Preparation method of functionalized double-layer nanofiber membrane

Abstract

The invention relates to a preparation method of a functional double-layer nanofiber membrane, and the double-layer nanofiber membrane obtained by the preparation method can be used as a dialysis membrane and has good hydrophilicity, pollution resistance and biocompatibility. The electrostatic spinning method is adopted to prepare two double-layer nanofiber membranes with different pores, and compared with nanofiber membranes with the same thickness, the double-layer nanofiber membranes have better permeability; the resveratrol and the polyacryloylmorpholine are introduced into the double-layer nanofiber membrane by a layer-by-layer self-assembly method, so that the nanofiber membrane has better pollution resistance and biocompatibility, and meanwhile, no additional additive is added in the preparation process, so that the nanofiber membrane has the advantages of lower energy consumption and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the field of nanofiber membranes, and particularly relates to a bilayer nanofiber membrane with anti-pollution and biocompatibility prepared by a layer-by-layer self-assembly method. Background Art

[0002] Membrane separation technology utilizes the selective separation performance of a membrane to selectively permeate a solution or other substances to be separated through the membrane, thereby achieving highly selective transmission of specific components and separating, concentrating, and purifying substances. Membrane separation technology has the characteristics of being relatively stable, having low energy consumption, and being operable at normal or high temperatures. The separation process has characteristics such as high efficiency, energy saving, simple operation, easy control, and a wide range of applications. Therefore, membrane separation technology has played an important role directly or indirectly in many application fields, such as water treatment, energy batteries, environmental engineering, chemical technology, food industry, and biomedicine.

[0003] Membrane separation technology has gradually been applied in the field of biomedicine, especially in blood purification. Blood purification technology mainly includes various methods such as hemodialysis, peritoneal dialysis, hemofiltration, and hemodiafiltration. Blood purification technology mainly applies the membrane to a hemodialyzer. The hemodialyzer allows excess salts, creatinine, and urea in the blood to pass through the membrane into the dialysate, while retaining blood cells, sugars, proteins, etc. in the blood and flowing them back into the blood, thereby enabling the removal of toxins and excess water in the body. Hemodialysis technology mainly removes solutes and excess water through the membrane by two basic transport processes, diffusion and convection, giving full play to the selective separation function of the membrane. In the field of blood purification, the required membrane needs to be functionally modified to make the membrane have good anti-protein fouling properties, biocompatibility, antioxidant properties, etc. Therefore, functional modification of the membrane is the main technical means to obtain a dialysis membrane.

[0004] The layer-by-layer self-assembly technology is one of the methods for membrane functional modification. It mainly uses non-covalent bond interactions such as hydrogen bonds, electrostatic interactions, and π-π bonds between two molecules to spontaneously assemble into the required structure. The layer-by-layer self-assembly technology for preparing a functionalized membrane requires preliminary modification of the base membrane to make the surface of the base membrane have groups that can be further functionalized. In the prior art, the layer-by-layer self-assembly process is relatively complex, and there is a good application prospect for preparing a functionalized membrane by a simple method.

[0005] Dopamine is a green reagent with phenolic hydroxyl and amino groups. Under the action of oxygen or an oxidant, it can be coated on the membrane surface. The phenolic hydroxyl and amino groups are beneficial for introducing other polymers through the layer-by-layer self-assembly method. At the same time, the method of coating dopamine on the membrane surface is relatively simple and does not require the addition of extra additives. The functionalized polymer enables the interaction between the nanofiber membrane and water molecules, forming a hydrated layer on the membrane surface, thereby endowing the membrane with good hydrophilicity and anti-fouling properties. The present invention uses a surface coating method to coat resveratrol, silybin, and polyacrylamide morpholine on the surface of the nanofiber membrane to improve the hydrophilicity, anti-fouling properties, and blood compatibility of the nanofiber membrane. Summary of the Invention

[0006] The present invention provides a preparation method of a functionalized double-layer nanofiber membrane and a double-layer nanofiber membrane in view of the deficiencies of the prior art. The double-layer nanofiber membrane has two base membranes with different pore sizes. At the same time, the film-forming polymer in the base membrane is modified by a hydrophilic polymer, so that the base membrane has certain hydrophilicity and anti-fouling properties, avoiding pollution caused by the base membrane; dopamine, polyacrylamide morpholine, silybin, and resveratrol are introduced onto the surface of the nanofiber membrane by using the layer-by-layer self-assembly technique, endowing the nanofiber membrane with good hydrophilicity, anti-fouling properties, and blood compatibility.

[0007] The present invention designs a preparation method of a functionalized double-layer nanofiber membrane, which specifically includes the following steps:

[0008] (1) Under an inert gas atmosphere, the alkali-treated polyvinylidene fluoride (PVDF) is placed in a solvent, heated and mixed evenly. Acrylamide morpholine and an initiator are added to the above solution. After reacting for a period of time, polyacrylamide morpholine (PACMO) grafts with polyvinylidene fluoride. After precipitation, washing, and drying, PVDF-g-PACMO is obtained.

[0009] (2) Under heating conditions, the PVDF-g-PACMO obtained in step (1) and PVDF are dissolved in a solvent, stirred evenly to form a spinning solution, and the spinning solution is subjected to filtration and high-pressure degassing treatment; the above spinning solution is placed in a syringe, and an electrospinning method is used to prepare a nanofiber membrane; the voltage and the distance between the syringe needle and the receiver are adjusted to introduce a second-layer nanofiber membrane on the surface of the nanofiber membrane, thereby obtaining a double-layer nanofiber membrane; further, the pores of the second layer of the double-layer nanofiber membrane are smaller than those of the first layer of the nanofiber membrane.

[0010] (3) Prepare a dopamine solution. The first layer of the double-layer nanofiber membrane obtained in step (2) is first immersed in a low-concentration dopamine solution and oscillated, and the second layer of the double-layer nanofiber membrane is immersed in a high-concentration dopamine and silybin solution and oscillated to obtain a functionalized double-layer nanofiber membrane.

[0011] (4) Prepare a polyacrylmorpholine solution. The second layer of the double-layer nanofiber membrane described in step (3) is contacted with the polyacrylmorpholine solution, so that polyacrylmorpholine is introduced into the second layer of the double-layer nanofiber membrane;

[0012] (5) Prepare a dopamine solution. The second layer of the double-layer nanofiber membrane obtained in step (4) is immersed in the dopamine solution;

[0013] (6) Prepare a resveratrol solution. The second layer of the double-layer nanofiber membrane obtained in step (5) is immersed in the resveratrol solution, thereby obtaining a functionalized double-layer nanofiber membrane;

[0014] Preferably, the addition amount of the alkali-treated polyvinylidene fluoride in step (1) is 10 - 20 g;

[0015] Preferably, the heating temperature in step (1) is 60 - 90 °C; the reaction time is 6 - 24 h;

[0016] Preferably, the mass ratio of acrylmorpholine to the addition amount of the alkali-treated polyvinylidene fluoride in step (1) is 1:1 - 2:1;

[0017] Preferably, the initiator in step (1) is azobisisobutyronitrile, and its addition amount is 1 - 3% of the addition amount of the alkali-treated polyvinylidene fluoride;

[0018] Preferably, the solvent in step (1) is one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethylacetamide, etc.;

[0019] Preferably, the mass ratio of PVDF-g-PACMO to PVDF in step (2) is 1 - 10:10 - 1, and the heating temperature is 60 - 90 °C;

[0020] Preferably, the solvent in step (2) is one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethylacetamide, etc.;

[0021] Preferably, the spinning solution in step (2) is filtered through a filter membrane and a porous plate; the spinning solution is degassed at 60 - 90 °C;

[0022] Preferably, the voltage in step (2) is 10 - 20 V, and the distance between the syringe needle and the receiver is 10 - 30 cm;

[0023] Preferably, the concentration of the low-concentration dopamine solution in step (3) is 0.5 - 1 mg / mL, and the concentration of the high-concentration dopamine solution is 1 - 2 mg / mL; the double-layer nanofibers are oscillated in the low-concentration dopamine solution for 6 - 12 h and in the high-concentration dopamine solution for 6 - 24 h; the concentration of the silybin solution in step (3) is 1 - 5 mg / mL;

[0024] Preferably, in step (4), the concentration of the polyacrylmorpholine solution is 0.5 - 2 mg / mL, the reaction temperature is 25 - 32 °C, and the reaction time is 1 - 6 h;

[0025] Preferably, in step (5), the concentration of the dopamine solution is 0.5 - 1 mg / mL, the reaction temperature is 25 - 32 °C, and the reaction time is 6 - 12 h;

[0026] Preferably, in step (6), the concentration of the resveratrol solution is 1 - 5 mg / mL, the reaction temperature is 25 - 32 °C, and the reaction time is 6 - 12 h.

[0027] The present invention has the following beneficial effects compared with the prior art:

[0028] (1) The functionalized nanofiber membrane of the present invention has a double-layer PVDF-g-PACMO-based membrane, and the pores of the first-layer nanofiber membrane are larger than those of the second-layer nanofiber membrane. Compared with nanofiber membranes of the same thickness, the functionalized double-layer nanofiber membrane of the present invention has better permeability. Polyacrylmorpholine endows the nanofiber membrane with good hydrophilicity and anti-pollution properties;

[0029] (2) Dopamine in the present invention belongs to a green reagent. The hydroxyl and amino groups in dopamine improve the hydrophilicity and anti-pollution properties of the nanofiber membrane and act as a secondary functionalization reagent; Silybin has good hydrophilicity and biocompatibility, and it and dopamine improve the hydrophilicity, anti-pollution properties and biocompatibility of the nanofiber membrane;

[0030] (3) Polyacrylmorpholine and resveratrol are introduced into the second layer of the nanofiber membrane of the present invention. Polyacrylmorpholine forms hydrogen bonds with the hydroxyl groups in dopamine and silybin, and resveratrol forms hydrogen bonds with the hydroxyl groups in dopamine, enabling polyacrylmorpholine and resveratrol to be introduced onto the surface of the nanofiber membrane, improving the hydrophilicity of the nanofiber membrane. At the same time, the nanofiber membrane has good anti-pollution properties, DPPH radical scavenging ability and ABTS + radical scavenging ability; the water contact angle of the nanofiber membrane of the present invention is below 75°, good anti-pollution property against bovine serum albumin, the scavenging ability of DPPH radicals and ABTS + radicals is above 90%, the hemolysis rate is about 5%, the clotting time is significantly increased, especially the APTT is extended to 63 s. At the same time, the nanofiber membrane of the present invention has low cytotoxicity. Detailed implementation manners

[0031] The technical features in the technical solutions provided by the present invention will be further clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0032] Those skilled in the art of the present technology can understand that, unless otherwise defined, all terms used herein (including technical terms and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless defined as such herein.

[0033] The term "preferred" in the present invention and the like refers to embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0034] Example 1

[0035] A method for preparing a functionalized double-layer nanofiber membrane specifically includes the following steps: (1) Under an inert gas atmosphere, 10 g of alkali-treated polyvinylidene fluoride (PVDF) is placed in 100 mL of N,N-dimethylformamide, heated and stirred evenly at 60 °C, 10 g of acryloylmorpholine is added to the solution, 0.1 g of azobisisobutyronitrile is added after mixing evenly, the reaction time is 24 h, and PVDF-g-PACMO powder is obtained after precipitation, washing, and drying;

[0036] (2) At 60 °C, 64 g of PVDF-g-PACMO and 8 g of PVDF obtained in step (1) are dissolved in 28 mL of N,N-dimethylformamide, stirred evenly to form a spinning solution, the spinning solution is filtered through a filter membrane to remove insoluble substances, and then degassed under high pressure at 60 °C; the above spinning solution is added into a syringe, and the first layer of nanofiber membrane is prepared by electrospinning method. At this time, the voltage is 15 V, the distance between the syringe needle and the receiver is 20 cm, and the spraying time is 20 min; then, the voltage and the distance between the syringe needle and the receiver are adjusted. At this time, the voltage is 12 V, the distance between the syringe needle and the receiver is 25 cm, and the spraying time is 30 min; the second layer of nanofiber membrane is introduced onto the surface of the first layer of nanofiber membrane, and thus a double-layer nanofiber membrane is obtained;

[0037] (3) Prepare dopamine solutions to obtain dopamine solutions with concentrations of 0.5 mg / mL and 1 mg / mL; Immerse the first layer of the double-layer nanofiber membrane obtained in step (2) in the dopamine solution with a concentration of 0.5 mg / mL, and the reaction time is 6 h; Immerse the second layer of the double-layer nanofiber membrane in a mixed solution of 1 mg / mL dopamine and 1 mg / mL silybin, and the reaction time is 6 h to obtain a dopamine and silybin-functionalized double-layer nanofiber membrane;

[0038] (4) Prepare a polyacrylmorpholine solution to obtain a polyacrylmorpholine solution with a concentration of 1 mg / mL; React the second layer of the double-layer nanofiber membrane described in step (3) with the polyacrylmorpholine solution for 6 h to introduce polyacrylmorpholine into the second layer of the double-layer nanofiber membrane;

[0039] (5) Prepare a dopamine solution to obtain a dopamine solution with a concentration of 1 mg / mL; React the second layer of the double-layer nanofiber membrane obtained in step (4) with the dopamine solution for 6 h to introduce dopamine into the second layer of the double-layer nanofiber membrane;

[0040] (6) Prepare a resveratrol solution to obtain a resveratrol solution with a concentration of 1 mg / mL. React the second layer of the double-layer nanofiber membrane described in step (5) with the resveratrol solution for 12 h to introduce resveratrol into the second layer of the double-layer nanofiber membrane, thereby obtaining a functionalized double-layer nanofiber membrane.

[0041] Example 2

[0042] A method for preparing a functionalized double-layer nanofiber membrane specifically includes the following steps: (1) Under an inert gas atmosphere, place 10 g of alkali-treated polyvinylidene fluoride (PVDF) in 100 mL of N,N-dimethylformamide, heat and stir evenly at 60 °C, add 15 g of acrylmorpholine to the solution, mix well and then add 0.2 g of azobisisobutyronitrile, and the reaction time is 24 h. After precipitation, washing and drying, PVDF-g-PACMO is obtained;

[0043] (2) At 60 °C, 48 g of PVDF-g-PACMO obtained in step (1) and 24 g of PVDF were dissolved in 28 mL of N,N-dimethylformamide, and after stirring evenly, a spinning solution was formed. The spinning solution was filtered through a filter membrane to remove insoluble substances, and then degassed under high pressure at 60 °C. The above spinning solution was added into a syringe, and a first-layer nanofiber membrane was prepared by electrospinning. At this time, the voltage was 17.5 V, the distance between the syringe needle and the receiver was 15 cm, and the spraying time was 20 min. Subsequently, the voltage and the distance between the syringe needle and the receiver were adjusted. At this time, the voltage was 15 V, the distance between the syringe needle and the receiver was 20 cm, and the spraying time was 30 min. A second-layer nanofiber membrane was introduced onto the surface of the first-layer nanofiber membrane to obtain a double-layer nanofiber membrane;

[0044] (3) Dopamine solutions with concentrations of 1 mg / mL and 2 mg / mL were prepared. The first layer of the double-layer nanofiber membrane obtained in step (2) was immersed in the dopamine solution with a concentration of 1 mg / mL for 6 h. The second layer of the double-layer nanofiber membrane was immersed in a mixed solution of dopamine with a concentration of 2 mg / mL and silybin with a concentration of 2 mg / mL for 6 h to obtain a dopamine and silybin-functionalized double-layer nanofiber membrane;

[0045] (4) A polyacrylmorpholine solution with a concentration of 1 mg / mL was prepared. The second layer of the double-layer nanofiber membrane described in step (3) was reacted with the polyacrylmorpholine solution for 6 h to introduce polyacrylmorpholine into the second layer of the double-layer nanofiber membrane;

[0046] (5) A dopamine solution with a concentration of 0.5 mg / mL was prepared. The second layer of the double-layer nanofiber membrane obtained in step (4) was reacted with the dopamine solution for 6 h to introduce dopamine into the second layer of the double-layer nanofiber membrane;

[0047] (6) A resveratrol solution with a concentration of 2 mg / mL was prepared. The second layer of the double-layer nanofiber membrane described in step (5) was reacted with the resveratrol solution for 6 h to introduce resveratrol into the second layer of the double-layer nanofiber membrane, thereby obtaining a functionalized double-layer nanofiber membrane.

[0048] Example 3

[0049] A preparation method of a functionalized double-layer nanofiber membrane specifically includes the following steps: (1) Under an inert gas atmosphere, 20 g of alkali-treated polyvinylidene fluoride (PVDF) is placed in 100 mL of N,N-dimethylformamide, heated and stirred evenly at 60 °C, 20 g of acryloylmorpholine is added to the solution, 0.4 g of azobisisobutyronitrile is added after mixing evenly, the reaction time is 24 h, and PVDF-g-PACMO is obtained after precipitation, washing, and drying;

[0050] (2) At 60 °C, 8 g of PVDF-g-PACMO obtained in step (1) and 64 g of PVDF are dissolved in 28 mL of N,N-dimethylformamide, stirred evenly to form a spinning solution, the spinning solution is filtered through a filter membrane to remove insoluble substances, and then degassed under high pressure at 60 °C; The above spinning solution is added into a syringe, and the first layer of nanofiber membrane is prepared by electrospinning. At this time, the voltage is 20 V, the distance between the syringe needle and the receiver is 15 cm, and the spraying time is 20 min; Adjust the voltage and the distance between the syringe needle and the receiver. At this time, the voltage is 12 V, the distance between the syringe needle and the receiver is 20 cm, and the spraying time is 30 min; The second layer of nanofiber membrane is introduced onto the surface of the first layer of nanofiber membrane to obtain a double-layer nanofiber membrane;

[0051] (3) Prepare dopamine solutions to obtain dopamine solutions with concentrations of 0.5 mg / mL and 1 mg / mL; The first layer of the double-layer nanofiber membrane obtained in step (2) is immersed in the dopamine solution with a concentration of 0.5 mg / mL for 6 h; The second layer of the double-layer nanofiber membrane is immersed in a mixed solution of 1 mg / mL of dopamine and 2 mg / mL of silybin for 12 h to obtain a dopamine and silybin-functionalized double-layer nanofiber membrane;

[0052] (4) Prepare an acryloylmorpholine solution to obtain an acryloylmorpholine solution with a concentration of 2 mg / mL; The second layer of the double-layer nanofiber membrane described in step (3) reacts with the acryloylmorpholine solution for 6 h to introduce acryloylmorpholine into the second layer of the double-layer nanofiber membrane;

[0053] (5) Prepare a dopamine solution to obtain a dopamine solution with a concentration of 1 mg / mL; The second layer of the double-layer nanofiber membrane obtained in step (4) reacts with the dopamine solution for 6 h to introduce dopamine into the second layer of the double-layer nanofiber membrane;

[0054] (6) Prepare a resveratrol solution to obtain a resveratrol solution with a concentration of 1 mg / mL. The second layer of the double-layer nanofiber membrane described in step (5) reacts with the resveratrol solution for 12 h to introduce resveratrol into the second layer of the double-layer nanofiber membrane, thereby obtaining a functionalized double-layer nanofiber membrane.

[0055] The above are only specific embodiments of the present invention, and do not limit the invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or equivalent embodiments of equivalent changes. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a functionalized double-layer nanofiber membrane, characterized in that, The preparation method specifically includes the following steps: Step (1): Under an inert gas atmosphere, the alkali-treated polyvinylidene fluoride (PVDF) is placed in a solvent, heated and mixed evenly. Acryloylmorpholine and an initiator are added to the above solution. After reacting for a period of time, polyacryloylmorpholine (PACMO) is grafted onto polyvinylidene fluoride. After precipitation, washing and drying, PVDF-g-PACMO is obtained; Step (2): Under heating conditions, the PVDF-g-PACMO obtained in step (1) and PVDF are dissolved in a solvent, stirred evenly to form a spinning solution, and the spinning solution is subjected to filtration and high-pressure degassing treatment; The above spinning solution is placed in a syringe, and a nanofiber membrane is prepared by electrospinning; the voltage and the distance between the syringe needle and the receiver are adjusted to introduce a second nanofiber membrane on the surface of the nanofiber membrane, thereby obtaining a double-layer nanofiber membrane; the pores of the second layer of the double-layer nanofiber membrane are smaller than those of the first layer of the nanofiber membrane; Step (3): Prepare dopamine solutions to obtain low-concentration and high-concentration dopamine solutions. The first layer of the double-layer nanofiber membrane obtained in step (2) is first immersed in the low-concentration dopamine solution, and the second layer of the double-layer nanofiber membrane is immersed in a mixed solution of high-concentration dopamine and silybin to obtain a functionalized double-layer nanofiber membrane; Step (4): Prepare a polyacryloylmorpholine solution, and the second layer of the double-layer nanofiber membrane described in step (3) is immersed in the polyacryloylmorpholine solution to introduce polyacryloylmorpholine into the second layer of the double-layer nanofiber membrane; Step (5): Prepare a dopamine solution, and the second layer of the double-layer nanofiber membrane in step (4) is immersed in the dopamine solution; Step (6): Prepare a resveratrol solution, and the second layer of the double-layer nanofiber membrane in step (5) is immersed in the resveratrol solution, thereby obtaining a functionalized double-layer nanofiber membrane.

2. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (1), the addition amount of the alkali-treated polyvinylidene fluoride is 10-20 g, the heating temperature is 60-90 °C, and the reaction time is 6-24 h; the mass ratio of acryloylmorpholine to the addition amount of the alkali-treated polyvinylidene fluoride is 1:1-2:1; the initiator includes azobisisobutyronitrile, and its addition amount is 1-3% of the addition amount of the alkali-treated polyvinylidene fluoride; the solvent is one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethylacetamide.

3. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, wherein, In step (2), the mass ratio of the addition amounts of PVDF-g-PACMO and PVDF is 1-10:10-1, the heating temperature is 60-90 °C, and the solvent is one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethylacetamide.

4. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (2), the spinning solution is treated by a filter membrane or a filter plate; the spinning solution is subjected to high-pressure degassing treatment at 60-90 °C; the voltage of electrospinning is 10-20 V, and the distance between the syringe needle and the receiver is 10-30 cm.

5. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (3), the concentration of the low-concentration dopamine solution is 0.5-1 mg / mL, and the concentration of the high-concentration dopamine solution is 1-2 mg / mL; the double-layer nanofiber reacts in the low-concentration dopamine solution for 6-12 h and in the high-concentration dopamine solution for 6-24 h.

6. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (3), the concentration of the silybin solution is 1-5 mg / mL.

7. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (4), the concentration of the polyacrylmorpholine solution is 0.5-2 mg / mL, the reaction temperature is 25-32 °C, and the reaction time is 1-6 h.

8. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (5), the concentration of the dopamine solution is 0.5-1 mg / mL, the reaction temperature is 25-32 °C, and the reaction time is 6-12 h.

9. The preparation method of a functionalized double-layer nanofiber membrane according to claim 1, characterized in that, In step (6), the concentration of the resveratrol solution is 1-5 mg / mL, the reaction temperature is 25-32 °C, and the reaction time is 6-12 h.

10. A functionalized double-layer nanofiber membrane obtained by the method for preparing a functionalized double-layer nanofiber membrane according to any one of claims 1-9.