Preparation method of elastic ceramic nanofiber membrane material

Abstract

The application discloses a preparation method of an elastic ceramic nanofiber membrane material, in particular to a preparation method of a stretchable elastic ceramic nanofiber membrane. A polymer thermal shrinkage shape memory polymer is dissolved in a solvent to prepare a polymer sacrifice template spinning solution; ceramic source components are added into a certain hydrolysis system to prepare a precursor solution containing the ceramic source components, and then the precursor solution is mixed with a polymer solution for spinning assistance to obtain a precursor solution; the two solutions are subjected to multi-layer combination spinning to obtain a multi-layer ceramic precursor nanofiber composite membrane; and then the multi-layer ceramic precursor nanofiber composite membrane is calcined under a certain atmosphere to obtain an elastic ceramic nanofiber membrane with a wrinkle structure. The application realizes a great change from flexibility to elasticity of the ceramic nanofiber, and the prepared elastic ceramic nanofiber membrane can effectively cope with complex deformation and impact load, and has a very wide application prospect in the fields of national defense and military industry, aerospace, flexible electronics and the like.

Description

Technical Field

[0001] This invention relates to the field of ceramic nanofiber membrane technology, specifically to a method for preparing an elastic ceramic nanofiber membrane. Background Technology

[0002] Ceramic materials are widely used in high-tech fields such as aerospace, chemical industry, electronics, and medical applications due to their excellent high-temperature resistance, corrosion resistance, high strength, and low density. However, due to defects such as dislocations, grain boundaries, and rigid ions / covalent bonds, ceramic materials typically exhibit brittleness and rigidity. Compared with metals with high toughness or organic materials that can withstand large strains (5-100%), their strain capacity is often less than 1%, resulting in poor workability, easy fracture during bending deformation, and poor mechanical stability, which severely restricts their practical application.

[0003] Due to the high aspect ratio and microstructure effects of nanofiber materials, the fiber network can bend, twist, and slip under external forces, thus exhibiting excellent deformation capacity and flexibility. Therefore, constructing fibrous ceramic materials at the nano or submicron scale is one of the effective ways to transform ceramic materials from brittle to flexible. Flexible ceramic nanofiber membranes obtained by nanofiberizing ceramic materials not only possess the inherent characteristics of ceramic materials such as high temperature resistance, oxidation resistance, and corrosion resistance, but also have the excellent properties of fiber materials such as high aspect ratio, high flexibility, and high porosity. Since there are many types of inorganic ceramic nanofiber materials, their preparation techniques are also diverse, currently mainly including chemical vapor deposition, electrospinning, centrifugal spinning, and blow spinning.

[0004] However, with the development of emerging application fields such as wearable devices and high-temperature, high-frequency strain sensing, the limited tensile strain capacity of ceramic nanofiber membrane materials with only single flexibility is insufficient to meet the demands of complex deformation and impact loads. Therefore, developing ceramic nanofiber membrane materials that combine excellent flexibility, elasticity, and high mechanical strength is of great significance for deepening the application of ceramic materials in many fields such as national defense, aerospace, flexible electronics, energy and environmental protection, biomedicine, and personal protective equipment. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing an elastic ceramic nanofiber membrane material, which realizes the preparation of an elastic ceramic nanofiber membrane material with a wrinkled structure. Its excellent tensile resilience can be widely used in the fields of national defense, aerospace, flexible electronics, energy and environmental protection, biomedicine, and personal protective equipment.

[0006] The objective of this invention is achieved through the following technical solution: a method for preparing an elastic ceramic nanofiber membrane material, the specific steps of which are as follows:

[0007] S1. Dissolve the heat-shrinkable shape memory polymer in a solvent and stir until homogeneous to obtain polymer sacrificial template spinning solution A;

[0008] S2. Add the ceramic source component to a certain hydrolysis system to prepare a precursor solution containing the ceramic source component, and then mix it with a polymer solution for spinning aids. After stirring evenly, a polymer / ceramic precursor solution B is obtained.

[0009] S3. Multi-layer combined spinning of solution A and solution B, peeling them off from the receiving substrate after a certain time, and then drying them in an oven at a certain temperature for a period of time to obtain multi-layer ceramic precursor nanofiber membrane C.

[0010] S4. The obtained multilayer ceramic precursor nanofiber membrane C is calcined under a certain atmosphere for a period of time to prepare an elastic ceramic nanofiber membrane material.

[0011] Preferably, in S1, the heat-shrinkable shape memory polymer is at least one of polyurethane, polyoxymethylene, polyethylene, polystyrene, polyvinyl chloride, polypropylene, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene-styrene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polydimethyl terephthalate, polybutylene terephthalate, polylactic acid, polyvinylpyrrolidone, polycaprolactone, and polyoxymethylene; the solvent is at least one of water, anhydrous ethanol, isopropanol, acetone, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, toluene, and acetylacetone, and the mass ratio of the heat-shrinkable shape memory polymer to the solvent is 1:3 to 1:13.

[0012] Preferably, in S2, the polymer is at least one of polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, and polyvinyl acetate; the solvent is at least one of water, anhydrous ethanol, isopropanol, acetone, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, toluene, and acetylacetone, and the mass ratio of the polymer to the solvent is 1:1.5 to 1:9.

[0013] Preferably, in S2, the ceramic source components include: a silicon source of tetramethoxysilane, tetraethoxysilane, tetraethyl orthosilicate, or isopropyl orthosilicate; a zirconium source of zirconium acetate or zirconium chloride; a zinc source of zinc acetate or zinc nitrate; a tin source of tin acetate or tin chloride; an aluminum source of aluminum isopropoxide, aluminum sec-butoxide, aluminum chloride, aluminum nitrate, or aluminum acetate; a titanium source of titanium trichloride, titanium tetrachloride, titanium oxysulfate, titanium oxyacetylacetonate, isopropyl titanate, tetrabutyl titanate, tetraethyl titanate, or diisopropoxydiacetylacetonate; and a barium source of carbonic acid. Barium, barium acetate, barium sulfate, barium nitrate, barium chloride, barium hydroxide, barium oxide; lanthanum source: lanthanum nitrate, lanthanum sulfate, lanthanum carbonate; lithium source: lanthanum chloride, lithium nitrate, lithium sulfate, lithium chloride; silicon carbide source: polycarbosilane; hydrolysis system: acidic or neutral, wherein the acidic substance corresponding to the acidic system is at least one of formic acid, acetic acid, oxalic acid, concentrated phosphoric acid, and concentrated hydrochloric acid, and the neutral substance corresponding to the neutral system is water; the mass fraction of the hydrolysis system in the precursor solution containing ceramic source components is 0.1% to 17%.

[0014] Preferably, in step S3, the spinning technology includes at least one of electrospinning, blow spinning, and centrifugal spinning. The process parameters for electrospinning are: ambient temperature 20–35°C, humidity 10%–60%, injection speed 0.5–2 mL / h, positive voltage 10–25 kV, negative voltage 0.5–3.0 kV, receiving distance 12–25 cm, and receiving speed 50–100 r / min. The process parameters for blow spinning are: ambient temperature 20–35°C, humidity 10%–60%, injection speed 0.5–2 mL / h, positive voltage 10–25 kV, negative voltage 0.5–3.0 kV, receiving distance 12–25 cm, and receiving speed 50–100 r / min. The feed rate is 10%–60%, the injection speed is 1–15 mL / h, the blowing pressure is 20–200 kPa, and the blowing distance is 5–80 cm; the process parameters for centrifugal spinning are: ambient temperature 20–35℃, humidity 10%–60%, feed rate 0.1–20 mL / h, spinning distance 5–30 cm, and spinneret speed 1000–20000 rpm; the receiving substrate includes at least one of silicone paper, release paper, nonwoven fabric, tin foil, copper mesh, breathable cage, and perforated mesh curtain.

[0015] Preferably, in S3, the multi-layer combined spinning is one of the following structures: polymer / ceramic nanofiber bilayer membrane, polymer / ceramic-polymer / ceramic nanofiber sandwich membrane, polymer / ceramic / polymer nanofiber sandwich membrane, polymer / ceramic-polymer / polymer nanofiber sandwich membrane, ceramic / ceramic-polymer / polymer nanofiber sandwich membrane, and ceramic / polymer / ceramic nanofiber sandwich membrane combination structure; the drying temperature is 40-70℃, and the drying time is 6-24h.

[0016] Preferably, in step S4, the calcination atmosphere is either an inert atmosphere or an inert atmosphere-to-oxidizing atmosphere, wherein the inert atmosphere is at least one of nitrogen and argon, and calcination under the inert atmosphere yields an elastic ceramic-carbon composite nanofiber membrane; the oxidizing atmosphere is at least one of air and oxygen, and calcination under the oxidizing atmosphere yields a pure inorganic elastic ceramic nanofiber membrane; the calcination temperature is gradually increased from room temperature to 500-1000℃, the heating rate is 0.5-10℃ / min, and the holding time is 0.5-8h.

[0017] Beneficial effects: The elastic ceramic nanofiber membrane prepared by this invention uses shape memory polymer sacrificial templates to induce the construction of micro-folded structures in the ceramic nanofiber membrane, overcoming the brittleness and rigidity defects of traditional ceramics, and realizing the performance transformation of ceramic nanofiber membranes from "brittle" to "elastic". Furthermore, by controlling the calcination atmosphere, elastic ceramic-carbon composite nanofiber membranes and pure inorganic elastic ceramic nanofiber membranes can be prepared. At the same time, the prepared stretchable elastic ceramic nanofiber membranes can meet the requirements of complex deformation and impact loads, which is of great significance for further promoting the application of ceramic materials in the fields of national defense, aerospace, flexible electronics, energy and environmental protection, biomedicine, and personal protective equipment. Attached Figure Description

[0018] Figure 1 This is a photograph of the silica elastic ceramic nanofiber membrane prepared in Example 2.

[0019] Figure 2 The image shows the laser confocal microscopy morphology of the silica elastic ceramic nanofiber membrane prepared in Example 2.

[0020] Figure 3 The image shown is an electron microscope image of the silica elastic ceramic nanofiber membrane prepared in Example 2.

[0021] Figure 4 The image shows an electron microscope image of the wrinkled structure of the silica elastic ceramic nanofiber membrane prepared in Example 2.

[0022] Figure 5 The diagram shows the cyclic tensile elastic properties of the silica elastic ceramic nanofiber membrane prepared in Example 2. Detailed Implementation

[0023] The present invention will be further explained below with reference to the embodiments. The following embodiments are only used to illustrate the present invention, but are not intended to limit the scope of the present invention. Example 1

[0024] S1. The shape memory polymer polyvinylidene fluoride-hexafluoropropylene is dissolved in a solvent of N,N-dimethylformamide and acetone (the mass ratio of shape memory polymer to solvent is 1:7). After stirring at 400 r / min for 6 h in a water bath at 40℃, a polymer sacrificial template spinning solution A is obtained.

[0025] S2. Add 4.3g of tetraethoxysilane to an acidic hydrolysis system (the mass fraction of concentrated hydrochloric acid in the ceramic precursor solution is 0.3%) to prepare a silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinyl alcohol, a polymer used for spinning (the mass ratio of polymer to solvent is 1:9). Stir at 200r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 7:3) solution B.

[0026] S3. Electrospinning was performed on solutions A and B in combination with polymer / ceramic nanofiber bilayer membranes under the conditions of humidity 30±10% and temperature 25±2℃, using silicone paper as the receiving substrate, with the injection speed set to 1mL / h, the receiving distance set to 20cm, and the receiving speed set to 60r / min. The spinning voltage of the first layer solution A was +17kV / -1.2kV, and the spinning voltage of the second layer solution B was +20kV / -1.3kV. The spinning time of each layer was 30min. Then, the membrane was peeled off from the silicone paper and dried in an oven at 70℃ for 12h to obtain polyvinylidene fluoride-hexafluoropropylene / silica ceramic nanofiber bilayer membrane C.

[0027] S4. The shape memory polymer polyvinylidene fluoride-hexafluoropropylene / silica ceramic nanofiber bilayer membrane C is placed in a tube furnace, and then heated to 800℃ at a heating rate of 1℃ / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, it is allowed to cool naturally to obtain a silica elastic ceramic-carbon composite nanofiber membrane. Example 2

[0028] S1. The shape memory polymer polystyrene was dissolved in a solvent of N,N-dimethylformamide and tetrahydrofuran (the mass ratio of shape memory polymer to solvent was 1:3). After stirring at 500 r / min for 6 h at room temperature, a polymer sacrificial template spinning solution A was obtained.

[0029] S2. Add 4.3g of tetraethoxysilane to an acidic hydrolysis system (the mass fraction of concentrated hydrochloric acid in the ceramic precursor solution is 0.3%) to prepare a silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinyl alcohol, a polymer used for spinning (the mass ratio of polymer to solvent is 1:9). Stir at 200r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 7:3) solution B.

[0030] S3. Electrospinning was performed on solutions A and B in a polymer / ceramic-polymer / ceramic nanofiber sandwich membrane combination layer under the conditions of humidity 20±10% and temperature 25±5℃, using silicone paper as the receiving substrate, with the injection speed set to 1mL / h, the receiving distance set to 20cm, and the receiving speed set to 60r / min. The spinning voltage of the first layer solution A was +20kV / -3.0kV, the spinning voltage of the second layer solution A and solution B was +20kV / -1.3kV, and the spinning voltage of the third layer solution B was +20kV / -1.3kV. The spinning time of each layer was 30min. Then, it was peeled off from the silicone paper and dried in an oven at 60℃ for 24h to obtain polystyrene / silica-polystyrene / silica nanofiber sandwich membrane C.

[0031] S4. Place the polystyrene / silica-polystyrene / silica nanofiber sandwich membrane C in a tube furnace, and then heat it to 800°C at a heating rate of 5°C / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, switch to an air atmosphere, continue holding at this temperature for 3 hours, and then allow it to cool naturally to obtain a silica elastic ceramic nanofiber membrane.

[0032] As can be seen from the attached figures, the silica elastic ceramic nanofiber membrane prepared in this invention exhibits a large number of wrinkled structures on its surface. Figure 1 Using a shape laser confocal microscopy system to characterize the three-dimensional morphology of the film material surface, it was found that the wrinkled structure is elongated, and that wrinkles of varying degrees are generated in both the transverse and longitudinal directions. Figure 2 The microstructure of the silica elastic ceramic nanofiber membrane was characterized by scanning electron microscopy. Figure 3 It was found that the fibers exhibited significant curvature, and the degree of curvature of the ceramic fibers at the edges of the folded structure was much greater than that of the protruding parts inside the folds. Figure 4 The fiber morphology within the folds is similar to that of conventional ceramic fibers. The elastic mechanical properties of the prepared silica elastic ceramic nanofiber membrane were characterized. Figure 5 Under a tensile strain of 40%, after 100 cycles of cyclic stretching, the elastic properties of the ceramic nanofiber membrane decreased slightly. After 500 cycles of loading and unloading, its tensile strength reached 0.92 MPa, and the plastic deformation tended to stabilize at only about 7.5%, indicating that the prepared elastic ceramic nanofiber membrane has excellent elastic recovery properties. Example 3

[0033] S1. Dissolve shape memory polymer polystyrene in a solvent of N,N-dimethylformamide and tetrahydrofuran (mass ratio of shape memory polymer to solvent is 1:6), and stir at 400 r / min for 6 h at room temperature to obtain polymer sacrificial template spinning solution A.

[0034] S2. Add 15g of zirconium acetate to a neutral hydrolysis system (the mass fraction of water in the ceramic precursor solution is 2%) to prepare a zirconium oxide ceramic precursor solution. Then mix it with an aqueous solution of polyethylene oxide, a polymer used for spinning (the mass ratio of polymer to solvent is 1:1.5). Stir at 300r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 30:1) solution B.

[0035] S3. Electrospinning was performed on solutions A and B in a polymer / ceramic-polymer / ceramic nanofiber sandwich membrane combination layer under the conditions of humidity 30±10% and temperature 25±2℃, using silicone paper as the receiving substrate, with the injection speed set to 2mL / h, the receiving distance set to 25cm, and the receiving speed set to 100r / min. The spinning voltage of the first layer solution A was +20kV / -1.3kV, the spinning voltage of the second layer solution A and solution B was +25kV / -3.0kV, and the spinning voltage of the third layer solution B was +25kV / -3.0kV. The spinning time of each layer was 30min. Then, it was peeled off from the silicone paper and dried in an oven at 60℃ for 6h to obtain polystyrene / zirconia-polystyrene / zirconia nanofiber sandwich membrane C.

[0036] S4. Place the polystyrene / zirconia-polystyrene / zirconia nanofiber sandwich membrane C in a tube furnace, and then heat it to 800℃ at a heating rate of 10℃ / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, switch to an air atmosphere, continue holding at this temperature for 3 hours, and then allow it to cool naturally to obtain a zirconia elastic ceramic nanofiber membrane. Example 4

[0037] S1. Dissolve shape memory polymer polystyrene in a solvent of N,N-dimethylformamide and tetrahydrofuran (mass ratio of shape memory polymer to solvent is 1:3), and stir at 400 r / min for 6 h at room temperature to obtain polymer sacrificial template spinning solution A.

[0038] S2. Add 4.3g of tetraethoxysilane to an acidic hydrolysis system (the mass fraction of concentrated hydrochloric acid in the ceramic precursor solution is 0.3%) to prepare a silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinyl alcohol, a polymer used for spinning (the mass ratio of polymer to solvent is 1:9). Stir at 200r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 7:3) solution B.

[0039] S3. Electrospinning was performed on solutions A and B in a polymer / ceramic-polymer / ceramic nanofiber sandwich membrane combination layer under the conditions of humidity 30±10% and temperature 25±2℃, using silicone paper as the receiving substrate, with the injection speed set to 1mL / h and the receiving speed to 50r / min. The spinning voltage of the first layer solution A was +10kV / -0.5kV and the receiving distance was set to 10cm. The spinning voltage of the second layer solutions A and B was +20kV / -1.3kV and the receiving distance was set to 20cm. The spinning voltage of the third layer solution B was +20kV / -1.3kV and the receiving distance was set to 20cm. The spinning time of each layer was 30min. Then, the membrane was peeled off from the silicone paper and dried in an oven at 40℃ for 24h to obtain polystyrene / silica-polystyrene / silica nanofiber sandwich membrane C.

[0040] S4. Place the polystyrene / silica-polystyrene / silica nanofiber sandwich membrane C in a tube furnace, and then heat it to 800°C at a heating rate of 5°C / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, switch to an air atmosphere, continue holding at this temperature for 3 hours, and then allow it to cool naturally to obtain a silica elastic ceramic nanofiber membrane. Example 5

[0041] S1. Dissolve shape memory polymer polystyrene in a solvent of N,N-dimethylformamide and tetrahydrofuran (mass ratio of shape memory polymer to solvent is 1:13), and stir at 400 r / min for 6 h at room temperature to obtain polymer sacrificial template spinning solution A.

[0042] S2. Add 4.3g of tetraethoxysilane to an acidic hydrolysis system (the mass fraction of concentrated hydrochloric acid in the ceramic precursor solution is 0.3%) to prepare a silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinyl alcohol, a polymer used for spinning (the mass ratio of polymer to solvent is 1:9). Stir at 200r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 7:3) solution B.

[0043] S3. Electrospinning was performed on solutions A and B in a combination of polymer / ceramic / polymer nanofiber sandwich membrane layers under the conditions of humidity 60±10% and temperature 25±2℃, with silicone paper as the receiving substrate, the injection speed was set to 1mL / h, the receiving distance was set to 20cm, the receiving speed was 60r / min, the spinning voltage of the first layer solution A was +15kV / -2.0kV, the spinning voltage of the second layer solution A and solution B was +20kV / -1.3kV, and the spinning voltage of the third layer solution A was +15kV / -2.0kV. The spinning time of each layer was 30min. Then, it was peeled off from the silicone paper and dried in an oven at 60℃ for 12h to obtain polystyrene / silica / polystyrene nanofiber sandwich membrane C.

[0044] S4. Place the polystyrene / silica / polystyrene nanofiber sandwich membrane C in a tube furnace, and then heat it to 500℃ at a heating rate of 0.5℃ / min under a nitrogen atmosphere. After holding at this temperature for 0.5h, switch to an air atmosphere, continue holding at this temperature for 8h, and then allow it to cool naturally to obtain a silica elastic ceramic nanofiber membrane. Example 6

[0045] S1. Dissolve shape memory polymer polystyrene in a solvent of N,N-dimethylformamide and tetrahydrofuran (mass ratio of shape memory polymer to solvent is 1:6), and stir at 400 r / min for 6 h at room temperature to obtain polymer sacrificial template spinning solution A.

[0046] S2. Add 3g aluminum isopropoxide, 1.5g aluminum chloride hexahydrate, and 1.5g tetraethoxysilane to an acidic hydrolysis system (acetic acid has a mass fraction of 0.1% in the ceramic precursor solution) to prepare a silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinyl alcohol (polymer for spinning) (the mass ratio of polymer to solvent is 1:9). Stir at 200r / min for 1h at room temperature to obtain polymer / ceramic precursor (mass ratio of 6:4) solution B.

[0047] S3. Solution A and solution B were subjected to blow spinning in combination layers of polymer / ceramic-polymer / ceramic nanofiber sandwich membrane. Under the conditions of humidity 30±10% and temperature 25±2℃, a breathable cage was used as the receiving substrate, the injection speed was set to 5mL / h, the blowing pressure was 50kPa, the blowing distance was 50cm, and the spinning time of each layer was 30min. Then, the membrane was peeled off from the breathable cage and dried in an oven at 60℃ for 12h to obtain polystyrene / mullite nanofiber sandwich membrane C.

[0048] S4. Place the polystyrene / mullite-polystyrene / mullite nanofiber sandwich membrane C in a tube furnace, and then heat it to 1000℃ at a heating rate of 5℃ / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, allow it to cool naturally to obtain a mullite elastic ceramic-carbon composite nanofiber membrane. Example 7

[0049] S1. Dissolve shape memory polymer polystyrene in a solvent of N,N-dimethylformamide and tetrahydrofuran (mass ratio of shape memory polymer to solvent is 1:6), and stir at 400 r / min for 6 h at room temperature to obtain polymer sacrificial template spinning solution A.

[0050] S2. Add 1.5g of isopropyl titanate, 0.03g of yttrium nitrate hexahydrate, and 1.7g of tetraethoxysilane to an acidic hydrolysis system (acetic acid has a mass fraction of 17% in the ceramic precursor solution) to prepare a titanium oxide-silica ceramic precursor solution. Then mix it with an aqueous solution of polyvinylpyrrolidone (polymer and solvent have a mass ratio of 1:8) at room temperature and stir at 200r / min for 1h to obtain polymer / ceramic precursor (mass ratio of 3:1) solution B.

[0051] S3. Electrospinning was performed on solutions A and B in a polymer / ceramic-polymer / ceramic nanofiber sandwich membrane combination layer under the conditions of humidity 10±10% and temperature 20±2℃, using silicone paper as the receiving substrate, with the injection speed set to 1mL / h, the receiving distance set to 15cm, and the receiving speed set to 60r / min. The spinning voltage of the first layer solution A was +17kV / -3.0kV, the spinning voltage of the second layer solution A and solution B was +17kV / -1.3kV, and the spinning voltage of the third layer solution A was +17kV / -1.3kV. The spinning time of each layer was 30min. Then, it was peeled off from the silicone paper and dried in an oven at 60℃ for 12h to obtain polystyrene / titanium oxide-silica-polystyrene / titanium oxide-silica nanofiber sandwich membrane C.

[0052] S4. Place the polystyrene / titanium oxide-silica-polystyrene / titanium oxide-silica nanofiber sandwich membrane C in a tube furnace, and then heat it to 600℃ at a heating rate of 5℃ / min under a nitrogen atmosphere. After holding at this temperature for 3 hours, allow it to cool naturally to obtain a titanium oxide-silica composite elastic ceramic-carbon nanofiber membrane.

Claims

1. A method for preparing an elastic ceramic nanofiber membrane material, characterized in that, Includes the following steps: S1. Dissolve the heat-shrinkable shape memory polymer in a solvent and stir until homogeneous to obtain polymer sacrificial template spinning solution A; S2. Add the ceramic source component to a certain hydrolysis system to prepare a precursor solution containing the ceramic source component, and then mix it with a polymer solution for spinning aids. After stirring evenly, a polymer / ceramic precursor solution B is obtained. S3. Multi-layer combined spinning of solution A and solution B, peeling them off from the receiving substrate after a certain time, and then drying them in an oven at a certain temperature for a period of time to obtain multi-layer ceramic precursor nanofiber membrane C. S4. The obtained multilayer ceramic precursor nanofiber membrane C is calcined under a certain atmosphere for a period of time to prepare an elastic ceramic nanofiber membrane material; the calcination atmosphere is one of an inert atmosphere or an inert atmosphere converted to an oxidizing atmosphere, wherein the inert atmosphere is at least one of nitrogen and argon, and an elastic ceramic-carbon composite nanofiber membrane is obtained after calcination under an inert atmosphere; the oxidizing atmosphere is at least one of air and oxygen, and a pure inorganic elastic ceramic nanofiber membrane is obtained after calcination under an oxidizing atmosphere; the calcination temperature is gradually increased from room temperature to 500-1000℃, the heating rate is 0.5-10℃ / min, and the holding time is 0.5-8h.

2. The method for preparing the elastic ceramic nanofiber membrane material according to claim 1, characterized in that, In S1, the heat-shrinkable shape memory polymer is at least one of polyurethane, polyoxymethylene, polyethylene, polystyrene, polyvinyl chloride, polypropylene, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene-styrene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polydimethyl terephthalate, polybutylene terephthalate, polylactic acid, polyvinylpyrrolidone, polycaprolactone, and polyoxymethylene; the solvent is at least one of water, anhydrous ethanol, isopropanol, acetone, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, toluene, and acetylacetone, and the mass ratio of the heat-shrinkable shape memory polymer to the solvent is 1:3 to 1:

13.

3. The method for preparing the elastic ceramic nanofiber membrane material according to claim 1, characterized in that, In S2, the polymer is at least one of polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, and polyvinyl acetate; the solvent is at least one of water, anhydrous ethanol, isopropanol, acetone, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, toluene, and acetylacetone, and the mass ratio of the polymer to the solvent is 1:1.5 to 1:

9.

4. The method for preparing the elastic ceramic nanofiber membrane material according to claim 1, characterized in that, In S2, the ceramic source components include: silicon source: tetramethoxysilane, tetraethoxysilane, tetraethyl orthosilicate, isopropyl orthosilicate; zirconium source: zirconium acetate, zirconium chloride; zinc source: zinc acetate, zinc nitrate; tin source: tin acetate, tin chloride; aluminum source: aluminum isopropoxide, aluminum sec-butoxide, aluminum chloride, aluminum nitrate, aluminum acetate; titanium source: titanium trichloride, titanium tetrachloride, titanium oxysulfate, titanium oxyacetylacetonate, isopropyl titanate, tetrabutyl titanate, tetraethyl titanate, diisopropoxydiacetylacetonate; barium source: barium carbonate. The source materials are barium acetate, barium sulfate, barium nitrate, barium chloride, barium hydroxide, and barium oxide; lanthanum source materials are lanthanum nitrate, lanthanum sulfate, and lanthanum carbonate; lithium source materials are lanthanum chloride, lithium nitrate, lithium sulfate, and lithium chloride; silicon carbide source material is polycarbosilane; the hydrolysis system is either acidic or neutral, wherein the acidic substance corresponding to the acidic system is at least one of formic acid, acetic acid, oxalic acid, concentrated phosphoric acid, and concentrated hydrochloric acid, and the neutral substance corresponding to the neutral system is water; the mass fraction of the hydrolysis system in the precursor solution containing the ceramic source component is 0.1% to 17%.

5. The method for preparing the elastic ceramic nanofiber membrane material according to claim 1, characterized in that, In S3, the spinning technology includes at least one of electrospinning, blow spinning, and centrifugal spinning. The process parameters for electrospinning are: ambient temperature 20–35℃, humidity 10%–60%, injection speed 0.5–2 mL / h, positive voltage 10–25 kV, negative voltage 0.5–3.0 kV, receiving distance 12–25 cm, and receiving speed 50–100 r / min. The process parameters for blow spinning are: ambient temperature 20–35℃, humidity 10%–25 kV, and centrifugal spinning speed 50–100 r / min. The process parameters for centrifugal spinning are: ambient temperature 20-35℃, humidity 10%-60%, feed rate 0.1-20mL / h, spinneret distance 5-30cm, and spinneret rotation speed 1000-20000rpm; the receiving substrate includes at least one of silicone paper, release paper, nonwoven fabric, tin foil, copper mesh, breathable cage, and perforated mesh curtain.

6. The method for preparing the elastic ceramic nanofiber membrane material according to claim 1, characterized in that, In S3, the multi-layer combined spinning is one of the following structures: polymer / ceramic nanofiber bilayer membrane, polymer / ceramic-polymer / ceramic nanofiber sandwich membrane, polymer / ceramic / polymer nanofiber sandwich membrane, polymer / ceramic-polymer / polymer nanofiber sandwich membrane, ceramic / ceramic-polymer / polymer nanofiber sandwich membrane, and ceramic / polymer / ceramic nanofiber sandwich membrane combination structure; the drying temperature is 40-70℃, and the drying time is 6-24h.

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