Photochromic supramolecular fluorescent ink, preparation method thereof and application of photochromic supramolecular fluorescent ink in fluorescent falsification prevention
A photochromic supramolecular fluorescent ink was prepared by using a supramolecular assembly composed of photochromic organic compounds and γ-cyclodextrin. This solved the stability and reversibility problems of existing fluorescent materials in the field of anti-counterfeiting, and realized the application of efficient and low-cost fluorescent anti-counterfeiting technology.
Patent Information
- Application Number
- CN202510943685.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-11-18
AI Technical Summary
Existing fluorescent materials have limitations in the field of anti-counterfeiting, including limited fluorescent color, poor stability, difficulty in achieving reversible fluorescence changes, complex and costly preparation processes, and difficulty in on-site verification, which affect the accuracy and reliability of anti-counterfeiting effects.
A supramolecular assembly composed of photochromic organic compounds and γ-cyclodextrin is used to form a photochromic supramolecular fluorescent ink through a simple preparation method, achieving reversible changes in fluorescent color, which is suitable for substrate materials such as paper.
It achieves high-precision and high-stability fluorescent pattern printing, provides multi-level anti-counterfeiting verification methods, is low-cost, easy to mass-produce, has good compatibility with common substrate materials, and its fluorescent performance is stable in various environments.
Smart Images
Figure CN120965587A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photochromic materials technology, specifically relating to a photochromic supramolecular fluorescent ink, its preparation method, and its application in fluorescent anti-counterfeiting. Background Technology
[0002] In the information age, fluorescent materials have attracted much attention in the fields of information storage and anti-counterfeiting due to their unique optical properties. However, traditional fluorescent materials have many limitations, such as limited fluorescence color, poor stability, and difficulty in achieving reversible fluorescence changes, which restricts their widespread application. Existing fluorescent anti-counterfeiting technologies mostly rely on complex chemical synthesis or special material preparation processes, which are costly and difficult to verify on-site. These technologies lack flexibility and reversibility; the fluorescence change of some fluorescent materials after light exposure is irreversible, increasing the cost of anti-counterfeiting; some materials have poor stability in water or hot environments, affecting the accuracy and reliability of anti-counterfeiting effects.
[0003] The development of supramolecular chemistry has provided new insights into the improvement of fluorescent materials. Supramolecular assemblies are formed through non-covalent intermolecular interactions, exhibiting high structural designability and functional diversity. Utilizing these properties, multi-stimulus responsive fluorescent materials can be developed, achieving reversible changes in fluorescence color and bringing breakthroughs to anti-counterfeiting technology. However, current research on the application of supramolecular fluorescent inks in anti-counterfeiting printing is limited, especially regarding achieving reversible fluorescence changes and compatibility with substrate materials such as paper, which still face challenges.
[0004] Therefore, the development of novel supramolecular fluorescent inks is of great significance. Such inks should possess simple preparation methods, low cost, excellent optical properties, and stability, meeting the diverse needs of anti-counterfeiting materials and providing an efficient and reliable solution for information storage and verification. This invention, based on this background, proposes a novel supramolecular fluorescent ink aimed at addressing the shortcomings of existing technologies and promoting the development of fluorescent anti-counterfeiting technology. Summary of the Invention
[0005] In order to solve the problems mentioned in the background art, the purpose of this invention is to provide a photochromic supramolecular fluorescent ink, its preparation method and its application in fluorescent anti-counterfeiting.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a photochromic organic compound, the structure of which is shown in Formula I:
[0007] It is abbreviated as WM-1.
[0008] On the other hand, the present invention provides a method for preparing the above-mentioned photochromic organic compound, comprising the following steps:
[0009] 1-((4-bromobutoxy)methyl)pyrene was completely dissolved in a solvent, and then 1,2-dimethylimidazole was added. The mixture was heated and stirred for a period of time to obtain a photochromic organic compound.
[0010] Furthermore, the structure of the 1-((4-bromobutoxy)methyl)pyrene is as follows:
[0011] Furthermore, the molar ratio of 1-((4-bromobutoxy)methyl)pyrene to 1,2-dimethylimidazole is 1:(2-5);
[0012] Preferably, the heating and stirring temperature is 60-85℃, and the heating and stirring time is 15h-24h;
[0013] Preferably, the solvent is selected from at least one of acetonitrile, tetrahydrofuran, and methanol.
[0014] On the other hand, the present invention provides a supramolecular assembly composed of a macrocyclic host and a fluorescent guest; wherein the macrocyclic host is γ-cyclodextrin (γ-CD) and the fluorescent guest is the photochromic organic compound described above.
[0015] Preferably, the inclusion ratio of the γ-cyclodextrin to the photochromic organic compound is 2:2, that is, two molecules of γ-cyclodextrin include two molecules of the photochromic organic compound.
[0016] Furthermore, the present invention provides a method for preparing the supramolecular assembly described above, comprising the following steps:
[0017] γ-cyclodextrin and photochromic organic compounds were added to water in a certain proportion, and the assembly between the two was promoted by shaking to form a stable supramolecular assembly aqueous solution.
[0018] Preferably, the molar ratio of the γ-cyclodextrin to the photochromic organic compound is (10-50):1.
[0019] Use enough water to completely dissolve WM-1.
[0020] γ-Cyclodextrin assembles with photochromic organic compounds relatively quickly. Shaking is to allow the added γ-cyclodextrin and photochromic organic compounds to diffuse rapidly in the water, so that γ-cyclodextrin can bind with more WM-1.
[0021] In another aspect, the present invention provides a photochromic supramolecular fluorescent ink, comprising an aqueous solution of the aforementioned photochromic organic compound and an aqueous solution of γ-cyclodextrin used to treat the substrate;
[0022] Preferably, the concentration of the aqueous solution of the photochromic organic compound is 0.1 mmol / L-5 mmol / L;
[0023] Preferably, the concentration of the aqueous solution of γ-cyclodextrin is 10 mmol / L-100 mmol / L;
[0024] Preferably, the substrate includes paper, film, or cloth strips made of filter paper material.
[0025] Furthermore, this invention provides a method for preparing the above-mentioned photochromic supramolecular fluorescent ink, comprising the following steps:
[0026] The photochromic organic compound was mixed with water and dissolved by ultrasound to obtain an aqueous solution of the photochromic organic compound.
[0027] γ-Cyclodextrin and water were mixed and dissolved by ultrasonication to obtain an aqueous solution of γ-cyclodextrin.
[0028] Furthermore, the present invention provides a method for using the aforementioned photochromic supramolecular fluorescent ink, comprising the following steps:
[0029] A functional substrate is prepared by pretreating the substrate with an aqueous solution of γ-cyclodextrin and then air-drying or baking it.
[0030] The functional substrate can be printed using an aqueous solution of a photochromic organic compound.
[0031] Furthermore, this invention provides a fluorescent color-changing anti-counterfeiting method based on the aforementioned photochromic supramolecular fluorescent ink, comprising the following steps:
[0032] A functional substrate is prepared by pretreating the substrate with an aqueous solution of γ-cyclodextrin and then air-drying or baking it.
[0033] A photochromic organic compound aqueous solution is used to print on the functional substrate. The printed content emits obvious cyan fluorescence under ultraviolet light. After being irradiated with ultraviolet light for a period of time, water is sprayed onto the substrate, and the cyan fluorescent text or pattern on the substrate instantly turns orange-yellow. When the substrate is heated, the orange-yellow fluorescence turns into white fluorescence, and when it is cooled by water spraying, the white fluorescence returns to orange-yellow fluorescence. This heating and cooling process is reversible and stable.
[0034] Preferably, the wavelength of the ultraviolet light is 365nm, and the irradiation time of the ultraviolet light is 20min-90min.
[0035] In another aspect, the present invention provides an application of the above-described photochromic organic compound, the above-described supramolecular assembly, or the above-described photochromic supramolecular fluorescent ink in fluorescent anti-counterfeiting.
[0036] Compared with the prior art, the present invention has the following beneficial effects:
[0037] This invention's photochromic supramolecular fluorescent ink enables high-precision, high-stability fluorescent pattern printing. Its unique fluorescence change characteristics provide extremely high security and recognizability for anti-counterfeiting labels, making them difficult to copy or tamper with. It can be widely applied to various documents, invoices, product packaging, and other fields requiring anti-counterfeiting measures. The preparation process of this photochromic supramolecular fluorescent ink does not require complex chemical synthesis steps, resulting in low cost and ease of large-scale production. This invention's photochromic supramolecular fluorescent ink also has the following significant advantages: First, the fluorescence color changes are rich and reversible, providing multi-layered anti-counterfeiting verification methods; second, the preparation method is simple, low-cost, and easy to promote and use; third, it has good compatibility with common substrate materials such as paper, without relying on complex substrate treatment processes; and fourth, it has high stability, maintaining good fluorescence performance even under the influence of environmental factors such as light and water spray. Therefore, this invention's photochromic supramolecular fluorescent ink and its fluorescent anti-counterfeiting method have broad application prospects and are expected to bring an innovative and efficient technical solution to the anti-counterfeiting field. Attached Figure Description
[0038] Figure 1 The hydrogen nuclear magnetic resonance spectrum of WM-1 prepared in Example 1 of this invention;
[0039] Figure 2 This is a schematic diagram of the assembly of the supramolecular assembly WM-1@γ-CD of the present invention;
[0040] Figure 3 The fluorescence spectrum of WM-1 bound to γ-CD prepared in Example 1 of this invention is shown.
[0041] Figure 4 The fluorescence spectrum of WM-1 prepared in Example 1 of this invention bound to γ-CD shows the trend of fluorescence intensity at 490 nm as the equivalent amount of γ-CD increases.
[0042] Figure 5 The fluorescence spectrum of the WM-1@γ-CD supramolecular assembly aqueous solution under a 365nm UV lamp over time is shown.
[0043] Figure 6 The fluorescence spectrum of the aqueous solution of the WM-1@γ-CD supramolecular assembly of the present invention under heating and cooling cycles (the inset shows the actual color of the sample);
[0044] Figure 7 This is a graph showing the peak change at 490 nm of the fluorescence spectrum of the aqueous solution of the WM-1@γ-CD supramolecular assembly of the present invention under heating and cooling cycles.
[0045] Figure 8The fluorescence spectrum of the WM-1@γ-CD supramolecular assembly aqueous solution of the present invention after being irradiated with 365nm ultraviolet light for 1 hour and then subjected to heating and cooling cycles (the inset shows the actual color of the sample);
[0046] Figure 9 This is a cycle diagram showing the peak change at 570 nm of the fluorescence curve of the aqueous solution of the WM-1@γ-CD supramolecular assembly of the present invention after heating and cooling cycles following 1 hour of exposure to 365 nm ultraviolet light.
[0047] Figure 10 This is a diagram illustrating the application of the fluorescent ink of the present invention. Detailed Implementation
[0048] To better understand the content of this invention, the following detailed description is provided in conjunction with specific implementation methods. However, the scope of protection of this invention is not limited to the following embodiments.
[0049] Unless otherwise specified, all chemicals and reagents are AR grade and purchased from Energie Corporation.
[0050] Example 1
[0051] The structure of a photochromic organic compound is shown below:
[0052] (Abbreviated as WM-1).
[0053] Preparation of WM-1:
[0054]
[0055] 100 mg of 1-((4-bromobutoxy)methyl)pyrene was added to a 50 mL round-bottom flask, followed by 10 mL of acetonitrile (ACN) and stirring until dissolved. Then, 146 mg of 1,2-dimethylimidazole was added. The mixture was stirred in an oil bath at 65 °C for 24 hours. The reaction mixture was precipitated with anhydrous diethyl ether, centrifuged to obtain a solid powder product, which was then dissolved in methanol and precipitated again with anhydrous diethyl ether. This precipitation-dissolution-precipitation process was repeated two or three times to obtain pure WM-1. WM-1... 1 HNMR spectrum as follows Figure 1 As shown, the obtained product is confirmed to be WM-1.
[0056] Example 2
[0057] Preparation of 1-((4-bromobutoxy)methyl)pyrene:
[0058]
[0059] Weigh 2.34 g of 1-pyrene methanol into a 250 mL round-bottom flask, add 100 mL of dry tetrahydrofuran (THF) and 8 g of sodium hydride (NaH), stir for 30 min, then add 11.94 mL of 1,4-dibromobutane, and react at 25 °C for 48 hours. Remove the solvent from the reaction mixture by rotary evaporation, quench the remaining NaH with water, and extract with 50 mL of dichloromethane (CH₂Cl₂) at least three times. Collect the organic phase, wash successively with 50 mL of dilute hydrochloric acid, 5% sodium carbonate aqueous solution, and saturated sodium chloride solution, dry to anhydrous sodium sulfate, and purify the product by rotary evaporation and column chromatography (dichloromethane:petroleum ether (V / V) = 1:3). The product is a white powder.
[0060] Example 3
[0061] The supramolecular assembly WM-1@γ-CD consists of a macrocyclic host and a fluorescent guest. The macrocyclic host is γ-cyclodextrin (γ-CD), and the fluorescent guest is WM-1 prepared in Example 1. The inclusion ratio of γ-cyclodextrin to WM-1 is 2:2, meaning that two molecules of γ-cyclodextrin encapsulate two molecules of WM-1. An assembly diagram is shown below. Figure 2 As shown.
[0062] Example 4
[0063] Photochromic supramolecular fluorescent ink: comprising an aqueous solution of 5 mmol / L WM-1 prepared in Example 1 and an aqueous solution of 50 mmol / L γ-CD.
[0064] Preparation of 5 mmol / L WM-1 aqueous solution: Weigh 23.72 mg of WM-1 powder into a 5 mL plastic centrifuge tube, add about 3 mL of deionized water and sonicate to dissolve. Then transfer the solution to a 10 mL volumetric flask and make up to volume to obtain a 5 mmol / L WM-1 aqueous solution.
[0065] Preparation of 50 mmol / L γ-CD aqueous solution: Weigh 648.56 mg of γ-CD solid powder into a 10 mL plastic centrifuge tube, add 5 mL of deionized water and sonicate to dissolve. Then transfer the solution to a 10 mL volumetric flask and make up to volume to obtain a 50 mmol / L γ-CD aqueous solution.
[0066] Example 5
[0067] A 0.1 mmol / L WM-1 aqueous solution was prepared (diluted with a 5 mmol / L WM-1 aqueous solution). Fluorescence emission spectra were measured after the addition of different equivalents of γ-CD (0 eq, 0.5 eq, 1 eq, 2 eq, 4 eq, 6 eq, 8 eq, 10 eq, 20 eq, 30 eq, 40 eq, 50 eq, 60 eq, 70 eq, 80 eq, 90 eq, 100 eq, 110 eq). The results are as follows: Figure 3 As shown. From Figure 3 It can be seen that as the amount of γ-CD gradually increases, the fluorescence spectrum exhibits a blue shift. This indicates that increasing the amount of γ-CD alters the packing pattern of the fluorescent molecule WM-1 within the γ-CD cavity. When the amount of γ-CD reaches 50 eq, further increases no longer result in a blue shift in the spectrum, only an increase in intensity. After 80 eq, further increases lead to near-saturation of fluorescence intensity, indicating that the interaction forces between the formed WM-1@γ-CD complexes tend to stabilize. A fluorescence intensity trend graph is plotted using the peak value at 490 nm. Figure 4 As shown.
[0068] Take 2 mL of 0.1 mmol / L WM-1 aqueous solution in a cuvette, then add 40 μL of 50 mmol / L γ-CD aqueous solution. Irradiate the cuvette under a 365 nm UV lamp, and measure the fluorescence emission spectrum every 5 minutes. The results are as follows. Figure 5 As shown. From Figure 5 It can be seen that the peak value reached saturation after 45 minutes of cumulative illumination, meaning that after 45 minutes of illumination, the WM-1 in the γ-CD cavity of the WM-1@γ-CD complex completed a new round of reassembly under 365nm light stimulation. Adding γ-CD and WM-1 to water and shaking promoted their assembly, forming a 2mL aqueous solution of WM-1@γ-CD supramolecular assembly, with a γ-CD concentration of 1 mmol / L and a WM-1 concentration of 0.1 mmol / L. The fluorescence emission spectra of the WM-1@γ-CD supramolecular assembly aqueous solution were measured after heating (75℃ for 5 min) and cooling (room temperature) cycles. The results are as follows. Figure 6 As shown. From Figure 6 It can be seen that before heating, the fluorescence under ultraviolet light is bluish, with a peak around 490 nm, which is the peak of the pyrene excimer. After heating at 75℃ for 5 minutes, the fluorescence color changes to pyrene monomeric emission, with a peak around 410 nm, and the fluorescence is bluish-violet. Then, after cooling to room temperature, the fluorescence color returns to bluish, and the spectrum shows a peak around 490 nm. This process is reversible. A dotted line graph of the peak value at 490 nm is obtained to show the heating and cooling cycle, as shown below. Figure 7 As shown. From Figure 7 As can be seen, more than 10 cycles do not affect the photophysical properties of the complex.
[0069] γ-CD and WM-1 were added to water, and shaking was used to promote their assembly, forming a 2 mL aqueous solution of WM-1@γ-CD supramolecular assembly, in which the concentration of γ-CD was 1 mmol / L and the concentration of WM-1 was 0.1 mmol / L. The fluorescence emission spectra of the WM-1@γ-CD supramolecular assembly aqueous solution were measured after irradiation with 365 nm UV light for 1 h, followed by heating (70℃) and cooling (room temperature) cycles. The results are as follows. Figure 8 As shown. From Figure 8 As can be seen, after 1 hour of illumination under a 365nm UV lamp, the fluorescence color turns orange-yellow. Heating to 70℃ causes the fluorescence color to turn blue, and the emission position and peak intensity change from around 570nm to around 480nm. Cooling to room temperature restores the fluorescence color to orange-yellow, and the peak position and intensity also recover. This process is reversible. A dotted-line plot of the peak value at 570nm yields a cycle diagram, as shown below. Figure 9 As shown. From Figure 9 As can be seen, more than 10 cycles do not affect the photophysical properties of the complex.
[0070] Example 6
[0071] Applications of photochromic supramolecular fluorescent inks:
[0072] (1) Preparation of functional paper: Take 50 mmol / L of γ-cyclodextrin (γ-CD) aqueous solution and uniformly impregnate filter paper. Let the impregnated paper air dry naturally or dry it in an oven at 50-70℃ to obtain a functional paper.
[0073] (2) Printing and characteristics of fluorescent patterns: The patterns were printed on the functional paper using a 5 mmol / L aqueous solution of WM-1. The printed patterns exhibited cyan fluorescence under ultraviolet light. The paper with the printed patterns was placed under a 365 nm ultraviolet light for about 30 minutes, and then water was sprayed onto the patterns. The color of the patterns instantly changed from cyan to orange-yellow.
[0074] (3) Reversible changes in fluorescent patterns (this process does not require continuous irradiation; only an ultraviolet lamp is needed for fluorescence): Placing paper with a cyan pattern in a 75°C oven for about 5 minutes will quench the fluorescence of the cyan pattern. Spraying water restores the fluorescence; reheating quenches it again, and this process can be repeated more than 10 times. Similarly, placing paper with an orange-yellow pattern in a 75°C oven for about 5 minutes will change the pattern color from orange-yellow to white. Spraying water immediately restores the orange-yellow color; reheating turns it white, and this process can also be repeated more than 10 times. Application demonstration diagrams are shown below. Figure 10 As shown.
[0075] The above description is only a specific embodiment of the present invention and not all embodiments. Any equivalent modifications made by those skilled in the art to the technical solutions of the present invention by reading the present invention specification shall be covered by the claims of the present invention.
Claims
1. A photochromic organic compound, characterized in that, Its structure is shown in Equation I:
2. The method for preparing the photochromic organic compound according to claim 1, characterized in that, Includes the following steps: 1-((4-bromobutoxy)methyl)pyrene was completely dissolved in a solvent, and then 1,2-dimethylimidazole was added. The mixture was heated and stirred for a period of time to obtain a photochromic organic compound.
3. The method for preparing the photochromic organic compound according to claim 2, characterized in that, The molar ratio of 1-((4-bromobutoxy)methyl)pyrene to 1,2-dimethylimidazole is 1:(2-5); Preferably, the heating and stirring temperature is 60-85℃, and the heating and stirring time is 15h-24h; Preferably, the solvent is selected from at least one of acetonitrile, tetrahydrofuran, and methanol.
4. A supramolecular assembly, characterized in that, It consists of a macrocyclic host and a fluorescent guest; the macrocyclic host is γ-cyclodextrin, and the fluorescent guest is the photochromic organic compound of claim 1; Preferably, the inclusion ratio of the γ-cyclodextrin to the photochromic organic compound is 2:2, that is, two molecules of γ-cyclodextrin include two molecules of the photochromic organic compound.
5. The method for preparing the supramolecular assembly according to claim 4, characterized in that, Includes the following steps: γ-cyclodextrin and photochromic organic compounds were added to water in a certain proportion, and the assembly between the two was promoted by shaking to form a stable supramolecular assembly aqueous solution. Preferably, the molar ratio of the γ-cyclodextrin to the photochromic organic compound is (10-50):
1.
6. A photochromic supramolecular fluorescent ink, characterized in that, Includes an aqueous solution of the photochromic organic compound of claim 1 and an aqueous solution of γ-cyclodextrin for substrate treatment; Preferably, the concentration of the aqueous solution of the photochromic organic compound is 0.1 mmol / L-5 mmol / L; Preferably, the concentration of the aqueous solution of γ-cyclodextrin is 10 mmol / L-100 mmol / L; Preferably, the substrate includes paper, film, or cloth strips made of filter paper material.
7. The method for preparing the photochromic supramolecular fluorescent ink according to claim 6, characterized in that, Includes the following steps: The photochromic organic compound was mixed with water and dissolved by ultrasound to obtain an aqueous solution of the photochromic organic compound. γ-Cyclodextrin and water were mixed and dissolved by ultrasonication to obtain an aqueous solution of γ-cyclodextrin.
8. A fluorescent color-changing anti-counterfeiting method based on the photochromic supramolecular fluorescent ink according to claim 6, characterized in that, Includes the following steps: A functional substrate is prepared by pretreating the substrate with an aqueous solution of γ-cyclodextrin and then air-drying or baking it. The printed content emits a distinct cyan fluorescence under ultraviolet light by printing an aqueous solution of a photochromic organic compound on the functional substrate. After being irradiated with ultraviolet light for a period of time, water is sprayed onto the substrate, and the cyan fluorescent text or pattern on the substrate instantly turns orange-yellow. When the substrate is heated, the orange-yellow fluorescence turns into white fluorescence, and when the substrate is cooled by water spraying, the white fluorescence returns to orange-yellow fluorescence. This heating and cooling process is reversible and stable. Preferably, the wavelength of the ultraviolet light is 365nm, and the irradiation time of the ultraviolet light is 20min-90min.
9. The application of the photochromic organic compound of claim 1, the supramolecular assembly of claim 4, and the photochromic supramolecular fluorescent ink of claim 6 in fluorescent anti-counterfeiting.