A sulfonated polybenzimidazole composite membrane and a preparation method thereof

Abstract

The application discloses a succinimide triptycyl compound organic solvent composite nanofiltration membrane and a preparation method thereof, and belongs to the technical field of separation membranes. The application is characterized in that, polyacrylonitrile or polyimide ultrafiltration membrane is used as a base film, after a surface pore preserving agent is removed, the base film is first soaked in an aqueous solution containing a succinimide triptycyl compound, then is soaked in an organic solution containing a polybasic acid chloride to perform an interfacial polymerization reaction, and finally is dried through heat crosslinking to obtain a composite nanofiltration membrane. The composite nanofiltration membrane prepared by the application has high stability in various polar organic solvents, has good selectivity to organic small molecules, and has high solvent permeability, and has high economic value in separation of organic solvent systems in industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of membrane separation technology, and in particular to a succinimidyl trisrubeanic compound organic solvent nanofiltration composite membrane and a preparation method thereof. BACKGROUND

[0002] Nanofiltration membrane is a new type of separation membrane that appeared in the late 80s. Its molecular weight cut-off is between reverse osmosis membrane and ultrafiltration membrane, about 100-1000 Da. It is speculated that nanofiltration membrane may have a microporous structure of about 1 nm, so it is called "nanofiltration". Organic liquid is considered indispensable to the development of petroleum, chemical, food and pharmaceutical industries. In particular, in the manufacture of active pharmaceutical ingredients (API), more than 80% of material consumption can be attributed to the use of organic solvents. This has prompted people to seek new strategies for recovering solvents, in which case membrane separation is a promising technology due to its low energy consumption and low carbon footprint. In particular, compared to those high-energy thermal separation processes, organic solvent nanofiltration (OSN) can save about 90% of energy consumption. More importantly, OSN technology has mild operating conditions, and the impact on product activity can be ignored. However, due to the lack of porosity and dispersed pore size distribution, traditional OSN membranes still face challenges in fast solvent permeation and separation of small molecules. In order to meet these stringent separation requirements, OSN membranes should have short and ordered transport channels, high pore connectivity and stable structure.

[0003] In order to make OSN membrane technology more widely used, high permeability / selectivity membranes are needed to handle large volumes of solvent in a feasible time frame, reducing processing costs. Strategies to improve membrane permeability include one at the molecular level to design the structure of the rejection layer polymer to provide greater interconnected microporosity. For example, Rahul Banerjee (Journal of the American Chemical Society, 2017, 139(37): 13083-13091) and others used a bottom-up interfacial crystallization method to make large-scale thin films from these micropowder under ambient conditions, with SBET as high as 1151 m 2 g -1 , and acetonitrile permeability reached an unprecedented 339 L m -2 h -1 bar -1 . The second method is to thin the thickness of the separation layer to reduce the solvent permeation resistance. For example, Karan (Science, 2015, 348(6241): 760-767) and others used chromium hydroxide nanowires as a sacrificial layer to adjust the morphology of the separation layer and prepared an ultra-thin separation layer with a thickness of about 10 nm. The methanol permeation flux after DMF activation reached 19.1 LMH bar.-1 .

[0004] At present, due to the low performance of the commercially available organic solvent nanofiltration membrane, the development and application has been stagnated, and it is urgent to find a higher cost-effective organic solvent nanofiltration membrane material. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the existing materials, and to provide a high permeation selectivity organic solvent nanofiltration membrane and a preparation method thereof.

[0006] In order to achieve the purpose of the present application, the technical solutions of the present application are as follows:

[0007] A preparation method of a succinimide triptycyl compound organic solvent composite nanofiltration membrane, prepared by the following steps:

[0008] a) Soak the base film in pure water for 2h to remove the pore-forming agent in the membrane, and the base film is polyacrylonitrile or polyimide ultrafiltration membrane;

[0009] b) After soaking, drain the base film, then soak it in a 0.1wt%-3wt% succinimide triptycyl compound aqueous solution at 25℃ for 1-10min, and the succinimide triptycyl compound aqueous solution also contains an alkaline solvent; after soaking, take out the base film, then remove the water droplets remaining on the surface of the base film, and prepare for use;

[0010] c) Soak the base film treated in step b) in an organic solution containing polyacyl chloride at 25℃ for 1-10min, and the concentration of the polyacyl chloride is 0.02wt%-0.5wt%;

[0011] d) Heat the filtration membrane after step c) in an oven at 50-70℃ for 1-10min for thermal crosslinking to obtain a succinimide triptycyl compound organic solvent composite nanofiltration membrane.

[0012] Preferably, the succinimide triptycyl compound of the present application has the following structure:

[0013]

[0014] In the formula, R1 is hydroxyl -OH or hydrogen -H.

[0015] Preferably, the alkaline solvent in step b) is at least one of sodium hydroxide, potassium hydroxide, triethylamine, and diisopropylethylamine. More preferably, the concentration of the alkaline solvent in step b) is 0.3%-2wt%.

[0016] Preferably, the water solution in step b) further comprises a phase transfer catalyst, and the phase transfer catalyst is dodecyltrimethylammonium chloride. More preferably, the concentration of the phase transfer catalyst in the water solution in step b) is 0.2wt%.

[0017] Preferably, the polybasic acid chloride is one or a mixture of several of trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride.

[0018] Preferably, the organic solution in step c) is prepared by dissolving polybasic acid chloride in an organic solvent, and the organic solvent is at least one of n-hexane, isomeric alkanes or toluene.

[0019] The present application has the following advantages:

[0020] The film preparation method provided by the present application is simple, the film preparation time is short, the conditions are mild, and the prepared organic solvent nanofiltration membrane has a high permeation flux and a low molecular weight cut-off. The succinimide triptycyl polyphenol can be ionized into phenolic oxygen negative ions in an aqueous solution, and has a large molecular structure, which will reduce the diffusion rate of the succinimide triptycyl polyphenol to the interface polymerization reaction zone, and thus help to prepare a thin selection layer, thereby facilitating the obtaining of a high flux; the succinimide triptycyl molecule is convenient to synthesize, separate and purify, and the structural rigidity is reduced to a certain degree, which is beneficial to the dissolution of the succinimide triptycyl molecule in alkaline water; in addition, the unique structure of the succinimide triptycyl molecule can obtain a polymer having a hypercrosslinked structure after polymerization with acid chloride, and the generated polymer thin film has a high free volume and a large number of micropores through the torsional rigid skeleton of the succinimide triptycyl polyphenol and the crosslinking effect, thereby improving the permeability of the composite nanofiltration membrane to organic solvents, while maintaining good organic molecule selectivity.

[0021] The composite nanofiltration membrane prepared by the present application has a high permeation flux (>7LMH or so) to organic solvents such as methanol, and can effectively cut off dye molecules such as methyl orange, orange red G, rhodamine B and bright blue R, and can be completely applied to the solution concentration, material separation and solvent recovery processes in the organic solvent system. In addition, the organic solvent nanofiltration membrane prepared by the present application can realize the accurate separation of methyl orange and methylene blue dye molecules with similar molecular weights based on charge effects and molecular sizes. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a diagram of the separation performance of various dyes by the composite nanofiltration membrane prepared in Example 1 of the present application;

[0023] Figure 2 is a diagram of the permeation performance of various solvents by the composite nanofiltration membrane prepared in Example 1 of the present application;

[0024] Figure 3 is a diagram of the solvent stability test of the composite nanofiltration membrane prepared in Example 1 of the present application;

[0025] Figure 4 is the UV absorption spectrum of the composite nanofiltration membrane prepared in embodiment 1 of the present application for the precise separation of methyl orange and methylene blue dye molecules with similar molecular weights;

[0026] Figure 5 is the separation performance diagram of the composite nanofiltration membrane prepared in embodiment 7 of the present application for various dyes;

[0027] Figure 6 is the permeation performance diagram of the composite nanofiltration membrane prepared in embodiment 7 of the present application for various solvents;

[0028] Figure 7 is the SEM diagram of the surface of the composite nanofiltration membrane prepared in embodiment 1 of the present application; DETAILED DESCRIPTION

[0029] The technical solutions of the present application are further limited in combination with specific embodiments, but the scope of protection is not limited to the description.

[0030] In the following examples, the structures of the different reaction site functional group compounds used are as shown in the diagram below, and are respectively named monomer (I), monomer (II) and monomer (III). The separation performance test conditions used are as follows: after pre-pressing for 2 hours under the conditions of 0.6 MPa and 25℃, the prepared composite nanofiltration membrane is tested for the rejection rate of 50 ppm dye methanol solution and the permeation flux of various solvents, with the flux unit being LMH / bar (liter / meter / hour / bar).

[0031]

[0032] Embodiment 1

[0033] A preparation method of a succinimide triptycene compound organic solvent composite nanofiltration membrane, the steps being as follows:

[0034] (1) The polyacrylonitrile ultrafiltration membrane is soaked in pure water for 2 hours to remove the pore-forming agent on the surface of the membrane;

[0035] (2) The polyacrylonitrile ultrafiltration membrane is taken out and soaked in a water solution with a monomer (I) concentration of 1.0 wt% and a triethylamine concentration of 2.0 wt% at 25℃, the ultrafiltration membrane is taken out and the water droplets remaining on the surface of the membrane are removed with a rubber roller, and the membrane is prepared for use;

[0036] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) is soaked in an isomeric alkane solution with a phthaloyl chloride concentration of 0.1 wt% at 25℃ for reaction;

[0037] (4) The filtration membrane after the reaction in step (3) is placed in an oven at 60℃ for heating, and a succinimide triptycene compound organic solvent composite nanofiltration membrane is obtained.

[0038] The permeation flux of the composite nanofiltration membrane of the application to methanol is 7.7 LMH / bar, and the permeation flux of the composite nanofiltration membrane to acetone is 10.21 LMH / bar; the rejection rate of the composite nanofiltration membrane to methyl orange is 93.3%.

[0039] The prepared composite nanofiltration membrane is used for separating p-nitroaniline, orange G (OG), acid red (AR), tetracycline (TC), rhodamine B (RDB) and brilliant blue R (BBR), and the test results are shown in Table 1. Figure 1 It is shown that the rejection ability gradually increases with the increase of the molecular weight of the dye; the rejection molecular weight of the above-mentioned organic solvent nanofiltration membrane is about 301 g / mol.

[0040] In addition, the composite nanofiltration membrane of the application is sequentially used for filtering water, methanol, ethanol, tetrahydrofuran and acetone, and the flux performance change is tested, and the results are shown in Table 2. Figure 2 The flux of the composite nanofiltration membrane changes little within 120 h, which shows that the composite nanofiltration membrane of the application has good solvent resistance and high running stability, as shown in Table 3. Figure 3

[0041] Based on the different charge properties of the dyes, the composite nanofiltration membrane of the application can realize the precise separation of methyl orange (MW 327) and methylene blue (MW 320) with similar molecular weights (as shown in Table 4). Figure 4

[0042] Example 2

[0043] A preparation method of a succinimide triptycyl compound organic solvent composite nanofiltration membrane, the steps are as follows:

[0044] (1) The polyacrylonitrile ultrafiltration membrane is soaked in pure water for 2 h to remove the pore-forming agent in the membrane;

[0045] (2) The polyacrylonitrile ultrafiltration membrane is taken out and soaked in a monomer (I) aqueous solution with a concentration of 1.0 wt% and a triethylamine aqueous solution with a concentration of 2.0 wt% at 25℃, then the membrane is taken out and the water droplets remaining on the surface of the membrane are removed by a rubber roller, and the membrane is prepared for use;

[0046] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) is soaked in an isomeric alkane solution with a concentration of 0.1 wt% of isophthaloyl chloride at 25℃ for reaction;

[0047] (4) The nanofiltration membrane after the reaction in step (3) is heated in an oven at 60℃ to obtain a succinimide triptycyl compound organic solvent composite nanofiltration membrane.

[0048] ​​The separation performance test of the prepared composite nanofiltration membrane shows that the flux of methanol is 8.2 LMH / bar, and the rejection rate of methyl orange (MW 327 Da) is 92.1%.

[0049] Example 3

[0050] A preparation method of a succinimidyl trisbiphenylphosphonium compound organic solvent composite nanofiltration membrane, the steps are as follows:

[0051] (1) The polyacrylonitrile ultrafiltration membrane is soaked in pure water for 2 h to remove the pore-forming agent on the membrane surface;

[0052] (2) The polyacrylonitrile ultrafiltration membrane is taken out and soaked in a monomer (I) aqueous solution with a concentration of 1.0 wt% and a triethylamine concentration of 2.0 wt% at 25°C, then the membrane is taken out and the water droplets remaining on the membrane surface are removed with a rubber roller, and the membrane is prepared for use;

[0053] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) is soaked in an isoparaffin solution with a terephthaloyl chloride concentration of 0.1 wt% at 25°C for reaction;

[0054] (4) The nanofiltration membrane after step (3) is heated in an oven at 60°C to obtain a succinimidyl trisbiphenylphosphonium compound organic solvent composite nanofiltration membrane.

[0055] The separation performance test of the prepared composite nanofiltration membrane shows that the flux of methanol is 7.6 LMH / bar, and the rejection rate of methyl orange (MW 327 Da) is 94.6%.

[0056] Example 4

[0057] A preparation method of a succinimidyl trisbiphenylphosphonium compound organic solvent composite nanofiltration membrane, the steps are as follows:

[0058] (1) The polyacrylonitrile ultrafiltration membrane is soaked in pure water for 2 h to remove the pore-forming agent on the membrane surface;

[0059] (2) The polyacrylonitrile ultrafiltration membrane is taken out and soaked in a monomer (II) aqueous solution with a concentration of 1.0 wt% and a NaOH concentration of 2.0 wt% at 25°C, then the ultrafiltration membrane is taken out and the water droplets remaining on the membrane surface are removed with a rubber roller, and the membrane is prepared for use;

[0060] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) is soaked in an isoparaffin solution with a terephthaloyl chloride concentration of 0.1 wt% at 25°C for reaction;

[0061] (4) The nanofiltration membrane after step (3) is heated in an oven at 60°C to obtain a succinimidyl trisbiphenylphosphonium compound organic solvent composite nanofiltration membrane.

[0062] The prepared composite nanofiltration membrane has a permeation flux of 11.59 LMH / bar for methanol, a permeation flux of 16.72 LMH / bar for acetone, and a rejection rate of 87.56% for methyl orange (MW 327 Da).

[0063] Example 5

[0064] A preparation method of a succinimide triptycyl compound organic solvent composite nanofiltration membrane, comprising the following steps:

[0065] (1) Soak the polyacrylonitrile ultrafiltration membrane in pure water for 2h to remove the pore-forming agent in the membrane;

[0066] (2) Take out the polyacrylonitrile ultrafiltration membrane, and soak it in a water solution with a monomer (II) concentration of 1.0wt% and a NaOH concentration of 2.0wt% at 25°C, then take out the membrane, and remove the water droplets remaining on the surface of the membrane with a rubber roller, and reserve it for use;

[0067] (3) Soak the polyacrylonitrile ultrafiltration membrane treated in step (2) in an isoparaffin solution with a terephthaloyl chloride concentration of 0.1wt% at 25°C for reaction;

[0068] (4) Heat the nanofiltration membrane after the reaction in step (3) in an oven at 60°C to obtain a succinimide triptycyl compound organic solvent composite nanofiltration membrane.

[0069] The separation performance test of the prepared composite nanofiltration membrane shows that the flux of methanol is 13.1 LMH / bar, and the rejection rate of methyl orange (MW 327 Da) is 86.84%.

[0070] Example 6

[0071] A preparation method of a succinimide triptycyl compound organic solvent composite nanofiltration membrane, comprising the following steps:

[0072] (1) Soak the polyacrylonitrile ultrafiltration membrane in pure water for 2h to remove the pore-forming agent in the membrane;

[0073] (2) Take out the polyacrylonitrile ultrafiltration membrane, and soak it in a water solution with a monomer (II) concentration of 1.0wt% and a NaOH concentration of 2.0wt% at 25°C, then take out the membrane, and remove the water droplets remaining on the surface of the membrane with a rubber roller, and reserve it for use;

[0074] (3) Soak the polyacrylonitrile ultrafiltration membrane treated in step (2) in an isoparaffin solution with a terephthaloyl chloride concentration of 0.1wt% at 25°C for reaction;

[0075] (4) The filtration membrane after step (3) is heated in an oven at 60 DEG C to obtain a succinimidyl trisbipyridyl organic solvent composite nanofiltration membrane.

[0076] The separation performance test of the prepared composite nanofiltration membrane shows that the flux of methanol is 15.21 LMH / bar, and the rejection rate of methyl orange (MW 327 Da) is 88.97%.

[0077] Example 7

[0078] A preparation method of a succinimidyl trisbipyridyl compound organic solvent composite nanofiltration membrane, comprising the following steps:

[0079] (1) The polyacrylonitrile ultrafiltration membrane is soaked in pure water for 2 h to remove the pore-forming agent on the surface of the membrane;

[0080] (2) The polyacrylonitrile ultrafiltration membrane is taken out and soaked in a monomer (III) aqueous solution with a concentration of 1.0 wt% and triethylamine with a concentration of 2.0 wt% at 25 DEG C, the ultrafiltration membrane is taken out and the water droplets remaining on the surface of the membrane are removed by a rubber roller, and the ultrafiltration membrane is prepared;

[0081] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) is soaked in an isoparaffin solution with a concentration of 0.1 wt% of isophthaloyl chloride at 25 DEG C for reaction;

[0082] (4) The filtration membrane after step (3) is heated in an oven at 60 DEG C to obtain a succinimidyl trisbipyridyl organic solvent composite nanofiltration membrane.

[0083] The permeation flux of the composite nanofiltration membrane of the application to methanol is 6.94 LMH / bar, the permeation flux of the composite nanofiltration membrane to acetone is 9.47 LMH / bar, and the rejection rate of the composite nanofiltration membrane to methyl orange is 95.59%.

[0084] The prepared composite nanofiltration membrane is used for separation of p-nitroaniline, orange G (OG), acid red (AR), tetracycline (TC), rhodamine B (RDB) and brilliant blue R (BBR), and the test results are shown in Table 1. Figure 5 It is shown that the rejection capacity gradually increases with the increase of the molecular weight of the dye; the rejection molecular weight of the above-mentioned organic solvent nanofiltration membrane is about 293 g / mol.

[0085] In addition, the composite nanofiltration membrane of the application is sequentially used for filtration of water, methanol, ethanol, tetrahydrofuran and acetone, and the flux performance change is tested, and the results are shown in Table 2. Figure 6

[0086] Example 8

[0087] A preparation method of a succinimidyl trisbipyridyl compound organic solvent composite nanofiltration membrane, comprising the following steps:​

[0088] (1) Polyacrylonitrile ultrafiltration membrane was immersed in pure water for 2 h to remove the pore-forming agent in the membrane;

[0089] (2) The polyacrylonitrile ultrafiltration membrane was taken out and immersed in a monomer (III) aqueous solution with a concentration of 1.0 wt% and NaOH with a concentration of 0.5 wt% at 25°C, then the membrane was taken out and the water droplets remaining on the surface of the membrane were removed with a rubber roller, and the membrane was prepared for use;

[0090] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) was immersed in an isomeric alkane solution with a concentration of 0.1 wt% of triformylphloroglucinol chloride at 25°C for reaction;

[0091] (4) The nanofiltration membrane after step (3) was heated in an oven at 60°C to obtain a succinimide triptycyl compound organic solvent composite nanofiltration membrane.

[0092] The separation performance test of the prepared composite nanofiltration membrane showed that the flux of methanol was 8.19 LMH / bar, and the rejection rate of p-methyl orange (MW 327 Da) was 96.87%.

[0093] Example 9

[0094] A preparation method of a succinimide triptycyl compound organic solvent composite nanofiltration membrane, the steps are as follows:

[0095] (1) Polyacrylonitrile ultrafiltration membrane was immersed in pure water for 2 h to remove the pore-forming agent in the membrane;

[0096] (2) The polyacrylonitrile ultrafiltration membrane was taken out and immersed in a monomer (III) aqueous solution with a concentration of 1.0 wt% and NaOH with a concentration of 0.5 wt% at 25°C, then the membrane was taken out and the water droplets remaining on the surface of the membrane were removed with a rubber roller, and the membrane was prepared for use;

[0097] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) was immersed in an isomeric alkane solution with a concentration of 0.1 wt% of terephthaloyl chloride at 25°C for reaction;

[0098] (4) The nanofiltration membrane after step (3) was heated in an oven at 60°C to obtain a succinimide triptycyl compound organic solvent composite nanofiltration membrane.

[0099] The separation performance test of the prepared composite nanofiltration membrane showed that the flux of methanol was 7.45 LMH / bar, and the rejection rate of p-methyl orange (MW 327 Da) was 94.58%.

[0100] Comparative Example 1

[0101] A preparation method of a composite nanofiltration membrane is as follows:

[0102] (1) Polyacrylonitrile ultrafiltration membrane was immersed in pure water for 2h to remove the pore-forming agent in the membrane;

[0103] (2) The polyacrylonitrile ultrafiltration membrane was taken out and immersed in a water solution with a concentration of 1.0wt% m-phenylenediamine and 2wt% triethylamine at 25℃. After 1min, the membrane was taken out and the water droplets on the surface of the membrane were removed by a rubber roller, and the membrane was prepared for use;

[0104] (3) The polyacrylonitrile ultrafiltration membrane treated in step (2) was immersed in a solution of isomeric alkanes with a concentration of 0.1wt% trimesoyl chloride at 25℃ for reaction;

[0105] (4) The composite membrane after step (3) was heated in an oven at 60℃ to obtain a m-phenylenediamine-based organic solvent composite nanofiltration membrane.

[0106] The separation performance test of the prepared composite nanofiltration membrane showed that the flux of methanol was 1.48LMH / bar, and the flux of acetone was 1.65LMH / bar. The rejection rate of the composite nanofiltration membrane to methyl orange was 96.5%, and the rejection rate to tetracycline (MW444) was 98.5%.

[0107] Comparing Example 1 with Comparative Example 1, it can be seen that under the same conditions, when a succinimide triptycene-based molecule is used instead of the traditional water-phase monomer m-phenylenediamine to prepare a composite nanofiltration membrane, the methanol flux is increased by 5.2 times, the acetone flux is increased by 9.52 times, and the rejection of organic molecules is slightly reduced. The rejection of tetracycline is only slightly reduced from 98.5% to 97.5%, and the rejection of methyl orange is reduced from only 96.5% to 93.3%. This fully illustrates the great performance advantage of the succinimide triptycene-based polyphenol molecule designed by us as an interfacial polymerization monomer molecule for membrane preparation.

[0108] It should be noted that the above enumeration is only a few specific embodiments of the present application, and obviously the present application is not limited to the above embodiments, but can also have other variations. All variations directly derived or indirectly derived by those skilled in the art from the disclosure of the present application should be considered as falling within the scope of protection of the present application.

Claims

1. A method for preparing a succinimide-triphenylene compound organic solvent composite nanofiltration membrane, characterized in that, Prepared by the following steps: a) Immerse the base membrane in pure water for 4 hours to remove the pore-retaining agent on the membrane surface. The base membrane is a polyacrylonitrile, polyimide, or polyketide ultrafiltration membrane. b) Remove the soaked base film and drain it. Then, immerse it in an aqueous solution of succinimide-triptene polyphenol compound with a concentration of 0.1 wt%-3.0 wt% at 25°C for 15 s-10 min. The aqueous solution of succinimide-triptene polyphenol compound also contains an alkaline co-solvent. After soaking, remove the base film and remove any residual water droplets from the surface of the base film for later use. c) At 25°C, the base film treated in step b) is immersed in an organic solution and reacted for 15 s to 10 min, wherein the organic solution contains polyacrylamide chloride at a concentration of 0.02 wt% to 0.5 wt%. d) The filter membrane after the reaction in step c) is placed in an oven at 50-70℃ and heated for 1-10 min to perform thermal crosslinking, thereby obtaining a succinimide triterpenoid organic solvent composite nanofiltration membrane; The structure of the succinimide triterpenoid polyphenol compound is shown in formula (1): （1） In the formula, R 1 It is a hydroxyl group -OH or a hydrogen group -H.

2. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 1, characterized in that, The alkaline co-solvent mentioned in step b) is at least one of sodium hydroxide, potassium hydroxide, and triethylamine.

3. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 1, characterized in that, The concentration of the alkaline co-solvent mentioned in step b) is 0.3%-2wt%.

4. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 1, characterized in that, The aqueous solution in step b) also includes a phase transfer catalyst, which is dodecyltrimethylammonium chloride.

5. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 4, characterized in that, The concentration of the phase transfer catalyst in the aqueous solution in step b) is 0.01wt%-0.2wt%.

6. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 1, characterized in that, The polyacryl chloride is one or a mixture of several of the following: pyromellitic chloride, isophthaloyl chloride, and terephthaloyl chloride.

7. The method for preparing the succinimide-triphenylene compound organic solvent composite nanofiltration membrane as described in claim 1, characterized in that, The organic solution in step c) is prepared by dissolving polyacrylamide chloride in an organic solvent, wherein the organic solvent is at least one of n-hexane, isoalkanes, or toluene.

8. A succinimide-triphenylene compound organic solvent composite nanofiltration membrane, characterized in that, It is prepared using the method described in any one of claims 1-7.

Images