Metal organic framework hollow fiber membrane filament and preparation method and application thereof

Abstract

The invention discloses a metal organic framework hollow fiber membrane filament as well as a preparation method and application thereof, and belongs to the technical field of gas separation membranes. The metal organic framework hollow fiber membrane silk comprises an inner membrane layer, a hollow layer and an outer membrane layer, polysulfone, polyvinylpyrrolidone, N, N-dimethylacetamide and an amino-modified metal organic framework material NH2-HKUST-1 are subjected to ultrasonic dispersion, heating and stirring are performed to form a uniform spinning solution, after defoaming, co-extrusion is performed through an annular spinning nozzle, and the hollow fiber membrane silk is prepared. And carrying out phase inversion forming through an air section and a coagulating bath, drafting, cleaning and drying to obtain the hollow fiber membrane filament. The amino-modified metal organic framework material in the hollow fiber membrane filament is uniformly dispersed to form a continuous porous structure, the hollow fiber membrane filament has the advantages of being stable in structure, simple and convenient to operate, energy-saving and efficient, nitrogen is preferentially adsorbed through the hydrogen-bond interaction of amino and nitrogen molecules, the oxygen / nitrogen separation selectivity is remarkably improved, and the oxygen / nitrogen separation efficiency is improved. High gas permeability and excellent separation performance are shown.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas separation membranes, and particularly relates to a metal organic framework hollow fiber membrane filament and a preparation method and application thereof. BACKGROUND

[0002] Air separation oxygen production technology is an industrial method for efficiently extracting nitrogen (N2) from air, which is widely used in chemical industry, electronics, food preservation and medical treatment and other fields. Traditional air is mainly composed of 78% nitrogen and 21% oxygen, and the core challenge of nitrogen production is to realize efficient separation of N2 and O2. At present, the mainstream technologies include cryogenic rectification method using boiling point difference liquefaction separation, pressure swing adsorption method (PSA) through molecular sieve adsorption selective separation and membrane separation method using selective permeation of polymer or inorganic membrane. In recent years, with the progress of material science, the membrane separation method shows potential in high-purity oxygen production and energy saving, and the development of this technology aims to balance the cost, energy consumption and purity demand, and promote the greenization and intelligentization of industrial gas production.

[0003] Hollow fiber membranes have great application potential in the field of gas separation due to their large specific surface area, high separation efficiency, simple operation and other advantages, and have gradually become a research hotspot in the field of gas separation technology. Hollow fiber membrane is a kind of membrane with self-supporting structure and fiber shape, which has large unit volume packing density, large specific surface area, low cost, simple preparation process, flexibility and processability, and is a good base for preparing gas separation composite membrane materials. As one of the most widely used hollow fiber membrane materials at present, polysulfone hollow fiber membrane occupies an important position in the field of gas separation due to its good chemical stability, mechanical strength and thermal stability.

[0004] However, the existing hollow fiber membrane materials often face problems such as difficulty in balancing gas permeation flux and separation selectivity, insufficient membrane stability, weak anti-pollution ability and other problems in the process of gas separation, which limits their large-scale application in the field of gas separation. Especially when dealing with complex mixed gas systems, the separation performance and service life of the existing hollow fiber membranes are difficult to meet the stringent requirements of industrial production.

[0005] Metal organic framework materials (MOFs) as a new type of nanomaterial have many advantages such as adjustable structure, accurate pore size, controllable chemical function and large specific surface area, and have wide application prospects in the field of gas separation membranes. MOF membranes with high flux and good gas selectivity can maximize the economic and technical advantages of membranes. However, MOFs are difficult to be processed by traditional solvent or thermal technology, and existing methods are mostly used to prepare MOF membranes on rigid inorganic substrates. For example, the application date is September 26, 2024, and the publication number is CN114593593A

[0006] CN118976381A discloses a MOFs loaded hollow fiber membrane composite membrane, a preparation method and an application thereof, the hollow fiber membrane is modified by introducing branched polyethylene imine with high degree of branching, and the branched polyethylene imine can be used for wrapping, complexing and stabilizing metal organic framework materials. The prepared composite membrane can be used for gas adsorption or gas separation. The composite membrane relies on branched polyethylene imine as a key functional material, and the high molecular chain of the branched polyethylene imine can lead to membrane densification, thereby significantly reducing the gas permeation flux, and meanwhile, the PEI can be aged or migrated in long-term operation, thereby affecting the stability of the membrane separation performance.

[0007] CN109529634A discloses a preparation method of a metal organic framework ZIF-7-VDF hollow fiber membrane, the formation of the membrane and the growth of the metal organic framework are combined by using a one-step method, the prepared ZIF-7-VDF hollow fiber membrane has good continuity and integrity, and exhibits good performance in gas separation and can be used for a long time in a high-temperature environment. However, the ZIF-7 has a regular pore channel, is very sensitive to moisture, and air moisture can cause structure degradation, thereby affecting the long-term stability of the separation performance.

[0008] In order to break through the separation efficiency of mixed gas, improve the application requirement of the flexibility of the membrane module processing and manufacturing, develop a new type of high-performance hollow fiber membrane preparation method combined with the metal organic framework material, and improve the comprehensive performance of the hollow fiber membrane in the field of gas separation, which has become a key research direction at present. SUMMARY

[0009] In order to solve the problems in the prior art, the present application provides a metal organic framework hollow fiber membrane and a preparation method and application thereof. The amino-modified metal organic framework material is uniformly dispersed in the hollow fiber membrane, a continuous porous structure is formed, and the method has the advantages of structural stability, simple operation, energy saving and high efficiency. The hydrogen bond between the amino group and the nitrogen molecule can preferentially adsorb nitrogen, and the method has high gas permeability and excellent separation performance.

[0010] The technical scheme of the present application is as follows:

[0011] One of the objects of the present application is to provide a preparation method of a metal organic framework hollow fiber membrane, which comprises the following steps:

[0012] S1, using benzene acid with an amino group as an organic ligand to react with a copper salt in an organic solvent to directly synthesize an amino-functionalized metal organic framework material NH2-HKUST-1;

[0013] S2, mixing dry polysulfone PSF, polyvinylpyrrolidone PVP and N,N-dimethylacetamide

[0014] DMAc and the amino-modified metal-organic framework material NH2-HKUST-1 are mixed and ultrasonically dispersed, and then continuously stirred at a constant temperature until a uniform spinning solution is formed;

[0015] S3, the spinning solution prepared in S1 is left to stand for defoaming treatment, and then is loaded into a casting solution tank to form a nascent membrane filament through a spinneret;

[0016] S4, the nascent membrane filament is rapidly volatilized of surface solvent in an air section, and then is immersed in a coagulation bath to separate phases and form a membrane, and after drying, the metal-organic framework hollow fiber membrane filament is obtained.

[0017] Further, the organic ligand in S1 is any one or a combination of 1-amino, 3,5-benzenedicarboxylic acid, 1,3-diamino, 5-benzoic acid, 4-amino, and 1,3,5-benzenetricarboxylic acid;

[0018] The copper salt is any one or a combination of copper acetate, copper nitrate, copper chloride, and copper sulfate;

[0019] The organic solvent is any one or a combination of methanol, ethanol, formamide, and N,N-dimethylformamide;

[0020] The reaction process is as follows:

[0021] The copper salt and the organic ligand are respectively dissolved in an equal volume of organic solvent at a molar ratio of 3:2, so that the concentration of the solution is 0.067-0.10M, the two solutions are combined and stirred until the mixed solution is clear, then transferred into a pressure-resistant reaction bottle and left to stand at 85°C for 12-24h for solvothermal reaction until deep blue cubic crystals are generated, and then naturally cooled to room temperature to collect the blue crystals, which are the metal-organic framework material NH2-HKUST-1.

[0022] Further, the polysulfone PSF in S2 is dried at 60-100°C for 8-24h.

[0023] Further, in S2, the mass ratio of polyvinylpyrrolidone PVP is 1-10%, the mass ratio of N,N-dimethylacetamide DMAc is 60-90%, and the mass ratio of the metal-organic framework material NH2-HKUST-1 is 1-20%.

[0024] Further, in S2, the ultrasonic dispersion power is 100-500W, the ultrasonic frequency is 20-60kHz, and the ultrasonic time is 30-180min; the stirring speed is 200-800rpm, the heating temperature is 60-100°C, and the stirring time is 2-10h.

[0025] Further, in S3, the standing time is 16-48h.

[0026] Further, in the S3, after the spinning solution is filled into the casting solution tank, the core liquid flow is adjusted to 0.1-5 mL / min, the extrusion pressure is 0.1-2 Mpa, and the dry run is 1-10 cm.

[0027] Further, in the S4, the length of the air section is 1-20 cm, the temperature of the air section is 20-40 DEG C, the coagulation bath is water or a mixed solution of water and N, N-dimethylacetamide (DMAc), the mass fraction of water is 50-100%, and the immersion time is 16-48 h.

[0028] Further, in the S4, the drying process is air drying for 12-48 h in an environment with a temperature of 20-40 DEG C and a relative humidity of 30-70%.

[0029] The second object of the present application is to provide a metal organic framework hollow fiber membrane filament.

[0030] Further, the metal organic framework hollow fiber membrane is a uniform three-dimensional coupling structure, which comprises an inner membrane layer, a hollow layer and an outer membrane layer, the hollow layer has a hollow tube hole inside, and the metal organic framework material NH2-HKUST-1 is uniformly dispersed in the middle of the membrane filament; the outer diameter of the membrane filament is 0.2-2 mm, the inner diameter is 0.1-1 mm, and the porosity of the membrane filament is 30-80%.

[0031] The third object of the present application is to provide an application of the metal organic framework hollow fiber membrane filament in air separation oxygen production.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] 1. The present application discloses a new type of metal organic framework hollow fiber membrane filament for the first time, and the core idea is to uniformly integrate the metal organic framework material NH2-HKUST-1 as a functional filler into a polysulfone hollow fiber matrix, combine a parameter combination of precise regulation, and uniformly disperse the metal organic framework material in the spinning solution in nanoscale, prevent agglomeration, form a uniform and stable casting solution, and cooperate with a dry-wet spinning technology, so that the metal organic framework material is stably anchored in the three-dimensional network structure of the polymer in the phase inversion process, the modification unevenness possibly existing in the traditional process is avoided, the harsh conditions of the in-situ growth method are avoided, and the high selective adsorption of NH2-HKUST-1 and the excellent film-forming property of the polymer are combined.

[0034] 2、The high selectivity gas separation membrane designed in the application has advantages of performance and stability in industrial gas separation, wherein the metal organic framework material NH2-HKUST-1 is uniformly dispersed in the hollow fiber membrane wire and forms an interconnected three-dimensional network, the effective separation area in unit volume is greatly improved, the defects that the MOF is easy to agglomerate or the interface combination is weak in the prior art are overcome, the structure does not need additional supporting materials, the gas flow of the double channels formed inside and outside endows the membrane wire with ideal space utilization and gas molecule separation efficiency. In terms of physical and chemical properties, the polysulfone matrix membrane wire provides good mechanical strength, thermal stability and chemical stability, ensuring the durability of the membrane wire in the operating environment, and the amino basic sites on the pore wall of the uniformly distributed NH2-HKUST-1 can form weak hydrogen bond action with nitrogen N2 molecules, preferentially adsorbing and slowing down the transmission rate of N2, so as to realize efficient screening of oxygen at the molecular level, so that it simultaneously has high permeability and high selectivity.

[0035] 3、In the application layer, the most direct application of the hollow fiber membrane wire in the application is air separation for producing nitrogen, the oxygen / nitrogen separation selectivity of which is significantly higher than that of many commercial polymer membranes, nitrogen can be produced with higher efficiency and lower energy consumption, and based on the amino adsorption-screening mechanism of the core, the technical platform of the membrane wire can also be extended to other important gas separation fields such as helium / methane separation and hydrogen / carbon dioxide separation, and has broad application prospects. Compared with the existing hollow fiber membrane, the functionality of the metal organic framework material in the hollow fiber membrane wire in the application is derived from the stable crystal structure rather than the easy aging and migration of the polymer chain, the separation performance is more stable, the long-term operation performance is more reliable, the performance is not dependent on the ZIFs type material which is afraid of water vapor environment, the environmental adaptability is stronger, the working conditions are wider, in addition, the hollow fiber membrane wire provides a large specific surface area, the module loading density is high, and the preparation process is compatible with the existing spinning equipment, easy to scale production, and has the basis of industrial application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The scanning electron microscope image of the metal organic framework material NH2-HKUST-1 used in embodiment 1 of the application;

[0037] Figure 2 The scanning electron microscope image of the metal organic porous material used in comparative example 1 of the application. DETAILED DESCRIPTION

[0038] The following further describes the application in connection with preferred embodiments, the endpoints of the ranges and any numerical values disclosed herein are not limited to the precise values recited as implicitly closed ranges should be understood to include values beyond the explicitly stated range. For example, a range of "from 1 to 5" should be interpreted to include values from 1 to 5, and 1 to 5 inclusive, as well as values beyond 5, e.g. 5.1 to 5.9, and beyond, e.g. 6. In this document, the terms "comprises", "comprising", "containing", "having" and "including" are open, and do not exclude other, additional components, integers, or steps.

[0039] The experimental methods in the following examples are all conventional methods, and are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions, unless otherwise specified.

[0040] The materials, reagents and the like used in the following examples can be obtained commercially, unless otherwise specified.

[0041] Example 1

[0042] The present embodiment provides a metal organic framework hollow fiber membrane filament, and a preparation method thereof, which comprises the following steps:

[0043] S1, reacting 1-amino, 3,5-benzenedicarboxylic acid with copper acetate in N,N-dimethylformamide to directly synthesize an amino-functionalized metal organic framework material NH2-HKUST-1;

[0044] S2, drying polysulfone (PSF) in an 80℃ oven for 12h, taking 3g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000, 75g of N,N-dimethylacetamide (DMAc), and 5g of NH2-HKUST-1, and placing them in a conical flask, and placing the conical flask in an ultrasonic cleaner with a power of 300W and a frequency of 40kHz for ultrasonic dispersion for 60min;

[0045] S3, adding the dried PSF into the conical flask, and heating and stirring at 80℃ and 500rpm for 5h until the PSF is completely dissolved, and continuously uniform stirring to form a uniform spinning solution;

[0046] S4, standing the spinning solution for 24h for defoaming, and then loading into a casting solution tank, connecting a conventional hollow fiber membrane spinning device, adjusting the core liquid flow rate to 1mL / min, the extrusion pressure to 0.5Mpa, and the dry run to 5cm;

[0047] S5, extruding the spinning solution through a spinneret to form a nascent membrane filament, and after passing through an air section with a length of 10cm and a temperature of 25℃, the nascent membrane filament enters a mixed coagulation bath of water and DMAc with a mass fraction of water of 80% to phase separate and form a membrane;

[0048] S6, after soaking in the coagulation bath for 24 h, the metal-organic framework hollow fiber membrane filaments are obtained by drying in an environment with a temperature of 25 °C and a relative humidity of 50% for 24 h.

[0049] Example 2

[0050] The present example provides a method for preparing metal-organic framework hollow fiber membrane filaments, comprising the following steps:

[0051] S1, reacting 1-amino, 3,5-benzenedicarboxylic acid with copper acetate in N,N-dimethylformamide to directly synthesize amino-functionalized metal-organic framework material NH2-HKUST-1;

[0052] S2, drying polysulfone (PSF) in an oven at 80 °C for 12 h, and placing 3 g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000, 75 g of N,N-dimethylacetamide (DMAc), and 10 g of NH2-HKUST-1 in a conical flask, and ultrasonically dispersing the conical flask in an ultrasonic cleaner with a power of 500 W and a frequency of 60 kHz for 30 min;

[0053] S3, adding the dried PSF into the conical flask, and heating and stirring at 100 °C and 200 rpm for 10 h until the PSF is completely dissolved, and continuously stirring at a uniform speed to form a uniform spinning solution;

[0054] S4, allowing the spinning solution to stand for 48 h to degas, and then loading into a casting solution tank and connecting a conventional hollow fiber membrane spinning device, and adjusting the core liquid flow rate to 5 mL / min, the extrusion pressure to 2 MPa, and the dry run to 10 cm;

[0055] S5, allowing the spinning solution to be extruded through a spinneret to form a nascent membrane filament, and after the nascent membrane filament passes through an air section with a length of 20 cm and a temperature of 20 °C, the nascent membrane filament enters a mixed coagulation bath of water and DMAc with a mass fraction of 100% to phase separate and form a membrane;

[0056] S6, after soaking in the coagulation bath for 16 h, the metal-organic framework hollow fiber membrane filaments are obtained by drying in an environment with a temperature of 20 °C and a relative humidity of 30% for 12 h.

[0057] Example 3

[0058] The present example provides a method for preparing metal-organic framework hollow fiber membrane filaments, comprising the following steps:

[0059] S1, reacting 1-amino, 3,5-benzenedicarboxylic acid with copper acetate in N,N-dimethylformamide to directly synthesize amino-functionalized metal-organic framework material NH2-HKUST-1;

[0060] S2, polysulfone (PSF) was placed in a 60°C oven for drying for 24h, 3g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000, 75g of N,N-dimethylacetamide (DMAc) and 10g of NH2-HKUST-1 were placed in a conical flask, and the conical flask was placed in an ultrasonic cleaner with a power of 100W and a frequency of 20kHz for ultrasonic dispersion for 180min;

[0061] S3, the dried PSF was added to the conical flask, and heated and stirred at 60°C and 800rpm for 2h until the PSF was completely dissolved, and uniform spinning solution was formed by continuous uniform stirring;

[0062] S4, the spinning solution was left to stand for 16h for degassing, and then was loaded into a casting solution tank, and a conventional hollow fiber membrane spinning device was connected, and the core liquid flow was adjusted to 0.1mL / min, the extrusion pressure was 0.1Mpa, and the dry run was 1cm;

[0063] S5, the spinning solution was extruded through the spinneret to form a nascent membrane filament, and after passing through an air section with a length of 1cm and a temperature of 40°C, the nascent membrane filament entered a mixed coagulation bath of water and DMAc with a mass fraction of 50% to phase separate and form a membrane;

[0064] S6, after soaking in the coagulation bath for 48h, the membrane filament was taken out and dried in an environment of 35°C and a relative humidity of 70% for 48h to obtain the metal organic framework hollow fiber membrane filament.

[0065] Example 4

[0066] The embodiment provides a preparation method of a metal organic framework hollow fiber membrane filament, which comprises the following steps:

[0067] S1, 5benzoic acid was reacted with copper sulfate in methanol to directly synthesize an amino-functionalized metal organic framework material NH2-HKUST-1;

[0068] S2, polysulfone (PSF) was placed in an 80°C oven for drying for 12h, 3g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000, 75g of N,N-dimethylacetamide (DMAc) and 10g of NH2-HKUST-1 were placed in a conical flask, and the conical flask was placed in an ultrasonic cleaner with a power of 500W and a frequency of 60kHz for ultrasonic dispersion for 30min;

[0069] S3, the dried PSF was added to the conical flask, and heated and stirred at 100°C and 200rpm for 10h until the PSF was completely dissolved, and uniform spinning solution was formed by continuous uniform stirring;

[0070] S4, the spinning solution is left to stand for 48 h for defoaming, and then is loaded into a casting solution tank and connected to a conventional hollow fiber membrane spinning device, the core solution flow rate is adjusted to 5 mL / min, the extrusion pressure is 2 MPa, and the dry run is 10 cm;

[0071] S4, the spinning solution is left to stand for 48 h for defoaming, and then is loaded into a casting solution tank and connected to a conventional hollow fiber membrane spinning device, the core solution flow rate is adjusted to 5 mL / min, the extrusion pressure is 2 MPa, and the dry run is 10 cm;

[0072] S5, the nascent membrane filaments are formed by extruding the spinning solution through a spinneret, and then enter a water and DMAc mixed coagulation bath with a water mass fraction of 100% after passing through an air section with a length of 20 cm and a temperature of 20℃.

[0073] Comparative Example 1

[0074] The present comparative example provides a preparation method of a hollow fiber membrane filament, comprising the following steps:

[0075] S1, polysulfone (PSF) is placed in an oven at 80℃ for drying for 12 h, 3 g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000 and 75 g of N,N-dimethylacetamide (DMAc) are placed in a conical flask, and the conical flask is placed in an ultrasonic cleaner with a power of 300 W and a frequency of 40 kHz for ultrasonic dispersion for 60 min;

[0076] S2, the dried PSF is added to the conical flask, and heated and stirred at 80℃ and 500 rpm for 5 h until the PSF is completely dissolved, and uniform spinning solution is formed by continuous uniform stirring;

[0077] S3, the spinning solution is left to stand for 24 h for defoaming, and then is loaded into a casting solution tank and connected to a conventional hollow fiber membrane spinning device, the core solution flow rate is adjusted to 1 mL / min, the extrusion pressure is 0.5 MPa, and the dry run is 5 cm;

[0078] S4, the nascent membrane filaments are formed by extruding the spinning solution through a spinneret, and then enter a water and DMAc mixed coagulation bath with a water mass fraction of 80% after passing through an air section with a length of 10 cm and a temperature of 25℃.

[0079] S5, the nascent membrane filaments are formed by extruding the spinning solution through a spinneret, and then enter a water and DMAc mixed coagulation bath with a water mass fraction of 100% after passing through an air section with a length of 20 cm and a temperature of 20℃.

[0080] Comparative Example 2

[0081] The present example provides a metal organic framework hollow fiber membrane filament, and a preparation method thereof comprises the following steps:

[0082] S1, reacting 1,3,5-benzenetricarboxylic acid with copper acetate in N,N- dimethylformamide to directly synthesize an amino-functionalized metal-organic framework material HKUST-1;

[0083] S2, drying polysulfone (PSF) in a 60°C oven for 24 h, placing 3 g of polyvinylpyrrolidone (PVP) with a molecular weight of 40000, 75 g of N,N-dimethylacetamide (DMAc), and 10 g of HKUST-1 in a conical flask, and placing the conical flask in an ultrasonic cleaner with a power of 100 W and a frequency of 20 kHz for ultrasonic dispersion for 180 min;

[0084] S3, adding the dried PSF to the conical flask, heating and stirring at 60°C and 800 rpm for 2 h until the PSF is completely dissolved, and continuously stirring at a uniform speed to form a uniform spinning solution;

[0085] S4, allowing the spinning solution to stand for 16 h for degassing, then loading it into a casting solution tank, connecting a conventional hollow fiber membrane spinning device, and adjusting the core liquid flow rate to 0.1 mL / min, the extrusion pressure to 0.1 MPa, and the dry run to 1 cm;

[0086] S5, allowing the spinning solution to extrude through a spinneret to form a nascent membrane filament, allowing the nascent membrane filament to pass through an air section with a length of 1 cm and a temperature of 40°C, and then entering a mixed coagulation bath of water and DMAc with a mass fraction of water of 50% to phase separate and form a membrane;

[0087] S6, after soaking in the coagulation bath for 48 h, taking out the membrane filament, and air-drying it in an environment with a temperature of 40°C and a relative humidity of 70% for 48 h to obtain the metal-organic framework hollow fiber membrane filament.

[0088] Performance test

[0089] 1. Gas separation performance test

[0090] The metal-organic framework hollow fiber membrane filaments prepared in Examples 1-3 and the hollow fiber membrane filaments prepared in the comparative examples were sealed with epoxy resin, and the gas separation performance was tested using gas chromatography.

[0091] The test results are as follows:

[0092] Sample Oxygen permeability (GPU) Nitrogen permeability (GPU) Oxygen / nitrogen selectivity Example 1 62 8 7.7 Example 2 57 6 9.5 Comparative Example 1 58 9 6.4 Comparative Example 2 66 9 7.3

[0093] As shown in the above table, Example 1 and Example 2 are membrane filaments prepared by processes with different contents of NH2-HKUST-1; Comparative Example 1 is a membrane filament without metal organic framework; Comparative Example 2 is a membrane filament prepared by HKUST-1. Comparing Example 1 with Example 2, the results show that increasing the number of amino sites can improve the oxygen / nitrogen selectivity; compared with Comparative Example 1, the material added with metal organic framework has higher oxygen / nitrogen selectivity; compared with Comparative Example 2, the material added with amino-modified metal organic framework has higher oxygen / nitrogen selectivity.

[0094] The above description is only examples of the present application, and does not limit the patent scope of the present application, and any equivalent transformation or direct or indirect application in the related technical field by using the content of the specification and drawings of the present application is also included in the patent protection scope of the present application.

Claims

1. A method of making a metal organic framework hollow fiber membrane filament, characterized by, It comprises the following steps: S1, using benzoic acid with amino as an organic ligand to react with copper salt in an organic solvent to directly synthesize amino-functionalized metal organic framework material NH2-HKUST-1; S2, after drying, polysulfone PSF, polyvinylpyrrolidone PVP, N,N-dimethylacetamide DMAc and amino-modified metal organic framework material NH2-HKUST-1 are mixed and ultrasonic dispersed, and then continuously stirred at a constant temperature until a uniform spinning solution is formed; S3, the spinning solution prepared in S1 is placed for defoaming treatment, and then is loaded into a casting solution tank to make the spinning solution extruded through a spinneret to form a nascent membrane filament; S4, the nascent membrane filament is quickly volatilized by surface solvent in an air section, and then is immersed in a coagulation bath to separate phases and form a membrane, and after drying, the metal organic framework hollow fiber membrane filament is prepared.

2. The method for preparing a metal-organic framework hollow fiber membrane filament according to claim 1, characterized in that, The organic ligand in S1 is any one or a combination of 1-amino, 3,5-benzenedicarboxylic acid, 1,3-diamino, 5-benzoic acid, 4-amino, and 1,3,5-benzenetricarboxylic acid; The copper salt is any one or a combination of copper acetate, copper nitrate, copper chloride, and copper sulfate; The organic solvent is any one or a combination of methanol, ethanol, formamide, and N,N-dimethylformamide; The reaction process is as follows: The copper salt and the organic ligand are respectively dissolved in equal volume of the organic solvent according to a molar ratio of 3:2, the concentration of the solution is 0.067-0.10M, the two solutions are combined and stirred until the mixed solution is clear, then are transferred into a pressure-resistant reaction bottle and left to stand at 85℃ for 12-24h for solvent thermal reaction until deep blue cubic crystals are generated, and then are naturally cooled to room temperature to collect the blue crystals, which are metal organic framework material NH2-HKUST-1.

3. The method of claim 1, wherein the MOF hollow fiber membrane is prepared by the steps of: The polysulfone PSF in S2 is dried at 60-100℃ for 8-24h.

4. The method of claim 1, wherein the MOF hollow fiber membrane is prepared by the steps of: The mass ratio of polyvinylpyrrolidone PVP in S2 is 1-10%, the mass ratio of N,N-dimethylacetamide DMAc is 60-90%, and the mass ratio of metal organic framework material NH2-HKUST-1 is 1-20%.

5. The method of claim 1, wherein the MOF hollow fiber membrane is prepared by the steps of: The ultrasonic dispersion power in S2 is 100-500W, the ultrasonic frequency is 20-60kHz, the ultrasonic time is 30-180min, the heating and stirring speed is 200-800rpm, the heating temperature is 60-100℃, and the stirring time is 2-10h.

6. The method of claim 1, wherein the MOF hollow fiber membrane is prepared by the steps of: After the spinning solution in S3 is loaded into the casting solution tank, the core liquid flow is adjusted to 0.1-5mL / min, the extrusion pressure is 0.1-2Mpa, and the dry run is 1-10cm.

7. The method for preparing a metal-organic framework hollow fiber membrane filament according to claim 1, characterized in that, The length of the air section in S4 is 1-20cm, and the temperature of the air section is 20-40℃; the coagulation bath immersion adopts water or a mixed solution of water and N,N-dimethylacetamide DMAc, wherein the mass fraction of water is 50-100%, and the immersion time is 16-48h.

8. The method for preparing a metal-organic framework hollow fiber membrane filament according to claim 1, characterized in that, The drying process in S4 is air drying at a temperature of 20-40℃ and a relative humidity of 30-70% for 12-48h.

9. A metal organic framework hollow fiber membrane filament prepared according to the method of any one of claims 1 to 8, characterized in that, The metal organic framework hollow fiber membrane is a uniform three-dimensional connection structure, comprising an inner membrane layer, a hollow layer and an outer membrane layer, the hollow layer has a hollow tube hole inside, and metal organic framework material NH2-HKUST-1 is uniformly dispersed in the middle of the membrane wire; the outer diameter of the membrane wire is 0.2-2mm, the inner diameter is 0.1-1mm, and the porosity of the membrane wire is 30-80%.

10. The use of the metal organic framework hollow fiber membrane wire prepared by the preparation method in any one of claims 1 to 8 in air separation oxygen production.

Images