Use of magnetic MOF composites for adsorbing drugs

Abstract

The application provides a use of a magnetic MOFs composite material in adsorption of drugs.The magnetic MOFs composite material comprises a functional core and a metal organic framework material, and the magnetic MOFs composite material can be applied to environmental sample water treatment, adsorption and removal of environmental pollutants in water.

Description

Technical Field

[0001] This invention belongs to the field of adsorption technology, specifically relating to the synthesis of magnetic MOF composite materials and their use in adsorbing drugs. Background Technology

[0002] As a novel type of porous material, the concept of metal-organic frameworks (MOFs) was first proposed in 1995 by the Yaghi group in Nature. MOFs are porous materials with a periodic network structure formed by the self-assembly of metal ions and organic ligands through complexation (coordination bonds); therefore, they are also known as porous coordination polymers (PCPs). Compared with simple coordination compounds and polymers, the metal centers and organic ligands in the MOF framework structure distinguish them significantly, exhibiting excellent properties such as porosity, large specific surface area, unsaturation, and metal coordination sites.

[0003] To date, MOF materials have been combined with numerous functional materials, including metal nanorods, metal oxides, hydrogels, and carbon nanotubes. By altering the composition, specific surface area, and structural morphology of MOF materials, they can be made to possess different functional properties, thus showing broad application prospects in fields such as catalysts, adsorption separation, and electrochemistry, which has attracted great interest and widespread attention from the scientific community.

[0004] Magnetic metal-organic frameworks (MMOFs) are a new type of composite material composed of magnetic metals and metal-organic framework materials. Common magnetic nanoparticles include Fe3O4, γ-Fe2O3, Fe, NiO, Co3O4, and MFe2O4 (M = Mn, Co, Ni), among which Fe3O4 is the most common example as a magnetic matrix.

[0005] In recent years, while the development of the chemical industry has brought benefits to humankind, it has also faced threats to environmental and ecosystem security and negative impacts on human health. Pollutants in water bodies mainly include heavy metal ions and organic pollutants.

[0006] MOF materials, with their adjustable porosity, large specific surface area, and good stability, are considered excellent materials for adsorbing and removing pollutants from water. MMOF materials combine many of the excellent properties of MOFs and magnetic materials, achieving substance separation through the action of an external magnetic field. They are also easy to recycle and have high utilization rates, showing broad application prospects in adsorption and becoming a new research hotspot.

[0007] Heavy metal ions are significant pollutants in the aquatic environment. Most metal ions are carcinogenic and can threaten human health by generating free radicals.

[0008] Morcos et al. studied the adsorption of Pb(II) ions in water by UiO-MOFs. Their research showed that the maximum adsorption capacities of Pb(II) by microporous thiourea-modified UiO-66 and UiO-67 MOFs were 246 and 367 mg·g, respectively. -1 Within a relatively high Pb(II) concentration range (25-250 mg / L), their effective removal efficiency can reach over 95%, exhibiting excellent selectivity in high-concentration multi-ion solutions. The adsorbed MOF crystals can undergo four complete regeneration cycles, providing a reliable adsorbent for Pb(II) removal from industrial wastewater.

[0009] Organic pollutants are another major category of pollutants in water. Organic pollutants mainly include macromolecular organic dyes, endocrine disruptors (EDCs), pharmaceuticals and personal care products (PPCPs), and persistent pollutants (POPs).

[0010] Yin Yue et al. reported a UiO-66@Fe3O4@UiO-66 enhanced ultrafiltration membrane that can efficiently adsorb two typical PPCPs, salicylic acid (SA) and dimethyl phthalate (DMP). Under neutral conditions, 10% MOFs / PVDF can effectively adsorb 0.1 mmol·L⁻¹ of PPCPs. -1 SA and DMP showed the highest adsorption efficiency, with removal rates of 64.2% and 46.1%, respectively, providing a new approach for the removal of PPCPs and the improvement of membrane antifouling performance in the process of deep purification of secondary effluent.

[0011] Abdullah et al. developed a class of activated carbon / MOF composite materials: AC / NH2-MIL-101(Cr), for the removal of p-nitrophenol (PNP) from water. The prepared composite material has a density of 2049 μm. 2 ·g -1 Specific surface area and 0.93 cm² 3 ·g- 1 The pore volume and adsorption capacity can reach 18.3 mg·g. -1 The adsorption mechanism is related to the affinity of PNP for the -NO2 group and the unsaturated chromium sites of AC-NH2-MIL-101(Cr), the Coulomb interaction between PNP and AC-NH2-MIL-101(Cr) through hydrogen bonding, and the π-π stacking interaction. Simultaneously, this type of MOF composite material exhibits excellent stability and reusability. This provides a new approach for developing and synthesizing highly efficient MOF-based nanoporous materials for the adsorption of organic pollutants in wastewater. Summary of the Invention

[0012] To address the aforementioned technical problems, this invention provides the use of a magnetic MOF composite material in drug adsorption, wherein the magnetic MOF composite material comprises a functional core and a metal-organic framework material.

[0013] According to an embodiment of the present invention, the magnetic MOFs composite material has a porous structure.

[0014] Preferably, the pore structure includes mesoporous structures and / or microporous structures.

[0015] According to an embodiment of the present invention, the functional core is made of a magnetic material, preferably Fe3O4.

[0016] According to an embodiment of the present invention, the functional core has a nanorod structure.

[0017] Preferably, the length of the nanorod is 100-500 nm, and more preferably 200 nm.

[0018] According to an exemplary embodiment of the present invention, the functional core is selected from Fe3O4 nanorods, which can be prepared using methods known in the art. Preferably, the length of the Fe3O4 nanorods is 100-500 nm, for example, 200 nm.

[0019] According to an embodiment of the present invention, the metal-organic framework material comprises a metal element and an organic ligand.

[0020] Preferably, the metallic element is selected from at least one of Cu, Zn, and Ni.

[0021] Preferably, the organic ligand is selected from at least one of 1,3,5-benzenetricarboxylic acid, 1,4-benzenedicarboxylic acid, and aminoterephthalic acid.

[0022] According to an embodiment of the present invention, the metal-organic framework material is loaded on the surface of the functional core.

[0023] According to an embodiment of the present invention, the magnetic MOF composite material is prepared by the following method: a functional core, a metal source, and an organic ligand are in a solvent, and a metal-organic framework material is loaded onto the surface of the functional core by a hydrothermal synthesis method.

[0024] Preferably, the solvent is selected from at least one of water, N,N dimethylformamide (DMF), ethanol, and methanol.

[0025] Preferably, the metal source is selected from at least one of the acetates and chlorides of a metal element, such as copper acetate or zinc acetate.

[0026] According to an embodiment of the present invention, the molar ratio of the functional core, the metal source, and the organic ligand is 1:(2-4):6, for example, 1:3.6:6.

[0027] According to an embodiment of the present invention, the conditions of the hydrothermal synthesis method include: a reaction temperature of 50-100℃, for example, 50℃, 60℃, 70℃, 80℃, 90℃, or 100℃; and a reaction time of 0.1-10h, for example, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, or 10h.

[0028] According to an exemplary embodiment of the present invention, the magnetic MOF composite material comprises Fe3O4 nanorods and a metal-organic framework material, wherein the metal-organic framework material is selected from Cu-MOF. Preferably, the magnetic MOF composite material substantially has the following properties: Figure 3 The XRD pattern of Fe3O4 / Cu-MOF is shown in the figure.

[0029] According to an exemplary embodiment of the present invention, the magnetic MOF composite material comprises Fe3O4 nanorods and a metal-organic framework material, wherein the metal-organic framework material is selected from Zn-MOF. Preferably, the magnetic MOF composite material substantially has the following properties: Figure 3 The XRD pattern of Fe3O4 / Zn-MOF is shown.

[0030] According to an embodiment of the present invention, the drug is selected from drugs that can exist stably in an aqueous phase, preferably ciprofloxacin, ibuprofen, enrofloxacin, naproxen, ofloxacin, etc.

[0031] According to an embodiment of the present invention, the method for adsorbing the drug includes: mixing the magnetic MOF composite material with the drug under aqueous conditions and then adsorbing the drug.

[0032] Preferably, during adsorption, the ratio of the magnetic MOF composite material to the drug is (1-100):(0.1-1), for example 10:(0.1-1), 20:(0.1-1), 30:(0.1-1), 40:(0.1-1), 50:(0.1-1), 60:(0.1-1), 70:(0.1-1), 80:(0.1-1), 90:(0.1-1), or for example 40:0.4.

[0033] Preferably, the adsorption rate of the drug by the magnetic MOF composite material is 10%, more preferably 50% or more, for example 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0034] According to an embodiment of the present invention, during adsorption, methods such as shaking or pH adjustment can be used to promote the adsorption effect.

[0035] Preferably, the oscillation time is 1-200 min, more preferably 5-90 min, for example 5 min, 10 min, 30 min, 60 min, 90 min, 120 min, or 180 min.

[0036] Preferably, pH adjustment includes using an acid-base regulator. Further, the acid-base regulator can be any known acid-base regulator in the art, such as hydrochloric acid, sodium hydroxide, acetic acid, ammonia, etc.

[0037] For example, when the drug is ciprofloxacin, an acid-base regulator is selected to adjust the pH to less than 7, preferably less than 6, for example, 3.84.

[0038] According to an embodiment of the present invention, the magnetic MOF composite material can be reused in pharmaceuticals after being treated with a detergent.

[0039] Preferably, the detergent is selected from methanol and acetonitrile.

[0040] Preferably, it can be repeated at least 5 times.

[0041] Beneficial effects

[0042] This invention uses ferromagnetic Fe3O4 as a functional core and 1,3,5-benzenetricarboxylic acid as an organic ligand. Through hydrothermal reaction, Cu-MOF and Zn-MOF metal-organic framework materials are loaded onto its surface to obtain magnetic MOF composite materials. The resulting magnetic MOF composite materials are then applied to adsorb drugs in the aqueous phase.

[0043] The magnetic MOFs composite material of the present invention can be applied to environmental sample water treatment to adsorb and remove environmental pollutants such as ibuprofen and quinolones from water. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the synthesis process of Fe3O4 nanorods;

[0045] Figure 2 A schematic diagram of the synthesis process of Fe3O4 / Cu3(BTC)2;

[0046] Figure 3 XRD spectra of different MOFs;

[0047] Figure 4 Scanning electron microscope images of different MOFs; (a) is Cu-BTC, (b) is Fe3O4 / Cu3(BTC)2, and (c) is Fe3O4 / Zn3(BTC)2.

[0048] Figure 5N2 adsorption-desorption curves for different MOFs;

[0049] Figure 6 This is the standard curve for ciprofloxacin solution;

[0050] Figure 7 The effect of oscillation time on the removal rate of ciprofloxacin adsorbed by MOFs;

[0051] Figure 8 The effect of oscillation time on the adsorption capacity of ciprofloxacin by MOFs;

[0052] Figure 9 The effect of pH on the removal rate of ciprofloxacin adsorbed by Fe3O4 / Zn3(BTC)2;

[0053] Figure 10 The effect of pH on the adsorption capacity of ciprofloxacin on Fe3O4 / Zn3(BTC)2;

[0054] Figure 11 This is the standard curve for ibuprofen solution.

[0055] Figure 12 The effect of oscillation time on the removal rate of ibuprofen adsorbed by MOFs;

[0056] Figure 13 The effect of oscillation time on the adsorption capacity of ibuprofen by MOFs;

[0057] Figure 14 The removal rate of ciprofloxacin by repeated adsorption in magnetic MOF composite materials;

[0058] Figure 15 The recovery rate of ciprofloxacin adsorbed by methanol washing magnetic MOF composite materials;

[0059] Figure 16 (a) Fe3O4 / Cu3(BTC)2 before adsorption; (b) Fe3O4 / Cu3(BTC)2 after repeated adsorption; (c) Fe3O4 / Zn3(BTC)2 before adsorption; (d) Fe3O4 / Zn3(BTC)2 after repeated adsorption. Detailed Implementation

[0060] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0061] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0062] Preparation Example 1: Fe3O4 nanorods were prepared by coprecipitation method.

[0063] Weigh 2.7g of ferric chloride hexahydrate and 2.7g of ferrous sulfate heptahydrate and add them to 100mL of ultrapure water. Gradually heat to 30℃, then slowly add 15mL of ammonia water dropwise to the above solution. Stir and heat to 80℃ and keep warm for 30min. Use an external magnet to separate the black precipitate in the above solution and wash it several times with an appropriate amount of ultrapure water and ethanol to obtain Fe3O4 nanorods. The test results show that the length of the Fe3O4 nanorods is 200nm.

[0064] Comparative Example 1: Synthesis method of MOF material Cu-BTC as follows Figure 1 As shown, the specific process is as follows:

[0065] (1) Weigh 0.43g of copper acetate and dissolve it in 20mL of ultrapure water to obtain an aqueous solution of copper acetate;

[0066] (2) Prepare a mixed solution of 0.25g 1,3,5-benzenetricarboxylic acid (H3BTC), 20mL NN dimethylformamide (DMF), and 20mL anhydrous ethanol, and add the above mixed solution to copper acetate aqueous solution;

[0067] (3) Heat the obtained solution to 70°C, stir magnetically for 4 hours, collect the product by centrifugation, wash with 30 mL of ethanol-water solution (1:1), and vacuum dry at 60-80°C to obtain a block solid. Grind it evenly with a mortar and pestle to finally obtain a blue powder, which is the MOF material Cu-BTC.

[0068] Example 1

[0069] The synthesis method of the magnetic MOF composite material Fe3O4 / Cu3(BTC)2 is as follows: Figure 2 As shown, the specific process is as follows: (1) Prepare a mixed solution by mixing 0.25g H3BTC, 20mL NN dimethylformamide (DMF) and 20mL anhydrous ethanol;

[0070] (2) Add 10 mL of Fe3O4 nanorod suspension (of which the content of Fe3O4 nanorod is 0.077 g) to the mixed solution in step (1), sonicate for 30 min, peel off into flakes, and form a stable aqueous dispersion; (3) Weigh 0.43 g of copper acetate and dissolve it in 20 mL of ultrapure water to prepare an aqueous solution of copper acetate, then add the aqueous dispersion in step (2) to the aqueous solution of copper acetate, and stir for 4 h at a reaction temperature of 70 °C by hydrothermal synthesis, and collect the product by centrifugation;

[0071] (4) The product of step (3) was washed with 30 mL of ethanol-water solution (volume ratio 1:1) and vacuum dried at 70±10℃ to obtain a block solid. It was then ground evenly with a mortar and pestle to finally obtain a blue-green powder, which is the magnetic MOFs composite material Fe3O4 / Cu3(BTC)2.

[0072] Example 2

[0073] The specific process for synthesizing the magnetic MOF composite material Fe3O4 / Zn3(BTC)2 is as follows:

[0074] Steps (1)-(2) are the same as in Example 1;

[0075] (3) Weigh 0.51g of zinc acetate, prepare 20mL of aqueous solution, add the mixed solution in (2) to the zinc acetate aqueous solution, and use hydrothermal synthesis method to magnetically stir at a reaction temperature of 70℃ for 4h, and collect the product by centrifugation.

[0076] (4) The product obtained in step (3) was washed with 30 mL of ethanol-water solution (1:1) and vacuum dried at 70±10℃ to obtain a block solid. It was then ground evenly with a mortar and pestle to finally obtain a brown powder, namely Fe3O4 / Zn3(BTC)2.

[0077] Test Example 1

[0078] The MOFs material of Comparative Example 1 and the magnetic MOFs composite materials prepared in Examples 1-2 were used as MOFs samples and tested according to the following test methods:

[0079] (1) X-ray diffractometer (XRD)

[0080] The MOFs samples were subjected to XRD analysis using an X-ray diffractometer (D8 Advance) manufactured by Bruker GmbH, Germany. The phase structure of the materials was observed within the range of 5-60°.

[0081] The XRD patterns of Cu-BTC, Fe3O4 / Cu3(BTC)2, and Fe3O4 / Zn3(BTC)2 are as follows: Figure 3 As shown, the crystal structure and purity of the MOF sample can be determined by the position of the characteristic diffraction peaks and the intensity of the diffracted light.

[0082] Depend on Figure 3As can be seen, comparing the XRD spectra of Cu-BTC and Fe3O4 / Cu3(BTC)2, there is no significant difference between them, indicating that the incorporation of magnetic nanoparticles Fe3O4 does not interfere with or destroy the crystal structure of Cu-BTC itself. Furthermore, characteristic diffraction peaks of Fe3O4 exist near 2θ of 30°-40°, and the same characteristic diffraction peaks of Fe3O4 appear in the XRD spectrum of Fe3O4 / Cu3(BTC)2. This phenomenon proves that Fe3O4 has been successfully incorporated into Fe3O4 / Cu3(BTC)2.

[0083] Similarly, the same main diffraction peak appeared at 2θ = 35° in the XRD pattern of Fe3O4 / Zn3(BTC)2, indicating that Fe3O4 was successfully loaded on the Zn-MOF surface.

[0084] (2) Scanning electron microscope (SEM)

[0085] The microstructure and particle size of MOF sample surfaces were observed using an S-4800 scanning electron microscope at an accelerating voltage of 3.0 kV (or 15.0 kV).

[0086] Figure 4 In the image, 'a' is a scanning electron microscope (SEM) image of Cu-BTC. Figure 4 Image b is a scanning electron microscope (SEM) image of Fe3O4 / Cu3(BTC)2. Figure 4 c is a scanning electron microscope image of Fe3O4 / Zn3(BTC)2.

[0087] Depend on Figure 4 It can be seen that there are pores on the surface of MOFs, which indicates that the hydrothermally synthesized MOFs have a porous structure, which is beneficial to the adsorption of target substances.

[0088] Depend on Figure 4 As can be seen from Figure a, Cu-BTC exhibits a molecular sieve shape with a smooth surface, mainly consisting of irregular nanoparticles. By observing and comparing the SEM images of Fe3O4 / Cu3(BTC)2 and Fe3O4 / Zn3(BTC)2, it can be seen that both composite materials exhibit a rod-like morphology, indicating that Fe3O4 nanoparticles are effectively loaded on the surface of MOFs materials.

[0089] (3) Specific Surface Area Analyzer (BET)

[0090] The specific surface area and pore size distribution of MOF samples were determined using an ASAP2020HD88 specific surface area analyzer manufactured by McMurray Instruments (Shanghai) Co., Ltd. The specific method involved weighing a certain amount of MOF sample, adding it to a glass tube, and obtaining the specific surface area, pore size, and pore volume of the MOF sample by passing it through the N2 adsorption-desorption isotherm, thereby analyzing the pore structure of the prepared sample.

[0091] The BET characterization results of three MOFs samples—Cu-BTC, Fe3O4 / Cu3(BTC)2, and Fe3O4 / Zn3(BTC)2—are shown in Table 1.

[0092] Table 1. Specific surface area, pore volume, and pore size of different MOF samples

[0093]

[0094] As shown in Table 1, Cu-BTC has the largest specific surface area, at 1054.36 m². 2 ·g -1 The pore volume is 0.97 cm. 3 ·g -1 The pore size can reach 3.68 nm. Compared with single Cu-BTC, Cu-BTC loaded with Fe3O4 nanoparticles shows a decrease in specific surface area, pore volume, and pore size to varying degrees. Calculations show that the specific surface area of ​​MOFs gradually decreases with increasing Fe3O4 nanoparticle content.

[0095] Increasing the pore size of MOF samples appropriately facilitates the adsorption of reactants at the active sites on the MOF sample surface. Through comparison, the three MOF samples, arranged in order of pore size, are Fe3O4 / Zn3(BTC)2, Cu-BTC, and Fe3O4 / Cu3(BTC)2. This indicates that Fe3O4 / Zn3(BTC)2 exhibits the best adsorption performance.

[0096] Simultaneously, N2 adsorption-desorption tests were conducted on three samples: Cu-BTC, Fe3O4 / Cu3(BTC)2, and Fe3O4 / Zn3(BTC)2, to investigate their porosity. The N2 adsorption-desorption curves of different MOF samples are shown below. Figure 5 As shown, analysis reveals that the specific surface area of ​​Cu-BTC, determined using the BET multi-point method (P / P0 = 0.2259), is 1082.65 m². 2 / g. Similarly, using the BET multi-point method (P / P0 = 0.2267) to analyze Fe3O4 / Cu3(BTC)2, its specific surface area is 633.07 m². 2 / g. The specific surface area of ​​Fe3O4 / Zn3(BTC)2 was analyzed using the BET multi-point method (P / P0 = 0.2251) and found to be 25.73 m² / g. 2 / g.

[0097] Combination Figure 5The N2 adsorption-desorption curves show that the desorption and adsorption curves of Cu-BTC and Fe3O4 / Cu3(BTC)2 do not completely close, exhibiting obvious hysteresis loops, indicating a certain degree of mesoporous structure. In contrast, the desorption and adsorption curves of Fe3O4 / Zn3(BTC)2 show less hysteresis, suggesting that this magnetic MOF composite material has low mesoporous content and is primarily composed of micropores.

[0098] Application Preparation Example

[0099] Solution preparation:

[0100] Accurately weigh a certain amount of ciprofloxacin and ibuprofen, dissolve them in a suitable reagent, transfer them to a 25mL brown volumetric flask, and dilute to the mark with chromatographic grade methanol to prepare a ciprofloxacin stock solution with a concentration of 4000mg / L and an ibuprofen stock solution with a concentration of 1000mg / L. Store them in a refrigerator for later use.

[0101] Application Example 1

[0102] Adsorption experiment of ciprofloxacin on MOF composite materials

[0103] (1) Plotting the standard curve: Take 0.5 mL of ciprofloxacin stock solution and dilute it to an 800 mg / L aqueous solution. Then accurately transfer 0.1, 0.2, 0.5, 1.0, and 2.0 mL into 10 mL volumetric flasks and dilute to volume with ultrapure water to obtain a series of ciprofloxacin standard solutions with concentrations of 1.0, 2.0, 5.0, 10.0, and 25.0 mg / L. Measure the peak area at a wavelength of 275 nm by high performance liquid chromatography. The results are shown in Table 2.

[0104] The testing conditions for the high-performance liquid chromatograph (Agilent 1100) were as follows: the chromatographic column was Athena C100. 18 (120A, 4.6×250mm, 5μm); mobile phase: 0.2% (volume fraction) acetic acid aqueous solution: methanol = 20:80; injection volume: 10μL; detection wavelength: 275nm; flow rate: 1.0mL·min -1 The column temperature is 25℃.

[0105] Table 2. Peak area of ​​ciprofloxacin at different concentrations determined by high performance liquid chromatography.

[0106]

[0107] Based on the peak area values ​​in the spectral results, the concentration changes are calculated and analyzed. A linear regression is performed on the peak area (Y) against the ciprofloxacin concentration (X), and a standard curve is plotted, as shown below. Figure 6As shown, the linear regression equation obtained is Y = 73.848x + 24.231 (R = 0.9993). It can be seen that the concentration of ciprofloxacin in the range of 1.0 to 25.0 mg / L shows a good linear relationship with its peak area.

[0108] (2) Adsorption and degradation of ciprofloxacin:

[0109] Use a pipette to take 0.5 mL of 4000 mg / L ciprofloxacin solution into a 100 mL volumetric flask, and dilute to the mark with ultrapure water. Take 20 mL of 20 mg / L ciprofloxacin solution from three groups into 50 mL iodine flasks, wrap them with aluminum foil, and add 40 mg of the material prepared in Examples 1-2 and Comparative Example 1 respectively. Then place the iodine flask on a shaker and react for 5, 10, 30, 60, 90, 120, and 180 min respectively. Use a 1 mL disposable syringe to draw 1.0 mL of the supernatant, filter it through a 0.45 μm aqueous MCE filter membrane, and determine and calculate its peak value by high performance liquid chromatography (test conditions as above). Calculate the concentration of the remaining ciprofloxacin according to the following removal rate formulas (Equations 1 and 2).

[0110] Removal rate = (C0 - C) t Formula 1 (C0)

[0111] q t =(C0-C t V / m Equation 2

[0112] Where: C0—initial concentration of the target solution, mg / L;

[0113] C t —The concentration of the target substance solution at time t, in mg / L;

[0114] q t —The amount of target analyte adsorbed by the MOF sample at reaction time t, in mg / g;

[0115] V—Solution volume, L;

[0116] m — mass of MOF sample, g.

[0117] (3) Effect of oscillation time on ciprofloxacin removal rate

[0118] The pH of the test solution was adjusted with HCl to maintain the initial pH of the ciprofloxacin solution at 3.84 and a concentration of 20 mg / L. The MOF sample dosage was 40 mg. The effect of MOFs on the degradation of ciprofloxacin was studied by varying the shaking time. Samples were taken at shaking times of 5, 10, 30, 60, 90, 120, and 180 min, for a total of 7 samples, to determine the ciprofloxacin removal rate. The effect of shaking time on ciprofloxacin removal was obtained. The experimental results are shown in [Figure number missing]. Figure 7 and Figure 8 As shown, the concentration refers to the concentration of ciprofloxacin.

[0119] Depend on Figure 7 It can be seen that, at the same initial concentration, the removal rate of ciprofloxacin by MOFs gradually slows down with the increase of shaking time. When the shaking time increases rapidly within 0 to 30 min, it exceeds 50% of the removal rate of ciprofloxacin by MOFs. When the shaking time increases from 90 to 180 min, the removal rate of ciprofloxacin by different MOFs only increases by 2.50% to 9.05%.

[0120] Depend on Figure 8 It can be seen that the adsorption capacity of MOFs for ciprofloxacin increases rapidly within 30 minutes, with Fe3O4 / Zn3(BTC)2 showing the highest adsorption capacity for ciprofloxacin reaching 4.13 mg·g⁻¹. -1 After 90 minutes of adsorption, the adsorption of ciprofloxacin by MOFs reached a basic equilibrium.

[0121] During the first 30 minutes of adsorption, the MOF sample had a higher solution concentration, resulting in a larger number of contact sites for the adsorbate ciprofloxacin. After 30 minutes, the number of contact sites decreased, and the solution concentration also decreased relatively, leading to a decline in the removal rate and adsorption capacity of ciprofloxacin by the MOF sample. The increasing trend of removal rate and adsorption capacity began to slow down.

[0122] (4) Effect of initial solution pH on ciprofloxacin removal

[0123] The initial pH of the solution has varying degrees of influence on the surface charge and ionization degree of the adsorbate in MOF samples. To investigate the effect of pH on the adsorption and degradation of ciprofloxacin by Fe3O4 / Zn3(BTC)2, the pH of the ciprofloxacin solution was adjusted using analytical grade acetic acid and ammonia. The reaction conditions were as follows: the initial pH of the ciprofloxacin solution was changed (pH adjusted to 3.84, 6.82, and 10.12, respectively), the solution concentration was maintained at 20 mg / L, the solution volume at 20 mL, the Fe3O4 / Zn3(BTC)2 dosage was 40 mg, and the reaction time was 90 min. Samples were taken at shaking times of 5, 10, 30, 60, and 90 min, for a total of 5 samples, to determine the ciprofloxacin removal rate and adsorption capacity. The effect of the initial pH of the solution on ciprofloxacin removal was determined, and the experimental results are as follows: Figure 9 and Figure 10 As shown.

[0124] Depend on Figure 9 and Figure 10 Observations show that the degradation efficiency of ciprofloxacin was affected to varying degrees under different pH conditions, indicating that changes in pH value have a certain impact on both ciprofloxacin and Fe3O4 / Zn3(BTC)2. At pH 3.84, the removal rate of ciprofloxacin was above that of other pH curves, reaching 63.06%, with a maximum adsorption capacity of 5.19 mg / g. -1 At pH 6.82, the removal rate of ciprofloxacin initially increased and then decreased, reaching 23.55%, with a maximum adsorption capacity of 4.03 mg / g. -1 At pH = 10.12, the removal rate reached 57.37%, and the maximum adsorption capacity reached 4.74 mg·g. -1 .

[0125] Application Example 2

[0126] Adsorption experiment of ibuprofen on MOF composite materials

[0127] (1) Take 1.0 mL of ibuprofen stock solution and dilute it to an aqueous solution of 100 mg / L. Then accurately transfer 0.10, 0.20, 0.50, 1.0 and 2.5 mL into 10 mL volumetric flasks and dilute to volume with ultrapure water to obtain a series of ibuprofen standard solutions of 1.0, 2.0, 5.0, 10.0 and 25.0 mg / L. Measure the peak area of ​​the solutions at a wavelength of 220 nm by high performance liquid chromatography. The results are shown in Table 3.

[0128] The testing conditions for the high-performance liquid chromatograph (Agilent 1100) were as follows: the chromatographic column was Athena C100. 18(120A, 4.6×250mm, 5μm); mobile phase: 0.2% (volume fraction) acetic acid aqueous solution: methanol = 20:80; injection volume: 10μL; detection wavelength: 220nm; flow rate: 1.0mL·min -1 The column temperature is 30℃.

[0129] Table 3 Peak area of ​​ibuprofen at different concentrations determined by high performance liquid chromatography (HPLC)

[0130]

[0131] A standard curve was plotted by performing a linear regression of peak area (Y) against ibuprofen concentration (X), as shown below. Figure 11 As shown, the linear regression equation is Y = 21.304x + 5.347 (R = 0.9990). Ibuprofen concentration in the range of 1.0 to 25.0 mg / L shows a good linear relationship with its peak area.

[0132] (2) Adsorption and degradation of ibuprofen

[0133] Use a pipette to take 1.0 mL of ibuprofen solution with a concentration of 1000 mg / L into a 100 mL volumetric flask, and dilute to the mark with ultrapure water. Take 20 mL of ibuprofen solution with a concentration of 20 mg / L into three 50 mL iodine flasks, wrap them with aluminum foil, and add 40 mg of the material prepared in Examples 1-2 and Comparative Example 1 respectively. Then place the iodine flask on a shaker and react for 5, 10, 30, 60, 90, 120, and 180 min respectively. Use a 1 mL disposable syringe to draw 1.0 mL of the supernatant, filter it through a 0.22 μm hydrophilic PTFE filter membrane, and determine and calculate the peak value by liquid chromatography. Calculate the concentration of remaining ibuprofen according to the above removal rate formulas (Equations 1 and 2).

[0134] The initial concentration of ibuprofen solution was maintained at 20 mg / L, and the amount of MOFs sample added was 40 mg. The effect of MOFs on ibuprofen degradation was studied by changing the shaking time. Samples were taken at shaking times of 5, 10, 30, 60, 90, 120, and 180 min, for a total of 7 samples, to determine the removal rate of ibuprofen. The effect of ibuprofen on the removal of ciprofloxacin was obtained. The experimental results are shown in […]. Figure 12 and Figure 13 As shown.

[0135] The carboxyl group of ibuprofen can react with Zn 2+ Cu 2+ Metal ions can effectively coordinate to form metal drugs. Figure 12 It can be seen that after shaking for 180 min, Fe3O4 / Cu3(BTC)2 showed the best adsorption effect on ibuprofen, with a removal rate of 24.30% and an adsorption capacity of 1.70 mg·g.-1 At the same initial concentration, the removal rate of ibuprofen by MOFs gradually slowed down with increasing shaking time. The removal rate increased rapidly when the shaking time was between 0 and 30 minutes, exceeding 50% of the removal rate of ibuprofen by MOFs. However, when the shaking time increased from 60 to 180 minutes, the removal rate of ibuprofen by different MOFs only increased by 3.55% to 6.90%.

[0136] Depend on Figure 13 It can be seen that the adsorption capacity of MOFs for ibuprofen increases rapidly within 30 minutes, and the maximum adsorption capacity of Fe3O4 / Cu3(BTC)2 for ibuprofen can reach 1.30 mg·g. -1 After 90 minutes of adsorption, the adsorption of ibuprofen by MOFs reached a basic equilibrium.

[0137] During the first 30 minutes of adsorption, the higher solution concentration of MOFs resulted in a larger number of contact sites, allowing for more interaction with the adsorbate ibuprofen. After 30 minutes, the number of contact sites decreased, and the solution concentration also relatively decreased, leading to a decline in the removal rate of ibuprofen by MOFs, and the rate of increase in removal rate began to slow down.

[0138] Application Example 3

[0139] The adsorption performance of ciprofloxacin was continuously tested using Fe3O4 / Cu3(BTC)2 and Fe3O4 / Zn3(BTC)2 composite materials. After the ciprofloxacin was adsorbed onto the magnetic MOF composite material, methanol was used for regeneration, and the reaction conditions were maintained as follows: initial concentration of 20 mg·L⁻¹. -1 Ciprofloxacin solution (pH = 3.84), 0.05 g of magnetic MOF composite material was added, and the reaction time was 1 h with shaking each time. The remaining concentration of ciprofloxacin solution was tested. Then, the magnetic MOF composite material was attracted by a magnet, the ciprofloxacin aqueous solution was discarded, and the adsorbed magnetic MOF composite material was washed with 2 mL of methanol (chromatographic grade). The methanol solution was then discarded, and the obtained magnetic MOF composite material was reserved for the next cycle. After five cycles of adsorption, the experimental results are shown in […]. Figure 14 , Figure 15 and Figure 16 As shown.

[0140] Depend on Figure 14 It can be seen that after five cycles of adsorption, the removal rates of ciprofloxacin by Fe3O4 / Cu3(BTC)2 were 61.20%, 28.55%, 26.30%, 22.40%, and 16.50%, respectively, and the removal rates of ciprofloxacin by Fe3O4 / Zn3(BTC)2 were 60.60%, 54.75%, 46.55%, 41.15%, and 31.45%, respectively.

[0141] Depend on Figure 15 It can be seen that when methanol is used as a solvent to clean the magnetic MOFs composite material after cyclic adsorption, the recovery rates of ciprofloxacin adsorbed by Fe3O4 / Cu3(BTC)2 are 10.45%, 11.40%, 8.00%, 12.00%, and 12.80%, respectively, and the recovery rates of ciprofloxacin adsorbed by Fe3O4 / Zn3(BTC)2 are 30.85%, 30.35%, 19.65%, 17.60%, and 13.30%, respectively.

[0142] The magnetic MOF composite material after five cycles of use was washed several times with ultrapure water, dried at 80°C, and the resulting solid powder was characterized by SEM. The results are as follows. Figure 16 As shown.

[0143] The results showed that after five cycles of use, irregular particles adhered to the surface of Fe3O4 / Cu3(BTC)2, and the morphology changed, blocking the original channels of Fe3O4 / Cu3(BTC)2 and causing the material to clump. Fe3O4 / Zn3(BTC)2 lost its original rod-shaped structure, but a uniform pore structure still existed on the surface.

[0144] Comparing the repeatability experiments of Fe3O4 / Cu3(BTC)2 and Fe3O4 / Zn3(BTC)2 on the adsorption of ciprofloxacin, it can be seen that Fe3O4 / Zn3(BTC)2 has better repeatability and certain economic applicability. It can be further modified to improve its removal rate of ciprofloxacin.

[0145] As can be seen from the above:

[0146] (1) The present invention uses hydrothermal method to synthesize magnetic MOFs composite materials and performs a series of characterizations. The results show that the MOFs materials modified by magnetic nanoparticles Fe3O4 still retain the original crystal structure. The prepared magnetic MOFs composite materials all have pores on the surface and have a porous structure, which is conducive to the adsorption of target substances.

[0147] (2) The magnetic MOF composite material synthesized in this invention was used as an adsorbent to study its adsorption application in ciprofloxacin and ibuprofen solutions. The adsorption and degradation effect of the magnetic MOF composite material was analyzed by measuring the peak area of ​​ciprofloxacin and ibuprofen solutions using high-performance liquid chromatography (HPLC) based on the shaking time, initial pH value of the solution, and the initial pH value. The results showed that the magnetic MOF composite material had a moderate adsorption effect on ibuprofen, with a removal rate of only 14.55-24.30%. When pH = 3.84, with an input amount of 40 mg, Fe3O4 / Zn3(BTC)2 showed a good adsorption effect on ciprofloxacin, with a removal rate of up to 72.15%.

[0148] (3) After being used 5 times, Fe3O4 / Zn3(BTC)2 achieved a ciprofloxacin removal rate of 31.45%. The scanning electron microscope characterization showed that it still had a relatively uniform pore structure, indicating that it has certain green application prospects and can be further modified and optimized to improve its stability and repeatability.

[0149] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The use of a magnetic MOF composite material for adsorbing drugs used in environmental sample water treatment, characterized in that, The magnetic MOF composite material is mixed with the drug under aqueous conditions and then adsorbs the drug. The drug removal rate of the magnetic MOF composite material is more than 10%. The drug is selected from at least one of ciprofloxacin, enrofloxacin, and ofloxacin. The magnetic MOFs composite material comprises a functional core and a metal-organic framework material; the magnetic MOFs composite material is prepared by the following method: the functional core, metal source, and organic ligand are in a solvent, and the metal-organic framework material is loaded onto the surface of the functional core by a hydrothermal synthesis method; the molar ratio of the functional core, metal source, and organic ligand is 1:2 to 4:6; The functional core is made of Fe3O4 nanorods with a length of 200-500 nm. The metal-organic framework material comprises a metal element and an organic ligand; the metal element is selected from Zn; and the organic ligand is selected from 1,3,5-benzenetricarboxylic acid.

2. The use according to claim 1, characterized in that, The magnetic MOFs composite material has a porous structure; The pore structure includes mesoporous structures and / or microporous structures.

3. The use according to claim 1, characterized in that, The Fe3O4 nanorods are 200 nm in length.

4. The use according to claim 1, characterized in that, The solvent is selected from at least one of water, N,N dimethylformamide, ethanol, and methanol; The metal source is selected from at least one of the acetates and chlorides of a metal element.

5. The use according to claim 1, characterized in that, The conditions for the hydrothermal synthesis method include: a reaction temperature of 50-100℃ and a reaction time of 0.1-10 h.

6. The use according to claim 1, characterized in that, During adsorption, the ratio of the magnetic MOF composite material to the drug is 1-100:0.1-1.

7. The use according to claim 1, characterized in that, During adsorption, shaking or pH adjustment methods are also used to promote the adsorption effect; The oscillation time is 1-200 min; pH adjustment involves using acid-base regulators.

8. The use according to claim 1, characterized in that, The magnetic MOF composite material has a drug removal rate of over 50%.

9. The use according to claim 1, characterized in that, The magnetic MOF composite material can be reused for drug adsorption after being treated with detergent.

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