A MOFs functionalized cyclodextrin-based composite fiber membrane, a preparation method and application thereof

Abstract

The application provides a MOFs functionalized cyclodextrin-based composite fiber membrane and a preparation method and application thereof, and belongs to the technical field of fiber membrane preparation.The MOFs functionalized cyclodextrin-based composite nanofiber membrane is prepared through an electrostatic spinning technology, the obtained MOFs functionalized cyclodextrin-based composite fiber membrane can be used as a drug and personal care product (PPCP) adsorbent in wastewater treatment, and the PPCP pollutants can be adsorbed onto the composite fiber membrane through host-guest coordination, electrostatic interaction, hydrogen bonding, pi-pi interaction and complexation interaction.The fiber membrane can solve the shortcomings that cyclodextrin is easily soluble in water and the problem that MOFs powder is not suitable for recycling.The MOFs functionalized cyclodextrin-based composite fiber membrane is simple in preparation, raw materials are easy to obtain, and has good regeneration performance, and has a wide application prospect in actual wastewater treatment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fiber membrane preparation, and particularly relates to a MOFs functionalized cyclodextrin-based composite fiber membrane and a preparation method and application thereof. BACKGROUND

[0002] Pharmaceutical and personal care products (PPCPs) are a new type of pollutants, which are discharged into the water environment after being metabolized by the human body or animals, causing great harm to aquatic organisms and ecosystems. With the passage of time, the long-term accumulation of PPCPs may pose potential risks to human health, such as causing endocrine system disorders, liver and nervous system disorders and other diseases. Therefore, in order to protect the environment and human health, it is urgent to reduce the pollution of PPCPs in the water environment. Adsorption is one of the methods commonly used by people to remove PPCPs pollutants in water, which has become a widely used technology in the field of sewage purification due to its easy operation, sustainable utilization and other advantages. As a kind of fiber material with high specific surface area, electrospun nanofibers are often modified by chemical modification or doped with other materials to change their surface properties, thereby improving their adsorption performance and being widely used in the removal of different types of pollutants in water. Among many adsorption materials, metal-organic framework materials (MOFs) with excellent performance have also attracted more and more attention. MOFs are a new type of porous material composed of metal ions and organic ligands, which exhibit high specific surface area, porosity and controllable pore size, and therefore have a wide application in the field of adsorption. In addition, cyclodextrins contain rich hydroxyl groups, have a hydrophilic outer part and a hydrophobic inner cavity. They can form complexes with various pharmaceutical pollutants. SUMMARY

[0003] The purpose of the present application is to provide a MOFs functionalized cyclodextrin-based composite fiber membrane and a preparation method and application thereof. The MOFs functionalized cyclodextrin-based composite nanofiber membrane prepared has high adsorption capacity.

[0004] The present application first provides a preparation method of a MOFs functionalized cyclodextrin-based composite fiber membrane, comprising:

[0005] Step one: polyacrylonitrile and cyclodextrin are added to an organic solvent for dissolution, and then an organic ligand is added to obtain a mixed solution, which is then spun to obtain a cyclodextrin / polyacrylonitrile composite nanofiber membrane;

[0006] Step two: the cyclodextrin / polyacrylonitrile composite nanofiber membrane obtained in step one is immersed in a mixed solution for heat crosslinking to obtain a cyclodextrin-based polymer fiber membrane;

[0007] Step three: mixing zirconium metal salt, hafnium metal salt, iron metal salt and organic ligand respectively to obtain a uniform solution, then transferring the solution into an autoclave, and then putting the cyclodextrin-based polymer fiber membrane obtained in step two into the autoclave to carry out hydrothermal reaction, thereby obtaining zirconium-based MOFs, hafnium-based MOFs and iron-based MOFs grown on the surface of the fiber membrane.

[0008] Preferably, the mass ratio of polyacrylonitrile, cyclodextrin and organic ligand in step one is (2-10):(0.2-8):(0.1-1).

[0009] Preferably, the organic ligand is 4,4-biphenyldicarboxylic acid, terephthalic acid, trimesic acid or 2-amino terephthalic acid.

[0010] Preferably, the mixed solution in step two is a mixture of ethylene glycol and ethylenediamine, and the volume ratio of ethylene glycol to ethylenediamine is (50-350):(0.1-0.7).

[0011] Preferably, the temperature of the thermal crosslinking in step two is 150℃, and the thermal crosslinking time is 3-5h.

[0012] Preferably, the zirconium metal salt is zirconium oxychloride or zirconium chloride, and the corresponding organic ligand is 4,4-biphenyldicarboxylic acid, trimesic acid or terephthalic acid.

[0013] The hafnium metal salt is hafnium chloride, and the corresponding organic ligand is 2-amino terephthalic acid or 4,4-biphenyldicarboxylic acid.

[0014] The iron metal salt is ferric chloride or ferric nitrate, and the corresponding organic ligand is terephthalic acid or trimesic acid.

[0015] The application also provides MOFs functionalized cyclodextrin-based composite fiber membranes prepared by the above preparation method.

[0016] Preferably, in the MOFs functionalized cyclodextrin-based composite fiber membrane, the zirconium-based MOFs are UiO-67, UiO-66 or MOF-808.

[0017] The hafnium-based MOFs are UiO-66(NH2) or UiO-67.

[0018] The iron-based MOFs are MIL-101, MIL-100 or MIL-88B.

[0019] The application also provides the application of the MOFs functionalized cyclodextrin-based composite fiber membrane as a PPCPs adsorbent in wastewater treatment.

[0020] Preferably, the MOFs functionalized cyclodextrin-based composite fiber membrane as a PPCPs adsorbent can adsorb non-steroidal anti-inflammatory drugs, antibiotics, fluoroquinolones, skin care products and sunscreens and other pollutants.

[0021] Advantages of the present application

[0022] The present application provides a MOFs functionalized cyclodextrin-based composite fiber membrane and a preparation method and application thereof, the MOFs functionalized cyclodextrin-based composite nanofiber membrane is prepared by an electrospinning technology, the obtained MOFs functionalized cyclodextrin-based composite fiber membrane can be applied to wastewater treatment as a PPCPs adsorbent, cyclodextrin has a hydrophilic exterior and a hydrophobic inner cavity, many molecules can enter the cavity structure and have host-guest coordination with cyclodextrin. In addition, organic molecules can also be adsorbed onto the MOFs functionalized cyclodextrin-based composite fiber membrane through hydrogen bond interaction, pi-pi interaction, electrostatic interaction and complexation interaction.

[0023] The fiber membrane of the present application solves the problem that MOFs are easy to fall off on a polymer, and the existence of cyclodextrin and MOFs both provides an adsorption site, and a synergistic effect is generated to enhance the adsorption efficiency of PPCPs. The MOFs functionalized cyclodextrin-based composite fiber membrane of the present application is simple to prepare, raw materials are easy to obtain, and has a wide application prospect in actual wastewater treatment. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 SEM picture of the composite fiber membrane prepared for the inventive example 1;

[0025] Figure 2 SEM picture of the composite fiber membrane prepared for the inventive example 2;

[0026] Figure 3 SEM picture of the composite fiber membrane prepared for the inventive example 3;

[0027] Figure 4 SEM picture of the composite fiber membrane prepared for the inventive example 6;

[0028] Figure 5 Cycle efficiency diagram of the composite nanofiber membrane prepared for the inventive example 1 in a cycle experiment;

[0029] Figure 6 Cycle efficiency diagram of the composite nanofiber membrane prepared for the inventive example 4 in a cycle experiment;

[0030] Figure 7 Cycle efficiency diagram of the composite nanofiber membrane prepared for the inventive example 6 in a cycle experiment;

[0031] Figure 8Figure of cycle efficiency of the composite nanofiber membrane prepared for Example 7 in the cycle experiment. DETAILED DESCRIPTION

[0032] The present application first provides a preparation method of MOFs functionalized cyclodextrin-based composite fiber membrane, comprising:

[0033] Step one: polyacrylonitrile and cyclodextrin are added into an organic solvent for dissolution and stirring until the solute is completely dissolved, then organic ligand is added and stirred until uniform, the obtained mixed solution is injected into a spinning tube for blending to obtain a cyclodextrin / polyacrylonitrile composite nanofiber membrane; the organic solvent is preferably N,N-dimethylformamide, the organic ligand is preferably 4,4-biphenyldicarboxylic acid, terephthalic acid, trimesic acid or 2-amino terephthalic acid, and the mass ratio of polyacrylonitrile, cyclodextrin and organic ligand is preferably (2-10):(0.2-8):(0.1-1); in the mixed solution, the concentration of polyacrylonitrile is preferably 5-10wt%, the concentration of organic ligand is preferably 5-10wt% of polyacrylonitrile, and the concentration of cyclodextrin is preferably 10-80wt% of polyacrylonitrile; the blending conditions are preferably as follows: the voltage of electrospinning is 8-18kV, the receiving distance is 5-20cm, the diameter of the spinneret is 1.0-1.5mm, the environmental temperature is 20-30℃, and the humidity is 20-40%;

[0034] Step two: the cyclodextrin / polyacrylonitrile composite nanofiber membrane obtained in step one is preferably first dried in an oven at 45℃ for 10h, then immersed in a mixed solution for thermal crosslinking, the thermal crosslinking temperature is preferably 150℃, and the thermal crosslinking time is preferably 3-5h, then the fiber membrane is washed with ethanol and water alternately for several times to obtain a cyclodextrin-based polymer fiber membrane; the mixed solution is preferably a mixture of ethylene glycol and ethylenediamine, and the volume ratio of ethylene glycol to ethylenediamine is preferably (50-350):(0.1-0.7);

[0035] Step three: zirconium metal salt, hafnium metal salt, iron metal salt and organic ligand are mixed and ultrasonicated to obtain a uniform solution, then the obtained solution is transferred into an autoclave, and then the cyclodextrin-based polymer fiber membrane of step two is placed into the autoclave for hydrothermal reaction, the hydrothermal temperature is preferably 120-150℃, and the reaction time is preferably 10-24h to obtain fiber membranes with zirconium-based MOFs, hafnium-based MOFs and iron-based MOFs grown on the surface.

[0036] Specifically, when the zirconium metal salt and the organic ligand are mixed, the zirconium metal salt is preferably zirconium oxychloride or zirconium chloride, the organic ligand is preferably 4,4-biphenyldicarboxylic acid, trimesic acid, terephthalic acid, the mass ratio of the zirconium metal salt and the organic ligand is preferably (0.1-0.5):(0.02-0.8), both are added to a mixed solution for ultrasonic treatment to obtain a uniform solution, the ultrasonic treatment time is preferably 5-30 min, the mixed solution is preferably a mixed solution of N,N-dimethylformamide and acetic acid or a mixed solution of N,N-dimethylformamide and formic acid or an N,N-dimethylformamide solution or a mixed solution of water and formic acid, and the uniform solution is quickly transferred into an autoclave; then the fiber membrane obtained in step two is completely immersed in the autoclave for hydrothermal reaction, the reaction temperature is preferably 120-135℃, and the reaction time is preferably 10-24 h; finally, Zr-based MOFs (including but not limited to UiO-67, UiO-66, MOF-808) are successfully grown on the surface of the fiber membrane, and the fiber membrane can be used for adsorption of drugs, preferably non-steroidal anti-inflammatory drugs, and more preferably ibuprofen, ketoprofen, naproxen and diclofenac.

[0037] When the hafnium metal salt and the organic ligand are mixed, the hafnium metal salt is preferably hafnium chloride, the organic ligand is preferably 2-amino terephthalic acid or 4,4-biphenyldicarboxylic acid, the mass ratio of the hafnium metal salt and the organic ligand is preferably (0.25-0.85):(0.15-2.05), both are added to a mixed solution for ultrasonic treatment to obtain a uniform solution, the ultrasonic treatment time is preferably 5-30 min, the mixed solution is preferably a mixed solution of acetic acid and methanol or a mixed solution of N,N-dimethylformamide and formic acid, the uniform solution is quickly transferred into an autoclave; then the fiber membrane obtained in step two is completely immersed in the autoclave for hydrothermal reaction, the reaction temperature is preferably 120-150℃, and the reaction time is preferably 24 h; finally, Hf-based MOFs (including but not limited to UiO-66(NH2), UiO-67) are successfully grown on the surface of the fiber membrane, and the fiber membrane can be used for adsorption of drugs and personal care products, preferably non-steroidal anti-inflammatory drugs, and more preferably salicylic acid, cefoperazone and furosemide; and preferably skin care products, and more preferably salicylic acid.

[0038] When the iron metal salt and the organic ligand are mixed, the iron metal salt is preferably ferric chloride or ferric nitrate, the organic ligand is preferably terephthalic acid or trimesic acid, the mass ratio of the iron metal salt and the organic ligand is preferably (0.2-7):(0.15-10.5), both are added into a mixed solution for ultrasonic, a uniform solution is obtained, the ultrasonic time is preferably 5-30 min, the mixed solution is preferably a mixed solution of N,N-dimethylformamide and acetic acid or an aqueous solution, the uniform solution is quickly transferred into an autoclave; then the fiber membrane obtained in step two is completely immersed in the autoclave for hydrothermal reaction, the reaction temperature is preferably 120-150℃; the reaction time is preferably 12-24 h; finally, Fe-based MOFs (including but not limited to MIL-101, MIL-100, MIL-88B) are successfully grown on the surface of the fiber membrane, and the fiber membrane can be used for adsorption of drugs, preferably antibiotics or fluoroquinolones such as tetracycline, oxytetracycline, ciprofloxacin, levofloxacin, etc.

[0039] The application further provides the MOFs functionalized cyclodextrin-based composite fiber membrane prepared by the above preparation method.

[0040] The application further provides the application of the MOFs functionalized cyclodextrin-based composite fiber membrane as a PPCPs adsorbent. According to the application, the MOFs functionalized cyclodextrin-based composite fiber membrane as a PPCPs adsorbent can adsorb non-steroidal anti-inflammatory drugs, antibiotic drugs or fluoroquinolone drugs, and can adsorb personal care products such as skin care products and sunscreens. The non-steroidal anti-inflammatory drugs are preferably ibuprofen, ketoprofen, naproxen, diclofenac, salicylic acid, cefoperazone or furosemide; the antibiotic drugs are preferably tetracycline and oxytetracycline; the fluoroquinolone drugs are preferably ciprofloxacin or levofloxacin; and the personal care products are preferably skin care products and sunscreens.

[0041] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application.

[0042] Example 1

[0043] Firstly, 4 g of PAN (Mw=80000) and 1.6 g of cyclodextrin were added into 36 mL of DMF solution and stirred on a magnetic stirrer for 8 h. After the PAN and cyclodextrin were completely dissolved, 0.4 g of organic ligand (4, 4-biphenyldicarboxylic acid (H2BPDC)) was added to the solution and continued to stir for 8 h. After the solution was completely dissolved, a uniform and stable electrospinning solution was obtained. The spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 °C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking. The crosslinking temperature was 150 °C, and the crosslinking time was 3 hours. After the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45 °C oven to dry overnight. Finally, an insoluble cyclodextrin-based nanofiber membrane was obtained. 0.24 g of ZrOCl2 was weighed and dissolved in a mixed solution of 20 mL of DMF and 1.6 mL of HAc, and ultrasonicated for 5 minutes. Then 0.198 g of H2BPDC was weighed and added to the above mixed solution and ultrasonicated for another 5 minutes. Then the solution was quickly transferred into an autoclave, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed into the mixed solution. Finally, the autoclave was placed in a 120 °C oven and heated for 24 h. After the reaction was completed, the fiber membrane was taken out after the autoclave cooled to room temperature and washed with water and ethanol alternately for 3-5 times. Finally, a UiO-67(Zr) functionalized cyclodextrin-based composite nanofiber membrane was obtained.

[0044] The obtained UiO-67(Zr) functionalized cyclodextrin-based composite nanofiber membrane has good adsorption capacity for drugs such as ibuprofen, ketoprofen and naproxen. The adsorption effect of ibuprofen can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for ibuprofen is 580 mg / g. In addition, the composite nanofiber membrane also shows good recycling performance in the recycling experiment, as shown in Figure 5 , the recycling efficiency of the fiber membrane can reach 85% after 5 cycles. And the fiber membrane after recycling still has good morphology, as shown in Figure 1 , the MOF nanoparticles are uniformly loaded on each nanofiber, which can indicate that the MOF particles can be successfully loaded on the surface of the cyclodextrin-based nanofiber. And in the dynamic filtration experiment with a solution concentration of 20-70 mg / L, the dynamic removal efficiency is almost close to 100%.

[0045] Example 2

[0046] First, 4g of PAN and 3.2g of cyclodextrin were added to 46mL of DMF solution and stirred on a magnetic stirrer for 8 hours. After the PAN and cyclodextrin were completely dissolved, 0.4g of organic ligand (tristyric acid (BTC)) was added to the solution and stirring was continued for 8 hours. After the solution was completely dissolved, a uniform and stable electrospinning solution was obtained. The spinning solution was transferred to a spinning apparatus, and the positive voltage of the spinning machine was set to 15KV, the negative voltage to 1KV, the receiving distance to 18cm, the spinneret diameter to 1.5mm, the ambient temperature to 30℃, and the humidity to 40%. Electrospinning was then performed. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350mL) and ethylenediamine (0.7mL) for thermal crosslinking at 150℃ for 5 hours. After the solution cooled to room temperature, the fiber membrane was removed and rinsed with ethanol and water alternately 3-5 times. It was then dried overnight in a 45℃ oven to obtain an insoluble cyclodextrin-based nanofiber membrane. Weigh 0.12 g of ZrOCl2 and dissolve it in a mixed solution of 15 mL DMF and 15 mL HCOOH, and sonicate for 5 minutes. Then weigh 0.083 g of BTC and add it to the above mixed solution, and continue sonicating for 5 minutes. Subsequently, quickly transfer the solution to a hydrothermal reactor, and then place the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step into the mixed solution. Finally, place the hydrothermal reactor in an oven at 135 °C and heat for 24 hours. After the reaction is complete, after the hydrothermal reactor cools to room temperature, remove the fiber membrane and rinse it alternately with water and ethanol 3-5 times to obtain the MOF-808(Zr) functionalized cyclodextrin-based composite fiber membrane.

[0047] The obtained MOF-808(Zr) functionalized cyclodextrin-based composite fiber membrane exhibits good adsorption capacity for drugs such as diclofenac, ibuprofen, and naproxen. The adsorption efficiency for diclofenac was determined through kinetic and isothermal experiments, and the calculated adsorption capacity of the prepared composite nanofiber membrane for diclofenac was 830 mg / g. Furthermore, this composite nanofiber membrane also demonstrated good cycling performance in cyclic experiments; after 5 cycles, the cycling efficiency of the fiber membrane reached over 90% while maintaining a good morphology. Figure 2 As shown, MOF nanoparticles are uniformly loaded on each nanofiber, indicating that MOF particles can be successfully loaded onto the surface of cyclodextrin-based nanofibers. Furthermore, in dynamic filtration experiments with solution concentrations of 20-70 mg / L, the dynamic removal efficiency can reach 96%.

[0048] Example 3

[0049] Firstly, 4 g of PAN, 0.4 g of cyclodextrin were added into 40 mL of DMF solution and stirred on a magnetic stirrer for 8 h. After the PAN and cyclodextrin were completely dissolved, 0.4 g of organic ligand (terephthalic acid (BDC)) was added to the solution and continued to stir for 8 h. After the solution was completely dissolved, a uniform and stable electrospinning solution was obtained. The spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 °C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking. The crosslinking temperature was 150 °C, and the crosslinking time was 3 hours. After the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45 °C oven to dry overnight to obtain an insoluble cyclodextrin-based nanofiber membrane. 0.466 g of ZrCl4 and 0.332 g of BDC were weighed and dissolved in 40 mL of DMF solution, and ultrasonic for 10 min. Then the solution was quickly transferred into a hydrothermal kettle, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed in the mixed solution. Finally, the hydrothermal kettle was placed in a 120 °C oven and heated for 24 h. After the reaction was completed, the fiber membrane was taken out after the hydrothermal kettle was cooled to room temperature and washed with water and ethanol alternately for 3-5 times to obtain a UiO-66(Zr) functionalized cyclodextrin-based composite fiber membrane.

[0050] The obtained UiO-66(Zr) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for naproxen, ketoprofen and diclofenac, etc. The adsorption effect of diclofenac can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for diclofenac is 321 mg / g. In addition, the composite nanofiber membrane also shows good cycle performance in the cycle experiment. After 5 cycles, the cycle efficiency of the fiber membrane can reach more than 90% and still has good morphology. As shown in FIG. 6, each nanofiber is uniformly loaded with MOF nanoparticles, which can indicate that the MOF particles can be successfully loaded on the surface of the cyclodextrin-based nanofiber. And in the dynamic filtration experiment with a solution concentration of 10-50 mg / L, the dynamic removal efficiency is almost close to 100%. Figure 3

[0051] Example 4

[0052] ​Firstly, 3 g of PAN, 1.2 g of cyclodextrin were added into 36 mL of DMF solution and stirred on a magnetic stirrer for 8 h, after the complete dissolution of PAN and cyclodextrin, 0.3 g of organic ligand (2-amino terephthalic acid (BDC-NH2)) was added to the solution and continued to stir for 8 h, after the complete dissolution of the solution, a uniform and stable electrospinning solution was obtained; the spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 °C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking, the crosslinking temperature was 150 °C, the crosslinking time was 3 hours, after the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45 °C oven to dry overnight to obtain an insoluble cyclodextrin-based nanofiber membrane. 0.32 g of HfCl4 and 0.18 g of BDC-NH2 were dissolved in a mixed solution of 24 mL of HAc and 16 mL of CH3OH, and ultrasonic was performed for 10 min. Then the solution was quickly transferred into a hydrothermal kettle, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed in the mixed solution; finally, the hydrothermal kettle was placed in a 120 °C oven and heated for 24 h. After the reaction was completed, the fiber membrane was taken out after the hydrothermal kettle was cooled to room temperature and washed with water and ethanol alternately for 3-5 times to obtain a UiO-66(Hf) functionalized cyclodextrin-based composite fiber membrane.

[0053] The obtained UiO-66(Hf) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for drugs such as salicylic acid, cefoperazone and furosemide, among which the adsorption effect of cefoperazone can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for cefoperazone is 346 mg / g. In addition, the composite nanofiber membrane also showed good cycle performance in the cycle experiment, as shown in Figure 6 , after 5 cycles, the cycle efficiency of the fiber membrane was close to 100%, and the morphology was still good. And in the dynamic filtration experiment with a solution concentration of 10-50 mg / L, the dynamic removal efficiency can reach 95%.

[0054] Example 5

[0055] Firstly, 3 g of PAN and 2.4 g of cyclodextrin were added into 30 mL of DMF solution and stirred on a magnetic stirrer for 8 h. After the PAN and cyclodextrin were completely dissolved, 0.3 g of organic ligand (2-amino terephthalic acid (BDC-NH2)) was added to the solution and stirring was continued for 8 h. After the solution was completely dissolved, a uniform and stable electrospinning solution was obtained. The spinning solution was transferred to a spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 °C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking. The crosslinking temperature was 150 °C, and the crosslinking time was 3 hours. After the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45 °C oven to dry overnight to obtain an insoluble cyclodextrin-based nanofiber membrane. 0.362 g of HfCl4 and 0.481 g of H2BPDC were dissolved in a mixed solution of 40 mL of DMF and 10 mL of HCOOH, and ultrasonic was performed for 10 min. Then the solution was quickly transferred into an autoclave, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed in the mixed solution. Finally, the autoclave was placed in a 150 °C oven and heated for 24 h. After the reaction was completed, the fiber membrane was taken out after the autoclave cooled to room temperature and washed with water and ethanol alternately for 3-5 times to obtain a UiO-67(Hf) functionalized cyclodextrin-based composite fiber membrane.

[0056] The obtained UiO-67(Hf) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for drugs such as salicylic acid, cefoperazone and furosemide. The adsorption effect of salicylic acid can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for salicylic acid is 320 mg / g. In addition, the composite nanofiber membrane also showed good recycling performance in the recycling experiment. After 5 cycles, the recycling efficiency of the fiber membrane was close to 100% and still had good morphology. And in the dynamic filtration experiment with a solution concentration of 10-50 mg / L, the dynamic removal efficiency can reach 95%.

[0057] Example 6

[0058] Firstly, 5 g of PAN, 0.5 g of cyclodextrin were added into 45 mL of DMF solution and stirred on a magnetic stirrer for 8 h, after the complete dissolution of PAN and cyclodextrin, 0.5 g of organic ligand (terephthalic acid (BDC)) was added into the solution and continued to stir for 8 h, after the complete dissolution of the solution, a uniform and stable electrospinning solution was obtained; the spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 °C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking, the crosslinking temperature was 150 °C, the crosslinking time was 3 hours, after the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45 °C oven to dry overnight to obtain an insoluble cyclodextrin-based nanofiber membrane. 1.675 g of FeCl3 was weighed and dissolved in a mixed solution of 20 mL of DMF and 5 mL of HAc, and ultrasonic was performed for 20 minutes. Then 2.625 g of BDC was weighed and added into the above mixed solution and continued to ultrasonic for 20 minutes; then the solution was quickly transferred into a hydrothermal kettle, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed into the mixed solution; finally, the hydrothermal kettle was placed into a 120 °C oven and heated for 20 h. After the reaction was completed, the fiber membrane was taken out after the hydrothermal kettle was cooled to room temperature and washed with water and ethanol alternately for 3-5 times to obtain a MIL-101(Fe) functionalized cyclodextrin-based composite fiber membrane.

[0059] The obtained MIL-101(Fe) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for tetracycline, oxytetracycline, ciprofloxacin and levofloxacin, etc. Among them, the adsorption effect of tetracycline can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for tetracycline is 392 mg / g. In addition, the composite nanofiber membrane also shows good cycle performance in the cycle experiment, as shown in Figure 7 , after 5 cycles, the cycle efficiency of the fiber membrane is close to 92%. And the fiber membrane after the cycle still has good morphology, as shown in Figure 4 , the MOF nanoparticles are uniformly loaded on each nanofiber, which can indicate that the MOF particles can be successfully loaded on the surface of the cyclodextrin-based nanofiber. And in the dynamic filtration experiment with a solution concentration of 10-30 mg / L, the dynamic removal efficiency can reach 90%.

[0060] Example 7

[0061] Firstly, 5 g of PAN, 1.5 g of cyclodextrin were added into 50 mL of DMF solution and stirred on a magnetic stirrer for 8 h, after the complete dissolution of PAN and cyclodextrin, 0.5 g of organic ligand (benzene-1, 3, 5-tricarboxylic acid (BTC)) was added into the solution and continued to stir for 8 h, after the complete dissolution of the solution, a uniform and stable electrospinning solution was obtained; the spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30 DEG C, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the above step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking, the crosslinking temperature was 150 DEG C, the crosslinking time was 3 hours, after the solution was cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and was placed in a 45 DEG C oven for drying overnight, to obtain an insoluble cyclodextrin-based nanofiber membrane. 3 g of FeNO3 was weighed and dissolved in 30 mL of H2O solution, and ultrasonic was performed for 20 minutes. 2.1 g of BTC was weighed and added into the above mixed solution and continued to ultrasonic for 20 minutes; then the solution was quickly transferred into a hydrothermal kettle, and the insoluble cyclodextrin-based nanofiber membrane obtained in the above step was placed into the mixed solution; finally, the hydrothermal kettle was placed into a 125 DEG C oven and heated for 24 h. After the reaction was completed, the fiber membrane was taken out after the hydrothermal kettle was cooled to room temperature and washed with water and ethanol alternately for 3-5 times, to obtain a MIL-100(Fe) functionalized cyclodextrin-based composite fiber membrane.

[0062] The obtained MIL-100(Fe) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for tetracycline, oxytetracycline, ciprofloxacin and levofloxacin, etc., wherein the adsorption effect of levofloxacin can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for levofloxacin is 403.23 mg / g. In addition, the composite nanofiber membrane also shows good cycle performance in the cycle experiment, as shown in FIG. 6, the cycle efficiency of the fiber membrane is still close to 85% after 5 cycles. And the fiber membrane after the cycle still has good morphology. In the dynamic filtration experiment with a solution concentration of 10-30 mg / L, the dynamic removal efficiency can reach 90%. Figure 8

[0063] Example 8

[0064] ​Firstly, 5 g of PAN, 2.5 g of cyclodextrin were added into 57.5 mL of DMF solution and stirred on a magnetic stirrer for 8 h, after the complete dissolution of PAN and cyclodextrin, 0.5 g of organic ligand (terephthalic acid (BDC)) was added to the solution and continued to stir for 8 h, after the complete dissolution of the solution, a uniform and stable electrospinning solution was obtained; the spinning solution was moved into the spinning device, and the positive voltage of the spinning machine was set to 15 KV, the negative voltage was set to 1 KV, the receiving distance was 18 cm, the spinneret diameter was 1.5 mm, the environmental temperature was 30℃, and the humidity was 40%. Electrospinning was carried out. The nanofiber membrane obtained in the previous step was completely immersed in a mixed solution of ethylene glycol (350 mL) and ethylenediamine (0.7 mL) for thermal crosslinking, the crosslinking temperature was 150℃, the crosslinking time was 3 hours, after the solution cooled to room temperature, the fiber membrane was taken out and washed with ethanol and water alternately for 3-5 times, and placed in a 45℃ oven to dry overnight to obtain an insoluble cyclodextrin-based nanofiber membrane. 1.08 g of FeCl3 was weighed and dissolved in a mixed solution of 40 mL of DMF and 0.4 mL of HAc, and ultrasonic was performed for 20 minutes. Then 0.6646 g of BTC was added to the above mixed solution and ultrasonic was continued for 20 minutes; then the solution was quickly transferred into a hydrothermal kettle, and the insoluble cyclodextrin-based nanofiber membrane obtained in the previous step was placed in the mixed solution; finally, the hydrothermal kettle was placed in a 150℃ oven and heated for 12 h. After the reaction was completed, the fiber membrane was taken out after the hydrothermal kettle was cooled to room temperature and washed with water and ethanol alternately for 3-5 times to obtain a MIL-88B(Fe) functionalized cyclodextrin-based composite fiber membrane.

[0065] The obtained MIL-88B(Fe) functionalized cyclodextrin-based composite fiber membrane has good adsorption capacity for tetracycline, oxytetracycline, ciprofloxacin and levofloxacin, etc. Among them, the adsorption effect of ciprofloxacin can be obtained by kinetic experiment and isothermal experiment, and the calculated adsorption capacity of the prepared composite nanofiber membrane for ciprofloxacin is 305 mg / g. In addition, the composite nanofiber membrane also showed good cycle performance in the cycle experiment, after 5 cycles, the cycle efficiency of the fiber membrane was close to 85% and still had good morphology. And in the dynamic filtration experiment with a solution concentration of 10-30 mg / L, the dynamic removal efficiency can reach 90%.

Claims

1. A method for preparing MOFs functionalized cyclodextrin-based composite fiber membranes, characterized in that, The application relates to a preparation method of MOFs functionalized cyclodextrin-based composite fiber membranes. Step one: polyacrylonitrile and cyclodextrin are dissolved in an organic solvent, then an organic ligand is added, and the obtained mixed solution is spun to obtain a cyclodextrin / polyacrylonitrile composite nanofiber membrane; Step two: the cyclodextrin / polyacrylonitrile composite nanofiber membrane obtained in step one is immersed in a mixed solution for heat crosslinking to obtain a cyclodextrin-based polymer fiber membrane; the mixed solution is a mixture of ethylene glycol and ethylenediamine, and the volume ratio of ethylene glycol to ethylenediamine is (50-350):(0.1-0.7); Step three: zirconium metal salt and an organic ligand, hafnium metal salt and an organic ligand, or iron metal salt and an organic ligand are mixed respectively, and a uniform solution is obtained through ultrasonic treatment; the obtained solution is transferred into an autoclave, and then the cyclodextrin-based polymer fiber membrane in step two is placed into the autoclave for hydrothermal reaction to obtain a fiber membrane surface growth zirconium-based MOFs, hafnium-based MOFs or iron-based MOFs; The mass ratio of polyacrylonitrile, cyclodextrin and the organic ligand in step one is (2-10):(0.2-8):(0.1-1).

2. The method for preparing a MOFs-functionalized cyclodextrin-based composite fiber membrane according to claim 1, characterized in that, The organic ligand is 4,4-biphenyldicarboxylic acid, terephthalic acid, trimesic acid or 2-amino terephthalic acid.

3. The method for preparing a MOFs-functionalized cyclodextrin-based composite fiber membrane according to claim 1, characterized in that, The heat crosslinking temperature in step two is 150 DEG C, and the heat crosslinking time is 3-5 h.

4. The method for preparing a MOFs-functionalized cyclodextrin-based composite fiber membrane according to claim 1, characterized in that, The zirconium metal salt is zirconium oxychloride or zirconium chloride, and the corresponding organic ligand is 4,4-biphenyldicarboxylic acid, trimesic acid or terephthalic acid; The hafnium metal salt is hafnium chloride, and the corresponding organic ligand is 2-amino terephthalic acid or 4,4-biphenyldicarboxylic acid; The iron metal salt is ferric chloride or ferric nitrate, and the corresponding organic ligand is terephthalic acid or trimesic acid.

5. The MOFs functionalized cyclodextrin-based composite fiber membrane obtained by the preparation method in claim 1.

6. The MOFs functionalized cyclodextrin-based composite fiber membrane according to claim 5, characterized in that, In the MOFs functionalized cyclodextrin-based composite fiber membrane, the zirconium-based MOFs are UiO-67, UiO-66 or MOF-808; The hafnium-based MOFs are UiO-66-NH2 or UiO-67; The iron-based MOFs are MIL-101, MIL-100 or MIL-88B.

7. The MOFs functionalized cyclodextrin-based composite fiber membrane in claim 6 is used as a PPCP adsorbent in wastewater treatment.

8. Use of MOFs functionalized cyclodextrin-based composite fibrous membranes as adsorbents of PPCPs in wastewater treatment according to claim 7, characterized in that, The MOFs functionalized cyclodextrin-based composite fiber membrane used as a PPCP adsorbent can adsorb non-steroidal anti-inflammatory drugs, antibiotics, fluoroquinolone drugs, skin care product or sunscreen cream pollutants.

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