Angle-dependent long-lasting photonic crystal material and preparation method and application thereof

Abstract

The present invention belongs to the technical field of organic light-emitting materials, and specifically relates to a long afterglow photonic crystal material with angle dependence, and a preparation method and application thereof. The preparation method of the long afterglow photonic crystal material with angle dependence comprises the following steps: adding long afterglow molecules to a monodisperse microsphere dispersion, shaking, obtaining a microsphere mother liquor containing long afterglow molecules, removing insoluble long afterglow molecule solids by centrifugation, re-shaking and dispersing, diluting, self-assembling, obtaining a photonic crystal, immersing the photonic crystal in a polymer solution, and then taking it out and drying it to obtain the long afterglow photonic crystal material with angle dependence. The preparation method of the present invention has the advantages of simple process and high controllability. At the same time, the obtained photonic crystal material has a long afterglow color that changes with the observation angle, and has a wide range of applications in information encryption, optical anti-counterfeiting, and specific identification of various high-end products.

Description

Technical Field

[0001] The invention belongs to the technical field of organic luminescent materials, and in particular relates to a long afterglow photonic crystal material with angle dependence, a preparation method and application thereof. Background Art

[0002] With the rapid development of economy and society, the importance of new anti-counterfeiting technologies in real life has become increasingly prominent. Photonic crystals have gradually become a hot material for anti-counterfeiting technology because of their optical properties such as structural color brought by their regular arrangement. Specifically, photonic crystals are periodic structures of dielectric materials with different refractive indices, which are used in basic science and for color displays, sensors, color printing, lasers, and many other photonic applications. The structural color in photonic crystals is obtained by using light that is prohibited from propagating within a certain wavelength range (called photonic band gap). The photonic band gap depends largely on the spatial arrangement of the constituent materials. Therefore, many experimental methods have been used to regulate the particle size of photonic crystals, thereby achieving the regulation of the spatial structure of photonic crystals. For this reason, photonic crystal materials have become the focus of anti-counterfeiting technology research due to their excellent optical effects and rich controllability. However, the application of optical response anti-counterfeiting technology of single photonic crystal materials currently also has a series of problems, such as low technical content, easy cracking of anti-counterfeiting information, and low information content. These shortcomings have limited the further application of single photonic crystal materials in the field of anti-counterfeiting to a certain extent.

[0003] Fluorescence has been widely used in the field of anti-counterfeiting due to its simple luminescence conditions and ease of use. For example, fluorescence technology is widely used on banknotes and commemorative coins of various countries. The luminescence of long-lasting materials has a visible luminescence delay, which is more difficult to imitate and copy than conventional fluorescent anti-counterfeiting. At the same time, long-lasting materials have also been widely used in fluorescent anti-counterfeiting technology due to their excellent delayed luminescence effect. However, general long-lasting luminescent materials do not have the characteristic that the luminescent color changes with the observation angle. Summary of the invention

[0004] The present invention aims to provide a long afterglow photonic crystal material with angle dependence and its preparation method and application. The preparation method of the present invention has the advantages of simple process and high controllability. At the same time, the prepared photonic crystal material has high response sensitivity and has a wide range of applications in information encryption, optical anti-counterfeiting and specific identification of various high-end products.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: a method for preparing a long afterglow photonic crystal material with angle dependence, comprising the following steps:

[0006] Long afterglow molecules are added to a monodisperse microsphere dispersion, and the material is shaken to exceed the saturated solubility of the long afterglow molecules in the solution to achieve penetration of the long afterglow molecules into the microspheres, thereby obtaining a microsphere mother liquor containing the long afterglow molecules, and removing insoluble long afterglow molecule solids by centrifugation, and the dispersion is re-shaken and self-assembled to obtain a photonic crystal, and the photonic crystal is immersed in a polymer solution, and then taken out and dried to achieve packaging, thereby obtaining the angle-dependent long afterglow photonic crystal material.

[0007] Preferably, the long afterglow molecule includes at least one of acridine or acridine derivatives, acridone or acridone derivatives, boric acid derivatives, and other molecules having a long afterglow effect.

[0008] More preferably, the structure of the acridine or acridine derivative is as shown in formula (I):

[0009]

[0010] The structure of the acridone or acridone derivative is shown in formula (II):

[0011]

[0012] Wherein, R2, R5, and R8 are selected from any one of hydrogen, amide, amine, or amino salt; R1, R3, R4, R6, R7, and R9 are selected from any one of hydrogen, alkyl, alkoxy, carboxyl, boric acid, or halogen atom; R 10 Any one selected from hydrogen, alkyl, and phenyl.

[0013] More preferably, the boronic acid derivatives include the following three types of structures:

[0014] Category B1:

[0015]

[0016] Where R is N, P, As atom, R' is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -COH, -SO3, -COOH, -CO-, Any of the following;

[0017] Category B2:

[0018]

[0019] Wherein R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -COH, -SO3, -COOH, -CO-, Any of the following;

[0020] Category B3:

[0021]

[0022] Wherein R is -H, -F, -Cl, -Br, -NO2, -CF3, -CN, -COH, -SO3, -COOH, -CO-, Any one of .

[0023] More preferably, the other molecules having a long afterglow effect include At least one of .

[0024] Preferably, the monodisperse microsphere dispersion is prepared by dispersing monodisperse polymer microspheres in a solution. The dispersion solvent of the monodisperse polymer microspheres includes but is not limited to water, ethanol, propylene glycol, and polyethylene glycol.

[0025] Preferably, the average particle size of the monodisperse polymer microspheres is 50-500 nm. Although microspheres outside this particle size range can be assembled into photonic crystals, their photon bandgap is obviously beyond the visible light range, and therefore will not have a regulating effect on the long afterglow luminescence spectrum.

[0026] More preferably, the average particle size of the monodisperse polymer microspheres is 180-260 nm.

[0027] Preferably, the chemical composition of the monodisperse polymer microspheres includes at least one of polystyrene, polymethacrylate, polyacrylate, polyacrylic acid, polyacrylamide, polyvinyl alcohol, polymaleic anhydride, polymethacrylic acid and copolymers thereof.

[0028] More preferably, the chemical composition of the monodisperse polymer microspheres is a copolymer and / or polyacrylamide made from styrene: methacrylate = 7:3.

[0029] Preferably, the mass fraction of monodisperse polymer microspheres in the monodisperse microsphere dispersion is 0.5-20%.

[0030] Preferably, the shaking time is 10 to 15 hours.

[0031] Preferably, the mass of the long afterglow molecules in the microsphere mother solution containing long afterglow molecules in the microsphere microspheres contains 0.01-5% of the total weight of the microspheres.

[0032] Preferably, the self-assembly solution is a microsphere dispersion containing long afterglow molecules in a mass fraction of 0.5-30%.

[0033] Preferably, the self-assembly condition is to place the microsphere dispersion containing the long afterglow molecule into a glass substrate and self-assemble for 3 to 5 days under constant temperature and humidity conditions, wherein the self-assembly growth temperature is 60 to 70°C.

[0034] Preferably, the photonic crystal is immersed for 4 to 6 hours.

[0035] Preferably, the polymer solution comprises any one of a polyvinyl alcohol aqueous solution, a polyacrylamide aqueous solution, a chitosan aqueous solution, and a hydroxypropyl cellulose aqueous solution. More preferably, the concentration of the polymer solution is 1-10%.

[0036] Preferably, the drying temperature is 60-80° C. and the drying time is 1-3 hours.

[0037] Preferably, the reflection peak of the photonic crystal is between 100-1000 nm.

[0038] In the process of preparing the angle-dependent long-afterglow photonic crystal material, the present invention obtains photonic crystals with different photonic bandgap by self-assembly of microspheres with different particle sizes (the required photonic bandgap can be adjusted by the particle size); at the same time, for the photonic crystals formed by microsphere mother solutions with different compositions and particle sizes, it is necessary to select long-afterglow molecules of specific components for infiltration, and use the photonic bandgap and scattering effect of the photonic crystals to adjust the spectral characteristics of the organic long-afterglow luminescence. If the particle size of the microspheres in the prepared microsphere mother solution does not match the long-afterglow molecules, the prepared photonic crystals cannot achieve the angle-dependent long-afterglow effect.

[0039] The inventors have found through extensive exploration and research that the key point to ensure that the angle-dependent long-lasting photonic crystal material has good optical properties and regulation properties is to study the luminescence properties of different long-lasting organic light-emitting molecules in different polymers during the preparation process (by controlling the structure of the long-lasting organic light-emitting molecules and the composition of the microspheres), and to control the penetration of different long-lasting molecules in different polymer microspheres (by controlling the composition of the solvent and the microspheres). The former determines the long-lasting luminescence lifetime of the material, and the latter determines the long-lasting luminescence quantum efficiency.

[0040] The present invention also requests protection for the angle-dependent long afterglow luminescence characteristics obtained by a preparation method of the angle-dependent long afterglow photonic crystal material, wherein the fluorescence quantum efficiency of the angle-dependent long afterglow photonic crystal material ranges from 30% to 100%, the afterglow quantum efficiency ranges from 5% to 80%, and the long afterglow visible time is 0.5 to 30 seconds.

[0041] The present invention also seeks to protect the application of the angle-dependent long afterglow photonic crystal material in the fields of oxygen concentration detection, gas temperature and humidity detection, content detection of specific substances, information encryption, optical anti-counterfeiting, and specific identification.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The long afterglow photonic crystal material prepared by the present invention has a unique angle-dependent long afterglow characteristic and has a high anti-counterfeiting level and information capacity.

[0044] (2) The synthesis process of the angle-dependent long afterglow photonic crystal material of the present invention is simple and convenient, the raw materials are cheap and easily available, and no complex instruments are required during the preparation process, which has the advantage of industrial batch preparation.

[0045] (3) The present invention combines the long afterglow material with the photonic crystal material, which not only retains the advantages of the two materials, but also regulates and enriches their applications in new anti-counterfeiting through different combinations of the long afterglow material and the photonic crystal material. The regulation methods include but are not limited to the particle size and spatial arrangement of the photonic crystal, different types of long afterglow materials, photonic crystals with specific particle sizes, and specific long afterglow molecular combinations.

[0046] (4) The long afterglow photonic crystal material prepared by the present invention has the combined advantages of photonic crystal material and long afterglow material, and has a wide range of applications in information encryption, optical anti-counterfeiting, and specific identification. It can also be used for oxygen concentration detection, gas temperature and humidity detection, and content detection of specific substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a long afterglow spectrum diagram of the angle-dependent long afterglow photonic crystal material prepared in Example 1 of the present invention.

[0048] Figure 2 This is a long afterglow spectrum of the long afterglow material without angle dependence prepared in Comparative Example 1 of the present invention.

[0049] Figure 3 The long afterglow lifetime attenuation diagram of the angle-dependent long afterglow photonic crystal material prepared in the embodiment of the present invention. Curve 1 is embodiment 1, curve 2 is embodiment 2, and curve 3 is embodiment 6. DETAILED DESCRIPTION

[0050] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] In the embodiments and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0052] Example 1

[0053] Preparation of monodisperse microsphere dispersion:

[0054] 11.25 mL of styrene, 3.75 mL of methyl methacrylate, 350 μL of α-methacrylic acid, 0.5 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 210 nm.

[0055] Preparation of long-lasting photonic crystal materials with angle dependence:

[0056] The monodisperse microsphere dispersion was centrifuged at 10000 r / min and ultrasonically dispersed to control the mass fraction of microspheres in the monodisperse microsphere dispersion to be 5%. 0.5 g of N-methylacridone was added to 100 mL of the monodisperse microsphere dispersion and shaken for 10 hours to allow the acridone to enter the microspheres through osmosis. The monodisperse microsphere dispersion that had completed the infiltration was first centrifuged at a low speed of 1000 r / min to precipitate the uninfiltrated N-methylacridone, and then the upper monodisperse microsphere dispersion was taken and subjected to high-speed centrifugation at 10000 r / min to remove the dissolved The method comprises the following steps: preparing a solution containing N-methylacridone, and finally adding deionized water and ultrasonicating to obtain a completely infiltrated microsphere mother solution; diluting the completely infiltrated microsphere mother solution to a solid content of 1%, adding the solution to a 10 ml vial, placing the solution in a glass sheet growth substrate treated with hydrophilicity, and self-assembling and growing the solution in an oven at 60° C. for 5 days to obtain a photonic crystal formed by self-assembly of the microspheres; soaking the prepared photonic crystal in a polyvinyl alcohol aqueous solution with a mass fraction of 10%, vertically pulling the prepared photonic crystal out of the solution, and drying the solution at 60° C. for 3 hours to obtain the angle-dependent long afterglow photonic crystal material.

[0057] Its angle-dependent long afterglow spectrum is as follows Figure 1 As shown. Figure 1It can be seen that when the ultraviolet excitation light is incident from the front and back sides of the material respectively, the long afterglow spectrum observed from the front side is obviously different.

[0058] Example 2

[0059] Preparation of monodisperse microsphere dispersion:

[0060] 15 mL of methyl methacrylate, 350 μL of α-methacrylic acid, 0.5 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 260 nm.

[0061] Preparation of long-lasting photonic crystal materials with angle dependence:

[0062] The monodisperse microsphere dispersion was centrifuged at 11000 r / min and ultrasonically dispersed to control the mass fraction of microspheres in the monodisperse microsphere dispersion to be 10%. 0.5 g of acridone was added to 100 mL of the monodisperse microsphere dispersion and shaken for 10 hours to allow the acridone to enter the microspheres through osmosis. The monodisperse microsphere dispersion that had completed the infiltration was first subjected to low-speed centrifugation at 2000 r / min to precipitate the uninfiltrated acridone, and then the upper monodisperse microsphere dispersion was taken and subjected to high-speed centrifugation at 11000 r / min. The solution containing acridone is removed, and finally deionized water is added for ultrasonic treatment to obtain a completely infiltrated microsphere mother solution; the completely infiltrated microsphere mother solution is diluted to a solid content of 5%, added to a 10 ml penicillin bottle, placed on a hydrophilic treated glass sheet growth substrate, and grown in an oven at 60° C. for 4 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a 1% mass fraction hydroxypropyl cellulose aqueous solution, and dried at 80° C. for 2 hours to obtain the angle-dependent long afterglow photonic crystal material.

[0063] Example 3

[0064] Preparation of monodisperse microsphere dispersion:

[0065] 15 mL of styrene, 350 μL of acrylic acid, 1 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 200 nm.

[0066] Preparation of long-lasting photonic crystal materials with angle dependence:

[0067] The monodisperse microsphere dispersion was centrifuged at 13000 r / min and ultrasonically dispersed to control the mass fraction of microspheres in the monodisperse microsphere dispersion to be 10%. 1 g of 3,6-diaminoacridine was added to 100 mL of the monodisperse microsphere dispersion and shaken for 15 h to allow 3,6-diaminoacridine to enter the microspheres through osmosis. The monodisperse microsphere dispersion that had completed the infiltration was first centrifuged at a low speed of 3000 r / min to precipitate the uninfiltrated 3,6-diaminoacridine, and then the upper monodisperse microsphere dispersion was centrifuged at a high speed of 13000 r / min to remove the solution dissolved with 3,6-diaminoacridine, and finally the monodisperse microsphere dispersion was added to remove the 3,6-diaminoacridine. The method comprises the following steps: obtaining a completely infiltrated microsphere mother solution by ultrasonic treatment with ionized water; diluting the completely infiltrated microsphere mother solution to a solid content of 5%, adding the solution to a 10 ml vial, placing the glass sheet growth substrate after hydrophilic treatment, and growing the glass sheet in an oven at 70° C. for 3 days to obtain a photonic crystal formed by self-assembly of the microspheres; soaking the prepared photonic crystal in a polyacrylamide aqueous solution with a mass fraction of 5%, and drying the solution at 80° C. for 1 hour to obtain the angle-dependent long afterglow photonic crystal material.

[0068] Example 4

[0069] Preparation of monodisperse microsphere dispersion:

[0070] 11.25 mL of styrene, 3.75 mL of methyl methacrylate, 350 mg of maleic acid, 0.8 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 220 nm.

[0071] Preparation of long-lasting photonic crystal materials with angle dependence:

[0072] The monodisperse microsphere dispersion was centrifuged at 13000r / min and ultrasonically dispersed in a solution of ethanol: water = 1:1. The mass fraction of microspheres in the monodisperse microsphere dispersion was controlled to be 5%. 0.2g 1-pyrene boric acid is added to 100 mL of microsphere mother solution, and the solution is shaken for 15 hours to allow the 1-pyrene boric acid to enter the microspheres through osmosis; the monodisperse microsphere dispersion liquid that has completed the infiltration is first subjected to low-speed centrifugation at 3000 r / min to precipitate the uninfiltrated 1-pyrene boric acid, and then the upper monodisperse microsphere dispersion liquid is taken and subjected to high-speed centrifugation at 13000 r / min to remove the solution dissolved with 1-pyrene boric acid, and finally deionized water is added to ultrasonically obtain a completely infiltrated microsphere mother solution; the completely infiltrated microsphere mother solution is diluted to a solid content of 5%, added to a 10 ml penicillin bottle, placed in a glass sheet growth substrate treated with hydrophilicity, and grown in an oven at 70° C. for 3 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a polyacrylamide aqueous solution with a mass fraction of 5%, and dried at 80° C. for 1 hour to obtain the angle-dependent long afterglow photonic crystal material.

[0073] Example 5

[0074] Preparation of monodisperse microsphere dispersion:

[0075] 15mL of styrene, 600mg of acrylamide, 1mL of 1% sodium dodecyl sulfate and 80mL of deionized water were added to a round-bottom flask, and stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1g of ammonium persulfate dissolved in 2mL of water was added and reacted for 12h to prepare a monodisperse microsphere dispersion. The particle size of the microspheres in the monodisperse microsphere dispersion was 220nm.

[0076] Preparation of long-lasting photonic crystal materials with angle dependence:

[0077] The monodisperse microsphere dispersion was centrifuged at 13000 r / min, ultrasonically dispersed in ethanol, and the mass fraction of microspheres in the monodisperse microsphere dispersion was controlled to be 3%. 0.1 g of hexabenzophenone was added to 100 mL of the monodisperse microsphere dispersion with ethanol as solvent, and shaken for 15 hours to allow the hexabenzophenone to enter the microspheres through osmosis. The microsphere mother liquor that had completed the infiltration was first subjected to low-speed centrifugation at 3000 r / min to precipitate the uninfiltrated hexabenzophenone, and then the upper monodisperse microsphere dispersion was taken and subjected to 13000 r / min centrifugation. The solution containing hexaphenylene is removed by high-speed centrifugation, and finally deionized water is added for ultrasonic treatment to obtain a completely infiltrated microsphere mother solution; the completely infiltrated microsphere mother solution is diluted to a solid content of 5%, added to a 10 ml penicillin bottle, placed on a hydrophilic treated glass sheet growth substrate, and grown in an oven at 70°C for 3 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a polyacrylamide aqueous solution with a mass fraction of 5%, and dried at 80°C for 1 hour to obtain the angle-dependent long afterglow photonic crystal material.

[0078] Example 6

[0079] Preparation of monodisperse microsphere dispersion:

[0080] 15 mL of styrene, 2 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 150 nm.

[0081] Preparation of long-lasting photonic crystal materials with angle dependence:

[0082] The monodisperse microsphere dispersion was centrifuged at 13000r / min and ultrasonically dispersed in water. The mass fraction of microspheres in the monodisperse microsphere dispersion was controlled at 3%. 0.1g 2-naphthaleneboric acid is added to 100 mL of monodisperse microsphere dispersion liquid, and the solution is shaken for 15 hours to allow the 2-naphthaleneboric acid to enter the microspheres through osmosis; the monodisperse microsphere dispersion liquid that has completed the infiltration is first subjected to low-speed centrifugation at 3000 r / min to precipitate the uninfiltrated hexaphenylene, and then the upper monodisperse microsphere dispersion liquid is taken and subjected to high-speed centrifugation at 13000 r / min to remove the solution dissolved with 2-naphthaleneboric acid, and finally deionized water is added to ultrasonically obtain a completely infiltrated microsphere mother liquid; the completely infiltrated microsphere mother liquid is diluted to a solid content of 5%, added to a 10 ml penicillin bottle, placed in a glass sheet growth substrate treated with hydrophilicity, and grown in an oven at 70° C. for 3 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a polyacrylamide aqueous solution with a mass fraction of 2%, and dried at 80° C. for 1 hour to obtain the angle-dependent long afterglow photonic crystal material.

[0083] Comparative Example 1

[0084] Preparation of microsphere dispersion:

[0085] 11.25 mL of styrene, 3.75 mL of methyl methacrylate, and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 h to prepare a polydisperse microsphere dispersion.

[0086] The microsphere dispersion was centrifuged at 10000 r / min and ultrasonically dispersed to control the mass fraction of microspheres in the microsphere dispersion to be 5%. 0.5 g of N-methylacridone was added to 100 mL of the microsphere dispersion and shaken for 10 hours to allow the acridone to penetrate into the microspheres. The microsphere dispersion that had completed penetration was first centrifuged at a low speed of 1000 r / min to precipitate the N-methylacridone that had not penetrated. The upper microsphere dispersion was then centrifuged at 10000 r / min and then ultrasonically dispersed to control the mass fraction of microspheres in the microsphere dispersion to be 5%. n high-speed centrifugation to remove the solution containing N-methylacridone, and finally adding deionized water and ultrasonication to obtain a completely infiltrated microsphere mother liquor; the completely infiltrated microsphere mother liquor is diluted to a solid content of 1%, added to a 10 ml penicillin bottle, placed in a hydrophilic treated glass sheet growth substrate, grown in an oven at 60°C for 5 days, the prepared film is immersed in a 10% by mass polyvinyl alcohol aqueous solution, vertically pulled out of the solution, and dried at 60°C for 3 hours to obtain a long afterglow material.

[0087] Compared with Example 1, the difference of this comparative example is that the microspheres are not monodisperse and cannot self-assemble into photonic crystals. Figure 2As shown, there is no obvious angle dependence. When the ultraviolet excitation light is incident from the front and back sides of the material respectively, the long afterglow spectrum observed from the front side is almost the same.

[0088] Comparative Example 2

[0089] Preparation of monodisperse microsphere dispersion:

[0090] 11.25 mL of styrene, 3.75 mL of methyl methacrylate, 350 μL of α-methacrylic acid, 0.5 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 210 nm.

[0091] Preparation of long-lasting photonic crystal materials with angle dependence:

[0092] The monodisperse microsphere dispersion liquid is centrifuged at 10000r / min, ultrasonically dispersed, and the mass fraction of microspheres in the monodisperse microsphere dispersion liquid is controlled to be 5%. 0.5g of N-methylacridone is added to 100mL of microsphere mother solution, and shaken for 10 hours to allow the acridone to enter the microspheres through osmosis; the monodisperse microsphere dispersion liquid that has completed infiltration is first subjected to low-speed centrifugation at 1000r / min to precipitate the uninfiltrated N-methylacridone, and then the upper monodisperse microsphere dispersion liquid is taken and subjected to high-speed centrifugation at 10000r / min to remove the solution dissolved with N-methylacridone, and finally deionized water is added to ultrasonically obtain a completely infiltrated microsphere mother solution; the completely infiltrated microsphere mother solution is diluted to a solid content of 1%, and directly dried, and the prepared film is immersed in a polyvinyl alcohol aqueous solution with a mass fraction of 10%, and after vertically pulled out of the solution, it is dried at 60°C for 3h to obtain a long afterglow material.

[0093] Compared with Example 1, the difference of this comparative example is that the microspheres are not self-assembled and cannot form photonic crystals.

[0094] Comparative Example 3

[0095] Preparation of monodisperse microsphere dispersion:

[0096] 11.25 mL of styrene, 3.75 mL of methyl methacrylate, 350 μL of α-methacrylic acid, 0.5 mL of 1% sodium dodecyl sulfate and 80 mL of deionized water were added to a round-bottom flask, and the mixture was stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1 g of ammonium persulfate dissolved in 2 mL of water was added and reacted for 12 hours to prepare a monodisperse microsphere dispersion. The particle size of the monodisperse polymer microspheres in the monodisperse microsphere dispersion was 210 nm.

[0097] Preparation of long-lasting photonic crystal materials with angle dependence:

[0098] The monodisperse microsphere dispersion liquid is centrifuged at 10000r / min, ultrasonically dispersed, and the mass fraction of microspheres in the monodisperse microsphere dispersion liquid is controlled to be 5%. 0.5g of N-methylacridone is added to 100mL of microsphere mother solution, and shaken for 10 hours to allow the acridone to enter the microspheres through osmosis; the monodisperse microsphere dispersion liquid that has completed infiltration is first subjected to low-speed centrifugation at 1000r / min to precipitate the uninfiltrated N-methylacridone, and then the upper monodisperse microsphere dispersion liquid is taken and subjected to high-speed centrifugation at 10000r / min to remove the solution dissolved with N-methylacridone, and finally deionized water is added to ultrasonically obtain a completely infiltrated microsphere mother solution; the completely infiltrated microsphere mother solution is diluted to a solid content of 1%, added to a 10ml penicillin bottle, placed on a glass sheet growth substrate treated with hydrophilicity, and grown in an oven at 60°C for 5 days to obtain a photonic crystal formed by self-assembly of microspheres.

[0099] Compared with Example 1, the difference of this comparative example is that the photonic crystal is not encapsulated in the polymer solution.

[0100] Comparative Example 4

[0101] Preparation of monodisperse microsphere dispersion:

[0102] 15mL of styrene, 600mg of acrylamide, 1mL of 1% sodium dodecyl sulfate and 80mL of deionized water were added to a round-bottom flask, and stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1g of ammonium persulfate dissolved in 2mL of water was added and reacted for 12h to prepare a monodisperse microsphere dispersion. The particle size of the microspheres in the monodisperse microsphere dispersion was 220nm.

[0103] Preparation of long-lasting photonic crystal materials with angle dependence:

[0104] The monodisperse microsphere dispersion liquid is centrifuged at 13000r / min, ultrasonically dispersed in water, the mass fraction of microspheres in the monodisperse microsphere dispersion liquid is controlled to be 3%, 0.1g of hexaphenylene is added to 100mL of monodisperse microsphere dispersion liquid with water as solvent, and shaken for 15h to allow the hexaphenylene to enter the microspheres through osmosis; the dispersion liquid that has completed the infiltration is first subjected to low-speed centrifugation at 3000r / min to precipitate the uninfiltrated hexaphenylene, and then the upper layer of the dispersion liquid is subjected to high-speed centrifugation at 13000r / min to remove the solution dissolved with hexaphenylene, and finally deionized water is added to ultrasonically obtain a microsphere mother liquid; the microsphere mother liquid is diluted to a solid content of 5%, added to a 10ml penicillin bottle, placed in a glass sheet growth substrate treated with hydrophilicity, and grown in an oven at 70°C for 3 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a polyacrylamide aqueous solution with a mass fraction of 5%, and dried at 80°C for 1h to obtain the material.

[0105] Compared with Example 5, the difference of this comparative example is that water is selected as the dispersing solvent of the monodisperse microsphere dispersion, resulting in that the long afterglow molecules cannot penetrate into the microspheres.

[0106] Comparative Example 5

[0107] Preparation of monodisperse microsphere dispersion:

[0108] 15mL of methyl methacrylate, 600mg of acrylamide, 1mL of 1% sodium dodecyl sulfate and 80mL of deionized water were added to a round-bottom flask, and stirred in a water bath and heated to 78°C. After reaching the temperature, 0.1g of ammonium persulfate dissolved in 2mL of water was added and reacted for 12h to prepare a monodisperse microsphere dispersion. The particle size of the microspheres in the monodisperse microsphere dispersion was 240nm.

[0109] Preparation of long-lasting photonic crystal materials with angle dependence:

[0110] The monodisperse microsphere dispersion was centrifuged at 13000r / min, ultrasonically dispersed in ethanol, and the mass fraction of microspheres in the monodisperse microsphere dispersion was controlled to be 3%. 0.1g of hexabenzophenone was added to 100mL of the monodisperse microsphere dispersion with ethanol as solvent, and shaken for 15h to allow the hexabenzophenone to enter the microspheres through osmosis. The monodisperse microsphere dispersion that completed the infiltration was first centrifuged at 3000r / min to precipitate the hexabenzophenone that had not been infiltrated, and then the upper monodisperse microsphere dispersion was taken. The liquid is then subjected to high-speed centrifugation at 13000r / min to remove the solution containing hexaphenylene oxide, and finally deionized water is added for ultrasonic treatment to obtain a microsphere mother solution; the microsphere mother solution is diluted to a solid content of 5%, added to a 10ml penicillin bottle, placed on a glass sheet growth substrate treated with hydrophilicity, and grown in an oven at 70°C for 3 days to obtain a photonic crystal formed by self-assembly of microspheres; the prepared photonic crystal is immersed in a polyacrylamide aqueous solution with a mass fraction of 5%, and dried at 80°C for 1h to obtain the material.

[0111] Compared with Example 5, the difference of this comparative example is that methyl methacrylate is used to replace the styrene component, which results in that the long afterglow molecules cannot penetrate into the microspheres.

[0112] Performance Testing

[0113] The angle-dependent long afterglow photonic crystal materials prepared in the examples and comparative examples were irradiated under 365nm ultraviolet light, and their color changes and long afterglow conditions were observed, and the long afterglow time was recorded.

[0114] The experimental data are shown in Table 1.

[0115] Table 1

[0116]

[0117] It can be seen from the data in Table 1 that the photonic crystal material prepared in the embodiment of the present invention can achieve good fluorescence and long afterglow effect.

[0118] In Comparative Examples 1-2, the microspheres did not self-assemble into photonic crystals, so the long afterglow had no angle dependence; the photonic crystals in Comparative Example 3 were not finally encapsulated in the polymer solution, resulting in the quenching of its long afterglow in the air by oxygen; the dispersing solvents and microsphere components selected in Comparative Examples 4-5 were not suitable, resulting in the failure of long afterglow molecular penetration, making the material have no fluorescence effect and long afterglow effect.

[0119] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a long afterglow photonic crystal material with angle dependence, characterized in that: The following steps are involved: Adding long afterglow molecules to a monodisperse microsphere dispersion, shaking to obtain a microsphere mother solution containing long afterglow molecules, removing insoluble long afterglow molecule solids by centrifugation, re-shaking and dispersing, self-assembling to obtain a photonic crystal, immersing the photonic crystal in a polymer solution, then taking it out and drying it to obtain the angle-dependent long afterglow photonic crystal material; The long afterglow molecule includes at least one of N-methylacridone, acridone, 3, 6-diaminoacridine, 1-pyreneboric acid, hexabenzophenone, and 2-naphthaleneboric acid; The polymer solution includes any one of a polyvinyl alcohol aqueous solution, a polyacrylamide aqueous solution, a chitosan aqueous solution, and a hydroxypropyl cellulose aqueous solution.

2. The method for preparing the angle-dependent long afterglow photonic crystal material according to claim 1, characterized in that: The monodisperse microsphere dispersion is prepared by dispersing monodisperse polymer microspheres in a solvent.

3. The method for preparing the angle-dependent long afterglow photonic crystal material according to claim 2, characterized in that: At least one of the following (1) to (3): (1) The average particle size of the monodisperse polymer microspheres is 50-500 nm; (2) The chemical composition of the monodisperse polymer microspheres includes at least one of polystyrene, polymethacrylate, polyacrylate, polyacrylic acid, polyacrylamide, polyvinyl alcohol, polymaleic anhydride, polymethacrylic acid and copolymers thereof; (3) The mass fraction of the monodisperse polymer microspheres in the monodisperse microsphere dispersion is 0.5-20%.

4. The method for preparing the angle-dependent long afterglow photonic crystal material according to claim 1, characterized in that: At least one of the following (1) to (7): (1) The shaking time is 10 to 15 hours; (2) The mass of the long afterglow molecules in the microsphere mother solution containing the long afterglow molecules in the microspheres contains 0.01-5% of the total weight of the microspheres; (3) The self-assembly solution is a microsphere dispersion containing long afterglow molecules with a mass fraction of 0.5-30%; (4) The self-assembly condition is to place the microsphere dispersion containing the long afterglow molecule into a glass substrate and self-assemble and grow for 3 to 5 days under constant temperature and humidity conditions, wherein the self-assembly growth temperature is 60 to 70°C; (5) The photonic crystal is immersed for 4 to 6 hours; (6) The concentration of the polymer solution is 1-10%; (7) The drying temperature is 60-80°C and the drying time is 1-3 hours.

5. A long afterglow photonic crystal material with angle dependence prepared by the method for preparing a long afterglow photonic crystal material with angle dependence according to any one of claims 1 to 4, characterized in that: The color and spectrum of the long afterglow luminescence of the angle-dependent long afterglow photonic crystal material change with the observation angle due to the bandgap effect and scattering regulation of the photonic crystal; the fluorescence quantum efficiency of the angle-dependent long afterglow photonic crystal material ranges from 30% to 100%, the afterglow quantum efficiency ranges from 5% to 80%, and the long afterglow visible time is 0.5 to 30 seconds.

6. Application of the angle-dependent long afterglow photonic crystal material as claimed in claim 5 in information encryption and optical anti-counterfeiting.

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