Electrochromic material doped with three components of viologen compound as well as preparation method and application of electrochromic material

Abstract

The invention discloses a viologen compound three-component doped electrochromic material as well as a preparation method and application thereof. The preparation method comprises the following steps: respectively dissolving an ethyl viologen compound, a cyano viologen compound and a methoxyl viologen compound in a DMSO solvent, and mixing according to a molar ratio of (1-6): (1-3): (1-6) to obtain a mixed solution; wherein the ethyl viologen compound is 1, 1 '-diethyl-3, 3'-difluoro-4, 4 '-bipyridine-1, 1'-dionium, and the ethyl viologen compound is one or more of ethyl viologen, ethyl viologen, ethyl viologen and ethyl viologen. The cyano viologen compound is mono (1, 1 '-bis (4-cyanophenyl)-[4, 4'-bipyridyl]-1, 1 '-dionium) monochloride; the methoxy viologen compound is mono (1, 1 '-bis (4-methoxyphenyl)-[4, 4'-bipyridyl]-1, 1 '-dionium) chloride; adding a polymerization catalyst into the mixed solution, stirring and reacting for 1.5 hours to form a reaction solution with a polymer network structure at the reaction temperature of 50-70 DEG C; introducing the reaction liquid into a film forming mold, uniformly coating a substrate with the reaction liquid by adopting a blade coating method, and carrying out heating curing and cross-linking strengthening to obtain the viologen compound three-component doped electrochromic material.

Description

Technical Field

[0001] The invention belongs to the technical field of functional materials, and in particular relates to an electrochromic material doped with three components of a viologen compound, and a preparation method and application thereof. Background Art

[0002] Electrochromic materials can change their optical properties by external means, achieving reversible switching between transparent and opaque states, and are widely used in the fields of architecture, automobiles and aviation. Some electrochromic materials are mainly based on inorganic materials such as tungsten oxide WO 3 Or organic materials such as polypyridine, polythiophene, etc. Inorganic materials have good stability and cycle life, but usually have problems such as slow response speed and single color; organic materials can achieve rich color selection and faster response speed due to their structural adjustability, but their processability still needs to be improved.

[0003] The existing technology mainly prepares electrochromic materials through single-component doping, double-component co-doping and other material design methods based on inorganic oxides. Single-component doping is a basic and widely used electrochromic technology. Commonly used single-component doping materials include tungsten oxide WO 3 , Molybdenum Oxide MoO 3 、Vanadium oxide V 2 O 5 By simply doping with metal elements such as titanium Ti, nickel Ni, and cobalt Co, researchers can improve the conductivity, color recovery, and response speed of these oxides; single-component doping technology has the advantages of simple preparation process and low cost, but its electrochromic performance, such as transmittance adjustment range, cycle stability, and color richness, has limitations. Two-component doping can greatly improve the electrochromic performance of materials by introducing two elements or compounds at the same time; for example, WO 3 Indigo Oxide 2 O 3 The composite material has better transmittance regulation and electrochromic efficiency. Dual-component doping can complement each other through the performance of different materials and improve the overall performance of the material. However, in actual operation, this method can easily cause uneven distribution or mutual interference between components, thus affecting long-term stability.

[0004] For example, Gu et al. studied the preparation of phosphorus-doped tungsten oxide (P-doped WO) by electrodeposition. 3) film, P doping improves the conductivity and coloring efficiency of tungsten oxide, especially in improving the response speed and optical recovery. This design enables the film to exhibit excellent coloring performance in smart perspective applications, especially enhancing its cycle stability and long-term use (GU H, TAN M, WANG T, et al. Boosting the electrochromic performance of P-doped WO3 films via electrodeposition for smart window applications [J]. RSC Advances, 2024, 14 (15): 10298-10303); However, P-doped WO 3 Thin film is a single doping structure. Although it can improve conductivity and response speed, its regulation within a specific wavelength range may be relatively limited, and the electrodeposition method may face challenges in wafer thickness and uniformity control in large-scale production.

[0005] Meng et al. studied the preparation of titanium-doped tungsten oxide thin films based on the sol-porous method. 3 The material exhibits excellent dual-band electrochromic properties, including the ability to adjust the transmittance of visible light and near-infrared light. Titanium doping improves the 3 The conductivity and electrochemical stability of the film are improved, thereby improving the coloring efficiency, cycle stability and reaction speed of the film, which is particularly suitable for the application of high-performance smart windows (MENG Q, CAO S, GUO J, et al. Sol-gel-based porous Ti-doped tungsten oxide films for high-performance dual-band electrochromic smart windows[J]. Journal of Energy Chemistry, 2023, 77: 137-143); however, the titanium oxide tungsten oxide system used is a binary doping structure. Although the sol-gel method can prepare thicker films, there may be problems such as complex preparation and difficult to control uniformity. In addition, although the tungsten oxide system performs well in the response to visible light and near-infrared light, it may be limited in regulation in other spectral ranges.

[0006] Ronn Goei et al. studied the co-doping of rare earth Nd and niobium Nb with tin dioxide / α-tungsten oxide electrochromic materials. Through the co-doping of Nd and Nb, the material showed significant improvements in coloring efficiency, switching speed and stability, especially in long-term cyclic use. This design helps to improve the performance of intelligent monitoring, especially its service and response speed (GOEI R, ONG AJ, TAN JH, et al. Nd–Nb Co-doped SnO2 / α-WO3 Electrochromic Materials: Enhanced Stability and Switching Properties[J]. ACS Omega, 2021, 6(40): 26251-26261); however, this scheme uses inorganic elements Nd and Nb for doping. Although it improves the conductivity and cyclic stability of the material, it is insufficient in the diversity of color regulation. α-WO 3 The main regulatory ability is weaker in certain spectral ranges, especially in the ultraviolet and near-infrared.

[0007] Patent CN113774343A discloses a new method for preparing electrochromic doped thin films by co-sputtering technology. This method can effectively control the composition and structure of the thin film by simultaneously introducing multiple doping elements during the sputtering process, thereby improving the electrochromic performance of the material, including coloring efficiency, response speed and cycle stability. This innovative preparation method simplifies the process flow, has high repeatability and stability, and is suitable for large-scale production of electrochromic devices; however, although the co-sputtering preparation method realizes the introduction of multiple doping elements in the preparation process, its doping system is mainly limited to inorganic elements, and it is difficult to provide the same diversified electrochemical response and flexible spectral regulation as organic dopants. In addition, although the preparation process of the co-sputtering method simplifies the introduction of multiple components, the sputtering technology itself is expensive and has complex equipment requirements. Especially in industrial production, how to ensure the uniformity of large-area thin films and the precise control of dopants remains a challenge. Summary of the invention

[0008] In view of this, some embodiments disclose a method for preparing an electrochromic material doped with three components of a viologen compound, comprising:

[0009] Dissolve an ethyl viologen compound, a cyano viologen compound, and a methoxy viologen compound in a DMSO solvent, respectively, and then mix them in a molar ratio of 1 to 6:1 to 3:1 to 6 to obtain a mixed solution; wherein the ethyl viologen compound is 1,1'-diethyl-3,3'-difluoro-4,4'-bipyridine-1,1'-diium; the cyano viologen compound is mono(1,1'-bis(4-cyanophenyl)-[4,4'-bipyridine]-1,1'-diium) monochloride; and the methoxy viologen compound is mono(1,1'-bis(4-methoxyphenyl)-[4,4'-bipyridine]-1,1'-diium) monochloride;

[0010] Adding a polymerization catalyst to the mixed solution, stirring and reacting for 1.5 hours to form a reaction solution having a polymer network structure, wherein the reaction temperature is 50-70° C.;

[0011] The reaction liquid is introduced into a film-forming mold, and the reaction liquid is evenly coated on a substrate by a scraping method, and then heated, cured, and cross-linked to obtain an electrochromic material doped with three components of a viologen compound.

[0012] In some embodiments, the preparation method of the three-component viologen compound doped electrochromic material is disclosed, wherein the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 1:1:1, 1:2:6, 1:3:6, 6:2:1, or 6:3:1.

[0013] Some embodiments disclose a method for preparing a three-component viologen compound doped electrochromic material, wherein the method for preparing an ethyl viologen compound comprises:

[0014] Mix 3,3'-difluoro-4,4'-bipyridine and ethyl bromide in proportion, add acetonitrile to dissolve, and condense and reflux at 80°C for 24 hours to precipitate a crude product of ethyl viologen;

[0015] The crude ethyl viologen product was recrystallized and purified by ethanol, and then placed in deionized water and heated at 60° C. to dissolve to obtain an intermediate product solution;

[0016] The ammonium hexafluorophosphate aqueous solution was slowly added dropwise to the intermediate product solution, and the reaction was stirred for 1 hour to obtain an ethyl viologen compound.

[0017] In the preparation method of the three-component viologen compound doped electrochromic material disclosed in some embodiments, the mass ratio of 3,3'-difluoro-4,4'-bipyridine to ethyl bromide is 1:5.

[0018] Some embodiments disclose a method for preparing a three-component viologen compound doped electrochromic material, wherein the method for preparing a cyano viologen compound comprises:

[0019] Tetrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, and the mixture was condensed and refluxed at 60°C for 72 hours to precipitate a crude cyanoviologen product;

[0020] The crude cyanoviolgin product and p-aminobenzonitrile are dissolved in ethanol solution respectively, and then the p-aminobenzonitrile-ethanol solution is added to the crude cyanoviolgin product-ethanol solution, and the reaction is condensed and refluxed at 80° C. for 72 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude cyanoviolgin product is obtained by suction filtration and rotary evaporation;

[0021] The secondary crude product of cyanoviolate was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly added dropwise, and the mixture was stirred for reaction for 30 minutes to obtain a cyanoviolate compound.

[0022] Some embodiments disclose a method for preparing a three-component viologen compound doped electrochromic material, wherein the method for preparing a methoxy viologen compound comprises:

[0023] Tetrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, and the mixture was condensed and refluxed at 60°C for 72 hours to precipitate a crude methoxyviologen product;

[0024] The crude methoxyviologen product and p-aminoanisole are dissolved in ethanol solution respectively, and then the p-aminoanisole-ethanol solution is added to the crude methoxyviologen product-ethanol solution, and the reaction is condensed and refluxed at 80° C. for 48 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude methoxyviologen product is obtained by suction filtration and rotary evaporation;

[0025] The secondary crude product of methoxyviologen was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly added dropwise, and the mixture was stirred for reaction for 30 minutes to obtain a methoxyviologen compound.

[0026] In the preparation method of the three-component viologen compound doped electrochromic material disclosed in some embodiments, the mass ratio of tetrapyridine to 2,4-dinitrochlorobenzene is 1:5.

[0027] In some embodiments, the preparation method of the three-component viologen compound doped electrochromic material is disclosed, wherein the polymerization catalyst is carbon tetrachloride or hydrogen sulfate.

[0028] Some embodiments disclose an electrochromic material doped with three components of a viologen compound, which is obtained by the preparation method of the electrochromic material doped with three components of a viologen compound.

[0029] Some embodiments disclose the application of an electrochromic material doped with three components of a viologen compound, and the electrochromic material doped with three components of a viologen compound is used for a smart dimming window.

[0030] The electrochromic material doped with three components of viologen compounds disclosed in the embodiment of the present invention selects ethyl viologen compound, cyano viologen compound and methoxy viologen compound for doping; the ethyl viologen compound has excellent electron migration ability and can enhance the electrochromic response speed; the cyano-substituted pyridinium salt improves the charge transfer performance of the material, while the methoxy group has a positive effect on the spectral response and infrared absorption of the material. The combination of these three compounds can regulate the optical properties of the material by optimizing the doping ratio, provide controllable electrochemical behavior, and enable it to show a wider range of color changes under a suitable voltage. At the same time, this doping system has strong electrochemical stability and cycle durability. The electrochromic material doped with three components of viologen compounds disclosed in the embodiments of the present invention is used for smart dimming windows, which can greatly improve the performance of the smart windows. The fast response time and excellent adjustable optical contrast brought by the three-component doping system of ethyl viologen compound, cyano viologen compound and methoxy viologen compound enable the windows to flexibly adjust the transmittance under different lighting conditions, thereby optimizing the indoor lighting environment; secondly, by introducing cyano and methoxy substituents, effective regulation of visible light and infrared light can be achieved, which can not only save energy consumption, but also adjust the thermal performance of windows, thereby improving the energy efficiency of buildings; in addition, this multifunctional doped material is suitable for smart glass in the fields of vehicles, aerospace, etc., providing adaptive light control effects, improving user experience and reducing energy consumption. DETAILED DESCRIPTION

[0031] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0032] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0033] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0034] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0035] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0036] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be arbitrarily combined, and the obtained technical solutions belong to the contents disclosed in the embodiments of the present application. It should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like mentioned in the present application indicate the orientation or positional relationship based on the orientation or positional relationship shown, which is only for the convenience of describing the technical features and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention, unless it conflicts with the context. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance, unless it conflicts with the context.

[0037] In some embodiments, the preparation method of the electrochromic material doped with three components of viologen compound comprises:

[0038] The ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound are respectively dissolved in a DMSO solvent, and then mixed at a molar ratio of 1-6:1-3:1-6 to obtain a mixed solution;

[0039] Among them, the ethyl viologen compound is 1,1'-diethyl-3,3'-difluoro-4,4'-bipyridin-1,1'-diium, and its structural formula is

[0040]

[0041] The cyanoviolate compound is mono(1,1'-bis(4-cyanophenyl)-[4,4'-bipyridyl]-1,1'-diol)monochloride, and its structural formula is

[0042]

[0043] The methoxyviologen compound is mono(1,1'-bis(4-methoxyphenyl)-[4,4'-bipyridyl]-1,1'-diol) monochloride, and its structural formula is

[0044]

[0045] Adding a polymerization catalyst to the mixed solution to promote the polymerization reaction, stirring the reaction for 1.5 hours to form a reaction solution with a polymer network structure, wherein the reaction temperature is 50-70° C.;

[0046] The reaction liquid is introduced into a film-forming mold, and the reaction liquid is evenly coated on the substrate by a scraping method, and then heated and cured to remove the solvent, and cross-linked and strengthened to improve its mechanical strength and chemical stability, so as to obtain an electrochromic material doped with three components of viologen compounds; generally, the material of the substrate is glass or plastic, and during the film-forming process, it is necessary to ensure the uniform thickness of the film to avoid the formation of bubbles; generally, heating and curing can be achieved by baking in an oven, and the temperature is controlled at about 110°C; generally, cross-linking and strengthening can be achieved by heat treatment or baking, and the temperature is controlled at about 60°C.

[0047] In some embodiments, the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 1:1:1, 1:2:6, 1:3:6, 6:2:1, or 6:3:1.

[0048] In some embodiments, the method for preparing an ethyl viologen compound comprises:

[0049] Mix 3,3'-difluoro-4,4'-bipyridine and ethyl bromide in proportion, add acetonitrile to dissolve, and condense and reflux at 80°C for 24 hours to precipitate a crude ethyl viologen product, which is a light yellow solid;

[0050] The crude ethyl viologen product was recrystallized and purified by ethanol, and then placed in deionized water and heated at 60° C. to dissolve to obtain an intermediate product solution;

[0051] Slowly add the ammonium hexafluorophosphate aqueous solution to the intermediate product solution, stop adding when the intermediate product solution is no longer turbid, stir and react for 1 hour, filter and dry to obtain the ethyl viologen compound;

[0052] The synthetic route of ethyl viologen compound is:

[0053]

[0054] In some embodiments, the mass ratio of 3,3'-difluoro-4,4'-bipyridine to ethyl bromide is 1:5.

[0055] In some embodiments, the method for preparing a cyanoviolate compound comprises:

[0056] Quadrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, the solution was transparent and light yellow, and condensed and refluxed at 60°C for 72 hours to precipitate a crude cyanoviologen product, which was a yellow-white powder; during the condensation and reflux process, after the light yellow solution reacted for 24 hours, the solution changed from light yellow to dark brown, a yellow-white solid began to precipitate after 48 hours of reaction, and changed to a yellow-white suspension after 72 hours of reaction, the yellow-white suspension was cooled to room temperature, filtered, and the precipitate was washed with ice ethanol, and finally dried to obtain a crude cyanoviologen product;

[0057] The crude cyanoviolgin product and p-aminobenzonitrile are dissolved in an ethanol solution respectively, and then the p-aminobenzonitrile-ethanol solution is added to the crude cyanoviolgin product-ethanol solution, and the reaction is carried out under condensation reflux at 80° C. for 72 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude cyanoviolgin product is obtained by suction filtration and rotary evaporation. The secondary crude cyanoviolgin product is a dark red solid; generally, the crude cyanoviolgin product is dissolved in an ethanol aqueous solution with a concentration of 50%, and the p-aminobenzonitrile is dissolved in a pure ethanol solution;

[0058] The secondary crude product of cyanovulogen was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly added dropwise, and the solution gradually became turbid. When the solution was no longer turbid after the addition, the addition was stopped, and the reaction was stirred for 30 minutes to obtain a brown-red cyanovulogen compound.

[0059] The synthetic route of cyanoviologen compounds is:

[0060]

[0061] In some embodiments, the method for preparing a methoxy viologen compound comprises:

[0062] Quadrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, the solution was transparent and light yellow, and condensed and refluxed at 60°C for 72 hours to precipitate a crude methoxyviologen product, which was a yellow-white powder; during the condensation and reflux process, after the light yellow solution reacted for 24 hours, the solution changed from light yellow to dark brown, a yellow-white solid began to precipitate after 48 hours of reaction, and changed to a yellow-white suspension after 72 hours of reaction, the yellow-white suspension was cooled to room temperature, filtered, and the precipitate was washed with ice ethanol, and finally dried to obtain a crude methoxyviologen product;

[0063] The crude methoxy viologen product and p-aminoanisole are dissolved in an ethanol solution respectively, and then the p-aminoanisole-ethanol solution is added to the crude methoxy viologen product-ethanol solution, and the reaction is condensed and refluxed at 80° C. for 48 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude methoxy viologen product is obtained by suction filtration and rotary evaporation. The secondary crude methoxy viologen product is a red solid; generally, the crude methoxy viologen product is dissolved in an ethanol aqueous solution with a concentration of 50%, and the p-aminoanisole is dissolved in a pure ethanol solution;

[0064] The secondary crude product of methoxyviologen was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly dripped in, and the solution gradually became turbid. When the solution was no longer turbid after the dripping, the dripping was stopped, and the reaction was stirred for 30 minutes to obtain a brown methoxyviologen compound;

[0065] The synthetic route of methoxyviologen compounds is:

[0066]

[0067] In some embodiments, the mass ratio of tetrapyridine to 2,4-dinitrochlorobenzene is 1:5.

[0068] In some embodiments, the polymerization catalyst is carbon tetrachloride or hydrogen sulfate.

[0069] In some embodiments, the electrochromic material doped with three components of viologen compounds is obtained by the preparation method of the electrochromic material doped with three components of viologen compounds described above.

[0070] In some embodiments, the electrochromic material doped with three components of viologen compounds is used, and the electrochromic material doped with three components of viologen compounds is used for smart dimming windows.

[0071] The technical details are further illustrated below in conjunction with embodiments.

[0072] Example 1

[0073] Example 1 discloses a method for preparing a three-component viologen compound doped electrochromic material, comprising:

[0074] The ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound are respectively dissolved in a DMSO solvent, and then mixed at a molar ratio of 1:1:1 to obtain a mixed solution;

[0075] Adding a polymerization catalyst to the mixed solution to promote the polymerization reaction, stirring the reaction for 1.5 hours to form a reaction solution with a polymer network structure, wherein the reaction temperature is 50-70° C.;

[0076] The reaction liquid is introduced into a film-forming mold, and the reaction liquid is evenly coated on a substrate by a scraping method, and then heated and cured to remove the solvent and strengthen cross-linking to obtain an electrochromic material doped with three components of the viologen compound.

[0077] Example 2

[0078] Example 2 discloses a method for preparing an electrochromic material doped with three components of viologen compounds, referring to Example 1, wherein the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 1:2:6.

[0079] Example 3

[0080] Example 3 discloses a method for preparing an electrochromic material doped with three components of viologen compounds, referring to Example 1, wherein the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 1:3:6.

[0081] Example 4

[0082] Example 4 discloses a method for preparing an electrochromic material doped with three components of viologen compounds, referring to Example 1, wherein the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 6:2:1.

[0083] Example 5

[0084] Example 5 discloses a method for preparing an electrochromic material doped with three components of viologen compounds, referring to Example 1, wherein the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound is 6:3:1.

[0085] Example 6

[0086] Example 6 discloses a method for preparing an ethyl viologen compound, comprising:

[0087] Mix 1g 3,3'-difluoro-4,4'-bipyridine with 5g ethyl bromide, add 40ml acetonitrile to dissolve, and condense and reflux at 80°C for 24h to precipitate the crude product of ethyl viologen, which is then filtered and dried;

[0088] The crude ethyl viologen product was recrystallized and purified by ethanol, and then placed in deionized water and heated at 60° C. to dissolve to obtain an intermediate product solution;

[0089] The ammonium hexafluorophosphate aqueous solution was slowly added dropwise to the intermediate product solution, and the addition was stopped when the system was no longer turbid. The reaction was stirred for 1 hour, and the ethyl viologen compound was obtained by suction filtration and drying.

[0090] Example 7

[0091] Example 7 discloses a method for preparing a cyanoviologen compound comprising:

[0092] Mix 1g of tetrapyridine and 5g of 2,4-dinitrochlorobenzene, add 25ml of ethanol to dissolve, the solution is transparent and light yellow, condense and reflux at 60°C for 72h, and a crude cyanoviologen product is precipitated;

[0093] Dissolve 0.5 g of crude cyanoviologen in 20 ml of 50% ethanol aqueous solution, dissolve 0.6 g of p-aminobenzonitrile in 5 ml of ethanol solution, then add the p-aminobenzonitrile-ethanol solution to the crude cyanoviologen-ethanol solution, condense and reflux at 80° C. for 72 h, then remove ethanol by rotary evaporation, add 150 ml of deionized water and react for 3 h, filter and rotary evaporate to obtain a secondary crude cyanoviologen product;

[0094] The secondary crude cyanoviolate product was dissolved in deionized water, and then 0.5 g of TFSI dissolved in 5 ml of a water-methanol mixed solution was slowly added dropwise until the solution was no longer turbid, and the addition was stopped. The reaction was stirred at room temperature for 30 min to obtain a cyanoviolate compound.

[0095] Example 8

[0096] Example 8 discloses a method for preparing a methoxyviologen compound comprising:

[0097] Mix 1g of tetrapyridine and 5g of 2,4-dinitrochlorobenzene, add 25ml of ethanol to dissolve, the solution turns transparent light yellow, and condenses and refluxes at 60°C for 72h to precipitate a crude methoxyviologen product;

[0098] Dissolve 0.5 g of the crude methoxyviologen product in 20 ml of 50% ethanol aqueous solution, dissolve 1.2 g of p-aminoanisole in 5 ml of ethanol solution, then add the p-aminoanisole-ethanol solution to the crude methoxyviologen product-ethanol solution, condense and reflux at 80° C. for 48 h, then remove the ethanol by rotary evaporation, add 150 ml of deionized water and react for 3 h, filter and rotary evaporation to obtain a secondary crude methoxyviologen product;

[0099] The secondary crude methoxyviologen product was dissolved in deionized water, and then 0.5 g of TFSI dissolved in 5 ml of a water-methanol mixed solution was slowly added dropwise until the solution was no longer turbid, and the reaction was stirred at room temperature for 30 min to obtain a methoxyviologen compound.

[0100] In summary, the three-component viologen compound doped electrochromic materials prepared in Examples 1 to 5, and the ethyl viologen compound, cyano viologen compound, and methoxy viologen compound prepared in Examples 6 to 8 were tested and characterized. The test comparative analysis results are shown in Table 1 below:

[0101] The ratio of the three components in Table 1 is the molar ratio of the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound;

[0102] Table 1 List of test performance numerical results of products of Examples 1 to 8

[0103]

[0104]

[0105] As shown in Table 1 above, the electrochromic material doped with the three components of the viologen compound prepared in Example 1 has a small change in the transmittance of the material, but the absorption coefficient increases, and the color becomes lighter when voltage is applied, showing a brighter gray; the electrochromic material doped with the three components of the viologen compound prepared in Example 2 and Example 3 has a significantly improved transmittance, especially reaching 81-82% after power is applied, and the color becomes brighter, close to light gray; the electrochromic material doped with the three components of the viologen compound prepared in Example 4 and Example 5 has a lower transmittance when no voltage is applied, which is 56%-58%, and a higher transmittance after voltage is applied, which is 75%-78%, and the color change is more obvious.

[0106] The transmittance of the ethyl viologen compound prepared in Example 6 decreased from 82% to 66% when voltage was applied, the molar absorption coefficient increased from 0.55 to 0.68, and the color changed from light gray to slightly dark purple-gray; the transmittance of the cyano viologen compound prepared in Example 7 decreased from 79% to 64% when voltage was applied, the molar absorption coefficient increased from 0.52 to 0.65, and the color change was similar, slightly darker; the methoxy viologen compound prepared in Example 8 showed a lower initial transmittance of 75%, which was further reduced to 60% after power was applied, and the color became darker and greener;

[0107] In summary, compared with a single-component viologen compound, the electrochromic material obtained by doping and mixing the three-component viologen compounds can achieve better optical response under the action of voltage, especially in terms of improving transmittance and maintaining brighter colors. According to different mixing proportions, the electrochromic performance can be optimized, especially when the ethyl viologen compound, the cyano viologen compound, and the methoxy viologen compound are mixed in a ratio of 1:3:6, the material has the best transmittance and visual performance.

[0108] The electrochromic material doped with three components of viologen compounds disclosed in the embodiment of the present invention selects ethyl viologen compound, cyano viologen compound and methoxy viologen compound for doping; the ethyl viologen compound has excellent electron migration ability and can enhance the electrochromic response speed; the cyano-substituted pyridinium salt improves the charge transfer performance of the material, while the methoxy group has a positive effect on the spectral response and infrared absorption of the material. The combination of these three compounds can regulate the optical properties of the material by optimizing the doping ratio, provide controllable electrochemical behavior, and enable it to show a wider range of color changes under a suitable voltage. At the same time, this doping system has strong electrochemical stability and cycle durability. The electrochromic material doped with three components of viologen compounds disclosed in the embodiments of the present invention is used for smart dimming windows, which can greatly improve the performance of the smart windows. The fast response time and excellent adjustable optical contrast brought by the three-component doping system of ethyl viologen compound, cyano viologen compound and methoxy viologen compound enable the windows to flexibly adjust the transmittance under different lighting conditions, thereby optimizing the indoor lighting environment; secondly, by introducing cyano and methoxy substituents, effective regulation of visible light and infrared light can be achieved, which can not only save energy consumption, but also adjust the thermal performance of windows, thereby improving the energy efficiency of buildings; in addition, this multifunctional doped material is suitable for smart glass in the fields of vehicles, aerospace, etc., providing adaptive light control effects, improving user experience and reducing energy consumption.

[0109] The technical solutions disclosed in the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the present invention. Any conventional changes, substitutions or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing an electrochromic material doped with three components of a viologen compound, characterized in that: include: Dissolve an ethyl viologen compound, a cyano viologen compound, and a methoxy viologen compound in a DMSO solvent, respectively, and then mix them in a molar ratio of 1 to 6:1 to 3:1 to 6 to obtain a mixed solution; wherein the ethyl viologen compound is 1,1'-diethyl-3,3'-difluoro-4,4'-bipyridine-1,1'-diium; the cyano viologen compound is mono(1,1'-bis(4-cyanophenyl)-[4,4'-bipyridine]-1,1'-diium) monochloride; and the methoxy viologen compound is mono(1,1'-bis(4-methoxyphenyl)-[4,4'-bipyridine]-1,1'-diium) monochloride; Adding a polymerization catalyst to the mixed solution, stirring and reacting for 1.5 hours to form a reaction solution having a polymer network structure, wherein the reaction temperature is 50-70° C.; The reaction liquid is introduced into a film-forming mold, and the reaction liquid is evenly coated on a substrate by a scraping method, and then heated, cured, and cross-linked to obtain an electrochromic material doped with three components of a viologen compound.

2. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 1, characterized in that: The molar ratio of the ethyl viologen compound, the cyano viologen compound and the methoxy viologen compound is 1:1:1, 1:2:6, 1:3:6, 6:2:1 or 6:3:

1.

3. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 1, characterized in that: The preparation method of the ethyl viologen compound comprises: Mix 3,3'-difluoro-4,4'-bipyridine and ethyl bromide in proportion, add acetonitrile to dissolve, and condense and reflux at 80°C for 24 hours to precipitate a crude product of ethyl viologen; The crude ethyl viologen product was recrystallized and purified by ethanol, and then placed in deionized water and heated at 60° C. to dissolve to obtain an intermediate product solution; The ammonium hexafluorophosphate aqueous solution was slowly added dropwise to the intermediate product solution, and the reaction was stirred for 1 hour to obtain an ethyl viologen compound.

4. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 3, characterized in that: The mass ratio of the 3,3'-difluoro-4,4'-bipyridine to the ethyl bromide is 1:

5.

5. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 1, characterized in that: The preparation method of the cyanoviologen compound comprises: Tetrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, and the mixture was condensed and refluxed at 60°C for 72 hours to precipitate a crude cyanoviologen product; The crude cyanoviolgin product and p-aminobenzonitrile are dissolved in ethanol solution respectively, and then the p-aminobenzonitrile-ethanol solution is added to the crude cyanoviolgin product-ethanol solution, and the reaction is condensed and refluxed at 80° C. for 72 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude cyanoviolgin product is obtained by suction filtration and rotary evaporation; The secondary crude product of cyanoviolate was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly added dropwise, and the mixture was stirred for reaction for 30 minutes to obtain a cyanoviolate compound.

6. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 1, characterized in that: The preparation method of the methoxy viologen compound comprises: Tetrapyridine and 2,4-dinitrochlorobenzene were mixed in proportion, ethanol was added to dissolve, and the mixture was condensed and refluxed at 60°C for 72 hours to precipitate a crude methoxyviologen product; The crude methoxyviologen product and p-aminoanisole are dissolved in ethanol solution respectively, and then the p-aminoanisole-ethanol solution is added to the crude methoxyviologen product-ethanol solution, and the reaction is condensed and refluxed at 80° C. for 48 hours, and then the ethanol is removed by rotary evaporation, and deionized water is added to react for 3 hours, and the secondary crude methoxyviologen product is obtained by suction filtration and rotary evaporation; The secondary crude product of methoxyviologen was dissolved in deionized water, and then a mixed solution of TFSI dissolved in water-methanol was slowly added dropwise, and the mixture was stirred for reaction for 30 minutes to obtain a methoxyviologen compound.

7. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 5 or 6, characterized in that: The mass ratio of the tetrapyridine to the 2,4-dinitrochlorobenzene is 1:

5.

8. The method for preparing the electrochromic material doped with three components of viologen compounds according to claim 1, characterized in that: The polymerization catalyst is carbon tetrachloride or hydrogen sulfate.

9. An electrochromic material doped with three components of a viologen compound, characterized in that: The invention is obtained by the preparation method of the three-component viologen compound doped electrochromic material according to any one of claims 1 to 8.

10. The use of the three-component viologen compound doped electrochromic material as claimed in claim 9, characterized in that: The electrochromic material doped with three components of the viologen compound is used for smart dimming glass.

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