A method for preparing desalination ceramic composite membranes by interfacial polymerization

Abstract

This invention discloses a method for preparing desalination ceramic composite membranes via interfacial polymerization, belonging to the field of separation membrane material technology. The method uses an inorganic ceramic ultrafiltration membrane as a substrate, first coating it with an aqueous solution containing acid and water-soluble additives, then reacting it with an alcohol solution containing metal alkoxides and alcohol-soluble additives via interfacial polymerization. After drying, curing, and post-treatment with ultraviolet / electron beam irradiation, a ceramic composite membrane with high-efficiency desalination function is obtained. This invention precisely constructs an ultrathin, dense desalination layer through interfacial polymerization, combined with irradiation-enhanced structure and performance, solving the problems of poor tolerance of organic membranes and the difficulty of efficient desalination with traditional ceramic membranes. The prepared membrane has advantages such as acid and alkali resistance, high temperature resistance, pollution resistance, high desalination efficiency, and good stability, and can be widely used in seawater desalination, brackish water desalination, and deep treatment of industrial wastewater. The process is mild and easy to industrialize.

Description

Technical Field

[0001] This invention belongs to the field of separation membrane material preparation technology, and relates to a method for preparing a desalination membrane, specifically a method for preparing a ceramic-based composite membrane that can be used for nanofiltration and reverse osmosis desalination using interfacial polymerization technology. Background Technology

[0002] With the increasing severity of global water scarcity and water environment problems, efficient water treatment and desalination technologies have become a research hotspot. Membrane separation technology, due to its advantages such as low energy consumption, no phase change, compact equipment, and easy automation, has been widely used in seawater desalination, brackish water desalination, industrial wastewater treatment, and pure water preparation. Currently, commercially available desalination membranes are mainly organic polymer membranes, but they have drawbacks such as poor temperature resistance, weak acid and alkali corrosion resistance, insufficient antifouling ability, and short service life, making it difficult to operate stably for a long time under harsh conditions such as high temperature, strong acid and alkali, and high pollution.

[0003] Inorganic ceramic membranes possess outstanding advantages such as good chemical stability, resistance to acids and alkalis, resistance to organic solvents, high temperature resistance, antifouling properties, high mechanical strength, and long service life, making them ideal materials for separation processes under extreme conditions. However, traditional ceramic membrane preparation processes (such as sol-gel methods and vapor deposition methods) struggle to precisely control the dense, ultra-thin separation layer required for desalination, resulting in problems such as uneven pore size distribution, weak interlayer bonding, susceptibility to cracking, and poor preparation repeatability. Consequently, existing ceramic membranes are unable to achieve efficient desalination, and the market lacks inorganic ceramic membrane products that can be stably applied to nanofiltration / reverse osmosis desalination.

[0004] Therefore, developing a new process that can precisely control the thickness, pore size, interfacial bonding force, and surface physicochemical properties of the desalination layer and can be used to prepare high-performance desalination ceramic composite membranes on a large scale has important scientific value and engineering application prospects. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies, such as the poor tolerance of organic desalination membranes and the difficulty of efficient desalination by inorganic ceramic membranes, and to provide a method for preparing desalination ceramic composite membranes through interfacial polymerization. This method constructs a dense, ultrathin desalination layer through an inorganic-organic interfacial polymerization reaction, and combines this with irradiation post-treatment to enhance the structure and separation performance, thus preparing a composite membrane that combines the excellent stability of the ceramic matrix with highly efficient desalination performance. This membrane can be widely used in seawater desalination, brackish water purification, and advanced industrial wastewater treatment.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for preparing desalination ceramic composite membranes by interfacial polymerization includes the following steps: (1) Base membrane pretreatment and aqueous phase coating: Inorganic ceramic ultrafiltration membrane is selected as the base membrane. After cleaning and drying, an aqueous solution containing acid and water-soluble additives is uniformly coated on its surface and allowed to air dry naturally until the surface is semi-dry. (2) Interfacial polymerization reaction: The semi-dry ceramic substrate film is brought into full contact with an alcohol solution containing metal alkoxides and alcohol-soluble additives to undergo an interfacial polymerization reaction. After the reaction is completed, the excess alcohol solution on the film surface is removed. (3) Drying and heat curing: The solvent in the membrane is evaporated at room temperature, and then heat curing is performed to stabilize the structure of the desalination layer; (4) Post-irradiation treatment: Post-treatment is carried out by one or a combination of ultraviolet irradiation and electron beam irradiation to regulate the crosslinking degree, pore size and surface properties of the desalination layer, and finally obtain a ceramic composite membrane with efficient desalination function.

[0007] Furthermore, the inorganic ceramic ultrafiltration membrane described in step (1) is made of one or more composites of alumina, zirconium oxide, titanium oxide, silicon oxide, or silicon carbide, with an average pore size of 2 to 50 nm.

[0008] Further, the acid mentioned in step (1) is an inorganic acid, selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and the pH of the aqueous solution is adjusted to 0 to 3.

[0009] Further, the water-soluble additive mentioned in step (1) is one or more of water-soluble polymerizable organic compounds, water-soluble polymer electrolytes, and crosslinking agents, selected from one or more of polyvinyl alcohol (PVA), polyethyleneimine (PEI), polyacrylamide hydrochloride (PAH), sodium polystyrene sulfonate (PSS), and glutaraldehyde (GA), and the total mass of the additive accounts for 0 to 10% of the total mass of the aqueous solution.

[0010] Furthermore, the solvent of the alcohol solution in step (2) is an alcohol solvent that is slightly soluble or insoluble in water, selected from one or more of n-butanol, n-pentanol, isopropanol, and ethanol.

[0011] Further, the metal alkoxide mentioned in step (2) is selected from one or more of silicon-based, titanium-based, aluminum-based, and zirconium-based metal alkoxides, including one or more of tetraethyl orthosilicate (TEOS), aluminum isopropoxide (AIP), titanium tetraisopropoxide (TIP), zirconium n-propoxide (ZIP), vinyltriethoxysilane (A151), vinyltrimethoxysilane (A171), and vinyltri(β-methoxyethoxy)silane (A172), and the mass concentration of the metal alkoxide is 0.05-5%.

[0012] Further, the alcohol-soluble additive mentioned in step (2) is one or more of alcohol-soluble multifunctional polymers, polymer electrolytes, and crosslinking agents, selected from one or more of polyvinyl alcohol (PVA), polyethyleneimine (PEI), polyacrylamide hydrochloride (PAH), sodium polystyrene sulfonate (PSS), and glutaraldehyde (GA), and the total mass of the additive accounts for 0 to 10% of the total mass of the alcohol solution.

[0013] Furthermore, the interfacial polymerization reaction time in step (2) is 10–3600 s.

[0014] Furthermore, in step (3), the heating and curing temperature is 60–250 °C, and the curing time is 0.5–3 h.

[0015] Furthermore, in step (4), the ultraviolet irradiation wavelength is 172–365 nm and the irradiation time is 10–600 s; the electron beam irradiation energy is 10 KeV–1 MeV and the irradiation time is 10–300 s.

[0016] The desalination ceramic composite membrane prepared by this invention has a desalination layer thickness of 10–1000 nm and a molecular weight cutoff of 50–1000 Da. Under the conditions of 25 °C, 0.75 MPa, and 500 ppm MgCl2 solution, the inorganic salt desalination rate can reach 10–99%, and the pure water flux is 0.2–20 LMH·bar.

[0017] The beneficial effects of this invention are: By employing interfacial polymerization technology to construct an ultrathin and dense desalination layer on the surface of a ceramic ultrafiltration membrane, the thickness, pore size, and structural uniformity of the desalination layer can be precisely controlled, solving the technical problem of traditional ceramic membranes being unable to achieve efficient desalination. By using UV / electron beam irradiation post-treatment, the cross-linking degree and structural stability of the desalination layer are enhanced, the pore size distribution and surface hydrophilicity and hydrophobicity are optimized, and the desalination performance and operational stability are significantly improved. The prepared ceramic composite membrane combines the high stability of the inorganic ceramic matrix with the high separation performance of the interfacial polymer desalination layer. It is resistant to acids and alkalis, high temperatures, and pollution, and can operate stably under harsh conditions. The preparation process is mild, reproducible, and easy to scale up, making it suitable for industrial mass production. It can be widely used in seawater desalination, brackish water desalination, deep treatment of industrial wastewater, and ultrapure water preparation. Detailed Implementation

[0018] The following are preferred embodiments of the present invention, used to describe the present invention in detail, but not to limit the present invention. Conventional improvements based on the present invention are all within the scope of protection of the appended claims.

[0019] (1) Selection and pretreatment of base membrane: Select an alumina ceramic ultrafiltration membrane with an average pore size of 15 nm, rinse it repeatedly with deionized water 3 times to remove surface impurities and residual pollutants, and dry it in a 60℃ oven for 2 hours for later use. (2) Preparation and coating of aqueous solution: Prepare hydrochloric acid aqueous solution with pH=1, immerse the pretreated ceramic ultrafiltration membrane in the aqueous solution for 5 minutes to ensure that the membrane surface is fully wetted, remove it and gently absorb the excess aqueous solution on the membrane surface with dust-free filter paper, and let it dry until the surface is semi-dry (i.e. there are no obvious droplets on the membrane surface and it feels slightly damp to the touch). (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% tetraethyl orthosilicate (TEOS), stir evenly and let stand for 10 min to remove air bubbles in the solution; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, control the reaction time to 30 min, and keep the solution temperature stable at 25℃ during the reaction. After the reaction is completed, take out the membrane, tilt it and let the excess alcohol solution on the surface dry naturally. (4) Drying and curing: Place the dried membrane in a room temperature environment to evaporate the solvent for 10 min, then put it in a 100℃ oven to dry for 10 min to remove residual solvent; then transfer the membrane to a muffle furnace, heat it to 200℃, keep it at this temperature for 1 h to cure, and then cool it naturally to room temperature to obtain the control membrane.

[0020] Performance testing: The performance of the control membrane was tested under the following conditions: 25℃, 0.75MPa pressure, 500 ppm MgCl2 aqueous solution, and 15% recovery rate. The test results were: pure water flux 500 LMH·bar, MgCl2 rejection rate 0%. Example 1

[0021] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: same as comparative example; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 254nm deuterium ultraviolet lamp, the irradiation distance was controlled at 5cm, the irradiation time was 60s, and the desalination ceramic composite membrane was obtained after the irradiation was completed.

[0022] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 350 LMH·bar, MgCl2 rejection rate 0%. Example 2

[0023] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 0.5 wt% polyvinyl alcohol (PVA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 254nm xenon ultraviolet lamp, the irradiation distance was controlled at 5cm, and the irradiation time was 120s to obtain a desalination ceramic composite membrane.

[0024] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 60 LMH·bar, MgCl2 rejection rate 20%. Example 3

[0025] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 0.5 wt% polyvinyl alcohol (PVA) and 1 wt% glutaraldehyde (GA), stir until completely dissolved, and adjust the pH of the solution to 1 with hydrochloric acid; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, take it out and drain the excess alcohol solution on the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 172nm deuterium ultraviolet lamp, and the irradiation distance was controlled at 5cm and the irradiation time was 60s to obtain a desalination ceramic composite membrane.

[0026] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 10 LMH·bar, MgCl2 rejection rate 30%. Example 4

[0027] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 2 wt% polyacrylamide hydrochloride (PAH) and 1 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 172nm deuterium ultraviolet lamp, and the irradiation distance was controlled at 5cm and the irradiation time was 60s to obtain a desalination ceramic composite membrane.

[0028] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 35 LMH·bar, MgCl2 rejection rate 55%. Example 5

[0029] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 5 wt% polyacrylamide hydrochloride (PAH) and 1 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane is placed in an electron beam irradiator, and the irradiation energy is controlled at 50 KeV and the irradiation time is 30s to obtain a desalination ceramic composite membrane.

[0030] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 22 LMH·bar, MgCl2 rejection rate 70%. Example 6

[0031] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 2 wt% sodium polystyrene sulfonate (PSS), 2 wt% polyacrylamide hydrochloride (PAH), 1 wt% aluminum isopropoxide (AIP) and 1 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane is placed in an electron beam irradiator, and the irradiation energy is controlled at 10 KeV and the irradiation time is 30s to obtain a desalination ceramic composite membrane.

[0032] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 34 LMH·bar, MgCl2 rejection rate 77%. Example 7

[0033] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 5 wt% polyethyleneimine (PEI) and 2 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 172nm deuterium ultraviolet lamp, and the irradiation distance was controlled at 5cm and the irradiation time was 60s to obtain a desalination ceramic composite membrane.

[0034] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 7.6 LMH·bar, MgCl2 rejection rate 65%. Example 8

[0035] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: Prepare hydrochloric acid aqueous solution with pH=0.5, immerse the pretreated ceramic ultrafiltration membrane in the aqueous solution for 5 minutes, take it out and let it dry until semi-dry; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 2 wt% sodium polystyrene sulfonate (PSS), 3 wt% glutaraldehyde (GA) and 1 wt% vinyltriethoxysilane (A151), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled film is first placed in an electron beam irradiator, the irradiation energy is controlled at 10 KeV and the irradiation time is 30s, and then placed under a 254nm ultraviolet lamp for irradiation for 30s to obtain a desalination ceramic composite film.

[0036] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 3.2 LMH·bar, MgCl2 rejection rate 80%. Example 9

[0037] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: Prepare hydrochloric acid aqueous solution with pH=0.5, immerse the pretreated ceramic ultrafiltration membrane in the aqueous solution for 5 minutes, take it out and let it dry until semi-dry; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare an alcohol solution consisting of 1 wt% aluminum isopropoxide (AIP), 94 wt% n-pentanol, 1 wt% water, 4 wt% glutaraldehyde (GA) and 5 wt% polyvinyl alcohol (PVA), and stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, and then remove and drain the excess alcohol solution on the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 172nm deuterium ultraviolet lamp, and the irradiation distance was controlled at 5cm and the irradiation time was 60s to obtain a desalination ceramic composite membrane.

[0038] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 2.1 LMH·bar, MgCl2 rejection rate 72%. Example 10

[0039] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: Prepare hydrochloric acid aqueous solution with pH=0.5, immerse the pretreated ceramic ultrafiltration membrane in the aqueous solution for 5 minutes, take it out and let it dry until semi-dry; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare an alcohol solution consisting of 1 wt% zirconium propoxide (ZIP), 94 wt% n-pentanol, 1 wt% water, 4 wt% glutaraldehyde (GA) and 5 wt% polyacrylamine hydrochloride (PAH), and stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution and react for 30 min, then remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane is placed in an electron beam irradiator, and the irradiation energy is controlled at 50 KeV and the irradiation time is 30s to obtain a desalination ceramic composite membrane.

[0040] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 1.5 LMH·bar, MgCl2 rejection rate 92%. Example 11

[0041] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: same as comparative example; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 5 wt% polyethyleneimine (PEI), 5 wt% tetraisopropoxide titanium (TIP), 1 wt% vinyltrimethoxysilane (A171) and 1 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse the semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane was placed under a 172nm deuterium ultraviolet lamp, and the irradiation distance was controlled at 5cm and the irradiation time was 60s to obtain a desalination ceramic composite membrane.

[0042] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 0.4 LMH·bar, MgCl2 rejection rate 99%. Example 12

[0043] The preparation steps in this embodiment are as follows: (1) Selection and pretreatment of base film: same as comparative example; (2) Preparation and coating of aqueous solution: Prepare hydrochloric acid aqueous solution with pH=0, immerse the pretreated ceramic ultrafiltration membrane in the aqueous solution for 5 minutes, take it out and let it dry until semi-dry; (3) Preparation of alcohol phase solution and interfacial polymerization: Prepare a n-butanol solution containing 5 wt% TEOS, add 5 wt% polyacrylamide hydrochloride (PAH), 5 wt% sodium polystyrene sulfonate (PSS), 1 wt% vinyltris(β-methoxyethoxy)silane (A172) and 1 wt% glutaraldehyde (GA), stir until completely dissolved and mixed evenly; immerse a semi-dry ceramic ultrafiltration membrane in the alcohol solution, react for 30 min, remove and drain excess alcohol solution from the surface; (4) Drying and curing: Same as comparative example; (5) Post-irradiation treatment: The cured and cooled membrane is placed in an electron beam irradiator, and the irradiation energy is controlled at 1MeV and the irradiation time is 30s to obtain a desalination ceramic composite membrane.

[0044] Performance testing: Under the same test conditions as the comparative example, the performance test results of the composite membrane are as follows: pure water flux 7.2 LMH·bar, MgCl2 rejection rate 90%.

[0045] The abbreviations and their corresponding full names used in this article are as follows: PVA: polyvinyl alcohol, PEI: polyethyleneimine, GA: glutaraldehyde, PSS: sodium polystyrene sulfonate, PAH: polyacrylamide hydrochloride, TEOS: tetraethyl orthosilicate, AIP: aluminum isopropoxide, TIP: tetraisopropoxide titanium, ZIP: zirconium propoxide, A151: vinyltriethoxysilane, A171: vinyltrimethoxysilane, A172: vinyltri(β-methoxyethoxy)silane.

[0046] The above embodiments are merely some examples of the present invention and are not intended to limit the implementation. Those skilled in the art will recognize many other variations or modifications that can be made based on this invention. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing desalination ceramic composite membranes via interfacial polymerization, characterized in that, Includes the following steps: (1) Base membrane pretreatment and aqueous phase coating: The inorganic ceramic ultrafiltration membrane is uniformly coated with an aqueous solution containing acid and water-soluble additives and dried until semi-dry; (2) Interfacial polymerization reaction: reacting with an alcohol solution containing metal alkoxides and alcohol-soluble additives to remove excess alcohol solution; (3) Drying and heat curing: After volatilization at room temperature, heat curing is performed; (4) Post-irradiation treatment: The desalination ceramic composite membrane is obtained by one or a combination of ultraviolet irradiation and electron beam irradiation.

2. The method according to claim 1, characterized in that, The inorganic ceramic ultrafiltration membrane described in step (1) has an average pore size of 2 to 50 nm and is made of one or more of alumina, zirconium oxide, titanium oxide, silicon oxide, and silicon carbide.

3. The method according to claim 1, characterized in that, The acid mentioned in step (1) is one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and the pH value of the aqueous solution is 0 to 3; the water-soluble additive is selected from one or more of polyvinyl alcohol, polyethyleneimine, polyacrylamide hydrochloride, sodium polystyrene sulfonate, and glutaraldehyde, and the mass content is 0 to 10%.

4. The method according to claim 1, characterized in that, The solvent of the alcohol solution in step (2) is one or more of n-butanol, n-pentanol, isopropanol, and ethanol; the metal alkoxide is selected from one or more of tetraethyl orthosilicate, aluminum isopropoxide, titanium tetraisopropoxide, zirconium n-propoxide, vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane, with a mass concentration of 0.05-5%.

5. The method according to claim 1, characterized in that, The alcohol-soluble additive in step (2) is selected from one or more of polyvinyl alcohol, polyethyleneimine, polyacrylamide hydrochloride, sodium polystyrene sulfonate, and glutaraldehyde, with a mass content of 0-10%; the interfacial polymerization reaction time is 10-3600 s.

6. The method according to claim 1, characterized in that, In step (3), the heating and curing temperature is 60-250 ℃ and the curing time is 0.5-3 h.

7. The method according to claim 1, characterized in that, In step (4), the ultraviolet irradiation wavelength is 172–365 nm and the irradiation time is 10–600 s; the electron beam irradiation energy is 10 KeV–1 MeV and the irradiation time is 10–300 s.

8. The desalination ceramic composite membrane prepared according to any one of claims 1-7, characterized in that, The desalination layer thickness is 10–1000 nm, the molecular weight cutoff is 50–1000 Da, and the inorganic salt desalination rate is 10–99% under the conditions of 25 ℃, 0.75 MPa, and 500 ppm MgCl2, with a pure water flux of 0.2–20 LMH·bar.