A self-positioning flexible circular polarizing film and a preparation method thereof

Abstract

The present application relates to the field of light-emitting materials, in particular to a self-positioning flexible circular polarized light conversion film and a preparation method thereof. The preparation method provided by the present application synthesizes high-quality photopolymerization materials represented by polyacrylamide prepolymer through a solvothermal method, selects suitable molecules with macro-assembly ability, chiral dopants and oil-water amphiphilic substances, mixes the four substances in a certain proportion, mixes them at a certain speed under the action of a homogenizer, and then performs self-assembly under the action of a certain temperature and ultraviolet light irradiation, so as to finally obtain a flexible film with circular polarized light conversion effect. The self-positioning flexible circular polarized light conversion film prepared by the present application can simultaneously improve the asymmetric factor and processing capacity of the material circular polarized light.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials technology, and in particular to a self-positioning flexible circularly polarized light conversion film and its preparation method. Background Technology

[0002] Chirality is an important phenomenon in nature, significantly impacting multiple fields such as chemistry, physics, and biology. The geometric configurations of chiral molecules endow them with unique optical properties, among which chiral luminescence (CPL), a special chiral phenomenon, has attracted widespread attention. Chiral luminescent systems, upon excitation, can produce left- and right-handed circularly polarized light with different characteristics. This property is of great value in cutting-edge applications such as asymmetric synthesis, chemical sensors, 3D display technology, and quantum computing. Studying these materials allows for a deeper understanding of the structural information of chiral molecules in the excited state, thereby revealing the mechanisms of chirality generation, transmission, and amplification. Simultaneously, a deeper understanding of chiral luminescence helps in the design and synthesis of higher-performance chiral materials, which are expected to offer unique advantages in a wider range of applications. For example, chiral luminescent materials show great application potential in optoelectronic devices and biological detectors. Therefore, continued research on chiral luminescent materials not only helps expand fundamental scientific knowledge but also opens up new possibilities for the development of related technologies.

[0003] As an important parameter of circularly polarized light, the asymmetry factor of circularly polarized light—g lum Its definition is:

[0004]

[0005] In the formula, I L and I R These are the luminous intensities of left-handed and right-handed circularly polarized light in the total luminous intensity of the luminous system, respectively. From the expression, g... lum The value of g ranges from -2 to +2. lum The magnitude of the luminescence asymmetry factor fundamentally determines the possibility of circularly polarized luminescent materials being put into practical applications. Therefore, how to maximize the luminescence asymmetry factor is one of the key issues in the current field of circularly polarized luminescent materials.

[0006] Liquid crystal materials are composed of rigid rod-shaped molecules that, when subjected to helical torsion, form a helical stacking structure, significantly increasing the emission asymmetry factor. Numerous studies have shown that chiral liquid crystals can effectively improve the emission asymmetry factor. The helical structure of chiral liquid crystals can transform microscopic chirality into macroscopic structure, thereby amplifying chirality. Furthermore, adjusting the pitch of chiral liquid crystals can alter their photon bandgap positions, enabling them to exhibit strong selective reflection of specific wavelengths of light.

[0007] Currently, the two main types of chiral liquid crystal materials reported are chiral dopant-induced hybrid liquid crystal materials and chiral liquid crystal materials formed by chiral liquid crystal molecules. Chiral dopant-induced hybrid liquid crystal materials have attracted attention due to their advantages such as simple preparation, a wide variety of liquid crystal types, and easy tuning of properties such as photonic band gap.

[0008] Chiral doped chiral liquid crystal materials can be prepared by mixing chiral agents with nematic liquid crystals, or by dissolving chiral dopants and nematic liquid crystals together in a solvent and then slowly evaporating the solvent. In 2019, researchers prepared three-component doped circularly polarized luminescent liquid crystal materials by changing the types of chiral dopants, luminescent materials, and liquid crystals, achieving a high asymmetry factor. Furthermore, researchers have obtained multi-component co-assembled chiral luminescent systems by mixing and assembling chiral dopants, mixed liquid crystals, upconversion particles, and perovskite nanoparticles, and achieved high levels of asymmetry factors by adjusting the pitch and photonic bandgap.

[0009] Significant progress has been made in the preparation methods and performance regulation of reported hybrid chiral liquid crystal materials. However, some shortcomings still exist. Most of the reported systems are still in the photoluminescence stage, exhibiting fixed circularly polarized light, which is mostly in a fluid state. Exhibiting circularly polarized light characteristics requires special equipment such as liquid crystal cells, which are usually rigid structures with fixed shapes. This greatly limits the processing of circularly polarized light-emitting materials, and there are certain problems in terms of the purity, stability, quantum yield, and practical applications of light emission, which is not conducive to the practical application of chiral liquid crystal materials with circularly polarized light emission capabilities. Summary of the Invention

[0010] In view of this, the present invention provides a self-positioning flexible circularly polarized light conversion film and its preparation method. The self-positioning flexible circularly polarized light conversion film prepared by the present invention can simultaneously improve the asymmetry factor and processing capability of the circularly polarized light of the material.

[0011] This invention provides a method for preparing a self-positioning flexible circularly polarized light conversion film, comprising the following steps:

[0012] S1. Acrylamide, polyacrylamide, photoinducer, crosslinking agent and solvent are mixed and heated to react, thus obtaining a photopolymer material;

[0013] S2. Mix the material with macroscopic co-assembly capability, the organic chiral dopant and the solvent, and then remove the solvent to obtain the chiral liquid crystal material;

[0014] S3. Mix the photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the oil-water amphiphilic substance solution, and irradiate with ultraviolet light to obtain a self-positioning flexible circularly polarized light conversion film.

[0015] There is no order restriction between steps S1 and S2.

[0016] .

[0017] Preferably, in step S2, the organic chiral dopant is a compound of formula (I) and / or a compound of formula (II):

[0018] Formula (I);

[0019] Formula (II).

[0020] Preferably, in step S3, the amphiphilic substance in the amphiphilic solution is PVA;

[0021] The mass percentage concentration of the amphiphilic substance solution is 8%~12%.

[0022] Preferably, the amounts of each substance, expressed as a percentage by mass, are as follows:

[0023] The photopolymer material obtained in step S1 accounts for 75.00%~85.00%;

[0024] The organic chiral dopant used in step S2 is 0.20%~0.60%;

[0025] The material with macroscopic co-assembly capability used in step S2 is 10.00%~20.00%;

[0026] Amphiphilic substances: 2.00%~6.00%.

[0027] Preferably, in step S1, the weight-average molecular weight of the polyacrylamide is 2 million to 20 million.

[0028] The mass ratio of polyacrylamide to acrylamide is 1:(6~7).

[0029] Preferably, in step S1, the photoinducer is N,N′-methylenebisacrylamide;

[0030] The amount of the photoinducer is 1.2% to 1.8% of the mass of the acrylamide.

[0031] Preferably, in step S1, the crosslinking agent is 2-hydroxy-2-methylpropenone;

[0032] The amount of the crosslinking agent is 1.2% to 1.8% of the mass of the acrylamide.

[0033] Preferably, in step S3, the conditions for ultraviolet light irradiation are: wavelength 365nm, irradiation time 5~20min, and temperature 25~40℃.

[0034] The present invention also provides a self-positioning flexible circularly polarized light conversion film prepared by the preparation method described in the above technical solution.

[0035] The preparation method provided by this invention synthesizes high-quality photopolymer materials, represented by polyacrylamide prepolymer, via a solvothermal method. Suitable molecules with macroscopic assembly capabilities, chiral dopants, and amphiphilic substances are selected and mixed in a certain proportion. The mixture is then homogenized at a specific speed using a homogenizer, followed by self-assembly under specific temperature and ultraviolet light irradiation, ultimately yielding a flexible film with circularly polarized light conversion capabilities. This invention introduces organic chiral dopants into molecules with macroscopic co-assembly capabilities and employs a layered confinement method using amphiphilic and photopolymeric materials to confine the macroscopic helical structure within microspheres. The stacking of multiple microspheres forms a circularly polarized light conversion film of suitable thickness. Due to the generation and amplification of chirality by this macroscopic co-assembly chiral system, and the excellent preservation of the helical structure by the photopolymeric and amphiphilic materials, the multi-element film structure prepared by this invention, when combined with the luminescent system, simultaneously possesses a large asymmetry factor and high processability, achieving the goal of obtaining a high-performance circularly polarized light generating film material that is easy to process. This results in a type of self-positioned flexible circularly polarized light conversion film with excellent application performance and broad application prospects. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 A schematic diagram of the self-positioning flexible circularly polarized light conversion film structure prepared according to the present invention;

[0038] Figure 2 This is a physical image of the self-positioning flexible circularly polarized light conversion film obtained in Embodiment 1 of the present invention;

[0039] Figure 3 The CD spectrum of the self-positioning flexible circularly polarized light conversion film obtained in Example 1;

[0040] Figure 4 The CPL spectrum of the self-positioning flexible circularly polarized light conversion film obtained in Example 1;

[0041] Figure 5 g is the self-positioning flexible circularly polarized light conversion film obtained in Example 1. lum picture;

[0042] Figure 6 The image shown is a POM diagram of the self-positioning flexible circularly polarized light conversion film obtained in Example 1. Detailed Implementation

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0044] In this article, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0045] The term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0046] In this document, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when a range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0047] In this article, when referring to units for data ranges, if the unit is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 1.5~2.0 mol / L means that the units for the left endpoint "1.5" and the right endpoint "2.0" are both mol / L.

[0048] This invention provides a method for preparing a self-positioning flexible circularly polarized light conversion film, comprising the following steps:

[0049] S1. Acrylamide, polyacrylamide, photoinducer, crosslinking agent and solvent are mixed and heated to react, thus obtaining a photopolymer material;

[0050] S2. Mix the material with macroscopic co-assembly capability, the organic chiral dopant and the solvent, and then remove the solvent to obtain the chiral liquid crystal material;

[0051] S3. Mix the photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the oil-water amphiphilic substance solution, and irradiate with ultraviolet light to obtain a self-positioning flexible circularly polarized light conversion film.

[0052] There is no order restriction between steps S1 and S2.

[0053] This invention aims to simultaneously improve the g of the circularly polarized light emission system. lum By leveraging the high value and deep processing capabilities of chiral systems with significant application potential, a method for preparing a self-positioning flexible circularly polarized light conversion film is proposed. By adding a certain proportion of chiral dopants, high-quality flexible photopolymer materials, and highly transparent amphiphilic substances to a selected host with macroscopic assembly capabilities (such as E7), a flexible circularly polarized light conversion film material capable of converting unpolarized light into high-quality circularly polarized light is prepared. The generation and amplification of circularly polarized light emission signals are achieved using chiral liquid crystals, thereby improving the luminescence asymmetry factor (g) of the circularly polarized light emission material. lum The polymer used retains the advantages of high flexibility and high transparency while maintaining the macroscopic helical structure of chiral liquid crystals, resulting in a self-positioning flexible circularly polarized light conversion film with a relatively simple preparation process and excellent circularly polarized light conversion performance.

[0054] [Regarding step S1]:

[0055] S1. Acrylamide, polyacrylamide, photoinducer, crosslinking agent and solvent are mixed and heated to react, thus obtaining a photopolymer material.

[0056] In this invention, the concentration of acrylamide in the solvent is preferably 1.5~2.0 mol / L, specifically 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, or 2.0 mol / L.

[0057] In this invention, the weight-average molecular weight (M) of the polyacrylamide is... w The preferred concentration is 2 million to 20 million. This invention does not impose any special restrictions on the source of the polyacrylamide; it can be a commercially available product or prepared using methods known in the art. In this invention, the mass ratio of polyacrylamide to acrylamide is preferably 1:(6-7), specifically 1:6 or 1:7.

[0058] In this invention, the photoinducer is preferably N,N′-methylenebisacrylamide. The amount of the photoinducer is preferably 1.2% to 1.8% of the mass of the acrylamide, specifically 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, or 1.8%.

[0059] In this invention, the crosslinking agent is preferably 2-hydroxy-2-methylpropenone. The amount of the crosslinking agent is preferably 1.2% to 1.8% of the mass of the acrylamide, specifically 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, or 1.8%.

[0060] In this invention, the solvent is preferably water, more preferably pure water. The amount of solvent used is based on the concentration of acrylamide in the solvent as described above, and will not be repeated here.

[0061] In this invention, the preferred mixing order is as follows: first, acrylamide is mixed with a solvent to form an acrylamide solution, and then polyacrylamide, a photoinducer, and a crosslinking agent are added to obtain a mixed solution.

[0062] This invention involves mixing acrylamide, polyacrylamide, a photoinducer, a crosslinking agent, and a solvent, followed by a heating reaction to obtain a high-quality photopolymer material; specifically, a high-quality photopolymer material is synthesized via a solvothermal / aqueous one-pot method. In this invention, the preferred heating temperature is 40-60°C, specifically 40°C, 45°C, 50°C, 55°C, or 60°C. The preferred heating time is 6-12 hours, specifically 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours.

[0063] In this invention, preferably, the heating process is accompanied by ultraviolet light excitation, that is, the reaction is carried out under heating and ultraviolet light excitation to obtain a photopolymer material. In this invention, the ultraviolet light used for ultraviolet light excitation is preferably 365nm ultraviolet light. The irradiation time for ultraviolet light excitation is preferably 5~10 min, specifically 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0064] In this invention, after the above reaction, a high-quality photopolymer material is obtained, mainly a polyacrylamide prepolymer, which can form a flexible polymer under certain temperature and photoexcitation conditions. In this invention, the light transmittance of the photopolymer material is 95%. The flexible bendable angle of the photopolymer material is 360°.

[0065] [Regarding step S2]:

[0066] S2. Mix the material with macroscopic co-assembly capability, the organic chiral dopant, and the solvent, and then remove the solvent to obtain the chiral liquid crystal material.

[0067]

[0068] In this invention, the organic chiral dopant is preferably a compound of formula (I) and / or a compound of formula (II):

[0069] Formula (I);

[0070] Formula (II).

[0071] Wherein, the compound shown in formula (I) can be a dextrorotatory chiral material R811 or a levorotatory chiral material S811. The compound shown in formula (II) can be a dextrorotatory chiral material R5011 or a levorotatory chiral material S5011. In this invention, the organic chiral dopant is more preferably S5011.

[0072] In this invention, the solvent is preferably an organic solvent. There are no particular limitations on the type of organic solvent; any conventional solvent in the art, such as toluene, chloroform, or n-hexane, is acceptable. In this invention, the preferred ratio of the solvent to the organic chiral dopant is (5~10) mL:0.028 g.

[0073] In this invention, a material with macroscopic co-assembly capability, an organic chiral dopant, and a solvent are mixed uniformly to form a homogeneous and transparent solution, which is then desolventized. The preferred method for desolventizing is to place the resulting solution in a vacuum drying oven to evaporate the solvent. The temperature of the vacuum drying oven is preferably 35-75°C, specifically 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or 75°C. The preferred evaporation time is 12-24 hours, specifically 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, or 24 hours. The solvent is completely removed through this evaporation process, yielding a chiral liquid crystal material system.

[0074] In this invention, there are no special restrictions on the order of steps S1 and S2.

[0075] [Regarding step S3]:

[0076] S3. The photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the oil-water amphiphilic substance solution are mixed and irradiated with ultraviolet light to obtain a self-positioning flexible circularly polarized light conversion film.

[0077] In this invention, the amphiphilic substance solution is an aqueous solution of the amphiphilic substance. The amphiphilic substance has an oleophilic end and a hydrophilic end. The amphiphilic substance can encapsulate macroscopic helical substances to form microspheres. In this invention, the amphiphilic substance is preferably PVA (polyvinyl alcohol). In this invention, the mass percentage concentration of the amphiphilic substance solution is preferably 8%~12%, specifically 8%, 9%, 10%, 11%, or 12%.

[0078] In this invention, the photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the amphiphilic solution are mixed, and the amounts of each substance are as follows by mass percentage:

[0079] The photopolymer material obtained in step S1 accounts for 75.00%~85.00%;

[0080] The organic chiral dopant used in step S2 is 0.20%~0.60%;

[0081] The material with macroscopic co-assembly capability used in step S2 is 10.00%~20.00%;

[0082] Amphiphilic substances: 2.00%~6.00%.

[0083] in:

[0084] The specific amounts of photopolymer material obtained in step S1 can be 75.00%, 76.00%, 77.00%, 78.00%, 79.00%, 80.00%, 80.65%, 81.00%, 82.00%, 83.00%, 84.00%, and 85.00%.

[0085] The amount of organic chiral dopant used in step S2 can be 0.20%, 0.29%, 0.30%, 0.32%, 0.35%, 0.38%, 0.40%, 0.44%, 0.50%, or 0.60%.

[0086] The specific amounts of materials with macroscopic co-assembly capabilities used in step S2 can be 10.00%, 11.00%, 12.00%, 13.00%, 14.00%, 15.00%, 15.68%, 15.74%, 15.77%, 15.80%, 15.83%, 16.00%, 17.00%, 18.00%, 18.80%, 19.00%, and 20.00%.

[0087] The specific amounts of the amphiphilic substance in the solution can be 2.00%, 3.00%, 3.23%, 3.47%, 4.00%, 5.00%, and 6.00%.

[0088] The amount of the above four components is preferably 100%.

[0089] In this invention, when mixing the photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the amphiphilic solution, the mixing method is not particularly limited, as long as it can mix all materials evenly. For example, it can be stirred in a homogenizer for a sufficient time to ensure that all components are completely mixed to form a homogeneous solution. The stirring rate is preferably 9000~12000 rpm, specifically 9000 rpm, 10000 rpm, 11000 rpm, or 12000 rpm. The stirring time is preferably 5~10 min, specifically 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0090] In this invention, after the above mixing, the resulting mixture is applied to a substrate. The preferred application method is spraying or printing. Then, photopolymerization is performed by ultraviolet (UV) light irradiation. Specifically, the UV light irradiation is UV lamp irradiation. The wavelength of the UV light irradiation is preferably 365 nm. The UV irradiation time is preferably 5-20 min, specifically 5 min, 10 min, 15 min, or 20 min. The UV irradiation temperature (i.e., ambient temperature) is preferably 25-40°C, specifically 25°C, 30°C, 35°C, or 40°C. Photopolymerization under the above-mentioned appropriate temperature and UV lamp irradiation can self-position a flexible circularly polarized light conversion film. In this invention, after the above photopolymerization, cooling is performed, specifically cooling to room temperature, thereby obtaining a self-positioning flexible circularly polarized light conversion film.

[0091] Compared to existing circularly polarized light conversion technologies, the system of this invention achieves high light transmittance and flexibility by selecting highly transparent and elastic photopolymer materials, such as polyacrylamide and PVA, making it suitable for various applications. Simultaneously, by utilizing a macroscopic chiral assembly system with selective transmission of both left-handed and right-handed light, a high asymmetry factor is obtained. Furthermore, due to the surface tension difference between hydrophilic and hydrophobic surfaces, this system achieves self-positioning, significantly reducing processing difficulty. In summary, the resulting flexible circularly polarized conversion film exhibits high luminescence asymmetry. This method is universal and provides a solution to the difficulties in processing and shape limitations of circularly polarized conversion layers in circularly polarized light emission systems, offering direction and guidance for the construction of novel circularly polarized light emission conversion systems.

[0092] The present invention also provides a self-positioning flexible circularly polarized light conversion film prepared by the preparation method described in the above technical solution.

[0093] The preparation method provided by this invention synthesizes high-quality photopolymer materials, represented by polyacrylamide prepolymer, via a solvothermal method. Suitable molecules with macroscopic assembly capabilities, chiral dopants, and amphiphilic substances are selected and mixed in a certain proportion. The mixture is then homogenized at a certain speed using a homogenizer, followed by self-assembly under specific temperature and ultraviolet light irradiation, ultimately yielding a flexible film with circularly polarized light conversion capabilities. Specifically, organic chiral dopants are introduced into molecules with macroscopic co-assembly capabilities. Simultaneously, an amphiphilic material and photopolymer material are used to construct a layered confinement method to confine the macroscopic helical structure within microspheres. The stacking of multiple microspheres forms a circularly polarized light conversion film of suitable thickness. Figure 1 As shown, the left side represents the overall structure of the film, the middle side represents the structure of the microspheres in the film, and the right side represents the specific structure inside and outside the shell of the microspheres, indicating its hydrophilicity and hydrophobicity.

[0094] Compared with the prior art, the present invention has the following beneficial effects:

[0095] This invention introduces organic chiral dopants into molecules possessing macroscopic co-assembly capabilities. Simultaneously, it employs a layered confinement method using amphiphilic and photopolymeric materials to confine macroscopic helical structures within microspheres. The stacking of multiple microspheres forms a circularly polarized light conversion film of suitable thickness. Due to the generation and amplification of chirality by this macroscopic co-assembly chiral system, and the excellent preservation of the helical structure by the photopolymeric and amphiphilic materials, the multi-element film structure prepared by this invention, when combined with the luminescent system, simultaneously possesses a large asymmetry factor and high processability. This achieves the goal of obtaining easily processed, high-performance circularly polarized light generating film materials. Consequently, this type of self-positioned flexible circularly polarized light conversion film exhibits excellent application performance and broad application prospects.

[0096] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention. Example

[0097] S1. Acrylamide is mixed with pure water to obtain a solution with a concentration of 1.8 mol / L. Polyacrylamide (M...) is then added to this solution. w =10 million, polyacrylamide to acrylamide mass ratio=1:6), photoinitiator N,N′-methylenebisacrylamide (1.5% of acrylamide), crosslinking agent 2-hydroxy-2-methylpropenone (1.5% of acrylamide), mixed evenly, and subjected to a solvothermal reaction at 50°C for 10 min, with 365nm ultraviolet light irradiation during the above heating process, to obtain photopolymer material (polyacrylamide prepolymer).

[0098] S2. In a light-proof, open sample vial, add 0.028 g of organic chiral dopant S5011, 0.972 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 hours to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0099] S3. Add 5.00g of the photopolymer material obtained in step S1 and 2.00g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0100] As can be seen, the proportions of each material used are as follows:

[0101] The photopolymer material obtained in step S1 accounts for 80.65%;

[0102] The organic chiral dopant used in step S2 is 0.44%;

[0103] The material used in step S2 has 15.68% macroscopic co-assembly capability;

[0104] Amphiphilic substances: 3.23%.

[0105] Product testing:

[0106] The actual photograph of the obtained self-positioning flexible polarization conversion film is shown below. Figure 2 As shown, the film has been demonstrated as a coating in practical applications, indicating that it can be used alone as a coating without the need for additional components such as a liquid crystal cell. The self-positioning flexible polarization conversion film obtained by this invention can work organically with common high-performance light-emitting devices on the market (such as LEDs, QLEDs, OLEDs, etc.), thereby exhibiting high light-emitting performance.

[0107] The CD spectrum of the obtained self-positioning flexible polarization conversion film is as follows: Figure 3 As shown, the peak value of the CD spectrum is around 400 nm.

[0108] The CPL spectrum and g of the obtained self-positioning flexible polarization conversion film lum Each as Figure 4 , Figure 5 As shown, it can be seen that the wavelength of its chiral emission (CPL) asymmetry factor is tunable, and the asymmetry factor g lum It can reach around 1.0, which is higher than previous materials.

[0109] The obtained POM image of the self-positioning flexible polarization conversion film is as follows: Figure 6 As shown, in the mixed material, the microspheres formed by the chiral liquid crystal are dispersed in the solution, and after solidification, the multilayer microsphere flexible polarization conversion film can be formed.

[0110] Example 2

[0111] S1. Following step S1 in Example 1, a photopolymer material is prepared.

[0112] S2. In a light-proof, open sample vial, add 0.026 g of organic chiral dopant S5011, 0.974 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 hours to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0113] S3. Add 4.00g of the photopolymer material obtained in step S1 and 1.80g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0114] As can be seen, the proportions of each material used are as follows:

[0115] The photopolymer material obtained in step S1 was 77.22%;

[0116] The organic chiral dopant used in step S2 is 0.50%;

[0117] The materials used in step S2 that have macroscopic co-assembly capability account for 18.80%;

[0118] Amphiphilic substances: 3.47%.

[0119] The asymmetry factor g of circularly polarized light emission obtained in this embodiment of the self-positioning flexible polarization conversion film lum The value is approximately 1.00, and the CD spectral peak is around 450 nm.

[0120] Example 3

[0121] S1. Following step S1 in Example 1, a photopolymer material is prepared.

[0122] S2. In a light-proof, open sample vial, add 0.024 g of organic chiral dopant S5011, 0.976 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 hours to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0123] S3. Add 5.00g of the photopolymer material obtained in step S1 and 2.00g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0124] As can be seen, the proportions of each material used are as follows:

[0125] The photopolymer material obtained in step S1 accounts for 80.65%;

[0126] The organic chiral dopant used in step S2 is 0.38%;

[0127] The material used in step S2 with macroscopic co-assembly capability accounts for 15.74%;

[0128] Amphiphilic substances: 3.23%.

[0129] The asymmetry factor g of circularly polarized light emission obtained in this embodiment of the self-positioning flexible polarization conversion film lum The value is approximately 1.00, and the peak value of the CD spectrum is around 490 nm.

[0130] Example 4

[0131] S1. Following step S1 in Example 1, a photopolymer material is prepared.

[0132] S2. In a light-proof, open sample vial, add 0.022 g of organic chiral dopant S5011, 0.978 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 hours to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0133] S3. Add 5.00g of the photopolymer material obtained in step S1 and 2.00g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0134] As can be seen, the proportions of each material used are as follows:

[0135] The photopolymer material obtained in step S1 accounts for 80.65%;

[0136] The organic chiral dopant used in step S2 is 0.35%;

[0137] The material used in step S2 has 15.77% macroscopic co-assembly capability;

[0138] Amphiphilic substances: 3.23%.

[0139] The asymmetry factor g of circularly polarized light emission obtained in this embodiment of the self-positioning flexible polarization conversion film lum The value is approximately 1.00, and the CD spectral peak is around 540 nm.

[0140] Example 5

[0141] S1. Following step S1 in Example 1, a photopolymer material is prepared.

[0142] S2. In a light-proof, open sample vial, add 0.020 g of organic chiral dopant S5011, 0.980 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 h to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0143] S3. Add 5.00g of the photopolymer material obtained in step S1 and 2.00g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0144] As can be seen, the proportions of each material used are as follows:

[0145] The photopolymer material obtained in step S1 accounts for 80.65%;

[0146] The organic chiral dopant used in step S2 is 0.32%;

[0147] The materials used in step S2 that have macroscopic co-assembly capability account for 15.80%;

[0148] Amphiphilic substances: 3.23%.

[0149] The asymmetry factor g of circularly polarized light emission obtained in this embodiment of the self-positioning flexible polarization conversion film lum The value is approximately 1.00, and the peak value of the CD spectrum is around 590 nm.

[0150] Example 6

[0151] S1. Following step S1 in Example 1, a photopolymer material is prepared.

[0152] S2. In a light-proof, open sample vial, add 0.018 g of organic chiral dopant S5011, 0.982 g of liquid crystal E7 with macroscopic co-assembly capability, and 5 mL of n-hexane solvent sequentially. The mixture is then sonicated to ensure complete mixing of all components, forming a homogeneous and transparent solution. The solution is then placed in a vacuum drying oven and slowly evaporated at 50°C for 20 h to obtain the chiral liquid crystal material. This material is then cooled to room temperature for later use.

[0153] S3. Add 5.00g of the photopolymer material obtained in step S1 and 2.00g of PVA aqueous solution (mass concentration of 10%) to the above open sample bottle, and stir at 10000rpm for 5min in a homogenizer to obtain a mixture. Spray the mixture onto a substrate, heat it to 30℃ and irradiate it with a 365nm ultraviolet lamp for 5min to obtain a self-positioning flexible polarization conversion film.

[0154] As can be seen, the proportions of each material used are as follows:

[0155] The photopolymer material obtained in step S1 accounts for 80.65%;

[0156] The organic chiral dopant used in step S2 is 0.29%;

[0157] The material used in step S2 has a macroscopic co-assembly capability of 15.83%;

[0158] Amphiphilic substances: 3.23%.

[0159] The asymmetry factor g of circularly polarized light emission obtained in this embodiment of the self-positioning flexible polarization conversion film lum The value is approximately 1.00, and the peak value of the CD spectrum is around 640 nm.

[0160] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A method for preparing a self-positioning flexible circularly polarized light conversion film, characterized in that, Includes the following steps: S1. Acrylamide, polyacrylamide, photoinducer, crosslinking agent and solvent are mixed and heated to react, thus obtaining a photopolymer material; S2. Mix the material with macroscopic co-assembly capability, the organic chiral dopant and the solvent, and then remove the solvent to obtain the chiral liquid crystal material; S3. Mix the photopolymer material obtained in step S1, the chiral liquid crystal material obtained in step S2, and the oil-water amphiphilic substance solution, and irradiate with ultraviolet light to obtain a self-positioning flexible circularly polarized light conversion film. There is no order restriction between steps S1 and S2; In step S2, the material with macroscopic co-assembly capability is at least one of 4'-n-pentyl-4-cyanobiphenyl, 4'-n-pentoxy-4-cyanobiphenyl, 4'-n-heptyl-4-cyanobiphenyl, 4'-n-octyloxy-4-cyanobiphenyl, 4'-n-pentyl-4-cyanoterphenyl and liquid crystal E7; In step S2, the organic chiral dopant is a compound of formula (I) and / or a compound of formula (II): Equation (I); Equation (II); In step S3, the amphiphilic substance in the amphiphilic solution is PVA; the mass percentage concentration of the amphiphilic solution is 8%~12%. The amounts of each substance, expressed as a percentage by mass, are as follows: The photopolymer material obtained in step S1 accounts for 75.00%~85.00%; The organic chiral dopant used in step S2 is 0.20%~0.60%; The material with macroscopic co-assembly capability used in step S2 is 10.00%~20.00%; Amphiphilic substances: 2.00%~6.00%; The total amount of the above four substances is 100%.

2. The preparation method according to claim 1, characterized in that, In step S1, the weight-average molecular weight of the polyacrylamide is 2 million to 20 million. The mass ratio of polyacrylamide to acrylamide is 1:(6~7).

3. The preparation method according to claim 1, characterized in that, In step S1, the photoinducer is N,N′-methylenebisacrylamide; The amount of the photoinducer is 1.2% to 1.8% of the mass of the acrylamide.

4. The preparation method according to claim 1, characterized in that, In step S1, the crosslinking agent is 2-hydroxy-2-methylpropenone; The amount of the crosslinking agent is 1.2% to 1.8% of the mass of the acrylamide.

5. The preparation method according to claim 1, characterized in that, In step S3, the conditions for ultraviolet light irradiation are: wavelength 365nm, irradiation time 5~20min, and temperature 25~40℃.

6. A self-positioning flexible circularly polarized light conversion film prepared by any one of claims 1 to 5.

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