Chiral phosphorescent material, preparation method and application thereof

Abstract

The application discloses a chiral phosphorescent material, which comprises an organic matter A and an ionic polysaccharide derivative with the structure shown in the following formula I. The chiral phosphorescent material is prepared by the ionic polysaccharide derivative and the organic matter A for the first time. The ionic polysaccharide derivative provides a chiral environment, transmits chirality and limits the movement of light particles. The change of the chemical structure and the aggregation state of the organic matter A can control the phosphorescent emission of the chiral phosphorescent material. The chiral phosphorescent material is a full-color chiral phosphorescent polymer material. The chiral phosphorescent material covers a wide color gamut from blue to yellow, green, orange and red. The excellent water solubility and processing formability can prepare a complex and diverse circularly polarized phosphorescent pattern as a coating, and show great application prospects. The universal chiral transmission strategy provides a new way for expanding the chiral phosphorescent material.

Description

Technical Field

[0001] This invention relates to a chiral phosphorescent material, its preparation method, and its application, belonging to the technical fields of organic optical materials and functional polymer materials. Background Technology

[0002] Circularly polarized luminescent materials, due to their excellent optical sensitivity and spatial resolution, hold promising applications in 3D displays, bioimaging, optoelectronic devices, anti-counterfeiting materials, and asymmetric photocatalysis. Organic room-temperature phosphorescent materials have attracted increasing attention due to their long emission lifetime, high signal-to-noise ratio, and multiple excited-state characteristics. Circularly polarized organic room-temperature phosphorescent materials, as novel chiral optical materials, possess both long emission lifetime, unique photophysical properties, and circularly polarized luminescence characteristics, and have garnered widespread interest. However, the preparation of circularly polarized room-temperature phosphorescent materials requires simultaneously satisfying three conditions: promoting intersystem crossing, suppressing nonradiative transitions, and forming stable chiral triplet states. Therefore, their preparation still faces significant challenges.

[0003] Existing methods for preparing circularly polarized organic room-temperature phosphorescent materials suffer from problems such as cumbersome processes, limited applicability, and energy loss. Therefore, developing simple and universal new methods is crucial for the expansion and application of chiral phosphorescent materials. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a chiral phosphorescent material, its preparation method, and its applications. The chiral phosphorescent material is made from natural polysaccharides. By introducing anionic groups to promote intersystem crossing, an ionic polysaccharide derivative with a helical structure as shown in Formula I is obtained. After doping with different organic compounds A, chiral phosphorescent materials of different colors are obtained. These materials can be made into circularly polarized phosphorescent films, coatings, and inks, and have significant application prospects in fields such as anti-counterfeiting, encryption, and 3D display.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] Chiral phosphorescent materials, comprising organic compound A and an ionic polysaccharide derivative having the structure shown in Formula I,

[0007]

[0008] Among them: A1, A2, and A3 may be the same or different, and are independently selected from H and -C. 1-12 Alkylene-COOP or -C(=O)-C 6-20 Aspartic-(COOP) nFurthermore, A1, A2, and A3 are not all H at the same time; P may be the same or different and is independently selected from one of Li, Na, K, Rb, or Cs; n is 1, 2, 3, or 4; DP (degree of aggregation) is an integer from 50 to 5000.

[0009] Wherein, the organic compound A is selected from at least one of the following structures:

[0010]

[0011] Sodium hexabenzoate or cesium hexabenzoate;

[0012] cation For: Na + Li + K + 、Rb + or Cs + At least one of them.

[0013] According to an embodiment of the present invention, A1, A2, and A3 may be the same or different, and are independently selected from H and -C. 1-6 Alkylene-COOP or -C(=O)-C 6-12 Aspartic-(COOP) n ;

[0014] According to embodiments of the present invention, A1, A2, and A3 may be the same or different, and are independently selected from H, -CH2COONa, -C(=O)-Ph-(COONa)2, -C(=O)-Ph-COONa, -C(=O)-Ph-(COOK)2, -C(=O)-Ph-(COOCs)2, -C(=O)-Ph-(COOLi)2, -C(=O)-naphthalene-COONa, or -C(=O)-biphenyl-COONa.

[0015] According to an embodiment of the present invention, the organic compound A is, for example, lithium 1,4,5,8-naphthalenetetracarboxylate, sodium hexacarboxylate, lithium 2,6-naphthalenedicarboxylate, rhodamine B, or cesium hexacarboxylate.

[0016] According to an embodiment of the present invention, in the structure shown in Formula I, the main chain is a natural polysaccharide, and the natural polysaccharide is at least one of cellulose, starch, pullulan, and dextran.

[0017] According to an embodiment of the present invention, the DP is an integer from 100 to 4000, such as 100, 220, 400, 500, 600, 650, 800, 1000, 2000, 3000 or 4000.

[0018] According to an embodiment of the present invention, the mass ratio of the ionic polysaccharide derivative of Formula I to organic compound A is (5-1000):1, preferably 15-400:1, and exemplary ratios are 15:1, 20:1, 30:1, 50:1, 60:1, 80:1, 100:1, 120:1, 130:1, 150:1, 160:1, 180:1, 200:1, 300:1, 350:1 or 400:1.

[0019] According to an embodiment of the present invention, the degree of substitution of the functional group -COOP in the ionic polysaccharide derivative with the structure shown in Formula I is 0.5-2.0, for example 0.7-1.8, such as 0.63, 0.7, 0.89, 0.82, 1, 1.2, 1.3, 1.5, 1.53 or 1.72.

[0020] This invention also provides a method for preparing the chiral phosphorescent material as described above, comprising the following steps:

[0021] (1) Prepare the ionic polysaccharide derivative with the structure shown in Formula I;

[0022] (2) The ionic polysaccharide derivative with the structure shown in Formula I is mixed with organic A to prepare a chiral phosphorescent material.

[0023] According to an embodiment of the present invention, the specific preparation method of step (1) includes:

[0024] (S1) Dissolve natural polysaccharides in ionic liquids, add esterification reagents and catalysts and mix to obtain polysaccharide esters;

[0025] (S2) The polysaccharide ester is mixed with an aqueous solution of an alkali metal salt and precipitated with ethanol to prepare an ionic polysaccharide derivative with the structure shown in Formula I.

[0026] According to the implementation scheme of this method, in step (S1), the ionic liquid is selected from at least one of the following, including but not limited to: 1-ethyl-3-methylimidazolium chloride ionic liquid, 1-ethyl-3-methylimidazolium bromide ionic liquid, 1-allyl-3-methylimidazolium chloride ionic liquid, 1-allyl-3-methylimidazolium bromide ionic liquid, 1-butyl-3-methylimidazolium chloride ionic liquid, 1-butyl-3-methylimidazolium bromide ionic liquid, 1-ethyl-3-methylimidazolium acetate ionic liquid, 1-... Propyl-3-methylimidazolium acetate ionic liquid, 1-butyl-3-methylimidazolium acetate ionic liquid, N-ethylpyridinium chloride ionic liquid, 1,3-dimethylimidazolium dimethyl phosphate ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid, N-ethylpyridinium bromide ionic liquid, 3-methylimidazolium carboxylate ionic liquid, N-methylpyridinium carboxylate ionic liquid, 1-ethyl-3-methylimidazolium carboxylate ionic liquid, or 1-butyl-3-methylimidazolium carboxylate ionic liquid;

[0027] According to the implementation scheme of this method, in step (S1), the esterification reagent is at least one of trimellitic anhydride or phthalic anhydride.

[0028] According to an embodiment of this method, in step (S1), the catalyst is 4-dimethylaminopyridine (DMAP). Preferably, the amount of the catalyst is 0.02-4 wt% of the natural polysaccharide, more preferably 0.05-3 wt%.

[0029] Preferably, in step (S1), the mass fraction of the natural polysaccharide in the ionic liquid is 5% to 15%, for example 5%, 6%, 8%, 12%, 14% or 15%.

[0030] Preferably, in step (S1), the molar ratio of the natural polysaccharide to the esterification reagent is 3:1 to 1:5, for example, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4 or 1:5.

[0031] Preferably, in step (S1), the temperature of the mixing reaction is 60-90°C, for example 60°C, 70°C, 80°C or 90°C. Further, the mixing time can be 5-10 hours, for example 5 hours, 7 hours, 8 hours or 9 hours.

[0032] Preferably, in step (S2), the alkali metal salt is selected from at least one of Li2CO3, NaHCO3, K2CO3, Cs2CO3, Rb2CO3, NH4HCO3 or (C(NH2)3)2CO3.

[0033] According to the implementation plan of this method, in step (2), there are no special limitations on the mixing temperature and time, as long as the mixed solution is visually free of particulate matter.

[0034] According to the implementation scheme of this method, the method further includes a post-processing step after step (2): drying the prepared product, preferably at a temperature of 40-70°C, for example 40°C, 50°C, 60°C or 70°C.

[0035] The present invention also provides the use of the chiral phosphorescent materials described above in anti-counterfeiting, encryption and 3D display.

[0036] The present invention also provides a thin film comprising the chiral phosphorescent material.

[0037] The present invention also provides a method for preparing the thin film, wherein the method comprises: dissolving the chiral phosphorescent material in water, coating the prepared solution onto a substrate, and thus preparing the thin film.

[0038] In the method for preparing the thin film, the concentration of the chiral phosphorescent material in water is 5-10 wt%.

[0039] In the method for preparing the thin film, the substrate is, for example, glass.

[0040] In the method for preparing the thin film, the method may employ a film scraper to scrape the film.

[0041] The present invention also provides a coating comprising the chiral phosphorescent material.

[0042] The present invention also provides a method for preparing the coating, wherein the method comprises: dissolving the chiral phosphorescent material in water, and then mixing it with the remaining coating components to obtain the coating.

[0043] According to an embodiment of the present invention, the concentration of the chiral phosphorescent material in water in the coating is 1-10 wt%.

[0044] According to an embodiment of the present invention, the concentration of the chiral phosphorescent material in the coating is 1-10 wt%.

[0045] The beneficial effects of this invention are:

[0046] This invention marks the first time that chiral phosphorescent materials have been prepared using ionic polysaccharide derivatives and organic compound A. The ionic polysaccharide derivatives provide a chiral environment, transfer chirality, and confine the movement of photons. Changes in the chemical structure and aggregation state of organic compound A can control the phosphorescence emission of the chiral phosphorescent material. The chiral phosphorescent material is a full-color chiral phosphorescent polymer. It covers a wide color gamut, from blue to yellow, green, orange, and red. Its excellent water solubility and processability allow it to be used as a coating to prepare complex and diverse circularly polarized phosphorescent patterns, demonstrating great application potential. This universal chiral transfer strategy provides a new avenue for expanding the development of chiral phosphorescent materials. Attached Figure Description

[0047] Figure 1 The image shows the circularly polarized emission spectrum of the chiral phosphorescent material in Example 1.

[0048] Figure 2 The phosphorescence spectrum of the chiral phosphorescent material in Example 1 is shown.

[0049] Figure 3 The image shows the fluorescence and phosphorescence of the chiral phosphorescent material in Example 1.

[0050] Figure 4 The image shows the phosphorescence lifetime spectrum of the chiral phosphorescent material in Example 1.

[0051] Figure 5 The image shows the circularly polarized emission spectrum of the chiral phosphorescent material in Example 2.

[0052] Figure 6 The image shows the fluorescence and phosphorescence of the chiral phosphorescent material in Example 2.

[0053] Figure 7 The image shows the circularly polarized emission spectrum of the chiral phosphorescent material in Example 3.

[0054] Figure 8 The image shows the fluorescence and phosphorescence of the chiral phosphorescent material in Example 3.

[0055] Figure 9 The fluorescence and phosphorescence of the chiral phosphorescent material in Example 4 are shown.

[0056] Figure 10 The fluorescence and phosphorescence images of the chiral phosphorescent material in Example 7 under a 365nm UV lamp with and without the patterning properties shown are shown. Detailed Implementation

[0057] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0058] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0059] In Examples 1-6, the circularly polarized emission spectrometer used for testing was a JASCO CPL-300 circularly polarized fluorescence spectrometer.

[0060] The phosphorescence spectroscopy was performed using a HITACHI F-7000 spectrophotometer with an excitation wavelength of 365 nm.

[0061] The fluorescence and phosphorescence of the chiral phosphorescent material were captured using a Sony camera with an excitation wavelength of 365 nm.

[0062] The phosphorescence lifetime spectrum was measured using an Edinburgh FLS980 steady-state and transient fluorescence spectrometer with an excitation wavelength of 365 nm.

[0063] Example 1

[0064] (1) 2 g of cellulose (DP 220) was dissolved in 38 g of 1-allyl-3-methylimidazolium chloride ionic liquid (AmimCl), 200 mg of 4-dimethylaminopyridine (DMAP) was added, and 4.9 g of trimellitic anhydride was added. The reaction was carried out at 70 °C for 5 h. After the reaction was completed, ethanol was added to the reaction system to terminate the reaction. The reaction solution was then precipitated in 200 mL of ethanol. During the washing process, about 1 mL of concentrated hydrochloric acid was added. The precipitate was then filtered, and the filter cake was washed three times with hydrochloric acid / ethanol solution (volume fraction 0.3%) and once with ethanol. The mixture was then filtered and dried under vacuum to obtain the final product, cellulose trimellitic ester. The degree of substitution was confirmed by NMR to be 0.63.

[0065] Take 2g of cellulose metaphenyl ester, 1g of NaHCO3 and 20mL of ultrapure water and stir at room temperature for 12h. Filter, dialyze the filtrate with water and dry to obtain the final product sodium cellulose metaphenyl ester.

[0066] (2) Take 1g of sodium cellulose metaphenylene (DS=0.7, A1, A2 and A3 are H or -C(=O)-Ph-(COONa)2) and dissolve it in 20mL of ultrapure water. Add 0.05g of lithium 1,4,5,8-naphthalenetetracarboxylate, stir and mix evenly, and dry at 40℃ to finally obtain the chiral phosphorescent material.

[0067] The circularly polarized emission spectrum of this material is as follows: Figure 1 As shown, CPL exhibits a peak at 570 nm and the signal is positive; its phosphorescence spectrum is as follows. Figure 2 As shown, a phosphorescence peak also appears at 570 nm. The fluorescence and phosphorescence luminescence are as follows: Figure 3 As shown, it emits pink fluorescence under 365nm ultraviolet light irradiation, and emits yellow phosphorescence at room temperature after the ultraviolet light is turned off, lasting for 3.6s. The phosphorescence lifetime spectrum is shown below. Figure 4 As shown, the phosphorescence lifetime is 259 ms.

[0068] Example 2

[0069] Dissolve 1g of sodium carboxymethyl cellulose (DS = 0.9, A1, A2, A3 are H or -CH2COONa) in 10mL of ultrapure water, add 0.01g of sodium hexamethyl benzoate, stir and mix evenly, and dry at 50℃ to finally obtain the chiral phosphorescent material.

[0070] The circularly polarized emission spectrum of this material is as follows: Figure 5 As shown, CPL peaks at 455 nm, and the signal is negative. Fluorescence and phosphorescence are as follows... Figure 6 As shown, it emits blue fluorescence under 365nm ultraviolet light irradiation, and emits blue phosphorescence at room temperature after the ultraviolet light is turned off, lasting for 3.6s.

[0071] Example 3

[0072] (1) 2 g pullulanose (DP 600) was dissolved in 48 g of 1-butyl-3-methylimidazolium chloride (BmimCl), 240 mg of 4-dimethylaminopyridine (DMAP) was added, and 6.8 g of trimellitic anhydride was added. The reaction was carried out at 80 °C for 9 h. After the reaction was completed, ethanol was added to the reaction system to terminate the reaction. The reaction solution was then precipitated in 200 mL of ethanol. During the washing process, about 1 mL of concentrated hydrochloric acid was added. The precipitate was then filtered, and the filter cake was washed three times with hydrochloric acid / ethanol solution (volume fraction 0.3%) and once with ethanol. The mixture was then filtered and dried under vacuum to obtain the final product, pullulanose trimellitic ester. The degree of substitution was confirmed by NMR to be 1.35.

[0073] Take 2g of pullulanose trimellitate, 1g of KHCO3 and 20mL of ultrapure water and stir at room temperature for 12h. Filter, dialyze the filtrate with water and dry to obtain the final product potassium pullulanose trimellitate.

[0074] (2) Take 1g of pullulanose potassium trimellitate (DS=1.2, A1, A2, A3 are H or -C(=O)-Ph-(COOK)2) and dissolve it in 20mL of ultrapure water. Add 0.05g of lithium 2,6-naphthalenedicarboxylate, stir and mix evenly, and dry at 50℃ to finally obtain the chiral phosphorescent material.

[0075] The circularly polarized emission spectrum of this material is as follows: Figure 7 As shown, CPL peaks at 550 nm, and the signal is positive. Fluorescence and phosphorescence are as follows... Figure 8 As shown, it emits green fluorescence under 365nm ultraviolet light irradiation, and emits green phosphorescence at room temperature after the ultraviolet light is turned off, lasting for 6.4s.

[0076] Example 4

[0077] (1) 3g of starch (DP 800) was dissolved in 57g of 1-allyl-3-methylimidazolium chloride ionic liquid (AmimCl), 240mg of 4-dimethylaminopyridine (DMAP) was added, and 10.5g of trimellitic anhydride was added. The reaction was carried out at 70℃ for 10h. After the reaction was completed, ethanol was added to the reaction system to terminate the reaction. The reaction solution was then precipitated in 200mL of ethanol. During the washing process, about 1mL of concentrated hydrochloric acid was added. The precipitate was then filtered, and the filter cake was washed three times with hydrochloric acid / ethanol solution (volume fraction 0.3%) and once with ethanol. The mixture was then filtered and dried under vacuum to obtain the final product, starch trimellitic ester. The degree of substitution was confirmed by NMR to be 1.12.

[0078] Take 2g of starch-tremella ester, 1g of Cs2CO3 and 20mL of ultrapure water, stir at room temperature for 12h, filter, dialyze the filtrate with water and dry to obtain the final product cesium starch-tremella ester.

[0079] (2) Take 1g of starch cesium trimellitate (DS=1.5, A1, A2, A3 are H or -C(=O)-Ph-(COOCs)2) and dissolve it in 20mL of ultrapure water. Add 0.03g of Rhodamine B, stir and mix evenly, and dry at 70℃ to finally obtain the chiral phosphorescent material.

[0080] Fluorescence and phosphorescence luminescence are as follows Figure 9 As shown, it emits red fluorescence under 365nm ultraviolet light irradiation, and emits red phosphorescence at room temperature after the ultraviolet light is turned off, lasting for 2.0s.

[0081] Example 5

[0082] (1) 2 g of cellulose (DP 800) was dissolved in 48 g of 1-butyl-3-methylimidazolium chloride ionic liquid (BmimCl), 240 mg of 4-dimethylaminopyridine (DMAP) was added, and 5.6 g of trimellitic anhydride was added. The reaction was carried out at 80 °C for 10 h. After the reaction was completed, ethanol was added to the reaction system to terminate the reaction. The reaction solution was then precipitated in 200 mL of ethanol. During the washing process, about 1 mL of concentrated hydrochloric acid was added. The precipitate was then filtered, and the filter cake was washed three times with hydrochloric acid / ethanol solution (volume fraction 0.3%) and once with ethanol. The mixture was then filtered and dried under vacuum to obtain the final product, cellulose trimellitic ester. The degree of substitution was confirmed by NMR to be 0.63.

[0083] Take 1g of cellulose metaphenyl ester, 1g of Li2CO3 and 20mL of ultrapure water, stir at room temperature for 12h, filter, dialyze the filtrate with water and dry to obtain the final product lithium cellulose metaphenyl ester.

[0084] (2) Take 1g of lithium cellulose trimellitate (DS=1.0, A1, A2, A3 are H or -C(=O)-Ph-(COOLi)2) and dissolve it in 20mL of ultrapure water. Add 0.05g of cesium hexabenzoate, stir and mix evenly, and dry at 50℃ to finally obtain the chiral phosphorescent material.

[0085] It emits blue fluorescence under 365nm ultraviolet light irradiation, and emits phosphorescence that changes from yellow to green at room temperature after the ultraviolet light is turned off, lasting for 3.2s.

[0086] Example 6

[0087] 1 g of sodium carboxymethyl cellulose (DS = 1.2, A1, A2, A3 are H or -CH2COONa) was dissolved in 10 mL of ultrapure water, and 0.01 g of rhodamine B was added. The mixture was stirred and mixed evenly, and then dried at 50 °C to obtain a red circularly polarized organic room temperature phosphorescent polymer material. The material emitted red phosphorescence for 2.4 s after the 365 nm UV lamp was turned off.

[0088] Example 7

[0089] Take 0.5g of the chiral phosphorescent material prepared in Examples 1-6 and dissolve it in water (the concentration of the chiral phosphorescent material in water is 5wt%). Add the solution to a glass plate covered with a mold and dry it to obtain the corresponding phosphorescent film. Alternatively, the solution can be used as a coating and drawn on paper. Figure 10 To demonstrate the patterning properties of the chiral phosphorescent material from Example 7 coated onto a glass plate, fluorescence and phosphorescence images can be obtained by turning a 365nm ultraviolet lamp on and off, such as... Figure 10 As shown, a full-color phosphorescent anti-counterfeiting pattern is obtained after the 365nm ultraviolet lamp is turned off.

[0090] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A chiral phosphorescent material, characterized in that, It includes organic compound A and an ionic polysaccharide derivative having the structure shown in Formula I: ； Among them: A1, A2, and A3 may be the same or different, and are independently selected from H and -C. 1-12 Alkylene-COOP or -C(=O)-C 6-20 Aspartic-(COOP) n And A1, A2, A3 are not all H at the same time; P is the same or different and is independently selected from Li, Na, K, Rb or Cs; n is 1, 2, 3 or 4; DP is an integer from 50 to 5000; Wherein, the organic compound A is selected from at least one of the following structures: 、 Sodium hexabenzoate or cesium hexabenzoate; Cation M ⊕ For: Na + Li + K + 、Rb + or Cs + At least one of them; The mass ratio of the ionic polysaccharide derivative with the structure shown in Formula I to organic compound A is (15~150):

1.

2. The material according to claim 1, characterized in that, A1, A2, and A3 may be the same or different, and are independently selected from H and -C. 1-6 Alkylene-COOP or -C(=O)-C 6-12 Aspartic-(COOP) n .

3. The material according to claim 1, characterized in that, A1, A2, and A3 may be the same or different, and are independently selected from H, -CH2COONa, -C(=O)-Ph-(COONa)2, -C(=O)-Ph-COONa, -C(=O)-Ph-(COOK)2, -C(=O)-Ph-(COOCs)2, -C(=O)-Ph-(COOLi)2, -C(=O)-naphthalene-COONa, or -C(=O)-biphenyl-COONa.

4. The material according to claim 1, characterized in that, The degree of substitution of the functional group -COOP in the ionic polysaccharide derivatives with the structure shown in Formula I is 0.5-2.

0.

5. The material according to claim 1, characterized in that, In the structure shown in Formula I, the main chain is a natural polysaccharide, which is at least one of cellulose, starch, and pullulanose.

6. A method for preparing the material according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Prepare ionic polysaccharide derivatives with the structure shown in Formula I; (2) The ionic polysaccharide derivative with the structure shown in Formula I is mixed with organic A to prepare a chiral phosphorescent material.

7. Use of the material according to any one of claims 1-5 in anti-counterfeiting, encryption or 3D display.

8. A thin film comprising the chiral phosphorescent material according to any one of claims 1-5.

9. The method for preparing the thin film according to claim 8, characterized in that, The method is as follows: dissolve the chiral phosphorescent material in water, coat the prepared solution onto a substrate, and prepare the thin film.

10. The method according to claim 9, characterized in that, The concentration of the chiral phosphorescent material in water is 5-10 wt%.

11. A coating comprising the chiral phosphorescent material according to any one of claims 1-5.

12. The method for preparing the coating according to claim 11, characterized in that, The method is as follows: dissolve the chiral phosphorescent material in water, and then mix it with the remaining coating components to obtain the coating.

13. The method according to claim 12, characterized in that, The concentration of chiral phosphorescent materials in the coating is 1-10 wt%.

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