CN115672029A - Acid-resistant nanofiltration membrane as well as preparation method and application thereof - Google Patents
Acid-resistant nanofiltration membrane as well as preparation method and application thereof Download PDFInfo
- Publication number
- CN115672029A CN115672029A CN202110823337.2A CN202110823337A CN115672029A CN 115672029 A CN115672029 A CN 115672029A CN 202110823337 A CN202110823337 A CN 202110823337A CN 115672029 A CN115672029 A CN 115672029A
- Authority
- CN
- China
- Prior art keywords
- nanofiltration membrane
- acid
- layer
- resistant nanofiltration
- membrane
- 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
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Abstract
The invention relates to an acid-resistant nanofiltration membrane and a preparation method and application thereof. The acid-resistant nanofiltration membrane sequentially comprises a bottom layer, a porous supporting layer and a separation layer, wherein the separation layer is cured and crosslinked amino thermosetting resin. The separation layer is a macromolecular layer with a cross-linked structure and is formed by heating, curing and cross-linking amino thermosetting resin. The nanofiltration membrane prepared by the method has good water permeability, salt interception property and acid resistance, and has simple process and great industrial application prospect.
Description
Technical Field
The invention relates to the field of nanofiltration membranes, and particularly relates to an acid-resistant nanofiltration membrane and a preparation method and application thereof.
Background
Nanofiltration is a pressure-driven membrane separation process between reverse osmosis and ultrafiltration, the pore size range of the nanofiltration membrane is about several nanometers, the removal of monovalent ions and organic matters with the molecular weight less than 200 is poor, and the removal rate of divalent or multivalent ions and organic matters with the molecular weight between 200 and 500 is high. Can be widely used in the fields of fresh water softening, seawater softening, drinking water purification, water quality improvement, oil-water separation, wastewater treatment and recycling, and the classification, purification, concentration and the like of chemical products such as dyes, antibiotics, polypeptides, polysaccharides and the like.
At present, most commercial nanofiltration membranes use polysulfone ultrafiltration membranes as a supporting layer, interfacial polymerization of polyamine aqueous phase and polyacyl chloride organic phase is carried out in situ on the upper surface of the ultrafiltration membrane, and the final product is a composite nanofiltration membrane. The common aqueous phase monomer is piperazine or piperazine substituted amine, the organic phase is trimesoyl chloride or a polyfunctional acyl halide, as disclosed in the patent numbers US4769148 and US4859384, a large amount of unreacted acyl chloride groups are hydrolyzed into carboxylic acid, so that the surface of the nanofiltration membrane is negatively charged, and by utilizing the charge effect, the polypiperazine amide composite nanofiltration membrane has higher rejection rate to high-valence anions and adjustable rejection rate to monovalent anions.
In addition, patent nos. US4765897, US4812270 and US 482474 also provide a method how to convert a polyamide composite reverse osmosis membrane into a nanofiltration membrane.
However, due to the limitation of the material characteristics, the traditional polyamide nanofiltration membrane is degraded in an extreme pH environment, and the polyamide nanofiltration membrane is only used for neutral media or weak-acid and weak-alkaline media close to neutral because the pH range of the polyamide nanofiltration membrane is generally 2-11. This also limits the use of polyamide nanofiltration membranes in certain specific industrial fields. For example, wastewater in the metallurgical and mining industries is generally strongly acidic, and excellent acid stability is required for a filtration membrane material.
Therefore, the development of the nanofiltration membrane with acid resistance has great significance for wastewater treatment in the metallurgy and mining industries of China.
Disclosure of Invention
The invention aims to overcome the defect of poor acid resistance of the existing nanofiltration membrane, and provides a composite nanofiltration membrane, a preparation method thereof, and application of the composite nanofiltration membrane and the composite nanofiltration membrane prepared by the method in the field of water treatment.
The invention aims to provide an acid-resistant nanofiltration membrane, which sequentially comprises a bottom layer, a porous supporting layer and a separation layer, wherein the separation layer is cured and crosslinked amino thermosetting resin.
The bottom layer is made of non-woven fabric, and the material of the non-woven fabric is preferably at least one of polyethylene and polypropylene.
The material of the porous support layer is preferably at least one of polyether sulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyether ketone, polyether ether ketone and polyarylether ketone.
The amino thermosetting resin is preferably at least one of urea-formaldehyde resin, melamine formaldehyde resin and polyamide polyamine epichlorohydrin resin. The structure of the above described amino thermosetting resin is listed below:
the thickness of the bottom layer is 30 to 150 μm, preferably 50 to 120 μm.
The thickness of the porous support layer is 10 to 100 μm, preferably 30 to 60 μm.
The thickness of the separation layer is 10 to 500nm, preferably 50 to 300nm.
The separation layer is obtained by heating, curing and crosslinking an amino thermosetting resin.
The second purpose of the invention is to provide a preparation method of the acid-resistant nanofiltration membrane, which comprises the following steps:
(1) Preparing a porous support layer on one surface of the base layer;
(2) Dissolving amino thermosetting resin in a solvent to prepare a coating solution, and coating the coating solution on the surface of the porous supporting layer;
(3) Heating and curing to obtain the acid-resistant nanofiltration membrane.
In the step (2), the solvent is at least one of water, ethanol, methanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, formic acid and acetic acid.
The pH of the coating solution in the step (2) is 0 to 6, preferably 1 to 4.
In the step (3), the heating curing conditions are as follows: the temperature is 40-150 ℃, preferably 80-120 ℃; the time is 5 to 120 minutes, preferably 10 to 30 minutes.
The third purpose of the invention is to provide the acid-resistant nanofiltration membrane obtained by the preparation method.
The fourth purpose of the invention is to provide the application of the acid-resistant nanofiltration membrane or the acid-resistant nanofiltration membrane obtained by the preparation method in the water treatment process.
The inventor of the invention has found through intensive research that the amino thermosetting resin forms a three-dimensional network structure after being heated, cured and crosslinked, has good retention rate on salt ions, and hydrophilic groups in the molecular structure are helpful for the permeation of water molecules. More importantly, after high crosslinking, the molecular structure of the resin is relatively stable, and the resin has no groups which are easy to hydrolyze under acidic conditions, and shows excellent acid resistance.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
FIG. 1 is a surface SEM photograph of a polysulfone porous support layer in an example.
Fig. 2 is a surface SEM photograph of the separation layer of the acid-resistant nanofiltration membrane obtained in example 1.
Detailed Description
While the present invention will be described in detail with reference to the following examples, it should be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the present invention.
The following examples are preferred embodiments of the present invention, but the present invention is not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and they are included in the scope of the present invention.
The acid-resistant nanofiltration membrane provided by the invention comprises three layers of structures: the bottom base material is non-woven fabric, one surface of the bottom layer of the non-woven fabric is attached with a porous supporting layer, the surface of the porous supporting layer is attached with a macromolecular separation layer with a cross-linking structure, and the cross-linked macromolecular separation layer is formed by heating, curing and cross-linking amino thermosetting resin.
According to a preferred embodiment of the present invention, the amino thermosetting resin is one or a mixture of several of urea-formaldehyde resin, melamine formaldehyde resin and polyamide polyamine epichlorohydrin resin.
The thicknesses of the non-woven fabric bottom layer, the porous supporting layer and the separation layer are not particularly limited and can be selected conventionally in the field, but in order to enable the three layers to have better synergistic interaction, the obtained acid-resistant nanofiltration membrane can better have excellent acid resistance, higher water flux and salt rejection rate, and preferably, the thickness of the bottom layer is 30-150 micrometers, and preferably 50-120 micrometers; the thickness of the porous supporting layer is 10-100 μm, preferably 30-60 μm; the thickness of the separation layer is 10 to 500nm, preferably 50 to 300nm.
The bottom layer and the porous supporting layer are not particularly limited, and can be made of various existing materials which have certain strength and can be used for nanofiltration and reverse osmosis membranes, and the material of the bottom layer non-woven fabric is one or the mixture of polyethylene and polypropylene. The porous support layer is made of one or more of polyethersulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyetherketone, polyetheretherketone and polyaryletherketone, which are known to those skilled in the art and will not be described herein again.
According to a preferred embodiment of the invention, the preparation method of the acid-resistant nanofiltration membrane comprises the following steps: (1) Preparing a porous support layer on one surface of the base layer; (2) Dissolving amino thermosetting resin in a solvent to prepare a coating solution; fixing the dried porous supporting layer on a glass plate, and uniformly coating the prepared coating liquid on the porous supporting layer; and (3) heating and curing to obtain the acid-resistant nanofiltration membrane.
Wherein, the method of step (1) can be selected conventionally in the field, and preferably a phase inversion method is adopted, and a material solution of a porous support layer can be coated on one surface of the bottom layer, and the bottom layer with the porous support layer attached on the surface can be obtained through phase inversion.
The phase inversion process preferably comprises: dissolving the polymer material of the porous support layer in a solvent to obtain a polymer solution with the concentration of 10-20 wt%, and defoaming at 20-40 ℃ for 10-180 min; then coating the polymer solution on the bottom layer to obtain an initial film, and then soaking the initial film in water with the temperature of 10-30 ℃ for 10-60 min to convert the polymer layer on the surface of the bottom layer into a porous film through phase transformation.
The solution or dispersion obtained in step (1) may be applied to a substrate using any conventional coating method, including but not limited to: brushing, curtain coating and spraying.
The material of the porous supporting layer is at least one of polyether sulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyether ketone, polyether ether ketone and polyarylether ketone.
According to a preferred embodiment of the present invention, the phase inversion process may specifically be: dissolving the polymer material of the porous supporting layer in a solvent to obtain a polymer solution, and filtering and defoaming the polymer solution; and then coating the polymer solution on the bottom layer to obtain an initial membrane, soaking the initial membrane in deionized water to promote complete phase inversion, and finally cleaning to obtain the porous support layer polymer membrane.
Among them, the solvent may be N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, etc.
According to a preferred embodiment of the present invention, the amino thermosetting resin is preferably one or a mixture of several of urea formaldehyde resin, melamine formaldehyde resin and polyamide polyamine epichlorohydrin resin.
According to a preferred embodiment of the present invention, the concentration of the amino thermosetting resin in the coating solution in step (2) of the nanofiltration membrane preparation process is not particularly limited as long as the resulting nanofiltration membrane can achieve excellent acid resistance, high water flux and salt rejection, and the amino thermosetting resin is preferably contained in an amount of 0.1 to 10 parts, more preferably 0.5 to 5 parts, for example, 0.1 part, 0.5 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., based on 100 parts by weight of the solvent.
According to a preferred embodiment of the present invention, the solvent used in step (2) of the nanofiltration membrane preparation process is not particularly limited as long as the amino thermosetting resin can be dissolved, and may be one or a mixture of water, ethanol, methanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, formic acid and acetic acid, and preferably water and methanol.
According to a preferred embodiment of the present invention, the pH of the coating solution in step (2) of the nanofiltration membrane preparation process is not particularly limited, and may be 0 to 6, preferably 1 to 4, such as 0, 1, 2, 3, 4, 5, and 6, as long as the nanofiltration membrane obtained by the present invention can combine excellent acid resistance, high water flux, and high salt rejection.
According to a preferred embodiment of the present invention, the conditions of the heat curing heat treatment in step (3) of the nanofiltration membrane preparation process are not particularly limited, as long as the obtained nanofiltration membrane can combine excellent acid resistance, high water flux and high salt rejection, and the heat treatment temperature is 40 to 150 ℃, preferably 80 to 120 ℃; the heat treatment time is 5 to 120 minutes, preferably 10 to 30 minutes.
The present invention will be described in detail below by way of examples.
In the following examples and comparative examples:
(1) The water flux of the composite nanofiltration membrane is obtained by testing the following method: the composite nanofiltration permeable membrane is put into a membrane pool, after prepressing for 0.5 hour under 1.2MPa, the water permeability of the nanofiltration membrane within 1 hour is measured under the conditions of the pressure of 2.0MPa and the temperature of 25 ℃, and the water permeability is calculated by the following formula:
j = Q/(A.t), wherein J is water flux, Q is water flux (L), and A is effective membrane area (m) of the composite nanofiltration membrane 2 ) T is time (h);
(2) The salt rejection of the composite nanofiltration membrane is obtained by testing the following method: the composite nanofiltration membrane is loaded into a membrane pool, after prepressing for 0.5h under 0.2MPa, the concentration change of sodium sulfate raw water solution with initial concentration of 1000ppm and sodium sulfate in permeate liquid within 1h is measured under the conditions of pressure of 0.5MPa and temperature of 25 ℃, and the composite nanofiltration membrane is obtained by calculating according to the following formula:
R＝(C p -C f )/C p x 100%, wherein R is the salt rejection, C p Is the concentration of sodium sulfate in the stock solution, C f Is the concentration of sodium sulfate in the permeate;
(3) And (3) testing the acid resistance of the composite nanofiltration membrane: soaking the composite nanofiltration membrane in a solution containing 20 wt% of H 2 SO 4 1 month in the water solution, and then testing the water flux and the salt rejection rate of the composite nanofiltration membrane;
in addition, in the following examples and comparative examples:
urea-formaldehyde resin was purchased from Henan Pashenxiang chemical Co., ltd, melamine-formaldehyde resin was purchased from Xinli practical Co., ltd, xinxiang city, polyamidopolyamine-epichlorohydrin resin was purchased from Chinese pulp and paper-making research institute Co., ltd, polysulfone (P3500) was purchased from Suwei Co., ltd, nonwoven fabric was purchased from Kidi, and other chemical reagents were purchased from national chemical group Co., ltd.
The supporting layer is prepared by adopting a phase inversion method, and the method comprises the following specific steps:
dissolving a certain amount of polysulfone (the number average molecular weight is 80000) in N, N-dimethylformamide to prepare a polysulfone solution with the concentration of 18 weight percent, and defoaming at 25 ℃ for 120min; then, the polysulfone solution was coated on a polyethylene nonwoven fabric (75 μm thick) using a doctor blade to obtain an initial film, which was then soaked in water at a temperature of 25 ℃ for 60min so that the polysulfone layer on the surface of the polyethylene nonwoven fabric was phase-converted into a porous film, and finally washed 3 times to obtain a support layer having a total thickness of 115 μm.
The surface structure is shown in fig. 1, and it can be seen that many nano-scale pores are distributed on the surface of the film.
Example 1
Dissolving polyamide polyamine epichlorohydrin resin in a mixed solvent consisting of deionized water and methanol, and adjusting the pH of the solution to 2 to prepare a coating dilute solution with the mass concentration of 2%; fixing the dried polysulfone porous support membrane on a glass plate, uniformly brushing the prepared coating dilute solution on the surface of the polysulfone porous support membrane, and then carrying out heat treatment at 100 ℃ for 30 minutes to obtain the nanofiltration membrane N1. The thickness of the separating layer was 156nm as measured by scanning electron microscopy.
The surface structure is shown in fig. 2, and compared with the surface of the porous support membrane, the surface of the N1 membrane is a layer of compact thin film.
Soaking the obtained composite membrane N1 in water for 24h, and measuring water flux and Na pair at 25 deg.C under 0.5MPa 2 SO 4 The salt rejection of (2) is shown in Table 1. Soaking the membrane in 20% by mass of H 2 SO 4 After 1 month in the water solution, the water flux and the salt rejection rate of the composite nanofiltration membrane are tested, and the results are shown in table 1.
Example 2
Dissolving urea-formaldehyde resin in a mixed solvent consisting of deionized water and ethylene glycol monomethyl ether, adjusting the pH of the solution to 2, and preparing a coating dilute solution with the mass concentration of 5%; fixing the dried polysulfone porous support membrane on a glass plate, uniformly brushing the prepared coating dilute solution on the surface of the polysulfone porous support membrane, and then carrying out heat treatment at 100 ℃ for 30 minutes to obtain the nanofiltration membrane N2. The thickness of the separating layer was 179nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane N2 in water for 24h, and measuring water flux and Na under the conditions of 0.5MPa of pressure and 25 DEG C 2 SO 4 The salt rejection of (2) is shown in Table 1. Soaking the membrane in 20% by mass of H 2 SO 4 After 1 month in the water solution, the water flux and the salt rejection rate of the composite nanofiltration membrane are tested, and the results are shown in table 1.
Example 3
Dissolving melamine formaldehyde resin in a mixed solvent consisting of deionized water and ethylene glycol monomethyl ether, adjusting the pH of the solution to 2, and preparing a coating dilute solution with the mass concentration of 0.5%; fixing the dried polysulfone porous support membrane on a glass plate, uniformly brushing the prepared coating dilute solution on the surface of the polysulfone porous support membrane, and then carrying out heat treatment at 120 ℃ for 20 minutes to obtain the nanofiltration membrane N3. The thickness of the separating layer was 132nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane N3 in water for 24h, and measuring water flux and Na pair at 25 deg.C under 0.5MPa 2 SO 4 The salt rejection of (2) is shown in Table 1. Soaking the membrane in 20% by mass of H 2 SO 4 After 1 month in the water solution, the water flux and the salt rejection rate of the composite nanofiltration membrane are tested, and the results are shown in table 1.
Comparative example 1
Contacting the upper surface (polysulfone layer surface) of the polysulfone porous support membrane with an aqueous solution containing 0.5wt% of piperazine at 25 ℃ for 30s, and discharging liquid; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.1wt% of trimesoyl chloride again, after contacting for 30s at 25 ℃, the liquid is discharged, the membrane is placed into an oven, and the membrane is heated for 3min at 70 ℃, so that the composite membrane D1 is obtained.
Soaking the obtained composite membrane D1 in water for 24h, and measuring water flux and Na at 25 deg.C under 0.5MPa 2 SO 4 The salt rejection of (2) is shown in Table 1. Soaking the membrane in 20% by mass of H 2 SO 4 Dissolving in waterAfter 1 month in the solution, the water flux and the salt rejection rate of the composite nanofiltration membrane are tested, and the results are shown in table 1.
TABLE 1
Claims (10)
1. An acid-resistant nanofiltration membrane sequentially comprises a bottom layer, a porous supporting layer and a separating layer, wherein the separating layer is cured and crosslinked amino thermosetting resin.
2. The acid-resistant nanofiltration membrane of claim 1, wherein:
the bottom layer is made of non-woven fabric, and the material of the non-woven fabric is preferably at least one of polyethylene and polypropylene; and/or the presence of a gas in the gas,
the material of the porous supporting layer is at least one of polyether sulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyether ketone, polyether ether ketone and polyaryletherketone; and/or the presence of a gas in the gas,
the amino thermosetting resin is at least one of urea-formaldehyde resin, melamine formaldehyde resin and polyamide polyamine epichlorohydrin resin.
3. The acid-resistant nanofiltration membrane of claim 1, wherein:
the thickness of the bottom layer is 30-150 μm, preferably 50-120 μm; and/or the presence of a gas in the atmosphere,
the thickness of the porous support layer is 10-100 μm, preferably 30-60 μm; and/or the presence of a gas in the atmosphere,
the thickness of the separation layer is 10 to 500nm, preferably 50 to 300nm.
4. A method of preparing the acid resistant nanofiltration membrane according to any one of claims 1 to 3, comprising the steps of:
(1) Preparing a porous support layer on one surface of the base layer;
(2) Dissolving amino thermosetting resin in a solvent to prepare a coating solution, and coating the coating solution on the surface of the porous supporting layer;
(3) Heating and curing to obtain the acid-resistant nanofiltration membrane.
5. The method of manufacturing according to claim 4, characterized in that:
in the step (2), the solvent is at least one of water, ethanol, methanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, formic acid and acetic acid.
6. The method of claim 4, wherein:
in the coating liquid of the step (2), the amino thermosetting resin is contained in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the solvent.
7. The method of claim 4, wherein:
the pH of the coating solution in the step (2) is 0 to 6, preferably 1 to 4.
8. The method of manufacturing according to claim 4, characterized in that:
in the step (3), the heating curing conditions are as follows: the temperature is 40-150 ℃, preferably 80-120 ℃; the time is 5 to 120 minutes, preferably 10 to 30 minutes.
9. An acid-resistant nanofiltration membrane obtained by the preparation method according to any one of claims 4 to 8.
10. Use of the acid resistant nanofiltration membrane of any one of claims 1 to 3 or obtained by the preparation method of any one of claims 4 to 8 in a water treatment process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110823337.2A CN115672029A (en) | 2021-07-21 | 2021-07-21 | Acid-resistant nanofiltration membrane as well as preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110823337.2A CN115672029A (en) | 2021-07-21 | 2021-07-21 | Acid-resistant nanofiltration membrane as well as preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115672029A true CN115672029A (en) | 2023-02-03 |
Family
ID=85044477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110823337.2A Pending CN115672029A (en) | 2021-07-21 | 2021-07-21 | Acid-resistant nanofiltration membrane as well as preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115672029A (en) |
-
2021
- 2021-07-21 CN CN202110823337.2A patent/CN115672029A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10040032B2 (en) | Complex nanofiltration membrane and the preparation thereof | |
| US5049282A (en) | Semipermeable composite membranes | |
| US6913694B2 (en) | Selective membrane having a high fouling resistance | |
| US5032282A (en) | Solvent-stable semipermeable composite membranes | |
| GB2390042A (en) | Membrane comprising cross-linked polyfunctional epoxy compound | |
| WO2021134060A1 (en) | High-flux water permeable membranes | |
| CN112516814A (en) | Preparation method of high-desalting solvent-resistant polyamide composite nanofiltration membrane | |
| Wei et al. | One-step fabrication of recyclable polyimide nanofiltration membranes with high selectivity and performance stability by a phase inversion-based process | |
| CN113509839B (en) | Acid/alkali-resistant composite nanofiltration membrane and preparation method and application thereof | |
| KR101659122B1 (en) | Polyamide water-treatment membranes having properies of high salt rejection and high flux and manufacturing method thereof | |
| CN107970779B (en) | Reverse osmosis membrane and preparation method and application thereof | |
| CN115672029A (en) | Acid-resistant nanofiltration membrane as well as preparation method and application thereof | |
| CN113634136A (en) | Nanofiltration membrane and preparation method and application thereof | |
| CN114432901B (en) | Composite membrane with acid resistance and alkali resistance as well as preparation method and application thereof | |
| CN110917903A (en) | Reverse osmosis membrane and preparation method | |
| CN114159979A (en) | Method for preparing amphiphilic pollution-resistant reverse osmosis membrane through grafting reaction | |
| KR102041657B1 (en) | Method for manufacturing water-treatment membrane, water-treatment membrane manufactured by thereof, and water treatment module comprising membrane | |
| CN115105967B (en) | Acid-resistant alkali-resistant nanofiltration membrane and preparation method and application thereof | |
| CN107970784B (en) | Reverse osmosis membrane and preparation method and application thereof | |
| Li et al. | A thin film composite membrane supported by a hydrophilic poly (vinyl alcohol‐co‐ethylene) nanofiber membrane: Preparation, characterization, and application in nanofiltration | |
| CN114432903B (en) | Composite membrane with acid resistance and preparation method and application thereof | |
| CN111760472A (en) | Composite membrane and preparation method and application thereof | |
| CN115475540B (en) | Polyamide composite membrane and preparation method and application thereof | |
| CN107970793B (en) | Reverse osmosis membrane and preparation method and application thereof | |
| CN115105967A (en) | Acid-resistant alkali-resistant nanofiltration membrane and preparation method and application thereof |
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 |