Device and method for ultrasonic-assisted continuous modification of hollow fiber membrane tube with high separation performance

Abstract

The invention relates to a device and method for ultrasonic-assisted continuous modification of a high-separation-performance hollow fiber membrane tube, and belongs to the technical field of material preparation and polymer modification.The preparation method comprises the steps that under the conditions of certain temperature and pressure, a precursor solution is pumped into a pretreated membrane material for oxidative polymerization, and a hollow fiber membrane tube is obtained; and applying ultrasonic treatment for a proper time to fully react, and then taking out, washing and drying. According to the technical scheme, the modified hollow fiber membrane tube can be rapidly prepared in a large scale at low cost, the operation steps are simple, the modification effect is lasting and stable, and the application prospect is wide.

Description

Technical Field

[0001] The present invention belongs to the technical field of material preparation and polymer modification, and particularly relates to a method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance. Background Art

[0003] As an efficient separation material, hollow fiber membranes are widely used in the fields of water treatment, gas separation, and biomedicine due to their advantages of high specific surface area and short mass transfer distance. However, their inherent hydrophobic properties (such as materials like polypropylene and polyvinylidene fluoride) limit their application effects in the fields of water treatment and liquid-liquid extraction. The hydrophobic surface is prone to adsorbing hydrophobic pollutants, exacerbating the membrane fouling problem. During the mass transfer process supported by hollow fiber membranes, the high membrane resistance of hydrophobic membrane tubes will significantly reduce the mass transfer efficiency. Therefore, surface modification of the membrane tubes is the key to solving the above problems. Traditional modification methods (such as plasma treatment, surface coating, etc.) are mostly batch technologies, which have problems such as long modification time, weak bonding between the coating and the membrane matrix, and only being able to modify the outer surface of the membrane tubes. However, in application scenarios such as liquid-liquid extraction and gas-liquid absorption, the aqueous phase mainly flows inside the tubes. Therefore, modifying the inner surface of the membrane tubes often can achieve better effects. Existing technologies are difficult to achieve this goal, seriously restricting the application potential of hollow fiber membranes in related fields. Summary of the Invention

[0005] The purpose of the present invention is to provide a device and method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance. The specific technical solutions are as follows: The device for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to the present invention is characterized in that: the device includes a liquid delivery pump (1), a sleeve membrane contact chamber (2), a solution storage container (3), and an ultrasonic cleaner (4). The ultrasonic cleaner (4) is connected to the solution storage container (3) to perform ultrasonic treatment on the solution in the solution storage container (3). The output end of the solution storage container (3) is connected to the liquid delivery pump (1), the output end of the liquid delivery pump (1) is connected to the inner tube of the membrane material of the sleeve membrane contact chamber (2), and the output end of the inner tube of the membrane material of the sleeve membrane contact chamber (2) is communicated with the input end of the solution storage container (3). Deionized water is pumped into the outer tube of the sleeve membrane contact chamber (2).

[0006] The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to the present invention is characterized in that: (1), the liquid delivery pump (1) delivers a cleaning solution to pre-treat and clean the membrane material in the sleeve membrane contact chamber (2) to obtain a clean membrane material; (2) The liquid delivery pump (1) delivers the precursor solution to oxidatively polymerize and modify the membrane material in the casing membrane contact chamber (2), and the precursor solution is subjected to ultrasonic treatment.

[0007] Preferably, the above-mentioned liquid delivery pump (1) is one of an injection pump, a peristaltic pump, or other pumps that can provide a stable flow rate.

[0008] Preferably, the membrane material used in the above-mentioned casing membrane contact chamber (2) is a hollow fiber membrane tube, the inner diameter of the hollow fiber membrane tube is 0.1 - 2 mm, and the membrane thickness is 0.05 - 1 mm; the material of the membrane material is one of polypropylene, polytetrafluoroethylene, poly(4-methyl-1-pentene) (PMP), or other polymer membrane materials.

[0009] Preferably, the cleaning of the above-mentioned membrane material is pre-treated successively with an organic solvent and water, and ultrasonic treatment is applied to both the organic solvent and water to increase the mutual contact between the organic solvent and water and the surface of the membrane material, obtaining a clean, flat, and smooth membrane material.

[0010] Preferably, the organic solvents used in the above-mentioned pretreatment include one or more of methanol, ethanol, acetone, and isopropanol.

[0011] Preferably, the above-mentioned precursor solution is one or more of a mixture of dopamine, a crosslinking agent, and a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution.

[0012] Preferably, the above-mentioned dopamine concentration is 0.5 - 4 g / L, the crosslinking agent concentration is 0.5 - 4 g / L, and the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution concentration is 10 - 50 mmol / L; the crosslinking agent includes one or more of polyethyleneimine, polyethylene glycol, and polyvinylpyrrolidone solution.

[0013] Preferably, the time of the above-mentioned ultrasonic treatment is 2 h - 12 h, the ultrasonic power is 100 W - 2000 W; the preparation pressure is 0.01 - 10 MPa.

[0014] Preferably, the surface of the modified membrane material obtained by the above-mentioned ultrasonic treatment is a uniformly loaded particulate, cluster, or film-like polymer structure.

[0015] The device and method for continuously modifying a hollow fiber membrane tube with high separation performance assisted by ultrasound proposed by the present invention. The device has a casing membrane contact chamber (2), which can control the flow path of the modification solution (i.e., the precursor solution) to achieve selective modification of the inner surface of the membrane tube. At the same time, the fluidity brought by the device provides a dynamic transport environment for the modification solution, enabling it to flow and penetrate rapidly on the surface of the membrane tube, further enhancing the uniformity and continuity of the modification. Further, during the modification process, ultrasonic technology is introduced. The high-frequency vibration and cavitation effect generated by ultrasonic technology effectively break the agglomeration phenomenon that may occur in the traditional modification process, increase the contact area and binding force between the modification solution and the membrane tube material, and significantly shorten the modification time. Through the synergistic effect of the casing structure and ultrasonic assistance, this patent realizes efficient and uniform continuous modification, improves the separation performance, anti-pollution ability and mechanical strength of the membrane tube, overcomes the limitations of traditional technologies, provides a new technical path for the preparation of high-performance hollow fiber membrane tubes, and can meet the urgent needs of different industrial application fields for high-performance membrane materials.

[0016] The beneficial effects of the present invention are as follows: (1) This invention patent can achieve in-situ and uniform growth of polydopamine nanoparticles / clusters / membranes on the surface of the membrane material. The continuous in-situ flow membrane modification not only realizes selective modification of the inner surface of the membrane tube, but also improves the reaction efficiency, reduces the use of the precursor solution, and thus can reduce costs. In addition, ultrasonic waves can promote the uniform distribution of the modification material on the membrane surface, form a more stable polymer layer, and reduce the shedding phenomenon during use. At the same time, ultrasonic waves can also accelerate the mixing and mass transfer of reactants, increase the reaction rate, and significantly shorten the modification time.

[0017] (2) Compared with the traditional modification method, the present invention uses a casing structure and is assisted by ultrasonic waves, which can reduce the modification preparation time and improve the preparation rate. This method has a low device cost, is easy to operate, and can maintain a high product consistency. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the device of the present invention; Figure 2 is the SEM image of the modified hollow fiber membrane tube prepared in Example 2 (SEM images at different PEI concentrations (a) original membrane, (b) 0.5 g / L, (c) 1 g / L, (d) 4 g / L); Figure 3 is the water contact angle image of the modified hollow fiber membrane tube prepared in Example 2; Figure 4 is the extraction efficiency image of the casing membrane contact chamber assembled with the modified hollow fiber membrane tube. Detailed implementation mode

[0021] The present invention provides a device and method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance. The present invention will be further described below by way of examples, but the content of the present invention is not limited thereby.

[0022] The device for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to the present invention comprises a liquid delivery pump 1, a casing membrane contact chamber 2, a solution storage container 3 and an ultrasonic cleaner 4. The ultrasonic cleaner 4 is connected to the solution storage container 3 to perform ultrasonic treatment on the solution in the solution storage container 3. The output end of the solution storage container 3 is connected to the liquid delivery pump 1, and the output end of the liquid delivery pump 1 is connected to the inner tube of the membrane material of the casing membrane contact chamber 2. The output end of the inner tube of the membrane material of the casing membrane contact chamber 2 communicates with the input end of the solution storage container 3, and deionized water is pumped into the outer tube of the casing membrane contact chamber 2.

[0023] The structure of the casing membrane contact chamber 2 comprises a housing with end caps on both sides and a membrane material (such as a hollow fiber membrane tube) provided in the housing. The first side end cap has a liquid inlet connected to the liquid delivery pump 1, and the solution introduced through the liquid inlet communicates with the inner pore channels of each hollow fiber membrane tube. The second side end cap has a liquid outlet connected to the solution storage container 3, and the liquid outlet communicates with the inner pore channels of each hollow fiber membrane tube. The housing has a deionized water inlet and an outlet, and the deionized water inlet and outlet communicate with the outer surfaces of each hollow fiber membrane tube in the casing membrane contact chamber 2.

[0024] The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to the present invention (1) The liquid delivery pump 1 delivers a cleaning solution to perform a pretreatment cleaning on the membrane material in the casing membrane contact chamber 2 to obtain a clean membrane material; (2) The liquid delivery pump 1 delivers a precursor solution to perform an oxidative polymerization modification treatment on the membrane material in the casing membrane contact chamber 2, and the precursor solution is subjected to ultrasonic treatment.

[0025] The liquid delivery pump can be one of an injection pump, a peristaltic pump or other pumps that can provide a stable flow rate.

[0026] The membrane material used in the casing membrane contact chamber (2) is a hollow fiber membrane tube, the inner diameter of the hollow fiber membrane tube is 0.1 - 2 mm, and the membrane thickness is 0.05 - 1 mm; the material of the membrane material is one of polypropylene, polytetrafluoroethylene, poly(4-methyl-1-pentene) (PMP) or other polymer membrane materials.

[0027] The cleaning of the membrane material is pre-treated successively with organic solvents and water, and ultrasonic treatment is applied to both the organic solvents and water to increase the mutual contact between the organic solvents and water and the surface of the membrane material, so as to obtain a clean, flat and smooth membrane material; the organic solvents used in the pre-treatment include one or more of methanol, ethanol, acetone, isopropanol, etc.

[0028] The precursor solution is one or more of a mixture of dopamine, a cross-linking agent and a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution; the dopamine concentration is 0.5 - 4 g / L, the cross-linking agent concentration is 0.5 - 4 g / L, and the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution concentration is 10 - 50 mmol / L; the cross-linking agent includes one or more of solutions containing polyethyleneimine, polyethylene glycol, polyvinylpyrrolidone, etc.

[0029] The time of ultrasonic treatment is 2 h - 12 h, and the ultrasonic power is 100 W - 2000 W; the preparation pressure is 0.01 - 10 MPa.

[0030] The surface of the modified membrane material obtained by ultrasonic treatment is a polymer structure with uniformly loaded particles, clusters and films.

[0031] Example 1: (1) Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then continuously clean it in methanol and water for 30 min respectively to obtain a clean hollow fiber membrane tube.

[0032] (2) Dissolve dopamine (1 g / L) and polyethyleneimine (2 g / L) in a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (50 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Pump the mixed solution into the inner tube of the casing membrane contact chamber (i.e., the inner pore of the hollow fiber membrane tube) through a peristaltic pump, and pump deionized water into the outer tube (i.e., the shell of the casing membrane contact chamber), and continuously circulate at 40°C for 8 h. Take out the membrane tube, wash it by oscillation in deionized water and then dry it in vacuum. The oscillation frequency is 80 times / minute, the washing temperature is 40°C, the washing time is 6 hours, the drying temperature is 60°C, and the drying time is 8 h to obtain a dried polydopamine / polyethyleneimine modified PTFE hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°, and the contact angle between the PTFE hollow fiber membrane tube modified by surface modification in this example and water drops to 75°.

[0033] Example 2: (1) Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then continuously clean it in absolute ethanol and water for 30 min respectively using ultrasonic circulation, with an ultrasonic power of 700 W, to obtain a clean hollow fiber membrane tube.

[0034] (2)Dissolve dopamine (1 g / L) and polyethyleneimine (0.5 g / L, 1 g / L, 4 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (50 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 40 °C and an ultrasonic power of 700 W. Pump the mixed solution into the inner tube of the casing membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 8 h at 40 °C. Take out the membrane tube, wash it by oscillation in deionized water and then dry it in vacuum. The oscillation frequency is 80 times / minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried poly-dopamine / polyethyleneimine modified hollow fiber membrane tube. The inner surface morphology of the PTFE hollow fiber membrane tube before and after modification is as Figure 2 shown. The contact angle of the unmodified PTFE hollow fiber membrane tube with water reaches 120°. After surface modification in this example, the contact angles of the PTFE hollow fiber membrane tube with water decrease to 75°, 54°, and 43° in sequence. The water contact angle diagram is as Figure 3 shown. At a low polyethyleneimine concentration, polydopamine exists in the form of particles and agglomerates to form amorphous clusters. As the polyethyleneimine concentration increases to 1 g / L, the polydopamine particles gradually decrease, and the agglomeration phenomenon is greatly reduced. When the polyethyleneimine concentration is as high as 4 g / L, the PDA particles completely disappear and exist in the form of a polydopamine film. Polyethyleneimine promotes the uniform distribution and the formation of smaller sizes of polydopamine particles, increases the surface area of polydopamine, and significantly improves the hydrophilic effect of the hollow fiber membrane tube.

[0035] Example 3: (1)Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then continuously wash it in methanol and water respectively by ultrasonic wave for 30 min with an ultrasonic power of 700 W to obtain a clean hollow fiber membrane tube.

[0036] (2) Dissolve dopamine (4 g / L) and polyethyleneimine (2 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (20 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 60 °C and an ultrasonic power of 100 W. Pump the mixed solution into the inner tube of the tubular membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 8 h at 60 °C. Take out the membrane tube, wash it by oscillation in deionized water and then dry it in vacuum. The oscillation frequency is 80 times per minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried polydopamine / polyethyleneimine modified PTFE hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 40°.

[0037] Example 4: (1) Assemble the PTFE hollow fiber membrane tube into a tubular membrane contact chamber, and then sequentially clean it continuously by ultrasonic circulation in acetone and water for 30 min each to obtain a clean hollow fiber membrane tube.

[0038] (2) Dissolve dopamine (4 g / L) and polyethyleneimine (4 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (50 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 60 °C and an ultrasonic power of 2000 W. Pump the mixed solution into the inner tube of the tubular membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 2 h at 60 °C. Take out the membrane tube, wash it by oscillation in deionized water and then dry it in vacuum. The oscillation frequency is 80 times per minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried polydopamine / polyethyleneimine modified PTFE hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 58°.

[0039] Example 5: (1) Assemble the PTFE hollow fiber membrane tube into a tubular membrane contact chamber, and then sequentially clean it continuously by ultrasonic circulation in absolute ethanol and water for 30 min each with an ultrasonic power of 700 W to obtain a clean hollow fiber membrane tube.

[0040] (2) Dissolve dopamine (0.5 g / L) and polyethyleneimine (0.5 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (40 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 40 °C and an ultrasonic power of 1000 W. Pump the mixed solution into the inner tube of the casing membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 12 h at 40 °C. Take out the membrane tube, wash it by oscillation in deionized water and then dry it under vacuum. The oscillation frequency is 80 times per minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried polydopamine / polyethyleneimine-modified hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 60°.

[0041] Example 6: (1) Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then successively use ultrasonic waves to continuously clean in absolute ethanol and water for 30 min respectively with an ultrasonic power of 700 W to obtain a clean hollow fiber membrane tube.

[0042] (2) Dissolve dopamine (2 g / L) and polyethyleneimine (1 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (30 mmol / L) to obtain a dopamine / polyethyleneimine mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 30 °C and an ultrasonic power of 800 W. Pump the mixed solution into the inner tube of the casing membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 6 h at 30 °C. Take out the membrane tube, wash it by oscillation in deionized water and then dry it under vacuum. The oscillation frequency is 80 times per minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried polydopamine / polyethyleneimine-modified hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 49°.

[0043] Example 7: (1) Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then successively use ultrasonic waves to continuously clean in absolute ethanol and water for 30 min respectively with an ultrasonic power of 700 W to obtain a clean hollow fiber membrane tube.

[0044] (2) Dissolve dopamine (1 g / L) and polyvinylpyrrolidone (2 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (40 mmol / L) to obtain a dopamine / polyvinylpyrrolidone mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 30 °C and an ultrasonic power of 1000 W. Pump the mixed solution into the inner tube of the casing membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 8 h at 30 °C. Take out the membrane tube, wash it by oscillating in deionized water and then dry it in vacuum. The oscillation frequency is 80 times / minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried poly-dopamine / polyethyleneimine modified hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 52°.

[0045] Example 8: (1) Assemble the PTFE hollow fiber membrane tube into a casing membrane contact chamber, and then successively use ultrasonic waves to continuously wash in anhydrous ethanol and water for 30 min respectively with an ultrasonic power of 700 W to obtain a clean hollow fiber membrane tube.

[0046] (2) Dissolve dopamine (3 g / L) and polyethylene glycol (3 g / L) in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (30 mmol / L) to obtain a dopamine / polyethylene glycol mixed solution. Place the mixed solution in an ultrasonic cleaner with a reaction temperature of 20 °C and an ultrasonic power of 1200 W. Pump the mixed solution into the inner tube of the casing membrane contact chamber through a peristaltic pump, and pump deionized water into the outer tube. Continuously circulate for 6 h at 20 °C. Take out the membrane tube, wash it by oscillating in deionized water and then dry it in vacuum. The oscillation frequency is 80 times / minute, the washing temperature is 40 °C, the washing time is 6 hours, the drying temperature is 60 °C, and the drying time is 8 h to obtain a dried poly-dopamine / polyethyleneimine modified hollow fiber membrane tube. The contact angle between the unmodified PTFE hollow fiber membrane tube and water reaches 120°. After surface modification in this example, the contact angle between the PTFE hollow fiber membrane tube and water drops to 55°.

[0047] Assemble the modified hollow fiber membrane tubes prepared in Example 1, Example 3, and Example 4 into a casing membrane contact chamber. Use dimethyl carbonate as the extractant and 6 g / L phenol aqueous solution as the phase to be extracted. Use a peristaltic pump to pump the extractant and the phase to be extracted into the outer tube and the inner tube of the casing membrane contact chamber respectively for liquid-liquid extraction experiments. The experimental results are as Figure 4 shown. Compared with the unmodified hollow fiber membrane tube, the casing membrane contact chambers using the modified hollow fiber membrane tubes all show more excellent extraction performance, and the extraction efficiency increases with the decrease of the contact angle.

[0048] The beneficial effects of the present invention are as follows: (1) The present invention patent can achieve the in-situ uniform growth of polydopamine nanoparticles / clusters / membranes on the surface of the membrane material; the continuous in-situ flow membrane modification not only realizes the selective modification of the inner surface of the membrane tube, but also improves the reaction efficiency, reduces the use of the precursor solution, and thus can reduce the cost. In addition, ultrasonic waves can promote the uniform distribution of the modified material on the membrane surface, form a more stable polymer layer, and reduce the shedding phenomenon during use. At the same time, ultrasonic waves can also accelerate the mixing and mass transfer of reactants, improve the reaction rate, and significantly shorten the modification time.

[0049] (2) Compared with the traditional modification method, the present invention uses a sleeve structure and ultrasonic assistance, which can reduce the modification preparation time and improve the preparation rate. This method has a low device cost, is easy to operate, and can maintain a high product consistency.

[0050] The above is only a specific embodiment of the present invention with relatively good creativity, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An ultrasonic-assisted continuous modification device for high separation performance hollow fiber membrane tubes, characterized in that: The device comprises a liquid delivery pump (1), a sleeve membrane contact chamber (2), a solution container (3) and an ultrasonic cleaning machine (4); the solution container (3) is connected to the ultrasonic cleaning machine (4) to perform ultrasonic treatment on the solution in the solution container (3); the output end of the solution container (3) is connected to the liquid delivery pump (1); the output end of the liquid delivery pump (1) is connected to the membrane material inner tube of the sleeve membrane contact chamber (2); the output end of the membrane material inner tube of the sleeve membrane contact chamber (2) is connected to the input end of the solution container (3); and deionized water is pumped into the outer tube of the sleeve membrane contact chamber (2).

2. A method for ultrasonically assisted continuous modification of a hollow fiber membrane tube with high separation performance, characterized in that: (1) The liquid delivery pump (1) delivers a cleaning liquid to pre-treat and clean the membrane material in the casing membrane contact chamber (2) to obtain a clean membrane material; (2) The liquid delivery pump (1) delivers a precursor solution to perform an oxidative polymerization modification treatment on the membrane material in the sleeve membrane contact chamber (2), wherein the precursor solution is subjected to ultrasonic treatment.

3. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 1 or 2, characterized in that: The liquid delivery pump (1) is a syringe pump, a peristaltic pump or other pumps that can provide a stable flow rate.

4. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 1 or 2, characterized in that: The membrane material used in the sleeve membrane contact chamber (2) is a hollow fiber membrane tube, the inner diameter of the hollow fiber membrane tube is 0.1-2 mm, and the membrane thickness is 0.05-1 mm; the material of the membrane material is polypropylene, polytetrafluoroethylene, poly-4-methyl-1-pentene (PMP) or one of other polymer membrane materials.

5. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 1 or 2, characterized in that: The membrane material is cleaned by pre-treating with organic solvent and water in sequence, and ultrasonic treatment is applied to the organic solvent and water to increase the mutual contact between the organic solvent and water and the surface of the membrane material, so as to obtain a clean, flat and smooth membrane material.

6. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 5, characterized in that: The organic solvent used in the pretreatment includes one or more of methanol, ethanol, acetone and isopropanol.

7. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 2, characterized in that: The precursor solution is one or more of a mixture of dopamine, a cross-linking agent and a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution.

8. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 7, characterized in that: The dopamine concentration is 0.5-4 g / L, the cross-linking agent concentration is 0.5-4 g / L, and the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution concentration is 10-50 mmol / L; the cross-linking agent includes one or more of polyethyleneimine, polyethylene glycol, and polyvinyl pyrrolidone solution.

9. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 1 or 2, characterized in that: The ultrasonic treatment time is 2 h-12 h, the ultrasonic power is 100 W-2000 W, and the preparation pressure is 0.01-10 MPa.

10. The method for ultrasonically assisted continuous modification of hollow fiber membrane tubes with high separation performance according to claim 1 or 2, characterized in that: The surface of the modified membrane material obtained by the ultrasonic treatment is a uniformly loaded particle, cluster, or film-like polymer structure.

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