A method for preparing a novel ceramic composite film of polycarbosilane aluminum oxide

Abstract

The application discloses a preparation method of a novel polycarbosilane-alumina ceramic composite membrane, and relates to the technical field of ceramic membrane processing. The novel ceramic composite membrane is prepared by using a ceramic precursor, polycarbosilane (PCS), ceramic powder, a polymer binder, a surfactant and mixed organic solvents as raw materials through a one-step phase inversion method. The polymer binder is a polysulfone-polyethylene glycol block copolymer, and the surfactant is composed of poloxamer and Arlacel-P135. The application adds polycarbosilane (PCS) into the polysulfone-polyethylene glycol block copolymer binder solution to form a liquid ceramic filler, so that the addition amount of ceramic particles in the slurry is reduced, and problems such as particle agglomeration, too large and uneven membrane holes and the like caused by high load solid ceramic particles in the slurry are avoided. The application adjusts and mixes the organic solvents, so that the polycarbosilane is successfully added into the ceramic slurry, and a novel ceramic composite membrane with small pore size and narrow distribution is prepared through one-step pore shrinkage.

Description

Technical Field

[0001] This invention belongs to the field of ceramic membrane processing technology, specifically relating to a novel ceramic composite membrane prepared by polycarbosilane pore reduction and its preparation method. Background Technology

[0002] As an important separation membrane material, ceramic membranes are widely used in various water treatment processes due to their advantages such as good antifouling performance, material stability, and high mechanical strength. However, currently, high-precision ultrafiltration ceramic membranes usually require multiple coating-sintering processes, which results in long preparation cycles, complex processes, and high costs, limiting the cost reduction of ceramic membrane applications. Using small-diameter ceramic fillers mixed into the membrane slurry to reduce pore size is a feasible solution; however, severe agglomeration between particles of different sizes easily occurs, leading to large pores, uneven distribution, and low particle loading.

[0003] Polycarbosilane (PCS) is an organosilicon polymer linked by Si-C bonds, with the chemical formula [Si-C]n, and is soluble in some organic solvents. As an organosilicon polymer containing a large amount of silicon and carbon, it can be ceramicized into SiC or SiOC ceramic particles under certain high-temperature pyrolysis conditions. Therefore, it can be used as a ceramic precursor for ceramic preparation. However, the currently reported impregnation-pyrolysis method increases the number of sintering cycles for the membrane. Furthermore, the large volume shrinkage of the organic phase of PCS during the transformation to inorganic ceramic, along with the release of a large amount of small molecule gases, makes the porous ceramic membrane prone to cracking, making it difficult to prepare complete ceramic sheets. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a novel polycarbosilane-alumina ceramic composite membrane. By screening and adjusting the mixed organic solution system, this invention enables the dissolved polycarbosilane to be successfully added to a slurry of polysulfone-polyethylene glycol block copolymer and alumina ceramic particles. Simultaneously, a one-step phase inversion and curing process is achieved, allowing the polycarbosilane to be sintered in situ with the solid particles in the initial membrane to form an ultrathin separation membrane material with a small and uniform pore size distribution.

[0005] The novel ceramic composite membrane prepared from polycarbosilane alumina according to the present invention is composed of the following raw materials in the indicated mass percentages:

[0006] Ceramic powder 30%-45%,

[0007] Polycarbosilane (PCS) 1%-10%,

[0008] 6%-10% polysulfone-polyethylene glycol block copolymer

[0009] Surfactant 1%-2%,

[0010] The remainder is a mixed organic solvent of tetrahydrofuran and N,N-dimethylpyrrolidone, and the surfactant is composed of poloxamer and Arlacel-P135.

[0011] Specifically, the ceramic powder of the present invention is at least one of metal oxides such as alumina, silicon oxide, and zirconium oxide.

[0012] Specifically, the polycarbosilane described in this invention has a molecular weight of 1000-2000 and a melting point between 200-220°C.

[0013] Specifically, the polyethylene glycol content in the polysulfone-polyethylene glycol block copolymer of the present invention is 17 wt%. The preparation method of the polysulfone-polyethylene glycol block copolymer can be referred to in the article "Preparation of Amphiphilic Polysulfone Block Copolymer and Its Application in Separation Membrane Field" published by our research group.

[0014] Specifically, the mass ratio of poloxamer to Arlacel-P135 in the surfactant described in this invention is 1-2:1.

[0015] Specifically, the organic solvent described in this invention is a mixture of N,N-methylpyrrolidone and tetrahydrofuran. The preferred ratio of the organic solvent is 2-3:1.

[0016] This invention also provides a method for preparing the novel polycarbosilane alumina ceramic composite film, comprising the following steps:

[0017] S1. Preparation of casting solution

[0018] Weigh the raw materials according to the proportion, first dissolve the polysulfone-polyethylene glycol block copolymer and surfactant in a mixed solution of N,N-dimethylpyrrolidone and tetrahydrofuran, then add solid polycarbosilane and stir thoroughly to dissolve, and finally add solid ceramic powder for ball milling and mixing evenly to obtain a fluid slurry casting solution.

[0019] S2, Defoaming

[0020] The casting solution was subjected to ultrasonic degassing in ice water, followed by low-temperature vacuum degassing.

[0021] S3, solidification

[0022] After degassing, the casting liquid is poured onto a clean glass plate and scraped to form a liquid film. Then, it is immersed in a polar solvent to solidify the liquid film on the glass plate and detach it from the glass plate to form a preliminary film. The polar solvent is anhydrous ethanol, the curing time is 1-5 hours, and the curing temperature is preferably room temperature.

[0023] S4. High-temperature sintering to form ceramic film

[0024] The initial blank film is placed in a tube furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, as follows:

[0025] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0026] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0027] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0028] Preferably, in step S2 of the present invention, the ultrasonic power during ultrasonic debubbling is 150-200w, the ultrasonic frequency is 30-50kHz, and the ultrasonic time is 10-30min, and it is preferably carried out in ice water.

[0029] Preferably, the vacuum degree during vacuum degassing in step S2 of the present invention is -101.325 kPa, and it is preferably carried out at a low temperature in ice water.

[0030] Preferably, the temperature ramp rate of the present invention is 3-4°C / min.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) The ceramic composite film prepared by polycarbosilane shrinkage according to the present invention has a thickness of 200-250μm. After one-step preparation, the pore size distribution is between 59-86nm, and 1%-10% polycarbosilane is uniformly added to the material, which significantly sharpens the pore size and distribution of the ceramic film (average pore size is 76nm), while the porosity of the ceramic film is maintained at 59%-65%.

[0033] 2) In this invention, polysulfone-polyethylene glycol block copolymer and a second solvent are added to the raw material system, which enables polycarbosilane to be dissolved and mixed uniformly with ceramic particles to form a casting liquid with low viscosity and high ceramic loading. The casting liquid can be used to form an ultra-thin liquid film on a glass plate. The liquid film can then be cured in a polar solvent to form a flat and uniform preform film. In the preform film, the ceramic precursor and the binder polymer chains are uniformly mixed with each other.

[0034] 3) The ceramic composite membrane prepared by polycarbosilane shrinkage as described in this invention has a small and narrow pore size distribution and good oil-water selective permeation performance. Attached Figure Description

[0035] Figure 1 This is a SEM image of a ceramic composite membrane prepared from polycarbosilane alumina in Example 10 of the present invention.

[0036] Figure 2 This is a SEM image of the alumina ceramic film prepared in Comparative Example 1 of this invention;

[0037] Figure 3 This is a SEM image of the alumina ceramic composite film prepared in Comparative Example 2 of this invention; Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments. In the following embodiments, the polyethylene glycol content in the polysulfone-polyethylene glycol block copolymer is 17 wt%, the melting point of the polycarbosilane is 220°C, the molecular weight is 1200, and the ratio of the organic solvent N-methylpyrrolidone to tetrahydrofuran is 1:2.5. The pore size detection method is as follows:

[0039] The pore size and distribution of membrane samples were characterized using a Porolux 1000 capillary flow pore size analyzer from Porometer (Belgium), employing a wet-dry curve method to determine the pore size. Specifically, the sample was immersed in Porefil wetting solution (surface tension 16 dyn / cm) for 10 minutes before testing until the membrane pores were completely wetted. The wetted membrane was then removed, placed in a membrane cell with a metal gasket, and sealed. The wet-dry curve of the membrane sample was measured first, followed by the dry curve, and the pore size data were exported from the instrument.

[0040] Examples 1-4

[0041] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0042] S1. Preparation of casting solution

[0043] Weigh out 45 wt% of alumina powder with a particle size of 200 nm, 3 wt% of polycarbosilane, and 1.5 wt% of surfactant, dissolve them in a mixed organic solvent, and then add 6 wt% of polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentages of each substance are percentages of the total liquid mass).

[0044] S2, Defoaming

[0045] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0046] S3, solidification

[0047] After degassing, the casting liquid is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250μm. Then, it is immersed in water at room temperature and cured for 4 hours to allow the liquid film on the glass plate to solidify and detach from the glass plate to form a preliminary film.

[0048] S4. High-temperature sintering to form ceramic film

[0049] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0050] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0051] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0052] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0053] One of the mixed solvents in Examples 1-4 was N-methylpyrrolidone, and the other was any one of common organic solvents such as xylene, n-hexane, 1,4-epoxyhexanes, and tetrahydrofuran. The two organic solvents were mixed in a 1:1 mass ratio. The results of Examples 1-4 are shown in Table 1 below.

[0054]

[0055] The large, flaky particles appearing on the membrane surface are due to the PCS not being uniformly mixed with the binder in the mixed solvent. The results in Table 1 of the case study show that when N-methylpyrrolidone and tetrahydrofuran are used as mixed solvents, the polymeric binder polysulfone-polyethylene glycol block copolymer and PCS can be well dissolved and mixed together.

[0056] Examples 5-9

[0057] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0058] S1. Preparation of casting solution

[0059] Weigh out 45 wt% of alumina powder with a particle size of 200 nm, 3 wt% of polycarbosilane, and 1.5 wt% of surfactant. Dissolve these in a mixed solvent of N-methylpyrrolidone and tetrahydrofuran in different proportions. Then add 6 wt% of polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentages of each substance are percentages of the total mass of the liquid).

[0060] S2, Defoaming

[0061] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0062] S3, solidification

[0063] After degassing, the casting solution is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250 μm. Then, it is immersed in water at room temperature for 4 hours to solidify the liquid film on the glass plate and detach it from the glass plate to form a preliminary film.

[0064] S4. High-temperature sintering to form ceramic film

[0065] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0066] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0067] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0068] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0069] In Examples 5-9, the ratio of the organic solvent N-methylpyrrolidone to tetrahydrofuran was 1:1, 1:2, 1:2.5, 1:3, 1:4, and 0:1. The results of these examples are shown in Table 2.

[0070]

[0071] By observing the particle size and surface morphology of the ceramic composite membrane prepared by polycarbosilane shrinkage, it was found that when the ratio of N-methylpyrrolidone and tetrahydrofuran in the mixed solvent was 1:2.5, PCS was completely dissolved and uniformly mixed in the slurry for preparing the initial membrane, and ceramic particles were formed in situ. The average pore size of the prepared membrane was 153 nm, and the pore size distribution range was 98-225 nm.

[0072] Example 10 / 11

[0073] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0074] S1. Preparation of casting solution

[0075] Weigh out 45 wt% alumina powder with a particle size of 200 nm, 6 / 9 wt% polycarbosilane, and 1.5 wt% surfactant, and dissolve them in a mixed organic solvent of N-methylpyrrolidone and tetrahydrofuran in a mass ratio of 1:2.5. Then add 6 wt% polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentages of each substance are percentages of the total mass of the liquid).

[0076] S2, Defoaming

[0077] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0078] S3, solidification

[0079] After degassing, the casting solution is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250 μm. Then, it is immersed in water at room temperature for 4 hours to solidify the liquid film on the glass plate and detach it from the glass plate to form a preliminary film.

[0080] S4. High-temperature sintering to form ceramic film

[0081] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0082] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0083] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0084] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0085] The prepared membrane composite ceramic membrane has an average pore size of 76 nm and a pore size distribution of 59-86 nm.

[0086] Comparative Example 1

[0087] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0088] S1. Preparation of casting solution

[0089] Weigh out 45 wt% alumina powder with a particle size of 200 nm and 1.5 wt% surfactant, dissolve them in a mixed organic solvent of N-methylpyrrolidone and tetrahydrofuran in a mass ratio of 1:2.5, and then add 6 wt% polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentage of the prepared substances is the percentage of the total liquid mass).

[0090] S2, Defoaming

[0091] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0092] S3, solidification

[0093] After degassing, the casting liquid is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250μm. Then, it is immersed in water at room temperature and cured for 4 hours to allow the liquid film on the glass plate to solidify and detach from the glass plate to form a preliminary film.

[0094] S4. High-temperature sintering to form ceramic film

[0095] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0096] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0097] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0098] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0099] The prepared membrane composite ceramic membrane has an average pore size of 291 nm and a pore size distribution of 194-403 nm.

[0100] Comparative Example 2

[0101] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0102] S1. Preparation of casting solution

[0103] Weigh out 45 wt% of alumina powder with a particle size of 200 nm, 8 wt% of alumina ceramic particles with a particle size of 30 nm, and 1.5 wt% of surfactant. Dissolve these in a mixed organic solvent of N-methylpyrrolidone and tetrahydrofuran with a mass fraction of 1:2.5. Then add 8 wt% of polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentages of each substance are percentages of the total mass of the liquid).

[0104] S2, Defoaming

[0105] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0106] S3, solidification

[0107] After degassing, the casting liquid is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250μm. Then, it is immersed in water at room temperature and cured for 4 hours to allow the liquid film on the glass plate to solidify and detach from the glass plate to form a preliminary film.

[0108] S4. High-temperature sintering to form ceramic film

[0109] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0110] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0111] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0112] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0113] The prepared membrane composite ceramic membrane has an average pore size of 250 nm and a pore size distribution of 177-398 nm.

[0114] Comparative Example 3

[0115] A method for preparing a novel polycarbosilane-alumina ceramic composite film is as follows:

[0116] S1. Preparation of casting solution

[0117] Weigh out 45 wt% alumina powder with a particle size of 200 nm, 8 wt% polysulfone binder, and 1.5 wt% surfactant, and dissolve them in a mixed organic solvent of N-methylpyrrolidone and tetrahydrofuran in a mass ratio of 1:2.5. Then add 8 wt% polysulfone-polyethylene glycol block copolymer. The surfactant is composed of poloxamer and Arlacel-P135 in a mass ratio of 1:1 (the mass percentages of each substance are percentages of the total mass of the liquid).

[0118] S2, Defoaming

[0119] The casting solution was subjected to ultrasonic degassing in ice water, with an ultrasonic power of 180W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 30min. Then, vacuum degassing was performed in an ice water bath under a vacuum of -101.325kPa to eliminate smaller bubbles in the casting solution.

[0120] S3, solidification

[0121] After degassing, the casting liquid is poured onto a clean glass plate and scraped to form a liquid film with a thickness of 250μm. Then, it is immersed in water at room temperature and cured for 4 hours to allow the liquid film on the glass plate to solidify and detach from the glass plate to form a preliminary film.

[0122] S4. High-temperature sintering to form ceramic film

[0123] The initial blank film is placed in a sintering furnace and sintered by programmed temperature rise to form a ceramic film; the programmed temperature rise includes three stages, and the heating rate of each stage is 3-4℃, as detailed below:

[0124] The first stage involves raising the temperature from room temperature to 220℃ and holding it at that temperature for 0.5 hours.

[0125] The second stage involves raising the temperature from 220℃ to 700℃ and holding it at that temperature for 2 hours.

[0126] The third stage involves raising the temperature from 700℃ to 1350℃ and holding it at that temperature for 2 hours.

[0127] The prepared membrane composite ceramic membrane has an average pore size of 218 nm and a pore size distribution of 157-255 nm.

[0128] The results of Examples 7, 10, and 11, and Comparisons 1-3 are summarized in Table 3.

[0129]

[0130] The ceramic membranes prepared in the examples and comparative examples were subjected to separation tests. An oil-water emulsion with a wide particle size distribution was selected as the feed liquid. The specific method is as follows:

[0131] A 1000 ppm oil-water emulsion, stabilized with a surfactant, was prepared using common high-viscosity lubricating oil at a mass ratio of 1:1000. After high-speed stirring, the particle size distribution ranged from 0.05 to 0.5 μm. Specifically, before testing, the sintered dry membrane was immersed in deionized water for approximately 10 minutes, and then placed in a vertical cross-flow membrane tank. The actual effective test membrane area was 2.25 cm². 2 For each membrane performance test, the average and standard deviation of at least three parallel samples should be taken.

[0132] The separation results in the embodiments are shown in Table 4.

[0133]

[0134] It should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and other modifications are possible. All modifications directly or indirectly derived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A novel poly-carbosilane-alumina ceramic composite film, characterized by, consists of the following raw materials by mass percentage: ceramic powder 30%-45%, polycarbosilane (PCS) 1%-10%, polysulfone-polyethylene glycol block copolymer 6%-10%, surfactant 1%-2%, the rest is a mixed organic solvent of tetrahydrofuran and N, N-dimethylpyrrolidone, and the surfactant consists of poloxamer and Arlacel-P135.

2. A polycarbosilane-alumina novel ceramic composite film according to claim 1, characterized by, The ceramic powder is at least one of aluminum oxide, silicon oxide, and zirconium oxide.

3. The polycarbosilane-alumina novel ceramic composite film according to claim 1, characterized by, The polycarbosilane has a molecular weight of 1000-2000 and a melting point of 200±20℃.

4. The polycarbosilane-alumina novel ceramic composite film according to claim 1, characterized by, The mass ratio of poloxamer to Arlacel-P135 in the surfactant is 1-2:

1.

5. The polycarbosilane-alumina novel ceramic composite film according to claim 1, characterized by, The organic solvent is a mixed two-solvent system, in which the ratio of tetrahydrofuran to N, N-dimethylpyrrolidone is 2-3:

1.

6. The polycarbosilane-alumina novel ceramic composite film according to claim 1, characterized by, The polyethylene glycol in the hydrophilic end of the polysulfone-polyethylene glycol block copolymer accounts for 17% in the block molecular chain.

7. The method according to any one of claims 1 to 6, wherein the method is characterized by, The method comprises the following steps: S1, preparing a casting solution The raw materials are weighed according to the proportion, the polysulfone-polyethylene glycol block copolymer and the surfactant are first dissolved in the mixed solution of N-N-dimethylpyrrolidone and tetrahydrofuran, then the solid polycarbosilane is added and stirred to dissolve, and finally the ceramic powder is added and ball milled to obtain a slurry-like casting solution with fluidity; S2, degassing The casting solution is subjected to ultrasonic degassing treatment in ice water, and then low-temperature vacuum degassing treatment; S3, curing The degassed casting solution is poured onto a clean glass plate to form a liquid film, which is then immersed in a polar solvent (anhydrous ethanol) for soaking treatment until it is cured and falls off from the glass plate to form a green membrane; S4, sintering at high temperature to form a ceramic membrane The green membrane is naturally dried and then sintered in a tube furnace by programmed temperature rising to form a ceramic membrane; the programmed temperature rising comprises three stages, specifically as follows: The first stage is to rise from room temperature to 220℃ and keep the temperature for 0.5h; The second stage is to rise from 220℃ to 700℃ and keep the temperature for 2h; The third stage is to rise from 700℃ to 1350℃ and keep the temperature for 2h.

8. The production method according to claim 7, characterized by, The ultrasonic power is 150-200w, the ultrasonic frequency is 30-50kHz, and the ultrasonic time is 10-50min during the ultrasonic degassing in step S2, and the ice water is used.

9. The preparation method according to claim 7, characterized in that, The rate of the programmed temperature rising is 3-4℃ / min.

10. The method of claim 7, wherein, The ceramic precursor polycarbosilane is added to the mixed organic solvent as a shrinkage filler, and the preparation and shrinkage of the new ultrafiltration ceramic composite membrane are completed in one step by the phase inversion method.

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