A coupling agent, an organic electrochromic layer, and a preparation method and application thereof

Abstract

The application relates to the field of organic electrochromic dimming, discloses a coupling agent, an organic electrochromic layer and a preparation method and application thereof, the coupling agent provided by the application comprises the following components in percentage by mass: 0.7wt%-2.8wt% of a sulfonic acid compound, 50wt%-70wt% of a silane coupling agent, 0.01wt%-0.05wt% of an interface agent, 0.2wt%-0.6wt% of a dispersing agent and 26.55wt%-48.99wt% of water; the interface agent comprises an acid-resistant polymer wetting agent; and the dispersing agent comprises a naphthalenesulfonate formaldehyde condensate. Under the joint action of the components in the coupling agent, the response speed, the cycle life, the adhesion of the organic electrochromic layer, the discoloring performance and the bending resistance of the electrochromic device are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of organic electrochromic color modulation, specifically to a coupling agent, an organic electrochromic layer, its preparation method, and its application. Background Technology

[0002] Organic electrochromic materials have attracted much attention due to their rich colors, fast response speed, and customizable molecular structure. However, the performance of organic electrochromic layers directly determines the final performance of devices, and many challenges remain, especially in terms of adhesion and optical contrast.

[0003] In the research and application of electrochromic devices, the adhesion of the organic electrochromic layer is one of the core indicators determining product performance. Poor adhesion not only leads to immediate device failure but also severely restricts its long-term reliability and lifespan. In existing technologies, organic electrochromic layers typically use conductive polymers (such as polythiophene and its derivatives, polyaniline, etc.). However, conductive polymers themselves have poor film-forming properties and poor adhesion to the substrate, causing organic electrochromic layers prepared solely from them to easily crack and peel off during the coating process, resulting in poor coating performance.

[0004] Furthermore, during redox cycles, the conductive polymer's inability to rapidly insert / extract ions prevents the device from achieving optimal optical modulation amplitude (i.e., optical contrast, equal to the difference between the transmittance of the faded state and the colored state), resulting in a longer response time and thus affecting electrochromic performance. Moreover, the volume expansion and contraction caused by ion insertion / extraction can lead to a loose film structure or even dissolution, degrading the device's cycling stability and making it difficult to meet the electrochromic performance requirements of practical applications.

[0005] To address the inherent performance limitations of organic electrochromic layers made solely from conductive polymers, existing technologies employ physical blending or chemical modification to introduce a second component and improve their overall performance. However, when applied to organic electrochromic layers, current modified formulations often fail to balance coating performance and electrochromic properties.

[0006] Therefore, there is an urgent need to develop a coupling agent formulation that enables the organic electrochromic layer prepared by combining it with a conductive polymer to have good coating performance and electrochromic properties, thereby obtaining an organic electrochromic layer with excellent comprehensive performance. Summary of the Invention

[0007] This invention provides a coupling agent, an organic electrochromic layer, a preparation method thereof, and its application. The prepared organic electrochromic layer has good electrochromic properties and coating properties.

[0008] In a first aspect, the present invention provides a coupling agent comprising, by weight percentage: 0.7wt%-2.8wt% of a sulfonic acid compound, 50wt%-70wt% of a silane coupling agent, 0.01wt%-0.05wt% of an interface agent, 0.2wt%-0.6wt% of a dispersant, and 26.55wt%-48.99wt% of water; The interface agent includes an acid-resistant polymer wetting agent; The dispersant includes naphthalene sulfonate formaldehyde condensate.

[0009] In one alternative implementation, the coupling agent satisfies at least one of the following conditions: (1) The silane coupling agent includes one or more of KH-550, KH-560, and KH-570; (2) The acid-resistant polymer wetting agent includes one or more of Span, Tween, and Triton; (3) The sulfonic acid compounds include one or more of dodecylbenzenesulfonic acid, aminosulfonic acid, methanesulfonic acid, p-toluenesulfonic acid and their sulfonates; (4) The naphthalene sulfonate formaldehyde condensate includes one or more of sodium methylene bisnaphthalene sulfonate, sodium methyl naphthalene sulfonate formaldehyde condensate, and benzyl naphthalene sulfonate formaldehyde condensate.

[0010] In one alternative implementation, the span includes one or more of span 20, span 60, and span 80.

[0011] In one alternative implementation, the Tween includes one or more of TW-20, TW-60, and TW-80.

[0012] In one alternative implementation, the Triton comprises Triton X-100.

[0013] In one alternative embodiment, the water includes one or more of deionized water and ultrapure water; In one optional embodiment, the mass concentration of the silane coupling agent is 0.9-1.1 g / mL.

[0014] In a second aspect, the present invention provides an organic electrochromic layer comprising the aforementioned coupling agent.

[0015] Thirdly, the present invention provides a method for preparing the aforementioned organic electrochromic layer, comprising the following steps: S1. A coupling agent is obtained by mixing sulfonic acid compounds, silane coupling agents, interfacial agents, dispersants, and water. S2. Prepare a conductive polymer aqueous dispersion, add the coupling agent from S1 to the prepared conductive polymer aqueous dispersion, then coat it, and after drying, obtain the organic electrochromic layer.

[0016] In one optional embodiment, the mass concentration of the conductive polymer in the conductive polymer aqueous dispersion in S2 is (0.01-0.03) g / mL.

[0017] In one optional embodiment, the S2 step further includes a stirring step before coating; Optionally, the stirring speed is 400-600 r / min and the stirring time is 2-10 min.

[0018] In one optional embodiment, the volume ratio of the conductive polymer aqueous dispersion in S2 to the coupling agent in S1 is (94-96):(4-6).

[0019] In one optional embodiment, the conductive polymer aqueous dispersion includes at least one of polythiophene aqueous dispersion and polyaniline aqueous dispersion.

[0020] In one optional embodiment, the coating thickness in S2 is 5-100 μm; Optionally, when the coating thickness in S2 is 15-25 μm, the transmittance of the organic electrochromic layer is 49-53%, and the transmittance of the ion storage layer (Prussian blue) is 49%-53%, with a maximum dimming range of 17%-65%. Optionally, when the coating thickness in S2 is 45-55 μm, the transmittance of the organic electrochromic layer is 41-45%, and the transmittance of the ion storage layer (Prussian blue) is 41%-45%, with a maximum dimming range of 5%-55%. Optionally, when the coating thickness in S2 is 95-105μm, the transmittance of the organic electrochromic layer is 23-27%, and the transmittance of the ion storage layer (Prussian blue) is 23%-27%, with a maximum dimming range of 1.5%-30%. Optionally, the polythiophene aqueous dispersion is a poly(3,4-ethylenedioxythiophene):polystyrene sulfonate aqueous dispersion.

[0021] In one optional embodiment, the drying temperature in step S2 is 80-95°C, and the drying time is 5-12 min.

[0022] Fourthly, the present invention provides an organic electrochromic device, comprising the organic electrochromic layer or an organic electrochromic layer prepared according to the preparation method described above; Optionally, the organic electrochromic device includes a first transparent substrate layer, a first transparent conductive layer, an ion storage layer, an electrolyte layer, an organic electrochromic layer, a second transparent conductive layer, and a second transparent substrate layer disposed sequentially. Optionally, the first transparent substrate layer and the second transparent substrate layer each independently comprise one or more of polyethylene terephthalate, polyethylene, polycarbonate, and silicon dioxide; Optionally, the first transparent conductive layer and the second transparent conductive layer each independently include one or more of indium tin oxide, fluorine-doped tin oxide, silver nanowires, copper mesh, polythiophene, polypyrrole, and polyaniline.

[0023] The technical solution of this invention has the following advantages: 1. This invention provides a coupling agent, which, by weight percentage, comprises the following components: 0.7wt%-2.8wt% sulfonic acid compound, 50wt%-70wt% silane coupling agent, 0.01wt%-0.05wt% interface agent, 0.2wt%-0.6wt% dispersant, and 26.55wt%-48.99wt% water; wherein the interface agent comprises an acid-resistant polymer wetting agent; and the dispersant comprises a naphthalene sulfonate formaldehyde condensate.

[0024] This invention introduces special types of dispersants and sulfonate compounds, which are beneficial for improving the ionic conductivity of electrochromic materials and enhancing their response speed; simultaneously, they improve the coloring and fading properties of the electrochromic materials. The introduction of dispersants slows down the aggregation and sedimentation of the electrochromic material in the solution before coating, improving its dispersion uniformity and stability. This results in electrochromic materials doped with coupling agents exhibiting better stability, faster response speeds, and improved coating performance, while also extending their service life.

[0025] Introducing specific types of interface agents can reduce surface tension, achieve uniform wetting, and thus improve the adhesion of the organic electrochromic layer, thereby enhancing its coating performance. Sulfonic acid compounds are introduced as catalysts and surfactants to catalyze the hydrolysis and condensation of silane coupling agents, while also adjusting the pH value to maintain system stability. The introduction of silane coupling agents further enhances the adhesion between the organic electrochromic layer and the transparent conductive layer, thereby improving coating performance. Through the combined action of the components in the coupling agent, the device's response speed, optical contrast, and adhesion are effectively improved, further enhancing the corresponding electrochromic performance, coating performance, and cycle stability.

[0026] 2. The method for preparing the organic electrochromic layer provided by the present invention includes the following steps: S1. Mixing sulfonic acid compound, silane coupling agent, interface agent, dispersant and water to obtain a coupling agent; S2. Preparing a conductive polymer aqueous dispersion, adding the coupling agent in S1 to the prepared conductive polymer aqueous dispersion, then coating, and drying to obtain the organic electrochromic layer.

[0027] The method for preparing the organic electrochromic layer provided by this invention has the following advantages compared with existing methods: (1) The optical modulation amplitude (i.e. optical contrast, which is equal to the difference between the transmittance of the faded state and the transmittance of the colored state) of the organic electrochromic layer prepared by the present invention can reach up to 50%.

[0028] (2) Simple process flow: This application does not require special process. The required materials are mixed and stirred evenly before coating. Compared with the existing process, this application omits the grinding and electrodeposition steps, the process is simple, and it can be mass-produced.

[0029] (3) Raw materials are easy to purchase and are inexpensive.

[0030] (4) No electroplating process is used, which facilitates quality control and is conducive to mass production. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 These are actual images of the coating performance tests of Example 2 and Comparative Example 2, where A1 is the sample image before the test of Example 2, A2 is the sample image after the test of Example 2, B1 is the sample image before the test of Comparative Example 2, and B2 is the sample image after the test of Comparative Example 2. Figure 2 This is a schematic diagram of the organic electrochromic device structure of Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the test sample structure of the organic electrochromic device in Embodiment 2 and Comparative Example 1 of the present invention; Figure 4 These are physical images of the colored states used in the color-changing performance test of Example 2 and Comparative Example 1, where C1 is the colored state image of Comparative Example 1 and D1 is the colored state image of Example 2. Figure 5These are actual images of the faded state of the color-changing performance test of Example 2 and Comparative Example 1, where C2 is the faded state image of Comparative Example 1 and D2 is the faded state image of Example 2. Figure 6 These are CV test samples of the electrochromic devices prepared in Example 2 and Comparative Example 1; Figure 7 This is the CV cycle curve diagram for comparison example 1; Figure 8 This is the CV cycle curve of Example 2.

[0033] Explanation of reference numerals in the attached figures: Figure 2 , Figure 3 1. First transparent substrate layer; 2. First transparent conductive layer; 3. Ion storage layer; 4. Electrolyte layer; 5. Organic electrochromic layer; 6. Second transparent conductive layer; 7. Second transparent substrate layer. Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0035] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0036] The raw materials and their sources in the embodiments and comparative examples of this invention are as follows: p-Toluenesulfonic acid, batch number: 250902D2, purity ≥99%, manufacturer: Xilong Scientific Co., Ltd.; Sodium p-toluenesulfonate, batch number: 8LRCREXS, purity: 89%, manufacturer: Anhui Zesheng Technology Co., Ltd.; Silane coupling agent KH-560, density: 1.065 g / mL, batch number: KS390209, purity: 98%, manufacturer: Shanghai Yuanye Biotechnology Co., Ltd.; Span 80, batch number: 2024 / 06 / 13, purity: chemically pure, manufacturer: Tianjin Zhonglian Chemical Reagent Co., Ltd.; Tween-20: Batch number: 2024 / 07 / 17, Purity: Chemically pure, Manufacturer: Sinopharm Chemical Reagent Co., Ltd.; Sodium methylene bis(naphthalene) sulfonate, CAS No.: 26545-58-4, Manufacturer: Guangzhou Qixu Chemical Co., Ltd.; Sodium methylnaphthalenesulfonate formaldehyde condensate, CAS No.: 9062-48-6, Manufacturer: Guangzhou Qixu Chemical Co., Ltd. Benzylnaphthalenesulfonic acid formaldehyde condensate, CAS No.: 36290-04-7, Manufacturer: Guangzhou Qixu Chemical Co., Ltd.; 3,4-Ethylenedioxythiophene (EDOT) monomer, model: PEDUTEVE, purity: 98%, manufacturer: Anhui Zesheng Technology Co., Ltd. Poly(4-styrenesulfonic acid) (PSS), batch number: HCPSS30-1KG, purity: 30%, manufacturer: Shanghai Zhouyuan Biotechnology Co., Ltd. Triton X-100, batch number: A2608148, manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd.

[0037] Example 1 This embodiment provides a method for preparing a coupling agent and an organic electrochromic layer, including the following steps: S1. Mix 0.5g of p-toluenesulfonic acid and 0.8g of sodium p-toluenesulfonate with 30g of deionized water to obtain solution A; Slowly add 50g of silane coupling agent KH-560 (silane coupling agent mass concentration is 1.026 g / mL) to solution A, taking care to avoid boiling and splashing during the process. After standing and cooling naturally for 1 hour, solution B is obtained. Prepare an interface agent solution by mixing 0.02g of interface agent (Span 80) with 10g of deionized water; A dispersant solution was prepared by mixing 0.2 g of dispersant (sodium methylene bis(naphthalene)sulfonate, sodium methylnaphthalenesulfonate formaldehyde condensate, and benzylnaphthalenesulfonate formaldehyde condensate in a mass ratio of 1:1:1) with 8.48 g of deionized water.

[0038] Add an interface agent solution to solution B and stir until homogeneous. Then add a dispersant solution and stir until homogeneous to obtain a coupling agent.

[0039] S2. Using an oxidative synthesis method, 3,4-ethylenedioxythiophene (EDOT) monomer and poly(4-styrenesulfonic acid) (PSS) were oxidatively polymerized to obtain a polythiophene aqueous dispersion (PEDOT-PSS aqueous dispersion, mass concentration of 0.01 g / mL). The above-mentioned coupling agent (PEDOT-PSS aqueous dispersion to coupling agent volume ratio of 95:5) was added to the above PEDOT-PSS aqueous dispersion, and the mixture was stirred for 3 min at a stirring speed of 500 r / min. A 50 μm wire rod was used for coating, and the coating was dried in a vacuum drying oven at 90℃ for 5 min, resulting in a coating thickness of 50 μm. The transmittance after drying was measured using a Linshang Technology LS162 transmittance meter, and was found to be 43%, yielding an organic electrochromic layer.

[0040] Example 2 This embodiment provides a method for preparing a coupling agent and an organic electrochromic layer, including the following steps: S1. Mix 1.17g of p-toluenesulfonic acid and 0.55g of sodium p-toluenesulfonate with 20g of deionized water to obtain solution A; 60.4g of silane coupling agent KH-560 (silane coupling agent mass concentration of 1.026g / mL) was slowly added to solution A. During the process, care should be taken to prevent boiling and splashing. After standing and cooling naturally for 1 hour, solution B was obtained. Prepare an interface agent solution by mixing 0.03g of interface agent (Span 80) with 10g of deionized water; Prepare a dispersant solution by mixing 0.35g of dispersant (sodium methylene bis(naphthalene)sulfonate, sodium methylnaphthalenesulfonate formaldehyde condensate, and benzylnaphthalenesulfonate formaldehyde condensate in a mass ratio of 1:1:1) with 7.5g of deionized water.

[0041] Add an interface agent solution to solution B and stir until homogeneous. Then add a dispersant solution and stir until homogeneous to obtain a coupling agent.

[0042] S2. Using an oxidative synthesis method, 3,4-ethylenedioxythiophene (EDOT) monomer and poly(4-styrenesulfonic acid) (PSS) were oxidatively polymerized to obtain a polythiophene aqueous dispersion (PEDOT-PSS aqueous dispersion, mass concentration of 0.015 g / mL). The above-mentioned coupling agent (PEDOT-PSS aqueous dispersion to coupling agent volume ratio of 95:5) was added to the above PEDOT-PSS aqueous dispersion, and the mixture was stirred for 3 min at a stirring speed of 500 r / min. A 50 μm wire rod was used for coating, and the coating was dried in a vacuum drying oven at 90℃ for 5 min, resulting in a coating thickness of 50 μm. The transmittance after drying was measured using a Linshang Technology LS162 transmittance meter, and was found to be 43%, yielding an organic electrochromic layer.

[0043] Example 3 This embodiment provides a method for preparing a coupling agent and an organic electrochromic layer, including the following steps: S1. Mix 2g of p-toluenesulfonic acid and 0.2g of sodium p-toluenesulfonate with 15g of deionized water to obtain solution A; Slowly add 65g of silane coupling agent KH-560 (silane coupling agent mass concentration is 1.026 g / mL) to solution A, taking care to avoid boiling and splashing during the process. After standing and cooling naturally for 1 hour, solution B is obtained. Prepare an interface agent solution by mixing 0.04g of interface agent (Span 80) with 10g of deionized water; Prepare a dispersant solution by mixing 0.5g of dispersant (sodium methylene bis(naphthalene)sulfonate, sodium methylnaphthalenesulfonate formaldehyde condensate, and benzylnaphthalenesulfonate formaldehyde condensate in a mass ratio of 1:1:1) with 7.26g of deionized water.

[0044] Add an interface agent solution to solution B and stir until homogeneous. Then add a dispersant solution and stir until homogeneous to obtain a coupling agent.

[0045] S2. Using an oxidative synthesis method, 3,4-ethylenedioxythiophene (EDOT) monomer and poly(4-styrenesulfonic acid) (PSS) were oxidatively polymerized to obtain a polythiophene aqueous dispersion (PEDOT-PSS aqueous dispersion, mass concentration of 0.01 g / mL). The above-mentioned coupling agent (PEDOT-PSS aqueous dispersion to coupling agent volume ratio of 95:5) was added to the above PEDOT-PSS aqueous dispersion, and the mixture was stirred for 3 min at a stirring speed of 500 r / min. A 50 μm wire rod was used for coating, and the coating was dried in a vacuum drying oven at 90℃ for 5 min, resulting in a coating thickness of 50 μm. The transmittance after drying was measured using a Linshang Technology LS162 transmittance meter, and was found to be 43%, yielding an organic electrochromic layer.

[0046] Comparative Example 1 This comparative example provides a method for preparing an organic electrochromic layer, including the following steps: An oxidative synthesis method was used to oxidatively polymerize 3,4-ethylenedioxythiophene (EDOT) monomer with poly(4-styrenesulfonic acid) (PSS) to prepare a polythiophene aqueous dispersion (PEDOT-PSS aqueous dispersion, mass concentration of 0.03 g / mL). The polythiophene aqueous dispersion was coated using a 50 μm wire rod and dried in a vacuum drying oven at 90 °C for 5 min, resulting in a coating thickness of 50 μm. The transmittance after drying was measured using a Linshang Technology LS162 transmittance meter, and was found to be 43%, yielding an organic electrochromic layer.

[0047] Comparative Example 2 This comparative example provides a method for preparing an organic electrochromic layer, including the following steps: An oxidative synthesis method was used to oxidatively polymerize 3,4-ethylenedioxythiophene (EDOT) monomer with poly(4-styrenesulfonic acid) (PSS) to prepare a polythiophene aqueous dispersion (PEDOT-PSS aqueous dispersion, mass concentration of 0.03 g / mL). An interface agent (Triton X-100 aqueous solution, volume fraction of Triton X-100 10%) was added to the above polythiophene aqueous dispersion, with a volume ratio of polythiophene aqueous dispersion to interface agent of 90:10. The mixture was then stirred (stirring time 3 min, stirring speed 500 r / min), coated using a 50 μm wire rod, and dried in a vacuum drying oven at 90℃ for 5 min, resulting in a coating thickness of 50 μm. The transmittance after drying was measured using a Linshang Technology LS162 transmittance meter, and was found to be 43%, yielding an organic electrochromic layer.

[0048] Test Example 1 The organic electrochromic layers obtained in Example 2 and Comparative Example 2 were subjected to coating performance tests according to the standard GB / T 9286-1998 "Scratch Test for Paint and Varnish Films". The specific test steps are as follows: Test Method: According to the standard GB / T 9286-1998 "Scratch Test for Paint and Varnish Films", a cross-cutting tool was used to cut a specified number of parallel scratches penetrating to the substrate on the coating surface, forming a checkerboard-like grid pattern. Then, 3M 600 tape was applied to the grid area and quickly peeled off. The adhesion was evaluated by observing the degree of paint film peeling. The test results are as follows: Figure 1 , Figure 1 These are actual images of the coating performance tests for Example 2 (with added coupling agent) and Comparative Example 2 (with only added interface agent). A1 is the sample image of Example 2 before testing, A2 is the sample image of Example 2 after testing, B1 is the sample image of Comparative Example 2 before testing, and B2 is the sample image of Comparative Example 2 after testing. The dark parts in the images are the parts still attached with the organic electrochromic layer, and the light-colored parts are the parts that have fallen off after being adhered by the tape.

[0049] By comparing the before and after photos of Example 2 and Comparative Example 2, it can be seen that Group A with added coupling agent showed better adhesion after being adhered to and quickly peeled off with tape compared to Group B of Comparative Example 2. This indicates that the adhesion of the organic electrochromic layer prepared in Example 2 of the present invention is significantly improved, and further shows that doping the conductive polymer with the coupling agent of the present invention can significantly improve the coating performance of the device.

[0050] Test Example 2 The organic electrochromic layers obtained in Example 2 and Comparative Example 1 were used to prepare organic electrochromic devices. The electrochromic performance of the prepared organic electrochromic devices and the three-electrode cyclic voltammetry (CV) test were performed. The test steps are as follows: 1. Preparations before testing: (1) The substrate A is composed of a first transparent base layer 1 and a first transparent conductive layer 2. The transparent base layer is polyethylene terephthalate (PET) and the transparent conductive layer is indium tin oxide (ITO). The substrate is cut to 80*150mm. The substrate B, composed of a second transparent conductive layer 6 and a second transparent base layer 7, is the same as the substrate A. Both are purchased from Anhui Pingyuan New Materials Co., Ltd., model: PYS-R25-T125PT, for later use.

[0051] (2) Prussian blue (PB) ion storage layer 3 was directly deposited on substrate A using an electrodeposition method. The PB electroplating solution was prepared as follows: 0.1% lithium chloride (LiCl), 0.15% ferric chloride (FeCl3), 0.2% potassium ferricyanide (K3Fe(CN)6), and 99.55% purified water. Electrodeposition was performed using an electrochemical workstation with a constant current or constant voltage method. In this scheme, a Linshang Technology LS162 transmittance meter was used, and the transmittance was measured to be 52%. After preparation, it was used as ion storage layer 3 for later use.

[0052] (3) A transparent colloidal electrolyte cured by ultraviolet light (wavelength 365nm) is used as electrolyte layer 4, wherein the components of the transparent colloidal electrolyte are as follows: propylene carbonate (PC) 68%, methoxy polyethylene glycol (MPEG) 28%, polyethylene glycol diacrylate (PEGDA) 0.45%, glycidyl methacrylate (GMA) 0.2%, lithium perchlorate (LiClO4) 3%, and diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (TPO) 0.35%.

[0053] (4) The electrolyte layer 4 is coated on the substrate A (first transparent base layer 1 and first transparent conductive layer 2) on which the ion storage layer 3 is deposited to obtain component 1; the organic electrochromic layer 5 prepared in each embodiment and comparative example is coated on the substrate B (second transparent conductive layer 6 and second transparent base layer 7) to obtain component 2; component 1 and component 2 are combined and cured using an ultraviolet UV curing oven to obtain an electrochromic device after curing. Figure 2 This is a schematic diagram of the organic electrochromic device structure of Embodiment 2 of the present invention. Figure 3 This is a schematic diagram of the test sample structure of the organic electrochromic device in Embodiment 2 and Comparative Example 1 of the present invention.

[0054] 2. Performance Testing: (1) Electrochromic performance test (optical contrast test) Optical contrast testing was performed on the device prepared in step (4) above. A DC regulated power supply was used, with the voltage adjusted to 1.5V and the power-on time being 10s. When a negative voltage was applied to the organic electrochromic layer, the color deepened and the transmittance decreased; conversely, the color lightened and the transmittance increased. See the physical image of the color-changing performance test. Figures 4-5 Comparative Example 1 (C1 and C2 are without coupling agent) and Example 2 (D1 and D2 are with coupling agent).

[0055] The optical contrast test results show that, under the same time conditions, the transmittance range (i.e., the range of transmittance variation) is as follows: C1 (colored state) transmittance and C2 (faded state) transmittance are 14% and 38%, respectively; D1 (colored state) transmittance and D2 (faded state) transmittance are 7% and 52%, respectively. This comparison clearly shows that, under the same conditions, the transmittance difference between D1 and D2 (45%) is greater than the difference between C1 and C2 (24%), indicating that doping the conductive polymer with a coupling agent can significantly improve the electrochromic performance of the device.

[0056] (2) Cyclic Voltammetry (CV) test The device prepared in step (4) above is cut into test samples (size: 40mm*60mm), such as Figure 6 As shown, the upper and lower conductive layers (indium tin oxide (ITO) and fluorine-doped tin oxide (FTO)) were kept intact. Copper foil electrode leads were fabricated, and three-electrode cyclic voltammetry (CV) was performed using an electrochemical workstation at a voltage of 1.5V. The CV cycle curves are shown below. Figures 7-8 .

[0057] The CV test results show that, according to Embodiment 2 of the present invention ( Figure 8 Compared to Comparative Example 1 () Figure 7 The increased electrochemical active surface area and reactive active sites of organic electrochromic layer materials result in faster response speeds, improved electrode storage capacity, shorter coloring / fading times, and better electrochromic performance.

[0058] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A coupling agent, characterized in that, The coupling agent comprises, by weight percentage, the following components: sulfonic acid compounds 0.7wt%-2.8wt%, silane coupling agent 50wt%-70wt%, interface agent 0.01wt%-0.05wt%, dispersant 0.2wt%-0.6wt%, and water 26.55wt%-48.99wt%. The interface agent includes an acid-resistant polymer wetting agent; The dispersant includes naphthalene sulfonate formaldehyde condensate.

2. The coupling agent according to claim 1, characterized in that, At least one of the following conditions must be met: (1) The silane coupling agent includes one or more of KH-550, KH-560, and KH-570; (2) The acid-resistant polymer wetting agent includes one or more of Span, Tween, and Triton; (3) The sulfonic acid compounds include one or more of dodecylbenzenesulfonic acid, aminosulfonic acid, methanesulfonic acid, p-toluenesulfonic acid and their sulfonates; (4) The naphthalene sulfonate formaldehyde condensate includes one or more of sodium methylene bisnaphthalene sulfonate, sodium methyl naphthalene sulfonate formaldehyde condensate, and benzyl naphthalene sulfonate formaldehyde condensate.

3. The coupling agent according to claim 2, characterized in that, The spouse includes one or more of spouse 20, spouse 60, and spouse 80; And / or, the Tween includes one or more of TW-20, TW-60, and TW-80; And / or, the Triton includes Triton X-100.

4. An organic electrochromic layer, characterized in that, Includes the coupling agent as described in any one of claims 1-3.

5. A method for preparing the organic electrochromic layer according to claim 4, characterized in that, Includes the following steps: S1. A coupling agent is obtained by mixing sulfonic acid compounds, silane coupling agents, interfacial agents, dispersants, and water. S2. Prepare a conductive polymer aqueous dispersion, add the coupling agent from S1 to the prepared conductive polymer aqueous dispersion, then coat it, and after drying, obtain the organic electrochromic layer.

6. The method for preparing the organic electrochromic layer according to claim 5, characterized in that, The mass concentration of the conductive polymer in the aqueous dispersion of the conductive polymer in S2 is (0.01-0.03) g / mL; And / or, the process of coating in S2 further includes a stirring step; Optionally, the stirring speed is 400-600 r / min, and the stirring time is 2-10 min.

7. The method for preparing the organic electrochromic layer according to claim 5 or 6, characterized in that, The volume ratio of the conductive polymer aqueous dispersion in S2 to the coupling agent in S1 is (94-96):(4-6). And / or, the conductive polymer aqueous dispersion includes at least one of polythiophene aqueous dispersion and polyaniline aqueous dispersion.

8. The method for preparing the organic electrochromic layer according to claim 5, characterized in that, The coating thickness in S2 is 5-100 μm.

9. The method for preparing the organic electrochromic layer according to claim 5 or 8, characterized in that, The drying temperature in S2 is 80-95℃, and the drying time is 5-12 min.

10. An organic electrochromic device, characterized in that, Includes the organic electrochromic layer as described in claim 4 or the organic electrochromic layer prepared by the preparation method according to any one of claims 5-9; Optionally, the organic electrochromic device includes a first transparent substrate layer (1), a first transparent conductive layer (2), an ion storage layer (3), an electrolyte layer (4), an organic electrochromic layer (5), a second transparent conductive layer (6), and a second transparent substrate layer (7) arranged sequentially. Optionally, the first transparent substrate layer (1) and the second transparent substrate layer (7) each independently include one or more of polyethylene terephthalate, polyethylene, polycarbonate, and silicon dioxide; Optionally, the first transparent conductive layer (2) and the second transparent conductive layer (6) may each independently include one or more of indium tin oxide, fluorine-doped tin oxide, silver nanowires, copper mesh, polythiophene, polypyrrole, and polyaniline.

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