Conjugated microporous polymer composite organic solvent nanofiltration membrane as well as preparation method and application thereof

Abstract

The invention discloses a conjugated microporous polymer composite organic solvent nanofiltration membrane as well as a preparation method and application thereof, and belongs to the technical field of composite membranes. The conjugated microporous polymer composite organic solvent nanofiltration membrane is prepared by adopting an electrochemical method and comprises a conjugated microporous polymer membrane layer and a conductive substrate with a porous network structure, and part of pore channels of the conjugated microporous polymer membrane layer correspond to and are communicated with part of macropores in the conductive substrate. The method is easy and convenient to operate and mild in reaction condition, controllable deposition of the film layer can be achieved, and the problems of film layer cracking, poor interface bonding and the like in a traditional film manufacturing process can be effectively solved. The thickness of the obtained conjugated microporous polymer composite organic solvent nanofiltration membrane is controllable, and good balance between the retention rate and the permeation flux can be realized; meanwhile, the polymer has excellent chemical stability and thermal stability, can run durably in an organic system, and is suitable for a molecular separation process in various organic solvent systems.

Description

Technical Field

[0001] This invention belongs to the field of composite membrane technology, specifically relating to a conjugated microporous polymer composite organic solvent nanofiltration membrane, its preparation method, and its application. Background Technology

[0002] Crude oil, as a crucial resource for the global energy and chemical industries, has its separation and purification processes directly impacting energy efficiency and carbon emission levels. Currently, the industry commonly employs distillation and rectification processes to separate complex hydrocarbon mixtures; these processes are extremely energy-intensive and generate significant carbon emissions. Statistics show that the energy consumption of primary crude oil separation processes accounts for approximately 1% of global energy consumption. In recent years, membrane separation technology has gained widespread attention as an energy-saving and environmentally friendly emerging separation method. Based on minute differences in the thermodynamic properties, kinetic behavior, and molecular-scale characteristics of the separated substances, this technology can achieve near-molecular-level precise separation. Compared to traditional processes, membrane separation offers significant energy-saving advantages and modular integration characteristics, demonstrating broad application prospects in the separation of crude oil and complex hydrocarbons. Currently, various polymer membrane materials are used in the separation of crude oil and complex hydrocarbon systems; however, traditional polymer organic separation membranes still generally suffer from problems such as poor stability, limited separation factors, high preparation costs, and limitations in large-scale processing. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a conjugated microporous polymer composite organic solvent nanofiltration membrane, its preparation method, and its application. The conjugated microporous polymer composite organic solvent nanofiltration membrane of this invention is prepared by an electrochemical method, which is simple to operate, mild under mild conditions, and easy to implement. The resulting membrane material has stable performance and can operate stably in organic systems for a long time, and can be widely used in molecular separation processes in organic solvent systems.

[0004] A conjugated microporous polymer composite organic solvent nanofiltration membrane includes a conjugated microporous polymer membrane layer and a conductive substrate having a porous network structure, wherein some channels of the conjugated microporous polymer membrane layer correspond to and are connected with some macropores in the conductive substrate.

[0005] The conjugated microporous polymer membrane is prepared by electrochemical polymerization of carbazole monomers; the carbazole monomers are 1,3,5-tris(9-carbazole)benzene; or a combination of 1,3,5-tris(9-carbazole)benzene with any one of carbazole, N-hexylcarbazole, and N-nonylcarbazole.

[0006] A method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane is specifically carried out according to the following steps:

[0007] 1. Add one or two carbazole monomers and supporting electrolytes to an anhydrous aprotic solvent and stir to dissolve, so as to obtain a homogeneous monomer solution;

[0008] The carbazole monomer mentioned in step one is 1,3,5-tris(9-carbazolyl)benzene; or a combination of 1,3,5-tris(9-carbazolyl)benzene with any one of carbazole, N-hexylcarbazole, or N-nonylcarbazole;

[0009] 2. The homogeneous monomer solution was transferred to a three-electrode sealed electrolytic cell and connected to an electrochemical workstation. A conductive substrate with a porous network structure was used as the working electrode, and a titanium plate was used as the counter electrode. Ag / Ag + A non-aqueous electrode was used as a reference electrode to carry out electrochemical polymerization reaction using cyclic voltammetry;

[0010] 3. After the polymerization reaction is completed, a conjugated microporous polymer membrane is obtained on a conductive substrate. The resulting composite membrane is taken out, soaked in anhydrous aprotic solvent for a period of time, and then stored in deionized water to obtain a conjugated microporous polymer composite organic solvent nanofiltration membrane.

[0011] Application of a conjugated microporous polymer composite organic solvent nanofiltration membrane in molecular separation of organic solvent systems.

[0012] The principle of this invention:

[0013] Conjugated microporous polymers (CMPs) are a typical class of rigid amorphous polymers. CMPs possess a fully rigid, extended π-conjugated backbone and a permanently interconnected intrinsic microporous structure, thus endowing them with excellent chemical stability, thermal stability, and uniform pore distribution. CMPs exhibit excellent resistance to swelling and plasticization, which is beneficial for their durable operation in organic systems; their uniformly sized sub-nanometer micropores can enhance the size sieving effect for target molecules. Therefore, the CMPs obtained in this invention become ideal membrane materials for crude oil separation, overcoming the "trade-off" effect that restricts solvent flux and selectivity in organic solvent nanofiltration membranes. The resulting membrane material exhibits stable performance, can operate stably in organic systems for extended periods, and can be widely applied in molecular separation processes within organic solvent systems.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] Membrane separation technology, as an energy-saving and environmentally friendly advanced separation method, can achieve high-precision molecular sieving based on the slight differences in the thermodynamic properties, kinetic behavior, and molecular size of the separated components. It is considered an ideal alternative to traditional high-energy-consuming separation processes such as thermal distillation. This invention employs an electrochemical polymerization method to construct a conjugated microporous polymer membrane layer in situ on a conductive porous substrate. This method is simple to operate, has mild reaction conditions, and allows for controllable membrane deposition, effectively overcoming problems such as membrane cracking and poor interfacial bonding in traditional membrane fabrication processes. The resulting conjugated microporous polymer composite organic solvent nanofiltration membrane has a controllable thickness, achieving a good balance between rejection rate and permeate flux; it also possesses excellent chemical and thermal stability, enabling durable operation in organic systems and making it suitable for molecular separation processes in various organic solvent systems. Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope image of the surface of the carbon nanotube support layer in Example 1;

[0017] Figure 2 This is a schematic diagram illustrating the preparation process of the conjugated microporous polymer composite organic solvent nanofiltration membrane in Example 1;

[0018] Figure 3 The cyclic voltammetry curves for the electrochemical polymerization process in Example 1 are shown.

[0019] Figure 4 A scanning electron microscope image of the surface of the conjugated microporous polymer composite organic solvent nanofiltration membrane prepared in Example 1;

[0020] Figure 5 Results of 1,3,5-triisopropylbenzene rejection and permeation flux obtained by separating a binary mixture (1 / 99 mol%) of toluene and 1,3,5-triisopropylbenzene using the conjugated microporous polymer composite organic solvent nanofiltration membranes prepared in Examples 1-4;

[0021] Figure 6 The correlation between dye rejection rate and dye molecular weight obtained by separating a binary mixture of methanol and dye (dye concentration of 20 mg / L) using the conjugated microporous polymer composite organic solvent nanofiltration membrane prepared in Example 1. Detailed Implementation

[0022] Specific Implementation Method 1: This embodiment provides a conjugated microporous polymer composite organic solvent nanofiltration membrane, comprising a conjugated microporous polymer membrane layer and a conductive substrate having a porous network structure, wherein some channels of the conjugated microporous polymer membrane layer correspond to and are connected to some macropores in the conductive substrate;

[0023] The conjugated microporous polymer membrane is prepared by electrochemical polymerization of carbazole monomers; the carbazole monomers are 1,3,5-tris(9-carbazole)benzene; or a combination of 1,3,5-tris(9-carbazole)benzene with any one of carbazole, N-hexylcarbazole, and N-nonylcarbazole.

[0024] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the thickness of the conjugated microporous polymer membrane layer is 70nm~300nm; the conductive substrate with a porous network structure is a carbon nanotube membrane supported by a hydrophilic polytetrafluoroethylene microfiltration membrane, carbon cloth, foamed graphene, foamed nickel, or foamed copper, with a thickness of 50μm~800μm. Other steps are the same as in Specific Implementation Method One.

[0025] In this embodiment, the thickness of the conjugated microporous polymer film is 70nm, 80nm, 100nm, 200nm, or 300nm.

[0026] In this embodiment, the thickness of the conjugated microporous polymer membrane is 70nm~300nm. If the membrane thickness is greater than 300nm, the permeation flux of the conjugated microporous polymer composite membrane will be significantly reduced. If the membrane thickness is less than 70nm, it is difficult to effectively cover the surface defects of the conductive substrate, resulting in a decrease in the selectivity of the composite membrane and easy structural damage during the separation process.

[0027] Specific Implementation Method 3: This implementation method is a method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane, specifically completed according to the following steps:

[0028] 1. Add one or two carbazole monomers and supporting electrolytes to an anhydrous aprotic solvent and stir to dissolve, so as to obtain a homogeneous monomer solution;

[0029] The carbazole monomer mentioned in step one is 1,3,5-tris(9-carbazolyl)benzene, or a combination of 1,3,5-tris(9-carbazolyl)benzene with any one of carbazole, N-hexylcarbazole, or N-nonylcarbazole;

[0030] 2. The homogeneous monomer solution was transferred to a three-electrode sealed electrolytic cell and connected to an electrochemical workstation. A conductive substrate with a porous network structure was used as the working electrode, and a titanium plate was used as the counter electrode. Ag / Ag + A non-aqueous electrode was used as a reference electrode to carry out electrochemical polymerization reaction using cyclic voltammetry;

[0031] 3. After the polymerization reaction is completed, a conjugated microporous polymer membrane is obtained on a conductive substrate. The resulting composite membrane is taken out, soaked in anhydrous aprotic solvent for a period of time, and then stored in deionized water to obtain a conjugated microporous polymer composite organic solvent nanofiltration membrane.

[0032] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that, when using two carbazole monomers in step one, the molar ratio of 1,3,5-tris(9-carbazole)benzene to any one of the carbazole monomers, namely carbazole, N-hexylcarbazole, and N-nonylcarbazole, is 1:(0.5~1.5). The other steps are the same as in Specific Implementation Methods One to Three.

[0033] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the supporting electrolyte mentioned in step one is tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, or tetrabutylammonium perchlorate; the anhydrous aprotic solvent mentioned in steps one and three is one or more of dichloromethane, acetonitrile, N,N-dimethylformamide, or propylene carbonate. The other steps are the same as in Specific Implementation Methods One to Four.

[0034] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the concentration of carbazole monomers in the homogeneous monomer solution described in step one is 1 mmol / L to 10 mmol / L; the concentration of supporting electrolytes in the homogeneous monomer solution described in step one is 0.1 mol / L. The other steps are the same as in Specific Implementation Methods One to Five.

[0035] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that: the cyclic voltammetry potential window in step two is −0.8V to 1.23V, the polymerization temperature is 18℃ to 25℃, the number of cycles is 20 to 100, and the scan rate is 10mV / s to 100mV / s. Other steps are the same as in Specific Implementation Methods One through Six.

[0036] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the conductive substrate with a porous network structure described in step two is a carbon nanotube membrane supported by a hydrophilic polytetrafluoroethylene microfiltration membrane, carbon cloth, graphene foam, nickel foam, or copper foam, with a thickness of 50 μm to 800 μm; the thickness of the conjugated microporous polymer membrane layer obtained on the conductive substrate in step three is 70 nm to 300 nm; the composite membrane obtained in step three is removed, soaked in anhydrous aprotic solvent for 8 h to 12 h, and then stored in deionized water. Other steps are the same as in Specific Implementation Methods One to Seven.

[0037] Specific Implementation Method Nine: This implementation method is an application of a conjugated microporous polymer composite organic solvent nanofiltration membrane in the molecular separation of organic solvent systems.

[0038] Specific Implementation Method 10: The organic solvent system described in this implementation method includes a binary mixture of toluene and 1,3,5-triisopropylbenzene, and a binary mixture of methanol and dye.

[0039] The beneficial effects of the present invention are verified using the following embodiments:

[0040] Example 1: A method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane, specifically completed according to the following steps:

[0041] I. Preparation of carbon nanotube (CNT) support layer:

[0042] 50 mg of single-walled carbon nanotubes (CNTs) and 500 mg of sodium dodecylbenzenesulfonate were weighed and dispersed in 500 mL of deionized water. The dispersion was ultrasonically dispersed for 10 h using an ultrasonic cell disruptor (360 W, 25 kHz). Subsequently, the resulting mixture was centrifuged at 10,000 rpm for 1 h to remove undispersed aggregates, and the supernatant was collected to obtain a homogeneous CNT dispersion. This dispersion was filtered under vacuum onto the surface of a commercial hydrophilic polytetrafluoroethylene (PTFE) microfiltration membrane and thoroughly dried in a 60°C vacuum oven. A target carbon nanotube (CNT) support layer was obtained on the surface of the commercial hydrophilic PTFE microfiltration membrane. Scanning electron microscopy (SEM) is shown in the image. Figure 1 As shown;

[0043] The hydrophilic polytetrafluoroethylene microfiltration membrane mentioned in step one has a pore size of 0.22 μm and a thickness of 0.16 mm.

[0044] The thickness of the carbon nanotube (CNT) support layer mentioned in step one is 450 μm;

[0045] 2. Add 23 mg of 1,3,5-tris(9-carbazolyl)benzene, 10.05 mg of N-hexylcarbazole, and 1.55 g of tetrabutylammonium hexafluorophosphate to 40 mL of anhydrous dichloromethane and acetonitrile mixed solvent (anhydrous dichloromethane to acetonitrile volume ratio 3:2) and stir to dissolve for 1 h to obtain a homogeneous monomer solution.

[0046] 3. Transfer the homogeneous monomer solution to a three-electrode sealed electrolytic cell and connect it to an electrochemical workstation. Use a dried carbon nanotube support layer as the working electrode, a titanium plate as the counter electrode, and Ag / Ag... + Using a non-aqueous electrode as a reference electrode, 30 cyclic voltammetric scans were performed at a scan rate of 100 mV / s within a potential window of -0.8 V to 1.23 V; the fabrication process is as follows. Figure 2 As shown, under the influence of an electric field, monomer molecules undergo a series of redox reactions to generate a three-dimensional continuous porous polymer, such as... Figure 3 As shown, with the progress of the polymerization reaction and the gradual growth of the film, both the oxidation peak current and the reduction peak current increase with the increase of the number of cyclic voltammetric scans, indicating that the polymer is deposited on the working electrode and forms a highly cross-linked thin film structure.

[0047] IV. After the polymerization reaction is completed, a conjugated microporous polymer membrane is obtained on a conductive substrate. The resulting composite membrane is taken out and soaked in a mixed solvent of anhydrous dichloromethane and acetonitrile for 10 hours to completely remove unreacted monomers and residual electrolytes. Finally, it is stored in deionized water to obtain a conjugated microporous polymer composite organic solvent nanofiltration membrane (denoted as TC@30).

[0048] Figure 1 This is a scanning electron microscope image of the surface of the carbon nanotube support layer in Example 1;

[0049] Figure 1 The carbon nanotube support layer prepared in step one of Example 1 shows a porous network structure.

[0050] Figure 4 A scanning electron microscope image of the surface of the conjugated microporous polymer composite organic solvent nanofiltration membrane prepared in Example 1;

[0051] Figure 4 The conjugated microporous polymer composite organic solvent nanofiltration membrane prepared in Example 1 exhibits a granular structure on its surface.

[0052] Example 2: The difference between this example and Example 1 is that in step two, 23 mg of 1,3,5-tris(9-carbazolyl)benzene and 1.55 g of tetrabutylammonium hexafluorophosphate were added to 40 mL of a mixed solvent of anhydrous dichloromethane and acetonitrile (volume ratio of anhydrous dichloromethane to acetonitrile 3:2) and stirred for 1 h to obtain a homogeneous monomer solution; the conjugated microporous polymer composite organic solvent nanofiltration membrane obtained in step four is designated as T@30. Other steps and parameters are the same as in Example 1.

[0053] Example 3: The difference between this example and Example 1 is that in step three, a cyclic voltammetric scan of 20 cycles was performed at a scan rate of 100 mV / s; the conjugated microporous polymer composite organic solvent nanofiltration membrane obtained in step four is denoted as TC@20. All other steps and parameters are the same as in Example 1.

[0054] Example 4: The difference between this example and Example 1 is that in step three, a cyclic voltammetric scan of 50 cycles was performed at a scan rate of 100 mV / s; the conjugated microporous polymer composite organic solvent nanofiltration membrane obtained in step four is denoted as TC@50. All other steps and parameters are the same as in Example 1.

[0055] Application of conjugated microporous polymer composite organic solvent nanofiltration membrane in molecular separation of organic solvent systems.

[0056] (1) The organic solvent nanofiltration performance of the conjugated microporous polymer composite organic solvent nanofiltration membranes prepared in Examples 1 to 4 was tested using a dead-end filtration device. A binary mixture of toluene and 1,3,5-triisopropylbenzene (molar ratio of toluene / 1,3,5-triisopropylbenzene was 1 / 99 mol%) was used as the feed liquid, and separation was performed at room temperature and an operating pressure of 5 bar. The relative contents of toluene and 1,3,5-triisopropylbenzene in the feed liquid and permeate were quantitatively determined by gas chromatography. The permeate flux was calculated by periodically collecting permeate samples and measuring their mass. The test results are as follows: Figure 5 As shown in Table 1.

[0057] Table 1

[0058]

[0059] As shown in Table 1, the conjugated microporous polymer composite organic solvent nanofiltration membranes prepared in Examples 1 to 4 can effectively separate toluene from 1,3,5-triisopropylbenzene and have a high permeation flux, indicating that the prepared conjugated microporous polymer composite organic solvent nanofiltration membranes have good application prospects in the field of organic solvent nanofiltration.

[0060] Comparing the performance of the conjugated microporous polymer composite organic solvent nanofiltration membranes prepared in Example 1 (TC@30) and Example 2 (T@30), it can be seen that the TC@30 membrane prepared by co-electropolymerization of two carbazole monomers exhibits a higher 1,3,5-triisopropylbenzene rejection rate compared to the T@30 membrane prepared by electropolymerization of only one carbazole monomer. The introduction of flexible carbon chain monomers makes the membrane pore size more suitable for small molecule sieving; the monomer molecular structure design allows for controllable adjustment of membrane performance, providing an effective approach for preparing high-performance organic solvent nanofiltration membranes.

[0061] Comparing the performance of the conjugated microporous polymer composite organic solvent nanofiltration membranes prepared in Example 1 (TC@30), Example 3 (TC@20), and Example 4 (TC@50), it can be seen that: when the number of cyclic voltammetry scans is increased from 20 to 30, the rejection rate of the composite membrane is significantly improved, indicating that moderately increasing the number of cycles helps to cover the surface defects of the conductive substrate layer and thus effectively improve the separation performance; when the number of cyclic voltammetry scans is further increased from 30 to 50, the rejection rate is not significantly improved, but the permeate flux is significantly reduced, indicating that excessively high scan numbers will lead to an excessively thick conjugated microporous polymer membrane layer and increased mass transfer resistance.

[0062] (2) The permeability curve and molecular weight cutoff (MWCO) of the conjugated microporous polymer composite organic solvent nanofiltration membrane prepared in Example 1 were tested using a dead-end filtration device to further evaluate its organic solvent nanofiltration performance. A methanol / dye binary mixture (dye concentration 20 mg / L) was used as the feed solution, and the dyes were tested separately. The dyes included Basic Orange (molecular weight 248.7 g / mol), Methylene Blue (molecular weight 319.8 g / mol), Methyl Orange (molecular weight 327.3 g / mol), Crystal Violet (molecular weight 407.9 g / mol), Eriochrome Black (molecular weight 461.3 g / mol), Congo Red (molecular weight 696.6 g / mol), and Coomassie Brilliant Blue (molecular weight 826.9 g / mol), and were separated at room temperature and an operating pressure of 5 bar. The dye concentrations in the feed solution and permeate were quantitatively determined using a UV-Vis spectrophotometer at a specific wavelength with methanol as a reference. MWCO determined the retention rate of dyes with different molecular weights by plotting curves showing the relationship between their molecular weight and molecular weight, and then used interpolation to calculate the results. The test results are as follows: Figure 6 As shown.

[0063] Depend on Figure 6 The test results show that the MWCO of the conjugated microporous polymer composite membrane prepared in Example 1 is about 323 Da. The steep cutoff curve indicates that the pore size distribution of the prepared conjugated microporous polymer composite membrane is highly uniform, which can achieve selective separation within a narrow molecular weight range. This is beneficial for achieving efficient and controllable molecular separation in organic solvent nanofiltration scenarios.

Claims

1. A conjugated microporous polymer composite organic solvent nanofiltration membrane, characterized in that... The conjugated microporous polymer composite organic solvent nanofiltration membrane includes a conjugated microporous polymer membrane layer and a conductive substrate with a porous network structure, wherein some channels of the conjugated microporous polymer membrane layer correspond to and are connected with some macropores in the conductive substrate. The conjugated microporous polymer membrane is prepared by electrochemical polymerization of carbazole monomers; the carbazole monomers are 1,3,5-tris(9-carbazole)benzene; or a combination of 1,3,5-tris(9-carbazole)benzene with any one of carbazole, N-hexylcarbazole, and N-nonylcarbazole.

2. The conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 1, characterized in that... The thickness of the conjugated microporous polymer membrane is 70nm~300nm; the conductive substrate with a porous network structure is a carbon nanotube membrane supported by a hydrophilic polytetrafluoroethylene microfiltration membrane, carbon cloth, foamed graphene, foamed nickel or foamed copper, with a thickness of 50μm~800μm.

3. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane as described in claim 1, characterized in that... The preparation method is specifically carried out according to the following steps:

1. Add one or two carbazole monomers and supporting electrolytes to an anhydrous aprotic solvent and stir to dissolve, so as to obtain a homogeneous monomer solution; The carbazole monomer mentioned in step one is 1,3,5-tris(9-carbazolyl)benzene; or a combination of 1,3,5-tris(9-carbazolyl)benzene with any one of carbazole, N-hexylcarbazole, or N-nonylcarbazole; 2. The homogeneous monomer solution was transferred to a three-electrode sealed electrolytic cell and connected to an electrochemical workstation. A conductive substrate with a porous network structure was used as the working electrode, and a titanium plate was used as the counter electrode. Ag / Ag + A non-aqueous electrode was used as a reference electrode to carry out electrochemical polymerization reaction using cyclic voltammetry; 3. After the polymerization reaction is completed, a conjugated microporous polymer membrane is obtained on a conductive substrate. The resulting composite membrane is taken out, soaked in anhydrous aprotic solvent for a period of time, and then stored in deionized water to obtain a conjugated microporous polymer composite organic solvent nanofiltration membrane.

4. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 3, characterized in that... When two carbazole monomers are used in step one, the molar ratio of 1,3,5-tris(9-carbazole)benzene to any one of the carbazole monomers, such as carbazole, N-hexylcarbazole, or N-nonylcarbazole, is 1:(0.5~1.5).

5. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 3, characterized in that... The supporting electrolyte mentioned in step one is tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, or tetrabutylammonium perchlorate; the anhydrous aprotic solvent mentioned in steps one and three is one or more of dichloromethane, acetonitrile, N,N-dimethylformamide, or propylene carbonate.

6. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 3, characterized in that... The concentration of carbazole monomers in the homogeneous monomer solution described in step one is 1 mmol / L to 10 mmol / L; the concentration of supporting electrolytes in the homogeneous monomer solution described in step one is 0.1 mol / L.

7. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 3, characterized in that... The cyclic voltammetry described in step two has a potential window of -0.8V to 1.23V, a polymerization temperature of 18℃ to 25℃, a cycle count of 20 to 100 times, and a scan rate of 10mV / s to 100mV / s.

8. The method for preparing a conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 3, characterized in that... The conductive substrate with a porous network structure mentioned in step two is a carbon nanotube membrane supported by a hydrophilic polytetrafluoroethylene microfiltration membrane, carbon cloth, foamed graphene, foamed nickel, or foamed copper, with a thickness of 50 μm to 800 μm; the conjugated microporous polymer membrane layer obtained on the conductive substrate in step three has a thickness of 70 nm to 300 nm; the composite membrane obtained in step three is taken out, soaked in anhydrous aprotic solvent for 8 h to 12 h, and then stored in deionized water.

9. The application of the conjugated microporous polymer composite organic solvent nanofiltration membrane as described in claim 1, characterized in that... Application of a conjugated microporous polymer composite organic solvent nanofiltration membrane in molecular separation of organic solvent systems.

10. The application of the conjugated microporous polymer composite organic solvent nanofiltration membrane according to claim 9, characterized in that... The organic solvent system includes a binary mixture of toluene and 1,3,5-triisopropylbenzene, and a binary mixture of methanol and dye.

Images