A high-performance single rare earth doped fluoride, flexible scintillating screen and its application
By preparing a flexible scintillating screen with single rare earth doped Cs1-xNaxLu2-yLnyF7 fluoride, the problems of imaging complexity and insufficient excitation luminescence of lanthanide-doped fluorides in the existing technology are solved, and high-resolution flexible non-planar imaging is achieved with strong X-ray excitation luminescence and continuous luminescence performance.
Patent Information
- Application Number
- CN202411378863.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2044-09-30
AI Technical Summary
Existing lanthanide-doped fluoride scintillators have problems in X-ray imaging, such as complex preparation, the need for the introduction of sensitizing ions or alivalent ions, insufficient excitation luminescence intensity, and imaging being limited to planar materials, making it difficult to achieve high-resolution flexible non-planar imaging.
Single rare earth doped Cs1-xNaxLu2-yLnyF7 fluoride is used as the luminescence center and prepared by a simple thermal decomposition method to make a thin film-based flexible scintillating screen. Single doping with rare earth ions Ln3+ is used to achieve strong X-ray excited luminescence and continuous luminescence. Combined with heat treatment to enhance the luminescence ability, it is used for high-resolution imaging of non-planar objects.
High-performance X-ray excited luminescence and continuous luminescence are achieved. The flexible scintillating screen has a flat surface, good environmental stability, high transparency, and can perform high-resolution non-planar delayed imaging with a spatial resolution of 16.1lp mm-1, simplifying the preparation process and reducing costs.
Smart Images
Figure CN119371969B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of luminescent materials, and in particular relates to a high-performance single rare earth doped fluoride, a flexible scintillating screen and applications thereof. Background Art
[0002] After rare earth ion-doped fluoride is excited by X-rays, the X-ray photons can interact with the matrix lattice through the photoelectric effect and Compton scattering to generate hot electrons and deep holes, and then generate a large number of low-kinetic energy carriers through electron-electron scattering and Auger process. These carriers are easily captured by the Frank defects generated in the material after X-ray excitation, thereby producing afterglow after the X-ray excitation is turned off.
[0003] X-ray imaging technology can be used in a wide range of applications, such as accurate medical diagnosis, automated security inspection, electronic component inspection, and biological specimen detection. Lanthanide-doped fluoride nanoparticles (LFMs) offer a versatile and superior scintillator for delayed X-ray imaging due to their low cytotoxicity, excellent stability, easily controllable size, and outstanding X-ray induced luminescence / persistent luminescence (SEL / PLE). However, while many excellent LFMs have been reported for use as X-ray imaging detectors, several limitations remain. First, achieving high-resolution imaging requires very strong SEL / PLE emissions from the activator, which often requires the precise introduction of sensitizing or alivalent ions and appropriate adjustment of their doping concentration, complicating experimental design. Second, complex core / shell / shell structures are required to amplify SEL / PLE intensity, but the continuous growth of the shell requires a time-consuming experimental process. Finally, most reports on the current generation of X-ray imaging scintillators focus on planar imaging, which is limited to imaging planar electronic components or materials with planar tendencies.
[0004] To date, it has been a significant challenge to develop a lanthanide-doped fluoride scintillator that is easy to fabricate, has a simple structure, exhibits strong excitation luminescence / persistent luminescence, and enables high-resolution flexible delayed non-planar imaging. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the present invention provides a high-performance single-rare-earth-doped fluoride, a flexible scintillator, and its applications. The present invention provides a single-ion-doped fluoride scintillator with a simple structure, controllable shape, and strong X-ray excited luminescence (XEOL) and X-ray excited sustained luminescence (XEPL). The fabrication process is simple, and a minimal amount of fluoride scintillator particles can be used to create a thin-film-based flexible scintillator, thereby achieving high-resolution flexible delayed non-planar imaging that responds to X-rays.
[0006] The technical solutions of the present invention are as follows:
[0007] 1. A high-performance single rare earth doped fluoride
[0008] The single rare earth doped fluoride is Cs 1-x Na x Lu 2-y Ln y F7, 0.3≤x<0.4, Ln represents a rare earth element, Ln is Tb, Dy or Pr; when the rare earth element Ln is Tb, 0.1≤y≤0.18, when the rare earth element Ln is Dy, y=0.05, when the rare earth element Ln is Pr, y=0.05.
[0009] The single rare earth doped fluoride can realize scintillation luminescence in the wavelength range of 490 nanometers to 620 nanometers under X-ray excitation; after the X-ray excitation stops, the single rare earth doped fluoride can exhibit luminescence afterglow in the wavelength range of 490 nanometers to 620 nanometers, and the luminescence afterglow lasts for at least thirty minutes.
[0010] The grain size distribution range of the single rare earth doped fluoride is 23-27 nm.
[0011] The single rare earth doped fluoride is composed of rare earth ions Ln 3+ The single dopant acts as a luminescence center and exhibits strong scintillation luminescence and sustained luminescence after X-ray excitation.
[0012] 2. A method for preparing high-performance single rare earth doped fluoride
[0013] The following steps are involved:
[0014] 1) mixing cesium oxide, sodium oxide, lutetium oxide or rare earth oxide with a co-solvent respectively to obtain a rare earth trifluoroacetate mixture, a cesium trifluoroacetate mixture, a sodium trifluoroacetate mixture and a lutetium trifluoroacetate mixture;
[0015] 2) adding a cesium trifluoroacetate mixture, a lutetium trifluoroacetate mixture, and a rare earth trifluoroacetate mixture to the oleic acid-octadecene solution, and heating to remove water to obtain a solution A; the ratio of the total molar amount of the lutetium trifluoroacetate and the rare earth trifluoroacetate to the volume of the oleic acid-octadecene solution is 2 mmol:10 mL to 20 mL;
[0016] A sodium trifluoroacetate mixture was added to the oleic acid-octadecene solution, and the mixture was heated to remove water to obtain solution B;
[0017] 3) heating the oleic acid-octadecene solution to remove water to obtain solution C; then heating solution C to 300-310° C. under an inert gas atmosphere;
[0018] 4) When solution C is heated to 300-310°C, solution A is injected into solution C at a constant rate and reacted at 300-310°C for 50-60 minutes;
[0019] 5) Injecting solution B into solution C after solution A was injected at a constant rate, reacting at 300-310°C for 80-90 minutes, and then cooling to room temperature;
[0020] 6) The solution cooled to room temperature is centrifuged to obtain a precipitate, which is then washed with a mixed solution of ethanol and cyclohexane, centrifuged, and dried at 60-70° C. to obtain the single rare earth doped fluoride.
[0021] In step 2), the process and conditions for heating to remove water are as follows: heating the solution to be heated to 140-150° C., maintaining the temperature at 140-150° C. for 90-120 minutes to remove water, and then cooling to room temperature.
[0022] In step 3), the heating and water removal process and conditions are as follows: heating the oleic acid-octadecene solution to 120-140° C. and maintaining the temperature at 120-140° C. for 60-90 minutes to remove water.
[0023] In the step 4), the injection rate of solution A is 1.25 mL / min to 2 mL / min; in the step 5), the injection rate of solution B is 1.25 mL / min to 2 mL / min.
[0024] 3. A flexible flashing screen
[0025] The flexible scintillator screen mainly consists of a substrate and a luminous scintillator loaded inside the substrate.
[0026] The luminescent scintillator adopts the high-performance single rare earth doped fluoride.
[0027] The flexible scintillating screen is mainly made by mixing a luminescent scintillator, an organic solvent and a prepolymer solution of a substrate in a mass ratio of 0.7 to 1.1:1:10, followed by spin coating and drying.
[0028] 4. Application of a flexible flashing screen
[0029] The flexible scintillating screen is mainly used for X-ray high-resolution imaging of objects.
[0030] The imaging includes one of real-time planar imaging, real-time non-planar imaging, delayed planar imaging and delayed non-planar imaging.
[0031] The flexible scintillating screen has a thickness of 0.9 to 1.2 mm and emits light under X-ray excitation. The radioluminescence wavelength is 490 to 620 nm and the maximum spatial resolution is 16.1 lp mm.-1 .
[0032] After being irradiated by X-rays, the flexible scintillating screen is first subjected to heat treatment and then to delayed imaging; the heat treatment conditions are: heating at an ambient temperature of 60 to 70° C. for 30 to 40 minutes.
[0033] The high-performance single rare earth doped fluoride flexible scintillating screen absorbs the X-rays emitted by the radiation source and converts them into strong visible light; after the radiation source X-rays are turned off, the high-performance single rare earth doped fluoride flexible scintillating screen emits strong and long-lasting light; the high-performance single rare earth doped fluoride flexible scintillating screen contains at least the Cs 1-x Na x Lu 2-y Tb y F7 (Ln is one of Tb, Dy, and Pr); this high-performance single rare earth doped fluoride flexible scintillator screen has high surface flatness, good environmental stability, and high transparency. It can perform high-resolution delayed imaging of the interior of non-planar objects.
[0034] Compared with the prior art, the present invention has the following beneficial effects:
[0035] 1. Cs provided by the present invention 1-x Na x Lu 2-y Ln y F7 (Ln is Tb, Dy and Pr) scintillator is composed of rare earth ions Ln 3+ As a luminescent center, a single dopant can produce strong scintillation luminescence and sustained luminescence after X-ray excitation without the introduction of sensitizing ions, heterovalent ions, and complex core-shell structures. Its physical and chemical properties are very stable and the preparation method is fast and simple.
[0036] 2. Cs provided by the present invention 1-x Na x Lu 2-y Ln y The F7 (Ln is Tb, Dy and Pr) scintillator can excite deep traps after heating, thereby significantly enhancing the sustained luminescence intensity, enhancing the luminescence ability of the scintillator and the imaging ability of the subsequent scintillator screen.
[0037] 3. The present invention provides a Cs-based 1-x Na x Lu 2-y Ln y The flexible scintillator screen of F7 (Ln is Tb, Dy and Pr) scintillator can use the minimum amount of particles to manufacture the flexible scintillator screen based on thin film, so that the flexible scintillator screen has high surface flatness, good environmental stability and high transparency.
[0038] 4. The present invention provides a Cs-based 1-x Na x Lu 2-y Ln y The flexible scintillator screen of F7 (Ln is Tb, Dy and Pr) scintillator can perform high-resolution delayed imaging of the interior of non-planar objects, with an imaging spatial resolution of up to 16.1lp mm -1 , which is much higher than medical CT scan (2lp mm -1 ) and X-ray imaging (3.5lp mm -1 )The typical spatial resolution required.
[0039] 5. The present invention provides a Cs-based 1-x Na x Lu 2-y Ln y The flexible scintillator screen with F7 (Ln is Tb, Dy and Pr) scintillator has a simple manufacturing process, low cost and can be mass-produced in a short time. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Figure 1 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15 X-ray diffraction spectrum of F7 scintillator;
[0041] Figure 2 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15 Transmission electron micrograph of F7 scintillator;
[0042] Figure 3 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15 Continuous luminescence spectrum of F7 scintillator;
[0043] Figure 4 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15 Comparison of the scintillation intensity of F7 scintillation and commercial scintillators;
[0044] Figure 5 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15Comparison of the sustained luminescence intensity of F7 and the common fluoride NaYF4:Tb@NaYF4:Tb scintillator;
[0045] Figure 6 Cs in Example 1 of the present invention 0.7 Na 0.3 Lu 1.85 Tb 0.15 The continuous luminous intensity of F7 scintillator changes over time and its spectrum after heat treatment;
[0046] Figure 7 Cs in Example 2 of the present invention 0.7 Na 0.3 Lu 1.95 Dy 0.05 F7 scintillator continuous luminescence spectrum;
[0047] Figure 8 Cs in Example 3 of the present invention 0.7 Na 0.3 Lu 1.95 Pr 0.05 F7 scintillator continuous luminescence spectrum;
[0048] Figure 9 The present invention is based on Cs in Example 1 0.7 Na 0.3 Lu 1.85 Tb 0.15 A photo of the flexible scintillator screen made of F7 scintillator;
[0049] Figure 10 The present invention is based on Cs in Example 1 0.7 Na 0.3 Lu 1.85 Tb 0.15 Flexible effect diagram of the flexible scintillator screen made of F7 scintillator;
[0050] Figure 11 The present invention is based on Cs in Example 1 0.7 Na 0.3 Lu 1.85 Tb 0.15 Real-time X-ray images at standard X-ray resolution using a flexible scintillator screen made of F7 scintillator;
[0051] Figure 12 The present invention is based on Cs in Example 1 0.7 Na 0.3 Lu 1.85 Tb 0.15 Non-planar imaging effect of the flexible scintillating screen made of F7 scintillator. DETAILED DESCRIPTION
[0052] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0053] A first aspect of the present invention provides a single rare earth doped fluoride.
[0054] The molecular formula of the single rare earth doped fluoride provided by the present invention is Cs 1-x Na x Lu 2-y Ln y F7.
[0055] Here, 0.3≤x<0.4. x is preferably 0.3, 0.35 or 0.38, and most preferably 0.3.
[0056] Wherein, Ln represents a rare earth element, and Ln is Tb, Dy or Pr.
[0057] The value of y depends on the element type of Ln:
[0058] When the rare earth element Ln is Tb, 0.1≤y≤0.18;
[0059] When the rare earth element Ln is Dy, y = 0.05;
[0060] When the rare earth element Ln is Pr, y=0.05.
[0061] The single rare earth doped fluoride provided by the present invention is a rare earth ion Ln 3+ The single dopant acts as a luminescent center, exhibiting strong scintillation and sustained luminescence after X-ray excitation. Specifically, under X-ray excitation, the single rare earth doped fluoride can achieve scintillation luminescence in the wavelength range of 490 to 620 nanometers. After the X-ray excitation stops, the single rare earth doped fluoride can exhibit a luminescent afterglow in the wavelength range of 490 to 620 nanometers, and the luminescent afterglow lasts for at least 30 minutes, and the luminescent afterglow can last for more than 300 minutes.
[0062] The grain size distribution range of the single rare earth doped fluoride provided by the present invention is 23 to 27 nm. Within this range, the single rare earth doped fluoride can exert the best luminescence performance.
[0063] The present invention further provides a method for preparing a single rare earth-doped fluoride. The single rare earth-doped fluoride provided by the present invention can be prepared by a thermal decomposition method. The method specifically comprises the following steps:
[0064] 1) mixing cesium oxide, sodium oxide, lutetium oxide or rare earth oxide with a co-solvent respectively to obtain a rare earth trifluoroacetate mixture, a cesium trifluoroacetate mixture, a sodium trifluoroacetate mixture and a lutetium trifluoroacetate mixture;
[0065] In step 1), the cosolvent is a mixed aqueous solution of trifluoroacetic acid; the mass percentages of the oxide and trifluoroacetic acid in the mixed aqueous solution range from 5% to 10% and 25% to 50%, respectively; the oxide is cesium oxide, sodium oxide, lutetium oxide, or a rare earth oxide. In a specific implementation, the mass percentages of the oxide and trifluoroacetic acid in the mixed aqueous solution can be adjusted according to the type of oxide.
[0066] 2) adding a cesium trifluoroacetate mixture, a lutetium trifluoroacetate mixture, and a rare earth trifluoroacetate mixture to 1 volume fraction of an oleic acid-octadecene solution (the volume ratio of oleic acid to octadecene is 1:1), and heating to remove water to obtain solution A; adding a sodium trifluoroacetate mixture to 1 volume fraction of an oleic acid-octadecene solution (the volume ratio of oleic acid to octadecene is 1:1), and heating to remove water to obtain solution B;
[0067] In step 2), the process and conditions for heating to remove water are specifically as follows: heating the solution to be heated to 140-150° C., maintaining the temperature at 140-150° C. for 90-120 minutes to remove water, and then cooling to room temperature.
[0068] 3) heating 1 volume fraction of an oleic acid-octadecene solution (the volume ratio of oleic acid to octadecene is 1:1) to remove water to obtain a solution C; then heating the solution C to 300-310° C. under an inert gas atmosphere;
[0069] In step 3), the heating and dehydration process and conditions are as follows: heating the oleic acid-octadecene solution to 120-140° C. and maintaining the temperature at 120-140° C. for 60-90 minutes to remove moisture.
[0070] 4) When solution C is heated to 300-310°C, solution A is injected into solution C at a constant rate of 1.25 mL / min-2 mL / min, and the reaction is carried out at 300-310°C for 50-60 min;
[0071] 5) Injecting solution B into solution C after solution A was injected at a constant rate of 1.25 mL / min to 2 mL / min, reacting at 300-310°C for 80-90 min, and then cooling to room temperature;
[0072] In specific implementations, the injection rates of solution A and solution B are both related to the luminescent effect of the material. Outside this injection rate range, too fast or too slow will cause the nanoparticles to be small in size and agglomerated or too large in size and uneven.
[0073] 6) The precipitate is collected by filtration or centrifugation, and then washed with a mixed solution of ethanol and cyclohexane (the volume ratio of ethanol to cyclohexane is generally 3:1), centrifuged, and dried at 60° C. to obtain a single rare earth doped fluoride.
[0074] A second aspect of the present invention provides a flexible scintillation screen.
[0075] The flexible scintillating screen provided by the present invention mainly consists of a substrate and a luminescent scintillator loaded inside the substrate, wherein the luminescent scintillator adopts the high-performance single rare earth doped fluoride provided by the present invention.
[0076] The flexible scintillating screen provided by the present invention is mainly formed by mixing a luminescent scintillator, an organic solvent and a prepolymer solution of a substrate in a mass ratio of 0.7 to 1.1:1:10, followed by spin coating and drying.
[0077] The prepolymer solution of the substrate contains a substrate binder and a cross-linking agent.
[0078] Preferably, the base material is polydimethylsiloxane, and the prepolymer solution of the base is mainly formed by mixing a cross-linking agent and polydimethylsiloxane (PDMS) in a mass ratio of 1:10.
[0079] A third aspect of the present invention provides an application of a flexible scintillating screen in X-ray high-resolution imaging of an object.
[0080] In the application provided by the present invention, the imaging mode includes one of real-time planar imaging, real-time non-planar imaging, delayed planar imaging and delayed non-planar imaging.
[0081] When the flexible scintillating screen is used for X-ray high-resolution imaging of an object, the thickness of the flexible scintillating screen is preferably 0.9 to 1.2 mm. The flexible scintillating screen emits light under X-ray excitation, the radioluminescence wavelength is 490 to 620 nm, and the maximum spatial resolution is 16.1 lp mm -1 .
[0082] The present invention also provides applications in which the flexible scintillating screen undergoes delayed imaging after X-ray irradiation and heat treatment. The delayed imaging may be delayed planar imaging or delayed non-planar imaging. The heat treatment conditions include heating at an ambient temperature of 60-70°C for 30-40 minutes.
[0083] The specific embodiments of the present invention are as follows:
[0084] The spectral data in the examples of this invention were obtained using the micro X-ray excitation source included with the OmniFluo-Xray-JL system (PMT-CR131-TE detector, 185-900 nm). The spectral acquisition range was 300-800 nm, and the X-ray power range was 3-12 W. Unless otherwise specified, the continuous luminescence spectra in the examples of this invention were obtained by irradiating with 10 W X-rays for 5 minutes, followed by 10 seconds of inactivity.
[0085] Example 1
[0086] In this example, single rare earth doped fluoride Cs was prepared by thermal decomposition. 0.7 Na 0.3 Lu 1.85 Tb 0.15 F7, and using the prepared single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 A thin-film-based flexible scintillating screen was prepared by combining F7 and polydimethylsiloxane (PDMS), thereby achieving high-resolution flexible delayed non-planar X-ray imaging.
[0087] In this embodiment, the single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 The specific preparation process of F7 is as follows:
[0088] 1) First, terbium oxide is added to a certain weight percentage of flux, and fully ground or stirred to obtain a terbium trifluoroacetate mixture. 0.7 Na 0.3 Lu 1.85 Tb 0.15 The required trifluoroacetates are weighed or prepared in a stoichiometric ratio of F7 to obtain a cesium trifluoroacetate mixture, a sodium trifluoroacetate mixture and a lutetium trifluoroacetate mixture.
[0089] 2) In a three-necked flask A with a volume of 100 mL, a cesium trifluoroacetate mixture (comprising 0.4 mmol cesium trifluoroacetate Cs-TFA), a lutetium trifluoroacetate mixture (comprising 1.85 mmol lutetium trifluoroacetate Lu-TFA), a terbium trifluoroacetate mixture (comprising 0.15 mmol terbium trifluoroacetate Tb-TFA), oleic acid OA (5 mL) and octadecene ODE (5 mL) were mixed. Simultaneously, in another three-necked flask B with a volume of 100 mL, a sodium trifluoroacetate mixture (comprising 0.6 mmol sodium trifluoroacetate Na-TFA), oleic acid OA (5 mL) and octadecene ODE (5 mL) were mixed.
[0090] The three-necked flasks A and B were heated to 140° C., maintained at 140° C. for 90 min to remove moisture, and then cooled to room temperature to obtain solutions A and B.
[0091] Transfer solution A and solution B into syringe A and syringe B, respectively. Syringe A and syringe B are both 10 mL in size.
[0092] 3) Oleic acid (OA) (5 mL) and octadecene (ODE) (5 mL) were added to a 100 mL three-necked flask C, which was then heated to 120° C. and maintained at 120° C. for 60 min to remove moisture, thereby obtaining a solution C;
[0093] Then, under N2 atmosphere, solution C in three-necked flask C was heated to 300°C;
[0094] 4) When solution C is heated to 300°C, solution A in syringe A is injected into three-necked flask C at a rate of 1.5 mL / min and reacted at 300°C for 60 min;
[0095] 5) Solution B in syringe B was injected into three-necked flask C at a rate of 1.5 mL / min, followed by reaction at 300°C for 90 min and then cooling to room temperature;
[0096] 6) The solution cooled to room temperature was centrifuged to obtain a precipitate, which was then washed again with a mixed solution of ethanol and cyclohexane, centrifuged and dried at 60°C to obtain a single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 F7.
[0097] Attachment Figure 1 is the Cs obtained in this example 0.7 Na 0.3 Lu 1.85 Tb 0.15 X-ray diffraction spectrum of F7 scintillator. Figure 1 It can be seen that Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 The F7 scintillator matches the standard card PDF-43-0504 well. The main crystal lattice of the luminescent material belongs to the hexagonal system.
[0098] Attachment Figure 2 is the Cs obtained in this example 0.7 Na 0.3 Lu 1.85 Tb 0.15 Transmission electron microscope image of F7 scintillator. Figure 2 It can be seen that the Cs obtained in this embodiment 0.7 Na 0.3 Lu 1.85 Tb 0.15 The grain size of F7 scintillator is normally distributed between 23 and 27 nm.
[0099] Attachment Figure 3This is the continuous luminescence emission spectrum of the scintillator of this embodiment after the excitation source X-ray irradiation is turned off for a period of time. Figure 3 It can be seen that the flashing and continuous luminescence of the scintillator are both visible green light, with the main peak wavelengths being 490nm, 540nm, 585nm and 620nm.
[0100] Attachment Figure 4 The following is a comparison of the scintillation intensity of the scintillator of this embodiment and commercial scintillators after irradiation with X-rays of the same power. The commercial scintillators refer to cesium iodide doped with thallium (CSI:TI) and bismuth germanium oxide (BGO) obtained by commercial means. Figure 4 It can be seen that the scintillator of this embodiment has obvious advantages in scintillation and luminescence compared with commercial scintillators.
[0101] Attachment Figure 5 This is a comparison chart of the sustained luminescence intensity of the scintillator of this embodiment and the common fluoride NaYF4:Tb@NaYF4:Tb scintillator. Figure 5 It can be seen that the scintillator of this embodiment has a more obvious advantage of continuous luminescence compared with the common fluoride scintillator.
[0102] In this embodiment, the obtained single rare earth doped fluoride was irradiated with X-rays of the same power and then heated at 65°C for 30 minutes to obtain heat-treated single rare earth doped fluoride. At different times after stopping the irradiation, the single rare earth doped fluoride Cs that had not been heat-treated was subjected to the following tests: 0.7 Na 0.3 Lu 1.85 Tb 0.15 F7 and heat-treated single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 The continuous luminous intensity of F7 was tested, and the results are attached. Figure 6 It can be seen that the single rare earth doped fluoride Cs obtained in this embodiment 0.7 Na 0.3 Lu 1.85 Tb 0.15 The continuous luminescence time of F7 can reach 300 minutes. Moreover, after heat treatment, the single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 The sustained luminous intensity of F7 has been further improved.
[0103] In this embodiment, multiple single rare earth doped fluoride Cs were prepared by repeating the above process. 0.7 Na 0.3 Lu 1.85 Tb 0.15F7. Then the prepared single rare earth doped fluoride Cs 0.7 Na 0.3 Lu 1.85 Tb 0.15 F7 was used as a scintillator and polydimethylsiloxane (PDMS) was used to prepare a thin film-based flexible scintillating screen.
[0104] The specific preparation process of the flexible scintillating screen is as follows: 180 mg of single rare earth doped fluoride and organic solvent chloroform (CHCl3) are mixed in a mass ratio of 1:1, stirred at room temperature for 30 minutes, and then 1.2 g of polydimethylsiloxane prepolymer solution (the weight ratio of prepolymer and cross-linker is 10:1) is added, and ultrasonicated for 60 minutes to obtain a precursor solution of the flexible scintillating screen; the precursor solution of the flexible scintillating screen is spin-coated on a 30 mm × 30 mm × 3 mm mold at 5000 rpm and dried at 80°C for 24 hours to obtain a thin film-based flexible scintillating screen.
[0105] Attachment Figure 9 The Cs-based 0.7 Na 0.3 Lu 1.85 Tb 0.15 The actual picture of the flexible scintillator screen made of F7 scintillator. Figure 9 It can be seen that the flexible scintillating screen obtained in this embodiment has high transparency and flatness.
[0106] Attachment Figure 10 The Cs-based 0.7 Na 0.3 Lu 1.85 Tb 0.15 The flexible effect diagram of the flexible scintillator screen prepared by F7 scintillator. Figure 10 It can be seen that the flexible scintillating screen obtained in this embodiment can still maintain its original properties after being bent and stretched.
[0107] In this embodiment, the film-based flexible scintillating screen is used to achieve high-resolution flexible delayed non-planar X-ray imaging.
[0108] The imaging process involves placing the prepared flexible scintillating screen below and covering the object being imaged. X-rays are then irradiated from above. The rays pass through the object, pass through the scintillating screen, and are converted into visible light, which is captured by a camera and formed into an image. The power of the X-rays and the imaging light emitted by the scintillating screen are directly proportional, but nonlinearly related.
[0109] Attachment Figure 11 The standard X-ray resolution real-time X-ray image is obtained by using the flexible scintillating screen obtained in this embodiment. The imaging light of the real-time X-ray image is the scintillation light after the flexible scintillating screen is irradiated from the surrounding Figure 11It can be seen that the imaging spatial resolution of the flexible scintillation screen obtained in this embodiment can reach 16.1 lp mm -1 , which is much higher than medical CT scan (2lpmm -1 ) and X-ray imaging (3.5lp mm -1 )The typical spatial resolution required.
[0110] Attachment Figure 12 This is a non-planar imaging effect diagram obtained by using the flexible scintillating screen obtained in this embodiment. This imaging light is the continuous light emitted by the flexible scintillating screen after the radiation stops. Figure 12 It can be seen that the flexible scintillating screen obtained in this embodiment can be used for non-planar imaging.
[0111] The present invention prepared single rare earth doped fluorides with different rare earth elements and different stoichiometric ratios according to the same process as Example 1. The chemical formula and luminescence properties of the single rare earth doped fluorides prepared in each example and comparative example are shown in the following table:
[0112]
[0113] The continuous luminescence spectrum integration is performed in the wavelength range of 400 to 700 nm.
[0114] After irradiating the single rare earth doped fluoride obtained in Example 2 and Example 3 of the present invention with 10W X-rays for 5 minutes, the emission spectrum was tested 10 seconds after the excitation was stopped. The continuous luminescence emission spectra of Examples 2 to 3 after the excitation source X-ray irradiation was turned off for a period of time were obtained. See the attached drawings respectively. Figure 7 , Attachment Figure 8 . It can be seen that when the rare earth element is Dy, the luminescence peaks are 481nm and 571nm. When the rare earth element is Pr, the luminescence peaks are 483nm and 607nm. Comparing Examples 1 to 3, it can be seen that the scintillation light and continuous luminescence of the high-performance single rare earth doped fluoride obtained by the present invention and the flexible scintillating screen based on the high-performance single rare earth doped fluoride after irradiation depend on the doping ion Ln 3+ :
[0115] When doped with ions Ln 3+ Tb 3+ When irradiated, the flashing light and continuous luminescence are visible green light;
[0116] When doped with ions Ln 3+ For Dy 3+ When irradiated, the flashing light and continuous luminescence are visible blue light;
[0117] When doped with ions Ln 3+ Pr 3+When irradiated, the flashing light and continuous glow are visible red light.
[0118] Comparing Example 1, Example 4 to Example 5 and Comparative Example 1 to Comparative Example 4, it can be seen that when the doping ion Ln 3+ Tb 3+ When x is less than 0.4, high performance single rare earth doped fluoride has better performance and better continuous luminescence effect.
[0119] Comparing Example 1, Example 6 to Example 8 and Comparative Example 5 to Comparative Example 6, it can be seen that when the doping ion Ln 3+ Tb 3+ When y is within the range of 0.1≤y≤0.18, high-performance single rare earth doped fluorides have better performance and better continuous luminescence effect.
[0120] Comparing Example 2, Example 3 and Comparative Example 7, Comparative Example 8, it can be seen that when the doping ion Ln 3+ For Dy 3+ and Pr 3+ When y=0.05, the performance of high-performance single rare earth doped fluoride is better and the continuous luminescence effect is better.
[0121] In summary, the Cs obtained in the present invention 1-x Na x Lu 2-y Ln y The F7 scintillator can achieve excellent sustained luminescence with the simplest structure and single activated particle doping. When the value range of x is: 0.3≤x<0.4, and when Ln is Tb, 0.1≤y≤0.18, when Ln is Dy, y=0.05, and when Ln is Pr, y=0.05, the sustained luminescence effect is better.
[0122] In summary, the present invention has a simple preparation process, good imaging effect, and can be widely used in detection, biology, medicine and other fields.
[0123] Obviously, the above embodiments are merely examples for the purpose of clarity of description, and other variations or modifications may be made based on the above description. Therefore, obvious variations or modifications derived therefrom still fall within the scope of protection of the present invention.
Claims
1. A high-performance single rare earth doped fluoride, characterized by: The single rare earth doped fluoride is Cs 1-x Na x Lu 2- y Ln y F7, 0.3≤x<0.4, Ln represents a rare earth element, Ln is Tb, Dy or Pr; when the rare earth element Ln is Tb, 0.1≤y≤0.18, when the rare earth element Ln is Dy, y=0.05, when the rare earth element Ln is Pr, y=0.05; The grain size distribution range of the single rare earth doped fluoride is 23-27 nm.
2. The high-performance single rare earth doped fluoride according to claim 1, characterized in that: Under X-ray excitation, the single rare earth doped fluoride realizes scintillation luminescence in the wavelength range of 490 nanometers to 620 nanometers; after the X-ray excitation stops, the single rare earth doped fluoride exhibits luminescence afterglow in the wavelength range of 490 nanometers to 620 nanometers, and the luminescence afterglow lasts for more than thirty minutes.
3. A method for preparing a high-performance single rare earth doped fluoride according to any one of claims 1 to 2, characterized in that: The following steps are involved: 1) mixing cesium oxide, sodium oxide, lutetium oxide or rare earth oxide with a co-solvent respectively to obtain a rare earth trifluoroacetate mixture, a cesium trifluoroacetate mixture, a sodium trifluoroacetate mixture and a lutetium trifluoroacetate mixture; 2) adding a cesium trifluoroacetate mixture, a lutetium trifluoroacetate mixture, and a rare earth trifluoroacetate mixture to the oleic acid-octadecene solution, and heating to remove water to obtain a solution A; the ratio of the total molar amount of the lutetium trifluoroacetate and the rare earth trifluoroacetate to the volume of the oleic acid-octadecene solution is 2 mmol:10 mL to 20 mL; A sodium trifluoroacetate mixture was added to the oleic acid-octadecene solution, and the mixture was heated to remove water to obtain solution B; 3) heating the oleic acid-octadecene solution to remove water to obtain solution C; then heating solution C to 300-310° C. under an inert gas atmosphere; 4) When solution C is heated to 300-310°C, solution A is injected into solution C at a constant rate and reacted at 300-310°C for 50-60 minutes; 5) Injecting solution B into solution C after solution A was injected at a constant rate, reacting at 300-310°C for 80-90 minutes, and then cooling to room temperature; 6) The solution cooled to room temperature is centrifuged to obtain a precipitate, which is then washed with a mixed solution of ethanol and cyclohexane, centrifuged and dried to obtain the single rare earth doped fluoride.
4. The preparation method according to claim 3, wherein: In the step 4), the injection rate of solution A is 1.25 mL / min to 2 mL / min; in the step 5), the injection rate of solution B is 1.25 mL / min to 2 mL / min.
5. A flexible scintillating screen based on high-performance single rare earth doped fluoride, characterized by: The flexible scintillating screen is mainly composed of a substrate and a luminescent scintillator loaded inside the substrate; the luminescent scintillator adopts the high-performance single rare earth doped fluoride as described in any one of claims 1 to 2 or the high-performance single rare earth doped fluoride obtained by the preparation method as described in any one of claims 3 to 4.
6. The flexible scintillation screen according to claim 5, characterized in that: The flexible scintillating screen is mainly formed by mixing a luminescent scintillator, an organic solvent and a prepolymer solution of a substrate in a mass ratio of 0.7-1.1:1:10, followed by spin coating and drying.
7. Use of the flexible scintillating screen according to claim 5 or 6 in high-resolution X-ray imaging of an object, characterized in that: The imaging includes one of real-time planar imaging, real-time non-planar imaging, delayed planar imaging and delayed non-planar imaging.
8. The use according to claim 7, characterized in that: The flexible scintillating screen has a thickness of 0.9 to 1.2 mm and emits light under X-ray excitation. The radioluminescence wavelength is between 490 and 620 nm, and the maximum spatial resolution is 16.1 lp mm. -1 .
9. The use according to claim 7, characterized in that: After being irradiated by X-rays, the flexible scintillating screen is first subjected to heat treatment and then to delayed imaging; the heat treatment conditions are: heating at an ambient temperature of 60-70° C. for 30-40 minutes.