Polymer-doped blue organic long-afterglow thin film material as well as preparation method and application thereof

Abstract

The invention belongs to the field of organic afterglow materials, and particularly relates to a polymer-doped blue organic long-afterglow thin film material as well as a preparation method and application thereof. According to the polymer-doped blue organic long-afterglow thin film material provided by the invention, an electron-rich material diphenylamine derivative which is easy to crystallize and is low in price and easy to obtain is selected as a host material, and meanwhile, an electron-rich carbazole derivative of the same type which is similar in structure and is low in price and easy to obtain is introduced as a guest material; a novel flexible film blue afterglow material is constructed by using a polymer polyvinyl alcohol (PVA) as a matrix, the material can be excited by a 365nm ultraviolet lamp, the afterglow time exceeds 10s in a room temperature atmospheric environment, the afterglow color is blue, the material has good afterglow luminescence performance and flexibility, the application potential of the material in the fields of information encryption and afterglow anti-counterfeiting is shown, and the application prospect is broad. And a theoretical basis and a material basis can be provided for practical applications such as data encryption and anti-counterfeiting.

Description

Technical Field

[0001] The invention belongs to the field of organic afterglow materials, and in particular relates to a polymer-doped blue organic long afterglow film material and a preparation method and application thereof. Background Art

[0002] As one of the three primary colors, blue is essential for making white light emitting devices. In addition, blue light is an indispensable core element of organic optoelectronics in solid-state lighting and full-color display technology. However, the luminescence of organic long afterglow materials mostly comes from the aggregation state of the material, and the large conjugated structure and the large Stokes shift of phosphorescence relative to fluorescence, the emission wavelength is concentrated in the range of 500-600nm, which causes the luminescence color of such materials to mainly appear as green or yellow light. Therefore, the design of organic blue light long afterglow materials is challenging and necessary. Moreover, in pure organic matter, due to weak spin-orbit coupling and very fast non-radiative decay, the development of organic long afterglow materials with high efficiency and long life is still a huge challenge. Therefore, how to achieve high-efficiency and long-life organic blue light long afterglow emission is a scientific problem of great value and urgent need to be solved.

[0003] In recent years, with the in-depth study of organic long afterglow materials in the field, some amorphous organic long afterglow materials often have blue afterglow luminescence phenomenon. Yang et al. [Su Y, Phua SZF, Li Y, et al. Scienceadvances, 2018, 4(5):s9732.] selected hexa(4-carboxylic acid-phenoxy)-cyclophosphazene (G) and its derivatives as guest molecules, and incorporated them into polyvinyl alcohol (PVA) at low concentrations, and used the hydrogen bonds between hydroxyl and carboxyl groups and the cross-linking of PVA under irradiation conditions to increase the overall rigidity and inhibit the non-radiative transition process, thereby obtaining an organic long afterglow material emitting blue light. Although the wavelength of the material can reach 415nm, the afterglow lifetime and quantum efficiency do not exceed 0.6s and 12% respectively, and the afterglow performance is poor. In addition to the host-guest doping system, Ma et al. [Ma X, Xu C, Wang J, et al. Angewandte ChemieInternational Edition, 2018, 57(34):10854-10858.] obtained an organic blue light afterglow material with a wavelength of 418-497nm by copolymerizing acrylamide with different organic small molecules containing oxygen atoms. Although the phosphorescence quantum efficiency reached 30%, the afterglow lifetime was still short and could not meet the application requirements.

[0004] It can be seen that organic blue light afterglow materials with excellent optical properties have not yet been realized. More importantly, most of them are excited by 254nm ultraviolet lamps and are difficult to be excited by 365nm ultraviolet lamps, which further limits the use of existing blue light afterglow materials in many fields. Therefore, how to effectively design new organic blue light afterglow materials that can be excited by 365nm ultraviolet lamps and have excellent optical properties will hopefully achieve the goal of obtaining specific blue afterglow materials on demand, so as to better apply them to information encryption, afterglow anti-counterfeiting and other fields. Summary of the invention

[0005] One of the purposes of the present invention is to provide a polymer-doped blue organic long afterglow film material, which can be excited by a 365nm ultraviolet lamp, has good afterglow luminescence performance under room temperature and atmospheric environment, and the afterglow color is blue. In addition, the material belongs to an organic flexible film material, which can be coated and prepared over a large area and emit light uniformly, and is suitable for application in the fields of flexible display, wearable devices, information encryption, high-end anti-counterfeiting, etc.

[0006] The second object of the present invention is to provide a method for preparing a polymer-doped blue organic long afterglow thin film material, which has a simple process, mild conditions, and cheap and readily available materials, and is suitable for the preparation of high-performance blue long afterglow materials.

[0007] The third object of the present invention is to provide an application of a polymer-doped blue organic long afterglow thin film material.

[0008] One of the purposes of the present invention adopts the technical solution: A polymer-doped blue organic long afterglow film material is prepared by heating a polymer, a host material and a guest material without solvent; Wherein, the polymer is polyvinyl alcohol; the main material is The object material is .

[0009] The polymer-doped blue organic long afterglow thin film material provided by the present invention selects diphenylamine derivatives, which are electron-rich materials that are easy to crystallize and cheap and easily available, as the main material, and introduces the same type of electron-rich carbazole derivatives with similar structure and cheap and easily available as the guest material, and then constructs a new type of flexible thin film blue afterglow material through a polymer polyvinyl alcohol (PVA) matrix. The material can be excited by a 365nm ultraviolet lamp, and the afterglow time exceeds 10s, the afterglow color is blue, and it has good afterglow luminescence performance and flexibility, demonstrating its application potential in the fields of information encryption and afterglow anti-counterfeiting, and can also provide a theoretical basis and material foundation for practical applications such as data encryption and anti-counterfeiting.

[0010] As a further improvement, the mass ratio of the polymer, the host material and the guest material is (800-1200):(300-500):1.

[0011] As a further improvement, the mass ratio of the polymer, the host material and the guest material is 1000:400:1.

[0012] As a further improvement, the relative molecular mass of the polyvinyl alcohol is 20,000 to 40,000.

[0013] As a further improvement, the relative molecular mass of the polyvinyl alcohol is 30,000.

[0014] As a further improvement, the excitation wavelength of the polymer-doped blue organic long afterglow thin film material is 360-370 nm, more preferably 365 nm.

[0015] The technical solution adopted in the second object of the present invention is: A method for preparing a polymer-doped blue organic long afterglow thin film material comprises the following steps: The polymer, the main material and the guest material are uniformly mixed according to the mass ratio to obtain a solid powder; the solid powder is heated at 150-180° C. and then allowed to stand to obtain a polymer-doped blue organic long afterglow thin film material.

[0016] The preparation method of the polymer-doped blue organic long afterglow thin film material provided by the present invention uses a simple structure, cheap and readily available electron-rich material as a host material and a guest material, and introduces a polymer PVA for wrapping to prepare the afterglow material. The entire preparation method is simple, the material is cheap and readily available, the conditions are mild, and harsh conditions such as high temperature and high pressure are not required. In addition, the method of the present invention can achieve effective regulation of the afterglow color by changing the structure of the host and the guest, and obtain a blue afterglow material with a long afterglow life, which is suitable for industrial market applications.

[0017] As a further improvement, the heating time is 0.5~2h.

[0018] As a further improvement, the standing temperature is 20-30°C and the time is 2-5 hours.

[0019] The technical solution adopted in the third object of the present invention is: The above polymer-doped blue organic long afterglow thin film material is used as a luminescent material in data encryption and / or afterglow anti-counterfeiting.

[0020] The beneficial effects of the above technical solution of the present invention are mainly: 1) Currently, there are few blue afterglow materials, and most of them are excited by 254nm ultraviolet light, and the afterglow time is short. The polymer-doped blue organic long afterglow film material provided by the present invention can be excited by 365nm ultraviolet light, and the afterglow time exceeds 10s, the afterglow life is long, and it is also conducive to realizing the full spectrum afterglow characteristics of organic long afterglow materials.

[0021] 2) Current afterglow materials are generally complex and expensive, while the host-guest materials and polymer materials used in the present invention are cheap, readily available, and simple in structure, which provides more possibilities for their actual commercial applications.

[0022] 3) The material prepared by the present invention is an organic flexible thin film afterglow material, has good flexibility, is suitable for large-area coating preparation, and can meet the application requirements in the fields of flexible display, wearable devices, information encryption, and high-end anti-counterfeiting.

[0023] The present invention's research on polymer-doped blue organic long afterglow thin film materials not only provides new ideas for designing and synthesizing new blue luminescent flexible long afterglow materials, but also provides theoretical basis and material foundation for practical applications such as data encryption and afterglow anti-counterfeiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The optical images of the afterglow display of the polymer-doped blue organic long afterglow thin film material obtained in Example 1 of the present invention before (a) and after (bf) irradiation with 365nm ultraviolet light; Figure 2 These are optical images of the afterglow display of the polymer-doped organic long afterglow thin film material obtained in Comparative Example 1 before (a) and after (be) irradiation with 365nm ultraviolet light. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings, embodiments and test examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of protection of the present invention. The experimental methods used in the following embodiments are conventional methods unless otherwise specified; the raw materials used are commonly used in the art, available to the public or commercially available unless otherwise specified; the terms and abbreviations involved are all conventional meanings in the art. Among them, in the following examples, the relative molecular mass of polyvinyl alcohol is 30,000. Example

[0026] This embodiment provides a polymer-doped blue organic long afterglow film material, which is prepared by heating a polymer, a host material and a guest material without solvent. The polymer is polyvinyl alcohol (PVA); the host material is ; The object material is (N 3 ,N 3 ,N 6 ,N 6 -tetramethyl-9H-carbazole-3,6-diamine). The mass ratio of the polymer, the host material and the guest material is 1000:400:1.

[0027] The above polymer-doped blue organic long afterglow thin film material is prepared by a method comprising the following steps: According to the mass ratio of polymer, host material and guest material of 1000:400:1, 0.1000g of polymer (PVA), 0.0400g of host material and 0.00010g of guest material were accurately weighed and mixed to obtain solid powder; the solid powder was heated on a heating plate for 1h at a heating temperature of 160°C, then cooled and placed at room temperature (20-30°C) for 3h to obtain the polymer-doped blue organic long afterglow thin film material of Example 1 for subsequent performance testing.

[0028] Comparative Example 1 This comparative example provides a polymer-doped organic long afterglow thin film material, and its preparation process is basically the same as that of Example 1, except that the guest material used is different, and the other conditions and parameters are the same as those of Example 1. The guest material used in this comparative example is 2,8-bis(1,1-dimethylethyl)-5,11-dihydro-indole[3,2-b]carbazole, and its structural formula is: .

[0029] Test Example 1: Afterglow Performance Test of the Material in Example 1 of the Present Invention Under room temperature and atmospheric environment, the polymer-doped blue organic long afterglow film material of Example 1 was excited by a 365nm ultraviolet lamp, and then the excitation light source was turned off, and the afterglow brightness change of the material after the light source was removed was recorded. The results are as follows: Figure 1 shown.

[0030] Depend on Figure 1 It can be seen that the 365nm ultraviolet lamp excites the material of Example 1 ( Figure 1 a), turn off the excitation light source. After removing the light source, the material emits a blue afterglow ( Figure 1 b) In the first 8 seconds, Figure 1 b~1d represent the afterglow brightness changes of 1s, 4s, and 8s after the light source is removed. During this time, the afterglow brightness of the material in Example 1 is relatively strong, and from the 10th second (such as Figure 1 e) and then the afterglow gradually weakened, and the 11th second ( Figure 1 f) The afterglow is not obvious. It can be seen that the afterglow time of the polymer-doped blue organic long afterglow thin film material of Example 1 is as high as 10s, and the afterglow performance is excellent.

[0031] Test Example 2: Afterglow Performance Test of Comparative Example 1 Material Under room temperature and atmospheric environment, the polymer-doped organic long afterglow thin film material of Comparative Example 1 was excited by a 365nm ultraviolet lamp, and then the excitation light source was turned off, and the afterglow brightness change of the material after the light source was removed was recorded. The results are as follows Figure 2 shown.

[0032] Depend on Figure 2 It can be seen that the 365nm ultraviolet lamp excites the material of Comparative Example 1 ( Figure 2 a), turn off the excitation light source. After removing the light source, the material emits a cyan afterglow ( Figure 2 b). Figure 2 b~2d represent the changes in the afterglow brightness of the material after the light source is removed for 1s, 2s, and 3s respectively. During this time, the afterglow brightness of the material in Example 1 is relatively strong. Figure 2 e) Afterglow is not obvious. It can be seen that the afterglow time of the material in comparative example 1 is 4s, and the afterglow color is cyan. The afterglow performance is not as good as the material in embodiment 1 of the present invention, and no blue afterglow light can be obtained.

[0033] In summary, the polymer-doped blue organic long afterglow thin film material provided by the present invention selects diphenylamine derivatives, which are easy to crystallize, cheap and easily available electron-rich materials, as the main material, and introduces the same type of electron-rich carbazole derivatives with similar structure, cheap and easily available as the guest material, and then constructs a new type of flexible thin film blue afterglow material through a polymer polyvinyl alcohol (PVA) matrix. The material can be excited by a 365nm ultraviolet lamp, and the afterglow time exceeds 10s, the afterglow color is blue, and it has good afterglow luminescence performance and flexibility, demonstrating its application potential in the fields of information encryption and afterglow anti-counterfeiting, and can also provide a theoretical basis and material basis for practical applications such as data encryption and anti-counterfeiting.

Claims

1. A polymer-doped blue organic long afterglow thin film material, characterized in that: It is prepared by heating a polymer, a host material and a guest material without solvent; Wherein, the polymer is polyvinyl alcohol; the main material is The object material is .

2. The polymer-doped blue organic long afterglow thin film material according to claim 1, characterized in that: The mass ratio of the polymer, the main material and the guest material is (800-1200):(300-500):

1.

3. The polymer-doped blue organic long afterglow thin film material according to claim 2, characterized in that: The mass ratio of the polymer, the host material and the guest material is 1000:400:

1.

4. The polymer-doped blue organic long afterglow thin film material according to claim 1, characterized in that: The relative molecular mass of the polyvinyl alcohol is 20,000 to 40,000.

5. The polymer-doped blue organic long afterglow thin film material according to claim 4, characterized in that: The relative molecular mass of the polyvinyl alcohol is 30,000.

6. The polymer-doped blue organic long afterglow thin film material according to claim 1, characterized in that: The excitation wavelength of the polymer-doped blue organic long afterglow thin film material is 360-370nm.

7. A method for preparing a polymer-doped blue organic long afterglow thin film material as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: The polymer, the main material and the guest material are uniformly mixed according to the mass ratio to obtain a solid powder; the solid powder is heated at 150-180° C. and then allowed to stand to obtain a polymer-doped blue organic long afterglow thin film material.

8. The method for preparing the polymer-doped blue organic long afterglow thin film material according to claim 7, characterized in that: The heating time is 0.5 to 2 hours.

9. The method for preparing a polymer-doped blue organic long afterglow thin film material according to claim 7, characterized in that: The standing temperature is 20-30° C. and the standing time is 2-5 hours.

10. An application of the polymer-doped blue organic long afterglow thin film material according to any one of claims 1 to 6, characterized in that: Application as luminescent material in data encryption and / or afterglow anti-counterfeiting.

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