Holographic polymer dispersed nanoparticle material and applications thereof

Abstract

This application belongs to the field of functional materials, and more specifically, relates to a holographic polymer-dispersed nanoparticle material and its applications. The holographic polymer-dispersed nanoparticle material provided in this application, through the design of the photoinitiator structure and its compounding with holographic recording monomers and nanoparticles, can improve the photosensitivity of the holographic polymer-dispersed nanoparticle material, while effectively increasing the processing efficiency and rapidly preparing the holographic polymer-dispersed nanoparticle material. This application enables the preparation of holographic polymer-dispersed nanoparticle materials with short holographic coherence exposure times (e.g., 0.01~5 s) and low holographic coherence exposure doses (e.g., 0.1~10 mJ / cm²). 2 Under the conditions of [condition], holographic polymer-dispersed nanoparticle materials with a photosensitivity greater than or equal to 100 cm / mJ were prepared, which are suitable for high-end anti-counterfeiting, information storage, virtual reality, augmented reality and other fields.

Description

Technical Field

[0001] This application belongs to the field of functional materials, and more specifically, relates to a holographic polymer dispersed nanoparticle material and its application. Background Technology

[0002] In holographic recording materials, holographic polymer-dispersed nanoparticles exhibit low volume shrinkage, good stability, high grating fidelity, and low light scattering, making them suitable for high-end anti-counterfeiting, information storage, virtual reality, and augmented reality applications. Holographic polymer-dispersed nanoparticles consist of a photoinitiation system, holographic recording monomers, and nanoparticles. Under irradiation by two coherent beams, the photoinitiation system in the coherent bright region absorbs photons and generates active centers, which in turn trigger the polymerization reaction of the holographic recording monomers. Simultaneously, the nanoparticles are displaced to the coherent dark region. Ultimately, a periodically ordered phase-separated structure is formed within the holographic polymer-dispersed nanoparticle material.

[0003] The photoinitiation systems disclosed in literature (Macromolecules 2015, 48, 2958-2966), literature (Opt. Express 2020, 28, 28366-28382), and patent documents CN104109217A and CN117950268A for preparing holographic polymer-dispersed nanoparticle materials have complex compositions, typically consisting of photosensitizers and co-initiators. During coherent laser irradiation, the photosensitizer and co-initiator undergo intermolecular photo-redox reactions, generating active centers (usually initiating free radicals) that polymerize the holographic recording monomers. However, the intermolecular photo-redox reactions are inefficient and have low conversion rates, resulting in long holographic coherent exposure times, which significantly limit the preparation efficiency. Furthermore, the photosensitivity of holographic polymer-dispersed nanoparticle materials still needs improvement. Therefore, providing a holographic polymer-dispersed nanoparticle material with a simple photoinitiation system, short holographic coherent exposure time, low holographic coherent exposure dose, and high photosensitivity is of great significance for its large-scale production. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application aims to provide a holographic polymer dispersed nanoparticle material and its application, thereby solving the problems of complex composition of existing photoinitiation systems for preparing holographic polymer dispersed nanoparticle materials, long holographic coherent exposure time, high holographic coherent exposure dose, low preparation efficiency, and the need to improve the photosensitivity of the prepared holographic polymer dispersed nanoparticle materials.

[0005] To achieve the above objectives, in a first aspect, this application provides a photoinitiator, the structural formula of which is shown in formula (a):

[0006] Formula (1) Wherein, R1 is hydrogen, C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; R2 and R4 are each independently C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; R3 is any one of hydrogen, chlorine, bromine, or iodine; R5 is C 1~12 Alkyl, C 1~12 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; Each time R6 appears, it is independently cyano, vinyl, or C. 1~6 Alkyl, C 1~6 Haloalkyl, C 1~6 Any one of the alkoxy groups.

[0007] Secondly, this application provides a holographic polymer dispersed nanoparticle material, the raw materials for preparing the holographic polymer dispersed nanoparticle material including the above-mentioned photoinitiator, holographic recording monomer and nanoparticles.

[0008] Preferably, the photoinitiator can be excited by visible light with a wavelength of 420~700 nm, causing the boron-carbon bonds in the photoinitiator to dissociate and generate initiating free radicals that can rapidly initiate the polymerization reaction of the holographic recording monomer; the maximum molar extinction coefficient of the photoinitiator at a wavelength of 420~700 nm is ≥ 40000 L / (mol·cm), and the chain dissociation energy of the boron-carbon bonds is ≤ 2.54 eV.

[0009] Preferably, the holographic recording monomer is one or more of acrylate monomers, acrylamide monomers, and vinyl monomers.

[0010] More preferably, the aforementioned holographic recording unit is N -Vinylpyrrolidone, N,N - One or more of the following: dimethacrylamide, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, acrylic acid, methacrylic acid, ethylene glycol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and hyperbranched acrylate.

[0011] Preferably, the refractive index of the above nanoparticles is ≥ 1.80 and the average particle size is < 50 nm.

[0012] More preferably, the nanoparticles are one or more of titanium dioxide nanoparticles, zirconium dioxide nanoparticles, silicon carbide nanoparticles, iron oxide nanoparticles, and zinc sulfide nanoparticles.

[0013] Preferably, the weight ratio of the photoinitiator, holographic recording monomer and nanoparticles is (0.01~5): (20~80): (15~79).

[0014] Thirdly, this application provides a method for preparing the above-mentioned holographic polymer-dispersed nanoparticle material, comprising the following steps: S1. Mix the photoinitiator, nanoparticles and holographic recording monomer to obtain a mixed solution; S2. The above mixed solution is encapsulated in a transparent container and exposed using a coherent laser to cause the boron-carbon bonds in the photoinitiator to dissociate and generate initiating free radicals. These initiating free radicals react with the above holographic recording monomers to obtain holographic polymer dispersed nanoparticle materials.

[0015] Preferably, the wavelength of the coherent laser is 420~700 nm, the exposure time is 0.01~5 s, and the exposure dose is 0.1~10 cm / mJ.

[0016] Preferably, the above preparation method further includes post-processing of the above holographic polymer dispersed nanoparticle material, the post-processing including light irradiation or heating.

[0017] Another objective of this application is to provide the application of the above-mentioned holographic polymer dispersed nanoparticle materials in the fields of high-end anti-counterfeiting, information storage, virtual reality or augmented reality.

[0018] This application also provides an optical device comprising the aforementioned holographic polymer dispersed nanoparticle material.

[0019] Preferably, the optical device includes one or more of the following: a holographic display, a holographic notch filter, a data storage device, and a holographic anti-counterfeiting device.

[0020] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: (1) The holographic polymer dispersed nanoparticle material provided in this application can effectively improve the processing efficiency of the holographic polymer dispersed nanoparticle material by designing the structure of the photoinitiator and compounding it with the holographic recording monomer and nanoparticles, and quickly prepare the holographic polymer dispersed nanoparticle material. At the same time, it can improve the photosensitivity of the holographic polymer dispersed nanoparticle material. This application can prepare holographic polymer dispersed nanoparticle material with high photosensitivity under the conditions of short holographic coherent exposure time and low exposure dose, which is suitable for high-end anti-counterfeiting, information storage, virtual reality, augmented reality and other fields.

[0021] (2) In the holographic polymer-dispersed nanoparticle material provided in this application, the photoinitiator can be excited by visible light with a wavelength of 420~700 nm to undergo intramolecular cleavage, i.e., homolytic cleavage of boron-carbon bonds, generating initiating free radicals that act on the holographic recording monomer, effectively improving the generation efficiency of initiating free radicals, and simplifying the composition of the holographic polymer-dispersed nanoparticle material. In addition, the reaction efficiency of the above-mentioned photoinitiator is much higher than that of existing multi-component photoinitiators, enabling faster holographic recording process.

[0022] (3) This application can achieve short holographic coherence exposure time (e.g., 0.01~5 s) and low holographic coherence exposure dose (e.g., 0.1~10 mJ / cm). 2 Under certain conditions, holographic polymer-dispersed nanoparticle materials with a photosensitivity greater than or equal to 100 cm / mJ were prepared. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation process of the holographic polymer-dispersed nanoparticle material provided in this application; Figure 2 The holographic polymer dispersed nanoparticle material provided in this application is used in the structure of augmented reality; Figure 3 This application demonstrates the display effect of holographic polymer dispersed nanoparticle materials used in augmented reality. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] In this application description, it should be understood that the term "and / or" describes a relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In this application, the symbol " / " indicates that the related objects are in an "or" relationship, for example, A / B means A or B.

[0026] In the description of the embodiments in this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0027] In the description of the embodiments in this application, unless otherwise stated, "multiple" means two or more.

[0028] The terms "group" and "chemical group" refer to specific segments or functional groups in a molecule.

[0029] In this application, unless otherwise specified, the number of "substitutions" may be one or more; when there are multiple substitutions, they may be two, three, or four. Furthermore, when there are multiple substitutions, the substitutions may be the same or different. Unless otherwise specified, the position of the substitutions may be arbitrary.

[0030] The term "alkyl" refers to a saturated aliphatic hydrocarbon group having a specified number of carbon atoms, including both straight-chain and branched structures. For example, C1~C 20 Alkyl groups include alkyl groups having 1 to 20 carbon atoms in a straight-chain or branched structure. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl (e.g., n-propyl, isopropyl), butyl (e.g., n-butyl, sec-butyl, isobutyl, or tert-butyl), and pentyl (e.g., n-pentyl, isopentyl, tert-pentyl, neopentyl).

[0031] The term "substituted alkyl" refers to an alkyl group that is substituted with one or more substituents at any available connection point. The term "haloalkyl" refers to an alkyl group having one or more halogen substituents, for example, halomethyl includes, but is not limited to, groups such as -CH2Br, -CH2I, -CH2Cl, -CH2F, -CHF2, and -CF3.

[0032] The term "alkoxy" refers to a group with the structure "-O-alkyl", in which an alkyl group is attached to another group via an oxygen atom. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentooxy, isopentoxy, tert-pentoxy, and neopentoxy.

[0033] The term "aryl" refers to a cyclic aromatic hydrocarbon group that does not contain heteroatoms in the ring. Examples of aryl groups include, but are not limited to, phenyl, diphenyl, triphenyl, and tetraphenyl. As defined in this application, an aryl group can be an unsubstituted aryl group or a substituted aryl group.

[0034] The term "substituted aryl" refers to an aryl group that is substituted at one or more positions on the aryl ring by one or more substituents. The term "substituted phenyl" refers to a phenyl group that is substituted at one or more positions at the 1, 2, 3, 4, 5, or 6 positions by a substituent. Examples of substituents include, but are not limited to, cyano, vinyl, alkyl, alkoxy, and halogen groups.

[0035] This application provides a photoinitiator, the structural formula of which is shown in formula (I):

[0036] Formula (1) Wherein, R1 is hydrogen, C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; preferably, R1 is hydrogen or C. 1~12 Alkyl, C 1~12 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; more preferably, R1 is hydrogen or C. 1~6 Alkyl, C 1~6 Any one of haloalkyl, phenyl, or phenyl substituted with one or more R6.

[0037] In equation (1), R2 and R4 are each independently C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; preferably, R2 and R4 are each independently C. 1~12 Alkyl, C 1~12 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; more preferably, R2 and R4 are each independently C. 1~6 Alkyl, C 1~6 Any one of haloalkyl, phenyl, or phenyl substituted with one or more R6.

[0038] In formula (a), R3 is any one of hydrogen, chlorine, bromine, and iodine.

[0039] In equation (1), R5 is C 1~12 Alkyl, C 1~12 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; preferably, R5 is C. 1~12Alkyl, C 1~12 Any one of haloalkyl, phenyl, or phenyl substituted with one or more R6 groups. More preferably, R5 is C6. 1~6 Alkyl, C 1~6 Any one of haloalkyl, phenyl, or phenyl substituted with one or more R6.

[0040] In some embodiments, R6 is independently cyano, vinyl, or C each time it appears. 1~6 Alkyl, C 1~6 Haloalkyl, C 1~6 Any one of the alkoxy groups.

[0041] On the other hand, this application provides a holographic polymer dispersed nanoparticle material, the raw materials for preparing the holographic polymer dispersed nanoparticle material including the above-mentioned photoinitiator, holographic recording monomer and nanoparticles.

[0042] Existing holographic polymer-dispersed nanoparticle materials generate initiating free radicals through intermolecular photo-redox reactions between photosensitizers and co-initiators, thereby initiating the polymerization reaction of holographic recording monomers. However, the intermolecular chemical reactions rely on effective collisions, resulting in low efficiency in free radical generation. The inventors of this application, through designing the structure of the photoinitiator, experimentally discovered that when the maximum molar extinction coefficient of the photoinitiator at wavelengths of 420–700 nm is ≥ 40000 L / (mol·cm), and the chain dissociation energy of the boron-carbon bonds in the photoinitiator is ≤ 2.54 eV, the photoinitiator can be excited by visible light at wavelengths of 420–700 nm and undergo intramolecular cleavage, i.e., the boron-carbon bonds dissociate, generating initiating free radicals that act on the holographic recording monomers. This effectively improves the efficiency of initiating free radical generation and simplifies the composition of the holographic polymer-dispersed nanoparticle materials. Furthermore, the reaction efficiency of the aforementioned photoinitiator is far higher than that of existing multi-component photoinitiators, enabling a faster holographic recording process. This application enables the preparation of holographic polymer-dispersed nanoparticle materials with high photosensitivity under conditions of short holographic coherent exposure time and low holographic coherent exposure dose.

[0043] The bond dissociation energy of the aforementioned boron-carbon bond can be calculated using existing techniques and quantum chemical calculation programs, such as the Gaussian 16 package, to calculate the enthalpy of reactants and products during the photoreaction process. Geometric optimization and frequency calculations were performed on all intermediates at the B3LYP-D3 / Def2-TZVP level until no imaginary frequencies were found. Subsequently, higher-precision single-point energy calculations were performed on the optimized structure at the M06-2X / Def2-TZVPP level. An implicit solvation model (SMD, acetonitrile as solvent) was used in all calculations. Finally, the enthalpy of reactants and products can be obtained using the Shermo program combined with the Gaussian 16 calculation results. Bond dissociation energy is generally defined as the enthalpy change of the reaction during the breaking of chemical bonds in a molecule, i.e., the enthalpy of the product minus the enthalpy of the reactants.

[0044] In some embodiments, the initiating radicals generated by the photoinitiator can act on the holographic recording monomer, causing it to undergo a polymerization reaction. The chain initiation rate of this polymerization reaction is superior to the chain growth rate, which can effectively improve the processing efficiency of the holographic polymer-dispersed nanoparticle material. The polymerization rate can be calculated according to the literature (J. Phys. Chem. A 2008, 112, 29, 6772-6782).

[0045] It is understood that this application does not limit the source of the above photoinitiator, which can be prepared by methods known to those skilled in the art.

[0046] In some embodiments, the holographic recording monomer is one or more of acrylate monomers, acrylamide monomers, and vinyl monomers.

[0047] In some embodiments, the aforementioned acrylate monomers include, but are not limited to, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, hyperbranched acrylates, trimethylolpropane triacrylate, triethylene glycol dimethacrylate, phenyl methacrylate, 1,6-hexanediol diacrylate, 2-ethylhexyl acrylate, ethyl acrylate, trimethylolpropane trimethacrylate, quinoline dimethacrylate, 2-(perfluorooctyl)ethyl methacrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate, ethoxyethyl acrylate, ethoxyethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, and so on. tert-butyl acrylate, hexyl acrylate, hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, butyloxyethyl acrylate, butyloxyethyl methacrylate, lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, phenyl acrylate, p-chlorophenyl acrylate, p-chlorophenyl methacrylate, p-bromophenyl acrylate, p-bromophenyl methacrylate, trichlorophenyl acrylate, trichlorophenyl methacrylate, tribromophenyl acrylate, tribromophenyl methacrylate, pentachlorophenyl acrylate, pentachlorophenyl methacrylate, pentabromophenyl acrylate, pentabromophenyl methacrylate, pentabromophenyl acrylate, pentabromophenyl methyl acrylate, pentabromophenyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxyethoxyethyl acrylate, dicyclopentenyl acrylate.

[0048] In some embodiments, the acrylamide monomers described above include, but are not limited to, those described above. N,N -Dimethylacrylamide, N,N -Diethylacrylamide, 4-Acryloylmorpholine, N -Propylacrylamide, N -Butylacrylamide, N -(isobutoxymethyl)acrylamide, N -(methoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N -[2-(dimethylamino)ethyl]acrylamide, N -[2-(diethylamino)ethyl]acrylamide, dimethylaminopropylacrylamide and its corresponding methacrylamide.

[0049] In some embodiments, the vinyl monomers described above include, but are not limited to, those described above. N -Vinylpyrrolidone, N -vinylcarbazole, N - Vinylcaprolactam, vinyl ethyl ether, hydroxybutyl vinyl ether.

[0050] In some embodiments of this application, the aforementioned holographic recording unit is N -Vinylpyrrolidone, N,N - One or more of the following: dimethacrylamide, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, acrylic acid, methacrylic acid, ethylene glycol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and hyperbranched acrylate.

[0051] In some embodiments, the refractive index of the nanoparticles is ≥ 1.80, and the average particle size is < 50 nm. The selection of nanoparticles with the aforementioned refractive index in this application is beneficial for increasing the difference in refractive index between the holographic recording monomer and the nanoparticles, thereby improving the refractive index modulation of the holographic polymer-dispersed nanoparticle material. The selection of nanoparticles with an average particle size < 50 nm in this application facilitates diffusion and effectively improves the phase separation degree of the material. It is understood that this application does not limit the specific type of nanoparticles mentioned above; any nanoparticles that meet the above requirements are within the scope of protection of this application. The nanoparticles can be purchased from commercially available products or prepared using methods known to those skilled in the art.

[0052] In some embodiments, the nanoparticles may be one or more of titanium dioxide nanoparticles, zirconium dioxide nanoparticles, silicon carbide nanoparticles, iron oxide nanoparticles, and zinc sulfide nanoparticles, but not limited to.

[0053] In some embodiments, the weight ratio of the photoinitiator, holographic recording monomer and nanoparticles is (0.01~5):(20~80):(15~79).

[0054] The holographic polymer-dispersed nanoparticle material provided in this application, through the design of the photoinitiator structure and the control of the ratio of photoinitiator, holographic recording monomer, and nanoparticles within a reasonable range, can improve the photosensitivity of the holographic polymer-dispersed nanoparticle material, while effectively increasing the processing efficiency, enabling rapid preparation of holographic polymer-dispersed nanoparticle materials. Specifically, this application can achieve short holographic coherence exposure time (e.g., 0.01~5 s) and low holographic coherence exposure dose (e.g., 0.1~10 mJ / cm²). 2 Under the conditions of ), holographic polymer-dispersed nanoparticle materials with photosensitivity greater than or equal to 100 cm / mJ were prepared.

[0055] On the other hand, such as Figure 1 As shown, this application also provides a method for preparing the above-mentioned holographic polymer-dispersed nanoparticle material, comprising the following steps: S1. Mix the photoinitiator, nanoparticles and holographic recording monomer to obtain a mixed solution; S2. The above mixed solution is encapsulated in a transparent container and exposed using a coherent laser to cause the boron-carbon bonds in the photoinitiator to dissociate and generate initiating free radicals. These initiating free radicals react with the above holographic recording monomers to obtain holographic polymer dispersed nanoparticle materials.

[0056] It is understood that this application does not limit the source of the above-mentioned photoinitiator, which can be purchased from commercial products or prepared using methods known to those skilled in the art. For example, by reacting 1 equivalent of the parent structure 4,4-difluoro-1,3,5,7-tetramethyl-4-boron-3A,4A-diaza-S-indenene and 10 equivalents of methyllithium at room temperature for 24 h, a photoinitiator with R1 being hydrogen, R2 being methyl, R3 being hydrogen, R4 being methyl, and R5 being methyl is obtained, which is the photoinitiator in Example 1.

[0057] It is understood that this application does not limit the mixing method in step S1. It can be, but is not limited to, stirring. As long as the photoinitiator, holographic recording monomer and nanoparticles are mixed evenly, they are all within the protection scope of this application.

[0058] In some embodiments, the solution encapsulation described above can be performed by filling the mixed solution into a liquid crystal cell under dark conditions, with the cavity thickness of the liquid crystal cell being 2~50 μm, so that the thickness of the prepared holographic polymer dispersed nanoparticle material is controlled within 2~50 μm.

[0059] In some embodiments, in step S2, the wavelength of the coherent laser is 420~700 nm. For example, the wavelength can be 420 nm, 491 nm, 532 nm, 577 nm, 640 nm, or 700 nm.

[0060] In some embodiments, in step S2, the exposure time of the coherent laser is 0.01~5 s and the exposure dose is 0.1~10 cm / mJ, which can cause homolytic cleavage of the boron-carbon bonds in the photoinitiator and improve the efficiency of free radical generation.

[0061] In some embodiments, the above preparation method further includes post-processing of the above holographic polymer dispersed nanoparticle material, the post-processing including light irradiation or heating.

[0062] In some embodiments, the illumination involves placing the exposed material under a high-pressure mercury lamp, UV light, or white LED light to ensure complete reaction of the remaining holographic recording monomers. In some embodiments, the illumination time is 1–20 minutes.

[0063] On the other hand, this application also provides the application of the above-mentioned holographic polymer dispersed nanoparticle materials in the fields of high-end anti-counterfeiting, information storage, virtual reality or augmented reality.

[0064] In some embodiments, the application of the above-mentioned holographic polymer-dispersed nanoparticle material in augmented reality is as follows: Two symmetrical holographic polymer-dispersed nanoparticle materials (holographic gratings) are exposed on both sides of a liquid crystal cell. The angle between the grating vector of the holographic grating and the substrate (glass slide) is 45°. Then, the material is irradiated with a high-pressure mercury lamp for 10 minutes to prepare a holographic polymer-dispersed nanoparticle material for augmented reality. Its application structure is as follows. Figure 2 As shown. In practical applications, an image (such as HOLOGRAPHIC AUGMENTED REALITY) is projected onto the incident grating (left holographic grating), and the information can be seen on the exit grating (right holographic grating), as shown. Figure 3 As shown, this achieves the effect of overlaying virtual and real elements in augmented reality.

[0065] On the other hand, this application also provides an optical device comprising the above-mentioned holographic polymer dispersed nanoparticle material.

[0066] In some embodiments, the optical device described above includes, but is not limited to, holographic displays, holographic notch filters, data storage devices, and holographic anti-counterfeiting devices. Because the optical device provided in this application contains the aforementioned holographic polymer-dispersed nanoparticle material, the fabrication efficiency of the optical device can be improved.

[0067] It should be understood that materials of the same or similar type, model, quality, properties, or function as the reagents and instruments used in the following embodiments can be used to implement this application. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0068] The following are examples and comparative examples: Example 1 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 0.01 parts photoinitiator 1 (corresponding to formula (I), where R1 is hydrogen, R2 is methyl, R3 is hydrogen, R4 is methyl, and R5 is methyl), 33.99 parts nanoparticles (zirconia nanoparticles, with an average particle size of 20 nm and a refractive index of 2.55), 66 parts holographic recording monomers (26 parts pentaerythritol triacrylate, 40 parts...). N,N -Dimethylacrylamide). The structural formula of photoinitiator 1 is shown below: .

[0069] The preparation method of the above-mentioned photoinitiator 1 includes the following steps: reacting 1 equivalent of the parent core structure 4,4-difluoro-1,3,5,7-tetramethyl-4-boron-3A,4A-diaza-S-indenene and 10 equivalents of methyllithium at room temperature for 24 h to obtain photoinitiator 1. Photoinitiator 1 has a molar extinction coefficient of 67014 L / (mol·cm) at a wavelength of 488 nm and a bond dissociation energy of 2.54 eV for the boron-carbon bond.

[0070] The method for preparing holographic polymer-dispersed nanoparticle materials provided in this embodiment includes the following steps: Photoinitiator 1, nanoparticles, and holographic recording monomers were mixed uniformly to obtain a mother liquor material. This mother liquor material was then poured into a liquid crystal cell and exposed using a coherent laser with a wavelength of 491 nm, where the total power density (I) of the exposure was 2 mW / cm². 2 The exposure time (t) is 5 s, and the exposure dose (D = I×t) is 10 mJ / cm². 2 Then, it is irradiated under a high-pressure mercury lamp for 10 minutes to allow the unreacted holographic recording monomers to fully polymerize, resulting in a stable holographic polymer-dispersed nanoparticle material.

[0071] Example 2 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 0.05 parts photoinitiator 2 (corresponding to formula (I), where R1 is hydrogen, R2 is phenyl, R3 is chlorine, R4 is phenyl, and R5 is methyl), 29.95 parts nanoparticles (zirconia nanoparticles, with an average particle size of 20 nm and a refractive index of 2.55), 70 parts holographic recording monomers (30 parts pentaerythritol triacrylate, 40 parts...). N,N -Dimethylacrylamide). The structural formula of photoinitiator 2 is shown below: .

[0072] The preparation method of the above-mentioned photoinitiator 2 includes the following steps: dissolving 1 equivalent of 3,5-Diphenyl-2-formylpyrrole and 1 equivalent of 2,4-Diphenyl-1H-pyrrole in tetrahydrofuran solvent, adding a catalytic amount of concentrated hydrochloric acid and refluxing for 24 h; then adding 1 equivalent of 2,3-dichloro-5,6-dicyanobenzoquinone and reacting at room temperature for 24 h; finally adding 3 equivalents of triethylamine and 5 equivalents of boron trifluoride diethyl ether complex sequentially and reacting at room temperature for 24 h to obtain the core structure of photoinitiator 2. Dissolving 1 equivalent of the core structure with 2 equivalents of N-chlorosuccinimide in tetrahydrofuran and reacting for 24 h; then adding 10 equivalents of methyllithium and reacting at room temperature for 24 h to obtain photoinitiator 2. The molar extinction coefficient of photoinitiator 2 at a wavelength of 637 nm is 84119 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.57 eV.

[0073] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 3 mW / cm². 2 The exposure time was 3 seconds, and the exposure dose was 9 mJ / cm³. 2 .

[0074] Example 3 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 0.1 parts photoinitiator 3 (corresponding to formula (I), where R1 is hydrogen, R2 is 4-methylphenyl, R3 is bromine, R4 is 4-methylphenyl, and R5 is methyl), 19.9 parts nanoparticles (zinc sulfide nanoparticles, with an average particle size of 5 nm and a refractive index of 1.80), 80 parts holographic recording monomers (40 parts pentaerythritol triacrylate, 40 parts...). N,N -Dimethylacrylamide). The structural formula of photoinitiator 3 is shown below: .

[0075] The preparation method of the above photoinitiator 3 is the same as that of photoinitiator 2 in Example 2, except that 2,4-Bis(4-methylphenyl)-1H-pyrrole (synthesized in Synlett. 2016, 27(11), 1738-1742) is used to replace 2,4-Diphenyl-1H-pyrrole in Example 2; 3,5-Bis(4-methylphenyl)-2-formylpyrrole (synthesized in Russian Journal of Inorganic Chemistry 2014, 59(10), 1187-1194) is used to replace 3,5-Diphenyl-2-formylpyrrole in Example 2; and N-bromosuccinimide is used to replace N-chlorosuccinimide in Example 2 to obtain photoinitiator 3. Photoinitiator 3 has a molar extinction coefficient of 86251 L / (mol·cm) at a wavelength of 643 nm and a bond dissociation energy of 1.55 eV for the boron-carbon bond.

[0076] The preparation method of the above zinc sulfide nanoparticles is described in Adv. Mater. 2006, 18, 1188.

[0077] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 1 mW / cm². 2 The exposure time was 0.1 s, and the exposure dose was 0.1 mJ / cm². 2 .

[0078] Example 4 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 0.5 parts photoinitiator 4 (corresponding to formula (I), where R1 is hydrogen, R2 is 4-methoxyphenyl, R3 is hydrogen, R4 is 4-methoxyphenyl, and R5 is methyl), 59.5 parts nanoparticles (zinc sulfide nanoparticles, with an average particle size of 5 nm and a refractive index of 1.80), 80 parts holographic recording monomers (30 parts pentaerythritol triacrylate, 10 parts...). N,N -Dimethylacrylamide). The structural formula of photoinitiator 4 is shown below: .

[0079] The preparation method of photoinitiator 4 is the same as that of photoinitiator 2 in Example 2, except that 2,4-Bis(4-methoxyphenyl)-1H-pyrrole (synthesized in Tetrahedron Letters 2002, 43(10), 1863-1865) is used instead of 2,4-Diphenyl-1H-pyrrole in Example 2; 3,5-Bis(4-methoxyphenyl)-2-formylpyrrole (synthesized in Russian Journal of Inorganic Chemistry 2014, 59(10), 1187-1194) is used instead of 3,5-Diphenyl-2-formylpyrrole in Example 2; and N-chlorosuccinimide is removed to obtain photoinitiator 4. The molar extinction coefficient of photoinitiator 4 at 631 nm is 83476 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.61 eV.

[0080] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 1 second, and the exposure dose was 6 mJ / cm². 2 .

[0081] Example 5 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: One part of photoinitiator 5 (corresponding to formula (I), where R1 is 4-methoxyphenyl, R2 is methyl, R3 is bromine, R4 is methyl, and R5 is phenyl), 79 parts of nanoparticles (silicon carbide nanoparticles, with an average particle size of 40 nm and a refractive index of 2.65), and 20 parts of holographic recording monomer (β-hydroxyethyl acrylate). The structural formula of photoinitiator 5 is shown below: .

[0082] The preparation method of the above photoinitiator 5 includes the following steps: dissolving 1 equivalent of p-anisaldehyde and 2 equivalents of 2,4-dimethylpyrrole in tetrahydrofuran solvent, adding a catalytic amount of concentrated hydrochloric acid and refluxing for 24 h; then adding 1 equivalent of 2,3-dichloro-5,6-dicyanobenzoquinone and reacting at room temperature for 24 h; finally adding 3 equivalents of triethylamine and 5 equivalents of boron trifluoride diethyl ether complex and reacting at room temperature for 24 h to obtain the core structure of the photoinitiator of Example 5. Dissolving 1 equivalent of this core structure with 2 equivalents of N-bromosuccinimide in tetrahydrofuran and reacting for 24 h; then adding 10 equivalents of phenyllithium and reacting at room temperature for 24 h to obtain photoinitiator 5. Photoinitiator 5 has a molar extinction coefficient of 71547 L / (mol·cm) at a wavelength of 529 nm and a bond dissociation energy of 1.89 eV for the boron-carbon bond.

[0083] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 532 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.1 s, and the exposure dose was 0.6 mJ / cm². 2 .

[0084] Example 6 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 1.5 parts photoinitiator 6 (corresponding to formula (I), where R1 is 4-methoxyphenyl, R2 is methyl, R3 is bromine, R4 is methyl, and R5 is 4-methoxyphenyl), 48.5 parts nanoparticles (titanium dioxide nanoparticles, with an average particle size of 20 nm and a refractive index of 2.55), and 50 parts holographic recording monomers (40 parts 6361-100 (hyperbranched acrylate) and 10 parts β-hydroxyethyl methacrylate). The structural formula of photoinitiator 6 is shown below: .

[0085] The preparation method of photoinitiator 6 is the same as that of photoinitiator 5 in Example 5, except that 20 equivalents of 4-methoxyphenyl magnesium bromide are used to replace 10 equivalents of phenyl lithium reagent in Example 5 to obtain photoinitiator 6. The molar extinction coefficient of photoinitiator 6 at a wavelength of 528 nm is 72167 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.88 eV.

[0086] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 532 nm and the total power density of the exposure is 40 mW / cm². 2 The exposure time was 0.05 s, and the exposure dose was 2 mJ / cm². 2 .

[0087] Example 7 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 1 part of photoinitiator 7 (corresponding to formula (I), where R1 is 4-methoxyphenyl, R2 is methyl, R3 is bromine, R4 is methyl, and R5 is 4-methylphenyl), 57 parts of nanoparticles (iron oxide nanoparticles with an average particle size of 20 nm and a refractive index of 3.0), and 42 parts of holographic recording monomers (21 parts of pentaerythritol triacrylate and 21 parts of β-hydroxyethyl methacrylate). The structural formula of photoinitiator 7 is shown below: .

[0088] The preparation method of photoinitiator 7 is the same as that of photoinitiator 5 in Example 5, except that 20 equivalents of p-tolyl magnesium bromide reagent are used to replace 10 equivalents of phenyl lithium in Example 5 to obtain photoinitiator 7. The molar extinction coefficient of photoinitiator 7 at a wavelength of 528 nm is 73598 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.88 eV.

[0089] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 532 nm and the total power density of the exposure is 100 mW / cm². 2 The exposure time was 0.01 s, and the exposure dose was 1 mJ / cm². 2 .

[0090] Example 8 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 2 parts photoinitiator 8 (corresponding to formula (I), where R1 is trifluoromethyl, R2 is phenyl, R3 is iodine, R4 is phenyl, and R5 is methyl), 32 parts nanoparticles (iron oxide nanoparticles with an average particle size of 20 nm and a refractive index of 3.0), 66 parts holographic recording monomers (26 parts pentaerythritol triacrylate, 40 parts...). N -Vinylpyrrolidone). The structural formula of photoinitiator 8 is shown below: .

[0091] The preparation method of the above-mentioned photoinitiator 8 includes the following steps: 1 equivalent of trifluoroacetaldehyde acetal condensate and 2 equivalents of 2,4-Diphenyl-1H-pyrrole are dissolved in tetrahydrofuran solvent, a catalytic amount of concentrated hydrochloric acid is added and refluxed for 24 h, then 1 equivalent of 2,3-dichloro-5,6-dicyanobenzoquinone is added, and the reaction is carried out at room temperature for 24 h. Finally, 3 equivalents of triethylamine and 5 equivalents of boron trifluoride diethyl ether complex are added sequentially, and the reaction is carried out at room temperature for 24 h to obtain the core structure of photoinitiator 8. 1 equivalent of the core structure is dissolved in tetrahydrofuran with 2 equivalents of N-iodosuccinimide and reacted for 24 h, then 10 equivalents of methyllithium is added, and the reaction is carried out at room temperature for 24 h to obtain photoinitiator 8. The photoinitiator 8 has a molar extinction coefficient of 89713 L / (mol·cm) at a wavelength of 651 nm and a bond dissociation energy of 1.52 eV for the boron-carbon bond.

[0092] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.4 s, and the exposure dose was 2.4 mJ / cm². 2 .

[0093] Example 9 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 3 parts photoinitiator 9 (corresponding to formula (I), where R1 is phenyl, R2 is methyl, R3 is hydrogen, R4 is styrene, and R5 is ethyl), 27 parts nanoparticles (iron oxide nanoparticles, with an average particle size of 20 nm and a refractive index of 3.0), 70 parts holographic recording monomers (30 parts pentaerythritol triacrylate, 40 parts...). N -Vinylpyrrolidone). The structural formula of photoinitiator 9 is shown below: .

[0094] The preparation method of the above-mentioned photoinitiator 9 includes the following steps: 1 equivalent of benzaldehyde and 2 equivalents of 2,4-dimethylpyrrole are dissolved in tetrahydrofuran solvent, a catalytic amount of concentrated hydrochloric acid is added and refluxed for 24 h, then 1 equivalent of 2,3-dichloro-5,6-dicyanobenzoquinone is added, and the reaction is carried out at room temperature for 24 h; finally, 3 equivalents of triethylamine and 5 equivalents of boron trifluoride diethyl ether complex are added, and the reaction is carried out at room temperature for 24 h to obtain intermediate 1. 1 equivalent of intermediate 1 and 2 equivalents of benzaldehyde are refluxed in DMF for 1 h to obtain the core structure of photoinitiator 9. 1 equivalent of the core structure and 10 equivalents of ethyl lithium are reacted in tetrahydrofuran at room temperature for 24 h to obtain photoinitiator 9. Photoinitiator 9 has a molar extinction coefficient of 86428 L / (mol·cm) at a wavelength of 632 nm and a bond dissociation energy of 1.53 eV for the boron-carbon bond.

[0095] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.6 s, and the exposure dose was 3.6 mJ / cm². 2 .

[0096] Example 10 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 5 parts photoinitiator 10 (corresponding to formula (I), where R1 is 4-cyanophenyl, R2 is methyl, R3 is iodine, R4 is methyl, and R5 is ethyl), 15 parts nanoparticles (zinc sulfide nanoparticles, with an average particle size of 5 nm and a refractive index of 1.80), 80 parts holographic recording monomers (40 parts pentaerythritol triacrylate, 40 parts...). N -Vinylpyrrolidone). The structural formula of photoinitiator 10 is shown below: .

[0097] The preparation method of the above-mentioned photoinitiator 10 includes the following steps: dissolving 1 equivalent of 4-cyanobenzaldehyde and 2 equivalents of 2,4-dimethylpyrrole in tetrahydrofuran solvent, adding a catalytic amount of concentrated hydrochloric acid and refluxing for 24 h, then adding 1 equivalent of 2,3-dichloro-5,6-dicyanobenzoquinone and reacting at room temperature for 24 h, and finally adding 3 equivalents of triethylamine and 5 equivalents of boron trifluoride diethyl ether complex and reacting at room temperature for 24 h to obtain the core structure of photoinitiator 10. Dissolving 1 equivalent of the core structure and 2 equivalents of N-iodosuccinimide in tetrahydrofuran and reacting for 24 h, then adding 10 equivalents of ethyllithium and reacting at room temperature for 24 h to obtain photoinitiator 10. The molar extinction coefficient of photoinitiator 10 at a wavelength of 522 nm is 77143 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.91 eV.

[0098] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 532 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.8 s, and the exposure dose was 4.8 mJ / cm². 2 .

[0099] Example 11 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 1 part photoinitiator 11 (corresponding to formula (I), where R1 is trifluoromethyl, R2 is methyl, R3 is iodine, R4 is methyl, and R5 is phenyl), 39 parts nanoparticles (titanium dioxide nanoparticles, with an average particle size of 30 nm and a refractive index of 2.55), 60 parts holographic recording monomers (40 parts ethylene glycol dimethacrylate, 20 parts...). N -Vinylpyrrolidone). The structural formula of photoinitiator 11 is shown below: .

[0100] The preparation method of photoinitiator 11 is the same as that of photoinitiator 10 in Example 10, except that trifluoroacetaldehyde acetal salicylate is used instead of 4-cyanobenzaldehyde in Example 10, and phenyl lithium is used instead of ethyl lithium in Example 10, to obtain photoinitiator 11. The molar extinction coefficient of photoinitiator 11 at a wavelength of 582 nm is 80588 L / (mol·cm), and the bond dissociation energy of the boron-carbon bond is 1.71 eV.

[0101] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 577 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.5 s, and the exposure dose was 3 mJ / cm³. 2 .

[0102] Example 12 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 1 part photoinitiator 12 (corresponding to formula (I), where R1 is 4-cyanophenyl, R2 is methyl, R3 is iodine, R4 is methyl, and R5 is methyl), 39 parts nanoparticles (titanium dioxide nanoparticles, with an average particle size of 30 nm and a refractive index of 2.55), and 60 parts holographic recording monomers (40 parts ethylene glycol dimethacrylate and 20 parts methacrylic acid). The structural formula of photoinitiator 12 is shown below: .

[0103] The preparation method of the above photoinitiator 12 is the same as that of photoinitiator 10 in Example 10, except that methyl lithium is used to replace ethyl lithium in Example 10 to obtain photoinitiator 12. The above photoinitiator 12 has a molar extinction coefficient of 79631 L / (mol·cm) at a wavelength of 522 nm and a bond dissociation energy of 1.88 eV for the boron-carbon bond.

[0104] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.5 s, and the exposure dose was 3 mJ / cm³. 2 .

[0105] Example 13 The holographic polymer-dispersed nanoparticle material provided in this embodiment includes the following components and their weight proportions: 1 part photoinitiator, 8 parts 39 parts nanoparticles (titanium dioxide nanoparticles, average particle size 50 nm, refractive index 2.55), 60 parts holographic recording monomers (40 parts ethylene glycol dimethacrylate, 20 parts...). N -Vinylpyrrolidone).

[0106] The preparation method of the above-mentioned holographic polymer-dispersed nanoparticle material is the same as that in Example 1, wherein the wavelength of the coherent laser is 640 nm and the total power density of the exposure is 6 mW / cm². 2 The exposure time was 0.5 s, and the exposure dose was 3 mJ / cm³. 2 .

[0107] Comparative Example 1 The components and their weight proportions of the holographic polymer-dispersed nanoparticle material provided in this comparative example are shown in Table 1: Table 1. Composition of the holographic polymer-dispersed nanoparticle material provided in Comparative Example 1

[0108] The preparation method of the holographic polymer-dispersed nanoparticle material provided in this comparative example is the same as that in Example 1, wherein the wavelength of the coherent laser is 460 nm and the total power density of the exposure is 6 mW / cm². 2 The prepared holographic polymer-dispersed nanoparticle material was exposed for a period of time, and its performance was tested. The experiment found that when the exposure time was 5 s and the exposure dose was 30 mJ / cm², the material performed optimally. 2 At that time, the diffraction efficiency of the prepared holographic polymer dispersed nanoparticle material was only 8%, and the diffraction efficiency was still in the rising stage.

[0109] When the exposure time is 30 seconds and the exposure dose is 180 mJ / cm² 2 At that time, the diffraction efficiency of the holographic polymer-dispersed nanoparticle material reached its maximum value. The diffraction efficiency and photosensitivity of the holographic polymer-dispersed nanoparticle material were calculated according to the formula.

[0110] Comparative Example 2 The components and their weight proportions of the holographic polymer-dispersed nanoparticle material provided in this comparative example are shown in Table 2: Table 2. Composition of the holographic polymer-dispersed nanoparticle material provided in Comparative Example 2

[0111] The preparation method of the holographic polymer-dispersed nanoparticle material provided in this comparative example is the same as that in Example 1, wherein the wavelength of the coherent laser is 532 nm and the total power density of the exposure is 6 mW / cm². 2 The prepared holographic polymer-dispersed nanoparticle material was exposed for a period of time, and its performance was tested. The experiment found that when the exposure time was 5 s and the exposure dose was 30 mJ / cm², the material performed optimally. 2 At that time, the diffraction efficiency of the prepared holographic polymer dispersed nanoparticle material was only 13%, and the diffraction efficiency was still in the rising stage.

[0112] When the exposure time is 15 s and the exposure dose is 90 mJ / cm² 2 At that time, the diffraction efficiency of the holographic polymer-dispersed nanoparticle material reached its maximum value. The diffraction efficiency and photosensitivity of the holographic polymer-dispersed nanoparticle material were calculated according to the formula.

[0113] Comparative Example 3 The composition and weight percentages of the holographic polymer-dispersed nanoparticle material provided in this comparative example are the same as those in Example 13, wherein the average particle size of the titanium dioxide nanoparticles is 100 nm. The holographic polymer-dispersed nanoparticle material was then prepared using the method provided in Example 13.

[0114] The performance of the holographic polymer-dispersed nanoparticle materials prepared in Examples 1-13 and Comparative Examples 1-3 was tested using the following methods: (1) Diffraction efficiency (η): According to the literature ("Holographic Polymer Dispersed Nanoparticle Materials", Science Press; Macromolecules 2024, 57, 6, 2557-2573), the diffraction intensity and transmission intensity of the holographic polymer dispersed nanoparticle material at the Bragg angle were measured using a photometer, and then the diffraction efficiency η was calculated using the following formula:

[0115] in, I d , I t The values ​​represent the diffraction intensity and transmission intensity of the holographic polymer-dispersed nanoparticle material at the Bragg angle, respectively.

[0116] (2) Photosensitivity ( S According to the literature ("Holographic Polymer Dispersed Nanoparticle Materials", Science Press), the photosensitivity is calculated using the following formula. S ):

[0117] in, η The diffraction efficiency of holographic polymer-dispersed nanoparticle materials. d The thickness of the holographic polymer-dispersed nanoparticle material (i.e., the thickness of the liquid crystal cell in this application). I To record the total holographic light intensity, t ind The time required to reach maximum diffraction efficiency.

[0118] The test results are shown in Table 3.

[0119] Table 3. Performance of holographic polymer-dispersed nanoparticle materials prepared in Examples 1-13 and Comparative Examples 1-3

[0120] Continued from Table 3

[0121] Test results show that this application can prepare holographic polymer-dispersed nanoparticle materials with both high diffraction efficiency and high photosensitivity under conditions of short exposure time and low exposure dose. The preparation efficiency is high, making it suitable for high-end anti-counterfeiting, information storage, virtual reality, and augmented reality applications. In contrast, Comparative Examples 1 and 2, which use existing photoinitiators (a mixture of photosensitizer and co-initiator) to prepare holographic polymer-dispersed nanoparticle materials, require long exposure times, high exposure doses, and have low preparation efficiency. Furthermore, the resulting holographic polymer-dispersed nanoparticle materials have low photosensitivity, failing to meet the requirements.

[0122] Those skilled in the art will readily understand that the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A photoinitiator, characterized in that, The structural formula of the photoinitiator is shown in Formula (I): Formula (1) Wherein, R1 is hydrogen, C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; R2 and R4 are each independently C 1~20 Alkyl, C 1~20 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; R3 is any one of hydrogen, chlorine, bromine, or iodine; R5 is C 1~12 Alkyl, C 1~12 Haloalkyl, C 6~18 aryl, C substituted with one or more R6 6~18 Any of the aryl groups; Each occurrence of R6 is independently of cyano, vinyl, or C. 1~6 Alkyl, C 1~6 Haloalkyl, C 1~6 Any one of the alkoxy groups.

2. A holographic polymer-dispersed nanoparticle material, characterized in that, The raw materials for preparing the holographic polymer-dispersed nanoparticle material include the photoinitiator, holographic recording monomer, and nanoparticles as described in claim 1.

3. The holographic polymer-dispersed nanoparticle material according to claim 2, characterized in that, The photoinitiator can be excited by visible light with a wavelength of 420~700 nm, causing the boron-carbon bonds in the photoinitiator to dissociate and generate initiating free radicals that can initiate the polymerization reaction of the holographic recording monomer. The photoinitiator has a maximum molar extinction coefficient ≥ 40000 L / (mol·cm) at wavelengths of 420~700 nm, and the chain dissociation energy of the boron-carbon bond is ≤ 2.54 eV.

4. The holographic polymer-dispersed nanoparticle material according to claim 3, characterized in that, The holographic recording monomer is one or more of acrylate monomers, acrylamide monomers, and vinyl monomers; and / or, The nanoparticles have a refractive index ≥ 1.80 and an average particle size < 50 nm.

5. The holographic polymer-dispersed nanoparticle material according to claim 4, characterized in that, The holographic recording unit is N -Vinylpyrrolidone, N,N - One or more of the following: dimethacrylamide, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, acrylic acid, methacrylic acid, ethylene glycol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and hyperbranched acrylates; and / or, The nanoparticles are one or more of the following: titanium dioxide nanoparticles, zirconium dioxide nanoparticles, silicon carbide nanoparticles, iron oxide nanoparticles, and zinc sulfide nanoparticles.

6. The holographic polymer-dispersed nanoparticle material according to claim 2, characterized in that, The weight ratio of the photoinitiator, holographic recording monomer and nanoparticles is (0.01~5):(20~80):(15~79).

7. A method for preparing holographic polymer-dispersed nanoparticle materials as described in any one of claims 2 to 6, characterized in that, Includes the following steps: S1. Mix the photoinitiator, nanoparticles and holographic recording monomer to obtain a mixed solution; S2. The mixed solution is encapsulated in a transparent container and exposed using a coherent laser to cause the boron-carbon bonds in the photoinitiator to dissociate and generate initiating free radicals. These initiating free radicals then undergo a polymerization reaction with the holographic recording monomer to obtain holographic polymer-dispersed nanoparticle materials.

8. The preparation method according to claim 7, characterized in that, The wavelength of the coherent laser is 420~700 nm, the exposure time is 0.01~5 s, and the exposure dose is 0.1~10 cm / mJ.

9. An application of a holographic polymer dispersed nanoparticle material as described in any one of claims 2 to 6 in the fields of high-end anti-counterfeiting, information storage, virtual reality, or augmented reality.

10. An optical device, characterized in that, The optical device comprises the holographic polymer-dispersed nanoparticle material as described in any one of claims 2 to 6.

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