Seawater desalination reverse osmosis membrane, preparation method and application

Abstract

The invention relates to the technical field of seawater desalination, in particular to a seawater desalination reverse osmosis membrane, a preparation method and application. The seawater desalination reverse osmosis membrane is prepared by the preparation method. The preparation method comprises the following steps: immersing the prepared support layer into a water phase solution, and then taking out the support layer adsorbing the water phase solution; immersing the support layer adsorbing the water phase solution into a first oil phase solution, and forming a primary reverse osmosis membrane through a first interfacial polymerization reaction; then, taking out the primary reverse osmosis membrane, and carrying out first drying treatment under a steam condition; and immersing the primary reverse osmosis membrane into a second oil phase solution, and carrying out a second interfacial polymerization reaction to form the seawater desalination reverse osmosis membrane. The application refers to the application of the reverse osmosis membrane for seawater desalination in the aspects of reclaimed water reuse, seawater desalination and brackish water desalination. According to the invention, the seawater desalination reverse osmosis membrane which simultaneously meets high desalination rate and high water flux can be prepared.

Description

Technical Field

[0001] The invention relates to the technical field of seawater desalination, and in particular to a seawater desalination reverse osmosis membrane, a preparation method and application thereof. Background Art

[0002] Seawater desalination reverse osmosis technology has become an important technology for the development of seawater resources. The core of this technology is the seawater desalination reverse osmosis membrane, which not only has stable operating performance but also has high separation performance. However, the seawater desalination reverse osmosis membranes on the market are difficult to meet both high desalination rate and high water flux, which greatly affects the industrial application of seawater desalination reverse osmosis membranes.

[0003] In summary, it is necessary to provide a seawater desalination reverse osmosis membrane, a preparation method and an application to solve the problem that the existing seawater desalination reverse osmosis membrane is difficult to simultaneously meet the requirements of high desalination rate and high water flux. Summary of the invention

[0004] The present invention aims to provide a seawater desalination reverse osmosis membrane, a preparation method and application. The specific technical scheme is as follows:

[0005] In a first aspect, the present invention provides a method for preparing a seawater desalination reverse osmosis membrane, comprising:

[0006] Step S1, immersing the prepared support layer in an aqueous solution, and then taking out the support layer adsorbing the aqueous solution; the aqueous solution includes an amine monomer, a phase transfer catalyst, a surfactant and a pH buffer; the phase transfer catalyst includes a quaternary ammonium salt and / or a pyridine substance;

[0007] Step S2, immersing the support layer adsorbing the aqueous phase solution into a first oil phase solution, and forming a primary reverse osmosis membrane through a first interfacial polymerization reaction; then, taking out the primary reverse osmosis membrane, and performing a first drying treatment under steam conditions; the first oil phase solution includes 0.20% to 0.50% of trimesoyl chloride and 0.10% to 0.40% of isophthaloyl chloride;

[0008] Step S3, immersing the primary reverse osmosis membrane in a second oil phase solution to form a seawater desalination reverse osmosis membrane through a second interfacial polymerization reaction; then, taking out the seawater desalination reverse osmosis membrane; the second oil phase solution includes an aromatic sulfonyl chloride monomer.

[0009] Optionally, the method for preparing the seawater desalination reverse osmosis membrane further comprises post-treatment of the seawater desalination reverse osmosis membrane; the post-treatment comprises sequentially rinsing, first soaking treatment, cleaning, second soaking treatment, third soaking treatment and second drying treatment under dry conditions of the seawater desalination reverse osmosis membrane;

[0010] The rinsing is performed with deionized water, the water temperature used for the rinsing is 50-85°C, and the rinsing time is 0.5-5min;

[0011] The solution used in the first immersion treatment is a NaHSO3 solution, and the immersion time is 0.5 to 6 minutes; the mass concentration of the NaHSO3 solution is 3% to 8%;

[0012] The cleaning is carried out using deionized water;

[0013] The solution used in the second soaking treatment is a glycerol aqueous solution, and the soaking time is 2 to 8 minutes; the mass concentration of the glycerol aqueous solution is 4% to 10%;

[0014] The solution used in the third immersion treatment is a polyvinyl alcohol solution, and the immersion time is 0.5 to 3 minutes; the mass concentration of the polyvinyl alcohol solution is 0.5% to 2.5%;

[0015] The second drying treatment under dry conditions adopts a drying temperature of 50 to 90° C. and a drying time of 1 to 10 minutes.

[0016] Optionally, the amine monomer includes at least one of p-phenylenediamine, m-phenylenediamine, 2,6-diaminotoluene, p-nitro-m-phenylenediamine, N,N-dimethylaniline, N,N-dipropyl-1-propylamine and N,N-dihydroxyethyl-p-methylaniline; the mass concentration of the amine monomer in the aqueous phase solution is 2.5% to 6.0%;

[0017] The phase transfer catalyst comprises at least one of 1-ethyl-(3-methylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine, lutidine, 2-amino-5-[(dimethylamino)methyl]pyridine, 3-hydroxymethylpyridine, 2-amino-3-methylpyridine, 2-pyridone, hexadecyltrimethylammonium bromide and triethyl(4-vinylbenzyl)ammonium chloride; the mass concentration of the phase transfer catalyst in the aqueous phase solution is 0.05% to 0.8%;

[0018] The surfactant comprises at least one of Triton X-100, Tween-80, sodium dodecyl sulfate and sodium dodecyl sulfonate; the mass concentration of the surfactant in the aqueous phase solution is 0.01% to 0.15%;

[0019] The pH buffer comprises camphorsulfonic acid and ethylenediamine; the mass concentration of the camphorsulfonic acid in the aqueous solution is 0.05% to 2.5%; the mass concentration of the ethylenediamine in the aqueous solution is 0.05% to 1.0%.

[0020] Optionally, the first oil phase solution also includes a first organic solvent; the first organic solvent includes at least one of n-hexane, cyclohexane, ethylcyclohexane, n-heptane and Isopar G isoparaffin.

[0021] Optionally, the aromatic sulfonyl chloride monomer includes at least one of benzenesulfonyl chloride, 3-(aminosulfonyl)benzenesulfonyl chloride, benzylsulfonyl chloride, 2,5-difluorobenzenesulfonyl chloride, 2,6-difluorobenzenesulfonyl chloride, 3,4-difluorobenzenesulfonyl chloride, 2,4-dibromobenzenesulfonyl chloride, 2,5-dibromobenzenesulfonyl chloride, 3,4-dibromobenzenesulfonyl chloride, 2,5-dichlorobenzenesulfonyl chloride, 2,6-dichlorobenzenesulfonyl chloride, 3,4-dichlorobenzenesulfonyl chloride, 1,2-benzenedisulfonyl chloride, 1,3-benzenedisulfonyl chloride and 1,4-benzenedisulfonyl chloride; the mass concentration of the aromatic sulfonyl chloride monomer in the second oil phase solution is 0.2% to 0.60%.

[0022] Optionally, the second oil phase solution also includes a second organic solvent; the second organic solvent includes at least one of n-hexane, cyclohexane, ethylcyclohexane, n-heptane and Isopar G isoparaffin.

[0023] Optionally, the first drying treatment adopts a drying temperature of 50 to 90° C. and a drying time of 1 to 8 minutes under steam conditions.

[0024] Optionally, the support layer is immersed in the aqueous solution for 10 to 120 seconds; the temperature of the aqueous solution is 20 to 30° C.;

[0025] The time for the support layer that absorbs the aqueous phase solution to be immersed in the first oil phase solution is 10 to 120 seconds; the temperature of the first oil phase solution is 20 to 30° C.;

[0026] The primary reverse osmosis membrane is immersed in the second oil phase solution for 10 to 300 seconds; the temperature of the second oil phase solution is 20 to 70°C.

[0027] In a second aspect, the present invention provides a seawater desalination reverse osmosis membrane, which is prepared by using the seawater desalination reverse osmosis membrane preparation method.

[0028] In a third aspect, the present invention provides an application of a seawater desalination reverse osmosis membrane, which uses the seawater desalination reverse osmosis membrane in the reuse of reclaimed water, seawater desalination and brackish water desalination.

[0029] The application of the technical solution of the present invention has at least the following beneficial effects:

[0030] (1) The present invention provides a method for preparing a seawater desalination reverse osmosis membrane, which can prepare a seawater desalination reverse osmosis membrane that meets both high desalination rate and high water flux. Specifically, the present invention uses a phase transfer catalyst and a surfactant in the aqueous phase solution, wherein the phase transfer catalyst includes a quaternary ammonium salt and / or a pyridine substance, which can not only combine with the amine monomer, but also has affinity for the oil phase solution, promotes more amine monomers to be enriched and transferred to the interface of the oil phase solution, and improves the interfacial polymerization reaction rate; the surfactant has fixed hydrophilic and lipophilic groups, has amphiphilicity, reduces the surface tension and interfacial free energy of the aqueous phase and the oil phase interface, can improve the solubility of the amine monomer, and promotes more amine monomers to immerse into the pores of the support layer; the combined use of the phase transfer catalyst and the surfactant can increase the effective concentration and diffusion rate of the amine monomer during the interfacial polymerization reaction, and accelerate the reaction rate of the interfacial polymerization; the present invention uses a specific mass concentration of trimesoyl chloride and isophthaloyl chloride in combination in the first oil phase solution, firstly, the high activity of trimesoyl chloride is used for interfacial polymerization with a large amount of amine monomers, and secondly, considering that the steric hindrance of the functional group of trimesoyl chloride is large, some amino groups of the amine monomers between two adjacent trimesoyl chloride molecules are not reacted, the present invention uses the steric hindrance The small isophthaloyl chloride further reacts with part of the amine monomers, thereby increasing the crosslinking degree of the polyamide functional layer and reducing the pore size of the polyamide functional layer. The first drying treatment is performed under steam conditions, and gaseous water molecules partially penetrate into the network channel of the polyamide functional layer and liquefy on the surface of the membrane to form a thin water layer, which prevents the water phase solution from volatilizing on the one hand, and on the other hand, the high temperature environment of the steam promotes the interfacial polymerization of the water phase solution and the first oil phase solution to increase the crosslinking degree. On the other hand, the byproduct hydrogen chloride gas formed by the interfacial polymerization cannot break through the water layer in time, and forms nanobubbles in the network channel of the polyamide functional layer. The nanobubbles move in the network channel of the polyamide functional layer to form water channels, increase the roughness of the polyamide functional layer, and improve the water flux. Finally, the water channels formed by the nanobubbles are retained, and the pH buffer absorbs the hydrogen chloride gas to maintain the appropriate pH value of the interfacial polymerization reaction, that is, the pH value is between 10.0 and 12.0. The present invention uses an aromatic sulfonyl chloride monomer in the second oil phase solution, which can react with the unreacted amine monomers in the primary reverse osmosis membrane, further increase the crosslinking degree of the polyamide functional layer, reduce the pore size of the polyamide functional layer, and improve the desalination rate.

[0031] (2) The post-treatment provided in the present invention includes rinsing, first immersion treatment, cleaning, second immersion treatment, third immersion treatment and second drying treatment under dry conditions of the seawater desalination reverse osmosis membrane in sequence; wherein, rinsing is used to remove unreacted substances remaining on the surface of the membrane; the first immersion treatment is completed by using a NaHSO3 solution to prevent the membrane from being contaminated by microorganisms and oxidative damage; the NaHSO3 solution remaining on the surface of the membrane is removed by cleaning; the second immersion treatment is completed by using a glycerol aqueous solution to keep the membrane moist; the third immersion treatment is completed by using a polyvinyl alcohol solution to form a protective layer on the surface of the membrane, which can reduce damage to the polyamide functional layer on the membrane during the rolling process; the second drying treatment under dry conditions is used to ensure the cross-linking degree of the seawater desalination reverse osmosis membrane and improve the structural stability of the seawater desalination reverse osmosis membrane.

[0032] (3) The seawater desalination reverse osmosis membrane prepared by the present invention has a water flux of 25.8 to 32.7 GFD and a desalination rate of 99.81% to 99.92%.

[0033] (4) The seawater desalination reverse osmosis membrane prepared by the present invention can be applied to reclaimed water reuse, seawater desalination and brackish water desalination, and has good industrial application prospects. DETAILED DESCRIPTION

[0034] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0035] Embodiment 1:

[0036] A method for preparing a seawater desalination reverse osmosis membrane, comprising:

[0037] Step S1, first soaking the prepared support layer in deionized water for 10 minutes, taking it out and draining the surface water droplets, and then immersing it in an aqueous solution for 10 to 120 seconds (specifically 40 seconds), then taking out the support layer adsorbing the aqueous solution, draining it and removing the surface droplets with a rolling rubber roller; the temperature of the aqueous solution is 20 to 30° C. (specifically 25° C.); the aqueous solution includes an amine monomer, a phase transfer catalyst, a surfactant and a pH buffer; the phase transfer catalyst includes a quaternary ammonium salt and / or a pyridine substance;

[0038] Step S2, immersing the support layer adsorbing the aqueous solution into a first oil phase solution for 10 to 120 seconds (specifically 30 seconds) to form a primary reverse osmosis membrane through a first interfacial polymerization reaction; then, taking out the primary reverse osmosis membrane, draining the first oil phase solution on the surface thereof, and performing a first drying treatment under steam conditions; the first oil phase solution includes trimesoyl chloride with a mass concentration of 0.20% to 0.50% (specifically 0.30%) and isophthaloyl chloride with a mass concentration of 0.10% to 0.40% (specifically 0.20%); the temperature of the first oil phase solution is 20 to 30° C. (specifically 25° C.);

[0039] Step S3, immersing the primary reverse osmosis membrane in the second oil phase solution for 10 to 300 seconds (specifically 30 seconds), and forming a seawater desalination reverse osmosis membrane through a second interfacial polymerization reaction; then, taking out the seawater desalination reverse osmosis membrane, and draining the second oil phase solution on the surface thereof; the second oil phase solution includes an aromatic sulfonyl chloride monomer; the temperature of the second oil phase solution is 20 to 70° C. (specifically 40° C.).

[0040] The method for preparing the seawater desalination reverse osmosis membrane also includes post-treatment of the seawater desalination reverse osmosis membrane; the post-treatment includes sequentially rinsing, first soaking treatment, cleaning, second soaking treatment, third soaking treatment and second drying treatment under dry conditions of the seawater desalination reverse osmosis membrane;

[0041] The rinsing is performed with deionized water, the water temperature used for the rinsing is 50-85°C (specifically 60°C), and the rinsing time is 0.5-5min (specifically 2min);

[0042] The solution used in the first immersion treatment is a NaHSO3 solution, and the immersion time is 0.5 to 6 minutes (specifically 2 minutes); the mass concentration of the NaHSO3 solution is 3% to 8% (specifically 3%);

[0043] The cleaning is carried out using deionized water;

[0044] The solution used in the second soaking treatment is a glycerol aqueous solution, and the soaking time is 2 to 8 minutes (specifically 3 minutes); the mass concentration of the glycerol aqueous solution is 4% to 10% (specifically 6%);

[0045] The solution used in the third immersion treatment is a polyvinyl alcohol solution, and the immersion time is 0.5 to 3 minutes (specifically 1 minute); the mass concentration of the polyvinyl alcohol solution is 0.5% to 2.5% (specifically 1.5%);

[0046] The second drying treatment under dry conditions adopts a drying temperature of 50 to 90° C. (specifically 60° C.) and a drying time of 1 to 10 minutes (specifically 2 minutes).

[0047] The amine monomer is m-phenylenediamine, and its mass concentration in the aqueous phase solution is 2.5% to 6.0% (specifically 3.5%);

[0048] The phase transfer catalyst is 1-ethyl-(3-methylaminopropyl) carbodiimide hydrochloride, and its mass concentration in the aqueous phase solution is 0.05% to 0.8% (specifically 0.15%);

[0049] The surfactant is sodium dodecyl sulfate, and its mass concentration in the aqueous phase solution is 0.01% to 0.15% (specifically 0.05%).

[0050] The pH buffer is camphorsulfonic acid and ethylenediamine; the mass concentration of the camphorsulfonic acid in the aqueous solution is 0.05% to 2.5% (specifically 1.5%); the mass concentration of the ethylenediamine in the aqueous solution is 0.05% to 1.0% (specifically 0.2%). The pH buffer is used to adjust the pH value of the aqueous solution to between 10.0 and 12.0, which is suitable for the rapid formation of a polyamide functional layer by interfacial polymerization reaction.

[0051] The first oil phase solution also includes a first organic solvent; the first organic solvent is Isopar G isoparaffin.

[0052] The aromatic sulfonyl chloride monomer is 3-(aminosulfonyl)benzenesulfonyl chloride, and its mass concentration in the second oil phase solution is 0.2% to 0.60% (specifically 0.40%).

[0053] The second oil phase solution also includes a second organic solvent; the second organic solvent is n-hexane.

[0054] The first drying treatment under steam conditions uses a drying temperature of 50 to 90° C. (specifically 60° C.) and a drying time of 1 to 8 minutes (specifically 3 minutes).

[0055] In this embodiment 1, the following steps are adopted when preparing the support layer:

[0056] The weighed polysulfone is added to N,N-dimethylformamide, and the polysulfone is fully dissolved in the N,N-dimethylformamide under stirring and heating conditions; wherein the stirring speed is 70-100 r / min (specifically 90 r / min), and the heating temperature is 90-100°C (specifically 90°C); then, N-methylpyrrolidone is added and stirred for 7-8h (specifically 8h) to obtain a solution for preparing a support layer; wherein, in the obtained support layer solution, the mass concentration of polysulfone is The mass concentration of the aqueous solution is 15% to 20% (specifically 17%), the mass concentration of N-methylpyrrolidone is 0.5% to 3.0% (specifically 1.5%), and the mass concentration of N,N-dimethylformamide is 77.0% to 84.5% (specifically 81.5%); then, the impurity particles are filtered out after vacuum degassing at -80 kPa, and the solution is cooled to room temperature, and the solution is coated on a non-woven fabric and put into a coagulation bath, and then placed in deionized water for washing for 5 minutes to obtain a support layer for standby use.

[0057] Embodiment 2:

[0058] The difference from Example 1 is that the surfactant is Triton X-100.

[0059] Embodiment 3:

[0060] The difference from Example 1 is that the mass concentration of trimesoyl chloride is 0.45%.

[0061] Embodiment 4:

[0062] The difference from Example 1 is that the aromatic sulfonyl chloride monomer is 1,3-benzenedisulfonyl chloride.

[0063] Embodiment 5:

[0064] The difference from Example 1 is that the temperature of the second oil phase solution is 50°C.

[0065] Embodiment 6:

[0066] Different from Example 1, the first drying treatment under steam conditions adopts a drying temperature of 80° C. and a drying time of 5 minutes.

[0067] Embodiment 7:

[0068] Different from Example 1, the first drying treatment under steam conditions uses a drying temperature of 80° C. and a drying time of 5 minutes; the second drying treatment under dry conditions uses a drying temperature of 80° C. and a drying time of 5 minutes.

[0069] Comparative Example 1:

[0070] The difference from Example 1 is that the amount of the phase transfer catalyst is zero.

[0071] Comparative Example 2:

[0072] The difference from Example 1 is that the amount of the surfactant used is zero.

[0073] Comparative Example 3:

[0074] The difference from the first embodiment is that step S3 is cancelled.

[0075] Comparative Example 4:

[0076] The difference from the first embodiment is that step S2 is cancelled.

[0077] Comparative Example 5:

[0078] Different from Example 1, the first drying process is performed under dry conditions.

[0079] The desalination membranes prepared in Examples 1-7 and Comparative Examples 1-5 were respectively sampled for desalination rate and water flux performance tests. The test results are shown in Table 1. The test operating conditions are: the raw water is 32000ppm sodium chloride aqueous solution, the operating pressure is 800psi / 5.52MPa, the temperature of the sodium chloride aqueous solution is 25°C, and the pH value is 7.0-8.0. The water flux and desalination rate after the membrane has been running for 30 minutes are measured, and the average value is taken for five points measured on the same membrane. Among them, water flux (F) is defined as: the volume of water passing through a unit membrane area per unit time under a certain operating pressure, and the unit is GFD. The desalination rate (R) is defined as: under certain operating conditions, the difference between the salt concentration of the feed liquid (Cf) and the salt concentration in the permeate (Cp), divided by the salt concentration of the feed liquid.

[0080] Table 1 Desalination rate and water flux performance test results

[0081]

[0082] From the data in Table 1, we know that:

[0083] Compared with comparative examples 1-5, the seawater desalination membranes prepared by using examples 1-7 of the present invention have higher water flux and desalination rate, wherein the water flux reaches 25.8-32.7 GFD, and the desalination rate reaches 99.81%-99.92%.

[0084] Compared with Example 1, Comparative Example 1 does not use a phase transfer catalyst, and the water flux and desalination rate of the prepared seawater desalination membrane are significantly reduced; this shows that the use of a phase transfer catalyst in Example 1 can promote more amine monomers to be enriched and transferred to the interface of the oil phase solution, increase the interfacial polymerization reaction rate, increase the crosslinking degree of the polyamide functional layer, reduce the pore size of the polyamide functional layer, and improve the desalination rate; because the use of a phase transfer catalyst increases the interfacial polymerization reaction rate, the thickness of the prepared seawater desalination membrane is thinner and the water flux is improved. However, Comparative Example 1 does not use a phase transfer catalyst, and it is difficult to promote the enrichment and transfer of amine monomers to the interface of the oil phase solution, and the interfacial polymerization reaction rate slows down, that is, the amine monomers slowly polymerize with the acyl chloride monomers in the first oil phase solution and the second oil phase solution, so that the thickness of the prepared seawater desalination membrane is thicker and the water flux decreases; in addition, Comparative Example 1 does not use a phase transfer catalyst, and it is difficult to promote more amine monomers to participate in interfacial polymerization, resulting in a decrease in the crosslinking degree of the polyamide functional layer and a decrease in the desalination rate.

[0085] Compared with Example 1, Comparative Example 2 does not use a surfactant, and the water flux and desalination rate of the seawater desalination membrane prepared therefrom are significantly reduced; this shows that the combination of a phase transfer catalyst and a surfactant in Example 1 can increase the effective concentration and diffusion rate of amine monomers during interfacial polymerization, accelerate the reaction rate of interfacial polymerization, increase the crosslinking degree of the polyamide functional layer, reduce the pore size of the polyamide functional layer, and improve the desalination rate; because the combination of a phase transfer catalyst and a surfactant in Example 1 accelerates the reaction rate of interfacial polymerization, the thickness of the prepared seawater desalination membrane is thinner and the water flux is improved. However, Comparative Example 2 does not use a surfactant, and cannot cooperate with the phase transfer catalyst to increase the effective concentration and diffusion rate of amine monomers during interfacial polymerization, resulting in a decrease in the crosslinking degree of the polyamide functional layer and a decrease in the desalination rate; Comparative Example 2 does not use a surfactant, and cannot cooperate with the phase transfer catalyst to accelerate the reaction rate of interfacial polymerization, that is, the interfacial polymerization reaction rate slows down, and the amine monomers slowly polymerize with the acyl chloride monomers in the first oil phase solution and the second oil phase solution, so that the thickness of the prepared seawater desalination membrane is thicker and the water flux decreases.

[0086] Compared with Example 1, Comparative Example 3 does not adopt step S3, and the water flux and desalination rate of the prepared seawater desalination membrane are significantly reduced; this shows that Example 1 adopts step S3, that is, the aromatic sulfonyl chloride monomer is used in the second oil phase solution, which can react with the unreacted amine monomer in the primary reverse osmosis membrane, further improve the crosslinking degree of the polyamide functional layer, reduce the pore size of the polyamide functional layer, and improve the desalination rate; because the second oil phase solution contains a second organic solvent, after the primary reverse osmosis membrane is immersed in the second oil phase solution, the second organic solvent causes the primary reverse osmosis membrane to swell, the water channel expands, and the water flux is increased. However, Comparative Example 3 does not adopt step S3, resulting in a downward trend in the water flux and desalination rate of the prepared seawater desalination membrane.

[0087] Compared with Example 1, Comparative Example 4 does not adopt step S2, and the desalination rate of the seawater desalination membrane prepared therefrom is significantly reduced, while the water flux is significantly increased; this shows that Example 1 adopts step S2, that is, the combination of trimesoyl chloride and isophthaloyl chloride of a specific mass concentration in the first oil phase solution can improve the crosslinking degree of the polyamide functional layer and reduce the pore size of the polyamide functional layer; the first drying treatment is carried out under steam conditions, and the gaseous water molecules partially penetrate into the network channel of the polyamide functional layer and liquefy on the surface of the membrane to form a thin water layer, which on the one hand prevents the volatilization of the aqueous phase solution, and on the other hand, the high temperature environment of steam promotes the interfacial polymerization of the aqueous phase solution and the first oil phase solution to increase the crosslinking degree; on the other hand, the byproduct hydrogen chloride gas formed by the interfacial polymerization cannot break through the water layer in time, and it forms nanobubbles in the network channel of the polyamide functional layer. The nanobubbles move in the network channel of the polyamide functional layer to form water channels, increase the roughness of the polyamide functional layer, and improve the water flux. However, in Comparative Example 4, step S2 is not adopted, and the decrease in crosslinking degree leads to a large pore size of the polyamide functional layer formed on the support layer, which reduces the desalination rate. In addition, the decrease in crosslinking degree not only leads to a large pore size of the polyamide functional layer formed on the support layer, but also leads to a thin thickness of the polyamide functional layer, which increases the water flux.

[0088] Compared with Example 1, Comparative Example 5 adopts the first drying treatment under dry conditions, and the water flux and desalination rate of the seawater desalination membrane prepared therefrom are significantly reduced; this shows that the first drying treatment under steam conditions in Example 1 is helpful to improve the water flux and desalination rate. However, Comparative Example 5 adopts the first drying treatment under dry conditions, and it is impossible to liquefy and form a thin water layer on the surface of the membrane. On the one hand, the aqueous phase solution is easy to volatilize, so that the effective amine monomers polymerized with the first oil phase solution interface are reduced, and the cross-linking degree of the polyamide functional layer is reduced, resulting in a decrease in the desalination rate; on the other hand, the byproduct hydrogen chloride gas is easy to volatilize, and it is difficult to form nanobubbles in the network channel of the polyamide functional layer, thereby reducing the water channels of the polyamide functional layer and reducing the water flux.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a seawater desalination reverse osmosis membrane, characterized in that: include: Step S1, immersing the prepared support layer in an aqueous solution, and then taking out the support layer that absorbs the aqueous solution; The aqueous phase solution includes an amine monomer, a phase transfer catalyst, a surfactant and a pH buffer; the phase transfer catalyst includes a quaternary ammonium salt and / or a pyridine substance; Step S2, immersing the support layer adsorbing the aqueous phase solution into a first oil phase solution to form a primary reverse osmosis membrane through a first interfacial polymerization reaction; Subsequently, the primary reverse osmosis membrane is taken out and subjected to a first drying treatment under steam conditions; the first oil phase solution includes 0.20% to 0.50% of trimesoyl chloride and 0.10% to 0.40% of isophthaloyl chloride; Step S3, immersing the primary reverse osmosis membrane in a second oil phase solution to form a seawater desalination reverse osmosis membrane through a second interfacial polymerization reaction; then, taking out the seawater desalination reverse osmosis membrane; the second oil phase solution includes an aromatic sulfonyl chloride monomer.

2. The method for preparing a seawater desalination reverse osmosis membrane according to claim 1, characterized in that: The method also includes post-treatment of the seawater desalination reverse osmosis membrane; the post-treatment includes sequentially rinsing, first soaking treatment, cleaning, second soaking treatment, third soaking treatment and second drying treatment under dry conditions of the seawater desalination reverse osmosis membrane; The rinsing is performed with deionized water, the water temperature used for the rinsing is 50-85°C, and the rinsing time is 0.5-5min; The solution used in the first immersion treatment is a NaHSO3 solution, and the immersion time is 0.5 to 6 minutes; the mass concentration of the NaHSO3 solution is 3% to 8%; The cleaning is carried out using deionized water; The solution used in the second soaking treatment is a glycerol aqueous solution, and the soaking time is 2 to 8 minutes; the mass concentration of the glycerol aqueous solution is 4% to 10%; The solution used in the third immersion treatment is a polyvinyl alcohol solution, and the immersion time is 0.5 to 3 minutes; the mass concentration of the polyvinyl alcohol solution is 0.5% to 2.5%; The second drying treatment under dry conditions adopts a drying temperature of 50 to 90° C. and a drying time of 1 to 10 minutes.

3. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The amine monomer includes at least one of p-phenylenediamine, m-phenylenediamine, 2,6-diaminotoluene, p-nitro-m-phenylenediamine, N,N-dimethylaniline, N,N-dipropyl-1-propylamine and N,N-dihydroxyethyl-p-methylaniline; the mass concentration of the amine monomer in the aqueous phase solution is 2.5% to 6.0%; The phase transfer catalyst comprises at least one of 1-ethyl-(3-methylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine, lutidine, 2-amino-5-[(dimethylamino)methyl]pyridine, 3-hydroxymethylpyridine, 2-amino-3-methylpyridine, 2-pyridone, hexadecyltrimethylammonium bromide and triethyl(4-vinylbenzyl)ammonium chloride; the mass concentration of the phase transfer catalyst in the aqueous phase solution is 0.05% to 0.8%; The surfactant comprises at least one of Triton X-100, Tween-80, sodium dodecyl sulfate and sodium dodecyl sulfonate; the mass concentration of the surfactant in the aqueous phase solution is 0.01% to 0.15%; The pH buffer comprises camphorsulfonic acid and ethylenediamine; the mass concentration of the camphorsulfonic acid in the aqueous solution is 0.05% to 2.5%; the mass concentration of the ethylenediamine in the aqueous solution is 0.05% to 1.0%.

4. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The first oil phase solution also includes a first organic solvent; the first organic solvent includes at least one of n-hexane, cyclohexane, ethylcyclohexane, n-heptane and Isopar G isoparaffin.

5. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The aromatic sulfonyl chloride monomer includes at least one of benzenesulfonyl chloride, 3-(aminosulfonyl)benzenesulfonyl chloride, benzylsulfonyl chloride, 2,5-difluorobenzenesulfonyl chloride, 2,6-difluorobenzenesulfonyl chloride, 3,4-difluorobenzenesulfonyl chloride, 2,4-dibromobenzenesulfonyl chloride, 2,5-dibromobenzenesulfonyl chloride, 3,4-dibromobenzenesulfonyl chloride, 2,5-dichlorobenzenesulfonyl chloride, 2,6-dichlorobenzenesulfonyl chloride, 3,4-dichlorobenzenesulfonyl chloride, 1,2-benzenedisulfonyl chloride, 1,3-benzenedisulfonyl chloride and 1,4-benzenedisulfonyl chloride; the mass concentration of the aromatic sulfonyl chloride monomer in the second oil phase solution is 0.2% to 0.60%.

6. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The second oil phase solution also includes a second organic solvent; the second organic solvent includes at least one of n-hexane, cyclohexane, ethylcyclohexane, n-heptane and Isopar G isoparaffin.

7. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The first drying treatment adopts a drying temperature of 50 to 90° C. and a drying time of 1 to 8 minutes under steam conditions.

8. The method for preparing a seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The time for immersing the support layer in the aqueous solution is 10 to 120 seconds; the temperature of the aqueous solution is 20 to 30° C.; The time for the support layer that absorbs the aqueous phase solution to be immersed in the first oil phase solution is 10 to 120 seconds; the temperature of the first oil phase solution is 20 to 30° C.; The primary reverse osmosis membrane is immersed in the second oil phase solution for 10 to 300 seconds; the temperature of the second oil phase solution is 20 to 70°C.

9. A seawater desalination reverse osmosis membrane, characterized in that: The desalination reverse osmosis membrane is prepared by the method for preparing the desalination reverse osmosis membrane according to any one of claims 2 to 8.

10. An application of a reverse osmosis membrane for seawater desalination, characterized in that: The seawater desalination reverse osmosis membrane as claimed in claim 9 is used in reclaimed water reuse, seawater desalination and brackish water desalination.

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