CN112691560A - Preparation method of MOFs-PVDF composite ultrafiltration membrane - Google Patents

Preparation method of MOFs-PVDF composite ultrafiltration membrane Download PDF

Info

Publication number
CN112691560A
CN112691560A CN202011143294.5A CN202011143294A CN112691560A CN 112691560 A CN112691560 A CN 112691560A CN 202011143294 A CN202011143294 A CN 202011143294A CN 112691560 A CN112691560 A CN 112691560A
Authority
CN
China
Prior art keywords
mofs
ultrafiltration membrane
pvdf
composite ultrafiltration
preparation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011143294.5A
Other languages
Chinese (zh)
Inventor
邓成
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
North South Brothers Pharmaceutical Investment Co ltd
North and South Brother Pharmacy Investment Co Ltd
Original Assignee
North South Brothers Pharmaceutical Investment Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by North South Brothers Pharmaceutical Investment Co ltd filed Critical North South Brothers Pharmaceutical Investment Co ltd
Priority to CN202011143294.5A priority Critical patent/CN112691560A/en
Publication of CN112691560A publication Critical patent/CN112691560A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
    • B01D71/78—Graft polymers
    • 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
    • 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
    • B01D67/0013—Casting processes
    • 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
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/48—Antimicrobial properties

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Dispersion Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

The invention relates to the technical field of membrane separation, and provides a preparation method of an MOFs-PVDF composite ultrafiltration membrane with a sterilization function. The method comprises the following steps: adding MOFs materials into a water solution containing an iron source and a silver source, and stirring and mixing to obtain a precursor solution; adding a sodium hydroxide solution into the precursor solution, stirring, introducing oxidizing gas, filtering and drying to obtain the AgO and FeOOH loaded modified MOFs material; adding PVDF (polyvinylidene fluoride) containing hydroxyl groups, a modified MOFs material and a pore-forming agent into an organic solvent, preparing a membrane casting solution, coating the membrane casting solution, and carrying out gel curing through a non-aqueous coagulating bath to obtain the MOFs-PVDF composite ultrafiltration membrane with the sterilization function. The MOFs-PVDF composite ultrafiltration membrane prepared by the method disclosed by the invention is good in hydrophilicity and strong in pollution resistance, has a sterilization and antibacterial function, and can be used in the field of water treatment.

Description

Preparation method of MOFs-PVDF composite ultrafiltration membrane
Technical Field
The invention relates to the technical field of membrane separation, in particular to a preparation method of an MOFs-PVDF composite ultrafiltration membrane with a sterilization function.
Background
The polymer separation membrane is a material applied to modern high-efficiency separation, concentration, purification and purification equipment, is widely applied to the fields of chemical industry, environmental protection, food, biology, pharmacy, electronics, electric power, metallurgy, light spinning and seawater desalination, and plays an important role in modern energy and resource and solving the problem of environmental pollution. Polyvinylidene fluoride, polysulfone, polyvinyl chloride membrane materials and the like are mainly used.
The metal organic framework compounds (MOFs) are materials with supermolecular microporous network structures formed by utilizing the complexation of metal-ligand between organic ligands and metal ions, and have the advantages of high porosity, large specific surface area, convenient synthesis, variable framework scale and size and the like due to the special topological structure, regular internal arrangement and pore channels with specific sizes and shapes, so the metal organic framework compounds are widely applied to the fields of adsorption, catalysis, membrane separation and the like.
For example, CN111135733A discloses a MOFs polymer hollow fiber composite ultrafiltration membrane and a preparation method thereof, wherein a high-strength polyvinylidene fluoride/polyacrylic acid ultrafiltration membrane, namely a PVDF/PAA ultrafiltration membrane, is prepared by a thermally induced phase separation method, and then an ultrathin MOFs separation layer is grown in situ on the outer surface of the separation membrane by a chelation-assisted interface reaction method, which can be applied to the field of water treatment. However, the composite ultrafiltration membrane has no bactericidal function.
At present, in the process of preparing pure water by using an ultrafiltration membrane as reverse osmosis pretreatment, on one hand, the ultrafiltration membrane can only adsorb proteins, fine microorganisms and the like in drinking water on the surface of the ultrafiltration membrane to prevent the proteins, the fine microorganisms and the like from passing through the ultrafiltration membrane, but cannot kill the proteins, the fine microorganisms and the like, so that the drinking water contains a large number of bacterial microorganisms, and the large number of bacterial microorganisms seriously threaten the health of the drinking water of people. Therefore, it is required to develop a method for preparing an ultrafiltration membrane having a sterilization function.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method of an MOFs-PVDF composite ultrafiltration membrane with a sterilization function, and the prepared MOFs-PVDF composite ultrafiltration membrane has good hydrophilicity, strong pollution resistance and a sterilization and antibacterial function, can be used in the field of water treatment, and particularly can be used for purification treatment of wastewater containing a large amount of iron ions, preparation of household drinking purified water and purification treatment of circulating water.
In order to achieve the purpose, the invention adopts the following technical scheme:
on one hand, the invention provides a preparation method of an MOFs-PVDF composite ultrafiltration membrane, which comprises the following steps:
(1) adding MOFs materials into a water solution containing an iron source and a silver source, and stirring and mixing to obtain a precursor solution;
(2) adding a sodium hydroxide solution into the precursor solution, stirring, introducing oxidizing gas, filtering and drying to obtain the AgO and FeOOH loaded modified MOFs material;
(3) adding hydroxyl-containing PVDF, a modified MOFs material and a pore-forming agent into an organic solvent, stirring and mixing, standing and defoaming to obtain a membrane casting solution, coating the membrane casting solution, and carrying out gel curing in a non-aqueous coagulation bath to obtain the MOFs-PVDF composite ultrafiltration membrane with a sterilization function;
wherein the MOFs material is one of ZIF-8, MIL-101 and UIO-66.
According to the preparation method of the MOFs-PVDF composite ultrafiltration membrane, on one hand, the polyvinylidene fluoride (PVDF) is modified to be rich in hydroxyl, the hydroxyl can increase the bonding force of an organic metal framework material and a polymer matrix, the introduction of the organic metal framework material can enhance the hydrophilicity and the anti-pollution capacity of the composite ultrafiltration membrane, on the other hand, the MOFs material is modified to load AgO and FeOOH, and the AgO can slowly release Ag2+Expensive Ag2+Has a lower valence of Ag+The composite ultrafiltration membrane has a stronger sterilization effect, AgO has a certain photocatalysis effect, electrons and holes are generated after the AgO is excited by light, and the existence of FeOOH can promote the photocatalysis process of the AgO, so that the composite ultrafiltration membrane has excellent sterilization and antibacterial properties.
As a preferred embodiment of the present invention, the iron source is iron nitrate; the silver source is silver nitrate.
In a preferred embodiment of the present invention, the sodium hydroxide solution is present in an amount of 1 to 10% by mass.
In a preferred embodiment of the present invention, the oxidizing gas is O3、O2、O3/O2Mixed gas, O3/N2Mixed gas, O2/N2Any one of the mixed gas. By introducing an oxidizing gas, the iron hydroxide is oxidized to FeOOH, Ag+Is oxidized to Ag2+。
In a preferred embodiment of the present invention, the introducing time of the oxidizing gas is 20 to 40min, and the drying is performed at 40 to 80 ℃ for 4 to 8 hours under vacuum.
In a preferred embodiment of the present invention, the mass of AgO is 5 to 15% of the mass of the MOFs material, for example: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.
In a preferred embodiment of the invention, the mass of the FeOOH is 1 to 10% of the mass of the MOFs material, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.
In a preferred embodiment of the present invention, the mass of the modified MOFs material is 1 to 10% of the total mass of the casting solution, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.
In a preferred embodiment of the present invention, the mass of the hydroxyl group-containing PVDF is 10 to 30% of the total mass of the casting solution.
As a preferred embodiment of the invention, the total mass of the casting solution is 100%, the hydroxyl-containing PVDF accounts for 10-30%, the modified MOFs material accounts for 1-10%, the pore-forming agent accounts for 1-3%, and the balance is the solvent.
As a preferred embodiment of the present invention, the organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide.
In a preferred embodiment of the present invention, the porogen is preferably polyvinylpyrrolidone.
On the other hand, the invention provides the MOFs-PVDF composite ultrafiltration membrane obtained by the preparation method.
On the other hand, the invention provides the application of the MOFs-PVDF composite ultrafiltration membrane in water treatment.
Compared with the prior art, the invention has the following technical effects:
(1) in the preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the invention, on one hand, the polyvinylidene fluoride (PVDF) is modified to be rich in hydroxyl, and the modified PVDF is rich in hydroxylThe hydroxyl can increase the binding force of an organic metal framework material and a polymer matrix, the introduction of the organic metal framework material can enhance the hydrophilicity and the anti-pollution capacity of the composite ultrafiltration membrane, and on the other hand, AgO can slowly release Ag2+Expensive Ag2+Has strong bactericidal performance, and the bactericidal effect is low-price Ag+About 200 times of the amount of the active AgO, AgO has certain photocatalysis effect, generates electrons and holes after being excited by light, and the existence of FeOOH (iron oxyhydroxide) can promote the photocatalysis process of AgO, thereby improving the sterilization performance.
(2) The MOFs-PVDF composite ultrafiltration membrane prepared by the method disclosed by the invention is good in hydrophilicity, strong in pollution resistance and excellent in sterilization performance, and can kill bacterial microorganisms in drinking water and guarantee the water safety of residents.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All patents and publications referred to herein are incorporated by reference in their entirety. The term "comprising" or "comprises" is open-ended, i.e. comprising what is specified in the present invention, but not excluding other aspects.
The following description will be made in detail on the preparation method of the MOFs-PVDF composite ultrafiltration membrane according to the embodiment provided by the invention.
1. Preparation of hydroxyl-containing PVDF
The preparation method of the PVDF containing hydroxyl can refer to CN 107626216A. The method comprises the following specific steps:
treating PVDF with alkali liquor, then reacting the PVDF treated with the alkali liquor in an isopropanol solution of sodium borohydride, and filtering and drying after the reaction is finished to obtain the PVDF containing hydroxyl.
Specifically, the alkali liquor is a lithium hydroxide aqueous solution, and the mass fraction of the lithium hydroxide aqueous solution is 3%; the reaction conditions of the alkali liquor treatment are as follows: stirring and reacting for 36-72h at 25-60 ℃.
Specifically, the mass fraction of the isopropanol solution of sodium borohydride is 0.1-1.5%, and more preferably 0.2%; the reduction reaction conditions in isopropanol solution of sodium borohydride are as follows: the reaction is stirred for 18 to 36 hours at room temperature.
According to some embodiments provided herein, the preparation of the hydroxyl-containing PVDF specifically comprises: 50g of PVDF was immersed in 200g of an aqueous solution (3% by mass) of lithium hydroxide, stirred at 50 ℃ for 48 hours, and then rinsed with water (2000mL) and isopropanol (2000mL), respectively; and then adding the washed PVDF into 200g of isopropanol solution (the mass fraction is 0.2%) of sodium borohydride, stirring and reacting for 24 hours at room temperature, filtering and drying to obtain the PVDF containing hydroxyl.
2. Preparation of modified MOFs materials
Adding MOFs materials into an aqueous solution containing ferric nitrate and silver nitrate, and stirring and mixing to obtain a precursor solution;
and adding a sodium hydroxide solution into the precursor solution, stirring, introducing oxidizing gas, filtering and drying to obtain the AgO and FeOOH loaded modified MOFs material.
Preferably, the MOFs material is one of ZIF-8, MIL-101 and UIO-66.
Examples of the MIL-101-based material include, but are not limited to, MIL-101 (Fe).
Examples of the UIO-66 include, but are not limited to, UiO-66(Ce), UiO-66(Zr), UiO-66(Ti), etc.
The preparation method of the MOFs material is not particularly limited, and can be performed by any method known in the art, such as a hydrothermal method.
In a preferred embodiment of the present invention, the sodium hydroxide solution is 1 to 10% by mass, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. The amount of the sodium hydroxide solution is not particularly limited, and the iron source and the silver source can be sufficiently reacted.
In a preferred embodiment of the present invention, the oxidizing gas is O3、O2、O3/O2Mixed gas, O3/N2Mixed gas, O2/N2Any one of the mixed gas. By introducing an oxidizing gas, the iron hydroxide is oxidized to FeOOH, Ag+Is oxidized to Ag2+。
In a preferred embodiment of the present invention, the introducing time of the oxidizing gas is 20 to 40min, and the drying is performed at 40 to 80 ℃ for 4 to 8 hours under vacuum.
In a preferred embodiment of the present invention, the mass of AgO is 5 to 15% of the mass of the MOFs material, for example: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.
In a preferred embodiment of the invention, the mass of the FeOOH is 1 to 10% of the mass of the MOFs material, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.
3. Preparation of MOFs-PVDF composite ultrafiltration membrane
Adding PVDF containing hydroxyl groups, modified MOFs materials and a pore-foaming agent into an organic solvent, stirring for 12-24h, and then standing and defoaming to obtain a membrane casting solution; and (3) coating the membrane casting solution on a substrate, standing in the air for 30-60 s, and immersing in a non-aqueous coagulating bath for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane with the sterilization function.
According to an embodiment provided by the present invention, the composition of the casting solution comprises: based on the total mass of the casting solution being 100%, 10-30% of hydroxyl-containing PVDF, 1-10% of modified MOFs material, 1-3% of pore-forming agent and the balance of organic solvent.
According to an embodiment provided by the present invention, the organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide.
According to an embodiment of the present invention, the porogen is polyvinylpyrrolidone.
Specifically, the non-aqueous coagulation bath may be a mixed solvent of acetone and the organic solvent.
The substrate includes but is not limited to glass plate, PET release film, mica, etc.
The coating method can be selected from blade coating, slit extrusion, dimple coating, and the like. In an embodiment of the present invention, the coating method is blade coating, and the blade gap can be adjusted according to the obtained film thickness.
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples were carried out under the conditions described in the specification, under the conventional conditions or under the conditions recommended by the manufacturer, unless otherwise specified. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
Example 1
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The MOFs material is ZIF-8, and in the obtained modified ZIF-8 material, the mass of AgO is 10% of that of ZIF-8, and the mass of FeOOH is 5% of that of ZIF-8.
Weighing Fe (NO) according to the proportion3)3And AgNO3Dissolving in water, and stirring for 30 min; adding ZIF-8, and stirring at room temperature for 1.5h to obtain a precursor solution;
adding a NaOH solution with the mass fraction of 8% into the precursor solution, and stirring for 15 min; then introducing O2/N2Mixing the gases, continuously stirring for 30min, filtering, washing, and drying in vacuum for 4h at 60 ℃ to obtain the AgO and FeOOH loaded modified ZIF-8 material.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 2
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that of example 1, and the modified ZIF-8 material obtained by the method comprises the following steps: the mass of AgO is 10 percent of that of ZIF-8, and the mass of FeOOH is 10 percent of that of ZIF-8.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 3
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that of example 1, and the modified ZIF-8 material obtained by the method comprises the following steps: the mass of AgO is 10 percent of that of ZIF-8, and the mass of FeOOH is 1 percent of that of ZIF-8.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 4
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that of example 1, and the modified ZIF-8 material obtained by the method comprises the following steps: the mass of AgO is 5 percent of that of ZIF-8, and the mass of FeOOH is 5 percent of that of ZIF-8.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 5
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that of example 1, and the modified ZIF-8 material obtained by the method comprises the following steps: the mass of AgO is 15 percent of that of ZIF-8, and the mass of FeOOH is 5 percent of that of ZIF-8.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 6
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that in example 1, replacing ZIF-8 with MIL-101 to obtain the modified MIL-101 material, wherein: the mass of AgO is 10 percent of the mass of MIL-101, and the mass of FeOOH is 5 percent of the mass of MIL-101.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified MIL-101 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Example 7
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the embodiment comprises the following steps:
(1) preparation of modified MOFs materials
The preparation method is the same as that of example 1, replacing ZIF-8 with UIO-66, and obtaining the modified UIO-66 material, wherein: the mass of AgO is 10 percent of that of UIO-66, and the mass of FeOOH is 5 percent of that of UIO-66.
(2) Preparation of MOFs-PVDF composite ultrafiltration membrane
Taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of modified UIO-66 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Comparative example 1
The preparation method of the MOFs-PVDF composite ultrafiltration membrane provided by the comparative example comprises the following steps:
taking the total mass of the casting solution as 100%, stirring and mixing 20% of PVDF containing hydroxyl groups, 5% of unmodified ZIF-8 material, 3% of polyvinylpyrrolidone and 72% of N-methylpyrrolidone for 12 hours, and then directly defoaming to obtain the casting solution; and coating the film casting solution on a glass plate, wherein the thickness of the coated film is 250 mu m, and after the coated film is kept in the air for 40s, soaking the coated film in a mixed solvent of acetone and N-methylpyrrolidone for gel curing to obtain the MOFs-PVDF composite ultrafiltration membrane.
Comparative example 2
The comparative example provides a preparation method of an MOFs-PVDF composite ultrafiltration membrane, which is different from the preparation method of the example 1 in that: in step (2), PVDF does not contain hydroxyl groups.
Performance testing
1. Water flux test
Placing the prepared composite ultrafiltration membrane in deionized water for a period of time, shearing a circular membrane with the diameter of 7.5cm, placing the circular membrane into an YL-300 ultrafiltration cup, prepressing for 40min under the pressure of 0.1MPa until the water flux is basically stable, and then measuring under the pressure of 0.1MPa, wherein the test results are shown in Table 1.
2. Anti-pollution Performance test
Bovine serum albumin with a molecular weight of 80000 at 1g/L was used as a test object at 0.1 MPa. The retention rate of the ultrafiltration membrane is determined by testing the residue of bovine serum albumin on the membrane. Retention rate
Figure BDA0002738853620000082
Wherein C ispAs the concentration of bovine serum albumin in the feed water, CfThe results are shown in Table 1 for the concentration of bovine serum albumin in the purified water.
3. Hydrophilic Property test
The contact angle of the prepared ultrafiltration membrane with water was measured by a contact angle tester, and the test results are shown in table 1.
4. Tensile strength
The tensile strength of the prepared ultrafiltration membrane was tested using a universal material tensile machine, and the test results are shown in table 1.
5. Test of antibacterial Property
Escherichia coli is used as indicator bacteria, the filtered solution of the prepared membrane is cultured, the number of the Escherichia coli in the filtered solution is calculated by a plate counting method, the antibacterial rate is calculated, and the test result is shown in table 1.
TABLE 1
Figure BDA0002738853620000081
Figure BDA0002738853620000091
As can be seen from the data in Table 1, the MOFs-PVDF composite ultrafiltration membrane obtained in the embodiment of the invention has the advantages of good hydrophilicity, large water flux, high rejection rate, good pollution resistance, excellent antibacterial performance and excellent mechanical performance. The comparative example 1 has no antibacterial property because it does not contain AgO and FeOOH; in comparative example 2, since PVDF does not contain hydroxyl, the bonding force with the MOFs material is poor, and the hydrophilic property and the mechanical property of the obtained ultrafiltration membrane are reduced to a certain extent.
In the description herein, references to the description of the terms "some embodiments," "other embodiments," "an embodiment," "an example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention and examples have been shown and described above, it is understood that the above embodiments, examples are illustrative and not to be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments, examples by those of ordinary skill in the art within the scope of the present invention.

Claims (10)

1. A preparation method of an MOFs-PVDF composite ultrafiltration membrane is characterized by comprising the following steps:
(1) adding MOFs materials into a water solution containing an iron source and a silver source, and stirring and mixing to obtain a precursor solution;
(2) adding a sodium hydroxide solution into the precursor solution, stirring, introducing oxidizing gas, filtering and drying to obtain the AgO and FeOOH loaded modified MOFs material;
(3) adding hydroxyl-containing PVDF, a modified MOFs material and a pore-forming agent into an organic solvent, stirring and mixing, standing and defoaming to obtain a membrane casting solution, coating the membrane casting solution, and carrying out gel curing in a non-aqueous coagulating bath to obtain the MOFs-PVDF composite ultrafiltration membrane with a sterilization function;
wherein the MOFs material is one of ZIF-8, MIL-101 and UIO-66.
2. The method for preparing the MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the iron source is ferric nitrate; the silver source is silver nitrate; the mass fraction of the sodium hydroxide solution is 1-10%.
3. The method for preparing the MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the oxidizing gas is O3、O2、O3/O2Mixed gas, O3/N2Mixed gas, O2/N2Any one of the mixed gas.
4. The preparation method of the MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the introducing time of the oxidizing gas is 20-40 min, and the drying is performed for 4-8 h at 40-80 ℃ in vacuum.
5. The preparation method of the MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the mass of the AgO is 5-15% of that of the MOFs material, and the mass of the FeOOH is 1-10% of that of the MOFs material.
6. The preparation method of the MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the mass of the modified MOFs material is 1-10% of the total mass of the membrane casting solution.
7. The preparation method of the MOFs-PVDF composite ultrafiltration membrane according to claim 6, wherein the composition of the membrane casting solution comprises: based on the total mass of the casting solution being 100%, 10-30% of hydroxyl-containing PVDF, 1-10% of modified MOFs material, 1-3% of pore-forming agent and the balance of organic solvent.
8. The process for preparing a MOFs-PVDF composite ultrafiltration membrane according to claim 1, wherein the organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone and dimethylsulfoxide; the pore-foaming agent is polyvinylpyrrolidone.
9. The MOFs-PVDF composite ultrafiltration membrane obtained by the preparation method according to any one of claims 1 to 8.
10. Use of the MOFs-PVDF composite ultrafiltration membrane of claim 9 in water treatment.
CN202011143294.5A 2020-10-23 2020-10-23 Preparation method of MOFs-PVDF composite ultrafiltration membrane Pending CN112691560A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011143294.5A CN112691560A (en) 2020-10-23 2020-10-23 Preparation method of MOFs-PVDF composite ultrafiltration membrane

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011143294.5A CN112691560A (en) 2020-10-23 2020-10-23 Preparation method of MOFs-PVDF composite ultrafiltration membrane

Publications (1)

Publication Number Publication Date
CN112691560A true CN112691560A (en) 2021-04-23

Family

ID=75507118

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011143294.5A Pending CN112691560A (en) 2020-10-23 2020-10-23 Preparation method of MOFs-PVDF composite ultrafiltration membrane

Country Status (1)

Country Link
CN (1) CN112691560A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113351177A (en) * 2021-05-27 2021-09-07 东南大学 Humidity capturing gel, preparation method and application
CN115282792A (en) * 2022-01-21 2022-11-04 浙江师范大学 Preparation method of polymer-magnetic organic metal framework compound composite separation membrane
CN115463563A (en) * 2022-09-28 2022-12-13 浙江工商大学 Broad-spectrum response type antibacterial composite membrane and preparation method and application thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113351177A (en) * 2021-05-27 2021-09-07 东南大学 Humidity capturing gel, preparation method and application
CN113351177B (en) * 2021-05-27 2022-08-26 东南大学 Humidity capturing gel, preparation method and application
CN115282792A (en) * 2022-01-21 2022-11-04 浙江师范大学 Preparation method of polymer-magnetic organic metal framework compound composite separation membrane
CN115463563A (en) * 2022-09-28 2022-12-13 浙江工商大学 Broad-spectrum response type antibacterial composite membrane and preparation method and application thereof
CN115463563B (en) * 2022-09-28 2023-11-21 浙江工商大学 Broad spectrum response type antibacterial composite film and preparation method and application thereof

Similar Documents

Publication Publication Date Title
CN112691560A (en) Preparation method of MOFs-PVDF composite ultrafiltration membrane
CN109621739B (en) Hydrophilic modification method for high-flux PVDF porous membrane
CN110743376B (en) PVDF-COF-MOFs ternary matrix mixed film and preparation method thereof
CN105498553A (en) Polyvinylidene fluoride and metal-organic framework composite ultra-filtration membrane and preparation and application
CN104548969A (en) Method for preparing anti-pollution polysulfone porous membrane by self-assembling immobilization of metal ions
CN111760461B (en) Preparation method of polyvinylidene fluoride mixed matrix membrane
CN107694357B (en) Preparation method of modified pollution-resistant hybrid reverse osmosis membrane
CN105617882A (en) Chitosan modified graphene oxide nano composite positive osmotic membrane and preparation method thereof
CN110479109B (en) Preparation method of polyvinylidene fluoride mixed matrix membrane with high flux and strong pollution resistance
CN107376673B (en) Loaded with TiO2PES ultrafiltration membrane of nanotube and preparation method and application thereof
CN110756065B (en) Hydrotalcite-like nanosheet modified separation membrane, and preparation method and application thereof
CN108854588B (en) Preparation method and application of hollow fiber ceramic membrane with double persulfate activation function
CN110917905B (en) Ultrafiltration membrane and preparation method thereof
CN109046029B (en) Preparation method of modified PVDF ultrafiltration membrane for complex heavy metal wastewater treatment
CN108854595A (en) Modified PVDF plate membrane of a kind of nano biological charcoal and the preparation method and application thereof
CN102512997B (en) Hydrophilic polyethersulfone with cardo alloy ultrafiltration membrane and preparation method thereof
CN113522038B (en) Preparation method and application of composite membrane for removing pollutants in water
Rameesha et al. Efficacy of MOF-199 in improvement of permeation, morphological, antifouling and antibacterial characteristics of polyvinylidene fluoride membranes
CN112691559A (en) Preparation method of antibacterial composite PVDF ultrafiltration membrane
CN116764606B (en) BPA molecular imprinting PAN/MOF nanofiber polymer membrane and preparation method and application thereof
CN113694742A (en) Nano-silver antibacterial ultrafiltration membrane and preparation method thereof
CN112121648A (en) Polyvinylidene fluoride mixed matrix membrane with photocatalytic self-cleaning performance and preparation method and application thereof
CN112090296A (en) Based on F-TiO2/Fe-g-C3N4Self-cleaning flat plate type PVDF ultrafiltration membrane and preparation method thereof
CN110743391A (en) Preparation method of functional polyvinylidene fluoride membrane
CN106422798B (en) Preparation method of antibacterial anti-pollution reproducible ultrafiltration membrane

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination