Polymer-based long-afterglow luminescent material as well as preparation method and application thereof

Abstract

The invention discloses a polymer-based long-afterglow luminescent material as well as a preparation method and application thereof, and belongs to the field of organic luminescent materials. The polymer-based long-afterglow luminescent material is a host-guest doped material of an organic small molecule guest based on a benzo [b] phenothiazine derivative and a host of polymethyl methacrylate. The macroscopic afterglow time of the obtained long-afterglow luminescent material can reach the hour level. The obtained material has excellent machinability, transparency and flexibility, and can be used in the fields of environment-friendly illumination, advanced anti-counterfeiting, information encryption, 3D printing, biological imaging and the like.

Description

Technical Field

[0001] This invention relates to the field of organic light-emitting materials, and particularly to a polymer-based long afterglow light-emitting material, its preparation method, and its application. Background Technology

[0002] Long persistent luminescence (LPL) materials, also known as phosphorescent materials, can store the energy of excitation light when excited by a light source and slowly release it as light energy after excitation stops. These materials have a wide range of applications, including nighttime lighting, safety signs, instrument displays, decorative materials, anti-counterfeiting information, and bio-imaging.

[0003] Currently, commercially available long-afterglow materials are all based on inorganic systems, requiring the doping of expensive rare metal elements and high-temperature manufacturing processes. Due to solubility issues, the luminescent compound raw materials often need to be ground and dispersed, and powder processing technology limits the transparency of the materials. In addition, long-afterglow luminescent materials based on inorganic systems also face biocompatibility problems.

[0004] To address the numerous challenges faced by inorganic long persistent luminescence (OLPL) systems, the development of easily processed, highly transparent, flexible, and biocompatible organic long persistent luminescence (OLPL) materials has become a current research hotspot.

[0005] To achieve organic long-afterglow luminescence, the system needs to generate effective charge-separated states under illumination. Classical organic long-afterglow luminescent materials are mostly mixtures of small organic molecules based on exciton complexes. However, these systems are often brittle, lacking the toughness required for applications such as fibers and films, and still suffer from problems such as high processing temperatures, poor formability, and low transparency. To overcome these bottlenecks and obtain easily processed, highly transparent, flexible organic long-afterglow luminescent materials, the development of polymer-based organic long-afterglow luminescent systems is urgently needed. Polymer-based organic long-afterglow luminescent materials typically employ copolymerization or doping to introduce guest chromophores or guest luminescent molecules into the polymer matrix to achieve long-afterglow luminescence. Compared to copolymerization, the host-guest doping strategy has the advantages of simpler preparation and easier system modification. Currently, the development of such long-afterglow luminescent materials is still in the basic research stage and has not yet been commercialized. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems, the present invention provides a transparent flexible polymer-based long afterglow luminescent material based on organic small molecule doping, its preparation method and application.

[0007] In a first aspect, the present invention provides a polymer-based long afterglow luminescent material, which is achieved through the following technical solution.

[0008] A polymer-based long-afterglow luminescent material, wherein the luminescent material is formed by doping a luminescent molecule (guest) with a polymer matrix (host); the luminescent molecule is a compound having the following structure:

[0009] Wherein, R is an alkyl, substituted or unsubstituted aryl group.

[0010] Furthermore, the substituent R is a straight-chain, branched, or cyclic alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group.

[0011] Furthermore, the alkyl substituent R is selected from methyl or ethyl.

[0012] Furthermore, the phenyl substituent R is selected from 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 4-benzoylphenyl or 4-[(12H-benzo[b]phenthiazine-12-yl)phenyl].

[0013] Furthermore, the doping ratio of luminescent molecules is 0.01%-10% (the mass percentage of the polymer matrix is ​​90.00%-99.99%, and the mass percentage of the luminescent molecules is 0.01%-10.00%). Preferably, the mass percentage of the polymer matrix is ​​99.90%-99.00%, and the mass percentage of the luminescent molecules is 0.1%-1%.

[0014] Furthermore, the polymer matrix is ​​selected from polymethyl methacrylate (PMMA).

[0015] Furthermore, the polymer-based long-afterglow luminescent material is also doped with additives, wherein the molar ratio of additives to luminescent molecules is 0.001-1000:1, preferably (0.1-10):1; the additive is benzophenone (BP). The addition of additives can achieve a better long-afterglow effect.

[0016] Secondly, the present invention provides a method for preparing a polymer-based long afterglow luminescent material, which is achieved through the following technical solution.

[0017] A method for preparing the above-mentioned polymer-based long afterglow luminescent material, wherein the luminescent molecules are doped by solvent blending or melt blending; When using the solvent blending method, the luminescent molecules and polymer matrix are dissolved in an organic solvent. After removing the solvent, the material is thermally annealed at a glass transition (Tg) temperature greater than or equal to that of the polymer matrix material. After cooling, a long afterglow luminescent material is obtained. When using the melt blending method, the luminescent molecules and polymer matrix are mixed evenly, heated to melt and stirred evenly, and then cooled to obtain a long afterglow luminescent material.

[0018] When using solvent blending, the thermal annealing process has a decisive impact on the long afterglow performance of the material. During solvent evaporation, adjacent polymer chains aggregate and become entangled, affecting the uniform dispersion of guest molecules within the bulk. Furthermore, materials produced by solvent blending may contain micropores and nanopores. Therefore, to obtain good long afterglow performance, thermal annealing is necessary after solvent evaporation.

[0019] Furthermore, the organic solvent selected N,N - One of dimethylformamide, toluene, tetrahydrofuran, dichloromethane, or chloroform.

[0020] Specifically, the steps for preparing long-afterglow luminescent materials via solvent blending are as follows: The luminescent molecules and polymethyl methacrylate are added to a sample vial in a specific ratio, followed by the addition of an organic solvent. After the solid dissolves, the solvent is removed by heating or rotary evaporation (to obtain materials of different shapes, the solution can be placed in a mold to evaporate the solvent). The resulting solid material is then annealed at 120-210°C for 1-6 hours to obtain a polymer-based long-afterglow luminescent material doped with the luminescent molecules. Preferably, the solid material is annealed at 170°C for 2 hours.

[0021] The steps for preparing this long-afterglow luminescent material by melt blending are as follows: The luminescent molecules and polymethyl methacrylate are mixed, the system is heated to 170-250℃ to melt, and after cooling, a polymer-based long afterglow luminescent material doped with luminescent molecules is obtained.

[0022] Thirdly, the present invention provides an application of a polymer-based long afterglow luminescent material, which is achieved through the following technical solution.

[0023] Application of the above-mentioned polymer-based long afterglow luminescent material in display devices or lighting devices containing luminescent materials, optical anti-counterfeiting devices, information storage devices, 3D printing or bioimaging.

[0024] Fourthly, the present invention provides a display device or lighting device containing luminescent material, which is achieved through the following technical solution.

[0025] A display device or lighting device containing a luminescent material, wherein the luminescent material is selected from the aforementioned polymer-based long afterglow luminescent material.

[0026] Furthermore, the display device includes a static display device and a mobile display device; the static display device includes a television and a computer monitor; the mobile display device includes a mobile phone, a laptop computer, and a vehicle display.

[0027] Fifthly, the present invention provides an optical anti-counterfeiting device, which is achieved through the following technical solution.

[0028] An optical anti-counterfeiting device includes the aforementioned polymer-based long afterglow luminescent material.

[0029] Sixthly, the present invention provides an information storage device, which is achieved through the following technical solutions.

[0030] An information storage device includes the aforementioned polymer-based long afterglow luminescent material.

[0031] Seventhly, the present invention provides a 3D printing material, which is achieved through the following technical solution.

[0032] A 3D printing material comprising the aforementioned polymer-based long afterglow luminescent material.

[0033] Eighthly, the present invention provides an optical imaging probe, which is achieved through the following technical solution.

[0034] An optical imaging probe comprising the aforementioned polymer-based long afterglow luminescent material.

[0035] This application has the following beneficial effects.

[0036] (1) The polymethyl methacrylate (PMMA) materials doped with benzo[b]phenothiazine derivatives of the present invention all exhibit long afterglow phenomena in response to ultraviolet light, with the longest visible afterglow time reaching the hour level. The materials obtained by the present invention have excellent processability, transparency and flexibility, and can be used in fields such as environmentally friendly lighting, advanced anti-counterfeiting, information encryption and 3D printing.

[0037] (2) This invention provides two methods for preparing small molecule doped polymer-based long afterglow materials. It is particularly noted that in the solvent evaporation method, subsequent heat treatment has a significant impact on the long afterglow performance of the material. Attached Figure Description

[0038] Figure 1 The 1H NMR spectrum of the benzo[b]phenothiazine derivative prepared in Example 6 of this invention at room temperature in deuterated chloroform; Figure 2 The 1H NMR spectrum of the benzo[b]phenothiazine derivative prepared in Example 7 of this invention at room temperature in deuterated chloroform; Figure 3X-ray single-crystal structure diagram of the benzo[b]phenothiazine derivative prepared at room temperature in Example 6 of the present invention; Figure 4 The fluorescence spectrum, phosphorescence spectrum, absorption spectrum, and fluorescence spectrum of the benzo[b]phenothiazine derivatives prepared in Examples 2 and 6 of this invention at room temperature are shown. Figure 5 The electron spin resonance (ESR) spectra of the long afterglow materials prepared in Examples 2 and 6 of this invention at room temperature. Figure 6 The long afterglow brightness decay curve of the long afterglow material prepared in Example 6 of the present invention at room temperature; Figure 7 The images show the room-temperature long afterglow emission of the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) films prepared in Examples 1-3 of this invention. Figure 8 The images show the room-temperature long afterglow emission of the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) films prepared in Examples 4 and 5 of this invention. Figure 9 The images show the room-temperature long afterglow emission of the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) films prepared in Examples 6 and 7 of this invention. Figure 10 The image shows the room-temperature long afterglow emission of the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) film prepared by two methods in Example 6 of this invention. Figure 11 The thermoluminescence phenomenon of the long afterglow material prepared in Example 6 of the present invention at room temperature; Figure 12 The afterglow emission pattern and electron spin resonance (ESR) spectrum of BPTZ-BPO@PMMA material obtained under different heat treatment conditions of the present invention (Example 6); Figure 13 Room temperature long afterglow emission pattern of polymethyl methacrylate (PMMA) materials doped with benzo[b]phenothiazine derivatives prepared in Example 6 of the present invention for processing different shapes; Figure 14 Photograph of the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) thin film material prepared in Example 6 of the present invention under natural light. Detailed Implementation

[0039] The invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise specified, the experimental methods used in the embodiments of the present invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0040] The polymethyl methacrylate used in the following embodiments of this application was purchased from Tianjin Xins Biochemical Technology Co., Ltd. The benzo[b]phenothiazine derivative BPTZ-Ph used in the following embodiments of this application was purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.

[0041] Example 1: Preparation of BPTZ-Et@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative BPTZ-Et (structure as shown in Formula 1, synthesized according to the method provided by patent CN117209451A) and a polymethyl methacrylate host, with a mass ratio of 1:99.

[0042]

[0043] Formula 1 The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-Et solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by 1 mL of solvent. N,N -Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-Et.

[0044] Example 2: Preparation of BPTZ-Ph@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative BPTZ-Ph (structure shown in Formula 2) and a polymethyl methacrylate host, with a mass ratio of 1:99.

[0045]

[0046] Formula 2 The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-Ph solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by 1 mL of solvent. N,N - Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-Ph.

[0047] Example 3: Preparation of BPTZ-Ph / BP@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative BPTZ-Ph (structure shown in Formula 2), an additive benzophenone, and a polymethyl methacrylate host, wherein the mass ratio of the organic small molecule guest to the polymer host is 1:99, and the molar ratio of the organic small molecule guest to the additive is 1:1.

[0048] The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-Ph solid, 1.0 mg of benzophenone solid, and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by adding 1 mL of solvent. N,N - Dimethylformamide was stirred at 80°C until a clear solution was obtained. The solvent was evaporated at 80°C, and the resulting solid material was annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-Ph and BP. Compared with Example 2, the addition of benzophenone resulted in a blue shift in the afterglow color of the material, and a significant improvement in afterglow brightness and duration. Figure 7 ).

[0049] Example 4: Preparation of BPTZ-Ph-Br@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative BPTZ-Ph-Br (structure shown in Formula 3, synthesized according to the method provided by patent CN117209451A) and a polymethyl methacrylate host, with a mass ratio of 1:99.

[0050]

[0051] Formula 3 The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-Ph-Br solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by adding 1 mL of solvent. N,N -Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-Ph-Br.

[0052] Example 5: Preparation of BPTZ-Ph-CF3@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of the benzo[b]phenothiazine derivative BPTZ-Ph-CF3. The structure is shown in Formula 4 and is synthesized according to the method provided by patent CN117209451A. It consists of an organic small molecule guest and a polymethyl methacrylate host in a mass ratio of 1:99.

[0053]

[0054] Formula 4 The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-Ph-CF3 solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by adding 1 mL of solvent. N,N - Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-Ph-CF3.

[0055] Example 6: Preparation of BPTZ-Ph-BPO@PMMA by melt blending or solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative BPTZ-BPO (structure shown in Formula 5) and a polymethyl methacrylate host in a mass ratio of 1:99.

[0056]

[0057] Formula 5 The synthetic route of BPTZ-BPO is as follows:

[0058] In a 250 mL three-necked flask, add the nucleophile 12H-benzo[b]phenothiazine (BPTZ) (2.49 g, 10.0 mmol, 2.0 eq), the electrophile 4-bromobenzophenone (2.77 g, 10.5 mmol, 1.05 eq), Pd(OAc)₂ (46.0 mg, 0.2 mmol, 0.02 eq), cesium carbonate (6.58 g, 20.0 mmol, 2.0 eq), and ligand L B(222.0 mg, 0.4 mmol, 0.04 eq) and a magnetic wave were used, then the argon gas was purged three times, and an argon balloon was inserted. Toluene (50 mL) was then added to the system using a syringe, and the mixture was refluxed at 110 °C overnight. The reaction was monitored by TLC. After the reaction was complete, the mixture was filtered through diatomaceous earth, the solvent was evaporated, and then subjected to rapid column chromatography (PE / EA = 100:1 → 50:1) to obtain 2.75 g of a pale yellow solid product, with a yield of 64%. 1 H NMR (600 MHz, Methylene Chloride- d 2) δ 7.98 (d, J = 8.2 Hz, 3H), 7.85 (d, J = 8.4Hz, 1H), 7.71-7.59 (m, 3H), 7.58-7.49 (m, 4H), 7.46 (d, J = 8.3 Hz, 3H),7.39-7.28 (m, 2H), 7.24 (d, J = 7.6 Hz, 1H), 7.06 (t, J = 7.8 Hz, 1H), 6.98(t, J = 7.5 Hz, 1H), 6.93 (s, 2H), 6.66 (d, J = 8.1 Hz, 1H). The steps for preparing this long-afterglow luminescent material by melt blending are as follows: 1.0 mg of BPTZ-BPO powder and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder were mixed, the system was heated to 200℃ to melt, and after cooling, a polymer-based long afterglow luminescent material doped with BPTZ-BPO was obtained.

[0059] The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of BPTZ-BPO solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by 1 mL of solvent. N,N - Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with BPTZ-BPO.

[0060] Example 7: Preparation of 2BPTZ-Ph@PMMA by solvent blending This embodiment provides a polymer-based long afterglow luminescent material, which is composed of an organic small molecule guest of benzo[b]phenothiazine derivative 2BPTZ-Ph (structure shown in Formula 6) and a polymethyl methacrylate host, with a mass ratio of 1:99.

[0061]

[0062] Formula 6 The synthetic route for 2BPTZ-Ph is as follows:

[0063] In a 250 mL three-necked flask, add the nucleophile 12H-benzo[b]phenothiazine (BPTZ) (2.49 g, 10.0 mmol, 2.0 eq), the electrophile p-dibromobenzene (1.19 g, 5.0 mmol, 1.0 eq), Pd(OAc)2 (23.0 mg, 0.1 mmol, 0.02 eq), cesium carbonate (3.29 g, 10.0 mmol, 2.0 eq), and ligand L... B (111.0 mg, 0.2 mmol, 0.04 eq) and a magnetic field were added, then the argon gas was purged three times, and an argon balloon was inserted. Toluene (50 mL) was then added to the system using a syringe, and the mixture was refluxed at 110 °C overnight. TLC monitoring was performed. After the reaction was complete, the mixture was filtered through diatomaceous earth, the solvent was evaporated, and then subjected to rapid column chromatography (PE / EA = 100:1 → 50:1) to obtain 1.49 g of a pale yellow solid product, with a yield of 52%. 1 H NMR (600 MHz, Chloroform- d ) δ 7.69 (s, 4H), 7.60 (d, J = 8.0 Hz, 2H), 7.57 (s, 2H), 7.44(d, J = 8.1 Hz, 2H), 7.31 (t, J = 6.8 Hz, 2H), 7.27 (d, J = 7.5 Hz, 2H), 7.17(d, J = 7.6 Hz, 2H), 7.05-7.01 (m, 2H), 6.92 (s, 2H), 6.66 (s, 2H), 6.51 (d, J = 8.2 Hz, 2H). The steps for preparing this long-afterglow luminescent material by solvent blending are as follows: Add 1.0 mg of 2BPTZ-Ph solid and 99.0 mg of polymethyl methacrylate (PMMA, Mw=130000) powder to the sample vial according to the specified ratio, followed by 1 mL of solvent. N,N - Dimethylformamide, the system was stirred at 80°C to obtain a clear solution, the solvent was evaporated at 80°C to remove it, and the resulting solid material was heated and annealed at 170°C for 2 hours to obtain a polymer-based long afterglow luminescent material doped with 2BPTZ-Ph.

[0064] The benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) materials prepared by solvent blending in Examples 1-7 all exhibited long afterglow luminescence, such as... Figure 7-9 As shown, after irradiating the doped thin film with a 20 W ultraviolet lamp for 30 seconds and then turning off the ultraviolet lamp, a noticeable long afterglow can be observed with the naked eye. This characteristic can be used to make optical anti-counterfeiting materials and for information storage.

[0065] In Example 6, the benzo[b]phenothiazine derivative-doped polymethyl methacrylate (PMMA) material prepared by melt blending also exhibited long-afterglow luminescence. The melt-blended films have lower dispersion uniformity of small molecules, resulting in poor overall material homogeneity and inferior long-afterglow performance compared to solvent blending (e.g., Figure 10 (As shown). Furthermore, this method requires melting and processing at relatively high temperatures, which not only increases energy consumption but also introduces certain safety risks. Simultaneously, the high-temperature processing places higher demands on the heat resistance of the mold, limiting its application in actual production.

[0066] Due to their unique structural properties, phenothiazine derivatives are widely used as photosensitive small organic molecules or as excited-state electron donors; however, long-afterglow luminescent materials based on phenothiazine derivatives have not yet been reported. Furthermore, long-afterglow luminescent materials based on commercially available, low-cost, and photoelectron-inert polymer matrices have not been extensively studied. Currently, only five polymer-based hour-scale organic long-afterglow luminescent systems have been reported. Adv. Mater., 36 (2024), e2312439 ; Angew. Chem. Int. Ed., 64 (2025), e202421634 ; Chem. Sci., 14 (2023), 8180–8186 ; Angew. Chem. Int. Ed., 63 (2024), e202314500; Materials Today 88 (2025) 355–367 ) was reported. Among them, only one case used unmodified commercially available PMMA organic long-afterglow luminescent materials ( Materials Today 88 (2025) 355–367 The small doped molecules in this material act as excited-state electron acceptors, and the charge carriers in the material are positively charged, belonging to a p-type organic long afterglow system. According to... Figure 5Electron spin resonance (ESR) data show that the doped small molecule in this application acts as an electron donor, and the system's charge carriers are free electrons, belonging to an n-type organic long-afterglow system. This is the first reported n-type organic long-afterglow system based on a PMMA matrix. This invention effectively fills a gap in the field of polymer-based organic long-afterglow systems.

[0067] It is worth mentioning that this application reveals the necessity of introducing thermal annealing treatment when preparing polymer-based doped long afterglow materials by solvent blending. Figure 12 Comparing BPTZ-BPO@PMMA materials prepared by two solvent blending methods—one with and one without thermal annealing—it can be seen that although both materials exhibit visible afterglow, the afterglow duration of the thermally annealed material is significantly longer than that of the untreated material. Further electron spin resonance (ESR) spectroscopy data also indicate that no electron carrier generation was observed in the untreated system after ultraviolet light excitation.

[0068] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A polymer-based long afterglow luminescent material, characterized in that: The luminescent material is formed by doping luminescent molecules with a polymer matrix; the luminescent molecules are compounds having the following structure: ； Wherein, R is an alkyl, substituted or unsubstituted aryl group.

2. The polymer-based long afterglow luminescent material according to claim 1, characterized in that: Substituent R is a straight-chain, branched, or cyclic alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group.

3. The polymer-based long afterglow luminescent material according to claim 2, characterized in that: The alkyl substituent R is selected from methyl or ethyl.

4. The polymer-based long afterglow luminescent material according to claim 2, characterized in that: The phenyl substituent R is selected from 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 4-benzoylphenyl or 4-[(12H-benzo[b]phenthiazine-12-yl)phenyl].

5. The polymer-based long afterglow luminescent material according to claim 1, characterized in that: The doping ratio of luminescent molecules is 0.01%-10%.

6. The polymer-based long afterglow luminescent material according to claim 1, characterized in that: The polymer matrix is ​​selected from polymethyl methacrylate.

7. The polymer-based long afterglow luminescent material according to claim 1, characterized in that: The polymer-based long afterglow luminescent material is also doped with additives, and the molar ratio of the additives to the luminescent molecules is 0.001-1000:1; the additive is benzophenone.

8. A method for preparing a polymer-based long afterglow luminescent material according to any one of claims 1-7, characterized in that: The luminescent molecules are doped by solvent blending or melt blending. When using the solvent blending method, the luminescent molecules and polymer matrix are dissolved in an organic solvent. After removing the solvent, the material is thermally annealed at a temperature greater than or equal to the glass transition temperature of the polymer matrix material. After cooling, a long afterglow luminescent material is obtained. When using the melt blending method, the luminescent molecules and polymer matrix are mixed evenly, heated to melt and stirred evenly, and then cooled to obtain a long afterglow luminescent material.

9. The application of the polymer-based long afterglow luminescent material according to any one of claims 1-7 in display devices or lighting devices containing luminescent materials, optical anti-counterfeiting devices, information storage devices, 3D printing or bioimaging.

10. A display device or lighting device containing a luminescent material, characterized in that: The luminescent material is selected from any of the polymer-based long afterglow luminescent materials described in claims 1-7.

Images