Hydrogen bond organic framework material composite membrane and its preparation method and application

Abstract

The present invention belongs to the field of membrane separation technology, and specifically relates to a hydrogen-bonded organic framework material composite membrane and a preparation method and application thereof, wherein the preparation method of the hydrogen-bonded organic framework material composite membrane comprises: dissolving the hydrogen-bonded organic framework material in a first solvent to obtain a hydrogen-bonded organic framework material solution; dissolving graphene oxide in a second solvent to obtain a graphene oxide solution; mixing the hydrogen-bonded organic framework material solution with the graphene oxide solution and then ultrasonically treating the solution to obtain a uniformly mixed GO / HOF composite solution; filtering the GO / HOF composite solution to the surface of the substrate membrane by vacuum filtration, and forming a composite membrane with uniform structure by hydrogen bonding and π-π conjugation between the hydrogen-bonded organic framework and the graphene oxide. The preparation method provided by the present invention is simple to operate, and the preparation conditions are mild, and the prepared hydrogen-bonded organic framework material composite membrane has a large flux and better interception performance.

Description

Technical Field

[0001] The invention belongs to the technical field of membrane separation, and in particular relates to a hydrogen-bonded organic framework material composite membrane and a preparation method and application thereof. Background Art

[0002] In recent years, researchers have proposed a variety of research and development directions for new membrane materials. Hydrogen-bonded organic frameworks (HOFs) are crystalline porous materials constructed by organic or metal-organic building blocks through hydrogen bonds. Due to their unique structural properties, such as high specific surface area, adjustable pore size, good thermal stability and chemical stability, they have become a hot direction in membrane material development. However, in most cases, HOF exists in the form of fine powder or tiny particles, which makes it less dispersible in the aqueous phase and difficult to self-assemble into a membrane. When HOF is grown directly on the membrane, the undirectional and rapid crystallization of HOF leads to inevitable defects between membranes and uneven distribution on the membrane surface, which affects the separation performance and stability of the membrane.

[0003] Therefore, in view of the above shortcomings, the present invention is proposed. Summary of the invention

[0004] The main purpose of the present invention is to propose a hydrogen-bonded organic framework material composite membrane and its preparation method and application. The preparation method of the hydrogen-bonded organic framework material composite membrane provided by the present invention is simple to operate and has mild preparation conditions. The prepared hydrogen-bonded organic framework material composite membrane has a large flux and better retention performance.

[0005] The first aspect of the present invention provides a method for preparing a hydrogen-bonded organic framework material composite membrane, the preparation method comprising: dissolving a hydrogen-bonded organic framework material in a first solvent to obtain a hydrogen-bonded organic framework material solution; dissolving graphene oxide in a second solvent to obtain a graphene oxide solution; mixing the hydrogen-bonded organic framework material solution and the graphene oxide solution to a constant volume and then performing ultrasonic treatment to obtain a uniformly mixed GO / HOF composite solution; filtering the GO / HOF composite solution onto the surface of a substrate membrane by vacuum filtration, and forming a composite membrane with a uniform structure by utilizing hydrogen bonds and π-π conjugation between the hydrogen-bonded organic framework and the graphene oxide.

[0006] In some embodiments of the present invention, the hydrogen-bonded organic framework material is prepared by dissolving 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin monomer in a mixed solvent of N,N-dimethylacetamide and methanol and performing solvent evaporation reaction.

[0007] In some embodiments of the present invention, the reaction temperature of the solvent evaporation reaction is 50° C. to 70° C., and the reaction time is 20 h to 30 h.

[0008] In some embodiments of the present invention, in the GO / HOF composite solution, the mass ratio of the graphene oxide to the hydrogen-bonded organic framework material is 1:2-8.

[0009] In some embodiments of the present invention, the total volume of the GO / HOF composite solution is 10 mL to 40 mL.

[0010] In some embodiments of the present invention, the ultrasonic frequency of the ultrasonic treatment is 30 kHz to 40 kHz, the ultrasonic time is 10 min to 20 min, and the ultrasonic treatment volume is 10 mL to 40 mL.

[0011] In some embodiments of the present invention, the first solvent and the second solvent are each independently selected from one of methanol, ethanol, and deionized water.

[0012] In some embodiments of the present invention, the base membrane is selected from a cellulose acetate membrane, a nylon membrane, and a polytetrafluoroethylene membrane.

[0013] The second aspect of the present invention provides a hydrogen-bonded organic framework material composite membrane, which is prepared by the preparation method of the hydrogen-bonded organic framework material composite membrane described in the first aspect, and the hydrogen-bonded organic framework material composite membrane is formed by a composite construction of hydrogen-bonded organic framework material and graphene oxide.

[0014] The third aspect of the present invention provides an application of the hydrogen-bonded organic framework material composite membrane described in the second aspect or the hydrogen-bonded organic framework material composite membrane prepared by the preparation method of the hydrogen-bonded organic framework material composite membrane described in the first aspect in water purification.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention forms a hydrogen-bonded organic framework material composite membrane with excellent performance by compounding a hydrogen-bonded organic framework material with a graphene oxide sheet. On the one hand, the carboxyl groups on the organic monomers in the porous rod-shaped hydrogen-bonded organic framework material can produce hydrogen bonding and conjugation with the carboxyl groups or hydroxyl groups in the graphene oxide sheet, thereby enhancing the interlamellar bonding force and increasing the HOF load in the composite membrane; on the other hand, the high porosity of the hydrogen-bonded organic framework material reduces the solute transmission resistance while providing an additional water transmission channel, significantly improving the permeability of the membrane. The combination of the above two aspects enables the hydrogen-bonded organic framework material and the graphene oxide composite membrane to maintain a high water permeability while maintaining good interception performance for dyes and micro-pollutants in water.

[0017] In the preparation method provided by the present invention, the hydrogen-bonded organic framework material can be prepared in an aqueous solvent at a relatively low temperature, and the GO / HOF complex solution can be prepared simply, and the composite membrane can be quickly prepared by a vacuum filtration method. The membrane preparation process is simple, does not require a large amount of organic solvent, is low in cost, and can be applied to large-scale industrial production.

[0018] The hydrogen-bonded organic framework material composite membrane provided by the present invention has high flux, excellent interception performance and anti-pollution ability, and is particularly suitable for fields such as water purification and wastewater treatment.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0021] Figure 1 Graph showing the separation performance of the GO / HOF composite membrane obtained in the embodiment of the present invention and the graphene oxide membrane obtained in Comparative Example 1;

[0022] Figure 2 : is a scanning electron microscope image of the GO / HOF composite film obtained in the embodiment of the present invention and the graphene oxide film obtained in Comparative Example 1; wherein, Figure 2 A and Figure 2 f in the middle are scanning electron microscope images of graphene oxide films at 10 μm and 1 μm respectively; Figure 2 Medium b and Figure 2 g in the figure are scanning electron microscopy images of GO / HOF-50 composite films at 10 μm and 1 μm respectively; Figure 2 Medium c and Figure 2 h in the middle are scanning electron microscope images of GO / HOF-200 composite membrane at 10 μm and 1 μm respectively; Figure 2 Medium D and Figure 2 i in the figure are scanning electron microscopy images of GO / HOF-400 composite membrane at 10 μm and 1 μm respectively; Figure 2 Zhongehe Figure 2 j in the middle are scanning electron microscopy images of GO / HOF-800 composite membrane at 10 μm and 1 μm respectively;

[0023] Figure 3is the static water contact angle of the GO / HOF composite film obtained in the embodiment of the present invention and the graphene oxide film obtained in Comparative Example 1;

[0024] Figure 4 This is a diagram showing the interception performance of the GO / HOF-400 composite membrane obtained in the embodiment of the present invention for different micropollutants;

[0025] Figure 5 This is a scanning electron microscope image of the HOF film obtained in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] In most cases, HOF exists in the form of fine powder or tiny particles, which makes it poorly dispersible in the aqueous phase and difficult to self-assemble into a membrane. Directly growing HOF on the membrane will inevitably lead to defects between membranes and uneven distribution on the membrane surface due to the rapid crystallization of HOF without orientation.

[0033] In the present invention, the processability of the flexible material is combined to mix the hydrogen-bonded organic framework material with the two-dimensional nanosheet graphene oxide material to promote the film formation of the hydrogen-bonded organic framework material.

[0034] The present invention provides a method for preparing a hydrogen-bonded organic framework material composite membrane with simple operation, mild preparation conditions and wide application. The key to the preparation method is to prepare a GO / HOF composite solution based on HOF and graphene oxide, and to assist its dispersion by ultrasonic treatment to obtain a uniformly mixed GO / HOF composite solution, and then to filter the GO / HOF composite solution to the surface of a polymer substrate membrane by vacuum filtration, and to form a composite membrane with uniform structure by utilizing hydrogen bonding and π-π conjugation between HOF and graphene oxide.

[0035] The method for preparing the hydrogen-bonded organic framework material composite film of the present invention is specifically carried out according to the following steps.

[0036] 1) Preparation of hydrogen-bonded organic framework materials.

[0037] In an embodiment of the present invention, an organic solution containing a hydrogen-bonded organic framework material monomer is dissolved in a solvent and reacted by solvent evaporation to obtain a purple hydrogen-bonded organic framework material.

[0038] In some embodiments of the present invention, the hydrogen-bonded organic framework material is prepared by dissolving 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin monomer in a mixed solvent of N,N-dimethylacetamide and methanol and performing a solvent evaporation reaction.

[0039] In some embodiments of the present invention, the reaction temperature of the solvent evaporation reaction is 50°C to 70°C, and the reaction time is 20 h to 30 h. Compared with the solvent evaporation reaction temperature in the prior art in the range of 80°C to 250°C, the present invention has a lower preparation temperature. The design of the reaction temperature and time in the present invention can accelerate the solvent evaporation process, improve the crystallinity and phase purity of the HOF material, and obtain a more uniform crystal structure.

[0040] For example, the reaction temperature may be one of 50° C., 55° C., 60° C., 65° C., 70° C., or any value satisfying the above range. The reaction time may be one of 20 h, 21 h, 22 h, 23 h, 24 h, 25 h, 26 h, 27 h, 28 h, 29 h, 30 h, or any value satisfying the above range.

[0041] 2) Prepare hydrogen bond organic framework material solution.

[0042] In an embodiment of the present invention, the hydrogen-bonding organic framework material is dissolved in a first solvent to obtain a hydrogen-bonding organic framework material solution.

[0043] In some embodiments of the present invention, the first solvent is selected from one of methanol, ethanol and deionized water.

[0044] 3) Prepare graphene oxide solution.

[0045] In an embodiment of the present invention, graphene oxide is dissolved in a second solvent to obtain a graphene oxide solution.

[0046] In some embodiments of the present invention, the second solvent is selected from one of methanol, ethanol and deionized water.

[0047] 4) Preparation of GO / HOF composite solution.

[0048] In an embodiment of the present invention, a hydrogen-bonded organic framework material solution and a graphene oxide solution are mixed to a fixed volume and then ultrasonically treated to obtain a uniformly mixed GO / HOF composite solution.

[0049] In some embodiments of the present invention, a hydrogen-bonded organic framework material solution and a graphene oxide solution are added to a preset volume of deionized water or other solvent, and then ultrasonically treated to obtain a uniformly mixed GO / HOF composite solution.

[0050] In some embodiments of the present invention, the ultrasonic frequency of the ultrasonic treatment is 30 kHz to 40 kHz, the ultrasonic time is 10 min to 20 min, and the ultrasonic treatment volume is 10 mL to 40 mL. Exemplarily, the ultrasonic frequency can be one of 30 kHz, 31 kHz, 32kHz, 33 kHz, 34 kHz, 35 kHz, 36 kHz, 37 kHz, 38 kHz, 39 kHz, 40 kHz or any value satisfying the above range value. The ultrasonic time can be one of 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min or any value satisfying the above range value. The ultrasonic treatment volume can be one of 10 mL, 15 mL, 20 mL, 25 mL, 30 mL, 35 mL, 40 mL or any value satisfying the above range value.

[0051] In some embodiments of the present invention, in the GO / HOF composite solution, the mass ratio of graphene oxide to the hydrogen-bonded organic framework material is 1:2 to 8. Exemplarily, the mass ratio of graphene oxide to the hydrogen-bonded organic framework material can be one of 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or any value satisfying the above range.

[0052] In some embodiments of the present invention, the total volume of the GO / HOF composite solution is 10 mL to 40 mL. For example, the total volume of the GO / HOF composite solution can be one of 10 mL, 15 mL, 20 mL, 25 mL, 30 mL, 35 mL, 40 mL, or any value satisfying the above range.

[0053] 5) Filtration to form membrane.

[0054] In an embodiment of the present invention, the GO / HOF composite solution is filtered onto the surface of the substrate membrane by vacuum filtration, and a composite membrane with uniform structure is formed by hydrogen bonding and π-π conjugation between the hydrogen-bonded organic framework and graphene oxide.

[0055] The GO / HOF composite solution is quickly filtered onto the surface of the substrate membrane by vacuum filtration to form a composite membrane with uniform structure and no defects. The preparation process does not require a large amount of organic solvent and has a low preparation cost.

[0056] In some embodiments of the present invention, the vacuum degree of vacuum filtration is 0.8 bar to 1.0 bar. For example, the vacuum degree can be one of 0.8 bar, 0.9 bar, 1.0 bar, or any value satisfying the above range.

[0057] In some embodiments of the present invention, the substrate membrane is selected from a cellulose acetate membrane, a nylon membrane, and a polytetrafluoroethylene membrane.

[0058] The present invention also provides a hydrogen-bonded organic framework material composite membrane, which is prepared by the above-mentioned method for preparing the hydrogen-bonded organic framework material composite membrane. Specifically, the hydrogen-bonded organic framework material composite membrane is formed by a composite construction of the hydrogen-bonded organic framework material and graphene oxide.

[0059] The hydrogen-bonded organic framework material composite membrane of the present invention has excellent permeability, interception performance and anti-pollution ability, and is suitable for water purification, wastewater treatment or other membrane separation applications.

[0060] The composite membrane described above or the composite membrane prepared by the composite membrane preparation method described above in the present invention is applied to water purification, and can efficiently intercept pollutants in the water, such as dyes and micro-pollutants in the water, while maintaining high water permeability.

[0061] The hydrogen-bonded organic framework material composite membrane provided by the present invention has the advantages of high efficiency, low cost, easy large-scale production, etc., and has broad application prospects.

[0062] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0063] Example 1

[0064] A hydrogen-bonded organic framework material composite film, which is formed by combining a hydrogen-bonded organic framework material with graphene oxide, and the specific preparation method is as follows:

[0065] (1) 236 mg of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, 2 mL of N,N-dimethylacetamide and 20 mL of methanol were fully dissolved, and then the obtained mixed solution was placed at 60 °C for solvent evaporation for 24 h to obtain a porous crystalline hydrogen-bonded organic framework material (HOF).

[0066] (2) Dissolve 20 μg of HOF material in 20 mL of deionized water to obtain a 1 mg / mL HOF aqueous solution. At the same time, dissolve 20 μg of graphene oxide material in 20 mL of deionized water to obtain a 1 mg / mL GO aqueous solution.

[0067] 100 μL of GO aqueous solution and 400 μL of HOF aqueous solution were added into 20 mL of deionized water and ultrasonically treated for 10 min at an ultrasonic frequency of 35 kHz to obtain a uniformly mixed GO / HOF composite solution.

[0068] (3) The GO / HOF composite solution obtained in step (2) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed composite membrane was stored and dried at room temperature and recorded as GO / HOF-400 composite membrane.

[0069] Example 2

[0070] A hydrogen-bonded organic framework material composite film, which is formed by combining a hydrogen-bonded organic framework material with graphene oxide, and the specific preparation method is as follows:

[0071] (1) 236 mg of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, 2 mL of N,N-dimethylacetamide and 20 mL of methanol were fully dissolved, and then the obtained mixed solution was placed at 60 °C for solvent evaporation for 24 h to obtain a porous crystalline hydrogen-bonded organic framework material (HOF).

[0072] (2) Dissolve 20 μg of HOF material in 20 mL of deionized water to obtain a 1 mg / mL HOF aqueous solution. At the same time, dissolve 20 μg of graphene oxide material in 20 mL of deionized water to obtain a 1 mg / mL GO aqueous solution.

[0073] 100 μL of GO aqueous solution and 200 μL of HOF aqueous solution were added into 20 mL of deionized water and ultrasonically treated for 10 min at an ultrasonic frequency of 35 kHz to obtain a uniformly mixed GO / HOF composite solution.

[0074] (3) The GO / HOF composite solution obtained in step (2) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed composite membrane was stored and dried at room temperature and recorded as GO / HOF-200 composite membrane.

[0075] Example 3

[0076] A hydrogen-bonded organic framework material composite film, which is formed by combining a hydrogen-bonded organic framework material with graphene oxide, and the specific preparation method is as follows:

[0077] (1) 236 mg of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, 2 mL of N,N-dimethylacetamide and 20 mL of methanol were fully dissolved, and then the obtained mixed solution was placed at 60 °C for solvent evaporation for 24 h to obtain a porous crystalline hydrogen-bonded organic framework material (HOF).

[0078] (2) Dissolve 20 μg of HOF material in 20 mL of deionized water to obtain a 1 mg / mL HOF aqueous solution. At the same time, dissolve 20 μg of graphene oxide material in 20 mL of deionized water to obtain a 1 mg / mL GO aqueous solution.

[0079] 100 μL of GO aqueous solution and 800 μL of HOF aqueous solution were added into 20 mL of deionized water and ultrasonically treated for 10 min at an ultrasonic frequency of 35 kHz to obtain a uniformly mixed GO / HOF composite solution.

[0080] (3) The GO / HOF composite solution obtained in step (2) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed composite membrane was stored and dried at room temperature and recorded as GO / HOF-800 composite membrane.

[0081] Example 4

[0082] A hydrogen-bonded organic framework material composite film, which is formed by combining a hydrogen-bonded organic framework material with graphene oxide, and the specific preparation method is as follows:

[0083] (1) 236 mg of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, 2 mL of N,N-dimethylacetamide and 20 mL of methanol were fully dissolved, and then the obtained mixed solution was placed at 60 °C for solvent evaporation for 24 h to obtain a porous crystalline hydrogen-bonded organic framework material (HOF).

[0084] (2) Dissolve 20 μg of HOF material in 20 mL of deionized water to obtain a 1 mg / mL HOF aqueous solution. At the same time, dissolve 20 μg of graphene oxide material in 20 mL of deionized water to obtain a 1 mg / mL GO aqueous solution.

[0085] 100 μL of GO aqueous solution and 50 μL of HOF aqueous solution were added into 20 mL of deionized water and ultrasonically treated for 10 min at an ultrasonic frequency of 35 kHz to obtain a uniformly mixed GO / HOF composite solution.

[0086] (3) The GO / HOF composite solution obtained in step (2) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed composite membrane was stored and dried at room temperature and recorded as GO / HOF-50 composite membrane.

[0087] Comparative Example 1

[0088] A graphene oxide film, the preparation method of which is as follows:

[0089] (1) 100 μg of graphene oxide was fully dissolved in 20 mL of deionized water and treated with ultrasound for 10 min at a frequency of 35 kHz to obtain a uniform graphene oxide solution.

[0090] (2) The graphene oxide solution obtained in step (1) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed membrane was stored and dried at room temperature and recorded as a GO membrane.

[0091] Comparative Example 2

[0092] A hydrogen bond organic framework material film, the preparation method of which is as follows:

[0093] (1) 236 mg of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, 2 mL of N,N-dimethylacetamide and 20 mL of methanol were fully dissolved, and then the obtained mixed solution was placed at 60 °C for solvent evaporation for 24 h to obtain a porous crystalline hydrogen-bonded organic framework material (HOF).

[0094] (2) Dissolve 400 μg of HOF material in 20 mL of deionized water and treat it with ultrasound for 10 min at a frequency of 35 kHz to ensure uniform dissolution and obtain a HOF solution.

[0095] (3) The HOF solution obtained in step (2) was vacuum filtered onto the surface of an organic nylon membrane with a diameter of 47 mm and a pore size of 0.22 μm. The vacuum degree was 1.0 bar. After the filtration was completed, the formed membrane was stored and dried at room temperature and recorded as a HOF membrane.

[0096] It is worth mentioning that the room temperature in room temperature drying refers to a temperature in the range of 20°C to 30°C, and the room temperature drying temperature in the embodiments and comparative examples of the present invention is set to 25°C.

[0097] Performance Testing

[0098] Membrane surface wettability determination: The surface hydrophilicity and hydrophobicity of the GO / HOF composite membrane were determined using a contact angle meter. During the measurement, the sample was first fixed on a glass slide with double-sided tape, and then placed directly below the micro-syringe. The droplet volume was set to 5.0 μL. After the droplet on the sample surface stabilized, the instrument's built-in camera was used to take photos and record them. The contact angle values ​​were calculated using the TrueDrop method, and each sample was measured three times and the average value was taken.

[0099] Method for characterizing membrane surface morphology: The surface morphology of the membrane was characterized by scanning electron microscopy (SEM, LEO1530vp, 5kV). Small pieces of GO / HOF composite membrane were cut out without violently squeezing the membrane surface and glued to the conductive adhesive. After gold was sprayed by ion sputtering for 45 s, the membrane was observed under a scanning electron microscope with a measuring voltage of 3.0 kV.

[0100] Membrane flux determination method: The flux of the prepared membrane was tested using a standard dead-end filtration device equipped with a nitrogen bottle, a digital balance and a computer. The mass of the filtrate at different times was recorded by an electronic balance connected to the computer. The flux was calculated using the following formula (1):

[0101] (Formula 1)

[0102] Where A is the effective membrane area (m 2 ), V is the permeate volume (L), t is the permeate time (h), and P is the transmembrane pressure (bar).

[0103] Membrane retention rate determination method: The retention performance of the membrane was measured by filtering a 5 ppm micropollutant solution. Using the above flux measurement device, the micropollutant concentration before and after filtration was measured by a UV-visible spectrophotometer. The retention rate was calculated by the following formula:

[0104] Formula (2)

[0105] Where R is the interception rate, C0 and C1 are the concentrations of micropollutants before and after filtration, respectively.

[0106] The GO / HOF composite membrane obtained in the example of the present invention was characterized by wettability, membrane surface morphology, etc.

[0107] The GO membrane obtained in Comparative Example 1 was structurally characterized and applied to the removal of dye molecules and micropollutants.

[0108] The HOF film obtained in Comparative Example 2 was characterized by scanning electron microscopy. Figure 5 shown.

[0109] The GO / HOF composite membrane obtained in the embodiment of the present invention is applied to the interception of common micropollutants such as Coomassie Brilliant Blue (BBG), Congo Red (CR), Crystal Violet (CV), Rhodamine B (RhB), Orange-Yellow G (OY-G) and Bisphenol A (BPA).

[0110] Combination Figures 1 to 4 Analysis, such as Figure 1 As shown in Figure 2, the flux of GO / HOF-400 composite membrane for dye BBG is 22.27 L·m -2 ·h -1 bar -1 , the interception rate is 100%. Figure 2 As shown in Figure 2, the amount of HOF on the surface of the GO / HOF-400 composite membrane is large and evenly distributed, and is adhered by a small amount of GO. Figure 3 As shown in Figure 2, the water contact angle of the GO / HOF-400 composite film is 58°, which shows good hydrophilicity. Figure 4 As shown in the figure, the GO / HOF-400 composite membrane has a good retention effect on common dye pollutants and micropollutants such as Coomassie Brilliant Blue, Congo Red, Crystal Violet, Rhodamine B, Orange G, and Bisphenol A.

[0111] like Figure 2 As shown in Figure 2, compared with the GO / HOF-400 composite membrane in Example 1, the HOF loading of the GO / HOF-200 composite membrane in Example 2 is less, and the surface is more hydrophilic than that of the GO / HOF-400 membrane. It was applied to the removal of the dye molecule BBG, showing a flux of 13.12 L·m -2 ·h -1 bar -1 , the rejection rate is close to 100%. Compared with Example 1, the amount of HOF in the GO / HOF-200 composite membrane is less, and the HOF intercalation between GO layers is less, so the flux is smaller. Compared with the GO membrane in Comparative Example 1, the rejection rate of the GO / HOF-200 composite membrane in Example 2 is slightly higher.

[0112] like Figure 2 As shown in Figure 2, compared with the GO / HOF-400 composite membrane in Example 1, the GO / HOF-800 composite membrane in Example 3 has a higher HOF loading and a more hydrophobic surface. It was applied to the removal of the dye molecule BBG, showing a flux of 18.35 L·m -2 ·h -1 bar -1 , the interception rate is close to 100%. Compared with Example 1, the excessive HOF in the GO / HOF-800 composite membrane will block the water transmission channel between the GO layers, resulting in a decrease in flux.

[0113] Compared with the GO / HOF-400 composite membrane in Example 1, the surface of the pure GO membrane in Comparative Example 1 is smooth and dense, which is not conducive to the transmission of water, and thus the flux is small.

[0114] Compared with the GO / HOF-400 composite membrane in Example 1, the HOF nanorods on the surface of the pure HOF membrane in Comparative Example 2 are dispersed on the surface of the base membrane, with large inter-crystal gaps, and cannot form a dense membrane structure.

[0115] like Figure 2 As shown, compared with the GO membrane in Comparative Example 1, the GO / HOF-50 composite membrane in Example 4 has only a very small amount of HOF loading, and the change in the membrane surface morphology is not obvious. Figure 3 The figure shows that the water contact angle on the surface of the GO / HOF-50 composite membrane is slightly increased due to the presence of hydrophobic HOF. At the same time, in the dye molecule BBG interception performance test, the flux is 7.73 L·m -2 ·h -1 bar -1 , the rejection rate remained at 100%, indicating that the enhancement of membrane hydrophobicity resulted in a very small membrane flux, but retained the excellent rejection performance of the original GO membrane.

[0116] The hydrogen-bonded organic framework material composite membrane provided in the present invention combines the high specific surface area of ​​the hydrogen-bonded organic framework material with the excellent mechanical properties and chemical stability of the graphene oxide material, and shows good application prospects in the field of water treatment. The hydrogen-bonded organic framework material composite membrane can be used for the interception and removal of organic micropollutants in wastewater.

[0117] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a hydrogen-bonded organic framework material composite film, characterized in that: The preparation method comprises: dissolving the hydrogen-bonded organic framework material in a first solvent to obtain a hydrogen-bonded organic framework material solution; dissolving graphene oxide in a second solvent to obtain a graphene oxide solution; The hydrogen-bonded organic framework material solution and the graphene oxide solution are mixed and fixed to volume, and then ultrasonically treated to obtain a uniformly mixed GO / HOF composite solution; in the GO / HOF composite solution, the mass ratio of the graphene oxide to the hydrogen-bonded organic framework material is 1:2-8; The GO / HOF composite solution is filtered onto the surface of the substrate membrane by vacuum filtration, and a composite membrane with uniform structure is formed by utilizing hydrogen bonding and π-π conjugation between the hydrogen-bonded organic framework and graphene oxide.

2. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 1, characterized in that: The hydrogen-bond organic framework material is prepared by dissolving 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin monomer in a mixed solvent of N,N-dimethylacetamide and methanol and performing solvent evaporation reaction.

3. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 2, characterized in that: The reaction temperature of the solvent evaporation reaction is 50°C to 70°C, and the reaction time is 20 h to 30 h.

4. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 1, characterized in that: The total volume of the GO / HOF composite solution is 10 mL to 40 mL.

5. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic treatment is 30 kHz to 40 kHz, the ultrasonic time is 10 min to 20 min, and the ultrasonic treatment volume is 10 mL to 40 mL.

6. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 1, characterized in that: The first solvent and the second solvent are each independently selected from one of methanol, ethanol and deionized water.

7. The method for preparing a hydrogen-bonded organic framework material composite film according to claim 1, characterized in that: The base film is selected from one of cellulose acetate film, nylon film and polytetrafluoroethylene film.

8. A hydrogen-bonded organic framework material composite film, characterized in that: The hydrogen-bonded organic framework material composite film is prepared by the method for preparing a hydrogen-bonded organic framework material composite film according to any one of claims 1 to 7, and the hydrogen-bonded organic framework material composite film is formed by a composite structure of a hydrogen-bonded organic framework material and graphene oxide.

9. Use of the hydrogen-bonded organic framework material composite membrane according to claim 8 or the hydrogen-bonded organic framework material composite membrane prepared by the method for preparing the hydrogen-bonded organic framework material composite membrane according to any one of claims 1 to 7 in water purification.

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