A quantum dot electrochromic smart dimming film and its preparation method

Abstract

This invention relates to the field of dimming film technology, specifically to a quantum dot electrochromic smart dimming film and its preparation method. A transparent polymer and quantum dots are dissolved together in an organic solvent to prepare an electrospinning precursor solution. The precursor solution is spun onto a substrate using electrospinning technology to form a quantum dot-polymer composite nanofiber film. An ion gel precursor solution is dropped onto the composite nanofiber film to fully impregnate it, and then a first transparent conductive substrate with an electrochromic layer is coated onto it. After curing, a semi-finished product is formed. A second transparent conductive substrate with an ion storage layer is aligned and bonded to the obtained semi-finished product and encapsulated to obtain the quantum dot electrochromic smart dimming film. This invention achieves efficient and stable loading of quantum dots and high-speed ion transport through a unique porous nanofiber network structure, while also possessing fast response, high optical contrast, multi-color adjustment capability, and excellent mechanical flexibility.

Description

Technical Field

[0001] This invention relates to the field of dimming film technology, specifically to a quantum dot electrochromic smart dimming film and its preparation method. Background Technology

[0002] Electrochromic smart dimming films are thin-film materials whose optical properties (such as transmittance, reflectance, and absorptivity) can undergo reversible and persistent changes under the influence of an applied electric field. They hold broad application prospects in fields such as smart windows, anti-glare rearview mirrors, and display devices. Traditional electrochromic materials (such as inorganic materials represented by WO3 and organic materials represented by polyaniline) typically suffer from problems such as limited color (commonly blue or green), slow response speed, and insufficient cycle stability. Quantum dots (QDs), as a type of nanoscale semiconductor material, possess excellent properties such as high color purity, tunable emission color, and high quantum yield, and are widely studied and applied in the optoelectronic field. Combining quantum dots with electrochromic materials holds promise for developing novel smart dimming devices with rich colors.

[0003] However, existing quantum dot-electrochromic composite structures typically employ simple stacking or blending methods, which have significant drawbacks:

[0004] 1. Interface problem: The interface compatibility between the quantum dot layer and the electrochromic layer is poor, which can easily lead to phase separation and affect the device lifespan.

[0005] 2. Low ion transport efficiency: Dense quantum dot layers or polymer matrices can hinder the migration of ions required by electrochromic materials, resulting in slow response speed.

[0006] 3. Quantum dot quenching: When quantum dots come into direct contact with electrochromic materials or ionic conductors, fluorescence quenching can easily occur, reducing luminescence efficiency.

[0007] 4. Poor mechanical properties: Multi-layered heterogeneous structures are prone to delamination and cracking when repeatedly bent or subjected to stress.

[0008] Electrospinning technology can produce nanofiber membranes with high specific surface area, high porosity, and good mechanical flexibility. Currently, although some studies have applied electrospun fibers to the field of electrochromism, they are mostly used as carriers for the electrochromic materials themselves. There are no reports of using them as multifunctional embedded networks to simultaneously address comprehensive issues such as quantum dot dispersion, high-speed ion transport, and mechanical enhancement.

[0009] Therefore, it is of great significance to develop a novel and high-performance composite smart dimming film. Summary of the Invention

[0010] The purpose of this invention is to provide a quantum dot electrochromic smart dimming film and its preparation method. This dimming film, through a unique porous nanofiber network structure, achieves efficient and stable loading of quantum dots and high-speed ion transport, while also possessing fast response, high optical contrast, multi-color adjustment capability, and excellent mechanical flexibility.

[0011] The objective of this invention can be achieved through the following technical solutions:

[0012] A method for preparing a quantum dot electrochromic smart dimming film includes the following steps:

[0013] Step 1: Dissolve the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution;

[0014] Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane.

[0015] Step 3: Drop an ion gel precursor solution onto the composite nanofiber membrane to fully impregnate it, then cover it with a first transparent conductive substrate with an electrochromic layer, and cure it to form a semi-finished product;

[0016] Step 4: Align and bond the second transparent conductive substrate with the ion storage layer prepared in step 3 with the semi-finished product obtained in step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

[0017] As a further aspect of the present invention: in step one, the mass ratio of quantum dots to transparent polymer is 1:50-200.

[0018] As a further aspect of the present invention: in step one, the transparent polymer is selected from one or more of polyethylene oxide, polymethyl methacrylate, polyacrylonitrile, and polyvinylpyrrolidone.

[0019] As a further aspect of the present invention: in step one, the quantum dot has a core-shell structure, and its core material is selected from one of CdSe, ZnCdS, InP or CsPbBr3; the shell material is selected from at least one of ZnS, ZnSe or SiO2; the emission wavelength of the quantum dot is adjusted in the range of 450-650 nm.

[0020] As a further aspect of the present invention: in step two, the electrospinning parameters are: voltage of 15-25 kV, receiving distance of 10-20 cm, solution propulsion speed of 0.5-2.0 mL / h, and ambient humidity controlled at 30%-50%.

[0021] As a further aspect of the present invention: in step two, the substrate is a PET film.

[0022] As a further aspect of the present invention: In step three, the liquid ion gel precursor is composed of a mixture of lithium salt, acrylate monomer, photoinitiator and organic solvent, wherein the mass ratio of lithium salt, acrylate monomer, photoinitiator and organic solvent is 2-5:50-92:0.5-10:3-10.

[0023] As a further aspect of the present invention: the electrochromic layer is an inorganic electrochromic material film selected from WO3, NiO, and V2O5; the ion storage layer is a complementary material that matches the electrochromic layer; when the electrochromic layer is WO3, the ion storage layer is NiO or V2O5.

[0024] As a further aspect of the present invention: the first transparent conductive layer and the second transparent conductive layer are indium tin oxide conductive glass, fluorine-doped tin oxide conductive glass, or flexible transparent conductive polymer film.

[0025] A method for preparing a quantum dot electrochromic smart dimming film, wherein the quantum dot electrochromic smart dimming film is prepared by the above method, and the quantum dot electrochromic smart dimming film comprises:

[0026] The membrane consists of a first transparent conductive layer, an electrochromic layer, a composite electrolyte layer, an ion storage layer, and a second transparent conductive layer; the composite electrolyte layer is a quantum dot-polymer composite nanofiber membrane.

[0027] The beneficial effects of this invention are:

[0028] 1. This invention designs a "nanofiber network embedded" composite electrolyte layer structure. The nanofiber network not only serves as an ideal host for quantum dots, physically isolating them to effectively prevent fluorescence quenching, but its three-dimensional interconnected porous structure also provides a perfect framework for ion gels, forming an ion transport "highway" that runs through the device, greatly improving ion conductivity and response speed.

[0029] 2. Multifunctional Synergy: Quantum dots, as abundant and vibrant fluorescence emission sources, provide the background color for the device; while the electrochromic layer achieves dynamic color changing by actively and reversibly modulating the transmitted light. By combining quantum dots with different emission wavelengths (such as CdSe / ZnS emitting red light) with electrochromic materials in different color-changing states (such as PEDOT in a transparent fading state and PEDOT in a blue tinting state), switching between multiple color states, from red to deep blue, can be achieved. This strategy effectively overcomes the limitation of traditional electrochromic devices having only one color.

[0030] 3. Excellent overall performance: The nanofiber network significantly enhances the mechanical strength and flexibility of the composite electrolyte, making the device suitable for flexible wearable devices. The porous structure ensures high electrolyte retention, guaranteeing long-term cycling stability of the device. Quantum dots are firmly embedded in the polymer fibers, preventing migration and aggregation, and ensuring the durability of optical performance.

[0031] 4. Highly efficient and compatible fabrication process: Electrospinning is simple, low-cost, and easily scalable. This method allows for flexible adjustment of fiber diameter, porosity, and film thickness, thereby precisely controlling the optical and electrochemical properties of the device. The entire fabrication process is highly compatible with existing roll-to-roll (R2R) production processes, demonstrating significant industrialization potential. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the sandwich structure of the smart dimming film of the present invention.

[0034] In the figure: 1. First transparent conductive layer; 2. Electrochromic layer; 3. Composite electrolyte layer; 4. Ion storage layer; 5. Second transparent conductive layer. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] Example 1

[0037] like Figure 1 As shown in the figure, the preparation method of a quantum dot electrochromic smart dimming film provided by the present invention includes the following steps:

[0038] Step 1: Dissolve / disperse the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution;

[0039] In more detail, the specific preparation process of the electrospinning precursor solution is as follows:

[0040] The selected transparent polymer is dissolved in an organic solvent and stirred until completely dissolved to form a homogeneous polymer solution. Then, core-shell quantum dots emitting at a specific wavelength are dispersed in the polymer solution and stirred under light-protected conditions until uniformly mixed to obtain a quantum dot-polymer precursor solution that can be used for electrospinning.

[0041] The polymer solution has a mass fraction of 8%, and the mass ratio of quantum dots to polymer is 1:50.

[0042] The transparent polymer is selected from polyethylene oxide (PEO).

[0043] Core-shell quantum dots have a core-shell structure, with the core material selected from CdSe and the shell material selected from ZnS; the emission wavelength of the quantum dots can be adjusted within the range of 450nm.

[0044] The organic solvent is selected from N,N-dimethylformamide (DMF);

[0045] Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane.

[0046] In more detail, the specific preparation process of the quantum dot-polymer composite nanofiber membrane is as follows:

[0047] The precursor solution obtained in step one was loaded into a syringe with a metal needle and connected to a high-voltage power supply. The spinning parameters were set as follows: voltage 15 kV, receiving distance 10 cm, solution propulsion speed 0.5 mL / h, and ambient humidity controlled at 30%. The substrate was covered on a uniformly rotating roller receiver, and electrospinning was performed to obtain a uniform, bead-free quantum dot / polymer composite nanofiber membrane on the substrate.

[0048] The substrate is a PET film;

[0049] Step 3: Drop an ion gel precursor solution onto the composite nanofiber membrane to fully impregnate it, then cover it with a first transparent conductive substrate on which an electrochromic layer 2 has been prepared, and cure it to form a semi-finished product;

[0050] In more detail, the specific preparation process of the semi-finished product is as follows:

[0051] Place the quantum dot-polymer composite nanofiber membrane obtained in step two (fiber membrane side up) flat, and drop liquid ion gel precursor into it to fully wet the entire quantum dot-polymer composite nanofiber membrane.

[0052] The prepared electrochromic electrode (electrochromic layer 2 facing down) was carefully covered on the impregnated quantum dot-polymer composite nanofiber membrane, and slight pressure was applied to remove air bubbles; wherein, the process of preparing the electrochromic electrode is as follows: on the first transparent conductive layer 1, the electrochromic layer 2 is prepared by electrochemical deposition.

[0053] The ion gel precursor is cross-linked and cured by ultraviolet light curing to form a solid quantum dot embedded composite gel electrolyte layer.

[0054] The liquid ion gel precursor is composed of a mixture of lithium salt (such as lithium perchlorate), acrylate monomer (such as polyethylene glycol diacrylate), photoinitiator (such as photoinitiator 1173), and organic solvent (such as propylene carbonate PC) in a mass ratio of 2:50:0.5:3.

[0055] The first transparent conductive layer 1 is indium tin oxide (ITO) conductive glass;

[0056] Electrochromic layer 2 is an inorganic electrochromic material film selected from WO3;

[0057] The UV curing process involves using a UV lamp (wavelength 365 nm, intensity 10 mW / cm²). 2 Irradiate for 10 minutes;

[0058] Step 4: Align and bond the second transparent conductive substrate with the ion storage layer 4 to the semi-finished product obtained in Step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

[0059] In more detail, the specific preparation process of the quantum dot electrochromic smart dimming film is as follows:

[0060] An ion storage layer 4 is prepared on the second transparent conductive layer 5 by electrochemical deposition;

[0061] The second transparent conductive substrate with the ion storage layer 4 is aligned and bonded to the above semi-finished structure, and the surrounding area is encapsulated with epoxy resin to obtain a quantum dot electrochromic smart dimming film.

[0062] The second transparent conductive layer 5 is indium tin oxide (ITO) conductive glass;

[0063] The ion storage layer 4 is a complementary material to the electrochromic layer 2; it is selected from NiO.

[0064] A quantum dot electrochromic smart dimming film is prepared by the above method, comprising: a first transparent conductive layer 1, an electrochromic layer 2, a composite electrolyte layer 3, an ion storage layer 4, and a second transparent conductive layer 5; the composite electrolyte layer 3 is a quantum dot-polymer composite nanofiber membrane.

[0065] Example 2

[0066] The present invention provides a method for preparing a quantum dot electrochromic smart dimming film, comprising the following steps:

[0067] Step 1: Dissolve / disperse the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution;

[0068] In more detail, the specific preparation process of the electrospinning precursor solution is as follows:

[0069] The selected transparent polymer is dissolved in an organic solvent and stirred until completely dissolved to form a homogeneous polymer solution. Then, core-shell quantum dots emitting at a specific wavelength are dispersed in the polymer solution and stirred under light-protected conditions until uniformly mixed to obtain a quantum dot-polymer precursor solution that can be used for electrospinning.

[0070] The polymer solution has a mass fraction of 10%, and the mass ratio of quantum dots to polymer is 1:100.

[0071] The transparent polymer is selected from polymethyl methacrylate (PMMA).

[0072] The core-shell quantum dot has a core-shell structure, with the core material selected from ZnCdS and the shell material selected from ZnSe; the emission wavelength of the quantum dot can be adjusted within the range of 500 nm.

[0073] The organic solvent is selected from tetrahydrofuran (THF);

[0074] Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane.

[0075] In more detail, the specific preparation process of the quantum dot-polymer composite nanofiber membrane is as follows:

[0076] The precursor solution obtained in step one was loaded into a syringe with a metal needle and connected to a high-voltage power supply. The spinning parameters were set as follows: voltage 18 kV, receiving distance 13 cm, solution propulsion speed 1.0 mL / h, and ambient humidity controlled at 35%. The substrate was covered on a uniformly rotating roller receiver, and electrospinning was performed to obtain a uniform, bead-free quantum dot / polymer composite nanofiber membrane on the substrate.

[0077] The substrate is a PET film;

[0078] Step 3: Drop an ion gel precursor solution onto the composite nanofiber membrane to fully impregnate it, then cover it with a first transparent conductive substrate on which an electrochromic layer 2 has been prepared, and cure it to form a semi-finished product;

[0079] In more detail, the specific preparation process of the semi-finished product is as follows:

[0080] Place the quantum dot-polymer composite nanofiber membrane obtained in step two (fiber membrane side up) flat, and drop liquid ion gel precursor into it to fully wet the entire quantum dot-polymer composite nanofiber membrane.

[0081] The prepared electrochromic electrode (electrochromic layer 2 facing down) was carefully covered on the impregnated quantum dot-polymer composite nanofiber membrane, and slight pressure was applied to remove air bubbles; wherein, the process of preparing the electrochromic electrode is as follows: on the first transparent conductive layer 1, the electrochromic layer 2 is prepared by sputtering.

[0082] The ion gel precursor is cross-linked and cured by ultraviolet light curing to form a solid quantum dot embedded composite gel electrolyte layer.

[0083] The liquid ion gel precursor is composed of a mixture of lithium salt (such as lithium hexafluorophosphate), acrylate monomer (such as polyethylene glycol diacrylate), photoinitiator and organic solvent (such as propylene carbonate PC) in a mass ratio of 3:70:5:7.

[0084] The first transparent conductive layer 1 is fluorine-doped tin oxide (FTO) conductive glass;

[0085] Electrochromic layer 2 is an inorganic electrochromic material film selected from WO3;

[0086] The UV curing process involves using a UV lamp (wavelength 365 nm, intensity 10 mW / cm²). 2 Irradiate for 10 minutes;

[0087] Step 4: Align and bond the second transparent conductive substrate with the ion storage layer 4 to the semi-finished product obtained in Step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

[0088] In more detail, the specific preparation process of the quantum dot electrochromic smart dimming film is as follows:

[0089] An ion storage layer 4 is prepared on the second transparent conductive layer 5 by sputtering.

[0090] The second transparent conductive substrate with the ion storage layer 4 is aligned and bonded to the above semi-finished structure, and the surrounding area is encapsulated with epoxy resin to obtain a quantum dot electrochromic smart dimming film.

[0091] The second transparent conductive layer 5 is fluorine-doped tin oxide (FTO) conductive glass.

[0092] The ion storage layer 4 is a complementary material to the electrochromic layer 2; it is selected from V2O5.

[0093] A quantum dot electrochromic smart dimming film is prepared by the above method, comprising: a first transparent conductive layer 1, an electrochromic layer 2, a composite electrolyte layer 3, an ion storage layer 4, and a second transparent conductive layer 5; the composite electrolyte layer 3 is a quantum dot-polymer composite nanofiber membrane.

[0094] Example 3

[0095] The present invention provides a method for preparing a quantum dot electrochromic smart dimming film, comprising the following steps:

[0096] Step 1: Dissolve / disperse the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution;

[0097] In more detail, the specific preparation process of the electrospinning precursor solution is as follows:

[0098] The selected transparent polymer is dissolved in an organic solvent and stirred until completely dissolved to form a homogeneous polymer solution. Then, core-shell quantum dots emitting at a specific wavelength are dispersed in the polymer solution and stirred under light-protected conditions until uniformly mixed to obtain a quantum dot-polymer precursor solution that can be used for electrospinning.

[0099] The polymer solution has a mass fraction of 12%, and the mass ratio of quantum dots to polymer is 1:150.

[0100] The transparent polymer is selected from polyacrylonitrile (PAN);

[0101] The core-shell quantum dot has a core-shell structure, with the core material selected from InP and the shell material selected from SiO2; the emission wavelength of the quantum dot can be adjusted within the range of 600 nm.

[0102] The organic solvent is selected from chloroform;

[0103] Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane.

[0104] In more detail, the specific preparation process of the quantum dot-polymer composite nanofiber membrane is as follows:

[0105] The precursor solution obtained in step one was loaded into a syringe with a metal needle and connected to a high-voltage power supply. The spinning parameters were set as follows: voltage 22 kV, receiving distance 18 cm, solution propulsion speed 1.5 mL / h, and ambient humidity controlled at 45%. The substrate was covered on a uniformly rotating roller receiver, and electrospinning was performed to obtain a uniform, bead-free quantum dot / polymer composite nanofiber membrane on the substrate.

[0106] The substrate is a PET film;

[0107] Step 3: Drop an ion gel precursor solution onto the composite nanofiber membrane to fully impregnate it, then cover it with a first transparent conductive substrate on which an electrochromic layer 2 has been prepared, and cure it to form a semi-finished product;

[0108] In more detail, the specific preparation process of the semi-finished product is as follows:

[0109] Place the quantum dot-polymer composite nanofiber membrane obtained in step two (fiber membrane side up) flat, and drop liquid ion gel precursor into it to fully wet the entire quantum dot-polymer composite nanofiber membrane.

[0110] The prepared electrochromic electrode (electrochromic layer 2 facing down) was carefully covered on the impregnated quantum dot-polymer composite nanofiber membrane, and slight pressure was applied to remove air bubbles. The process of preparing the electrochromic electrode is as follows: the electrochromic layer 2 is prepared on the first transparent conductive layer 1 (such as ITO glass or PET / ITO) by sputtering.

[0111] The ion gel precursor is cross-linked and cured by ultraviolet light curing to form a solid quantum dot embedded composite gel electrolyte layer.

[0112] The liquid ion gel precursor is composed of a mixture of lithium salt (such as lithium bis(trifluoromethanesulfonylimide)), acrylate monomer (such as polyethylene glycol diacrylate), photoinitiator and organic solvent (such as propylene carbonate PC) in a mass ratio of 5:92:10:10.

[0113] The first transparent conductive layer 1 is a flexible transparent conductive polymer (such as PEDOT:PSS) film;

[0114] Electrochromic layer 2 is an inorganic electrochromic material film selected from WO3;

[0115] The UV curing process involves using a UV lamp (wavelength 365 nm, intensity 10 mW / cm²). 2 Irradiate for 10 minutes;

[0116] Step 4: Align and bond the second transparent conductive substrate with the ion storage layer 4 to the semi-finished product obtained in Step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

[0117] In more detail, the specific preparation process of the quantum dot electrochromic smart dimming film is as follows:

[0118] An ion storage layer 4 is prepared on the second transparent conductive layer 5 by sputtering.

[0119] The second transparent conductive substrate with the ion storage layer 4 is aligned and bonded to the above semi-finished structure, and the surrounding area is encapsulated with epoxy resin to obtain a quantum dot electrochromic smart dimming film.

[0120] The second transparent conductive layer 5 is a flexible transparent conductive polymer (such as PEDOT:PSS) film.

[0121] The ion storage layer 4 is a complementary material to the electrochromic layer 2; it is selected from NiO.

[0122] A quantum dot electrochromic smart dimming film is prepared by the above method, comprising: a first transparent conductive layer 1, an electrochromic layer 2, a composite electrolyte layer 3, an ion storage layer 4, and a second transparent conductive layer 5; the composite electrolyte layer 3 is a quantum dot-polymer composite nanofiber membrane.

[0123] Example 4

[0124] The present invention provides a method for preparing a quantum dot electrochromic smart dimming film, comprising the following steps:

[0125] Step 1: Dissolve / disperse the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution;

[0126] In more detail, the specific preparation process of the electrospinning precursor solution is as follows:

[0127] The selected transparent polymer is dissolved in an organic solvent and stirred until completely dissolved to form a homogeneous polymer solution. Then, core-shell quantum dots emitting at a specific wavelength are dispersed in the polymer solution and stirred under light-protected conditions until uniformly mixed to obtain a quantum dot-polymer precursor solution that can be used for electrospinning.

[0128] The polymer solution has a mass fraction of 15%, and the mass ratio of quantum dots to polymer is 1:200.

[0129] The transparent polymer is selected from polyvinylpyrrolidone (PVP);

[0130] The core-shell quantum dot has a core-shell structure, with the core material selected from CsPbBr3 and the shell material selected from SiO2; the emission wavelength of the quantum dot can be adjusted within the range of 650 nm.

[0131] The organic solvent is selected from N,N-dimethylformamide (DMF);

[0132] Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane.

[0133] In more detail, the specific preparation process of the quantum dot-polymer composite nanofiber membrane is as follows:

[0134] The precursor solution obtained in step one was loaded into a syringe with a metal needle and connected to a high-voltage power supply. The spinning parameters were set as follows: voltage 25 kV, receiving distance 20 cm, solution propulsion speed 2.0 mL / h, and ambient humidity controlled at 50%. The substrate was then covered on a uniformly rotating roller receiver for electrospinning, ultimately yielding a uniform, bead-free quantum dot / polymer composite nanofiber membrane on the substrate.

[0135] The substrate is a PET film;

[0136] Step 3: Drop an ion gel precursor solution onto the composite nanofiber membrane to fully impregnate it, then cover it with a first transparent conductive substrate on which an electrochromic layer 2 has been prepared, and cure it to form a semi-finished product;

[0137] In more detail, the specific preparation process of the semi-finished product is as follows:

[0138] Place the quantum dot-polymer composite nanofiber membrane obtained in step two (fiber membrane side up) flat, and drop liquid ion gel precursor into it to fully wet the entire quantum dot-polymer composite nanofiber membrane.

[0139] The prepared electrochromic electrode (electrochromic layer 2 facing down) was carefully covered on the impregnated quantum dot-polymer composite nanofiber membrane, and slight pressure was applied to remove air bubbles; wherein, the process of preparing the electrochromic electrode is as follows: on the first transparent conductive layer 1, the electrochromic layer 2 is prepared by electrochemical deposition.

[0140] The ion gel precursor is cross-linked and cured by ultraviolet light curing to form a solid quantum dot embedded composite gel electrolyte layer.

[0141] The liquid ion gel precursor is composed of a mixture of lithium salt (such as lithium perchlorate), acrylate monomer (such as polyethylene glycol diacrylate), photoinitiator and organic solvent (such as propylene carbonate PC) in a mass ratio of 5:92:10:10.

[0142] The first transparent conductive layer 1 is indium tin oxide (ITO) conductive glass;

[0143] Electrochromic layer 2 is an inorganic electrochromic material film selected from WO3;

[0144] The UV curing process involves using a UV lamp (wavelength 365 nm, intensity 10 mW / cm²). 2 Irradiate for 10 minutes;

[0145] Step 4: Align and bond the second transparent conductive substrate with the ion storage layer 4 to the semi-finished product obtained in Step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

[0146] In more detail, the specific preparation process of the quantum dot electrochromic smart dimming film is as follows:

[0147] An ion storage layer 4 is prepared on the second transparent conductive layer 5 by electrochemical deposition;

[0148] The second transparent conductive substrate with the ion storage layer 4 is aligned and bonded to the above semi-finished structure, and the surrounding area is encapsulated with epoxy resin to obtain a quantum dot electrochromic smart dimming film.

[0149] The second transparent conductive layer 5 is indium tin oxide (ITO) conductive glass;

[0150] The ion storage layer 4 is a complementary material to the electrochromic layer 2; it is selected from NiO.

[0151] A quantum dot electrochromic smart dimming film is prepared by the above method, comprising: a first transparent conductive layer 1, an electrochromic layer 2, a composite electrolyte layer 3, an ion storage layer 4, and a second transparent conductive layer 5; the composite electrolyte layer 3 is a quantum dot-polymer composite nanofiber membrane.

[0152] Comparative Example 1

[0153] The present invention provides a comparative example of a method for preparing a quantum dot electrochromic smart dimming film, comprising the following steps:

[0154] Step 1: Preparation of quantum dot-doped liquid electrolyte:

[0155] More specifically, lithium salt (lithium perchlorate), acrylate monomer (polyethylene glycol diacrylate), photoinitiator (photoinitiator 1173), organic solvent (propylene carbonate) are mixed with the core-shell quantum dots and stirred under light-protected conditions until completely dissolved and uniformly dispersed to obtain a quantum dot-doped liquid ionic gel precursor.

[0156] The proportions of each component are as follows: lithium salt is added at 3% (consistent with Example 1), acrylate monomers are added at 85%, photoinitiator is added at 2%, and organic solvent is added at 10%.

[0157] Step 2: Adding quantum dots:

[0158] More specifically, the type, structure, and emission wavelength of the core-shell quantum dots are exactly the same as in Example 1 (i.e., the core is CdSe, the shell is ZnS, and the emission wavelength is 450 nm). The total amount of quantum dots added, measured by their mass in the final cured electrolyte layer, is consistent with the mass of quantum dots in the composite fiber membrane in Example 1.

[0159] Step 3: Assembly and Curing

[0160] More specifically, a 100 μm thick spacer was placed on a first transparent conductive substrate (ITO glass) with an electrochromic layer 2 (WO3). The quantum dot-doped liquid ion gel precursor prepared in step one was dropped onto the electrochromic layer 2, filling the area defined by the spacer. Subsequently, a second transparent conductive substrate (ITO glass) with an ion storage layer 4 (NiO) was aligned and bonded to the first substrate. Slight pressure was applied to remove air bubbles, and a UV lamp (wavelength 365 nm, intensity 10 mW / cm²) was used. 2 Irradiation for 10 minutes crosslinks and solidifies the ionogel precursor, forming a quantum dot-doped gel electrolyte layer. Finally, the device is encapsulated around its perimeter with epoxy resin to obtain a conventional quantum dot electrochromic color-changing film.

[0161] Performance testing:

[0162] The quantum dot electrochromic smart dimming films obtained in Examples 1-4 were subjected to performance tests by applying a DC voltage of ±3.0 V; the test results are shown in the table below:

[0163]

[0164] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for preparing a quantum dot electrochromic smart dimming film, characterized in that, Includes the following steps: Step 1: Dissolve the transparent polymer and quantum dots together in an organic solvent to prepare an electrospinning precursor solution; Step 2: Using electrospinning technology, the precursor solution from Step 1 is spun onto the substrate to form a quantum dot-polymer composite nanofiber membrane. Step 3: Add an ion gel precursor solution to the composite nanofiber membrane to fully wet it, then cover it with a first transparent conductive substrate on which an electrochromic layer (2) has been prepared, and solidify it to form a semi-finished product; Step 4: Align and bond the second transparent conductive substrate with the ion storage layer (4) prepared with the semi-finished product obtained in Step 3, and encapsulate it to obtain a quantum dot electrochromic smart dimming film.

2. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step one, the mass ratio of quantum dots to transparent polymer is 1:50-200.

3. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step one, the transparent polymer is selected from one or more of polyethylene oxide, polymethyl methacrylate, polyacrylonitrile, and polyvinylpyrrolidone.

4. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step one, the quantum dot has a core-shell structure, with the core material selected from one of CdSe, ZnCdS, InP or CsPbBr3; the shell material is selected from at least one of ZnS, ZnSe or SiO2; and the emission wavelength of the quantum dot is adjusted in the range of 450-650 nm.

5. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step two, the electrospinning parameters are as follows: voltage is 15-25 kV, receiving distance is 10-20 cm, solution propulsion speed is 0.5-2.0 mL / h, and ambient humidity is controlled at 30%-50%.

6. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step two, the substrate is a PET film.

7. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, In step three, the liquid ion gel precursor is composed of a mixture of lithium salt, acrylate monomer, photoinitiator and organic solvent; wherein the mass ratio of lithium salt, acrylate monomer, photoinitiator and organic solvent is 2-5:50-92:0.5-10:3-10.

8. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, The electrochromic layer (2) is an inorganic electrochromic material film selected from WO3, NiO, and V2O5; the ion storage layer (4) is a complementary material that matches the electrochromic layer (2); when the electrochromic layer (2) is WO3, the ion storage layer (4) is NiO or V2O5.

9. The method for preparing a quantum dot electrochromic smart dimming film according to claim 1, characterized in that, The first transparent conductive layer (1) and the second transparent conductive layer (5) are indium tin oxide conductive glass, fluorine-doped tin oxide conductive glass or flexible transparent conductive polymer film.

10. A quantum dot electrochromic smart dimming film, characterized in that, The quantum dot electrochromic smart dimming film is prepared by the method described in any one of claims 1-9 above. The quantum dot electrochromic smart dimming film includes: a first transparent conductive layer (1), an electrochromic layer (2), a composite electrolyte layer (3), an ion storage layer (4), and a second transparent conductive layer (5); the composite electrolyte layer (3) is a quantum dot-polymer composite nanofiber membrane.

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