CN113083032B - Positively charged blended ultrafiltration membrane and preparation method thereof - Google Patents
Positively charged blended ultrafiltration membrane and preparation method thereof Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/14—Ultrafiltration; Microfiltration
- B01D61/145—Ultrafiltration
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0011—Casting solutions therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0093—Chemical modification
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/16—Membrane materials having positively charged functional groups
Abstract
The invention belongs to the technical field of ultrafiltration membrane preparation, and particularly relates to a positively charged blended ultrafiltration membrane and a preparation method thereof; in the membrane preparation process, secondary amine groups are introduced by one-step amination, and a positively charged ultrafiltration membrane is prepared by quaternization reaction, so that the membrane is synchronously aminated and modified during membrane preparation, the prepared positively charged membrane has lasting hydrophilicity and stable positively charged performance, has higher pure water flux and cationic dye retention performance under low pressure, and has the retention rate of rhodamine B and Victoria blue B of 99.9 percent. And the preparation process is simple, the cost is low, and large-scale industrial production can be carried out.
Description
Technical Field
The invention belongs to the technical field of ultrafiltration membrane preparation, and particularly relates to a positively charged blended ultrafiltration membrane and a preparation method thereof.
Background
The membrane separation technology, which is a novel separation technology rapidly rising in recent years, has been widely applied to fields closely related to the life and production of people, such as sewage treatment, seawater desalination, drinking water purification, petrochemical industry, chemical metallurgy, medical care, food safety and the like, and brings huge economic, environmental and social benefits. In today's society of energy shortage, environmental deterioration and increasingly scarce water resources, membrane separation technology is receiving unprecedented high attention on a global scale. Ultrafiltration (UF) is the most widely used of various separation membranes, can efficiently and environmentally solve the problems of petrochemical industry, wastewater treatment and the like, is a technical means with simple operation and low cost, and is suitable for large-scale production. The ultrafiltration process has no phase change, and under a certain pressure, the small molecular solute and the solvent pass through a special membrane with a certain aperture, so that the large molecular solute cannot permeate and is left on one side of the membrane, and the large molecular substance is partially purified. Because the polymer ultrafiltration membrane is electrically neutral, the retention mechanism is mainly the pore size sieving effect. As the size of the components to be separated by the membrane continues to decrease, the required membrane pore size also decreases, which leads to increased operating costs and decreased filtration efficiency. The charged separation membrane generally refers to a cation exchange membrane and an anion exchange membrane which take potential difference as driving force, and due to the existence of fixed charges on the surface of the charged separation membrane and the existence of electrostatic adsorption and electrostatic repulsion between the charged separation membrane and charged particles, the ionic groups can also increase the hydrophilicity and the pollution resistance of the membrane surface. Therefore, the membrane can have high retention to small-particle-size substances under higher filtration efficiency, and the charged membrane is receiving more and more attention.
At present, the preparation of the charged separation membrane is mainly divided into two types: the first method is to introduce charges by chemically and physically modifying the membrane from the membrane itself, and the surface treatment method, the impregnation method and the grafting method are common; the second is to develop and research a novel membrane material with charged groups from the membrane material. The introduction of positively charged functional groups (such as the introduction of amine groups or the further quaternization of amine groups) on the membrane surface or on the membrane material itself is a common method for realizing the preparation of positively charged ultrafiltration membranes. Since the membrane introduced with amine groups has a weak positive charge property, the membrane introduced with amine groups is usually further quaternized to obtain a highly positively charged membrane with stable charge property. Therefore, a method of introducing an amine-based membrane for further quaternization is often adopted, for example, an additive or a high polymer material containing an amine group is prepared first, then the additive or the high polymer material is added into a membrane casting solution to prepare a membrane, and finally the positively charged membrane is prepared through quaternization reaction.
Patent document CN200810200554.0 discloses a preparation method of a positively charged ultrafiltration membrane and a product thereof, wherein benzyl brominated polyphenylene oxide is dissolved in a good solvent to prepare a membrane casting solution, an amination reagent is added into the membrane casting solution for reaction, and the membrane casting solution after defoaming is converted into a membrane through a dry phase and a wet phase. The method realizes the preparation of the positively charged ultrafiltration membrane by introducing the amine group, but only carries out amination reaction, and the membrane introduced with the amine group has weaker positively charged performance, fewer substances which can be intercepted and small application range. In addition, experiments show that bromic acid byproducts are generated in the preparation process, and the polyphenylene ether substances are poor in film forming property and limited in application.
Patent document CN200410064753.5 discloses a preparation method of a positively charged ultrafiltration membrane, which comprises dissolving benzyl brominated polyphenylene oxide in a good solvent, dropwise adding an amine organic solution, stirring to obtain a homogeneous solution, standing and defoaming the membrane casting solution, placing the membrane casting solution on a substrate, flowing and expanding the membrane casting solution, and then placing the membrane casting solution in a poor solvent to form a membrane. Like the above patent document, this method also achieves preparation of a positively charged ultrafiltration membrane by introducing an amine group, but only an amination reaction is performed, and the positively charged property of the membrane introduced with an amine group is weak. In addition, experiments show that bromic acid byproducts are generated in the preparation process, and the polyphenylene ether substances have poor film forming property and limited application.
Disclosure of Invention
The invention provides a positively charged blended ultrafiltration membrane and a preparation method thereof to solve the problems.
The method is realized by the following technical scheme:
a method for preparing a positively-charged blended ultrafiltration membrane by adopting a two-step method specifically comprises the following steps:
1. preparing a casting solution by a one-step process: dissolving a copolymer, a polyamine compound, a high-molecular film-making material, a pore-forming agent and a catalyst in a solvent at the temperature of 25-80 ℃ and reacting for 1-7h to obtain the catalyst, wherein the copolymer accounts for 1-10% of the total weight of the film-casting solution, the catalyst accounts for 1-10% of the mass of the copolymer, the high-molecular film-making material accounts for 13-25% of the total weight of the film-casting solution, the pore-forming agent accounts for 2-10% of the total weight of the film-casting solution, and the mass ratio of the polyamine compound to the copolymer is 1:8-50. The polyamine compound containing amino and the copolymer are directly introduced into the membrane casting solution and grafted in the membrane casting solution under the action of a catalyst, so that the membrane casting solution is modified while being prepared. The product of the polyamine compound and the copolymer after the grafting reaction is soluble in the solvent and insoluble in water.
Further, the copolymer is a water-insoluble compound with carboxyl or carboxylic anhydride groups, and the carboxyl-containing polymer is polyacrylic acid; the polymer containing carboxylic anhydride groups is one of polystyrene-carboxylic anhydride functional group copolymer, polystyrene-N-phenylmaleimide-carboxylic anhydride functional group terpolymer, polyacrylonitrile-styrene-butadiene rubber-carboxylic anhydride functional group terpolymer and polybutadiene-acrylonitrile-styrene-carboxylic anhydride functional group tetrapolymer.
Further, the polyamine compound is one of triethylene tetramine, tetraethylene pentamine, polyethylene polyamine and polyethylene imine polymer.
Further, the solvent is one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, triethyl phosphate, trimethyl phosphate and dimethyl sulfoxide.
Further, the polymer membrane material is one of chlorinated polyvinyl chloride, polyether sulfone, polysulfone, polyvinylidene fluoride and polyacrylonitrile.
Further, the pore-foaming agent is polyvinylpyrrolidone, and the K value of the pore-foaming agent is one of 15, 30, 80, 85 and 90.
Further, the catalyst is triethanolamine.
2. Film preparation:
(1) Preparation of active precursor film: and (2) scraping the casting solution obtained in the step (1) on the surface of the non-woven fabric to form a flat membrane, specifically, coating the casting solution on the non-woven fabric with the thickness of 50-150 mu m at the speed of 1.0-5.0m/s by using a membrane scraping knife with the size of 100-400 mu m, wherein the thickness of the flat membrane is 400 mu m. Cooling with air for 1-30s, coagulating in water bath at 25-50 deg.C to obtain film, and washing for 1-30 times to obtain active precursor film containing secondary amine group;
further, the non-woven fabric is one of polyethylene terephthalate non-woven fabric or polyamide non-woven fabric.
(2) Quaternization: and (2) blending the active precursor membrane obtained in the step (1) with a quaternization reaction catalyst for quaternization reaction, wherein the concentration of the added quaternization reaction catalyst is 1-20%, the reaction time is 1-30min, and washing and drying to obtain the positively charged blended ultrafiltration membrane.
Further, the quaternization catalyst is one of methyl iodide, ethyl bromide, p-dichlorobenzyl, dibromide benzyl and tribromobenzyl.
3. The preparation method of the positively charged blended ultrafiltration membrane can be used for preparing a hollow fiber membrane besides the positively charged blended ultrafiltration membrane.
In conclusion, the beneficial effects of the invention are as follows: according to the invention, a secondary amine group is introduced by one-step amination in the membrane preparation process, and the positively charged ultrafiltration membrane is prepared by a quaternization reaction, so that the membrane is synchronously aminated and modified during membrane preparation, the prepared positively charged membrane has lasting hydrophilicity and stable positively charged performance, has higher pure water flux and cationic dye retention performance under low pressure, the retention rate on rhodamine B is 99.0-99.9%, and the retention rate on Victoria blue B is 96.7-99.9%. The method used in the patent has mild reaction conditions for grafting polyamine in the casting solution, can not generate such by-products as bromic acid, has complete grafting reaction, good film-forming property of the casting solution, simple film preparation process and low cost, can be used for large-scale industrial production, and is not limited in application.
The polymer for preparing the ultrafiltration membrane is used as a high-molecular membrane preparation material, the water-insoluble substance containing the carboxylic acid or anhydride polymer is used as a blended polymer, the copolymer and the polymer have certain compatibility, the copolymer and the polymer are added into a solvent together with a polyamine compound containing primary amine and secondary amine, a pore-forming agent and a catalyst for dissolving, and the catalyst triethylamine in the membrane casting solution can combine the copolymer and the polyamine compound by chemical bonds to accelerate the reaction of amine groups and carboxylic acid or anhydride groups. Because the activity of the primary amine is higher than that of the secondary amine, a high-hydrophilicity secondary amine-containing high-molecular copolymer is generated in the membrane casting solution after the grafting reaction is finished, so that the membrane casting solution containing strong basic groups is obtained, the membrane can be directly quaternized after the membrane casting, so that the ultrafiltration membrane is charged, and the process is simpler and more convenient. The active precursor membrane is prepared by adopting a non-solvent induced phase separation method (NIPS method), so that a high molecular copolymer generated in the membrane casting solution is embedded into a membrane structure, and introduced hydrophilic groups and secondary amino groups of strong basic groups are not easy to lose. In the film forming process, the copolymer is subjected to surface segregation, so that a large number of functional groups with high reaction activity appear on the surface of the ultrafiltration membrane, and the positively charged blended ultrafiltration membrane is prepared through surface quaternization. The positively charged membrane prepared by quaternization reaction has durable hydrophilicity and stable positively charged performance, and has higher pure water flux and separation precision under low pressure. In the prior art, a process of membrane preparation-amino introduction-quaternization is mostly adopted to prepare the positively charged ultrafiltration membrane, so that the prepared ultrafiltration membrane is thick in skin layer, and the process of amino introduction is relatively complicated.
Detailed Description
The following description will explain the embodiments of the present invention in further detail, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are still within the scope of the present invention as claimed in the claims.
Example 1
1. A positive charge blending ultrafiltration membrane is prepared by directly carrying out grafting reaction in membrane casting solution and then carrying out quaternary ammonium reaction, and the preparation method comprises the following steps:
(1) Preparing a casting solution: weighing 1.2g of polyacrylic acid, 0.05g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K15) to dissolve in 50mL of N, N-dimethylformamide, dissolving, mixing and fully reacting at 70 ℃ for 7h to form a casting solution, and standing and defoaming for 12h.
(2) Preparation of active precursor film: uniformly coating the casting solution obtained in the step (1) on the surface of a polyamide non-woven fabric with the thickness of 100 micrometers by using a flat membrane film scraper with the NIPS method at the speed of 0.3m/s, wherein the thickness of the flat membrane is 400 micrometers, rapidly immersing the nascent membrane in a coagulating bath at room temperature after air cooling for 10 seconds, taking out a membrane sample after the membrane is completely cured, washing with deionized water, removing residual solvent, catalyst and the like, immersing in pure water for 12 hours, and drying for later use.
(3) Quaternization: and (3) uniformly spraying a layer of p-dichlorobenzyl-isopropanol solution on the active precursor film containing the secondary amine group obtained in the step (2) at room temperature, carrying out quaternization reaction under the action of the p-dichlorobenzyl, wherein the concentration of the p-dichlorobenzyl is 5%, the reaction time is 5min, then sequentially cleaning the film with isopropanol and water, removing unreacted p-dichlorobenzyl, and drying to obtain the p-dichlorobenzyl-containing active precursor film.
Example 2
1. A positive charge blending ultrafiltration membrane directly carrying out grafting reaction in membrane casting liquid and then carrying out quaternary ammonium reaction is prepared by the following specific preparation method:
(1) Preparing a casting solution: weighing 1.2g of polyacrylonitrile-styrene-butadiene rubber-carboxylic anhydride functional group terpolymer, 0.15g of tetraethylenepentamine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K30) and dissolving in 50mL of triethyl phosphate, dissolving at 70 ℃, mixing, fully reacting for 5h to form a casting solution, standing and defoaming for 12h.
(2) Preparation of active precursor film: uniformly coating the casting solution obtained in the step (1) on the surface of 50 mu m polyethylene terephthalate non-woven fabric by a flat membrane film scraper at a speed of 0.3m/s by adopting an NIPS method, wherein the thickness of the flat membrane is 400 mu m, rapidly immersing the nascent membrane in a coagulating bath at room temperature after 10s of air cooling, taking out a membrane sample after the membrane is completely cured, washing with deionized water, removing residual solvent, catalyst and the like, immersing in pure water for 12h, and drying for later use.
(3) Quaternization: and (3) uniformly spraying a layer of ethyl bromide-isopropanol solution on the active precursor film containing the secondary amine group obtained in the step (2) at room temperature, carrying out quaternization reaction under the action of ethyl bromide, wherein the concentration of the ethyl bromide is 2%, the reaction time is 10min, then sequentially cleaning the film with isopropanol and water, removing unreacted ethyl bromide, and drying to obtain the active precursor film.
Example 3
1. A positive charge blending ultrafiltration membrane is prepared by directly carrying out grafting reaction in membrane casting solution and then carrying out quaternary ammonium reaction, and the preparation method comprises the following steps:
(1) Preparing a casting solution: weighing 1.2g of polystyrene-N-phenylmaleimide-carboxylic anhydride functional group terpolymer, 0.15g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K80), dissolving in 50mL of dimethyl sulfoxide, dissolving at 70 ℃, mixing, fully reacting for 7h to form a casting solution, and standing and defoaming for 12h.
(2) Preparation of active precursor film: uniformly coating the casting solution obtained in the step (1) on the surface of 100 mu m polyethylene terephthalate non-woven fabric by a flat membrane film scraper at a speed of 0.3m/s by adopting an NIPS method, wherein the thickness of the flat membrane is 400 mu m, rapidly immersing the nascent membrane in a coagulating bath at room temperature after 10s of air cooling, taking out a membrane sample after the membrane is completely cured, washing with deionized water, removing residual solvent, catalyst and the like, immersing in pure water for 12h, and drying for later use.
(3) Quaternization: and (3) uniformly spraying a layer of methyl iodide-isopropanol solution on the active precursor film obtained in the step (2) at room temperature, carrying out quaternization reaction under the action of methyl iodide, wherein the concentration of the methyl iodide is 10%, the reaction time is 3min, then sequentially washing the film with isopropanol and water, removing unreacted methyl iodide, and drying to obtain the active precursor film.
Example 4
1. A positive charge blending ultrafiltration membrane directly carrying out grafting reaction in membrane casting liquid and then carrying out quaternary ammonium reaction is prepared by the following specific preparation method:
(1) Preparing a casting solution: 1.2g of polybutadiene-acrylonitrile-styrene-carboxylic anhydride functional group quadripolymer, 0.15g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K85) are weighed and dissolved in 50mL of N-methyl pyrrolidone, dissolved, mixed and fully reacted at 70 ℃ for 4 hours to form a casting solution, and the casting solution is kept stand and defoamed for 12 hours.
(2) Preparation of active precursor film: uniformly coating the casting solution obtained in the step (1) on the surface of a polyamide non-woven fabric with the thickness of 100 micrometers by using a flat membrane film scraper with the NIPS method at the speed of 0.3m/s, wherein the thickness of the flat membrane is 400 micrometers, rapidly immersing the nascent membrane in a coagulating bath at room temperature after air cooling for 10 seconds, taking out a membrane sample after the membrane is completely cured, washing with deionized water, removing residual solvent, catalyst and the like, immersing in pure water for 12 hours, and drying for later use.
(3) Quaternization: and (3) uniformly spraying a layer of dibromide benzyl-isopropanol solution on the active precursor film containing the secondary amine group obtained in the step (2) at room temperature, carrying out quaternization reaction under the action of dibromide benzyl, wherein the concentration of dibromide benzyl is 15%, the reaction time is 1min, then sequentially washing the film with isopropanol and water, removing unreacted dibromide benzyl, and draining to obtain the active precursor film.
1. Ultrafiltration membrane performance test
1.1 Experimental materials
Ultrafiltration membranes prepared by the methods of examples 1-4 were used.
1.2 Experimental methods
The stable flux and contact angle after 8 hours at 0.1Mpa were measured and compared with a pure PVC membrane under the same conditions, and the results are shown in table 1.
The rejection rates of rhodamine B and victoria blue B by the ultrafiltration membrane were tested and compared with that of a pure polyvinyl chloride membrane, and the results are shown in table 2.
1.3 results of the experiment
TABLE 1
According to experimental results, the copolymer containing secondary amino is directly introduced into the membrane casting solution through a chemical grafting reaction, and after a quaternary ammonium reaction, the hydrophilicity and the flux of the ultrafiltration membrane are improved, and long-term tests prove that the ultrafiltration membranes prepared by the methods in examples 1 to 4 are more durable in hydrophilicity.
TABLE 2
| Retention rate | Pure polyvinyl chloride film | Example 1 | Example 2 | Example 3 | Example 4 |
| Rhodamine B | 76％ | 99.3％ | 99.5％ | 99.0％ | 99.0％ |
| Victoria blue B | 8％ | 96.7％ | 98.5％ | 96.5％ | 96.0％ |
According to experimental results, stable strong-charge electropositivity is endowed to the membrane after blending and grafting of the amino groups, and the rejection rate of the ultrafiltration membrane to cationic dyes is greatly improved.
2. Other embodiments
The method of example 1 is adopted, the raw material composition of the membrane casting solution is changed to prepare the positively charged blended ultrafiltration membrane, and the performance test is carried out on the prepared ultrafiltration membrane by the method of experiment one, the specific formula is as follows, and the performance test results are shown in table 3.
Formula 1: weighing 1.2g of polyacrylic acid, 0.15g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K15) to dissolve in 50mL of N, N-dimethylacetamide, dissolving, mixing and fully reacting at 70 ℃ for 7h to form a casting solution, and standing and defoaming for 12h.
And (2) formula: weighing 1.2g of polyacrylic acid, 0.2g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K30) and dissolving in 50mL of trimethyl phosphate, dissolving at 70 ℃, mixing, fully reacting for 7 hours to form a casting solution, and standing and defoaming for 12 hours.
And (3) formula: weighing 1.2g of polyacrylic acid, 0.1g of triethylene tetramine, 0.1g of triethanolamine, 10.8g of polyvinyl chloride and 4.8g of polyvinylpyrrolidone (K80) and dissolving in 50mL of dimethyl sulfoxide, dissolving at 70 ℃, mixing, fully reacting for 7h to form a casting solution, standing and defoaming for 12h.
And (4) formula: weighing 1.2g of polystyrene-carboxylic anhydride functional group copolymer, 0.15g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K85) and dissolving in 50mL of dimethyl sulfoxide, dissolving at 70 ℃, mixing, fully reacting for 7h to form a casting solution, and standing and defoaming for 12h.
And (5) formula: weighing 1.2g of polyacrylic acid, 0.15g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K90) to dissolve in 50mL of dimethyl sulfoxide, dissolving, mixing and fully reacting at 70 ℃ for 7h to form a casting solution, and standing and defoaming for 12h.
And (6) formula: weighing 2.0g of polyacrylic acid, 0.05g of triethylene tetramine, 0.1g of triethanolamine, 12g of polyvinyl chloride and 3.6g of polyvinylpyrrolidone (K80) to dissolve in 50mL of dimethyl sulfoxide, dissolving, mixing and fully reacting at 70 ℃ for 7h to form a casting solution, and standing and defoaming for 12h.
TABLE 3
In addition, the hollow fiber membranes prepared by the method of example 1 were also prepared by the method of examples 1 to 4, and the performance of the hollow fiber membranes prepared by the method of example 1 was tested according to the test method of experiment one, and the results are shown in table 4.
TABLE 4
3. Screening experiments
3.1 Experimental materials
Sample 1: the method of embodiment 1 is adopted to prepare the positively charged blended ultrafiltration membrane, and the difference is that after the active precursor membrane containing secondary amine groups is prepared, quaternization reaction is not carried out, and the membrane is washed and dried.
Sample 2: a positively charged blended ultrafiltration membrane was prepared by the method of example 1 except that the amount of polyacrylic acid used was changed to 10.8g.
Sample 3: a positively charged blended ultrafiltration membrane was prepared by the method of example 1 except that the amount of polyvinyl chloride used was changed to 15g.
Sample 4: a positively charged ultrafiltration membrane prepared by the method disclosed in the patent document with the application number of CN 200410064753.5.
3.2 Experimental methods
The performance of the positively charged ultrafiltration membranes prepared in samples 1-4 was tested by the experimental method, and the results are shown in table 5.
3.3 results of the experiment
TABLE 5
According to the experimental result, the sample 1 does not undergo the quaternization reaction, the retention rate of rhodamine B and Victoria blue B is reduced, and the positive charge performance of the membrane is weaker. Sample 2 increased the amount of polyacrylic acid used and resulted in an ultrafiltration membrane having a greater flux than example 1, but a lower retention of cationic dye, and a more optimal amount of example 1 from a cost economic standpoint. Sample 3 increased the amount of polyvinyl chloride and resulted in an ultrafiltration membrane with a higher retention of cationic dye than in example 1, but with a lower flux, and the amount of example 1 was more optimal from a cost economic standpoint. Sample 4 was tested with a positively charged ultrafiltration membrane prepared by the method disclosed in patent document CN200410064753.5, and it can be seen that the ultrafiltration membrane prepared without grafting and ammonification reaction has low flux, weak positive charge performance of the membrane, and low retention rate of cationic dye.
Claims (7)
1. A preparation method of a positively charged blended ultrafiltration membrane is characterized by adopting a two-step method to prepare: preparing a membrane casting solution by adopting a one-step process, preparing a membrane by adopting an NIPS method, and performing quaternization treatment;
the one-step process is characterized in that polyamine compounds containing amino and copolymers are directly introduced into a casting solution and grafted under the action of a catalyst, wherein the mass ratio of the polyamine compounds to the copolymers is 1:8-50 parts of;
the copolymer is a water-insoluble compound with carboxyl or carboxylic anhydride groups, and the carboxyl-containing polymer is polyacrylic acid; the polymer containing carboxylic anhydride groups is one of polystyrene-carboxylic anhydride functional group copolymer, polystyrene-N-phenylmaleimide-carboxylic anhydride functional group terpolymer, polyacrylonitrile-styrene-butadiene rubber-carboxylic anhydride functional group terpolymer and polybutadiene-acrylonitrile-styrene-carboxylic anhydride functional group tetrapolymer;
the polyamine compound is one of triethylene tetramine, tetraethylene pentamine, polyethylene polyamine and polyethylene imine polymer.
2. The preparation method of the positively charged blended ultrafiltration membrane according to claim 1, wherein the quaternization treatment is carried out by spraying a quaternization catalyst on the surface of the membrane and carrying out catalytic reaction for 1-30 min.
3. The method for preparing a positively charged blended ultrafiltration membrane according to claim 2, wherein the quaternization catalyst is one of methyl iodide, ethyl bromide, p-dichlorobenzyl, dibromide benzyl and tribromobenzyl.
4. The method for preparing the positively-charged blended ultrafiltration membrane according to claim 1, wherein the two-step method specifically comprises the following steps:
(1) Preparing a casting solution: dissolving the copolymer, the polyamine compound, the polymer film-making material, the pore-forming agent and the catalyst in a solvent at the temperature of 25-80 ℃ and reacting for 1-7h to obtain the catalyst;
(2) Film preparation:
2-1) preparation of active precursor film: scraping the casting solution obtained in the step (1) on the surface of non-woven fabric to form a flat membrane, cooling the flat membrane by air for 1 to 30 seconds, solidifying the flat membrane in a water bath at the temperature of between 25 and 50 ℃ to form a membrane, and washing the membrane for 1 to 30 times to obtain an active precursor membrane containing secondary amine groups;
2-2) quaternization: and (3) blending the active precursor membrane obtained in the step (2-1) with a quaternization reaction catalyst for quaternization reaction, wherein the concentration of the added quaternization reaction catalyst is 1-20%, the reaction time is 1-30min, and washing and drying to obtain the positively charged blended ultrafiltration membrane.
5. The method for preparing the positively-charged blended ultrafiltration membrane according to claim 4, wherein the scraping flat membrane is prepared by coating a casting solution on a non-woven fabric with the thickness of 50-150 μm at the speed of 1.0-5.0m/s by using a scraping knife with the size of 100-400 μm, and the thickness of the flat membrane is 400 μm.
6. The positively charged blended ultrafiltration membrane prepared by the preparation method as claimed in any one of claims 1 to 5.
7. The use of a positively charged blended ultrafiltration membrane of any one of claims 1 to 5 in the preparation of hollow fiber membranes.
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| CN116531848B (en) * | 2023-06-26 | 2023-09-12 | 江苏奥凯环境技术有限公司 | Colored aramid fiber filter material for flue gas purification and production process thereof |
| CN116531961B (en) * | 2023-07-04 | 2023-09-19 | 中国农业大学 | Positively charged nanofiltration membrane for removing uranium and cesium in nuclear radioactive wastewater and preparation method thereof |
Family Cites Families (17)
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| DE19836514A1 (en) * | 1998-08-12 | 2000-02-17 | Univ Stuttgart | Modification of engineering polymers with N-basic groups and ion exchange groups in the side chain gives membranes of good thermal and mechanical stability useful for fuel cells, diffusion dialysis, electrodialysis, and reverse osmosis |
| JP2001079374A (en) * | 1999-09-17 | 2001-03-27 | Saehan Ind Inc | Polyamide reverse osmosis combined membrane and its production |
| CN1110354C (en) * | 1999-12-28 | 2003-06-04 | 世韩工业株式会社 | Polyamide reverse osmosis composite film and its producing method |
| JP3611795B2 (en) * | 2001-02-15 | 2005-01-19 | サエハン インダストリーズ インコーポレーション | Polyamide-based reverse osmosis composite membrane and method for producing the same |
| CN1156335C (en) * | 2002-03-18 | 2004-07-07 | 天津膜天膜工程技术有限公司 | Positively charged membrane and its preparing process |
| CN101850218A (en) * | 2010-02-09 | 2010-10-06 | 厦门大学 | Preparation method of QAS polymer anion exchange membrane |
| CN102153690B (en) * | 2010-12-20 | 2013-06-12 | 广州天赐高新材料股份有限公司 | Alternating or random copolymer containing polyquaternium lateral group and preparation method thereof |
| CN102122720B (en) * | 2011-01-25 | 2013-06-19 | 厦门大学 | Fluorine-containing acrylate polymer anion exchange membrane and preparation method thereof |
| CN103285745A (en) * | 2013-05-20 | 2013-09-11 | 燕山大学 | Method for preparing N-aminoethyl-gamma-aminopropyl trimethoxysilane-diethylene triamine pentaacetic acid/polyvinylidene fluoride exchange membrane |
| CN104190265A (en) * | 2014-08-31 | 2014-12-10 | 浙江大学 | Low-pressure high-flux chlorine-containing polymer nanofiltration membrane with stable separation layer and preparation method thereof |
| CN106582315A (en) * | 2016-11-29 | 2017-04-26 | 华中科技大学 | Polyamide composite membrane and preparation method thereof |
| CN110314561A (en) * | 2018-03-29 | 2019-10-11 | 东华大学 | A kind of polymeric film material and preparation method thereof |
| CN110066415B (en) * | 2019-04-23 | 2021-07-20 | 吕剑阳 | Preparation method of porous membrane with functionalized surface |
| CN110743377B (en) * | 2019-10-21 | 2022-06-21 | 浙江理工大学 | Method for synchronously improving flux and anti-pollution performance of polyamide reverse osmosis composite membrane |
| CN110975654B (en) * | 2019-11-25 | 2022-08-02 | 苏州科技大学 | In-situ grafted anti-pollution hydrophilic modified membrane and preparation method thereof |
| CN111330447B (en) * | 2020-02-26 | 2022-03-15 | 天津科技大学 | Positively charged composite nanofiltration membrane, and preparation method and application thereof |
| CN111790275A (en) * | 2020-06-30 | 2020-10-20 | 浙江工业大学 | Preparation method of nanofiltration composite membrane for softening water |
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