Manganese (II)-based scintillator film capable of being used for flexible X-ray imaging and preparation method and application of manganese (II)-based scintillator film

Abstract

The invention belongs to the field of photoelectric materials, and discloses a manganese (II)-based scintillator film capable of being used for flexible X-ray imaging, and a preparation method and application of the manganese (II)-based scintillator film. The chemical structural formula of the scintillator is [(C9H14N) 2] MnX4, the scintillator is synthesized by reacting C9H14NX and MnX2, X is one of Cl and Br, thermoplastic polyurethane elastomer rubber (TPU) is used as a matrix, and the scintillator and the matrix are mixed to prepare the film. The film has great application potential in the fields of X-ray imaging, radiation detection, industrial inspection, safety inspection and the like.

Description

Technical Field

[0001] The invention belongs to the field of optoelectronic materials, and in particular relates to a manganese (II)-based scintillator film that can be used for flexible X-ray imaging, and a preparation method and application thereof. Background Art

[0002] X-rays are a type of electromagnetic radiation with a very short wavelength, high frequency and strong penetrating power. As a derivative of its own special properties, X-ray detection technology plays a key role in many fields such as medical reflectometry, security monitoring, industrial flaw detection, scientific and technological research, etc. Modern X-ray detectors have almost replaced traditional film detectors with their advantages such as digital image processing, massive storage capacity, and data sharing. At present, there are two available solutions for X-ray detection: direct detection based on semiconductor materials working in current-current mode and indirect detection based on scintillators working in photon-current mode. Among them, indirect detection X-ray detectors occupy most of the market share with their relatively low cost and stability. Scintillators are the core part of detectors because of their ability to convert X-rays into ultraviolet / visible light.

[0003] In the past few decades, various traditional inorganic materials, such as CsI:TI, Gd2O2S:Tb, NaI:TI, etc., have been well applied in commercial X-ray scintillators. However, they still have typical disadvantages, including difficult preparation process and high cost, which seriously hinder the development of X-ray imaging applications. In addition to inorganic scintillators, organic scintillators cannot meet the requirements of practical applications due to their poor X-ray absorption ability and unsatisfactory scintillation performance. In addition, lead halide perovskites such as CsPbBr3 have been explored as promising candidates for high-performance scintillators due to their efficient X-ray absorption ability and special radioluminescence. However, the lead toxicity in these materials limits their further commercialization.

[0004] In recent years, manganese (II)-based luminescent materials have attracted great research interest in the field of scintillators due to their advantages of low cost, excellent luminescent properties, high stability and low toxicity. The luminescence of manganese (II)-based materials originates from the dd orbital transition of the metal center and is extremely sensitive to the ligand field and coordination crystal field environment of the manganese (II) center. Therefore, considering the low toxicity, low cost and excellent optical properties, organic-inorganic hybrid manganese (II) halide complexes are expected to become promising scintillators for X-ray detection and imaging. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies in the prior art and propose a manganese (II) based scintillator film that can be used for flexible X-ray imaging and a preparation method and application thereof.

[0006] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a manganese (II)-based scintillator film that can be used for flexible X-ray imaging, the method comprising the following steps:

[0008] Step (1): According to the molar ratio of C9H 14 NX:MnX2=2:1,Weigh C9H 14 NX and MnX2 are added to an alcohol solvent, stirred at room temperature, and then concentrated by rotary evaporation. The concentrated solution is added to ethyl acetate and then ultrasonicated. Then, the solution is filtered, washed, and dried to obtain a target scintillator powder, wherein X is Cl or Br.

[0009] Step (2): taking the target scintillator powder obtained in step (1), adding acetonitrile, dissolving by ultrasonication, adding reverse solvent ethyl acetate, and then washing and drying to obtain the target scintillator crystal;

[0010] Step (3): grinding the target scintillator crystal obtained in step (2) into powder, weighing the target scintillator crystal powder and TPU, adding them into DMF, heating and stirring until the solution is clear, wherein the mass ratio of the target scintillator crystal powder to TPU is 1:2-4;

[0011] Step (4): Take the solution obtained in step (3) and drip it into a polytetrafluoroethylene mold, put it into an oven and heat it to obtain the target flexible film.

[0012] Preferably, the alcohol solvent in step (1) is methanol or ethanol.

[0013] Preferably, the specific steps of step (2) are as follows: take the target scintillator powder obtained in step (1) and add it to a reaction bottle, and add 5-10 ml of acetonitrile solvent, ultrasonicate for 3 minutes, and after it is fully dissolved, put the reaction bottle into a beaker containing 20-40 ml of ethyl acetate, and then seal the beaker. Ethyl acetate evaporates into the reaction bottle as a reverse solvent. After the reaction is completed, wash and dry with anhydrous ether to obtain a single crystal of the target scintillator.

[0014] Preferably, the amount of DMF used in step (3) is 3-5 ml.

[0015] Preferably, in step (3), the heating temperature is 60-90° C. and the stirring time is 1-2 h.

[0016] Preferably, in step (4), the heating temperature is 60-90° C. and the heating time is 72-120 h.

[0017] In a second aspect, the present invention provides a manganese (II) based scintillator film that can be used for flexible X-ray imaging. The film is prepared using the above-mentioned preparation method.

[0018] In a third aspect, the present invention provides the use of the manganese (II) based scintillator film that can be used for flexible X-ray imaging in the fields of X-ray imaging, radiation detection, industrial inspection or security inspection.

[0019] The present invention has the following beneficial effects:

[0020] (1) The method for preparing the manganese (II)-based scintillator of the present invention has a simple experimental synthesis. The complex is synthesized using the "anti-solvent method" and can be produced and applied on a large scale with low cost and low toxicity.

[0021] (2) The manganese (II)-based scintillator prepared by the present invention has excellent photophysical properties, green emission in the solid state, high light quantum yield, high light output, and low detection limit.

[0022] (3) The manganese (II)-based flexible scintillator film prepared by the present invention has good bendability and can be applied to the field of X-ray planar and non-planar imaging.

[0023] (4) When the manganese (II)-based flexible scintillator film prepared by the present invention is used for imaging non-planar objects, it can effectively avoid the problems of distortion, phase difference, vignetting, etc. that occur in planar imaging of non-planar objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 [(C9H 14 N)2] Single crystal structure of MnBr4;

[0025] Figure 2 [(C9H 14 Normalized solid-state excited emission spectrum of N)2]MnBr4;

[0026] Figure 3 [(C9H 14 Normalized solid-state excited emission spectrum of N)2]MnCl4;

[0027] Figure 4 [(C9H 14 N)2]Solid-state photoluminescence decay curve of MnBr4;

[0028] Figure 5 [(C9H 14 N)2]Solid-state photoluminescence decay curve of MnCl4;

[0029] Figure 6 [(C9H 14 N)2] Photoluminescence quantum yield spectrum of MnBr4;

[0030] Figure 7 [(C9H 14 N)2] Photoluminescence quantum yield spectrum of MnCl4;

[0031] Figure 8 [(C9H 14 N)2]Thermogravimetric analysis curve of MnBr4;

[0032] Fig. 9 [(C9H 14 N)2]MnBr4 linear response spectrum to X-ray;

[0033] Fig.10 [(C9H 14 N)2]MnBr4 detection limit spectrum;

[0034] Fig.11 [(C9H 14 N)2] Comparison of light production between MnBr4 and LuAG;

[0035] Fig.12 [(C9H 14 N)2] Flexible scintillator film prepared by MnBr4;

[0036] Fig.13 [(C9H 14 Planar and non-planar imaging of flexible scintillator films prepared by N)2]MnBr4. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the embodiments, but they are not intended to limit the present invention.

[0038] Example 1: [(C9H 14 Preparation of N)2]MnBr4@TPU flexible scintillator film

[0039] [(C9H 14 Preparation of N)2]MnBr4 powder: weigh 2mmol C9H 14 NBr (0.4322 g) and 1 mmol MnBr2·4H2O (0.2868 g) were added to ethanol solvent and stirred at room temperature for 1 h to dissolve the reactants. The solution was concentrated by rotary evaporation, ethyl acetate was added to the concentrated solution and ultrasonicated in an ultrasonic cleaning machine to obtain a precipitate. The target scintillator was obtained by suction filtration and washed with anhydrous ether and dried.

[0040] [(C9H 14Preparation of [(C9H 14 N)2]MnBr4 powder is added to a reaction bottle, and 5-10 ml of acetonitrile solvent is added, and ultrasonication is performed for 3 minutes. After sufficient dissolution, the reaction bottle is placed in a beaker containing 20-40 ml of ethyl acetate, and the beaker is sealed. Ethyl acetate is evaporated into the reaction bottle as a reverse solvent, and finally a single crystal of the target scintillator is obtained, which is washed and dried with anhydrous ether.

[0041] [(C9H 14 N)2] Preparation of MnBr4@TPU flexible scintillator film: Grind the single crystal of the above target scintillator into powder in a mortar, weigh 0.15g of the above powder and 0.5g of TPU, add them into 3ml of DMF and stir at 60℃ for 1h until clear and transparent, take the above solution and drop it into a polytetrafluoroethylene mold, put it into an oven and heat it at 90℃ for 72h to obtain the target flexible film.

[0042] Embodiment 2:

[0043] [(C9H 14 Preparation of N)2]MnBr4 powder: weigh 2mmol C9H 14 NBr (0.4322 g) and 1 mmol MnBr2·4H2O (0.2868 g) were added to methanol solvent and stirred at room temperature for 1 h to dissolve the reactants. The solution was concentrated by rotary evaporation, ethyl acetate was added to the concentrated solution and ultrasonicated in an ultrasonic cleaning machine to obtain a precipitate. The target scintillator was obtained by suction filtration and washed with anhydrous ether and dried.

[0044] [(C9H 14 Preparation of [(C9H 14 N)2]MnBr4 powder is added to a reaction bottle, and 5-10 ml of acetonitrile solvent is added, and ultrasonication is performed for 3 minutes. After sufficient dissolution, the reaction bottle is placed in a beaker containing 20-40 ml of ethyl acetate, and the beaker is sealed. Ethyl acetate is evaporated into the reaction bottle as a reverse solvent, and finally a single crystal of the target scintillator is obtained, which is washed and dried with anhydrous ether.

[0045] [(C9H 14 N)2] Preparation of MnBr4@TPU flexible scintillator film: Grind the single crystal of the above target scintillator into powder in a mortar, weigh 0.15g of the above powder and 0.35g of TPU, add them into 4ml of DMF, stir at 80℃ for 1.5h until clear and transparent, take the above solution and drop it into a polytetrafluoroethylene mold, put it into an oven and heat it at 80℃ for 100h to obtain the target flexible film.

[0046] Embodiment 3:

[0047] [(C9H 14 Preparation of N)2]MnBr4 powder: weigh 2mmol C9H 14 NBr (0.4322 g) and 1 mmol MnBr2·4H2O (0.2868 g) were added to ethanol solvent and stirred at room temperature for 1 h to dissolve the reactants. The solution was concentrated by rotary evaporation, ethyl acetate was added to the concentrated solution and ultrasonicated in an ultrasonic cleaning machine to obtain a precipitate. The target scintillator was obtained by suction filtration and washed with anhydrous ether and dried.

[0048] [(C9H 14 Preparation of [(C9H 14 N)2]MnBr4 powder is added to a reaction bottle, and 5-10 ml of acetonitrile solvent is added, and ultrasonication is performed for 3 minutes. After sufficient dissolution, the reaction bottle is placed in a beaker containing 20-40 ml of ethyl acetate, and the beaker is sealed. Ethyl acetate is evaporated into the reaction bottle as a reverse solvent, and finally a single crystal of the target scintillator is obtained, which is washed and dried with anhydrous ether.

[0049] [(C9H 14 N)2] Preparation of MnBr4@TPU flexible scintillator film: Grind the single crystal of the above target scintillator into powder in a mortar, weigh 0.15g of the above powder and 0.6g of TPU, add them into 5ml of DMF, stir at 90℃ for 1.5h until clear and transparent, take the above solution and drop it into a polytetrafluoroethylene mold, put it into an oven and heat it at 90℃ for 120h to obtain the target flexible film.

[0050] Example 4: [(C9H 14 Preparation of N)2]MnCl4@TPU scintillator film

[0051] [(C9H 14 Preparation of N)2]MnCl4 powder: weigh 2mmol C9H 14 NCl (0.3433 g) and 1 mmol MnCl2·4H2O (0.1979 g) were added to ethanol solvent and stirred at room temperature for 1 h to dissolve the reactants. The solution was concentrated by rotary evaporation, ethyl acetate was added to the concentrated solution and ultrasonicated in an ultrasonic cleaning machine to obtain a precipitate. The target scintillator was obtained by suction filtration and washed with anhydrous ether and dried.

[0052] [(C9H 14 Preparation of [(C9H 14N)2]MnCl4 powder is added to the reaction bottle, and 5-10ml of acetonitrile solvent is added, and ultrasonication is performed for 3 minutes. After sufficient dissolution, the reaction bottle is placed in a beaker containing 20-40ml of ethyl acetate, and the beaker is sealed. Ethyl acetate is evaporated into the reaction bottle as a reverse solvent, and finally a single crystal of the target scintillator is obtained, which is washed and dried with anhydrous ether.

[0053] [(C9H 14 N)2] Preparation of MnCl4@TPU flexible scintillator film: Grind the single crystal of the above target scintillator into powder in a mortar, weigh 0.15g of the above powder and 0.5g of TPU, add them into 3ml of DMF and stir at 60℃ for 1h until clear and transparent, take the above solution and drop it into a polytetrafluoroethylene mold, put it into an oven and heat it at 90℃ for 72h to obtain the target flexible film.

[0054] Experimental Example 1: Acquisition of SC-XRD Data

[0055] SC-XRD data were obtained on a Bruker Smart Apex CCD diffractometer at room temperature using the ω-2θ scanning technique with graphite monochromator Mo-Kα As the radiation source. The [(C9H 14 The structure of the N)2]MnBr4 single crystal was solved and refined using Olex2 and SHELXS (full matrix least squares on F2). The solution is shown in Figure 1 The structure [(C9H 14 The crystal of N)2]MnBr4 is monoclinic and its space group is P21 / n.

[0056] Experimental Example 2: Measurement of excitation emission spectrum and luminescence lifetime decay curve

[0057] The excitation emission spectrum and luminescence lifetime decay curve were measured on an Edinburgh FLS-980 spectrophotometer. The excitation emission spectrum used a 450W xenon lamp, the excitation spectrum ranged from 250nm-400nm, and the emission spectrum ranged from 400nm-800nm. The test results are shown in the figure below. Figure 2 , Figure 3 The excitation wavelength of the scintillator prepared in Example 1 is 385nm, and the emission wavelength is 524nm. The excitation wavelength of the scintillator prepared in Example 4 is 328nm, and the emission wavelength is 521nm. The luminescence lifetime decay curve test in Example 1 uses a 385nm laser, and the luminescence lifetime decay curve test in Example 4 uses a 328nm laser. The test results are shown in FIG. Figure 4 , Figure 5As shown, the luminescence lifetime of the scintillator prepared in Example 1 is 371 μs, and the luminescence lifetime of the scintillator prepared in Example 4 is 3.479 ms. Compared with commercial scintillators such as LuAG, the time resolution is high, and the detection sensitivity and accuracy are higher.

[0058] Experimental Example 3: Test of Photoluminescence Quantum Yield

[0059] The photoluminescence quantum yield test was conducted using an integrating sphere mode under a 450W xenon lamp light source. The test results are shown in Figure 6 , Figure 7 As shown, the photoluminescence quantum efficiency of the scintillator prepared in Example 1 is close to 100%, and the photoluminescence quantum efficiency of the scintillator prepared in Example 4 is 87.67%.

[0060] Experimental Example 4: TGA Measurement

[0061] TGA measurement uses NETZSCH STA-2500 thermal analyzer. In 40mL / min nitrogen atmosphere, the heating rate is 10K / min, the heating range is RT-500℃, and the test results are as follows Figure 8 The decomposition temperature T of the scintillator prepared in Example 1 is d =250℃, with good thermal stability.

[0062] Experimental Example 5: Measurement of X-ray Linear Response and Detection Limit

[0063] The irradiation emission spectrum and detection limit were measured on an Edinburgh FLS-980 spectrophotometer. The irradiation intensity during the measurement was 0.578 μGy air ·s -1 -4.5μGy air ·s -1 , the test results are as follows Fig. 9 As shown. With two tungsten sheets and four copper sheets as attenuation sheets, when the signal-to-noise ratio is 3, the detection limit LoD = 43.64nGy air ·s -1 , the test results are as follows Fig.10 As shown, the scintillator prepared in Example 1 has a certain linear relationship between the irradiation intensity and the X-ray dose rate under X-ray irradiation and a lower detection limit.

[0064] Experimental Example 6: Measurement of Light Production

[0065] The light production was measured on an Edinburgh FLS-980 spectrophotometer. Using commercial LuAG as a reference, a scintillator with a thickness of 100 μm was placed in the same position as the LuAG. The steady-state XEL spectrum was then integrated to obtain the corresponding photon counting results. The light production of LuAG is known to be 22,000 photons MeV. -1 The light output of the scintillator is calculated by the following formulas (1) and (2): 57739 photons MeV -1 , the test results are as follows Fig.11 As shown, the scintillator prepared in Example 1 has a higher light yield.

[0066]

[0067] Experimental Example 7: Imaging of Flexible Scintillator Films

[0068] The size of the flexible scintillator film prepared in Example 1 is 5×5 cm, it does not emit light in sunlight, only displays the translucent white color of the TPU film, and emits the color of the complex under ultraviolet and X-ray irradiation; Fig.12 (a) is a scintillator film made by doping manganese (II) complex with TPU. The prepared film has a certain flexibility and can be bent 360°. Fig.12 As shown in (b), it emits green under ultraviolet light. Due to the different absorption of X-rays by different metals, the spatial saturation formed on the scintillator is different, thus forming optical imaging. The copper tape is pasted on the PET board, and the PET board can be bent to a certain extent, which has the possibility of realizing planar imaging and non-planar imaging. Self-made planar imaging and non-planar imaging objects such as Fig.13 (a) and (c) show that the copper strip is made into a CPO style, and the imaging results are shown in Fig.13 (b) and (d). It is worth noting that the object image obtained by plane imaging of a curved object has a certain degree of distortion, while the object image obtained by curved surface imaging of a curved object is more consistent with the original shape of the object. The flexible scintillator film prepared in this example can realize plane imaging and non-plane imaging.

[0069] The above shows and describes the basic principles, main features and advantages of the present invention. However, the above is only a specific embodiment of the present invention, and the technical features of the present invention are not limited thereto. Any other implementation methods derived by any technician in the field without departing from the technical solution of the present invention should be included in the patent scope of the present invention.

Claims

1. A method for preparing a manganese (II)-based scintillator film that can be used for flexible X-ray imaging, characterized in that: The method comprises the following steps: Step (1): According to the molar ratio of C9H 14 NX:MnX2=2:1,Weigh C9H 14 NX and MnX2 are added to an alcohol solvent, stirred at room temperature, and then concentrated by rotary evaporation. The concentrated solution is added to ethyl acetate and then ultrasonicated. Then, the solution is filtered, washed, and dried to obtain a target scintillator powder, wherein X is Cl or Br. Step (2): taking the target scintillator powder obtained in step (1), adding acetonitrile, dissolving by ultrasonication, adding reverse solvent ethyl acetate, and then washing and drying to obtain the target scintillator crystal; Step (3): grinding the target scintillator crystal obtained in step (2) into powder, weighing the target scintillator crystal powder and TPU, adding them into DMF, heating and stirring until the solution is clear, wherein the mass ratio of the target scintillator crystal powder to TPU is 1:2-4; Step (4): Take the solution obtained in step (3) and drip it into a polytetrafluoroethylene mold, put it into an oven and heat it to obtain the target flexible film.

2. The method for preparing a manganese (II)-based scintillator thin film for flexible X-ray imaging according to claim 1, characterized in that: The alcohol solvent in step (1) is methanol or ethanol.

3. The method for preparing a manganese (II)-based scintillator thin film for flexible X-ray imaging according to claim 1, characterized in that: The specific steps of step (2) are as follows: take the target scintillator powder obtained in step (1) and add it to a reaction bottle, and add 5-10 ml of acetonitrile solvent, ultrasonicate for 3 minutes, and after it is fully dissolved, put the reaction bottle into a beaker containing 20-40 ml of ethyl acetate, and then seal the beaker. Ethyl acetate evaporates into the reaction bottle as a reverse solvent. After the reaction is completed, wash and dry with anhydrous ether to obtain a single crystal of the target scintillator.

4. The method for preparing a manganese (II)-based scintillator thin film for flexible X-ray imaging according to claim 1, characterized in that: The amount of DMF used in step (3) is 3-5 ml.

5. The method for preparing a manganese (II)-based scintillator thin film for flexible X-ray imaging according to claim 1, characterized in that: In step (3), the heating temperature is 60-90° C. and the stirring time is 1-2 h.

6. The method for preparing a manganese (II)-based scintillator thin film for flexible X-ray imaging according to claim 1, characterized in that: In step (4), the heating temperature is 60-90° C. and the heating time is 72-120 h.

7. A manganese (II) based scintillator film for flexible X-ray imaging, characterized in that: The film is prepared by the preparation method described in any one of claims 1 to 6.

8. Use of the manganese (II) based scintillator film for flexible X-ray imaging as claimed in claim 7 in the fields of X-ray imaging, radiation detection, industrial inspection or security inspection.

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