A three-dimensional raspberry-shaped CdS@MXene microsphere and a multi-component antifouling polyarylene ether nitrile film containing it, its preparation method and application

Abstract

This invention relates to the field of polymer materials technology. Addressing the problem of dense stacking of two-dimensional MXene sheets in existing composite membrane materials for oily wastewater treatment, this invention specifically discloses a three-dimensional raspberry-shaped CdS@MXene microspheres and a multi-fouling antifouling polyarylene ether nitrile membrane material containing these microspheres, along with their preparation method and applications. The preparation method includes the following steps: mixing an aqueous solution of polymethyl methacrylate with an MXene suspension, stirring and reacting, separating after the reaction, washing and drying to obtain three-dimensional MXene microspheres; mixing the three-dimensional MXene microspheres with an aqueous solution of CdCl2, stirring magnetically, then adding thiourea, continuing stirring, and then placing the mixture at 160-200℃ for a hydrothermal reaction, separating after the reaction, washing and drying to obtain three-dimensional raspberry-shaped CdS@MXene microspheres. Introducing these three-dimensional raspberry-shaped CdS@MXene microspheres into the polyarylene ether nitrile membrane material can effectively solve the problems of dense stacking and complex membrane fouling inherent in existing two-dimensional MXene sheets, thereby overcoming the limitation on separation flux.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a three-dimensional raspberry-shaped CdS@MXene microsphere and a multi-layer antifouling polyarylene ether nitrile film material containing it, as well as its preparation method and application. Background Technology

[0002] In the industrial processes of oil extraction, metallurgy, textiles, and chemicals, large quantities of complex oily wastewater are generated. If this wastewater is discharged directly without effective treatment, it will not only severely pollute water resources but also damage the ecological environment and even threaten human health. Therefore, achieving efficient treatment of oily wastewater has become a critical problem urgently needing to be solved in the industrial and environmental protection sectors. Among various types of oily wastewater, emulsified oily wastewater presents a greater challenge to wastewater treatment due to its characteristics such as small oil droplet size, high oil-water interface stability, and difficulty in demulsification. Traditional methods for treating emulsified oily wastewater generally suffer from high energy consumption and low treatment efficiency, making it difficult to meet the needs of large-scale industrial treatment. In contrast, membrane separation technology, with its significant advantages of high treatment efficiency, low energy consumption, and simple operation, has shown unique application potential in the field of oily emulsion treatment and has become a hot research topic in recent years.

[0003] Currently, most of the core membrane materials used in membrane separation technology are prepared through non-solvent-induced phase separation methods. These membrane materials have inherent defects such as low porosity and poor resistance to oil adhesion, making them prone to membrane pore blockage and irreversible fouling during oil-water emulsion separation, thus affecting separation and filtration efficiency. For example, patent CN117753227A provides a method for preparing a two-dimensional transition metal material-aerogel composite membrane and its application. In the preparation process, a two-dimensional transition metal material is dispersed in a mixed solution of water and alcohol, aerogel is added, and after stirring and mixing evenly, the mixture is filtered to obtain the two-dimensional transition metal material-aerogel composite membrane. This invention utilizes the attraction between positively charged aerogel particles in solution and negatively charged MXene or graphene oxide nanosheets in aqueous solution. The MXene or graphene oxide nanosheets then combine with the aerogel particles, and finally, through filtration, the layers are stacked to obtain a two-dimensional layered material-aerogel composite membrane. The preparation process is simple and easy to promote. By adding aerogel materials to form the membrane, it has good retention performance and high filtration efficiency, which can optimize the nanofiltration performance of the composite membrane and can be used in the field of dye wastewater treatment.

[0004] However, the two-dimensional MXene sheet materials used in the existing composite membrane materials for oily wastewater treatment have the problem of dense stacking, which limits the separation flux and results in poor performance in terms of stability and complex membrane fouling treatment. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that the two-dimensional MXene sheet materials used in existing composite membrane materials for oily wastewater treatment, which improve separation efficiency by introducing MXene and other materials, have a dense stacking problem, resulting in limited separation flux and poor performance in terms of stability and complex membrane fouling treatment.

[0006] This invention is achieved through the following technical solution:

[0007] This invention provides a method for preparing three-dimensional raspberry-shaped CdS@MXene microspheres, comprising the following steps:

[0008] (1) Mix the aqueous solution of polymethyl methacrylate with the MXene suspension, stir and react, separate after the reaction, wash and dry to obtain three-dimensional MXene microspheres;

[0009] (2) Mix the three-dimensional MXene microspheres with CdCl2 aqueous solution, stir magnetically, then add thiourea, continue stirring, and place at 160-200℃ for hydrothermal reaction. After the reaction is completed, separate, wash and dry to obtain the three-dimensional raspberry-like CdS@MXene microspheres.

[0010] Preferably, in step (2), the mass ratio of the three-dimensional MXene microspheres to CdCl2 and thiourea is 0.1-0.3:0.3-0.8:0.4.

[0011] Preferably, in step (2), the magnetic stirring time is 8-12h, the stirring time after adding thiourea is 0.5-1.5h, and the hydrothermal reaction time is 10-15h.

[0012] The present invention relates to three-dimensional raspberry-shaped CdS@MXene microspheres, comprising three-dimensional MXene microspheres, wherein CdS nanoparticles are grown in situ on the surface of the three-dimensional MXene microspheres.

[0013] The present invention also provides a multi-fouling antifouling polyarylene ether nitrile membrane material, comprising a polyarylene ether nitrile base membrane and a composite layer coated on the surface of the polyarylene ether nitrile base membrane, wherein the composite layer comprises three-dimensional raspberry-shaped CdS@MXene microspheres.

[0014] The present invention also provides a method for preparing the above-described multi-fouling antifouling polyarylene ether nitrile membrane material, comprising the following steps:

[0015] S1 Constructs a surface-activated polyarylene ether nitrile film:

[0016] Polyarylene ether nitrile, polyethylene glycol and surface segregating agent are dissolved together in an organic solvent, heated and stirred until completely dissolved to obtain a casting solution; the casting solution is coated onto the surface of a glass plate by a scraper, and then immersed in a zinc-containing coagulation bath to solidify and form a film, rinsed, and a polyarylene ether nitrile activated film is obtained and stored in deionized water for later use.

[0017] S2 Constructs the hydrogel interfacial bonding layer:

[0018] Take a mixture of silane coupling agent, ethanol and water, place the polyarylene ether nitrile activated membrane in the mixture, shake it, then take it out and rinse it to obtain a polyarylene ether nitrile-based membrane, and store it in deionized water for later use.

[0019] S3 Preparation of multi-antifouling polyarylene ether nitrile membrane materials:

[0020] A composite liquid containing three-dimensional raspberry-like CdS@MXene microspheres was sprayed onto a polyarylene ether nitrile-based membrane and dried to obtain the multi-fouling antifouling polyarylene ether nitrile membrane material.

[0021] Preferably, in step S3, the composite liquid containing three-dimensional raspberry-shaped CdS@MXene microspheres is sprayed 1-5 times, and each spraying is dried before the next spraying.

[0022] Preferably, in step S3, the composite liquid containing three-dimensional raspberry-shaped CdS@MXene microspheres includes three-dimensional raspberry-shaped CdS@MXene microspheres, polyvinyl alcohol, and a surface segregating agent; further, the mass ratio of polyvinyl alcohol to surface segregating agent is 1:0.8-1.2.

[0023] The multi-fouling antifouling polyarylether nitrile membrane material of the present invention can be used as a membrane separation material for industrial oily wastewater treatment, and has advantages such as good separation effect and stability.

[0024] The technical solution of the present invention has the following beneficial effects:

[0025] The present invention introduces three-dimensional raspberry-shaped CdS@MXene microspheres into the multi-fouling antifouling polyarylene ether nitrile membrane material. The three-dimensional raspberry-shaped CdS@MXene microspheres proposed in this invention, through the improvement and optimization of their structure, are arranged in an orderly manner, which can effectively solve the problem of dense stacking of existing two-dimensional MXene sheets, and thus break through the limitation of separation flux.

[0026] A composite material containing the aforementioned three-dimensional raspberry-like CdS@MXene microspheres was sprayed onto the surface of a polyarylene ether nitrile (PAEN)-based membrane. The heterojunction structure of the three-dimensional raspberry-like CdS@MXene microspheres endowed the composite membrane with excellent photocatalytic and photothermal conversion properties. After 60 minutes of light irradiation, the PAEN membrane material achieved degradation rates of 96.88%, 96.38%, 93.5%, and 94.64% for methylene blue, crystal violet, Congo red, and methyl orange, respectively, demonstrating excellent photocatalytic self-cleaning properties. Furthermore, after 30 seconds of simulated sunlight irradiation, its temperature reached 85.34°C, effectively reducing the viscosity of the oil contaminants to be separated.

[0027] The polyarylene ether nitrile membrane material, synergistically modified with gradient durable gel and three-dimensional raspberry-like CdS@MXene microspheres, exhibited a reduced contact angle of 26.67° and an increased underwater oil contact angle of 159.16°, demonstrating both hydrophilic and underwater superoleophobic properties. This indicates excellent oil resistance, making it better suited for applications such as the separation of oily wastewater. The pure water flux of this polyarylene ether nitrile membrane material reached 883.23 L·m⁻¹. -2 ·h -1 The emulsion flux for oil-water emulsions stabilized by various surfactants is 215.15 L·m. -2 ·h -1 The retention rate is as high as 99.64%; at the same time, it can still maintain excellent structural and chemical stability after physical damage such as long-term water flushing, sandpaper friction, tape peeling and ultrasonic treatment, as well as long-term harsh environmental treatment. Attached Figure Description

[0028] Figure 1 Here is a SEM image of the three-dimensional MXene microspheres in Example 1;

[0029] Figure 2 SEM image of the three-dimensional raspberry-shaped CdS@MXene microspheres in Example 1;

[0030] Figure 3 The XRD diffraction patterns of various microspheres in Example 1 are shown below.

[0031] Figure 4 This is a comparison diagram of the water contact angles of different polyarylether nitrile membrane materials in Examples 1-5;

[0032] Figure 5 The diagram shows a comparison of the underwater oil contact angles of different polyarylether nitrile membrane materials in Examples 1-5.

[0033] Figure 6 This is a comparison diagram of the underwater oil contact angle of the polyarylene ether nitrile membrane material in Example 3 under different oils;

[0034] Figure 7 The following are diagrams illustrating the physical destructive testing procedures for the polyarylether nitrile membrane material in Example 3: (a) water rinsing treatment, (b) sandpaper rubbing treatment, (c) tape peeling treatment, and (d) ultrasonic treatment.

[0035] Figure 8 This is a comparison chart of the chemical destructive test results of the polyarylether nitrile membrane material in Example 3 under high salt conditions;

[0036] Figure 9 This is a comparison chart of the chemical destructive test results of the polyarylether nitrile membrane material in Example 3 under a strong acid environment;

[0037] Figure 10This is a comparison chart of the chemical destructive test results of the polyarylether nitrile membrane material in Example 3 under a strong alkaline environment;

[0038] Figure 11 This is a comparison chart of the pure water flux of different polyarylether nitrile membrane materials in Examples 1-5;

[0039] Figure 12 This is a comparison chart of the flux and rejection rate of SDS-stabilized n-hexane emulsions of different polyarylene ether nitrile membrane materials in Examples 1-5.

[0040] Figure 13 This is a comparison chart of the emulsion flux and rejection rate of the polyarylene ether nitrile membrane material for different oils in Example 3;

[0041] Figure 14 This is a comparison chart of the cyclic test results of the polyarylether nitrile membrane material in Example 3;

[0042] Figure 15 This is a comparison chart of the photocatalytic degradation performance of the polyarylether nitrile membrane material in Example 3;

[0043] Figure 16 This is a comparison diagram of the photothermal effect of the polyarylether nitrile film material in Example 3. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, they are performed according to conventional conditions or conditions recommended by the manufacturer; where the manufacturers of the instruments, equipment, reagents, or raw materials used are not specified, they are all conventional products that can be purchased commercially.

[0045] This invention provides a three-dimensional raspberry-shaped CdS@MXene microsphere and a multi-component antifouling polyarylene ether nitrile film material containing it, as well as its preparation method and application.

[0046] In this invention, the preparation method of three-dimensional raspberry-shaped CdS@MXene microspheres includes the following steps:

[0047] (1) Take 1g of polymethyl methacrylate (PMMA), completely disperse it in 50mL of deionized water, mix it with MXene suspension, stir for 2h, centrifuge and wash, collect the precipitate, place it at 60℃ and dry it to obtain three-dimensional MXene microspheres.

[0048] (2) At room temperature, 0.0016-0.004 mol of anhydrous CdCl2 was added to 50 mL of deionized water and stirred to dissolve. Then, 0.1-0.3 g of three-dimensional MXene microspheres were added and magnetically stirred for 8-12 h. Then, 0.001-0.01 mol of thiourea was added to the stirred suspension and stirred for 0.5-1.5 h. The mixed suspension was then transferred to a 100 mL hydrothermal reactor and placed in a vacuum oven. The hydrothermal reaction was carried out at 160-200 °C for 10-15 h. After the reaction, the mixture was cooled, centrifuged and washed, and the precipitate was collected. The precipitate was then dried in a vacuum oven at 60 °C to obtain three-dimensional raspberry-shaped CdS@MXene microspheres.

[0049] The mass ratio of the three-dimensional MXene microspheres to CdCl2 and thiourea is 0.1-0.3:0.3-0.8:0.4. In the above preparation process, CdS nanoparticles are grown in situ on the surface of the three-dimensional MXene microspheres. These nanoparticles possess good visible light bandgap, excellent carrier mobility, and cost-effectiveness, allowing the construction of three-dimensional raspberry-like CdS@MXene hybrid microspheres. The photothermal-photocatalyst heterojunction structure prepared by combining MXene and CdS can efficiently achieve the synergistic treatment of organic pollutants, especially high-viscosity oils, through photothermal / photocatalytic synergistic processing. Based on the abundant -OH and -F end groups on the MXene surface, three-dimensional raspberry-like CdS@MXene microspheres are prepared using a template-assisted method through hydrogen bonding. Their ordered arrangement avoids the problem of dense stacking of existing two-dimensional MXene sheets, thus overcoming the limitation of separation flux.

[0050] In this invention, the polyarylene ether nitrile membrane material with multiple antifouling properties comprises the above-mentioned three-dimensional raspberry-like CdS@MXene microspheres, and its preparation method specifically includes the following steps:

[0051] (1) Construct a surface-activated polyarylene ether nitrile activated film.

[0052] Polyarylene ether nitrile (PEN), polyethylene glycol, and surface segregating agent were dissolved together in an organic solvent at a mass ratio of 2:3:0.5. The mixture was then placed at 60-90℃ and stirred until the solids were completely dissolved to obtain the casting solution.

[0053] Take an appropriate amount of casting solution and carefully pour it onto one side of a clean glass plate. Use a 200μm casting tool to evenly spread the casting solution onto the glass plate. Quickly immerse it in a zinc-containing coagulation bath, such as a 0.0025mol / L ZnCl2 aqueous solution. When the liquid film has completely precipitated and transformed into a solid film, rinse with deionized water to obtain a polyarylene ether nitrile activated membrane. Store the membrane in deionized water for later use.

[0054] (2) Construct a hydrogel interface bonding layer.

[0055] Take an appropriate amount of silane coupling agent, add it to 10 mL of anhydrous ethanol, stir well, then add it to 90 mL of deionized water, and adjust the pH value to 5.8-6.5; place the polyarylene ether nitrile activated membrane in the above solution containing silane coupling agent, etc., and shake at 35℃ for 4 h, take it out and rinse it with deionized water to obtain the polyarylene ether nitrile base membrane, and then transfer it to deionized water for storage.

[0056] (3) Preparation of a multi-layer antifouling polyarylene ether nitrile membrane material with synergistic effect of three-dimensional raspberry-shaped CdS@MXene microspheres and gel.

[0057] A suitable amount of three-dimensional raspberry-shaped CdS@MXene microspheres were added to a mixture of 3% (w / w) polyvinyl alcohol and a surface segregating agent, wherein the mass ratio of polyvinyl alcohol to surface segregating agent was 1:0.8-1.2. The mixture was ultrasonically dispersed and then stirred at 60°C for 1 hour to obtain a composite solution for surface spraying. The composite solution was placed in a spray gun and sprayed onto the surface of a polyarylene ether nitrile film using an air compressor at a pressure of 0.2 MPa. After drying, the mixture could be sprayed again. The number of coating layers was controlled to be 1-5 layers to obtain a multi-layer antifouling polyarylene ether nitrile film material.

[0058] This invention proposes a multi-scale antifouling polyarylene ether nitrile membrane material. Employing a multi-scale synergistic stabilization strategy involving multiple bonding, gradient functionalization, and nano-interpenetration enhancement, a gradient durable hydrogel is constructed on the membrane surface. This enhances the stability of the hydrogel structure and its interaction with the base membrane, overcoming the bottleneck of hydrogel layer instability under harsh conditions, such as peeling and network collapse, as well as wettability degradation. This fundamentally improves the durability of the polymer membrane material in harsh environments. This multi-scale antifouling polyarylene ether nitrile membrane material, possessing photocatalytic and photothermal effects, is applied to oil-water separation membranes. Combined with the gradient durable hydrogel on the membrane surface, a photothermal-photocatalytic assisted gradient durable hydrogel is constructed, enhancing the membrane material's antifouling performance and separation flux, enabling efficient separation of complex oil-water emulsions.

[0059] Example 1

[0060] Step 1: Dissolve 2g PEN, 3g PEG6000, and 0.5g tannic acid powder in 15mL of N,N-dimethylformamide. Stir at 80℃ until the solid is completely dissolved to obtain a casting solution. Then, take 5mL of the casting solution and carefully pour it onto one side of a clean glass plate. Use a 200μm casting tool to evenly spread the casting solution to form a film 8cm long, 5cm wide, and with an area of ​​40cm². 2 A uniform liquid film is formed, and then it is quickly immersed in a 0.0025 mol / L ZnCl2 aqueous solution. When the liquid film is completely precipitated and transformed into a solid film, the polyarylene ether nitrile is activated, rinsed with deionized water, and stored for later use.

[0061] Step 2: Take 1.5g of silane coupling agent KH-550, add it to 10mL of anhydrous ethanol, stir well, then add it to 90mL of deionized water and adjust the pH value to about 6.0; then place the polyarylene ether nitrile activated membrane in the above solution and shake it at 35℃ for 4h. After shaking, take it out, rinse it with deionized water to obtain the polyarylene ether nitrile base membrane, and then transfer it to deionized water for storage.

[0062] Step 3: Take 1g PMMA, disperse it in 50mL deionized water, mix it with MXene suspension, stir for 2h, centrifuge and wash, collect the precipitate, dry it at 60℃ to obtain three-dimensional MXene microspheres. At room temperature, add 0.0025mol anhydrous CdCl2 to 50mL deionized water, stir to dissolve, then add 0.2g three-dimensional MXene microspheres, and magnetically stir for 10h; then add 0.005mol thiourea to the stirred suspension, and continue stirring for 1h; then transfer the mixed suspension to a 100mL hydrothermal reactor and place it in a vacuum oven, hydrothermally react at 180℃ for 12h. After the reaction, cool, centrifuge and wash, collect the precipitate, and dry it in a vacuum oven at 60℃ to obtain three-dimensional raspberry-shaped CdS@MXene microspheres.

[0063] Step 4: Take 0.3g of three-dimensional raspberry-shaped CdS@MXene microspheres and add them to 50mL of a 3% (w / w) mixture of polyvinyl alcohol and tannic acid (TA), wherein the mass ratio of polyvinyl alcohol to surface segregating agent is 1:1. Disperse the mixture evenly using ultrasonication. Then, stir at 60℃ for 1h to obtain a surface coating mixture. Place the surface coating mixture in an R2-F-08 spray gun and, using an air compressor, spray 2mL of the mixture onto the surface of the polyarylene ether nitrile film at a pressure of 0.2MPa. Dry the mixture to form a three-dimensional raspberry-shaped CdS@MXene microsphere coating layer, obtaining a multi-layer antifouling polyarylene ether nitrile film material, denoted as CM-1.

[0064] Example 2

[0065] The difference between this embodiment and Embodiment 1 is that the surface coating mixture is sprayed onto the surface of the polyarylene ether nitrile film, dried, and then sprayed again to form a two-layer three-dimensional raspberry-like CdS@MXene microsphere coating, denoted as CM-2.

[0066] Example 3

[0067] The difference between this embodiment and Embodiment 1 is that: a surface coating mixture is sprayed three times to form a three-dimensional raspberry-like CdS@MXene microsphere coating layer, denoted as CM-3.

[0068] Example 4

[0069] The difference between this embodiment and Embodiment 1 is that: a total of four surface coating mixtures are sprayed to form a four-layer three-dimensional raspberry-like CdS@MXene microsphere coating, denoted as CM-4.

[0070] Example 5

[0071] The difference between this embodiment and Embodiment 1 is that: a total of five layers of surface coating mixture are sprayed to form a 5-layer three-dimensional raspberry-like CdS@MXene microsphere coating, denoted as CM-5.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 1 is that the surface was not coated with a surface-coated mixture, and the polyarylene ether nitrile film surface did not have a three-dimensional raspberry-like CdS@MXene microsphere coating, denoted as CM-0.

[0074] Test case

[0075] Samples: Three-dimensional raspberry-shaped CdS@MXene microspheres from Example 1, and polyarylether nitrile membrane materials from Examples 1-5 and Comparative Example 1. (1)

[0077] The three-dimensional MXene microspheres and three-dimensional raspberry-like CdS@MXene microspheres prepared in Example 1 were observed under a scanning electron microscope, and the results are as follows. Figure 1 and Figure 2 The images shown are SEM images of three-dimensional MXene microspheres and three-dimensional raspberry-shaped CdS@MXene microspheres, respectively. Figure 3 The image shows the XRD diffraction pattern of three-dimensional raspberry-shaped CdS@MXene microspheres.

[0078] The surface of MXene monolayer nanosheets contains fluorine and oxygen-containing functional groups. These polar groups can interact with the functional groups on the surface of polymethyl methacrylate (PMMA) microspheres through hydrogen bonds and van der Waals forces, thereby encapsulating the MXene monolayer nanosheets onto the PMMA microspheres to form three-dimensional MXene microspheres. Figure 1 As shown, after being encapsulated in two-dimensional sheet-like MXene nanosheets, the surface of the microspheres exhibits a distinct wrinkled structure, while simultaneously... Figure 3 The XRD pattern shows that the characteristic peaks at 34.25° and 60.80° of MXene appear on the three-dimensional MXene microspheres, which proves that the monolayer MXene nanosheets were successfully encapsulated on polymethyl methacrylate microspheres. Because the MXene surface contains a negative charge, it can adsorb Cd through electrostatic interactions. 2+ Positive ions were used to generate CdS nanoparticles in situ on the surface of three-dimensional MXene microspheres via a hydrothermal method; for example... Figure 2As shown, CdS nanoparticles with a size of 50-60 nm are loaded onto the surface of the microspheres to form a raspberry-like structure; characteristic peaks of CdS can be observed from the XRD diffraction spectrum, proving that CdS was successfully loaded onto the surface of 3D MXene microspheres. (2)

[0080] The polyarylene ether nitrile film materials prepared in Examples 1-5 and Comparative Example 1 were subjected to contact angle tests to test the wetting performance of different sprayed coating composite films.

[0081] like Figures 4 to 6 The figures show comparisons of water contact angles, underwater oil contact angles, and underwater oil contact angles of different polyarylene ether nitrile (PEN) membrane materials, as well as comparisons of the PEN membrane material in Example 3 with different oils. It can be observed that due to the hydrophobicity of PEN, the contact angle of water droplets on the membrane surface reaches as high as 92.49°. After synergistic modification with PVA-TA gel and three-dimensional raspberry-like CdS@MXene hybrid microspheres, the contact angle of the PEN membrane material with 1 to 5 layers gradually decreased from 39.16° to 26.67°, indicating that the spraying layer can improve the hydrophilicity of the PEN membrane material. On the one hand, the hydrogel layer on the surface of the PEN membrane material has abundant hydrophilic functional groups, and the constructed hydrogen bond network can significantly enhance the hydrophilicity of the PEN membrane material; on the other hand, the three-dimensional CdS@MXene hybrid microspheres constructed in this invention can significantly improve the surface roughness of the PEN membrane material and form a large number of micro- and nano-sized pores. The hydrophilic surface formed by hydrophilic groups and micron or nano-rough structures promotes the formation of a hydration layer through interaction with water molecules, hindering the interaction between oil droplets and the polymer matrix, thereby improving the wettability of the membrane. Measurements of the underwater oil contact angle of the polyarylene ether nitrile membrane material show that the underwater oil contact angle increased from 137.1° to 159.16°. Furthermore, the underwater oil contact angles of the polyarylene ether nitrile membrane material in Example 3 for n-hexane, n-heptane, petroleum ether, 1,3,5-trimethylbenzene, and isooctane were 145.69°, 141.37°, 143.89°, 141.33°, and 143.65°, respectively. These water and underwater oil contact angles indicate that the prepared composite membrane exhibits excellent anti-oil adhesion ability when facing underwater oil erosion. (3)

[0083] The polyarylene ether nitrile membrane material prepared in Example 3, which contains three layers of three-dimensional raspberry-like CdS@MXene microsphere spray coating, was subjected to physical destructive tests such as long-term water rinsing, sandpaper friction, tape peeling and ultrasonic treatment, and chemical destructive tests such as long-term immersion in harsh environments of high salt, strong acid and strong alkali, to evaluate the durability and stability of the composite membrane.

[0084] like Figure 7The diagram shows the chemical destructive testing procedures for the polyarylether nitrile membrane material in Example 3, where (a) is water rinsing treatment, (b) sandpaper abrasion treatment, (c) tape peeling treatment, and (d) ultrasonic treatment; Figures 8 to 10 The figures shown are comparative chemical destructive tests of the polyarylene ether nitrile membrane material in Example 3 under different environments of high salt, strong acid, and strong alkali. After long-term physical damage such as water rinsing, sandpaper friction, tape peeling, and ultrasonic treatment, the surface of the polyarylene ether nitrile membrane material still maintains a uniform functional gel modification layer, indicating the membrane's ultra-high structural stability. Furthermore, after 10 hours of rigorous treatment with 1M NaOH, 1M HCl, and 1M NaCl, the pure water flux of this polyarylene ether nitrile membrane material can still be maintained at 800 L·m⁻¹. -2 ·h -1 The above demonstrates the excellent chemical stability of the composite membrane. This invention employs a unique "multiple bonding-gradient functionalization-nano-interpenetrating reinforcement" strategy to achieve structural stability and durability of the membrane material. Firstly, by constructing an activation layer, an interfacial bonding layer, and a functional hydrogel layer of the base membrane material, a gradient of the membrane material is achieved, and adhesion to the base membrane is enhanced through multiple bonding processes such as chemical crosslinking and hydrogen bonding. Secondly, three-dimensional CdS@MXene microspheres can serve as nano-reinforcing materials, improving the stability of the hydrogel structure on the membrane surface through nano-interpenetrating reinforcement. (4)

[0086] The polyarylene ether nitrile membrane materials prepared in Examples 1-5 and Comparative Example 1 were used to characterize the pure water flux and emulsion flux, and the total organic carbon (TOC) test was used to calculate the oil-water separation efficiency to test its oil-water separation effect.

[0087] like Figures 11 to 14 The figures show comparisons of pure water flux, SDS-stabilized n-hexane emulsion flux, and rejection rate of different polyarylene ether nitrile membrane materials in Examples 1-5, as well as comparisons of separation flux and rejection rate of different oils for the polyarylene ether nitrile membrane material in Example 3, and comparisons of cyclic tests of the polyarylene ether nitrile membrane material. Compared to existing physically stacked two-dimensional sheet-like dense MXene membranes, the three-dimensional MXene microsphere arrangement effectively avoids the stacking of two-dimensional MXene sheets, overcoming the limitation of separation flux. Figure 11 As shown, the pure water flux of the polyarylene ether nitrile membrane material in Comparative Example 1 is 1569.43 L·m. -2 ·h -1 As the number of coating layers increases, the flux of the composite membrane decreases, but it can still be maintained at a high level.

[0088] This invention uses sodium dodecyl sulfonate (SDS, 0.02 mg / mL) as a surfactant and a water-in-hexane emulsion (hexane:water = 1:100) to test the oil-water emulsion separation ability of polyarylene ether nitrile membrane materials. The polyarylene ether nitrile membrane material in Example 3 is used to test the separation ability of different types of water-in-oil emulsions.

[0089] The hydrophilicity and underwater oleophobicity of composite membranes endow them with the ability to selectively separate surfactant-stabilized oil / water emulsions. For example... Figure 12 As shown, the emulsion flux of CM-0 reaches 516.35 L·m -2 ·h -1 The retention rate was only 83.67%. With the increase of the number of coating layers, the amount of hydrophilic substances increased, and the emulsion flux of the polyarylene ether nitrile membrane material decreased significantly, from 311.19 L·m⁻¹ in CM-1. -2 ·h -1 Reduced to 98.51 L·m in CM-5 -2 ·h -1 However, the rejection rate for surfactant-stabilized oil-water emulsions increased significantly, from 98.81% to 99.68%. Considering both emulsion flux and rejection rate, the CM-3 polyarylene ether nitrile membrane material with the best overall performance was selected to evaluate its separation performance for different types of oil-in-water emulsions. Figure 13 As shown, the CM-3 polyarylene ether nitrile membrane material can achieve good separation of oil-water emulsions stabilized by different surfactants. (e.g., n-hexane: 215.15 L·m⁻¹) -2 ·h -1 99.56%; n-Heptane: 194.65 L·m -2 ·h -1 99.43%; petroleum ether: 181.74 L·m -2 ·h -1 99.2%; isooctane: 167.30 L·m -2 ·h -1 99.64%. To evaluate the durability and recyclability of the composite membrane, the CM-3 polyarylether nitrile membrane material was subjected to 10 cycle tests. Figure 14 As shown, the emulsion flux and rejection rate of the CM-3 polyarylether nitrile membrane material can still reach 179.82 L·m. -2 ·h -1 And 98.99%. This demonstrates that the polyarylene ether nitrile membrane material of the present invention has excellent ability to separate oil-water emulsions. (5)

[0091] The polyarylene ether nitrile membrane material prepared in Example 3 was used to conduct a photocatalytic degradation performance test on pollutants, in order to test the effect of the coupling of photocatalytic technology and membrane separation technology on the antifouling ability of the separation membrane and its ability to treat organic pollutants in oily wastewater.

[0092] To evaluate the actual degradation capacity of the photocatalytic polyarylether nitrile membrane material, PMS and four dyes (methylene blue, crystal violet, Congo red, and methyl orange) were selected as oxidants and target pollutants, respectively, with the polyarylether nitrile membrane material serving as the catalyst, for photocatalytic experiments. Figure 15 The figure shows a comparison of the photocatalytic degradation performance of the polyarylene ether nitrile membrane material in Example 3. After 60 minutes of light irradiation, the degradation rates of the four target pollutants—methylene blue, crystal violet, Congo red, and methyl orange—were 96.88%, 96.38%, 93.5%, and 94.64%, respectively. These data indicate that the polyarylene ether nitrile membrane material can efficiently degrade organic pollutants while maintaining good and stable photocatalytic self-cleaning performance in the treatment of complex oily wastewater. The excellent photocatalytic properties of polyarylene ether nitrile membrane materials benefit from the Schottky heterojunction photocatalyst formed by the tight bonding of CdS and MXene microspheres. On the one hand, under visible light excitation, CdS generates photogenerated electrons and holes. These photogenerated electrons are rapidly transferred from the conduction band of CdS to the conductive MXene surface through the tight coupling interface between CdS and MXene, achieving rapid carrier separation and hindering the charge complexation rate, thereby inducing the generation of reactive oxygen species (ROS). On the other hand, the three-dimensional raspberry-shaped CdS@MXene microspheres have a high specific surface area and active sites, which can effectively adsorb target pollutants in the early stage of degradation, improving degradation efficiency. During the degradation process, the generated active substances can effectively decompose the dirt and organic pollutants attached to the surface of the photocatalyst through redox reactions, degrading them into harmless water and carbon dioxide. (6)

[0094] The polyarylene ether nitrile membrane material prepared in Example 3 was used to verify, through light absorption test, that the introduction of photothermal treatment in the oil-water separation process can solve the irreversible membrane fouling accumulated during operation through in-situ self-cleaning. That is, through the photothermal effect, the surface temperature of the composite membrane can be increased, effectively reducing the viscosity of the oil.

[0095] MXene materials exhibit excellent light absorption properties across a wide wavelength range, effectively absorbing sunlight and converting it into heat energy, such as... Figure 16The figure shows a comparison of the photothermal effect of the polyarylene ether nitrile membrane material in Example 3. After simulated solar irradiation, compared with the pure PEN membrane, the CM-3 polyarylene ether nitrile membrane material modified with photothermal material functionalization showed a significant temperature change, rapidly rising to 85.34℃ within 30 seconds. The mechanism by which the photothermal conversion characteristics of the PEN polyarylene ether nitrile membrane material improves the membrane's antifouling performance in this invention includes the following two aspects: First, under the excitation of a specific light source, the PEN polyarylene ether nitrile membrane material utilizes the photothermal conversion of MXene hybrid material to achieve a significant increase in membrane temperature in a short time, which can greatly reduce the viscosity of high-viscosity oil and effectively remove oil stains from the membrane surface; Second, the excellent photothermal conversion performance of the composite membrane can promote the photocatalytic degradation of organic pollutants, and the photothermal-photocatalytic synergy enhances the antifouling ability of the separation membrane in treating complex oily wastewater.

[0096] The above experiments demonstrate that this invention presents a three-dimensional raspberry-like CdS@MXene heterojunction structure with photothermal-photocatalytic synergy, designed based on three-dimensional MXene microspheres. This structure is combined with PVA-TA hydrogel via hydrogen bonding and chemical crosslinking, and assembled onto the surface of a polyarylene ether nitrile separation membrane with a hydrogel interfacial adhesive layer using a simple spraying method. By constructing high-density chemical anchoring points, a chemically bonded gradient hydrogel layer, and coupling nano-reinforcement effects with multiple bonds to form a multi-scale synergistic stabilization strategy of multi-bonding-gradient functionalization-nano-interpenetrating enhancement, the stability of the hydrogel structure and its interfacial force with the base membrane are effectively improved, resulting in a durable, synergistically wastewater-resistant gel membrane material that combines photothermal-photocatalysis and high-efficiency oil-water emulsion separation capabilities. The results show that the ordered arrangement of the three-dimensional raspberry-like CdS@MXene microspheres effectively solves the problem of dense stacking of two-dimensional MXene sheets, overcoming the limitation of separation flux. The pure water flux of the composite membrane can reach 883.23 L·m⁻¹. -2 ·h -1 The emulsion flux of surfactant-stabilized oil-water emulsions can reach 215.15 L·m. -2 ·h -1The rejection rate reached as high as 99.64%. The separation membrane, synergistically modified with gradient durable gel and three-dimensional raspberry-like CdS@MXene microspheres, exhibited a contact angle reduced to 26.67° and an underwater oil contact angle increased to 159.16°, indicating hydrophilic and underwater superoleophobic properties, and excellent anti-oil properties. Furthermore, the composite membrane maintained excellent structural and chemical stability even after long-term water rinsing, sandpaper abrasion, tape peeling, and ultrasonic treatment, as well as prolonged exposure to harsh environments. In addition, the three-dimensional raspberry-like CdS@MXene heterojunction structure endowed the composite membrane with excellent photocatalytic and photothermal conversion properties. After 60 minutes of visible light irradiation, the degradation rates of methylene blue, crystal violet, Congo red, and methyl orange reached 96.88%, 96.38%, 93.5%, and 94.64%, respectively. Simultaneously, the composite membrane reached a temperature of 85.34℃ after 30 seconds of simulated sunlight irradiation, effectively reducing the viscosity of the oil contaminants to be separated. Therefore, the gradient durable hydrogel-based polyarylether membrane material developed in this invention, which combines photothermal conversion, photocatalytic self-cleaning, and anti-oil adhesion, has significant application advantages and prospects in the purification of complex emulsified oily wastewater.

[0097] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-layer antifouling polyarylether nitrile membrane material, characterized in that, The invention includes a polyarylene ether nitrile base film and a composite layer coated on the surface of the polyarylene ether nitrile base film. The composite layer includes three-dimensional raspberry-shaped CdS@MXene microspheres. The preparation method of the three-dimensional raspberry-shaped CdS@MXene microspheres includes the following steps: (1) Mix the aqueous solution of polymethyl methacrylate with the MXene suspension, stir and react, separate after the reaction, wash and dry to obtain three-dimensional MXene microspheres; (2) Mix the three-dimensional MXene microspheres with CdCl2 aqueous solution, stir magnetically, then add thiourea, continue stirring, and place at 160-200℃ for hydrothermal reaction. After the reaction is completed, separate, wash and dry to obtain the three-dimensional raspberry-shaped CdS@MXene microspheres. The preparation method of the multi-antifouling polyarylene ether nitrile membrane material includes the following steps: S1 Constructs a surface-activated polyarylene ether nitrile film: Polyarylene ether nitrile, polyethylene glycol and surface segregating agent are dissolved together in an organic solvent, heated and stirred until completely dissolved to obtain a casting solution; the casting solution is coated onto the surface of a glass plate by a scraper, and then immersed in a zinc-containing coagulation bath to solidify and form a film, rinsed, and a polyarylene ether nitrile activated film is obtained and stored in deionized water for later use. S2 Constructs the hydrogel interfacial bonding layer: Take a mixture of silane coupling agent, ethanol and water, place the polyarylene ether nitrile activated membrane in the mixture, shake it, then take it out and rinse it to obtain a polyarylene ether nitrile-based membrane, and store it in deionized water for later use. S3 Preparation of multi-antifouling polyarylene ether nitrile membrane materials: A composite liquid containing three-dimensional raspberry-like CdS@MXene microspheres was sprayed onto a polyarylene ether nitrile-based membrane and dried to obtain the multi-fouling antifouling polyarylene ether nitrile membrane material.

2. The multi-fouling antifouling polyarylether nitrile membrane material according to claim 1, characterized in that, In step (2), the mass ratio of the three-dimensional MXene microspheres to CdCl2 and thiourea is 0.1-0.3:0.3-0.8:0.

4.

3. The multi-fouling antifouling polyarylether nitrile membrane material according to claim 1, characterized in that, In step (2), the magnetic stirring time is 8-12h, the stirring time after adding thiourea is 0.5-1.5h, and the hydrothermal reaction time is 10-15h.

4. The multi-fouling antifouling polyarylether nitrile membrane material according to claim 1, characterized in that, In step S3, a composite liquid containing three-dimensional raspberry-shaped CdS@MXene microspheres is sprayed 1-5 times, and each spray is dried before the next spray is performed.

5. The multi-antifouling polyarylene ether nitrile membrane material according to claim 1, characterized in that, In step S3, the composite liquid containing three-dimensional raspberry-shaped CdS@MXene microspheres includes three-dimensional raspberry-shaped CdS@MXene microspheres, polyvinyl alcohol, and a surface segregating agent.

6. The multi-fouling antifouling polyarylether nitrile membrane material according to claim 5, characterized in that, The mass ratio of polyvinyl alcohol to surface segregating agent is 1:0.8-1.2.

Images