High-load transparent rare earth complex organic glass scintillator and preparation method and application thereof

Abstract

This invention discloses a high-load transparent rare-earth complex organic glass scintillator, its preparation method, and its applications. The scintillator comprises a polymer matrix and an ionic rare-earth complex dispersed therein. The rare-earth complex includes a coordinating anion and an ionic liquid cation. The coordinating anion includes rare-earth ions and organic ligands, and the loading of the rare-earth complex in the polymer matrix can reach 80-90 wt%. By introducing an ionic liquid to construct an ionic supramolecular structure, the scintillator effectively isolates the luminescent center using steric hindrance and charge shielding effects, suppressing concentration quenching and enhancing compatibility with the matrix, allowing the material to maintain transparency of over 90% even under ultra-high loading. The scintillator exhibits a radiative luminescence intensity up to 23.9 times that of commercial LYSO, with a detection limit as low as 56 nGy / s, making it suitable for high-energy particle detection and X-ray imaging.

Description

Technical Field

[0001] This application relates to the fields of scintillator materials and X-ray detection technology, and mainly to a high-load transparent rare earth complex organic glass scintillator, its preparation method and application. Background Technology

[0002] X-rays, as high-energy electromagnetic waves with strong penetrating power, have played an irreplaceable role in imaging technology in fields such as medical diagnosis, industrial non-destructive testing, security monitoring, and scientific research. Scintillators, as the core material of X-ray detection systems, are responsible for converting high-energy X-ray photons into visible or ultraviolet photons, and their performance directly affects the sensitivity, spatial resolution, and signal-to-noise ratio of the imaging system. However, while widely used traditional inorganic crystal scintillators (such as CsI:Tl and BGO) have high light yields, they generally suffer from complex fabrication processes, high costs, strong mechanical brittleness, and difficulty in fabricating flexible devices, making it difficult to meet the demands of next-generation lightweight, high-resolution, and curved-surface imaging equipment.

[0003] In recent years, rare earth-organic complex materials have become a research hotspot in novel scintillators due to their tunable structure and excellent luminescent properties. Rare earth ions (such as Eu) 3+ 、Tb 3+ Rare earth ions (such as β-diketones) possess distinctive line emission spectra, large Stokes shifts, and long luminescence lifetimes, giving them unique advantages in light conversion and radiation detection. However, due to the parity-selectivity constraint on the 4f-4f transitions of rare earth ions, their direct light absorption ability is extremely weak. Effective excitation is typically achieved through the "antenna effect," where energy is absorbed by organic ligands with strong light absorption capabilities, followed by intramolecular energy transfer to sensitize the rare earth ions and induce luminescence. Among these, β-diketone ligands with strong light absorption capabilities are frequently used to sensitize rare earth ions with characteristic line emission spectra to achieve efficient energy transfer and luminescence. However, such molecular rare-earth complex scintillators still face many serious challenges in solid-state composite systems: First, there is the problem of concentration quenching, where high concentrations of doping reduce the interionic spacing, leading to excitation energy dissipation; second, there is poor dispersibility and compatibility, with complexes prone to phase separation or crystallization aggregation under high loading conditions, resulting in severe scattering losses and reduced material transparency; furthermore, residual water molecules or ambient moisture in the complexes often induce nonradiative relaxation through OH vibrations, significantly quenching rare-earth luminescence and affecting the material's stability and environmental adaptability. Although existing technologies attempt to introduce a second ligand or use ionic liquids to adjust the coordination environment, it remains difficult to simultaneously achieve high transparency and high luminescence efficiency under extremely high loading.

[0004] While attempts have been made to replace coordinated water molecules with second ligands (such as phenanthroline and triphenylphosphine oxide) or to improve the coordination environment through ionic liquids to weaken the quenching effect, these methods often struggle to simultaneously resolve the trade-off between dispersibility, transparency, and luminescence efficiency under high loading. For example, when the typical molecular complex Eu(TTA)3(TPPO)2 is doped into polymethyl methacrylate (PMMA), when Eu... 3+ Concentration exceeding 3×10 -5 mol·L -1 Upon examination, a significant fluorescence quenching phenomenon occurs. Furthermore, transmission electron microscopy reveals that these complexes are typically dispersed in the matrix in the form of microcrystals, leading to decreased film transmittance and limited imaging resolution, making it difficult to meet the requirements of high-performance X-ray imaging.

[0005] In summary, developing a rare-earth complex organic glass scintillator with high loading capacity, excellent optical transparency, strong luminescence performance, and good environmental stability, and exploring a preparation method that can achieve molecular-level uniform dispersion and suppress concentration quenching, is of great scientific significance and application value for promoting the development of high-performance, large-area X-ray imaging technology. Summary of the Invention

[0006] To address the technical problems of rare earth complexes in solid-state composite systems, such as severe concentration quenching, easy phase separation or crystallization agglomeration under high load leading to decreased transparency, and susceptibility to moisture interference causing reduced luminescence efficiency, this application proposes a high-load transparent rare earth complex organic glass scintillator, its preparation method, and its application.

[0007] According to one aspect of the present invention, a high-load transparent rare earth complex organic glass scintillator is provided, comprising a polymer matrix and a rare earth complex dispersed in the polymer matrix; the rare earth complex comprises a coordinating anion and an ionic liquid cation, the coordinating anion comprising a rare earth ion and an organic ligand; the loading amount of the rare earth complex in the polymer matrix is ​​80-90 wt%.

[0008] The core of this high-load transparent rare-earth complex organic glass scintillator lies in the construction of an ionic supramolecular structure composed of "coordinating anions" and "ionic liquid cations." The ionic liquid cations, through steric hindrance and charge shielding, effectively isolate the rare-earth luminescent centers at the molecular level, suppressing energy transfer between ions and thus eliminating concentration quenching. Simultaneously, this ionic structure greatly enhances the compatibility between the complex and the polymer matrix, ensuring uniform molecular-level dispersion and avoiding light scattering caused by precipitation or aggregation. This allows the complex to maintain over 90% visible light transmittance even at ultra-high loadings of 80-90 wt%.

[0009] Preferably, the structure of the rare earth complex is as follows:

[0010] ,

[0011] Wherein, Ln is the rare earth ion, L is the organic ligand, and B... + The cation of the ionic liquid is [the cation]. This structure not only stabilizes the coordination environment of rare earth ions, but also [B...]. + As an outer component, it can effectively encapsulate and protect the coordination center, preventing the intrusion of environmental water molecules that could lead to luminescence quenching.

[0012] More preferably, the rare earth ion includes one of europium ion, terbium ion, samarium ion, and dysprosium ion; the organic ligand includes one of 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, acetylacetone, and 2,2,6,6-tetramethyl-3,5-heptadecanedione. The selected β-diketone ligand has excellent sensitization ability, can absorb excitation energy and efficiently transfer it to the energy level of rare earth ions, maximizing the excited photoefficiency of rare earth ions.

[0013] More preferably, the ionic liquid cation includes imidazole cations or quaternary ammonium salt cations. Imidazole or quaternary ammonium salt cations typically have long alkyl chains, which can provide a hydrophobic environment for the complex, further blocking the quenching pathway of luminescence by water molecules, and regulating the solubility of the complex in organic solvents and polymers.

[0014] More preferably, the imidazole cation includes one of 1-butyl-2,3-dimethylimidazolium ion, 1-allyl-3-methylimidazolium ion, and 1-propanoyl-3-methylimidazolium ion; the quaternary ammonium salt cation includes trimethylbenzylammonium ion.

[0015] Preferably, the polymer matrix comprises one of polymethyl methacrylate, polyvinylpyrrolidone, or polycarbonate. The above-mentioned polymer matrix has good polarity matching and refractive index consistency with the ionic complex of the present invention, which helps to further reduce interface scattering and improve the extraction efficiency of optical signals.

[0016] According to a second aspect of the present invention, a method for preparing a highly loaded transparent rare-earth complex organic glass scintillator is provided, comprising the following steps:

[0017] S1. Rare earth precursors, organic ligands and ionic liquids are mixed and assembled to obtain rare earth complexes composed of coordinating anions and ionic liquid cations.

[0018] S2. Dissolve the polymer matrix and add the rare earth complex, stir until homogeneous to obtain a mixture; the mass ratio of the polymer matrix to the rare earth complex is 1:4-4.5.

[0019] S3. The mixture is placed in a constant temperature environment for volatilization, and then vacuum dried to obtain the high-load transparent rare earth complex organic glass scintillator.

[0020] Preferably, the specific steps of S1 are as follows:

[0021] S11. The aqueous solution of the rare earth precursor is added to an ethanol solution containing an organic ligand and a base, and the mixture is stirred and reacted at room temperature. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain a preliminary complex powder. The molar ratio of the rare earth precursor to the organic ligand is 1:3.

[0022] S12. Dissolve the preliminary complex powder in dichloromethane, and recrystallize by adding excess unsuitable solvent to obtain purified complex powder.

[0023] S13. Dissolve the purified complex powder and ionic liquid together in dichloromethane, filter and take the clear solution, add excess unsuitable solvent to the clear solution to precipitate crystals or powder, and obtain the rare earth complex; the molar ratio of the purified complex powder to the ionic liquid is 1:0.75-1:2.

[0024] More preferably, the unsuitable solvent includes one of petroleum ether or ethanol. Dichloromethane, as a good solvent, ensures that the components mix at the molecular level, while petroleum ether or ethanol, as unsuitable solvents, can induce the orderly precipitation of purified ionic complexes, thereby obtaining high-quality crystalline or powder materials.

[0025] Preferably, in step S3, the isothermal evaporation temperature is 40-60℃, the isothermal evaporation time is 12-36 hours, the vacuum drying temperature is 40-60℃, and the vacuum drying time is 36-60 hours. Isothermal evaporation allows the solvent to escape slowly, avoiding cracks caused by rapid shrinkage; subsequent vacuum drying further removes deep trace amounts of solvent, ensuring the thermal stability and radiation detection stability of the material.

[0026] According to a third aspect of the present invention, an application of a highly loaded transparent rare-earth complex plexiglass scintillator in high-energy particle detection, X-ray imaging, or dose detection is proposed. With its extremely high loading (high absorption) and excellent luminescence intensity, this scintillator exhibits extremely high sensitivity and signal-to-noise ratio in low-dose detection, dynamic imaging, and high-energy particle capture.

[0027] Compared with the prior art, this application has the following beneficial effects:

[0028] (1) The high-load transparent rare-earth complex organic glass scintillator of this application constructs an ionic rare-earth complex structure through a supramolecular self-assembly strategy. By utilizing the charge shielding and spatial isolation effect formed by the ionic liquid cations on the coordinating anions at the supramolecular level, the average distance between rare-earth ions is effectively increased, fundamentally suppressing the cross-relaxation and concentration quenching phenomena that are common under high-concentration doping. The radiative luminescence intensity of this scintillator increases linearly with the increase of loading, and its radiative luminescence intensity can reach up to 23.9 times that of the commercial inorganic scintillator LYSO, exhibiting extremely high radiation detection sensitivity.

[0029] (2) The ionic complex prepared in this application has excellent interfacial compatibility with the polymer matrix. Even under extreme conditions with a loading of up to 90 wt%, it can still maintain uniform dispersion at the molecular level without the precipitation of microcrystals. The prepared plexiglass scintillator has a transmittance of more than 90% in the visible light region, ensuring efficient extraction of scintillating light and high spatial resolution imaging.

[0030] (3) This application introduces ionic liquids to participate in self-assembly, thereby increasing the effective coordination number of rare earth ions to a saturated state and effectively eliminating water molecules in the coordination layer of traditional complexes that are prone to luminescence quenching. This structural transformation blocks the non-radiative transition path caused by OH bond vibrations, and combined with the efficient "antenna effect" of organic ligands, significantly improves the excited light efficiency and energy conversion yield of rare earth ions.

[0031] (4) Thanks to the strong X-ray interception capability and ultra-high light yield brought about by the high load, the high-load transparent rare earth complex organic glass scintillator of this application exhibits a detection limit far superior to the prior art and far lower than the medical and commercial detection standards. In X-ray imaging applications, this material can achieve high-contrast, high-definition static or dynamic imaging at extremely low radiation doses, effectively reducing radiation damage to the human body or sensitive detectors.

[0032] (5) The low-temperature solution preparation process used in this application is simple and low-cost. It not only avoids the complex high-temperature growth process of traditional inorganic scintillators, but also, due to the introduction of the polymer matrix, the material has good mechanical flexibility and is easy to prepare into a large-area imaging screen or flexible detection device. Attached Figure Description

[0033] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of this application. Other embodiments and many anticipated advantages of these embodiments will be readily recognized as they become better understood through reference to the following detailed description. Elements in the drawings are not necessarily to scale. The same reference numerals refer to corresponding similar parts.

[0034] Figure 1 A schematic diagram of the core mechanism of a high-load transparent rare-earth complex organic glass scintillator according to an embodiment of this application is shown.

[0035] Figure 2 A flowchart illustrating the preparation process of a high-load transparent rare-earth complex organic glass scintillator according to an embodiment of this application is shown;

[0036] Figure 3 A schematic diagram of the crystal structure of a rare earth complex according to a specific embodiment of this application is shown;

[0037] Figure 4 A schematic diagram of rare earth complex crystal stacking according to a specific embodiment of this application is shown;

[0038] Figure 5 The single-crystal excitation and emission spectra of a rare-earth complex crystal according to a specific embodiment of this application are shown;

[0039] Figure 6 A schematic diagram showing the radiation spectrum and light yield of a rare earth complex crystal and a commercially available LYSO crystal under X-ray excitation according to a specific embodiment of this application is provided.

[0040] Figure 7 The radioluminescence intensity of a rare earth complex crystal according to a specific embodiment of this application is shown under different gradient X-ray doses.

[0041] Figure 8 A schematic diagram showing the detection limits of a rare earth complex crystal and a commercially available LYSO crystal under different X-ray dose excitations according to a specific embodiment of this application is illustrated.

[0042] Figure 9 A schematic diagram of the photoluminescence quantum yield of a rare earth complex crystal and a scintillator thin film according to a specific embodiment of this application is shown.

[0043] Figure 10 The radiation emission spectrum of a rare earth complex crystal according to a specific embodiment of this application is shown;

[0044] Figure 11 The radiative emission spectrum of a scintillator thin film according to a specific embodiment of this application is shown;

[0045] Figure 12 A transmittance graph of a scintillator film according to a specific embodiment of this application is shown;

[0046] Figure 13 A scanning electron microscope (SEM) image of a rare earth complex crystal powder according to a specific embodiment of this application is shown;

[0047] Figure 14 The radiation stability test results of a rare earth complex crystal according to a specific embodiment of this application are shown;

[0048] Figure 15 The images show a comparison of a scintillator film according to a specific embodiment of the present application under natural light and ultraviolet light excitation.

[0049] Figure 16 The image shown is a line-pair card X-ray imaging image obtained using a high-load transparent rare-earth complex organic glass scintillator film according to a specific embodiment of this application;

[0050] Figure 17 A chip X-ray imaging image obtained using a high-load transparent rare-earth complex organic glass scintillator film according to a specific embodiment of this application is shown;

[0051] Figure 18 A copper mesh X-ray imaging image obtained using a high-load transparent rare-earth complex organic glass scintillator film according to a specific embodiment of this application is shown. Detailed Implementation

[0052] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0053] Where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0054] A high-load transparent rare earth complex plexiglass scintillator includes a polymer matrix and a rare earth complex dispersed in the polymer matrix; the loading of the rare earth complex in the polymer matrix is ​​80-90 wt%.

[0055] Specifically, the structure of the rare earth complex is shown below:

[0056] ,

[0057] Including coordinating anions and ionic liquid cations B + The coordinating anions include rare earth ions Ln and organic ligands L.

[0058] In specific embodiments, the rare earth ions include one of europium ions, terbium ions, samarium ions, and dysprosium ions; the organic ligands include one of 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (NTA), 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (TAT), 4,4,4-trifluoro-1-phenyl-1,3-butanedione (BTFA), acetylacetone (ACAC), and 2,2,6,6-tetramethyl-3,5-heptadecane (DPM). The ionic liquid cation includes trimethylbenzylammonium ions (C... BTM N + ), 1-Butyl-2,3-dimethylimidazolium ion (C4dmim + ), 1-allyl-3-methylimidazolium ion (C3amim) + ), 1-propanoyl-3-methylimidazolium ion (Cpamim + One of the following: The polymer matrix includes one of polymethyl methacrylate, polyvinylpyrrolidone, or polycarbonate.

[0059] The high-load transparent rare-earth complex organic glass scintillator provided by this invention achieves a visible light transmittance of over 90% even at an ultra-high loading of 80-90 wt% by introducing an ionic liquid-driven supramolecular self-assembly mechanism. Its core mechanism can be found in [reference needed]. Figure 1 This method transforms traditional molecular complexes into ionic supramolecular structures composed of coordinating anions and ionic liquid cations during ion exchange. In this structure, the ionic liquid cations, with specific volume and charge distribution, effectively isolate and charge-shield the rare-earth luminescent centers at the supramolecular level, increasing the average distance between rare-earth ions. This fundamentally suppresses energy cross-relaxation and concentration quenching phenomena that easily occur under high-concentration doping, resulting in a linear increase in radiative emission intensity with increasing loading. Simultaneously, the ionic structure significantly enhances the interfacial compatibility between the complex and the polymer matrix, promoting uniform dispersion of the complex at the molecular level within the matrix. This avoids the microscopic inhomogeneities caused by phase separation or crystallization agglomeration in traditional materials under high loading, eliminating light scattering losses. Thus, while achieving extremely high radiation detection efficiency, it also ensures excellent optical transparency and high spatial resolution imaging performance.

[0060] Figure 2 The following is a flowchart of the preparation process of the highly loaded transparent rare earth complex organic glass scintillator, with reference to... Figure 2 The specific steps are as follows:

[0061] S1. Preparation of rare earth complexes.

[0062] S11. Dissolve rare earth carbonates in water to prepare an aqueous solution of rare earth precursors; dissolve organic ligands in ethanol and add sodium hydroxide solution to prepare an organic ligand alkaline solution; slowly add the aqueous solution of rare earth precursors dropwise to the organic ligand alkaline solution and stir the reaction at room temperature; after the reaction is completed, centrifuge, wash and dry to obtain a preliminary complex powder.

[0063] S12. Dissolve the preliminary complex powder in dichloromethane, add excess unsuitable solvent, and precipitate the purified complex powder after standing.

[0064] S13. Dissolve the purified complex powder and ionic liquid together in dichloromethane, filter and take the clear solution. Add excess unsuitable solvent to the clear solution to precipitate crystals or powder, and obtain rare earth complex.

[0065] S2. Weigh the polymer matrix into a mold, add solvent, and heat and stir at 40-60℃ to fully dissolve it, obtaining a polymer matrix solution; dissolve the rare earth complex in the polymer matrix solution to obtain a mixture. The mass ratio of the polymer matrix to the rare earth complex is 1:4-4.5.

[0066] S3. Place the mixture in a constant temperature environment of 40-60℃ for 12-36 hours to volatilize; then perform vacuum drying at a temperature of 40-60℃ for 36-60 hours; after drying and demolding, a high-load transparent rare earth complex organic glass scintillator is obtained.

[0067] In a specific embodiment, the unsuitable solvents for S12 and S13 include one of petroleum ether or ethanol, and the solvent for S2 includes N,N-dimethylformamide or dimethyl sulfoxide.

[0068] Preparation Example 1

[0069] A101. Weigh out 658 mg and 1598 mg of samples respectively, based on a molar ratio of europium acetate to 4,4,4-trifluoro-1(2-naphthyl)-1,3-butanedione (NTA) of 1:3. Dissolve europium acetate in 10 ml of ultrapure water to prepare an aqueous solution of the rare earth precursor; dissolve NTA in 60 ml of ethanol, and dissolve 240 mg of NaOH in 20 ml of high-purity water. Then pour the NaOH solution into the NTA ethanol solution to prepare an organic ligand base solution; slowly add the aqueous solution of the rare earth precursor to the organic ligand base solution dropwise, and stir the reaction at room temperature for 4 h; after the reaction is completed, centrifuge, wash and dry to obtain a preliminary complex powder.

[0070] A102. Dissolve the preliminary complex powder in dichloromethane, add three times the amount of petroleum ether, and after standing, precipitate to obtain the purified complex powder.

[0071] A103. The purified complex powder and the ionic liquid 1-butyl-2,3-dimethylimidazole chloride (C4dmimCl) were dissolved together in dichloromethane at a molar ratio of 1:2. After complete dissolution, the insoluble matter was filtered off, and the clear solution was collected. Three times the amount of petroleum ether was added to the clear solution, and the mixture was allowed to stand for 24 hours to allow crystals or powder to precipitate. After obtaining the crystals or powder by vacuum filtration or centrifugation, the mixture was dried under vacuum at 50°C to obtain the rare earth complex Eu(C 14 H9F3O2)4 - C9H 17 N2 + .

[0072] Preparation Example 2

[0073] A201. Weigh out 658 mg and 1334 mg of samples respectively, based on a molar ratio of europium acetate to 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (tta) of 1:3. Dissolve europium acetate in 10 ml of ultrapure water to prepare an aqueous solution of the rare earth precursor; dissolve tta in 60 ml of ethanol, and dissolve 240 mg of NaOH in 20 ml of high-purity water. Then pour the NaOH solution into the tta ethanol solution to prepare an organic ligand base solution; slowly add the aqueous solution of the rare earth precursor to the organic ligand base solution dropwise, and stir the reaction at room temperature for 4 h; after the reaction is completed, centrifuge, wash and dry to obtain a preliminary complex powder.

[0074] A202. Dissolve the preliminary complex powder in dichloromethane, add three times the amount of petroleum ether, and after standing, precipitate to obtain the purified complex powder.

[0075] A203. The purified complex powder and the ionic liquid 1-allyl-3-methylimidazolium bromide (C3amimBr) were dissolved together in dichloromethane at a molar ratio of 1:2. After complete dissolution, the insoluble matter was filtered off, and the clear solution was collected. Three times the amount of petroleum ether was added to the clear solution, and the mixture was allowed to stand for 24 hours to precipitate crystals or powder. After obtaining the crystals or powder by vacuum filtration or centrifugation, the mixture was dried under vacuum at 50°C to obtain the rare earth complex Eu(C8H5F3O2S)4. - C7H 11 N2 + .

[0076] Preparation Example 3

[0077] A301. Weigh out 658 mg and 1296 mg of samples respectively, based on a molar ratio of europium acetate to 4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) of 1:3. Dissolve europium acetate in 10 ml of ultrapure water to prepare an aqueous solution of the rare earth precursor; dissolve btfa in 60 ml of ethanol, and dissolve 240 mg of NaOH in 20 ml of high-purity water. Then pour the NaOH solution into the btfa ethanol solution to prepare an organic ligand base solution; slowly add the rare earth precursor aqueous solution dropwise to the organic ligand base solution, and stir the reaction at room temperature for 4 h; after the reaction is completed, centrifuge, wash and dry to obtain a preliminary complex powder.

[0078] A302. Dissolve the preliminary complex powder in dichloromethane, add three times the amount of petroleum ether, and after standing, precipitate to obtain the purified complex powder.

[0079] A303. The purified complex powder and the ionic liquid 1-propanoyl-3-methylimidazolium bromide (CpamimBr) were dissolved together in dichloromethane at a molar ratio of 1:2. After complete dissolution, the insoluble matter was filtered off, and the clear solution was collected. Three times the amount of petroleum ether was added to the clear solution, and the mixture was allowed to stand for 24 hours to allow crystals or powder to precipitate. After obtaining the crystals or powder by vacuum filtration or centrifugation, the mixture was dried under vacuum at 50°C to obtain the rare earth complex Eu(C 10 H7F3O2)4 - C7H 11 N2O2 + .

[0080] Preparation Example 4

[0081] A401. 729 mg and 1334 mg of samples were weighed according to the molar ratio of samarium chloride to 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (tta) of 1:3. A rare earth precursor aqueous solution was prepared by dissolving samarium chloride in 10 ml of ultrapure water; tta was dissolved in 60 ml of ethanol, and 240 mg of NaOH was dissolved in 20 ml of high-purity water. The NaOH solution was then added to the tta ethanol solution to prepare an organic ligand base solution. The rare earth precursor aqueous solution was slowly added dropwise to the organic ligand base solution, and the reaction was stirred at room temperature for 4 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain a preliminary complex powder.

[0082] A402. Dissolve the preliminary complex powder in dichloromethane, add three times the amount of petroleum ether, and after standing, precipitate to obtain the purified complex powder.

[0083] A403. The purified complex powder and the ionic liquid 1-butyl-2,3-dimethylimidazolium chloride (C4dmimCl) were dissolved together in dichloromethane at a molar ratio of 1:2. After complete dissolution, the insoluble matter was filtered off, and the clear solution was collected. Three times the amount of petroleum ether was added to the clear solution, and the mixture was allowed to stand for 24 hours to allow crystals or powder to precipitate. After obtaining the crystals or powder by vacuum filtration or centrifugation, the mixture was dried under vacuum at 50°C to obtain the rare earth complex Sm(C8H5F3O2S)4. - C9H 17 N2 + .

[0084] Preparation Example 5

[0085] A501. Weigh out 658 mg and 1598 mg of samples respectively, based on a molar ratio of europium acetate to 4,4,4-trifluoro-1(2-naphthyl)-1,3-butanedione (NTA) of 1:3. Dissolve europium acetate in 10 ml of ultrapure water to prepare an aqueous solution of the rare earth precursor; dissolve NTA in 60 ml of ethanol, and dissolve 240 mg of NaOH in 20 ml of high-purity water. Then pour the NaOH solution into the NTA ethanol solution to prepare an organic ligand base solution; slowly add the aqueous solution of the rare earth precursor to the organic ligand base solution dropwise, and stir the reaction at room temperature for 4 h; after the reaction is completed, centrifuge, wash and dry to obtain a preliminary complex powder.

[0086] A502. Dissolve the preliminary complex powder in dichloromethane, add three times the amount of petroleum ether, and after standing, precipitate to obtain the purified complex powder.

[0087] A503, The purified complex powder is reacted with the ionic liquid benzyltrimethylammonium chloride (C BTM NCl) was dissolved in dichloromethane at a molar ratio of 1:2. After complete dissolution, the insoluble matter was filtered off, and the clear solution was collected. Three times the amount of petroleum ether was added to the clear solution, and the mixture was allowed to stand for 24 hours to allow crystals or powder to precipitate. The crystals or powder were obtained by vacuum filtration or centrifugation and then dried under vacuum at 50°C to obtain the rare earth complex Eu(C) 14 H9F3O2)4 - C 10 H 16 N + .

[0088] Example 1

[0089] B101. Weigh 100 mg of polymethyl methacrylate (PMMA) into a 2.5 cm × 2.5 cm mold, add N,N-dimethylformamide, heat and stir at 40 °C for 40 min to fully dissolve it, and obtain a polymer matrix solution; dissolve 400 mg of the rare earth complex prepared in Preparation Example 1 into the polymer matrix solution, and heat and stir at 40 °C for 6 h to obtain a mixture.

[0090] B102. The mixture was placed in a constant temperature environment of 50℃ for 24 hours to evaporate; then vacuum dried at 40℃ for 48 hours; after drying and demolding, a high-load transparent rare earth complex organic glass scintillator film with a rare earth complex loading of 80wt% and a thickness of about 320µm was obtained.

[0091] Example 2

[0092] B201. Weigh 50 mg of polymethyl methacrylate (PMMA) into a 2.5 cm × 2.5 cm mold, add N,N-dimethylformamide, heat and stir at 40 °C for 40 min to fully dissolve it, and obtain a polymer matrix solution; dissolve 450 mg of the rare earth complex prepared in Preparation Example 2 into the polymer matrix solution, and heat and stir at 40 °C for 6 h to obtain a mixture.

[0093] B202. The mixture was placed in a constant temperature environment of 50℃ for 24 hours to evaporate; then vacuum dried at 40℃ for 48 hours; after drying and demolding, a high-load transparent rare earth complex organic glass scintillator film with a rare earth complex loading of 90wt% and a thickness of about 332µm was obtained.

[0094] Eu(C) prepared in Preparation Example 1 14 H9F3O2)4 - C9H 17 N2 + The rare earth complex was subjected to X-ray single-crystal diffraction, excitation and emission spectra, radiation spectra, light yield, and detection limit tests. The scintillator thin film prepared in Example 1 was subjected to macroscopic and SEM phase analysis, radiation stability testing, and X-ray imaging applications.

[0095] Figure 3 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + A schematic diagram of its crystal structure shows that it belongs to the monoclinic crystal system with space group P21 / c, and the structural units within the unit cell are arranged in zero dimensions. Structural analysis reveals that the rare earth ion Eu... 3+By coordinating with the oxygen atoms in the four β-diketone ligands nta molecules to form a negative charge center, the ionic liquid is anchored to the surface of the rare earth organic anion supramolecular cage through intramolecular forces. This indicates that through the self-assembly of the ionic liquid, rare earth ions can form complexes with higher coordination, further enhancing their luminescence.

[0096] Figure 4 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + A schematic diagram of crystal packing. From the packing diagram, it can be observed that C4-dmim + The H atom in Eu(NTA)4 can interact with the adjacent Eu(NTA)4 - The F and O atoms of the complex anion nta molecule form intermolecular hydrogen bonds CH…F, CH…O, which further restricts molecular vibration, suppresses nonradiative transitions, and enhances radiative luminescence. At the same time, the introduction of ionic liquid effectively isolates the distance between rare earth ions, prevents energy transfer caused by the rare earth ions being too close, and helps to improve luminescence performance.

[0097] Figure 5 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + The single-crystal excitation and emission spectra are shown in the figure. As can be seen from the figure, under 380 nm excitation, the material emits four characteristic peaks of Eu, located at 592, 612, 653, and 703 nm, which are attributed to Eu(III). 5 D0→ 7 F1 5 D0→ 7 F2 5 D0→ 7 F3 and 5 D0→ 7 The F4 transition has the strongest emission peak at 612 nm, and the spectrum shows a large Stokes shift, indicating that the material has efficient luminescence properties.

[0098] Figure 6 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + Schematic diagram of the radiation spectrum and light yield of the crystal and the commercial LYSO crystal under X-ray excitation. All tests were performed in an integrating sphere. As shown in the figure, Eu(C 14 H9F3O2)4 - C9H 17 N2 +The radiative emission of the crystal is much higher than that of the commercial inorganic scintillator LYSO, approximately 24 times that of LYSO; by fitting the integral area of ​​the radiative emission, it can be seen that Eu(C 14 H9F3O2)4 - C9H 17 N2 + The optical yield of the crystal is 45552 PhMeV. -1 It is far higher than the light output of the commercial inorganic scintillator LYSO, and about 1.8 times that of LYSO.

[0099] Figure 7 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + The radioluminescence intensity of the crystal under different X-ray dose gradients Figure 8 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + Schematic diagram of the detection limits of the crystal and the commercial LYSO crystal under different X-ray dose excitation. As can be seen from the figure, the radiative emission increases with increasing X-ray dose, and its radiative emission is linear with the X-ray dose rate. Furthermore, at a signal-to-noise ratio of 3, the calculated detection limit of this crystal is only 56 nGys. -1 It is far below the limits for medical and commercial testing.

[0100] Figure 9 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + A schematic diagram of the photoluminescence quantum yield of the crystal powder and the 80% Eu-complex-PMMA thin film prepared in Example 1. Figure 10 and Figure 11 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + The radiative emission spectra of crystalline powder and 80% Eu-complex-PMMA thin film. As can be seen from the figure, the high-transmittance scintillator film prepared by doping microcrystalline powder with the polymer PMMA exhibits a quantum yield comparable to that of microcrystalline powder, without concentration quenching, and is slightly higher than that of the same amount of powder, demonstrating the excellent optical waveguide performance of the transparent film.

[0101] Figure 12 This is a transmittance curve for an 80% Eu-complex-PMMA film. As shown in the figure, at 612 nm (corresponding to Eu...3+ At the characteristic emission wavelength, the transmittance of the thin film is as high as 96.2%. This result indicates that the thin film has excellent optical transmittance at the emission wavelength, which can effectively reduce signal loss during the imaging process, and therefore has the potential to achieve high-resolution X-ray imaging.

[0102] Figure 13 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + Scanning electron microscopy (SEM) images of the crystalline powder. The SEM results show that the film surface has a dense, non-porous structure with no crystalline powder precipitation. This dense and uniform microstructure helps reduce light scattering, thereby effectively reducing optical crosstalk during imaging.

[0103] Figure 14 Eu(C) 14 H9F3O2)4 - C9H 17 N2 + The crystal's radiation stability was tested. After continuous irradiation for 30 minutes under 50 kV, 50 µA X-ray conditions, the crystal still maintained 98.5% of its initial radiation intensity. This result demonstrates the material's excellent structural stability and signal retention under irradiation conditions, providing crucial support for its reliability in applications such as radiation detection and persistent imaging.

[0104] Figure 15 The images show a comparison of a large-area transparent film (5cm x 5cm) prepared by solution processing under natural light and ultraviolet light excitation. The logo on the substrate beneath the film is clearly visible, indicating that the film has extremely high transparency.

[0105] Figures 16-18 A schematic diagram of an X-ray image of the transparent film is shown. Testing was conducted using a self-made imaging system: the X-ray source, the object being imaged, and the highly transparent scintillation film were placed collimated and collinear, and the image was reflected to a CCD camera via a prism. (Line-to-card alignment...) Figure 16 ),chip( Figure 17 ) and copper mesh ( Figure 18 Imaging results of samples such as [sample name] show that the film can clearly distinguish line pairs of 20 lp / mm and clearly present the internal structure of the chip, indicating that it has excellent X-ray imaging performance.

[0106] The specific embodiments of this application have been described above, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0107] In the description of this application, it should be understood that the word 'comprising' does not exclude the presence of elements or steps not listed in the claims. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The simple fact that certain measures are recited in mutually different dependent claims does not suggest that combinations of these measures cannot be used for improvement. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A high-load transparent rare-earth complex plexiglass scintillator, characterized in that, The product comprises a polymer matrix and rare earth complexes dispersed in the polymer matrix; the rare earth complexes comprise coordination anions and ionic liquid cations, wherein the coordination anions comprise rare earth ions and organic ligands; the loading of the rare earth complexes in the polymer matrix is ​​80-90 wt%. The structure of the rare earth complex is as follows: Wherein, Ln is the rare earth ion, L is the organic ligand, and B... + The cation of the ionic liquid; The preparation method of the high-load transparent rare-earth complex organic glass scintillator includes the following steps: S1. A rare earth precursor, organic ligand, and ionic liquid are mixed and assembled to obtain a rare earth complex composed of a coordinating anion and an ionic liquid cation. Specific steps include: An aqueous solution of a rare earth precursor was added to an ethanol solution containing an organic ligand and a base, and the mixture was stirred at room temperature. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain a preliminary complex powder. The molar ratio of the rare earth precursor to the organic ligand was 1:

3. The preliminary complex powder was dissolved in dichloromethane, and recrystallized by adding an excess of unsuitable solvent to obtain a purified complex powder; the unsuitable solvent included one of petroleum ether or ethanol. The purified complex powder and ionic liquid were dissolved together in dichloromethane, filtered, and the clear solution was collected. An excess of unsuitable solvent was added to the clear solution to precipitate crystals or powder, thus obtaining the rare earth complex. The molar ratio of the purified complex powder to the ionic liquid was 1:0.75-1:

2. S2. Dissolve the polymer matrix in N,N-dimethylformamide or dimethyl sulfoxide solvent, add the rare earth complex, and stir until homogeneous to obtain a mixture; the mass ratio of the polymer matrix to the rare earth complex is 1:4-9; S3. The mixture is placed in a constant temperature environment for volatilization, and then vacuum dried to obtain the high-load transparent rare earth complex organic glass scintillator; The rare earth ions include one of europium ions, terbium ions, samarium ions, and dysprosium ions; the organic ligands include one of 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, acetylacetone, and 2,2,6,6-tetramethyl-3,5-heptadecanedione; The ionic liquid cations include imidazole cations or quaternary ammonium salt cations; The imidazole cations include one of 1-butyl-2,3-dimethylimidazolium ion, 1-allyl-3-methylimidazolium ion, and 1-propanoyl-3-methylimidazolium ion; the quaternary ammonium cations include trimethylbenzylammonium ion; The polymer matrix includes one of polymethyl methacrylate, polyvinylpyrrolidone, or polycarbonate.

2. The high-load transparent rare-earth complex plexiglass scintillator according to claim 1, characterized in that, In step S3, the constant temperature evaporation temperature is 40-60℃, the constant temperature evaporation time is 12-36h, the vacuum drying temperature is 40-60℃, and the vacuum drying time is 36-60h.

3. The application of a high-load transparent rare-earth complex organic glass scintillator as described in claim 1 or 2 in the fields of high-energy particle detection, X-ray imaging, or dosimetry for non-disease diagnosis and treatment purposes.

Images