Self-assembled ion separation membrane based on pillararene derivatives and preparation method thereof

Abstract

The present application relates to the technical field of separation membrane, and particularly relates to a self-assembled ion separation membrane based on a pillar [6] arene derivative and a preparation method thereof. The pillar [6] arene derivative and triaminoguanidine hydrochloride are respectively dissolved, thereby effectively avoiding the problems of instantaneous precipitation and phase separation that are prone to occur when directly mixed. Meanwhile, the two functional monomers are dispersed by ultrasonic, thereby avoiding the problem of molecular aggregation during the mixing process and ensuring that the reaction solution is uniform, which lays a foundation for the subsequent formation of a defect-free separation membrane. The pillar [6] arene derivative contained in the structure of the separation membrane provides a macrocyclic pore structure with ion recognition capability, and the triaminoguanidine hydrochloride further strengthens the selective separation performance of the membrane through multiple hydrogen bond / ion bond action sites. The synergistic design of the material makes it have both precise molecular recognition capability and adjustable pore size, and can realize efficient and selective separation of target objects such as organic small molecules, ions or dyes.

Description

Technical Field

[0001] This invention relates to the field of separation membrane technology, and in particular to a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives and its preparation method. Background Technology

[0002] Lithium ion (Li + ), potassium ions (K) + Sodium ions (Na) + As the most common monovalent cation in nature, it is widely found in salt lake brines, seawater, ore leachates, nuclear waste liquids, industrial wastewater, and biological samples. These three substances have similar chemical properties and small differences in ionic radius, making efficient separation technology of them significant for many fields such as new energy, agriculture, salt chemical industry, and environmental remediation.

[0003] However, Li + K + Na + Both belong to the alkali metal group, have similar electron configurations, and have relatively small differences in ionic radii (Li). + 0.76Å, Na + 1.02Å, K + The MgO content is 1.38 Å. These molecules have highly similar chemical properties and often coexist at high concentrations in real-world systems (such as salt lake brine and seawater). Some systems also contain Mg. 2+ Ca 2+ Interfering ions can lead to poor separation selectivity.

[0004] On the one hand, traditional processes have extremely low selectivity; for example, solvent extraction for Li + with Na + K + The separation coefficient is low, making it difficult to separate Na + K + The concentration steadily decreased to the ppm level, affecting the preparation of battery-grade lithium salts; precipitation methods are difficult to achieve K... + with Na + Precise separation can easily lead to co-precipitation, resulting in the loss of target ions or excessive impurity content; evaporation crystallization method has high energy consumption and low separation precision, making it difficult to obtain high-purity single ion products.

[0005] On the other hand, while new technologies have made improvements, they still have limitations, such as the fact that most adsorbent materials are not effective against Li. + K + The selectivity of membrane separation technology is not strong and it is easily affected by coexisting ions. In high-salt systems, membrane separation technology is difficult to achieve efficient separation of the three types of ions and is prone to problems such as membrane fouling and degradation, which leads to a decrease in separation accuracy. Traditional extraction systems also suffer from severe dissolution of the separation medium, which further affects the separation effect and product purity.

[0006] At present, Li + K + Na + The separation of ions has developed into a pattern dominated by traditional processes and with breakthroughs in the large-scale application of new technologies. However, due to limitations imposed by the inherent characteristics of ions, application scenarios, and technological bottlenecks, many problems still need to be solved. Therefore, how to provide a highly selective ion separation membrane is a pressing technical issue that needs to be addressed. Summary of the Invention

[0007] The present invention aims to at least solve one of the technical problems existing in the related art. Therefore, the first objective of the present invention is to provide a method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives; the second objective of the present invention is to provide a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives.

[0008] To achieve the first objective, the technical solution adopted by this invention is as follows:

[0009] The preparation method of self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives includes the following steps:

[0010] S100, prepare solutions of columnar aromatic hydrocarbon derivatives and triaminoguanidine hydrochloride;

[0011] The concentration of the columnar aromatic derivative solution ranges from 50 mg / mL to 85 mg / mL, and the concentration of the triaminoguanidine hydrochloride solution ranges from 5.5 mg / mL to 12.5 mg / mL.

[0012] S200. The columnar aromatic hydrocarbon derivative solution and the triaminoguanidine hydrochloride solution are mixed and continuously ultrasonically dispersed for 20 min to 25 min, and then reacted at 55℃ to 65℃ for 10 h to 15 h to obtain a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivative.

[0013] The self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives is a covalent network separation membrane formed with the columnar aromatic hydrocarbon derivatives as the main molecules and the triaminoguanidine hydrochloride as the crosslinking units. The crosslinking unit structure is shown below.

[0014] .

[0015] Further, in step S100, the solvent of the columnar aromatic derivative solution is selected from N-methylpyrrolidone.

[0016] Further, in step S100, the solvent of the triaminoguanidine hydrochloride solution is selected from dimethyl sulfoxide and / or water.

[0017] Furthermore, when the solvent is selected from dimethyl sulfoxide and water, the volume ratio of dimethyl sulfoxide to water is (1.5-2.5):1.

[0018] Furthermore, the structural formula of the columnar aromatic derivative is shown below:

[0019] .

[0020] Furthermore, the synthesis of the columnar aromatic derivative includes the following steps:

[0021] S110, using 1,4-dimethoxybenzene as a monomer and paraformaldehyde as a crosslinking agent, intermediate I was synthesized under Lewis acid catalysis, with the structural formula shown below:

[0022] ;

[0023] S120. Under the action of an oxidizing agent, one methoxy group on intermediate I is oxidized to a carbonyl group to obtain intermediate II, with the following structural formula:

[0024] ;

[0025] S130. Under the action of a reducing agent, the carbonyl group on intermediate II is reduced to a hydroxyl group to obtain P5-OH, with the following structural formula:

[0026] ;

[0027] S140. P5-OTf is synthesized by reacting P5-OH with trifluoromethanesulfonic anhydride, with the structural formula shown below:

[0028] ;

[0029] S150. The aromatic derivative was synthesized by coupling reaction of P5-OTf with arylboronic acid.

[0030] Further, in step S110, the Lewis acid is selected from boron trifluoride diethyl ether;

[0031] In step S120, the oxidant is selected from cerium ammonium nitrate;

[0032] In step S130, the reducing agent is selected from sodium dithionite;

[0033] In step S150, the arylboronic acid is selected from 4-formylphenylboronic acid.

[0034] Further, in step S200, the volume ratio of the columnar aromatic derivative solution to the triaminoguanidine hydrochloride solution is 5:6 to 15:8.

[0035] To achieve the second objective, the technical solution adopted by this invention is as follows:

[0036] The self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives is prepared using any one of the above-described methods for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives.

[0037] Furthermore, the ions include any one or more of potassium ions, sodium ions, and lithium ions.

[0038] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0039] This invention provides a method for preparing a self-assembled ion-separation membrane based on columnar aromatic hydrocarbon derivatives. The method involves dissolving the columnar aromatic hydrocarbon derivative and triaminoguanidine hydrochloride separately, effectively avoiding the problems of instantaneous precipitation and phase separation that easily occur when the two functional monomers are directly mixed. Simultaneously, ultrasonic dispersion of the two functional monomers avoids molecular aggregation during mixing, ensuring a uniform reaction solution and laying the foundation for the subsequent formation of a defect-free separation membrane. This effectively avoids the negative impact of structural defects such as pinholes and cracks on separation performance. The mild isothermal reaction conditions of 55–65℃ for 10–15 h activate the hydrogen bonds, ionic bonds, and weak covalent interactions between the columnar aromatic hydrocarbon derivative and triaminoguanidine hydrochloride, while effectively avoiding molecular structure damage or excessively rapid solvent evaporation caused by high temperatures. This low-temperature, long-duration reaction mode makes the molecular assembly / crosslinking process more controllable, enabling the formation of a continuous, dense supramolecular / covalent network structure, significantly improving the mechanical strength and chemical stability of the membrane. Meanwhile, precise control of the reaction degree can avoid pore blockage caused by excessive cross-linking, thereby ensuring the separation flux and selectivity of the separation membrane and achieving synergistic optimization of structural stability and excellent performance.

[0040] The self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives provided by this invention has a macrocyclic pore structure with ion recognition capabilities provided by the columnar aromatic hydrocarbon derivatives, while TAG further enhances the selective separation performance of the membrane through multiple hydrogen / ionic bond interaction sites. This synergistic design of materials enables it to combine precise molecular recognition capabilities with tunable pore size, achieving efficient and selective separation of target analytes such as small organic molecules, ions, or dyes.

[0041] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the columnar aromatic hydrocarbon derivative provided in Example 1 of the present invention ( 1 H NMR).

[0043] Figure 2The Fourier transform infrared (FTIR) spectra of the FPP5-TAG separation membrane and its control provided in Example 2 of this invention are shown.

[0044] Figure 3 The photoelectron spectroscopy (XPS) of the FPP5-TAG separation membrane provided in Embodiment 2 of the present invention.

[0045] Figure 4 This is a scanning electron microscope (SEM) image of the FPP5-TAG separation membrane provided in Embodiment 2 of the present invention.

[0046] Figure 5 This is an atomic force microscope (AFM) image of the FPP5-TAG separation membrane provided in Embodiment 2 of the present invention.

[0047] Figure 6 This is the IV curve of the FPP5-TAG separation membrane provided in Embodiment 3 of the present invention.

[0048] Figure 7 This describes the selectivity of the FPP5-TAG separation membrane provided in Example 3 of the present invention for different ions in a binary system.

[0049] Figure 8 This describes the selectivity of the FPP5-TAG separation membrane provided in Example 3 of the present invention for different ions in a ternary system. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention, but cannot be used to limit the scope of this invention.

[0051] In the following embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available, unless otherwise specified, and are carried out in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions.

[0052] Example 1

[0053] The synthetic route for preparing columnar aromatic derivatives (FPP5) is shown below:

[0054]

[0055] Its preparation process is as follows:

[0056] I. Preparation of intermediate I.

[0057] 1,4-Dimethoxybenzene (10.0 g, 72.4 mmol) and paraformaldehyde (10.9 g, 350.3 mmol) were added to a three-necked reaction flask. Then, under nitrogen protection, 1,2-dichloroethane (100 mL) was added, and the mixture was stirred at 25 °C for 2 h. Then, boron trifluoride diethyl ether (9.4 mL, 175.5 mmol) was slowly added dropwise to the reaction system, and the mixture was stirred at room temperature for another 1 h. After the reaction was completed, the reaction solution was slowly poured into methanol (200 mL) to quench the reaction, and the precipitate was collected by filtration. The collected precipitate was purified by silica gel column chromatography (using a mixed solvent of dichloromethane and petroleum ether in a volume ratio of 1:1) to obtain a white powder intermediate I.

[0058] II. Preparation of intermediate II.

[0059] Intermediate I (5.0 g, 6.667 mmol) and dichloromethane (100 mL) were added sequentially to a three-necked reaction flask and stirred until intermediate I was completely dissolved. Then, cerium ammonium nitrate (7.3 g, 13.394 mmol) was dissolved in deionized water (10 mL) and added dropwise to the above reaction system. The reaction was stirred at room temperature for 10 min. After the reaction was completed, the aqueous phase was extracted three times with dichloromethane (50 mL). The organic phases were combined, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (using a mixed solvent of ethyl acetate and petroleum ether in a volume ratio of 1:1) to obtain dark red solid intermediate II.

[0060] III. Preparation of P5-OH.

[0061] Intermediate II (5 g, 6.941 mmol) and sodium dithionite (27.5 g, 158.0 mmol) were added sequentially to a two-necked reaction flask. Then, under a nitrogen atmosphere, dichloromethane (200 mL) and water (10 mL) were added, and the mixture was stirred overnight at room temperature. After the reaction was complete, the aqueous phase was extracted three times with dichloromethane (50 mL). The combined organic phases were washed once with saturated brine and three times with deionized water, dried over anhydrous Na₂SO₄, and concentrated under reduced pressure to obtain a pale yellow solid, P₅₃OH.

[0062] IV. Preparation of P5-OTf.

[0063] P5-OH (0.2 g, 0.2 mmol) was added to a three-necked reaction flask. Under a nitrogen atmosphere, dichloromethane (120 mL) and anhydrous pyridine (6 mL) were added. The mixture was cooled to 0 °C, and trifluoromethanesulfonic anhydride (12 mL) was added dropwise through a constant pressure dropping funnel. After the addition was complete, the mixture was allowed to warm to room temperature naturally and stirred for 24 h. After the reaction was completed, the reaction solution was purified by silica gel column chromatography (the eluent was a mixed solvent of petroleum ether and dichloromethane in a volume ratio of 1:1) to obtain a white powder, P5-OTf.

[0064] V. Preparation of FPP5.

[0065] P5-OTf (0.2 g, 2.65 mmol) and Na2CO3 (0.13 g, 1.3 mmol) were added sequentially to a three-necked reaction flask. Then, under a nitrogen atmosphere, tetrahydrofuran (10 mL) and deionized water (2.5 mL) were added and stirred to disperse the mixture. Tetra(triphenylphosphine)palladium (0.03 g, 0.027 mmol) and 4-formylphenylboronic acid (0.12 g, 0.8 mmol) were added sequentially. The mixture was purged with nitrogen three times, and the temperature was raised to 80 °C with stirring for 24 h. After the reaction was complete, the mixture was cooled to room temperature, quenched with deionized water, and extracted three times with dichloromethane (10 mL). The organic phases were combined, dried over Na2SO4, and concentrated under reduced pressure to obtain a crude product. This crude product was purified by silica gel column chromatography (using a 1:1 volume ratio of petroleum ether and dichloromethane as eluent) to obtain a white powder, FPP5. 1 H NMR, such as Figure 1 As shown.

[0066] Example 2

[0067] The preparation process of a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives is as follows:

[0068] 1. Prepare FPP5 solution and triaminoguanidine hydrochloride (TAG) solution separately.

[0069] Preparation of FPP5 solution: Add FPP5 (7.5-8.5 mg) to N-methylpyrrolidone (NMP) (0.10-0.15 mL), and sonicate at room temperature for 10-15 min to fully dissolve and disperse it evenly to obtain FPP5 solution;

[0070] Preparation of TAG solution: Add TAG (0.7-1.0 mg) to a mixed solvent of dimethyl sulfoxide (DMSO) and water (0.08-0.12 mL), wherein the volume ratio of DMSO to H2O in the mixed solvent is (1.5-2.5):1, and sonicate for 10-15 min to obtain the solution;

[0071] II. Preparation of self-assembled ion separation membranes based on columnar aromatic hydrocarbon derivatives using FPP5 solution and TAG solution.

[0072] FPP5 solution was added dropwise to TAG solution while shaking. After the addition was complete, sonication was continued for 20-25 minutes, and then the reaction was carried out at 55-65℃ for 10-15 hours to obtain a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives. The membrane was washed with hexane, petroleum ether or isopropanol solvent and stored in deionized water for later use. It was designated as FPP5-TAG.

[0073] FTIR of FPP5-TAG separation membrane and its controls (FPP5 and TAG), such as Figure 2 As shown in the figure, it can be seen that the FPP5-TAG separation membrane contains C=O (1700cm). -1 ), CN (1130cm) -1 ) and C=N (1610cm) -1 The presence of functional groups indicates that FPP5 reacted chemically with TAG, successfully introducing a nitrogen-containing covalent bond structure into the FPP5-TAG separation membrane.

[0074] XPS of FPP5-TAG separation membrane, such as Figure 3 As shown in the figure, three core peaks were detected: C1s (corresponding to the 1s orbital electrons of carbon), O1s (corresponding to the 1s orbital electrons of oxygen), and N1s (corresponding to the 1s orbital electrons of nitrogen). The presence of the N1s peak is highly consistent with the results of the CN bond in the infrared spectrum, further confirming that nitrogen was successfully introduced into the reaction product FPP5-TAG, forming a nitrogen-containing covalent bond.

[0075] SEM image of FPP5-TAG separation membrane, as shown Figure 4 As shown in the figure, the surface diagram shows that the surface of the separation membrane is highly dense, flat and uniform, without obvious large pores, cracks or particulate defects. This dense surface structure can effectively prevent the non-selective permeation of the target analyte while ensuring the membrane's antifouling performance.

[0076] The cross-sectional view of the figure clearly shows that the membrane thickness is 1.8 μm. The ultra-thin thickness design can significantly reduce mass transfer resistance and greatly improve the membrane permeation flux, while still maintaining good separation selectivity. At the same time, it can be seen that the internal structure of the membrane layer is continuous, with fine wrinkles or textures, which are formed during the membrane fabrication process and help maintain the mechanical integrity of the membrane.

[0077] AFM diagram of the FPP5-TAG separation membrane, as shown Figure 5As shown in the figure, the cross-sectional view shows that the separation membrane and the silicon substrate form a clearly identifiable interface structure with no obvious diffusion or adhesion, indicating that the membrane-substrate interface has good compatibility and structural integrity.

[0078] The figure shows that the arithmetic mean roughness (Ra) is only 8.7 nm, which is in the low roughness range, confirming that the membrane surface has excellent smoothness, providing a structural basis for reducing mass transfer resistance and improving separation efficiency during the separation process. The figure also shows a small number of nanoscale protrusions (about 10-20 nm in height). These protrusions are not defects, but rather material aggregate structures formed by the hybridization of FPP5 and TAG. Combined with the characteristic peak of CN bond in FTIR and the N1s signal in XPS, these protrusions correspond to nitrogen-rich regions in the hybrid material and are active sites of the functional layer, which help to improve separation selectivity.

[0079] Example 3

[0080] Performance testing of FPP5-TAG separation membrane.

[0081] I. Testing of the IV curve of FPP5-TAG separation membrane.

[0082] The current response characteristics of the FPP5-TAG separation membrane were characterized using a Keithley 6487 picoammeter. The experiment was conducted in a double-chamber glass H-type electrolytic cell, with the membrane tightly clamped between the two chambers, each with a liquid reservoir volume of 15 mL.

[0083] Electrode system: A two-electrode measurement mode is adopted, with a pair of Ag / AgCl electrodes as the reference electrode and the counter electrode, respectively. The solutions on both sides of the membrane are in direct contact with the electrodes to construct an ion conduction circuit.

[0084] Solution system: Equal volumes of mixed electrolyte solutions of LiCl, NaCl, and KCl were simultaneously added to both reservoirs. The concentration of each of the three salts was 100 ppm to ensure that the ion concentrations on both sides of the membrane were symmetrical in the initial state and to eliminate the interference of concentration polarization on the current measurement.

[0085] The measurement procedure is as follows: Before starting the measurement, the membrane was immersed in the mixed solution for 30 minutes to allow it to fully swell and reach ion transport equilibrium. A linear scan voltage was applied using a Keithley 6487 picoammeter, with a scan range of -1.0V to +1.0V. The current-voltage (IV) response curve was recorded, and the results are as follows: Figure 6 As shown.

[0086] II. Investigation of the selectivity of FPP5-TAG separation membrane for different ions.

[0087] The ion separation selectivity of the FPP5-TAG separation membrane was investigated using an ion permeation testing device. The membrane was tightly clamped between the feed chamber and the receiver chamber of the device to fix the effective permeation area of ​​the membrane and ensure good sealing between the two chambers to prevent solution leakage. The test consisted of two steps: a binary mixed ion system and a ternary mixed ion system. The specific procedures are as follows:

[0088] Before testing, the FPP5-TAG separation membrane was soaked in deionized water for 24 hours;

[0089] Three sets of binary mixed ionic solutions were prepared, each containing two types of ions (K+, K ... + With Li + Na + With Li + K + with Na + The concentration of each ion was controlled at 100 ppm. The three binary mixed ion solutions were transferred to the raw material chamber of the ion permeation testing device, while an equal volume of deionized water was added to the receiving chamber. After the permeation process reached a stable state, the ion concentration in the receiving chamber was determined using ion chromatography. The flux of each ion was then obtained. Based on the ratio of the permeation flux of the two ion groups, the separation selectivity coefficients of the three binary ion pairs were calculated. The results are as follows: Figure 7 As shown.

[0090] Preparation of K + Na + Li + A ternary mixed ion solution (each of the three ions at a concentration of 100 ppm) was used, and the above detection steps were repeated to obtain the K ion concentration in the ternary system. + Na + Li + The permeation flux of each ion was used to calculate the selectivity coefficient of each ion pair in the ternary system, and the results are as follows: Figure 8 As shown.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives, characterized in that, Includes the following steps: S100, prepare solutions of columnar aromatic hydrocarbon derivatives and triaminoguanidine hydrochloride; The concentration of the columnar aromatic derivative solution ranges from 50 mg / mL to 85 mg / mL, and the concentration of the triaminoguanidine hydrochloride solution ranges from 5.5 mg / mL to 12.5 mg / mL. Wherein, the solvent of the columnar aromatic derivative solution is selected from N-methylpyrrolidone, and the solvent of the triaminoguanidine hydrochloride solution is selected from dimethyl sulfoxide and / or water; S200. The columnar aromatic hydrocarbon derivative solution and the triaminoguanidine hydrochloride solution are mixed and continuously ultrasonically dispersed for 20 min to 25 min, and then reacted at 55℃ to 65℃ for 10 h to 15 h to obtain a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivative. The self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives is a covalent network separation membrane formed with the columnar aromatic hydrocarbon derivatives as the main molecules and the triaminoguanidine hydrochloride as the crosslinking units. The crosslinking unit structure is shown below: 。 2. The method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 1, characterized in that, When the solvent is selected from dimethyl sulfoxide and water, the volume ratio of dimethyl sulfoxide to water is (1.5~2.5):

1.

3. The method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 1, characterized in that, The structural formula of the columnar aromatic hydrocarbon derivative is shown below: 。 4. The method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 3, characterized in that, The synthesis of the columnar aromatic derivative includes the following steps: S110, using 1,4-dimethoxybenzene as a monomer and paraformaldehyde as a crosslinking agent, intermediate I was synthesized under Lewis acid catalysis, with the structural formula shown below: ； S120. Under the action of an oxidizing agent, one methoxy group on intermediate I is oxidized to a carbonyl group to obtain intermediate II, with the following structural formula: ； S130. Under the action of a reducing agent, the carbonyl group on intermediate II is reduced to a hydroxyl group to obtain P5-OH, with the following structural formula: ； S140. P5-OTf is synthesized by reacting P5-OH with trifluoromethanesulfonic anhydride, with the structural formula shown below: ； S150. The aromatic derivative was synthesized by coupling reaction of P5-OTf with arylboronic acid.

5. The method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 4, characterized in that, In step S110, the Lewis acid is selected from boron trifluoride diethyl ether; In step S120, the oxidant is selected from cerium ammonium nitrate; In step S130, the reducing agent is selected from sodium dithionite; In step S150, the arylboronic acid is selected from 4-formylphenylboronic acid.

6. The method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 1, characterized in that, In step S200, the volume ratio of the columnar aromatic derivative solution to the triaminoguanidine hydrochloride solution is 5:6 to 15:

8.

7. A self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives, characterized in that, It is prepared using the method for preparing a self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in any one of claims 1 to 6.

8. The self-assembled ion separation membrane based on columnar aromatic hydrocarbon derivatives as described in claim 7, characterized in that, The ions include any one or more of potassium ions, sodium ions, and lithium ions.

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