A high-temperature resistant silicon carbide ceramic membrane and its preparation method

Abstract

This invention belongs to the field of ceramic membrane technology, specifically relating to a high-temperature resistant silicon carbide ceramic membrane and its preparation method. The silicon carbide ceramic membrane sequentially comprises a silicon carbide support and a coating layer. By weight, the silicon carbide support comprises the following raw materials: 80-100 parts of first silicon carbide powder, 3-5 parts of sintering aid, 5-10 parts of polyvinyl alcohol, 2-3 parts of modified ammonium polyacrylate, and 0.1-0.4 parts of dibutyl phthalate. The ceramic membrane of this invention exhibits good high-temperature resistance and excellent mechanical properties, and can be used to prepare high-temperature resistant materials, possessing significant application value.

Description

Technical Field

[0001] This invention belongs to the field of ceramic membrane technology, specifically relating to a high-temperature resistant silicon carbide ceramic membrane and its preparation method. Background Technology

[0002] Ceramic membrane separation technology is a highly efficient and energy-saving separation technology with applications in industries such as chemical, petroleum and petrochemical, biochemical, food, electronics, and pharmaceuticals. Ceramic membranes on the market are mainly made of materials such as alumina, titanium dioxide, silicon dioxide, zirconium oxide, and silicon carbide. Among them, silicon carbide ceramic membranes have received considerable attention due to their superior performance. They are primarily composed of a silicon carbide ceramic support and a silicon carbide membrane layer. Silicon carbide materials are widely used in functional ceramics, advanced refractory materials, mechanical seals, abrasives, and metallurgical raw materials due to their high thermal conductivity, low coefficient of thermal expansion, stable chemical properties, good wear resistance, high hardness, and resistance to chemical corrosion.

[0003] Chinese patent CN 109824381 B relates to a silicon carbide ceramic membrane, its preparation method, and its uses. The silicon carbide ceramic membrane includes a support and a pure silicon carbide film layer uniformly attached to the support. The film layer is composed of interconnected silicon carbide fibers. The preparation method of the silicon carbide ceramic membrane includes the following steps: coating a dispersion A onto the surface of a silicon carbide support and drying it to obtain a pre-film; coating a silicon monoxide dispersion onto the surface of the pre-film and drying it to obtain a reaction membrane; calcining the reaction membrane under vacuum conditions to obtain a porous ceramic membrane precursor; and then subjecting the precursor to acid or alkali treatment and calcining it in an air or oxygen atmosphere. However, this preparation method requires further acid or alkali treatment, making the process relatively complex and unsuitable for widespread production.

[0004] Therefore, the present invention aims to provide a silicon carbide ceramic membrane with a relatively simple production process, while also giving it high temperature resistance and excellent mechanical properties. Summary of the Invention

[0005] To address the existing technical problems, the present invention aims to provide a high-temperature resistant silicon carbide ceramic membrane and its preparation method. The ceramic membrane of the present invention has good high-temperature resistance and excellent mechanical properties, and can be used to prepare high-temperature resistant materials, thus having good application value.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a high-temperature resistant silicon carbide ceramic membrane, wherein the silicon carbide ceramic membrane comprises a silicon carbide support and a coating layer in sequence; the silicon carbide support is prepared by weight of the following raw materials: 80-100 parts of first silicon carbide powder, 3-5 parts of sintering aid, 5-10 parts of polyvinyl alcohol, 2-3 parts of modified ammonium polyacrylate, and 0.1-0.4 parts of dibutyl phthalate.

[0008] The reaction mechanism and function of this invention are as follows:

[0009] 1. Ammonium polyacrylate possesses unique steric stabilization and electrostatic stabilization mechanisms, which can effectively regulate the viscosity and stability of ceramic slurries, thereby contributing to improved performance of the final product. However, the hydrophilicity of ammonium polyacrylate hinders its application in silicon carbide ceramic membranes requiring high-temperature resistance.

[0010] The applicant introduced N,N-methylenebisacrylamide, diethylenetriamine, and lauryl acrylate to co-modify ammonium polyacrylate. On the one hand, copolymerizing lauryl acrylate with ammonium polyacrylate increases the hydrophobicity of the polymer, improves its compatibility with nonpolar substances, and also increases the mechanical properties and high-temperature resistance of the polymer. On the other hand, the introduction of N,N-methylenebisacrylamide and diethylenetriamine can increase the degree of crosslinking of the polymer, thereby improving the mechanical strength, chemical stability, and high-temperature resistance of the silicon carbide support.

[0011] 2. Talc is stable at high temperatures, does not easily decompose, and is chemically inert. It also enhances mechanical properties. However, it is difficult to disperse evenly in water and is prone to agglomeration.

[0012] This invention introduces chitosan to modify talc powder. Firstly, chitosan can adsorb and penetrate the surface and interior of talc powder, reducing its tendency to agglomerate. Secondly, chitosan contains abundant functional groups (such as amino and hydroxyl groups), which can form hydrogen bonds with the hydroxyl groups in the second silicon carbide powder, further improving the dispersibility of the second silicon carbide powder. Next, the applicant introduces 3-trimethoxysilane propylene acrylate and N-allyl-N-methylpyrrolidone chloride to modify the pretreated talc powder. The use of 3-trimethoxysilane propylene acrylate ensures good dispersion uniformity of the talc powder, guaranteeing the performance of the coating layer. Furthermore, N-allyl-N-methylpyrrolidone chloride interacts strongly with the hydroxyl groups on the surface of the first silicon carbide, allowing the modified talc powder coating layer to be uniformly coated on the surface of the silicon carbide support, thereby making the silicon carbide support highly dense and further improving the overall mechanical properties and high-temperature resistance of the silicon carbide ceramic film.

[0013] In some embodiments, the coating layer is prepared by weight of the following raw materials: 20-30 parts of second silicon carbide powder, 5-10 parts of modified talc powder, 2-4 parts of polyvinylpyrrolidone, and 50-70 parts of deionized water.

[0014] Preferably, the average particle size of the first silicon carbide powder is 40-60 μm, and the average particle size of the second silicon carbide powder is 2-8 μm.

[0015] In some embodiments, the sintering aid is a mixture of alumina and titanium dioxide.

[0016] Preferably, the mass ratio of alumina to titanium dioxide is 3:(1.5-2).

[0017] In some embodiments, the preparation method of the modified ammonium polyacrylate includes the following steps:

[0018] Ammonium polyacrylate, N,N-methylenebisacrylamide, diethylenetriamine, lauryl acrylate, and deionized water were mixed and allowed to stand at 50-60℃ for 30-40 minutes. The mixture was then vacuum homogenized and vacuum spray dried to obtain modified ammonium polyacrylate.

[0019] In some embodiments, the conditions for vacuum homogenization are: a vacuum level of 0.04-0.06 MPa, a rotation speed of 2000-2600 rpm, and a homogenization time of 15-25 min.

[0020] In some embodiments, the mass ratio of ammonium polyacrylate, N,N-methylenebisacrylamide, diethylenetriamine, and lauryl acrylate is 1:(0.3-0.5):(0.7-0.9):(0.2-0.4).

[0021] In some embodiments, the method for preparing the modified talc powder includes the following steps:

[0022] Q1. Mix talc powder, chitosan, and 2-3 wt% acetic acid aqueous solution, stir for 2-4 hours, filter, wash, and dry to obtain pretreated talc powder;

[0023] Q2. Mix the pretreated talc powder obtained in step Q1, 3-trimethoxysilane propylene acrylate, water, and ethanol, heat to 60-70℃ and react for 5-6 hours, add N-allyl-N-methylpyrrolidine chloride and azobisisobutyronitrile, keep warm and react for 2-3 hours, wash, and dry to obtain modified talc powder.

[0024] In some embodiments, the mass ratio of talc to chitosan in step Q1 is 1:(0.3-0.5).

[0025] In some embodiments, the mass ratio of the pretreated talc, 3-trimethoxysilane propylene acrylate, and N-allyl-N-methylpyrrolidine chloride in step Q2 is 1:(0.3-0.5):(0.25-0.4).

[0026] Another aspect of the present invention provides a method for preparing a high-temperature resistant silicon carbide ceramic film, comprising the following steps:

[0027] S1. Mix the first silicon carbide powder, sintering aid, polyvinyl alcohol, modified ammonium polyacrylate, and dibutyl phthalate, stir for 1-2 hours, ball mill for 5-6 hours, extrude and form, raise the temperature to 300-350℃ at a heating rate of 1-3℃ / min, then raise the temperature to 600-620℃ at a heating rate of 2-4℃ / min, hold for 1-2 hours, then raise the temperature to 1400-1500℃ at a heating rate of 3-5℃ / min, hold for 2.5-3.5 hours, cool, and obtain the silicon carbide support;

[0028] S2. Mix the second silicon carbide powder, modified talc powder, polyvinylpyrrolidone, and deionized water, and stir for 1-1.5 hours to obtain the coating material.

[0029] S3. Coat the surface of the silicon carbide support obtained in step S1 with the coating material obtained in step S2, and heat it to 1400-1500℃ at a heating rate of 3-5℃ / min, and hold it for 2.5-3.5h to obtain a silicon carbide ceramic film.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The ceramic membrane of the present invention has good high temperature resistance and excellent mechanical properties. It can be used to prepare high temperature resistant materials and has good application value. When the ceramic membrane is used as a filter membrane, its filtration accuracy can reach up to 0.1 μm.

[0032] (2) This invention introduces N,N-methylenebisacrylamide, diethylenetriamine, and lauryl acrylate to co-modify ammonium polyacrylate. On the one hand, copolymerizing lauryl acrylate with ammonium polyacrylate increases the hydrophobicity of the polymer, improves its compatibility with non-polar substances, and also increases the mechanical properties and high-temperature resistance of the polymer. On the other hand, the introduction of N,N-methylenebisacrylamide and diethylenetriamine can increase the degree of crosslinking of the polymer, thereby improving the mechanical strength, chemical stability, and high-temperature resistance of the silicon carbide support.

[0033] (3) The modified talc powder of the present invention can reduce the agglomeration tendency of talc powder and ensure the performance of the coating layer. Secondly, the chitosan contains abundant functional groups that can form hydrogen bonds with the hydroxyl groups in the second silicon carbide powder, further improving the dispersibility of the second silicon carbide powder. In addition, N-allyl-N-methylpyrrolidone chloride will have a strong interaction with the hydroxyl groups on the surface of the first silicon carbide, so that the coating layer formed after the modification of talc powder can be uniformly coated on the surface of the silicon carbide support, further improving the overall mechanical properties and high temperature resistance of the silicon carbide ceramic film. Detailed Implementation

[0034] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0035] Ceramic membranes were prepared according to the proportions and preparation methods of the raw materials specified in the following examples and comparative examples. To facilitate implementation of this invention by those skilled in the art, the manufacturers of some raw materials used in the examples and comparative examples are described below:

[0036] Polyvinyl alcohol: purchased from Wuhan Runxingyuan Technology Co., Ltd., model number 1788;

[0037] Polyvinylpyrrolidone: Purchased from Huzhou Shenhua Polymer Materials Co., Ltd., model K30;

[0038] Ammonium polyacrylate: purchased from Wuhan Meiqilin New Materials Co., Ltd., model number 568a;

[0039] Chitosan: Purchased from Qingdao Bozhi Huili Biotechnology Co., Ltd.;

[0040] The average particle size of the first silicon carbide powder is 50 μm; the average particle size of the second silicon carbide powder is 5 μm.

[0041] Unless otherwise specified, other relevant raw materials can be purchased from the market.

[0042] Preparation Example 1

[0043] The preparation method of modified ammonium polyacrylate A includes the following steps:

[0044] 100g of ammonium polyacrylate, 40g of N,N-methylenebisacrylamide, 80g of diethylenetriamine, 28g of lauryl acrylate, and 2L of deionized water were mixed and allowed to stand at 55℃ for 40min. Vacuum homogenization was then performed, with the vacuum degree controlled at 0.05MPa, the rotation speed at 2400rpm, and the homogenization time at 20min. Vacuum spray drying was then performed, with the vacuum degree controlled at 0.06MPa, the atomization pressure at 0.5MPa, the inlet air temperature at 100℃, and the outlet air temperature at 40℃ to obtain modified ammonium polyacrylate A.

[0045] Preparation Example 2

[0046] The preparation method of modified ammonium polyacrylate B is the same as that of Preparation Example 1, except that the amount of lauryl acrylate added is 27g.

[0047] Preparation Example 3

[0048] The preparation method of modified ammonium polyacrylate C is the same as that of Preparation Example 1, except that the amount of N,N-methylenebisacrylamide added is 67g.

[0049] Preparation Example 4

[0050] The preparation method of modified talc powder A includes the following steps:

[0051] Q1. Mix 30g talc powder, 12g chitosan, and 200mL of 2.5wt% acetic acid aqueous solution, stir for 3h, filter, wash 3 times with deionized water, and dry at 85℃ for 4h to obtain pretreated talc powder.

[0052] Q2. Mix 20g of pretreated talc obtained in step Q1, 8g of 3-trimethoxysilane propylene acrylate, 300mL of water, and 200mL of ethanol, heat to 65℃ and react for 5.5h, add 6g of N-allyl-N-methylpyrrolidine chloride and 0.1g of azobisisobutyronitrile, keep warm and react for 2.5h, wash once with deionized water and once with anhydrous ethanol, and dry at 85℃ to constant weight to obtain modified talc A.

[0053] Preparation Example 5

[0054] The preparation method of modified talc B is the same as that of preparation example 4, except that the amount of chitosan added in step Q1 is 8.2g.

[0055] Preparation Example 6

[0056] The preparation method of modified talc powder C is the same as that of preparation example 4, except that the amount of talc powder added to the 3-trimethoxysilane propylene acrylate in step Q2 is 5.6g.

[0057] Preparation Example 7

[0058] The preparation method of modified talc powder D is the same as that of preparation example 4, except that the amount of N-allyl-N-methylpyrrolidine chloride added in step Q2 is 4.4g.

[0059] Example 1

[0060] A high-temperature resistant silicon carbide ceramic membrane, comprising a silicon carbide support and a coating layer, wherein the silicon carbide support comprises, by weight, the following raw materials: 90 parts of first silicon carbide powder, 4 parts of sintering aid, 7.5 parts of polyvinyl alcohol, 2.5 parts of modified ammonium polyacrylate A, and 0.25 parts of dibutyl phthalate; the coating layer comprises the following raw materials: 25 parts of second silicon carbide powder, 7.5 parts of modified talc powder A, 3 parts of polyvinylpyrrolidone, and 60 parts of deionized water; wherein the sintering aid is a mixture of alumina and titanium dioxide in a mass ratio of 3:1.75.

[0061] The method for preparing the silicon carbide ceramic film in this embodiment includes the following steps:

[0062] S1. Mix the first silicon carbide powder, sintering aid, polyvinyl alcohol, modified ammonium polyacrylate A, and dibutyl phthalate, stir for 1.5 h, ball mill for 5.5 h, extrude and mold, raise the temperature to 330°C at a heating rate of 2°C / min, then raise the temperature to 610°C at a heating rate of 3°C / min, hold for 1.5 h, then raise the temperature to 1450°C at a heating rate of 4°C / min, hold for 3 h, and cool to room temperature to obtain the silicon carbide support.

[0063] S2. Mix the second silicon carbide powder, modified talc powder A, polyvinylpyrrolidone, and deionized water, and stir for 1 hour to obtain the coating material.

[0064] S3. Coat the surface of the silicon carbide support obtained in step S1 with the coating material obtained in step S2, raise the temperature to 1450°C at a heating rate of 4°C / min, and hold for 3 hours to obtain a silicon carbide ceramic film.

[0065] Example 2

[0066] A high-temperature resistant silicon carbide ceramic membrane, comprising a silicon carbide support and a coating layer, wherein the silicon carbide support comprises, by weight, the following raw materials: 80 parts of first silicon carbide powder, 3 parts of sintering aid, 5 parts of polyvinyl alcohol, 2 parts of modified ammonium polyacrylate A, and 0.1 parts of dibutyl phthalate; the coating layer comprises the following raw materials: 20 parts of second silicon carbide powder, 5 parts of modified talc powder A, 2 parts of polyvinylpyrrolidone, and 50 parts of deionized water; wherein the sintering aid is a mixture of alumina and titanium dioxide in a mass ratio of 2:1.

[0067] The method for preparing the silicon carbide ceramic film in this embodiment includes the following steps:

[0068] S1. Mix the first silicon carbide powder, sintering aid, polyvinyl alcohol, modified ammonium polyacrylate A, and dibutyl phthalate, stir for 1 hour, ball mill for 5 hours, extrude and form, raise the temperature to 300°C at a heating rate of 1°C / min, then raise the temperature to 600°C at a heating rate of 2°C / min, hold for 1 hour, then raise the temperature to 1400°C at a heating rate of 3°C / min, hold for 2.5 hours, and cool to room temperature to obtain the silicon carbide support.

[0069] S2. Mix the second silicon carbide powder, modified talc powder A, polyvinylpyrrolidone, and deionized water, and stir for 1 hour to obtain the coating material.

[0070] S3. Coat the surface of the silicon carbide support obtained in step S1 with the coating material obtained in step S2, raise the temperature to 1400°C at a heating rate of 3°C / min, and hold for 2.5 hours to obtain a silicon carbide ceramic film.

[0071] Example 3

[0072] A high-temperature resistant silicon carbide ceramic membrane, wherein the silicon carbide ceramic membrane comprises a silicon carbide support and a coating layer in sequence; the silicon carbide support is prepared by weight of the following raw materials: 100 parts of first silicon carbide powder, 5 parts of sintering aid, 10 parts of polyvinyl alcohol, 3 parts of modified ammonium polyacrylate A, and 0.4 parts of dibutyl phthalate; the coating layer is prepared by the following raw materials: 30 parts of second silicon carbide powder, 10 parts of modified talc powder A, 4 parts of polyvinylpyrrolidone, and 70 parts of deionized water; wherein the sintering aid is a mixture of alumina and titanium dioxide in a mass ratio of 1.5:1.

[0073] The method for preparing the silicon carbide ceramic film in this embodiment includes the following steps:

[0074] S1. Mix the first silicon carbide powder, sintering aid, polyvinyl alcohol, modified ammonium polyacrylate A, and dibutyl phthalate, stir for 2 hours, ball mill for 6 hours, extrude and form, raise the temperature to 350°C at a heating rate of 3°C / min, then raise the temperature to 620°C at a heating rate of 4°C / min, hold for 2 hours, then raise the temperature to 1500°C at a heating rate of 5°C / min, hold for 3.5 hours, and cool to room temperature to obtain the silicon carbide support.

[0075] S2. Mix the second silicon carbide powder, modified talc powder A, polyvinylpyrrolidone, and deionized water, and stir for 1.5 hours to obtain the coating material.

[0076] S3. Coat the surface of the silicon carbide support obtained in step S1 with the coating material obtained in step S2, raise the temperature to 1500°C at a heating rate of 5°C / min, and hold for 3.5 hours to obtain a silicon carbide ceramic film.

[0077] Example 4

[0078] A high-temperature resistant silicon carbide ceramic membrane and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that modified ammonium polyacrylate B is used instead of modified ammonium polyacrylate A.

[0079] Example 5

[0080] A high-temperature resistant silicon carbide ceramic membrane and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified ammonium polyacrylate C is used instead of modified ammonium polyacrylate A.

[0081] Example 6

[0082] A high-temperature resistant silicon carbide ceramic film and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified talc powder B is used instead of modified talc powder A.

[0083] Example 7

[0084] A high-temperature resistant silicon carbide ceramic film and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified talc powder C is used instead of modified talc powder A.

[0085] Example 8

[0086] A high-temperature resistant silicon carbide ceramic film and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified talc powder D is used instead of modified talc powder A.

[0087] Comparative Example 1

[0088] A high-temperature resistant silicon carbide ceramic membrane and its preparation method are described. The specific implementation method is the same as in Example 1, except that commercially available ammonium polyacrylate 568a is used instead of modified ammonium polyacrylate A.

[0089] Comparative Example 2

[0090] A high-temperature resistant silicon carbide ceramic film and its preparation method are described. The specific implementation method is the same as in Example 1, except that commercially available talc powder is used instead of modified talc powder A.

[0091] Effect evaluation:

[0092] Each ceramic membrane was prepared according to Examples 1-8 and Comparative Examples 1-2 above, and tested. The specific test methods are as follows, and the test results are shown in Table 1.

[0093] Performance testing:

[0094] (1) Compressive strength: Refer to GB / T 4740-1999 Test method for compressive strength of ceramic materials, and use a strip of silicon carbide ceramic film with a diameter of 30mm×5mm×6mm to test its compressive strength;

[0095] (2) High temperature resistance: A strip of silicon carbide ceramic film with a diameter of 30mm×5mm×6mm was placed in a high temperature of 850℃ for 1 hour. After cooling, its compressive strength was tested using the above method.

[0096] Table 1 Performance Tests

[0097]

[0098]

[0099] The ceramic membranes prepared in Examples 1-3 of the present invention have good compressive strength and high temperature resistance.

[0100] Compared to Example 1, Examples 4-5 changed the mass ratio of ammonium polyacrylate, N,N-methylenebisacrylamide, diethylenetriamine, and lauryl acrylate during the preparation of modified ammonium polyacrylate. Example 4 resulted in weakened compatibility, and Example 5 resulted in a change in the degree of crosslinking. Both of these changes led to a decrease in the compressive strength and high-temperature resistance of the ceramic membrane.

[0101] Compared to Example 1, Examples 6-8 show that in preparing modified talc, Example 6 changed the mass ratio of talc to chitosan, which weakened the dispersibility of both talc and the second silicon carbide powder. Examples 7-8 changed the mass ratio of pretreated talc, 3-trimethoxysilane propylene acrylate, and N-allyl-N-methylpyrrolidine chloride, which weakened the dispersibility of talc and reduced the densification degree, thus affecting the compressive strength and high-temperature resistance of the ceramic film.

[0102] Comparative Example 1 used commercially available ammonium polyacrylate to replace modified ammonium polyacrylate A, and Comparative Example 2 used commercially available talc to replace modified talc A. Both of these changes resulted in a decrease in the compressive strength and high-temperature resistance of the ceramic membrane.

[0103] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present application in any way. Although the present application discloses the preferred embodiment as described above, it is not intended to limit the present application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A high-temperature resistant silicon carbide ceramic membrane, characterized in that, The silicon carbide ceramic film comprises a silicon carbide support and a coating layer in sequence; by weight, the silicon carbide support comprises the following raw materials: 80-100 parts of first silicon carbide powder, 3-5 parts of sintering aid, 5-10 parts of polyvinyl alcohol, 2-3 parts of modified ammonium polyacrylate, and 0.1-0.4 parts of dibutyl phthalate. The coating layer comprises the following raw materials in parts by weight: 20-30 parts of second silicon carbide powder, 5-10 parts of modified talc powder, 2-4 parts of polyvinylpyrrolidone, and 50-70 parts of deionized water. The preparation method of the modified ammonium polyacrylate includes the following steps: Ammonium polyacrylate, N,N-methylenebisacrylamide, diethylenetriamine, lauryl acrylate, and deionized water were mixed, placed at 50-60℃ and allowed to stand for 30-40 minutes, then vacuum homogenized and vacuum spray dried to obtain modified ammonium polyacrylate. The mass ratio of ammonium polyacrylate, N,N-methylenebisacrylamide, diethylenetriamine, and lauryl acrylate is 1:(0.3-0.5):(0.7-0.9):(0.2-0.4). The method for preparing the modified talc powder includes the following steps: Q1. Mix talc powder, chitosan, and 2-3 wt% aqueous acetic acid solution, stir for 2-4 hours, filter, wash, and dry to obtain pretreated talc powder; Q2. Mix the pretreated talc powder obtained in step Q1, 3-trimethoxysilane propylene acrylate, water, and ethanol, heat to 60-70℃ and react for 5-6 hours, add N-allyl-N-methylpyrrolidine chloride and azobisisobutyronitrile, keep warm and react for 2-3 hours, wash, and dry to obtain modified talc powder. The mass ratio of talc to chitosan in step Q1 is 1:(0.3-0.5). The mass ratio of the pretreated talc, 3-trimethoxysilane propylene acrylate, and N-allyl-N-methylpyrrolidine chloride in step Q2 is 1:(0.3-0.5):(0.25-0.4).

2. The high-temperature resistant silicon carbide ceramic membrane according to claim 1, characterized in that, The sintering aid is a mixture of alumina and titanium dioxide.

3. The high-temperature resistant silicon carbide ceramic membrane according to claim 1, characterized in that, The conditions for vacuum homogenization are as follows: vacuum level is controlled at 0.04-0.06 MPa, rotation speed is 2000-2600 rpm, and homogenization time is 15-25 min.

4. A method for preparing a high-temperature resistant silicon carbide ceramic film according to any one of claims 1-3, characterized in that, It includes the following steps: S1. Mix the first silicon carbide powder, sintering aid, polyvinyl alcohol, modified ammonium polyacrylate, and dibutyl phthalate, stir for 1-2 hours, ball mill for 5-6 hours, extrude and form, raise the temperature to 300-350℃ at a heating rate of 1-3℃ / min, then raise the temperature to 600-620℃ at a heating rate of 2-4℃ / min, hold for 1-2 hours, then raise the temperature to 1400-1500℃ at a heating rate of 3-5℃ / min, hold for 2.5-3.5 hours, cool, and obtain the silicon carbide support; S2. Mix the second silicon carbide powder, modified talc powder, polyvinylpyrrolidone, and deionized water, and stir for 1-1.5 hours to obtain the coating material. S3. Coat the surface of the silicon carbide support obtained in step S1 with the coating material obtained in step S2, raise the temperature to 1400-1500℃ at a heating rate of 3-5℃ / min, and hold for 2.5-3.5h to obtain a silicon carbide ceramic film.

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