A polyaniline metal-organic framework hybrid matrix membrane and preparation and application thereof

Abstract

The present application relates to a kind of polyphenylamine metal organic framework mixed matrix membrane and its preparation and application, by metal organic framework as basic filler, polyphenylamine as modified polymer, polyvinylidene fluoride as polymer base, using post-synthesis modification method, by the formation of coordination bond, hydrogen bond polyphenylamine can be modified on the surface of metal organic framework to achieve grafting purpose, further by phase transfer method, polyphenylamine metal organic framework mixed matrix membrane is prepared.The mixed matrix membrane not only has the double advantages of the selective performance of metal organic framework to carbon dioxide and the permeability of polyvinylidene fluoride to carbon dioxide, in addition, polyphenylamine molecule provides more nitrogen binding sites for mixed matrix membrane to bind carbon dioxide, so that its permeability is more outstanding, and preparation process is simple, saves time and labor, without sample pretreatment, green and environmental protection, low cost and other advantages, and shows broad application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of film material preparation, and relates to a polyaniline metal organic framework mixed matrix film and a preparation and application thereof. BACKGROUND

[0002] The emission amount of pollution gas generated by the combustion of a large amount of fossil fuels increases year by year, and the greenhouse effect caused thereby causes a serious global warming problem, and carbon dioxide is the main gas causing the greenhouse effect. Coal power plants are the main source of carbon dioxide, so separating and capturing excess carbon dioxide can greatly reduce its emission into the atmosphere. Common methods for separating carbon dioxide include low-temperature capture, absorption and membrane separation, etc. Among them, the membrane separation method has great potential due to its unique advantages of low energy consumption and high efficiency, so developing a membrane material with high mechanical strength, good chemical stability and high gas selectivity has become a research hotspot today.

[0003] The mixed matrix film has attracted widespread attention from scientific workers as a new type of membrane material. The mixed matrix film is made by mixing inorganic materials as fillers and organic polymers as matrix phases. However, the mixed matrix film is subject to the trade-off effect of permeability and selectivity, that is, the trade-off relationship between gas flux and selectivity, so solving the trade-off effect of permeability and selectivity to improve the efficiency of the film and obtaining a film material with high permeability and high selectivity is a research focus. Metal organic framework materials have become the first choice for mixed matrix film fillers due to their regular pore structure, flexible controllability and a large number of unsaturated sites. Although the metal organic framework material-based mixed matrix film exhibits good gas selectivity and permeability, there is still a universal problem of mutual mismatch and poor adaptability between the fillers and the matrix polymers.

[0004] Currently, the interface relationship between the fillers and the matrix can be improved and the gas permeability and selectivity can be further optimized by modifying the metal organic framework material through a synergistic method. However, there are great differences in the structure and performance of the prepared mixed matrix film due to the variety of metal organic frameworks and polymers, and in addition, most of the synthesis methods are complex and high in cost, which is not conducive to commercial production. SUMMARY

[0005] The purpose of the present application is to provide a polyaniline metal organic framework mixed matrix film and a preparation and application thereof.

[0006] The purpose of the present application can be achieved by the following technical solutions.

[0007] One of the technical solutions of the present application provides a preparation method of a polyaniline metal organic framework mixed matrix film, comprising the following steps:

[0008] (1) taking polyaniline into an organic solvent, then adding a metal organic framework, stirring to obtain a polyaniline metal organic framework material;

[0009] (2) then dispersing the polyaniline metal organic framework material into N-methyl pyrrolidone, adding polyvinylpyrrolidone and polyvinylidene fluoride, heating and stirring, cooling the obtained mixed solution to room temperature, then casting onto a substrate, and using a phase transfer method to prepare a polyaniline metal organic framework mixed matrix membrane, which is the target product.

[0010] Further, in step (1), the organic solvent is N,N-dimethylformamide, N-methyl pyrrolidone or dimethyl sulfoxide.

[0011] Further, in step (1), the metal organic framework is Cu-BDC. In addition, the particle size of the polyaniline metal organic framework obtained in step (1) is smaller than that of the metal organic framework.

[0012] Further, in step (1), the mass ratio of the metal organic framework to the polyaniline is 1-2:1.

[0013] Further, in step (1), the stirring temperature is 60-80℃, and the stirring time is 0.5-1.5h.

[0014] Further, in step (2), the mass ratio of the polyaniline metal organic framework material to N-methyl pyrrolidone is 0.05-0.1:1.

[0015] Further, in step (2), the mass ratio of N-methyl pyrrolidone to polyvinylpyrrolidone is 15-20:1.

[0016] Further, in step (2), the mass ratio of N-methyl pyrrolidone to polyvinylidene fluoride is 1-5:1.

[0017] Further, in step (2), the heating and stirring temperature is 50-70℃, and the heating and stirring time is 7-9h.

[0018] Further, in step (2), the phase transfer method process is as follows:

[0019] After the mixed solution is cast onto the substrate and forms a film with uniform thickness, it is placed into ultrapure water, so that the film is separated from the substrate, and the target product is obtained.

[0020] The second technical scheme of the present application provides a polyaniline metal organic framework mixed matrix membrane, which is prepared by the preparation method described in any one of the above.

[0021] The third technical scheme of the present application provides an application of a polyaniline metal organic framework mixed matrix membrane, which is used for selective separation of carbon dioxide.

[0022] The polyphenylamine in the application contains a large number of amino and imino nitrogen atoms as a polymer material, can promote the interaction between carbon dioxide molecules and nitrogen atoms and provide a large number of sites to highly selectively separate carbon dioxide from mixed gas, in addition, the polyphenylamine has good compatibility with polyvinylidene fluoride, can solve the adaptability problem between inorganic phase and organic phase, in addition, the reaction condition is mild, without crosslinking agent and initiator; the metal organic framework is used as a basic filler particle, the preparation process of the polyphenylamine metal organic framework is simple and pollution-free. The mixed matrix membrane prepared by the method not only retains the high permeability of the metal organic framework, but also greatly protects the selectivity and chemical stability of the polymer, and further improves the selective separation performance of the mixed matrix membrane to gas.

[0023] Compared with the prior art, the application has the following advantages:

[0024] 1) In the application, the polyphenylamine metal organic framework prepared has a large number of nitrogen-containing groups on the surface, which can be effectively crosslinked with organic polymers through hydrogen bonding, thereby improving the interface relationship between inorganic phase and organic phase, solving the interface defects of the filler and the substrate, improving the permeability and selectivity of the mixed matrix membrane, and the modification process is relatively simple, and the environmental impact is small.

[0025] 2) In the application, the high solubility of the polymer polyphenylamine in the organic solvent and the easy grafting characteristics under heating conditions are used, without adding initiators and catalysts in the modification synthesis, the preparation process is simplified, the multi-factor interference is reduced, the cost is saved, and the environmental pollution is reduced. And the structure of the polyphenylamine metal organic framework can be controlled by controlling the polyphenylamine concentration, the modification time and the type of organic solvent, which is beneficial to the crosslinking with polyvinylidene fluoride and reduces the invalid gap volume, thereby significantly improving the permeability and selectivity of the mixed matrix membrane.

[0026] 3) The polyphenylamine metal organic framework mixed matrix membrane has a carbon dioxide permeability of 1130.7 Barrer and a selectivity coefficient of 10.89. Compared with similar mixed matrix membranes, the mixed matrix membrane has good permeability to carbon dioxide. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The preparation process flow chart of the application is shown in the figure;

[0028] Figure 2 The scanning electron microscope images of the metal organic framework and the polyphenylamine metal organic framework prepared in Example 1 are shown in the figure;

[0029] Figure 3The scanning electron microscope images of the mixed matrix membranes without metal-organic framework and without polyaniline modified metal-organic framework and the mixed matrix membranes with polyaniline modified metal-organic framework prepared in Example 1 are shown in the following figures:

[0030] Figure 4 The physical images of the polyaniline metal-organic framework mixed matrix membranes in Example 1 are shown in the following figures:

[0031] Figure 5 The columnar graphs of the carbon dioxide permeability and selectivity of the polyaniline metal-organic framework mixed matrix membranes in Example 4 are shown in the following figures. DETAILED DESCRIPTION

[0032] The present application will be described in detail below with reference to the accompanying drawings and specific examples. The present examples are implemented on the premise of the technical solutions of the present application, and detailed implementation manners and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0033] In the following examples, Cu-BDC is self-prepared by the following method: 0.0241 g of copper sulfate trihydrate and 0.0166 g of terephthalic acid are dissolved in 10 mL of N,N-dimethylformamide. After ultrasonic treatment for 15 min, the solution is poured into a tetrafluoroethylene container, and then a high-pressure kettle is used to heat at 120°C for 48 h. The obtained powder is repeatedly washed with N,N-dimethylformamide and methanol to obtain Cu-BDC finally.

[0034] The remaining raw materials or processing techniques, if not specifically mentioned, are all conventional commercially available raw materials or conventional raw materials in the art.

[0035] Example 1:

[0036] This example relates to a preparation method of a polyaniline metal-organic framework mixed matrix membrane, and the specific flow is shown in the following figure: Figure 1 The scanning electron microscope images of the metal-organic framework and the polyaniline metal-organic framework are shown in the following figures: Figure 2 The polyaniline metal-organic framework mixed matrix membrane is shown in the following figure: Figure 3 The preparation method comprises the following steps:

[0037] 1) Preparation of polyaniline metal-organic framework material: 0.01 g of polyaniline is dissolved in 10 mL of N,N-dimethylformamide and ultrasonically treated for 30 min, and then Cu-BDC (the mass ratio of polyaniline to Cu-BDC is 0.5) is added, stirred at 70°C for 1 h, and repeatedly washed and centrifuged with methanol to obtain Cu-BDC powder modified by polyaniline, which is denoted as PANI-F@Cu-BDC.

[0038] 2) Preparation of poly-aniline metal organic framework mixed matrix membrane: PANI-F@Cu-BDC was weighed and added into N-methyl pyrrolidone and was ultrasonically treated for 1 h (mass ratio of PANI-F@Cu-BDC and N-methyl pyrrolidone was 0.05), then polyvinylpyrrolidone and polyvinylidene fluoride were added into the above mixed solution (mass ratio of N-methyl pyrrolidone, polyvinylpyrrolidone and polyvinylidene fluoride was 5:0.3:1), and the mixture was continuously stirred at 60°C for 8 h, and after cooling to room temperature, the mixture was cast onto a glass plate, and the liquid was made into a uniform and flat membrane with a thickness of a coating device, and then the glass plate was quickly placed into ultrapure water to make the membrane separate from the glass plate by phase inversion, thereby obtaining a poly-aniline metal organic framework mixed matrix membrane.

[0039] Example 2:

[0040] In this example, in step 1) of Example 1, the organic solvent N,N-dimethylformamide was replaced with dimethyl sulfoxide, denoted as PANI-O@Cu-BDC, and the rest was the same as Example 1.

[0041] Example 3:

[0042] In this example, in step 1) of Example 1, the organic solvent N,N-dimethylformamide was replaced with N-methyl pyrrolidone, denoted as PANI-P@Cu-BDC, and the rest was the same as Example 1.

[0043] Example 4:

[0044] The poly-aniline metal organic framework mixed matrix membranes prepared in Examples 1-3 above were subjected to carbon dioxide selective separation experiments, and the experimental results are as follows Figure 4 , and the steps are as follows:

[0045] 1) The permeation properties of CO2 and N2 gases were tested by the constant pressure variable volume method. The membrane material was placed in a sealed device, and the temperature was kept constant at 25°C, the pressure difference before and after the membrane was 0.1 MPa, and the effective membrane area was 3.14 cm 2 . Through the carbon dioxide selective separation experiment, the permeation rates of PANI-P@Cu-BDC, PANI-F@Cu-BDC and PANI-O@Cu-BDC were 503.01, 1130.76 and 682.93 Barrer, and the selectivities were 5.02, 10.89 and 6.71.

[0046] Example 5:

[0047] In this example, the permeation rate and selectivity measured in Example 4 were compared with those of a pure polyvinylidene fluoride membrane (PVDF) and a mixed matrix membrane with only Cu-BDC added (Cu-BDC / PVDF, i.e., compared with Example 1, the introduction of poly-aniline was omitted, and the rest was the same), and the selective separation performance is shown in Table 1:

[0048] Table 1 Separation performance comparison of polyaniline metal organic framework mixed matrix membrane and other membrane materials

[0049] Membrane material CO2permeability coefficient (Barrer) Selectivity PVDF 7.24 0.66 Cu-BDC / PVDF 156.56 3.72 PANI-P@Cu-BDC 503.01 5.02 PANI-F@Cu-BDC 1130.76 10.89 PANI-O@Cu-BDC 682.93 6.71

[0050] From the results, it can be seen that the permeability of carbon dioxide of the polyaniline metal organic framework mixed matrix membranes prepared in Examples 1-3 is higher than that of other mixed matrix membranes, which shows that the polyaniline metal organic framework mixed matrix membrane has excellent permeability and good selectivity.

[0051] Comparative Example 1:

[0052] Most of them are the same as in Example 1, except that polyaniline is not added, and the experimental data are as shown in Table 1 Cu-BDC / PVDF.

[0053] Comparative Example 2:

[0054] Most of them are the same as in Example 1, except that Cu-BDC is not added, and the experimental data are as shown in Table 1 PVDF.

[0055] Example 6:

[0056] Most of them are the same as in Example 1, except that in this example, the mass ratio of the metal organic framework to polyaniline in step (1) is adjusted to 1:1.

[0057] Example 7:

[0058] Most of them are the same as in Example 1, except that in this example, the mass ratio of the metal organic framework to polyaniline in step (1) is adjusted to 1.5:1.

[0059] Example 8:

[0060] Most of them are the same as in Example 1, except that in this example, the mass ratio of the polyaniline metal organic framework material to N-methyl pyrrolidone in step (2) is adjusted to 0.1:1; the mass ratio of N-methyl pyrrolidone to polyvinylpyrrolidone is 15:1; and the mass ratio of N-methyl pyrrolidone to polyvinylidene fluoride is 1:1.

[0061] Example 9:

[0062] Most of them are the same as in Example 1, except that in this example, the mass ratio of the polyaniline metal organic framework material to N-methyl pyrrolidone in step (2) is adjusted to 0.08:1; the mass ratio of N-methyl pyrrolidone to polyvinylpyrrolidone is 20:1; and the mass ratio of N-methyl pyrrolidone to polyvinylidene fluoride is 5:1.

[0063] The foregoing description of the embodiments has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed. Modifications and variations are possible in light of the above teachings or can be acquired from practice of the application. As well, the description is presented in the context of the preferred embodiments as a number of alternatives. It is not intended to limit the application to the precise form described.

Claims

1. A method for preparing a polyaniline metal organic framework hybrid matrix membrane, characterized in that, The method comprises the following steps: (1) taking polyaniline dissolved in an organic solvent, then adding a metal organic framework, stirring to obtain a polyaniline metal organic framework material; (2) dispersing the polyaniline metal organic framework material in N-methyl pyrrolidone, adding polyvinylpyrrolidone and polyvinylidene fluoride, heating and stirring, cooling the obtained mixture to room temperature, then casting on a substrate, and using a phase transfer method to prepare a polyaniline metal organic framework mixed matrix membrane, which is the target product; In step (1), the metal organic framework is Cu-BDC; In step (1), the mass ratio of the metal organic framework to polyaniline is 1-2:1; In step (2), the mass ratio of the polyaniline metal organic framework material to N-methyl pyrrolidone is 0.05-0.1:1; The mass ratio of N-methyl pyrrolidone to polyvinylpyrrolidone is 15-20:1; The mass ratio of N-methyl pyrrolidone to polyvinylidene fluoride is 1-5:

1.

2. The method of claim 1, wherein the polyaniline metal-organic framework hybrid matrix film is prepared by the steps of: (a) preparing a polyaniline matrix film; (b) preparing a metal-organic framework; and (c) mixing the polyaniline matrix film and the metal-organic framework. In step (1), the organic solvent is N,N-dimethylformamide, N-methyl pyrrolidone or dimethyl sulfoxide.

3. The method of claim 1, wherein the polyaniline metal-organic framework hybrid matrix film is prepared by the steps of: (a) preparing a polyaniline matrix film; (b) preparing a metal-organic framework; and (c) mixing the polyaniline matrix film and the metal-organic framework. In step (1), the stirring temperature is 60-80℃, and the stirring time is 0.5-1.5h.

4. The method of claim 1, wherein the polyaniline metal-organic framework hybrid matrix film is prepared by the steps of: (a) preparing a polyaniline matrix film; (b) preparing a metal-organic framework; (c) mixing the polyaniline matrix film and the metal-organic framework to form a polyaniline metal-organic framework hybrid matrix film. In step (2), the heating and stirring temperature is 50-70℃, and the heating and stirring time is 7-9h.

5. The method of claim 1, wherein the polyaniline metal-organic framework hybrid matrix film is prepared by the steps of: (a) preparing a polyaniline matrix film; (b) preparing a metal-organic framework; (c) mixing the polyaniline matrix film and the metal-organic framework to form a polyaniline metal-organic framework hybrid matrix film. In step (2), the phase transfer method process specifically comprises: After the mixture is cast on the substrate and forms a film with uniform thickness, it is placed in ultrapure water, so that the film is separated from the substrate, and the target product is obtained.

6. A polyaniline metal organic framework mixed matrix membrane prepared by the method of any one of claims 1-5.

7. Use of a polyaniline metal organic framework mixed matrix membrane according to claim 6, characterized in that, The mixed matrix membrane is used for selective separation of carbon dioxide.

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