Design, method of preparation and use of highly stable glassy organic x-ray scintillator host materials

Abstract

The application discloses a kind of glassy X-ray scintillator host materials, the host material is with cholesterin lipids carbazole derivative as skeleton, heavy atom is introduced in the compound at different sites of carbazole ring;And using the host material and luminescent guest compound preparation stable and have high luminous efficiency glassy X-ray scintillator;The host material plays dual core role in system: one is to utilize heavy atom effect high efficient capture X-ray energy and the electron-hole pair generated is transferred to guest;Two is to construct uniform confined environment by glassy state characteristics to inhibit phase separation and concentration quenching, to realize the decoupling of energy absorption and light emitting process.Optimized, the material has excellent comprehensive performance, detection limit is as low as 471 nGy / s, 1800 s light emitting retention rate is 99.8% under continuous irradiation, and 120 times switching cycle has no attenuation of super stable radiation light emitting performance.The application provides reliable design paradigm and preparation path for developing easy scale, high-performance organic X-ray scintillator.

Description

Technical Field

[0001] This invention relates to the fields of organic optoelectronic functional materials and radiation detection technology, specifically to a glassy X-ray scintillator host material, a glassy X-ray scintillator composite material, and their preparation methods and applications. Background Technology

[0002] Scintillators are materials that emit light after absorbing high-energy particles or radiation, and they have crucial application value in fields such as medical imaging diagnosis, industrial non-destructive testing, and high-energy physics detection. Although traditional inorganic scintillators such as CsI:Tl possess excellent radiation response performance and luminous efficiency, they also have inherent drawbacks such as demanding preparation conditions, poor material flexibility, and high production costs, making them unsuitable for emerging applications such as flexible imaging and portable detection. Compared to inorganic scintillators, organic scintillators have unique advantages such as light weight, good flexibility, tunable molecular structure, and excellent solution processing performance, making them a key research direction for next-generation high-performance scintillator materials.

[0003] However, conventional organic materials are composed only of low atomic number elements such as carbon, hydrogen, oxygen, and nitrogen, resulting in low X-ray absorption coefficients and weak interactions with high-energy radiation. This leads to poor X-ray responsibility, making it difficult to meet practical detection requirements. Introducing halogen heavy atoms such as chlorine, bromine, and iodine is currently an effective means to improve the X-ray absorption capacity of organic materials. However, while enhancing X-ray absorption, the introduction of heavy atoms simultaneously exacerbates the intramolecular spin-orbit coupling effect, leading to an irreconcilable core performance contradiction: enhanced spin-orbit coupling promotes efficient intersystem crossing of singlet excitons, generating more triplet excitons. However, triplet transition confinement leads to nonradiative quenching, directly causing a decrease in the material's radiative luminescence efficiency.

[0004] Furthermore, existing doped organic scintillator materials are prone to phase separation during processing, resulting in poor material uniformity and affecting energy transfer efficiency and luminescence stability. Therefore, developing novel molecular design strategies and processing techniques to synergistically optimize heavy atom-mediated X-ray absorption performance, suppress concentration quenching, and construct a homogeneous matrix, in order to achieve a balance between high radiation absorption and high luminescence performance, has become an urgent need for the research and development of high-performance organic X-ray scintillator materials. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a glassy X-ray scintillator main material, a glassy X-ray scintillator composite material, its preparation method, and its application.

[0006] Technical solution: This invention provides a glassy X-ray scintillator host material, wherein the host material is a compound with a cholesterol ester carbazole derivative as the backbone and heavy atoms introduced at different sites of the carbazole ring; the structural formula of the host material is as follows:

[0007]

[0008] Where a, b, c, and d are one or more of H, Cl, Br, and I.

[0009] Preferably, the host material has both strong X-ray absorption and glass-state formation capabilities. As a matrix component of the composite system, it efficiently captures X-ray energy using the heavy atom effect and transfers the generated electron-hole pairs to the guest. At the same time, it utilizes the glass-state properties of cholesterol esters to construct a uniform confined environment to suppress phase separation and concentration quenching, thereby achieving decoupling of the energy absorption and luminescence processes.

[0010] The present invention also provides a glassy X-ray scintillator composite material, which is prepared by combining the X-ray scintillator host material and the luminescent guest material as described above.

[0011] Preferably, the luminescent object is one or more of the following: the fluorescent dye rhodamine (e.g., 6G (R6G)), room temperature phosphorescent material (e.g., N-phenylcarbazole, NPC), or thermally activated delayed fluorescence molecule (e.g., DMAC-DPS).

[0012] Preferably, the mass doping ratio of the X-ray scintillator host material to the luminescent object is 0.5% to 3.0 wt%.

[0013] The present invention also provides a method for preparing the glassy X-ray scintillator composite material as described above, comprising the following steps:

[0014] (1) Synthesizing heavy atom-modified cholesterol ester carbazole derivatives as host materials;

[0015] (2) Thoroughly grind and mix the main material with the luminescent object powder;

[0016] (3) Using a melt processing technology, the mixed powder is heated at high temperature until it is completely melted to form a homogeneous transparent mixture, and then cooled and solidified to obtain a glassy organic X-ray scintillator film.

[0017] Preferably, in step (1), the reaction route for synthesizing the host material of the heavy atom modified cholesterol carbazole derivative is as follows: reacting halocarbazole with cholesterol chloroformate under inert gas protection.

[0018] Preferably, in step (3), the heating temperature in the melting process is 200℃~320℃, the holding time is no more than 1 hour, and the cooling method is natural cooling or temperature reduction cooling.

[0019] The present invention also provides the application of the X-ray scintillator body material as described above or the glassy X-ray scintillator composite material as described above in radiation detection and X-ray imaging.

[0020] Preferably, the composite material used as an X-ray imaging screen has characteristics including low detection limit, high radiation stability, and high-resolution imaging.

[0021] Preferably, the composite material retains more than 99% of its luminescence after continuous irradiation for 1800s, and has a detection limit as low as 471 nGy / s.

[0022] The design principle of this invention is as follows: Through molecular structure design, a matrix modified with heavy atoms is constructed, giving it both excellent X-ray trapping capability and native glass-forming properties. Guest luminescent molecules with different luminescent pathways are screened by energy level matching, and combined with a simple melt blending process, a series of thermoplastic, processable, high-performance organic X-ray scintillators are prepared. This system achieves decoupled control and independent optimization of the two major processes of radiation trapping and photon emission—heavy atoms endow the matrix with an extremely strong X-ray absorption cross-section, efficiently completing the energy deposition of high-energy radiation; while the inherent amorphous glass structure of the matrix forms a continuous, rigid, confined matrix, avoiding phase separation problems during two-phase miscibility and ensuring efficient energy transfer from the matrix to the guest. The luminescent guest receives the transferred excitation energy and, relying on its unique exciton transition path, achieves high-efficiency conversion of excitation energy into visible light photons.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Synergistic Performance Enhancement: While significantly enhancing the material's X-ray absorption performance, the glassy matrix effectively suppresses non-radiative transitions, achieving organic coupling and synergistic optimization of efficient X-ray absorption and high-intensity phosphorescence / fluorescence emission. Performance verification shows that the prepared material exhibits significantly enhanced radiative emission intensity, excellent sensitivity and detection limit (as low as 471 nGy / s, less than one-tenth of the medical standard), good linear response, and high imaging resolution under X-ray excitation.

[0025] 2. Excellent stability: The glassy matrix suppresses molecular motion and non-radiative channels, resulting in high luminescence retention under continuous irradiation. It also possesses long lifespan and fatigue resistance, meeting the stringent requirements for long-term reliability in practical radiation detection and imaging applications. The luminescence retention rate is 99.8% after 1800 s of continuous irradiation, and there is no decay after 120 switching cycles.

[0026] 3. Easy to process and scale up: The melt processing technology is simple to operate and does not require solvent evaporation, making it easy to achieve large-area, highly uniform scintillator material production. It provides a new preparation path and design paradigm for the development of high-performance, low-cost, and customizable organic X-ray scintillators. Attached Figure Description

[0027] Figure 1 Thermogravimetric analysis curves of the main body material of representative material CB2Cz;

[0028] Figure 2 Differential scanning calorimetry curves of the representative CB2Cz bulk material;

[0029] Figure 3 Photoluminescence spectra of three representative host materials in dilute solutions;

[0030] Figure 4 The absorption spectra of three different guest materials in dilute solutions;

[0031] Figure 5 Photoluminescence spectra of thin films prepared from three representative host materials;

[0032] Figure 6 The photoluminescence spectra of composite films after R6G is doped with three representative host materials are shown.

[0033] Figure 7 The radiation emission spectra of composite films after R6G is doped with three representative host materials are shown.

[0034] Figure 8 The photoluminescence spectrum of the composite film after NPC is doped with three representative host materials;

[0035] Figure 9 The radiation emission spectra of the composite thin film after NPC is doped with three representative host materials are shown.

[0036] Figure 10 Photoluminescence spectra of thin films composited with DMAC-DPS and different substrates;

[0037] Figure 11 The radiation emission spectra of thin films composed of DMAC-DPS with different substrates are shown.

[0038] Figure 12 The radiation emission spectra of films composed of DMAC-DPS and CB2Cz at different concentrations are shown.

[0039] Figure 13 The radiation emission spectra of the thin film after DMAC-DPS and CB2Cz are combined with a doping concentration of 3.0 wt% under different X-ray doses;

[0040] Figure 14 The graph shows the linear relationship between radiation intensity and dose rate of the film after DMAC-DPS and CB2Cz are composited at a doping concentration of 3.0 wt% under different X-ray doses.

[0041] Figure 15 The X-ray continuous irradiation stability and switching cycle stability test results of the thin film after DMAC-DPS and CB2Cz were combined with a doping concentration of 3.0 wt% are shown.

[0042] Figure 16 This is a radiometric image of a thin film after DMAC-DPS and CB2Cz are combined with a doping concentration of 3.0 wt%. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods not specifying specific conditions in the embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0044] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. The present invention is based on an X-ray excited organic scintillator material of an intrinsic glassy host-guest doped system obtained by melt processing. The host material is modified with heavy atoms that have intrinsic glass-forming ability, and guest molecules with different luminescence mechanisms are selected. The high-stability organic glassy X-ray scintillator composite material is prepared by high-temperature melt blending.

[0045] The preparation method is as follows:

[0046] Step 1: Under anhydrous, oxygen-free, and inert gas protection conditions, synthesize three types of heavy atom (chlorine, bromine, iodine) modified host materials (such as CC2Cz, CC3Cz, CB2Cz, CB3Cz, CI2Cz, CI3Cz) with excellent glass-forming ability and strong X-ray absorption ability.

[0047] The specific reaction route is as follows: a series of derivatives with bromine / chlorine heavy atoms introduced at different sites on the carbazole ring undergo nucleophilic substitution reactions with cholesterol chloroformate. The halocarbazoles include one of the following: 2-chlorocarbazole, 2-bromocarbazole, 2-iodocarbazole, 2,7-dichlorocarbazole, 2,7-dibromocarbazole, 2,7-diiodocarbazole, 3,6-dichlorocarbazole, 3,6-dibromocarbazole, and 3,6-diiodocarbazole. The halocarbazole and sodium hydride are weighed into a two-necked round-bottom flask, a magnetic stir bar is added, and the flask is purged with argon gas three times. Ultra-dry tetrahydrofuran (THF) is injected into the flask, and stirring is started. After the solid is completely dissolved, the system is placed in an ice bath and stirred for 30 min. Then, a THF solution containing cholesterol chloroformate is slowly added dropwise. The ice bath is removed, and the reaction is stirred at room temperature for 6 h. After the reaction is complete, the solvent is removed by rotary evaporation, and the crude product is purified by column chromatography (petroleum ether / dichloromethane = 3:1) to obtain a white solid product.

[0048] Step 2: Three classic organic light-emitting molecules are selected as guests: the fluorescent dye Rhodamine 6G (R6G), the room-temperature phosphorescent material N-phenylcarbazole (NPC), and the thermally activated delayed fluorescence molecule (DMAC-DPS). The host powder and guest powder are weighed according to the precise doping ratio, thoroughly ground and mixed, and then evenly spread on a quartz plate. The mixture is heated at 220°C until completely melted to form a homogeneous transparent melt. Subsequently, another quartz plate is used to cover and press it into a uniform film. The film is then transferred to a 100°C hot stage and kept at that temperature for 30 minutes. After natural cooling or rapid cooling to room temperature, a highly transparent and highly uniform amorphous X-ray imaging screen is obtained for subsequent imaging performance testing.

[0049] The mass ratio of the reactants, such as bromobenzoic acid, carbazole, and sodium hydride, is in the range of 1.4:1:0.1.

[0050] The preferred mass doping ratio of the host material to the guest material is 3.0 wt%.

[0051] Example 1

[0052] The synthesis route of the organic phosphorescent scintillator CC2Cz is as follows:

[0053]

[0054] 1) Weigh 2,7-dichlorocarbazole (2.36 g, 10.0 mmol) and sodium hydride (0.36 g, 15.0 mmol) into a 250 mL double-necked round-bottom flask, add a magnetic stir bar, and purge with argon gas three times. Pour ultra-dry tetrahydrofuran (50.00 mL) into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0055] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CC2Cz (5.2 g, yield 82%).

[0056] Example 2

[0057] The synthesis route of the organophosphorescent scintillator CC3Cz is as follows:

[0058]

[0059] 1) Weigh 2.36 g (10.0 mmol) of 3,6-dichlorocarbazole and 0.36 g (15.0 mmol) of sodium hydride into a 250 mL double-necked round-bottom flask. Add a magnetic stir bar and purge with argon gas three times. Pour 50.00 mL of ultra-dry tetrahydrofuran into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0060] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CC3Cz (5.2 g, yield 85%).

[0061] Example 3

[0062] The synthesis route of the organic phosphorescent scintillator CB2Cz is as follows:

[0063]

[0064] 1) Weigh 3.25 g (10.0 mmol) of 2,7-dibromocarbazole and 0.36 g (15.0 mmol) of sodium hydride into a 250 mL double-necked round-bottom flask, add a magnetic stir bar, and purge with argon gas three times. Pour 50.00 mL of ultra-dry tetrahydrofuran into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0065] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CB2Cz (6.1 g, yield 74%).

[0066] Example 4

[0067] The synthesis route of the organophosphorescent scintillator CB3Cz is as follows:

[0068]

[0069] 1) Weigh 3,6-dibromocarbazole (3.25 g, 10.0 mmol) and sodium hydride (0.36 g, 15.0 mmol) into a 250 mL double-necked round-bottom flask, add a magnetic stir bar, and purge with argon gas three times. Pour ultra-dry tetrahydrofuran (50.00 mL) into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0070] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CB3Cz (5.8 g, yield 81%).

[0071] Example 5

[0072] The synthesis route for the organic host material CI2Cz is as follows:

[0073]

[0074] 1) Weigh 4.19 g (10.0 mmol) of 2,7-diiodocarbazole and 0.36 g (15.0 mmol) of sodium hydride into a 250 mL double-necked round-bottom flask, add a magnetic stir bar, and purge with argon gas three times. Pour 50.00 mL of ultra-dry tetrahydrofuran into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0075] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CI2Cz (6.8 g, yield 77%).

[0076] Example 6

[0077] The synthesis route for the organic host material CI3Cz is as follows:

[0078]

[0079] 1) Weigh 4.19 g (10.0 mmol) of 3,6-diiodocarbazole and 0.36 g (15.0 mmol) of sodium hydride into a 250 mL double-necked round-bottom flask, add a magnetic stir bar, and purge with argon gas three times. Pour 50.00 mL of ultra-dry tetrahydrofuran into the double-necked flask, start stirring, and after the solid has completely dissolved, place the system in an ice bath and stir for 30 min.

[0080] 2) Subsequently, a solution of tetrahydrofuran (30.00 mL) containing cholesterol chloroformate (4.49 g, 10.0 mmol) was slowly added dropwise. The ice bath was removed, and the reaction was stirred at room temperature for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the crude product was purified by column chromatography (petroleum ether / dichloromethane = 3:1) to give a white solid product CI3Cz (6.7 g, yield 65%).

[0081] like Figures 1-2 As shown, the thermal properties of the CB2Cz host material are as follows: the TGA curve shows that its initial decomposition temperature is above 280℃, indicating excellent thermal stability that meets the temperature requirements for melt processing. The DSC curve shows a clear glass transition at 75℃ without a significant crystallization melting peak, confirming that CB2Cz possesses excellent intrinsic glass-forming ability, providing a reliable structural basis for the melt-processing of stable amorphous composite thin films.

[0082] like Figure 3 As shown, the emission spectra of the three host materials (CB2Cz, CB3Cz, CC3Cz) are almost completely identical, with a shoulder peak at 315 nm, a main peak at 330 nm, and an emission band covering 300-450 nm. This indicates that the difference in heavy atom substitution sites on the carbazole ring has no effect on the intrinsic luminescence of the host, ensuring the consistency of energy transfer conditions between different hosts and the same guest.

[0083] like Figure 4As shown, the three guest materials, R6G, NPC, and DMAC-DPS, exhibit characteristic absorptions: R6G has two absorption peaks at 300 nm and 355 nm; NPC's main absorption peak is located at 305 nm, with significant absorption at 340 nm; and DMAC-DPS's absorption peak is located at 305 nm, with a significant shoulder peak at 320 nm, and an absorption cutoff wavelength of approximately 340 nm. The comparison reveals significant spectral overlap between the host emission and the main absorption of the guest materials, completely covering the characteristic absorption bands of the three guest materials, satisfying the resonant energy transfer condition. This indicates the possibility of efficient energy transfer from the host to all three guest materials, laying the foundation for subsequent X-ray-excited efficient scintillation luminescence.

[0084] like Figure 5 As shown, the solid-state emission spectra of the three host materials (CB2Cz, CB3Cz, and CC3Cz) almost completely overlap, with the main peak located at approximately 370 nm. Compared to the solution state, there is a significant redshift, and the emission band covers a wide wavelength range of 300-600 nm. Furthermore, the wider emission band in the solid state further enhances the overlap with the absorption spectra of various guest materials, providing favorable conditions for achieving efficient energy transfer.

[0085] Example 7

[0086] Preparation of R6G@CB2Cz, R6G@CB3Cz, and R6G@CC3Cz organic scintillator thin films:

[0087] A glassy X-ray imaging screen was prepared using a melt processing technique: CB2Cz, CB3Cz, and CC3Cz host powders and R6G guest powders were precisely weighed at a doping ratio of 3.0 wt%, thoroughly ground and mixed, and then uniformly spread on a quartz sheet. The mixture was heated to 220℃ until completely melted to form a homogeneous transparent melt. Subsequently, another quartz sheet was used to cover and press the melt into a uniform film, which was then transferred to a 100℃ hot stage and kept at that temperature for 30 min. After natural cooling to room temperature, a highly transparent and highly uniform amorphous X-ray imaging screen was obtained.

[0088] like Figure 6 As shown, for the R6G@CB2Cz, R6G@CB3Cz, and R6G@CC3Cz organic scintillator films, PL spectroscopy shows that the three composite samples exhibit only the characteristic emission of R6G at 580 nm under the host characteristic excitation, and the host emission in the 300-500 nm range is completely quenched, proving that the energy transfer efficiency is extremely high.

[0089] like Figure 7As shown, for the R6G@CB2Cz, R6G@CB3Cz, and R6G@CC3Cz organic scintillator films, the corresponding RL spectra also only show the strong fluorescence signal of the guest, and the luminescence intensity shows the rule of R6G@CB2Cz > R6G@CB3Cz > R6G@CC3Cz, which directly confirms that the heavy atom modification on the carbazole ring has a key regulatory role in the X-ray absorption of the system.

[0090] Example 8

[0091] Preparation of NPC@CB2Cz, NPC@CB3Cz, and NPC@CC3Cz organic scintillator films:

[0092] The preparation steps are the same as in Example 7, except that the guest powder is replaced with NPC to obtain a highly transparent and highly uniform amorphous X-ray imaging screen.

[0093] like Figure 8 As shown, the PL spectra of NPC@CB2Cz, NPC@CB3Cz, and NPC@CC3Cz organic scintillator films exhibit typical phosphorescence emission characteristics, with a main peak at 350 nm accompanied by a significant long-wavelength tail. These results demonstrate that efficient energy transfer can be achieved from the host to the phosphorescent guest NPC.

[0094] like Figure 9 As shown, for NPC@CB2Cz, NPC@CB3Cz, and NPC@CC3Cz organic scintillator films, the order of RL intensity under the three host systems is completely consistent with that of the R6G system, i.e., NPC@CB2Cz > NPC@CB3Cz > NPC@CC3Cz. This indicates that the heavy atom effect is universal in guest systems with different luminescence mechanisms.

[0095] Example 9

[0096] Preparation of DMAC-DPS@CB2Cz, DMAC-DPS@CB3Cz, and DMAC-DPS@CC3Cz organic scintillator thin films:

[0097] The preparation steps are the same as in Example 7, except that the guest powder is replaced with DMAC-DPS to obtain a highly transparent and highly uniform amorphous X-ray imaging screen.

[0098] like Figure 10 As shown, for the DMAC-DPS@CB2Cz, DMAC-DPS@CB3Cz, and DMAC-DPS@CC3Cz organic scintillator films, PL spectroscopy confirms that the host achieves efficient energy transfer to the TADF guest, exhibiting only the characteristic narrowband emission of DMAC-DPS at 470 nm.

[0099] like Figure 11As shown, for the DMAC-DPS@CB2Cz, DMAC-DPS@CB3Cz, and DMAC-DPS@CC3Cz organic scintillator films, this system also exhibits excellent radiative emission performance under X-ray irradiation, with the emission intensity order remaining DMAC-DPS@CB2Cz > DMAC-DPS@CB3Cz > DMAC-DPS@CC3Cz, completely consistent with the pattern observed for the first two types of guest materials. This result not only verifies the good compatibility of the glassy matrix with TADF-type scintillators but also further confirms the regulatory role of heavy atom substitution sites on X-ray absorption and radiative emission.

[0100] Example 10

[0101] Preparation of DMAC-DPS@CB2Cz organic scintillator films with different mass doping ratios:

[0102] The preparation steps are the same as in Example 7, except that the host material is only CB2Cz, the guest powder is replaced with DMAC-DPS, and the mass doping ratios of the host material and the guest material are 0.5 wt%, 1.0 wt%, 2.0 wt%, and 3.0 wt%, respectively.

[0103] like Figure 12 As shown, all exhibit characteristic TADF emission of DMAC-DPS at 470 nm. The luminescence intensity monotonically increases with increasing doping concentration, reaching a maximum at 3.0 wt%, without significant concentration quenching. This indicates that in the glassy rigid matrix, guest molecules are effectively isolated, nonradiative transitions are significantly suppressed, and the system can maintain high-efficiency luminescence at high doping concentrations. Considering both luminescence efficiency and processing stability, 3.0 wt% was ultimately selected as the optimal doping concentration for subsequent tests.

[0104] Example 11

[0105] Application of the DMAC-DPS@CB2Cz organic scintillation screen with a doping ratio of 3.0 wt% obtained in Example 10 above in X-ray imaging:

[0106] like Figure 13 As shown, within a wide dose rate range from 0.041 mGy / s to 210.2 mGy / s, the RL intensity gradually increases with increasing dose rate. All samples exhibit only the characteristic TADF emission of DMAC-DPS at 470 nm, with no significant changes in spectral shape and peak position, indicating that the luminescence behavior of the material is stable under different dose irradiation.

[0107] like Figure 14As shown, the RL intensity exhibits an excellent linear response relationship with the X-ray dose rate, with a detection limit as low as 471 nGy / s, which is far below the conventional dose requirements for medical X-ray imaging, demonstrating its great application potential in the field of low-dose radiation detection and imaging.

[0108] like Figure 15 As shown, under continuous X-ray irradiation for 1800 seconds, the radiative luminescence intensity decreased by only 0.2%, with a luminescence retention rate as high as 99.8%, demonstrating the excellent structural and chemical stability of this glassy system under long-term radiation fields. Simultaneously, 120 X-ray on-off cycle tests showed no significant attenuation in the material's luminescence intensity and stable signal, indicating that the exciton generation and recombination processes are reversible and possess excellent fatigue resistance. This superior stability fully confirms that this molten glassy scintillator can meet the stringent long-term reliability requirements of practical radiation detection and imaging applications.

[0109] like Figure 16 As shown, the scintillator film exhibits high-contrast and clear imaging under X-ray irradiation, accurately distinguishing the internal structure of the helical coil and the chip, with sharp edge contours and no obvious blurring or artifacts. This excellent imaging clarity confirms the material's efficient radiative emission performance under X-ray excitation, fully demonstrating its great potential in high-resolution X-ray radiation detection and related practical applications.

Claims

1. A glassy X-ray scintillator substrate material, characterized in that: The host material is a compound with a cholesterol ester carbazole derivative as its backbone and heavy atoms introduced at different sites on the carbazole ring; the structural formula of the host material is as follows: Where a, b, c, and d are one or more of H, Cl, Br, and I.

2. A glassy X-ray scintillator composite material, characterized in that, The composite material is prepared by combining the X-ray scintillator host material as described in claim 1 with a luminescent guest material.

3. The glassy X-ray scintillator composite material according to claim 2, characterized in that, The luminescent guest is selected from one or more of the following: the fluorescent dye rhodamine, room temperature phosphorescent materials, or thermally activated delayed fluorescent molecules.

4. The glassy X-ray scintillator composite material according to claim 2, characterized in that, The mass doping ratio of the X-ray scintillator host material to the luminescent object is 0.5% to 3.0 wt%.

5. The method for preparing the glassy X-ray scintillator composite material as described in claim 2, characterized in that, Includes the following steps: (1) Synthesizing heavy atom-modified cholesterol ester carbazole derivatives as host materials; (2) Thoroughly grind and mix the main material with the luminescent object powder; (3) Using a melt processing technology, the mixed powder is heated at high temperature until it is completely melted to form a homogeneous transparent mixture, and then cooled and solidified to obtain a glassy organic X-ray scintillator film.

6. The method for preparing the glassy X-ray scintillator composite material according to claim 5, characterized in that, In step (1), the reaction route for synthesizing the host material of the heavy atom modified cholesterol carbazole derivative is as follows: the halocarbazole is reacted with cholesterol chloroformate under inert gas protection.

7. The method for preparing the glassy X-ray scintillator composite material according to claim 5, characterized in that, In step (3), the heating temperature in the melting process is 200℃~320℃, the holding time is no more than 1 hour, and the cooling method is natural cooling or temperature reduction cooling.

8. The application of the X-ray scintillator main material as described in claim 1 or the glassy X-ray scintillator composite material as described in any one of claims 2-7 in radiation detection and X-ray imaging.

9. The application according to claim 8, characterized in that, The composite material, used as an X-ray imaging screen, has characteristics including low detection limit, high radiation stability, and high-resolution imaging.

10. The application according to claim 8, characterized in that, The composite material retains more than 99% of its luminescence after continuous irradiation for 1800 s, with a detection limit as low as 471 nGy / s.

Images