A long-life room-temperature phosphorescent polymer with photochromic properties and its preparation method and application

Abstract

The present invention belongs to the field of optical anti-counterfeiting materials, and specifically relates to a long-life room-temperature phosphorescent polymer with photochromism, and its preparation method and application. The present invention grafts an ionic luminescent monomer containing a boronic acid group and a violet photochromic monomer containing a boronic acid group onto polyvinyl alcohol to prepare a long-life room-temperature ionic luminescent polymer and a photochromic polymer, respectively, and further prepares a long-life room-temperature phosphorescent polymer with photochromism based on a polymer blending film-forming method. In addition, the present invention also provides a method of co-grafting an ionic luminescent monomer containing a boronic acid group and a violet photochromic monomer containing a boronic acid group onto polyvinyl alcohol to prepare a long-life room-temperature phosphorescent polymer with photochromism. The obtained long-life room-temperature phosphorescent polymer with photochromism exhibits multiple dynamic characteristics such as fluorescence, long-life phosphorescence, adjustable phosphorescence lifetime, and photochromism, and has important application potential in achieving high-level anti-counterfeiting and information storage.

Description

Technical Field

[0001] The present invention belongs to the field of optical anti-counterfeiting materials, and particularly relates to a long-life room-temperature phosphorescent polymer with photochromism, a preparation method and application thereof. Background Art

[0002] With the development of society, the emergence of counterfeit and shoddy goods has seriously affected people's daily lives and social and economic development. In order to prevent and eliminate counterfeit and shoddy products, various anti-counterfeiting technologies have emerged, such as optical anti-counterfeiting technology, watermarks, barcodes, QR codes, etc. Among them, optical anti-counterfeiting is easy to operate and identify, has been widely studied, and has been put into practical application. As for optical anti-counterfeiting materials, they include fluorescent anti-counterfeiting materials and phosphorescent anti-counterfeiting materials. Among them, fluorescent anti-counterfeiting materials exhibit a short-lived luminescence when excited by light, that is, when the light excitation stops, the luminescence stops immediately. In particular, long-life room temperature phosphorescent materials (afterglow longer than 0.1 seconds) emit light under light excitation, and after the excitation light source is removed, they can still continue to emit light for a period of time, and it is visible to the naked eye. Due to its unique optical properties, it has higher anti-counterfeiting capabilities than fluorescent anti-counterfeiting materials and shows greater application potential in advanced anti-counterfeiting technologies. Therefore, long-life room temperature phosphorescent materials have attracted research and development by a large number of researchers at home and abroad.

[0003] At present, although a large number of high-efficiency long-life room-temperature phosphorescent materials (such as inorganic compounds, carbon dots, metal-organic framework polymers, organic crystalline materials, supramolecular composites, organic polymers, etc.) are being continuously developed, a large part of the long-life room-temperature phosphorescent materials constructed often require complex and time-consuming synthesis, some crystalline phosphorescent materials are not suitable for processing, and some multi-component doped composite materials are optically unstable. These shortcomings seriously limit the practical application of related phosphorescent materials. In order to meet the requirements of practical applications, it is urgent to develop long-life room-temperature phosphorescent organic polymer materials that are simple to synthesize, low-cost, easy to process, and efficient. It is worth noting that a large part of the reported dynamic long-life room-temperature phosphorescent organic polymers mainly respond to one external stimulus and achieve one dynamic change, while long-life room-temperature phosphorescent organic polymers that can respond to one stimulus or multiple stimulus patterns and achieve multiple dynamic changes are still very rare. Summary of the Invention

[0004] In order to solve the problems of the prior art, the present invention provides a long-life room-temperature phosphorescent polymer with photochromism and its preparation method and application, so as to achieve higher-level anti-counterfeiting and information storage applications.

[0005] The technical solutions of the present invention are as follows:

[0006] A long-life room-temperature phosphorescent polymer with photochromism is a blend of a polymer P1 represented by formula (1) and a polymer P2 represented by formula (1) or a polymer P3 represented by formula (3);

[0007]

[0008]

[0009] The polymer P1 is formed by the polymerization reaction of the functional monomer L1 represented by formula (IV) and polyvinyl alcohol (PVA); the polymer P2 is formed by the polymerization reaction of the functional monomer L2 represented by formula (V) and PVA; the polymer P3 is formed by the polymerization reaction of the functional monomer L1 and the functional monomer L2 with PVA;

[0010]

[0011] The preparation process of the blend of polymer P1 and polymer P2 includes:

[0012] (1) PVA was dissolved in 100°C water, and then a methanol solution of functional monomer L1 was added to the PVA aqueous solution, stirred at 80-100°C for 6-10 hours, and then cooled to room temperature. After filtering, an aqueous solution of polymer P1 was obtained;

[0013] (2) PVA was dissolved in 100°C water, and then a methanol solution of the functional monomer L2 was added to the PVA aqueous solution, stirred at 80-100°C for 6-10 hours, and then cooled to room temperature. After filtering, an aqueous solution of polymer P2 was obtained;

[0014] (3) The aqueous solution of polymer P1 and the aqueous solution of polymer P2 were mixed uniformly at room temperature, then drop-coated on a quartz plate and dried at 60°C to form a film.

[0015] Preferably, in step (1), the mass ratio of the functional monomer L1 to PVA is 1-30:100.

[0016] Preferably, the mass ratio of the functional monomer L2 to PVA in step (2) is 1-30:100.

[0017] Preferably, in step (3), the volume ratio of the aqueous solution of polymer P1 to the aqueous solution of polymer P2 is 1-10:10-1.

[0018] The preparation process of the polymer P3 includes: dissolving PVA in 100°C water, adding methanol solutions of functional monomers L1 and L2 to the PVA aqueous solution, stirring and reacting at 80-100°C for 6-10 hours, then cooling to room temperature, and filtering to obtain polymer P3.

[0019] Preferably, the mass ratio of the functional monomer L1, the functional monomer L2 and PVA is 1-30:1-30:100.

[0020] The long-life room-temperature phosphorescent polymer with photochromism is used in the fields of high-level anti-counterfeiting and information storage.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The present invention introduces ionic luminescent monomers containing boric acid groups and viologen photochromic monomers containing boric acid groups into the polymer system to develop a long-life room-temperature phosphorescent polymer that is both photochromic and multi-color tunable, and can simultaneously achieve multiple dynamic changes in structural color, luminescence intensity, phosphorescence lifetime, and luminescence color.

[0023] 2. The polymer material developed in this invention exhibits different luminescent colors under ultraviolet light. After the light source is removed, the phosphorescence lifetime can reach over 1 second, and the afterglow lasts for over 6 seconds. With continued exposure to light, the polymer changes color, the luminescence weakens, and the phosphorescence lifetime shortens. When the polymer material is exposed to water, the color fades, the phosphorescence disappears, and the luminescent color changes. After drying, the polymer material returns to its original state.

[0024] 3. The raw materials used in the present invention are easily available and the synthesis method is simple, and the present invention has great application prospects in the fields of advanced anti-counterfeiting, information storage, smart windows, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a photograph of the fluorescence and phosphorescence emission of polymer P1 after film formation;

[0026] Figure 2 is the fluorescence and phosphorescence emission spectra of polymer P1 after film formation;

[0027] Figure 3 This is the phosphorescence lifetime diagram of polymer P1 after film formation;

[0028] Figure 4 This is the paramagnetic resonance image of polymer P2 after film formation;

[0029] Figure 5 The fluorescence and phosphorescence emission photos of polymer P1 and polymer P2 after blending into a film, as well as the natural emission photos after continuous illumination;

[0030] Figure 6 This is the phosphorescence lifetime diagram before and after light irradiation after polymer P1 and polymer P2 are blended into a film;

[0031] Figure 7 The fluorescence and phosphorescence emission images of polymer P3 after film formation, as well as the natural emission image after continuous illumination;

[0032] Figure 8 This is the phosphorescence lifetime diagram of polymer P3 before and after illumination after film formation;

[0033] Figure 9 It is the afterglow luminescence image and fabric color change image of polymer P3 imprinted on the fabric as anti-counterfeiting information. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] Example 1

[0036] S1: In air, first dissolve 300 mg of PVA in 10 ml of 100°C water, then dissolve 3 mg of L1 in 2 ml of methanol, and add the mixture to the PVA aqueous solution. Stir the reaction at 80°C for 10 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P1.

[0037] S2: In air, first dissolve 200 mg of PVA in 10 ml of 100°C water, then dissolve 10 mg of L2 in 3 ml of methanol, and add them to the PVA aqueous solution. Stir the reaction at 80°C for 10 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P2.

[0038] S3: 3 ml of the aqueous solution of polymer P1 and 1 ml of the aqueous solution of polymer P2 were mixed evenly to obtain a blended solution, which was then drop-coated on a quartz plate and dried at 60° C. to form a film.

[0039] Under 365nm ultraviolet light excitation, polymer P1 emits bright green light. After the excitation light source is removed, it emits yellow-green phosphorescence. Figure 1 The fluorescence and phosphorescence emission photos of polymer P1 after film formation show that the afterglow time can reach 7s. Figure 2 The fluorescence and phosphorescence emission spectra of polymer P1 after film formation are shown in the figure. As can be seen from the spectra, the maximum fluorescence emission peak and the phosphorescence emission peak are both located at 510nm, but the peak widths are slightly different. Moreover, the luminescence decay lifetime of the phosphorescence emission peak at 510nm reaches 1.34s. Figure 3 shown.

[0040] Figure 4 These are the paramagnetic resonance images of polymer P2 before and after illumination. Under natural light, the polymer P2 film is colorless and shows no free radical signal. However, with continued illumination, the color changes from colorless to purple. This is because during illumination, polymer P2 generates stable viologen free radicals due to photoinduction. Furthermore, the polymer film returns to its original colorless state when stimulated by water vapor.

[0041] Figure 5Photographs of the fluorescence and phosphorescence emission from a film formed from a blend of polymers P1 and P2. Under 365nm UV excitation, the blended polymer film exhibits green luminescence. After the excitation light is removed, the film emits yellow-green phosphorescence with a lifetime of 1.22 seconds and a visible afterglow of 7 seconds. With continued illumination, the blended polymer film changes from colorless to blue. Figure 6 The following graph shows the phosphorescence lifetime of a film formed by blending polymers P1 and P2 before and after illumination. The graph shows that the phosphorescence lifetime of the blended polymers is shortened. Furthermore, the blended polymer film returns to its original colorless state upon exposure to water vapor.

[0042] Example 2

[0043] S1: In air, first dissolve 100 mg of PVA in 15 ml of 100°C water, then dissolve 30 mg of L1 in 3 ml of methanol, and add the mixture to the PVA aqueous solution. Stir the reaction at 100°C for 6 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P1.

[0044] S2: In air, first dissolve 200 mg of PVA in 10 ml of 100°C water, then dissolve 10 mg of L2 in 3 ml of methanol, and add them to the PVA aqueous solution. Stir the reaction at 80°C for 10 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P2.

[0045] S3: 4 ml of the aqueous solution of polymer P1 and 2 ml of the aqueous solution of polymer P2 were mixed evenly to obtain a blended solution, and the blended solution was drop-coated on a quartz plate and dried at 60° C. to form a film.

[0046] Under 365nm ultraviolet light excitation, the polymer blend exhibits a yellow-green luminescence. After the excitation light source is removed, the visible yellow-green phosphorescence persists for up to 6 seconds. With continued illumination, the polymer blend film changes from light yellow to blue, and the phosphorescence lifetime shortens. Furthermore, the polymer blend film returns to its initial state when stimulated by water vapor.

[0047] Example 3

[0048] S1: In air, first dissolve 300 mg of PVA in 10 ml of 100°C water, then dissolve 3 mg of L1 in 2 ml of methanol, and add the mixture to the PVA aqueous solution. Stir the reaction at 80°C for 10 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P1.

[0049] S2: In air, first dissolve 200 mg of PVA in 10 ml of 100°C water, then dissolve 5 mg of L2 in 2 ml of methanol, and add them to the PVA aqueous solution. Stir the reaction at 80°C for 6 hours, stop the reaction, cool to room temperature, and filter to obtain an aqueous solution of polymer P2.

[0050] S3: 2 ml of the aqueous solution of polymer P1 and 2 ml of the aqueous solution of polymer P2 were mixed evenly to obtain a blended solution, and the blended solution was drop-coated on a quartz plate and dried at 60° C. to form a film.

[0051] Under 365nm ultraviolet light excitation, the polymer blend exhibits green luminescence. After the excitation light source is removed, the visible green phosphorescence persists for up to 6 seconds. With continued illumination, the polymer blend film changes from colorless to blue, and the phosphorescence lifetime shortens. Furthermore, the polymer blend film returns to its initial state when stimulated by water vapor.

[0052] Example 4

[0053] In air, 300 mg of PVA was dissolved in 20 ml of 100°C water. 8 mg of L2 was then dissolved in 2 ml of methanol and added to the PVA aqueous solution. The mixture was stirred at 80°C for 2 hours. Subsequently, 3 mg of L1 was dissolved in 2 ml of methanol and added to the PVA aqueous solution. The mixture was stirred at 80°C for another 6 hours. The reaction was stopped, cooled to room temperature, and filtered to obtain an aqueous solution of polymer P3. This solution was then drop-coated on a quartz wafer and dried at 60°C to form a film.

[0054] Figure 7 The fluorescence and phosphorescence emission patterns of polymer P3 after film formation. Under 365nm UV excitation, polymer P3 exhibits green luminescence. After the excitation light is removed, it emits yellow-green phosphorescence with a lifetime of 1.04 seconds and a visible afterglow of 6 seconds. With continued illumination, the polymer film changes from colorless to blue. Figure 8 The following graph shows the phosphorescence lifetime of polymer P3 before and after light exposure. The graph shows a shortened phosphorescence lifetime. Furthermore, the polymer film returns to its original colorless state when stimulated by water vapor.

[0055] Example 5

[0056] In air, 200 mg of PVA was dissolved in 20 ml of 100°C water. 10 mg of L2 was then dissolved in 3 ml of methanol and added to the PVA aqueous solution. The mixture was stirred at 100°C for 2 hours. Subsequently, 10 mg of L1 was dissolved in 3 ml of methanol and added to the PVA aqueous solution. The mixture was stirred at 100°C for another 4 hours. The reaction was stopped, cooled to room temperature, and filtered to obtain an aqueous solution of polymer P3. This solution was then drop-coated on a quartz wafer and dried at 60°C to form a film.

[0057] Under 365nm ultraviolet light excitation, the polymer film exhibits a yellow-green luminescence. After the excitation light source is removed, the film emits yellow-green phosphorescence with a lifetime of 0.87 seconds and a visible afterglow of 4 seconds. With continued illumination, the film changes from light yellow to blue, and the phosphorescence lifetime shortens. Furthermore, the film returns to its initial state when stimulated by water vapor.

[0058] Example 6

[0059] In an anti-counterfeiting application example, a polymer P3 aqueous solution is printed on fabric and then dried at 60°C. Figure 9 Images of the afterglow and color change of polymer P3 printed on fabric as anti-counterfeiting information. Under 365nm UV light, the printed portion of the fabric glows green. Even after the excitation light is removed, the printed portion continues to emit yellow-green phosphorescence, with a visible afterglow lasting up to 6 seconds. With continued illumination, the printed portion changes from light yellow to blue. Furthermore, upon exposure to water vapor, the color returns to its original state.

Claims

1. A long-life room-temperature phosphorescent polymer with photochromic properties, characterized in that: The phosphorescent polymer is a blend of polymer P1 represented by formula (I) and polymer P2 represented by formula (II) or polymer P3 represented by formula (III); ， ， ； The preparation method of the blend comprises the following steps: (1) Dissolve polyvinyl alcohol in water at 100°C, then add the methanol solution of functional monomer L1 to the polyvinyl alcohol aqueous solution, stir at 80-100°C for 6-10 hours, then cool to room temperature, and filter to obtain an aqueous solution of polymer P1; (2) Dissolve polyvinyl alcohol in water at 100°C, then add the methanol solution of functional monomer L2 to the polyvinyl alcohol aqueous solution, stir at 80-100°C for 6-10 hours, then cool to room temperature, and filter to obtain an aqueous solution of polymer P2; (3) The aqueous solution of polymer P1 and the aqueous solution of polymer P2 were mixed evenly at room temperature, then drop-coated on a quartz plate and dried at 60°C to form a film; In the preparation method of the blend, the mass ratio of the functional monomer L1 to the polyvinyl alcohol in step (1) is 1-30:100; In the preparation method of the blend, the mass ratio of the functional monomer L2 to the polyvinyl alcohol in step (2) is 1-30:100; In the preparation method of the blend, the volume ratio of the aqueous solution of polymer P1 to the aqueous solution of polymer P2 in step (3) is 1-10:10-1; The preparation method of the polymer P3 comprises the following steps: Dissolve polyvinyl alcohol in water at 100°C, then add methanol solution of functional monomer L1 and methanol solution of functional monomer L2 to the polyvinyl alcohol aqueous solution, stir and react at 80-100°C for 6-10h, then cool to room temperature, and filter to obtain polymer P3; In the preparation method of polymer P3, the mass ratio of functional monomer L1, functional monomer L2 and polyvinyl alcohol is 1-30:1-30:

100.

2. The long-life room-temperature phosphorescent polymer with photochromic properties according to claim 1, characterized in that: The polymer P1 is formed by the polymerization reaction of the functional monomer L1 represented by formula (IV) and polyvinyl alcohol; the polymer P2 is formed by the polymerization reaction of the functional monomer L2 represented by formula (V) and polyvinyl alcohol; the polymer P3 is formed by the polymerization reaction of the functional monomer L1 and the functional monomer L2 with polyvinyl alcohol; ， 。 3. A long-life room-temperature phosphorescent polymer with photochromic properties according to any one of claims 1 to 2, characterized in that: It can be used in the fields of high-level anti-counterfeiting and information storage.

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