Inorganic-organic hybrid photoelectrochromic material, preparation method and application thereof

Abstract

This invention provides an inorganic-organic hybrid photochromic material, its preparation method, and its applications. The invention employs a solvothermal method to uniformly mix a metal source, 2,4,6-tris(4-pyridyl)-1,3,5-triazine, trimesic acid, water, N,N′-dimethylacetamide, and methanol, and reacts the mixture at 120–140°C for 24–72 hours to obtain colorless crystals. This invention investigates the photochromic and electrochromic processes of this inorganic-organic hybrid material. This material has broad application prospects in inkless printing, electrochromic devices, photochromic decoration, optical memory, optical switches, and optoelectronic displays.

Description

Technical Field

[0001] This invention relates to the field of photochromic technology, specifically to an inorganic-organic hybrid photochromic material based on 2,4,6-tris(4-pyridyl)-1,3,5-triazine, its preparation method, and its application. Background Technology

[0002] Photochromic compounds are compounds that change color under light of a certain wavelength and intensity, and this change is reversible. Due to their ability to switch reversibly between two different steady states, these materials have been used in many fields, such as inks, automobiles, molecular switches, X-ray detection, and bioimaging, showing broad application prospects.

[0003] Photochromic materials are classified into inorganic photochromic materials, organic photochromic materials, and inorganic-organic hybrid photochromic materials. Inorganic photochromic compounds include polyacids, alkali metal azides, and Prussian blue compounds with tautomerism; organic photochromic compounds include diarylethenes, spiropyrans, spiroxazines, azo compounds, and violet alkaloids. Inorganic compounds possess thermal stability, while organic compounds are diverse and easy to process. Inorganic-organic hybrid materials combine the advantages of both inorganic and organic photochromic compounds, and their application in photochromism has attracted considerable research interest.

[0004] Electrochromic devices are optical devices that exhibit reversible changes in transmittance or reflectance when an external voltage is applied. Due to their unique adjustable optical properties, electrochromic devices have attracted widespread attention in fields such as smart windows, sensing, and displays.

[0005] However, due to the late start of the development of this type of material, the research on photochromic materials still suffers from problems such as single stimulus response, single application mode, and slow response rate. Summary of the Invention

[0006] To address the issues of limited stimulus response, single application mode, and slow response rate, this invention provides an inorganic-organic hybrid photoelectric color-changing material, its preparation method, and its application.

[0007] The present invention adopts the following technical solution:

[0008] An inorganic-organic hybrid photochromic material, wherein the chemical formula of the hybrid photochromic material is C 36 H 30 N6O 18 Zn3, the inorganic part is Zn 2+The organic part is 2,4,6-tris(4-pyridyl)-1,3,5-triazine and pyromellitic acid. It is a monoclinic crystal system with space group P21 / n and unit cell parameters a=7.347(3)Å, b=29.365(7)Å, c=17.723(5)Å, α=90°, β=95.60(3)°, γ=90°.

[0009] A method for preparing an inorganic-organic hybrid photochromic material includes the following steps: mixing a metal source, 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT), trimesolic acid (BTC), water, N,N′-dimethylacetamide (DMA), and methanol to obtain a uniform mixture; loading the mixture into a reaction vessel for reaction to obtain a blocky colorless crystal, which is the hybrid photochromic material.

[0010] Furthermore, the metal source is zinc perchlorate Zn(ClO4)2.

[0011] Further, the mass ratio of the metal source, 2,4,6-tris(4-pyridyl)-1,3,5-triazine, and trimesic acid is (2-4):1:(1-2), preferably 3:1:2.

[0012] Furthermore, the volume ratio of water, N,N′-dimethylacetamide, and methanol is 4:1:(0-1), preferably 4:1:1.

[0013] Furthermore, the reaction temperature of the mixture is 120–140°C, preferably 140°C, and the reaction time is 24–72 hours.

[0014] Furthermore, the preparation method of the hybrid photochromic material includes the following steps: 30 mg of zinc perchlorate, 10 mg of 2,4,6-tris(4-pyridyl)-1,3,5-triazine, 20 mg of trimesic acid, 4 mL of water, 1 mL of N,N′-dimethylacetamide, and 1 mL of methanol are mixed evenly to obtain a mixture. Then, the mixture is added to a stainless steel reactor lined with polytetrafluoroethylene (the volume of the stainless steel reactor is 20 mL) and sealed. The mixture is then reacted in an oven at 140°C for more than 24 hours. After the reaction is completed, the stainless steel reactor is gradually cooled to room temperature. The crystals generated in the stainless steel reactor are then removed to obtain colorless blocky crystals, which are the hybrid photochromic material.

[0015] This invention provides an application of an inorganic-organic hybrid photochromic material in inkless printing, electrochromic devices, photochromic decoration, optical memory, optical switches, and optoelectronic displays.

[0016] This invention provides a method for preparing an inorganic-organic hybrid photochromic material. The prepared hybrid photochromic material has applications in inkless printing, electrochromic devices, photochromic decoration, optical memory, optical switches, and optoelectronic displays.

[0017] The hybrid photochromic material prepared in this invention changes color from colorless to light blue in 10 seconds under ultraviolet light irradiation, exhibiting a fast response rate.

[0018] The hybrid photochromic material crystals prepared in this invention are added to a mixed solution of 0.2 mL PMMA solution and 0.2 mL anhydrous ethanol, and sonicated for 30 min until the crystals are uniformly dispersed in the solution. The solution is then encapsulated into an electrochromic device (the electrochromic device comprises two ITO conductive glass plates, with the solution coated between the two ITO conductive glass plates and allowed to air dry). When the electrochromic device is energized under a certain voltage, a significant color change occurs.

[0019] The inorganic-organic hybrid photochromic material based on 2,4,6-tris(4-pyridyl)-1,3,5-triazine group prepared in this invention exhibits rapid and reversible photochromism. The photochromic principle of this hybrid photochromic material mainly involves charge separation within the TPT molecule and the formation of triplet dimer radical products. The hybrid photochromic material prepared in this invention possesses excellent rapid and reversible photochromic properties.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] This invention employs a solvothermal synthesis method, which is simple to operate and safe in process. This invention studies the photochromic changes of 2,4,6-tris(4-pyridyl)-1,3,5-triazine-based inorganic-organic hybrid materials. The material changes from colorless to light blue after 10 seconds of light irradiation, and reaches a visible blue color after 30 seconds. Compared to the photochromic rate of existing inorganic-organic hybrid photochromic materials, the photochromic rate of the target product of this invention, the organic-inorganic hybrid material, is significantly improved. The hybrid photochromic material is dispersed in ethanol, and the solution is uniformly coated onto a 50mm diameter microporous filter membrane. Under 365nm ultraviolet light irradiation, a significant color change occurs, from colorless to blue, enabling inkless printing. The inorganic-organic hybrid photochromic material described in this invention is used to fabricate electrochromic devices, which change color upon application of voltage. The hybrid photochromic material prepared by this invention has broad application prospects in inkless printing, electrochromic devices, photochromic decoration, optical memory, optical switches and optoelectronic displays. Attached Figure Description

[0022] Figure 1 This is a stacked diagram of the crystal structure of compound 1 obtained in Example 1 of the present invention;

[0023] Figure 2 These are photochromic images of compound 1 obtained in Example 1 of this invention as a function of time;

[0024] Figure 3 These are the infrared spectra of compound 1 obtained in Example 1 of this invention before and after illumination;

[0025] Figure 4 These are powder diffraction patterns of compound 1 obtained in Example 1 of this invention before and after light irradiation;

[0026] Figure 5 This is a thermogravimetric analysis diagram of compound 1 obtained in Example 1 of the present invention;

[0027] Figure 6 The EPR of compound 1 obtained in Example 1 of this invention before and after light exposure;

[0028] Figure 7 This is the light-time dependent solid-state diffuse reflectance spectrum of compound 1 obtained in Example 1 of the present invention;

[0029] Figure 8 The inkless printing performance of compound 1 obtained in Example 1 of this invention;

[0030] Figure 9 These are the cyclic voltammetry curves and electrochromic images of compound 1 obtained in Example 1 of this invention;

[0031] Figure 10 This is the solid-state diffuse reflectance spectrum of compound 1 obtained in Example 1 of the present invention as a function of voltage. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] To achieve the above objectives, the molecular formula of the hybrid photochromic material of the present invention is C. 36 H 30 N6O 18 Zn3, monoclinic crystal system, space group P21 / n, unit cell parameters are a=7.347(3)Å, b=29.365(7)Å, c=17.723(5)Å, α=90°, β=95.60(3)°, γ=90°.

[0034] The specific process for preparing the inorganic-organic hybrid photochromic material according to this invention is as follows:

[0035] (1) Mix 30 mg of metal source, 10 mg of TPT, 20 mg of BTC, 4 ml of H2O, 1 ml of DMA, and 1 ml of CH3OH evenly; the metal source is Zn(ClO4)2;

[0036] (2) The mixture prepared in step (1) is placed into a stainless steel high-pressure reaction vessel with a polytetrafluoroethylene reactor and reacted in an oven at 140°C for more than 24 hours to obtain blocky colorless crystals; the volume of the stainless steel reactor is 20 mL.

[0037] (3) The crystals obtained in step (2) are dried at room temperature (to remove the residual solution on the crystal surface) to prepare an inorganic-organic hybrid photochromic material.

[0038] Example 1

[0039] In this embodiment, TPT (10 mg), BTC (20 mg), zinc perchlorate (30 mg), H2O (4 mL), DMA (1 mL), and CH3OH (1 mL) were sequentially added to a stainless steel reactor lined with polytetrafluoroethylene, mixed thoroughly, and then sealed. After reacting in an oven at 140°C for 36 hours, the stainless steel reactor was gradually cooled to room temperature after the reaction was completed. The reactor was then removed, and the crystals generated inside were removed to obtain colorless blocky crystals, which were the target product, denoted as compound 1, with a yield of 58.6%. Figure 1 This is a stacked diagram of the crystal structure of compound 1 obtained in this embodiment.

[0040] Figure 5 This is the thermogravimetric analysis (TGA) chromatogram of compound 1, from Figure 5 It can be seen that compound 1 is stable up to 350℃. Before 350℃, the water that is physically adsorbed is released, indicating that compound 1 has good thermal stability.

[0041] Comparison of reaction conditions in Example 2

[0042] Comparative experiments were conducted by changing a single reaction condition in Example 1, as follows:

[0043] (1) The yields of compound 1 were obtained by varying the amount of CH3OH added, as shown in Table 1:

[0044] Table 1

[0045]

[0046] (2) The yields of compound 1 were obtained by changing the reaction time, as shown in Table 2:

[0047] Table 2

[0048]

[0049] (3) The yield of compound 1 was obtained by changing the reaction temperature, as shown in Table 3:

[0050] Table 3

[0051]

[0052] Example 2: Photochromic Experiment

[0053] The light source used was a 365nm ultraviolet lamp. The bulk crystals of compound 1 prepared in Example 1 were placed under a microscope and irradiated at room temperature. After 10 seconds, the crystal color changed from colorless to light blue. After 30 seconds, the crystal color reached a visible blue. After 5 minutes, the crystal color turned deep blue and reached saturation. (See details...) Figure 2 .

[0054] Figure 3 These are the infrared spectra of compound 1 before and after illumination, with an illumination time of 3 minutes. Figure 3 It can be seen that the infrared spectrum of the sample after photochromism of compound 1 has similar peak positions compared with the infrared spectrum of the sample before photochromism, indicating that the structure of the crystal did not change before and after light exposure.

[0055] Figure 4 These are simulated X-ray powder diffraction patterns of compound 1, X-ray powder diffraction patterns of the sample before photochromism, and X-ray powder diffraction patterns of the sample after photochromism (sample irradiated with UV lamp for 5 min). Figure 4 It can be seen that the X-ray powder diffraction patterns of the sample before and after photochromism of compound 1 have similar peak positions compared with the simulated X-ray powder diffraction pattern, indicating that the structure of the crystal did not change before and after irradiation.

[0056] Figure 6 It is the EPR of compound 1 before and after light exposure, by Figure 6 It can be seen that after 5 minutes of UV light irradiation, the peak intensity of the sample at g=2.004 increased, indicating the generation of free radicals.

[0057] Figure 7 Compound 1 is a time-dependent solid-state diffuse reflectance spectrum. The photochromic process was detected in the 365nm ultraviolet light wavelength region. As the illumination time increased, the color changed from white to blue. After continuous irradiation for 5 minutes, the color no longer changed.

[0058] Example 3

[0059] 10 mg of compound 1 prepared in Example 1 was added to 0.5 mL of anhydrous ethanol and sonicated for 30 min until compound 1 was evenly dispersed in the anhydrous ethanol. The solution was then evenly coated onto a 50 mm diameter microporous filter membrane and allowed to air dry. A pattern template (a butterfly pattern template was used in this example) was then placed on top, and compound 1 was irradiated with a 365 nm ultraviolet lamp. The color changed to a more obvious blue, achieving inkless printing. After 12 hours, the irradiated compound was placed in a dark environment and returned to colorless state (see [link to documentation]). Figure 8 ).

[0060] Example 4

[0061] 10 mg of compound 1 prepared in Example 1 was added to a mixed solution of 0.2 mL PMMA solution and 0.2 mL anhydrous ethanol. The mixture was sonicated for 30 min until compound 1 was uniformly dispersed in the solution. The solution was then encapsulated into an electrochromic device (the electrochromic device comprises two ITO conductive glass plates, with the solution coated between the two ITO conductive glass plates and allowed to air dry). After applying a certain voltage to the electrochromic device, a significant color change was observed (see...). Figure 9 ).

[0062] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made to the principles and process conditions of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A method for preparing an inorganic-organic hybrid photochromic material, characterized in that, Includes the following steps: A metal source, 2,4,6-tris(4-pyridyl)-1,3,5-triazine, pyromellitic acid, water, N,N′-dimethylacetamide, and methanol were mixed evenly to obtain a mixture. The mixture was then placed in a reaction vessel to react and obtain blocky colorless crystals, which are the hybrid photochromic materials. The chemical formula of the hybrid photoelectric color-changing material is C. 36 H 30 N6O 18 Zn3, the inorganic part is Zn 2+ The organic part is 2,4,6-tris(4-pyridyl)-1,3,5-triazine and pyromellitic acid. It is monoclinic, space group P21 / n, and the unit cell parameters are a=7.347(3)Å, b=29.365(7)Å, c=17.723(5)Å, α=90°, β=95.60(3)°, γ=90°. The mass ratio of the metal source, 2,4,6-tris(4-pyridyl)-1,3,5-triazine, and pyromellitic acid is (2-4):1:(1-2). The volume ratio of water, N,N′-dimethylacetamide, and methanol is 4:1:1; The reaction temperature of the mixture is 140°C, and the reaction time is 36 hours. The metal source is zinc perchlorate.

2. The method for preparing an inorganic-organic hybrid photochromic material according to claim 1, characterized in that, The process includes the following steps: 30 mg of zinc perchlorate, 10 mg of 2,4,6-tris(4-pyridyl)-1,3,5-triazine, 20 mg of trimesic acid, 4 mL of water, 1 mL of N,N′-dimethylacetamide, and 1 mL of methanol are mixed evenly to obtain a mixture. The mixture is then added to a stainless steel reactor lined with polytetrafluoroethylene and sealed. The reactor is then reacted in an oven at 140°C for 36 hours. After the reaction is completed, the stainless steel reactor is gradually cooled to room temperature. The crystals generated inside the stainless steel reactor are then removed, yielding colorless blocky crystals, which are the hybrid photochromic material.

3. The application of the hybrid photochromic material prepared by the method for preparing an inorganic-organic hybrid photochromic material according to any one of claims 1 to 2 in electrochromic devices and electro-displays, wherein the application is based on the electrochromic principle of the hybrid photochromic material.

Images