bond at the terminal. 4. The method of claim 3,
The first repeating unit is
A method for producing a micelle polymer protective film comprising quantum dots, characterized in that it contains any one selected from vinylbenzene, nitrile group (-CN) and derivatives thereof at the terminal. 3. The method of claim 2,
The second repeating unit is
A method for producing a micelle polymer protective film comprising quantum dots, characterized in that it comprises a functional group including a hetero atom selected from O, N, P and S so as to be chemically bonded to the quantum dots. 6. The method of claim 5,
The second repeating unit is
A method for producing a micelle polymer protective film comprising quantum dots, comprising any one selected from pyridine, bipyridine, and derivatives thereof. delete delete delete According to claim 1,
The quantum dots are
Although solvated in the first solvent, the method for producing a micelle polymer protective film comprising quantum dots, characterized in that it is aggregated in the second solvent and located in the block copolymer micelle polymer protective film. delete According to claim 1,
The quantum dots are
an organic ligand formed to surround the light-emitting core and the shell promoting the quantum confinement effect; and
A method for producing a micelle polymer protective film including quantum dots, which is positioned in a block copolymer micelle polymer protective film formed through solvent change of polymers having different properties. delete delete delete 13. The method of claim 12,
The quantum dots are
A method of producing a micelle polymer protective film comprising quantum dots, characterized in that it is solvated in chloroform, but is aggregated in dimethylformamide (DMF) and located in the block copolymer micelle polymer protective film. 13. The method of claim 12,
The quantum dots are
A method for producing a micellar polymer protective film comprising quantum dots, comprising the core of indium phosphide (InP) and the shell of zinc sulfide (ZnS), the organic ligand being formed to surround the core and the shell.

Images