A high-temperature-resistant temperature-sensitive composite nanofiber membrane and its preparation method and application

Abstract

The present invention discloses a high-temperature-resistant, temperature-sensitive composite nanofiber membrane, its preparation method, and application. The thermosensitive composite nanofiber membrane is an electrospun polydiacetylene / polyarylethernitrile composite nanofiber membrane. It undergoes a cross-linking reaction upon ultraviolet irradiation, changing its apparent color to blue. It then turns red at temperatures of 60°C or above and can withstand temperatures up to 170°C without shrinking. The high-temperature-resistant, temperature-sensitive composite nanofiber membrane prepared by the present invention not only exhibits high heat resistance but can also detect alkaline solutions. Therefore, it has broad application prospects in the fields of high-temperature detection and detection of alkaline environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanofiber membranes, and in particular relates to a high-temperature resistant temperature-sensitive composite nanofiber membrane and a preparation method and application thereof. Background Art

[0002] Polydiacetylene (PDA) is widely used in detection fields due to its unique color-changing properties, such as pH sensing, metal ion sensing, organic solvent sensing, gas sensing, and temperature sensing. Among them, temperature sensors are one of the most studied areas, because PDA changes color when stimulated by temperature. Existing research believes that the color change of PDA is caused by its conformational change. Generally speaking, PDA is obtained by polymerizing diacetylene monomers under ultraviolet light. At this time, PDA appears blue. Its main chain is a regularly arranged planar structure with a large number of conjugated π orbitals. When subjected to external stimuli, the conformation of PDA changes, that is, it rotates around the CC bond of the main chain, and the overlap of the π orbitals changes, resulting in a blue shift in the absorption spectrum, thus appearing red.

[0003] Currently, common methods for preparing PDA-based sensing materials involve forming PDA into vesicles, nanoparticles, or thin films via casting or spin coating. These methods often suffer from drawbacks such as complexity, lack of portability, and low sensitivity. Electrospinning, on the other hand, can produce nanofiber membranes with large surface areas and high porosity. Compared to other methods, these membranes typically exhibit higher sensitivity and faster response efficiency, making them a powerful approach for preparing ultrasensitive sensors.

[0004] In recent years, with the maturity of electrospinning technology, more and more PDA nanofiber membrane sensors have appeared in the preparation of PDA sensors. The preparation of this type of sensor is relatively simple, usually only requiring the PDA and substrate material to be mixed evenly before spinning. Therefore, when selecting the substrate material, its compatibility with PDA needs to be considered. In addition, many substrate materials currently under research, such as polyvinyl alcohol, polyethylene glycol, and polyvinyl pyrrolidone, cannot withstand high temperatures. The color transition range of PDA is generally 60-110°C. In order to fully utilize the performance of PDA temperature-sensitive sensing materials and expand the operating temperature range, choosing a high-temperature resistant substrate material is an effective way to achieve this goal. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-temperature resistant temperature-sensitive composite nanofiber membrane and its preparation method and application, which can keep the fiber from shrinking at high temperatures, enhance the high-temperature dimensional stability of the sensor, and enable the polydiacetylene temperature sensor to be used in high-temperature environments.

[0006] To achieve the above object, the present invention provides a method for preparing a high-temperature resistant temperature-sensitive composite nanofiber membrane, comprising the following steps:

[0007] (1) preparing a poly(arylene ether nitrile) solution and a 10,12-pentacosadiynoic acid solution, mixing them evenly, and allowing them to stand to remove bubbles, thereby preparing an electrospinning solution;

[0008] (2) preparing a composite nanofiber membrane by electrospinning, and placing the composite nanofiber membrane in a dark environment at room temperature for 40-50 hours;

[0009] (3) Using ultraviolet light to irradiate the composite nanofiber membrane obtained in step (2) to cause a cross-linking reaction to prepare a high-temperature resistant temperature-sensitive composite nanofiber membrane.

[0010] Preferably, the polyarylethernitrile is a phenolphthalein type polyarylethernitrile or a bisphenol A type polyarylethernitrile.

[0011] Preferably, the 10,12-pentacosadiynoic acid solution is prepared by the following method: dissolving 10,12-pentacosadiynoic acid in N,N-dimethylformamide to prepare a 10,12-pentacosadiynoic acid solution with a concentration of 0.05-0.2 g / mL.

[0012] Preferably, the poly(arylene ether nitrile) solution is prepared by the following method: dissolving 1-2 g of poly(arylene ether nitrile) in 2-4 mL of N,N-dimethylformamide.

[0013] Preferably, the mass ratio of poly(arylene ether nitrile) to 10,12-pentacosadiynoic acid in the electrospinning solution is 5:1.

[0014] Preferably, the wavelength of the ultraviolet light is 254 nm, and the ultraviolet cross-linking time is 2-4 minutes.

[0015] Preferably, the electrospinning parameters are: spinning voltage of 20-25 kV, pushing speed of 0.001 mm / s, needle tip distance from collector of 15 cm, and rotation speed of 200-500 rpm / min.

[0016] The present invention also discloses a high-temperature resistant temperature-sensitive composite nanofiber membrane prepared by adopting the preparation method of the high-temperature resistant temperature-sensitive composite nanofiber membrane.

[0017] The present invention also discloses the use of the high-temperature resistant temperature-sensitive composite nanofiber membrane in the preparation of a temperature sensor. The temperature sensing range of the sensor is 60°C to 110°C, and the maximum operating temperature can reach 170°C.

[0018] The invention also discloses the application of the high-temperature-resistant temperature-sensitive composite nanofiber membrane in detecting alkaline solutions.

[0019] In summary, the present invention has the following advantages:

[0020] 1. This invention utilizes electrospinning technology and UV crosslinking to produce a high-temperature-resistant composite nanofiber membrane, resulting in a high-temperature-resistant, temperature-sensitive composite nanofiber membrane. The prepared composite membrane exhibits high heat resistance. The phenolphthalein-based poly(arylene ether nitrile) composite nanofiber membrane can withstand temperatures up to 170°C without shrinking. Both fiber membranes are responsive to pH changes, changing from blue to red in an alkaline environment. Therefore, this sensor has broad application prospects in temperature and pH sensing.

[0021] 2. In the present invention, polyarylethernitrile (PEN), a material with excellent overall performance, is used as the substrate material to prepare a PDA temperature sensor. PEN possesses excellent heat resistance due to its large number of alternating ether bonds and rigid benzene rings. Furthermore, the cyano groups in PEN make it excellent for molding and processing. Furthermore, PEN is also resistant to acid and alkali corrosion. PEN containing different aromatic groups exhibits different properties. For example, using phenolphthalein (PPL) for synthesis yields PEN with carboxyl groups in the side chains (PEN-PPL). This PEN has a higher glass transition temperature, and the carboxyl groups in the side chains enhance its compatibility with PDA. Using bisphenol A (BPA) for synthesis yields bisphenol A-based polyarylethernitrile (PEN-BPA), which exhibits a higher thermal decomposition temperature and improved alkali resistance. This provides a rich selection of substrate materials for the preparation of PDA temperature sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 These are the Fourier transform infrared spectra of the nanofiber membranes prepared in Examples 1-2 and Comparative Examples 1-2.

[0023] in Figure 1 A is the infrared spectrum of the nanofiber membranes prepared in Example 1 and Comparative Example 1, Figure 1 B is the infrared spectrum of the nanofiber membranes prepared in Example 2 and Comparative Example 2.

[0024] Figure 2 is the absorption spectrum of the composite nanofiber membrane prepared in Examples 1 and 2,

[0025] in Figure 2 A is the absorption spectrum of the composite nanofiber membrane prepared in Example 1 after heating at different temperatures, Figure 2 B is the absorption spectrum of the composite nanofiber membrane prepared in Example 2 after heating at different temperatures.

[0026] Figure 3 is the Raman spectrum of the composite nanofiber membrane prepared in Examples 1 and 2;

[0027] in Figure 3A is the Raman spectrum of the composite nanofiber membrane prepared in Example 1 after heating at different temperatures, Figure 3 B is the Raman spectrum of the composite nanofiber membrane prepared in Example 2 after heating at different temperatures.

[0028] Figure 4 It is the microscopic morphology of Examples 1 and 2 before and after heating.

[0029] in Figure 4 A is the microscopic morphology of the composite nanofiber membrane prepared in Example 1 before heating. Figure 4 B is a microscopic morphology of the composite nanofiber membrane prepared in Example 1 after heating, and 4C is a microscopic morphology of the composite nanofiber membrane prepared in Example 2 before heating. Figure 4 D is a microscopic morphology of the composite nanofiber membrane prepared in Example 2 after heating; the illustration in the upper right corner of the figure is the corresponding local enlarged picture.

[0030] Figure 5 These are the thermogravimetric analysis patterns (TGA) and differential scanning calorimetry patterns (DSC) of Examples 1-2 and Comparative Examples 1-2.

[0031] Figure 6 This is a real picture of the composite nanofiber membrane prepared in Examples 1 and 2 under an alkaline environment. DETAILED DESCRIPTION

[0032] The present invention provides a high-temperature resistant temperature-responsive thermosensitive composite nanofiber membrane, the preparation method of which comprises the following steps:

[0033] (1) Phenolphthalein-type poly(arylether nitrile) (PEN-PPL) or bisphenol A-type poly(arylether nitrile) (PEN-BPA) was used as the substrate material, and 10,12-pentacosadiynoic acid (PCDA) was used as the stimuli-responsive material. N,N-dimethylformamide was used as the organic solvent to prepare solutions of certain concentrations. The poly(arylether nitrile) solution and the PCDA solution were then mixed uniformly in a certain proportion to prepare a spinning solution.

[0034] (2) The spinning solution is drawn into a syringe and placed on an electrospinning device for electrospinning to obtain a composite nanofiber membrane having a certain thickness. The composite nanofiber membrane is then removed and placed in a dark, light-proof environment to dry to remove any residual organic solvent.

[0035] Specifically, PCDA is first dissolved in N,N-dimethylformamide (DMF) solution to prepare PCDA solution in advance; PEN-PPL powder is weighed and added to the DMF solution, and then the prepared PCDA solution is added;

[0036] Alternatively, weigh PEN-BPA and add it to DMF solution, and then add PCDA solution.

[0037] (3) The resulting composite nanofiber membrane is exposed to ultraviolet light to crosslink the PCDA monomers in the fibers to form a polymer, resulting in a blue composite nanofiber membrane. This is a high-temperature-resistant, thermosensitive composite nanofiber membrane. The composite nanofiber membrane is then cut into appropriate sizes for subsequent structural characterization and performance testing.

[0038] The thermosensitive composite nanofiber membrane is a polydiacetylene / polyarylether nitrile electrospun composite nanofiber membrane, which can undergo a cross-linking reaction through ultraviolet irradiation, so that the apparent color changes to blue, and then changes to red under temperature stimulation of 60°C and above, and can withstand high temperatures of up to 170°C without shrinking. The high-temperature resistant thermosensitive composite nanofiber membrane prepared by the present invention not only has rapid response, good portability and high heat resistance, but also can withstand corrosion from alkaline solutions and perform alkaline solution detection. At the same time, the pH value ranges of the composite nanofiber membranes prepared from polyarylether nitrile with different structures are also different. Therefore, it has broad application prospects in the field of high-temperature detection and detection of alkaline environments. In other words, the present invention has successfully prepared a composite sensing material that can be well composited with polydiacetylene and is resistant to high temperatures and acid and alkali, expanding its application prospects.

[0039] The principles and features of the present invention are described below in conjunction with the examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0040] Example 1

[0041] This embodiment provides a high-temperature resistant thermosensitive composite nanofiber membrane (polydiacetylene / phenolphthalein type polyarylethernitrile, PEN-PPL-P), which is prepared by the following method:

[0042] (1) First, 10,12-pentacosadiynoic acid (PCDA) was dissolved in N,N-dimethylformamide (DMF) solution to prepare a 0.1 g / mL PCDA solution.

[0043] (2) 2 g of PEN-PPL was weighed and added to 2 mL of DMF solution, and then 2 mL of the above-mentioned PCDA solution was added. After mechanical stirring and ultrasonic dispersion for 30 min, the mixture was allowed to stand for 12 h to remove bubbles and prepare a uniformly mixed electrospinning solution.

[0044] (3) The electrospinning solution obtained in step (2) was then placed in a 5 mL medical syringe for electrospinning. The electrospinning voltage was 25 kV, the feed speed was 0.001 mm / s, the needle tip was 15 cm from the collector, and the rotation speed was 300 rpm / min. Aluminum foil was used as a collection substrate on the collector, and spinning was carried out at room temperature in the dark.

[0045] (4) After spinning, the nanofiber membrane was placed in a dark environment and dried at room temperature for 48 h to ensure that DMF was completely evaporated.

[0046] Example 2

[0047] This embodiment provides a high-temperature resistant thermosensitive composite nanofiber membrane (polydiacetylene / bisphenol A type polyarylethernitrile, PEN-BPA-P), which is prepared by the following method:

[0048] (1) First, 10,12-pentacosadiynoic acid (PCDA) was dissolved in N,N-dimethylformamide (DMF) solution to prepare a 0.1 g / mL PCDA solution.

[0049] (2) 1 g of PEN-BPA was weighed and added to 4 mL of DMF solution, and then 2 mL of the above-mentioned PCDA solution was added. After mechanical stirring and ultrasonic dispersion for 30 minutes, the mixture was allowed to stand for 12 hours to remove bubbles, thereby preparing a uniformly mixed electrospinning solution.

[0050] (3) The electrospinning solution obtained in step (2) was then placed in a 5 mL medical syringe for electrospinning. The electrospinning voltage was 20 kV, the feed speed was 0.001 mm / s, the needle tip was 15 cm from the collector, and the rotation speed was 300 rpm / min. Aluminum foil was used as a collection substrate on the collector, and spinning was performed at room temperature in the dark.

[0051] (4) After spinning, the nanofiber membrane was placed in a dark environment and dried at room temperature for 48 h to ensure that DMF was completely evaporated.

[0052] Comparative Example 1

[0053] This comparative example provides a method for preparing a pure phenolphthalein-type poly(arylene ether nitrile) nanofiber membrane, comprising the following steps:

[0054] 2g of PEN-PPL was added to 4mL of DMF solution. After mechanical stirring and ultrasonic dispersion for 30 minutes, the solution was allowed to stand for 12 hours to remove bubbles, creating the electrospinning solution. The resulting electrospinning solution was then placed in a 5mL medical syringe and electrospun at a voltage of 25kV. The feed speed was 0.001mm / s, the needle tip was held 15cm from the collector, and the spinning speed was 300rpm / min. Aluminum foil was used as a collection substrate on the collector, and spinning was performed at room temperature in the dark. After spinning, the nanofiber membrane was dried in an 80°C oven for 24 hours to ensure complete evaporation of the DMF.

[0055] Comparative Example 2

[0056] This comparative example provides a method for preparing a pure bisphenol A type poly (arylene ether nitrile) nanofiber membrane, comprising the following steps:

[0057] 1g of PEN-BPA was added to 6mL of DMF solution. After mechanical stirring and ultrasonic dispersion for 30 minutes, the solution was allowed to stand for 12 hours to remove bubbles, creating the electrospinning solution. The resulting electrospinning solution was then placed in a 5mL medical syringe and electrospun at a voltage of 20kV. The feed speed was 0.001mm / s, the needle tip was 15cm from the collector, and the spin speed was 300rpm / min. Aluminum foil was used as a collection substrate on the collector, and spinning was performed at room temperature in the dark. After spinning, the nanofiber membrane was dried in an 80°C oven for 24 hours to ensure complete evaporation of the DMF.

[0058] Test Example 1

[0059] In this test example, Fourier transform infrared spectroscopy was used to characterize the structures of Examples 1-2 and Comparative Examples 1-2, and to characterize the structures of the polydiacetylene / poly(arylene ether nitrile) composite nanofiber membranes, so as to prove that the composite of polydiacetylene and poly(arylene ether nitrile) was successful.

[0060] PEN-PPL is similar to PEN-BPA. The difference between these two polymers lies in the different bisphenol monomers used. PEN-PPL uses phenolphthalein monomers containing carboxyl groups, while PEN-BPA uses bisphenol A containing two methyl groups. Figure 1 As shown, both Examples 1-2 and Comparative Examples 1-2 showed a peak at 2240 cm -1 Stretching vibration peak from cyano group (-CN), 1610 cm -1 -1465cm -1 It is a non-absorption peak of the benzene ring vibration, located at 1024cm -1 The absorption peak near is the asymmetric stretching vibration peak of the ether bond (-O-). However, the difference is that PEN-PPL has a peak at 1710 cm -1The carbonyl (C=O) vibration absorption peak of PEN-BPA appears at 2981cm -1 After adding PCDA for blending, characteristic peaks belonging to PCDA appeared in the infrared spectra of Examples 1 and 2, which were located at 2865 cm -1 、2937cm -1 The methylene stretching vibration peak (-CH2) and the peak at 1714 cm -1 The above results prove the successful preparation of polydiacetylene / polyarylethernitrile composite nanofiber membrane.

[0061] Test Example 2

[0062] This test example will use UV-diffuse reflectance to characterize the composite nanofiber membrane prepared in Examples 1 and 2 to characterize its thermal response performance.

[0063] The film cut into 1cm*1cm pieces was placed on a heating table and heated for 5 seconds. Starting from 60℃, the temperature of each sample was increased by 10℃ until it reached 110℃. The heated film was then subjected to a UV-diffuse reflectance test to obtain the absorption spectrum of the film. The results are as follows: Figure 2 shown.

[0064] After PCDA was mixed with PEN and spun, it exhibited typical blue-red absorption peaks at approximately 640nm and 540nm, respectively. Starting at 60°C, both nanofiber membranes began to exhibit a red absorption peak, and the intensity of the blue absorption peak decreased. When heated to 90°C, the blue absorption peak almost disappeared, and the intensity of the red absorption peak barely increased, indicating the completion of the color transition. This demonstrates that the fiber membranes obtained by combining PCDA and PEN have temperature-sensitive response properties. Their apparent color transition from blue to red occurs above 60°C, with a rapid response and significant color change, providing excellent visual detection.

[0065] Test Example 3

[0066] This test example will use Raman spectroscopy to characterize Examples 1 and 2 to further demonstrate the thermal response characteristics of PCDA in PEN nanofiber membranes. The resulting structure is as follows: Figure 3 shown.

[0067] The nanofiber membranes obtained in Experimental Examples 1 and 2 were further analyzed using Raman spectroscopy. Figure 3As shown. Based on Raman spectra at three different temperatures, the structural changes of PEN-PPL-P and PEN-BPA-P under color transition were studied (PEN-PPL-RT and PEN-BPA-RT refer to PEN-PPL-P and PEN-BPA-P at room temperature without heating. PEN-PPL-P-80℃ and PEN-BPA-P-80℃ refer to PEN-PPL-P and PEN-BPA-P after heating at 80℃). It can be seen that the nanofiber membrane before heating has a color transition at 1457cm -1 Left and right (C≡C) and 2085cm -1 A typical blue phase Raman peak appeared around (C=C), and a red phase Raman peak appeared after heating, located at 1518 cm -1 and 2132cm -1 When heated to 110 °C, only the red phase Raman peak is displayed, which also proves the color transition characteristics of the obtained composite nanofiber membrane.

[0068] Test Example 4

[0069] This test example will characterize the microstructure of Examples 1 and 2 before and after heating. The results are as follows Figure 4 shown.

[0070] The composite nanofiber membranes prepared using electrospinning technology are uniform, continuous, and have a network structure with a large specific surface area. Because both PCDA and PEN-PPL contain carboxyl groups, the two are more compatible and have a relatively smooth surface. In contrast, PEN-BPA has poor compatibility with PCDA. The surface of PEN-BPA-P fibers is rougher and more uneven than that of PEN-PPL-P, and PCDA agglomerates. This proves that PEN-PPL has good compatibility with PCDA. The nanofibers of Examples 1 to 2 all melted slightly after heating.

[0071] Test Example 5

[0072] In this test example, examples 1 to 2 and comparative examples 1 to 2 were tested by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to characterize the heat resistance of the composite nanofibers. Figure 5 shown.

[0073] After PCDA and PEN are compounded, the heat resistance of the nanofibers is slightly enhanced. The 5% thermal decomposition temperature (T 5％ ) increased from 392°C in comparative example 1 and 498°C in comparative example 2 to 402°C and 506°C, respectively, and the corresponding glass transition temperature (T g) increased from 214°C and 165°C to 219°C and 169°C. This is likely due to the PCDA loading on PEN. After the fibers are initially heated, the conformational transition of PCDA dissipates some of the heat energy, which may contribute to the heat resistance of PEN. Furthermore, when PCDA undergoes cross-linking under UV irradiation, it may weld the contacting fibers together, resulting in a stronger network structure in the nanofiber membrane, thus improving its heat resistance. Based on this, the cut films were subjected to heat resistance testing. As shown in the figure, PEN-PPL-P fibers remain intact when heated to 170°C, and only experience significant fiber structural collapse at 200°C. In contrast, PEN-BPA-P fibers shrink significantly at 120°C. This difference is also due to the different glass transition temperatures of the two fibers. The methyl groups on the PEN-BPA-P molecular chain slide more easily than the benzene rings and carboxyl groups on the side chains of PEN-PPL-P, resulting in its lower glass transition temperature. The above results indicate that Examples 1 and 2 exhibit good heat resistance and can be used to develop high-temperature resistant PDA sensors.

[0074] Test Example 6

[0075] In this test example, the alkali resistance of Examples 1 and 2 was tested by immersing the membranes in an alkali solution.

[0076] PEN is a special polymer material with acid and alkali resistance and corrosion resistance, while PCDA is - ) has a colorimetric response. Therefore, the effect of the composite nanofibers on OH in alkaline solution was investigated. - The color response. Figure 6 As shown, PEN-PPL-P undergoes a color change from blue to red in solutions with a pH greater than 8, and the color change becomes more pronounced as the pH increases. However, PEN-BPA-P, due to its poor PCDA dispersibility, forms aggregates on the fiber surface, which protects it from low-alkalinity environments. Therefore, a higher alkalinity is required to induce color change, with a distinct red color appearing only at a pH of 13. These results demonstrate the potential of this invention for testing in diverse alkaline environments.

[0077] Although the specific embodiments of the present invention have been described in detail, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work are still within the scope of protection of this patent.

Claims

1. A method for preparing a high-temperature resistant temperature-sensitive composite nanofiber membrane, characterized in that: The following steps are involved: (1) preparing a poly(arylether nitrile) solution and a 10,12-pentacosadiynoic acid solution, mixing them evenly, and letting them stand to expel bubbles to prepare an electrospinning solution; the poly(arylether nitrile) is a phenolphthalein type poly(arylether nitrile) or a bisphenol A type poly(arylether nitrile); the solvent of the 10,12-pentacosadiynoic acid solution is N,N-dimethylformamide, and its concentration is 0.05-0.2 g / mL; the solvent of the poly(arylether nitrile) solution is N,N-dimethylformamide, and its concentration is 0.25-1 g / mL; the mass ratio of the poly(arylether nitrile) to the 10,12-pentacosadiynoic acid in the electrospinning solution is 5:1; (2) preparing a composite nanofiber membrane by electrospinning, and placing the composite nanofiber membrane in a dark environment at room temperature for 40-50 hours; (3) The composite nanofiber membrane obtained in step (2) is irradiated with ultraviolet light to cause a cross-linking reaction to occur, thereby preparing a high-temperature resistant thermosensitive composite nanofiber membrane.

2. The method for preparing a high-temperature resistant temperature-sensitive composite nanofiber membrane according to claim 1, wherein: The wavelength of the ultraviolet light is 254 nm, and the time of ultraviolet light cross-linking is 2-4 minutes.

3. The method for preparing a high-temperature resistant temperature-sensitive composite nanofiber membrane according to claim 1, wherein: The electrospinning parameters are as follows: spinning voltage of 20-25 kV, pushing speed of 0.001 mm / s, needle tip distance from collector of 15 cm, and rotation speed of 200-500 rpm. 4 . The high-temperature resistant temperature-sensitive composite nanofiber membrane prepared by the method for preparing the high-temperature resistant temperature-sensitive composite nanofiber membrane according to claim 1 .

5. Use of the high-temperature resistant temperature-sensitive composite nanofiber membrane as claimed in claim 4 in the preparation of a temperature sensor.

6. Use of the high-temperature resistant temperature-sensitive composite nanofiber membrane according to claim 4 in detecting alkaline solutions.

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