ZrMOF nanosheet composite membrane as well as preparation method and application thereof
By preparing ZrMOF nanosheet composite membranes, the problems of uniformity and stability of mixed matrix membranes were solved, achieving efficient retention of organic dyes, which is suitable for wastewater treatment.
Patent Information
- Application Number
- CN202511386865.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-26
- Publication Date
- 2025-11-28
AI Technical Summary
Existing mixed matrix membranes suffer from poor uniformity, low dye rejection rate, and poor stability, especially when treating organic dye wastewater, making it difficult to achieve both high permeability and high rejection rate.
ZrMOF nanosheets were blended with a polymer substrate and a ZrMOF nanosheet composite film was prepared by spin coating to ensure that the nanosheets were uniformly distributed on the substrate surface and formed a stable film.
It achieves high dye rejection rate, improves membrane stability and uniformity, provides a solid foundation for organic dye separation and wastewater treatment, and has a simple preparation method, low cost and easy industrialization.
Smart Images
Figure CN121016512A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of sewage treatment, and particularly relates to a ZrMOF nanosheet composite membrane and a preparation method and application thereof. BACKGROUND
[0002] With the rapid development of the textile, printing and dyeing, papermaking and pharmaceutical industries, a large amount of wastewater containing organic dyes is discharged into natural water bodies. Water pollution caused by them can induce problems such as carcinogenesis, teratogenesis and chromosome breakage, seriously threatening human health. Membrane separation technology is considered to be a promising sewage treatment method because of its simple operation, low energy consumption and no secondary pollution. However, traditional polymer membranes have the problem of being difficult to simultaneously achieve high permeation rate and high dye rejection rate, which is not conducive to their practical application in industry.
[0003] Metal-organic frameworks (MOFs) are a class of emerging porous materials formed by coordination of inorganic metal centers (ions or clusters) and organic ligands through a molecular self-assembly process. MOF materials have the advantages of high specific surface area, adjustable pore size and easy functional modification, and are considered to be ideal materials for preparing high-efficiency sewage treatment membranes. Blending MOF materials with polymer materials to prepare hybrid matrix membranes is a common strategy to improve the separation performance of traditional polymer membranes. However, the existing hybrid matrix membranes have the following problems: (1) MOF fillers are prone to aggregation, affecting the uniformity of the membrane; (2) MOF fillers have poor dispersibility in the polymer matrix, which can easily cause non-selective interfacial voids, affecting the dye rejection rate and stability of the membrane.
[0004] MOF composite membranes are usually prepared by depositing MOF materials on the surface of a porous substrate using techniques such as blade coating or suction filtration. Compared with hybrid matrix membranes, MOF composite membranes can effectively avoid the problem of poor dispersibility of MOF materials in the polymer matrix. ZrMOF nanosheets (such as Zr-TATB, Zr-BTB and Zr-BTB-NH2) have the advantages of being ultra-thin, water-stable and chemically stable. These characteristics make ZrMOF nanosheets ideal materials for preparing high-performance sewage treatment membranes, which are expected to simultaneously achieve high permeation rate, high dye rejection rate and excellent stability. Therefore, it is extremely important to design a ZrMOF nanosheet composite membrane for organic dye separation to meet the further application requirements in the future. SUMMARY
[0005] The application provides a ZrMOF nanosheet composite membrane and a preparation method thereof to solve the problems of poor uniformity, low dye rejection rate and poor stability in the existing hybrid matrix membranes.
[0006] To solve the above technical problems, the application discloses a preparation method of a ZrMOF nanosheet composite membrane, which comprises the following steps:
[0007] S1. adding zirconium chloride and organic ligand into a mixed solvent, ultrasonic dissolving the solid to obtain a reactant solution; warming the reactant solution for reaction, centrifuging and washing after the reaction to obtain ZrMOF nanosheets;
[0008] S2. adding the ZrMOF nanosheets prepared in S1 into ethanol to obtain a ZrMOF nanosheet suspension; spin coating the ZrMOF nanosheet suspension on a PES substrate, and drying to obtain the ZrMOF nanosheet composite film.
[0009] Preferably, the molar ratio of the zirconium chloride to the organic ligand is 0.129:0.068; and the molar concentration of the zirconium chloride in the mixed solvent is 6.79 mM.
[0010] Specifically, the organic ligand includes any one of H3TATB, H3BTB and H3BTB-NH2.
[0011] Preferably, the organic ligand is H3TATB.
[0012] Preferably, the mixed solvent is a mixture of N,N-dimethylformamide, formic acid and deionized water; and the volume ratio of the N,N-dimethylformamide, the formic acid and the deionized water is 15:2:2.
[0013] In S1, the ultrasonic conditions are 37 kHz and 10 mins.
[0014] In S1, the warming reaction conditions are a reaction temperature of 120 ℃ and a reaction time of 24 h.
[0015] In S1, the centrifugal washing includes the following specific steps: sequentially centrifuging and washing the ZrMOF nanosheet suspension with N,N-dimethylformamide and ethanol at least 3 times each, and the centrifugal washing conditions are controlled to be 4500 rpm and 30 mins each time.
[0016] In S2, the concentration of the ZrMOF nanosheet suspension is 2.5 mg / mL.
[0017] In S2, the size of the PES substrate is a diameter of 47 mm and a pore size of 200 nm.
[0018] In S2, the spin coating includes the following specific steps: spin coating 1 mL of the ZrMOF nanosheet suspension onto the PES substrate twice, 500 µL each time, and the spin coating parameters are 2500 rpm and 640 s.
[0019] Further, the ZrMOF nanosheet composite film prepared by the above preparation method is also within the protection scope of the present application.
[0020] Specifically, in some embodiments of the present application, Zr-TATB / PES, Zr-BTB / PES and Zr-BTB-NH2 / PES composite films are successfully prepared by the above preparation method. AFM and SEM are used to characterize the three kinds of ZrMOF nanosheets, and it is found that the thickness of the three kinds of ZrMOF nanosheets is similar to the van der Waals size of Zr6 cluster, which indicates that single-layer nanosheets are successfully prepared. At the same time, the three kinds of ZrMOF nanosheets have good adhesion with the PES substrate and can form a uniform film on the surface of the PES substrate.
[0021] Further, the application of the ZrMOF nanosheet composite film prepared by the above preparation method in separating organic dyes in sewage is also within the protection scope of the present application.
[0022] Preferably, the organic dye is acid brilliant blue G dye.
[0023] Specifically, in some embodiments of the present application, the Zr-TATB / PES, Zr-BTB / PES and Zr-BTB-NH2 / PES composite films are tested for acid brilliant blue G dye removal performance in a nanofiltration device, and it is found that the rejection rate of ZrMOF nanosheet composite film to acid brilliant blue G can reach 94%, which is much higher than that of pure PES membrane. Therefore, it is proved that the ZrMOF nanosheet composite film provided by the present application has a good application prospect in separating organic dyes in sewage.
[0024] Beneficial effects:
[0025] The present application provides a preparation method of ZrMOF nanosheet composite film for organic dye separation. Compared with the mixed matrix membrane prepared by using the prior art, the ZrMOF nanosheet composite film prepared by the method has good uniformity, which effectively avoids the problem of poor dispersibility of MOF filler in the polymer matrix. At the same time, the ZrMOF nanosheet composite film prepared by the method has high dye rejection rate, which lays a solid foundation for future application in the fields of organic dye separation and sewage treatment. In addition, the preparation method is simple, low in cost and easy to industrialize. BRIEF DESCRIPTION OF DRAWINGS
[0026] The above and / or other aspects of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:
[0027] Figure 1 The AFM images of Zr-TATB nanosheets, Zr-BTB nanosheets and Zr-BTB-NH2 nanosheets prepared in the embodiments of the present application are as follows, wherein, Figure 1 a in the above formula is the AFM picture of Zr-TATB nanosheets obtained in Example 1, Figure 1b is the AFM picture of Zr-BTB nanosheet obtained in Example 2, Figure 1 c is the AFM picture of Zr-BTB-NH2 nanosheet obtained in Example 3.
[0028] Figure 2 are SEM pictures of pure PES membrane, Zr-TATB / PES composite membrane, Zr-BTB / PES composite membrane and Zr-BTB-NH2 / PES composite membrane in the embodiments of the present application, wherein, Figure 2 a is the SEM picture of pure PES membrane, Figure 2 b is the SEM picture of Zr-TATB / PES composite membrane, Figure 2 c is the SEM picture of Zr-BTB / PES composite membrane, Figure 2 d is the SEM picture of Zr-BTB-NH2 / PES composite membrane.
[0029] Figure 3 are comparative diagrams of the retention rates of pure PES membrane, Zr-TATB / PES composite membrane, Zr-BTB / PES composite membrane and Zr-BTB-NH2 / PES composite membrane for acid brilliant blue G dye in the embodiments of the present application. DETAILED DESCRIPTION
[0030] The experimental methods in the following examples are all conventional methods unless otherwise specified; and the reagents and materials can be obtained from commercial channels unless otherwise specified.
[0031] The present technical achievement is supported by 'Jiangsu Funding Program for Excellent Postdoctoral Talent', and the funding number is 2025ZB884.
[0032] Example 1:
[0033] The present embodiment provides a ZrMOF nanosheet composite membrane, and the specific preparation steps are as follows:
[0034] S1. Zirconium chloride (0.129 mmol), H3TATB (0.068 mmol), N,N- dimethylformamide (15 mL), formic acid (2 mL) and deionized water (2 mL) were added into a glass bottle, and the solids were dissolved by ultrasonic treatment under the following conditions: 37 kHz, 10 mins. The glass bottle was placed in a reaction oven at 120 °C for 24 h, and the obtained product (Zr-TATB nanosheets) was centrifugally washed with N,N-dimethylformamide and ethanol three times, respectively. The washed Zr-TATB nanosheets were preserved in a uniform suspension with a concentration of 2.5 mg / mL using ethanol, and each washing condition was 4500 rpm, 30 mins.
[0035] S2. 1 mL of the Zr-TATB nanosheet suspension was spin-coated on a PES substrate in two times, 500 µL of the suspension was spin-coated each time, and the spin-coating conditions were controlled at 2500 rpm, 640 s, the diameter of the PES substrate was 47 mm, and the pore size was 200 nm; after drying at room temperature, a Zr-TATB / PES composite film was obtained.
[0036] Example 2:
[0037] This example provides a ZrMOF nanosheet composite film, and the specific preparation steps are as follows:
[0038] S1. Zirconium chloride (0.129 mmol), H3TATB (0.068 mmol), N,N- dimethylformamide (15 mL), formic acid (2 mL) and deionized water (2 mL) were added into a glass bottle, and the solids were dissolved by ultrasonic treatment under the following conditions: 37 kHz, 10 mins. The glass bottle was placed in a reaction oven at 120 °C for 24 h, and the obtained product (Zr-TATB nanosheets) was centrifugally washed with N,N-dimethylformamide and ethanol three times, respectively. The washed Zr-TATB nanosheets were preserved in a uniform suspension with a concentration of 2.5 mg / mL using ethanol, and each washing condition was 4500 rpm, 30 mins.
[0039] S2. 1 mL of the Zr-TATB nanosheet suspension was spin-coated on a PES substrate in two times, 500 µL of the suspension was spin-coated each time, and the spin-coating conditions were controlled at 2500 rpm, 640 s, the diameter of the PES substrate was 47 mm, and the pore size was 200 nm; after drying at room temperature, a Zr-TATB / PES composite film was obtained.
[0040] Example 3:
[0041] This example provides a ZrMOF nanosheet composite film, and the specific preparation steps are as follows:
[0042] S1. Zirconium chloride (0.129 mmol), H3BTB-NH2 (0.068 mmol), N,N-dimethylformamide (15 mL), formic acid (2 mL), and deionized water (2 mL) were added to a glass bottle, and the solid was dissolved by sonication. The glass bottle was placed in a reaction oven at 120 °C for 24 h, and the obtained product (Zr-BTB-NH2 nanosheets) was centrifuged and washed three times with N,N-dimethylformamide and ethanol, respectively. The washed Zr-BTB-NH2 nanosheets were then prepared into a homogeneous suspension with ethanol at a concentration of 2.5 mg / mL for storage.
[0043] S2. Spin-coat 1 mL of Zr-BTB-NH2 nanosheet suspension onto a PES substrate in two separate spin-coats, each time with 500 µL of suspension; after drying at room temperature, a Zr-BTB-NH2 / PES composite membrane can be obtained.
[0044] The materials prepared in Examples 1-3 were characterized respectively:
[0045] 1. Zr-TATB nanosheets, Zr-BTB nanosheets, and Zr-BTB-NH2 nanosheets were characterized by atomic force microscopy (AFM). Figure 1 AFM images of Zr-TATB nanosheets, Zr-BTB nanosheets, and Zr-BTB-NH2 nanosheets, where... Figure 1 In the image, 'a' represents the AFM image of the Zr-TATB nanosheets obtained in Example 1. Figure 1 In the image, b is an AFM image of the Zr-BTB nanosheets obtained in Example 2. Figure 1 In the image, 'c' represents the AFM image of the Zr-BTB-NH2 nanosheets obtained in Example 3. Figure 1 As shown in Figure a, the thickness of the Zr-TATB nanosheets prepared in Example 1 is 1 nm; Figure 1 As shown in Figure b, the thickness of Zr-BTB is 1.5 nm; Figure 1 As shown in Figure c, the thickness of Zr-BTB-NH2 is 1.5 nm; the thickness of the three ZrMOF nanosheets is similar to the van der Waals size of the Zr6 cluster (1.2 nm), indicating that a single-layer nanosheet was successfully prepared.
[0046] 2. The pure PES membrane and the Zr-TATB / PES composite membrane, Zr-BTB / PES composite membrane and Zr-BTB-NH2 / PES composite membrane prepared in Examples 1-3 were characterized by scanning electron microscopy (SEM). Figure 2 SEM images of pure PES membrane, Zr-TATB / PES composite membrane, Zr-BTB / PES composite membrane, and Zr-BTB-NH2 / PES composite membrane are shown. Figure 2In the image, 'a' represents a SEM image of a pure PES membrane. Figure 2 In the image, b represents the SEM image of the Zr-TATB / PES composite membrane. Figure 2 In the image, 'c' represents the SEM image of the Zr-BTB / PES composite membrane. Figure 2 In the image, 'd' represents the SEM image of the Zr-BTB-NH2 / PES composite membrane. (Example:) Figure 2 As shown in a, the pure PES substrate itself exhibits porous characteristics, such as... Figure 2 As shown in b, c, and d, the three spin-coated ZrMOF nanosheets (i.e., Zr-TATB, Zr-BTB, and Zr-BTB-NH2) exhibit good adhesion to the PES substrate and can form a uniform thin film on the PES substrate surface.
[0047] 3. The pure PES membrane and the Zr-TATB / PES composite membrane, Zr-BTB / PES composite membrane and Zr-BTB-NH2 / PES composite membrane prepared in Examples 1 to 3 were tested for dye removal performance in a nanofiltration device. The feed solution was an aqueous solution of 10 mg / L Acid Brilliant Blue G (Mw = 831 g / mol), and the test pressure was 1 bar. Figure 3 This is a comparison of the retention rates of Acid Brilliant Blue G dye for pure PES membranes, Zr-TATB / PES composite membranes, Zr-BTB / PES composite membranes, and Zr-BTB-NH2 / PES composite membranes. Figure 3 It can be seen that the Zr-TATB / PES composite membrane prepared in Example 1 has a rejection rate of 94% for Acid Brilliant Blue G dye, which is higher than the rejection rate of 88% for Zr-BTB / PES composite membrane and 90% for Zr-BTB-NH2 / PES composite membrane, and significantly higher than the rejection rate of 24% for pure PES membrane.
[0048] This invention provides a ZrMOF nanosheet composite film, its preparation method, and its application. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.
Claims
1. A method for preparing a ZrMOF nanosheet composite film, characterized in that, Includes the following steps: S1. Add zirconium chloride and organic ligands to a mixed solvent, and dissolve the solid by sonication to obtain a reactant solution; heat the reactant solution to react, and after the reaction is complete, centrifuge and wash to obtain ZrMOF nanosheets; S2. Add the ZrMOF nanosheets prepared in S1 to ethanol to prepare a ZrMOF nanosheet suspension; spin-coat the ZrMOF nanosheet suspension onto a PES substrate and dry it to obtain the ZrMOF nanosheet composite film.
2. The preparation method according to claim 1, characterized in that, The molar ratio of zirconium chloride to organic ligand is 0.129:0.068; the molar concentration of zirconium chloride in the mixed solvent is 6.79 mM.
3. The preparation method according to claim 2, characterized in that, The organic ligand includes any one of H3TATB, H3BTB, and H3BTB-NH2.
4. The preparation method according to claim 2, characterized in that, The mixed solvent is a mixture of N,N-dimethylformamide, formic acid and deionized water; the volume ratio of N,N-dimethylformamide, formic acid and deionized water is 15:2:
2.
5. The preparation method according to claim 1, characterized in that, In S1, the heating reaction is carried out under the following conditions: reaction temperature 120 °C and reaction time 24 h.
6. The preparation method according to claim 1, characterized in that, In S2, the concentration of the ZrMOF nanosheet suspension was 2.5 mg / mL.
7. The preparation method according to claim 1, characterized in that, In S2, the dimensions of the PES substrate are: a diameter of 47 mm and a pore size of 200 nm.
8. The preparation method according to claim 1, characterized in that, In S2, the spin coating process specifically involves spin coating 1 mL of ZrMOF nanosheet suspension onto the PES substrate in two separate applications, with each spin coating being 500 µL and the spin coating parameters being 2500 rpm and 640 s.
9. The ZrMOF nanosheet composite film prepared by the preparation method according to any one of claims 1 to 8.
10. The application of the ZrMOF nanosheet composite membrane according to claim 9 in the separation of organic dyes in wastewater.