Nanofiber heat detection film, method for preparing same, and use thereof

Abstract

The application discloses a kind of nanofiber thermal detection film and its preparation method and application, wherein the nanofiber thermal detection film includes pixel point array and connecting portion, every two adjacent pixel points in the pixel point array are connected by the connecting portion, the pixel point and the connecting portion all include nanofiber, and the nanofiber of the pixel point is dense arrangement fiber, the nanofiber of the connecting portion is sparse arrangement fiber, and the nanofiber includes temperature-sensitive fluorescent material.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of infrared imaging technology, and particularly relates to a nanofiber thermal detection film and a preparation method and application thereof. BACKGROUND

[0002] Infrared thermal imaging technology has the advantages of non-contact, rapidness, high efficiency, etc., and is widely applied to the fields of biological detection, medical pathological diagnosis, vehicle-mounted night vision system and security monitoring. The basic principle of an infrared thermal detector is that infrared radiation signals emitted by a target detection object are imaged on a thermal detection unit through a lens, causing the temperature of corresponding pixel points in the imaging area to rise. The pixel points are composed of temperature-sensitive materials, and when the temperature changes, the electrical or optical response of the pixel points changes, and the shape and temperature of the detected object can be identified by capturing the signal change. In order to obtain sufficient contrast, good thermal insulation is required between the pixel points and between the pixel points and the substrate or support. According to different readout signals, the infrared thermal detector can be divided into two types: electrical readout type and optical readout type. Among them, the electrical readout type thermal detector identifies the image by reading the resistance or capacitance change of the pixel points, and a readout circuit needs to be designed for each pixel point on the detection unit, and the circuit is composed of high-thermal-conductivity metal materials, which seriously affects the thermal insulation effect between the pixel points and between the pixel points and the substrate.

[0003] There are various types of optical readout type thermal detectors in related technologies. One type of optical readout type thermal detector is composed of temperature-sensitive fluorescent materials. Under the excitation of light at a specific wavelength, the temperature change of the pixel points will cause a change in the intensity of light emission, and this difference can be captured by a common optical CCD and the image can be identified. Therefore, the optical readout type thermal detector can realize non-contact acquisition of signals, avoiding the heat loss and thermal interference caused by the readout circuit of the electrical readout type thermal detector.

[0004] For the optical readout type thermal detector, in order to improve the contrast of imaging, good thermal insulation is also required between the pixel points and between the pixel points and the substrate or support. At present, a complex slender beam structure is mainly used to connect between the pixel points and the substrate or support, so as to reduce the heat transfer between the pixel points and the substrate or support. However, this scheme mainly has the following disadvantages:

[0005] 1) In order to ensure the strength and rigidity of the connection between the pixel points and the substrate or support, the cross section of the slender beam structure connecting therebetween needs to be large and the length needs to be short; and in order to obtain good thermal insulation effect, the cross section of the slender beam structure connecting therebetween needs to be small and the length needs to be long. Therefore, the structural stability and thermal insulation performance are difficult to be balanced.

[0006] 2) In order to avoid direct contact between the pixel points and the base or support, the pixel points and the connecting beams need to be designed as a three-dimensional hollow structure, which has a complex processing technology, a long production process and a high manufacturing cost.

[0007] Therefore, the existing optical readout thermal detector needs to be improved. SUMMARY

[0008] The present application aims to at least partly solve one of the problems in the related art. To this end, one object of the present application is to provide a nanofiber thermal detection film, a preparation method and an application thereof, wherein the thermal crosstalk between the pixel points is small and the pixel points have sufficient connection strength and rigidity, and the application of the nanofiber thermal detection film to a thermal detector can achieve good detection imaging quality.

[0009] In one aspect of the present application, a nanofiber thermal detection film is provided. According to an embodiment of the present application, the nanofiber thermal detection film comprises a pixel point array and a connecting portion, each two adjacent pixel points in the pixel point array are connected through the connecting portion, the pixel points and the connecting portion both comprise nanofibers, the nanofibers of the pixel points are densely arranged fibers, the nanofibers of the connecting portion are sparsely arranged fibers, and the nanofibers comprise a temperature-sensitive fluorescent material.

[0010] The nanofiber thermal detection film according to the embodiment of the present application comprises a pixel point array and a connecting portion, each two adjacent pixel points in the pixel point array are connected through the connecting portion, the pixel points and the connecting portion both comprise nanofibers, the nanofibers of the pixel points are densely arranged fibers, the nanofibers of the connecting portion are sparsely arranged fibers, and the nanofibers comprise a temperature-sensitive fluorescent material. The infrared radiation signal emitted by the target detection object is imaged on the thermal detection unit through a lens, causing the temperature of the pixel points in the imaging area to rise, while the temperature of the pixel points outside the imaging area remains basically unchanged. Since the nanofibers comprise a temperature-sensitive fluorescent material, the fluorescent intensity emitted by the pixel points in the imaging area decreases, while the fluorescent intensity emitted by the pixel points outside the imaging area remains unchanged, and the range and intensity of the signal difference can be captured by an optical CCD to identify the shape and temperature of the detected object. Since the nanofibers of the pixel points are densely arranged fibers, a higher signal intensity can be provided; since the connecting portion is sparsely arranged fibers, the heat transfer between the pixel points can be effectively avoided, the imaging accuracy is improved, and the connecting portion can ensure sufficient connection strength and rigidity between the pixel points. In addition, since the nanofibers of the pixel points are more densely arranged than the nanofibers of the connecting portion, the fluorescent intensity emitted by the nanofibers of the pixel points is higher than that emitted by the nanofibers of the connecting portion, which can avoid the influence of the connecting portion on imaging. In summary, the nanofiber thermal detection film of the present application has small thermal crosstalk between the pixel points and sufficient connection strength and rigidity, and can achieve good detection imaging quality.

[0011] In addition, the nanofiber thermal detection film according to the above-mentioned embodiments of the present application can further have the following additional technical features:

[0012] In some embodiments of the present application, the porosity of the pixel points is not more than 30%, and the porosity of the connecting portions is 75% to 90%. In this way, the pixel point regions can provide higher signal intensity, while the thermal crosstalk between the pixel points in the nanofiber thermal detection film is small and the connecting strength and rigidity are sufficient, which can improve the detection imaging quality.

[0013] In some embodiments of the present application, the width of the pixel points to the width of the connecting portions is 1:(0.2-1). In this way, the thermal crosstalk between the pixel points in the nanofiber thermal detection film is small and the connecting strength and rigidity are sufficient, which can improve the detection imaging quality.

[0014] In some embodiments of the present application, the nanofiber further comprises a high molecular polymer, wherein the mass fraction of the high molecular polymer in the nanofiber is 96wt% to 99wt%, and the mass fraction of the temperature-sensitive fluorescent material is 1wt% to 4wt%. In this way, it is beneficial to improve the signal intensity and the detection imaging quality.

[0015] In some embodiments of the present application, the temperature-sensitive fluorescent material comprises at least one of a ruthenium-based metal complex, an iridium-based metal complex, and an europium-based metal complex.

[0016] In some embodiments of the present application, the high molecular polymer comprises at least one of polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, polyvinylpyrrolidone, polymethyl methacrylate, and polyvinyl alcohol.

[0017] In some embodiments of the present application, the pixel points are square or circular.

[0018] In a second aspect of the present application, a method for preparing the above-mentioned nanofiber thermal detection film is provided. According to an embodiment of the present application, the method comprises:

[0019] (1) mixing a temperature-sensitive fluorescent material, a high molecular polymer, and a solvent to obtain a spinning precursor;

[0020] (2) using a template electrode as a receiving platform, selectively depositing the spinning precursor by electrospinning, and then drying to obtain a nanofiber thermal detection film.

[0021] According to the method for preparing the nanofiber thermal detection film provided in the embodiments of the present application, the temperature-sensitive fluorescent material, the polymer and the solvent are mixed, the temperature-sensitive fluorescent material and the polymer are dissolved in the solvent to obtain a spinning precursor; then the template electrode is used as a receiving platform, the spinning precursor is selectively deposited through electrospinning, and the material obtained after spinning is dried to volatilize the solvent therein, so that the nanofiber thermal detection film is obtained. The method has simple process, the template electrode can be repeatedly used, the production efficiency is high, the preparation cost is low, the thermal crosstalk between the pixel points in the nanofiber thermal detection film is small, and the nanofiber thermal detection film has sufficient connection strength and rigidity, so that good detection imaging quality can be obtained.

[0022] In addition, the method for preparing the nanofiber thermal detection film provided in the embodiments of the present application can further have the following additional technical features:

[0023] In some embodiments of the present application, the concentration of the polymer in the spinning precursor is 10wt%-25wt%.

[0024] In some embodiments of the present application, in step (2), the template electrode comprises an electrode array and a conductive layer from top to bottom, dielectric material is arranged between every two adjacent electrodes in the electrode array, and the electrode array is in contact with and conducts with the conductive layer. Thus, the ordered nanofiber thermal detection film with sparse and dense structures can be prepared in one step.

[0025] In a third aspect, the present application provides a thermal detector. According to the embodiments of the present application, the thermal detector comprises the nanofiber thermal detection film or the nanofiber thermal detection film prepared by the method. Thus, the thermal detector has high imaging precision, and has wide application prospects in the fields of biological detection, medical pathological diagnosis, vehicle-mounted night vision system and security monitoring.

[0026] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0028] Figure 1 is a structural schematic diagram of a nanofiber thermal detection film according to an embodiment of the present application;

[0029] Figure 2 is a flowchart of a method for preparing the nanofiber thermal detection film according to an embodiment of the present application;

[0030] Figure 3 is a structural schematic diagram of a template electrode according to an embodiment of the present application;

[0031] Figure 4 is a working principle diagram of a template electrode-based selective electrospinning deposition for preparing a film according to an embodiment of the present application;

[0032] Figure 5 is a microscope image of a nanofiber thermal detection film prepared in Example 1;

[0033] Figure 6 is a scanning electron microscope image of a pixel area of the nanofiber thermal detection film prepared in Example 1;

[0034] Figure 7 is a microscope image of a nanofiber thermal detection film prepared in Example 2;

[0035] Figure 8 is a scanning electron microscope image of a pixel area of the nanofiber thermal detection film prepared in Example 2;

[0036] Figure 9 is a microscope image of a nanofiber thermal detection film prepared in Example 3;

[0037] Figure 10 is a scanning electron microscope image of a pixel area of the nanofiber thermal detection film prepared in Example 3. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described in detail below with reference to the attached drawings, which show examples of embodiments of the present application. The same or similar components have the same or similar reference numbers throughout the drawings. The embodiments described below are examples and are intended to explain the present application, and should not be understood as limiting the present application.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In the present application, unless otherwise clearly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise clearly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] In the first aspect of the present application, the present application proposes a nanofiber thermal detection film. According to an embodiment of the present application, referring to Figure 1 , the nanofiber thermal detection film includes a pixel array 100 and a connecting part 200.

[0042] According to some embodiments of the present application, the pixels in the pixel array 100 include densely arranged nanofibers, and the nanofibers include temperature-sensitive fluorescent materials. The inventors found that the infrared radiation signal emitted by the target detection object is imaged on the thermal detection unit through the lens, causing the temperature of the pixels in the imaging area to rise, while the temperature of the pixels outside the imaging area remains basically unchanged. Since the nanofibers include temperature-sensitive fluorescent materials, the fluorescent intensity emitted by the pixels in the imaging area decreases, while the fluorescent intensity emitted by the pixels outside the imaging area remains unchanged, and the range and intensity of this signal difference can be captured by an optical CCD to identify the shape and temperature of the detected object. At the same time, since the nanofibers of the pixels are densely arranged fibers, they can provide higher signal strength. It should be noted that the specific type of the above-mentioned temperature-sensitive fluorescent material is not particularly limited, and those skilled in the art can select it according to actual needs, for example, the temperature-sensitive fluorescent material includes at least one of ruthenium-based metal complexes, iridium-based metal complexes and europium-based metal complexes. Specifically, the ruthenium-based metal complex includes at least one of Ru(phen)3, Ru(bpy)3 and Ru(bpz)3; the iridium-based metal complex includes at least one of Ir(btpy)3 and Ir(ppy)2(carbac); the europium-based metal complex includes at least one of Eu(tta)3 and Eu(ppp)3.

[0043] Further, the above-mentioned nanofibers also include a high molecular polymer. Thus, electrospinning can be achieved by using a high molecular polymer. It should be noted that the specific type of the above-mentioned high molecular polymer is not particularly limited, and those skilled in the art can select it according to actual needs, for example, the high molecular polymer includes at least one of polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, polyvinylpyrrolidone, polymethyl methacrylate and polyvinyl alcohol.

[0044] Further, the mass fraction of the polymer in the nanofiber is 96wt%-99wt%, and the mass fraction of the temperature-sensitive fluorescent material is 1wt%-4wt%. The inventors have found that if the mass fraction of the polymer in the nanofiber is too large or the mass fraction of the temperature-sensitive fluorescent material is too small, the light-emitting intensity of the fluorescent material is reduced, and the signal-to-noise ratio of the thermal imaging test is reduced; and if the mass fraction of the polymer in the nanofiber is too small or the mass fraction of the temperature-sensitive fluorescent material is too large, the fluorescent light-emitting will be quenched due to the concentration, that is, the light-emitting intensity is reduced. Therefore, the mass fraction of the polymer and the mass fraction of the temperature-sensitive fluorescent material in the present application are beneficial to improve the signal intensity and the imaging quality of the detection.

[0045] It should be noted that the skilled person in the art can select the specific shape of the pixel according to actual needs, for example, the pixel is square or circular.

[0046] According to some embodiments of the present application, each two adjacent pixels in the pixel array 100 are connected by a connecting part 200, and the connecting part 200 comprises sparsely arranged nanofibers. It should be noted that the specific type of the nanofiber is the same as described above, which will not be repeated here. The inventors have found that since the connecting part is a sparsely arranged fiber, the heat transfer between the pixels can be effectively avoided, the imaging accuracy is improved, and the connecting part can ensure sufficient connection strength and rigidity between the pixels. At the same time, since the nanofibers of the pixel are more dense than the nanofibers of the connecting part, the fluorescent intensity emitted by the nanofibers of the pixel is higher than that emitted by the nanofibers of the connecting part, which can avoid the influence of the connecting part on imaging.

[0047] It should be noted that the "connecting part comprises sparsely arranged nanofibers" in this document can be understood as having a lower distribution density relative to the densely arranged nanofibers of the pixel. According to one embodiment of the present application, the porosity of the pixel is not more than 30%. The inventors have found that if the porosity of the pixel is too large, the internal gap of the pixel is large, the heat transfer performance is poor, the temperature rise is uneven, and the signal intensity is low; the porosity of the connecting part 200 is 75%-90%. The inventors have found that if the porosity of the connecting part is too large, the connecting part cannot meet the rigidity requirement of connecting the pixels, and the film is easy to be damaged; and if the porosity of the connecting part is too small, the heat insulation effect between the pixels is reduced, the heat conduction is increased, and the thermal crosstalk effect is enhanced. Therefore, the pixel porosity and the connecting part porosity of the present application can provide a higher signal intensity in the pixel area, while the thermal crosstalk between the pixels in the nanofiber thermal detection film is small and has sufficient connection strength and rigidity, which can improve the detection imaging quality. Preferably, the nanofibers of the pixel are randomly oriented, and the nanofibers of the connecting part are radially oriented. The inventors have found that the radially oriented connecting part is beneficial to further improve the strength and rigidity of the connection between the pixels.

[0048] Further, the ratio of the width of the pixel point to the width of the connecting part 200 is 1:(0.2-1). The inventor finds that if the ratio is too large, the heat insulation effect of the connecting part is lost, and heat cross-talk occurs between the pixel points; and if the ratio is too small, the ratio of the total area occupied by the pixel point array of the detection film decreases, and the area utilization rate of the film decreases, i.e., when the radiation of the measured object is focused on the film, a large part of the radiation will leak through because the pixel points are too far apart, and no temperature rise occurs on the pixel points, which reduces the light energy utilization rate of the detection film. Therefore, the width ratio of the present application is beneficial to reducing the heat cross-talk between the pixel points and improving the light energy utilization rate of the detection film.

[0049] The inventor finds that the nanofiber thermal detection film of the present application includes a pixel point array and a connecting part, each two adjacent pixel points in the pixel point array are connected by the connecting part, the pixel point and the connecting part are both nanofibers including temperature-sensitive fluorescent material, and the nanofibers of the pixel point are densely arranged fibers, and the nanofibers of the connecting part are sparsely arranged fibers. The infrared radiation signal emitted by the target detection object is imaged on the thermal detection unit through the lens, causing the temperature of the pixel points in the imaging area to rise, while the temperature of the pixel points outside the imaging area remains basically unchanged. Since the nanofibers include temperature-sensitive fluorescent material, the fluorescent intensity emitted by the pixel points in the imaging area decreases, while the fluorescent intensity emitted by the pixel points outside the imaging area remains unchanged, and the range and intensity of this signal difference can be captured by an optical CCD to identify the shape and temperature of the detected object. Since the nanofibers of the pixel point are densely arranged fibers, a higher signal intensity can be provided; since the connecting part is sparsely arranged fibers, heat transfer between the pixel points can be effectively avoided, the imaging accuracy is improved, and the connecting part can ensure sufficient connection strength and rigidity between the pixel points. In addition, since the nanofibers of the pixel point are more densely arranged than the nanofibers of the connecting part, the fluorescent intensity emitted by the nanofibers of the pixel point is higher than that emitted by the nanofibers of the connecting part, which can avoid the influence of the connecting part on imaging. In summary, the nanofiber thermal detection film of the present application has small heat cross-talk between the pixel points and sufficient connection strength and rigidity, and can obtain good detection imaging quality.

[0050] In a second aspect of the present application, a method for preparing the nanofiber thermal detection film described above is provided. According to an embodiment of the present application, referring to Figure 2 , the method comprises:

[0051] S100: mixing temperature-sensitive fluorescent material, high molecular polymer and solvent

[0052] In this step, the temperature-sensitive fluorescent material, the polymer and the solvent are mixed, and the temperature-sensitive fluorescent material and the polymer are dissolved in the solvent to obtain the spinning precursor. It should be noted that the specific types of the temperature-sensitive fluorescent material and the polymer and the mixing ratio of the two are the same as described above, which will not be repeated here. It should be noted that those skilled in the art can select the specific type of the above-mentioned solvent according to actual needs, as long as the temperature-sensitive fluorescent material and the polymer can be completely dissolved, for example, the solvent can be at least one of butyl acetate, toluene, acetone and dimethylformamide.

[0053] Further, in the above-mentioned spinning precursor, the concentration of the polymer is 10wt%-25wt%. The inventors found that if the concentration of the polymer is too high, the nanofiber obtained by spinning is uneven and the fiber is relatively thick, and when the mixing ratio of the polymer and the temperature-sensitive fluorescent material is constant, the temperature-sensitive fluorescent material is also difficult to completely dissolve, and the undissolved particles are easy to block the spinning needle, affecting the spinning quality; and if the concentration of the polymer is too low, the nanofiber obtained by spinning is discontinuous, and appears as a string of beads, and even may be converted from electrospinning to electrostatic spraying. Therefore, the concentration of the polymer used in the present application is beneficial to improve the spinning quality, obtain nanofiber with fine and uniform particle size, and further improve the detection imaging quality.

[0054] S200: using a template electrode as a receiving platform, selectively depositing the spinning precursor by electrospinning, and then drying

[0055] In this step, the template electrode 300 is used as a receiving platform, the spinning precursor is selectively deposited on the template electrode 300 by electrospinning, and then the material obtained after spinning is dried to volatilize the solvent therein, thereby obtaining the nanofiber thermal detection film. Further, referring to Figure 3 and 4 The template electrode 300 comprises an electrode array 31 and a conductive layer 32 from top to bottom, and a dielectric material 33 is arranged between every two adjacent electrodes in the electrode array 31, and the electrode array 31 is in contact with and conducts with the conductive layer 32. Specifically, when the above-mentioned nanofiber thermal detection film is prepared by electrospinning, referring to Figure 4It is understood that the above-mentioned spinning precursor is supplied to the injector 400, the needle of the injector 400 is connected with the positive electrode of the high-voltage power supply 500, and the electrode array 31 is connected with the ground end of the high-voltage power supply 500 through the conductive layer 32 and is negatively charged. Under the action of the electrostatic field and the pushing force of the injector 400, the mixed solution ejected by the injector 400 forms positively charged nanofibers, and under the action of the electrostatic force, the charged fibers are attracted by the electrode array 31 and are preferentially deposited directly above the electrode array 31, forming dense pixel points with random orientation. A small amount of nanofibers moving above the dielectric material 33 are stretched to both sides under the action of the electrode array 31 on both sides, forming a connecting part 200 composed of sparsely arranged nanofibers between adjacent pixel points. Therefore, using the method, the dense and sparse ordered nanofiber film can be prepared in one step, the template electrode can be reused, the production efficiency is high, and the preparation cost is low. Specifically, the above-mentioned drying method can be drying, the drying temperature is 75-85°C, preferably 80°C, and the drying time is 8-12 minutes, preferably 10 minutes. It should be noted that the width ratio of the pixel point to the connecting part 200 and the porosity are the same as described above, and the specific shape of the pixel point is also the same as described above, which will not be repeated here.

[0056] The inventors have found that by mixing a temperature-sensitive fluorescent material, a high-molecular polymer and a solvent, the temperature-sensitive fluorescent material and the high-molecular polymer are dissolved in the solvent to obtain a spinning precursor; then using a template electrode as a receiving platform, the above-mentioned spinning precursor is selectively deposited by electrospinning, and then the material obtained after spinning is dried to volatilize the solvent therein, thereby obtaining a nanofiber thermal detection film. The method of the present application has simple process, the template electrode can be reused, the production efficiency is high, and the preparation cost is low, the thermal crosstalk between each pixel point in the prepared nanofiber thermal detection film is small, and there is sufficient connection strength and rigidity, and good detection imaging quality can be obtained.

[0057] In a third aspect of the present application, a thermal detector is provided. According to an embodiment of the present application, the thermal detector comprises the above-mentioned nanofiber thermal detection film or the nanofiber thermal detection film prepared by the above-mentioned method. Therefore, the thermal detector has high imaging accuracy and has wide application prospects in the fields of biological detection, medical pathological diagnosis, vehicle-mounted night vision system and security monitoring. It should be noted that the features and advantages described above for the nanofiber thermal detection film and the preparation method thereof are also applicable to the thermal detector, which will not be repeated here.

[0058] Embodiments of the present application are described in detail below, it should be noted that the embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. In addition, if not specifically stated, all reagents used in the following examples are commercially available or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also readily available to those skilled in the art.

[0059] Example 1

[0060] Step 1: dichlorotris(1,10-phenanthroline)ruthenium(II) hydrate, polyvinylidene fluoride and DMF were mixed to obtain a spinning precursor (the mass ratio of dichlorotris(1,10-phenanthroline)ruthenium(II) hydrate to polyvinylidene fluoride was 2:98, and the concentration of polyvinylidene fluoride was 15wt%);

[0061] Step 2: as shown in Figure 3 and Figure 4 , a template electrode was used as a receiving platform, and the spinning precursor was selectively deposited by electrospinning, and then the material obtained after spinning was dried at 80℃ for 10 minutes to obtain a nanofiber thermal detection film (the microscope image of the thermal detection film is shown in Figure 5 , and the scanning electron microscope image of the pixel area is shown in Figure 6 ). In the nanofiber thermal detection film, the pixel points are square, the porosity of the pixel points is about 26.2%, the porosity of the connecting part is about 85%, and the width ratio of the pixel points to the connecting part is 1:1. The nanofiber thermal detection film prepared has small thermal cross-talk between each pixel point and has sufficient connection strength and rigidity, and when it is applied to a thermal detector, the imaging quality is high.

[0062] Example 2

[0063] Step 1: tris(2,2-bipyridyl)ruthenium(II) chloride hexahydrate, polymethyl methacrylate and DMF were mixed to obtain a spinning precursor (the mass ratio of tris(2,2-bipyridyl)ruthenium(II) chloride hexahydrate to polymethyl methacrylate was 1:25, and the concentration of polymethyl methacrylate was 25wt%);

[0064] Step 2: as shown in Figure 3 and Figure 4 , a template electrode was used as a receiving platform, and the spinning precursor was selectively deposited by electrospinning, and then the material obtained after spinning was dried at 80℃ for 10 minutes to obtain a nanofiber thermal detection film (the microscope image of the thermal detection film is shown in Figure 7 , and the scanning electron microscope image of the pixel area is shown in Figure 8The pixel points in the nanofiber thermal detection film are square, the porosity of the pixel points is about 19%, the porosity of the connecting part is about 77.9%, and the width ratio of the pixel points to the connecting part is 1:1. The nanofiber thermal detection film prepared has small thermal cross-talk between the pixel points and has sufficient connecting strength and rigidity, and when the nanofiber thermal detection film is applied to a thermal detector, the imaging quality of the thermal detector is high.

[0065] Example 3

[0066] Step 1: trifluoroacetyl thiophene formyl europium, polyvinylidene fluoride and DMF were mixed to obtain a spinning precursor (the mass ratio of trifluoroacetyl thiophene formyl europium to polyvinylidene fluoride was 2:98, and the concentration of polyvinylidene fluoride was 15 wt%);

[0067] Step 2: as shown in Figure 3 and Figure 4 , a template electrode was used as a receiving platform, the spinning precursor was selectively deposited by electrospinning, and then the material obtained after spinning was dried at 80°C for 10 minutes to obtain a nanofiber thermal detection film (the microscope image of the thermal detection film is shown in Figure 9 , and the scanning electron microscope image of the pixel point area is shown in Figure 10 ). The pixel points in the nanofiber thermal detection film are square, the porosity of the pixel points is about 29.4%, the porosity of the connecting part is about 86.5%, and the width ratio of the pixel points to the connecting part is 1:1. The nanofiber thermal detection film prepared has small thermal cross-talk between the pixel points and has sufficient connecting strength and rigidity, and when the nanofiber thermal detection film is applied to a thermal detector, the imaging quality of the thermal detector is high.

[0068] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and modified by those skilled in the art without contradiction.

[0069] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A nanofiber thermal detection film, characterized in that, It includes a pixel array and a connecting part. Each pair of adjacent pixels in the pixel array is connected by the connecting part. Both the pixels and the connecting part include nanofibers. The nanofibers of the pixels are densely arranged fibers, and the nanofibers of the connecting part are sparsely arranged fibers. The nanofibers include a thermosensitive fluorescent material. The porosity of the pixel is no greater than 30%, and the porosity of the connecting part is 75% to 90%.

2. The nanofiber thermal detection film according to claim 1, characterized in that, The ratio of the width of the pixel to the width of the connecting portion is 1:(0.2~1).

3. The nanofiber thermal detection film according to claim 1, characterized in that, The nanofibers further comprise a polymer, wherein the mass fraction of the polymer in the nanofibers is 96wt%~99wt%, and the mass fraction of the thermosensitive fluorescent material is 1wt%~4wt%.

4. The nanofiber thermal detection film according to claim 3, characterized in that, The thermosensitive fluorescent material includes at least one of ruthenium-based metal complexes, iridium-based metal complexes, and europium-based metal complexes.

5. The nanofiber thermal detection film according to claim 3, characterized in that, The polymer includes at least one of polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, polyvinylpyrrolidone, polymethyl methacrylate, and polyvinyl alcohol.

6. The nanofiber thermal detection film according to claim 1, characterized in that, The pixels are square or circular.

7. A method for preparing a nanofiber thermal detection thin film according to any one of claims 1 to 6, characterized in that, include: (1) Mix the thermosensitive fluorescent material, polymer and solvent to obtain the spinning precursor; (2) Using a template electrode as a receiving platform, the spinning precursor is selectively deposited by electrospinning and then dried to obtain a nanofiber thermal detection film.

8. The method according to claim 7, characterized in that, In the spinning precursor, the concentration of the polymer is 10wt%~25wt%; Optionally, in step (2), the template electrode comprises an electrode array and a conductive layer from top to bottom, wherein a dielectric material is provided between each two adjacent electrodes in the electrode array, and the electrode array is in contact with and connected to the conductive layer.

9. A thermal detector, characterized in that, The nanofiber thermal detection film includes any one of claims 1 to 6 or the nanofiber thermal detection film prepared by the method of claim 7 or 8.

Images