WO2023024379A1

WO2023024379A1 - Method for preparing quantum dot composite material

Info

Publication number: WO2023024379A1
Application number: PCT/CN2021/142279
Authority: WO
Inventors: 伏睿; 夏本利; 钟海政
Original assignee: 致晶科技（北京）有限公司; 北京理工大学
Priority date: 2021-08-24
Filing date: 2021-12-29
Publication date: 2023-03-02
Also published as: CN114262474B; CN114262474A

Abstract

The present application discloses a method for preparing a quantum dot article. The method comprises the steps of: (1) granulating a mixture comprising a first precursor and a plastic material to obtain a first precursor particle; (2) granulating a mixture comprising a second precursor and a plastic material to obtain a second precursor particle, wherein the second precursor comprises an X precursor; and the second precursor particle comprises X particles; and (3) molding a mixture comprising the first precursor particle, the second precursor particle and a plastic material to obtain the quantum dot composite material. According to the method, three precursors of a perovskite quantum dot are respectively pre-granulated by means of pre-distributed granulation, such that three components are separated from one another in space, the contact time of the three components during an extrusion process is greatly shortened, further growth of the perovskite quantum dot in a plastic molten state is further limited, and after the plasticization is completed, a high-quality quantum dot optical article can be obtained.

Description

A kind of preparation method of quantum dot composite material

technical field

The application relates to a method for preparing a quantum dot composite material, which belongs to the field of material preparation.

Background technique

As an emerging semiconductor material, quantum dots have the advantages of narrow luminescence peak and adjustable wavelength due to the existence of size confinement effect. Therefore, compared with traditional fluorescent materials, quantum dot materials show great advantages. It is a more excellent luminescent material. In recent years, quantum dot luminescent materials have been applied to the backlight source of liquid crystal display devices, which can significantly improve the color gamut of liquid crystal display devices and restore colors more realistically.

The display backlight module is composed of various optical films and optical plates. These films and plates are usually processed from optical-grade plastic materials (including PS, PMMA, PC, etc.) by melt extrusion.

In the existing one-time molding extrusion process, the precursor materials of perovskite quantum dots are used to blend with plastic particles and then directly extruded, and the perovskite quantum dots are grown in situ during the melt extrusion process. However, the precursor components of perovskite contain inorganic salts (such as lead salts PbBr ₂ , PbI _{2 ,} etc.), which are highly ionic. In the process of melt extrusion, inorganic salts are easy to precipitate and grow into large-grained perovskite crystals instead of nanocrystalline perovskite quantum dots.

Contents of the invention

According to one aspect of the present application, a method for preparing a quantum dot composite material is provided. The method uses a step-by-step granulation method to separately prefabricate at least one of the three precursors of perovskite quantum dots Particles, so that several components are separated from each other in space, so that the contact time of the components in the extrusion process is greatly shortened, which in turn limits the further growth of perovskite quantum dots in the plastic molten state. After the plasticization is completed, high-quality quantum dot composite materials or quantum dot optical products can be obtained.

The preparation method of described quantum dot composite material, comprises the following steps:

(1) Granulating the mixture containing the first precursor and the plastic material to obtain the first precursor particles; wherein, the first precursor includes at least one of the A precursor and the B precursor; the first Precursor particles include A particles, B particles, and A+B particles;

(2) Granulating the mixture containing the second precursor and the plastic material to obtain second precursor particles; wherein, the second precursor includes X precursor; the second precursor particles include X particles;

(3) molding the first precursor particle, the second precursor particle and a plastic material to obtain the quantum dot composite material;

Wherein, the A precursor, the B precursor and the X precursor form perovskite quantum dots during the forming process.

Optionally, the preparation method of the quantum dot product comprises the following steps:

(2-1) granulating the first mixture containing the A precursor and the plastic material to obtain A particles;

(2-2) granulating the second mixture containing the B precursor and the plastic material to obtain B particles;

(2-3) granulating the third mixture containing the X precursor and the plastic material to obtain X particles;

(2-4) Molding the fourth mixture containing A particles, B particles, X particles and plastic material to obtain the quantum dot composite material.

Optionally, the preparation method comprises the following steps:

(3-1) granulating the fifth mixture containing the A precursor, the B precursor and the plastic material to obtain A+B particles;

(3-2) granulating the sixth mixture containing the X precursor and the plastic material to obtain X particles;

(3-3) Forming the seventh mixture containing A+B particles, X particles and plastic material to obtain the quantum dot composite material.

Optionally, the A precursor includes at least one of MA ⁺ , FA ⁺ , and Cs ⁺ salts.

Optionally, the A precursors include CsCl, CsBr, CsI, CsAc (cesium acetate), cesium formate, cesium carbonate, cesium valerate, cesium trimethylacetate, cesium stearate, FACl, FABr, FAI, FAAc At least one of (formamidine acetic acid), MACl, MABr, MAI, MAAc (methylaminoacetic acid).

Optionally, the B precursor includes at least one of lead salt, tin salt, and bismuth salt.

Optionally, the B precursor includes at least one of PbCl ₂ , PbBr ₂ , PbI ₂ , lead carbonate, basic lead acetate, lead tartrate, lead laurate, lead stearate, and PbAc ₂ (lead acetate).

Optionally, the X precursor includes at least one of CH ₃ COO ^- , Cl ^- , Br ^- , and I ^-salt .

Optionally, the X precursor includes MACl (methylamine hydrochloride), ethylamine hydrochloride, propylamine hydrochloride, n-butylamine hydrochloride, n-hexylamine hydrochloride, n-octylamine hydrochloride, FACl (formamidine hydrochloride), CsCl, MABr (methylamine hydrobromide), ethylamine hydrobromide, propylamine hydrobromide, n-butylamine hydrobromide, n-hexylamine hydrobromide, n- Octylamine hydrobromide, FABr (formamidine hydrobromide), CsBr, MAI (methylamine hydroiodide), ethylamine hydroiodide, propylamine hydroiodide, n-butylamine hydroiodide, At least one of n-hexylamine hydriodide, n-octylamine hydriodide, FAI (formamidine hydriodide), and CsI.

Optionally, the perovskite quantum dots have an ABX ₃ structure.

Optionally, the mass ratio of precursor A, precursor B and precursor X is 30:29-45:25-30.

Optionally, the A particles, B particles and X particles all contain a single A precursor, B precursor and X precursor.

Optionally, the A particles comprise at least one of the particles comprising a single A precursor;

the B particles include at least one of the particles comprising a single B precursor;

The X particles include at least one of particles containing a single X precursor.

Optionally, the plastic material is an optically transparent material.

Optionally, the plastic material includes PS (polystyrene), PMMA (polymethyl methacrylate), PE (polyethylene), PP (polypropylene), PC (polycarbonate), PET (polyparaphenylene At least one of ethylene glycol diformate).

Optionally, the plastic materials in steps (1)-(3), (2-1)-(2-4) can be independently selected from the above-mentioned plastic materials.

Optionally, in step (2-1), the mass percentage of precursor A in the first mixture is 5-11%;

In step (2-2), the mass percentage of precursor B in the second mixture is 4-7%;

In step (2-3), the mass percentage of precursor X in the third mixture is 2-3%.

Optionally, in step (2-4), the mass ratio of A particles, B particles, X particles and plastic material is 30:29-45:25-30:100.

Optionally, in step (2-1), the mass percentage of precursor A in the first mixture is any value among 5%, 6%, 8%, 11% and the value between any two values thereof range value.

Optionally, in step (2-2), the mass percentage of precursor B in the second mixture is any value among 4%, 5%, 6%, 7% and the value between any two values thereof range value.

Optionally, in step (2-3), the mass percentage of precursor X in the third mixture is 2% or 3%.

Optionally, in step (2-4), the mass ratio of A particles, B particles, X particles and plastic material is 26:40:30:100, 30:45:27:100, 30:29:25:100 , any value in 30:40:30:100.

Optionally, step (3) includes:

Extruding and granulating the mixture containing the first precursor particles, the second precursor particles and the plastic material to obtain quantum dot master batches; or

Casting the mixture containing the first precursor particle, the second precursor particle and the plastic material into a film to obtain a quantum dot film.

Optionally, step (3) includes:

(4-11) Add the diffusion masterbatch to the first and third layers of the three-layer co-extrusion sheet extruder;

(4-12) adding the mixture containing the first precursor particles, the second precursor particles and the plastic material to the second layer of the three-layer co-extrusion sheet extruder;

(4-13) Co-extrude through a three-layer co-extrusion plate extruder to obtain a quantum dot light diffusion plate.

Optionally, step (3) includes:

(4-21) Add the water blocking material to the first layer of the five-layer film co-extrusion casting machine;

(4-22) adding the oxygen barrier material to the second layer of the five-layer film co-extrusion casting machine;

(4-23) adding the mixture containing the first precursor particles, the second precursor particles and the plastic material to the third layer of the five-layer film co-extrusion casting machine;

(4-24) adding the oxygen barrier material to the fourth layer of the five-layer film co-extrusion casting machine;

(4-25) Adding the water-blocking material to the fifth layer of the five-layer film co-extrusion casting machine;

(4-23) Casting through a five-layer film co-extrusion casting machine to obtain a quantum dot composite film with a barrier layer.

Optionally, the water blocking material includes PVDC or EVOH.

Optionally, the oxygen barrier material includes PVA.

The present application provides the application of the quantum dot composite material prepared according to the above method in the field of display and/or lighting.

Optionally, the quantum dot composite material is selected from at least one of quantum dot masterbatches, quantum dot films, quantum dot light diffusion plates, and quantum dot composite films with a barrier layer.

In this application, "PVDC" refers to polyvinylidene chloride.

In this application, "EVOH" refers to ethylene-vinyl alcohol copolymer.

In the present application, "PVA" refers to polyvinyl alcohol.

The beneficial effect that this application can produce comprises:

1) In the preparation method of quantum dot products provided by this application, the perovskite quantum dots are melted and extruded directly into the optical plastic material, and finally co-extruded to obtain a quantum dot light diffusion plate, or Add it to a film extrusion casting machine for casting to obtain a quantum dot film, or directly perform extruder strand cutting to obtain a quantum dot fluorescent masterbatch.

2) The preparation method of quantum dot products provided by this application has no solvent discharge in the overall process, realizes 100% raw material yield, is safe and environmentally friendly, and this in-situ preparation process greatly reduces the cost of separately synthesizing quantum dots, quantum dot composite optics The finished product can also reduce the assembly process of the original independent quantum dot film, improve the production yield, and bring greater economic benefits.

Description of drawings

Figure 1 is a schematic diagram of distributed granulation to realize in-situ growth and extrusion of perovskite quantum dots.

Figure 2 is a schematic diagram of a five-layer co-extruded quantum dot composite film with a barrier.

Fig. 3 is the spectrogram of the quantum dot film under the PE substrate in embodiment 4, wavelength λ=525nm, full width at half maximum FWHM=21nm, fluorescence quantum yield PLQY=79%.

Detailed ways

The present application is described in detail below in conjunction with the examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials in the examples of the present application were purchased through commercial channels.

Analytic method is as follows in the embodiment of the application:

Fluorescence quantum yield analysis was performed using DeltaFLex-01 ultrafast time-resolved fluorescence spectrometer.

In the embodiments of the present application, the fluorescence quantum yield is calculated as follows:

In this application, an appropriate extruder can be selected according to needs, and parameters of the extruder can be adjusted to prepare the quantum dot composite material.

As a kind of implementation mode, the extruder model that adopts in the embodiment: KTE-20 twin-screw granulator

Parameters: 150-170-175-175-175-170

Host speed: 400rpm

Feeding auxiliary machine speed: 280rpm.

Example 1 Formula-1 Use PE pre-distributed granulation

As shown in Figure 1, the preparation method of quantum dot product comprises the following steps:

(1) Granulating the first mixture containing the A precursor and the plastic material to obtain the A particles;

(2) granulating the second mixture containing the B precursor and the plastic material to obtain B particles;

(3) granulating the third mixture containing the X precursor and the plastic material to obtain X particles;

(4) The fourth mixture extruder containing A particles, B particles, X particles and plastic materials is cut into pellets to obtain quantum dot fluorescent masterbatches, which can be processed into other forms of quantum dots optical products;

As an embodiment, the plastic materials are all PE (polyethylene). In step (1), the A precursor is cesium stearate, and the mass fraction of the A precursor in the first mixture is 8%. In step (2), the B precursor is lead stearate, and the mass fraction of the B precursor in the second mixture is 5%. In step (3), the X precursor is n-octylamine hydrobromide, and the mass fraction of the X precursor in the third mixture is 2%.

In step 4, the mass percentages of each component are as follows:

PEPE	A粒子Particle A	B粒子B particle	X粒子X particle	塑胶纯料pure plastic material
质量quality	2626	4040	3030	100100

The performance of the quantum dot fluorescent master batch that step (4) obtains is as follows:

荧光量子产率PLQYFluorescence quantum yield PLQY	发光波长λLuminous wavelength λ	半高宽FWHMFWHM
0.800.80	523523	21twenty one

Example 2 Formula-2 Use PS pre-distributed granulation

As an embodiment, the plastic materials are all PS (polystyrene). In step (1), the A precursor is cesium acetate, and the mass fraction of the A precursor in the first mixture is 6%. In step (2), the B precursor is lead acetate, and the mass fraction of the B precursor in the second mixture is 4%. In step (3), the X precursor is n-hexylamine hydrobromide, and the mass fraction of the X precursor in the third mixture is 3%.

In step 4, the mass percentages of each component are as follows:

PEPE	A粒子Particle A	B粒子B particle	X粒子X particle	塑胶纯料pure plastic material
质量quality	3030	4545	2727	100100

荧光量子产率PLQYFluorescence quantum yield PLQY	发光波长λLuminous wavelength λ	半高宽FWHMFWHM
0.600.60	524524	21twenty one

Example 3 Formula-2 uses PMMA to pre-distribute granulation

(4) The fourth mixture extruder containing A particles, B particles, X particles and plastic materials is cut into particles to obtain quantum dot fluorescent masterbatches, which can be processed into other forms of quantum dots optical products;

As an embodiment, the plastic materials are all PMMA (polymethyl methacrylate). In step (1), the A precursor is cesium stearate, and the mass fraction of the A precursor in the first mixture is 5%. In step (2), the B precursor is lead acetate, and the mass fraction of the B precursor in the second mixture is 4%. In step (3), the X precursor is n-butylamine hydrobromide, and the mass fraction of the X precursor in the third mixture is 3%.

In step 4, the mass percentages of each component are as follows:

PEPE	A粒子Particle A	B粒子B particle	X粒子X particle	塑胶纯料pure plastic material
质量quality	3030	2929	2525	100100

荧光量子产率PLQYFluorescence quantum yield PLQY	发光波长λLuminous wavelength λ	半高宽FWHMFWHM
0.660.66	524524	23twenty three

Example 4 Formula-2 Pre-distributed granulation using PE

(1) granulating the first mixture containing the A1 precursor and the plastic material to obtain the A1 particle; granulating the 1' mixture containing the A2 precursor and the plastic material to obtain the A2 particle;

Wherein, the A precursor, the B precursor and the X precursor form perovskite quantum dots during the molding process.

As an embodiment, the plastic materials are all PE (polyethylene). In step (1), the A1 precursor is cesium acetate, and the mass fraction of the A1 precursor in the first mixture is 10%; the A2 precursor is methylamine hydrobromide, and the mass fraction of the A2 precursor in the 1' mixture 1%; Al precursor and A2 precursor were pelletized separately. In step (2), the B precursor is lead stearate, and the mass fraction of the B precursor in the second mixture is 7%. In step (3), the X precursor is n-butylamine hydrobromide, and the mass fraction of the X precursor in the third mixture is 2%.

In step 4, the mass percentages of each component are as follows:

PEPE	A粒子Particle A	A2粒子A2 particles	B粒子B particle	X母粒XMasterbatch	塑胶纯料pure plastic material
质量quality	2626	44	4040	3030	100100

荧光量子产率PLQYFluorescence quantum yield PLQY	发光波长λLuminous wavelength λ	半高宽FWHMFWHM
0.790.79	525525	21twenty one

Example 5 Forming 1 quantum dot fluorescent masterbatch

1. Use plastic particles/powder to mix with precursor materials A, B, and X respectively, and then granulate to obtain three types of particles: A, B, and X;

2. Mix the three kinds of particles A, B, and X according to a specific concentration ratio, and add a specific amount of pure plastic particles to fully mix;

3. Put the above-mentioned mixed particles into the extruder and cut into pellets to obtain quantum dot fluorescent masterbatch, which can be processed into other forms of quantum dot optical products.

Example 6 Forming 2 Three-layer co-extrusion

3. Add the above-mentioned mixed particles into the ABC three-layer co-extrusion sheet extruder to obtain a quantum dot light diffusion plate, wherein the above-mentioned particles are added to the functional layer B layer extruder as the precursor material of the quantum dot , Layers A and C are added with diffusion masterbatch to achieve co-extrusion, and the finished product is obtained after forming by a three-roller machine.

Example 7 Forming 3 Cast monolayer film

3. Add the above-mentioned mixed particles into a single-layer film extrusion casting machine for casting to obtain a single-layer quantum dot film.

Example 8 Forming 3 Cast composite film

3. The above-mentioned mixed particles are added to a five-layer film co-extrusion caster in the form of ABCBA and cast to obtain a multilayer quantum dot composite film with a barrier layer, wherein A and B are barrier materials, For example, A is a water-blocking material such as PVDC or EVOH, B is a PVA oxygen-blocking material, and C is a quantum dot layer, as shown in Figure 2.

Comparative example 1

The comparison ratio is as follows:

Use the distributed granulation method to first granulate the precursor material and the plastic material PE, and then mix and extrude the in-situ growth quantum dots. In step (1), the A precursor is cesium stearate, and the A precursor is in the first mixture. The quality fraction in 8%. In step (2), the B precursor is lead stearate, and the mass fraction of the B precursor in the second mixture is 5%. In step (3), the X precursor is n-octylamine hydrobromide, and the mass fraction of the X precursor in the third mixture is 2%;

If distribution granulation is not used, take precursor material A precursor stearate 2g, B precursor lead stearate 2.05g, X precursor n-octylamine hydrobromide 0.64g, mix with 197.31g plastic material PE After uniformity, it is directly extruded through the extruder;

The two are actually the same formula, but the luminous efficiency is significantly improved by using the distribution method, and the fluorescence quantum yield is increased from 0.66 without this method to 0.77. See the table below and Figure 3 for details.

the	荧光量子产率PLQYFluorescence quantum yield PLQY	发光波长λLuminous wavelength λ	半高宽FWHMFWHM
采用分布法distribution method	0.770.77	525525	21twenty one
未采用分布法distribution method not used	0.650.65	524524	2020

The above are only a few embodiments of the application, and do not limit the application in any form. Although the application is disclosed as above with preferred embodiments, it is not intended to limit the application. Any skilled person familiar with this field, Without departing from the scope of the technical solution of the present application, any changes or modifications made using the technical content disclosed above are equivalent to equivalent implementation cases, and all belong to the scope of the technical solution.

Claims

A method for preparing a quantum dot composite material, comprising the following steps:

(1) Granulating the mixture containing the first precursor and the plastic material to obtain the first precursor particles; wherein, the first precursor includes at least one of the A precursor and the B precursor; the first Precursor particles include A particles, B particles, and A+B particles;

(2) Granulating the mixture containing the second precursor and the plastic material to obtain second precursor particles; wherein, the second precursor includes X precursor; the second precursor particles include X particles;

(3) molding the mixture containing the first precursor particles, the second precursor particles and the plastic material to obtain the quantum dot composite material;

Wherein, the A precursor, the B precursor and the X precursor form perovskite quantum dots during the forming process.
The preparation method according to claim 1, is characterized in that, comprises the following steps:

(2-1) granulating the first mixture containing the A precursor and the plastic material to obtain A particles;

(2-2) granulating the second mixture containing the B precursor and the plastic material to obtain B particles;

(2-3) granulating the third mixture containing the X precursor and the plastic material to obtain X particles;

(2-4) Molding the fourth mixture containing A particles, B particles, X particles and plastic material to obtain the quantum dot composite material.
The preparation method according to claim 1, is characterized in that, comprises the following steps:

(3-1) granulating the fifth mixture containing the A precursor, the B precursor and the plastic material to obtain A+B particles;

(3-2) granulating the sixth mixture containing the X precursor and the plastic material to obtain X particles;

(3-3) Forming the seventh mixture containing A+B particles, X particles and plastic material to obtain the quantum dot composite material.
The preparation method according to claim 1, wherein the A precursor includes at least one of MA + , FA + , and Cs + salts;

The B precursor includes at least one of lead salt, tin salt, bismuth salt;

The X precursor includes at least one of CH 3 COO - , Cl - , Br - , and I -salt .
The preparation method according to claim 1, wherein the A precursor comprises CsCl, CsBr, CsI, CsAc, cesium formate, cesium carbonate, cesium valerate, cesium trimethyl acetate, cesium stearate, FACl , FABr, FAI, FAAc, MACl, MABr, MAI, MAAc at least one.
The preparation method according to claim 1, wherein the B precursors include PbCl 2 , PbBr 2 , PbI 2 , lead carbonate, basic lead acetate, lead tartrate, lead laurate, lead stearate, PbAc 2 at least one of the
The preparation method according to claim 1, wherein the X precursor comprises MACl, ethylamine hydrochloride, propylamine hydrochloride, n-butylamine hydrochloride, n-hexylamine hydrochloride, n-octylamine salt Acid salt, FACl, CsCl, MABr, ethylamine hydrobromide, propylamine hydrobromide, n-butylamine hydrobromide, n-hexylamine hydrobromide, n-octylamine hydrobromide, FABr, CsBr, MAI , ethylamine hydriodide, propylamine hydriodide, n-butylamine hydriodide, n-hexylamine hydriodide, n-octylamine hydriodide, FAI, CsI at least one.
The preparation method according to claim 1, wherein the plastic material is an optically transparent material.
preparation method according to claim 1, is characterized in that, described plastic material comprises at least one in PS, PMMA, PE, PP, PC, PET.
The preparation method according to claim 1, characterized in that the mass ratio of precursor A, precursor B and precursor X is 30:29-45:25-30.
The preparation method according to claim 1, wherein the perovskite quantum dot is an ABX 3 structure.
The preparation method according to claim 2, characterized in that, in step (2-1), the mass percentage of precursor A in the first mixture is 5-11%;

In step (2-2), the mass percentage of precursor B in the second mixture is 4-7%;

In step (2-3), the mass percentage of precursor X in the third mixture is 2-3%.
The preparation method according to claim 2, characterized in that, in step (2-4), the mass ratio of A particle, B particle, X particle and plastic material is 30:29-45:25-30:100.
preparation method according to claim 1, is characterized in that, step (3) comprises:

Extruding and granulating the mixture containing the first precursor particles, the second precursor particles and the plastic material to obtain quantum dot master batches; or

Casting the mixture containing the first precursor particle, the second precursor particle and the plastic material into a film to obtain a quantum dot film.
preparation method according to claim 1, is characterized in that, step (3) comprises:

(4-11) Add the diffusion masterbatch to the first and third layers of the three-layer co-extrusion sheet extruder;

(4-12) adding the mixture containing the first precursor particles, the second precursor particles and the plastic material to the second layer of the three-layer co-extrusion sheet extruder;

(4-13) Carry out co-extrusion by a three-layer co-extrusion plate extruder to obtain a quantum dot light diffusion plate.
preparation method according to claim 1, is characterized in that, step (3) comprises:

(4-21) Add the water blocking material to the first layer of the five-layer film co-extrusion casting machine;

(4-22) adding the oxygen barrier material to the second layer of the five-layer film co-extrusion casting machine;

(4-23) Adding the fourth mixture containing the first precursor particles, the second precursor particles and the plastic material to the third layer of the five-layer film co-extrusion casting machine;

(4-24) adding the oxygen barrier material to the fourth layer of the five-layer film co-extrusion casting machine;

(4-25) Adding the water-blocking material to the fifth layer of the five-layer film co-extrusion casting machine;

(4-23) Casting through a five-layer film co-extrusion casting machine to obtain a quantum dot composite film with a barrier layer.
The application of the quantum dot composite material prepared by the method according to any one of claims 1 to 16 in the field of display and/or lighting.