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

Abstract

The invention discloses a polymer-doped blue organic long-afterglow material as well as a preparation method and application thereof, and relates to the field of organic long-afterglow materials, and the polymer-doped blue organic long-afterglow material is prepared from a polymer, a host material and a guest material through solvent evaporation; the polymer is polymethyl methacrylate; the main body material is an electron-rich material diphenylamine derivative; the object material is an electron-rich carbazole derivative, the prepared material belongs to an organic afterglow material and can meet the application requirements in the fields of information encryption, high-end anti-counterfeiting and the like, research on the polymer-doped blue organic long-afterglow material provides a new thought for design and synthesis of a novel blue light-emitting long-afterglow material, and the application prospect of the polymer-doped blue organic long-afterglow material is wide. And a theoretical basis and a material basis can be provided for practical applications such as data encryption and afterglow anti-counterfeiting.

Description

Technical Field

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

[0002] Organic afterglow luminescent materials have the advantages of large Stokes shift and long lifetime, and have great application prospects in flexible display, optoelectronic devices, bio-imaging, information storage, anti-counterfeiting and other fields. Blue light is an indispensable core component in solid-state lighting and full-color display technology. However, due to the large conjugated structure and large Stokes characteristics of phosphorescence, the emission of most ultra-long room temperature phosphorescent materials is mostly located in the yellow-green color range. Therefore, it is both necessary and challenging to realize blue room temperature phosphorescent materials with adjustable lifetime, high efficiency and long-lasting performance.

[0003] The polymer doping strategy has been reported as a common strategy for achieving long-life room temperature phosphorescence. Because the polymer matrix can provide a rigid environment and disperse the luminophore, thereby suppressing non-radiative jumping and aggregation-induced luminescence red shift, but there are few reports on polymer-assisted preparation of blue afterglow materials, which may be because there are too few blue luminescent guest materials. Because blue afterglow materials require small conjugation, and small conjugated structures are not conducive to the generation of room temperature phosphorescence, it is difficult to achieve the afterglow effect. At the same time, the selected organic small molecules are limited by performance, energy levels, electron transfer and energy transfer, and are also accompanied by the disadvantages of phase separation. Most organic small molecules are difficult to fuse with polymers to achieve afterglow effects. Therefore, it is particularly important to develop more organic small molecules that can match polymers to achieve room temperature phosphorescence performance. Therefore, the development of reasonable blue phosphorescent emission materials is currently a top priority.

[0004] Recently, researchers have successfully prepared afterglow polymer materials with room temperature phosphorescent properties by adding inducing salts, small molecule compounds, polymers, etc. However, the lifetime of the reported blue afterglow polymers is usually short, and most of them are excited at 254nm, which is very limited in many fields of application. Therefore, it is particularly important to develop room temperature blue afterglow materials that can be excited by visible ultraviolet light (365nm) and have adjustable blue afterglow time. Summary of the invention

[0005] In view of the deficiencies of the prior art, the technical solution adopted by the present invention to solve the technical problems is as follows: the polymer-doped blue organic long afterglow material of the present invention is prepared by evaporating a polymer, a host material and a guest material through a solvent;

[0006] The polymer is polymethyl methacrylate, and its structural formula is as follows:

[0007]

[0008] The main material is an electron-rich material diphenylamine derivative, and its structural formula is as follows:

[0009]

[0010] The guest material is an electron-rich carbazole derivative, and its structural formula is as follows:

[0011]

[0012] Preferably, the mass ratio of the polymer, the host material and the guest material is 700-1200:400-500:1.

[0013] Preferably, the mass ratio of the polymer, the host material and the guest material is 1000:400:1.

[0014] Preferably, the relative molecular mass of the polymethyl methacrylate is 10,000-30,000.

[0015] Preferably, the relative molecular mass of the polymethyl methacrylate is 13,000.

[0016] Preferably, the excitation wavelength of the polymer-doped blue organic long afterglow thin film material is 360-370 nm, more preferably 365 nm.

[0017] The preparation method of the above polymer-doped blue organic long afterglow material comprises the following steps:

[0018] 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 evaporated in ethanol and then allowed to stand to obtain a polymer-doped blue organic long afterglow film material.

[0019] The preparation method of the polymer-doped blue organic long afterglow 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 polymethyl methacrylate (PMMA) 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.

[0020] The polymer-doped blue organic long afterglow material provided by the present invention selects diphenylamine derivatives, which are easy to crystallize and cheap and readily available electron-rich materials, as the main material, such as diphenylamine, methoxydiphenylamine, and methyldiphenylamine, and introduces the same type of electron-rich carbazole derivatives with similar structure and cheap and readily available as the guest material (carbazole), and then constructs a new blue afterglow material through a polymer polymethyl methacrylate (PMMA) matrix. The material can be excited by a 365nm ultraviolet lamp, and the afterglow time exceeds 5s, the afterglow color is blue, and has good afterglow luminescence performance, showing its application potential in the field 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. Energy transfer occurs between the main material and the guest material, and the rigid environment constructed by the polymer suppresses the quenching of triplet states by water and oxygen.

[0021] The above polymer-doped blue organic long afterglow material is used as a luminescent material in data encryption or afterglow anti-counterfeiting.

[0022] The beneficial effects of the present invention are as follows:

[0023] 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 5s, the afterglow life is long, and it is also conducive to realizing the full spectrum afterglow characteristics of organic long afterglow materials.

[0024] 2. The current afterglow materials are generally complex and expensive. The host-guest materials and polymer materials used in the present invention are cheap, easy to obtain and simple in structure, which provides more possibilities for its actual commercial application.

[0025] 3. The material prepared by the present invention is an organic afterglow material, which can be used in the fields of information encryption, high-end anti-counterfeiting, etc. The research on polymer-doped blue organic long afterglow materials in the present invention not only provides new ideas for the design and synthesis of new blue luminescent 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

[0026] Figure 1 The optical images of the afterglow display of the polymer-doped blue organic long afterglow material obtained in Example 1 of the present invention before (a) and after (bf) irradiation with 365nm ultraviolet light;

[0027] Figure 2 These are optical images of the afterglow display of the polymer-doped organic long afterglow material obtained in Comparative Example 1 before (a) and after (be) irradiation with 365nm ultraviolet light.

[0028] Figure 3 The optical images of the afterglow display of the polymer-doped organic long afterglow thin film material obtained in Comparative Example 2 before (a) and after (bd) irradiation with 365nm ultraviolet light. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes, wherein, in the following embodiments, the relative molecular mass of polyvinyl alcohol is 30,000.

[0030] Embodiment: This embodiment provides a polymer-doped blue organic long afterglow material, which is prepared by heating a polymer, a host material and a guest material without solvent. The polymer is polymethyl methacrylate (PMMA); the host material is

[0031]

[0032] The object material is

[0033]

[0034] The mass ratio of polymer, host material and guest material is 1000:400:1.

[0035] The above polymer-doped blue organic long afterglow material is prepared by a method comprising the following steps:

[0036] According to the mass ratio of polymer, host material and guest material of 1000:400:1, accurately weigh 0.1000g of polymer (PMMA), 0.0400g of host material and 0.00010g of guest material and mix them to obtain a solid powder; 1mL of ethanol and 5mL of dichloromethane are added dropwise to the solid powder, and then static evaporation and crystallization are performed to obtain the polymer-doped blue organic long afterglow material of Example 1 for subsequent performance testing.

[0037] Comparative Example 1: This comparative example provides a polymer-doped organic long afterglow material, and its preparation process is basically the same as that of Example 1, except that different polymer materials are used, and the other conditions and parameters are the same as those of Example 1. In Comparative Example 1, no polymer is added, only host and guest materials are included.

[0038] Comparative Example 2: This comparative example provides a polymer-doped organic long afterglow material, and its preparation process is basically the same as that of Example 1. The difference between the two is 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 7-bromo-5,9-dioxa-13b-boronaphtho[3,2,1-de]anthracene, and the structural formula is:

[0039]

[0040] Test Example 1: Afterglow performance test of the material of the embodiment of the present invention:

[0041] Under room temperature and atmospheric environment, a 365nm ultraviolet lamp was used to excite the polymer-doped blue organic long afterglow material of the embodiment, 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.

[0042] 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 4 seconds, Figure 1 b~1e represent the afterglow brightness changes of 1s, 2s, 3s and 4s after the light source is removed. During this time, the afterglow brightness of the material of Example 1 is relatively strong, and from the 4th second (such as Figure 1 e) and then the afterglow gradually weakened. 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 5s, and the afterglow performance is excellent.

[0043] Test Example 2: Afterglow performance test of the material of Comparative Example 1:

[0044] Under room temperature and atmospheric environment, the polymer-doped organic long afterglow 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.

[0045] 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 blue afterglow ( Figure 2 b). Figure 2 b~2d represent the afterglow brightness changes of the material after the light source is removed at 0s, 1s, and 2s respectively. During this time, the afterglow brightness of the material of Example 1 is stronger, and at 3s ( Figure 2e) The afterglow is not obvious. It can be seen that the afterglow time of the material in comparative example 1 is 3s, and the afterglow performance is not as good as that of the material in embodiment 1 of the present invention, indicating that the addition of polymer has a good effect of extending the afterglow performance.

[0046] Test Example 3: Afterglow performance test of the material of Comparative Example 2:

[0047] Under room temperature and atmospheric environment, the polymer-doped organic long afterglow thin film material of Comparative Example 2 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 3 shown.

[0048] Depend on Figure 3 It can be seen that the 365nm ultraviolet lamp excites the material of Comparative Example 2 ( Figure 3 a), turn off the excitation light source. After removing the light source, the material emits a turquoise afterglow ( Figure 3 b). Figure 3 b~3c represent the changes in the afterglow brightness of the material after the light source is removed 1s and 1.5s respectively. During this time, the afterglow brightness of the material of Example 2 is stronger, and the afterglow brightness of the material of Example 2 is stronger. Figure 3 d) The afterglow is not obvious. It can be seen that the afterglow time of the material in comparative example 2 is 2s, and the afterglow performance is not as good as that of the material in example 1 of the present invention. Moreover, it is a green material and it is difficult to reach the blue material, which shows that the blue afterglow can only be achieved by adding a suitable host-guest combination to the polymer.

[0049] In summary, the polymer-doped blue organic long afterglow 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 blue afterglow material through a polymer (PMMA) matrix. The material can be excited by a 365nm ultraviolet lamp, and the afterglow time exceeds 5s, the afterglow color is blue, and it has good afterglow luminescence performance, demonstrating its application potential in the field 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.

[0050] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. Polymer-doped blue organic long afterglow material, characterized in that: Prepared by evaporation of solvent from polymer, host material and guest material; The polymer is polymethyl methacrylate; The main material is an electron-rich material diphenylamine derivative; The guest material is an electron-rich carbazole derivative.

2. The polymer-doped blue organic long afterglow material according to claim 1, characterized in that: The mass ratio of the polymer, the host material and the guest material is 700-1200:400-500:

1.

3. The polymer-doped blue organic long afterglow 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 material, preparation method and application according to claim 1 are characterized in that: The relative molecular mass of the polymethyl methacrylate is 10,000-30,000.

5. The polymer-doped blue organic long afterglow material, preparation method and application according to claim 4 are characterized in that: The relative molecular mass of the polymethyl methacrylate is 13000.

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

7. The method for preparing a polymer-doped blue organic long afterglow material according to 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 evaporated in ethanol and then allowed to stand to obtain a polymer-doped blue organic long afterglow film material.

8. The use of the polymer-doped blue organic long afterglow material according to any one of claims 1 to 6, characterized in that: Application as luminescent material in data encryption or afterglow anti-counterfeiting.

Images