A method for preparing a high-stability mixed matrix membrane by an interfacial induction strategy

Abstract

The application relates to a method for preparing a high-stability mixed matrix membrane through an interface induction strategy and belongs to the field of membrane separation technology. The preparation method comprises the following steps: providing a polyether block amide membrane liquid with a zeolitic imidazolate framework-8; adding the polyether block amide membrane liquid with the zeolitic imidazolate framework-8 into water with a temperature of 10 DEG C drop by drop, so as to prepare a mixed matrix membrane at a liquid-liquid interface; adhering a base membrane to the polyether block amide membrane with the zeolitic imidazolate framework-8 and pulling off the water surface, and then drying and heat-treating overnight to obtain the mixed matrix membrane. The mixed matrix membrane is prepared through the liquid-liquid interface, the zeolitic imidazolate framework-8 particles are redistributed in the polymer matrix, direct contact between the zeolitic imidazolate framework and the aqueous solution is avoided, excessive flushing to cause the destruction of the crystal structure of the zeolitic imidazolate framework is avoided, the long-time use stability of the zeolitic imidazolate framework / polymer mixed matrix membrane is ensured, and the structural stability and service life of the mixed matrix membrane are improved.

Description

Technical Field

[0001] This invention relates to a method for preparing a metal-organic framework / polymer hybrid matrix membrane and its separation application, belonging to the fields of hybrid matrix membrane preparation technology and separation technology, and specifically to the field of pervaporation separation. Background Technology

[0002] Biomass fuel, as an alternative to fossil fuels, can be used to alleviate the energy crisis caused by the overconsumption of fossil fuels through ethanol produced by bio-fermentation. Related studies estimate that ethanol produced from waste crops and crop straw worldwide could replace 32% of global gasoline consumption. Furthermore, pervaporation membrane separation technology can continuously and effectively extract fermentation products from the fermentation broth. However, the choice of membrane material and its preparation method determine the separation effect achievable.

[0003] Zeolitic imidazolate framework-8 (ZIM-8) is a metal-organic framework created by linking transition metal cations such as Zn and imidazolate anions to a tetrahedral framework similar to many zeolite structures. It possesses high specific surface area and porosity, as well as good thermal and chemical stability. However, ZIM-8 exhibits relatively low mechanical strength and is susceptible to structural damage due to mechanical stress and moisture. Polyether block amide is a thermoplastic block copolymer prepared from polyether and polyamide blocks. The polyether blocks provide good component permeability, while the polyamide blocks provide good mechanical support strength. Polyether block amides have advantages such as no crosslinking required, simple film formation, and high affinity for organic matter, allowing for the preparation of high-performance separation membranes for mixtures with different separation objectives.

[0004] Therefore, in view of the phenomenon that the crystal structure of zeolite imidazole framework-8 is prone to instability in water and aqueous solution environments, this invention reports a method for inducing the rearrangement of zeolite imidazole framework in polyether block amide matrix through liquid-liquid interface. This film formation method can effectively avoid direct contact between zeolite imidazole framework and aqueous solution, avoid excessive scouring leading to destruction of zeolite imidazole framework crystal structure, thereby ensuring the long-term stability of zeolite imidazole framework / polyether block amide mixed matrix film.

[0005] This invention further elucidates the synergistic effect of polyether block amide matrix and nanoparticles in the phase transformation process by precisely controlling the liquid-liquid interface phase transformation process. Summary of the Invention

[0006] The purpose of this invention is to prepare a zeolite imidazole framework / polyether block amide hybrid matrix membrane and apply it to fermentation broth separation. This method overcomes the limitations of current hybrid matrix membranes in the process of preferential alcohol pervaporation, such as easy loss of nanoparticles and short stabilization period. The prepared hybrid matrix membrane has good stability in use, as well as high throughput and a high separation factor.

[0007] In view of this, the present invention provides a method for preparing and separating a hybrid matrix membrane with interface-induced particle directional distribution, which can solve the technical problems existing in related technologies.

[0008] Specifically, the following technical solutions are included:

[0009] This invention provides a method for preparing a hybrid matrix membrane by interface-induced nanoparticle distribution, the method comprising the following steps:

[0010] (1) Weigh a certain amount of zeolite imidazole framework-8 and add it to the mixed solvent. Sonicate it to make it evenly dispersed in the solvent. Then add polyether block amide and heat it in a water bath to form a uniform casting solution. After ultrasonic defoaming, place it in a forced-air drying oven overnight to completely remove the bubbles.

[0011] (2) Take an appropriate amount of deionized water into a petri dish, use a pipette to transfer the casting solution from step (1) and quickly drop it onto the water surface to form a zeolite imidazole framework / polyether block amide membrane on the water surface. Adhere the base membrane from the upper surface of the zeolite imidazole framework / polyether block amide membrane to the zeolite imidazole framework / polyether block amide membrane and lift it off the water surface.

[0012] (3) The mixed matrix membrane prepared in step (2) is dried overnight in a forced-air drying oven, and then the mixed matrix membrane is heat-treated to form a mixed matrix membrane with uniform surface, dense structure and oriented particle distribution.

[0013] In the mixed matrix membrane and the method for preparing the mixed matrix membrane described in this invention, in step (1), the polyether block amide is any one of polyether block amide 2533 / 3533 / 1074 / 1657. For example, polyether block amide 2533.

[0014] In the mixed matrix membrane and the preparation method of the mixed matrix membrane described in this invention, in step (1) the concentration of the polyether block amide in the casting solution is 1-11 wt.%, for example: 1 wt.%, 3 wt.%, 5 wt.%, 7 wt.%, 9 wt.%, 11 wt.%.

[0015] In the mixed matrix membrane and its preparation method described in this invention, in step (1) of the casting solution, the mass percentage of zeolite imidazole framework-8 in the polyether block amide is 0-50 wt.%, for example, the mass fraction of zeolite imidazole framework-8 is 0 wt.%, 10 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, or 50 wt.%. For example, the mass fraction of zeolite imidazole framework-8 is 20 wt.%.

[0016] In the mixed matrix membrane and its preparation method described in this invention, in step (2), the mixed solvent is a mixture of n-butanol and isopropanol with a mass ratio of 1:0 to 0:1, for example: the mass ratio of n-butanol to isopropanol is 1:0; 1:3; 1:2; 1:1; 2:1; 3:1; 0:1. For example, the mass ratio of n-butanol to isopropanol is 2:1.

[0017] The aforementioned mixed solvent can avoid excessive solvent-non-solvent exchange, which could lead to porous defects in the film, and also promote the spreading of the casting solution on the water surface. During the film formation process on the liquid surface, the zeolite imidazole framework-8 comes into contact with water. Its strong hydrophobic properties promote the zeolite imidazole framework-8 in the polyether block amide matrix to change from a uniform distribution to an oriented distribution away from the water surface. Combined with the method of adhering and lifting the zeolite imidazole framework / polyether block amide film from above in the air, the mixed matrix film avoids direct contact between the zeolite imidazole framework-8 and the feed solution during testing, reducing particle loss caused by feed solution scouring and damage to the crystal structure of the zeolite imidazole framework-8.

[0018] In the mixed matrix membrane and its preparation method described in this invention, in step (2), the temperature of the deionized water is 0-20℃, for example: 0℃, 5℃, 10℃, 15℃, 20℃, with an example temperature of 10℃. The film formation time on the water surface is 1-5 min, for example: 1 min, 2 min, 3 min, 4 min, 5 min. The control of the aqueous phase temperature and the film formation time helps to suppress the excessive phase transformation process between the oil phase (zeolite imidazole framework-8 / polyether block amide membrane liquid) and the aqueous phase (deionized water) during the liquid-liquid interface film formation process, thereby avoiding the formation of pore defects.

[0019] In the mixed matrix membrane and its preparation method described in this invention, in step (2), the amount of casting solution used is [amount] per 176.6 cm³. 2 The amount of casting solution used corresponds to 100-1000 μL, for example, 100 μL, 200 μL, 300 μL, 400 μL, 500 μL, and 1000 μL. This amount of casting solution helps prevent the solution from failing to diffuse effectively on the water surface or undergoing rapid phase inversion, which could lead to film formation defects.

[0020] In the mixed matrix membrane and its preparation method described in this invention, in step (2), the selected base membrane is one of polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, and polypropylene. For example, polytetrafluoroethylene.

[0021] In the mixed matrix membrane and its preparation method described in this invention, in step (3), the mixed matrix membrane prepared by the liquid surface film-forming method is placed in a 40°C forced-air drying oven for drying. At this low temperature, the solvent evaporates, and the lower drying temperature avoids excessive shrinkage of the polyether block amide segments, thereby preventing the formation of interfacial gaps between the polyether block amide matrix and the zeolite imidazole framework-8. Subsequently, the mixed matrix membrane is heat-treated to promote the close arrangement of the polyether block amide molecular segments, thereby forming a dense and continuous mixed matrix membrane.

[0022] In the mixed matrix membrane and the preparation method of the mixed matrix membrane described in this invention, in step (3), the heat treatment temperature of the mixed matrix membrane is 60-100℃, for example 60℃, 70℃, 80℃, 90℃, 100℃. An exemplary temperature is 80℃.

[0023] The beneficial effects of this invention are: the mixed matrix membrane prepared by this invention exhibits high throughput and good selectivity when used for separating alcohol / water systems. Through the contact of the zeolite imidazole framework-8 with water, its strong hydrophobic properties promote the transformation of the zeolite imidazole framework-8 from a uniform distribution state to an oriented distribution away from the water surface within the polyether block amide matrix. This avoids direct contact and excessive scouring of the feed liquid, thereby ensuring the crystal structure of the particles and their stability during long-term use.

[0024] While ensuring the density and continuity of the pervaporation membrane, the flux and selectivity of the butanol-water system are improved. Under the same processing capacity, long-term stability testing of the mixed matrix membrane can be achieved, ensuring separation performance and improving production efficiency. Attached Figure Description

[0025] Figure 1 Composite membranes were prepared using the liquid-liquid interface film-forming method provided in Examples 1 and 6;

[0026] Figure 2 These are schematic diagrams of the mixed matrix membrane formation provided in Examples 2-5 and 7-11;

[0027] Figure 3 Electron micrographs and surface roughness of mixed matrix films with different zeolite imidazole framework-8 loadings provided in Examples 2-5 (a1, a2: 0 wt.%; b1, b2: 10 wt.%; c1, c2: 20 wt.%; d1, d2: 30 wt.%; e1, e2: 40 wt.%).

[0028] Figure 4 Electron micrographs of cross-sectional areas of the hybrid matrix membranes provided in Examples 2-5;

[0029] Figure 5 XRD and infrared spectra of the mixed matrix membranes provided in Examples 2-5;

[0030] Figure 6 This is a test graph showing the long-term stability of the hybrid matrix membrane provided in Example 3; Detailed Implementation

[0031] To make the technical solution and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto.

[0032] The evaluation indicators for membrane pervaporation performance are flux J and separation factor α. Flux J refers to the mass of permeate passing through a unit area per unit time, which characterizes the membrane's permeation performance. The calculation formula is as follows.

[0033]

[0034] The physical meanings of J, W, S, and Δt are as follows:

[0035] J—Osmium flux, g·m -2 ·h -1 ;

[0036] W—mass of permeate, in g;

[0037] S—Effective membrane area, m 2 ;

[0038] Δt—Evaluation time, h.

[0039] The separation factor α characterizes the separation efficiency of the membrane. It is calculated by measuring the content of each component using a gas chromatograph, and the calculation formula is as follows.

[0040]

[0041] α, Y SOLVENT Y WATER X SOLVENT and X WATER The physical meaning represented by α: separation factor;

[0042] Y SOLVENT —The content of organic matter in the permeate, wt.%;

[0043] Y WATER —Water content in the liquid, wt.%;

[0044] X SOLVENT —The content of organic matter in the feed liquid, wt.%;

[0045] X WATER —Water content in the feed liquid, wt.%.

[0046] Example 1: 9 wt.% and 7 wt.% polyether block amide-polytetrafluoroethylene composite membranes were used for the preparation and separation process of 1 wt.% butanol water by pervaporation.

[0047] Examples 2-5 illustrate the use of mixed matrix membranes with different zeolite imidazole framework-8 loadings (polyether block amide concentration of 9 wt.%, casting liquid volume of 400 μL) for the preparation and separation of 1 wt.% butanol-water via pervaporation.

[0048] Examples 7-11 illustrate the use of mixed matrix membranes (polyether block amide concentration of 7 wt.% and zeolite imidazole framework-8 concentration of 10 wt.%) prepared with different casting solution amounts for the preparation and separation of 1 wt.% butanol-water by pervaporation.

[0049] Example 1 (Comparative Example):

[0050] Dissolve 9g of polyether block amide 2533 in 91g of a mixed solvent (n-butanol:isopropanol = 2:1) and stir vigorously in an 80℃ water bath for 5 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, then transfer the solution to a ground glass joint conical flask and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene (PTFE) membrane and the polyether block amide (PTFE) membrane were adhered. The composite membrane was dried in a 40°C forced-air drying oven for 24 hours, followed by heat treatment at 80°C for 5 hours to form a uniform and dense polyether block amide-PTFE composite membrane. The membrane fabrication process flow chart is shown below. Figure 1 .

[0051] The composite membrane obtained in this embodiment was tested for separation performance of the n-butanol / water system. The effective area of ​​the composite membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 2.73 kg·m³. -2 ·h -1 The separation factor was 17.41.

[0052] Example 2:

[0053] Weigh 0.9g of zeolite imidazole framework-8 and add it to 91g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 6g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane and the zeolite imidazole framework-8 / polyether block amide membrane were adhered to and lifted off the water surface. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0054] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 3.7 kg·m³. -2 ·h -1 The separation factor is 17.53.

[0055] Example 3:

[0056] Weigh 1.8g of zeolite imidazole framework-8 and add it to 91g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 6g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0057] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 4.9 kg·m³. -2 ·h -1 The separation factor is 18.8.

[0058] Example 4:

[0059] Weigh 2.7g of zeolite imidazole framework-8 and add it to 91g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 6g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0060] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 3.7 kg·m³. -2 ·h-1 The separation factor is 15.3.

[0061] Example 5:

[0062] Weigh 3.6g of zeolite imidazole framework-8 and add it to 91g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 6g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0063] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 3.2 kg·m³. -2 ·h -1 The separation factor was 13.67.

[0064] Example 6 (Comparative Example):

[0065] Dissolve 7g of polyether block amide 2533 in 93g of a mixed solvent (n-butanol:isopropanol = 2:1) and stir vigorously in an 80℃ water bath for 5 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, then transfer the solution to a ground glass joint conical flask and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene (PTFE) membrane and the polyether block amide (PTFE) membrane were adhered. The composite membrane was dried in a 40°C forced-air drying oven for 24 hours, followed by heat treatment at 80°C for 5 hours to form a uniform and dense polyether block amide-PTFE composite membrane. The membrane fabrication process flow chart is shown below. Figure 1 .

[0066] The composite membrane obtained in this embodiment was tested for separation performance of the n-butanol / water system. The effective area of ​​the composite membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 4.68 kg·m³. -2 ·h -1 The separation factor was 12.39.

[0067] Example 7:

[0068] Weigh 0.7g of zeolite imidazole framework-8 and add it to 93g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 2.3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 4.7g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 200μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0069] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 4.41 kg·m³. -2 ·h -1 The separation factor is 12.51.

[0070] Example 8:

[0071] Weigh 0.7g of zeolite imidazole framework-8 and add it to 93g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 2.3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 4.7g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 400μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0072] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 4.11 kg·m³. -2 ·h -1 The separation factor was 12.96.

[0073] Example 9:

[0074] Weigh 0.7g of zeolite imidazole framework-8 and add it to 93g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 2.3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 4.7g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 600μL of the casting solution to the water surface (176.6cm). 2On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0075] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 3.9 kg·m³. -2 ·h -1 The separation factor is 10.68.

[0076] Example 10:

[0077] Weigh 0.7g of zeolite imidazole framework-8 and add it to 93g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 2.3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 4.7g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 800μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0078] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 4.62 kg·m³. -2 ·h-1 The separation factor was 11.96.

[0079] Example 11:

[0080] Weigh 0.7g of zeolite imidazole framework-8 and add it to 93g of mixed solvent (n-butanol:isopropanol = 2:1). Weigh 2.3g of polyether block amide 2533 and add it to the zeolite imidazole framework-8 mixed solvent. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Then weigh 4.7g of polyether block amide 2533 and add it to the casting solution. Stir vigorously in an 80℃ water bath for 3 hours (300 rpm) to form a homogeneous casting solution. Sonicate for 10 minutes, transfer the film solution to a ground glass joint conical flask, and place it in a 60℃ oven overnight to completely remove air bubbles. Take an appropriate amount of 10℃ deionized water in a petri dish, and use a pipette to quickly add 1000μL of the casting solution to the water surface (176.6cm). 2 On the water surface, a film was formed for 3 minutes. Using a self-made lifting device, the polytetrafluoroethylene membrane was adhered to the zeolite imidazole framework-8 / polyether block amide membrane. The mixed matrix membrane was dried in a 40℃ forced-air drying oven for 24 hours, followed by heat treatment at 80℃ for 5 hours to form a zeolite imidazole framework-8 / polyether block amide-polytetrafluoroethylene mixed matrix membrane with a uniform surface, dense structure, and oriented particle distribution. The membrane formation process flow diagram is shown below. Figure 2 .

[0081] The separation performance of the hybrid matrix membrane obtained in this embodiment for the n-butanol / water system was tested, and the effective area of ​​the hybrid matrix membrane was 4.9 cm². 2 The feed concentration was 1 wt.%, the feed temperature was 60℃, and pressure was provided by a vacuum pump, with the downstream permeation pressure reaching -0.1 MPa. After membrane separation, the permeation flux was 3.07 kg·m³. -2 ·h -1 The separation factor was 16.91.

[0082] The above description is merely for the purpose of enabling those skilled in the art to understand the technical solutions of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a hybrid matrix film by interface-induced nanoparticle distribution, characterized in that, Includes the following steps: (1) Weigh a certain amount of zeolite imidazole framework-8 and add it to the mixed solvent. Sonicate it to make it evenly dispersed in the solvent. Then add polyether block amide and heat it in a water bath to form a uniform casting solution. After ultrasonic defoaming, place it in a forced-air drying oven overnight to completely remove the bubbles. (2) Take an appropriate amount of deionized water into a petri dish, use a pipette to transfer the casting solution from step (1) and quickly drop it onto the water surface to form a zeolite imidazole framework / polyether block amide membrane on the water surface. Then, attach the base membrane to the zeolite imidazole framework / polyether block amide membrane from the upper surface of the zeolite imidazole framework / polyether block amide membrane and lift it off the water surface. (3) The mixed matrix membrane prepared in step (2) is dried overnight in a forced-air drying oven, and then the mixed matrix membrane is heat-treated to form a mixed matrix membrane with uniform surface, dense structure and oriented particle distribution; In step (1), the mixed solvent is a mixture of n-butanol and isopropanol with a mass ratio of 1:3 to 3:

1. In step (2), the temperature of the deionized water is 0-20 ℃; the film formation time on the water surface is 1-5 min; in step (2), the amount of casting solution used is per 176.6 cm³ 2 The water surface area corresponds to 100-1000 μL.

2. The method according to claim 1, characterized in that, In step (1), the polyether block amide is any one of polyether block amide 2533 / 3533 / 1074 / 1657.

3. The method according to claim 1, characterized in that, In step (1), the concentration of the polyether block amide in the casting solution is 1-11 wt%.

4. The method according to claim 1, characterized in that, In step (1), the mass percentage of zeolite imidazole framework-8 in the casting solution is 10-50 wt% of the polyether block amide.

5. The method according to claim 1, characterized in that, In step (3), the mixed matrix membrane prepared by the liquid surface film formation method is placed in a 40°C forced-air drying oven for drying. At low temperature, the solvent evaporates. In step (3), the heat treatment temperature of the mixed matrix membrane is 60-100°C.

6. A hybrid matrix membrane prepared according to any one of claims 1-5.

7. The application of the mixed matrix membrane prepared according to any one of claims 1-5 as a pervaporation membrane.

8. The application according to claim 7, for the separation of alcohol / water systems.

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