High-flux and high-boron-removal seawater desalination reverse osmosis membrane and preparation method thereof

Abstract

The invention relates to the technical field of reverse osmosis membranes, in particular to a high-flux and high-boron-removal seawater desalination reverse osmosis membrane and a preparation method thereof.The preparation method comprises the following steps that S1, a polyamide desalination layer is formed on the surface of a porous base membrane through an interfacial polymerization reaction, and the polyamide desalination layer is completely cured; and S2, coating the surface of the polyamide desalination layer with a solution containing amino-terminated polysiloxane, after the reaction is finished, spraying the membrane surface with a solvent in the solution containing amino-terminated polysiloxane, removing oil again, and rinsing the membrane surface to obtain the high-flux and high-boron-removal seawater desalination reverse osmosis membrane. The flux of the seawater desalination reverse osmosis membrane is greater than 33LMH, the boron removal rate is greater than 91.5%, and the desalination rate is greater than 99.8%.

Description

Technical Field

[0001] The invention relates to the technical field of reverse osmosis membranes, and in particular to a high-flux, high-boron removal seawater desalination reverse osmosis membrane and a preparation method thereof. Background Art

[0002] Reverse osmosis membrane separation technology has the separation characteristics of no phase change, low energy consumption, high efficiency, and high selectivity. It has been widely used in the fields of seawater desalination, brackish water desalination, pure water preparation, industrial wastewater treatment, and separation and concentration of industrial process substances. Due to the high salt concentration of the influent (TDS value 5000-50000ppm), high operating pressure (greater than 30 kg), and extremely high requirements for desalination rate and deboronization rate, the production process of seawater desalination reverse osmosis membrane has very high requirements for the control of microscale defects. Micron-level defects are sufficient to cause a significant decrease in desalination rate and deboronization rate. Conventional seawater desalination reverse osmosis membranes are prepared by interfacial polymerization of an aqueous solution containing m-phenylenediamine and an oily solution containing trimesoyl chloride on the surface of a polysulfone porous base membrane. In the reverse osmosis composite membrane, the polyamide desalination layer formed by interfacial polymerization is a three-dimensional cross-linked network structure with strong rigidity. During the formation of polyamide, due to the limitation of steric hindrance, once the polyamide skeleton is formed, it is difficult to continuously cross-link inside. Therefore, the density distribution of the polyamide desalination layer is inevitably uneven. The presence of these large pores reduces the desalination rate and the deboronization rate. In addition, the modification of conventional reverse osmosis membranes, such as coating the surface with a polymer solution, forms a polymer coating on the surface after drying. The drying of the polymer solution is a process of solute concentration. Even if the solution concentration is dilute enough, the membrane surface is still over-coated. The polymer coating will evenly cover the dense and loose areas of the desalination layer, and the redundant polymer coating will increase the mass transfer resistance of water molecules during the separation process, thereby reducing the membrane flux. Summary of the invention

[0003] In order to solve the above technical problems, a high-flux, high-boron removal seawater desalination reverse osmosis membrane and a preparation method thereof are provided. The seawater desalination reverse osmosis membrane prepared by the invention has high-flux and high-boron removal effects.

[0004] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0005] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0006] S1, forming a polyamide desalination layer on the surface of the porous base membrane through interfacial polymerization reaction, and completely solidifying the polyamide desalination layer;

[0007] S2. Coating a solution containing amino-terminated polysiloxane on the surface of the polyamide desalination layer, degreasing after the reaction is completed, spraying the membrane surface with the solvent in the solution containing amino-terminated polysiloxane, degreasing and rinsing the membrane surface again, thereby obtaining a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0008] Furthermore, the amino-terminated polysiloxane is a double-terminated amino-polydimethylsiloxane (NH 2 -PDMS-NH 2 ), the number average molecular weight is in the range of 800 g / mol to 60,000 g / mol, and its molecular structure is as follows:

[0009]

[0010] Furthermore, the mass percentage of the solution containing amino-terminated polysiloxane is 0.01wt%-10wt%; the solvent in the solution containing amino-terminated polysiloxane is a good solvent capable of dissolving the amino-terminated polysiloxane, for example, the same solvent used in the oil phase in the interfacial polymerization reaction.

[0011] Further, step S1 is specifically as follows: the surface of the porous base film is fully contacted with the aqueous phase containing the amine monomer and then with the oil phase containing the amine reactive substance, the interfacial polymerization reaction is carried out for 1 second to 5 minutes, the oil phase is removed and completely solidified, and a suitable temperature is selected for solidification according to the type of the oil phase, and the general solidification temperature range is 0-150° C.; generally, the time for the porous base film to fully contact the aqueous phase containing the amine monomer is 10 seconds to 5 minutes;

[0012] The oil phase containing the amine reactive substance is an oil phase solution containing an acyl halide functional group compound, and the mass percentage is 2wt%-4wt%, wherein the acyl halide functional group compound includes but is not limited to phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesoyl chloride, biphenyltrichloride, etc.;

[0013] The aqueous phase containing amine monomers is an aqueous phase solution containing amine monomers, and the mass percentage is 0.1wt%-0.3wt%, wherein the amine monomers include but are not limited to m-phenylenediamine, propylenediamine or triethylenetetramine.

[0014] Furthermore, in step S2, the reaction time after coating the oil phase solution containing the amino-terminated polysiloxane is 30 seconds to 2 minutes, after which 50% to 95% of the volume of the oil phase solution on the membrane surface is removed before subsequent operations are performed.

[0015] Furthermore, the coating method in step S2 is selected from one or more of slit coating, immersion coating, and single-sided back roller coating; the degreasing method in step S2 is selected from one or more of oven heating to volatilize the solvent, liquid spraying, pressure roller, air knife, and air knife removal.

[0016] Furthermore, the porous base membrane is selected from one of a polysulfone porous support membrane, a polyethersulfone porous support membrane, a polyetherimide porous support membrane, and a polytetrafluoroethylene porous support membrane.

[0017] Another aspect of the present invention provides a high-flux, high-boron removal seawater desalination reverse osmosis membrane obtained by the above preparation method.

[0018] Beneficial technical effects: After the desalination layer is completely solidified, the present invention grafts and inserts the PDMS flexible polymer modified with double-terminal amino groups into the loose area of ​​the rigid polymer skeleton. On the one hand, the grafted and inserted PDMS is not easy to fall off, and can achieve long-term effectiveness, increase the overall cross-linking degree and density of the desalination layer, and can significantly improve the desalination rate and deboronization rate of the composite membrane;

[0019] The amino groups at both ends of the PDMS molecular chain can react chemically with the acyl chloride groups remaining on the membrane surface, thereby grafting the PDMS molecules into the defects of the polyamide desalination layer, repairing the micro-scale defects of the desalination layer, and thus improving the removal rate of salt ions and boron;

[0020] After the chemical grafting is completed on the membrane surface, the double-terminated amino PDMS solution is removed in time. Before the grafted PDMS is finally physically solidified on the membrane surface, the excess solution is removed in time to avoid over-coating and the loss of composite membrane flux caused by transitional coating, thereby achieving the effect of improving membrane flux.

[0021] The overall process of the present invention only needs to add two steps, namely, solution coating and solvent spraying, in the conventional interfacial polymerization reaction zone, without changing the length and layout of the production line, and the transformation is simple and the investment cost is low;

[0022] The seawater desalination reverse osmosis membrane prepared by the invention has a flux greater than 33LMH, a boron removal rate greater than 91.5%, and a desalination rate greater than 99.8%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The process roadmap for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane is shown in the example. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. The technology and method known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and method should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0026] The experimental methods in the following examples without specifying specific conditions are usually measured in accordance with national standards; if there is no corresponding national standard, the method is carried out in accordance with the general standard requirements or general methods.

[0027] In the present invention, coating and applying have the same meaning.

[0028] In the following cases, the porous base membrane is a polysulfone porous support membrane as an example, and the cut-off molecular weight of the polysulfone porous support membrane is 35 KDa.

[0029] Example 1

[0030] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0031] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0032] S2. Immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A21 purchased from Gelest, number average molecular weight 5000g / mol), react for 1 minute after coating, remove 90% of the volume of the solution on the membrane surface with a roller, then use Isopar E pure solvent spray to wash away the residual solution on the membrane surface, then put it into a 30℃ oven for degreasing to thoroughly dry the solvent on the membrane surface, and then immerse it in 90℃ hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0033] Example 2

[0034] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0035] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0036] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A21 purchased from Gelest, number average molecular weight 5000g / mol), after coating, react for 1 minute and then use a roller to remove 90% of the volume of the solution on the membrane surface, then use Isopar E pure solvent spray to wash away the residual solution on the membrane surface, then put it into a 30℃ oven for degreasing to completely dry the solvent on the membrane surface, and then immerse it in 90℃ hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0037] Example 3

[0038] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0039] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0040] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A21 purchased from Gelest, number average molecular weight 5000g / mol), after coating, react for 1 minute and then use a roller to remove 90% of the volume of the solution on the membrane surface, then use Isopar E pure solvent spray to wash away the residual solution on the membrane surface, then put it into a 30℃ oven for degreasing to completely dry the solvent on the membrane surface, and then immerse it in 90℃ hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0041] Example 4

[0042] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0043] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0044] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A15 purchased from Gelest, number average molecular weight 3000g / mol), after coating, react for 1 minute and then use a roller to remove 90% of the volume of the solution on the membrane surface, then use Isopar E pure solvent spray to wash away the residual solution on the membrane surface, then put it into a 30℃ oven for degreasing to completely dry the solvent on the membrane surface, and then immerse it in 90℃ hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0045] Example 5

[0046] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0047] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0048] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A12 purchased from Gelest, number average molecular weight 900g / mol-1000g / mol), after coating, react for 1 minute and use a roller to remove 90% of the volume of the solution on the membrane surface, then use Isopar E pure solvent spray to wash away the residual solution on the membrane surface, then put it into a 30℃ oven for degreasing to completely dry the solvent on the membrane surface, and then immerse it in 90℃ hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0049] Example 6

[0050] A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane comprises the following steps:

[0051] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0052] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 , model DMS-A35 purchased from Gelest, number average molecular weight 50000g / mol), after coating and reacting for 1 minute, 90% volume of the solution on the membrane surface was removed by a roller, and then the residual solution on the membrane surface was washed away by spraying with pure Isopar E solvent, and then the membrane was placed in a 30°C oven for degreasing to thoroughly dry the solvent on the membrane surface, and then immersed in 90°C hot water for rinsing for 3 minutes to obtain the final product, a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

[0053] Comparative Example 1

[0054] The preparation process of the reverse osmosis membrane in this case is as follows:

[0055] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0056] S2. Immediately at the oven outlet of the previous step, an Isopar E solution containing 0.01 wt% m-phenylenediamine is coated on the surface of the polyamide desalting layer by a slit coating method. After reacting for 1 minute after coating, 90% of the volume of the solution on the membrane surface is removed by a roller, and then the residual solution on the membrane surface is washed away by spraying with pure Isopar E solvent. The membrane is then placed in a 30°C oven for degreasing to completely dry the solvent on the membrane surface, and then immersed in 90°C hot water for rinsing for 3 minutes to obtain the reverse osmosis membrane of this case.

[0057] Comparative Example 2

[0058] The preparation process of the reverse osmosis membrane in this case is as follows:

[0059] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0060] S2, immediately at the oven outlet of the previous step, the surface of the polyamide desalting layer is coated with an Isopar E solution (NH 2 -PDMS-NH 2 The membrane was prepared by using a DMS-A21 model purchased from Gelest with a number average molecular weight of 5000 g / mol. After coating, the membrane was directly placed in a 30°C oven for degreasing to completely dry the solvent on the membrane surface. The membrane was then immersed in 90°C hot water for rinsing for 3 minutes to obtain the reverse osmosis membrane in this case.

[0061] Comparative Example 3

[0062] The preparation process of the reverse osmosis membrane in this case is as follows:

[0063] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0064] S2. Immediately at the oven outlet of the previous step, an Isopar E solution containing 0.01 wt% polydimethylsiloxane (PDMS) is coated on the surface of the polyamide desalination layer by slit coating. After reacting for 1 minute after coating, 90% of the solution on the membrane surface is removed by a roller, and then the residual solution on the membrane surface is washed away by spraying with pure Isopar E solvent. The membrane is then placed in a 30°C oven for degreasing to thoroughly dry the solvent on the membrane surface, and then immersed in 90°C hot water for rinsing for 3 minutes to obtain the reverse osmosis membrane of this case.

[0065] Comparative Example 4

[0066] The preparation process of the reverse osmosis membrane in this case is as follows:

[0067] S1. The polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2 wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2 wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, thereby forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30° C. oven to remove the oil phase on the membrane surface, so that the polyamide desalting layer is completely solidified;

[0068] S2. Immediately at the oven outlet of the previous step, pure Isopar E solvent is coated on the surface of the polyamide desalination layer by slit coating. After reacting for 1 minute after coating, 90% of the solution on the membrane surface is removed by a roller. Then, the residual solution on the membrane surface is washed away by spraying with pure Isopar E solvent. Then, the membrane is placed in a 30°C oven for degreasing to completely dry the solvent on the membrane surface. Then, the membrane is immersed in 90°C hot water for rinsing for 3 minutes to obtain the reverse osmosis membrane of this case.

[0069] Comparative Example 5

[0070] This case is a blank control case. The preparation process of the reverse osmosis membrane in this case is as follows: the polysulfone porous support membrane is first fully contacted with an aqueous solution containing 3.2wt% of m-phenylenediamine for 1 minute, and then contacted with an Isopar E oil solution containing 0.2wt% of trimesoyl chloride for 1 minute to perform interfacial polymerization reaction, forming a polyamide desalting layer on the surface of the polysulfone porous support membrane, and then placed in a 30°C oven to remove the oil phase on the membrane surface, allowing the polyamide desalting layer to completely solidify, and then directly immersed in 90°C hot water for rinsing for 3 minutes to obtain the reverse osmosis membrane in this case.

[0071] Test Case

[0072] Performance evaluation of seawater desalination reverse osmosis membrane:

[0073] The reverse osmosis membrane samples prepared in the above embodiments and comparative examples were tested under the following conditions: 32000 mg / L sodium chloride solution was used as the feed solution, and 5 ppm of boric acid was contained, the solution temperature was 25°C, pH=7.5, and the test pressure was 5.5 MPa. After the separation membrane was started and operated for 1 hour, the flux, desalination rate and deboronization rate of the separation membrane were tested, and the test results are shown in Table 1.

[0074] Table 1 Reverse osmosis membrane performance of each case

[0075] FluxLMH Desalination rate % Boron removal rate % Example 1 36.5 99.83 92.4 Example 2 36.1 99.86 92.5 Example 3 35.8 99.87 92.7 Example 4 36.3 99.82 92.1 Example 5 36.4 99.80 91.8 Example 6 33.7 99.87 92.8 Comparative Example 1 36.2 99.76 90.4 Comparative Example 2 21.5 99.82 92.1 Comparative Example 3 36.2 99.71 89.9 Comparative Example 4 37.1 99.69 89.6 Comparative Example 5 36.7 99.68 89.4

[0076] From the test results of Examples 1-6 in Table 1, it can be seen that the use of double-terminated amino polydimethylsiloxane (NH 2 -PDMS-NH 2 ) modified reverse osmosis membrane has a high desalination rate and deboronization rate while maintaining a high flux, and the higher the molecular weight or the higher the concentration of the double-terminal amino polydimethylsiloxane used, the higher the desalination rate and deboronization rate, but the flux tends to decrease.

[0077] It can be seen from Example 1 and Comparative Example 1 that the effect of low molecular weight diamine monomer (m-phenylenediamine) on the modification of the desalination layer is not as good as that of double-terminated amino polydimethylsiloxane. It can be seen from Example 1 and Comparative Example 2 that if the coated modification solution is not completely removed after the desalination layer is grafted and modified, the modified polymer will form a coating on the surface of the desalination layer, greatly reducing the flux of the reverse osmosis membrane. It can be seen from Example 1 and Comparative Example 3 that PDMS without amino groups cannot be chemically grafted and modified on the desalination layer. It can be seen from Comparative Examples 4 and 5 that the desalination rate and deboronization rate of conventional composite membranes that have not been grafted and modified are low.

[0078] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane, characterized in that: The steps include: S1, forming a polyamide desalination layer on the surface of the porous base membrane through interfacial polymerization reaction, and completely solidifying the polyamide desalination layer; S2. Coating a solution containing amino-terminated polysiloxane on the surface of the polyamide desalination layer, degreasing after the reaction is completed, spraying the membrane surface with the solvent in the solution containing amino-terminated polysiloxane, degreasing and rinsing the membrane surface again, thereby obtaining a high-flux, high-boron removal seawater desalination reverse osmosis membrane.

2. The method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to claim 1, characterized in that: The amino-terminated polysiloxane is a double-terminated amino-polydimethylsiloxane, with a number average molecular weight ranging from 800 g / mol to 60,000 g / mol, and its molecular structure is as follows:

3. The method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to claim 2, characterized in that: The mass percentage of the solution containing amino-terminated polysiloxane is 0.01wt%-10wt%; the solvent in the solution containing amino-terminated polysiloxane is a good solvent capable of dissolving the amino-terminated polysiloxane.

4. A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to any one of claims 1 to 3, characterized in that: Step S1 specifically includes: making the surface of the porous base film fully contact with the aqueous phase containing the amine monomer and then contacting with the oil phase containing the amine reactive substance, after the interfacial polymerization reaction lasts for 1 second to 5 minutes, removing the oil phase and completely curing.

5. A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to any one of claims 1 to 3, characterized in that: The reaction time after coating the oil phase solution containing the amino-terminated polysiloxane in step S2 is 30 seconds to 2 minutes, after which 50% to 95% of the volume of the oil phase solution on the membrane surface is removed before subsequent operations are performed.

6. The method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to claim 5, characterized in that: The coating method in step S2 is selected from one or more of slit coating, immersion coating, and single-sided back roller coating; the degreasing method in step S2 is selected from one or more of oven heating to volatilize solvent, liquid spraying, extrusion roller, air knife, and air knife removal.

7. A method for preparing a high-flux, high-boron removal seawater desalination reverse osmosis membrane according to any one of claims 1 to 3, characterized in that: The porous base membrane is selected from one of a polysulfone porous support membrane, a polyethersulfone porous support membrane, a polyetherimide porous support membrane, and a polytetrafluoroethylene porous support membrane.

8. A high-flux, high-boron removal seawater desalination reverse osmosis membrane obtained according to the preparation method according to any one of claims 1 to 7.

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