Semi-interpenetrating polymer network polyamide reverse osmosis membrane with anti-pollution and chlorine-resistant performance as well as preparation method and application of semi-interpenetrating polymer network polyamide reverse osmosis membrane

Abstract

The invention discloses a semi-interpenetrating polymer network polyamide reverse osmosis membrane with anti-fouling and chlorine-resistant performance and a preparation method and application thereof, the reverse osmosis membrane comprises a supporting base membrane and a semi-interpenetrating polymer network polyamide film located on the surface of the supporting base membrane, the supporting base membrane is an asymmetric composite membrane, the semi-interpenetrating network polyamide film material is of a semi-interpenetrating three-dimensional structure of a hydrophilic polyethylene glycol network and a polyamide cross-linked network, and is formed by polymerizing a pegylated polyamine aromatic monomer and multi-element acyl chloride on a water-oil interface. The semi-interpenetrating network polyamide reverse osmosis membrane disclosed by the invention shows the characteristic of body chlorine resistance, can be directly applied to the desalination process of seawater containing high-concentration active chlorine, and obviously enhances the resistance of the reverse osmosis membrane material to active chlorine and biological pollution on the basis of keeping the excellent separation performance of the traditional full-aromatic polyamide reverse osmosis membrane; the method has a wide application prospect in the fields of advanced sewage treatment, seawater desalination, high-quality drinking water preparation and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of membrane separation technology, and particularly relates to a semi-interpenetrating network polyamide reverse osmosis membrane with anti-fouling and chlorine resistance performance as well as a preparation method and application thereof. BACKGROUND

[0002] With the intensification of global industrialization, rapid economic development and intensification of climate change, the shortage of fresh water resources has become a global problem. Reverse osmosis technology, as an energy-saving, environmentally friendly and efficient seawater desalination and brackish water desalination technology, shows good market application prospects. The long-term stability of the reverse osmosis membrane as the core component of the technology is crucial to the normal operation of the membrane water treatment system.

[0003] In actual seawater desalination processes, non-specific or specific adsorption of suspended particles, colloids and microorganisms in the feed liquid on the membrane surface leads to serious membrane fouling problems, which can cause membrane pore blockage, thus reducing the separation performance of the membrane, increasing the operating pressure, increasing the maintenance cost and shortening the service life, and seriously limiting the long-term development of the membrane material. According to the types of pollutants in the feed liquid, the pollution is divided into inorganic, organic and microbial pollution. For the former, an acid-base cleaning process is usually used; for the latter, the water body is usually sterilized and pre-disinfected in engineering applications, and the chlorine-containing sterilizing agent has a significant sterilization performance. However, through the pre-chlorination of raw water, the sterilizing agent may still have a certain residue in the feed water body, and the chlorine resistance of most commercial reverse osmosis membranes is poor, and the aromatic ring and amide nitrogen in the separation layer will be quickly attacked by chlorine, resulting in a sharp decline in the performance of the reverse osmosis membrane.

[0004] Due to the inherent characteristics of polyamide materials, the current mainstream commercial reverse osmosis membranes cannot fundamentally solve the oxidation problem of the membrane material. Therefore, in order to meet the more extensive separation requirements and reduce the production cost, it has become a technical problem to be solved in the field to improve the separation capacity, chlorine resistance and anti-pollution performance of the polyamide reverse osmosis membrane. SUMMARY

[0005] In order to overcome the deficiencies in the prior art, the main purpose of the present application is to provide a semi-interpenetrating network polyamide film material (PEG-DAB), which is a semi-interpenetrating three-dimensional structure of a hydrophilic polyethylene glycol network and a polyamide crosslinking network, and is polymerized from polyglycolated polyamine aromatic monomers and polyacyl chloride at a water-oil interface.

[0006] The second purpose of the present application is to provide a preparation method of the semi-interpenetrating network polyamide film material, which is obtained by first performing a nucleophilic addition reaction and then performing a reduction reaction.

[0007] The third object of the present application is to provide a semi-interpenetrating network polyamide reverse osmosis membrane with anti-fouling and chlorine resistance, which comprises a support base film and a semi-interpenetrating network polyamide film on the surface of the support base film, and has excellent separation capacity, chlorine resistance and anti-fouling performance.

[0008] The fourth object of the present application is to provide a preparation method of the semi-interpenetrating network polyamide reverse osmosis membrane with anti-fouling and chlorine resistance, which is simple in process and easy to scale up.

[0009] The fifth object of the present application is to provide an application of the semi-interpenetrating network polyamide reverse osmosis membrane with anti-fouling and chlorine resistance in deep treatment of sewage, seawater desalination and preparation of high-quality drinking water.

[0010] To achieve the above objects, the present application adopts the following technical solutions:

[0011] In the first aspect of the present application, a semi-interpenetrating network polyamide film material is provided, and its chemical structure is as follows: In which n = 16.

[0012] In the second aspect of the present application, a preparation method of the semi-interpenetrating network polyamide film material is provided, and the technical route is as follows:

[0013]

[0014] The preparation method comprises the following steps:

[0015] (1) 3,5-dinitrobenzoyl chloride (compound 1), polyethylene glycol monomethyl ether (compound 2) and triethylamine are subjected to nucleophilic addition reaction in an organic solvent a to obtain a reaction intermediate product (compound 3);

[0016] (2) The reaction intermediate product is subjected to reduction reaction in the presence of an inert gas atmosphere and under the action of an organic solvent b and a reducing agent SnCl.2H2O to obtain the target product (compound 4).

[0017] As a preferred, in step (1), the molar ratio of 3,5-dinitrobenzoyl chloride, polyethylene glycol monomethyl ether and triethylamine is 5:1:8;

[0018] And / or the organic solvent a is anhydrous dichloromethane;

[0019] And / or the chemical structure of the reaction intermediate product is as follows: n = 16;

[0020] And / or the time of the nucleophilic addition reaction is 12-36 hours.

[0021] Preferably, in step (2), the molar ratio of the reaction intermediate to the reducing agent SnCl2.2H2O is 1:12;

[0022] and / or the organic solvent b is super-dry ethyl acetate;

[0023] and / or the reducing reaction is refluxed for 24 hours under the condition of 78℃ and magnetic stirring in the atmosphere of inert gas.

[0024] In a third aspect of the present application, a semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance is provided, comprising a support base membrane and a semi-interpenetrating network polyamide film on the surface of the support base membrane; wherein:

[0025] The support base membrane is an asymmetric composite membrane, one side of which comprises a non-woven fabric and the other side of which comprises a polymer layer;

[0026] The semi-interpenetrating network polyamide film is composed of the aforementioned semi-interpenetrating network polyamide film material, and is a semi-interpenetrating three-dimensional structure of a hydrophilic polyethylene glycol network and a polyamide crosslinking network, which is polymerized from polyglycolated polyamine aromatic monomers and polyacyl chlorides at a water-oil interface.

[0027] Preferably, the molecular weight cut-off (MWCO) of the support base membrane is 50 kDa.

[0028] The support base membrane is an ultrafiltration flat membrane or an ultrafiltration hollow fiber membrane, and the forming material of the polymer layer is selected from one or more of polysulfone, polyethersulfone, polysulfone, polyimide, polyamide, polyetherimide, polyacrylonitrile, polymethyl methacrylate, polyethylene, polypropylene, and polyvinylidene fluoride.

[0029] In a fourth aspect of the present application, a preparation method of the semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance is provided, comprising the following steps:

[0030] (a) taking polyamine and polyacyl chloride as polymer raw materials, and performing in-situ amide reaction for 1-10 minutes at a water-oil interface by interfacial polymerization to obtain a semi-interpenetrating network polyamide film;

[0031] (b) taking out the semi-interpenetrating network polyamide film, releasing it in deionized water first, and then placing it on the support base membrane for natural air drying for 1-4 hours to obtain the semi-interpenetrating network polyamide reverse osmosis membrane.

[0032] Preferably, in step (a), the polyacyl chloride is selected from one or more of trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, cyclohexane tricarbonyl chloride, and cyclopentane tricarbonyl chloride;

[0033] and / or the organic solvent used in the water-oil interface is selected from one of n-hexane, n-heptane, dodecane, and toluene;

[0034] and / or the concentration of the organic phase solution of the polybasic acid chloride is 0.2wt%;

[0035] and / or the concentration of the aqueous solution of the polybasic amine is 1.0wt%.

[0036] More preferably, the in-situ amide reaction time is 5 minutes.

[0037] In a fifth aspect, the application provides the application of the semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the deep treatment of sewage, seawater desalination and the preparation of high-quality drinking water.

[0038] Compared with the prior art, the application has the following beneficial effects:

[0039] 1. The semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the application is simple and easy to control, and is easy to scale up, and has a wide application prospect in the fields of deep treatment of sewage, seawater desalination and preparation of high-quality drinking water.

[0040] 2. The semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the application exhibits strong hydrophilicity on the surface, effectively improves the antifouling performance by forming a dense hydration layer, and prevents the adsorption behavior of pollutants on the membrane surface and in the membrane holes.

[0041] 3. The semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the application exhibits the characteristics of bulk chlorine resistance due to its unique polyethylene glycol-polyamide semi-interpenetrating network structure, can be directly applied to the seawater desalination process containing high-concentration active chlorine, breaks through the strict limitation (<0.1 ppm) of traditional commercial composite polyamide reverse osmosis membranes on the content of active chlorine in seawater, and significantly enhances the resistance of the reverse osmosis membrane material to active chlorine and biological pollution on the basis of maintaining the excellent separation performance of traditional wholly aromatic polyamide reverse osmosis membranes.

[0042] 4. The semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the application has high water flux and high rejection rate, and the water treatment effect is remarkable.

[0043] 5. The organic phase layer (front surface) of the composite membrane prepared by the traditional interfacial polymerization process is exposed to the outside, the semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the application exposes the water phase layer (back surface) to the surface layer of the composite membrane by reversing the polyamide layer structure, can realize the optimization of the antifouling performance, chlorine resistance and permeation performance of the semi-interpenetrating network polyamide reverse osmosis membrane, effectively improves the antifouling efficiency and chlorine resistance of the reverse osmosis membrane, and maximizes the operation stability in long-term operation. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1Schematic diagram of the synthesis route of the semi-interpenetrating network polyamide film material in the examples.

[0045] Figure 2 Schematic diagram of the preparation process of the semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance in the examples.

[0046] Figure 3 SEM images of the surface of the semi-interpenetrating network polyamide reverse osmosis membrane (RO-R-PEG750) in the examples: (a) front side; (b) back side.

[0047] Figure 4 Solid surface zeta potential analysis results of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples.

[0048] Figure 5 Static water contact angle (WCA) analysis results of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples.

[0049] Figure 6 Salt rejection rate and pure water flux of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples under single feed conditions.

[0050] Figure 7 The semi-interpenetrating network polyamide reverse osmosis membrane in the examples was evaluated for antibacterial performance using E. coli and by paper disc diffusion method; (a) SEM images of the surface of the RO-R-PEG750 membrane after the antibacterial experiment; (b) SEM images of the surface of the RO-R-MPD membrane after the antibacterial experiment.

[0051] Figure 8 Dynamic cycle anti-adhesion results of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples under simulated seawater conditions.

[0052] Figure 9 Long-term static chlorine resistance results of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples.

[0053] Figure 10 UV absorption spectra of the semi-interpenetrating network polyamide reverse osmosis membrane in the examples before and after seawater desalination. DETAILED DESCRIPTION

[0054] In order to more fully understand the technical solutions, objectives and advantages of the present application, the technical effects produced by the present application will be further described in detail below in conjunction with the drawings and specific examples. Obviously, the described examples are only some of the embodiments of the present application, not all. It should be noted that for those skilled in the art, other embodiments obtained without departing from the concept of the present application all belong to the protection scope of the present application.

[0055] Unless otherwise indicated, the experimental procedures employed in the following examples are conventional procedures.

[0056] Unless otherwise indicated, the materials and reagents used in the following examples are commercially available.

[0057] Example 1

[0058] This example provides a method for preparing a semi-interpenetrating network polyamide film material, the synthetic route is shown in Figure 1 which comprises the following steps:

[0059] (1) Dissolve polyethylene glycol monomethyl ether (750 Da) (3.0 g, 4 mmol, 1.0 equivalent) and triethylamine (4.473 mL, 32 mmol, 8.0 equivalents) in 50 mL of anhydrous dichloromethane (CH2Cl2) under ice bath conditions, and dropwise add a 30 mL solution of 3,5-dinitrobenzoyl chloride (44.6112 g, 20 mmol, 5.0 equivalents) in anhydrous CH2Cl2. The dropwise addition process lasts about 1 hour. After the dropwise addition is complete, the reaction mixture is stirred at room temperature overnight. After the reaction is complete, the reaction mixture is washed with half-saturated brine three times to remove the triethylamine salt in the reaction system, the organic layer is collected and dried with anhydrous Na2SO4, concentrated to 20 mL, precipitated in 300 mL of ice ethanol, and 2.525 g of the target product is obtained (yield 67.80%). After the components containing the target product are concentrated, 3.39 g of the intermediate product is obtained (yield 79%), and the product is in the form of a brown solid. 1 HNMR (400 MHz, CDC13, 298 K) δ = 9.24 (t, J = 2.4 Hz, 1H), 9.18 (d, J = 2.6 Hz, 2H), 4.62 (m, -CH2OOC-, 2H), 3.64 (m, -OCH2CH2O-, 70H), 3.38 (s, CH3O-, 3H).

[0060] (2) Dissolve the intermediate product obtained in step (1) (1.862 g, 2.0 mmol, 1.0 equivalent) and SnCl2·2H2O (5.415 g, 24.0 mmol, 12.0 equiv.) in 30.0 mL of anhydrous ethyl acetate, place the reaction system in an oil bath preheated to 78°C, and reflux under nitrogen protection. Monitor the reaction until it is complete. After the reaction is complete, the crude product is concentrated and diluted with 100 mL of CH2Cl2, then washed with half-saturated brine three times, dried with anhydrous Na2SO4, and the organic phase is concentrated to 20 mL and precipitated in 200 mL of ice ethanol twice to obtain 1.427 g of the target product (yield: 81.29%), and the product is in the form of a brown solid. 1HNMR (400 MHz, CDC13, 298 K) δ = 6.76 (d, J = 3.2 Hz, 2H), 6.24 (d, J = 2.4 Hz, 1H), 4.43 (m, -CH20OC-, 2H), 3.64 (m, -OCH2CH20-, 76H), 3.38 (s, CH30-, 3H).

[0061] Example 2

[0062] The embodiment provides a preparation method of a semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance, and steps are as follows:

[0063] (1) taking polyamine and polyacyl chloride as polymerization raw materials, in-situ amide reaction is carried out at a water-oil interface for 5 minutes through interfacial polymerization to obtain a semi-interpenetrating network polyamide film;

[0064] (2) the semi-interpenetrating network polyamide film is taken out, released in deionized water first, and then placed on a support base film to be naturally air-dried for 1-4 hours to obtain a semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine resistance.

[0065] The preparation method of the semi-interpenetrating network polyamide film comprises the following steps: 3,5-dinitrobenzoyl chloride and polyethylene glycol monomethyl ether are subjected to nucleophilic addition reaction under the action of an initiator, and after the reaction is completed, a semi-interpenetrating network polyamide film is obtained through reduction reaction; wherein:

[0066] The molar ratio of 3,5-dinitrobenzoyl chloride, polyethylene glycol monomethyl ether and triethylamine in the nucleophilic addition reaction is 5:1:8;

[0067] The organic solvent of the nucleophilic addition reaction is anhydrous dichloromethane;

[0068] The chemical structure of the product of the nucleophilic addition reaction is as follows: Wherein n = 16;

[0069] The reduction reaction is refluxed for 24 hours under the condition of magnetic stirring at a temperature of 78 DEG C in an inert gas atmosphere;

[0070] The organic solvent of the reduction reaction is ultradry ethyl acetate;

[0071] The reducing agent of the reduction reaction is stannous chloride;

[0072] The molar ratio of the reduced substance and the reducing agent in the reduction reaction is 1:12;

[0073] The molecular weight cut-off of the support base film is 50 kDa;

[0074] The support base film is an asymmetric composite film, one side of which comprises a non-woven fabric, and the other side of which comprises a polymer layer, wherein the forming material of the polymer layer can be selected from one or more of polysulfone, polyethersulfone, polysulfone, polyimide, polyamide, polyetherimide, polyacrylonitrile, polymethyl methacrylate, polyethylene, polypropylene, and polyvinylidene fluoride;

[0075] The polybasic acid chloride is selected from one or more of trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, cyclohexane tricarboxylic acid chloride, and cyclopentane tricarboxylic acid chloride, and the organic solvent is selected from one of n-hexane, n-heptane, dodecane, and toluene;

[0076] The concentration of the organic phase solution of the polybasic acid chloride is 0.2wt%;

[0077] The concentration of the aqueous solution of the polyamine aromatic monomer is 1.0wt%.

[0078] Example 3

[0079] The semi-interpenetrating network polyamide reverse osmosis membrane is prepared by a conventional interfacial polymerization method, mainly including the following steps: dissolving the polyamine aromatic monomer (i.e. PEG-DAB or m-phenylenediamine (MPD)) in deionized water to prepare an aqueous phase solution with a mass fraction of 1.0wt%. In addition, trimesoyl chloride is dissolved in n-hexane to prepare an organic phase solution with a mass fraction of 0.2wt%. In a culture dish, 15mL of the aqueous phase solution and the organic phase solution are slowly poured in sequence, and after a certain period of time, a defect-free interpenetrating network polyamide nanomembrane can be obtained at the water-oil interface. In order to make the polyamine aromatic monomer and trimesoyl chloride fully react, the interfacial polymerization time is set to 5 minutes, and then the independent polyamide nanomembrane is released into a container filled with deionized water, and then transferred to a support substrate and naturally air-dried for 3 hours before being used for subsequent testing and characterization.

[0080] The organic phase layer (front side) of the composite membrane prepared by the conventional interfacial polymerization process is exposed to the outside, and by turning over the polyamide layer structure, the aqueous phase layer (back side) is exposed to the surface layer of the composite membrane, which can achieve the optimization of the anti-pollution performance, chlorine resistance and permeation of the semi-interpenetrating network polyamide reverse osmosis membrane. According to the types and preparation methods of the membrane-forming monomers of the reverse osmosis membrane, the obtained reverse osmosis membranes are respectively marked as RO-PEG750, RO-R-PEG750, RO-MPD and RO-R-MPD.

[0081] Example 1: Physical and chemical characterization of semi-interpenetrating network polyamide reverse osmosis membranes

[0082] The following quantitative experiment is set up with three repetitions, and the average value is taken.

[0083] Table 1: X-ray photoelectron spectroscopy (XPS) analysis results of semi-interpenetrating network polyamide reverse osmosis membranes

[0084]

[0085] Table 2: X-ray photoelectron spectroscopy (XPS) depth profiling analysis results of RO-R-PEG750

[0086]

[0087] The prepared semi-IPN polyamide RO membranes were analyzed by SEM analysis Figure 3 ), XPS analysis (Table 1-2), solid surface zeta potential analyzer analysis Figure 4 ), and WCA analysis Figure 5 ). In addition, by reversing the polyamide layer structure, the surface function of the membrane can be maximized.

[0088] Example 2: Analysis of separation selectivity performance

[0089] The semi-IPN polyamide RO membranes prepared in Examples 1-3 were tested for water flux and sodium chloride rejection. In a custom-made cross-flow filtration device, the test samples were pre-pressurized with pure water at 8 bar for 1 hour until the water flux was stable. Then, under a test pressure of 6 bar, pure water was used as the feed liquid, and the pure water flux of the membrane was recorded. At the same time, a 2000 ppm NaCl solution was used as the feed liquid, and the concentrations of inorganic salts in the feed liquid and the permeate were recorded during the test to calculate the corresponding rejection rate of the membrane, as shown in Table 3. Figure 6

[0090] Example 3: Analysis of antibacterial performance

[0091] The semi-IPN polyamide RO membranes prepared in Examples 1-3 were tested for antibacterial performance, with Gram-negative Escherichia coli as the model bacteria to evaluate the antibacterial activity of the prepared semi-IPN polyamide RO membranes. Figure 7 The distribution of bacteria on the membrane surface after paper disc diffusion was shown, and the results showed that compared with RO-R-MPD, RO-R-PEG750 formed a clear antibacterial ring. Further SEM analysis of the RO-R-MPD and RO-R-PEG750 membrane surfaces showed that the RO-R-MPD membrane surface was covered with colonies, while the RO-R-PEG750 membrane surface had no bacterial colonies attached, indicating that the introduction of PEG network could effectively prevent bacterial adsorption and deposition on the membrane surface.

[0092] Example 4: Analysis of anti-adhesion performance

[0093] ​Dynamic cyclic anti-fouling experiments were performed on the semi-IPN polyamide reverse osmosis membranes prepared in Examples 1-3. In a custom-made dead-end filtration device, the test samples were pre-pressurized with pure water at 8 bar for more than 1 hour until the water flux was stable. Subsequently, under a test pressure of 6 bar, the pure water flux (JW1) of the membranes was recorded while using pure water as the feed. To better simulate seawater, 50 ppm humic acid (HA), 1000 ppm bovine serum albumin (BSA), and 50 ppm E. coli were introduced into the feed as representative contaminants under a fixed stirring speed of 500 rpm, and the permeate flux (JW2) was recorded every 15 minutes for 5 hours of continuous filtration. After the 5-hour test, the membranes were cleaned with deionized water until the permeation performance was stable, and the permeate flux (JW3) was recorded to evaluate the recovery of water flux and the anti-fouling performance. After about 24 hours of continuous testing, the results showed that the semi-IPN polyamide reverse osmosis membranes maintained a water flux recovery rate of more than 95% in each cycle, which was significantly better than the RO-R-MPD membrane (58.82%). Figure 8

[0094] Effect Example 5: Long-term anti-chlorine performance test

[0095] Long-term anti-chlorine performance tests were performed on the semi-IPN polyamide reverse osmosis membranes prepared in Examples 1-3. In a custom-made cross-flow device, the test samples were pre-pressurized with pure water at 8 bar for more than 1 hour until the water flux was stable. Subsequently, under a test pressure of 6 bar, the pure water flux and desalination rate of the membranes were recorded while using pure water as the feed under conditions containing 2000 ppm sodium chloride. Static chlorine experiments were performed on the RO-R-MPD and RO-R-PEG750 membranes using an active chlorine solution of sodium hypochlorite with an initial concentration of 50 ppm, and the pH value was adjusted as needed, and the solution was replaced every 24 hours. After the membrane pieces were soaked in the solution for a certain period of time, they were washed with deionized water and then tested for their basic separation selectivity performance. The test results showed that the rejection rate of sodium chloride of the RO-R-MPD membrane significantly decreased in different pH sodium hypochlorite solutions under a cumulative contact of 8000 ppm·h of chlorine conditions, indicating that the polyamide active layer had been completely destroyed. In contrast, the RO-R-PEG750 membrane still maintained a rejection rate of more than 90% for sodium chloride under the same conditions, showing its excellent anti-chlorine performance. Figure 9

[0096] Effect Example 6: Seawater desalination capacity analysis

[0097] ​​The semi-interpenetrating network polyamide reverse osmosis membranes prepared by Examples 1-3 were further evaluated for their purification ability of seawater. The experimental water was taken from Qingdao Jiaozhou Bay (near the Yellow Sea). After the seawater was collected, it was first pre-filtered by 0.7 μm glass fiber filter paper to remove suspended particles. In a custom-made cross-flow filtration device, the pretreated seawater was used as the feed liquid, and the test membrane samples were pre-pressurized in pure water at 8 bar for more than 1 hour until the water flux was stable. Subsequently, the initial water flux was recorded at a test pressure of 6 bar, and the permeation flux was recorded every 24 hours for 14 days to evaluate the separation stability of the semi-interpenetrating network polyamide reverse osmosis membrane. The results show that Figure 10 ), the UV absorbance at 254 nm was reduced from 0.2956 cm -1 -1to 0.0051 cm -1 -1, with a purification efficiency of more than 98%, indicating that the semi-interpenetrating network polyamide reverse osmosis membrane has application potential in efficient and sustainable separation processes such as seawater desalination.

[0098] In summary, the semi-interpenetrating network polyamide reverse osmosis membrane prepared by the present application has both antifouling and chlorine resistance, and can be prepared in situ by a one-step method relying on the traditional interfacial polymerization, providing a new idea for the large-scale and low-cost production of functional membrane materials in various fields. The polyamine aromatic monomer preparation method proposed by the present application can be used to customize the synthesis of new functional membrane materials.

[0099] The preferred embodiments of the present application have been described above by way of example only, not for the purpose of limiting the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A semi-interpenetrating network polyamide film material, characterized by, The chemical structure is as follows: where n = 16.

2. The method of making a semi-interpenetrating network polyamide film material of claim 1, wherein, The technical route is as follows: The preparation method comprises the following steps: (1) 3,5-dinitrobenzoyl chloride, polyethylene glycol monomethyl ether and triethylamine are subjected to nucleophilic addition reaction in an organic solvent a to obtain a reaction intermediate product; (2) The reaction intermediate product is subjected to reduction reaction in an inert gas atmosphere, in the presence of an organic solvent b and a reducing agent SnCl2·H2O, to obtain the target product, wherein n = 16.

3. The method for preparing the semi-interpenetrating network polyamide thin film material according to claim 2, characterized in that, In step (1), the molar ratio of 3,5-dinitrobenzoyl chloride, polyethylene glycol monomethyl ether and triethylamine is 5:1:8; And / or the organic solvent a is anhydrous dichloromethane; and / or the chemical structure of the reaction intermediate products is as follows: n = 16; And / or the nucleophilic addition reaction is performed for 12-36 hours.

4. The method of claim 2, wherein the semi-interpenetrating network polyamide film material is prepared by the steps of: In step (2), the molar ratio of the reaction intermediate product to SnCl2·H2O is 1:12; And / or the organic solvent b is super-dry ethyl acetate; And / or the reduction reaction is performed under reflux for 24 hours at 78°C under the condition of magnetic stirring in an inert gas atmosphere.

5. A semi-interpenetrating network polyamide reverse osmosis membrane having both antifouling and chlorine resistance performance, characterized in that, The semi-interpenetrating network polyamide membrane comprises a support base film and a semi-interpenetrating network polyamide film on the surface of the support base film; wherein: The support base film is an asymmetric composite membrane, one side of which comprises a non-woven fabric and the other side of which comprises a polymer layer; The semi-interpenetrating network polyamide film comprises the semi-interpenetrating network polyamide film material of claim 1, which is a semi-interpenetrating three-dimensional structure of a hydrophilic polyethylene glycol network and a polyamide crosslinking network, and is polymerized from polyglycolated polyamine aromatic monomers and polyacyl chlorides at a water-oil interface.

6. The semi-IPN polyamide reverse osmosis membrane with antifouling and chlorine resistant performance according to claim 5, wherein, The support base film is an ultrafiltration flat membrane or an ultrafiltration hollow fiber membrane, and the molecular weight cut-off is 50 kDa.

7. The semi-IPN polyamide reverse osmosis membrane with antifouling and chlorine resistant performance according to claim 6, wherein, The material for forming the polymer layer is selected from one or more of polysulfone, polyethersulfone, polysulfone sulfone, polyimide, polyamide, polyetherimide, polyacrylonitrile, polymethyl methacrylate, polyethylene, polypropylene and polyvinylidene fluoride.

8. The method for preparing a semi-interpenetrating network polyamide reverse osmosis membrane with antifouling and chlorine-resistant properties according to any one of claims 5 to 7, characterized in that, The method comprises the following steps: (a) polyamine and polyacyl chloride are used as polymerization raw materials, and in-situ amide reaction is performed at a water-oil interface for 1-10 minutes by interfacial polymerization to obtain a semi-interpenetrating network polyamide film; (b) the semi-interpenetrating network polyamide film is taken out, released in deionized water first, and then placed on the support base film and naturally air-dried for 1-4 hours to obtain the semi-interpenetrating network polyamide reverse osmosis membrane.

9. The method for preparing the semi-interpenetrating network polyamide reverse osmosis membrane with both antifouling and chlorine-resistant properties according to claim 8, characterized in that, In step (a), the polyacyl chloride is selected from one or more of trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, cyclohexane trisoyl chloride and cyclopentane trisoyl chloride; And / or the organic solvent used at the water-oil interface is selected from one of n-hexane, n-heptane, dodecane and toluene; And / or the concentration of the organic phase solution of polyacyl chloride is 0.2 wt%; And / or the concentration of the aqueous solution of polyamine is 1.0 wt%.

10. The semi-interpenetrating network polyamide reverse osmosis membrane with anti-fouling and chlorine-resistant properties is applied to sewage advanced treatment, seawater desalination and preparation of high-quality drinking water.

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