Photochromic material introducing hofs framework material and preparation method and application thereof

Abstract

This invention discloses a photochromic material incorporating a HOF (Hormone-Organic-Flatform) framework, its preparation method, and its applications. Belonging to the field of organic solid-state photochromic materials technology, it utilizes a host-guest eutectic method to load photochromic molecules onto the HOF framework material. This invention also discloses the photochromic material prepared by the above method, and its applications in information storage encryption and anti-counterfeiting. While achieving photochromism, the host-guest eutectic method exhibits a faster photoresponse rate and better photochromic performance compared to physical adsorption methods, showing greater potential in anti-counterfeiting and excellent information storage encryption capabilities.

Description

Technical Field

[0001] This invention belongs to the field of organic solid-state photochromic materials technology, and particularly relates to a photochromic material incorporating HOFs framework materials, its preparation method and application. Background Technology

[0002] Hydrogen-bonded organic frameworks (HOFs) are a new type of porous crystalline material assembled from organic or metallic organic building blocks through intermolecular hydrogen bonding. They are widely used in gas adsorption and separation, proton conduction, heterogeneous catalysis, fluorescence and sensing, biological applications, enantiomeric resolution and separation of aromatic compounds, removal of environmental pollutants, and determination of organic structures.

[0003] Spiropyrans are photochromic molecules. Current research shows that solid-state spiropyran molecules are difficult to undergo photochromism. The main reason is that in the solid state, spiropyrans are tightly packed and do not have enough space to undergo the ring-opening-ring-closing isomerization process. This results in poor color-changing performance under ultraviolet light irradiation, which greatly limits their application prospects in information storage and anti-counterfeiting fields.

[0004] Therefore, how to combine HOF framework materials with spiropyran compounds and apply them to photochromic materials for anti-counterfeiting and information storage encryption is an important technical problem that researchers in this field urgently need to solve. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a photochromic material incorporating HOFs framework materials, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing photochromic materials incorporating HOF framework materials, wherein photochromic molecules are loaded onto HOF framework materials using a host-guest eutectic method.

[0008] Preferably, it includes the following steps:

[0009] The ligands of the HOF framework material and the photochromic molecules are mixed evenly by liquid-assisted grinding to obtain a eutectic powder, which is then dissolved in an organic solvent and left to stand for one week under light-protected conditions to obtain the photochromic material.

[0010] Preferably, the molar mass ratio of the ligand to the photochromic molecule is 1:1.

[0011] Preferably, the ligand comprises 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) (H4TCBP).

[0012] Preferably, the photochromic molecules include methylspiropyran (SP-CH3), carboxyspiropyran (SP-COOH), and hydroxyspiropyran (SP-OH).

[0013] More preferably, the photochromic molecule is methylspiropyran (SP-CH3).

[0014] Preferably, the grinding time is 15 minutes.

[0015] Preferably, the organic solvent is a mixed solution of dichloromethane and ethanol;

[0016] The volume ratio of dichloromethane to methanol is 20-40 mL: 3-6 mL.

[0017] Preferably, the mass-to-volume ratio of the eutectic powder to the organic solvent is 20-40 mg: 23-46 mL.

[0018] A method for preparing photochromic materials by introducing HOFs framework materials.

[0019] Application of a photochromic material incorporating HOFs frameworks in the field of information storage encryption.

[0020] Application of a photochromic material incorporating HOF frameworks in the field of anti-counterfeiting.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] This invention grows a host-guest eutectic by combining two ligands with photochromic molecules in a mixed solution of dichloromethane and methanol using a simple liquid-assisted milling method. The resulting photochromic material exhibits well-formed crystals, high crystallinity, and the process is simple, low-cost, and highly reproducible. Furthermore, this invention utilizes a solvent evaporation method to load the photochromic molecules into the pores of a HOF (Hormone-Organic Framework) material during ligand self-assembly. This disperses the densely packed spiropyran molecules, increasing their free volume. Simultaneously, the spiropyran molecules possess sufficient spatial freedom in the solid state to undergo ring-opening and ring-closing reactions, resulting in a more pronounced color-changing effect and significantly improving the solid-state photochromic properties of spiropyran molecules.

[0023] The photochromic material prepared by this invention exhibits a significant change in both its physical and fluorescent colors within 10 seconds under 365nm ultraviolet light irradiation. The physical color changes from white to purple, and the fluorescent color changes from orange to red. Furthermore, while achieving photochromism, the host-guest eutectic method of this invention has a faster photoresponse rate compared to the physical adsorption method, resulting in better photochromic performance and promising prospects in the anti-counterfeiting field. It also possesses excellent information storage and encryption capabilities. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 The image shows the ultraviolet absorption spectrum of the H3TATB@SP-CH3 photochromic material obtained in Example 1 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0026] Figure 2 The images show the fluorescence emission spectra of the H3TATB@SP-CH3 photochromic material obtained in Example 1 under 365nm wavelength excitation at different times of 365nm ultraviolet light irradiation, and the color change of solid fluorescence after different times of 365nm ultraviolet light irradiation.

[0027] Figure 3 The image shows the ultraviolet absorption spectrum of the H3TATB@SP-COOH photochromic material obtained in Example 2 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0028] Figure 4 The fluorescence emission spectra of the H3TATB@SP-COOH photochromic material obtained in Example 2 under 365nm wavelength excitation at different times of 365nm ultraviolet light irradiation, and the solid fluorescence color change graph after different times of 365nm ultraviolet light irradiation;

[0029] Figure 5 The image shows the ultraviolet absorption spectrum of the H3TATB@SP-OH photochromic material obtained in Example 3 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0030] Figure 6 The images show the fluorescence emission spectra of the H3TATB@SP-OH photochromic material obtained in Example 3 under 365nm ultraviolet light irradiation for different times and the solid fluorescence color change after 365nm ultraviolet light irradiation for different times.

[0031] Figure 7 The image shows the ultraviolet absorption spectrum of the H4TCBP@SP-CH3 photochromic material obtained in Example 4 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0032] Figure 8 The images show the fluorescence emission spectra of the H4TCBP@SP-CH3 photochromic material obtained in Example 4 under 365nm wavelength excitation at different times of 365nm ultraviolet light irradiation, and the solid fluorescence color change after different times of 365nm ultraviolet light irradiation.

[0033] Figure 9 The image shows the ultraviolet absorption spectrum of the H4TCBP@SP-COOH photochromic material obtained in Example 5 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0034] Figure 10 The images show the fluorescence emission spectra of the H4TCBP@SP-COOH photochromic material obtained in Example 5 under 365nm wavelength excitation at different times of 365nm ultraviolet light irradiation, and the color change of the solid fluorescence after different times of 365nm ultraviolet light irradiation.

[0035] Figure 11 The image shows the ultraviolet absorption spectrum of the H4TCBP@SP-OH photochromic material obtained in Example 6 after irradiation with 365nm ultraviolet light for different times, and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times.

[0036] Figure 12 The images show the fluorescence emission spectra of the H4TCBP@SP-OH photochromic material obtained in Example 6 under 365nm ultraviolet light irradiation for different times and the solid fluorescence color change after 365nm ultraviolet light irradiation for different times.

[0037] Figure 13 The ultraviolet absorption spectra of the PFC-12@SP-CH3 photochromic material obtained in Comparative Example 1 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0038] Figure 14 The fluorescence emission spectra of the PFC-12@SP-CH3 photochromic material obtained in Comparative Example 1 under 365nm ultraviolet light irradiation for different times and under 365nm wavelength excitation, as well as the solid fluorescence color change after 365nm ultraviolet light irradiation for different times.

[0039] Figure 15The ultraviolet absorption spectra of the PFC-12@SP-COOH photochromic material obtained in Comparative Example 2 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0040] Figure 16 The fluorescence emission spectra of the PFC-12@SP-COOH photochromic material obtained in Comparative Example 2 under 365nm ultraviolet light irradiation for different times and under 365nm wavelength excitation, as well as the solid fluorescence color change after 365nm ultraviolet light irradiation for different times;

[0041] Figure 17 The ultraviolet absorption spectra of the PFC-12@SP-OH photochromic material obtained in Comparative Example 3 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0042] Figure 18 The fluorescence emission spectra of the PFC-12@SP-OH photochromic material obtained in Comparative Example 3 under 365nm ultraviolet light irradiation for different times and under 365nm wavelength excitation, as well as the solid fluorescence color change after 365nm ultraviolet light irradiation for different times;

[0043] Figure 19 The ultraviolet absorption spectra of the PFC-13@SP-CH3 photochromic material obtained in Comparative Example 4 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0044] Figure 20 The fluorescence emission spectra of the PFC-13@SP-CH3 photochromic material obtained in Comparative Example 4 under 365nm ultraviolet light irradiation for different times under 365nm wavelength excitation, and the solid fluorescence color change after 365nm ultraviolet light irradiation for different times.

[0045] Figure 21 The ultraviolet absorption spectra of the PFC-13@SP-COOH photochromic material obtained in Comparative Example 5 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0046] Figure 22 The fluorescence emission spectra of the PFC-13@SP-COOH photochromic material obtained in Comparative Example 5 under 365nm ultraviolet light irradiation for different times and under 365nm wavelength excitation, as well as the solid fluorescence color change after 365nm ultraviolet light irradiation for different times.

[0047] Figure 23The ultraviolet absorption spectra of the PFC-13@SP-OH photochromic material obtained in Comparative Example 6 after irradiation with 365nm ultraviolet light for different times and the color change of the solid powder after irradiation with 365nm ultraviolet light for different times are shown.

[0048] Figure 24 The fluorescence emission spectra of the PFC-13@SP-OH photochromic material obtained in Comparative Example 6 under 365nm ultraviolet light irradiation for different times and under 365nm wavelength excitation, as well as the solid fluorescence color change after 365nm ultraviolet light irradiation for different times;

[0049] Figure 25 This is a schematic diagram illustrating the application of the H3TATB@SP-CH3 material described in Example 1 in information encryption applications;

[0050] Figure 26 The result obtained from Example 2 Ultraviolet absorption spectrum of flexible anti-counterfeiting film after 365nm ultraviolet light irradiation for different times and color change of film after 365nm ultraviolet light irradiation for different times.

[0051] Figure 27 The result obtained from Example 2 Fluorescence emission spectra of flexible anti-counterfeiting film under 365nm wavelength excitation for different durations of 365nm ultraviolet light irradiation, and changes in the fluorescence color of the film after 365nm ultraviolet light irradiation for different durations. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] All raw materials used in the embodiments of this invention were purchased through commercial channels;

[0055] The room temperature in all embodiments of this invention is 25°C.

[0056] Example 1

[0057] A photochromic material incorporating HOF framework materials, specifically H3TATB@SP-CH3 photochromic material, is prepared by the following steps:

[0058] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (11.7664 mg of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB)) and guest (8.2336 mg of methylspiropyran (SP-CH3)) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0059] (2) Dissolve the above eutectic powder in dichloromethane (20.00 mL) and methanol (3.00 mL), and place it at room temperature in the dark for one week to obtain the photochromic material H3TATB@SP-CH3.

[0060] Example 2

[0061] A photochromic material incorporating HOF framework materials, specifically H3TATB@SP-COOH photochromic material, is prepared by the following steps:

[0062] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (H3TATB 10.7656 mg) and guest (carboxyspiropyran (SP-COOH) 9.2345 mg) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0063] (2) Dissolve the above eutectic powder in dichloromethane (20.00 mL) and methanol (3.00 mL), and place it at room temperature in the dark for one week to obtain the photochromic material H3TATB@SP-COOH.

[0064] Example 3

[0065] A photochromic material incorporating HOFs framework materials, specifically H3TATB@SP-OH photochromic material, is prepared by the following steps:

[0066] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (H3TATB 11.1446 mg) and guest (hydroxyspiropyran (SP-OH) 8.8554 mg) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0067] (2) Dissolve the above eutectic powder in dichloromethane (20.00 mL) and methanol (3.00 mL), and place it at room temperature in the dark for one week to obtain the photochromic material H3TATB@SP-OH.

[0068] Example 4

[0069] A photochromic material incorporating HOF framework materials, specifically H4TCBP@SP-CH3 photochromic material, is prepared by the following steps:

[0070] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid)(H4TCBP) 13.431 mg) and guest (methylspiropyran SP-CH3 6.568 mg) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0071] (2) The eutectic powder produced by grinding was dissolved in dichloromethane (20.00 mL) and methanol (3.00 mL), and placed at room temperature in the dark for one week to obtain the photochromic material H4TCBP@SP-CH3.

[0072] Example 5

[0073] A photochromic material incorporating HOF framework materials, specifically an H4TCBP@SP-COOH photochromic material, is prepared by the following steps:

[0074] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (H4TCBP 12.5037 mg) and guest (carboxyspiropyran (SP-COOH) 7.4963 mg) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0075] (2) The eutectic powder produced by grinding is dissolved in dichloromethane (20.00 mL) and methanol (3.00 mL), and placed at room temperature in the dark for one week to obtain the photochromic material H4TCBP@SP-COOH.

[0076] Example 6

[0077] A photochromic material incorporating HOF framework materials, specifically H4TCBP@SP-OH photochromic material, is prepared by the following steps:

[0078] (1) Add 50 μL of dichloromethane to a solid mixture (20.00 mg) of host (H4TCBP 12.8622 mg) and guest (hydroxyspiropyran (SP-OH) 7.1378 mg) in a molar ratio of 1:1, grind for 15 minutes to obtain eutectic powder;

[0079] (2) The eutectic powder produced by grinding is dissolved in dichloromethane (20.00 mL) and methanol (3.00 mL), and placed at room temperature in the dark for one week to obtain the photochromic material H4TCBP@SP-OH.

[0080] Comparative Example 1

[0081] A photochromic material incorporating HOF framework materials, specifically PFC-12@SP-CH3 photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0082] (1) Dissolve 1 g of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) in 100 mL of N,N-dimethylformamide solution (DMF), add 300 mL of deionized water to the solution, stir at 1000 r / min for 12 h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain HOFs framework material PFC-12;

[0083] (2) Dissolve 30 mg of methylspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly add the solution to 100 mg of the above PFC-12 framework material. After standing at room temperature for 3 h, let it dry naturally to obtain PFC-12@SP-CH3 photochromic material.

[0084] Comparative Example 2

[0085] A photochromic material incorporating HOFs framework materials, specifically PFC-12@SP-COOH photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0086] (1) Dissolve 1 g of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) in 100 mL of N,N-dimethylformamide solution (DMF), add 300 mL of deionized water to the solution, stir at 1000 r / min for 12 h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain HOFs framework material PFC-12;

[0087] (2) Dissolve 30 mg of carboxyspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly add the solution to 100 mg of the above PFC-12 framework material. After standing at room temperature for 3 h, let it dry naturally to obtain PFC-12@SP-COOH photochromic material.

[0088] Comparative Example 3

[0089] A photochromic material incorporating HOF framework materials, specifically PFC-12@SP-OH photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0090] (1) Dissolve 1 g of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) in 100 mL of N,N-dimethylformamide solution (DMF), add 300 mL of deionized water to the solution, stir at 1000 r / min for 12 h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain HOFs framework material PFC-12;

[0091] (2) Dissolve 30 mg of hydroxyspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly add the solution to 100 mg of the above PFC-12 framework material. After standing at room temperature for 3 h, let it dry naturally to obtain PFC-12@SP-OH photochromic material.

[0092] Comparative Example 4

[0093] A photochromic material incorporating HOF framework materials, specifically PFC-13@SP-CH3 photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0094] (1) Dissolve 1g of biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) (H4TCBP) in 100mL of N,N-dimethylformamide solution (DMF), add 300mL of deionized water to the solution, stir at 1000r / min for 12h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain PFC-13 framework material;

[0095] (2) Dissolve 30 mg of methylspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly drop the solution into 100 mg of PFC-13 framework material. After standing at room temperature for 3 hours to dry naturally, PFC-13@SP-CH3 photochromic material is obtained.

[0096] Comparative Example 5

[0097] A photochromic material incorporating HOF framework materials, specifically PFC-13@SP-COOH photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0098] (1) Dissolve 1g of biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) (H4TCBP) in 100mL of N,N-dimethylformamide solution (DMF), add 300mL of deionized water to the solution, stir at 1000r / min for 12h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain PFC-13 framework material;

[0099] (2) Dissolve 30 mg of carboxyspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly drop the solution into 100 mg of PFC-13 framework material. After standing at room temperature for 3 hours to dry naturally, PFC-13@SP-COOH photochromic material is obtained.

[0100] Comparative Example 6

[0101] A photochromic material incorporating HOFs framework materials, specifically PFC-13@SP-OH photochromic material, is prepared using a physical adsorption method. The preparation method includes the following steps:

[0102] (1) Dissolve 1g of biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) (H4TCBP) in 100mL of N,N-dimethylformamide solution (DMF), add 300mL of deionized water to the solution, stir at 1000r / min for 12h at room temperature, collect the white solid by centrifugation, wash three times with acetone by centrifugation, then soak the washed solid in dichloromethane solution (CH2Cl2) for three days, and finally centrifuge and vacuum dry to obtain PFC-13 framework material;

[0103] (2) Dissolve 30 mg of hydroxyspiropyran in toluene solution to prepare a solution with a concentration of 0.2 mol / L. Then, use a dropper to evenly drop the solution into 100 mg of PFC-13 framework material. After standing at room temperature for 3 hours to dry naturally, PFC-13@SP-OH photochromic material is obtained.

[0104] The ultraviolet absorption spectra of the photochromic materials obtained in Examples 1-6 and Comparative Examples 1-6 under 365nm ultraviolet light irradiation for different times, the color change of the solid powder after 365nm ultraviolet light irradiation for different times, and the fluorescence emission spectra under 365nm wavelength excitation at different times under 365nm ultraviolet light irradiation, and the color change of the solid fluorescence after 365nm ultraviolet light irradiation for different times are shown in the figures. Figure 1-24 As shown.

[0105] Depend on Figure 1 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 Compared to Figure 13 , Figure 15 , Figure 17 , Figure 19 , Figure 21 and Figure 23 It can be seen that the photochromic materials prepared by the host-guest eutectic method are much more sensitive to ultraviolet light than those prepared by the physical adsorption method. They can respond quickly within 10 seconds and undergo a color change. The color change is obvious and the contrast is high, which significantly improves the photochromic performance of spiropyran in the solid state. Moreover, this method is universal and can achieve the same effect for two different HOF framework materials.

[0106] Depend on Figure 14 , Figure 16 , Figure 18 , Figure 20 , Figure 22 , Figure 24 , Figure 2 , Figure 4 , Figure 6 , Figure 8 , Figure 10 and Figure 12 It can be seen that the fluorescence emission peak of the present invention first rises and then falls under ultraviolet light irradiation. This is due to the fluorescence quenching phenomenon caused by the close packing of spiropyran molecules after ring opening.

[0107] In Examples 1-3 and Examples 4-6, by Figure 1 and Figure 7 Compared to Figure 3 , Figure 5 , Figure 9 and 11 It can be seen that when the guest molecule is methylspiropyran, its color-changing effect is better than that of carboxyspiropyran or hydroxyspiropyran. This is because the carboxyl and hydroxyl groups in carboxyspiropyran or hydroxyspiropyran polarize the entire crystal framework, disrupting its stability and resulting in low color-changing efficiency and instability of the photochromic material. This phenomenon is also universal, with similar results for both different host molecules.

[0108] Application Example 1

[0109] Application of a photochromic material incorporating HOF frameworks in the field of information storage encryption, such as... Figure 25 As shown, it includes the following steps:

[0110] Utilizing the fact that both 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) and the H3TATB@SP-CH3 eutectic material obtained in Example 1 are initially white and exhibit different fluorescent colors, the two materials were randomly combined into a pixel square to form the number "888". When irradiated with ultraviolet light, the squares in the H3TATB@SP-CH3 eutectic region showed red fluorescence, while 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (H3TATB) showed blue fluorescence. The true information was displayed as the actual number in the red fluorescent portion, and after irradiation, the true information was also reflected in the purple color of the H3TATB@SP-CH3 eutectic material. When the ultraviolet light was removed and white light was used for irradiation, the true information was hidden again, reverting to the number "888".

[0111] Depend on Figure 25 As can be seen, the initial information is the number "888". Under ultraviolet light, the real information "123" appears as red fluorescence. After the ultraviolet light is removed and white light is used, the real information will be hidden again and will revert to the number "888".

[0112] Application Example 2

[0113] The application of a photochromic material incorporating HOFs (Homogeneous Field-Oriented Framework) materials in the field of anti-counterfeiting includes the following steps:

[0114] 10 mg of H3TATB@SP-CH3 obtained in Example 1 was added to a glass-faced container containing 2 g of PDMS. After stirring evenly, the glass-faced container was placed in a 60°C oven and baked for 6 hours to obtain the desired product. Flexible anti-counterfeiting film.

[0115] Depend on Figure 26 It can be seen that, The flexible anti-counterfeiting film is very sensitive to ultraviolet light and can respond quickly within 10 seconds, changing the actual color from yellow to red. This significantly improves the photochromic properties of spiropyran in the solid state and broadens its application in the field of anti-counterfeiting.

[0116] Depend on Figure 27 It can be seen that, The fluorescence emission peak of the flexible anti-counterfeiting film first rises and then falls under ultraviolet irradiation. This is due to the fluorescence quenching phenomenon caused by the close packing of spiropyran molecules after ring opening.

[0117] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a photochromic material incorporating HOF framework materials, characterized in that, Loading photochromic molecules onto HOF framework materials using a host-guest eutectic method; specifically including the following steps: The ligands of the HOF framework material and the photochromic molecules are mixed uniformly by liquid-assisted grinding to obtain a eutectic powder, which is then dissolved in an organic solvent and left to stand for one week under light-protected conditions to obtain the photochromic material. The ligands include 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid).

2. The method for preparing a photochromic material incorporating HOF framework materials according to claim 1, characterized in that, The molar ratio of the ligand to the photochromic molecule is 1:

1.

3. The method for preparing a photochromic material incorporating HOF framework materials according to claim 1, characterized in that, The photochromic molecules include methylspiropyran, carboxyspiropyran, and hydroxyspiropyran.

4. The method for preparing a photochromic material incorporating HOFs framework materials according to claim 1, characterized in that, The organic solvent is a mixed solution of dichloromethane and ethanol; The volume ratio of dichloromethane to methanol is (20-40):(3-6).

5. The method for preparing a photochromic material incorporating HOFs framework materials according to claim 1, characterized in that, The mass-to-volume ratio of the eutectic powder to the organic solvent is 20-40 mg: 23-46 mL.

6. The photochromic material prepared by the method for preparing a photochromic material incorporating HOFs framework materials as described in any one of claims 1-5.

7. The application of a photochromic material incorporating HOFs framework materials as described in claim 6 in the field of information storage encryption.

8. The application of a photochromic material incorporating HOFs framework materials as described in claim 6 in the field of anti-counterfeiting.

Images