A method for preparing a rapidly dissolving reverse osmosis base membrane, the reverse osmosis base membrane obtained therefrom, and its applications.
By adding amphiphilic block copolymers during the reverse osmosis membrane preparation process to form modified polysulfone and polyamide layers, the problem of slow TOC leaching rate is solved, achieving efficient TOC leaching and rapid membrane stability, and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-04-03
AI Technical Summary
Existing reverse osmosis membranes have a slow TOC leaching rate during use, resulting in severe initial water pollution, affecting process stability, and increasing production costs and time.
By adding amphiphilic block copolymers during the preparation process, a reverse osmosis base membrane with a larger surface area and optimized pore distribution is prepared. A modified polysulfone layer and a polyamide layer are formed by a non-solvent-induced phase transition method, thereby improving the TOC dissolution rate.
This achieves efficient TOC leaching, reduces the initial TOC leaching amount, ensures membrane performance stability and rapid attainment of water quality standards, and lowers production costs.
Smart Images
Figure CN119701689B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of reverse osmosis membrane preparation technology, specifically to a method for preparing a rapidly leached reverse osmosis membrane, the reverse osmosis membrane obtained therefrom, and its applications. Background Technology
[0002] In the fields of pharmaceutical and electronic-grade ultrapure water, there are stringent requirements for the TOC (Total Organic Carbon) content in the water. Reverse osmosis (RO) elements efficiently remove dissolved impurities, ions, organic matter, and microorganisms from the water. RO systems provide a high-quality water source for subsequent treatment processes, ensuring the final ultrapure water quality. It not only ensures the stringent water quality requirements during manufacturing but also reduces the burden on subsequent treatment processes, guarantees the stability of the production process, and reduces equipment wear and maintenance costs. Reverse osmosis technology has become an indispensable core component in the preparation of ultrapure water.
[0003] Currently, the mainstream reverse osmosis membrane is a composite membrane, composed of a polysulfone support layer (base membrane) and an ultrathin polyamide functional layer. Although numerous reverse osmosis manufacturers both domestically and internationally add organic matter during production to modify the membrane or ensure its preservation performance before operation, the base membrane carries a large amount of organic matter. During initial commissioning and actual use, the membrane itself generates a significant amount of total organic matter (TOC). Due to the membrane's inherent characteristics, the interaction between TOC and the membrane significantly impacts its leaching rate. Furthermore, the base membrane's porous structure also significantly affects TOC leaching efficiency and continuous leaching. Therefore, before installation, a large amount of water and energy is required to repeatedly flush the membrane to remove TOC, preventing disruption to the system's normal operation.
[0004] In summary, the main disadvantages of existing reverse osmosis membranes include: 1. During the preparation or use process, the membrane surface easily releases a high amount of TOC, especially when new membranes are put into use, the TOC leaching phenomenon is more obvious, resulting in heavy water pollution in the early stage and affecting the stability of the process; 2. Although some existing membrane materials have a certain TOC leaching control capability, the leaching rate is slow and cannot effectively reduce the leached substances in a short time, resulting in a longer "membrane washing" process or pretreatment stage in the early stage of membrane use, which increases production costs and time.
[0005] In view of this, the present invention is hereby proposed. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing a rapidly dissolving reverse osmosis membrane, the resulting reverse osmosis membrane, and its applications. The reverse osmosis membrane of this invention has a membrane structure with a larger surface area and optimized pore distribution, improving the membrane's dissolution efficiency and ensuring the uniform and rapid release of the desired substances during the dissolution process. The reverse osmosis membrane prepared based on this membrane significantly improves the TOC dissolution rate.
[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:
[0008] In a first aspect, the present invention provides a method for preparing a rapidly leached reverse osmosis base membrane, the preparation method comprising:
[0009] A pre-casting solution containing polysulfone and a solution containing an amphiphilic block copolymer are mixed to obtain a casting solution;
[0010] The casting solution is coated onto the surface of a substrate to obtain a substrate with a wet film layer; the substrate with the wet film layer is immersed in a coagulation bath, and a base film with a modified polysulfone layer is obtained by a non-solvent-induced phase transition method.
[0011] The base membrane with the modified polysulfone layer is sequentially contacted with an aqueous monomer solution containing m-phenylenediamine and an oil monomer solution containing trimesoyl chloride, and then cured to form a polyamide layer, thereby obtaining the rapidly dissolving reverse osmosis base membrane.
[0012] Preferably, the mass ratio of the polysulfone to the amphiphilic block copolymer is (12-20):(0.001-10).
[0013] Preferably, the casting solution comprises, by mass percentage: 12-20% polysulfone and 0.001-10% amphiphilic block copolymer, with the balance being a mixed solvent.
[0014] Preferably, the structure of the amphiphilic block copolymer includes any one or a combination of at least two of the following: AB type copolymer, ABA type copolymer, or ABC type copolymer;
[0015] The polymer segments A, B, and C are each independently selected from any one of polyacrylic acid, polyacrylamide, polyethylene oxide, poly-4-vinylpyridine, glycidyl acrylate, poly-N-isopropylacrylamide, polystyrene, polymethyl methacrylate, polybenzyl methacrylate, poly-4-hydroxymethylstyrene, or polyhexafluorobutyl methacrylate, and each polymer segment A, B, and C contains at least one hydrophilic segment and one hydrophobic segment.
[0016] Preferably, the polysulfone has a molecular weight of 10,000 to 100,000 Da.
[0017] Preferably, the molecular weight of the amphiphilic block copolymer is 2000-50000 Da.
[0018] Preferably, the preparation steps of the polysulfone-containing pre-casting solution include:
[0019] Polysulfone is dissolved in an organic solvent, heated and stirred, and then degassed under vacuum to obtain the polysulfone-containing precast film solution.
[0020] Preferably, the heating and stirring temperature is 50–70°C, and the heating and stirring time is 12–24 hours.
[0021] Preferably, the polysulfone-containing precast film liquid comprises, by mass percentage, 10-20% polysulfone, with the balance being an organic solvent.
[0022] Preferably, the organic solvent includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.
[0023] Preferably, the preparation step of the solution containing the amphiphilic block copolymer includes:
[0024] The amphiphilic block copolymer is dissolved in a good solvent, and self-assembly is carried out by adding a poor solvent dropwise to form nanoparticles of the amphiphilic block copolymer. Then, a mixed solvent of the good and poor solvents is added and stirred to dilute the solution to obtain the solution containing the amphiphilic block copolymer.
[0025] Preferably, the good solvent includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.
[0026] Preferably, the unsuitable solvent includes any one or a combination of at least two of water, methanol, ethanol, or acetone.
[0027] Preferably, the mass ratio of the amphiphilic block copolymer, good solvent, poor solvent, mixed solvent and precast film liquid is 1:(1~20):(1~20):(1~200):(100~500).
[0028] Preferably, in the mixed solvent, the mass ratio of the good solvent to the bad solvent is (10-90):(10-90).
[0029] Preferably, the temperature for self-assembly by adding the unsuitable solvent is 10–40°C, and the self-assembly time is 0.5–2 h.
[0030] Preferably, the temperature for stirring and diluting is 10–40°C, and the stirring and diluting time is 0.5–2 hours.
[0031] Preferably, the substrate comprises a nonwoven fabric.
[0032] Preferably, the coagulation bath comprises any one or a combination of at least two of the following: water, methanol, ethanol, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone.
[0033] Preferably, the temperature of the coagulation bath is 20–60°C.
[0034] Preferably, the thickness of the modified polysulfone layer is 20–50 μm.
[0035] Preferably, the aqueous monomer solution containing m-phenylenediamine comprises, by mass percentage: 0.5-4% m-phenylenediamine, with the remainder being an aqueous solvent.
[0036] Preferably, the oil-phase monomer solution containing trimesoyl chloride comprises, by mass percentage: 0.01-0.3% trimesoyl chloride, with the remainder being an oil-phase solvent.
[0037] Preferably, the aqueous solvent comprises water.
[0038] Preferably, the aqueous solvent further includes any one or a combination of at least two of dimethyl sulfoxide, methanol, or isopropanol.
[0039] Preferably, the oil phase solvent includes any one or a combination of at least two of hexane, heptane, or isoalkanes.
[0040] Preferably, the curing temperature is 70–100°C and the curing time is 2–60 min.
[0041] Preferably, the thickness of the polyamide layer is 100–500 nm.
[0042] In a second aspect, the present invention provides a reverse osmosis base membrane, which is prepared by the preparation method described in the first aspect.
[0043] Preferably, the reverse osmosis base membrane comprises a nonwoven fabric layer, a modified polysulfone composite layer, and a polyamide layer stacked sequentially.
[0044] Preferably, the pore size of the reverse osmosis base membrane is 10–400 nm.
[0045] Preferably, the pore size distribution parameters of the reverse osmosis base membrane include: the pore volume of pores with a pore size of 200-250 nm accounts for 80-100% of the total pore volume.
[0046] Preferably, the TOC leaching amount of the reverse osmosis base membrane is 0.1–20 ppm / dm³. 2The TOC leaching rate of the reverse osmosis base membrane is 0.003–1 ppm / dm³. 2 / min.
[0047] Preferably, the flux of the reverse osmosis base membrane is 58 LMH or higher.
[0048] Preferably, the desalination rate of the reverse osmosis base membrane is above 99%.
[0049] Thirdly, the present invention provides an application of the reverse osmosis base membrane as described in the second aspect in the preparation of ultrapure water.
[0050] Compared with the prior art, the present invention has the following beneficial effects:
[0051] (1) By adding an amphiphilic block copolymer during the preparation of the base membrane, the pore structure of the base membrane is more uniform. After the reverse osmosis membrane is prepared, TOC is efficiently dissolved, significantly improving the dissolution rate of TOC, and there is no continuous dissolution.
[0052] (2) The amphiphilic block copolymer improves the hydrophilicity of the base membrane and has a better cleaning effect during the preparation of the reverse osmosis membrane. It can effectively reduce the initial TOC leaching of the reverse osmosis membrane material, so as to ensure that the predetermined water quality standard can be quickly achieved in the early stage of membrane use, thereby improving the performance stability of the membrane and reducing the adverse effects in the production process. Attached Figure Description
[0053] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0054] Figure 1 The pore size distribution diagram of the reverse osmosis base membrane provided in Example 3.
[0055] Figure 2 A pore size distribution diagram of the reverse osmosis base membrane provided for Comparative Example 1.
[0056] Figure 3 The TOC leaching comparison diagrams are shown for the reverse osmosis base membranes provided in Examples 1-7 and the reverse osmosis base membranes provided in Comparative Examples 1-3. Detailed Implementation
[0057] Unless otherwise defined herein, scientific and process terms used in conjunction with this invention should have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms should be clear; however, in any case of potential ambiguity, the definitions provided herein take precedence over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.
[0058] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0059] The embodiments and examples of the present invention will be described in detail below. However, those skilled in the art will understand that the following embodiments and examples are for illustrative purposes only and should not be considered as limiting the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specified, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.
[0060] In a first aspect, the present invention provides a method for preparing a rapidly leached reverse osmosis base membrane, the preparation method comprising:
[0061] A pre-casting solution containing polysulfone and a solution containing an amphiphilic block copolymer are mixed to obtain a casting solution;
[0062] The casting solution is coated onto the surface of a substrate to obtain a substrate with a wet film layer; the substrate with the wet film layer is immersed in a coagulation bath, and a base film with a modified polysulfone layer is obtained by a non-solvent-induced phase transition method.
[0063] The base membrane with the modified polysulfone layer is sequentially contacted with an aqueous monomer solution containing m-phenylenediamine and an oil monomer solution containing trimesoyl chloride, and then cured to form a polyamide layer, thereby obtaining the rapidly dissolving reverse osmosis base membrane.
[0064] In this invention, by adding an amphiphilic block copolymer during the preparation of the base membrane, a more uniform pore structure is obtained. After the reverse osmosis membrane is prepared, TOC is efficiently dissolved without continuous dissolution. The amphiphilic block copolymer improves the hydrophilicity of the base membrane, resulting in better cleaning during the reverse osmosis membrane preparation process and lower initial TOC dissolution.
[0065] As an optional embodiment, the mass ratio of the polysulfone to the amphiphilic block copolymer is (12-20):(0.001-10); wherein, "12-20" can be, for example, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.; wherein, "0.001-10" can be, for example, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.
[0066] As an optional implementation, the casting solution comprises, by mass percentage: 12-20% polysulfone and 0.001-10% amphiphilic block copolymer, with the balance being a mixed solvent.
[0067] As a preferred embodiment, the polysulfone content is 12-20% based on the total mass of the casting solution as 100%, for example, it can be 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.
[0068] As a preferred embodiment, based on the total mass of the casting solution as 100%, the content of the amphiphilic block copolymer is 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.
[0069] As an optional embodiment, the mixed solvent in the casting solution includes solvent A in the pre-casting solution containing polysulfone and solvent B in the solution containing the amphiphilic block copolymer. More specifically, solvent A includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone; solvent B includes a good solvent and a poor solvent, wherein the good solvent includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone, and the poor solvent includes any one or a combination of at least two of water, methanol, ethanol, or acetone.
[0070] As an optional implementation, the structure of the amphiphilic block copolymer includes any one or a combination of at least two of the following: AB type copolymer, ABA type copolymer, or ABC type copolymer.
[0071] The polymer segments A, B, and C are each independently selected from any one of polyacrylic acid, polyacrylamide, polyethylene oxide, poly-4-vinylpyridine, glycidyl acrylate, poly-N-isopropylacrylamide, polystyrene, polymethyl methacrylate, polybenzyl methacrylate, poly-4-hydroxymethylstyrene, or polyhexafluorobutyl methacrylate, and each polymer segment A, B, and C contains at least one hydrophilic segment and one hydrophobic segment.
[0072] It should be noted that the hydrophilic segments in the above polymer chains include any one of polyacrylic acid, polyacrylamide, poly-4-vinylpyridine, glycidyl acrylate, or polyethylene oxide.
[0073] It should be noted that the hydrophobic segments in the above polymer chains include any one of polystyrene, polymethyl methacrylate, polybenzyl methacrylate, poly-4-hydroxymethylstyrene, or polyhexafluorobutyl methacrylate.
[0074] It should be noted that poly-N-isopropylacrylamide in the above polymer chain segments exhibits hydrophilicity at low temperatures and hydrophobicity at high temperatures.
[0075] In a preferred embodiment, the amphiphilic block copolymer includes any one or a combination of at least two of the following: polyacrylic acid-polymethyl methacrylate, polyethylene oxide-polybenzyl methacrylate-polyethylene oxide, or polyacrylamide-poly(4-hydroxymethylstyrene).
[0076] In a preferred embodiment, the molecular weight of the polysulfone is 10,000 to 100,000 Da, for example, it can be 10,000 Da, 20,000 Da, 30,000 Da, 40,000 Da, 50,000 Da, 60,000 Da, 70,000 Da, 80,000 Da, 90,000 Da, 100,000 Da, etc.
[0077] In a preferred embodiment, the molecular weight of the amphiphilic block copolymer is 2000-50000 Da, for example, it can be 2000 Da, 3000 Da, 4000 Da, 5000 Da, 6000 Da, 7000 Da, 8000 Da, 9000 Da, 10000 Da, 15000 Da, 20000 Da, 25000 Da, 30000 Da, 35000 Da, 40000 Da, 45000 Da, 50000 Da, etc.
[0078] In a preferred embodiment, the preparation steps of the polysulfone-containing pre-casting solution include:
[0079] Polysulfone is dissolved in an organic solvent, heated and stirred, and then degassed under vacuum to obtain the polysulfone-containing precast film solution.
[0080] In a preferred embodiment, the heating and stirring temperature is 50-70°C, for example, 50°C, 52°C, 54°C, 55°C, 56°C, 58°C, 60°C, 62°C, 64°C, 65°C, 68°C, 70°C, etc., and the heating and stirring time is 12-24 hours, for example, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, etc.
[0081] In a preferred embodiment, the polysulfone-containing precast film liquid comprises, by mass percentage, 10-20% polysulfone, with the balance being an organic solvent.
[0082] As a preferred embodiment, the polysulfone content is 10-20% based on the total mass of the polysulfone-containing precast film liquid as 100%, for example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.
[0083] In a preferred embodiment, the organic solvent in the polysulfone-containing pre-casting solution includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.
[0084] In a preferred embodiment, the preparation steps of the solution containing the amphiphilic block copolymer include:
[0085] The amphiphilic block copolymer is dissolved in a good solvent, and self-assembly is carried out by adding a poor solvent dropwise to form nanoparticles of the amphiphilic block copolymer. Then, a mixed solvent of the good and poor solvents is added and stirred to dilute the solution to obtain the solution containing the amphiphilic block copolymer.
[0086] It is important to note that the amphiphilic block copolymer is first dissolved in a good solvent, and then a poor solvent is added to form block copolymer nanoparticles through self-assembly. These nanoparticles are then added to the pre-casting solution to form the casting solution, which is then immersed in a coagulation bath to prepare the reverse osmosis base membrane through solvent-inducing phase inversion. This further results in a lower TOC dissolution rate and improved rapid TOC dissolution capability of the prepared reverse osmosis membrane. Furthermore, dilution with a mixed solvent of good and poor solvents can prevent gel formation when added to the casting solution.
[0087] In a preferred embodiment, the good solvent includes any one or a combination of at least two of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.
[0088] In a preferred embodiment, the unsuitable solvent includes any one or a combination of at least two of water, methanol, ethanol, or acetone.
[0089] In a preferred embodiment, the mass ratio of the amphiphilic block copolymer, good solvent, poor solvent, mixed solvent and pre-casting solution is 1:(1~20):(1~20):(1~200):(100~500);
[0090] Among them, good solvents: "1~20" can be, for example, 1, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, etc.;
[0091] Among them, the undesirable solvents: "1 to 20" can be, for example, 1, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, etc.
[0092] Among them, the mixed solvent: "1~200" can be, for example, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, etc.;
[0093] The precast film liquid “100-500” can be, for example, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 220, 240, 250, 260, 280, 300, 320, 340, 350, 360, 380, 400, 420, 440, 450, 460, 480, 500, etc.
[0094] It should be noted that the "good solvent" in the above proportions refers to the "good solvent" in "dissolving the amphiphilic block copolymer in a good solvent"; the "bad solvent" in the above proportions refers to the "bad solvent" in "self-assembly by adding a bad solvent dropwise"; and the "mixed solvent" in the above proportions refers to the "mixed solvent" in "adding a mixed solvent of good and bad solvents and stirring to dilute". The mass ratios of the good and bad solvents in this "mixed solvent" are shown in the following paragraph.
[0095] In a preferred embodiment, the mass ratio of the good solvent to the bad solvent in the mixed solvent is (10-90):(10-90), for example, it can be 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, etc.
[0096] In a preferred embodiment, the temperature for self-assembly by adding the unsuitable solvent is 10–40°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc., and the self-assembly time is 0.5–2 hours, for example, 0.5 hours, 0.6 hours, 0.8 hours, 1 hour, 1.2 hours, 1.4 hours, 1.5 hours, 1.6 hours, 2 hours, etc.
[0097] In a preferred embodiment, the temperature for stirring and diluting is 10–40°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc., and the stirring and diluting time is 0.5–2 hours, for example, 0.5 hours, 0.6 hours, 0.8 hours, 1 hour, 1.2 hours, 1.4 hours, 1.5 hours, 1.6 hours, 2 hours, etc.
[0098] In a preferred embodiment, the substrate comprises a nonwoven fabric.
[0099] In a preferred embodiment, the coagulation bath comprises any one or a combination of at least two of the following: water, methanol, ethanol, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone.
[0100] In a preferred embodiment, the temperature of the coagulation bath is 20 to 60°C, for example, it can be 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, etc.
[0101] In a preferred embodiment, the thickness of the modified polysulfone layer is 20 to 50 μm, for example, it can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc.
[0102] It should be noted that the thickness of the base film is adjusted by coating it onto a substrate layer (such as non-woven fabric) and then smoothing it with a scraper of a certain thickness. By controlling the thickness of the scraper to be within the range of 20 to 50 μm, the thickness of the prepared base film can also reach between 20 and 50 μm.
[0103] In a preferred embodiment, the aqueous monomer solution containing m-phenylenediamine comprises, by mass percentage: 0.5-4% m-phenylenediamine, with the remainder being an aqueous solvent.
[0104] In a preferred embodiment, based on the total mass of the aqueous monomer solution containing m-phenylenediamine as 100%, the content of m-phenylenediamine is 0.5% to 4%, for example, it can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.5%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, etc.
[0105] In a preferred embodiment, the oil-phase monomer solution containing pyromellitic chloride comprises, by mass percentage: 0.01-0.3% pyromellitic chloride, with the remainder being an oil-phase solvent.
[0106] In a preferred embodiment, based on the total mass of the oil-phase monomer solution containing trimesoyl chloride as 100%, the content of trimesoyl chloride is 0.01% to 0.3%, for example, it can be 0.01%, 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.16%, 0.18%, 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, etc.
[0107] In a preferred embodiment, the aqueous solvent includes water.
[0108] In a preferred embodiment, the aqueous solvent further includes any one or a combination of at least two of dimethyl sulfoxide, methanol, or isopropanol.
[0109] In a preferred embodiment, the oil phase solvent includes any one or a combination of at least two of hexane, heptane, or isoalkanes.
[0110] In a preferred embodiment, the curing temperature is 70-100℃, for example, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the curing time is 2-60min, for example, 2min, 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, etc.
[0111] In a preferred embodiment, the thickness of the polyamide layer is 100-500 nm, for example, it can be 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc.
[0112] In a second aspect, the present invention provides a reverse osmosis base membrane, which is prepared by the preparation method described in the first aspect.
[0113] In a preferred embodiment, the reverse osmosis base membrane comprises a nonwoven fabric layer, a modified polysulfone layer (the modified polysulfone layer is a composite layer of polysulfone and amphiphilic block copolymer), and a polyamide layer stacked sequentially.
[0114] In a preferred embodiment, the pore size of the reverse osmosis base membrane is 10-400 nm, for example, it can be 10 nm, 50 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 280 nm, 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, etc.
[0115] In a preferred embodiment, the pore size distribution of the reverse osmosis base membrane includes: the pore volume of pores with a pore size of 200-250 nm accounts for 80-100% of the total pore volume, for example, 80%, 85%, 90%, 95%, 100%, etc.
[0116] In a preferred embodiment, the TOC leaching amount of the reverse osmosis base membrane is 0.1–20 ppm / dm³. 2 For example, it could be 0.1 ppm / dm 2 0.5ppm / dm 2 1ppm / dm 2 2ppm / dm 2 3ppm / dm 2 4ppm / dm 2 5ppm / dm 2 6ppm / dm 2 7ppm / dm 2 8ppm / dm 2 9ppm / dm 2 10ppm / dm 2 11ppm / dm 2 12ppm / dm 2 13ppm / dm 2 14ppm / dm 2 15ppm / dm 2 16ppm / dm 2 17ppm / dm 2 18ppm / dm 2 19ppm / dm 2 20ppm / dm 2 wait.
[0117] In a preferred embodiment, the TOC leaching rate of the reverse osmosis base membrane is 0.003–1 ppm / dm³. 2 / min, for example, could be 0.003ppm / dm 2 / min, 0.004ppm / dm 2 / min, 0.005ppm / dm2 / min, 0.006ppm / dm 2 / min, 0.007ppm / dm 2 / min, 0.008ppm / dm 2 / min, 0.009ppm / dm 2 / min, 0.01ppm / dm 2 / min, 0.02ppm / dm 2 / min, 0.03ppm / dm 2 / min, 0.04ppm / dm 2 / min, 0.05ppm / dm 2 / min, 0.06ppm / dm 2 / min, 0.08ppm / dm 2 / min, 0.09ppm / dm 2 / min, 0.1ppm / dm 2 / min, 0.2ppm / dm 2 / min, 0.3ppm / dm 2 / min, 0.4ppm / dm 2 / min, 0.5ppm / dm 2 / min, 0.6ppm / dm 2 / min, 0.7ppm / dm 2 / min, 0.8ppm / dm 2 / min, 0.9ppm / dm 2 / min, 1ppm / dm 2 / min etc.
[0118] It is important to note that the dissolution amount here refers to the TOC dissolution amount after the first soaking. "First soaking" means immersing the reverse osmosis membrane in pure water at 25°C for 30 minutes, then removing it and measuring the difference in TOC concentration before and after soaking; this is the TOC dissolution amount. Similarly, repeated soakings using fresh pure water constitute the second, third, and so on, representing the second and third TOC dissolution rates. Furthermore, since the TOC concentration decreases with each subsequent soak, only the TOC dissolution rate of the first two soaks is compared: TOC dissolution rate = (First TOC dissolution amount - Second TOC dissolution amount) / Soaking time.
[0119] In a preferred embodiment, the flux of the reverse osmosis base membrane is 58 LMH or higher, for example, it can be 58 LMH, 59 LMH, 60 LMH, 61 LMH, 62 LMH, 63 LMH, 64 LMH, 65 LMH, 66 LMH, 67 LMH, 68 LMH, etc.
[0120] In a preferred embodiment, the desalination rate of the reverse osmosis base membrane is above 99%, for example, it can be 99.00%, 99.10%, 99.20%, 99.30%, 99.40%, 99.50%, 99.60%, 99.70%, 99.80%, 99.90%, etc.
[0121] Thirdly, the present invention provides an application of the reverse osmosis base membrane as described in the second aspect in the preparation of ultrapure water.
[0122] The present invention will be further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.
[0123] Example 1
[0124] This embodiment provides a method for preparing a rapidly leaching reverse osmosis base membrane, the preparation method comprising the following steps:
[0125] S1. Preparation of casting solution:
[0126] 540g of polysulfone granules (molecular weight 71000Da) were dissolved in 2260g of DMF, heated and stirred at 60℃ for 12h, and degassed under vacuum to obtain a pre-casting solution containing polysulfone, which was set aside. 10g of polyacrylic acid-polymethyl methacrylate (molecular weight 11000Da) was dissolved in 90g of THF, and 100g of water was slowly added dropwise to THF. The mixture was stirred for 1h to allow self-assembly, forming nanoparticles of amphiphilic block copolymer. Then, 100g of a 1:1 mixture of water and DMF was added, and the mixture was stirred for another 2h to obtain the solution containing the amphiphilic block copolymer, which was set aside. The pre-casting solution containing polysulfone and the solution containing the amphiphilic block copolymer were mixed to obtain the casting solution.
[0127] S2. Preparation of a base film with a modified polysulfone layer:
[0128] The casting solution obtained in S1 was coated onto a nonwoven fabric, smoothed with a 35μm doctor blade, and then immersed in pure water at 30℃ to obtain a base film with a modified polysulfone layer (the thickness of the modified polysulfone layer on the base film is 35μm).
[0129] S3. Preparation of the polyamide layer:
[0130] The base membrane with the modified polysulfone layer obtained in S2 was first immersed in a 2 wt% m-phenylenediamine solution (solvent is water) for 1 min. The excess aqueous phase on the surface was removed with a rubber roller. Then, it was coated with a 0.1 wt% trimesoyl chloride solution (solvent is hexane) for 1 min. The excess oil phase on the surface was poured off, and it was placed in a 100°C forced-air drying oven for 10 min to form a polyamide layer with a thickness of 200 nm, thus obtaining the rapidly dissolving reverse osmosis base membrane. The reverse osmosis base membrane comprises a non-woven fabric layer, a polysulfone and polyacrylate-polymethyl methacrylate composite layer, and a polyamide layer stacked sequentially.
[0131] Example 2
[0132] This embodiment provides a method for preparing a rapidly leaching reverse osmosis base membrane, the preparation method comprising the following steps:
[0133] S1. Preparation of casting solution:
[0134] 500g of polysulfone granules (molecular weight 65000Da) were dissolved in 2300g of DMF, heated and stirred at 60℃ for 12h, and degassed under vacuum to obtain a pre-casting solution containing polysulfone, which was set aside. 20g of polyethylene oxide-polybenzyl methacrylate-polyethylene oxide (molecular weight 21300Da) was dissolved in 80g of THF, and 100g of water was slowly added dropwise to THF. The mixture was stirred for 1h to allow self-assembly, forming nanoparticles of amphiphilic block copolymer. Then, 200g of a 1:1 mixture of water and DMF was added, and the mixture was stirred for another 1h to obtain the solution containing the amphiphilic block copolymer, which was set aside. The pre-casting solution containing polysulfone and the solution containing the amphiphilic block copolymer were mixed to obtain the casting solution.
[0135] S2. Preparation of a base film with a modified polysulfone layer:
[0136] The casting solution obtained in S1 was coated onto a nonwoven fabric, smoothed with a 35μm doctor blade, and then immersed in a mixed solvent of water and DMF at a mass ratio of 1:4 at 25℃ to obtain a base film with a modified polysulfone layer (the thickness of the modified polysulfone layer on the base film is 35μm).
[0137] S3. Preparation of the polyamide layer:
[0138] The base membrane with the modified polysulfone layer obtained in S2 was first immersed in a 3.5 wt% m-phenylenediamine solution (solvent is water) for 1 min. The excess aqueous phase on the surface was removed with a rubber roller. Then, it was coated with a 0.15 wt% trimesoyl chloride solution (solvent is hexane) for 1 min. The excess oil phase on the surface was poured off, and it was placed in a 100°C forced-air drying oven for 30 min to form a polyamide layer with a thickness of 250 nm, thus obtaining the rapidly dissolving reverse osmosis base membrane. The reverse osmosis base membrane comprises a nonwoven base membrane layer, a polysulfone and polyethylene oxide-polymethyl methacrylate-polyethylene oxide composite layer, and a polyamide layer stacked sequentially.
[0139] Example 3
[0140] This embodiment provides a method for preparing a rapidly leaching reverse osmosis base membrane, the preparation method comprising the following steps:
[0141] S1. Preparation of casting solution:
[0142] 300g of polysulfone granules (molecular weight 71000Da) were dissolved in 2300g of DMF, heated and stirred at 60℃ for 12h, and degassed under vacuum to obtain a pre-casting solution containing polysulfone, which was set aside. 40g of polyacrylamide-poly(4-hydroxymethylstyrene) (molecular weight 8800Da) was dissolved in 60g of THF, and 100g of water was slowly added dropwise to THF. The mixture was stirred for 1h to allow self-assembly, forming nanoparticles of amphiphilic block copolymer. Then, 200g of a 1:1 mixture of water and DMF was added, and the mixture was stirred for another 1h to obtain the solution containing the amphiphilic block copolymer, which was set aside. The pre-casting solution containing polysulfone and the solution containing the amphiphilic block copolymer were mixed to obtain the casting solution.
[0143] S2. Preparation of a base film with a modified polysulfone layer:
[0144] The casting solution obtained in S1 was coated onto a nonwoven fabric, smoothed with a 35μm doctor blade, and then immersed in a mixed solvent of water and DMF at a mass ratio of 1:4 at 25℃ to obtain a base film with a modified polysulfone layer (the thickness of the modified polysulfone layer on the base film is 35μm).
[0145] S3. Preparation of the polyamide layer:
[0146] The base membrane with the modified polysulfone layer obtained in S2 was first immersed in a 3 wt% m-phenylenediamine solution (solvent is water) for 1 min. The excess aqueous phase on the surface was removed with a rubber roller. Then, it was coated with a 0.15 wt% trimesoyl chloride solution (solvent is heptane) for 1 min. The excess oil phase on the surface was poured off, and it was placed in a 100°C forced-air drying oven for 15 min to form a polyamide layer with a thickness of 320 nm, thus obtaining the rapidly dissolving reverse osmosis base membrane. The reverse osmosis base membrane comprises a non-woven fabric base membrane layer, a polysulfone and polyacrylic acid-polymethyl methacrylate composite layer, and a polyamide layer stacked sequentially.
[0147] Example 4
[0148] This embodiment provides a method for preparing a rapidly dissolving reverse osmosis base membrane. The only difference from Example 1 is that in S1, polyacrylic acid-polymethyl methacrylate is replaced with an equal mass of polyacrylic acid-polymethyl methacrylate. The other steps are completely consistent with Example 1.
[0149] Example 5
[0150] This embodiment provides a method for preparing a rapidly dissolving reverse osmosis base membrane. The only difference from Example 1 is that in S1, polyacrylic acid-polymethyl methacrylate is replaced with an equal mass of polyacrylamide-polymethyl methacrylate. The other steps are completely consistent with Example 1.
[0151] Example 6
[0152] This embodiment provides a method for preparing a rapidly dissolving reverse osmosis base membrane. The only difference from Embodiment 1 is that, in S1, the method for preparing the solution containing the amphiphilic block copolymer is as follows:
[0153] 10g of polyacrylic acid-polymethyl methacrylate (molecular weight 11000Da) was directly dissolved in a mixed solvent of 50g DMF, 90g THF and 150g water, and stirred at room temperature for 3h to obtain a solution containing an amphiphilic block copolymer. Other steps were exactly the same as in Example 1.
[0154] Example 7
[0155] This embodiment provides a method for preparing a rapidly dissolving reverse osmosis base membrane. The only difference from Embodiment 1 is that, in S1, the method for preparing the solution containing the amphiphilic block copolymer is as follows:
[0156] 10g of polyacrylic acid-polymethyl methacrylate (molecular weight 11000Da) was dissolved in 140g of THF, and 150g of water was slowly added dropwise to THF. The mixture was stirred for 1 hour to allow self-assembly, and the solution containing the amphiphilic block copolymer was obtained for later use. The other steps were completely consistent with those in Example 1.
[0157] Comparative Example 1
[0158] This comparative example provides a method for preparing a reverse osmosis base membrane, the method comprising the following steps:
[0159] S1. Preparation of casting solution:
[0160] 540g of polysulfone granules (molecular weight 71000Da) were dissolved in 2260g of DMF, heated and stirred at 60℃ for 12h, and degassed under vacuum to obtain the casting solution.
[0161] S2. Preparation of polysulfone-based films:
[0162] The casting solution obtained in S1 was coated onto a nonwoven fabric, smoothed with a 35μm doctor blade, and then immersed in pure water at 30℃ to obtain a base film with a polysulfone layer (the thickness of the polysulfone layer on the base film is 35μm).
[0163] S3. Preparation of the polyamide layer:
[0164] The polysulfone-based membrane obtained in S2 was first immersed in a 2 wt% m-phenylenediamine solution (solvent is water) for 1 min, and the excess aqueous phase on the surface was removed with a rubber roller. Then, it was coated with a 0.1 wt% trimesoyl chloride solution (solvent is hexane) for 1 min, and the excess oil phase on the surface was poured off. It was then placed in a 100°C forced-air drying oven for 10 min to form a polyamide layer with a thickness of 190 nm, thus obtaining the rapidly dissolving reverse osmosis base membrane. The reverse osmosis base membrane comprises a nonwoven base membrane layer, a polysulfone layer, and a polyamide layer stacked sequentially.
[0165] Comparative Example 2
[0166] This comparative example provides a method for preparing a reverse osmosis base membrane, the method comprising the following steps:
[0167] S1. Preparation of casting solution:
[0168] 540g of polysulfone granules (molecular weight 71000Da) were dissolved in 2260g of DMF, heated and stirred at 60℃ for 12h, and degassed under vacuum to obtain the casting solution.
[0169] S2. Preparation of polysulfone-based films:
[0170] The casting solution obtained in S1 was coated onto a nonwoven fabric, smoothed with a 35μm doctor blade, and then immersed in pure water at 30℃ to obtain a base film with a polysulfone layer (the thickness of the polysulfone layer on the base film is 35μm).
[0171] S3. Preparation of amphiphilic block copolymer films:
[0172] 10g of polyacrylic acid-polymethyl methacrylate (molecular weight 11000 Da) was dissolved in 90g of THF. 100g of water was slowly added dropwise to THF, and the mixture was stirred for 1h to allow self-assembly, forming nanoparticles of amphiphilic block copolymer. Then, 100g of a 1:1 mixture of water and DMF was added, and the mixture was stirred for another 2h to obtain the solution containing the amphiphilic block copolymer, which was then set aside. The solution containing the amphiphilic block copolymer was then coated onto the polysulfone-based membrane obtained in step S2, smoothed with a scraper, and then immersed in pure water at 30°C to form an amphiphilic block copolymer membrane, resulting in a bilayer modified composite membrane.
[0173] S4. Preparation of the polyamide layer:
[0174] The bilayer modified composite membrane obtained from S3 was first immersed in a 2wt% m-phenylenediamine solution (solvent is water) for 1 min, and the excess aqueous phase on the surface was removed with a rubber roller. Then, it was coated with a 0.1wt% trimesoyl chloride solution (solvent is hexane) for 1 min, and the excess oil phase on the surface was poured off. It was then placed in a 100°C forced-air drying oven for 10 min to form a polyamide layer with a thickness of 200 nm, thus obtaining the rapidly dissolving reverse osmosis base membrane. The reverse osmosis base membrane comprises a nonwoven base membrane layer, a polysulfone layer, an amphiphilic block copolymer layer, and a polyamide layer stacked sequentially.
[0175] Comparative Example 3
[0176] This comparative example provides a method for preparing a reverse osmosis base membrane. The only difference from Example 1 is that in S1, polyacrylic acid-polymethyl methacrylate is replaced with an equal mass of polyacrylic acid, while the other steps are the same as in Example 1.
[0177] Test Example 1
[0178] Pore size distribution test
[0179] Test samples: the rapidly dissolving reverse osmosis base membranes provided in Examples 1-7 and the reverse osmosis base membranes provided in Comparative Examples 1-3.
[0180] Test method: The pore size distribution of the reverse osmosis base membrane was tested using a pore size distribution tester.
[0181] The specific test results are shown in Table 1 below. Figure 1 and Figure 2 As shown:
[0182] Table 1
[0183]
[0184]
[0185] As shown in Table 1, the membrane prepared by the invention's rapid dissolution reverse osmosis base membrane has a membrane structure with a larger surface area and optimized pore distribution, and the pore size distribution is more uniform.
[0186] Test Example 2
[0187] TOC dissolution test
[0188] Test samples: the rapidly dissolving reverse osmosis base membranes provided in Examples 1-7 and the reverse osmosis base membranes provided in Comparative Examples 1-3.
[0189] Test method: First soaking: This refers to immersing the reverse osmosis membrane in pure water at 25°C for 30 minutes, then removing it and testing the TOC content in the solution. This process is repeated for the 2nd to 5th soakings. The TOC value of the pure water used for membrane soaking is approximately 0.4 ppm. At low TOC levels, the interference from pure water cannot be ignored.
[0190] The specific test results are shown in Table 2 below. Figure 3 As shown:
[0191] Table 2
[0192]
[0193] As shown in Table 2, this invention designs a hydrophilic base membrane with a uniform pore structure, possessing a larger surface area and optimized pore distribution, thus improving the membrane's dissolution efficiency and ensuring the uniform and rapid release of desired substances during the dissolution process. The reverse osmosis membrane prepared based on this base membrane significantly enhances the TOC dissolution rate.
[0194] Test Example 3
[0195] Test samples: the rapidly dissolving reverse osmosis base membranes provided in Examples 1-8 and the reverse osmosis base membranes provided in Comparative Examples 1-4.
[0196] Test method: The test pressure was 1.03 MPa, the raw water was a 1500 ppm sodium chloride aqueous solution, the concentrate flow rate was 3.5 GPM, the pH of the raw water was 7-7.5, and the ambient temperature was 25℃.
[0197] The flux is calculated by the volume of water passing through the reverse osmosis membrane within a certain time period; the calculation formula is: F=V / (A×T), where V is the volume of water passing through the reverse osmosis membrane per unit time, A is the effective membrane area, and T is time.
[0198] The desalination rate is calculated using the concentrations of the concentrate and the permeate. The formula is: R = (1 - C1 / C0) × 100%, where C1 is the concentration of the concentrate and C0 is the concentration of the permeate.
[0199] The specific test results are shown in Table 3 below:
[0200] Table 3
[0201]
[0202]
[0203] As shown in Table 3, the reverse osmosis membranes prepared using the above steps exhibit increased flux due to the increased hydrophilicity of the base membrane in the examples. This modification has little impact on the membrane's desalination rate. This demonstrates that the reverse osmosis membrane prepared on this base membrane can effectively reduce the TOC leaching of the reverse osmosis membrane material and accelerate the TOC leaching process, ensuring that the membrane can quickly reach the predetermined water quality standards in the initial stage of use. This, in turn, improves the membrane's performance stability and reduces adverse effects during the production process.
[0204] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a rapidly leaching reverse osmosis base membrane, characterized in that, The preparation method includes: A pre-casting solution containing polysulfone and a solution containing an amphiphilic block copolymer are mixed to obtain a casting solution; The casting solution is coated onto the surface of a substrate to obtain a substrate with a wet film layer; the substrate with the wet film layer is immersed in a coagulation bath, and a base film with a modified polysulfone layer is obtained by a non-solvent-induced phase transition method. The base membrane with the modified polysulfone layer is sequentially contacted with an aqueous monomer solution containing m-phenylenediamine and an oil monomer solution containing trimesoyl chloride, and then cured to form a polyamide layer, thereby obtaining the rapidly dissolving reverse osmosis base membrane. The preparation steps of the solution containing the amphiphilic block copolymer include: dissolving the amphiphilic block copolymer in a good solvent, performing self-assembly by adding a poor solvent dropwise to form nanoparticles of the amphiphilic block copolymer, and then adding a mixed solvent of the good and poor solvents for stirring and dilution to obtain the solution containing the amphiphilic block copolymer.
2. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The mass ratio of the polysulfone to the amphiphilic block copolymer is (12~20):(0.001~10).
3. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The casting solution comprises, by mass percentage: 12-20% polysulfone and 0.001-10% amphiphilic block copolymer, with the remainder being a mixed solvent; The mixed solvent in the casting solution includes the solvent in the pre-casting solution containing polysulfone, and the solvent in the solution containing the amphiphilic block copolymer.
4. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1 or 2, characterized in that, The structure of the amphiphilic block copolymer includes any one or a combination of at least two of the following: AB type copolymer, ABA type copolymer, or ABC type copolymer; Among them, polymer segments A, B, and C are each independently selected from polyacrylic acid, polyacrylamide, polyethylene oxide, poly-4-vinylpyridine, glycidyl acrylate, and poly- N - Any one of isopropylacrylamide, polystyrene, polymethyl methacrylate, polybenzyl methacrylate, poly-4-hydroxymethylstyrene, or polyhexafluorobutyl methacrylate, and the polymer segments A, B, and C contain at least one hydrophilic segment and one hydrophobic segment.
5. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1 or 2, characterized in that, The molecular weight of the polysulfone is 10,000 to 100,000 Da.
6. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1 or 2, characterized in that, The molecular weight of the amphiphilic block copolymer is 2000~50000 Da.
7. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The preparation steps of the polysulfone-containing pre-casting solution include: Polysulfone is dissolved in an organic solvent, heated and stirred, and then degassed under vacuum to obtain the polysulfone-containing precast film solution.
8. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 7, characterized in that, The heating and stirring temperature is 50~70℃, and the heating and stirring time is 12~24 h.
9. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The polysulfone-containing precast film liquid comprises, by mass percentage: 10-20% polysulfone, with the balance being organic solvent.
10. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 9, characterized in that, The organic solvent includes tetrahydrofuran, N,N -Dimethylformamide, N,N -dimethylacetamide, dimethyl sulfoxide or N Any one or a combination of at least two of the following methylpyrrolidones.
11. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The good solvent includes tetrahydrofuran, N,N -Dimethylformamide, N,N -dimethylacetamide, dimethyl sulfoxide or N Any one or a combination of at least two of the following methylpyrrolidones.
12. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The unsuitable solvents include any one or a combination of at least two of water, methanol, ethanol, or acetone.
13. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The mass ratio of the amphiphilic block copolymer, good solvent, poor solvent, mixed solvent and precast film solution is 1:(1~20):(1~20):(1~200):(100~500).
14. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, In the mixed solvent, the mass ratio of the good solvent to the bad solvent is (10~90):(10~90).
15. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The temperature for self-assembly by adding the poor solvent is 10~40℃, and the self-assembly time is 0.5~2 h.
16. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The temperature for stirring and diluting is 10~40℃, and the stirring and diluting time is 0.5~2 h.
17. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The substrate includes nonwoven fabric.
18. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The coagulation bath includes water, methanol, ethanol, acetone, N,N -Dimethylformamide, N,N -Dimethylacetamide or N Any one or a combination of at least two of the following methylpyrrolidones.
19. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The temperature of the coagulation bath is 20~60℃.
20. The method for preparing a rapidly leaching reverse osmosis base membrane according to claim 1, characterized in that, The thickness of the modified polysulfone layer is 20~50 μm.
21. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The aqueous monomer solution containing m-phenylenediamine comprises, by mass percentage: 0.5-4% m-phenylenediamine, with the remainder being an aqueous solvent.
22. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The oil-phase monomer solution containing pyromellitic chloride comprises, by mass percentage: 0.01-0.3% pyromellitic chloride, with the remainder being an oil-phase solvent.
23. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 21, characterized in that, The aqueous solvent includes water.
24. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 23, characterized in that, The aqueous solvent also includes any one or a combination of at least two of dimethyl sulfoxide, methanol, or isopropanol.
25. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 22, characterized in that, The oil phase solvent includes any one or a combination of at least two of hexane, heptane, or isoalkanes.
26. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The curing temperature is 70~100℃, and the curing time is 2~60 min.
27. The method for preparing a rapidly leaching reverse osmosis membrane according to claim 1, characterized in that, The thickness of the polyamide layer is 100~500 nm.
28. A reverse osmosis base membrane, characterized in that, The reverse osmosis base membrane is prepared by the preparation method according to any one of claims 1 to 27.
29. The reverse osmosis membrane according to claim 28, characterized in that, The reverse osmosis base membrane comprises a non-woven fabric layer, a modified polysulfone composite layer, and a polyamide layer stacked sequentially.
30. The reverse osmosis membrane according to claim 28, characterized in that, The pore size of the reverse osmosis base membrane is 10~400 nm.
31. The reverse osmosis membrane according to claim 28, characterized in that, The pore size distribution parameters of the reverse osmosis base membrane include: the pore volume of pores with a pore size of 200~250 nm accounts for 80~100% of the total pore volume.
32. The reverse osmosis membrane according to claim 28, characterized in that, The TOC leaching rate of the reverse osmosis base membrane is 0.1~20 ppm / dm³. 2 The TOC leaching rate of the reverse osmosis base membrane is 0.003~1 ppm / dm³. 2 / min.
33. The reverse osmosis membrane according to claim 28, characterized in that, The flux of the reverse osmosis base membrane is above 58 LMH.
34. The reverse osmosis membrane according to claim 28, characterized in that, The desalination rate of the reverse osmosis membrane is over 99%.
35. The application of a reverse osmosis base membrane according to any one of claims 28 to 34 in the preparation of ultrapure water.
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