Organic phosphorescent material and preparation method and application thereof

Abstract

The present invention relates to an organic phosphorescent material and a preparation method and application thereof, belonging to the technical field of functional polymer materials. The preparation method of the organic phosphorescent material of the present invention comprises the following steps: mixing a polyhydroxy polymer material, an aromatic phosphorescent molecule containing a boric acid group and an alkaline catalyst to obtain a mixture A; adding the obtained mixture A to a banbury mixer for banburying, the banburying temperature is 20-500°C, the rotation speed is 10-100rpm, the maximum torque is 10-80dNm, an esterification reaction occurs, and the reaction time is 0.1-24h, and the organic phosphorescent material is obtained. The preparation method of the present invention does not require the use of an organic solvent, is simple to operate, green and environmentally friendly, has high efficiency, and the synthesis process is easy to control, and can achieve large-scale preparation. The prepared organic phosphorescent material has the advantage of a long phosphorescence life, and can be applied to optical encryption, anti-counterfeiting technology, biological imaging, optoelectronic devices, and smart sensors.

Description

Technical Field

[0001] The invention belongs to the technical field of functional polymer materials, and in particular relates to an organic phosphorescent material and a preparation method and application thereof. Background Art

[0002] Long-life organic room temperature phosphorescent (RTP) materials have the advantages of long emission lifetime, high signal-to-noise ratio, no background fluorescence and scattered light interference, and large Stokes shift. They have broad application prospects in information security, bioimaging, optoelectronic devices, and smart sensors, and have received extensive attention in recent years. Compared with conventional fluorescence, the RTP phenomenon originates from the slow radiative transition of triplet excitons. Therefore, improving the intersystem crossing rate from the lowest excited singlet state (S1) to the excited triplet state and suppressing the non-radiative relaxation channel of the lowest excited triplet state (T1) are effective ways to achieve efficient RTP. Based on this, in the past few decades, scientists have designed efficient RTP materials based on these two key factors, introducing heavy atoms, aromatic carbonyls, and heteroatoms with abundant lone pairs of electrons to strengthen spin-orbit coupling, thereby effectively promoting the intersystem crossing (ISC) process; at the same time, a rigid environment is constructed to restrict intramolecular motion and intermolecular collisions to reduce excited state energy dissipation.

[0003] Among them, amorphous organic polymer materials with long-life RTP characteristics have the advantages of easy processing and good flexibility, so they are extremely advantageous in practical applications. The chain entanglement structure and long chain structure of the polymer form a rigid environment with multiple interactions. This rigid environment can effectively inhibit the non-radiative relaxation of triplet excitons and protect the triplet excitons from the influence of the surrounding environment, which is conducive to achieving ultra-long and high-efficiency RTP performance. Common polymer matrices mainly include: polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyacrylamide (PAM), poly-4-vinylpyridine (PVP), cellulose, chitosan, cyclodextrin and other macromolecules with strong intermolecular forces. There are three main ways to combine polymers with luminescent molecules: (1) embedding luminescent small molecules into polymer matrices by physical blending; (2) fixing the luminescent center on the polymer molecular chain by polymerization; (3) encapsulating the polymer luminophore into the cavity of the macrocycle. The interaction between the polymer and the luminescent molecule can effectively inhibit the non-radiative relaxation of triplet excitons and improve the RTP efficiency. Common interactions include hydrogen bonds, ionic bonds and covalent bonds (Yan Su, Yanli Zhao et al. Angew. Chem. Int. Ed. 2020, 59, 9967-9971; Xin Zhang, Jun Zhang et al. Nature Communications, 2022, 13, 1117; Long Gu, Yanli Zhao et al. J. Am. Chem. Soc. 2021, 143, 44, 18527-18535). Compared with hydrogen bonds and ionic bonds, covalent bonds are stronger and more stable, and the use environment of the prepared RTP materials is more demanding and has a wider range of uses. At present, the main way to obtain RTP polymers by covalent bonds is the copolymerization of polymer monomers and organic luminescent small molecules. However, the use of organic solvents in the polymerization process and the limited structural monomers that can be used for polymerization make it limited to the requirements of green chemistry and cannot be prepared on a large scale. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an organic phosphorescent material and a preparation method and application thereof. The preparation method does not require the use of organic solvents, has the advantages of high efficiency and environmental protection, can prepare organic phosphorescent materials on a large scale, and the prepared organic phosphorescent materials have the characteristics of long phosphorescence life.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a method for preparing an organic phosphorescent material, comprising the following steps:

[0007] (1) mixing a polyhydroxy polymer material, an aromatic phosphorescent molecule containing a boric acid group, and a basic catalyst to obtain a mixture A;

[0008] (2) Adding the mixture A obtained in step (1) into an internal mixer for internal mixing, the internal mixing temperature is 20-500° C., the rotation speed is 10-100 rpm, the maximum torque is 10-80 dNm, and an esterification reaction occurs for a reaction time of 0.1-24 h to obtain the organic phosphorescent material.

[0009] The polyhydroxy polymer material of the present invention is a polymer material containing multiple hydroxyl groups in its structure, and the aromatic phosphorescent molecule containing a boric acid group refers to a long afterglow material containing a boric acid group in its molecular structure. The preparation method of the present invention is based on the presence of an alkaline catalyst, and the polyhydroxy polymer polymer and the boric acid long afterglow molecule are melted and high sheared in an internal mixer to undergo an esterification reaction, and the one-step method realizes the effective fixation of the long afterglow molecule on the polymer chain, thereby reducing the non-radiative transition of the triplet state and effectively improving the excited state gap crossing.

[0010] The esterification reaction of the polymer molecules and the aromatic phosphorescent molecules containing boric acid groups of the present invention is carried out in an internal mixer. When the temperature condition in the internal mixer is set to near the glass transition temperature of the corresponding material during internal mixing, the hydroxyl groups on the polymer chain react with the boric acid groups on the organic light-emitting molecules to fix the light-emitting groups on the polymer chain through borate ester bonds. The effective covalent bond link and the rigid environment provided by the polyhydroxy polymer can effectively inhibit the non-radiative relaxation of triplet excitons and protect the triplet excitons from being affected by the surrounding environment, which is conducive to achieving ultra-long and high-efficiency RTP performance and fundamentally solves the problems of the use of organic solvents and large-scale preparation in the copolymerization process.

[0011] The preparation method of the present invention can select different types of polyhydroxy polymer materials and different types of aromatic phosphorescent molecules containing boric acid groups as raw materials. By controlling the parameter conditions during mixing, organic phosphorescent materials with different phosphorescence lifetimes can be obtained. The phosphorescence lifetime of the obtained organic phosphorescent materials can reach 652ms-2056ms.

[0012] The preparation method of the present invention does not require the use of organic solvents, has simple process, mild reaction conditions, is green and environmentally friendly, has high efficiency, and the synthesis process is easy to control and can be mass-produced.

[0013] Preferably, in step (2), the temperature of the banburying is 80-300°C.

[0014] Preferably, in step (2), the banburying temperature is 180-220°C, the rotation speed is 30-50rpm, and the maximum torque is 10-15dNm. Under the banburying temperature conditions, it can better match the glass transition temperature of the raw materials, and under the conditions, a good esterification reaction effect can be obtained, the energy consumption cost can be reduced, and the prepared organic phosphorescent material has a good phosphorescence life of 680ms-1270ms.

[0015] Preferably, in step (2), the kneading temperature is set to 180° C., the rotation speed is set to 30 rpm, and the maximum torque is set to 10 dNm. The phosphorescence lifetime of the phosphorescent material prepared under these conditions is above 1260 ms.

[0016] Preferably, in step (1), the polyhydroxy polymer material is at least one of cellulose, starch, chitosan, chitin, polyvinyl alcohol, polyacrylic acid, and polyvinyl alcohol-polyacrylic acid block copolymer.

[0017] The cellulose used in the polyhydroxy polymer material of the present invention is a melt-processable cellulose material with a melting temperature range of 20-500° C., which is suitable for the banburying process of the present invention.

[0018] Preferably, the alkaline catalyst is at least one of 1,1,3,3-tetramethylguanidine, triethylamine, K2CO3, Cs2CO3, LiCl, and Na2CO3.

[0019] Preferably, the structural formula of the aromatic phosphorescent molecule containing a boric acid group is any one of the structures of series A, B, C, and D:

[0020] A Series:

[0021]

[0022] In the A series structure, R is N, P, As atom; R' is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH,

[0023] Any of the following:

[0024] B Series:

[0025]

[0026] In the B series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH,

[0027] Any of the following:

[0028] C Series:

[0029]

[0030] In the C series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH,

[0031] Any of the following:

[0032] D Series:

[0033]

[0034] In the D series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH,

[0035] Any one of .

[0036] Preferably, in step (1), the polyhydroxy polymer material is at least one of chitosan, polyvinyl alcohol and polyacrylic acid; and the alkaline catalyst is triethylamine.

[0037] Preferably, the structural formula of the aromatic phosphorescent molecule containing a boronic acid group is any one of the D series structures.

[0038] Preferably, the aromatic phosphorescent molecule containing a boronic acid group is 9-phenanthreneboric acid.

[0039] The inventors have found through experiments that different polyhydroxy polymer materials can be used to obtain organic phosphorescent materials with different phosphorescence lifespans. When polyhydroxy polymer materials are selected as polyvinyl alcohol, polyacrylic acid and chitosan, the obtained organic phosphorescent materials have a lifespan of more than 1000ms. When polyvinyl alcohol with different alcoholysis degrees is selected as the raw material, the higher the alcoholysis degree of the polyvinyl alcohol is, the longer the lifespan of the obtained polymer phosphorescent material is. When the aromatic phosphorescent molecule containing a boric acid group is selected as 9-phenanthrene boric acid, under the same preparation conditions, an organic phosphorescent material with a longer lifespan can be obtained, and the lifespan can reach more than 2000ms.

[0040] Preferably, in step (1), the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the polyhydroxy polymer material is (0.01-10):100, and the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the alkaline catalyst is 1:(0.5-10).

[0041] Preferably, in step (1), the mass ratio of the aromatic phosphorescent molecule containing a boronic acid group to the polyhydroxy polymer material is (0.1-1):100, and the mass ratio of the aromatic phosphorescent molecule containing a boronic acid group to the alkaline catalyst is 1:(1-3). When the raw material ratio is selected, a faster esterification reaction rate can be obtained and the esterification reaction time can be shortened.

[0042] Preferably, in step (2), the esterification reaction time is 0.5-5h.

[0043] In a second aspect, the present invention provides an organic phosphorescent material prepared by the above preparation method.

[0044] The preparation method of the present invention is applicable to raw materials of different types of polyhydroxy polymer materials and aromatic phosphorescent molecules containing boric acid groups, and the obtained organic phosphorescent material is an organic room temperature (20-30°C) phosphorescent material, which can emit phosphorescence under ultraviolet light irradiation. The obtained organic phosphorescent material has excellent phosphorescent properties and a long phosphorescent life.

[0045] In a third aspect, the present invention provides the use of the above-mentioned organic phosphorescent material in the preparation of optical encryption, anti-counterfeiting technology, bio-imaging, optoelectronic devices and smart sensor materials.

[0046] Preferably, the application comprises the following steps:

[0047] S1, cutting and granulating the organic phosphorescent material prepared above to obtain polymer particles;

[0048] S2, obtaining a polymer solution by a solvent method or obtaining a melt-processable polymer material by a melting method from the polymer particles obtained in step S1;

[0049] S3, further processing the polymer solution or polymer material obtained in step S2 to form a structural pattern or device;

[0050] S4. Apply the structure pattern or device obtained in step S3 to the fields of optical encryption, anti-counterfeiting technology, bio-imaging, optoelectronic devices and smart sensors.

[0051] When the organic phosphorescent material of the present invention is used, the polymer organic phosphorescent material is first cut and granulated to obtain polymer particles, which can facilitate the storage and application of the material. On the one hand, the obtained polymer particles can be dissolved by a solvent method to obtain a polymer solution, and the polymer solution is further processed to obtain a customized structural pattern or device; on the other hand, the obtained polymer particles can also be melt-processed to obtain a melt-processable polymer material by a melting method, such as preparing a polymer fiber with a long afterglow property by melt spinning, and then preparing a customized structural pattern or device by a mold hot pressing method, which is used for optical encryption, anti-counterfeiting technology, biological imaging and other applications.

[0052] Preferably, in step S1, the polymer particles are cylindrical particles or round particles.

[0053] Preferably, in step S1, the cutting and granulation method is any one of a sheet pulling cold cutting method, a sheet extrusion cold cutting method, a strip extrusion cold cutting method, a dry hot cutting method, an underwater hot cutting method and an aerial hot cutting method.

[0054] Preferably, in step S2, the solvent used in the solvent method is at least one of water, ethanol, methanol, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), tetramethyl urea, tetraethyl urea, N,N-dimethylimidazolidinone, N,N-dimethylformamide, N,N-diethylacetamide, pyrrolidone, 2-azolopyridine, ε-caprolactam, N,N-dimethylpropylene urea, cyclopentane sulfone and isobutylene sulfone.

[0055] Preferably, the solvent used in the solvent method is at least one of water, dimethyl sulfoxide (DMSO), N,N-dimethylimidazolidinone, N,N-dimethylformamide, sulfolane, and piperyl sulfone.

[0056] Preferably, in the step S1, the mass fraction of the organic phosphorescent material solute in the polymer solution is 0.1-30%.

[0057] Preferably, the mass fraction of the organic phosphorescent material solute in the polymer solution is 2-20%.

[0058] Preferably, the polymer solution is used as ink to obtain corresponding structural patterns or devices through writing, screen printing, inkjet printing, spray printing, 3D printing, scraping and other technologies for applications such as optical encryption, anti-counterfeiting technology, and biological imaging.

[0059] Preferably, the melting method is a melt spinning method. The polymer particles can be melt-spinned to prepare polymer fibers with long afterglow properties, and then mold hot pressing can be used to prepare customized structural patterns or devices for applications such as optical encryption, anti-counterfeiting technology, and biological imaging.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] (1) The present invention prepares organic phosphorescent materials through a banburying process without using organic solvents, has simple process, mild reaction conditions, is green and environmentally friendly, has high efficiency, and is easy to control during the synthesis process, and can achieve large-scale preparation. The present invention selects specific polyhydroxy polymer materials and specific aromatic phosphorescent molecules containing boric acid groups as raw materials, controls the process parameters during banburying, and obtains an organic phosphorescent material with a long phosphorescent life and good stability.

[0062] (2) When the organic phosphorescent material of the present invention is used, it is first cut and granulated, which facilitates the storage and application of the material. It can be customized and applied to the fields of optical encryption, anti-counterfeiting technology, bio-imaging, optoelectronic devices and smart sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 The figure is a flow chart for preparing the organic phosphorescent material of the present invention.

[0064] Figure 2 These are the effect diagrams of the organic phosphorescent material described in Effect Example 1 under ultraviolet light irradiation and after the ultraviolet light is turned off. DETAILED DESCRIPTION

[0065] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation methods of the present invention are not limited thereto.

[0066] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0067] Example 1

[0068] An embodiment of the method for preparing the organic phosphorescent material of the present invention specifically comprises the following steps:

[0069] Weigh 100 g of polyvinyl alcohol with a degree of alcoholysis of 78%, 3 g of organic base triethylamine and 1 g of 4-biphenylboric acid, and add them together into an internal mixer. The internal mixer is maintained at a temperature of 180° C., a rotation speed of 30 rpm and a maximum torque of 10 dNm for internal mixing to cause esterification reaction. The reaction time is 1 hour to obtain a polymer phosphorescent material (the organic phosphorescent material).

[0070] Example 2

[0071] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 1 except that the alcoholysis degree of the selected polyvinyl alcohol is 88%.

[0072] Example 3

[0073] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 1 except that the alcoholysis degree of the selected polyvinyl alcohol is 98%.

[0074] The polymer phosphorescent materials prepared in Examples 1-3 were hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 1.

[0075] Table 1

[0076]

[0077] It can be seen from Table 1 that when the alcoholysis degree of the selected polyvinyl alcohol is higher, the lifetime of the obtained polymer phosphorescent material is longer.

[0078] Example 4

[0079] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of Embodiment 2 except that the polyhydroxy polymer selected is polyacrylic acid.

[0080] Example 5

[0081] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of Embodiment 2 except that the polyhydroxy polymer selected is a polyacrylic acid-polyacrylamide copolymer.

[0082] Example 6

[0083] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 2 except that the polyhydroxy polymer selected is hydroxyethyl cellulose.

[0084] Example 7

[0085] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 2 except that the polyhydroxy polymer selected is a thermoplastic chitosan derivative.

[0086] The polymer phosphorescent materials prepared in Examples 4-7 were hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 2.

[0087] Table 2

[0088]

[0089] It can be seen from Table 2 that the polymer phosphorescent materials obtained from different types of polyhydroxy polymers have different lifespans. When polyvinyl alcohol, polyacrylic acid and thermoplastic chitosan derivatives are selected, the polymer phosphorescent materials prepared under the same preparation conditions have a longer phosphorescent lifespan.

[0090] Example 8

[0091] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of Embodiment 2 except that the aromatic phosphorescent molecule containing the boronic acid group is 9-phenanthreneboric acid.

[0092] Example 9

[0093] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of Embodiment 2 except that the aromatic phosphorescent molecule containing a boronic acid group is 4-isoquinoline borate.

[0094] The polymer phosphorescent material prepared in Examples 8-9 was hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 3.

[0095] Table 3

[0096]

[0097] As shown in Table 3, the lifetimes of the polymer phosphorescent materials obtained by using boric acid-based phosphorescent molecules with different structures vary greatly. When 9-phenanthreneboric acid is used, the lifetime of the obtained polymer phosphorescent material reaches 2056 ms; when 4-isoquinolineborate is used, the lifetime of the obtained polymer phosphorescent material is shorter.

[0098] Example 10

[0099] An embodiment of the method for preparing the organic phosphorescent material of the present invention specifically comprises the following steps:

[0100] Weigh 100 g of polyvinyl alcohol with a degree of alcoholysis of 88%, 3 g of organic base triethylamine and 1 g of 4-biphenylboric acid, and add them into an internal mixer. Maintain the mixer temperature at 160°C, rotate at 30 rpm and perform internal mixing at a maximum torque of 10 dNm. Esterification reaction occurs for 1 hour to obtain a polymer phosphorescent material.

[0101] Embodiment 11

[0102] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 10 except that the mixing temperature is 200°C.

[0103] Example 12

[0104] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 10 except that the mixing temperature is 220°C.

[0105] The polymer phosphorescent materials prepared in Examples 10-12 were hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 4.

[0106] Table 4

[0107]

[0108] It can be seen from Table 4 that when the mixing temperature is 180°C, the obtained polymer phosphorescent material has a longer phosphorescent lifetime.

[0109] Embodiment 13

[0110] An embodiment of the method for preparing the organic phosphorescent material of the present invention specifically comprises the following steps:

[0111] Weigh 100 g of polyvinyl alcohol with a degree of alcoholysis of 88%, 3 g of organic base triethylamine and 1 g of 4-biphenylboric acid, and add them into an internal mixer. Maintain the temperature of the internal mixer at 180°C, and perform internal mixing at a speed of 10 rpm and a maximum torque of 10 dNm. Esterification reaction occurs for 1 hour to obtain a polymer phosphorescent material.

[0112] Embodiment 14

[0113] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 13 except that the rotation speed during kneading is 20 rpm.

[0114] Embodiment 15

[0115] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as that of embodiment 13 except that the rotation speed during kneading is 40 rpm.

[0116] Example 16

[0117] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as Embodiment 13 except that the rotation speed during kneading is 50 rpm.

[0118] The polymer phosphorescent materials prepared in Examples 13-16 were hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 5.

[0119] Table 5

[0120]

[0121] It can be seen from Table 5 that different rotation speed conditions during internal mixing have a great influence on the life of the obtained polymer phosphorescent material. When the rotation speed is slow, the life of the obtained phosphorescent material is more than 680ms. When the rotation speed is 30rpm, the phosphorescence life is the longest, reaching more than 1260ms. If the rotation speed continues to increase, the life of the polymer phosphorescent material will be shortened.

[0122] Embodiment 17

[0123] An embodiment of the method for preparing the organic phosphorescent material of the present invention specifically comprises the following steps:

[0124] Weigh 100 g of polyvinyl alcohol with a degree of alcoholysis of 88%, 3 g of organic base triethylamine and 1 g of 4-biphenylboric acid, and add them into an internal mixer. The temperature of the internal mixer is maintained at 180°C, the speed is 30 rpm, and the internal mixer is kneaded at a maximum torque of 5 dNm. Esterification reaction occurs for 1 hour to obtain a polymer phosphorescent material.

[0125] Embodiment 18

[0126] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as Embodiment 17 except that the maximum torque is 8 dNm.

[0127] Embodiment 19

[0128] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as Embodiment 17 except that the maximum torque is 12 dNm.

[0129] Embodiment 20

[0130] An embodiment of the method for preparing the organic phosphorescent material of the present invention is the same as Embodiment 17 except that the maximum torque is 15 dNm.

[0131] The polymer phosphorescent materials prepared in Examples 17-20 were hot pressed to prepare film samples. The prepared films were observed to have a long afterglow phenomenon under ultraviolet light of different wavelengths. The lifespan of the samples was tested respectively. The measured performance results are shown in Table 6.

[0132] Table 6

[0133]

[0134] It can be seen from Table 6 that as the maximum torque increases, the lifetime of the obtained polymer phosphorescent material first increases and then decreases. When the maximum torque is 10 dNm, the phosphorescence lifetime is the longest, reaching more than 1260 ms.

[0135] Embodiment 21

[0136] The examples of preparing organic phosphorescent materials by the preparation method of the present invention and the traditional method, and the specific test methods are as follows.

[0137] Sample preparation:

[0138] Sample 1: The polymer phosphorescent material prepared in Example 2 was hot-pressed to prepare a thin film sample, which was recorded as Sample 1.

[0139] Sample 2: A polymer phosphorescent material was obtained according to the preparation method described in Example 2, and then the prepared polymer phosphorescent material was cut and granulated to obtain polymer particles. The polymer particles were prepared into a polymer aqueous solution with a mass concentration of 5% to prepare a film, which was recorded as Sample 2.

[0140] Sample 3: The polymer phosphorescent material prepared in Example 7 was hot-pressed to prepare a thin film sample, which was recorded as Sample 3.

[0141] Control sample 1: Weigh 5 g of polyvinyl alcohol with a degree of alcoholysis of 88%, dissolve it in 95 g of water to prepare a polyvinyl alcohol aqueous solution with a mass concentration of 5%, add 3 g of triethylamine and 1 g of 4-biphenylboric acid, stir and react for 1 hour, and prepare a film material after obtaining a homogeneous solution, which is recorded as control sample 1.

[0142] Control sample 2: Use 95g DMSO to dissolve 5g of thermoplastic chitosan derivative to prepare a thermoplastic chitosan derivative solution with a mass concentration of 5%, add 3g triethylamine and 1g 4-biphenylboric acid, react at 80°C for 12h, use deionized water for reverse precipitation and washing, and after drying, hot press the prepared sample to prepare a film, which is recorded as control sample 2.

[0143] Then at the same excitation wavelength (λ ex =300nm), the lifespans of three samples and two control samples were tested respectively, and the performance results are shown in Table 7.

[0144] Table 7

[0145]

[0146] It can be seen from Table 7 that, compared with the long afterglow material prepared by the traditional method, the life of the polymer phosphorescent material obtained by the preparation method of the present invention is significantly better than that of the polymer phosphorescent material prepared by the traditional method.

[0147] Effect Example 1

[0148] An example of the effect of customized application of the organic phosphorescent material of the present invention.

[0149] The polymer phosphorescent material prepared in Example 2 is cut and granulated to obtain polymer particles; the polymer particles are prepared into a polymer aqueous solution of a certain concentration, which is used as ink to obtain a customized structural pattern by handwriting or printing technology, and the information is encrypted and displayed, and the effect is as follows: Figure 2 shown.

[0150] Depend on Figure 2 It can be seen that when the polymer phosphorescent material prepared by the present invention is used as ink, there is no obvious change under sunlight, and it emits blue phosphorescence under ultraviolet irradiation. The structural pattern can still be clearly seen 2 seconds after the ultraviolet irradiation is turned off, indicating that the prepared polymer phosphorescent material has excellent phosphorescent properties. When the polymer phosphorescent material of the present invention is used, its pattern can be customized, and it can be applied to the fields of optical encryption, anti-counterfeiting technology, biological imaging, optoelectronic devices and smart sensors.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above descriptions and ideas. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing an organic phosphorescent material, characterized in that: The steps include: (1) mixing a polyhydroxy polymer material, an aromatic phosphorescent molecule containing a boric acid group, and a basic catalyst to obtain a mixture A; (2) adding the mixture A obtained in step (1) into an internal mixer for internal mixing at a temperature of 180-220° C., a rotation speed of 30-50 rpm, a maximum torque of 10-15 dNm, and causing an esterification reaction for a reaction time of 0.1-24 h to obtain the organic phosphorescent material; The alkaline catalyst is at least one of 1,1,3,3-tetramethylguanidine, triethylamine, K2CO3, Cs2CO3, LiCl, and Na2CO3.

2. The method for preparing an organic phosphorescent material according to claim 1, characterized in that: In the step (2), the kneading temperature is 180° C., the rotation speed is 30 rpm, and the maximum torque is 10 dNm.

3. The method for preparing an organic phosphorescent material according to claim 1, characterized in that: In the step (1), the polyhydroxy polymer material is at least one of cellulose, starch, chitosan, chitin, polyvinyl alcohol, polyacrylic acid, and polyvinyl alcohol-polyacrylic acid block copolymer; The structural formula of the aromatic phosphorescent molecule containing a boric acid group is any one of the structures of series A, B, C, and D: A Series: In the A series structure, R is N, P, As atom; R' is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH, Any of the following: B Series: In the B series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH, Any of the following: C Series: In the C series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH, Any of the following: D Series: In the D series structure, R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -CHO, -SO3, -COOH, Any one of .

4. The method for preparing an organic phosphorescent material according to claim 3, characterized in that: In the step (1), the polyhydroxy polymer material is at least one of chitosan, polyvinyl alcohol, and polyacrylic acid; the alkaline catalyst is triethylamine; and the structural formula of the aromatic phosphorescent molecule containing a boric acid group is any one of the D series structures.

5. The method for preparing an organic phosphorescent material according to claim 1, characterized in that: In the step (1), the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the polyhydroxy polymer material is (0.01-10):100, and the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the alkaline catalyst is 1:(0.5-10).

6. The method for preparing an organic phosphorescent material according to claim 5, characterized in that: In the step (1), the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the polyhydroxy polymer material is (0.1-1):100, and the mass ratio of the aromatic phosphorescent molecules containing boronic acid groups to the alkaline catalyst is 1:(1-3).

7. An organic phosphorescent material prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the organic phosphorescent material as claimed in claim 7 in the preparation of optical encryption, anti-counterfeiting technology, bio-imaging, optoelectronic devices and intelligent sensor materials.

9. The use according to claim 8, characterized in that The application comprises the following steps: S1. Cutting and granulating the organic phosphorescent material according to claim 7 to obtain polymer particles; S2, obtaining a polymer solution by a solvent method or obtaining a melt-processable polymer material by a melting method from the polymer particles obtained in step S1; S3, further processing the polymer solution or polymer material obtained in step S2 to form a structural pattern or device; S4. Apply the structure pattern or device obtained in step S3 to the fields of optical encryption, anti-counterfeiting technology, bio-imaging, optoelectronic devices and smart sensors.

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