Fluorine-containing covalent organic framework pervaporation membrane as well as preparation method and application thereof
By preparing a fluorinated covalent organic framework pervaporation membrane, the problems of high water transport resistance and insufficient salt tolerance of pervaporation membranes under high salt conditions were solved, achieving high efficiency of pervaporation desalination performance and improving the water flux and salt rejection rate of the membrane.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-04-14
AI Technical Summary
Existing pervaporation membranes suffer from high water transport resistance, insufficient salt tolerance, and difficulty in controlling the interfacial chemistry of nanochannels under high salinity conditions, which limits their application in high-salt desalination processes.
Fluorine-containing covalent organic framework materials were used to synthesize fluorine-containing COF nanosheets by reacting fluorine-aldehyde monomers with amino monomers. These nanosheets were then assembled into a membrane to form a pervaporation membrane with fluorine-containing nanochannels. The COF nanosheets were then filtered onto a base membrane using vacuum-assisted self-assembly technology to prepare the fluorine-containing covalent organic framework pervaporation membrane.
The water flux, salt rejection capacity, and chlorine resistance of the pervaporation membrane were improved, achieving high permeability, high salt rejection rate, and high stability of pervaporation desalination performance.
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Figure CN121846933A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of membrane separation technology, and in particular to a method for preparing a fluorinated covalent organic framework pervaporation membrane. Background Technology
[0002] With the expansion of the population and the acceleration of industrialization, the contradiction between freshwater supply and demand is becoming increasingly prominent, especially in coastal areas and high-salinity industrial water use scenarios. A stable supply of usable freshwater has become a key issue restricting sustainable development. Although the total amount of water resources on Earth is abundant, the vast majority exists in the form of seawater or high-salinity water, and the proportion of directly usable freshwater is limited. Therefore, efficient desalination of seawater and high-salinity industrial brine is an important technological approach to expanding water resource supply. Currently, although reverse osmosis, a membrane separation technology, is widely used in conventional seawater desalination, it must withstand significantly increased osmotic pressure under high-salinity conditions. This leads to a significant increase in system energy consumption, membrane material load, and operational complexity, thus limiting its application in high-salinity systems.
[0003] Against this backdrop, novel membrane separation pathways that do not rely on high operating pressures are gaining increasing attention. Pervaporation technology, driven by the chemical potential difference across the membrane, boasts advantages such as ultra-high salt rejection rates, wide salt range processing capabilities, and broad applicability, demonstrating promising application prospects. However, the pervaporation process places higher demands on membrane material performance. Water molecules need to be transported within nanoscale channels within the membrane material, and its flux is highly dependent on the channel structure and interfacial properties of the membrane material. Existing pervaporation membrane materials are mostly based on polymer systems, enhancing their affinity for water by introducing hydrophilic functional groups. However, in high-salt environments, these membrane materials often face problems such as limited water transport efficiency, insufficient operational stability, and limited resistance to fouling and oxidation, making them difficult to apply stably in high-salt desalination processes over the long term.
[0004] High-performance membrane materials are crucial for achieving efficient separation in pervaporation technology. Covalent organic frameworks (COFs) have attracted widespread attention in membrane separation due to their long-range ordered crystal structure, regularly controllable nanopores, and excellent chemical designability, and are considered ideal candidate materials for constructing highly selective separation membranes. Meanwhile, fluorinated materials, due to their good chemical stability and unique interfacial interaction properties, have been studied in some membrane systems. However, current research mainly focuses on polymer membranes or surface-modified layers, and a mature technical solution for incorporating fluorinated building blocks into COF structures for pervaporation desalination has not yet been developed. Therefore, developing a covalent organic framework pervaporation membrane that combines ordered nanochannel structure with fluorinated interfacial properties is of great significance for promoting the development of high-salinity desalination membrane materials. Summary of the Invention
[0005] To address the problems of high water transport resistance, insufficient salt tolerance, and lack of nanochannel interface modulation in existing pervaporation membranes for desalination, this invention provides a fluorinated covalent organic framework pervaporation membrane to fully leverage the advantages of ordered nanochannels and designable chemical properties of COF materials. Fluorinated COF nanosheets are synthesized by reacting fluoroaldehyde monomers with amino monomers, and then assembled into a membrane to prepare a functional membrane with fluorinated nanochannels. This method expands the application of COF materials in pervaporation desalination and is expected to inspire the optimization of pervaporation membrane materials through fluorinated design. The membrane consists of a covalent organic framework functional layer and a base membrane, and its preparation is simple and controllable. The prepared fluorinated COF pervaporation membrane exhibits high permeability, high salt rejection rate, and high stability when used for pervaporation desalination.
[0006] To address the aforementioned technical problems, this invention proposes a fluorinated covalent organic framework (COF) pervaporation membrane. This membrane consists of a top COF functional layer and a bottom base membrane. The COF functional layer is assembled from fluorinated COF nanosheets, which are prepared by water-oil phase transfer polymerization of fluoroaldehyde monomers and amino monomers. The fluorinated COF nanosheets are then vacuum-assisted self-assembly transferred onto the base membrane to obtain the fluorinated covalent organic framework pervaporation membrane. The fluoroaldehyde monomer is a type of fluorinated aromatic polyaldehyde monomer, containing one aromatic ring, two aldehyde groups, and 1-4 CF substituents in its molecular structure. The amino monomer is triaminoguanidine hydrochloride. In the fluorinated COF pervaporation membrane assembled from fluorinated COF nanosheets of this invention, fluorine atoms enhance the membrane's pervaporation desalination flux, salt repulsion capability, and chlorine resistance, comprehensively improving the pervaporation desalination performance.
[0007] Furthermore, the base membrane described in this invention is selected from one of hydrophilic polytetrafluoroethylene membrane, polyacrylonitrile ultrafiltration membrane, and polyethersulfone ultrafiltration membrane.
[0008] The fluoroaldehyde monomer is selected from one of 2,3,5,6-tetrafluoroterephthalaldehyde, 2,5-difluoroterephthalaldehyde, 2-fluoroterephthalaldehyde, and 2,6-difluoroterephthalaldehyde.
[0009] The preparation method of the fluorinated covalent organic framework pervaporation membrane of the present invention mainly includes synthesizing COF nanosheets by water-oil phase transfer polymerization of fluoroaldehyde monomers and amino monomers, and then filtering the above COF nanosheet dispersion onto a base membrane through a vacuum-assisted self-assembly process. The specific steps are as follows:
[0010] Step 1: Synthesis of fluorinated COF nanosheets, comprising: dissolving a certain mass of fluoroaldehyde monomer in octanoic acid to prepare a fluoroaldehyde monomer solution with a concentration of 0.0005~0.0015 mmol / mL, and ultrasonically homogenizing it for later use; dissolving a certain mass of triaminoguanidine hydrochloride in deionized water to prepare an amino monomer solution, and ultrasonically homogenizing it for later use; the concentration of amino monomer in the amino monomer solution is equal to the concentration of fluoroaldehyde monomer in the fluoroaldehyde monomer solution; adding the amino monomer solution to a container, and then, according to the volume ratio of the fluoroaldehyde monomer solution to the amino monomer solution of 3:2, slowly and evenly dripping the fluoroaldehyde monomer solution dropwise onto the surface of the amino monomer solution, and sealing the container; placing the above system in a constant temperature incubator at 18~20 ℃ for 7 days, the upper layer solution is yellow-brown; collecting the upper layer solution with a dropper into a diffusion cell containing ethanol for diffusion for 60~72 h, to obtain a fluorinated COF nanosheet dispersion;
[0011] Step 2, preparation of the fluorine-containing COF pervaporation membrane, includes: diluting the fluorine-containing COF nanosheet dispersion obtained in Step 1 with anhydrous ethanol at a volume ratio of 1~2:15, ultrasonically treating to obtain a casting solution, fixing the base membrane in a vacuum filter holder, first wetting by filtering anhydrous ethanol; then filtering the casting solution onto the base membrane by a vacuum-assisted self-assembly method, and drying to obtain the fluorine-containing COF pervaporation membrane.
[0012] Furthermore, in step one, the ultrasonic homogenization time for the fluoroaldehyde monomer solution and the ultrasonic homogenization time for the amino monomer solution are both 40 min. The filter membrane of the diffusion cell has a pore size of 0.1 μm.
[0013] In step two, the ultrasonic treatment time is 20 minutes, and the casting solution is filtered onto the base membrane. The amount of casting solution used is 6.2~6.8 mL per square centimeter of base membrane. The casting solution is filtered onto the base membrane and dried at room temperature for 18 hours.
[0014] Compared with existing technologies, the beneficial effects of this invention are: the fluorinated COF pervaporation membrane achieves low water transport resistance, high salt rejection rate, and strong stability through interfacial chemical regulation via nanochannels with fluorinated walls. Fluorination alters the performance of the COF membrane in pervaporation desalination; compared to non-fluorinated COF pervaporation membranes, the fluorinated COF pervaporation membrane exhibits significant improvements in permeate flux and salt rejection rate for pervaporation desalination.
[0015] The fluorinated covalent organic framework (COF) pervaporation membrane prepared according to this invention was used for pervaporation desalination. It exhibits high water flux, high salt rejection rate, and high stability during the pervaporation desalination process, comprehensively improving the performance of pervaporation desalination. Under conditions of 70℃ and 3.5wt% NaCl, the pervaporation desalination flux of the fluorinated COF pervaporation membrane is 263.62~395.75 kg·m³. -2 ·h -1 The salt rejection rate is 99.83–99.99%; under conditions of 70℃ and 15 wt% NaCl, the pervaporation desalination flux is 154–176 kg·m³. -2 ·h -1 The salt rejection rate is 99.90–99.96%; in a mixed solution of 3.5 wt% NaCl and 200 ppm NaClO, at 40 °C, the pervaporation desalination flux is 180–223 kg·m³. -2 ·h -1 And the duration can be as long as 153 hours. Attached Figure Description
[0016] Figure 1 This is an electron microscope image of the surface of film 1 obtained in Example 1;
[0017] Figure 2 This is an electron microscope image of the surface of film 2 obtained in Example 2;
[0018] Figure 3 This is an electron microscope image of the surface of film 3 obtained in Example 3;
[0019] Figure 4 This is an electron microscope image of the surface of film 4 obtained in Example 4;
[0020] Figure 5 This is a comparative electron microscope image of the surface of the film obtained in the example.
[0021] Figure 6 The permeation flux and salt rejection rate of the membranes in Examples 1-4 and the comparative membranes were compared when a 3.5 wt% NaCl solution was treated at 70°C.
[0022] Figure 7 This is a graph showing the salt concentration performance of membrane 1 obtained in Example 1;
[0023] Figure 8 This is a schematic diagram of the long-term operational stability of membrane 1 obtained in Example 1 in a sodium hypochlorite-containing environment. Detailed Implementation
[0024] This invention addresses the problems of existing pervaporation desalination membranes, such as high resistance to water molecule transport under high salinity conditions, insufficient salt tolerance, and difficulty in controlling the interfacial chemistry of nanochannels. It proposes a fluorinated covalent organic framework pervaporation membrane. This membrane introduces fluorinated building blocks within the covalent organic framework nanochannels. Fluorine atoms are orderly distributed along the inner wall of the nanochannels, and the resulting C–F bonds endow the nanochannels with weak polarity and strong electronegativity. This weakens the interaction between water molecules and the channel walls and alters the hydrogen bonding structure of water molecules within the channels, resulting in lower binding energy and higher migration capacity for water molecules. Simultaneously, the fluorinated structure on the channel inner wall creates an electrostatic repulsion effect during membrane separation, effectively enhancing the repulsion of salt ions and improving chlorine resistance. Overall, this significantly improves the performance of pervaporation desalination.
[0025] The present invention will be further described below through specific embodiments and comparative examples. The specific embodiments described are only for illustrative purposes and are not intended to limit the present invention. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are all conventional reagents, which can be purchased commercially or synthesized according to conventional methods in the art; the experimental methods, unless otherwise specified, are all conventional methods.
[0026] Example 1: Preparation of a fluorine-containing covalent organic framework pervaporation membrane, the steps are as follows:
[0027] Step 1, synthesis of fluorine-containing COF nanosheets, includes:
[0028] (1-1) Dissolve 3.2 mg of 2,3,5,6-tetrafluoro-terephthalaldehyde in 30 mL of octanoic acid to prepare a fluoroaldehyde monomer solution with a concentration of 0.0005 mmol / mL. Sonicate for 30 min to disperse the solution evenly.
[0029] (1-2) Dissolve 1.4 mg of triaminoguanidine hydrochloride in 20 mL of deionized water to prepare an amino monomer solution with a concentration of 0.0005 mmol / mL. Sonicate for 30 min to disperse the solution evenly.
[0030] (1-3) First, add the amino monomer solution obtained in step (1-2) to a 100 mL beaker. Then, slowly and evenly drop the fluoroaldehyde monomer solution obtained in step (1-1) onto the amino monomer solution, and seal the beaker. Place the system in a constant temperature incubator at 18°C for 7 days. The upper layer of solution is yellow-brown and is collected with a dropper.
[0031] (1-4) The collected yellow-brown solution was diffused in an ethanol diffusion cell for 72 h through a filter membrane with a pore size of 0.1 μm to obtain a dispersion of fluorinated COF nanosheets.
[0032] Step 2, Preparation of the fluorine-containing COF pervaporation membrane, including:
[0033] Take 1 mL of the fluorinated COF nanosheet dispersion prepared in step one, and dilute it in a test tube with 15 mL of anhydrous ethanol (i.e., the volume ratio of the fluorinated COF nanosheet dispersion to anhydrous ethanol is 1:15). Sonicate the solution for 20 min to obtain the casting solution. Fix a hydrophilic polytetrafluoroethylene membrane with a pore size of 0.22 μm and an area of 2.4 square centimeters in a vacuum filter holder. First, wet the base membrane by filtering 5 mL of anhydrous ethanol. Then, use a vacuum-assisted self-assembly method to filter the casting solution onto the base membrane. Dry at room temperature for 12 h to obtain a fluorinated COF pervaporation membrane. This membrane is designated as membrane 1. The surface electron micrograph of membrane 1 is shown below. Figure 1 As shown.
[0034] Membrane 1 was used for pervaporation desalination, treating a 3.5 wt% NaCl solution at 70 °C with a permeation flux of 395.75 kg·m³. -2 ·h -1 The salt interception rate is 99.99%, such as Figure 6 As shown, when the concentration of NaCl increases from 3.5 wt% to 15 wt%, the flux reaches 176 kg·m. -2 ·h -1 Salt rejection rate 99.96% (70℃), such as Figure 7 As shown. In a mixed solution of 3.5 wt% NaCl and 200 ppm NaClO, a high flux (186-223 kg·m) was maintained at 40 °C. -2 ·h -1 It has a lifespan of up to 153 hours and exhibits strong stability, such as Figure 8 As shown.
[0035] Example 2: Preparation of a fluorinated covalent organic framework pervaporation membrane. The steps were basically the same as in Example 1, except that in step (1-1) preparing the fluorinated aldehyde monomer solution, the 3.2 mg of 2,3,5,6-tetrafluoroterephthalaldehyde monomer was replaced with 5.4 mg of 2,5-difluoroterephthalaldehyde monomer, resulting in a fluorinated aldehyde monomer solution with a concentration of 0.001 mmol / mL; in step (1-2) preparing the amino monomer solution, the 1.4 mg of triaminoguanidine hydrochloride was replaced with 2.8 mg of triaminoguanidine hydrochloride, resulting in an amino monomer solution with a concentration of 0.001 mmol / mL. The fluorinated COF pervaporation membrane finally obtained in Example 2 is designated as membrane 2. The surface electron micrograph of membrane 2 is shown below. Figure 2 As shown.
[0036] Membrane 2 was used for pervaporation desalination, treating a 3.5 wt% NaCl solution at 70 °C, with a permeation flux of 338.62 kg·m³. -2 ·h -1 The salt interception rate is 99.88%, such as Figure 4 As shown.
[0037] Example 3: Preparation of a fluorinated covalent organic framework pervaporation membrane. The steps were basically the same as in Example 1, except that in step (1-1) preparing the fluorinated aldehyde monomer solution, the 3.2 mg of 2,3,5,6-tetrafluoroterephthalaldehyde monomer was replaced with 6.8 mg of 2-fluoroterephthalaldehyde monomer, resulting in a fluorinated aldehyde monomer solution with a concentration of 0.0015 mmol / mL; in step (1-2) preparing the amino monomer solution, the 1.4 mg of triaminoguanidine hydrochloride was replaced with 4.2 mg of triaminoguanidine hydrochloride, resulting in an amino monomer solution with a concentration of 0.0015 mmol / mL. The fluorinated COF pervaporation membrane finally obtained in Example 3 is designated as membrane 3. The surface electron micrograph of membrane 3 is shown in Figure 3. Figure 3 As shown.
[0038] Membrane 3 was used for pervaporation desalination, treating a 3.5 wt% NaCl solution at 70 °C, with a permeation flux of 287.17 kg·m³. -2 ·h -1 The salt interception rate is 99.83%, such as Figure 6 As shown.
[0039] Example 4: Preparation of a fluorinated covalent organic framework pervaporation membrane. The steps were basically the same as in Example 1, except that the 1 mL of fluorinated COF nanosheet dispersion used in step 2 was changed to 2 mL (i.e., the volume ratio of fluorinated COF nanosheet dispersion to anhydrous ethanol was 2:15). The final fluorinated COF pervaporation membrane obtained in Example 4 is designated as membrane 4. The surface electron micrograph of membrane 4 is shown below. Figure 4 As shown.
[0040] Membrane 4 was used for pervaporation desalination, treating a 3.5 wt% NaCl solution at 70 °C, with a permeation flux of 263.62 kg·m³. -2 ·h -1 The salt interception rate is 99.85%, such as Figure 6 As shown.
[0041] Comparative Example: A fluorine-free covalent organic framework pervaporation membrane was prepared, following a process essentially the same as in Example 1, except that the fluoroaldehyde monomer solution prepared in step (1-1) was replaced with an aldehyde monomer solution; specifically, the 3.2 mg 2,3,5,6-tetrafluoroterephthalaldehyde monomer was replaced with 2.1 mg terephthalaldehyde monomer. The resulting fluorine-free COF pervaporation membrane was designated as the control membrane, and its surface electron microscopy image is shown below. Figure 5 As shown.
[0042] A control membrane was used for pervaporation desalination, treating a 3.5 wt% NaCl solution at 70 °C with a permeation flux of 106.09 kg·m⁻¹. -2 ·h -1 The salt interception rate is 99.21%, such as Figure 6 As shown.
[0043] like Figures 1 to 5 The fluorine-containing covalent organic framework pervaporation membranes prepared in Examples 1-4 and the fluorine-free covalent organic framework pervaporation membranes prepared in the comparative examples have relatively smooth and dense membrane surfaces, while the fluorine-free covalent organic framework pervaporation membranes have relatively rough membrane surfaces with uneven protrusions.
[0044] like Figure 6 As shown in the comparison between Examples 1-4 and the comparative example, the fluorinated COF pervaporation membrane exhibits superior performance compared to the non-fluorinated COF pervaporation membrane, demonstrating significant improvements in permeate flux and salt rejection rate during pervaporation desalination. When treating a 3.5 wt% NaCl solution at 70°C, the fluorinated COF pervaporation membrane achieved a water flux of 263.62–395.75 kg·m³ during the pervaporation desalination process. -2 ·h -1 It also exhibits excellent high-salt-concentration treatment capability and chlorine-resistant stability. Therefore, the fluorinated covalent organic framework pervaporation membrane and its preparation method proposed in this invention have broad application potential in pervaporation desalination.
[0045] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many improvements and changes under the guidance of the present invention without departing from the spirit of the present invention, and these improvements and changes are all within the protection scope of the present invention.
Claims
1. A fluorinated covalent organic framework pervaporation membrane, characterized in that, The membrane consists of a top COF functional layer and a bottom base membrane. The COF functional layer is assembled from fluorinated COF nanosheets, which are prepared by water-oil phase transfer polymerization of fluoroaldehyde monomers and amino monomers. The fluorinated COF nanosheets are then filtered onto the base membrane through a vacuum-assisted self-assembly process to obtain a fluorinated covalent organic framework permeation evaporation membrane. The fluoroaldehyde monomer is one of the fluorinated aromatic polyaldehyde monomers. The molecular structure of the fluorinated aromatic polyaldehyde monomer contains an aromatic ring, two aldehyde groups and 1 to 4 CF substituents. The amino monomer is triaminoguanidine hydrochloride.
2. The fluorinated covalent organic framework pervaporation membrane according to claim 1, characterized in that, The base membrane is selected from one of hydrophilic polytetrafluoroethylene membrane, polyacrylonitrile ultrafiltration membrane, and polyethersulfone ultrafiltration membrane.
3. The fluorinated covalent organic framework pervaporation membrane according to claim 2, characterized in that, The fluoroaldehyde monomer is selected from one of 2,3,5,6-tetrafluoroterephthalaldehyde, 2,5-difluoroterephthalaldehyde, 2-fluoroterephthalaldehyde, and 2,6-difluoroterephthalaldehyde.
4. A method for preparing a fluorinated covalent organic framework pervaporation membrane as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1, synthesis of fluorine-containing COF nanosheets, includes: A certain mass of fluoroaldehyde monomer was dissolved in octanoic acid to prepare a fluoroaldehyde monomer solution with a concentration of 0.0005~0.0015 mmol / mL. The solution was then sonicated and used for later use. A certain mass of triaminoguanidine hydrochloride was dissolved in deionized water to prepare an amino monomer solution, which was then sonicated and used for later use. The concentration of amino monomer in the amino monomer solution is equal to the concentration of fluoroaldehyde monomer in the fluoroaldehyde monomer solution; Add the amino monomer solution to a container, and then slowly and evenly drip the fluoroaldehyde monomer solution onto the surface of the amino monomer solution drop by drop according to the volume ratio of the fluoroaldehyde monomer solution to the amino monomer solution of 3:2, and seal the container. The above system was placed in a constant temperature chamber at 18~20 ℃ and allowed to stand for 7 days. The upper layer solution turned yellow-brown. The upper layer solution was collected with a dropper and diffused into a diffusion cell containing ethanol for 60~72 h to obtain a fluorine-containing COF nanosheet dispersion. Step 2, Preparation of the fluorine-containing COF pervaporation membrane, including: The fluorinated COF nanosheet dispersion obtained in step one was diluted with anhydrous ethanol at a volume ratio of 1~2:15, and ultrasonic treatment was performed to obtain a casting solution. The base membrane was fixed in a vacuum filter holder, and the casting solution was first wetted by filtering anhydrous ethanol. Then, the casting solution was filtered onto the base membrane by a vacuum-assisted self-assembly method. After drying, a fluorinated COF pervaporation membrane was obtained.
5. The preparation method according to claim 4, characterized in that, In step one, the ultrasonic homogenization time for the fluoroaldehyde monomer solution and the ultrasonic homogenization time for the amino monomer solution are both 40 min.
6. The preparation method according to claim 2, characterized in that, In step one, the filter membrane of the diffusion cell is a filter membrane with a pore size of 0.1 μm.
7. The preparation method according to claim 2, characterized in that, In step two, the ultrasonic treatment time is 20 minutes, and the casting solution is filtered onto the base membrane. The amount of casting solution used is calculated as 6.2~6.8 mL per square centimeter of base membrane.
8. The preparation method according to claim 2, characterized in that, In step two, the casting solution is filtered onto the base membrane and dried at room temperature for 18 hours.
9. An application of a fluorinated covalent organic framework pervaporation membrane, characterized in that, The fluorinated covalent organic framework pervaporation membrane obtained by any of the preparation methods described in claims 2 to 8 is used for pervaporation desalination.
10. The application of the fluorinated covalent organic framework pervaporation membrane according to claim 1, characterized in that, Using fluorinated covalent organic framework perevaporation membranes for perevaporation desalination results in high water flux, high salt rejection rate, and high stability during the process, comprehensively improving perevaporation desalination performance, including: Under conditions of 70℃ and 3.5wt% NaCl, the pervaporation desalination flux was 263.62~395.75 kg·m⁻². -2 ·h -1 The salt interception rate is 99.83%~99.99%; Under conditions of 70℃ and 15 wt% NaCl, the pervaporation desalination flux is 154 ~ 176 kg·m. -2 ·h -1 The salt interception rate is 99.90~99.96%; In a mixed solution of 3.5 wt% NaCl and 200 ppm NaClO, at 40 °C, the pervaporation desalination flux was 180–223 kg·m³. -2 ·h -1 And the duration can be as long as 153 hours.