Short-life strong-radiation-luminescence organic laser gain material as well as preparation and application of short-life strong-radiation-luminescence organic laser gain material

Abstract

The invention belongs to the technical field of new materials, and particularly discloses a short-service-life strong-radiation-light-emitting organic laser gain material and preparation and application thereof.The preparation method of the organic laser gain material comprises the following steps that 1, 4-bis [4-(N, N-dimethylaminophenyl) styryl] biphenyl and 4, 4 '-dibromo terphenyl are sequentially added into methylbenzene, stirring is carried out, and the organic laser gain material is obtained; after ultrasonic dissolution, cooling, then adding ethanol, standing, and separating out a yellow green solid; and collecting the solid, and carrying out vacuum drying to obtain microcrystals, namely the organic laser gain material. Based on the organic laser gain material, a microcrystalline deposition layer with uniform thickness is formed on the surface of a quartz plate through a self-settling strategy, luminescence quenching caused by introduction of a high polymer material is avoided, and the organic laser gain material can be used for high-resolution imaging. Through a host-guest eutectic engineering strategy, collaborative optimization of X-ray absorption and ultrafast radiation luminescence in the organic scintillator material is successfully realized, and a universal path is developed for solving the contradiction between heavy atom introduction and fluorescence quenching.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically relating to a short-lifetime, high-radiative luminescence organic laser gain material and its preparation and application. Background Technology

[0002] Scintillator materials can efficiently and rapidly convert high-energy X-ray photons into detectable ultraviolet / visible light. With the surge in demand for high-speed imaging in applications such as tomography and high-energy physics, it is necessary to develop new scintillator materials that combine high luminous efficiency (high brightness) and ultrafast response (short lifetime). Although traditional inorganic scintillators have high radiative luminescence efficiency, they have problems such as heavy metal toxicity, environmental sensitivity (easy to moisture), harsh preparation process (high temperature of 1700℃), and long afterglow (residual image). Although organic scintillators have the advantages of molecular designability, abundant sources, low cost, easy processing and molding, and short intrinsic fluorescence lifetime, the main constituent elements are low Z-value elements such as C, H, O, and N, resulting in a small X-ray absorption cross section and sluggish X-ray response. To improve the X-ray absorption cross section of organic scintillator materials, there are currently two solutions: (1) introducing heavy atoms (Br, I, etc.). Strong spin-orbit coupling (SOC) of halogen elements usually causes significant fluorescence quenching and inevitably introduces microsecond to second-level delayed emission (TADF / RTP), making it difficult to achieve ultrafast (<3 ns) response. At the same time, high concentration of triplet excitons easily induces self-quenching, posing a challenge to the stability of materials. Eutectic engineering can effectively integrate the performance of different component units. The halogen bond eutectic strategy constructs binary organic eutectic scintillator materials through halogen bond interaction. Unfortunately, halogen bond eutectic usually also has the above problems, affecting the response speed of organic materials to X-rays. (2) Cultivating high quantum yield fluorescent crystals (such as 9,10-diphenylanthracene, DPA). Large-size single crystal growth is difficult and has a long cycle, making it difficult to meet the needs of large-area applications. In addition, organic microcrystals are usually doped into polymer matrices to prepare thin film materials for imaging. Although this can solve the area problem, it will cause severe luminescence quenching, thus affecting the imaging clarity.

[0003] Based on this, the present invention is proposed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a short-lifetime, high-radiative-luminescence organic laser gain material, its preparation and application, which significantly improves the X-ray absorption cross-section of traditional organic semiconductor materials while maintaining the material's high fluorescence quantum yield ΦF and ultra-short fluorescence lifetime τ.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a short-lifetime, high-radiative-luminescence organic laser gain material, comprising the following steps: 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl and 4,4′-dibromotriphenyl are sequentially added to toluene, dissolved by ultrasonication, cooled, and then ethanol is added. After standing, a yellow-green solid precipitates; the solid is collected and vacuum dried to obtain microcrystals, which are the organic laser gain material.

[0006] In the above technical solution, the structural formula of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl is as follows: .

[0007] It should be noted that there are existing reports on its synthesis and application. It can be synthesized by referring to the method in the literature (Dyes and Pigments, 2013, 99, 339-347). The general synthesis route is as follows: .

[0008] 4,4′-Dibromotriphenyl was purchased from the market with a purity >99%, and its structural formula is as follows: .

[0009] In the above technical solution, based on the host-guest eutectic strategy, a "guest" molecule rich in heavy atoms (such as halogens) is assembled with a "host" (laser gain unit) with high-efficiency luminescence properties through non-covalent bonds (such as weak CH•••π interactions) to synthesize a low-threshold laser gain material. This effectively avoids the fluorescence quenching and lifetime delay problems caused by strong SOC in traditional halogen eutectic. Specifically, in the above technical solution, a stilbene derivative 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl modified with terminal steric hindrance groups is used as the host, and a biphenyl derivative 4,4′-dibromotriphenyl (PBr3P) modified with bromine atoms at the para position is used as the guest. Based on the weak intermolecular CH•••π interactions and the synergistic stability of steric hindrance, a novel host-guest eutectic material with laser gain properties is prepared.

[0010] As a preferred embodiment of the present invention, the molar ratio of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl to 4,4′-dibromotriphenyl is 0.5~2:1. Preferably, the molar ratio of the two is 1:1.

[0011] As a preferred embodiment of the technical solution of the present invention, the ultrasonic power is 800 W and the ultrasonic time is 10 min.

[0012] As a preferred embodiment of the technical solution of the present invention, the temperature is cooled to 25°C and the vacuum drying time is 6~24h.

[0013] As a preferred embodiment of the present invention, the amount of toluene used is 10-30 mL, the amount of ethanol used is 10-30 mL, the molar amount of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl is 0.05-0.2 mol, and the molar amount of 4,4′-dibromotriphenyl is 0.05-0.2 mmol.

[0014] Secondly, the present invention also claims protection for the organic laser gain material prepared by the above method.

[0015] Thirdly, the present invention also provides a method for preparing a microcrystalline thin film based on the aforementioned organic laser gain material, comprising the following steps: dispersing the aforementioned organic laser gain material in ethanol, ultrasonically treating it to obtain a suspension; then pouring the suspension onto a quartz plate, allowing it to settle, to obtain a uniform thin film, which is the microcrystalline thin film.

[0016] In the above technical solutions, a new microcrystalline thin film preparation strategy is developed. Through a self-settling strategy, a microcrystalline deposition layer of uniform thickness is formed on the surface of a quartz sheet, avoiding luminescence quenching caused by the introduction of polymer materials. This can be used for high-resolution imaging.

[0017] As a preferred embodiment of the present invention, the amount of organic laser gain material used is 10~100mg, the amount of ethanol solution used is 5~20mL, the ultrasonic power is 800W, and the ultrasonic time is 5min.

[0018] Fourthly, the present invention seeks protection for the microcrystalline thin film prepared by the above method.

[0019] Fifthly, the present invention seeks protection for the application of the aforementioned organic laser gain materials in the preparation of high-resolution imaging analysis materials.

[0020] Sixthly, the present invention also claims protection for the application of the aforementioned microcrystalline thin film in high-resolution imaging analysis.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention successfully achieved synergistic optimization of X-ray absorption and ultrafast radiative emission in organic scintillator materials through a host-guest eutectic engineering strategy. Using a eutectic system with halobiphenyls as the guest and DSB derivatives as the host, and through weak interactions and steric hindrance design, the X-ray absorption efficiency was significantly improved while maintaining a high ΦF (78.74%) and a short τ (<3 ns). The 1·PBr3P microcrystalline film exhibited a high-resolution imaging capability of 17 lp / mm and an ultra-low detection limit of 71.12 nGy / s, outperforming traditional inorganic scintillators. In summary, this invention's host-guest separation strategy provides a universal pathway to resolving the contradiction between heavy atom introduction and fluorescence quenching. Attached Figure Description

[0022] Figure 1 These are the single-crystal test results for each substance. Substance 1 represents 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl.

[0023] Figure 2 The following are test results for application examples; (a) radiative luminescence intensity related to dose (0.688 to 278 μGy / s); (b) radiative luminescence intensity of 1·PBr3P and BGO scintillators as a function of X-ray dose rate; (c) MTF of X-ray images. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0025] Although the steps in this invention are arranged by reference numerals, this is not intended to limit the order of the steps. Unless the order of the steps is explicitly stated or the execution of a step requires other steps as a basis, the relative order of the steps can be adjusted. It is understood that the term "and / or" as used herein refers to and covers any and all possible combinations of one or more of the associated listed items.

[0026] Unless otherwise specified, all raw materials used in this invention are purchased from the market.

[0027] Example 1 A method for preparing a short-lifetime, high-emissivity organic laser gain material includes the following steps: 0.1 mmol of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl and 0.1 mmol of 4,4′-dibromotriphenyl are sequentially added to 20 mL of toluene, sonicated (800 W, 35 °C, 10 min), cooled to 25 °C, and then 20 mL of ethanol (as a poor solvent) is added at once. After standing for 5 min, a yellow-green solid precipitates. The solid is collected and vacuum dried at 40 °C for 12 h to obtain microcrystals, which is the organic laser gain material (denoted as 1·PBr3P), with a yield greater than 90%.

[0028] Example 2 A method for preparing a short-lifetime, high-radiative-luminescence organic laser gain material includes the following steps: 0.12 mmol of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl and 0.1 mmol of 4,4′-dibromotriphenyl are sequentially added to 20 mL of toluene, dissolved by ultrasonication (800 W, 35 °C, 10 min), cooled to 25 °C, and then 20 mL of ethanol (as a poor solvent) is added at once. After standing for 5 min, a yellow-green solid precipitates. The solid is collected and vacuum dried at 40 °C for 12 h to obtain microcrystals, which are the organic laser gain material.

[0029] Example 3 A method for preparing a short-lifetime, high-radiative-luminescence organic laser gain material includes the following steps: 0.1 mmol of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl and 0.12 mmol of 4,4′-dibromotriphenyl are sequentially added to 20 mL of toluene, sonicated (800 W, 35 °C, 10 min), cooled to 25 °C, and then 20 mL of ethanol (as a poor solvent) is added at once. After standing for 5 min, a yellow-green solid precipitates. The solid is collected and vacuum dried at 40 °C for 12 h to obtain microcrystals, which are the organic laser gain material.

[0030] Example 4 A method for preparing a microcrystalline thin film includes the following steps: dispersing 50 mg of the organic laser gain material described in Example 1 in 10 mL of ethanol, ultrasonicating (800 W, 25 °C, 5 min) for 5 min to obtain a suspension; then pouring the suspension onto a quartz plate with a diameter of 3 cm, allowing it to settle at 40 °C for 6 h to obtain a uniform film with a thickness of 5 mm, which is the microcrystalline thin film.

[0031] Example 5 A method for preparing a microcrystalline thin film includes the following steps: 50 mg of the organic laser gain material described in Example 2 is dispersed in 10 mL of ethanol, and ultrasonically treated (800 W, 25 °C, 5 min) for 5 min to obtain a suspension; then the suspension is poured onto a quartz plate with a diameter of 3 cm and allowed to stand at 40 °C for 6 h to obtain a uniform film with a thickness of 5 mm, which is the microcrystalline thin film.

[0032] Example 6 A method for preparing a microcrystalline thin film includes the following steps: 50 mg of the organic laser gain material described in Example 3 is dispersed in 10 mL of ethanol, and ultrasonically treated (800 W, 25 °C, 5 min) for 5 min to obtain a suspension; then the suspension is poured onto a quartz plate with a diameter of 3 cm and allowed to stand at 40 °C for 6 h to settle, resulting in a uniform film with a thickness of 5 mm, which is the microcrystalline thin film.

[0033] Application examples The microcrystalline film prepared in Example 4 was placed in the imaging path, and the X-rays not absorbed by the sample stimulated the 1·PBr3P / quartz plate to produce radiative emission. The objective lens collected the radiative emission and expanded the field of view, and a Cannon EOS R5 camera captured the light signal and recorded it as the result of X-ray imaging. The detection limit of the 1·PBr3P microcrystalline film was 71.12 nGy / s, significantly lower than that of the commercial scintillator material BGO (94.97 nGy / s), and far below the current medical standard of 5.5 μGy / s (only 1 / 80th of that standard). The image resolution of the 1·PBr3P microcrystalline scintillator was 17 lp / mm, far superior to most reported halide perovskites (below 10 lp / mm) and typical commercial CsI(Tl)-based scintillators (approximately 10 lp / mm) X-ray imaging.

[0034] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of individual raw materials in the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a short-lifetime, high-radiative luminescence organic laser gain material, characterized in that, The process includes the following steps: 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl and 4,4′-dibromotriphenyl are added to toluene in sequence, dissolved by sonication, cooled, and then ethanol is added. After standing, a yellow-green solid precipitates out. The solid is collected and dried under vacuum to obtain microcrystals, which are the organic laser gain material.

2. The method for preparing a short-lifetime, high-radiative luminescence organic laser gain material according to claim 1, characterized in that, The ratio of 1,4-bis[4-(N,N-dimethylaminophenyl)styryl]biphenyl to 4,4′-dibromotriphenyl is 0.5~2:

1.

3. The method for preparing a short-lifetime, high-radiative luminescence organic laser gain material according to claim 1, characterized in that, The ultrasonic power was 800 W and the ultrasonic time was 10 min.

4. The method for preparing a short-lifetime, high-radiative luminescence organic laser gain material according to claim 1, characterized in that, Cool to 25°C and vacuum dry for 6-24 hours.

5. The method for preparing a short-lifetime, high-radiative luminescence organic laser gain material according to claim 1, characterized in that, The amount of toluene used is 10-30 mL, and the amount of ethanol used is 10-30 mL.

6. An organic laser gain material prepared by the method according to any one of claims 1 to 5.

7. A method for preparing a microcrystalline thin film, characterized in that, The process includes the following steps: dispersing the organic laser gain material of claim 5 in ethanol, ultrasonically treating it to obtain a suspension; then pouring the suspension onto a quartz plate, allowing it to settle, to obtain a uniform film, which is a microcrystalline film.

8. The microcrystalline thin film prepared by the method of claim 7.

9. The application of the organic laser gain material of claim 6 in the preparation of high-resolution imaging analysis materials.

10. The application of the microcrystalline thin film of claim 8 in high-resolution imaging analysis.

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