A method for producing a flexible metal halide film and products and applications thereof

Abstract

This invention relates to a method for preparing flexible films based on metal halides, as well as the products and applications thereof, belonging to the field of flexible film preparation technology. The invention primarily utilizes a hybrid formed by mixing halides and metal halides, which reacts with a flexible substrate to obtain a flexible film. In the preparation process, the flexible substrate isolates oxygen, forming a dense protective film that isolates moisture while also providing high-temperature resistance, thus producing a flexible and bendable film with promising applications in X-ray scintillator imaging. Furthermore, the one-step film formation method employed in this invention offers advantages such as simple process, fast preparation speed, good repeatability, and high efficiency, enabling large-area preparation of flexible films.

Description

Technical Field

[0001] This invention belongs to the field of flexible membrane preparation technology, and relates to a method for preparing a metal halide-based flexible membrane, its products, and applications. Background Technology

[0002] As a widely used high-energy radiation detector, the scintillator absorbs the energy of high-energy rays or particles and immediately emits visible light or light with wavelengths close to the visible light. The image signal can be obtained by receiving the light using charge-coupled devices (CCD), complementary metal-oxide-semiconductor (CMOS), or thin-film transistor (TFT) arrays. Scintillators are widely used in medical imaging, security inspection, non-destructive testing, aerospace, and the nuclear industry. Currently, scintillator materials mainly use alkali metal halide crystals such as NaI(Tl) and CsI(Tl).

[0003] According to incomplete statistics, the global market size for X-ray detectors reached $6 billion in 2023, with medical X-ray detectors accounting for two-thirds of the market. Furthermore, in the past two years, the share of X-ray detectors used in industrial security has been increasing year by year, highlighting their future development potential. Taking a medical computed tomography (CT) scanner as an example, in order to perform a 360° scan of the target object, its internal X-ray receiving part is usually made in a ring shape. The installation diagrams of rigid and flexible scintillators are shown below. Figure 1 As shown in Figures a and b. However, existing scintillators are rigid crystals that cannot be bent and can only be assembled from multiple scintillator crystals. During scanning, there are inevitably gaps in the information at these seams. If a patient's pathological area happens to be located at one of these seams, the symptom may not be displayed, potentially leading to misdiagnosis. Therefore, further research on this technology is urgently needed.

[0004] Facing hard X-ray incidence, the requirement for scintillators to be thick, large in area, highly uniform, and stable has always been a challenge. Patent application number 2020106552294 disperses bismuth oxide nanoparticles in an organic solvent to obtain ink; the ink is then injected into an inkjet printer cartridge, printing is performed with adjusted parameters, and the printed film is dried. This patent requires high-precision equipment and is complex to prepare; the bismuth oxide nanoparticles are ultimately dispersed on the surface of a flexible substrate, which is not conducive to long-term preservation. In contrast, this invention disperses the nanoparticles within a polymer, isolating them from the water and oxygen environment of the air, making it more suitable for nanoparticles with poor stability. Patent application number 2020102129370, in preparing a flexible X-ray detector, first peels off a second substrate and then laminates a flexible molding layer to the photosensitive array. Its lamination process makes it difficult to achieve a tight bond at the lamination surface, and the scintillator uses traditional CsI, requiring high-temperature vapor deposition.

[0005] Therefore, there is an urgent need to study a one-step method to prepare large-area flexible scintillator films, which can continuously receive X-rays from all directions, while the preparation method is simple, easy to prepare on a large scale, and low in cost. Summary of the Invention

[0006] In view of this, one objective of the present invention is to provide a method for preparing a flexible metal halide film; a second objective of the present invention is to provide a flexible metal halide film; and a third objective of the present invention is to provide an application of a flexible metal halide film in X-ray or neutron scintillator imaging of non-planar objects.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] 1. A method for preparing a flexible metal halide membrane, the method comprising the following steps:

[0009] (1) Mix halide and metal halide to form a hybrid, add it to a flexible substrate and place it in a mortar, and grind it repeatedly until it becomes a semi-transparent colloidal substance;

[0010] (2) Pour the product ground in step (1) into a pre-made mold, anneal at 25°C or above, and then cool naturally to room temperature to obtain a flexible film.

[0011] Preferably, the halide includes an organic halide or an inorganic halide, wherein the organic halide is any one or more of guanidine halide (GuaX), ammonium halide, and phosphorus halide, and the inorganic halide includes any one or more of potassium halide (KX), rubidium halide (RbX), or cesium halide (CsX), wherein the halogen in the halide is any one or more of chlorine, bromine, or iodine.

[0012] Preferably, the metal halide is any one of cuprous halide, potassium halide, chromium halide, manganese halide, copper halide, zinc halide, rubidium halide, silver halide, cadmium halide, indium halide, tin halide, antimony halide, cesium halide, thallium halide, lead halide, bismuth halide, cerium halide, samarium halide, europium halide, gadolinium halide, thulium halide, or ytterbium halide, wherein the halogen in the metal halide is any one or more of chlorine, bromine, or iodine.

[0013] Preferably, the flexible substrate is any one of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), vinylidene fluoride (PVDF), polyvinyl alcohol (PVA), polystyrene (PS), or polyurethane (PU).

[0014] Preferably, in step (1), the molar ratio of the halide to the metal halide is 1:4 to 4:1.

[0015] Preferably, in step (1), the mass ratio of the hybrid to the flexible substrate is 20:1 to 1:200.

[0016] 2. The flexible membrane prepared according to the above preparation method.

[0017] 3. Application of the above-mentioned flexible film in X-ray or neutron scintillator imaging of non-planar objects.

[0018] The beneficial effects of this invention are as follows: This invention discloses a method for preparing flexible films based on metal halides. The method mainly involves mixing halides and metal halides to form a hybrid, which then reacts with a flexible substrate to obtain the flexible film. In the preparation process of the metal halide flexible film, this invention uses a flexible substrate to isolate oxygen, forming a dense protective film that isolates moisture while also providing high-temperature resistance. This results in a flexible and bendable film with promising applications in X-ray scintillator imaging. Furthermore, the one-step film formation method of this invention has advantages such as simple process, fast preparation speed, good repeatability, and high efficiency, and can be used for large-area preparation of flexible films.

[0019] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 Schematic diagrams of the installation of rigid (a) and flexible (b) scintillators;

[0022] Figure 2 This is a flowchart illustrating the preparation process of the flexible film (Gua3Cu2I5@PDMS) based on copper halide in Example 1.

[0023] Figure 3 The state of the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1 under visible light and ultraviolet light;

[0024] Figure 4 The luminescence of the flexible copper halide-based film (Gua3Cu2I5@PDMS) prepared in Example 1 under bending (a) and stretching (b);

[0025] Figure 5Photoluminescence and excitation spectra of the flexible copper halide-based film (Gua3Cu2I5@PDMS) prepared in Example 1;

[0026] Figure 6 The transient fluorescence decay spectrum of the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1;

[0027] Figure 7 In Figures a and b, the circuit diagrams of the flexible copper halide-based film (Gua3Cu2I5@PDMS) prepared in Example 1 before and after being applied to X-ray scintillator imaging are shown. Detailed Implementation

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] Example 1

[0030] A flexible membrane based on copper-based halides (Gua3Cu2I5@PDMS) is prepared as follows: Figure 2 As shown, the specific preparation method includes the following steps:

[0031] (1) Guanidine iodide (GuaI) and cuprous iodide (CuI) are mixed in a molar ratio of 3:2 to form a hybrid. Polydimethylsiloxane (PDMS) is added (the mass ratio of the hybrid to PDMS is 1:10). The mixture is then placed in a mortar and ground repeatedly until it becomes a semi-transparent colloidal substance (Gua3Cu2I5).

[0032] (2) Pour the product ground in step (1) into a pre-made mold, heat it to 50°C and anneal it for 4 hours, then cool it naturally to room temperature to obtain a flexible film (Gua3Cu2I5@PDMS).

[0033] Example 2

[0034] A flexible membrane based on copper-based halides (Gua3Cu2Cl5@PMMA) is prepared by the following steps:

[0035] (1) Guanidine chloride (GuaCl) and cuprous chloride (CuCl) are mixed in a molar ratio of 1:4 to form a hybrid. Polymethyl methacrylate (PMMMA) is added (the mass ratio of the hybrid to PMMA is 2:1). The mixture is then placed in a mortar and ground repeatedly until it becomes a semi-transparent colloidal substance (Gua3Cu2Cl5).

[0036] (2) Pour the product ground in step (1) into a pre-made mold, heat it to 50°C and anneal it for 4 hours, then let it cool naturally to room temperature to obtain a flexible film (Gua3Cu2Cl5@PMMA).

[0037] Example 3

[0038] A flexible membrane based on copper-based halides (Gua3Cu2Br5@PVDF) is prepared by the following steps:

[0039] (1) Guanidine bromide (GuaBr) and cuprous bromide (CuBr) are mixed in a molar ratio of 3:2 to form a hybrid. Vinylidene fluoride (PVDF) is added (the mass ratio of the hybrid to PVDF is 1:20). The mixture is then placed in a mortar and ground repeatedly until it becomes a semi-transparent colloidal substance (Gua3Cu2Br5).

[0040] (2) Pour the product ground in step (1) into a pre-made mold, heat it to 50°C and anneal it for 4 hours, then cool it naturally to room temperature to obtain a flexible film (Gua3Cu2Br5@PVDF).

[0041] Performance testing

[0042] Figure 3 The states of the flexible copper-based halide film (Gua3Cu2I5@PDMS) prepared in Example 1 under visible and ultraviolet light. Figure 4 The luminescence of the copper-based halide-based flexible film (Gua3Cu2I5@PDMS) prepared in Example 1 under tension (a) and bending (b). Figure 3 and Figure 4 As can be seen, the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1 of this invention is translucent under visible and ultraviolet light, and bending and stretching do not affect its luminescence. Therefore, the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in this invention is very advantageous for X-ray scintillator imaging of non-planar objects.

[0043] Figure 5 The photoluminescence and excitation spectra of the flexible copper halide-based film (Gua3Cu2I5@PDMS) prepared in Example 1 are shown. Figure 5As can be seen, the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1 has a large Stokes shift (242nm), which can effectively avoid the self-absorption effect; at the same time, it also has a high photoluminescence quantum efficiency (PLQY), which can effectively convert high-energy rays into low-energy visible light photons.

[0044] Figure 6 The transient fluorescence decay spectrum of the flexible copper-based halide film (Gua3Cu2I5@PDMS) prepared in Example 1 is shown. Figure 6 As can be seen, the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1 has a short photon emission lifetime, which enables it to be applied to real-time imaging.

[0045] Figure 7 Figures a and b show the circuit diagrams of the flexible copper-based halide film (Gua3Cu2I5@PDMS) prepared in Example 1 before and after its application in X-ray scintillator imaging, respectively. Figure 7 As can be seen, the internal circuit diagram of the chip can be clearly seen under X-rays in the flexible film (Gua3Cu2I5@PDMS) based on copper halide prepared in Example 1.

[0046] Similarly, the flexible membrane (Gua3Cu2Cl5@PMMA) prepared in Example 2 and the flexible membrane (Gua3Cu2Br5@PVDF) prepared in Example 3 were subjected to the above performance tests, and the test results showed that they had similar performance to the flexible membrane (Gua3Cu2I5@PDMS) prepared in Example 1.

[0047] Furthermore, through numerous experiments, it has been found that: Substituting some of the raw materials in Examples 1-3 above (e.g., the halides used in the above examples can be replaced with other organic halides (ammonium halides, phosphorus halides, where the halogen in the halide is any one or more of chlorine, bromine, or iodine) or inorganic halides (potassium halides (KX), rubidium halides (RbX), or cesium halides (CsX), where the halogen in the halide is any one or more of chlorine, bromine, or iodine); and using metal halides such as cuprous halide, potassium halide, chromium halide, manganese halide, copper halide, zinc halide, rubidium halide, silver halide, etc.) The flexible film obtained by using any one of cadmium halide, indium halide, tin halide, antimony halide, cesium halide, thallium halide, lead halide, bismuth halide, cerium halide, samarium halide, europium halide, gadolinium halide, thulium halide, or ytterbium halide, wherein the halogen in the metal halide is any one or more of chlorine, bromine, or iodine; and the flexible substrate is any one of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), vinylidene fluoride (PVDF), polyvinyl alcohol (PVA), polystyrene (PS), or polyurethane (PU), also has similar properties to the flexible films in Examples 1-3.

[0048] In summary, this invention discloses a method for preparing a flexible polymer film based on copper-based halides. The method primarily involves mixing halides and metal halides to form a hybrid, which is then reacted with a flexible substrate to obtain the flexible film. During the preparation process, the flexible substrate isolates oxygen, forming a dense protective film that isolates moisture while also providing high-temperature resistance. This results in a flexible and bendable film with promising applications in X-ray scintillator imaging. Furthermore, the one-step film formation method employed in this invention offers advantages such as simple process, fast preparation speed, good repeatability, and high efficiency, enabling large-area fabrication of flexible films.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a flexible metal halide membrane, characterized in that, The preparation method includes the following steps: (1) Mix organic halides and metal halides to form a hybrid, add it to a flexible substrate, place it in a mortar, and grind it repeatedly until it becomes a semi-transparent colloidal substance; (2) Pour the product ground in step (1) into a pre-made mold, anneal at above 25°C and then cool naturally to room temperature to obtain a flexible film; The organohalides are any one or more of guanidine halides, ammonium halides, and phosphorus halides, wherein the halogen in the organohalides is any one or more of chlorine, bromine, or iodine; The metal halide is any one of cuprous halide, potassium halide, chromium halide, manganese halide, copper halide, zinc halide, rubidium halide, silver halide, cadmium halide, indium halide, tin halide, antimony halide, cesium halide, thallium halide, lead halide, bismuth halide, cerium halide, samarium halide, europium halide, gadolinium halide, thulium halide, or ytterbium halide, wherein the halogen in the metal halide is any one or more of chlorine, bromine, or iodine; In step (1), the molar ratio of the organic halide to the metal halide is 1:4 to 4:

1.

2. The preparation method according to claim 1, characterized in that, The flexible substrate is any one of polydimethylsiloxane, polymethyl methacrylate, polyvinylidene fluoride, polyvinyl alcohol, polystyrene, or polyurethane.

3. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the hybrid to the flexible substrate is 20:1 to 1:

200.

4. The flexible membrane prepared by the preparation method according to any one of claims 1 to 3.

5. The application of the flexible film according to claim 4 in X-ray or neutron scintillator imaging of non-planar objects.

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