Anti-counterfeiting material based on solvoluminescence discoloration as well as preparation method and application of anti-counterfeiting material

Abstract

The invention discloses an anti-counterfeiting material based on solvoluminescence discoloration as well as a preparation method and application of the anti-counterfeiting material, and belongs to the technical field of optical anti-counterfeiting. The anti-counterfeiting material is a lanthanide series metal organic framework anti-counterfeiting material Tb / Eu-MOFs composed of lanthanide series ions Tb < 3 + > and Eu < 3 + > and an organic ligand. When the lanthanide series metal organic framework anti-counterfeiting material Tb / Eu-MOFs is dispersed in H2O, methanol, ethanol, N, N-dimethylformamide and dimethyl sulfoxide solvents, the lanthanide series metal organic framework anti-counterfeiting material Tb / Eu-MOFs shows different luminescence colors under ultraviolet irradiation. And after the ultraviolet lamp is removed and the solvent is volatilized, no trace can be seen under the fluorescent lamp. After different solvents are dropwise added again, different colors are displayed again. The lanthanide series metal organic framework anti-counterfeiting material Tb / Eu-MOFs can be used for information transmission and reproduction.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical anti-counterfeiting, and in particular relates to an anti-counterfeiting material based on solvent-induced luminescence color change, and a preparation method and application thereof. Background Art

[0002] With the rapid development of information technology, information leakage incidents have become a problem that cannot be ignored, and the development of highly reliable anti-counterfeiting technology has become a difficult problem that needs to be solved urgently in various industries. Regardless of the type of anti-counterfeiting product, it must meet the following requirements: have specific identification features, a long stability period, a long safety period, good compatibility and easy identification, and meet the requirements of the use environment. In the development of anti-counterfeiting technology, there is an urgent need for fluorescent materials with excellent optical properties, good chemical stability and unique physical properties. Therefore, it is particularly important to continue to explore advanced fluorescent anti-counterfeiting strategies. In recent years, anti-counterfeiting technology based on advanced functional materials has become a research hotspot. Among them, lanthanide metal-organic frameworks (Ln-MOFs) have shown great application potential due to their unique structural designability, excellent optical properties and multiple response characteristics.

[0003] Ln-MOFs are typically composed of metal ions and organic ligands that form a three-dimensional network structure through coordination. This highly ordered pore structure can effectively capture and store information. By adjusting the type of metal ions and the structure of the organic ligands, MOFs with specific optical properties can be designed, which can be used for information transmission. In addition, the chemical and thermal stability of rare earth metal organic frameworks make their application in anti-counterfeiting materials durable. Compared with traditional anti-counterfeiting technologies, Ln-MOFs can still maintain the stability of their structure and function in extreme environments such as high temperature and high humidity. This feature enables rare earth metal organic frameworks to be widely used in anti-counterfeiting labels for various commodities such as luxury goods, medicines and electronic products. The unique structural characteristics, excellent stability and versatility of Ln-MOFs make them an ideal choice for modern anti-counterfeiting materials. Summary of the Invention

[0004] To address the low security level and widespread imitation challenges of traditional anti-counterfeiting technologies, the present invention aims to design an anti-counterfeiting material based on solvent-induced luminescence. This anti-counterfeiting material, dispersed in H2O, methanol, ethanol, N,N-dimethylformamide, and dimethyl sulfoxide (DMSO), displays information in different colors under UV light. When the UV light is removed, the solvent evaporates, leaving no trace, thus meeting advanced anti-counterfeiting requirements.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: an anti-counterfeiting material based on solvent-induced luminescence color change, the anti-counterfeiting material is composed of lanthanide ions Tb 3+ and Eu 3+Lanthanide metal organic framework anti-counterfeiting materials Tb / Eu-MOFs composed of organic ligands.

[0006] Furthermore, the organic ligand is selected from one of trimesic acid, terephthalic acid, isophthalic acid and 2-aminoterephthalic acid.

[0007] Furthermore, the lanthanide metal organic framework anti-counterfeiting material Tb / Eu-MOFs has a molar ratio of Tb 3+ :Eu 3+ =(0.95-0.98):(0.05-0.02).

[0008] A method for preparing an anti-counterfeiting material based on solvent-induced luminescence color change comprises the following steps:

[0009] 1) Lanthanide ion Tb 3+ and Eu 3+ The nitrate or chloride salt and the organic ligand are added to the organic solvent, dissolved by ultrasonication, and then sodium acetate is added and the ultrasonication is continued to obtain a suspension;

[0010] 2) placing the obtained suspension in a polytetrafluoroethylene-lined reactor and placing it in a forced air drying oven for hydrothermal reaction to obtain a precursor;

[0011] 3) The obtained precursor is washed with N,N-dimethylformamide, anhydrous ethanol and deionized water in sequence, dried and ground to obtain the target product anti-counterfeiting material.

[0012] Furthermore, in step 1), the organic solvent is N,N-dimethylformamide.

[0013] Furthermore, in step 1), in molar ratio, Tb 3+ and Eu 3+ Nitrate or chloride salt: organic ligand: N,N-dimethylformamide: sodium acetate = 1:0.5:(1.0-1.5):0.5.

[0014] Furthermore, in step 2), the hydrothermal reaction is carried out at a temperature of 120° C. to 160° C. and for a time of 12 h to 48 h.

[0015] The invention provides an application of an anti-counterfeiting material based on solvent-induced luminescence color change in optical anti-counterfeiting.

[0016] Furthermore, under the irradiation of ultraviolet light, the information recorded in the anti-counterfeiting material based on solvent-induced luminescence color changes displays different colors in different solvents.

[0017] Furthermore, the solvent is selected from H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0018] The design principle of the present application is that the energy gap between Tb 3+ -Eu 3+ is close to the stretching vibration of methylene and methyl in CH3OH and C2H5OH, thereby increasing the probability of radiative recombination. Radiative recombination promotes the energy transfer process of Tb 3+ and Eu 3+ in Tb / Eu-MOFs. This results in a significant luminescence color change of Tb / Eu-MOFs in CH3OH and C2H5OH. With the color change of Tb / Eu-MOFs in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide, the encryption and transmission of information are realized.

[0019] The present application has the following beneficial effects:

[0020] 1. The anti-counterfeiting material Tb / Eu-MOFs provided by the present application has a simple preparation method, readily available raw materials and stable optical properties.

[0021] 2. The anti-counterfeiting material Tb / Eu-MOFs provided by the present application can realize the encryption and transmission of information.

[0022] 3. The anti-counterfeiting material Tb / Eu-MOFs provided by the present application can realize the hiding and reproduction of information and is not affected by high temperature and high humidity environments.

[0023] 4. The anti-counterfeiting material Tb / Eu-MOFs provided by the present application is made into luminescent ink, and information is written on non-fluorescent paper with a brush. Under the irradiation of an ultraviolet lamp, the content of the information on the paper can be clearly seen. After the ultraviolet lamp is removed, no trace can be seen on the paper after the solvent evaporates. After adding the solvent again, the information is clearly visible again under the ultraviolet lamp, which can meet the needs of high-level anti-counterfeiting BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the SEM spectrum of Tb 0.98 / Eu 0.02 -MOFs solid powder.

[0025] Figure 2 It is the emission spectrum of Tb 0.98 / Eu 0.02 -MOFs dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0026] Figure 3 It is the CIE coordinate diagram and the photo under the ultraviolet lamp of Tb 0.98 / Eu 0.02 -MOFs dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0027] Figure 4 Tb 0.98 / Eu 0.02 -Schematic diagram of MOFs' anti-counterfeiting capabilities.

[0028] Figure 5 Tb 0.95 / Eu 0.05 -Schematic diagram of MOFs' anti-counterfeiting capabilities. DETAILED DESCRIPTION

[0029] Example 1 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.98 / Eu 0.02 -MOFs)

[0030] The anti-counterfeiting material of this embodiment is based on solvent-induced luminescence color change, which is composed of lanthanide ions Tb 3+ and Eu 3+ and organic ligand trimesic acid composed of lanthanide metal organic framework anti-counterfeiting material Tb / Eu-MOFs, in molar ratio, Tb 3+ :Eu 3+ =0.98:0.02. The chemical formula is Tb 0.98 / Eu 0.02 -MOFs.

[0031] 1. Preparation method is as follows

[0032] Terbium chloride (0.3659 g, 0.98 mol), europium chloride (0.0073 g, 0.02 mol) and trimesic acid (0.1051 g, 0.5 mol) were placed in a beaker, and then N,N-dimethylformamide (100 mL, 1.3 mol) was added to the beaker, and ultrasonic dissolution was performed for 30 minutes to obtain a clear solution. Then, sodium acetate (0.1361 g, 0.5 mol) was added and ultrasonic dissolution was continued for 30 minutes to obtain a white suspension.

[0033] The obtained white suspension was charged into a 100 mL polytetrafluoroethylene liner reactor, and the reactor was placed in a forced air drying oven for hydrothermal reaction at 120°C for 24 hours. After the reaction was completed, the reactor was allowed to stand for 24 hours to obtain a precursor.

[0034] The obtained precursor was washed three times with N,N-dimethylformamide, anhydrous ethanol and deionized water at 5000 r / min, dried at 60 ° C for 24 h, and ground to obtain the white target product Tb 0.98 / Eu 0.02 -MOFs anti-counterfeiting materials.

[0035] 2. Performance Testing

[0036] 1. If Figure 1 As shown, Tb 0.98 / Eu 0.02 The SEM images of the MOFs are rod-like with a length of about 2.5 μm.

[0037] 2、Tb 0.98 / Eu 0.02 The MOFs were dispersed in H2O, methanol, ethanol, N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare luminescent inks. Figure 2 Tb 0.98 / Eu 0.02 The emission spectra of the MOFs dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide showed different intensities of luminescence. It was proved that Tb 0.98 / Eu 0.02 The MOFs showed different colors of luminescence under UV light in different solvents.

[0038] 3、 Figure 3 Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide, and the photos under UV light are shown in the drawings. It can be seen that Tb Figure 3 Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in H2O were (0.3558, 0.5211), and the photo under UV light showed green color; Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in methanol were (0.3504, 0.5592), and the photo under UV light showed yellow color; Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in ethanol were (0.3575, 0.5440), and the photo under UV light showed orange-yellow color; Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in N,N-dimethylformamide (DMF) were (0.4813, 0.4689), and the photo under UV light showed orange color; Tb 0.98 / Eu 0.02 The CIE coordinates of the MOFs dispersed in dimethyl sulfoxide (DMSO) were (0.4699, 0.4397), and the photo under UV light showed orange color. It can be seen that the luminescence color of the sample changed when dispersed in different solvents.

[0039] III. Anti-fake application

[0040] Tb 0.98 / Eu 0.02-MOFs were dispersed in H2O to make luminescent ink, and then LNU was written on non-fluorescent white paper with a brush.

[0041] like Figure 4 As shown, under 254nm UV light, the paper displays green LNU. After removing the UV light, no trace of the image is visible on the white paper. Then, CH₃OH and DMSO are reintroduced via a dropper. LNU appears yellow in CH₃OH and orange in DMSO. After the ink dries, no trace of the image is visible on the white paper.

[0042] Example 2 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.95 / Eu 0.05 -MOFs)

[0043] The anti-counterfeiting material of this embodiment is based on solvent-induced luminescence color change, which is composed of lanthanide ions Tb 3+ and Eu 3+ and organic ligand trimesic acid composed of lanthanide metal organic framework anti-counterfeiting material Tb / Eu-MOFs, in molar ratio, Tb 3+ :Eu 3+ =0.95:0.05. The chemical formula is Tb 0.95 / Eu 0.05 -MOFs.

[0044] 1. Preparation method is as follows

[0045] Terbium chloride (0.2547 g, 0.95 mol), europium chloride (0.0183 g, 0.05 mol) and trimesic acid (0.1051 g, 0.5 mol) were placed in a beaker, and then N,N-dimethylformamide (100 mL, 1.3 mol) was added to the beaker, and ultrasonic dissolution was performed for 30 minutes to obtain a clear solution. Then, sodium acetate (0.1361 g, 0.5 mol) was added and ultrasonic dissolution was continued for 30 minutes to obtain a white suspension.

[0046] The obtained white suspension was charged into a 100 mL polytetrafluoroethylene liner reactor, and the reactor was placed in a forced air drying oven for hydrothermal reaction at 120°C for 24 hours. After the reaction was completed, the reactor was allowed to stand for 24 hours to obtain a precursor.

[0047] The obtained precursor was washed three times with N,N-dimethylformamide, anhydrous ethanol and deionized water at 5000 r / min, dried at 60 ° C for 24 h, and ground to obtain the white target product Tb 0.95 / Eu 0.05 -MOFs anti-counterfeiting materials.

[0048] 2. Performance Testing

[0049] Tb0.95 / Eu 0.05 -MOFs were dispersed in H2O, methanol, ethanol, N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare luminescent ink. 0.95 / Eu 0.05 -MOFs dispersed in H2O showed yellow under UV light; Tb 0.95 / Eu 0.05 -MOFs dispersed in methanol showed orange-yellow color under UV light; Tb 0.95 / Eu 0.05 -MOFs dispersed in ethanol showed orange-yellow color under UV light; Tb 0.95 / Eu 0.05 -MOFs dispersed in N,N-dimethylformamide (DMF) showed orange-red color under ultraviolet light; Tb 0.95 / Eu 0.05 The photo of MOFs dispersed in dimethyl sulfoxide (DMSO) shows an orange-red color under UV light. It can be seen that the luminescence color of the sample changes when dispersed in different solvents.

[0050] 3. Anti-counterfeiting Application

[0051] Tb 0.95 / Eu 0.05 -MOFs were dispersed in H2O to make luminescent ink, and then LNU was written on non-fluorescent white paper with a brush.

[0052] like Figure 5 As shown, under 254nm UV light, the paper displays yellow LNU. After removing the UV lamp, no trace of the image is visible on the white paper. Then, CH₃OH and DMSO are reintroduced via a dropper. LNU displays an orange-yellow color in CH₃OH and an orange-red color in DMSO. After the ink dries, no trace of the image is visible on the white paper.

[0053] Example 3 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.98 / Eu 0.02 -MOFs)

[0054] The preparation method is the same as that in Example 1, except that the organic ligand is replaced with terephthalic acid (0.0830 g, 0.5 mol), and the other conditions remain unchanged to obtain the target product Tb 0.98 / Eu 0.02 -MOFs anti-counterfeiting materials.

[0055] It is dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide to prepare luminous ink, which still has anti-counterfeiting effect.

[0056] Example 4 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.98 / Eu 0.02 -MOFs)

[0057] The preparation method is the same as that in Example 1, except that the organic ligand is replaced by isophthalic acid (0.0906 g, 0.5 mol), and the other conditions remain unchanged, to obtain the target product Tb 0.98 / Eu 0.02 -MOFs anti-counterfeiting material.

[0058] It is still anti-counterfeiting effective to prepare a luminescent ink by dispersing it in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0059] Example 5 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.98 / Eu 0.02 -MOFs)

[0060] The preparation method is the same as that in Example 1, except that the organic ligand is replaced by 2-amino terephthalic acid (0.0905 g, 0.5 mol), and the other conditions remain unchanged, to obtain the target product Tb 0.98 / Eu 0.02 -MOFs anti-counterfeiting material.

[0061] It is still anti-counterfeiting effective to prepare a luminescent ink by dispersing it in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0062] Example 6 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.95 / Eu 0.05 -MOFs)

[0063] The preparation method is the same as that in Example 2, except that the organic ligand is replaced by terephthalic acid (0.0830 g, 0.5 mol), and the other conditions remain unchanged, to obtain the target product Tb 0.95 / Eu 0.05 -MOFs anti-counterfeiting material.

[0064] It is still anti-counterfeiting effective to prepare a luminescent ink by dispersing it in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

[0065] Example 7 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.95 / Eu 0.05 -MOFs)

[0066] The preparation method is the same as that in Example 2, except that the organic ligand is replaced by isophthalic acid (0.0906 g, 0.5 mol), and the other conditions remain unchanged, to obtain the target product Tb 0.95 / Eu 0.05 -MOFs anti-counterfeiting materials.

[0067] It is dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide to prepare luminous ink, which still has anti-counterfeiting effect.

[0068] Example 8 Anti-counterfeiting material based on solvent-induced luminescence color change (Tb 0.95 / Eu 0.05 -MOFs)

[0069] The preparation method is the same as that in Example 2, except that the organic ligand is replaced with 2-aminoterephthalic acid (0.0905 g, 0.5 mol), and the other conditions remain unchanged to obtain the target product Tb 0.95 / Eu 0.05 -MOFs anti-counterfeiting materials.

[0070] It is dispersed in H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide to prepare luminous ink, which still has anti-counterfeiting effect.

Claims

1. An anti-counterfeiting material based on solvent-induced luminescence color change, characterized in that: The anti-counterfeiting material is composed of lanthanide ions Tb 3+ and Eu 3+ Lanthanide metal organic framework anti-counterfeiting materials Tb / Eu-MOFs composed of organic ligands.

2. The anti-counterfeiting material based on solvent-induced luminescence color change according to claim 1, characterized in that: The organic ligand is selected from one of trimesic acid, terephthalic acid, isophthalic acid and 2-aminoterephthalic acid.

3. The anti-counterfeiting material based on solvent-induced luminescence color change according to claim 1 or 2, characterized in that: The lanthanide metal organic framework anti-counterfeiting material Tb / Eu-MOFs, in molar ratio, Tb 3+ :Eu 3+ =(0.95-0.98):(0.05-0.02).

4. The method for preparing an anti-counterfeiting material based on solvent-induced luminescence color change according to claim 1, characterized in that: The preparation method comprises the following steps: 1) Lanthanide ion Tb 3+ and Eu 3+ The nitrate or chloride salt and the organic ligand are added to the organic solvent, dissolved by ultrasonication, and then sodium acetate is added and the ultrasonication is continued to obtain a suspension; 2) placing the obtained suspension in a polytetrafluoroethylene-lined reactor and placing it in a forced air drying oven for hydrothermal reaction to obtain a precursor; 3) The obtained precursor is washed with N,N-dimethylformamide, anhydrous ethanol and deionized water in sequence, dried and ground to obtain the target product anti-counterfeiting material.

5. The method for preparing an anti-counterfeiting material based on solvatoluminescence color change according to claim 4, characterized in that: In step 1), the organic solvent is N,N-dimethylformamide.

6. The method for preparing an anti-counterfeiting material based on solvatoluminescence color change according to claim 5, characterized in that: In step 1), in molar ratio, Tb 3+ and Eu 3+ Nitrate or chloride salt: organic ligand: N,N-dimethylformamide: sodium acetate = 1:0.5:(1.0-1.5):0.

5.

7. The method for preparing an anti-counterfeiting material based on solvatoluminescence color change according to claim 4, characterized in that: In step 2), the hydrothermal reaction is carried out at a temperature of 120° C. to 160° C. and for a time of 12 h to 48 h.

8. Use of the anti-counterfeiting material based on solvent-induced luminescence color change according to any one of claims 1 to 3 in optical anti-counterfeiting.

9. The use according to claim 8, characterized in that Under ultraviolet light, the information recorded on the anti-counterfeiting material based on solvent-induced luminescence shows different colors in different solvents.

10. The use according to claim 9, characterized in that The solvent is selected from H2O, methanol, ethanol, N,N-dimethylformamide and dimethyl sulfoxide.

Images