CN107413206B - Montmorillonite modified polyvinyl chloride flat ultrafiltration membrane and preparation method thereof - Google Patents
Montmorillonite modified polyvinyl chloride flat ultrafiltration membrane and preparation method thereof Download PDFInfo
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- CN107413206B CN107413206B CN201710682513.9A CN201710682513A CN107413206B CN 107413206 B CN107413206 B CN 107413206B CN 201710682513 A CN201710682513 A CN 201710682513A CN 107413206 B CN107413206 B CN 107413206B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/30—Polyalkenyl halides
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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
- B01D67/0079—Manufacture of membranes comprising organic and inorganic components
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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
- B01D69/06—Flat membranes
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
Abstract
The invention relates to the technical field of membrane separation, and discloses a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane and a preparation method thereof. Preparing a casting solution from modified montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating to obtain the modified montmorillonite hydrophilic modified polyvinyl chloride film; the casting solution comprises the following components in percentage by mass: 10-20% of polyvinyl chloride, 0.3-2% of modified montmorillonite, 3-7% of polyethylene glycol and the balance of N, N-dimethylacetamide solvent. The ultrafiltration membrane prepared by the method has good stability and higher flux and rejection rate to oily sewage.
Description
Technical Field
The invention relates to the technical field of membrane separation, in particular to a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane and a preparation method thereof.
Background
Oil energy which is the first energy can generate a large amount of oily sewage in the processes of production, extraction and use, and the method which is commonly used at present is used for treating the oily sewage by a membrane treatment technology, but the problem of membrane pollution caused by the oily sewage causes a new trouble to people, and the main reason for the hindered development of the membrane technology is membrane pollution. The problem of membrane pollution can be reduced to a great extent by improving the hydrophilic performance of the membrane, so people begin to search a method for modifying an organic membrane with insufficient hydrophilic capacity, the hydrophilicity of the modified membrane is improved, and the modified membrane can be used for treating oily sewage.
Polyvinyl chloride (PVC), one of the most productive synthetic resins, has good comprehensive properties such as corrosion resistance, flame retardancy, insulation and wear resistance, and many raw material supply methods, wide sources and low price, but the most serious defects of PVC are that PVC does not have excellent hydrophilicity and strong hydrophobicity. The disadvantage can cause that the PVC membrane can be separated only by a large driving force, pollutants are easy to adsorb, the separation index is reduced, the service life of the membrane is obviously influenced, and the conditions become reasons for restricting the mature application of PVC. Therefore, the hydrophilic modification of the PVC membrane has great practical significance.
Chinese patent publication No. CN103495348B discloses a polyvinyl chloride hollow fiber ultrafiltration membrane, which is formed by film forming and hydrophilic treatment of a casting solution and then drying, wherein the casting solution comprises the following components in percentage by mass: 8-30% of polyvinyl chloride, 1-3% of polyacrylonitrile, 4-15% of polyethylene glycol, 1-5% of a hydrophilic agent and the balance of a solvent, wherein although the hydrophilic agent has high water flux and rejection rate, the hydrophilic property is poor, and the prepared ultrafiltration membrane is easy to be polluted, so that the water flux is reduced, and the service life of the membrane is shortened; chinese patent publication No. CN103212310B discloses a method for preparing a modified polyvinyl chloride-vinyl acetate flat microfiltration membrane, which comprises mixing polyvinyl chloride-vinyl acetate, polyethylene glycol and dimethylformamide uniformly to obtain a casting solution, salivating the casting solution on treated nonwoven fabric to obtain a flat membrane intermediate, and finally immersing in a gel bath to obtain the modified polyvinyl chloride-vinyl acetate flat microfiltration membrane.
Disclosure of Invention
The invention provides a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane which has good hydrophilic property and a simple and convenient preparation method, and aims to solve the problems of poor pollution resistance and complex preparation process of a polyvinyl chloride ultrafiltration membrane in the prior art.
The invention also provides a preparation method of the montmorillonite modified polyvinyl chloride flat ultrafiltration membrane.
In order to achieve the purpose, the invention adopts the following technical scheme: a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
10 to 20 percent of polyvinyl chloride
Montmorillonite 0.3-2%
3 to 7 percent of polyethylene glycol
The balance of N, N-dimethylacetamide.
Polyvinyl chloride, one of the most productive synthetic resins, has good comprehensive properties such as corrosion resistance, flame retardance, insulation and abrasion resistance, and has the advantages of multiple raw material supply modes, wide sources and low price.
Montmorillonite is also a mineral with unbalanced charge, and due to class-like transformation, the surface of a lamellar tissue is negatively charged, and can be balanced only by adsorbing cations, so that the montmorillonite has the property similar to that of a surfactant and has hydrophilic and lipophilic surfaces, and the montmorillonite is used for modifying polyvinyl chloride, so that the hydrophilic performance of the ultrafiltration membrane is improved, and the anti-pollution performance of the ultrafiltration membrane is improved; in addition, part of montmorillonite can be mixed in membrane pores in the polyvinyl chloride flat membrane, and the membrane pore diameter is reduced, so that the retention rate of macromolecular organic matters is improved; montmorillonite is silicate with a layered structure, exchangeable cations are arranged among layers, and a polyvinyl chloride macromolecular chain is intercalated into the layers of the montmorillonite in a certain mode by utilizing the special structure of the montmorillonite, so that the strength of the ultrafiltration membrane is greatly enhanced, higher water pressure can be borne, materials such as non-woven fabrics are not needed as a support body, preparation raw materials are saved, and preparation steps are simplified.
Polyethylene glycol is used as a pore-foaming agent of the polyvinyl chloride membrane, and N, N-dimethylacetamide is used as a solvent.
Preferably, the polyethylene glycol has a molecular weight of 400, 600 or 800.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine according to the mass ratio of 0.7-1: 1, heating to 60-70 ℃, and stirring and reacting for 5-6 hours at the rotating speed of 1600-2000 rpm;
2) filtering the reacted product, and drying at 65-80 ℃ for 24-48 hours;
3) and adding the dried product into a ball mill, crushing, and screening by a screen of 180-220 meshes to obtain the modified montmorillonite.
According to the principle of cation exchange reaction, modifying montmorillonite with lauramidopropyl hydroxysulfobetaine; due to the fact that the lauramidopropyl hydroxysulfobetaine has a longer carbon chain structure, the surface energy between the montmorillonite and the polyvinyl chloride is reduced, the montmorillonite and the polyvinyl chloride can be mixed with each other more easily, and the texture of the membrane material is more uniform. In addition, sulfo of the lauramidopropyl hydroxysulfobetaine has strong hydrophilicity, and the hydrophilic performance of the modified montmorillonite is greatly increased, so that the hydrophilic performance of the membrane is improved, and the anti-pollution characteristic of the membrane is improved.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 60-80 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating, continuously stirring for 20-40 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating and stirring to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven for static defoaming;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for preservation, wherein the volume ratio of the glycerol to the distilled water is 0.8-1: 1.
The casting solution is placed in a vacuum drying oven for static defoaming, so that air in the casting solution is removed, the casting solution is more uniformly coated on a steel plate, the compactness of the ultrafiltration membrane is improved, and the rejection rate of the ultrafiltration membrane to oil stains is improved.
After the casting solution was coated on the steel plate, it was immersed in a deionized water coagulation bath in order to solidify the viscous casting solution and remove the N, N-dimethylacetamide solvent.
The solution prepared by the glycerol and distilled water in the volume ratio of 0.8-1: 1 has a good preservation effect on the polyvinyl chloride ultrafiltration membrane, and the interception performance and flux of the membrane are kept stable.
Preferably, the montmorillonite is added in the step 1), and then the mixture is heated to 70-90 ℃.
Preferably, after the dried polyvinyl chloride powder is added in the step 1), the mixture is heated to 65-80 ℃ and stirred for 10-16 hours.
Preferably, the defoaming time in the step 2) is 25 to 35 minutes.
Preferably, the temperature of the deionized water coagulation bath in the step 4) is 25-40 ℃.
Therefore, the invention has the following beneficial effects: (1) the montmorillonite modified polyvinyl chloride can improve the hydrophilicity of the ultrafiltration membrane and enhance the anti-pollution performance of the ultrafiltration membrane; (2) the lauramidopropyl hydroxysulfobetaine is used for modifying the montmorillonite, and then the modified montmorillonite is used for modifying the polyvinyl chloride, so that the hydrophilic performance of the ultrafiltration membrane is further enhanced, and the prepared ultrafiltration membrane has stronger anti-pollution performance; (3) by utilizing the special structure of the montmorillonite, polyvinyl chloride macromolecular chains are intercalated into the montmorillonite layers in a certain mode, so that the strength of the ultrafiltration membrane is greatly enhanced, and higher water pressure can be borne; (4) part of montmorillonite can be mixed in membrane pores in the polyvinyl chloride flat membrane, the membrane pore size is reduced, and the retention rate of macromolecular organic matters is improved; (5) no support body is needed, the preparation raw materials are saved, and the preparation steps are simplified.
Drawings
FIG. 1 scanning electron microscope image of the interior surface of an unmodified PVC ultrafiltration membrane after oil contamination filtration
FIG. 2 is an electron scanning microscope image of the inner surface of the oil-contaminated polyvinyl chloride membrane after being subjected to oil filtration by the montmorillonite-modified polyvinyl chloride ultrafiltration membrane.
Detailed Description
The technical solution of the present invention is further illustrated by the following specific examples.
In the present invention, unless otherwise specified, all the raw materials and equipment used are commercially available or commonly used in the art, and the methods in the examples are conventional in the art unless otherwise specified.
Example 1
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
Montmorillonite 0.3%
Molecular weight 400 polyethylene glycol 3%
The balance of N, N-dimethylacetamide.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine at a mass ratio of 0.7:1, heating to 60 ℃, and stirring at a rotating speed of 1600rpm for reaction for 5 hours;
2) filtering the reacted product, and drying at 65 deg.c for 24 hr;
3) and adding the dried product into a ball mill, crushing, and sieving by a 180-mesh sieve to obtain the modified montmorillonite.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 60 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 70 ℃, continuously stirring for 20 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 65 ℃, and stirring for 10 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 25 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 25 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.8: 1.
Example 2
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
13 percent of polyvinyl chloride
Montmorillonite 0.5%
Molecular weight 400 polyethylene glycol 4%
The balance of N, N-dimethylacetamide.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine at a mass ratio of 0.8:1, heating to 63 ℃, and stirring and reacting at the rotating speed of 1700rpm for 5.3 hours;
2) filtering the reacted product, and drying at 70 deg.c for 30 hr;
3) and adding the dried product into a ball mill, crushing, and sieving by a 190-mesh sieve to obtain the modified montmorillonite.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 65 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 75 ℃, continuously stirring for 25 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 70 ℃, and stirring for 12 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 28 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 27 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.85: 1.
Example 3
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
polyvinyl chloride 15%
Montmorillonite 0.7%
Molecular weight 600 polyethylene glycol 5%
The balance of N, N-dimethylacetamide.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine at a mass ratio of 0.85:1, heating to 65 ℃, and stirring at the rotation speed of 1800rpm for reaction for 5.5 hours;
2) filtering the reacted product, and drying at 75 deg.c for 35 hr;
3) and adding the dried product into a ball mill, crushing, and sieving by a 200-mesh sieve to obtain the modified montmorillonite.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 70 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 80 ℃, continuously stirring for 30 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 72 ℃, and stirring for 13 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 30 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 30 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.9: 1.
Example 4
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
polyvinyl chloride 17%
Molecular weight 800% polyethylene glycol 6%
The balance of N, N-dimethylacetamide.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine at a mass ratio of 0.9:1, heating to 68 ℃, and stirring at a rotation speed of 1900rpm for reaction for 5.8 hours;
2) filtering the reacted product, and drying at 78 deg.c for 40 hr;
3) and adding the dried product into a ball mill, crushing, and sieving by a 210-mesh sieve to obtain the modified montmorillonite.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 75 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 85 ℃, continuously stirring for 35 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 75 ℃, and stirring for 14 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 32 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 35 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.95: 1.
Example 5
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
polyvinyl chloride 20%
2 percent of montmorillonite
Molecular weight 800% polyethylene glycol 7%
The balance of N, N-dimethylacetamide.
Wherein, the montmorillonite is modified, and the modification method comprises the following steps:
1) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine according to the mass ratio of 1:1, heating to 70 ℃, and stirring and reacting for 6 hours at the rotating speed of 2000 rpm;
2) filtering the reacted product, and drying at 80 deg.c for 48 hr;
3) and adding the dried product into a ball mill, crushing, and screening by a 220-mesh screen to obtain the modified montmorillonite.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 80 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 90 ℃, continuously stirring for 40 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 80 ℃, and stirring for 16 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 35 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 40 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 1: 1.
Example 6
A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is prepared by preparing casting solution from montmorillonite hydrophilic modified polyvinyl chloride, defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
polyvinyl chloride 15%
Montmorillonite 0.7%
Molecular weight 600 polyethylene glycol 5%
The balance of N, N-dimethylacetamide.
A method for preparing a montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 70 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating to 80 ℃, continuously stirring for 30 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 72 ℃, and stirring for 13 hours to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 30 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 30 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.9: 1.
Comparative example 1
Preparing a membrane casting solution by using polyvinyl chloride, and preparing an ultrafiltration membrane through defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
Molecular weight 400 polyethylene glycol 3%
The balance of N, N-dimethylacetamide.
The preparation method of the polyvinyl chloride ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 60 ℃, stirring to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating to 65 ℃, and stirring for 10 hours to obtain a homogeneous membrane casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven, standing and defoaming for 25 minutes;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath at 25 ℃ until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for storage, wherein the volume ratio of the glycerol to the distilled water is 0.8: 1.
The ultrafiltration membranes prepared in examples 1 to 5 and comparative example were tested for hydrophilicity, flux level, tensile strength and water purification effect (examples 1 to 5 are ultrafiltration membranes prepared using modified montmorillonite modified polyvinyl chloride, example 6 is an ultrafiltration membrane prepared using unmodified montmorillonite modified polyvinyl chloride, and comparative example is an ultrafiltration membrane prepared using polyvinyl chloride), and the test results are shown in the following table:
| contact angle (°) | Water flux (L.h)-1·m-2) | Tensile Strength (MPa) | Oil retention (%) | |
| Example 1 | 65.3 | 201.32 | 8.14 | 85.69 |
| Example 2 | 63.2 | 168.73 | 8.52 | 87.16 |
| Example 3 | 59.5 | 127.32 | 9.34 | 90.78 |
| Example 4 | 58.3 | 95.33 | 10.98 | 95.34 |
| Example 5 | 51.5 | 84.76 | 12.33 | 97.88 |
| Example 6 | 70.5 | 100.25 | 9.56 | 89.75 |
| Comparative example 1 | 80.2 | 56.32 | 5.45 | 78.6 |
Compared with the polyvinyl chloride ultrafiltration membrane without modification, the ultrafiltration membrane prepared by adding the montmorillonite modified polyvinyl chloride has improved hydrophilic performance, water flux, tensile strength and oil retention rate; the hydrophilicity of the ultrafiltration membrane prepared by modifying the montmorillonite by the lauramidopropyl hydroxysulfobetaine and then modifying the polyvinyl chloride by the modified montmorillonite is improved compared with that of the ultrafiltration membrane prepared by modifying the polyvinyl chloride by the unmodified montmorillonite, the flux is increased, and the difference between the pull-up strength and the retention rate is not large.
Fig. 1 and 2 are respectively an electron scanning microscope image of the inner surface of a flat membrane prepared without modification with montmorillonite and an electron scanning microscope image of the inner surface of a flat membrane prepared with polyvinyl chloride prepared with modification with montmorillonite, which are obtained after filtering oil stains of the same concentration under the same test conditions for 48 hours; the image shows that the inner surface of the flat membrane which is not modified by the montmorillonite is attached with more pollutants, so that the membrane is polluted to a greater extent, and the inner surface of the flat membrane which is modified by the montmorillonite does not have pollutants, so that the ultrafiltration membrane prepared by modifying the polyvinyl chloride by the montmorillonite has stronger pollution resistance.
Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (5)
1. A montmorillonite modified polyvinyl chloride flat ultrafiltration membrane is characterized in that montmorillonite hydrophilic modified polyvinyl chloride is used for preparing a membrane casting solution, and the membrane is prepared by defoaming, coating, curing and separating; the casting solution comprises the following components in percentage by mass:
10-20% of polyvinyl chloride
Montmorillonite 0.3% -2%
3% -7% of polyethylene glycol
The balance of N, N-dimethylacetamide;
the molecular weight of the polyethylene glycol is 400, 600 or 800;
the montmorillonite is subjected to modification treatment, and the modification method comprises the following steps:
a) mixing montmorillonite and lauramidopropyl hydroxysulfobetaine according to the mass ratio of 0.7-1: 1, heating to 60-70 ℃, and stirring and reacting for 5-6 hours at the rotating speed of 1600-2000 rpm;
b) filtering the reacted product, and drying at 65-80 ℃ for 24-48 hours;
c) adding the dried product into a ball mill, crushing, and screening by a screen of 180-220 meshes to obtain modified montmorillonite;
the preparation method of the montmorillonite modified polyvinyl chloride flat ultrafiltration membrane comprises the following steps:
1) preparing a casting solution: mixing polyethylene glycol and an N, N-dimethylacetamide solvent according to a formula ratio in a stirrer, heating to 60-80 ℃, stirring to obtain a homogeneous solution, adding montmorillonite according to the formula ratio, heating, continuously stirring for 20-40 minutes to obtain a homogeneous solution, adding dry polyvinyl chloride powder according to the formula ratio, heating and stirring to obtain a homogeneous casting solution;
2) defoaming: placing the casting solution into a vacuum drying oven for static defoaming;
3) coating: pouring the defoamed casting solution on a dry and flat steel plate, and pushing a film scraping knife at a constant speed to uniformly coat the casting solution on the steel plate;
4) curing and separating: immersing the steel plate into a deionized water coagulating bath until the flat membrane falls off from the steel plate;
5) and (3) storage: and (3) putting the polyvinyl chloride flat membrane into a mixed solution of glycerol and distilled water for preservation, wherein the volume ratio of the glycerol to the distilled water is 0.8-1: 1.
2. The preparation method of the montmorillonite-modified polyvinyl chloride flat ultrafiltration membrane according to claim 1, wherein montmorillonite is added in the step 1) and then heated to 70-90 ℃.
3. The preparation method of the montmorillonite-modified polyvinyl chloride flat ultrafiltration membrane according to claim 1, wherein the dried polyvinyl chloride powder is added in the step 1), and then the mixture is heated to 65-80 ℃ and stirred for 10-16 hours.
4. The preparation method of the montmorillonite-modified polyvinyl chloride flat ultrafiltration membrane according to claim 1, wherein the defoaming time in the step 2) is 25-35 minutes.
5. The preparation method of the montmorillonite-modified polyvinyl chloride flat ultrafiltration membrane according to claim 1, wherein the temperature of the deionized water coagulation bath in the step 4) is 25-40 ℃.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1709558A (en) * | 2005-04-26 | 2005-12-21 | 哈尔滨工业大学 | Method for preparing polymer/montmorillnoite nano composite hydrophilic membrance |
| CN102743980A (en) * | 2012-08-01 | 2012-10-24 | 柳州森淼环保技术开发有限公司 | Manufacture method of polyvinyl chloride panel ultrafiltration membrane |
| CN104258742A (en) * | 2014-07-11 | 2015-01-07 | 哈尔滨工程大学 | Preparation method of cheap ultra-filtration membrane for treating oil producing wastewater |
| CN104667768A (en) * | 2013-11-29 | 2015-06-03 | 贵阳时代沃顿科技有限公司 | Preparation method for novel anti-pollution polysulfone flat plate ultrafiltration membrane |
| CN106179188A (en) * | 2016-07-19 | 2016-12-07 | 深圳市裕农科技股份有限公司 | Bipolarity bentonite clay material and preparation method thereof |
-
2017
- 2017-08-10 CN CN201710682513.9A patent/CN107413206B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1709558A (en) * | 2005-04-26 | 2005-12-21 | 哈尔滨工业大学 | Method for preparing polymer/montmorillnoite nano composite hydrophilic membrance |
| CN102743980A (en) * | 2012-08-01 | 2012-10-24 | 柳州森淼环保技术开发有限公司 | Manufacture method of polyvinyl chloride panel ultrafiltration membrane |
| CN104667768A (en) * | 2013-11-29 | 2015-06-03 | 贵阳时代沃顿科技有限公司 | Preparation method for novel anti-pollution polysulfone flat plate ultrafiltration membrane |
| CN104258742A (en) * | 2014-07-11 | 2015-01-07 | 哈尔滨工程大学 | Preparation method of cheap ultra-filtration membrane for treating oil producing wastewater |
| CN104258742B (en) * | 2014-07-11 | 2017-04-12 | 哈尔滨工程大学 | Preparation method of cheap ultra-filtration membrane for treating oil producing wastewater |
| CN106179188A (en) * | 2016-07-19 | 2016-12-07 | 深圳市裕农科技股份有限公司 | Bipolarity bentonite clay material and preparation method thereof |
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