Chiral photonic crystal toner as well as preparation method and application thereof

Abstract

The invention provides chiral photonic crystal toner as well as a preparation method and application thereof. The chiral photonic crystal toner is composed of chiral photonic crystal particles and a luminous substance loaded on the chiral photonic crystal particles, the preparation method comprises the following steps: mixing a liquid crystal polymer monomer, a chiral dopant and a luminescent substance, polymerizing to obtain a luminescent substance-loaded chiral photonic crystal polymer film, and crushing to obtain the chiral photonic crystal toner, the chiral photonic crystal particles have chiral structural colors, and the chiral structural colors are generated in a chiral photonic forbidden band. The chiral photonic crystal toner provided by the invention has the characteristics of chiral structural color and circular polarization luminescence, and can greatly improve the security of information anti-counterfeiting encryption when being applied to an anti-counterfeiting technology.

Description

Technical Field

[0001] The invention belongs to the technical field of optical materials, and in particular relates to a chiral photonic crystal color powder and a preparation method and application thereof. Background Art

[0002] With the improvement of productivity, there are more and more counterfeiting methods. In the process of commodity circulation, counterfeit products have seriously damaged the interests of producers and consumers. Existing anti-counterfeiting technologies, including physical means and chemical technologies such as digital anti-counterfeiting query, electronic tags, and anti-counterfeiting packaging, are easy to imitate and have poor concealment, and are increasingly unable to meet actual needs. For example, holographic anti-counterfeiting and radio frequency anti-counterfeiting technologies are more commonly used physical anti-counterfeiting in the market, but there are problems with high equipment and maintenance costs. For chemical anti-counterfeiting, chemiluminescence is more common, and the selected luminescence system tends to be visible light luminescence. Visible light anti-counterfeiting can be identified by the naked eye, which can improve the convenience of identification, but at the same time it also reduces safety and is easy to be counterfeited. In addition, the organic luminescent dyes commonly used in chemiluminescent anti-counterfeiting often rely on the color of their luminescence, facing the challenges of poor stability and easy photobleaching and loss of color. The structural color of photonic crystals can just avoid this.

[0003] Photonic crystals are a type of material with periodically arranged microstructures of media with different refractive indices. The periodic distribution of the refractive index prevents light of a certain wavelength from passing through this structure and is reflected. The range of light waves that cannot pass through is called the photonic bandgap. When the bandgap of a photonic crystal is in the visible light region, it means that light of a certain frequency in the visible light band will be reflected, showing a color visible to the naked eye in that band, which is also called structural color. For chiral photonic crystal materials, the photonic bandgap has chiral enantioselectivity, which is manifested as the ability to selectively reflect left-handed or right-handed circularly polarized light and transmit circularly polarized light of the other rotation direction. Most of the existing methods of using photonic crystals for anti-counterfeiting combine photonic crystals with other anti-counterfeiting methods, and there is relatively little development of the optical properties of photonic crystals themselves, especially chiral photonic crystals. Therefore, how to simply and quickly prepare a chiral photonic crystal and use its chiral optical properties in combination with optical anti-counterfeiting technology for anti-counterfeiting has become an urgent problem to be solved in this field. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a chiral photonic crystal toner and its preparation method and application. The chiral photonic crystal toner provided by the present invention has the characteristics of chiral structural color and circularly polarized luminescence, and can be applied in anti-counterfeiting technology to greatly improve the security of information anti-counterfeiting encryption.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a chiral photonic crystal color powder, wherein the chiral photonic crystal color powder is composed of chiral photonic crystal particles and a luminescent substance loaded on the chiral photonic crystal particles;

[0007] The preparation method comprises the following steps:

[0008] Mixing a liquid crystal polymer monomer, a chiral dopant, and a luminescent substance, polymerizing to obtain a chiral photonic crystal polymer film loaded with the luminescent substance, and then crushing to obtain the chiral photonic crystal toner;

[0009] The chiral photonic crystal particles have chiral structural colors, and the chiral structural colors are generated in the chiral photon bandgap.

[0010] The luminescent material can generate circularly polarized luminescence after being loaded onto the chiral photonic crystal particles.

[0011] The above-mentioned specific chiral photonic crystal color powder has chiral structural color and circularly polarized luminescence characteristics. While producing chiral structural color, the chiral photonic crystal particles provide a chiral environment for the luminescent material loaded therein, so that the luminescent material emits circularly polarized light. In addition, the luminescent material loaded inside the particles reduces direct contact with air to a certain extent, increasing the stability of the luminescent dye; the particles combined with the luminescent material can select two luminescence ranges of visible light luminescence and near-infrared luminescence, which can be used in anti-counterfeiting technology to greatly improve the security of information anti-counterfeiting encryption.

[0012] Preferably, in parts by weight, the liquid crystal polymer monomer accounts for 80-120 parts, the chiral dopant accounts for 0.8-4 parts, and the luminescent substance accounts for 0.1-1 parts.

[0013] Among them, the number of parts of liquid crystal polymer monomers can be 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts, 110 parts, 115 parts or 120 parts, etc., the number of parts of chiral dopants can be 0.8 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts or 4 parts, etc., the number of parts of luminescent substances can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 parts, etc., but are not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are equally applicable.

[0014] Preferably, the polymerized monomers include 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (C6M) and / or 1,4-bis-[4-(3-acryloyloxypropoxy)benzoyloxy]-2-methylbenzene (RM257).

[0015] Preferably, the chiral dopant includes any one of S5011, R5011, S811 or R811, or a combination of at least two of them.

[0016] Preferably, the luminescent material is colorless or white when observed by naked eyes under visible light; the luminescent wavelength of the luminescent material is aligned with the wavelength center of the photon bandgap of the chiral photonic crystal particles, and the emission wavelength half-peak width of the luminescent material is smaller than the width of the photon bandgap.

[0017] For example, the luminescent material may be: inorganic materials including silver-gold-selenium quantum dots, rare earth nanoparticles, and lanthanide metal-doped lead halide cesium perovskite; organic materials including 9,10-diphenylanthracene and other common blue light dyes. In addition, organic green or red light dyes will produce absorption at a slightly shorter wavelength, so there will be color, but the color of the dye itself can be diluted by reducing the doping amount, so as not to affect the performance of the structural color, so it can also be used.

[0018] Preferably, the mixing further includes mixing with a crosslinking agent and a photoinitiator.

[0019] Preferably, in parts by weight, the amount of the crosslinking agent is 4-8 parts, and the amount of the photoinitiator is 1-3 parts.

[0020] The number of cross-linking agents can be 4 parts, 5 parts, 6 parts, 7 parts or 8 parts, etc., and the number of photoinitiators can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts, etc., but are not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0021] Preferably, the crosslinking agent comprises trimethylolpropane triacrylate (TMPTA) and / or 2-methyl-1,4-phenylenebis(4-(((4-(acryloyloxy)butoxy)carbonyl)oxy)benzoate) (LC242).

[0022] Preferably, the photoinitiator comprises 2,2-dimethoxy-2-phenylacetophenone (I651) and / or methyl benzoylformate (MBF).

[0023] Preferably, the mixing further comprises mixing with a solvent, and after the mixing, the solvent is removed;

[0024] Preferably, the solvent comprises dichloromethane.

[0025] In a second aspect, the present invention provides a chiral photonic crystal toner prepared by the preparation method described above.

[0026] Preferably, the chiral photonic crystal color powder has chiral structural color and circularly polarized luminescence characteristics in the visible light band and / or near infrared band.

[0027] In a third aspect, the present invention provides the application of the chiral photonic crystal color powder as described above in anti-counterfeiting technology.

[0028] In a fourth aspect, the present invention also provides an anti-counterfeiting method, which comprises the following steps:

[0029] (1) filling the chiral photonic crystal color powder as described above to form an anti-counterfeiting pattern;

[0030] (2) observing the anti-counterfeiting pattern with naked eyes to obtain a first pattern, and then observing the first pattern through a circular polarizer whose use range covers the chiral structural color range of the chiral photonic crystal toner, and observing changes in the first pattern;

[0031] The luminescent material in the chiral photonic crystal toner is excited to obtain a second pattern, and then the second pattern is observed through a circular polarizer whose range covers the luminescent range of the luminescent material in the chiral photonic crystal toner, and changes in the second pattern are observed.

[0032] Preferably, step (1) further includes filling the anti-counterfeiting pattern with chiral photonic crystal color powder (a luminescent material carrying a near-infrared luminescence wavelength aligned with the photon bandgap) with structural colors invisible to the naked eye; after observing the second pattern change, observing the third pattern with a near-infrared camera, and observing the third pattern change through a circular polarizer in the chiral structural color range of the chiral photonic crystal color powder with structural colors invisible to the naked eye.

[0033] Compared with the existing technical solutions that partially use an integral chiral photonic crystal film, the above anti-counterfeiting method utilizes the randomness of the dye loading inside the film cavity for design, emphasizing the anti-counterfeiting of the non-repeatable pattern formed by the irregular distribution in space, while the present invention mainly considers the diversity of patterns. While combining structural color and dye luminescence, the selection of different luminescence bands further increases the difficulty and cost of counterfeiting, and significantly improves the anti-counterfeiting effect.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a method for preparing a chiral photonic crystal color powder, wherein the prepared specific chiral photonic crystal color powder has chiral structural color and circularly polarized luminescence characteristics, and the chiral photonic crystal particles provide a chiral environment for the luminescent material loaded therein while generating chiral structural color, so that the luminescent material emits circularly polarized light. In addition, the luminescent material loaded inside the particles reduces direct contact with air to a certain extent, and increases the stability of the luminescent dye. The particles combined with the luminescent material can select two luminescence ranges of visible light and near infrared, and can be used in anti-counterfeiting technology to greatly improve the security of information anti-counterfeiting encryption. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Photoluminescence and transmittance spectra of the chiral photonic crystal toner provided in Example 1-2;

[0037] Figure 2 The circularly polarized luminescence spectrum of the chiral photonic crystal toner provided in Example 1-2;

[0038] Figure 3 Photoluminescence and transmittance spectra of the chiral photonic crystal toner provided in Example 3-4;

[0039] Figure 4 The circularly polarized luminescence spectrum of the chiral photonic crystal toner provided in Example 3-4;

[0040] Figure 5 The chiral structural color anti-counterfeiting effect diagram of the chiral photonic crystal color powder in the visible light range provided in Application Example 1;

[0041] Figure 6 This is an anti-counterfeiting effect diagram of the circularly polarized luminescence in the visible light range of the chiral photonic crystal color powder provided in Application Example 1;

[0042] Figure 7 This is a diagram of the anti-counterfeiting effect of the near-infrared circularly polarized luminescence of the chiral photonic crystal color powder provided in Application Example 1. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] Example 1

[0045] This embodiment provides three chiral photonic crystal color powders and preparation methods thereof. The chiral photonic crystal color powders include chiral photonic crystal particles and luminescent substances loaded on the chiral photonic crystal particles; the structural color is in the visible light range.

[0046] The luminescent materials (the maximum emission wavelength is aligned with the center of the photon bandgap) are blue light luminescent dye (9,10-diphenylanthracene) with a maximum emission wavelength of 430 nanometers and a half-peak width of 80 nanometers; green light luminescent dye (coumarin 6) with a maximum emission wavelength of 520 nanometers and a half-peak width of 70 nanometers; and red light luminescent dye (Nile red) with a maximum emission wavelength of 640 nanometers and a half-peak width of 100 nanometers.

[0047] The raw materials for preparing the chiral photonic crystal toner include the following components in parts by weight:

[0048] Liquid crystal polymer monomer C6M 100 parts, crosslinking agent TMPTA 7.8 parts, photoinitiator I651 2.5 parts, chiral dopant R5011 2, 3 or 4 parts, luminescent substance 0.1 parts;

[0049] The chiral photonic crystal color powder has a photon bandgap (structural color), the center positions of the bandgap are 430 nanometers (corresponding to 4 parts of chiral dopant), 520 nanometers (corresponding to 3 parts of chiral dopant) and 640 nanometers (corresponding to 2 parts of chiral dopant), and the bandgap width is 150 nanometers;

[0050] The preparation method of the chiral photonic crystal toner is as follows:

[0051] The above-mentioned raw materials and dichloromethane (500 parts) were mixed evenly, and the temperature was raised to 80°C to volatilize the dichloromethane. The mixture was then poured into a polymerization template and irradiated with ultraviolet light with a wavelength of 365 nanometers. The mixture was polymerized for 20 minutes to obtain a chiral photonic crystal polymer film. The chiral photonic crystal polymer film was then placed in a cutting machine for crushing to obtain chiral photonic crystal toners of the three structural colors, which were named R-blue toner, R-green toner and R-red toner, respectively.

[0052] Example 2

[0053] This embodiment provides three chiral photonic crystal toners and preparation methods thereof, which differ from Embodiment 1 only in that the chiral dopant R5011 is replaced by the chiral dopant S5011 of equal weight, and other conditions are the same as Embodiment 1. The products are named S-blue toner, S-green toner and S-red toner respectively.

[0054] The chiral photonic crystal toners of the three structural colors provided in Examples 1-2 were tested for luminescence spectrum, transmittance spectrum and circularly polarized luminescence spectrum. Figure 1 , 2 It can be seen that the emission wavelengths of the three dyes are aligned with the photon bandgap of the chiral photonic crystal particles. The luminescent substance in the R-chiral photonic crystal color powder corresponding to the chiral dopant R5011 can obtain a positive circularly polarized luminescence signal, representing left-handed circularly polarized luminescence; the S-chiral photonic crystal color powder corresponding to the chiral dopant S5011 can obtain a negative circularly polarized luminescence signal, representing right-handed circularly polarized luminescence.

[0055] Example 3

[0056] This embodiment provides two chiral photonic crystal color powders and preparation methods thereof. The chiral photonic crystal color powders include chiral photonic crystal particles and a luminescent substance loaded on the chiral polymer film. The structural color is in the near-infrared range and is invisible to the naked eye.

[0057] The luminescent materials (the maximum emission wavelength is aligned with the center of the photon band gap) are near-infrared quantum dots (silver, gold, selenium quantum dots, the preparation method refers to J.Am.Chem.Soc.2021,143,2601-2607), with a maximum emission wavelength of 1000 nanometers and a half-peak width of 120 nanometers; near-infrared quantum dots (silver, gold, selenium quantum dots, the preparation method refers to J.Am.Chem.Soc.2021,143,2601-2607), with a maximum emission wavelength of 1250 nanometers and a half-peak width of 110 nanometers.

[0058] The raw materials for preparing the chiral photonic crystal toner include the following components in parts by weight:

[0059] 100 parts of liquid crystal polymer monomer C6M, 7.8 parts of cross-linking agent TMPTA, 2.5 parts of photoinitiator I651, 0.8 or 1.3 parts of chiral dopant R5011, and 0.3 parts of luminescent substance.

[0060] The chiral photonic crystal color powder has a photon bandgap (structural color), the center positions of the bandgap are 1000 nanometers (corresponding to 1.3 parts of chiral dopant) and 1250 nanometers (corresponding to 0.8 parts of chiral dopant) respectively, and the bandgap width is 160 nanometers.

[0061] The preparation method of the chiral photonic crystal toner is as follows:

[0062] After the above raw materials and dichloromethane (500 parts) were mixed evenly, the temperature was raised to 80°C to volatilize the dichloromethane, and then poured into a polymerization template, irradiated with ultraviolet light with a wavelength of 365 nanometers, and polymerized for 20 minutes to obtain a chiral photonic crystal polymer film, and then the chiral photonic crystal polymer film was placed in a cutting machine for crushing to obtain the chiral photonic crystal toner, which were named R-near infrared toner 1 and R-near infrared toner 2 respectively.

[0063] Example 4

[0064] This embodiment provides two chiral photonic crystal toners and preparation methods thereof, which differ from the embodiment 3 only in that the chiral dopant R5011 is replaced by the chiral dopant S5011 of equal weight, and other conditions are the same as those of the embodiment 3. The products are named S-near infrared toner 1 and S-near infrared toner 2, respectively.

[0065] The chiral photonic crystal toner provided in Examples 3-4 was tested for luminescence spectrum, transmittance spectrum and circularly polarized luminescence spectrum. Figure 3 , 4It can be seen that the near-infrared emission wavelength is aligned with the photon bandgap of the chiral photonic particles. The luminescent substance in the R-chiral photonic crystal color powder corresponding to the chiral dopant R5011 can obtain a positive circularly polarized luminescence signal, representing left-handed circularly polarized luminescence; the S-chiral photonic crystal color powder corresponding to the chiral dopant S5011 can obtain a negative circularly polarized luminescence signal, representing right-handed circularly polarized luminescence.

[0066] Application Example 1

[0067] This application example provides an anti-counterfeiting method for chiral photonic crystal toner, and the anti-counterfeiting method is as follows:

[0068] Taking the three visible light structural colors and two near-infrared R-chiral photonic crystal color powders provided in Example 1 and Example 3 as an example, the R-blue color powder, R-green color powder and R-red color powder are respectively filled into the first three "8s" of the pattern "8888", among which the R-blue color powder is filled into the first "8", the R-green color powder is filled into the second "8", and the R-red color powder is filled into the third "8"; the R-near-infrared color powder 1 and the R-near-infrared color powder 2 are mixed together and filled into the fourth "8".

[0069] Under naked eye observation, the first "8" shows a blue structural color, the second "8" shows a green structural color, the third "8" shows a red structural color, and the fourth "8" has no color because the photon bandgap is invisible to the naked eye in the near-infrared. Figure 5 shown.

[0070] Then observe through the circular polarizer. Under the left-handed circular polarizer corresponding to the blue light range alone, the color of the first "8" disappears while the colors of the second and third "8" remain unchanged; under the left-handed circular polarizer corresponding to the green light range alone, the color of the second "8" disappears while the colors of the first and third "8" remain unchanged; under the left-handed circular polarizer corresponding to the red light range alone, the color of the third "8" disappears while the colors of the first and second "8" remain unchanged; and under the left-handed circular polarizer in the visible light range, the structural colors of the three "8"s all disappear. Figure 5 shown.

[0071] When the pattern "8888" is illuminated by 365-nanometer ultraviolet light, a luminescent pattern can be observed, in which the first "8" emits blue light, the second "8" emits green light, the third "8" emits red light, and in the fourth "8", the near-infrared luminescent material is not excited and therefore does not emit light. Under a right-handed circular polarizer corresponding to the blue light range, the brightness of the first "8" luminescent pattern decreases, while the second and third "8s" remain unchanged. Under a right-handed circular polarizer corresponding to the green light range alone, the brightness of the second "8" luminescent pattern decreases, while the first and third "8s" remain unchanged. Under a right-handed circular polarizer corresponding to the red light range alone, the brightness of the third "8" luminescent pattern decreases, while the first and second "8s" remain unchanged. Under a right-handed circular polarizer in the visible light range, the brightness of the luminescent patterns of the three "8s" decreases, as shown in Figure 1. Figure 6 shown.

[0072] The pattern "8888" is illuminated with 808-nanometer light, which only excites near-infrared luminescent substances. Since near-infrared luminescence is invisible to the naked eye, a near-infrared camera is used to observe the luminescent pattern. At this time, the luminescent pattern "8" at the fourth position formed by the luminescence of R-near-infrared toner 1 and R-near-infrared toner 2 can be seen. The luminescence of R-near-infrared toner 2 can be filtered out with a 1100-nanometer short-wave filter while retaining the luminescence of R-near-infrared toner 1. At this time, the luminescent pattern "6" belonging to R-near-infrared toner 1 can be seen ( Figure 7 In the middle of the row), under the right-hand circular polarizer corresponding to the near-infrared range, the luminous intensity is significantly weakened ( Figure 7 The luminescence of R-near infrared toner 2 can be retained by using a 1100 nm long-wave filter, and the luminescence pattern "9" ( Figure 7 The luminous intensity is obviously weakened under the right-handed circular polarizer corresponding to the near-infrared range ( Figure 7 Second row, right picture).

[0073] In summary, the present invention designs and cuts and crushes the specific composition of the chiral photonic crystal material to obtain a chiral photonic crystal toner with chiral structural color and circularly polarized luminescence characteristics. This chiral photonic crystal toner can select two ranges of visible light luminescence and near-infrared luminescence, and also has two characteristics of chiral structural color and circular polarization. Combined with these luminescence ranges and luminescence characteristics, the information anti-counterfeiting encryption security of the chiral photonic crystal toner in the anti-counterfeiting field is greatly improved.

[0074] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the chiral photonic crystal toner and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0075] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0076] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a chiral photonic crystal toner, characterized in that: The chiral photonic crystal toner is composed of chiral photonic crystal particles and a luminescent substance loaded on the chiral photonic crystal particles; The preparation method comprises the following steps: Mixing a liquid crystal polymer monomer, a chiral dopant, and a luminescent substance, polymerizing to obtain a chiral photonic crystal polymer film loaded with the luminescent substance, and then crushing to obtain the chiral photonic crystal toner; The chiral photonic crystal particles have chiral structural colors, which are generated in the chiral photon bandgap. The luminescent material can generate circularly polarized luminescence after being loaded onto the chiral photonic crystal particles.

2. The preparation method according to claim 1, characterized in that: In terms of weight, the liquid crystal polymer monomer accounts for 80-120 parts, the chiral dopant accounts for 0.8-4 parts, and the luminescent substance accounts for 0.1-1 parts.

3. The preparation method according to claim 1 or 2, characterized in that: The polymerizable monomers include 1,4-bis[4-(6-acryloxyhexyloxy)benzoyloxy]-2-methylbenzene and / or 1,4-bis-[4-(3-acryloxypropoxy)benzoyloxy]-2-methylbenzene; Preferably, the chiral dopant includes any one of S5011, R5011, S811 or R811, or a combination of at least two of them.

4. The preparation method according to any one of claims 1 to 3, characterized in that The luminescent material is colorless or white when observed by naked eyes under visible light; the luminescent wavelength of the luminescent material is aligned with the wavelength center of the photon bandgap of the chiral photonic crystal particles, and the half-peak width of the emission wavelength of the luminescent material is smaller than the width of the photon bandgap.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The mixing also includes mixing with a cross-linking agent and a photoinitiator; Preferably, in parts by weight, the crosslinking agent is 4-8 parts, and the photoinitiator is 1-3 parts; Preferably, the crosslinking agent comprises trimethylolpropane triacrylate and / or 2-methyl-1,4-phenylenebis(4-(((4-(acryloyloxy)butoxy)carbonyl)oxy)benzoate); Preferably, the photoinitiator comprises 2,2-dimethoxy-2-phenylacetophenone and / or methyl benzoylformate.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The mixing further comprises mixing with a solvent, and after the mixing, the solvent is removed; Preferably, the solvent comprises dichloromethane.

7. A chiral photonic crystal toner prepared by the preparation method according to any one of claims 1 to 6.

8. The chiral photonic crystal toner according to claim 7, characterized in that: The chiral photonic crystal color powder has chiral structural color and circularly polarized luminescence characteristics in the visible light band and / or near infrared band.

9. Application of the chiral photonic crystal toner according to claim 7 or 8 in anti-counterfeiting technology.

10. An anti-counterfeiting method, characterized in that: The anti-counterfeiting method comprises the following steps: (1) Filling the chiral photonic crystal color powder described in claim 7 or 8 to form an anti-counterfeiting pattern; (2) observing the anti-counterfeiting pattern with naked eyes to obtain a first pattern, and then observing the first pattern through a circular polarizer whose use range covers the chiral structural color range of the chiral photonic crystal toner, and observing changes in the first pattern; The luminescent material in the chiral photonic crystal toner is excited to obtain a second pattern, and then the second pattern is observed through a circular polarizer whose range covers the luminescent range of the luminescent material in the chiral photonic crystal toner, and changes in the second pattern are observed.

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