Preparation method of Janus type organic porous material coated PPS oil-water separation composite membrane

Abstract

The application discloses a preparation method of a Janus type organic porous material coated PPS oil-water separation composite membrane, adopts high-performance material PPS as a carrier, first hydrolyzes the PPS microporous membrane by using a nitric acid aqueous solution, then grows the organic porous material on the surface of the hydrolyzed PPS microporous membrane in situ by a high-temperature hydrothermal method, and finally obtains the Janus type organic porous material coated PPS oil-water separation composite membrane with the top layer being super-hydrophilic and the bottom layer being super-hydrophobic by adopting an oil-water interface grafting method. The PPS microporous membrane is hydrolyzed by using the nitric acid aqueous solution, the thioether bond is oxidized into a sulfoxide bond, so that the surface of the PPS microporous membrane is negatively charged. The amino-organic porous material is grown on the surface of the PPS microporous membrane in situ by adopting the high-temperature hydrothermal method, the roughness of the membrane is improved, and the PPS membrane is endowed with super-hydrophilicity and instantaneous super-wetting behavior. The hydrophobic alkyl chain is subjected to amidation reaction with the organic porous material of the bottom layer of the membrane by adopting the oil-water interface grafting method, so that the bottom layer of the membrane is endowed with super-hydrophobicity.

Description

Technical Field

[0001] This invention belongs to the field of oil-water separation membrane preparation, specifically a method for preparing a Janus-type organic porous material-coated PPS oil-water separation composite membrane. Background Technology

[0002] With societal development, the demand for energy has increased dramatically. However, frequent industrial chemical spills, oil spills, and the discharge of oily wastewater have caused significant pollution to the global ecological environment. Therefore, the development of efficient oil-water separation processes for treating oily wastewater is urgently needed.

[0003] Oil-water mixtures can be classified into three main categories: simple oil-water mixtures, stable emulsions containing surfactants, and unstable emulsions without surfactants. Emulsions can be further classified into oil-in-water and water-in-oil types. Traditional oil-water separation technologies mainly include centrifugation, adsorption, skimming, chemical coagulation, and flotation. Membrane separation technology offers advantages such as high separation precision, low cost, simple operation, and environmental friendliness in the field of oil-water separation. It avoids the problems of low separation efficiency, high energy consumption, and serious secondary pollution associated with traditional oil-water separation technologies, and has shown significant advantages, particularly in the separation of oil-water emulsions.

[0004] Polymer membranes typically suffer from defects such as short lifespan, poor stability, and low selectivity, necessitating the use of suitable inorganic-organic hybrid porous crystalline materials to compensate for these shortcomings. Porous materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have attracted widespread attention in recent years due to their ability to meet the requirements for pore size and structure in separation.

[0005] Currently, the loading methods for MOFs and COFs materials mainly focus on deposition, adhesive bonding, blending, and low-temperature hydrothermal methods. Among these, composites prepared by deposition suffer from poor adhesion between MOFs and the substrate. The use of commonly used adhesives such as dopamine or polyethyleneimine increases preparation costs. Blending methods embed MOFs within the matrix, significantly limiting the loading capacity. MOF polymer films prepared by low-temperature hydrothermal methods exhibit low crystallinity, making it difficult to form a continuous and dense MOF layer. The resulting MOF layer has weak interaction with the substrate and is prone to detachment.

[0006] Common polymer materials cannot withstand high temperatures, limiting hydrothermal reactions to relatively low temperatures (typically below 100°C). However, achieving higher crystallinity requires even higher hydrothermal temperatures. Polyphenylene sulfide (PPS) exhibits excellent chemical resistance and thermal stability, allowing hydrothermal reactions to proceed at higher temperatures. This enables the in-situ generation of MOF nanoparticles with higher crystallinity on the PPS membrane surface. Therefore, PPS microporous membranes are an ideal substrate for preparing oil-water separation membrane materials. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a method for preparing a Janus-type organic porous material-coated PPS oil-water separation composite membrane.

[0008] The technical solution of this invention to solve the aforementioned technical problem is to provide a method for preparing a Janus-type organic porous material-coated PPS oil-water separation composite membrane, characterized in that the method includes the following steps:

[0009] (1) Prepare an organic porous material precursor solution; the organic porous material includes COFs and MOFs;

[0010] Hydrolyzed PPS microporous membrane: The PPS microporous membrane is immersed in a nitric acid aqueous solution for hydrolysis, and the sulfide bonds are oxidized into sulfoxide bonds, so that the surface of the PPS microporous membrane is negatively charged, and the hydrolyzed PPS microporous membrane is obtained.

[0011] (2) Hydrothermal in-situ generation of organic porous material @PPS composite membrane: The hydrolyzed PPS microporous membrane is immersed in a sufficient or excessive amount of organic porous material precursor solution for hydrothermal reaction, and organic porous material is grown on the membrane surface; after the reaction is completed, the membrane is washed to remove the organic porous material that has not grown on the membrane surface, and after drying, the organic porous material @PPS composite membrane is obtained.

[0012] (3) Preparation of Janus-type organic porous material @PPS oil-water separation composite membrane: First, prepare an oil phase solution, then pour water into the oil phase solution, and let it stand to obtain a stable oil-water interface with water on the upper layer and oil phase solution on the lower layer; then place the organic porous material @PPS composite membrane at the oil-water interface for amidation reaction, then wash to remove the residual water and oil phase solution on the membrane surface, and after drying, obtain Janus-type organic porous material @PPS oil-water separation composite membrane with superhydrophilic top layer and superhydrophobic bottom layer.

[0013] Compared with the prior art, the beneficial effects of the present invention are: in-situ growth of organic porous materials

[0014] (1) This invention uses PPS, a high-performance material that is resistant to acid and alkali corrosion, solvents, and high temperatures, as a carrier. Without damaging the mechanical properties of the PPS microporous membrane, the PPS microporous membrane is first hydrolyzed with nitric acid aqueous solution. Then, organic porous material is grown in situ on the surface of the hydrolyzed PPS microporous membrane by high-temperature hydrothermal method. Finally, the membrane bottom layer is given superhydrophobicity by oil-water interface grafting method, and a PPS oil-water separation composite membrane coated with Janus-type organic porous material with a superhydrophilic top layer and a superhydrophobic bottom layer is obtained.

[0015] (2) In this invention, PPS microporous membranes are hydrolyzed using nitric acid aqueous solution to oxidize sulfide bonds into sulfoxide bonds, making the surface of PPS microporous membranes negatively charged and providing chemical bonding sites. In subsequent reactions, positively charged MOF metal sources and COF monomers can be captured on the surface of the hydrolyzed PPS microporous membranes through electrostatic attraction. Combined with the dendritic pore structure, high porosity and specific surface area of ​​PPS membranes, abundant growth sites are provided for organic porous materials, realizing in-situ growth of organic porous materials and improving the bonding force between MOFs and the membrane substrate.

[0016] (3) The present invention uses a high-temperature hydrothermal method to grow aminated organic porous materials in situ on the surface of PPS microporous membrane, which improves the roughness of the membrane and endows the PPS membrane with superhydrophilicity and instantaneous superwetting behavior, so that water droplets can completely penetrate into the membrane in only 0.6 to 4.6 seconds. A surface with high loading capacity, large specific surface area, high porosity, strong bonding and controllable morphology is obtained without the use of adhesives, which effectively improves the oil-water separation performance of PPS-based materials.

[0017] (4) This invention utilizes an oil-water interface grafting method to enable the hydrophobic alkyl chains to undergo an amidation reaction with the organic porous material at the membrane bottom layer, constructing a superhydrophobic layer at the membrane bottom layer and imparting superhydrophobicity to the membrane bottom layer. This achieves effective control over the surface wettability of the membrane material, resulting in a Janus-type organic porous material-coated PPS oil-water separation composite membrane. Simultaneously, it achieves precise design of the superhydrophilic membrane, enabling it to efficiently separate different types of oil-in-water and water-in-oil mixtures and emulsions.

[0018] (5) The porous material of the top layer of the oil-water separation composite membrane obtained in this invention contains a large number of amino, carboxyl, and hydroxyl groups, which makes water molecules more inclined to form hydrogen bonds with the functional groups of the porous material layer structure of the top layer of the membrane, thereby constructing a stable water layer on the top layer of the membrane to prevent oil droplet contact, and the pores in the porous material provide more water flow channels. At the same time, the bottom layer of the oil-water separation composite membrane is superhydrophobic, which allows oil, as the continuous phase, to quickly wet the surface of the membrane and pass through the membrane. Due to the low water adhesion, its flux can be completely recovered after simple cleaning. Since the membrane surface after the amidation reaction forms partial cavities, after being wetted by oil, the cavities are filled with tiny oil droplets. The resulting composite interface prevents water droplet intrusion, resulting in extremely high separation efficiency for oil-in-water mixtures and promising application prospects for the efficient treatment of various industrial wastewaters.

[0019] (6) This invention has low energy consumption, simple preparation process, mild and controllable reaction conditions, short preparation process, convenient operation and green environmental protection. Attached Figure Description

[0020] Figure 1 This is a SEM image of the PPS microporous membrane used in Example 2 of the present invention;

[0021] Figure 2 This is a SEM image of the hydrolyzed PPS microporous membrane prepared in Example 2 of the present invention;

[0022] Figure 3 This is a SEM image of the organic porous material@PPS composite membrane prepared in Example 2 of the present invention;

[0023] Figure 4 This is a SEM image of the oil-water separation composite membrane prepared in Example 2 of the present invention;

[0024] Figure 5 The FTIR spectra of the PPS microporous membrane prepared in Example 2 of this invention, the hydrolyzed PPS microporous membrane, the organic porous material@PPS composite membrane, and the oil-water separation composite membrane are shown.

[0025] Figure 6 The XRD patterns of the PPS microporous membrane, organic porous material@PPS composite membrane, and oil-water separation composite membrane prepared in Example 2 of the present invention are shown.

[0026] Figure 7 Dynamic water contact angle test diagrams of the hydrolyzed PPS microporous membrane, organic porous material@PPS composite membrane, and oil-water separation composite membrane prepared in Example 2 of the present invention;

[0027] Figure 8 This is a test diagram of the underwater oil and water separation composite membrane prepared in Example 2 of the present invention for its anti-oil and anti-fouling performance.

[0028] Figure 9 This is a test diagram of the underwater water resistance and antifouling performance of the oil-water separation composite membrane prepared in Example 2 of the present invention;

[0029] Figure 10 The image shows the test results of the oil-water separation composite membrane prepared in Example 2 of this invention for oil-in-water emulsions and oil-in-water mixtures.

[0030] Figure 11 The image shows the test results of the oil-water separation composite membrane prepared in Example 2 of this invention for separating water-in-oil emulsions and water-in-oil mixtures.

[0031] Figure 12 The graph shows the number of cycles of the oil-water separation composite membrane prepared in Example 2 of this invention for an oil-in-water emulsion and an oil-in-water mixture with toluene as the oil phase.

[0032] Figure 13 This is a test chart showing the number of cycles of the oil-water separation composite membrane prepared in Example 2 of the present invention for water-in-oil emulsions and water-in-oil mixtures with toluene as the oil phase. Detailed Implementation

[0033] Specific embodiments of the present invention are given below. These specific embodiments are only used to further illustrate the present invention in detail and do not limit the scope of protection of the claims of the present invention.

[0034] This invention provides a method for preparing a Janus-type organic porous material-coated PPS oil-water separation composite membrane (hereinafter referred to as the method), characterized in that the method includes the following steps:

[0035] (1) Prepare an organic porous material precursor solution; the organic porous material includes COFs and MOFs;

[0036] Hydrolyzed PPS microporous membrane: PPS microporous membrane is immersed in nitric acid aqueous solution at room temperature for hydrolysis, oxidizing the sulfide bond to sulfoxide bond, making the surface of PPS microporous membrane negatively charged, and obtaining the hydrolyzed PPS microporous membrane (named h-PPS).

[0037] Preferably, in step (1), the preparation of the organic porous material precursor solution specifically involves mixing and stirring substance A, substance B, and solution C at room temperature until homogeneous to obtain the organic porous material precursor solution.

[0038] The substance A is zirconium tetrachloride, zirconium n-propoxide, zirconium disulfide, zirconium oxychloride octahydrate, chromium nitrate nonahydrate, tetrabutyl titanate, aluminum nitrate nonahydrate, zinc acetate dihydrate, tris(4-formylphenyl)amine, 2,5-dihydroxyphenylbenzenealdehyde, or trialdehyde-based phloroglucinol (preferably zirconium tetrachloride).

[0039] The substance B is diaminoterephthalic acid, p-phenylenediamine, 1,3,5-tris(4-aminophenyl)benzene or melamine (preferably diaminoterephthalic acid);

[0040] The solution C is at least one of N,N-dimethylformamide, deionized water, acetic acid, methanol, 1,4-dioxane, mesitylene, dimethyl sulfoxide, or N,N-dimethylacetamide.

[0041] Preferably, in step (1), the concentration of substance A is 1-50 g / L (preferably 5-20 g / L) and the concentration of substance B is 1-50 g / L (preferably 5-20 g / L); the molar ratio of substance A, substance B and solution C is 1-9:1-9:20-620 (preferably 1-5:1-5:30-560).

[0042] Preferably, in step (1), in the process of hydrolyzing the PPS microporous membrane, the PPS microporous membrane is first wetted in an alcohol compound at room temperature (preferably at least 5 minutes) so that the alcohol penetrates into the pores of the PPS microporous membrane, increasing the membrane weight and enhancing the affinity between the hydrophobic membrane and the aqueous solution, thereby enabling the membrane to be immersed in the aqueous solution instead of floating on the surface of the aqueous solution; then, it is washed with deionized water to remove the alcohol from the membrane surface and pores, and then immersed in a nitric acid aqueous solution for hydrolysis. At this time, the PPS microporous membrane can be immersed in the nitric acid aqueous solution instead of floating on the surface of the nitric acid aqueous solution, which is more conducive to hydrolysis, and the hydrolyzed PPS microporous membrane is obtained; the alcohol compound is a low molecular weight monohydric alcohol, preferably methanol or ethanol.

[0043] Preferably, in step (1), the concentration of the nitric acid aqueous solution in the hydrolysis process is 5-55 wt.% (preferably 10-50 wt.%), the impregnation temperature is 10-60℃ (preferably 20-50℃), and the impregnation time is 0.5-48h (preferably 0.5-24h).

[0044] (2) Hydrothermal in-situ generation of organic porous material@PPS composite membrane: The hydrolyzed PPS microporous membrane is immersed in a sufficient or excessive amount of organic porous material precursor solution for hydrothermal reaction, and organic porous material is grown on the membrane surface; after the reaction is completed, it is washed to remove the organic porous material that has not grown on the membrane surface (i.e., substances A, B and solution C that did not participate in the reaction), and dried to constant weight to obtain organic porous material@PPS composite membrane (i.e. PPS composite membrane coated with organic porous material);

[0045] Preferably, in step (2), each square centimeter of hydrolyzed PPS microporous membrane is added to 0.01 to 1 mL of organic porous material precursor solution.

[0046] Preferably, in step (2), the hydrothermal reaction is carried out in a hydrothermal reactor.

[0047] Preferably, in step (2), the hydrothermal reaction time is 2 to 96 hours (preferably 2 to 72 hours, more preferably 24 to 72 hours), and the reaction temperature is 60 to 240°C (preferably 80 to 160°C, more preferably 120 to 150°C).

[0048] Preferably, in step (2), the hydrothermal reaction time is 24 to 72 hours for COFs and 24 to 28 hours for MOFs.

[0049] Preferably, in step (2), after washing to remove the organic porous material that has not grown on the membrane surface, the membrane is then soaked in ethanol and dried to remove the ethanol, thus obtaining an organic porous material@PPS composite membrane.

[0050] Preferably, in step (2), solution D is used to wash away organic porous materials that have not grown on the membrane surface; the solution D is N,N-dimethylformamide, ethanol, deionized water or N,N-dimethylacetamide.

[0051] Preferably, in step (2), the drying temperature is 60-120°C and the time is 8-24 hours.

[0052] (3) Preparation of Janus-type organic porous material@PPS oil-water separation composite membrane: First, prepare an oil phase solution, then pour water into the oil phase solution, and let it stand to obtain a stable oil-water interface with water on the upper layer and oil phase solution on the lower layer; then place the organic porous material@PPS composite membrane at the oil-water interface for amidation reaction, then wash to remove residual water and oil phase solution on the membrane surface, and then dry to remove residual dichloromethane or trichloromethane on the membrane surface until constant weight is obtained, resulting in a Janus-type organic porous material@PPS oil-water separation composite membrane with a superhydrophilic top layer and a superhydrophobic bottom layer (i.e., PPS oil-water separation composite membrane coated with Janus-type organic porous material, abbreviated as oil-water separation composite membrane).

[0053] Preferably, in step (3), the oil phase solution is a dichloromethane or trichloromethane solution of triethylamine and alkyl acyl chloride, which is prepared by ultrasonic dispersion of triethylamine and alkyl acyl chloride in dichloromethane or trichloromethane; the concentration of triethylamine is 5-60 g / L (preferably 10-40 g / L), the concentration of alkyl acyl chloride is 10-120 g / L (preferably 20-90 g / L); and the molar ratio of triethylamine, alkyl acyl chloride and dichloromethane is 1-8:1-16:10-120 (preferably 1-4:1-8:20-80).

[0054] Preferably, in step (3), the alkyl acyl chloride is lauroyl chloride (i.e., dodecyl chloride), palmitoyl chloride (i.e., hexadecyl chloride), stearoyl chloride (i.e., octadecyl chloride) or behenyl chloride (i.e., docosyl chloride) (preferably palmitoyl chloride).

[0055] Preferably, in step (3), the amidation reaction time is 5 min to 2 h (preferably 20 min to 1 h, more preferably 0.5 h), and the temperature is room temperature.

[0056] Preferably, in step (3), solution E is used to clean and remove residual water and oil phase solution from the membrane surface; solution E is dichloromethane or trichloromethane.

[0057] Preferably, in step (3), the drying is performed by placing the product in a vacuum drying oven at 60–200°C for at least 5 minutes.

[0058] This invention provides an application of Janus-type organic porous material@PPS oil-water separation composite membrane, characterized in that the Janus-type organic porous material@PPS oil-water separation composite membrane is applied to the separation of oil-water mixtures.

[0059] The testing method in the embodiment is as follows:

[0060] Water contact angle test method: All samples were placed in a vacuum oven and dried at 35℃ for 6 hours. After complete drying, they were cut into strips of 50mm × 10mm. The contact angle was then measured using a contact angle meter. A 3μL water droplet was placed on the surface of the membrane using a dropper, and the change in the contact process between the membrane surface and the water droplet was observed. The contact angle at this point, after the water droplet stabilized, was recorded as the air-water contact angle. The in-air water contact angle (CA) was measured by dropping a 3μL oil droplet onto the surface of the membrane using a dropper, recording the change in the contact process between the oil droplet and the membrane surface, and the contact angle at which it stabilized. The under-oil water contact angle (CA) was measured by immersing the membrane in the oil phase, and after thorough wetting, dropping a 3μL water droplet onto its surface using a dropper, recording the contact angle at which the water droplet stabilized. Measurements were taken at 3–5 different locations for each sample, and the average value was recorded.

[0061] Porosity testing method: The gravimetric method is used. After soaking the sample membrane in deionized water for 24 hours, the surface moisture of the sample membrane is absorbed and it is weighed (m1). After the sample membrane is thoroughly dried, it is weighed again (m2). The porosity is then calculated using the formula... Its porosity (P) was tested. A, l, and ρ represent the area, thickness, and density of the sample membrane, respectively.

[0062] Pure water flux testing method: Place the sample membrane on a sand core filter device and test at a pressure of 0.2 MPa. Pure water flux (J) w ) through formula Calculation. V is the filtrate volume, A is the effective filtration area, and Δt is the separation time.

[0063] Equipment for testing the separation efficiency of oil-in-water mixtures: Total Organic Carbon (TOC) analyzer. Test method: A certain amount of the oil-in-water mixture is injected into the TOC analyzer. The data read by the instrument is the organic carbon content in the oil-in-water mixture. J = (T1 - T2) / T1; J is the separation efficiency, T1 is the organic carbon content (ppm) of the oil-in-water mixture before separation, and T2 is the organic carbon content of the oil-in-water mixture after separation.

[0064] Test equipment for the separation efficiency of water-in-oil mixtures: Karl Fischer micro moisture analyzer. Test method: 50 μL of the water-in-oil mixture is injected into the Karl Fischer micro moisture analyzer. The data read by the instrument is the moisture content of the water-in-oil mixture. Q = (Q1 - Q2) / Q1; Q is the separation efficiency, Q1 is the moisture content (ppm) of the water-in-oil mixture before separation, and Q2 is the moisture content of the water-in-oil mixture after separation.

[0065] In the examples, the emulsion contains a surfactant, while the mixture does not.

[0066] Example 1

[0067] (1) Zirconium oxychloride octahydrate, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0068] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0069] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain UiO-66-NH2@PPS composite membrane.

[0070] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride (PC), and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then placed in a vacuum drying oven at 60 °C for 24 h to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0071] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 2.5 seconds to completely wet a water droplet, while the WCAs (water contact angle) value of its hydrophobic bottom layer is 139.2°.

[0072] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 96.36% and 95.61%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 96.07% and 95.28%, respectively.

[0073] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 5924.5 L / (m³). 2 h·bar) and 7033.74L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3368.17 L / (m²). 2 h·bar) and 2172.14L / (m 2 h·bar).

[0074] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 36.25%.

[0075] Example 2

[0076] (1) Zirconium tetrachloride, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0077] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0078] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0079] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 60 °C for 24 h to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0080] Depend on Figure 1 It can be seen that the PPS microporous membrane exhibits a multi-level dendritic pore structure.

[0081] Depend on Figure 2It can be seen that the surface of the hydrolyzed PPS microporous membrane is as smooth as that of the PPS microporous membrane, indicating that the microstructure of the membrane was not significantly damaged after nitric acid treatment.

[0082] Depend on Figure 3 It can be seen that the surface of the UiO-66-NH2@PPS composite membrane exhibits an uneven and rough structure, and it is obvious that a large number of UiO-66-NH2 nanocrystals have been uniformly grown on the surface of the membrane, indicating that UiO-66-NH2 has been successfully generated on the surface of the membrane.

[0083] Depend on Figure 4 It can be seen that the surface of the UiO-66-NH2-PC@PPS oil-water separation composite membrane is uniformly covered with a rough coating, which indicates that palmitoyl chloride has been successfully grafted onto the membrane.

[0084] Depend on Figure 5 It can be seen that 3492cm -1 and 3377cm -1 The absorption peak at 1570 cm⁻¹ corresponds to the asymmetric and symmetric stretching vibrations of the NH bond. -1 and 1241cm -1 The absorption peak observed at [location] is attributed to the stretching vibrations of CO and CN in 2-aminoterephthalic acid, confirming the successful growth of UiO-66-NH2 on the membrane surface. PC was introduced onto the surface of the UiO-66-NH2@PPS composite membrane, and the absorption peak at 2930 cm⁻¹ was [value missing]. -1 and 2860cm -1 The new absorption peak appearing at 1033 cm⁻¹ is attributed to the CH stretching vibration of the added PC. -1 The new absorption peaks appearing at the point are attributed to the C-C stretching vibration of PC; the appearance of these three absorption peaks confirms the existence of the amidation reaction and proves that UiO-66-NH2-PC has been successfully generated on the surface of the membrane.

[0085] Depend on Figure 6 It can be seen that the intensity of the PPS characteristic peaks weakens with the formation of UiO-66-NH2 on the surface. 7.3°, 8.4°, and 25.7° correspond to the (111), (200), and (600) crystal planes of UiO-66-NH2, respectively. After palmitoyl chloride modification, the XRD pattern of the UiO-66-NH2-PC@PPS oil-water separation composite membrane remains unchanged, confirming that the crystal structure of UiO-66-NH2 remains unchanged.

[0086] Depend on Figure 7It can be seen that water droplets on the surface of the hydrolyzed PPS microporous membrane require 6 seconds to completely penetrate into the membrane, and its water contact angle (WCAs) drops to 0° within 6 seconds. Water droplets on the surface of the UiO-66-NH2@PPS composite membrane penetrate instantly, and the water contact angle drops to 0° within 0.6 seconds, only 1 / 10 of the time required for the hydrolyzed PPS microporous membrane, exhibiting instantaneous superhydrophilicity. The hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 0.6 seconds for water droplets to be completely wetted, while its hydrophobic bottom layer has a WCA value of 149.7°. The initial WCAs of the UiO-66-NH2-PC@PPS oil-water separation composite membrane are close to 150°, exhibiting superhydrophobicity.

[0087] Depend on Figure 8 It can be seen that loading UiO-66-NH2-PC onto the surface of the hydrolyzed PPS microporous membrane endows the top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane with superhydrophilic properties. The top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane has very low adhesion to oil stains, and no oil stains were found adhering to its surface. Therefore, the UiO-66-NH2-PC@PPS oil-water separation composite membrane has excellent anti-oil contamination performance.

[0088] Depend on Figure 9 It can be seen that loading UiO-66-NH2-PC onto the surface of the hydrolyzed PPS microporous membrane endows the bottom layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane with superhydrophobic properties. The bottom layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane has very low adhesion to water contaminants, and no water contaminants were found adhering to its surface. Therefore, the UiO-66-NH2-PC@PPS oil-water separation composite membrane has excellent anti-water pollution performance.

[0089] Depend on Figure 8 and Figure 9 It can be seen that the UiO-66-NH2-PC@PPS oil-water separation composite membrane has excellent antifouling properties.

[0090] Figures 10-11 Five oil phases were selected, with H, P, T, D, and C being n-hexane, petroleum ether, toluene, dichloromethane, and carbon tetrachloride, respectively.

[0091] Depend on Figure 10 It can be seen that the separation efficiency of the oil-in-water emulsion is above 98.17%, and the separation efficiency of the mixture is above 98.22%. Using dead-end filtration, the highest flux for the oil-in-water emulsion at 1 bar pressure can reach 4468.25 L / (m³). 2 The highest flux for the mixture (h·bar) can reach 7024.47 L / (m³). 2(h·bar). For oil-in-water emulsions and mixtures, the oil content after filtration is less than 181 ppm, demonstrating excellent oil-water separation performance.

[0092] Depend on Figure 11 It can be seen that the separation efficiency of the water-in-oil emulsion is above 98.09%, and the separation efficiency of the mixture is above 98.3%. Using dead-end filtration, the highest flux for the water-in-oil emulsion at 1 bar pressure can reach 3521.81 L / (m³). 2 The highest flux for the mixture (h·bar) can reach 8437.29 L / (m³). 2 (h·bar). For water-in-oil emulsions and mixtures, the oil content after filtration is less than 213 ppm, demonstrating excellent oil-water separation performance.

[0093] Depend on Figure 10 and Figure 11 As can be seen from the water flow pressure test, with water flow recorded every 10 minutes at 2 bar pressure for 150 minutes, the flux decreased by 20.17%, indicating that the in-situ grown UiO-66-NH2 was relatively firm and not easily detached.

[0094] Figures 12-13 In this process, toluene was selected as the oil phase, and the membrane surface was thoroughly cleaned with anhydrous ethanol and dried after each cycle.

[0095] Depend on Figure 12 It can be seen that after 10 cycles of the UiO-66-NH2-PC@PPS oil-water separation composite membrane, the flux change of the top layer of the membrane for the mixed liquid is less than ±3.00%; after 10 cycles of the membrane for the emulsion, the flux change is less than ±3.52%; and the separation efficiency of the top layer of the oil-water separation composite membrane for both the mixed liquid and the emulsion remains above 98.50% after 10 cycles of the membrane.

[0096] Depend on Figure 13 It can be seen that the flux change of the bottom layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane for the mixed liquid after 10 cycles of testing is less than ±2.90%; the flux change of the bottom layer for the emulsion after 10 cycles of testing is less than ±4.12%; and the separation efficiency of the bottom layer of the oil-water separation composite membrane for both the mixed liquid and the emulsion after 10 cycles of testing remains above 98.42%.

[0097] Depend on Figure 12 and Figure 13It can be seen that the UiO-66-NH2-PC@PPS oil-water separation composite membrane maintained a separation efficiency of over 98% for both the mixture and the emulsion after 10 cycles of cycling tests. Throughout the 10 cycles, both the separation efficiency and flux remained relatively stable, fully demonstrating the excellent cycling performance of the prepared UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0098] Comparative Example 1

[0099] (1) Prepare the organic porous material precursor solution in the same way as in Example 2; the PPS microporous membrane is not treated.

[0100] (2) Same as Example 2;

[0101] (3) Same as Example 2.

[0102] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane can be completely wetted by water droplets in just 3.4s, while the WCAs of its hydrophobic bottom layer is 135.35°.

[0103] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 95.37% and 94.52%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 94.48% and 92.73%, respectively.

[0104] Under gravity conditions, the highest fluxes for oil-in-water and water-in-oil mixtures reached 5986.27 L / (m³). 2 h·bar) and 6141.15L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 2527.54 L / (m²). 2 h·bar) and 2614.29L / (m 2 h·bar).

[0105] After a water flow pressure test, with water flow recorded every 10 minutes at 2 bar for 150 minutes, the flux decreased by 68.68%. A significant amount of UIO-66-NH2 from the load detached, causing pore blockage and rendering the material unusable.

[0106] Comparative Example 2

[0107] (1) Zirconium tetrachloride, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0108] (2) 50 mL of UiO-66-NH2 precursor solution was transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The solution was washed by centrifugation with N,N-dimethylformamide and ethanol, and then dried in an oven at 120 °C for 24 h to obtain UiO-66-NH2.

[0109] (3) The UiO-66-NH2 obtained in step 2) was added to the casting solution at a mass fraction of 5% to prepare a UiO-66-NH2@PPS composite membrane. Then, it was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Then, it was placed in a vacuum drying oven at 60°C for 24 h to obtain a UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0110] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane can be completely wetted by water droplets in just 2.9s, while the WCAs of its hydrophobic bottom layer is 121.37°.

[0111] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 96.42% and 90.26%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 94.38% and 90.54%, respectively.

[0112] Under gravity conditions, the highest fluxes for oil-in-water and water-in-oil mixtures reached 6648.31 L / (m³). 2 h·bar) and 4158.73L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3394.54 L / (m²). 2 h·bar) and 1755.81L / (m 2 h·bar).

[0113] Water flow and pressure tests were conducted, with water flow recorded every 10 minutes at 2 bar for 150 minutes. The flux decreased by 7.36%. The loaded UiO-66-NH2 was robust, but mostly embedded in the membrane. The hydrophobic sublayer of the membrane had a low grafting rate of palmitoyl chloride, resulting in poor separation efficiency for water-in-oil emulsions and water-in-oil mixtures.

[0114] Example 3

[0115] (1) Zirconium propoxide, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0116] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0117] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0118] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then placed in a vacuum drying oven at 120°C for 24 h to obtain Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0119] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 1.9s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 141.1°.

[0120] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 97.15% and 97.48%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 96.17% and 95.09%, respectively.

[0121] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6226.35 L / (m³). 2 h·bar) and 7350.7L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3455.28 L / (m²). 2 h·bar) and 2787.81L / (m 2 h·bar).

[0122] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 35.46%.

[0123] Example 4

[0124] (1) Layered zirconium disulfide (ZrS2), diaminoterephthalic acid, N,N-dimethylformamide and acetic acid were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid, DMF and acetic acid in UiO-66-NH2 precursor solution was 2:1:500:100;

[0125] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0126] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0127] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 1 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 120°C for 24 h to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0128] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 1.3s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 145.52°.

[0129] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.05% and 97.94%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.04% and 97.83%, respectively.

[0130] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6848.33 L / (m³). 2 h·bar) and 7314.91L / (m 2The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3982.58 L / (m²). 2 h·bar) and 3019.52L / (m 2 h·bar).

[0131] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 28.37%.

[0132] Example 5

[0133] (1) Zirconium tetrachloride, diaminoterephthalic acid, N,N-dimethylformamide and acetic acid were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid, DMF and acetic acid in UiO-66-NH2 precursor solution was 2:1:400:30;

[0134] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0135] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0136] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 2 hours. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 60°C for 24 hours to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0137] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 1 second to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 147.24°.

[0138] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.1% and 98.24%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.05% and 98.13%, respectively.

[0139] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6955.31 L / (m³). 2 h·bar) and 8081.64L / (m 2 The highest flux for oil-in-water emulsions and water-in-oil emulsions can reach 4310.88 L / (m·bar). 2 h·bar) and 3290.16L / (m 2 h·bar).

[0140] After water flow pressure test, water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 27.29%.

[0141] Example 6

[0142] (1) Zirconium n-propoxide, diaminoterephthalic acid, N,N-dimethylformamide and concentrated HCl (37wt%) catalyst were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid, DMF and concentrated HCl in UiO-66-NH2 precursor solution was 2:1:400:20;

[0143] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0144] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0145] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then dried in a vacuum at 200 °C for 24 h to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0146] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 1.7s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 143.3°.

[0147] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.02% and 98.15%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 97.62% and 98.07%, respectively.

[0148] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6837.61 L / (m³). 2 h·bar) and 7960.27L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3815.68 L / (m³). 2 h·bar) and 3272.35L / (m 2 h·bar).

[0149] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 28.74%.

[0150] Example 7

[0151] (1) Zirconium tetrachloride, diaminoterephthalic acid, water, acetic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid, water, acetic acid and DMF in UiO-66-NH2 precursor solution was 2:1:1:150:500;

[0152] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0153] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2-PC@PPS composite membrane.

[0154] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 60 °C for 24 h to obtain the Janus type UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0155] According to the water contact angle test, the hydrophilic top layer of the UiO-66-NH2-PC@PPS oil-water separation composite membrane requires 2.5s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 140.36°.

[0156] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 97.48% and 96.03%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 97.36% and 96.14%, respectively.

[0157] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6618.24 L / (m³). 2 h·bar) and 6934.98L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3882.31 L / (m³). 2 h·bar) and 3024.47L / (m 2 h·bar).

[0158] After a water flow pressure test, with water flow recorded every 10 minutes at a pressure of 2 bar for 150 minutes, the flux decreased by 33.57%.

[0159] Example 8

[0160] (1) Zirconium tetrachloride, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0161] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0162] (2) 20cm 2The hydrolyzed PPS microporous membrane was immersed in UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain UiO-66-NH2@PPS composite membrane.

[0163] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, dodecyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 120 °C for 24 h to obtain the UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0164] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 2.8 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 130.26°.

[0165] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 93.18% and 94.37%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 93.52% and 91.28%, respectively.

[0166] Using dead-end filtration, the maximum flux for oil-in-water mixtures and water-in-oil mixtures at 1 bar pressure can reach 6137.15 L / (m³). 2 h·bar) and 5774.24L / (m 2 The highest flux for oil-in-water emulsions and water-in-oil emulsions can reach 3215.27 L / (m·bar), respectively. 2 h·bar) and 2494.61L / (m 2 h·bar).

[0167] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 21.66%.

[0168] Example 9

[0169] (1) Zirconium tetrachloride, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0170] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0171] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0172] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, octadecyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 120 °C for 24 h to obtain the UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0173] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 3.7 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 155.53°.

[0174] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 96.25% and 97.04%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 96.37% and 97.22%, respectively.

[0175] Using dead-end filtration, the highest fluxes for oil-in-water and water-in-oil mixtures at 1 bar pressure reached 5873.24 L / (m³). 2 h·bar) and 6537.59L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3070.84 L / (m²). 2 h·bar) and 3308.07L / (m 2 h·bar).

[0176] After a water flow pressure test, water flow was applied at 2 bar for 150 minutes, with the water flux recorded every 10 minutes. The flux decreased by 20.47%.

[0177] Example 10

[0178] (1) Zirconium tetrachloride, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain UiO-66-NH2 precursor solution; the molar ratio of zirconium source, diaminoterephthalic acid and DMF in UiO-66-NH2 precursor solution was 2:1:400.

[0179] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0180] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in 50 mL of UiO-66-NH2 precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain the UiO-66-NH2@PPS composite membrane.

[0181] (3) The UiO-66-NH2@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, docosyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 120°C for 24 h to obtain the UiO-66-NH2-PC@PPS oil-water separation composite membrane.

[0182] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 4.6 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 163.08°.

[0183] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 88.35% and 97.52%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 89.24% and 97.318%, respectively.

[0184] Using dead-end filtration, the highest fluxes for oil-in-water and water-in-oil mixtures at 1 bar pressure reached 3849.32 L / (m³). 2 h·bar) and 5018.83L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 1617.47 L / (m²). 2 h·bar) and 2455.08L / (m 2 h·bar).

[0185] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 21.85%.

[0186] Example 11

[0187] (1) Chromium nitrate nonahydrate, diaminoterephthalic acid and deionized water were mixed and stirred at room temperature until homogeneous to obtain NH2-MiL-101(Cr) precursor solution; the molar ratio of chromium (Cr) source, diaminoterephthalic acid and deionized water in NH2-MiL-101(Cr) precursor solution was 1:1:560.

[0188] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0189] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in NH2-MiL-101(Cr) precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 28 h at a reaction temperature of 130 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain NH2-MiL-101(Cr)@PPS composite membrane.

[0190] (3) The NH2-MiL-101(Cr)@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then dried in a vacuum drying oven at 120℃ for 24 h to obtain the NH2-MiL-101(Cr)-PC@PPS oil-water separation composite membrane.

[0191] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 0.85s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 148.33°.

[0192] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.28% and 98.32%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.15% and 98.23%, respectively.

[0193] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6818.77 L / (m³). 2 h·bar) and 7628.41L / (m 2The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 4031.24 L / (m²). 2 h·bar) and 3273.81L / (m 2 h·bar).

[0194] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 24.49%.

[0195] Example 12

[0196] (1) Tetrabutyl titanate, diaminoterephthalic acid, N,N-dimethylformamide and methanol were mixed and stirred at room temperature until homogeneous to obtain NH2-MiL-125(Ti) precursor solution; the molar ratio of titanium (Ti) source, diaminoterephthalic acid, N,N-dimethylformamide and methanol in NH2-Mil-125(Ti) precursor solution was 1:1:30:60;

[0197] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0198] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in an NH2-MiL-125(Ti) precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 24 h at a reaction temperature of 150 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain an NH2-MiL-125(Ti)@PPS composite membrane.

[0199] (3) The NH2-MiL-125(Ti)@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then dried in a vacuum drying oven at 120℃ for 24 h to obtain the NH2-MiL-125(Ti)-PC@PPS oil-water separation composite membrane.

[0200] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 1.56s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 142.67°.

[0201] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.15% and 98.22%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.04% and 98.11%, respectively.

[0202] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6724.16 L / (m³). 2 h·bar) and 7157.22L / (m 2 The highest fluxes (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3646, 3817, and 47 L / (m³), respectively. 2 h·bar) and 3170.14L / (m 2 h·bar).

[0203] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 22.57%.

[0204] Example 13

[0205] (1) Aluminum nitrate nonahydrate, diaminoterephthalic acid, and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain an NH2-MiL-53(Al) precursor solution; the molar ratio of aluminum (Al) source, diaminoterephthalic acid, and N,N-dimethylformamide in the NH2-MiL-53(Al) precursor solution was 2:1:130;

[0206] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0207] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in NH2-MiL-53(Al) precursor solution and transferred to a hydrothermal reactor for hydrothermal reaction for 72 h at a reaction temperature of 120 °C. The resulting membrane was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain NH2-MiL-53(Al)@PPS composite membrane.

[0208] (3) The NH2-MiL-53(Al)@PPS composite membrane was placed on the oil-water interface constructed by a mixture of triethylamine, palmitoyl chloride and dichloromethane with a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Then, it was placed in a vacuum drying oven at 120℃ for 24 h to obtain the NH2-MiL-53(Al)-PC@PPS oil-water separation composite membrane.

[0209] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 1.8 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 140.61°.

[0210] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.11% and 98.16%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.04% and 98.12%, respectively.

[0211] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6257.55 L / (m³). 2 h·bar) and 6818.28L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3441.41 L / (m³). 2 h·bar) and 3018.95L / (m 2 h·bar).

[0212] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 24.14%.

[0213] Example 14

[0214] (1) Zinc acetate dihydrate, diaminoterephthalic acid and N,N-dimethylformamide were mixed and stirred at room temperature until homogeneous to obtain NH2-MOF-5 precursor solution; the molar ratio of zinc (Zn) source, diaminoterephthalic acid and N,N-dimethylformamide in NH2-MOF-5 precursor solution was 3:1:160;

[0215] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0216] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in an NH2-MOF-5 precursor solution and stirred at room temperature for 24 h. The membrane obtained from the reaction was then washed with ethanol and dried in an oven at 120 °C for 24 h to obtain an NH2-MOF-5@PPS composite membrane.

[0217] (3) The NH2-MOF-5@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface. Finally, it was placed in a vacuum drying oven at 120 °C for 24 h to obtain the NH2-MOF-5-PC@PPS oil-water separation composite membrane.

[0218] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 2.4 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 138.93°.

[0219] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 97.915% and 98.08%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.0% and 98.15%, respectively.

[0220] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6136.77 L / (m³). 2 h·bar) and 6671.48L / (m 2 The highest flux for oil-in-water emulsions and water-in-oil emulsions can reach 3224.35 L / (m·bar), respectively. 2 h·bar) and 2988.48L / (m 2 h·bar).

[0221] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 28.33%.

[0222] Example 15

[0223] (1) Tris(4-formylphenyl)amine, p-phenylenediamine, ethanol and o-dichlorobenzene were mixed and stirred at room temperature until homogeneous, and then acetic acid was slowly added dropwise and mixed and stirred until homogeneous to obtain a COF precursor solution; the molar ratio of tris(4-formylphenyl)amine, p-phenylenediamine, ethanol, o-dichlorobenzene and acetic acid was 1:1.5:400:200:35;

[0224] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0225] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in the precursor solution of COFs and transferred to a mixing reactor for reaction at 120℃ for 72 h. The resulting membrane was then washed with ethanol and dried in an oven at 120℃ for 24 h to obtain a COFs superhydrophilic modified PPS-based composite membrane.

[0226] (3) The COFs superhydrophilic modified PPS-based composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then placed in a vacuum drying oven at 60 °C for 24 h to obtain an oil-water separation composite membrane.

[0227] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 2.9 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 135.72°.

[0228] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 97.76% and 97.91%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.04% and 98.08%, respectively.

[0229] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 5973.88 L / (m³). 2 h·bar) and 6228.49L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3051.31 L / (m²). 2 h·bar) and 2775.27L / (m 2 h·bar).

[0230] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 26.67%.

[0231] Example 16

[0232] (1) 2,5-Dihydroxy-terephthalaldehyde, 1,3,5-tris(4-aminophenyl)benzene, 1,4-dioxane, acetic acid and mesitylene were mixed and stirred at room temperature until homogeneous to obtain a TBP-DMTP precursor solution; the molar ratio of 2,5-dihydroxy-terephthalaldehyde, 1,3,5-tris(4-aminophenyl)benzene, 1,4-dioxane, acetic acid and mesitylene was 1:1:35:35:200;

[0233] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0234] (2) 20cm 2The hydrolyzed PPS microporous membrane was immersed in the TBP-DMTP precursor solution and transferred to a mixing reactor for reaction at 120℃ for 72 h. The resulting membrane was then washed with ethanol and dried in an oven at 120℃ for 24 h to obtain the TBP-DMTP@PPS composite membrane.

[0235] (3) The TBP-DMTP@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a molar ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface, and then placed in a vacuum drying oven at 60 °C for 24 h to obtain an oil-water separation composite membrane.

[0236] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 1.1 seconds to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 142.35°.

[0237] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.21% and 98.23%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.16% and 98.20%, respectively.

[0238] Using dead-end filtration, the maximum flux for oil-in-water and water-in-oil mixtures at 1 bar pressure can reach 6634.66 L / (m³). 2 h·bar) and 7458.15L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3922.11 L / (m²). 2 h·bar) and 3381.46L / (m 2 h·bar).

[0239] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 23.16%.

[0240] Example 17

[0241] (1) Trialdehyde resorcinol, melamine, acetic acid, dimethyl sulfoxide and N,N-dimethylacetamide were mixed and stirred at room temperature until homogeneous to obtain TpTt precursor solution; the molar ratio of trialdehyde resorcinol, melamine, acetic acid, dimethyl sulfoxide and N,N-dimethylacetamide was 1:1:17:50:70;

[0242] The PPS microporous membrane was moistened in ethanol, washed with deionized water, and then transferred to a 25% nitric acid aqueous solution and immersed at 25°C for 24 hours to obtain the hydrolyzed PPS microporous membrane.

[0243] (2) 20cm 2 The hydrolyzed PPS microporous membrane was immersed in TpTt precursor solution and transferred to a mixing reactor for reaction at 120℃ for 72 h. The resulting membrane was then washed with ethanol and dried in an oven at 120℃ for 8 h to obtain a TpTt@PPS composite membrane.

[0244] (3) The TpTt@PPS composite membrane was placed on an oil-water interface constructed by water and a mixture of triethylamine, palmitoyl chloride and dichloromethane in a mass ratio of 2:1:60 and reacted for 0.5 h. Then, it was washed with dichloromethane to remove the residual water and oil phase solution on the membrane surface and then dried in a vacuum drying oven at 60 °C to obtain an oil-water separation composite membrane.

[0245] According to the water contact angle test, the hydrophilic top layer of the oil-water separation composite membrane requires 1.75s to completely wet a water droplet, while the WCAs value of its hydrophobic bottom layer is 138.33°.

[0246] According to the oil-water separation performance test, the separation efficiency for oil-in-water mixtures and water-in-oil mixtures is above 98.11% and 98.02%, respectively, and the separation efficiency for oil-in-water emulsions and water-in-oil emulsions is above 98.09% and 98.05%, respectively.

[0247] Using dead-end filtration, the highest fluxes for oil-in-water and water-in-oil mixtures at 1 bar pressure reached 6734.79 L / (m³). 2 h·bar) and 6527.18L / (m 2 The highest flux (h·bar) for oil-in-water emulsions and water-in-oil emulsions can reach 3557.22 L / (m²). 2 h·bar) and 2954.73L / (m 2 h·bar).

[0248] After water flow pressure test, the water flow was carried out at 2 bar pressure for 150 minutes, and the water flux was recorded every 10 minutes. The flux decreased by 30.57%.

[0249] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A method for preparing a Janus-type organic porous material-coated PPS oil-water separation composite membrane, characterized in that, The method comprises the following steps: (1) configuring an organic porous material precursor solution; the organic porous material comprises COFs and MOFs; The configuration of the organic porous material precursor solution is specifically: mixing and stirring substances A, B and a solution C at room temperature until homogeneous to obtain the organic porous material precursor solution; The substance A uses zirconium tetrachloride, zirconium n-propyl alcohol, zirconium disulfide, zirconium oxychloride octahydrate, chromium nitrate nonahydrate, butyl titanate, aluminum nitrate nonahydrate, zinc acetate dihydrate, tris(4-formylphenyl)amine, 2,5-dihydroxyterephthalaldehyde or triformylphloroglucinol; The substance B uses diaminoterephthalic acid, p-phenylenediamine, 1,3,5-tris(4-aminophenyl)benzene or melamine; The solution C uses at least one of N,N-dimethylformamide, deionized water, acetic acid, methanol, 1,4-dioxane, mesitylene, dimethyl sulfoxide or N,N-dimethylacetamide; The concentration of the substance A is 1-50 g / L, and the concentration of the substance B is 1-50 g / L; the molar ratio of the substance A, the substance B and the solution C is 1-9:1-9:20-620; Hydrolysis of the PPS microporous membrane: first, the PPS microporous membrane is placed in an alcohol compound for wetting, then washed with deionized water to remove the alcohol on the surface of the membrane and in the membrane holes, and then immersed in a nitric acid aqueous solution for hydrolysis, so that the thioether bond is oxidized into a sulfoxide bond, so that the surface of the PPS microporous membrane is negatively charged, and a hydrolyzed PPS microporous membrane is obtained; The alcohol compound uses a low-molecular-weight monohydric alcohol; In the hydrolysis process, the concentration of the nitric acid aqueous solution is 5-55 wt%, the immersion temperature is 10-60℃, and the immersion time is 0.5-48 h; (2) In-situ generation of an organic porous material@PPS composite membrane by a hydrothermal method: the hydrolyzed PPS microporous membrane is immersed in sufficient or excessive organic porous material precursor solution for hydrothermal reaction, and the organic porous material grows on the surface of the membrane; after the reaction is completed, the organic porous material that is not grown on the surface of the membrane is removed by washing, then immersed in ethanol, and dried to remove ethanol, to obtain an organic porous material@PPS composite membrane; The hydrothermal reaction time is 2-96 h, and the reaction temperature is 60-240℃; (3) Preparation of a Janus-type organic porous material@PPS oil-water separation composite membrane: first, an oil phase solution is configured, then water is poured into the oil phase solution, and the oil-water interface is obtained by standing, with the upper layer being water and the lower layer being the oil phase solution; then the organic porous material@PPS composite membrane is placed at the oil-water interface for amidation reaction, then washed to remove the residual water and oil phase solution on the surface of the membrane, and dried to obtain a Janus-type organic porous material@PPS oil-water separation composite membrane with superhydrophilic top layer and superhydrophobic bottom layer; The oil phase solution is a dichloromethane or trichloromethane solution of triethylamine and alkyl acid chloride; the concentration of the triethylamine is 5-60 g / L, and the concentration of the alkyl acid chloride is 10-120 g / L; the molar ratio of the triethylamine, the alkyl acid chloride and dichloromethane is 1-8:1-16:10-120; The alkyl acid chloride uses lauryl chloride, palmitoyl chloride, stearoyl chloride or behenoyl chloride.

2. The method for preparing the Janus-type organic porous material-coated PPS oil-water separation composite membrane according to claim 1, characterized in that, In step (1), the alcohol compound uses methanol or ethanol.

3. The method for preparing the Janus-type organic porous material-coated PPS oil-water separation composite membrane according to claim 1, characterized in that, In step (2), the organic porous material not grown on the surface of the membrane is removed by washing with solution D; the solution D is N,N-dimethylformamide, ethanol, deionized water or N,N-dimethylacetamide.

4. The method for preparing the Janus-type organic porous material-coated PPS oil-water separation composite membrane according to claim 1, characterized in that, The time of the amidation reaction is 5 min to 2 h, and the temperature is room temperature.

5. The method for preparing the Janus-type organic porous material-coated PPS oil-water separation composite membrane according to claim 1, characterized in that, In step (3), the residual water and oil phase solution on the surface of the membrane are removed by washing with solution E; the solution E is dichloromethane or trichloromethane.

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