Homopore membrane as well as preparation method and application thereof

Abstract

The invention provides a pore homogenizing membrane and a preparation method and application thereof. The uniform pore membrane is obtained by curing a substrate with a self-assembly mixture on the surface; the self-assembly mixture is prepared from modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with acyl chloride. According to the invention, the amphiphilic property of poloxamer molecules is utilized to induce the poloxamer molecules to spontaneously form an ordered micelle structure in a water phase through hydrophobic-hydrophilic interaction force, and the ordered micelle structure is further stacked to form a stable highly ordered body. Furthermore, poloxamer is modified through acyl chloride, a photosensitive polymerizable functional group can be introduced into poloxamer, after curing, original ordered arrangement is'frozen 'in a polymer network, and a porous structure membrane with regular arrangement and uniform pore diameter is obtained. In addition, the structure provides a physical channel for selective transmission of water molecules, and the separation precision and stability of the membrane are improved.

Description

Technical Field

[0001] This invention belongs to the field of membrane technology, and relates to a uniformly porous membrane, its preparation method, and its application. Background Technology

[0002] In recent years, developing efficient and sustainable water treatment and reuse technologies has become a key means of alleviating water resource pressure. Among them, membrane separation technology, due to its advantages such as energy saving, environmental protection, simple operation, and high separation efficiency, has been widely used in many fields such as seawater desalination, wastewater reuse, drinking water purification, and industrial wastewater treatment, and is regarded as one of the core technologies in the field of water treatment.

[0003] However, current mainstream membrane materials (such as polyamide composite membranes and polyethersulfone membranes) still face certain bottlenecks in terms of structural control and functional regulation. On the one hand, membrane materials prepared by traditional phase inversion or interfacial polymerization methods lack precise control over pore size distribution, channel order, and thickness uniformity, leading to a "mutual constraint" between permeability and selectivity—that is, it is difficult to simultaneously achieve high water flux and high selectivity. On the other hand, membrane surfaces are prone to fouling or structural degradation, severely affecting their service life and long-term operational stability. Therefore, there is an urgent need to develop novel membrane materials and controllable assembly strategies to overcome the limitations of existing technologies in improving membrane performance and regulating structure. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a uniformly porous membrane, its preparation method, and its application. The uniformly porous membrane possesses a porous structure with regularly arranged pores and uniform pore size (e.g., Figure 2 and Figure 4 As shown in the figure, it can provide a physical channel for the selective transport of water molecules, thereby improving the separation accuracy and stability of the membrane.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a uniformly porous membrane, which is obtained by curing a substrate on which a self-assembled mixture exists on the surface;

[0007] The self-assembled mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride.

[0008] Preferably, the modified poloxamer is obtained by reacting poloxamer and acyl chloride in an organic solvent.

[0009] Preferably, the molecular weight of the poloxamer is 500 to 100,000.

[0010] Preferably, the acyl chloride is selected from methacryloyl chloride and / or acryloyl chloride.

[0011] Preferably, the molar ratio of poloxamer to acyl chloride is 1:1 to 5:1.

[0012] Preferably, the organic solvent is selected from any one or more of toluene, chloroform, acetone, dichloromethane, or tetrahydrofuran.

[0013] Preferably, the reaction temperature is 10~80℃ and the time is 1~48 h.

[0014] Preferably, the poloxamer is selected from PEO. 99 -PPO 65 -PEO 99 PEO 20 -PPO 70 -PEO 20 or PEO 41 -PPO 76- PEO 41 Any one or more of the following.

[0015] Preferably, the mass ratio of the modified poloxamer to water is (0.1~10):1.

[0016] Preferably, the curing is carried out in the presence of a crosslinking agent and an initiator.

[0017] Preferably, the crosslinking agent is selected from 1,6-hexanediol diacrylate and / or ethylene glycol dimethacrylate.

[0018] Preferably, the initiator is selected from any one or more of 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or azobisisobutyronitrile.

[0019] Preferably, the amount of the crosslinking agent is 1 to 10 wt% of the mass of the self-assembled mixture.

[0020] Preferably, the amount of the initiator is 1 to 5 wt% of the mass of the self-assembled mixture.

[0021] Preferably, the substrate is selected from polyester nonwoven fabric, polyethylene, polyvinylidene fluoride, polysulfone, polyethersulfone, inorganic ceramics, inorganic alumina, etc.

[0022] Preferably, the thickness of the uniformly porous membrane is 50 nm to 5 µm, and the pore size is 2 to 20 nm.

[0023] Secondly, the present invention provides a method for preparing the above-mentioned uniformly porous membrane, comprising the following steps:

[0024] S1: Provides a substrate on which a self-assembled mixture exists on the surface;

[0025] The self-assembly mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride;

[0026] S2: The substrate is cured in the presence of an initiator and a crosslinking agent to obtain a uniformly porous membrane.

[0027] Preferably, the curing is ultraviolet curing, and the curing time is 0.5~10 min.

[0028] Thirdly, the present invention provides an application of the above-mentioned uniformly porous membrane in water treatment.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] This invention provides a uniformly porous membrane obtained by curing a substrate with a self-assembled mixture on its surface. The self-assembled mixture comprises modified poloxamer and water, wherein the modified poloxamer is obtained by acylation of poloxamer and an acyl chloride. First, this invention utilizes the amphiphilic properties of poloxamer molecules to induce the spontaneous formation of ordered micelle structures in an aqueous phase through hydrophobic-hydrophilic interactions, further stacking to form a stable, highly ordered mass. Second, this invention modifies poloxamer with an acyl chloride, introducing photosensitive polymerizable functional groups (ester groups) into the poloxamer. After UV curing, the original ordered arrangement is "frozen" in the polymer network, resulting in a porous membrane with a regularly arranged, uniform pore size. Furthermore, this structure provides a physical channel for the selective transport of water molecules, improving the separation accuracy and stability of the membrane. Attached Figure Description

[0031] Figure 1 The above are the proton NMR spectra of F127 and F127-MA in Example 1 of this invention;

[0032] Figure 2 Images of the self-assembled phase diagram and polarized light microstructure of F127-MA blended with water;

[0033] Figure 3 This is a SEM image of the uniformly porous membrane obtained in Example 1 of the present invention;

[0034] Figure 4 The image shows the AFM phase structure and interplanar spacing curve of the uniformly porous film obtained in Example 1 of this invention.

[0035] Among them, (a) corresponds to the AFM phase structure image; (b) corresponds to the interplanar spacing curve measured by the white highlight in (a);

[0036] Figure 5 This is a graph showing the retention curves of polyethylene glycol of different molecular weights for the uniformly porous membrane obtained in Example 1 of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] To address the challenge of improving the performance of membrane materials in existing technologies, this invention provides a uniformly porous membrane, obtained by curing a substrate with a self-assembled mixture on its surface. The self-assembled mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride (methacryloyl chloride and / or acryloyl chloride). This invention does not impose any particular restriction on the source of the poloxamer; any commercially available product is acceptable.

[0039] In some embodiments of the present invention, the molecular weight of the poloxamer is 500-100,000, such as 500, 1000, 5000, 10,000, 30,000, 50,000, 80,000, or 100,000. Specifically, in some embodiments of the present invention, the poloxamer is selected from poloxamer F127 (PEO). 99 -PPO 65 -PEO 99 M w =12600), polyether 123 (PEO) 20 -PPO 70 -PEO 20 M w =5800) or Synperonic® PE / P84 (PEO 41 -PPO 76- PEO 41 M w Any one or more of (=9000).

[0040] In some preferred embodiments of the present invention, poloxamers of different molecular weights and acyl chlorides are reacted in an organic solvent. The organic solvent is selected from any one or more of toluene, chloroform, acetone, dichloromethane, or tetrahydrofuran, and the molar ratio of poloxamer to acyl chloride is 1:1 to 5:1, which can be 1:1, 2:1, 3:1, 4:1, or 5:1, etc.

[0041] In some preferred embodiments of the present invention, poloxamer and acyl chloride of different molecular weights are preferably dissolved in an organic solvent and magnetically stirred until completely dissolved; then the mixture is transferred to an oil bath at 10-80°C and reacted for 1-48 h; the mixture is washed successively with saturated sodium bicarbonate and sodium chloride until neutral, and then extracted three times with dichloromethane in a separatory funnel. The resulting organic layer is dried overnight with anhydrous magnesium sulfate, and then the solvent is removed by vacuum distillation to obtain a white powder product.

[0042] In summary, this invention uses commercially available poloxamer as a base material and leverages its amphiphilic properties to induce the spontaneous formation of ordered micelle structures in an aqueous phase through hydrophobic-hydrophilic interactions, which further accumulate to form a stable, highly ordered mass. Simultaneously, this invention modifies poloxamer with acyl chlorides, introducing photosensitive polymerizable functional groups into the poloxamer. After UV curing, the original ordered arrangement is "frozen" within the polymer network, resulting in a porous membrane with a regular arrangement and uniform pore size (2-20 nm).

[0043] The present invention also provides a method for preparing the above-mentioned uniformly porous membrane, comprising the following steps:

[0044] S1: Provides a substrate on which a self-assembled mixture exists on the surface;

[0045] The self-assembly mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride;

[0046] S2: The substrate is cured in the presence of an initiator and a crosslinking agent to obtain a uniformly porous membrane.

[0047] According to the present invention, a modified poloxamer is first provided. The preparation of the modified poloxamer is as described in the above-mentioned related content, and will not be repeated here.

[0048] Then, according to the present invention, the modified poloxamer is mixed with water to form a self-assembled mixture.

[0049] In some embodiments of the present invention, the mixing of the modified poloxamer and water is preferably carried out under stirring conditions, wherein the mass ratio of the modified poloxamer to water is (0.1~10):1, which can be 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, etc.

[0050] In some embodiments of the present invention, it is preferable to mix modified poloxamer with water, stir repeatedly until homogeneous, then add a photoinitiator and a photocrosslinking agent, mix again until homogeneous, and then coat the mixture onto a substrate to obtain a substrate with a self-assembled mixture on its surface. The amount of the crosslinking agent is 1-10 wt% of the mass of the self-assembled mixture, such as 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%; the amount of the initiator is 1-10 wt% of the mass of the self-assembled mixture, such as 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%.

[0051] In this invention, the photoinitiator is used to initiate crosslinking, and can be selected from any one or more of 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or azobisisobutyronitrile.

[0052] In this invention, the photocrosslinking agent is used in the ultraviolet light-induced photocuring process, and can be specifically selected from 1,6-hexanediol diacrylate and / or ethylene glycol dimethacrylate, preferably 1,6-hexanediol diacrylate and ethylene glycol dimethacrylate.

[0053] It should be noted that the crosslinking agent is selected from 1,6-hexanediol diacrylate and ethylene glycol dimethacrylate. Compared with 1,6-hexanediol diacrylate (or ethylene glycol dimethacrylate), the mechanical strength of the prepared membrane is insufficient.

[0054] In this invention, the substrate is used to increase the strength of the uniformly porous membrane, and can be selected from polyester nonwoven fabric, polyethylene, polyvinylidene fluoride, polysulfone, polyethersulfone, inorganic ceramics, inorganic alumina, or other flexible substrates.

[0055] In some embodiments of the present invention, the substrate is selected from polymethyl terephthalate nonwoven fabric.

[0056] According to the present invention, after obtaining the substrate, it is preferable to cure the substrate.

[0057] In this invention, the curing is preferably ultraviolet curing, and the curing time is 0.5 to 10 min, such as 0.5 min, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, etc.

[0058] After the above curing is completed, a uniformly porous membrane with regular pore size and flexible characteristics can be obtained.

[0059] Tests showed that the thickness of the uniformly porous membrane prepared according to the above preparation method provided by the present invention is 50 nm to 5 µm, and the pore size is 2 to 20 nm.

[0060] In summary, in some specific embodiments of the present invention, the method for preparing a uniformly porous membrane includes the following steps:

[0061] (1) Molecular design and synthesis: Poloxamer, a low-cost molecule, was selected as a precursor. Polymerizable groups were introduced at the tail end of the molecule through chemical synthesis. First, 100 mL of organic reagents (dichloromethanol, tetrahydrofuran) were added to a 200 mL round-bottom flask. Then, poloxamer and acyl chloride were added in a molar ratio of 1 to 5:1. The reactants were completely dissolved in the solvent using a magnetic stirrer, and the reaction was carried out at room temperature for 0 to 48 h. After the reaction was completed, the mixture was washed with saturated sodium bicarbonate and sodium chloride until neutral. Then, the mixture was extracted three times with dichloromethane in a separatory funnel. The resulting organic layer was dried overnight with anhydrous magnesium sulfate, and then the solvent was removed by vacuum distillation to obtain the modified poloxamer product.

[0062] (2) Induced self-assembly into ordered structure: The obtained product is mixed with deionized water at different mass ratios (0.1~10:1) to form a transparent or semi-transparent gel mixture. Its anisotropic structure is observed by polarized light microscopy to determine whether it forms an ordered structure such as hexagonal columnar, cubic or layered structure.

[0063] (3) Curing into a stable polymer film: Add crosslinking agent (1,6-hexanediol diacrylate and / or ethylene glycol dimethacrylate) to the self-assembled mixture and coat it on non-woven fabric or other flexible substrate. Irradiate with a UV curing system for 0.5 to 10 minutes to complete the crosslinking reaction and prepare a uniformly porous film with regular pore size and flexible characteristics.

[0064] In summary, the preparation method provided by this invention uses inexpensive poloxamer as a base material, employs mild reaction conditions, and has a simple synthetic route, making it suitable for large-scale preparation. Furthermore, the uniformly porous membrane in this invention has an adjustable structure and diverse functions. Specifically, the pore size and membrane thickness can be controlled by adjusting the molecular weight, concentration, and crosslinking conditions of poloxamer to adapt to different separation requirements. Moreover, the uniformly porous membrane is flexible, processable, and highly adaptable, possessing good flexibility and mechanical properties, and can be applied to various carriers and complex water treatment conditions.

[0065] Based on this, the present invention also provides an application of the above-mentioned uniformly porous membrane in water treatment.

[0066] In some embodiments of the present invention, the prepared uniformly porous membrane is cut to a suitable size, and its separation performance is tested using an ultrafiltration cup apparatus. Polyethylene glycol solutions with concentrations of 1 g / L and molecular weights of 10, 20, 100, and 300 kDa are prepared as the initial solutions. The filtrate after membrane treatment is collected and used to determine the total organic carbon removal rate. The uniformly porous membrane exhibits a retention rate of over 90% for 100 kDa molecules.

[0067] To further illustrate the present invention, the following embodiments provide a detailed description. The experimental materials used in the following embodiments of the present invention are all commercially available products.

[0068] Example 1

[0069] Using 100 mL of anhydrous dichloromethane as a solvent, add 25 g of poloxamer F127 (PEO) 99 -PPO 65 -PEO 99 M w =12600), 0.3 g of methacryloyl chloride was slowly added using a dropping funnel, and the mixture was reacted at room temperature under a nitrogen atmosphere for 14 h. After the reaction was complete, the mixture was washed successively with saturated sodium bicarbonate and sodium chloride until neutral, and then extracted three times with dichloromethane in a separatory funnel. The resulting organic layer was dried overnight with anhydrous magnesium sulfate, and then the solvent was removed by vacuum distillation to obtain a white powder product (abbreviated as: F127-MA).

[0070] Add 100 mg of the above white powder product to a 1.5 mL centrifuge tube, add 40 mg of deionized water, stir repeatedly to mix evenly, then add about 2 mg of photoinitiator (2,2-dimethoxy-phenylacetophenone) and 2 mg of photocrosslinking agent (1,6-hexanediol diacrylate), mix evenly again, and then coat it onto a nonwoven fabric support layer. Then, use a UV curing system to irradiate with UV light for 60 s to obtain a fully cured sample, i.e., a uniformly porous membrane.

[0071] The above-mentioned poloxamer F127 and white powder product were analyzed on a Bruker AVANCE AV III 400 liquid NMR spectrometer at the Physical and Chemical Experiment Center of the University of Science and Technology of China, using deuterated chloroform as solvent, and their proton NMR spectra were obtained. Figure 1 As can be seen, F127-MA exhibits a double bond hydrogen signal at the methacryloyloxy terminus at 5.0~6.5 ppm, indicating the successful introduction of the double bond.

[0072] Figure 2 Images of the self-assembled phase diagram and polarized light microstructure of F127-MA blended with water. Figure 2 It was obtained from the DM750 at the Integrated Instrument Research and Sharing Center of the University of Science and Technology of China. Figure 2 It is known that when the poloxamer mass ratio is in the range of 0–51 wt%, the solution exhibits a micellar phase structure. At this point, molecules self-assemble to form a micellar structure, and only an extinction state is observed under a polarizing microscope (POM), indicating that this phase structure has isotropic properties, with relatively loose molecular arrangement and low overall order. With further increases in poloxamer concentration, when the mass ratio reaches 51–92 wt%, the self-assembled structure transforms into a hexagonal columnar structure. This structure exhibits strong directionality, with molecules arranged regularly to form hexagonal columnar morphology. Under POM, this structure displays a fan-shaped texture and significant anisotropy. When the poloxamer mass ratio reaches 92 wt%, the self-assembled structure in the solution becomes a mixed phase of columnar structure and crystalline state.

[0073] The surface morphology of the uniformly porous membrane obtained in Example 1 was characterized using a Gemini SEM450 field emission scanning electron microscope at the Physical and Chemical Experiment Center of the University of Science and Technology of China. The results are as follows: Figure 3 As shown, the prepared uniformly porous membrane has a smooth surface and is free of defects such as cracks.

[0074] The present invention uses atomic force microscopy to analyze the uniformly porous membrane obtained in Example 1. The specific characterization experiments were conducted using a Multimode V microscope at the Physical and Chemical Experiment Center of the University of Science and Technology of China. The resulting atomic force microscopy phase diagram is shown below. Figure 4 As shown in (a), the highly ordered arrangement of the self-assembled columnar structure of the uniformly porous film is clearly visible, indicating the formation of a regular nanoscale periodic structure. To further analyze the interplanar spacing of the self-assembled structure, the interplanar spacing of typical regions in the atomic force microscopy phase diagram was measured, and the results are as follows: Figure 4 As shown in (b), the periodic spacing of the columnar structure is approximately 14 nm. Based on the monomer content in the self-assembled body, the pore size is preliminarily estimated to be approximately 10 nm.

[0075] This invention involves cutting the prepared uniformly porous membrane into suitable sizes and testing its separation performance using an ultrafiltration cup apparatus. Polyethylene glycol solutions with concentrations of 1 g / L and molecular weights of 10, 20, 100, and 300 kDa were prepared as the initial solutions. The filtrate after membrane treatment was collected and used to determine the total organic carbon removal rate. The uniformly porous membrane exhibited a retention rate of over 90% for 100 kDa polyethylene glycol molecules (e.g., ...). Figure 5 When the membrane thickness is 1.5 µm and the flux is 45 L m, -2 h -1 .

[0076] Example 2

[0077] Using 100 mL of anhydrous dichloromethane as a solvent, add 14 g of polyether 123 (PEO)20 -PPO 70 -PEO 20 M w =5800), 0.25 g of methacryloyl chloride was slowly added using a dropping funnel, and the mixture was reacted at room temperature under a nitrogen atmosphere for 14 h. After the reaction was complete, the mixture was washed with saturated sodium bicarbonate and sodium chloride until neutral, and then extracted three times with dichloromethane in a separatory funnel. The resulting organic layer was dried overnight with anhydrous magnesium sulfate, and then the solvent was removed by vacuum distillation to obtain a white powder product.

[0078] Add 100 mg of the above white powder product to a 1.5 mL centrifuge tube, add 40 mg of deionized water, stir repeatedly to mix evenly, then add about 2 mg of photoinitiator (2,2-dimethoxy-phenylacetophenone) and 2 mg of photocrosslinking agent (1,6-hexanediol diacrylate), mix evenly again, and then coat it onto a nonwoven fabric support layer. Then, use a UV curing system to irradiate with UV light for 60 s to obtain a fully cured sample, i.e., a uniformly porous membrane.

[0079] The prepared uniformly porous membrane was cut to a suitable size and placed in an ultrafiltration cup to test its retention of polyethylene glycol molecules of different molecular weights (concentration of 1 g / L). The uniformly porous membrane achieved a retention rate of over 85% for 100 kDa polyethylene glycol molecules.

[0080] Example 3

[0081] Using 100 mL of anhydrous dichloromethane as a solvent, add 25 g of poloxamer F127 (PEO) 99 -PPO 65 -PEO 99 M w =12600), 0.8 g of methacryloyl chloride was slowly added using a dropping funnel, and the mixture was reacted at room temperature under a nitrogen atmosphere for 14 h. After the reaction was complete, the mixture was washed with saturated sodium bicarbonate and sodium chloride until neutral, and then extracted three times with dichloromethane in a separatory funnel. The resulting organic layer was dried overnight with anhydrous magnesium sulfate, and then the solvent was removed by vacuum distillation to obtain a white powder product.

[0082] Add 100 mg of the above white powder product to a 1.5 mL centrifuge tube, add 40 mg of deionized water, stir repeatedly to mix evenly, then add about 2 mg of photoinitiator (2,2-dimethoxy-phenylacetophenone) and 2 mg of photocrosslinking agent (ethylene glycol dimethacrylate), mix evenly again, coat it on a non-woven fabric support layer, and irradiate it with ultraviolet light for 60 s in an ultraviolet curing system to obtain a fully cured sample, i.e., a uniformly porous membrane.

[0083] The prepared uniformly porous membrane was cut to an appropriate size and placed in an ultrafiltration cup to test its retention of polyethylene glycol molecules of different molecular weights (concentration of 1 g / L).

[0084] Example 4

[0085] The difference between this embodiment and Example 1 is that a mixed crosslinking agent was used, with a total amount of 2 mg: 1,6-hexanediol diacrylate and ethylene glycol dimethacrylate (mass ratio 1:1). All other parameters and steps remained the same as in Example 1. The prepared uniformly porous membrane was cut to a suitable size and placed in an ultrafiltration cup to test its retention of polyethylene glycol molecules of different molecular weights (concentration 1 g / L). The uniformly porous membrane achieved a 94% retention rate for 100 kDa polyethylene glycol molecules.

[0086] Example 5

[0087] Compared with Example 1, this embodiment uses polyvinylidene fluoride instead of nonwoven fabric support layer, while the other parameters and steps remain the same as in Example 1.

[0088] In summary, the uniformly porous membrane provided by this invention can use poloxamer with different molecular weights and block ratios as base materials, and introduce polymerizable functional groups onto its molecular chain through chemical grafting reactions, thereby constructing a precursor structure with cross-linking and curing capabilities. Subsequently, the modified poloxamer is blended with water or alcohol solvents to induce the formation of a self-assembled structure with ordered arrangement under the action of the solvent, such as a hexagonal columnar structure, a layered structure, or a cubic structure. Subsequently, appropriate amounts of cross-linking agents and photo / thermal initiators are introduced into the system, and through photo-initiated or thermally initiated cross-linking reactions, the unstable self-assembled state is transformed into a solid thin film material while maintaining its ordered arrangement, ultimately forming a stable, tunable pore size, and uniform pore structure uniformly porous membrane. The pore structure of the uniformly porous membrane is highly ordered, the pore size distribution is uniform, and it has good thermal stability and solvent resistance. This invention uses various characterization methods such as Fourier transform infrared spectroscopy, atomic force microscopy, and transmission electron microscopy to systematically analyze and verify the chemical structure and microstructure of the uniformly porous membrane, confirming the formation and controllability of the uniformly porous structure. Meanwhile, the preparation method provided by this invention has the advantages of simple operation, mild conditions, and high precision in structural control. It is suitable for the development of various high-performance membrane materials such as functional separation membranes, catalytic membranes, and sensing membranes, and has broad application prospects.

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A uniformly porous membrane, characterized in that, It is obtained by curing a substrate with a self-assembled mixture on its surface; The self-assembled mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride.

2. The uniformly porous membrane according to claim 1, characterized in that, The modified poloxamer was obtained by reacting poloxamer and acyl chloride in an organic solvent; The molecular weight of the poloxamer is 500 to 100,000; The acyl chloride is selected from methacryl chloride and / or acryl chloride; The molar ratio of poloxamer to acyl chloride is 1:1 to 5:1; The organic solvent is selected from any one or more of toluene, chloroform, acetone, dichloromethane, or tetrahydrofuran; The reaction is carried out at a temperature of 10~80℃ for a time of 1~48 h.

3. The uniformly porous membrane according to claim 1 or 2, characterized in that, The poloxamer is selected from PEO 99 -PPO 65 -PEO 99 PEO 20 -PPO 70 -PEO 20 or PEO 41 -PPO 76- PEO 41 Any one or more of the following.

4. The uniformly porous membrane according to any one of claims 1 to 3, characterized in that, The mass ratio of the modified poloxamer to water is (0.1~10):

1.

5. The uniformly porous membrane according to any one of claims 1 to 4, characterized in that, The curing is carried out in the presence of a crosslinking agent and an initiator; The crosslinking agent is selected from 1,6-hexanediol diacrylate and / or ethylene glycol dimethacrylate; The initiator is selected from any one or more of 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or azobisisobutyronitrile; The amount of the crosslinking agent is 1-10 wt% of the mass of the self-assembled mixture. The amount of the initiator is 1 to 5 wt% of the mass of the self-assembled mixture.

6. The uniformly porous membrane according to any one of claims 1 to 5, characterized in that, The substrate is selected from polyester nonwoven fabric, polyethylene, polyvinylidene fluoride, polysulfone, polyethersulfone, inorganic ceramics or inorganic alumina.

7. The uniformly porous membrane according to any one of claims 1 to 6, characterized in that, The thickness of the uniformly porous membrane is 50 nm to 5 µm, and the pore size is 2 to 20 nm.

8. A method for preparing a uniformly porous membrane as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Provides a substrate on which a self-assembled mixture exists on the surface; The self-assembly mixture comprises modified poloxamer and water; the modified poloxamer is obtained by reacting poloxamer with an acyl chloride; S2: The substrate is cured in the presence of an initiator and a crosslinking agent to obtain a uniformly porous membrane.

9. The preparation method according to claim 8, characterized in that, The curing is ultraviolet curing, and the curing time is 0.5~10 min.

10. The application of the uniformly porous membrane according to any one of claims 1 to 7 or the uniformly porous membrane prepared by the preparation method according to claim 8 or 9 in water treatment.

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