Polysulfone fiber membrane, preparation method and application in hemodialysis

Abstract

The invention relates to the technical field of medical dialysis membranes, and discloses a polysulfone fiber membrane, a preparation method and application of the polysulfone fiber membrane in hemodialysis. The preparation method of the polysulfone fiber membrane comprises the following steps: carrying out modification treatment on polysulfone to obtain functionalized polysulfone; the preparation method comprises the following steps: preparing UIO-66-NH2 by taking zirconium tetrachloride and 2-aminoterephthalic acid as raw materials; enabling the functionalized polysulfone to react with UIO-66-NH2, so as to obtain hybrid modified polysulfone; tannic acid reacts with hybrid modified polysulfone to obtain tannic acid modified polysulfone; loading copper on the tannic acid modified polysulfone to obtain composite modified polysulfone; adding composite modified polysulfone, a polymer additive and polyvinylpyrrolidone into a composite solvent to obtain a membrane casting solution; performing filtration, spinning and the like on the membrane casting solution to obtain a polysulfone fiber membrane; the polysulfone fiber membrane has excellent dialysis performance, antifouling performance, anticoagulation performance and oxidation resistance, has an enhanced urea removal effect, and is used in hemodialysis materials.

Description

Technical Field

[0001] The present invention relates to the technical field of medical dialysis membranes, in particular to a polysulfone fiber membrane, a preparation method and application thereof in hemodialysis. Background Art

[0002] When a person suffers from kidney disease, toxic substances will accumulate in the body in large quantities and eventually lead to uremic syndrome. Hemodialysis is currently the most feasible and effective technology for the clinical treatment of patients with end-stage renal disease. Hemodialysis membrane is an important component of dialysis equipment, and polysulfone membrane is one of the commonly used hemodialysis membrane materials. However, polysulfone materials have poor hydrophilicity, and organic membranes are easily contaminated during application. In order to solve this problem, Chinese patent CN110756066B discloses a sulfonated citric acid chitosan modified polysulfone hemodialysis membrane and a preparation method thereof, using sulfonated citric acid chitosan modified polysulfone (SCACS-PSF) as the membrane material. The mass percentage of the content of the sulfonated citric acid chitosan in the membrane liquid is 15%-25%, and the solvent is 75%-85%. A sulfonated citric acid chitosan modified polysulfone hemodialysis membrane with good biocompatibility is prepared by a dry-wet spinning method. The skeleton of the sulfonated citric acid chitosan modified polysulfone is a main chain polysulfone skeleton, and the side chain is covalently grafted with a chitosan structure containing polycarboxyl groups and a heparin-like substance containing sulfonic acid groups. The hydrophilicity and blood compatibility are further improved through the synergistic effect of the polycarboxyl citric acid structure and the sulfonic acid group. However, the sulfonated citric acid chitosan modified polysulfone hemodialysis membrane has insufficient antioxidant properties, and patients may develop complications caused by oxidative stress during use. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for preparing a polysulfone fiber membrane, comprising the following steps:

[0004] Step (1), modifying the polysulfone to introduce carboxyl groups to obtain functionalized polysulfone;

[0005] Step (2), using zirconium tetrachloride and 2-aminoterephthalic acid as raw materials to prepare UIO-66-NH2;

[0006] Functionalized polysulfone reacts with UIO-66-NH2 to obtain hybrid modified polysulfone;

[0007] Step (3), tannic acid reacts with hybrid modified polysulfone to obtain tannic acid modified polysulfone; copper is loaded on the tannic acid modified polysulfone to obtain composite modified polysulfone;

[0008] Step (4), adding the composite modified polysulfone, polymer additive and polyvinyl pyrrolidone into the composite solvent, stirring, standing and degassing to obtain a casting solution, and then preparing a polysulfone fiber membrane through a dry-wet spinning process;

[0009] The preparation method of the polymer additive comprises the following steps:

[0010] Step S1, preparing carbon dot powder by a hydrothermal method, and modifying the carbon dot powder by 1,2-epoxy-5-hexene to obtain modified carbon dots;

[0011] Step S2, 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride, and modified carbon dots react to obtain a polymer additive.

[0012] Preferably, in step (1), the preparation method of the functionalized polysulfone is as follows: dissolving the polysulfone in dichloromethane, adding aluminum chloride, adding succinic anhydride in an ice-water bath within 1-2 hours, and then continuing the reaction in a 25-35° C. water bath for 3-4 hours, filtering the resulting solution and pouring it into ethanol to precipitate the obtained precipitate, crushing, washing, and drying; wherein the mass ratio of polysulfone, dichloromethane, aluminum chloride, and succinic anhydride is 1:(20-40):(1-3):(1-2);

[0013] In the above process, aluminum chloride is used as a Lewis acid catalyst, and succinic anhydride is used as an acylating agent to react with polysulfone through ring opening, thereby introducing a side chain containing a carboxyl group into the polysulfone.

[0014] Preferably, in step (2), the preparation method of UIO-66-NH2 is as follows: zirconium tetrachloride, 2-aminoterephthalic acid and glacial acetic acid are added to N,N-dimethylformamide, stirred at 110-130°C and ultrasonically treated at 35-45KHz for 20-30h, and after the reaction is completed, centrifuged, washed and dried; wherein the mass ratio of zirconium chloride, 2-aminoterephthalic acid, glacial acetic acid and N,N-dimethylformamide is (0.6-0.8):(0.5-0.7):(4.7-6.6):(140-200);

[0015] In the above process, zirconium tetrachloride and 2-aminoterephthalic acid were used as reactants to synthesize the zirconium-based MOF material UIO-66-NH2 rich in amino and carboxyl groups. An ultrasonic bath was added in the last step of MOF synthesis to increase the specific surface area of ​​the nanoparticles.

[0016] Preferably, in step (2), the preparation method of the hybrid modified polysulfone is:

[0017] Adding functionalized polysulfone to tetrahydrofuran, stirring at a speed of 200-300 r / min for 2-4 hours at room temperature, adding oxalyl chloride, continuing to stir and react at room temperature for 6-8 hours, after the reaction is completed, removing the solvent and oxalyl chloride by reduced pressure distillation at 20-45° C. to obtain an intermediate product; wherein the mass ratio of functionalized polysulfone, tetrahydrofuran, and oxalyl chloride is 1:(300-400):(50-65);

[0018] The intermediate product is added to tetrahydrofuran, and then UIO-66-NH2 is added. After stirring at a speed of 200-300 r / min at room temperature for 6-10 hours, the temperature is raised to 40-60°C, and the stirring reaction is continued for 6-10 hours. After the reaction is completed, the precipitate is precipitated with deionized water, filtered, washed, and dried to obtain a hybrid modified polysulfone; wherein the mass ratio of the intermediate product, tetrahydrofuran, and UIO-66-NH2 is 1:(20-30):(0.03-0.08);

[0019] In the above process, the carboxyl group in the functionalized polysulfone reacts with oxalyl chloride, the carboxyl group is converted into an acyl chloride group, and the acyl chloride group reacts with the amino group of UIO-66-NH2 in the functionalized polysulfone to introduce UIO-66-NH2 into the polysulfone side chain in the form of a chemical bond.

[0020] Preferably, in step (3), the preparation method of the composite modified polysulfone is:

[0021] The hybrid modified polysulfone is added into deionized water, heated to 70-80°C and stirred for reaction for 5-7h, the pH is adjusted to 4.6-4.8 by a 1 mol / L hydrochloric acid aqueous solution, and then tannic acid is added dropwise, stirred for reaction at 70-80°C for 20-24h, filtered, washed, and dried to obtain tannic acid modified polysulfone; wherein the mass ratio of the hybrid modified polysulfone to tannic acid is 17.5:(0.1-0.5);

[0022] Add tannic acid modified polysulfone and copper nitrate to ethanol, react at room temperature for 5-7 hours, filter, wash and dry after the reaction to obtain composite modified polysulfone; wherein the mass ratio of tannic acid modified polysulfone, copper nitrate and ethanol is 1:(0.05-0.09):(15-25);

[0023] In the above process, the carboxyl group in the MOF of the hybrid modified polysulfone undergoes an esterification reaction with the catechol hydroxyl group in tannic acid, and the tannic acid containing rich catechol groups is connected to the polysulfone. The excellent metal complexing ability of the catechol group complexes with the divalent copper ions in copper nitrate to obtain a composite modified polysulfone loaded with copper ions.

[0024] Preferably, in step (4), the mass ratio of the composite modified polysulfone, the polymer additive, polyvinyl pyrrolidone and the composite solvent is 1:(0.04-0.08):(0.2-0.6):(3-6); the composite solvent is obtained by mixing ethanol and N-methyl-2-pyrrolidone in a volume ratio of 1:5; stirring conditions: stirring at 60-80°C for 4-5h; standing degassing time: 18-24h.

[0025] Preferably, in step (4), the pore size of the polysulfone fiber membrane is 180-220 μm, and the membrane thickness is 35-55 μm;

[0026] Preferably, in the step (4), the dry-wet spinning process method: in a nitrogen atmosphere, the casting liquid and the core liquid are sprayed out simultaneously, the driving pressure of the casting liquid is adjusted to 0.05-0.20MPa, the casting liquid flow rate is 0.5-2.0mL / min, the core liquid is water, and the core liquid flow rate is 1.0-2.0mL / min, to obtain a primary ecological membrane; the primary ecological membrane passes through an air segment spacing of 10-25cm and is pulled into a coagulation bath and a rinsing bath at a winding speed of 20-50m / min, the coagulation bath temperature is 5-30°C, the rinsing bath temperature is 10-30°C, the coagulation liquid used in the coagulation bath is water, and the rinsing liquid used in the rinsing bath is water.

[0027] Furthermore, in step (4), the preparation method of the polymer additive is:

[0028] Step S1, adding banana to a 60% ethanol aqueous solution, stirring for 10-20 minutes, heating to 175-185°C under sealed conditions for reaction for 5.5-6.5 hours, cooling to room temperature, and filtering with suction. The obtained filtrate is filtered through a 0.22 μm filter membrane and centrifuged. The obtained supernatant is dialyzed through a 500 Da dialysis bag for 3-5 days, and the water is changed 2-4 times a day during the dialysis process. The final dialysate is freeze-dried to obtain carbon dot powder; wherein the mass ratio of banana to ethanol aqueous solution is (30-40):(10-15);

[0029] The carbon dot powder, 1,2-epoxy-5-hexene and N,N-dimethylformamide are mixed, stirred at a speed of 400-500 r / min, heated to 120-130° C., and triphenylphosphine is added to react for 40-50 hours. After the reaction is completed, the reaction product mixture is dialyzed for 3-5 days through a 500Da dialysis bag, and water is changed 2-4 times a day during the dialysis process. The final dialysate is freeze-dried to obtain modified carbon dots; wherein the mass ratio of the carbon dot powder, 1,2-epoxy-5-hexene, N,N-dimethylformamide and triphenylphosphine is (3-5):(1-1.5):(30-60):(0.001-0.003);

[0030] In the above process, nano-carbon dots with abundant hydrophilic groups such as hydroxyl and carboxyl are synthesized by a hydrothermal method, and carbon-carbon double bonds are introduced into the modified carbon dots by reacting the epoxy groups in 1,2-epoxy-5-hexene with the carboxyl groups in the carbon dots.

[0031] Step S2, under an argon atmosphere, adding 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride, and modified carbon dots to ethanol, and then adding azobisisobutyronitrile, stirring and reacting at 70-80° C. for 10-15 hours, after the reaction is completed, precipitating the product from the reaction solution by tetrahydrofuran, and then dissolving the product in water, freeze-drying, to obtain a polymer additive; wherein the mass ratio of 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride, modified carbon dots, ethanol, and azobisisobutyronitrile is (3-6):(1.8-3.6):(1.5-2.5):(30-50):(0.03-0.05);

[0032] In the above process, 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride, and modified carbon dots are polymerized under the action of an initiator to obtain a polymer additive.

[0033] The polysulfone fiber membrane is prepared by the polysulfone fiber membrane preparation method.

[0034] The polysulfone fiber membrane is used in hemodialysis membrane materials.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The present invention forms a polymer additive containing phosphorylcholine and hydrophilic carbon dots through a copolymerization reaction between 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride and modified carbon dots. The polymer additive is added to the membrane material. On the one hand, hydrophilic functional groups such as hydroxyl, carboxyl and phosphorylcholine can be introduced to improve the hydrophilicity of the polysulfone membrane, thereby improving the dialysis effect of the polysulfone membrane, effectively removing toxins, reducing membrane pollution caused by protein adhesion on the membrane surface, and inhibiting the adhesion and activation of platelets, preventing the aggregation and release of coagulation factors, thereby hindering the formation of coagulation and thrombus; on the other hand, the addition of the polymer additive accelerates the phase separation rate of the membrane, increases the porosity of the membrane, and thus improves the dialysis effect; and the polysulfone membrane containing the polymer additive can effectively inhibit complement activation and has good blood compatibility; further, the polymer additive of the present invention introduces carbon dots rich in hydroxyl and carboxyl groups, which improves the hydrophilicity of the polysulfone membrane while improving the antioxidant properties of the membrane, thereby avoiding oxidative stress caused by contact between the polysulfone membrane material and blood.

[0037] 2. The present invention functionalizes polysulfone to introduce carboxyl groups into the polysulfone. The carboxyl groups react with the amino groups of the MOF material UIO-66-NH2, and the UIO-66-NH2 is introduced into the polysulfone side chain in the form of a chemical bond to obtain a hybrid modified polysulfone. The hydrophilic porous MOF material increases the hydrophilicity, porosity and pore size of the polysulfone membrane, improves the dialysis effect of the polysulfone membrane, and enhances the anti-pollution and anti-coagulation properties of the polysulfone membrane. In addition, the MOF material is introduced into the polysulfone structure in the form of chemical grafting, which improves the dispersibility and stability of the MOF material and makes the pores more uniform. Furthermore, through the esterification reaction between the hybrid modified polysulfone and tannic acid, a catechol-rich monomer is introduced on the surface of the polysulfone. Tannic acid can better improve the hydrophilicity and antioxidant properties of the polysulfone membrane; the catechol group of tannic acid can complex with divalent copper ions to form a divalent copper ion-phenol complex, which has an enhanced adsorption effect on urea, and can efficiently remove urea in hemodialysis through the synergistic effect of diffusion and enhanced adsorption; and divalent copper ions can catalyze the release of NO, so that the polysulfone membrane can better inhibit platelet activation, prolong coagulation time, and inhibit oxidative immune response; in addition, by performing the above modification treatment on polysulfone, hydrogen bonds and charge interactions (phosphate groups and copper ions) can be formed between the composite modified polysulfone and the polymer additive, thereby reducing the risk of elution and leaching of the polymer additive.

[0038] In summary, the present invention combines the modification of the polysulfone structure with the addition of polymer additives to prepare a polysulfone fiber membrane having excellent dialysis performance, antifouling performance, anticoagulation performance and antioxidant performance, and has an enhanced removal effect on urea, and is applied to hemodialysis materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process flow chart of the preparation method of the polysulfone fiber membrane of the present invention;

[0040] Figure 2 It is a schematic diagram of the synthesis of the functionalized polysulfone of the present invention;

[0041] Figure 3 It is a schematic diagram of the synthesis of the hybrid modified polysulfone of the present invention;

[0042] Figure 4 Schematic diagram of the synthesis of modified carbon dots of the present invention;

[0043] Figure 5 It is a schematic diagram of the synthesis of the polymer addition of the present invention;

[0044] Figure 6 It is a comparison chart of pure water flux test of polysulfone fiber membranes of Examples 2-4 of the present invention and Comparative Examples 2-6;

[0045] Figure 7It is a comparison chart of the flux recovery rate test of the polysulfone fiber membrane of Example 2-4 of the present invention and Comparative Example 2-6;

[0046] Figure 8 is a comparison chart of urea removal rate tests of the polysulfone fiber membranes of Examples 2-4 of the present invention and Comparative Examples 2-6;

[0047] Fig. 9 It is a comparison chart of the activated partial thromboplastin time test of the polysulfone fiber membrane of Example 2-4 of the present invention and Comparative Example 2-6;

[0048] Fig.10 It is a comparison chart of lipid peroxidation inhibition rate test of polysulfone fiber membranes of Examples 2-4 of the present invention and Comparative Examples 2-6. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] This embodiment discloses a method for preparing a polymer additive, comprising the following steps:

[0052] Step S1, adding 35g of banana to 12.5g of 60% ethanol aqueous solution, stirring for 15min, heating to 180°C for reaction for 6h under sealed conditions, cooling to room temperature, and filtering with suction. The obtained filtrate is filtered through a 0.22μm filter membrane, and centrifuged at a speed of 150000r / min for 20min. The obtained supernatant is dialyzed through a 500Da dialysis bag for 4 days. The water is changed 3 times a day during the dialysis process. The final dialysate is freeze-dried to obtain carbon dot powder;

[0053] 4 g of carbon dot powder, 1.2 g of 1,2-epoxy-5-hexene, and 45 g of N,N-dimethylformamide were mixed, stirred at a speed of 450 r / min, heated to 125°C, and 0.002 g of triphenylphosphine was added. The reaction was allowed to react for 45 h. After the reaction was completed, the reaction product mixture was dialyzed through a 500 Da dialysis bag for 4 days. The water was changed 3 times a day during the dialysis process. The final dialysate was freeze-dried to obtain modified carbon dots.

[0054] Step S2, under an argon atmosphere, add 4.5 g of 2-methacryloyloxyethyl phosphorylcholine, 2.7 g of N-(3-aminopropyl)methacrylamide hydrochloride, and 2 g of modified carbon dots to 40 g of ethanol, and then add 0.04 g of azobisisobutyronitrile, and stir to react at 75° C. for 12 h. After the reaction is completed, the product is precipitated from the reaction solution by tetrahydrofuran, and then the product is dissolved in water and freeze-dried to obtain a polymer additive.

[0055] Example 2

[0056] This embodiment discloses a method for preparing a polysulfone fiber membrane, comprising the following steps:

[0057] Step (1), dissolving polysulfone in dichloromethane, adding aluminum chloride, adding succinic anhydride in an ice-water bath within 1 hour, and then continuing the reaction in a 25° C. water bath for 4 hours, filtering the resulting solution and pouring it into ethanol for precipitation, then crushing the obtained precipitate and washing it in deionized water for 3 times, and then vacuum drying it at 80° C. to obtain a functionalized polysulfone; wherein the mass ratio of polysulfone, dichloromethane, aluminum chloride and succinic anhydride is 1:20:1:1;

[0058] Step (2), adding 0.6 g zirconium tetrachloride, 0.5 g 2-aminoterephthalic acid, and 4.7 g glacial acetic acid to 140 g N, N-dimethylformamide, stirring at 110°C and ultrasonically treating at 35 kHz for 20 h, after the reaction is completed, centrifuging, washing the obtained solid product with N, N-dimethylformamide three times, and vacuum drying at 100°C for 30 h to obtain UIO-66-NH2;

[0059] The functionalized polysulfone is added to tetrahydrofuran, and stirred at a speed of 200 r / min at room temperature for 4 hours, and then oxalyl chloride is added, and the reaction is continued at room temperature for 6 hours by stirring. After the reaction is completed, the solvent and oxalyl chloride are removed by reduced pressure distillation at 20° C. to obtain an intermediate product; wherein the mass ratio of the functionalized polysulfone, tetrahydrofuran, and oxalyl chloride is 1:300:50;

[0060] The intermediate product was added to tetrahydrofuran, and then UIO-66-NH2 was added. After stirring at a speed of 200 r / min at room temperature for 10 hours, the temperature was raised to 40°C, and the stirring reaction was continued for 6 hours. After the reaction was completed, the precipitate was precipitated with deionized water, filtered, and the obtained filter residue was washed with deionized water and ethanol for 3 times each, and dried to obtain a hybrid modified polysulfone; wherein the mass ratio of the intermediate product, tetrahydrofuran, and UIO-66-NH2 was 1:20:0.03;

[0061] Step (3), adding the hybrid modified polysulfone into deionized water, heating to 70°C and stirring for reaction for 7h, adjusting the pH to 4.6 with a 1 mol / L hydrochloric acid aqueous solution, then adding tannic acid dropwise, stirring for reaction at 70°C for 20h, filtering, washing the obtained filter residue with deionized water for 5 times, and drying at 40°C for 24h to obtain tannic acid modified polysulfone; wherein the mass ratio of the hybrid modified polysulfone to the tannic acid is 17.5:0.1;

[0062] Adding tannic acid-modified polysulfone and copper nitrate into ethanol, reacting at room temperature for 5 hours, filtering, washing, and drying after the reaction to obtain a composite modified polysulfone; wherein the mass ratio of tannic acid-modified polysulfone, copper nitrate, and ethanol is 1:0.05:15;

[0063] Step (4), mixing ethanol and N-methyl-2-pyrrolidone in a volume ratio of 1:5 to obtain a composite solvent, adding the composite modified polysulfone, the polymer additive, and polyvinyl pyrrolidone to the composite solvent, stirring at 60° C. for 4 hours, and standing for degassing for 18 hours to obtain a casting solution; wherein the mass ratio of the composite modified polysulfone, the polymer additive, the polyvinyl pyrrolidone, and the composite solvent is 1:0.04:0.2:3;

[0064] Open the nitrogen valve and adjust the pressure of the raw material tank to 0.05MPa. The casting liquid is filtered and pressed into the spinning head through a metering pump. The flow rate of the casting liquid is controlled to be 0.5mL / min. At the same time, the core liquid is introduced with a core liquid flow rate of 1.0mL / min. The obtained primary ecological membrane passes through an air segment spacing of 10cm, and then enters a coagulation bath and a rinsing bath under the traction of a winding machine, and then is wound on a rotating drum to obtain a polysulfone fiber membrane with a pore size of 183μm and a membrane thickness of 37μm. Among them, the winding speed of the winding machine is 20m / min, the coagulation bath temperature is 5°C, the rinsing bath temperature is 10°C, the core liquid is water, the coagulation liquid used in the coagulation bath is water, and the rinsing liquid used in the rinsing bath is water.

[0065] Example 3

[0066] This embodiment discloses a method for preparing a polysulfone fiber membrane, comprising the following steps:

[0067] Step (1), dissolving polysulfone in dichloromethane, adding aluminum chloride, adding succinic anhydride in an ice-water bath within 2 hours, and then continuing the reaction in a 35° C. water bath for 3 hours, filtering the resulting solution and pouring it into ethanol for precipitation, then crushing the obtained precipitate and washing it in deionized water for 5 times, and then vacuum drying it at 100° C. to obtain a functionalized polysulfone; wherein the mass ratio of polysulfone, dichloromethane, aluminum chloride and succinic anhydride is 1:40:3:2;

[0068] Step (2), adding 0.8 g zirconium tetrachloride, 0.7 g 2-aminoterephthalic acid, and 6.6 g glacial acetic acid to 200 g N, N-dimethylformamide, stirring at 130°C and ultrasonically treating at 45 kHz for 20 h, after the reaction is completed, centrifuging, washing the obtained solid product with N, N-dimethylformamide 5 times, and vacuum drying at 120°C for 20 h to obtain UIO-66-NH2;

[0069] The functionalized polysulfone is added to tetrahydrofuran, and stirred at a speed of 300 r / min for 2 hours at room temperature, and then oxalyl chloride is added, and the reaction is continued at room temperature for 8 hours by stirring. After the reaction is completed, the solvent and oxalyl chloride are removed by reduced pressure distillation at 45° C. to obtain an intermediate product; wherein the mass ratio of the functionalized polysulfone, tetrahydrofuran, and oxalyl chloride is 1:400:65;

[0070] The intermediate product was added to tetrahydrofuran, and then UIO-66-NH2 was added. After stirring at a speed of 300 r / min at room temperature for 6 hours, the temperature was raised to 60°C, and the stirring reaction was continued for 6 hours. After the reaction was completed, the precipitate was precipitated with deionized water, filtered, and the obtained filter residue was washed with deionized water and ethanol for 5 times each, and dried to obtain a hybrid modified polysulfone; wherein the mass ratio of the intermediate product, tetrahydrofuran, and UIO-66-NH2 was 1:30:0.08;

[0071] Step (3), adding the hybrid modified polysulfone into deionized water, heating to 80° C. and stirring for reaction for 5 h, adjusting the pH to 4.8 with a 1 mol / L hydrochloric acid aqueous solution, then dropping tannic acid, stirring for reaction at 80° C. for 20 h, filtering, washing the obtained filter residue with deionized water for 8 times, and drying at 60° C. for 16 h to obtain tannic acid modified polysulfone; wherein the mass ratio of the hybrid modified polysulfone to the tannic acid is 17.5:0.5;

[0072] Adding tannic acid-modified polysulfone and copper nitrate into ethanol, reacting at room temperature for 7 hours, filtering, washing, and drying after the reaction to obtain a composite modified polysulfone; wherein the mass ratio of tannic acid-modified polysulfone, copper nitrate, and ethanol is 1:0.09:25;

[0073] Step (4), mixing ethanol and N-methyl-2-pyrrolidone in a volume ratio of 1:5 to obtain a composite solvent, adding the composite modified polysulfone, the polymer additive, and polyvinyl pyrrolidone to the composite solvent, stirring at 80° C. for 4 hours, and standing for degassing for 24 hours to obtain a casting solution; wherein the mass ratio of the composite modified polysulfone, the polymer additive, the polyvinyl pyrrolidone, and the composite solvent is 1:0.08:0.6:6;

[0074] Open the nitrogen valve and adjust the pressure of the raw material tank to 0.2MPa. The casting liquid is filtered and pressed into the spinning head through a metering pump. The flow rate of the casting liquid is controlled to be 2.0mL / min. At the same time, the core liquid is introduced with a flow rate of 2.0mL / min. The obtained primary ecological membrane passes through an air section spacing of 25cm, and then enters a coagulation bath and a rinsing bath under the traction of a winding machine, and then is wound on a rotating drum to obtain a polysulfone fiber membrane with a pore size of 215μm and a membrane thickness of 52μm. Among them, the winding speed of the winding machine is 50m / min, the coagulation bath temperature is 30℃, the rinsing bath temperature is 30℃, the core liquid is water, the coagulation liquid used in the coagulation bath is water, and the rinsing liquid used in the rinsing bath is water.

[0075] Example 4

[0076] This embodiment discloses a method for preparing a polysulfone fiber membrane, comprising the following steps:

[0077] Step (1), dissolving polysulfone in dichloromethane, adding aluminum chloride, adding succinic anhydride in an ice-water bath within 1.5 hours, and then continuing the reaction in a 30° C. water bath for 3.5 hours, filtering the resulting solution and pouring it into ethanol for precipitation, then crushing the obtained precipitate and washing it in deionized water for 4 times, and then vacuum drying it at 90° C. to obtain a functionalized polysulfone; wherein the mass ratio of polysulfone, dichloromethane, aluminum chloride, and succinic anhydride is 1:30:2:1.5;

[0078] Step (2), adding 0.7 g zirconium tetrachloride, 0.6 g 2-aminoterephthalic acid, and 5.6 g glacial acetic acid to 170 g N, N-dimethylformamide, stirring at 120°C and ultrasonically treating at 40 kHz for 25 h, after the reaction is completed, centrifuging, washing the obtained solid product with N, N-dimethylformamide 4 times, and vacuum drying at 110°C for 25 h to obtain UIO-66-NH2;

[0079] The functionalized polysulfone is added to tetrahydrofuran, and stirred at a speed of 250 r / min for 3 hours at room temperature, and then oxalyl chloride is added, and the reaction is continued at room temperature for 7 hours by stirring. After the reaction is completed, the solvent and oxalyl chloride are removed by reduced pressure distillation at 30° C. to obtain an intermediate product; wherein the mass ratio of the functionalized polysulfone, tetrahydrofuran, and oxalyl chloride is 1:350:57.5;

[0080] The intermediate product was added to tetrahydrofuran, and then UIO-66-NH2 was added. After stirring at a speed of 250 r / min at room temperature for 8 hours, the temperature was raised to 50°C, and the stirring reaction was continued for 8 hours. After the reaction was completed, the precipitate was precipitated with deionized water, filtered, and the obtained filter residue was washed with deionized water and ethanol for 4 times respectively, and dried to obtain a hybrid modified polysulfone; wherein the mass ratio of the intermediate product, tetrahydrofuran, and UIO-66-NH2 was 1:25:0.06;

[0081] Step (3), adding the hybrid modified polysulfone into deionized water, heating to 75°C and stirring for reaction for 6 hours, adjusting the pH to 4.7 with a 1 mol / L hydrochloric acid aqueous solution, then dropping tannic acid, stirring for reaction at 75°C for 22 hours, filtering, washing the obtained filter residue with deionized water for 7 times, and drying at 50°C for 20 hours to obtain tannic acid modified polysulfone; wherein the mass ratio of the hybrid modified polysulfone to tannic acid is 17.5:0.3;

[0082] Add tannic acid modified polysulfone and copper nitrate into ethanol, react at room temperature for 6 hours, filter, wash and dry after the reaction to obtain composite modified polysulfone; wherein the mass ratio of tannic acid modified polysulfone, copper nitrate and ethanol is 1:0.07:20;

[0083] Step (4), mixing ethanol and N-methyl-2-pyrrolidone in a volume ratio of 1:5 to obtain a composite solvent, adding the composite modified polysulfone, the polymer additive, and polyvinyl pyrrolidone to the composite solvent, stirring at 70° C. for 4.5 hours, standing and degassing for 21 hours, to obtain a casting solution; wherein the mass ratio of the composite modified polysulfone, the polymer additive, the polyvinyl pyrrolidone, and the composite solvent is 1:0.06:0.4:4.5;

[0084] Open the nitrogen valve and adjust the pressure of the raw material tank to 0.12MPa. The casting liquid is filtered and pressed into the spinning head through a metering pump. The flow rate of the casting liquid is controlled to be 1.2mL / min. At the same time, the core liquid is introduced with a core liquid flow rate of 1.5mL / min. The obtained primary ecological membrane passes through an air section spacing of 15cm, and then enters the coagulation bath and the rinsing bath under the traction of a winding machine, and then is wound on a rotating drum. A polysulfone fiber membrane with a pore size of 197μm and a membrane thickness of 46μm is obtained. Among them, the winding speed of the winding machine is 35m / min, the coagulation bath temperature is 20℃, the rinsing bath temperature is 20℃, the core liquid is water, the coagulation liquid used in the coagulation bath is water, and the rinsing liquid used in the rinsing bath is water.

[0085] The polymer additive used in the above Examples 2-4 is the polymer additive prepared in Example 1.

[0086] Comparative Example 1

[0087] Compared with Example 1, in the process of preparing the polymer additive in Comparative Example 1, no modified carbon dots were added, and other conditions remained unchanged.

[0088] Comparative Example 2

[0089] Compared with Example 4, Comparative Example 2 uses the polymer additive prepared in Comparative Example 1, and other conditions remain unchanged.

[0090] Comparative Example 3

[0091] Compared with Example 4, in Comparative Example 3, no polymer additive was added during the polysulfone fiber membrane process, and other conditions remained unchanged.

[0092] Comparative Example 4

[0093] Compared with Example 4, in the process of preparing the composite modified polysulfone in Comparative Example 4, tannic acid modification was not used, and other conditions remained unchanged.

[0094] Comparative Example 5

[0095] Compared with Example 4, in the process of preparing the polysulfone fiber membrane in Comparative Example 5, tannic acid-modified polysulfone was used instead of composite modified polysulfone, and other conditions remained unchanged.

[0096] Comparative Example 6

[0097] Compared with Example 4, in Comparative Example 6, in the process of preparing tannic acid-modified polysulfone, functionalized polysulfone was used instead of hybrid modified polysulfone, and other conditions remained unchanged.

[0098] In the above embodiments and comparative examples, polysulfone, CAS No.: 25135-51-7, molecular weight: 1327.58, comes from Shanghai Yingxin Laboratory Equipment Co., Ltd.; 0.22 μm filter membrane, pore size of 0.22 μm, diameter of 47 mm, comes from Nanjing Kehang Experimental Instrument Co., Ltd.; 500Da dialysis bag, molecular weight cutoff (MWCO) of 500D, diameter of 20 mm, flattened width (MD) of 31 mm, comes from Shanghai Zeye Biotechnology Co., Ltd.

[0099] Experimental example

[0100] The performance of the polysulfone fiber membranes prepared in Examples 2-3 and Comparative Examples 2-6 was tested.

[0101] 1. Pure water flux test: In each experiment, the membrane pool was thoroughly cleaned before and after use. After ensuring that the device had no leaks, it was pressurized with pure water (considered to be feed) at 0.5 bar for 30 minutes. When the water flux stabilized, the pure water flux was calculated by the following formula:

[0102]

[0103] Among them, Jw(L / m 2 h) is the pure water flux, V(L) is the permeation volume, Δt(h) is the test duration, A(m 2 ) is the area of ​​the membrane; the higher the pure water flux, the better the dialysis performance of the membrane.

[0104] 2. Antifouling performance test: Using a BSA solution with a concentration of 1 g / L as a model pollutant, ultrafiltration was performed at a pressure of 0.5 bar to study the antifouling performance of the membrane. The feed was replaced with BSA solution and the permeation flux of BSA was measured (J B ). The membrane was then cleaned with pure water and immersed in water for further cleaning for 1 h, and the pure water flux (Jr) of the cleaned membrane was estimated. All tests were repeated five times. Finally, in order to evaluate the antifouling performance of the sample, the flux recovery rate (FRR) was calculated by the following formula:

[0105]

[0106] The higher the FRR, the better the membrane's anti-fouling performance.

[0107] 3. Urea clearance test: Deionized water was used as the dialysate, with urea (1.5 g / L), creatinine (0.1 g / L), and bovine serum albumin (1 g / L) as simulated solutions, and the experimental temperature was 37°C. The simulated solution flow rate was 100 mL / min, and the dialysate flow rate was 50 mL / min. The test was run for 4 hours, and 10 ml of the solution was collected every hour. The urea clearance after 4 hours was calculated using the following formula:

[0108]

[0109] Among them C 0D and C tD are the urea concentrations in the simulated solution at t=0 and t=4h respectively.

[0110] 4. Anticoagulation test: The activated partial thromboplastin time (APTT) was measured using a coagulation analyzer (Pun2048B) to characterize the anticoagulation performance of the membrane.

[0111] 5. Lipid peroxidation inhibition test: Clean the blood on the surface of the pig liver with ice saline, chop the pig liver in an ice water bath, stir for 30 minutes to break the pig liver, and dilute the pig liver homogenate to a volume fraction of 10% with saline. Centrifuge at 3000rpm to obtain the supernatant, and obtain the pig liver tissue homogenate as the lipid source. Dilute the pig liver tissue homogenate supernatant to 0.65±0.05 at 532nm with PBS solution. Then, 1cm 2Membrane sample, H2O2 (0.3mL, 100mM) and pig liver tissue homogenate (3mL, 10% (v / v)) were reacted at 37℃ for 1h, trichloroacetic acid (3mL, 15%) was added to terminate the reaction, the mixture was centrifuged at 3000rpm for 10min, barbituric acid (3mL, 0.67%) was added to the supernatant, heated in a 100℃ oil bath for 20min, cooled in running water for 15min, and the absorbance was measured at 532nm with a UV-visible spectrophotometer. The lipid peroxidation inhibition rate (IR) was calculated by the following formula:

[0112]

[0113] Among them, A m is the absorbance of the H2O2 solution containing the membrane, A s is the absorbance of the control solution without membrane H2O2, A n is the absorbance of the control solution without membrane H2O2.

[0114] The test results are shown in Table 1:

[0115] Table 1

[0116]

[0117]

[0118] From the test results in Table 1, it can be seen that the polysulfone fiber membranes prepared in Examples 2-4 of the present invention have excellent dialysis performance, anti-fouling performance, anti-coagulation performance and antioxidant performance, and have a high removal efficiency for urea. From the comparison of Comparative Examples 2 and 4 with Example 4, it can be seen that the modified carbon dots and tannic acid modification mainly improve the hydrophilicity of the polysulfone membrane by introducing hydrophilic functional groups and their own antioxidant effects, thereby improving the dialysis performance, urea clearance rate, anti-fouling performance, anti-coagulation performance and antioxidant performance of the polysulfone membrane; from the comparison of Comparative Examples 3 and Comparative Example 6 with Example 4, it can be seen that the addition of polymer additives and MOF material UIO-66-NH2 mainly improves the hydrophilicity and porosity of the membrane material, thereby improving the dialysis performance, urea clearance rate, anti-fouling performance, anti-coagulation performance and antioxidant performance of the polysulfone membrane. The polysulfone membrane containing the polymer additive has good antioxidant properties. Since the polymer additive contains carbon dots, the polysulfone membrane containing the polymer additive also has good antioxidant properties. From the comparison between Comparative Example 5 and Example 4, it can be seen that the divalent copper ions are complexed with tannic acid to form a divalent copper ion-phenol complex, which has an enhanced adsorption effect on urea, and can efficiently remove urea in hemodialysis through the synergistic effect of diffusion and enhanced adsorption. In addition, the divalent copper ions can catalyze the release of NO, so that the polysulfone membrane exhibits better inhibition of platelet activation, prolongation of coagulation time, and inhibition of oxidative immune response.

[0119] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a polysulfone fiber membrane, characterized in that: The following steps are involved: Step (1), modifying the polysulfone to introduce carboxyl groups to obtain functionalized polysulfone; Step (2), using zirconium tetrachloride and 2-aminoterephthalic acid as raw materials to prepare UIO-66-NH2; Functionalized polysulfone reacts with UIO-66-NH2 to obtain hybrid modified polysulfone; Step (3), tannic acid reacts with hybrid modified polysulfone to obtain tannic acid modified polysulfone; copper is loaded on the tannic acid modified polysulfone to obtain composite modified polysulfone; Step (4), adding the composite modified polysulfone, polymer additive and polyvinyl pyrrolidone into the composite solvent, stirring, standing and degassing to obtain a casting solution, and then preparing a polysulfone fiber membrane through a dry-wet spinning process; The preparation method of the polymer additive comprises the following steps: Step S1, preparing carbon dot powder by a hydrothermal method, and modifying the carbon dot powder by 1,2-epoxy-5-hexene to obtain modified carbon dots; Step S2, 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl)methacrylamide hydrochloride, and modified carbon dots react to obtain a polymer additive.

2. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (1), the preparation method of the functionalized polysulfone is as follows: dissolving the polysulfone in dichloromethane, adding aluminum chloride, adding succinic anhydride in an ice-water bath within 1-2 hours, and then continuing the reaction in a 25-35°C water bath for 3-4 hours, filtering the resulting solution and pouring it into ethanol to precipitate the obtained precipitate, crushing, washing, and drying; wherein the mass ratio of polysulfone, dichloromethane, aluminum chloride, and succinic anhydride is 1:(20-40):(1-3):(1-2).

3. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (2), the preparation method of UIO-66-NH2 is as follows: zirconium tetrachloride, 2-aminoterephthalic acid and glacial acetic acid are added to N,N-dimethylformamide, stirred at 110-130°C and ultrasonically treated at 35-45KHz for 20-30h, and after the reaction is completed, centrifuged, washed and dried; wherein the mass ratio of zirconium chloride, 2-aminoterephthalic acid, glacial acetic acid and N,N-dimethylformamide is (0.6-0.8):(0.5-0.7):(4.7-6.6):(140-200).

4. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (2), the preparation method of the hybrid modified polysulfone is: Adding functionalized polysulfone to tetrahydrofuran, stirring at a speed of 200-300 r / min for 2-4 hours at room temperature, adding oxalyl chloride, continuing to stir and react at room temperature for 6-8 hours, after the reaction is completed, removing the solvent and oxalyl chloride by reduced pressure distillation at 20-45° C. to obtain an intermediate product; wherein the mass ratio of functionalized polysulfone, tetrahydrofuran, and oxalyl chloride is 1:(300-400):(50-65); The intermediate product is added to tetrahydrofuran, and then UIO-66-NH2 is added. After stirring at a speed of 200-300 r / min at room temperature for 6-10 hours, the temperature is raised to 40-60°C, and the stirring reaction is continued for 6-10 hours. After the reaction is completed, the precipitate is precipitated with deionized water, filtered, washed, and dried to obtain a hybrid modified polysulfone; wherein the mass ratio of the intermediate product, tetrahydrofuran, and UIO-66-NH2 is 1:(20-30):(0.03-0.08).

5. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (3), the preparation method of the composite modified polysulfone is: The hybrid modified polysulfone is added into deionized water, heated to 70-80°C and stirred for reaction for 5-7h, the pH is adjusted to 4.6-4.8 by a 1 mol / L hydrochloric acid aqueous solution, and then tannic acid is added dropwise, stirred for reaction at 70-80°C for 20-24h, filtered, washed, and dried to obtain tannic acid modified polysulfone; wherein the mass ratio of the hybrid modified polysulfone to tannic acid is 17.5:(0.1-0.5); Add tannic acid modified polysulfone and copper nitrate into ethanol, react at room temperature for 5-7 hours, filter, wash and dry after the reaction to obtain composite modified polysulfone; wherein the mass ratio of tannic acid modified polysulfone, copper nitrate and ethanol is 1:(0.05-0.09):(15-25).

6. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (4), the mass ratio of the composite modified polysulfone, the polymer additive, the polyvinyl pyrrolidone, and the composite solvent is 1:(0.04-0.08):(0.2-0.6):(3-6); the composite solvent is obtained by mixing ethanol and N-methyl-2-pyrrolidone in a volume ratio of 1:5; the stirring conditions are: stirring at 60-80°C for 4-5h; and the standing degassing time is 18-24h.

7. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (4), the pore size of the polysulfone fiber membrane is 180-220 μm, and the membrane thickness is 35-55 μm; the dry-wet spinning process method: in a nitrogen atmosphere, the casting liquid and the core liquid are sprayed out simultaneously, the driving pressure of the casting liquid is adjusted to 0.05-0.20 MPa, the casting liquid flow rate is 0.5-2.0 mL / min, the core liquid is water, and the core liquid flow rate is 1.0-2.0 mL / min, to obtain a nascent ecological membrane; the nascent ecological membrane passes through an air segment spacing of 10-25 cm and is pulled into a coagulation bath and a rinsing bath at a winding speed of 20-50 m / min, the coagulation bath temperature is 5-30°C, the rinsing bath temperature is 10-30°C, the coagulation liquid used in the coagulation bath is water, and the rinsing liquid used in the rinsing bath is water.

8. The method for preparing a polysulfone fiber membrane according to claim 1, characterized in that: In the step (4), the preparation method of the polymer additive is: Step S1, adding banana to a 60% ethanol aqueous solution, stirring for 10-20 minutes, heating to 175-185°C under sealed conditions for reaction for 5.5-6.5 hours, cooling to room temperature, and filtering with suction. The obtained filtrate is filtered through a 0.22 μm filter membrane and centrifuged. The obtained supernatant is dialyzed through a 500 Da dialysis bag for 3-5 days, and the water is changed 2-4 times a day during the dialysis process. The final dialysate is freeze-dried to obtain carbon dot powder; wherein the mass ratio of banana to ethanol aqueous solution is (30-40):(10-15); The carbon dot powder, 1,2-epoxy-5-hexene and N,N-dimethylformamide are mixed, stirred at a speed of 400-500 r / min, heated to 120-130° C., and triphenylphosphine is added to react for 40-50 hours. After the reaction is completed, the reaction product mixture is dialyzed for 3-5 days through a 500Da dialysis bag, and water is changed 2-4 times a day during the dialysis process. The final dialysate is freeze-dried to obtain modified carbon dots; wherein the mass ratio of the carbon dot powder, 1,2-epoxy-5-hexene, N,N-dimethylformamide and triphenylphosphine is (3-5):(1-1.5):(30-60):(0.001-0.003); Step S2, under an argon atmosphere, add 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl) methacrylamide hydrochloride, and modified carbon dots to ethanol, then add azobisisobutyronitrile, and stir the reaction at 70-80°C for 10-15h. After the reaction, precipitate the product from the reaction solution by tetrahydrofuran, and then dissolve the product in water, freeze-dry, and obtain a polymer additive; wherein the mass ratio of 2-methacryloyloxyethyl phosphorylcholine, N-(3-aminopropyl) methacrylamide hydrochloride, modified carbon dots, ethanol, and azobisisobutyronitrile is (3-6):(1.8-3.6):(1.5-2.5):(30-50):(0.03-0.05).

9. A polysulfone fiber membrane prepared by the method for preparing a polysulfone fiber membrane according to any one of claims 1 to 8.

10. Use of the polysulfone fiber membrane according to claim 9 in hemodialysis membrane materials.

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