CN113509840B - Composite nanofiltration membrane and preparation method and application thereof - Google Patents
Composite nanofiltration membrane and preparation method and application thereof Download PDFInfo
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- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
- B01D61/027—Nanofiltration
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- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/10—Supported membranes; Membrane supports
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- B01D69/125—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
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- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
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- B32B27/00—Layered products comprising a layer of synthetic resin
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- B32B27/00—Layered products comprising a layer of synthetic resin
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
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Abstract
The invention relates to a composite nanofiltration membrane as well as a preparation method and application thereof. The composite nanofiltration membrane comprises a bottom layer, a middle porous supporting layer and a surface separation layer, wherein the separation layer is a polyurea-polyurethane compact separation layer with a cross-linking structure. The polyurea-polyurethane functional layer has a high crosslinking density area and a low crosslinking density area; the addition of the polyol effectively increases the free volume between molecular chains, which is beneficial for the improvement of the water flux of the membrane, and the polyurea structure having a high degree of crosslinking with its high hydrogen bonding is beneficial for the improvement of the acid/alkali resistance of the membrane. The composite nanofiltration membrane can stably operate in an aqueous solution with the pH =0-14, has high desalination rate and water permeability, high acid/alkali resistance and simple preparation method, and has wide industrial application prospect.
Description
Technical Field
The invention relates to the field of membranes, in particular to a composite nanofiltration membrane as well as a preparation method and application thereof.
Background
Nanofiltration is a pressure-driven membrane separation process between reverse osmosis and ultrafiltration, the pore size of the nanofiltration membrane is about several nanometers, the removal of monovalent ions and organic matters with molecular weight less than 200 is poor, and the removal rate of divalent or polyvalent ions and organic matters with 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 multifunctional acyl halide, as disclosed in 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 retention rate on high-valence anions and adjustable retention rate on 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 characteristics of the materials, the traditional polyamide nanofiltration membrane can be degraded in an extreme pH environment, particularly under a strong alkaline condition, and the polyamide nanofiltration membrane can only be used for a neutral medium or a weak acid and weak alkaline medium close to neutral because the pH range of the polyamide nanofiltration membrane is generally 2-11.
In recent years, researchers have developed various nanofiltration membranes, and various commercial products have appeared. In addition, many new materials, such as sulfonated polyether ketone, sulfonated polyether sulfone, and the like, are also applied to the field of nanofiltration.
The literature "Acid stable thin-film composite membrane prepared from a naphthalene-1,3, 6-trisulfosylchloride (NTSC) and piperazine (PIP)", J.Membr.Sci.,415-416,122-131,2012 ": the sulfonamide material has strong acid resistance, and a composite nanofiltration membrane obtained by interfacial polymerization of a polynary sulfonyl chloride monomer and piperazine can keep stable separation performance in an environment with pH = 0.
Reported in the literature "Sulfonated poly (ethylene ketone) based composite membranes for nanofilamentation of acidic and alkaline media, J.Membr.Sci.,381,81-89, 2011": the sulfonated polyether-ether-ketone has acid resistance and strong alkali resistance, a nanofiltration membrane material with excellent interception performance can be obtained through Crosslinking, and the crosslinked polyether-ether-ketone material has strong solvent resistance and can separate dyes in polar solvents such as isopropanol and acetone (Crosslinking of modified poly (ether ketone) membranes for use in solvent nanofiltration,447,212-221 and 2013).
The document shows that acid and alkali resistant and high temperature resistant nanofiltration membrane HYDRACoRe70pHT is used for waste alkali liquor recovery in sugar industry, and the membrane science and technology is reported in 32,11-15, 2006): the commercial sulfonated polyether sulfone composite nanofiltration membrane is HYDRACoRe series developed by Nindon electrician Heidenen, can be used in strong acid and strong alkali solutions, and is widely applied to the recovery of waste alkali.
The acid-resistant nanofiltration membrane Duracid NF1812C developed by GE company is a three-layer composite structure, and the material of a separation layer is polysulfonamide (patent number US 7138058), so that the stability can be kept under the conditions of 20% hydrochloric acid, sulfuric acid and phosphoric acid, and the stability can be still kept under the conditions of 70 ℃ and 20% sulfuric acid concentration.
Patent No. US5265734, EP0392982 (A3) reported that nanofiltration membranes capable of stable long-term operation at pH =0 to 14 were only the SelRO MPS34 developed by KOCH corporation, which was first developed by israel scientists and was first applied to pervaporation.
AMS company develops an acid-resistant, alkali-resistant and solvent-resistant composite nanofiltration membrane, and the material of a separation layer is polyamine (US 9943811), which is prepared by interfacial polymerization reaction of polyamine and cyanuric chloride or a derivative thereof.
Documents (Journal of Membrane Science 523 (2017) 487-496) and (Journal of Membrane Science 478 (2015) 75-84) report modification of a polyaniline separation layer on a porous support layer using interfacial polymerization, and composite membranes have strong permeation and separation stability in a medium environment of pH = 0-14.
The literature (Journal of Membrane Science 572 (2019) 489-495) utilizes phase inversion and post-treatment to prepare polyvinylidene fluoride nanofiltration Membrane material, which has strong stability in strong acid and strong alkali environments.
Disclosure of Invention
The invention aims to overcome the defects of poor acid resistance and poor alkali 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 composite nanofiltration membrane comprises a bottom layer, a middle porous supporting layer and a surface separation layer, wherein the separation layer is a polyurea-polyurethane separation layer.
The composite nanofiltration membrane comprises a three-layer structure: the bottom substrate is provided with a porous support layer on one surface and a compact polyurea-polyurethane separation layer with a cross-linking structure on the other surface.
According to the present invention, the base layer and the porous support layer are not particularly limited, and may be made of various existing materials having a certain strength and capable of being used for a nanofiltration membrane.
The bottom layer can be made of non-woven fabric, and the material of the non-woven fabric is one or the mixture of polyethylene and polypropylene;
the material of the porous support layer is one or a mixture of several of polyethersulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyetherketone, polyetheretherketone, polyacrylonitrile, polyvinylidene fluoride and polyaryletherketone, which can be known to those skilled in the art and will not be described herein again.
The polyurea-polyurethane separation layer is obtained by interfacial polymerization of a component A and a component B, wherein the component A comprises polyamine polymer, polyol and a chain extender, and the component B is polyisocyanate.
Preferably, the polyamine polymer is at least one of polyethyleneimine and polyether amine, and the polyethyleneimine can be linear polyethyleneimine or branched polyethyleneimine;
preferably, the polyol is at least one of polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol, and more preferably the polyether polyol;
preferably, the chain extender is one or more of 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, 1-methyl-3, 5-diethyl-2, 6-diaminobenzene, 1,3, 5-triethyl-2, 6-diaminobenzene, 3,5,3',5' -tetraethyl-4, 4 '-diaminodiphenylmethane, bis (methylthio) -toluenediamine, N' -bis (t-butyl) ethylenediamine, 4 '-methylenebis (2-isopropyl-6-methylaniline), 4' -methylenebis (2, 6-diisopropylaniline);
preferably, the polyisocyanate is one or more of m-xylylene diisocyanate, isophorone diisocyanate, 1, 6-hexamethylene diisocyanate, toluene-2, 6-diisocyanate, 1, 4-phenylene diisocyanate, toluene-2, 4-diisocyanate, 4 '-methylenebis (phenyl isocyanate), 1, 3-phenylene diisocyanate, 3' -dichloro-4, 4 '-diisocyanate biphenyl, dicyclohexylmethane-4, 4' -diisocyanate, trimethylhexamethylene diisocyanate, L-lysine-ethyl ester-diisocyanate, 1, 4-cyclohexyl diisocyanate, 4-chloro-6-methyl-m-phenylene diisocyanate.
According to the invention, the thicknesses of the bottom layer, the porous support 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 cooperation, the obtained composite nanofiltration membrane can better have excellent acid and alkali resistance, higher water flux and higher desalination rate, and preferably, the thickness of the bottom layer is 30-150 μm, and preferably 50-120 μm; the thickness of the porous supporting layer is 10-100 μm, preferably 30-60 μm; the thickness of the polyurea-polyurethane separating layer is 10-500 nm, preferably 50-300 nm.
The invention also aims to provide a preparation method of the composite nanofiltration membrane, which comprises the following steps:
(1) Preparing a porous support layer on one surface of the base layer:
(2) On the other surface of the porous support layer, a polyurea-polyurethane separation layer is obtained by interfacial polymerization of a component a comprising a polyamine polymer, a polyol and a chain extender, with a polyisocyanate component B.
According to the present invention, the method of step (1) may be a routine choice in the art, and preferably a solution of the polymer of the support layer material may be applied to one surface of the substrate by phase inversion to provide a porous support layer.
The phase inversion process may preferably be: dissolving a polymer material of a support layer in a solvent to obtain a polymer solution with the concentration of 10-20 wt%, and defoaming the polymer solution for 10-180 min at the temperature of 20-40 ℃; then coating the polymer solution on the bottom layer to obtain an initial membrane, soaking the initial membrane in water with the temperature of 10-30 ℃ for 10-60 min, and carrying out phase inversion layer on the support layer polymer porous membrane.
Among them, the solvent may be N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, or the like.
According to the invention, the polyamine polymer is one of polyethyleneimine and polyether amine, wherein the polyethyleneimine can be linear polyethyleneimine or branched polyethyleneimine;
according to the invention, the polyol is one of polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol, preferably polyether polyol;
according to the invention, the chain extender is one or more of 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, 1-methyl-3, 5-diethyl-2, 6-diaminobenzene, 1,3, 5-triethyl-2, 6-diaminobenzene, 3,5,3',5' -tetraethyl-4, 4 '-diaminodiphenylmethane, bis (methylthio) -toluenediamine, N' -bis (t-butyl) ethylenediamine, 4 '-methylenebis (2-isopropyl-6-methylaniline), 4' -methylenebis (2, 6-diisopropylaniline);
according to the invention, the polyisocyanate is one or more of m-xylylene diisocyanate, isophorone diisocyanate, 1, 6-hexamethylene diisocyanate, toluene-2, 6-diisocyanate, 1, 4-phenylene diisocyanate, toluene-2, 4-diisocyanate, 4 '-methylenebis (phenyl isocyanate), 1, 3-phenylene diisocyanate, 3' -dichloro-4, 4 '-diisocyanate biphenyl, dicyclohexylmethane-4, 4' -diisocyanate, trimethylhexamethylene diisocyanate, L-lysine-ethyl ester-diisocyanate, 1, 4-cyclohexyl diisocyanate, 4-chloro-6-methyl-m-phenylene diisocyanate.
According to the present invention, in step (2), the other surface of the porous support layer is contacted with an aqueous phase containing a polyamine polymer, a polyol and a chain extender, and an organic phase containing a polyisocyanate in this order, followed by heat treatment.
Specifically, the porous support layer is firstly contacted with water containing polyamine polymer, polyol and chain extender, and then contacted with organic phase containing polyisocyanate after liquid discharge, and then heat treatment is carried out.
According to the invention, the concentrations of the polyamine polymer, the polyol, the chain extender and the polyisocyanate in the interfacial polymerization process are not particularly limited as long as the obtained nanofiltration membrane has excellent acid and alkali resistance and higher water flux and desalination rate.
Preferably, the polyamine polymer is present in an aqueous phase comprising a polyamine polymer, a polyol and a chain extender in an amount of 0.2 to 10% by weight, preferably 0.5 to 5% by weight;
the content of the polyol is 0.02 to 1% by weight, preferably 0.05 to 0.5% by weight;
the content of the chain extender is 0.05 to 5% by weight, preferably 0.1 to 2.5% by weight.
The organic phase containing the polyisocyanate is in a content of 0.025 to 1% by weight, preferably 0.05 to 0.5% by weight.
According to the invention, the mass concentration ratio of the component A (polyamine polymer, polyol and chain extender) to the component B (polyisocyanate) in the interfacial polymerization process is not particularly limited as long as the obtained nanofiltration membrane can combine excellent acid and alkali resistance, higher water flux and desalination rate, and the mass concentration ratio of the component A to the component B is preferably (0.5-100): 1, more preferably (1 to 65): 1.
according to the invention, in the interface polymerization process, the contact time of the porous support layer with the water phase and the organic phase is not particularly limited as long as the obtained nanofiltration membrane has excellent acid and alkali resistance, high water flux and high desalination rate, and preferably, the contact time of the porous support layer with the water phase containing the polyamine polymer, the polyol and the chain extender is 5-100 s, preferably 10-60 s; the time for contacting the polyisocyanate-containing organic phase is 10 to 200 seconds, preferably 20 to 120 seconds.
According to the present invention, the kind of the solvent of the organic phase is not particularly limited as long as it can dissolve the polyisocyanate, and preferably, the solvent of the organic phase is one or more of n-hexane, dodecane, n-heptane, alkane solvent oils (Isopar E, isopar G, isopar H, isopar L and Isopar M).
According to the invention, the post-treatment conditions of the interfacial polymerization are not particularly limited, as long as the monomers can be completely polymerized, and the nanofiltration membrane has excellent acid and alkali resistance, higher water flux and desalination rate, and preferably the heat treatment temperature is 40-150 ℃, and preferably 50-120 ℃; the heat treatment time is 0.5 to 20 minutes, preferably 1 to 10 minutes.
The third object of the invention is to provide the composite nanofiltration membrane obtained by the preparation method of the second object of the invention.
The fourth purpose of the invention is to provide the application of the composite nanofiltration membrane or the composite nanofiltration membrane prepared by the preparation method of the invention in the field of water treatment.
The inventors of the present invention have intensively studied to find that, on the one hand, the polyurea-polyurethane separation layer according to the present invention has a molecular structure containing both a high crosslink density region (crosslinked polyurea structure) and a low crosslink density region (crosslinked polyurethane structure); the addition of the polyalcohol effectively increases the free volume between molecular chains, which is beneficial to the improvement of the water flux of the membrane, while the polyurea structure with high crosslinking degree and high hydrogen bonding degree is beneficial to the improvement of the acid resistance/alkali resistance of the membrane, and the composite nanofiltration membrane material with good water permeability and salt rejection and excellent acid resistance/alkali resistance can be prepared by adjusting the proportion of the polyurethane and the polyurea in the molecular structure.
The composite nanofiltration membrane can stably operate in an aqueous solution with the pH =0-14, has high desalination rate and water permeability (water flux), strong acid/alkali resistance, simple preparation method and wide industrial application prospect.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
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 is measured within 1 hour under the conditions that the pressure is 2.0MPa and the temperature is 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: loading the composite nanofiltration membrane into a membrane pool, prepressing for 0.5h under 1.2MPa, measuring the concentration change of a magnesium sulfate raw water solution with initial concentration of 2000ppm and a magnesium sulfate in a permeation solution within 1h under the conditions that the pressure is 2.0MPa and the temperature is 25 ℃, and calculating by the following formula:
R＝(C p -C f )/C p x 100%, wherein R is the salt rejection, C p Is the concentration of magnesium sulfate in the stock solution, C f Is the concentration of magnesium sulfate in the permeate;
(3) And (3) testing the acid resistance of the composite nanofiltration membrane: respectively soaking the composite nanofiltration membrane diaphragms in an aqueous solution containing 20 mass percent of HCl for 6 months, and then testing the changes of the water flux and the salt rejection rate of the composite nanofiltration membrane every other week;
(4) And (3) testing alkali resistance of the composite nanofiltration membrane: the composite nanofiltration membrane is soaked in an alkali aqueous solution containing 20 mass percent of NaOH for 6 months, and then the changes of the water flux and the salt rejection rate of the composite nanofiltration membrane are tested every other week.
In addition, in the following examples and comparative examples:
branched polyethyleneimines (number average molecular weights 600, 10000 and 60000, respectively), polyether polyols, 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, 1-methyl-3, 5-diethyl-2, 6-diaminobenzene, 1,3, 5-triethyl-2, 6-diaminobenzene, 3,5,3',5' -tetraethyl-4, 4 '-diaminodiphenylmethane, m-xylylene diisocyanate, 1, 6-hexamethylene diisocyanate, 1, 4-cyclohexyl diisocyanate, 1, 4-phenylene diisocyanate, 4' -methylenebis (phenyl isocyanate), isophorone diisocyanate, and the like are available from Bailingwei scientific Co., ltd, and other chemicals are available from national pharmaceutical group chemical 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 the polysulfone solution at 25 ℃ for 120min; then, the polysulfone solution was coated on a polyethylene nonwoven fabric (thickness: 75 μm) with 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 polyester nonwoven fabric was phase-converted into a porous film, and finally washed with water 3 times to obtain a nonwoven fabric layer and a porous support layer having a total thickness of 115 μm.
Example 1
Contacting the upper surface of the polysulfone support layer with an aqueous solution containing 0.5 wt% of branched polyethyleneimine (number average molecular weight of 10000), 0.05 wt% of polyether polyol and 2.5 wt% of 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, and discharging liquid after contacting for 60s at 25 ℃; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.05 weight percent of 4,4' -methylene bis (phenyl isocyanate) and is contacted for 60s at the temperature of 25 ℃ for liquid drainage; then, the film was put into an oven and heated at 70 ℃ for 3min to obtain a composite film. The thickness of the separating layer was 155nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane N1 in water for 24h, and measuring water flux and MgSO at 25 deg.C and 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membranes were immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, the water flux and salt rejection were measured, and the results are shown in table 1.
Example 2
Contacting the upper surface of the polysulfone support layer with an aqueous solution containing 2 wt% of branched polyethyleneimine (number average molecular weight of 60000), 0.1 wt% of polyether polyol and 1 wt% of 1-methyl-3, 5-diethyl-2, 6-diaminobenzene, and discharging the liquid after contacting for 60s at 25 ℃; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.2 weight percent of m-xylylene diisocyanate, and liquid drainage is carried out after the contact for 60s at 25 ℃; then, the film was put into an oven and heated at 70 ℃ for 3min to obtain a composite film. The thickness of the separating layer was 190nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane N2 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and pressure of 2.0MPa 4 The salt rejection of (2) is shown in Table 1. The water flux and salt rejection of the membranes were measured after soaking the membranes in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, and the results are shown in table 1.
Example 3
Contacting the upper surface of the polysulfone support layer with an aqueous solution containing 5 wt% of branched polyethyleneimine (number average molecular weight of 600), 0.5 wt% of polyether polyol and 0.1 wt% of 1,3, 5-triethyl-2, 6-diaminobenzene, and discharging liquid after contacting for 60s at 25 ℃; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.5 weight percent of 1, 6-hexamethylene diisocyanate and is discharged after being contacted for 60s at the temperature of 25 ℃; then, the film was put into an oven and heated at 70 ℃ for 3min to obtain a composite film. The thickness of the separating layer was 235nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane N3 in water for 24h, and measuring water flux and MgSO at 25 deg.C and 2.0MPa 4 The salt rejection of (2) is shown in Table 1. The water flux and salt rejection of the membranes were measured after soaking the membranes in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, and the results are shown in table 1.
Example 4
A method of preparing a composite membrane was performed as in example 1, except that 3,5,3',5' -tetraethyl-4, 4' -diaminodiphenylmethane was used in place of 1-methyl-3, 5-diethyl-2, 4-diaminobenzene to obtain a composite membrane N4.
Soaking the obtained composite membrane N4 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and pressure of 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membranes were immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, the water flux and salt rejection were measured, and the results are shown in table 1.
Example 5
A composite film was prepared as in example 1, except that 1, 4-phenylene diisocyanate was used in place of 4,4' -methylenebis (phenylisocyanate) to obtain composite film N5.
Soaking the obtained composite membrane N5 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and pressure of 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membranes were immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, the water flux and salt rejection were measured, and the results are shown in table 1.
Example 6
A composite membrane was prepared as in example 1, except that m-xylylene diisocyanate was used in place of 4,4' -methylenebis (phenyl isocyanate) to obtain a composite membrane N6.
Soaking the obtained composite membrane N6 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and pressure of 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membranes were immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, the water flux and salt rejection were measured, and the results are shown in table 1.
Example 7
A composite film was prepared as in example 1, except that isophorone diisocyanate was used instead of 4,4' -methylenebis (phenyl isocyanate) to obtain composite film N7.
Soaking the obtained composite membrane N7 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membrane was immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, the water flux and salt rejection of the composite nanofiltration membrane were measured, and the results are shown in table 1.
Example 8
A composite membrane was prepared as in example 1, except that 1, 4-cyclohexyl diisocyanate was used in place of 4,4' -methylenebis (phenyl isocyanate) to obtain a composite membrane N8.
Soaking the obtained composite membrane N8 in water for 24h, and measuring water flux and MgSO at 25 deg.C and 2.0MPa 4 The salt rejection of (2) is shown in Table 1. After the membrane was immersed in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, the water flux and salt rejection of the composite nanofiltration membrane were measured, and the results are shown in table 1.
Comparative example 1
Contacting the upper surface of the polysulfone support layer with an aqueous solution containing 0.5 wt% of branched polyethyleneimine (number average molecular weight of 10000) and 2.5 wt% of 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, and discharging liquid after contacting for 60s at 25 ℃; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.05 weight percent of 4,4' -methylene bis (phenyl isocyanate) and is contacted for 60 seconds at the temperature of 25 ℃ for liquid drainage; then, the film was put into an oven and heated at 70 ℃ for 3min to obtain a composite film. The thickness of the separating layer was 145nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane D1 in water for 24h, and measuring water flux and p-MgSO at 25 deg.C and pressure of 2.0MPa 4 The salt rejection of (2) is shown in Table 1. The water flux and salt rejection of the membranes were measured after soaking the membranes in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, and the results are shown in table 1.
Comparative example 2
Contacting the upper surface of the polysulfone supporting layer with an aqueous solution containing 0.5 wt% of branched polyethyleneimine (number average molecular weight of 10000) and 0.05 wt% of polyether polyol, and discharging liquid after contacting for 60s at 25 ℃; then, the upper surface of the supporting layer is contacted with Isopar E solution containing 0.05 weight percent of 4,4' -methylene bis (phenyl isocyanate) and is contacted for 60 seconds at the temperature of 25 ℃ for liquid drainage; then, the film was put into an oven and heated at 70 ℃ for 3min to obtain a composite film. The thickness of the separating layer was 140nm as measured by scanning electron microscopy.
Soaking the obtained composite membrane D2 in water for 24h, and measuring water flux and MgSO 2 at 25 deg.C and 2.0MPa 4 The salt rejection of (2) is shown in Table 1. The water flux and salt rejection of the membranes were measured after soaking the membranes in aqueous solutions of 20 mass% HCl and 20 mass% NaOH for 6 months, respectively, and the results are shown in table 1.
The results in table 1 show that the introduction of polyether polyol can increase the free volume between the molecular chains and improve the water flux of the membrane; the introduction of the chain extender is beneficial to improving the compact structure of the functional layer and improving the salt rejection rate of the membrane, thereby increasing the acid/alkali resistance of the membrane.
TABLE 1
Claims (17)
1. The composite nanofiltration membrane is characterized by comprising a bottom layer, a middle porous supporting layer and a surface separation layer, wherein the separation layer is a polyurea-polyurethane separation layer; the polyurea-polyurethane separating layer is obtained by interfacial polymerization of a component A and a component B, wherein the component A comprises a polyamine polymer, a polyol and a chain extender, the component B is a polyisocyanate, the polyamine polymer is at least one selected from polyethyleneimine and polyetheramine, the polyol is at least one selected from polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol, the chain extender is at least one selected from 1-methyl-3, 5-diethyl-2, 4-diaminobenzene, 1-methyl-3, 5-diethyl-2, 6-diaminobenzene, 1,3, 5-triethyl-2, 6-diaminobenzene, 3,5,3',5' -tetraethyl-4, 4 '-diaminodiphenylmethane, di (methylthio) -toluenediamine and N, at least one of N' -di (t-butyl) ethylenediamine, 4 '-methylenebis (2-isopropyl-6-methylaniline) and 4,4' -methylenebis (2, 6-diisopropylaniline), the polyisocyanate is selected from m-xylylene diisocyanate, isophorone diisocyanate, 1, 6-hexamethylene diisocyanate, toluene-2, 6-diisocyanate, 1, 4-phenylene diisocyanate, toluene-2, 4-diisocyanate, 4 '-methylenebis (phenyl isocyanate), 1, 3-phenylene diisocyanate, 3' -dichloro-4, 4 '-diisocyanate biphenyl, dicyclohexylmethane-4, 4' -diisocyanate, trimethylhexamethylene diisocyanate, at least one of L-lysine-ethyl ester-diisocyanate, 1, 4-cyclohexyl diisocyanate, and 4-chloro-6-methyl m-phenylene diisocyanate.
2. The composite nanofiltration membrane according to claim 1, wherein:
the porous supporting layer is made of at least one of polyether sulfone, polysulfone, polyaromatic ether, polybenzimidazole, polyacrylonitrile, polyvinylidene fluoride and polyaryletherketone.
3. The composite nanofiltration membrane of claim 2, wherein:
the polyaryletherketone is polyether ketone or polyetheretherketone.
4. A composite nanofiltration membrane according to any one of claims 1 to 3, wherein:
the thickness of the bottom layer is 30 to 150 mu m; the thickness of the porous supporting layer is 10 to 100 micrometers; the thickness of the polyurea-polyurethane separation layer is 10 to 500nm.
5. The composite nanofiltration membrane of claim 4, wherein:
the thickness of the bottom layer is 50 to 120 mu m; the thickness of the porous support layer is 30 to 60 micrometers; the thickness of the polyurea-polyurethane separation layer is 50 to 300nm.
6. A preparation method of the composite nanofiltration membrane according to any one of claims 1 to 5, which is characterized by comprising the following steps:
(1) Preparing a porous support layer on one surface of the base layer;
(2) And (B) obtaining a polyurea-polyurethane separation layer on the other surface of the porous support layer by interfacial polymerization of component a comprising a polyamine polymer, a polyol and a chain extender, with a polyisocyanate component B.
7. The preparation method of the composite nanofiltration membrane according to claim 6, wherein the preparation method comprises the following steps:
in a water phase containing polyamine polymer, polyalcohol and a chain extender, the content of the polyamine polymer is 0.2 to 10 weight percent; the content of the polyhydric alcohol is 0.02 to 1 percent by weight; the content of the chain extender is 0.05 to 5 percent by weight; and/or the presence of a gas in the gas,
the content of the polyisocyanate in the organic phase containing the polyisocyanate is 0.025 to 1% by weight.
8. The preparation method of the composite nanofiltration membrane according to claim 7, wherein the preparation method comprises the following steps:
the content of the polyamine polymer is 0.5 to 5 wt%; the content of the polyhydric alcohol is 0.05 to 0.5 wt%; the content of the chain extender is 0.1 to 2.5 percent by weight; and/or the presence of a gas in the atmosphere,
the content of the polyisocyanate is 0.05 to 0.5 wt%.
9. The preparation method of the composite nanofiltration membrane according to claim 6, wherein the preparation method comprises the following steps:
the mass concentration ratio of the component A to the component B is (0.5-100): 1.
10. the preparation method of the composite nanofiltration membrane according to claim 9, wherein the preparation method comprises the following steps:
the mass concentration ratio of the component A to the component B is (1-65): 1.
11. the preparation method of the composite nanofiltration membrane according to claim 6, wherein the preparation method comprises the following steps:
in the step (2), the other surface of the porous support layer is contacted with an aqueous phase containing a polyamine polymer, a polyol and a chain extender, and an organic phase containing a polyisocyanate in this order, and then subjected to a heat treatment.
12. The preparation method of the composite nanofiltration membrane according to claim 11, wherein the preparation method comprises the following steps:
the contact time of the porous supporting layer and a water phase containing a polyamine polymer, a polyol and a chain extender is 5 to 100s; and/or the presence of a gas in the gas,
the time for the porous support layer to contact with the organic phase containing the polybasic isocyanate is 10 to 200s.
13. The preparation method of the composite nanofiltration membrane according to claim 12, wherein the preparation method comprises the following steps:
the contact time of the porous support layer and a water phase containing polyamine polymer, polyol and a chain extender is 10 to 60s; and/or the presence of a gas in the gas,
the time for the porous support layer to contact with the organic phase containing the polybasic isocyanate is 20 to 120s.
14. The preparation method of the composite nanofiltration membrane according to claim 11, wherein the preparation method comprises the following steps:
the conditions of the heat treatment include: the heat treatment temperature is 40 to 150 ℃; the heat treatment time is 0.5 to 20 minutes.
15. The preparation method of the composite nanofiltration membrane according to claim 14, wherein the preparation method comprises the following steps:
the heat treatment temperature is 50 to 120 ℃; the heat treatment time is 1 to 10 minutes.
16. A composite nanofiltration membrane obtained by the preparation method according to any one of claims 6 to 15.
17. Use of a composite nanofiltration membrane according to any one of claims 1 to 5 or a composite nanofiltration membrane obtained by the preparation method according to any one of claims 6 to 15 in the field of water treatment.
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| WO2024120196A1 (en) * | 2022-12-07 | 2024-06-13 | 中国石油化工股份有限公司 | Acid- and alkali-resistant composite nanofiltration membrane, and preparation method therefor and use thereof |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0312375A2 (en) * | 1987-10-14 | 1989-04-19 | Exxon Research And Engineering Company | Highly aromatic polymer alloy membrane of polyurea and polyurethane and its use in aromatic/non-aromatic separations |
| US4914064A (en) * | 1987-10-14 | 1990-04-03 | Exxon Research And Engineering Company | Highly aromatic polyurea/urethane membranes and their use for the separation of aromatics from non-aromatics |
| CN1973971A (en) * | 2006-12-01 | 2007-06-06 | 北京工业大学 | Prepn process of soiling resistant modified PVA film |
| CN101306329A (en) * | 2007-05-17 | 2008-11-19 | 深圳市龙澄高科技环保有限公司 | Preparation method of polyurethane hollow fiber filter membrane |
| CN102712736A (en) * | 2009-10-30 | 2012-10-03 | 三菱化学株式会社 | Polyester polyol, polyurethane utilizing the polyester polyol and process for production thereof, and polyurethane molded article |
| KR20130049627A (en) * | 2011-11-04 | 2013-05-14 | 웅진케미칼 주식회사 | Polyamid nanofiltration membrane and manufacturing method thereof |
| CN105617875A (en) * | 2014-11-03 | 2016-06-01 | 株洲时代新材料科技股份有限公司 | High-throughput hollow fiber composite nanofiltration membrane, and preparation method thereof |
| CN107148311A (en) * | 2014-08-13 | 2017-09-08 | Iab离子交换股份有限公司 | The method for preparing the nonpolluting coating being made up of utilized thin film composite membranes for counter-infiltration and nanofiltration, the utilized thin film composite membranes and application thereof |
| CN107469639A (en) * | 2017-08-04 | 2017-12-15 | 深圳先进技术研究院 | Composite nanometer filtering film and preparation method thereof |
| KR20190142019A (en) * | 2018-06-15 | 2019-12-26 | 경희대학교 산학협력단 | Nanofiltration Composition Membrane Having Improved Acid and Heat Resistance And Manufacturing Method Thereof |
-
2020
- 2020-04-09 CN CN202010271965.XA patent/CN113509840B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0312375A2 (en) * | 1987-10-14 | 1989-04-19 | Exxon Research And Engineering Company | Highly aromatic polymer alloy membrane of polyurea and polyurethane and its use in aromatic/non-aromatic separations |
| US4914064A (en) * | 1987-10-14 | 1990-04-03 | Exxon Research And Engineering Company | Highly aromatic polyurea/urethane membranes and their use for the separation of aromatics from non-aromatics |
| CN1973971A (en) * | 2006-12-01 | 2007-06-06 | 北京工业大学 | Prepn process of soiling resistant modified PVA film |
| CN101306329A (en) * | 2007-05-17 | 2008-11-19 | 深圳市龙澄高科技环保有限公司 | Preparation method of polyurethane hollow fiber filter membrane |
| CN102712736A (en) * | 2009-10-30 | 2012-10-03 | 三菱化学株式会社 | Polyester polyol, polyurethane utilizing the polyester polyol and process for production thereof, and polyurethane molded article |
| KR20130049627A (en) * | 2011-11-04 | 2013-05-14 | 웅진케미칼 주식회사 | Polyamid nanofiltration membrane and manufacturing method thereof |
| CN107148311A (en) * | 2014-08-13 | 2017-09-08 | Iab离子交换股份有限公司 | The method for preparing the nonpolluting coating being made up of utilized thin film composite membranes for counter-infiltration and nanofiltration, the utilized thin film composite membranes and application thereof |
| CN105617875A (en) * | 2014-11-03 | 2016-06-01 | 株洲时代新材料科技股份有限公司 | High-throughput hollow fiber composite nanofiltration membrane, and preparation method thereof |
| CN107469639A (en) * | 2017-08-04 | 2017-12-15 | 深圳先进技术研究院 | Composite nanometer filtering film and preparation method thereof |
| KR20190142019A (en) * | 2018-06-15 | 2019-12-26 | 경희대학교 산학협력단 | Nanofiltration Composition Membrane Having Improved Acid and Heat Resistance And Manufacturing Method Thereof |
Non-Patent Citations (1)
| Title |
|---|
| 界面聚合技术及其应用研究进展;崔绍波等;《化工进展》;20060131(第01期);第47-50页 * |
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