Preparation method of lignin-based room-temperature phosphorescent composite film and application of lignin-based room-temperature phosphorescent composite film in anti-counterfeiting encryption
By preparing a lignin-based room-temperature phosphorescent composite film, the problems of environmental unfriendliness and difficulty in molecular control of existing RTP materials have been solved, realizing the application of a green and simple composite film in intelligent anti-counterfeiting, and possessing humidity-responsive phosphorescent properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING FORESTRY UNIV
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-19
AI Technical Summary
Existing RTP materials mostly rely on rare earth materials, which are complex to synthesize and environmentally unfriendly. The complexity of natural polymer skeletons limits molecular design and control capabilities, making it difficult to prepare green, simple, and renewable composite films for smart anti-counterfeiting encryption.
Aqueous carrier solutions were prepared by dissolving lignin-based materials and carrier materials such as CMC, PVA, PEG, PMMA, NCC, and CMC-H. The solutions were then mixed with a carbazole-benzophenone lignin-based phosphorescent molecular mother liquor and dried in an oven to form a film, thus preparing a lignin-based room temperature phosphorescent composite film.
The prepared composite film exhibits excellent performance, is environmentally friendly, possesses TICT-AIE properties and RTP performance, and displays different phosphorescence effects through humidity response, making it suitable for the field of intelligent anti-counterfeiting.
Smart Images
Figure CN122060198A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lignin catalytic conversion to room temperature phosphorescent materials, specifically relating to a method for preparing a lignin-based room temperature phosphorescent composite film and its application in anti-counterfeiting encryption. Background Technology
[0002] Phosphorescent materials, especially room-temperature phosphorescent (RTP) materials, have received continuous attention due to their wide application in organic light-emitting diodes (OLEDs), bioimaging, and smart anti-counterfeiting. Significant progress has been made in RTP material research, with numerous inorganic RTP materials developed and widely used in lighting and bioimaging. However, the development of these materials is limited by the availability, high cost, and high toxicity of rare earth materials, as well as complex synthesis processes. In contrast, organic RTP materials have developed rapidly in recent years, benefiting from advantages such as low cost, simple synthesis, excellent biocompatibility, and tunable functional groups. Integration with aggregation-induced emission (AIE) further enhances their potential, making them a candidate material for bioimaging, information storage, and anti-counterfeiting encryption. Furthermore, with increasing emphasis on environmental protection and sustainable development strategies, there is a growing exploration of using natural resources as alternatives to petroleum-based materials for RTP applications. These include natural polymers such as cellulose, hemicellulose, lignin, and proteins. The diverse functional groups in these polymers can be chemically modified and physically treated to reduce non-radiative transitions. These properties can be used to create RTP materials through doping / chemical crosslinking. Although natural products possess advantages such as renewability, sustainability, and excellent environmental compatibility, the complexity of their skeletons limits the design and controllability of molecules. Therefore, current bio-based luminescent materials are inferior to petroleum-based materials. Consequently, developing a composite film material using renewable natural polymers as a substrate, employing a green and simple preparation process, and exhibiting both humidity response and long-afterglow room-temperature phosphorescence properties, and realizing its precise application in intelligent anti-counterfeiting encryption, has become a pressing technical problem in this field. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a method for preparing a lignin-based room temperature phosphorescent composite film. The preparation method is simple, easy to operate, and conforms to the concept of green chemistry. Another technical problem to be solved by the present invention is to provide the application of the lignin-based room temperature phosphorescent composite film in anti-counterfeiting encryption.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0005] A method for preparing a lignin-based room temperature phosphorescent composite film involves dissolving a carrier material in deionized water to prepare an aqueous carrier solution, dissolving carbazole-benzophenone lignin-based phosphorescent molecules in an organic solvent to prepare a phosphorescent molecule mother liquor, mixing the aqueous carrier solution and the phosphorescent molecule mother liquor, ultrasonically homogenizing them, transferring them to a mold, and drying them in an oven to form a film, thereby obtaining the lignin-based room temperature phosphorescent composite film.
[0006] Furthermore, the carrier material is selected from one of CMC, PVA, PEG, PMMA, NCC, and CMC-H.
[0007] Furthermore, the carbazole-benzophenone lignin-based phosphorescent molecule is selected from... , , , , , One of them.
[0008] Furthermore, the mass ratio of the carrier material to the carbazole-benzophenone lignin-based phosphorescent molecule is 500~1000:1.
[0009] Furthermore, the mass-to-volume ratio of the carbazole-benzophenone lignin-based phosphorescent molecule to the organic solvent is 1~3:1~2.
[0010] Furthermore, the organic solvent is selected from acetonitrile, ethanol, and dichloromethane.
[0011] Furthermore, the volume ratio of the aqueous carrier solution to the phosphorescent molecular mother liquor is 2~3:1.
[0012] Furthermore, the drying temperature is 40~80℃.
[0013] Furthermore, the lignin-based room temperature phosphorescent composite film prepared by the aforementioned method is a lignin-based room temperature phosphorescent composite film.
[0014] Furthermore, the lignin-based room temperature phosphorescent composite film is used in anti-counterfeiting encryption.
[0015] Compared with the prior art, the present invention has the following advantages:
[0016] (1) The composite membrane prepared by this invention has excellent performance and is environmentally friendly: the process of preparing the composite membrane is simple and easy to operate, and has good phosphorescence performance; at the same time, the composite membrane uses natural and renewable lignin and natural carrier materials as raw materials, replacing conventional synthetic polymer materials that are difficult to degrade, which is in line with the concept of green chemistry.
[0017] (2) The molecules synthesized in this invention have TICT-AIE properties and RTP performance, and can be confined to membranes using natural polymers.
[0018] (3) The membrane prepared by the present invention exhibits different phosphorescence effects during the water absorption and water removal processes, including duration and color differences. Through these differences, it has broad application prospects in the field of intelligent anti-counterfeiting and can be used for anti-counterfeiting of medicine bottles. Attached Figure Description
[0019] Figure 1 These are afterglow comparison images of lignin-based room-temperature phosphorescent composite films with different doping systems prepared in Examples 1 and 7-8 of this application;
[0020] Figure 2 The emission spectra of lignin-based room-temperature phosphorescent composite films with different doping systems prepared in Examples 1-6 of this application are shown.
[0021] Figure 3 Comparison of afterglow images of lignin-based room temperature phosphorescent composite films prepared at different drying temperatures in Examples 1 and 9-12 of this application;
[0022] Figure 4 The graphs show the changes in phosphorescence intensity of the lignin-based room temperature phosphorescent composite membranes prepared in Examples 1 and 9-12 of this application; in the graphs, (a) shows the changes in phosphorescence intensity of the membrane during the heating and dehydration process, and (b) shows the changes in phosphorescence intensity of the membrane during the water fumigation process.
[0023] Figure 5 The anti-counterfeiting encryption pattern and anti-counterfeiting application diagram of the crystal and natural polymer doping system of the lignin-based room temperature phosphorescent composite film prepared in Example 1 of this application are shown. Detailed Implementation
[0024] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.
[0025] The carbazole-benzophenone lignin-based phosphorescent molecule used in the following examples is (4n) (4o) (4v) (4s) (4r) (4u) was prepared using the method described in Sustainable production of carbazole-based BioAlEgens from lignin major motifs.
[0026] Example 1
[0027] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0028] 2g of CMC was dissolved in 100mL of deionized water and stirred continuously in an oil bath at 90℃ to obtain a clear, uniform, colorless solution, thus preparing a 2% aqueous solution. Then, 4mg of carbazole-benzophenone lignin-based phosphorescent molecules were dissolved in 2mL of acetonitrile (ACN) until completely dissolved. Next, 5mL of the prepared aqueous solution was mixed with 2mL of the phosphorescent molecule stock solution. After homogenizing the mixture by sonication, it was transferred to a circular mold and dried in an oven at 80℃ to obtain a lignin-based room-temperature phosphorescent composite film.
[0029] Example 2
[0030] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0031] The difference from Example 1 is that CMC is replaced with PVA to obtain a lignin-based room temperature phosphorescent composite film.
[0032] Example 3
[0033] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0034] The difference from Example 1 is that CMC is replaced with PEG to obtain a lignin-based room temperature phosphorescent composite film.
[0035] Example 4
[0036] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0037] The difference from Example 1 is that CMC is replaced with PMMA to obtain a lignin-based room temperature phosphorescent composite film.
[0038] Example 5
[0039] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0040] The difference from Example 1 is that CMC is replaced with NCC to obtain a lignin-based room temperature phosphorescent composite film.
[0041] Example 6
[0042] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0043] The difference from Example 1 is that CMC is replaced with CMC-H to obtain a lignin-based room temperature phosphorescent composite film.
[0044] Depend on Figure 1A comparison of the afterglow images of the lignin-based room-temperature phosphorescent composite films prepared in Examples 1-6 shows that the phosphorescence is most pronounced when CMC is doped, exhibiting the longest green phosphorescence lasting up to 3 seconds.
[0045] Example 7
[0046] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0047] The difference from Example 1 is that 2 mg of carbazole-benzophenone lignin-based phosphorescent molecules were dissolved in 2 mL of acetonitrile (ACN) until completely dissolved to obtain a lignin-based room temperature phosphorescent composite film.
[0048] Example 8
[0049] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0050] The difference from Example 1 is that 3 mg of carbazole-benzophenone lignin-based phosphorescent molecules were dissolved in 2 mL of acetonitrile (ACN) until completely dissolved to obtain a lignin-based room temperature phosphorescent composite film.
[0051] Depend on Figure 1 Comparison of afterglow images of lignin-based room temperature phosphorescent composite films prepared in Examples 1 and 7-8 shows that, under different solid doping ratios, the effect is best after doping with CMC, and the phosphorescence effect is best when the mass ratio is 500:1.
[0052] The lignin-based room-temperature phosphorescent composite films prepared in Examples 1-6 were subjected to spectral testing, such as... Figure 2 As shown, the findings and Figure 1 The phenomenon is consistent with that observed in the images, with the best effect and highest phosphorescence intensity after doping with CMC, which also proves the rationality of the afterglow image phenomenon.
[0053] Example 9
[0054] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0055] The difference from Example 1 is that the oven temperature was adjusted to 40°C for drying, resulting in a lignin-based room temperature phosphorescent composite film.
[0056] Example 10
[0057] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0058] The difference from Example 1 is that the oven temperature was adjusted to 50°C for drying, resulting in a lignin-based room temperature phosphorescent composite film.
[0059] Example 11
[0060] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0061] The difference from Example 1 is that the oven temperature was adjusted to 60°C for drying, resulting in a lignin-based room temperature phosphorescent composite film.
[0062] Example 12
[0063] A method for preparing a lignin-based room temperature phosphorescent composite film includes the following steps:
[0064] The difference from Example 1 is that the oven temperature was adjusted to 70°C for drying, resulting in a lignin-based room temperature phosphorescent composite film.
[0065] The lignin-based room-temperature phosphorescent composite films prepared in Examples 1 and 9-12 were observed at 10°C intervals as the temperature was gradually increased from room temperature to 80°C. The results are as follows: Figure 3 The afterglow images of the film at different temperatures show that as the temperature gradually increases, the phosphorescence performance of the film changes from a light green to a very obvious green, and the duration is extended to 3 seconds. This process also qualitatively demonstrates the characteristics of the film's humidity response.
[0066] In Examples 1 and 9-12, the lignin-based room-temperature phosphorescent composite films prepared were monitored for phosphorescence spectrum changes gradually from room temperature during temperature variations. As the temperature increased and moisture was removed, the phosphorescence spectrum... Figure 4 As shown in (a), the phosphorescence intensity of the membranes in Examples 9-12 steadily increased, reaching its highest intensity at 80°C (the membrane prepared in Example 1), and this phosphorescence lasted for 3 seconds. To verify that moisture indeed affected the membrane's phosphorescence performance, the membranes were continuously steamed starting at 80°C. With each 15 minutes of steaming, the phosphorescence intensity showed a decreasing trend, as shown in (a). Figure 4 As shown in (b), the "humidity quenching and drying recovery" phenomenon demonstrated in this application proves the controllability of the membrane and further confirms the humidity response performance of the membrane.
[0067] Application Example 1
[0068] The lignin-based room-temperature phosphorescent composite film prepared in Example 1 was cut into different shapes, such as... Figure 5 As shown in (a), the film made of 4o@CMC is cut into the shape of a "flower". After the process of heating and dehydration, it shows obvious green phosphorescence. However, after the "flower stem" part is smoldered with water, the "flower stem" part can be seen to extinguish, but the "petal" part is still lit, thus achieving the effect of pattern anti-counterfeiting.
[0069] Application Example 2
[0070] The application has been expanded to include digital encryption processes, such as... Figure 5As shown in (b), using 4o@CMC, 4s@CMC, and CMC as the basic representation, they are arranged into a blue "888" pattern with almost similar fluorescent colors. After being heated to 80°C for 0.1 seconds, the initial decryption of "493" is displayed, but it is still not the final password. After waiting for a while, the final password "147" is presented, achieving a simple two-level encryption effect.
[0071] Application Example 3
[0072] Based on the simple pattern above, a complete story chain was created, as follows: Figure 5 As shown in (c), the story begins during the day, before sunset. The three elements "house, indoor light, and street light" made of 4o@CMC, 4n@CMC, and 4v@CMC are displayed in blue. When the sun is just setting, the indoor light is turned on, but the street light is not on, presenting a state of "green house, red light". When it is almost time to go to sleep, the indoor light is turned off and the street light is turned on, achieving the effect of "green house, green street light". When it is almost dawn, the street light is turned off, achieving the effect of "green house". The whole process is achieved by different phosphorescence durations after dehydration treatment at 50℃ and 80℃.
[0073] Application Example 4
[0074] Extending the application to practical fields, using medicine bottles as the main body, the prepared membrane is placed on the bottle, such as... Figure 5 As shown in (d), different phosphorescence effects can be achieved at different temperatures. At 40℃, there is only one phosphorescence color, but at 50℃, a second color appears, thus achieving anti-counterfeiting of the medicine bottle.
[0075] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a lignin-based room-temperature phosphorescent composite film, characterized in that, An aqueous carrier solution is prepared by dissolving the carrier material in deionized water, and a phosphorescent molecule mother liquor is prepared by dissolving the carbazole-benzophenone lignin-based phosphorescent molecule in an organic solvent. The aqueous carrier solution and the phosphorescent molecule mother liquor are mixed and ultrasonically homogenized, transferred to a mold, and dried in an oven to form a film, thus obtaining a lignin-based room temperature phosphorescent composite film.
2. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The carrier material is selected from one of CMC, PVA, PEG, PMMA, NCC, and CMC-H.
3. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The carbazole-benzophenone lignin-based phosphorescent molecule is selected from... , , , , , One of them.
4. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The mass ratio of the carrier material to the carbazole-benzophenone lignin-based phosphorescent molecule is 500~1000:
1.
5. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The mass-to-volume ratio of the carbazole-benzophenone lignin-based phosphorescent molecule to the organic solvent is 1~3:1~2.
6. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The organic solvent is selected from acetonitrile, ethanol, and dichloromethane.
7. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The volume ratio of the aqueous carrier solution to the phosphorescent molecular mother liquor is 2~3:
1.
8. The method for preparing the lignin-based room-temperature phosphorescent composite film according to claim 1, characterized in that: The drying temperature is 40~80℃.
9. The lignin-based room temperature phosphorescent composite film prepared by the preparation method of any one of claims 1 to 8.
10. The application of the lignin-based room temperature phosphorescent composite film according to claim 9 in anti-counterfeiting encryption.