Hybrid hollow fiber oxygenation membranes and methods of making the same
By preparing a hybrid hollow fiber oxygenation membrane, the problem of insufficient gas permeability of the oxygenation membrane was solved by combining metal-organic molecular sieve materials with polyolefins, thus achieving efficient carbon dioxide and oxygen transport and improving the performance of the oxygenation membrane.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 天津大学浙江研究院
- Filing Date
- 2023-01-13
- Publication Date
- 2026-06-23
AI Technical Summary
Existing oxygenation membranes have poor gas permeability, resulting in low carbon dioxide removal efficiency, which cannot meet the carbon dioxide transport requirements of arterial blood, and high gas velocities can easily lead to serious consequences such as air embolism.
Hybrid hollow fiber oxygen membranes are prepared by combining metal-organic molecular sieve materials with polyolefins and spinning them through thermally induced phase separation. This enhances the carbon dioxide transport performance. Materials such as metal-organic frameworks Cu-TAPB, ZIF-8, and hydrogen-bonded organic frameworks HOF-21 are combined with polyolefins to form porous and dense layer structures.
It significantly improved the carbon dioxide permeability and oxygen permeability of the oxygenation membrane, with the carbon dioxide permeation rate increasing by 122.77% and the oxygen permeation rate increasing by 68.87%, while maintaining anti-plasma leakage properties and reducing transmission resistance.
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Figure CN116059853B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of membrane technology, specifically relating to a hybrid hollow fiber oxygenation membrane and its preparation method. Background Technology
[0002] Extracorporeal membrane oxygenation (ECMO) is used in acute respiratory distress syndrome, cardiovascular surgery, and other procedures. It facilitates the exchange of oxygen and carbon dioxide between blood and scavenging gas outside the body to assist blood circulation and provide respiratory support. The membrane oxygenator performs both membrane oxygenation and carbon dioxide removal; the gas permeability, blood compatibility, and resistance to plasma leakage of its key component, the oxygenation membrane, directly affect the performance of the oxygenator.
[0003] To achieve arterial blood quality comparable to venous blood, the carbon dioxide to oxygen mass transfer ratio of the oxygenation membrane should be greater than 12. However, in clinical practice, this ratio is only around 3. This is mainly because existing oxygenation membranes have strong resistance to plasma permeability but less than ideal gas permeability. Even at the highest sweeping flow rate within a safe range, approximately 50% of patients with acute respiratory distress syndrome still do not have sufficient carbon dioxide removal to prevent potential spontaneous breathing; respiratory distress persists, and the carbon dioxide delivery is only barely sufficient to meet the respiratory needs of stationary patients. Furthermore, excessively high sweeping gas rates can easily lead to serious consequences such as air embolism. Therefore, the development of high-performance carbon dioxide removal oxygenation membranes with reasonable gas rates is urgently needed. Summary of the Invention
[0004] The purpose of this application is to provide a hybrid hollow fiber oxygenation membrane and its preparation method, so as to solve the technical problems existing in the prior art, such as poor gas permeability of oxygenation membrane, resulting in poor carbon dioxide removal efficiency of oxygenation membrane for blood, persistent respiratory distress, and carbon dioxide transport capacity that can only basically meet the respiratory needs of stationary patients.
[0005] To achieve the above objectives, one technical solution adopted in this application is:
[0006] A hybrid hollow fiber oxygenation membrane is provided, comprising the following raw materials: metal-organic molecular sieve material and polyolefin; wherein the metal-organic molecular sieve material comprises one or more combinations of metal-organic framework materials, metal covalent organic framework materials and hydrogen-bonded organic framework materials.
[0007] In one or more embodiments, the metal-organic molecular sieve material includes one or more combinations of metal-covalent organic framework Cu-TAPB, metal-organic framework ZIF-8, and hydrogen-bonded organic framework HOF-21.
[0008] In one or more embodiments, the polyolefin includes one or more combinations of polypropylene, polyethylene, poly(4-methyl-1-pentene), and poly(ethylene-vinyl alcohol); the mass ratio of the metal-organic molecular sieve material to the polyolefin is (0.1-10):100.
[0009] In one or more embodiments, the hybrid hollow fiber oxygenation membrane includes a porous layer and a non-porous, dense layer on the surface of the porous layer. The thickness of the hybrid hollow fiber oxygenation membrane is 255-550 μm, the thickness of the dense layer is 0.64-0.86 μm, and the cross-section of the porous layer is a cellular, loose structure.
[0010] To achieve the above objectives, another technical solution adopted in this application is:
[0011] A method for preparing the hybrid hollow fiber oxygen membrane according to any of the above embodiments is provided, comprising the following steps:
[0012] The metal-organic molecular sieve material is uniformly dispersed in a diluent to obtain a dispersion.
[0013] Polyolefin is added to the dispersion, heated and stirred until homogeneous, and then allowed to stand to obtain a casting solution;
[0014] Using the casting solution as raw material, a hybrid hollow fiber oxygen membrane was obtained by thermally induced phase separation spinning.
[0015] In one or more embodiments, the diluent comprises one or more combinations of dioctyl adipate, dioctyl sebacate, dibutyl phthalate, dioctyl phthalate, glyceryl triacetate, glyceryl triacetate, castor oil, tributyl acetyl citrate, trioctyl acetyl citrate, tributyl citrate, and trioctyl citrate; the mass ratio of the metal-organic molecular sieve material to the diluent in the dispersion is 0.5:9.5 to 5:5.
[0016] In one or more embodiments, the step of heating and stirring until uniform and then allowing to stand specifically includes:
[0017] Heat to 230-240℃ and stir for 8 hours, then raise the temperature to 235-245℃ and let stand for 12 hours to remove bubbles.
[0018] In one or more embodiments, the step of spinning using thermally induced phase separation specifically includes:
[0019] The casting solution is kept at a constant temperature of 235-245°C. The casting solution is extruded through a spinneret and introduced into a water coagulation bath at room temperature for solidification and molding. The spinning speed is 0.5-1.5 m / s and the core liquid flow rate is 0.4-1.7 ml / min.
[0020] In one or more embodiments, it further includes:
[0021] The hybrid hollow fiber oxygen membrane was thoroughly immersed in the extraction solution to extract and remove the diluent, and then air-dried.
[0022] The extract includes one or more of anhydrous ethanol, isopropanol, and diethyl ether.
[0023] To achieve the above objectives, another technical solution adopted in this application is:
[0024] The invention provides an application of the hybrid hollow fiber oxygenation membrane described in any of the above embodiments or the hybrid hollow fiber oxygenation membrane prepared by the preparation method described in any of the above embodiments as an oxygenation membrane in extracorporeal membrane lung oxygenation.
[0025] The advantages of this application, which differ from existing technologies, are:
[0026] 1. The hybrid hollow fiber oxygen membrane of this application contains a hybrid dispersion of metal-organic molecular sieve material. Due to its high content of imine and benzene ring groups and high density of copper sites, the metal-organic molecular sieve can interact with polar carbon dioxide, thereby enhancing the dissolution-diffusion process of carbon dioxide molecules through the membrane and the rapid conversion between bicarbonate and carbon dioxide. Furthermore, the good interaction and compatibility between the metal-organic molecular sieve nanosheets and polyolefins enhance the free volume of the membrane and reduce the resistance to carbon dioxide transport within the membrane. The coordinated action of these multiple mechanisms results in a hybrid hollow fiber oxygen membrane with highly efficient carbon dioxide transport performance, significantly improving the gas permeability of the oxygen membrane, especially carbon dioxide permeability. The carbon dioxide permeation rate of the hybrid hollow fiber oxygen membrane of this application can reach 6.75 ml / (min·cm). 2 The oxygen permeation rate of the hybrid hollow fiber oxygenation membrane of this application is 122.77% higher than that of the unhybridized hollow fiber membrane, reaching 2.55 ml / (min·cm). 2 The efficiency (bar) was increased by 68.87% compared to unhybridized hollow fiber membranes.
[0027] 2. The metal-organic molecular sieve nanosheets and polyolefins in the hybrid hollow fiber oxygen membrane of this application have good interfacial compatibility, avoiding the generation of defects and agglomeration;
[0028] 3. The preparation method of this application involves uniformly dispersing metal-organic molecular sieves in a casting solution and spinning them using a thermally induced phase separation method. This method simplifies the membrane preparation process, effectively reduces the difficulty of membrane preparation, and the prepared hybrid hollow fiber oxygenation membrane is highly competitive among oxygenation membranes used in extracorporeal membrane lung oxygenation. Attached Figure Description
[0029] Figure 1This is a schematic flowchart of one embodiment of the preparation method of the hybrid hollow fiber oxygen membrane of this application;
[0030] Figure 2 This is a scanning electron microscope image of the hybrid hollow fiber oxygen membrane of Embodiment 1 of this application. Detailed Implementation
[0031] The present application will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present application.
[0032] Extracorporeal membrane oxygenation (ECMO) is used in acute respiratory distress syndrome, cardiovascular surgery, and other procedures. It facilitates the exchange of oxygen and carbon dioxide between blood and scavenging gas to assist blood circulation and provide respiratory support. The membrane lung performs both membrane oxygenation and carbon dioxide removal, and the gas permeability, blood compatibility, and resistance to plasma leakage of its key component, the oxygenation membrane, directly affect the performance of the oxygenator.
[0033] To achieve the same level of venous blood as arterial blood, the carbon dioxide to oxygen mass transfer coefficient ratio of the oxygenation membrane should be greater than 12. However, the clinical mass transfer coefficient ratio is only around 3. At the highest scavenging flow rate within the safe range, approximately 50% of ARDS patients do not receive enough carbon dioxide to prevent potential spontaneous breathing, and dyspnea persists, with the carbon dioxide delivery only barely meeting the respiratory needs of stationary patients. Excessive air velocity can easily lead to serious consequences such as air embolism. Therefore, the development of high-performance carbon dioxide removal membrane lungs with reasonable air velocities is urgently needed.
[0034] Currently, poly(4-methyl-1-pentene) hollow fiber membranes are the most advantageous among oxygenation membranes. Poly(4-methyl-1-pentene) hollow fiber membranes have a porous, cellular main structure and a dense skin layer, exhibiting strong resistance to plasma leakage, but their gas permeability is not ideal. Therefore, it is crucial to efficiently prepare and produce poly(4-methyl-1-pentene) oxygenation membranes with high carbon dioxide transport rates.
[0035] To address the issue of poor gas permeability in currently commercially available oxygenation membranes, the applicant has developed a hybrid hollow fiber oxygenation membrane. This hybrid hollow fiber oxygenation membrane utilizes the characteristics of metal-organic molecular sieves, adding them as raw materials to the oxygenation membrane. The embedding of the metal-organic molecular sieves provides additional adsorption and transport channels for oxygen and carbon dioxide, significantly improving the carbon dioxide gas permeability of the oxygenation membrane. At the same time, it avoids the complex manufacturing process of adjusting the membrane structure to improve the gas transport performance of current oxygenation membrane production.
[0036] The hybrid hollow fiber oxygen membrane of this application comprises the following raw materials: metal-organic molecular sieve materials and polyolefins.
[0037] Specifically, the metal-organic molecular sieve material of this application can be any material with a porous structure, large specific surface area, high density of metal nodes and functional groups, such as metal-organic frameworks (MOF), metal-organic polyhedra (MOP), metal-induced polymer frameworks (MPF), metal-intrinsically porous polymers (MPIMs), metal-conjugated microporous polymers (MCMPs), metal-covalent triazine frameworks (MCTFs), metal-covalent organic frameworks (MCOFs), metal-porous organic cages (MPOCs), hydrogen-bonded organic frameworks (HOFs), etc.
[0038] In one embodiment, the metal-organic molecular sieve material of this application may include one or more combinations of metal-organic frameworks (MOFs), metal covalent organic frameworks (MCOFs), and hydrogen-bonded organic frameworks (HOFs).
[0039] Specifically, the metal-organic molecular sieve material of this application may include one or more combinations of metal-covalent organic framework Cu-TAPB, metal-organic framework ZIF-8, and hydrogen-bonded organic framework HOF-21.
[0040] Inspired by carbonic anhydrase, metal-organic molecular sieve materials with suitable metal sites can be screened to enable rapid conversion of bicarbonate and carbon dioxide when applied to oxygenation membranes. At the same time, the porous structure of the metal-organic molecular sieve materials facilitates the permeation of oxygen and carbon dioxide, and the polar groups can interact with polar carbon dioxide. Hybridizing metal-organic molecular sieves with polyolefins to form oxygenation membranes can provide channels for rapid carbon dioxide transport and improve the dissolution-diffusion performance of oxygenation membranes for carbon dioxide.
[0041] In one embodiment, the polyolefin of this application may include one or more combinations of polypropylene, polyethylene, poly(4-methyl-1-pentene), and poly(ethylene-vinyl alcohol).
[0042] To ensure a balance between the strength, resistance to plasma leakage, and gas leakage of the hybrid hollow fiber oxygen membrane, in one embodiment, the mass ratio of the metal-organic molecular sieve material to the polyolefin can be (0.1–10):100.
[0043] The applicant also provided a method for preparing the aforementioned hybrid hollow fiber oxygen membrane; please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic flowchart of one embodiment of the preparation method of the hybrid hollow fiber oxygen membrane of this application.
[0044] Specifically, the preparation method includes:
[0045] S100. The metal-organic molecular sieve material is uniformly dispersed in the diluent to obtain a dispersion.
[0046] The diluent is used to dissolve the metal-organic molecular sieve material and polyolefin at high temperatures.
[0047] In one application scenario, the diluent may include one or more combinations of dioctyl adipate, dioctyl sebacate, dibutyl phthalate, dioctyl phthalate, glyceryl triacetate, glyceryl triacetate, castor oil, acetylated tributyl citrate, acetylated trioctyl citrate, tributyl citrate, and trioctyl citrate.
[0048] The mass ratio of the metal-organic molecular sieve material to the diluent in the dispersion can be 0.5:9.5 to 5:5.
[0049] In one application scenario, uniform dispersion can be achieved by using one or more methods such as ultrasonic dispersion and cell disruption to ensure sufficient dispersion and improve the quality of subsequent products.
[0050] S200. Add polyolefin to the dispersion, heat and stir until uniform, then let stand to obtain casting solution.
[0051] After adding polyolefin to the dispersion, the polyolefin and the metal-organic molecular sieve material are thoroughly mixed and dissolved in the diluent by heating and stirring.
[0052] In one application scenario, the heating and stirring process followed by standing can be specifically described as follows: heating to 230-240℃ and stirring for 8 hours, then raising the temperature to 235-245℃ and standing for 12 hours to remove bubbles.
[0053] Understandably, heating the diluent first, followed by stirring, helps the polyolefin and metal-organic molecular sieve materials to fully dissolve and mix in the diluent. Then, the temperature is increased and the mixture is allowed to stand to remove air bubbles that could affect the quality of subsequent products.
[0054] S300. Using casting solution as raw material, a hybrid hollow fiber oxygen membrane is obtained by thermally induced phase separation spinning method.
[0055] Specifically, the thermally induced phase separation spinning method involves maintaining the casting solution at a temperature that allows the polyolefin and metal-organic molecular sieve materials to dissolve, then using a spinneret to extrude the casting solution into a water coagulation bath at room temperature for solidification, and finally collecting the formed membrane fibers from the water coagulation bath to obtain the final product.
[0056] The temperature of the casting solution can be kept constant at 235-245℃, the temperature of the filter before spinning can be kept constant at 225-235℃, and the temperature of the spinneret can be kept constant at 215-22℃.
[0057] The spinneret can be an annular spinneret with an outer diameter of 1.2 mm and an inner diameter of 0.7 mm. The distance between the spinneret and the surface of the water coagulation bath can be 3 cm. The spinning speed is 0.5–1.5 m / s, and the core liquid flow rate can be 0.4–1.7 ml / min.
[0058] To remove residual diluent from the hybrid hollow fiber oxygen membrane and thoroughly clean the membrane, the following steps may be included after step S300:
[0059] S400: Immerse the hybrid hollow fiber oxygen membrane thoroughly in the extraction solution to remove the diluent, and then air dry.
[0060] The extractant is a solvent that is miscible with the diluent and water but insoluble in the polymer. In one application scenario, the extractant may include one or more of anhydrous ethanol, isopropanol, and diethyl ether.
[0061] Soaking in the extract can effectively remove residual diluent, and then air drying will achieve thorough cleaning.
[0062] The technical solution of this application will be further explained in detail below with reference to specific embodiments.
[0063] The metal-covalent organic framework Cu-TAPB involved in the following examples was prepared by a solvothermal method using the metal coordination compound Cu3L3 as the COF synthesis monomer.
[0064] First, the cyclic trinuclear complex Cu3L3 with an aldehyde group was synthesized. The specific experimental steps are as follows: 240 mg of 1H-pyrazole-4-carboxaldehyde (HL), 482 mg of copper nitrate trihydrate (Cu(NO3)2·3H2O), 13.4 mL of N,N-dimethylformamide (DMF), 13.4 mL of ethanol, and 10 mL of water were added to a 50 mL polytetrafluoroethylene liner. The mixture was then thoroughly stirred with a glass rod and ultrasonically dispersed for 30 min. The liner was then placed in a reaction vessel, tightened, and placed in a 120 °C oven for 24 h. After the reaction vessel cooled to room temperature, the solution was filtered, thoroughly washed with ethanol, and then dried in a 60 °C vacuum oven for 12 h to obtain pale yellow needle-like crystals of Cu3L3.
[0065] Cu-TAPB-COF powder was then synthesized via a solvothermal method. The specific experimental steps are as follows: 118.5 mg Cu3L3, 131.5 mg 1,3,5-tris(4-aminophenyl)benzene (TAPB), 2.5 mL 1,4-dioxane, 2.5 mL mesitylene, and 150 μL glacial acetic acid were added sequentially to a 15 mL heat- and pressure-resistant glass reaction tube. After thorough stirring with a glass rod, the mixture was ultrasonically dispersed for 10 min. The reaction tube was declimaticated by three cycles of liquid nitrogen freezing-vacuuming-thawing, and then placed in a 120 °C oven for 3 days. After filtration, the reaction solution was washed sequentially with tetrahydrofuran (THF, 30 mL × 3) and N,N-dimethylformamide (DMF, 30 mL × 3), followed by solvent exchange with THF for 2 days, and then dried in a 120 °C vacuum oven for 12 h to obtain light green Cu-TAPB-COF powder.
[0066] Cu-TAPB nanosheets were prepared by ball milling. The specific experimental steps are as follows: 200 mg of Cu-TAPB-COF powder sample and 15 mL of methanol were added to a ball mill jar, and the mixture was milled at 400 rpm for 12 h. After sonicating the above solution for 1 h, the upper dispersion was collected and then dried in a vacuum oven at 60 °C to obtain Cu-TAPB-COF nanosheets.
[0067] Example 1:
[0068] A hybrid hollow fiber oxygenation membrane is prepared using the following steps:
[0069] Weigh 0.03g of metal-covalent organic framework Cu-TAPB, 142.5g of trioctyl citrate, and 427.5g of acetylated trioctyl citrate. Sonicate the mixture of metal-covalent organic framework Cu-TAPB, trioctyl citrate, and acetylated trioctyl citrate for 30 minutes and then disrupt the cells for 30 minutes to ensure uniform dispersion of the metal-covalent organic framework Cu-TAPB and obtain a suspension.
[0070] The suspension was placed in the reactor of a hollow fiber membrane spinning machine, and then 30g of poly(4-methyl-1-pentene) was weighed and added to the reactor. The mixture was stirred at 235℃ for 8 hours. After that, the temperature was raised to 240℃ and allowed to stand for 12 hours to obtain the casting solution.
[0071] Using casting solution as raw material, hollow fiber membrane spinning was performed using a hollow fiber membrane spinning machine. The casting solution was extruded and introduced into a water coagulation bath at room temperature. The reaction vessel was kept at a constant temperature of 240℃, the filter at a constant temperature of 230℃, and the spinneret at a constant temperature of 220℃. The outer diameter and inner diameter of the annular spinneret were 1.2 mm and 0.7 mm, respectively. The distance between the spinneret and the surface of the water coagulation bath was 3 cm. The spinning speed was 1.5 m / s, and the core liquid flow rate was 1.5 ml / min.
[0072] The formed hollow fiber membrane was extracted in isopropanol for 2 days to ensure the removal of trioctyl citrate and acetylated trioctyl citrate, with the isopropanol being replaced 4 times during the process. It was then dried in a fume hood for 2 days.
[0073] Example 2:
[0074] A hybrid hollow fiber oxygenation membrane is prepared using the following steps:
[0075] Weigh 2.1g of metal-covalent organic framework Cu-TAPB and 490g of dioctyl phthalate. Sonicate the mixture of metal-covalent organic framework Cu-TAPB and dioctyl phthalate for 30 minutes and then disrupt the cells for 30 minutes to ensure uniform dispersion of the metal-covalent organic framework Cu-TAPB and obtain a suspension.
[0076] The suspension was placed in the reactor of a hollow fiber membrane spinning machine, and then 210 g of poly(4-methyl-1-pentene) was weighed and added to the reactor. The mixture was stirred at 235 °C for 8 h. After that, the temperature was raised to 240 °C and allowed to stand for 12 h to obtain the casting solution.
[0077] Using casting solution as raw material, hollow fiber membrane spinning was performed using a hollow fiber membrane spinning machine. The casting solution was extruded and introduced into a water coagulation bath at room temperature. The reaction vessel was kept at a constant temperature of 240℃, the filter at a constant temperature of 230℃, and the spinneret at a constant temperature of 220℃. The outer diameter and inner diameter of the annular spinneret were 1.2 mm and 0.7 mm, respectively. The distance between the spinneret and the surface of the water coagulation bath was 3 cm. The spinning speed was 1 m / s, and the core liquid flow rate was 1 ml / min.
[0078] The formed hollow fiber membrane was extracted in isopropanol for 2 days to ensure the removal of dioctyl phthalate, with the isopropanol being replaced 4 times during the process, and then dried in a fume hood for 2 days.
[0079] Example 3:
[0080] A hybrid hollow fiber oxygenation membrane is prepared using the following steps:
[0081] Weigh 3.15g of metal-organic framework ZIF-8 and 210g of dioctyl phthalate. Sonicate the mixture of metal-covalent organic framework ZIF-8 and dioctyl phthalate for 30 minutes and then disrupt the cells for 30 minutes to ensure uniform dispersion of metal-covalent organic framework ZIF-8 and obtain a suspension.
[0082] The suspension was placed in the reactor of a hollow fiber membrane spinning machine, and then 210 g of poly(4-methyl-1-pentene) was weighed and added to the reactor. The mixture was stirred at 235 °C for 8 h. After that, the temperature was raised to 240 °C and allowed to stand for 12 h to obtain the casting solution.
[0083] Using casting solution as raw material, hollow fiber membrane spinning was performed using a hollow fiber membrane spinning machine. The casting solution was extruded and introduced into a water coagulation bath at room temperature. The reactor was kept at a constant temperature of 240℃, the filter at 230℃, and the spinneret at 220℃. The outer diameter and inner diameter of the annular spinneret were 1.2 mm and 0.7 mm, respectively. The distance between the spinneret and the surface of the water coagulation bath was 3 cm. The spinning speed was 0.5 m / s, and the core liquid flow rate was 0.4 ml / min.
[0084] The formed hollow fiber membrane was extracted in anhydrous ethanol for 2 days to ensure the removal of dioctyl phthalate, with the anhydrous ethanol being replaced twice during the process. It was then dried in a fume hood for 2 days.
[0085] Example 4:
[0086] A hybrid hollow fiber oxygenation membrane is prepared using the following steps:
[0087] Weigh 21g of hydrogen-bonded organic framework HOF-21 and 490g of dioctyl phthalate. Sonicate the mixture of hydrogen-bonded organic framework HOF-21 and dioctyl phthalate for 30 minutes and then break down the cells for 30 minutes to ensure that the hydrogen-bonded organic framework HOF-21 is uniformly dispersed and a suspension is obtained.
[0088] The suspension was placed in the reactor of a hollow fiber membrane spinning machine, and then 210g of polypropylene was weighed and added to the reactor. The mixture was stirred at 235℃ for 8 hours. After that, the temperature was raised to 240℃ and allowed to stand for 12 hours to obtain the casting solution.
[0089] Using casting solution as raw material, hollow fiber membrane spinning was performed using a hollow fiber membrane spinning machine. The casting solution was extruded and introduced into a water coagulation bath at room temperature. The reactor was kept at a constant temperature of 240℃, the filter at 230℃, and the spinneret at 220℃. The outer diameter and inner diameter of the annular spinneret were 1.2 mm and 0.7 mm, respectively. The distance between the spinneret and the surface of the water coagulation bath was 3 cm. The spinning speed was 0.5 m / s, and the core liquid flow rate was 0.4 ml / min.
[0090] The formed hollow fiber membrane was extracted in anhydrous ethanol for 2 days to ensure the removal of dioctyl phthalate, with the anhydrous ethanol being replaced twice during the process. It was then dried in a fume hood for 2 days.
[0091] Comparative example:
[0092] A hollow fiber membrane is prepared using the following steps:
[0093] 490g of dioctyl phthalate and 210g of poly(4-methyl-1-pentene) were weighed and placed into the reactor of a hollow fiber membrane spinning machine, and stirred at 235℃ for 8 hours. Then the temperature was raised to 240℃ and allowed to stand for 12 hours to obtain the casting solution.
[0094] Using casting solution as raw material, hollow fiber membrane spinning was performed using a hollow fiber membrane spinning machine. The casting solution was extruded and introduced into a water coagulation bath at room temperature. The reaction vessel was kept at a constant temperature of 240℃, the filter at a constant temperature of 230℃, and the spinneret at a constant temperature of 220℃. The outer diameter and inner diameter of the annular spinneret were 1.2 mm and 0.7 mm, respectively. The distance between the spinneret and the surface of the water coagulation bath was 3 cm. The spinning speed was 1 m / s, and the core liquid flow rate was 1 ml / min.
[0095] The formed hollow fiber membrane was extracted in isopropanol for 2 days to ensure the removal of dioctyl phthalate, with the isopropanol being replaced 4 times during the process, and then dried in a fume hood for 2 days.
[0096] Example of effect 1:
[0097] The hybrid hollow fiber oxygenation membrane prepared in Example 1 was characterized by scanning electron microscopy and analyzed to obtain... Figure 2 . Figure 2 This is a scanning electron microscope image of the hybrid hollow fiber oxygen membrane of Embodiment 1 of this application.
[0098] like Figure 2 As shown, the hybrid hollow fiber oxygenated membrane prepared in Example 1 has an internal hollow structure, including a porous layer and a non-porous dense layer wrapped around the surface of the porous layer.
[0099] The hybrid hollow fiber oxygen membrane has a thickness of about 500 μm, and the cross-section of the porous layer has a cellular loose structure.
[0100] Scanning electron microscopy characterization analysis of the hybrid hollow fiber oxygenation membranes prepared in each embodiment showed that the membrane thickness of the hybrid hollow fiber oxygenation membrane of this application is 255-550 μm, and the thickness of the dense layer is 0.64-0.86 μm, which can effectively prevent plasma leakage.
[0101] Example of effect 2:
[0102] The hybrid hollow fiber oxygenation membranes prepared in Examples 1 to 4 and the hollow fiber membranes prepared in the comparative examples were encapsulated into membrane modules with epoxy resin AB glue. Oxygen or carbon dioxide at 1 bar was introduced into the membrane modules, and the gas flow rate was measured with a soap membrane flow meter. The oxygen permeation rate and carbon dioxide permeation rate of each fiber membrane were calculated, and the data in the table below were obtained.
[0103]
[0104] As shown in the table above, the hybrid hollow fiber oxygenation membranes prepared in Examples 1 to 4 exhibited significantly better carbon dioxide and oxygen permeation rates than the comparative hollow fiber membranes; among them, the hybrid hollow fiber oxygenation membrane prepared in Example 2 achieved a carbon dioxide permeation rate of 6.75 ml / (min·cm). 2The oxygen permeation rate (O2) was 2.55 ml / (min·cm), representing a 122.77% increase compared to the control group. 2 (bar), which is 68.87% higher than the comparison ratio.
[0105] This is mainly because the hybrid hollow fiber oxygenation membranes prepared in Examples 1 to 4 contain dispersed metal-organic molecular sieve materials. The high content of imine and benzene ring groups and the high density of copper sites in the metal-organic molecular sieves allow them to interact with polar carbon dioxide, thereby enhancing the dissolution-diffusion process of carbon dioxide molecules through the membrane and the rapid conversion between bicarbonate and carbon dioxide. Furthermore, the good interfacial compatibility between the metal-organic molecular sieve nanosheets and polyolefins avoids the formation of defects and agglomeration. Moreover, the good interaction and compatibility between the metal-organic molecular sieve nanosheets and polyolefins enhance the free volume of the membrane, reducing the resistance to carbon dioxide transport within the membrane. These multiple synergistic mechanisms enable the prepared hybrid hollow fiber oxygenation membrane to exhibit highly efficient carbon dioxide transport performance, significantly improving the gas permeability, especially carbon dioxide, of the oxygenation membrane.
[0106] The foregoing description of this disclosure is provided to enable any person skilled in the art to implement or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles applicable herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is consistent with the widest scope of the principles and novel features disclosed herein.
Claims
1. A method for preparing a hybrid hollow fiber oxygen membrane, characterized in that, Includes the following steps: The metal-organic molecular sieve material is uniformly dispersed in a diluent to obtain a dispersion. Polyolefin is added to the dispersion, heated and stirred until homogeneous, and then allowed to stand to obtain a casting solution; Using the casting solution as raw material, a hybrid hollow fiber oxygen membrane was obtained by thermally induced phase separation spinning. The metal-organic molecular sieve material includes one or more combinations of metal-covalent organic framework Cu-TAPB, metal-organic framework ZIF-8, and hydrogen-bonded organic framework HOF-21; The polyolefin includes one or more combinations of polypropylene, polyethylene, poly(4-methyl-1-pentene), and poly(ethylene-vinyl alcohol); the mass ratio of the metal-organic molecular sieve material to the polyolefin is (0.1~10):100; The hybrid hollow fiber oxygen membrane includes a porous layer and a non-porous dense layer on the surface of the porous layer. The thickness of the hybrid hollow fiber oxygen membrane is 255-550 μm, the thickness of the dense layer is 0.64-0.86 μm, and the cross-section of the porous layer is a cellular loose structure. The step of heating, stirring evenly, and then allowing to stand is specifically as follows: Heat to 230~240℃ and stir for 8 hours, then raise the temperature to 235~245℃ and let stand for 12 hours to remove bubbles; The specific steps of spinning using the thermally induced phase separation method are as follows: The casting solution is kept at a constant temperature of 235~245℃, and the casting solution is extruded through a spinneret and introduced into a water coagulation bath at room temperature for solidification and molding. The spinning speed is 0.5~1.5m / s, and the core liquid flow rate is 0.4~1.7 ml / min.
2. The preparation method according to claim 1, characterized in that, The diluent includes one or more combinations of dioctyl adipate, dioctyl sebacate, dibutyl phthalate, dioctyl phthalate, glyceryl triacetate, glyceryl triacetate, castor oil, tributyl acetyl citrate, trioctyl acetyl citrate, tributyl citrate, and trioctyl citrate; the mass ratio of the metal-organic molecular sieve material to the diluent in the dispersion is 0.5:9.5 to 5:
5.
3. The preparation method according to claim 1, characterized in that, Also includes: The hybrid hollow fiber oxygen membrane was thoroughly immersed in the extraction solution to extract and remove the diluent, and then air-dried. The extract includes one or more of anhydrous ethanol, isopropanol, and diethyl ether.
4. The application of a hybrid hollow fiber oxygenation membrane prepared by any one of claims 1 to 3 as an oxygenation membrane in extracorporeal membrane lung oxygenation.