CN103357281A - Modifying method for polyvinylidene fluoride (PVDF) microfiltration membrane capable of effectively resisting to protein pollution - Google Patents
Modifying method for polyvinylidene fluoride (PVDF) microfiltration membrane capable of effectively resisting to protein pollution Download PDFInfo
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- CN103357281A CN103357281A CN2013102736104A CN201310273610A CN103357281A CN 103357281 A CN103357281 A CN 103357281A CN 2013102736104 A CN2013102736104 A CN 2013102736104A CN 201310273610 A CN201310273610 A CN 201310273610A CN 103357281 A CN103357281 A CN 103357281A
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Abstract
The invention discloses a modifying method for a polyvinylidene fluoride (PVDF) microfiltration membrane capable of effectively resisting to protein pollution. The modifying method comprises the following steps of: (1) cleaning the PVDF microfiltration membrane, and then, drying the PVDF microfiltration membrane; (2) immersing the dried PVDF microfiltration membrane into a methanol solution, and sequentially adding palmityldimethylbetaine, copper chloride, pentamethyldiethylenetriamine and deionized water under the protection of nitrogen gas to react; (3) adding ascorbic acid to carry out copolymerization, wherein the ascorbic acid is subjected to deoxygenation treatment by using the nitrogen gas; (4) taking out and cleaning the product, and then, drying the product; (5) mixing a N, N-methylenebisacrylamide solution, a ceric ammonium nitrate solution, nitric acid and a [3-(methacrylamide)propyl]dimethyl(3-sulfo-propyl) palmityldimethylbetaine solution, placing a membrane into the mixture, sealing and introducing nitrogen gas to deoxidize; and (6) after the reaction is ended, sequentially cleaning the product by using an ethanol/PSB (Polystyrene) buffer solution with the pH value of 7.4+/-0.02 and deionized water, and then, drying to obtain the modified PVDF microfiltration membrane capable of effectively resisting to protein pollution.
Description
Technical field
The invention belongs to film modification field, relate to particularly a kind of method of modifying to polyvinylidene fluoride microporous filtering film.
Background technology
Membrane technology is described as " water technology of 21 century ", is mainly used in drink water purifying and processes dirty wastewater treatment and utilization.Yet film pollutes and remains the bottleneck that hinders the membrane technology extensive use.Pollutant is accumulated or is adsorbed in film surface and the fenestra in the membrane filtration process, causes the film effective filtration area to reduce, and causes that flux descends.And the intrinsic characteristic of film also may affect the resistant to pollution ability of film.The hydrophilic and hydrophobic of film has material impact to the contamination resistance of film, and hydrophobicity is stronger, more is vulnerable to pollute, and flux also more is vulnerable to impact.Can effectively remove polluted membrane by preconditioning technique, reduce film and pollute.By the film modification, can improve the resistant to pollution ability of film and prolong its service life simultaneously.
Kynoar (PVDF) is as a kind of macromolecular material of function admirable, and its outstanding chemical stability, radiation hardness characteristic, resistance tocrocking and heat resistance is found broad application it in the film separation field.Wherein PVDF micro-filtration membrane and milipore filter have been successfully applied to the fields such as chemical industry, electronics, weaving, food, biochemistry, but the PVDF resin surface can be extremely low, and extremely strong hydrophobicity is arranged, and easily produces adsorption fouling, and membrane flux is descended, and reduce the service life of film.Therefore, become focus for the pvdf membrane modification.Current material for modification PVDF mostly is the hydrophily grafted monomers, such as acrylic acid, methacrylic acid hydroxyl salt, acrylamide etc.In the last few years, the amphion group material that comprised phosphoric acid betaine, DMPT, carboxybetaine side chain more and more causes extensive concern as the antipollution material of a new generation.The amphion group refers to comprise simultaneously the group of cation and anion, and it has following four characteristics: strongly hydrophilic, hydrogen bond receptor, non-hydrogen bond donor and electroneutral.
Summary of the invention
The method of modifying that the purpose of this invention is to provide a kind of PVDF micro-filtration membrane surface hydrophilicity that can effectively anti-protein contamination, that method of modifying of the present invention has is simple to operate, characteristics fast, the Modified Membrane that obtains simultaneously is stable, and hydrophily increases substantially, and anti-protein contamination ability strengthens.
For achieving the above object, method of modifying of the present invention is the impurity of removing first the polyvinylidene fluoride film surface with acetone, hydroxyethyl methacrylate is grafted to the film surface again.Then take ammonium ceric nitrate as initator, N, the N-methylene-bisacrylamide is crosslinking agent, by polymerisation zwitterionic monomer 3-(methacryl amido) propyl group-dimethyl (3-sulfonic acid) ammonium hydroxide successfully is grafted to the film surface, can makes the Modified Membrane of effective anti-protein contamination.By the different copolyreaction time, obtain to have the Modified Membrane of different grafting amounts.This surface modifying method improves the hydrophilicity on film surface by the amphion material of graft copolymerization at polymeric film surface introducing strong hydrophilicity, and the outer ability of its anti-albumen is improved.Simultaneously, method of operating is simple, easily goes, and raw material is easy to get, and is with low cost, and the possibility of practical application is larger.
Specifically, the method for modifying of the polyvinylidene fluoride microporous filtering film of effective anti-protein contamination provided by the invention is comprised of following step:
1) the polyvinylidene fluoride microporous filtering film film is cleaned up rear drying;
2) polyvinylidene fluoride microporous filtering film with drying immerses in the methanol solution, under the nitrogen protection, adds successively ammonium hydroxide inner salt, copper chloride, pentamethyl-diethylenetriamine and deionized water and reacts;
3) add again the ascorbic acid that the nitrogen deoxidation treatment crosses and carry out copolyreaction;
4) take out the rear drying of cleaning;
5) with N, salting liquid mixing in N methylene-bisacrylamide solution, ceric ammonium nitrate solution, nitric acid and [3-(methacryl amido) propyl group] dimethyl (the 3-sulfo-propyl group) ammonium hydroxide is put into diaphragm, seals and pass into the nitrogen deoxidation;
6) after the reaction, be 7.4 ± 0.02 ethanol/PBS buffer solution for cleaning with pH, drying after the washed with de-ionized water, namely make can effectively anti-protein contamination modification PVDF micro-filtration membrane.
In the described method of modifying, step 1) the polyvinylidene fluoride microporous filtering film film is cut into the disk that diameter is 4.70cm, clean up with deionized water again after 12 hours with the acetone immersion, the forced air drying temperature is 40 ℃, blasting time 24 hours.
In the described modification side, step 2) salt content is 97% in the ammonium hydroxide that adds in, and addition is 6-8ml; Copper chloride addition 25-35mg; The mass concentration of pentamethyl-diethylenetriamine is 96%, addition 40-50ul.
In the described method of modifying, ascorbic acid concentrations is 0.03mol/L in the step 3, and addition is 1.5-3ml.
In the described method of modifying, step 4) be to clean with ethanol first, use again washed with de-ionized water, at last in forced air drying.
In the described method of modifying, step 5) solution in is by 50mL, N wherein, N methylene-bisacrylamide 0.15-0.25g, 0.07mol/L ceric ammonium nitrate solution 2-5ml, 0.60mol/L nitric acid 2-5ml, and [3-(methacryl amido) propyl group] dimethyl (3-sulfo-propyl group) ammonium hydroxide of 3% in salting liquid 0.5-1.5ml.
In the described method of modifying, step 5) temperature that passes into the nitrogen deoxidation in is 40 ℃.
In the described method of modifying, step 6) changes water, 40 ℃ of forced air dryings in during washed with de-ionized water and every 24 hours.
Effect of the present invention is:
1) this surface modifying method is introduced a kind of amphion material of strong hydrophilicity by graft copolymerization in polymeric film surface, increases substantially the hydrophilicity on film surface.
2) grafting method is simple, and operation is easily gone, and raw material is easy to get, and is with low cost, and the possibility of practical application is larger.
3) the anti-protein contamination ability of grafting caudacoria improves.
Description of drawings
Fig. 1 is graft modification process of the present invention.
Fig. 2 is the SEM figure before and after polyvinylidene fluoride microporous filtering film of the present invention (pvdf membrane) grafting, and a among Fig. 2 is the former film of the PVDF of modification, b, c, d be after the modification grafting time be respectively 2h (grafting amount 288.34 μ g/cm
2), 3h (grafting amount 392.142 μ g/cm
2) and 4h (grafting amount 478.644 μ g/cm
2) pvdf membrane.
Fig. 3 is polyvinylidene fluoride microporous filtering film flux ratio (J of the present invention
P, 1/ J
V, 0) over time.
Fig. 4 is the variation of polyvinylidene fluoride microporous filtering film flux of the present invention with grafting amount and time.
Description of symbols among Fig. 1:
1-modified-reaction process; 2-ethanol/PBS (1/9) cleans 24h; 3-washed with de-ionized water 48h; 4-vacuum drying 24h.
The specific embodiment
The grafted monomers MPDSAH ([3-(methacryl amido) propyl group] dimethyl (3-sulfo-propyl group) ammonium hydroxide inner salt) that the present invention adopts contains the amphion group, be a kind of in the DMPT, have preferably hydrophily and antifouling property.Because hydrogen bond and electrostatic interaction can pin a large amount of hydrones on the surface of DMPT, form one deck water and layer on its surface.Therefore, the film that the surface has sulfo-beet base has strong repulsive force to protein in certain distance, and the Links stitch that contacts with protein does not have large variation.Therefore surface graft modification be can pass through, in the situation that does not change the pvdf membrane internal structure, its hydrophily and antifouling property improved.
The method of modifying of micro-filtration membrane of the present invention is characterized in the ampholytic monomer of grafting strongly hydrophilic on the film surface, thereby improves hydrophily and the contamination resistance on film surface.
Method of modifying of the present invention may further comprise the steps:
Step 1) commercial PVDF micro-filtration membrane is cut into the disk that diameter is 4.70cm, and soaks 12h with acetone, with deionized water it is thoroughly cleaned up again.
Step 2) pvdf membrane of rinsing well is for subsequent use through forced air drying 24h under 40 ℃.Then film is immersed methanol solution, take out behind the 1min, put into dry beaker.
Step 3) under nitrogen protection, adds successively 97%, 7.47ml ammonium hydroxide inner salt (HEMA), 30.80mg copper chloride (CuCl
2), the pentamethyl-diethylenetriamine of 96%, 46ul (PMDETA) and 43ml deionized water.
Step 3) film reacts the ascorbic acid that adds again behind the 30min after 2.40ml (0.03mol/L) the nitrogen deoxidation treatment in mentioned solution, at 40 ℃ of lower copolyreaction 6h.
Step 4) reacted rear taking-up, under 40 ℃, cleaned 24h with ethanol first, used again washed with de-ionized water 24h, at last at 40 ℃ of lower forced air drying 48h.
Step 5) gets respectively 0.2312g N, N methylene-bisacrylamide (MBAA), 4ml0.07mol/L ammonium ceric nitrate (CAN), 4ml0.60mol/L nitric acid (HNO
3) and 1.22ml3%MPDSAH solution adding 50ml volumetric flask, constant volume, mixing.
Step 6) mixed liquor is moved into beaker, put into diaphragm, pass into nitrogen deoxidation 30min, sealing reacts respectively 1,2,3,4,5h under 40 ℃.
Step 7) the above-mentioned reaction film after complete, at first use the mixed solution of ethanol/PBS buffer solution (PH7.4 ± 0.02) (volume ratio 1/9) to clean 24h, use again washed with de-ionized water 48h (every 24h changes deionized water one time), cleaned rear 40 ℃ of forced air drying 24h, namely make can effectively anti-protein contamination modification PVDF micro-filtration membrane.
Be described in detail below in conjunction with accompanying drawing.
See also Fig. 1, modifying process mainly contained for 2 steps, and first is a step grafting process, and second step is grafting MPDSAH process.
In order to remove the film surface impurity, be that the film of 4.70cm soaks 12h with acetone first with diameter, clean up with deionized water again.
At first that the pvdf membrane of rinsing well is for subsequent use through forced air drying 24h under 40 ℃.Pvdf membrane is immersed methanol solution 1min take out, put into a dry beaker, under nitrogen protection, add successively 7.47ml HEMA, 30.80mgCuCl
2, 46ul PMDETA, 43ml deionized water.Add 2.40ml (0.03mol/L) ascorbic acid behind the reaction 30min, at 40 ℃ of copolyreaction 6h, wherein ascorbic acid solution utilizes the nitrogen deoxidation treatment to cross again.Reacted rear taking-up, under 40 ℃, cleaned 24h with ethanol first, used again washed with de-ionized water 24h, cleaned rear at 40 ℃ of lower forced air drying 48h.Get respectively 0.2312gMBAA, 4ml0.07mol/L CAN solution, 4ml0.60mol/L HNO
3, 1.22ml3%MPDSAH solution adds 50ml volumetric flask, constant volume, mixing.Mixed liquor is moved into beaker, put into the diaphragm after the above-mentioned processing, pass into nitrogen deoxidation 30min, sealing reacts respectively 1,2,3,4,5h under 40 ℃.After having reacted, at first use the mixed solution of ethanol/PBS buffer solution (PH7.4 ± 0.02) (volume ratio 1/9) to clean 24h, use again washed with de-ionized water 48h (every 24h changes deionized water one time), cleaned rear 40 ℃ of forced air drying 24h.The grafting amount on the film surface of differential responses time sees Table 1.
Along with the increase in reaction time, the grafting amount raises by (table 1) gradually, and the surface apertures of film diminishes, and porosity also reduces gradually, as shown in Figure 2.When the grafting amount reaches 478.644 μ g/cm
2, film surface fenestra is almost completely capped.Can tentatively infer thus for the properties of film, a best grafting weight range is arranged.Flux, flux recovery rate also are important parameters of characterization of membrane antifouling property.Flux and flux recovery rate situation of change see Table 2 and Fig. 3 before and after the pvdf membrane grafting.The pvdf membrane pure water flux of different grafting amounts has in various degree and descends, and the flux recovery rate is compared former film and increased.The grafting amount is 288.340 μ g/cm
2The time, although pure water flux has decrease, the flux recovery rate reaches 94.96%.For the variation of film pollution course in filter process before and after the clearer analysis modification, utilize flux ratio (J
p/ J
V, 0) carried out over time deep analysis (shown in Figure 4).Through modification, along with the rising of grafting amount, J
p/ J
V, 0Initial value raises, and this trend that reduces along with the increase of time slows down.Comprehensive above the analysis can illustrate that the antifouling property through Modified Membrane increases.
By R
z/ R ratio can find out that membrane pollution resistance is the principal element that causes film to pollute.Along with the increase of grafting amount, R
z/ R ratio reduces gradually, irreversible membrane fouling resistance R
IrShared ratio also decreases.Be 288.340 μ g/cm in the grafting amount
2The time, R
Ir/ R
zIt is minimum that ratio has reached, and illustrates that the antifouling property of film this moment is relatively best.
Table 1: the grafting amount over time
| Reaction time (h) | 1 | 2 | 3 | 4 | 5 |
| Grafting amount (μ g/cm 2) | 92.269 | 288.340 | 392.142 | 478.644 | 582.446 |
Table 2: membrane resistance is with the variation of grafting amount
Claims (8)
1. the method for modifying of the polyvinylidene fluoride microporous filtering film of an effective anti-protein contamination is comprised of following step:
1) polyvinylidene fluoride microporous filtering film is cleaned up rear drying;
2) polyvinylidene fluoride microporous filtering film with drying immerses in the methanol solution, under the nitrogen protection, adds successively ammonium hydroxide inner salt, copper chloride, pentamethyl-diethylenetriamine and deionized water and reacts;
3) add again the ascorbic acid that the nitrogen deoxidation treatment crosses and carry out copolyreaction;
4) take out the rear drying of cleaning;
5) with N, salting liquid mixing in N methylene-bisacrylamide solution, ceric ammonium nitrate solution, nitric acid and [3-(methacryl amido) propyl group] dimethyl (the 3-sulfo-propyl group) ammonium hydroxide is put into diaphragm, seals and pass into the nitrogen deoxidation;
6) after the reaction, be 7.4 ± 0.02 ethanol/PBS buffer solution for cleaning with pH, drying after the washed with de-ionized water, namely make can effectively anti-protein contamination modification PVDF micro-filtration membrane.
2. method of modifying according to claim 1, wherein, step 1) the polyvinylidene fluoride microporous filtering film film is cut into the disk that diameter is 4.70cm, clean up with deionized water again after 12 hours with the acetone immersion, the forced air drying temperature is 40 ℃, blasting time 24 hours.
3. add mass concentration method of modifying according to claim 1, wherein, step 2) and be 97% ammonium hydroxide inner salt, addition is 6-8ml; Copper chloride addition 25-35mg; Mass concentration is 96% pentamethyl-diethylenetriamine, addition 40-50ul.
4. method of modifying according to claim 1, wherein, ascorbic acid concentrations is 0.03mol/L in the step 3, addition is 1.5-3ml.
5. method of modifying according to claim 1, wherein, step 4) be to clean with ethanol first, use again washed with de-ionized water, at last in forced air drying.
6. method of modifying according to claim 1, wherein, step 5) solution in is by 50mL, N wherein, N methylene-bisacrylamide 0.15-0.25g, 0.07mol/L ceric ammonium nitrate solution 2-5ml, the nitric acid 2-5ml of 0.60mol/L, and mass concentration is salting liquid 0.5-1.5ml in [3-(methacryl amido) propyl group] dimethyl (3-sulfo-propyl group) ammonium hydroxide of 3%.
7. the temperature that passes into the nitrogen deoxidation method of modifying according to claim 1, wherein, step 5) is 40 ℃.
8. change water, 40 ℃ of forced air dryings method of modifying according to claim 1, wherein, step 6) during washed with de-ionized water and every 24 hours.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106823805A (en) * | 2017-03-08 | 2017-06-13 | 哈尔滨工业大学 | A kind of method that post processing prepares the positive impregnating polyamide composite membrane of antipollution |
| CN113244780A (en) * | 2021-05-17 | 2021-08-13 | 江苏泷膜环境科技有限公司 | Scale-resistant anti-yellowing reverse osmosis membrane and preparation method thereof |
| CN115400595A (en) * | 2022-08-24 | 2022-11-29 | 哈尔滨工业大学 | Method for self-assembling ultrathin hydrogel organic microfiltration membrane |
| CN115704118A (en) * | 2021-08-03 | 2023-02-17 | 安徽东锦服饰有限公司 | Anti-fouling fabric and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102516584A (en) * | 2011-12-14 | 2012-06-27 | 清华大学 | Method for modifying polyvinylidene fluoride microporous film to be protein contamination resistant |
| CN102746477A (en) * | 2012-07-05 | 2012-10-24 | 天津大学 | Fluorine-containing amphiphilic modification material used for preparation of membrane with excellent performances and preparation method |
-
2013
- 2013-07-02 CN CN2013102736104A patent/CN103357281A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102516584A (en) * | 2011-12-14 | 2012-06-27 | 清华大学 | Method for modifying polyvinylidene fluoride microporous film to be protein contamination resistant |
| CN102746477A (en) * | 2012-07-05 | 2012-10-24 | 天津大学 | Fluorine-containing amphiphilic modification material used for preparation of membrane with excellent performances and preparation method |
Non-Patent Citations (1)
| Title |
|---|
| 陈春霖等: ""ATRP直接介质改性PVDF膜"", 《2010全国高分子材料科学与工程研讨会》, 29 October 2010 (2010-10-29) * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106823805A (en) * | 2017-03-08 | 2017-06-13 | 哈尔滨工业大学 | A kind of method that post processing prepares the positive impregnating polyamide composite membrane of antipollution |
| CN113244780A (en) * | 2021-05-17 | 2021-08-13 | 江苏泷膜环境科技有限公司 | Scale-resistant anti-yellowing reverse osmosis membrane and preparation method thereof |
| CN115704118A (en) * | 2021-08-03 | 2023-02-17 | 安徽东锦服饰有限公司 | Anti-fouling fabric and preparation method thereof |
| CN115400595A (en) * | 2022-08-24 | 2022-11-29 | 哈尔滨工业大学 | Method for self-assembling ultrathin hydrogel organic microfiltration membrane |
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Application publication date: 20131023 |