Temperature-responsive ion imprinting magnetic mesoporous microspheres, preparation method and application thereof in selective capture of uranium in high-salt wastewater

Abstract

The present application relates to a kind of temperature response type ion imprinted magnetic mesoporous microspheres and its application in selectively capturing uranium in high-salt wastewater;The preparation method of the present application comprises the following steps: first, magnetic mesoporous silica nanospheres are prepared, and imprinted microspheres are synthesized on the shell of magnetic mesoporous silica (Fe3O4@mSiO2) by free radical polymerization with uranium ions as template ions;The heat response structure of the adsorbent can effectively realize U (VI) desorption by changing temperature, which provides a solution to solve secondary pollutants and material damage in high-salinity uranium-containing wastewater treatment, and is expected to be widely used in high-salt wastewater and uranium extraction from seawater.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear pollutant treatment, and particularly relates to preparation of temperature-responsive ion imprinting magnetic mesoporous microspheres and application thereof in selective capture of uranium in high-salinity wastewater. BACKGROUND

[0002] As an important nuclear energy raw material, uranium brings about environmental pollution problems with the rapid development of nuclear energy industry, and a large amount of high-salinity and high-radioactivity uranium-containing wastewater seriously threatens human health. Therefore, development of a new material and new process with high selectivity for extracting uranium from high-salinity uranium-containing wastewater is an urgent problem to be solved in the current international society.

[0003] At present, the capture of uranium (VI) mainly includes chemical precipitation, ion exchange, evaporation and solvent extraction. Although these methods are effective, they often require high cost investment, thereby weakening the economic and technological attractiveness. In recent years, solid-phase adsorption has attracted much attention due to its economy and convenience. Existing solid-phase uranium adsorption research mainly focuses on polyimine dioxime, graphene oxide, mesoporous molecular sieve and metal-organic framework, and magnetic adsorption material.

[0004] However, high salinity and coexisting nuclides make these methods have low selectivity and slow adsorption speed, and there are challenges in designing adsorbents suitable for seawater pH. In addition, adsorbents containing strong affinity ligands often require the use of high-concentration acidic solution, thereby causing secondary pollution and seriously polluting the environment. In view of this problem, how to design and regulate the adsorption material to realize the selective enrichment of high-salinity uranium ions in seawater is still a difficulty in the current research in the field.

[0005] Ion imprinted polymers (IIPs) are considered as a promising adsorbent for uranium (VI) due to their high selectivity and affinity for target ions. They show a broad application prospect in the treatment of radionuclides in high salinity low level waste (SLLWs). For example, Hua et al. synthesized a uranyl ion imprinted adsorbent based on biological dopamine and sodium alginate, which has better selectivity for uranium (VI) ions than non-imprinted polymers, showing a broad application prospect in the treatment of radionuclides in high salinity low level waste (SLLWs). However, it is difficult to remove the template by traditional ion imprinting technology. In recent years, surface ion imprinting technology (SIIT) has attracted much attention due to its unique ion coordination configuration, more easily accessible adsorption sites, and other advantages. Sodium phytate (SP), one of the phytic acid (PA) derivatives, can be used as a good hard base to bind uranium (VI) in seawater due to its structure containing 6 phospholipids. The positively charged sodium ions help to adjust the surface properties of the material to better adsorb U(VI) at the appropriate seawater pH. These characteristics can be integrated into the synthesis of ion imprinted polymers.

[0006] However, the desorption of IIPs usually requires a large amount of acid to elute uranium from adsorbents with strong affinity ligands, which causes more secondary pollutants and material damage. Therefore, it is necessary and extremely urgent to find alternative ion imprinting technology elution schemes. Based on the related patents of temperature-sensitive materials in the field of high salinity uranium ion selective adsorption and desorption, there is no report so far.

[0007] In view of the above technical problems, improvement is needed. SUMMARY

[0008] The technical problem to be solved by the present application is that in the prior art, a large amount of acid is generally required to elute uranium from the adsorbent with a strong affinity ligand, which causes more secondary pollutants and material damage. Therefore, it is necessary and extremely urgent to find an alternative ion imprinting technology elution scheme. At present, many studies have reported that Pluronic tri-block copolymer (Pluronic F-127) is one of the most widely used temperature-sensitive polymers, and its critical solution temperature (CMT) is relatively low, about 298K. The contraction and expansion state of the Pluronic F-127 polymer chain is reversible with temperature change. When the temperature is higher than 298K, the polymer chain is not dissolved, and when the temperature is lower than 298K, the polymer chain is dissolved and expanded in the aqueous solution. However, there is no related patent report in the field of high-salinity uranium ion selective adsorption and desorption at present, so this new method based on temperature-sensitive materials has innovation and important significance. Through the agglomeration and separation of micelles at different temperatures, the adsorption and elution of toxic pollutants are realized. Therefore, the thermal response structure of the adsorbent can be effectively desorbed by changing the temperature, thereby solving the problems of secondary pollutants and material damage in the treatment of high-salinity uranium-containing wastewater, and having important value for the preparation of temperature-sensitive U(VI) adsorbents and the selective capture and controllable release of uranium in high-salinity wastewater.

[0009] In order to achieve the above-mentioned objects and other advantages according to the present application, a temperature-responsive ion imprinting magnetic mesoporous microsphere is provided, characterized in that it comprises magnetic mesoporous silica microspheres and temperature-sensitive uranium ion imprinting polymers polymerized on the magnetic mesoporous silica microspheres; the magnetic mesoporous silica microspheres comprise magnetic Fe3O4 particles in the core-shell and SiO2 mesoporous layers outside the core-shell.

[0010] A preparation method of a temperature-responsive ion imprinting magnetic mesoporous microsphere comprises the following steps:

[0011] Step 1: preparing monodisperse Fe3O4 nanoparticles by a hot solvent method;

[0012] Step 2: preparing magnetic mesoporous microspheres Fe3O4@mSiO2 with different sizes, pore sizes and specific surface areas by adjusting the amount of silicon source, the ratio of surfactants and the reaction time;

[0013] Step 3: using SP and uranyl ions as functional monomers, and synthesizing ion imprinting polymers with uranium ions as template ions on the magnetic mesoporous microspheres Fe3O4@mSiO2 by free radical polymerization;

[0014] Step 4: adding silane coupling agent KH560, temperature-sensitive polymer Pluronic F-127 and magnetic mesoporous microspheres Fe3O4@mSiO2 into the above solution to prepare a precursor of the uranium ion imprinted magnetic mesoporous silica composite material;

[0015] Step 5: eluting the product with hydrochloric acid and EDTA to remove UO2 2+ A temperature-responsive ion imprinted magnetic mesoporous microsphere (Fe3O4@mSiO2@UIIP) is prepared.

[0016] Preferably, the iron source used in step 1 is at least one of ferric chloride and ferric sulfate; and the silicon source in step 2 is an organosiloxane.

[0017] Preferably, the surfactant in step 2 includes cetyltrimethylammonium bromide and fluorion surfactant FS-66.

[0018] Preferably, step 2 of preparing the magnetic mesoporous microsphere Fe3O4@mSiO2 specifically includes the following steps:

[0019] Step 2.1: mixing cetyltrimethylammonium bromide, triethanolamine and ultrapure water in a ratio of 0.6:0.1:30 and stirring at 50-60°C for 30-60 minutes to prepare a CTAB template solution;

[0020] Step 2.2: according to the mass ratio of FS-66 to cetyltrimethylammonium bromide of 0.1:1, FS-66 surfactant is weighed and dissolved in isopropyl alcohol to prepare a solution with a concentration of 0.15-0.30 g / mL;

[0021] Step 2.3: adding the solution in step 2.2 to the aforementioned CTAB template solution and continuing to stir for 1-2 hours;

[0022] Step 2.4: adding TEOS in a ratio of 10-15 mLTEOS / g cetyltrimethylammonium bromide, and stirring for 1-2 minutes to obtain a double-template solution;

[0023] Step 2.5: mixing the double-template solution with the magnetic microsphere dispersion liquid in a ratio of 2:1, then ultrasonic treatment for 3-5 minutes, followed by oscillation on a circular shaker at a speed of r=500-700 r / min for 30-60 minutes, and then shaking at a speed of r=200-300 r / min for 6-8 hours;

[0024] Step 2.6: separating the product and removing the template solution, and adding a saturated ammonium nitrate ethanol solution to oscillate and wash for 10-12 hours;

[0025] Step 2.7: The obtained solid product is washed with anhydrous ethanol and water for 3 times respectively, and dried to obtain the flower-shaped core-shell magnetic mesoporous microspheres.

[0026] Preferably, in step 2.5, the concentration of Fe3O4@mSiO2 magnetic microspheres in the magnetic microsphere dispersion liquid is 0.01 g / mL.

[0027] Preferably, in step 4, the total amount of Pluronic F-1270.1 g, silane coupling agent (KH560) and ethanol mixture is 11 mL, and the volume ratio of the silane coupling agent (KH560) and ethanol mixture is 1:10.

[0028] Preferably, in step 4, after adding each component, the mixture is ultrasonically treated for 5 minutes to fully mix, and then polymerization is carried out by stirring in a water bath at 80℃ for 3 hours to obtain the precursor of the uranium ion imprinted magnetic mesoporous silica composite material.

[0029] Preferably, the specific steps in steps 3 and 4 are: by using different SP / Pluronic F-127 molar ratios (Table 1), samples are synthesized by the above method and compared. In comparison, non-imprinted magnetic microspheres (Fe3O4@mSiO2@NIP) without uranyl ions and imprinted polymers (UIIP) without Fe3O4@mSiO2 are also synthesized. In order to study the adsorption thermodynamics of SP for uranium (VI), phosphonic acid functional uranyl ion imprinted magnetic microspheres (Fe3O4@mSiO2@SP) are synthesized without the addition of Pluronic F-127.

[0030] Table 1 Different feeding ratios for synthesizing Fe3O4@mSiO2@UIIP.

[0031]

[0032] Preferably, in step 4, the reaction conditions of the precursor of the uranium ion imprinted magnetic mesoporous silica composite material are: Pluronic F-127 (0.1 g), silane coupling agent (KH560) and ethanol mixture (11 mL, V / V, 1:10) are added to the uranium ion polymer prepared in step 3. The above mixture is ultrasonically treated for 5 minutes to fully mix, and then polymerization is carried out by stirring in a water bath at 80℃ for 3 hours.

[0033] In order to achieve the above purpose, the application also provides the use of the temperature-responsive ion imprinted magnetic mesoporous microspheres in the selective capture and controllable release of uranium in high-salt wastewater.

[0034] Preferably, the use of temperature-assisted elution of uranyl ions at 308 K can avoid environmental pollution caused by the use of a large amount of eluent. The desorption efficiency of uranium is high when 0.01 mol / L HCl is used as the eluent, which is an economical and feasible elution method.

[0035] Preferably, this application covers the process of selectively capturing U(VI) in high-salinity wastewater and achieving temperature-sensitive controlled release of U(VI). Compared with the prior art, the significant advantages of the present application are:

[0036] 1. This invention uses a new preparation process to successfully synthesize a temperature-responsive ion imprinted magnetic mesoporous microsphere Fe3O4@mSiO2@UIIP, and apply it to the selective capture of U(VI) in high-salinity wastewater. Among them, Fe3O4@mSiO2@UIIP-2 has a larger adsorption capacity (q max = 537.63 mg / g) and fast adsorption kinetics (adsorption equilibrium is reached within 60 min), which is attributed to the unique mesoporous structure of Fe3O4@mSiO2@UIIP-2 and the synergistic effect between U(VI) and ion imprinted material.

[0037] 2. The adsorption process of temperature-responsive ion imprinted magnetic mesoporous microsphere Fe3O4@mSiO2@UIIP-2 to U(VI) follows the pseudo-second-order kinetics equation, and the adsorption isotherm conforms to the Langmuir model. It is worth noting that the presence of coexisting ions does not affect the capture efficiency of U(VI). The study of adsorption mechanism shows that the interaction between the phosphonic acid groups on the surface of Fe3O4@mSiO2@UIIP-2 and U(VI) plays a dominant role in the adsorption process.

[0038] 3. This invention realizes efficient elution by regulating the elution temperature, avoiding the secondary pollution that may be caused by the use of a large amount of eluent. In addition, the adsorbent is recovered by magnetic separation technology, greatly reducing the cost. This invention not only develops a high-efficiency U(VI) adsorbent with good selectivity and reusability in high-salinity wastewater, but also realizes effective U(VI) desorption by regulating the temperature based on the thermal response structure of the adsorbent. This provides a solution to the problem of secondary pollution and material damage that may occur in the treatment of high-salinity uranium-containing wastewater. This technology is expected to be widely used in the field of high-salinity wastewater and seawater uranium extraction. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a schematic diagram of the preparation process of the temperature-responsive ion imprinted magnetic mesoporous microsphere of the present invention;

[0040] Figure 2The adsorption of the temperature-responsive ion imprinted magnetic mesoporous microspheres on U(VI) under different temperature conditions is shown.

[0041] Figure 3 Fig. 1 is a scanning electron microscope image of the temperature-responsive ion imprinted magnetic mesoporous microspheres, wherein a is a scanning electron microscope image of Fe3O4@mSiO2@UIIP-1, b is a scanning electron microscope image of Fe3O4@mSiO2@UIIP-2, and c is a scanning electron microscope image of Fe3O4@mSiO2@UIIP-3;

[0042] Figure 4 Fig. 2 is a graph for evaluating the adsorption capacity of Fe3O4@mSiO2@UIIP-2 on U(VI), wherein a is the influence of adsorption time on the adsorption of Fe3O4@mSiO2@UIIP-2 on U(VI), and b is a pseudo-first-order and pseudo-second-order kinetic model of the adsorption of Fe3O4@mSiO2@UIIP-2 on U(VI);

[0043] Figure 5 Fig. 3 presents an ion competition experiment of the temperature-responsive ion imprinted magnetic mesoporous microspheres in a high-salt wastewater environment, which aims to explore the adsorption capacity thereof, wherein a is the influence of salinity on the adsorption of Fe3O4@mSiO2@UIIP-2 and Fe3O4@mSiO2@NIP on U(VI), and b is the K d value of various ions;

[0044] Figure 6 Fig. 4 shows the results of the verification of the cyclic adsorption-desorption performance of the temperature-responsive ion imprinted magnetic mesoporous microspheres Fe3O4@mSiO2@UIIP-2 of the present application, wherein a is the desorption efficiency of different eluents at 288 and 308 K, and b is a cyclic adsorption-desorption graph of the temperature-responsive ion imprinted magnetic mesoporous microspheres for 8 times; DETAILED DESCRIPTION

[0045] In order to make the present application more apparent and easy to understand, the preferred embodiments are described in detail below with reference to the accompanying drawings.

[0046] Example 1: Preparation of a temperature-responsive ion imprinted magnetic mesoporous microsphere, the preparation process is as shown in Figure 1 Fig. 1, which comprises the following steps:

[0047] Preparation of Fe3C>4: FeCl3-6H2O (1.62 g), PSSMA (1.50 g), anhydrous sodium acetate (4.50 g) and calcium fluoride (0.50 g) were added to ethylene glycol (60 mL) solution, respectively, and to make the solution well mixed, we put the solution in a constant temperature water bath at 60 °C and continue to stir for 2 hours. Then, it was transferred to an autoclave (lined with polytetrafluoroethylene) and reacted at a reaction temperature of 220 °C for 15 hours. After the reaction was completed, the reaction kettle was cooled to room temperature, and then the black precipitated reaction product was washed once with anhydrous ethanol and three times with deionized water (DI), and finally dried in a 60 °C air-drying oven for 12 hours to obtain Fe3C>4 nanospheres.

[0048] Preparation of Fe3C>4@SiO2: Deionized water (10 mL), NaF solution (0.5 mL) (wt. 1%) and TEOS (0.3 mL) were added to the ethanol dispersion of Fe3C>4 microspheres (3 mL) (about 0.1 g of Fe3C>4 microspheres), and then continue to shake at 500 r / min on a digital circular shaker for 15 hours. After the reaction was completed, the product was washed repeatedly with anhydrous EtOH and deionized H2O for 3 times, and finally dried in a 60 °C air-drying oven for 12 hours to obtain the product.

[0049] Synthesis of Fe3C>4@mSiO2 nanospheres: CTAB (0.64 g) and TEA (0.12 mL) were added to deionized water (33.3 mL) and stirred at 60 °C for 15 minutes, then FS-66 (0.13 g) was added and stirred for 1 hour. Finally, the precursor of silica TEOS (5 mL) was added to the template solution and stirred for 2 minutes to obtain a double-template surfactant solution containing a silicon source. The above double-surfactant solution (10 mL) was added to the water dispersion of Fe3C>4@SiO2 (0.05 g), treated with ultrasonic wave for 3 minutes, and then stirred at 250 r / min on a digital circular shaker for 5 hours. After the reaction was completed, the product was washed repeatedly with anhydrous ethanol and deionized water for 3 times to obtain Fe3C>4@mSiO2 nanospheres. Finally, dried in a 60 °C air-drying oven for 12 hours to obtain Fe3C>4@mSiO2 magnetic nanospheres.

[0050] Synthesis of temperature-responsive ion-imprinted magnetic mesoporous microspheres Fe3C>4@mSiO2@UIIP: As Figure 1, the prepared Fe3O4@mSiO2(0.1 g) was first suspended in ethanol (10 mL) by ultrasonication, the pH of the solution was adjusted to 6 with HNO3, then functional monomer SP (0.2 mmol) and template UO2(NO3)2·6H2O (0.1 mmol) were added, and the mixture was continuously stirred at room temperature for 2 h under nitrogen. Then a mixture of Pluronic F-127 (0.1 g), silane coupling agent (KH560) and ethanol (11 mL, V / V, 1:10) was added. The mixture was ultrasonicated for 5 min to ensure a homogeneous mixture, and then was stirred at 80 °C for 3 h for polymerization. After the reaction, the product was magnetically separated with a magnet, and then was eluted with 0.1 M HCl and 0.1 M EDTA, respectively, until no UO2 2+ Next, the product was washed with ethanol and ultrapure water for 3 times, respectively, and vacuum dried at 50 °C for 12 h to obtain the U(VI) ion imprinted polymer Fe3O4@mSiO2@UIIP microspheres. By adjusting different SP / Pluronic F-127 molar ratios, comparable samples were synthesized by the same method as described above.

[0051] Example 2: Batch adsorption experiments:

[0052] 10.0 mg of adsorbent was dispersed in UO2(NO3)2·6H2O aqueous solution (20.0 mL) and shaken on a constant temperature shaker for different times to conduct adsorption kinetics experiments. To investigate its adsorption capacity, isotherm adsorption experiments were conducted on uranyl with an initial concentration of 50-500 mg / L at pH = 8. The thermodynamics of Fe3O4@mSiO2@UIIP-2 was studied in uranium solution (pH = 8 and 400 mg / L) at 288.15 K, 298.15 K, and 308.15 K, respectively. In the experiment, the pH value of the uranium solution was adjusted with HNO3 (2 mol / L) and sodium carbonate solution (2 mol / L). After adsorption, the filtrate was filtered with a 0.22 μm filter, and the concentration of U(VI) in the filtrate was determined at 652 nm by ultraviolet-visible spectrophotometry (UV-765100B, Metash, Shanghai) with arsenazo III as a chromogenic agent. The determination of multi-component ion concentration was performed by inductively coupled plasma optical emission spectrometry (ICP-OES).

[0053]

[0054]

[0055]

[0056] wherein C0(mg / g) is the initial value of U(VI) solution, C t，e(mg / g) is t time U(VI) concentration, M(mg) is adsorbent dosage, V(mL) is solution volume, W% is adsorption efficiency.

[0057] The results of the experiment show that (as Figure 2 and Figure 4 ), Fe3O4@mSiO2@UIIP-2 has higher selectivity and faster adsorption kinetics, and the equilibrium adsorption capacity within 60 min at 298 K is 537.63 mg / g. The adsorption isotherm conforms to the Langmuir model, and the adsorption kinetics conforms to the pseudo-second-order rate equation.

[0058] Example 3: High-salinity wastewater and ion competition experiment:

[0059] High concentrations of Cl - , SO4 2- , NO3 - , CO3 2- and other salinity are one of the main challenges for the separation of uranium from high-salinity radioactive wastewater. Therefore, we use NaCl (1 mol / L), Na2SO4 (1 mol / L), NaNO3 (1 mol / L) and Na2CO3 (1 mol / L) to simulate SLLWS.

[0060] With 1 mol / L NaCl, NaNO3, Na2SO4 and Na2CO3 as solvents, the effect of salinity was investigated. In the mixed solution of ZnCl2, SrCl2·6H2O, MnCl2, Cd(NO3)2, Ni(NO3)2·6H2O, MgSO4, Cu(NO3)2, Pb(NO3)2, Ba(NO3)2, AlCl3, CrCl3·6H2O, EuCl3·6H2O and UO2(NO3)2·6H2O, 10.0 mg of adsorbent was used for competitive adsorption.

[0061] The results of the experiment show that (as Figure 5 ), the uranium ion imprinted adsorbent Fe3O4@mSiO2@UIIP-2 has good salt tolerance, which is due to the high affinity between the imprinted cavity and uranium. In the ion competition experiment, a more stable complex is formed between U(VI) and the phospholipid group of Fe3O4@mSiO2@UIIP-2, indicating that the selectivity of Fe3O4@mSiO2@UIIP-2 for uranyl ions is much higher than that of other cations.

[0062] Example 4: Regeneration and repeatability experiment:

[0063] In the regeneration test, Fe3O4@mSiO2@UIIP-2-U (10.0 mg) after adsorption was added to the eluent for elution experiment. In order to determine the effective eluent, 0.01 M HCl (10.0 mL) and 0.01 M EDTA (10.0 mL) (10.0 mL) solution were used to elute for 6 h at 308 K, respectively. The resulting suspension was separated by magnet, washed with water until the supernatant became neutral. The concentration of uranium in the eluent was determined by ICP-MS, and the desorption efficiency of Fe3O4@mSiO2@UIIP-2 was evaluated. In order to test the reusability of Fe3O4@mSiO2@UIIP-2, the adsorption-desorption cycle was repeated for 8 times, and the adsorption capacity of each time was recorded.

[0064] The results of the experiment show that (as shown in Figure 6 ), the desorption efficiency of uranium is higher at 308 K with 0.01 mol / L HCl as eluent. The use of temperature-assisted elution can avoid environmental pollution caused by the use of large amounts of eluent, which is an economical and feasible elution method. It can be found that after 8 adsorption-desorption cycles, the adsorption efficiency (SE%) does not decrease significantly. The results show that U(VI) in Fe3O4@mSiO2@UIIP-2 can be completely washed out with 0.01 mol / L HCl.

[0065] The above examples are only preferred embodiments of the present application, and are not any form and substantial limitation of the present application. It should be noted that for ordinary skilled in the art, without departing from the present application, a number of improvements and supplements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres, characterized in that: The magnetic mesoporous microspheres comprise magnetic mesoporous silica microspheres and temperature-sensitive uranium ion imprinted polymers polymerized on the magnetic mesoporous silica microspheres; the magnetic mesoporous silica microspheres comprise magnetic Fe3O4 particles in the core-shell and SiO2 mesoporous layers outside the core-shell; The preparation method of the magnetic mesoporous microspheres comprises the following steps: Step 1: preparing monodisperse Fe3O4 nanoparticles by a hot solvent method; Step 2: preparing magnetic mesoporous microspheres Fe3O4@mSiO2 with different sizes, pore diameters and specific surface areas by adjusting the amount of silicon source, the ratio of surfactants and the reaction time; Step 3: synthesizing imprinted polymers with uranium ions as template ions on the magnetic mesoporous microspheres Fe3O4@mSiO2 by free radical polymerization with SP and uranyl ions as functional monomers; Step 4: adding a mixture of silane coupling agent KH560, temperature-sensitive polymer Pluronic F-127 and ethanol into the imprinted polymer solution obtained in Step 3 to prepare a precursor of uranium ion imprinted magnetic mesoporous silica composite material; Step 5: The precursor of the prepared uranium ion imprinted magnetic mesoporous silica composite material was washed with hydrochloric acid and EDTA to remove UO2 2+ Temperature-responsive ion imprinted magnetic mesoporous microspheres Fe3O4@mSiO2@UIIP were prepared.

2. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 1, characterized in that: The iron source used in Step 1 is at least one of ferric chloride and ferric sulfate; and the silicon source in Step 2 is an organosiloxane.

3. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 1, characterized in that: The surfactants in Step 2 include cetyltrimethylammonium bromide and fluorion surfactant FS-66.

4. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 3, characterized in that: In Step 2, the preparation of the magnetic mesoporous microspheres Fe3O4@mSiO2 specifically comprises the following steps: Step 2.1: mixing cetyltrimethylammonium bromide, triethanolamine and ultrapure water according to a ratio of 0.6:0.1:30, and stirring at 50-60℃ for 30-60 minutes to prepare a CTAB template solution; Step 2.2: according to a mass ratio of FS-66 to cetyltrimethylammonium bromide of 0.1:1, weighing the FS-66 surfactant, dissolving it in isopropyl alcohol to prepare a solution with a concentration of 0.15-0.30 g / mL; Step 2.3: adding the solution in Step 2.2 into the aforementioned CTAB template solution and continuing to stir for 1-2 hours; Step 2.4: adding TEOS according to a ratio of 10-15 mL TEOS / g cetyltrimethylammonium bromide, and stirring for 1-2 minutes to obtain a double-template solution; Step 2.5: mixing the double-template solution with the magnetic microsphere dispersion liquid according to a ratio of 2:1, then performing ultrasonic treatment for 3-5 minutes, then oscillating on a circular oscillator at a rate of r=500-700 r / min for 30-60 minutes, and then shaking at a rate of r=200-300 r / min for 6-8 hours; Step 2.6: separating the product and removing the template solution, and adding a saturated ammonium nitrate ethanol solution to oscillate and wash for 10-12 hours; Step 2.7: washing the obtained solid product with anhydrous ethanol and water for 3 times respectively, and drying to obtain the flower-shaped core-shell magnetic mesoporous microspheres.

5. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 4, characterized in that: In Step 2.5, the concentration of Fe3O4@mSiO2 magnetic microspheres in the magnetic microsphere dispersion liquid is 0.01 g / mL.

6. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 2, characterized in that: In the step 4, Pluronic F-127 0.1 g, a mixture of silane coupling agent KH560 and ethanol with a total volume of 11 mL, and a volume ratio of 1:10 were added.

7. The method for preparing temperature-responsive ion-imprinted magnetic mesoporous microspheres as described in claim 6, characterized in that: In the step 4, after adding each component, ultrasonic treatment was performed for 5 minutes to fully mix, and then polymerization was performed by stirring in a water bath at 80°C for 3 hours to obtain a precursor of the uranium ion imprinted magnetic mesoporous silica composite material.

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