A poly(amidoxime-ethyleneimine) modified foam-like mesoporous silica and preparation and application thereof

Abstract

This invention discloses a poly(amylated oxime-ethyleneimine) modified foam-like mesoporous silica, its preparation, and its application, belonging to the fields of environmental energy chemistry and new materials technology. Firstly, using Pluronic P123 / mesotriene as a pore-forming / expanding agent and tetraethyl silicate as a raw material, foam-like mesoporous silica is obtained through hydrolysis, aging, high-temperature pore expansion, and calcination. After activation, epoxy-modified foam-like mesoporous silica is obtained through a silanization reaction. Subsequently, polyethyleneimine-modified foam-like mesoporous silica is prepared by reacting amino groups with epoxy groups. Then, it is reacted with acrylonitrile to obtain poly(acrylonitrile-ethyleneimine) modified foam-like mesoporous silica. Finally, it is reacted with NH2OH·HCl to obtain poly(amylated oxime-ethyleneimine) modified foam-like mesoporous silica. The poly(amylated oxime-ethyleneimine) modified foam-like mesoporous silica of this invention exhibits extremely high adsorption capacity and extremely fast adsorption rate for uranyl ions, and demonstrates high affinity, selectivity, and good reusability, making it applicable to large-scale seawater uranium extraction projects.

Description

Technical Field

[0001] This invention relates to the preparation and application of poly(geminoxime-ethyleneimine) modified foam-like mesoporous silica for selective enrichment and extraction of uranium ions from simulated and real seawater, belonging to the fields of environmental energy chemistry and new materials technology. Background Technology

[0002] Nuclear power, as a highly efficient and clean energy source, is gradually becoming an important guarantee for my country to adjust its energy structure, achieve coordinated economic and environmental development, and promote industrial upgrading. However, my country's uranium reserves are not abundant, with proven onshore uranium reserves of only about 200,000 tons, which is insufficient to meet the needs of my country's nuclear power development over the next 10-15 years. Therefore, uranium resource supply has become a significant constraint on the large-scale development of nuclear power in my country. Developing unconventional uranium resources is of great importance to ensure the sustainable development of nuclear power in my country.

[0003] The world's oceans contain approximately 4.5 billion tons of uranium, thousands of times the proven uranium reserves on land, making it an inexhaustible resource. Currently, seawater uranium extraction is considered one of the most challenging yet most rewarding nuclear fuel resource development projects, and has even been named one of the "seven world-changing chemical separation technologies" by *Nature*. my country started its research on seawater uranium extraction applications relatively late. However, with the country's positioning of future energy development and its deployment of marine resource development, several domestic research institutions have successively carried out the design and research and development of seawater uranium extraction materials in recent years. However, most of this research is still in the experimental verification stage.

[0004] Currently, there is a high level of global attention and efforts to advance research on seawater uranium extraction technology. However, the application of this technology still faces some insurmountable bottlenecks. Firstly, the poor uranium extraction capacity of the developed adsorption materials in real seawater is one of the most critical issues. Existing seawater uranium extraction materials have a theoretical adsorption capacity of over 1000 mg U / g, but their uranium extraction efficiency in real seawater is less than 1% of that. This is because uranium in seawater primarily exists as the highly stable uranyl tricarbonate complex ion [UO2(CO3)3]. 4- The presence of uranium ions in seawater, at extremely low concentrations (approximately 3.3 μg / L), makes them difficult for adsorbents to capture. Furthermore, the high concentrations of coexisting metal ions in seawater significantly reduce the material's adsorption capacity for uranium. Secondly, the currently assessed cost of seawater uranium extraction is still far higher than that of uranium extraction from terrestrial uranium mines, rendering it commercially unfeasible. Currently, no country in the world possesses commercially available seawater uranium extraction technology. Therefore, developing more efficient uranium extraction materials, improving their adsorption capacity, selectivity, and affinity for uranium ions, while simultaneously accelerating and improving the adsorption rate and reusability of these materials, will significantly optimize and enhance their seawater uranium extraction performance and reduce operating costs. This will provide a technological reserve for the long-term development of my country's seawater uranium extraction industry. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a poly(aminoxime-ethyleneimine) modified foam mesoporous silica, its preparation and application. The poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared by this invention has extremely high adsorption capacity and extremely fast adsorption rate for uranyl ions in simulated seawater and real seawater.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing poly(geminoxime-ethyleneimine) modified foam-like mesoporous silica mainly includes the following steps:

[0008] (1) Dissolve 2-50g of Pluronic P123 in 50-500mL of HCl aqueous solution, add 3-60g of mesitylene, stir at 20-80℃ for 0.5-6h, then add 5-100mL of tetraethyl silicate, stir for 2-20min, age for 5-80h, add 20-500mg of NH4F, mix well, transfer to a high-pressure reactor, and continue aging at 60-200℃ for 6-48h. Filter the obtained precipitate and wash it with deionized water and ethanol respectively, dry it, and then calcine the obtained solid material at 200-800℃ for 2-18h to obtain foamy mesoporous silica.

[0009] (2) Disperse 5-50g of the foam-like mesoporous silica obtained in step (1) into 50-500mL of HCl aqueous solution and stir for 3-48h. Then filter and wash with deionized water until neutral. After drying, disperse in 50-500mL of dry toluene. Under inert gas protection, add 5-50mL of 3-epoxypropoxytriethoxysilane to the foam-like mesoporous silica toluene dispersion and stir and reflux at 100-140℃ for 3-48h. Filter the obtained material and wash with dry toluene and ethanol respectively. After drying, obtain epoxy-modified foam-like mesoporous silica.

[0010] (3) Dissolve 5-50g of polyethyleneimine in 50-500mL of methanol / water mixture, add 5-50g of epoxy-modified foam mesoporous silica obtained in step (2), and then stir and reflux at 60-100℃ for 1-8h; filter the obtained material and wash it with deionized water and ethanol respectively, and dry it to obtain polyethyleneimine-modified foam mesoporous silica.

[0011] (4) Disperse 2-20g of the polyethyleneimine-modified foamed mesoporous silica obtained in step (3) into 20-200mL of methanol, add 4-40mL of acrylonitrile under inert gas protection, and stir and reflux at 40-80℃ for 6-24h; filter the obtained material and wash it with ethanol, and dry it to obtain poly(acrylonitrile-ethyleneimine) modified foamed mesoporous silica;

[0012] (5) Dissolve 2-20g of NH2OH·HCl in 20-200mL of methanol / water mixture and adjust the pH to neutral. Then disperse 2-20g of poly(acrylonitrile-ethyleneimine) modified foam mesoporous silica in it and stir and reflux at 60-100℃ for 1-8h. Filter the obtained material and wash it with deionized water and ethanol respectively. After thorough drying, poly(aminoxime-ethyleneimine) modified foam mesoporous silica is obtained.

[0013] Based on the above technical solution, further, the average molecular weight of Pluronic P123 in step (1) is 5800; the concentration of the HCl aqueous solution is 0.4-4M; the calcination temperature is 500-700℃; and the calcination time is 4-8h.

[0014] Based on the above technical solution, further, the concentration of the HCl aqueous solution in step (2) is 2-4M.

[0015] Based on the above technical solution, further, the polyethyleneimine mentioned in step (3) has an average molecular weight of 600, 1800, 10000, 25000 or 70000.

[0016] Based on the above technical solution, the inert gas mentioned in steps (2) and (4) further includes nitrogen, argon and helium.

[0017] Based on the above technical solution, further, the volume ratio of methanol to water in the methanol / water mixture described in steps (3) and (5) is 1:5 to 5:1.

[0018] Based on the above technical solution, further, the solution used to adjust the pH in step (5) includes NaHCO3 solution, Na2CO3 solution, and NaOH solution.

[0019] In another aspect, the present invention provides poly(geminoxime-ethyleneimine) modified foam-like mesoporous silica prepared by the above-described preparation method.

[0020] The present invention also provides the application of the above-mentioned poly(gammoxime-ethyleneimine) modified foam mesoporous silica as an adsorbent for the enrichment and extraction of low- to medium-concentration uranyl ions.

[0021] Based on the above technical solution, the poly(geminoxime-ethyleneimine) modified foam mesoporous silica is further used as an adsorbent to enrich and extract low- to medium-concentration uranyl ions from simulated seawater and real seawater.

[0022] Based on the above technical solution, the concentration of the uranyl ion is further 8.5 to 503.5 ppb.

[0023] Based on the above technical solution, the poly(aminoxime-ethyleneimine) modified foam mesoporous silica exhibits high affinity and selectivity for uranyl ions, and has high adsorption capacity and removal rate for uranyl ions in both simulated seawater and real seawater containing multiple coexisting ions.

[0024] Based on the above technical solution, further, the concentration of U in the real seawater is approximately 3.3 ppb; the concentrations of U (330 ppb), V (200 ppb), Fe (150 ppb), Co (55 ppb), Ni (100 ppb), Cu (60 ppb), Zn (400 ppb), and Pb (3 ppb) in the prepared simulated seawater are all approximately 100 times the concentration levels of the real seawater, and Na (10.06 × 10⁻⁶) is also approximately 100 times higher. 6 ppb), Mg(1.23×10 6 ppb), K(3.53×10 5 ppb), Ca(4.01×10 5 The ppb concentration level is the same as that of real seawater.

[0025] The advantages of this invention over the prior art are as follows:

[0026] This invention utilizes Pluronic P123 / trimethylbenzene as a pore-forming / expanding agent to prepare foam-like mesoporous silica. Compared to materials such as MCM-41 and SBA-15, this foam exhibits a larger pore capacity, meaning it can support more hyperbranched polymer groups. Furthermore, its unique 3D interconnected pore structure results in a more ideal mass transfer rate. Experimental results show that the poly(amineoxime-ethyleneimine) modified foam-like mesoporous silica prepared in this invention possesses extremely high adsorption capacity and a very fast adsorption rate for uranyl ions. Simultaneously, this material exhibits high affinity and selectivity for uranyl ions, demonstrating high adsorption capacity and removal rates for uranyl ions in both simulated and real seawater containing multiple coexisting metal ions. Moreover, this material exhibits good reusability during uranyl ion adsorption. This material significantly improves upon the bottleneck problems of poor selectivity, low adsorption capacity, and poor reusability of uranyl ions in real seawater extraction materials, showing great application potential and prospects in large-scale seawater uranium extraction projects. Attached Figure Description

[0027] To more clearly illustrate the embodiments of the present invention, the accompanying drawings involved in the embodiments will be briefly described below.

[0028] Figure 1 The results of the dynamic adsorption and kinetic model fitting of uranyl ions by poly(aminoxime-ethyleneimine) modified foam mesoporous silica of the present invention under three different initial concentrations (U, 20, 40, 60 ppm);

[0029] Figure 2 The present invention relates to poly(aminoxime-ethyleneimine) modified foam-like mesoporous silica, which exhibits uranyl ion (U, C) ion retrieval during five adsorption-desorption processes. o The adsorption capacity and desorption efficiency results for (20 ppm);

[0030] Figure 3 This is the adsorption result of the poly(geminoxime-ethyleneimine) modified foam mesoporous silica of the present invention in simulated seawater containing multiple competing adsorption ions;

[0031] Figure 4 The results show the adsorption and removal rates of poly(geminoxime-ethyleneimine) modified foamed mesoporous silica of the present invention in real seawater with different concentrations of uranyl ions (U, 5, 10, 20, 50, 100, 200, 500 ppb). Detailed Implementation

[0032] The present invention will be described in detail below with reference to the embodiments. However, the implementation of the present invention is not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments can be obtained without creative effort and all fall within the protection scope of the present invention.

[0033] Example 1

[0034] A method for preparing poly(amineoxime-ethyleneimine) modified foam-like mesoporous silica for selective enrichment and extraction of uranyl ions mainly includes the following steps:

[0035] (1) Dissolve 10g of Pluronic P123 (average molecular weight: 5800) in 190mL of 1.6M HCl aqueous solution, add 12.5g of mesitylene, stir at 40℃ for 2h, then add 23mL of tetraethyl silicate at 40℃, stir for 5min, and age for 20h. After aging, add 115mg of NH4F to the above solution, mix well, transfer to a high-pressure reactor, and continue aging at 140℃ for 24h (to further expand the pore size of the foamed mesoporous silica). Filter the obtained precipitate and wash it with deionized water and ethanol respectively, and dry it at 100℃. Then calcine the obtained solid material at 600℃ for 6h (to remove residual Pluronic P123 / mesitylene in the foamed mesoporous silica pores), thus completing the preparation of foamed mesoporous silica;

[0036] (2) 20g of foam-like mesoporous silica was dispersed in 200mL of 3M HCl aqueous solution and stirred for 12h (to activate the surface of the material pores, which is helpful for the subsequent silanization reaction). The material was then filtered and washed with deionized water until neutral. After being thoroughly dried, it was dispersed in 200mL of dry toluene. Under nitrogen protection, 20mL of 3-epoxypropoxytriethoxysilane was added to the foam-like mesoporous silica toluene dispersion and stirred and refluxed at 110℃ for 12h. The material was filtered and washed with dry toluene and ethanol respectively. After being thoroughly dried, the preparation of epoxy-modified foam-like mesoporous silica was completed.

[0037] (3) Dissolve 10g of polyethyleneimine (average molecular weight: 10000) in 100mL of 1:1 (v:v) methanol / water mixture, and add 10g of epoxy-modified foam mesoporous silica to it. Then stir and reflux at 80℃ for 4h. Filter the obtained material and wash it with deionized water and ethanol respectively. After thorough drying, polyethyleneimine-modified foam mesoporous silica is obtained.

[0038] (4) Disperse 10g of polyethyleneimine-modified foamed mesoporous silica into 100mL of methanol, add 20mL of acrylonitrile under nitrogen protection, and stir and reflux at 60℃ for 12h; filter the obtained material and wash it with ethanol, and dry it thoroughly to obtain poly(acrylonitrile-ethyleneimine) modified foamed mesoporous silica.

[0039] (5) Dissolve 10g of NH2OH·HCl in 100mL of 1:1 (v:v) methanol / water mixture and adjust the pH to neutral with Na2CO3 (to maximize the conversion of nitrile groups to amine oxime groups). Then disperse 10g of poly(acrylonitrile-ethyleneimine) modified foam mesoporous silica in it and stir and reflux at 80℃ for 4h. Filter the obtained material and wash it with deionized water and ethanol respectively. After thorough drying, poly(amine oxime-ethyleneimine) modified foam mesoporous silica is obtained.

[0040] Example 2

[0041] The dynamic adsorption of the poly(mercaptoime-ethyleneimine) modified foam mesoporous silica prepared in Example 1 was evaluated. Three 25 mg portions of the poly(mercaptoime-ethyleneimine) modified foam mesoporous silica prepared in Example 1 were accurately weighed and dispersed into 500 mL glass Erlenmeyer flasks containing uranyl ion aqueous solutions of three different concentrations (U, 20, 40, and 60 ppm; pH = 7). The Erlenmeyer flasks were placed in a constant temperature water bath at 25°C and continuously shaken at a speed of 150 rpm. Starting from the start of oscillation timing, 0.5 mL of solution was taken from the Erlenmeyer flask at time points of 0.1, 0.25, 0.5, 1, 1.5, 2, 3, 5, 7, 10, 15, 20, 30, 40, and 50 h. Using azoarsin III as the colorimetric reagent, the remaining concentration of uranyl ions in the solution was determined by UV-Vis spectroscopy. The adsorption capacity of the adsorbent material for uranyl ions at the aforementioned time points was then calculated. The final dynamic adsorption and kinetic model fitting results are shown below. Figure 1 As shown. By Figure 1 It is evident that the poly(aminoxime-ethyleneimine) modified foam-like mesoporous silica of this invention exhibits extremely high adsorption capacity and extremely fast adsorption rate for uranyl ions. In the above three aqueous solutions of uranyl ions with different initial concentrations, adsorption equilibrium was reached within 20 hours, with equilibrium adsorption capacities for U reaching as high as 324.9, 516.3, and 656.6 mg / g, respectively. Kinetic model fitting shows that the adsorption of uranyl ions by the poly(aminoxime-ethyleneimine) modified foam-like mesoporous silica of this invention conforms more closely to the pseudo-second-order kinetic model.

[0042] Example 3

[0043] Accurately weigh 5 mg of the poly(geminoxime-ethyleneimine) modified foam mesoporous silica prepared in Example 1, encapsulate it in a dialysis bag (for easy reuse), and place it in a glass Erlenmeyer flask containing 100 mL of uranyl ion aqueous solution (U, 20 ppm; pH = 7). Place the Erlenmeyer flask in a constant temperature water bath at 25°C and shake continuously at 150 rpm for 20 h. Then, take out 0.5 mL of the solution and use azoarsine III as a colorimetric reagent to determine the remaining concentration of uranyl ions in the solution by UV-Vis spectroscopy, thereby calculating the adsorption capacity of the adsorbent material for uranyl ions. After adsorption was complete, the dialysis bag was removed and placed in a glass Erlenmeyer flask containing 100 mL of 0.5 M HNO3 aqueous solution. The flask was then placed in a constant temperature water bath at 25 °C and continuously shaken at 150 rpm for 1 hour. 0.5 mL of the solution was then removed, and the concentration of uranyl ions in the solution was determined by UV-Vis spectroscopy using azoarsin III as the colorimetric reagent, thus calculating the elution efficiency for uranyl ions. After elution, the dialysis bag containing poly(aminoxime-ethyleneimine) modified foam mesoporous silica was removed, washed with deionized water until neutral, and the adsorption-elution experiment was repeated following the above steps. This cycle was repeated 5 times. The adsorption capacity and elution efficiency results are shown below. Figure 2 As shown. By Figure 2 It can be seen that the adsorption capacity of the prepared material did not decrease significantly after being reused 5 times, and all of them achieved good elution efficiency, indicating that the poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared in this invention has excellent reusability for adsorbing uranyl ions.

[0044] Example 4

[0045] Accurately weigh 5 mg of the poly(geminoxime-ethyleneimine) modified foam-like mesoporous silica prepared in Example 1, and disperse it in 500 mL of simulated seawater containing various competing adsorption ions (U, 330 ppb; V, 200 ppb; Fe, 150 ppb; Co, 55 ppb; Ni, 100 ppb; Cu, 60 ppb; Zn, 400 ppb; Pb, 3 ppb; Na, 10.06 × 10⁻⁶). 6 ppb; Mg, 1.23 × 10⁻⁶ 6 ppb; K, 3.53 × 10 5 ppb; Ca, 4.01 × 10⁻⁶ 5 The solution was placed in a glass Erlenmeyer flask containing ppb, and then continuously shaken at 150 rpm for 48 hours in a constant temperature water bath at 25°C. 0.1 mL of the solution was then taken out, diluted 50 times, and the remaining concentrations of U, V, Fe, Co, Ni, Cu, Zn, and Pb were simultaneously determined by ICP-MS. The adsorption capacity of the adsorbent material for these elements was then calculated. The results are as follows: Figure 3 As shown. By Figure 3It is evident that the poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared in this invention exhibits the highest affinity and adsorption capacity for uranyl ions in the prepared simulated seawater, with an adsorption capacity for U up to 29.3 mg / g, accounting for 88.79% of the highest adsorption capacity (33 mg / g), which is significantly better than the results reported in relevant literature.

[0046] Example 5

[0047] The enrichment and extraction efficiency of uranyl ions by poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared in Example 1 was evaluated in a real seawater environment. 25 mg of the poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared in Example 1 was accurately weighed and dispersed into 100 mL of real seawater containing standard added uranyl ions (U, 5, 10, 20, 50, 100, 200, 500 ppb) (the original U concentration in the seawater was determined to be 3.5 ppb by ICP-MS). The flasks were placed in a constant temperature water bath at 25°C and continuously shaken at 150 rpm for 48 h. Subsequently, the concentration of residual U in the real seawater was determined by ICP-MS. The final residual U concentration and adsorption efficiency are shown below. Figure 4 As shown. By Figure 4 It is known that the poly(aminoxime-ethyleneimine) modified foam mesoporous silica prepared in this invention has good affinity and extraction effect on medium and low concentration uranyl ions (U, 8.5~503.5ppb) in complex seawater environments, and the final extraction efficiency of uranyl ions is above 90%.

[0048] In summary, the poly(metamine oxime-ethyleneimine) modified foam-like mesoporous silica of this invention exhibits extremely high adsorption capacity and extremely fast adsorption rate for uranyl ions. Simultaneously, this material demonstrates high affinity and selectivity for uranyl ions, showing high adsorption capacity and removal rate for uranyl ions in both simulated and real seawater containing multiple coexisting metal ions. Furthermore, this material exhibits good reusability during the uranyl ion adsorption process. This material significantly improves upon the bottleneck problems of poor selectivity, low adsorption capacity, and poor reusability of uranium extraction materials in real seawater, and can be applied to large-scale seawater uranium extraction projects.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing poly(geminoxime-ethyleneimine) modified foam-like mesoporous silica, characterized in that, The main steps include: (1) Dissolve 2-50g of Pluronic P123 in 50-500mL of HCl aqueous solution, add 3-60g of mesitylene, stir at 20-80℃ for 0.5-6h, then add 5-100mL of tetraethyl silicate, stir for 2-20min, age for 5-80h, add 20-500mg of NH4F, mix well, transfer to a high-pressure reactor, and continue aging at 60-200℃ for 6-48h. Filter, wash and dry the obtained precipitate, and then calcine the obtained solid material at 200-800℃ for 2-18h to obtain foamy mesoporous silica. (2) Disperse 5-50g of the foam-like mesoporous silica obtained in step (1) into 50-500mL of HCl aqueous solution and stir for 3-48h. Then filter and wash with deionized water until neutral. After drying, disperse in 50-500mL of dry toluene. Under inert gas protection, add 5-50mL of 3-epoxypropoxytriethoxysilane to the foam-like mesoporous silica toluene dispersion and stir and reflux at 100-140℃ for 3-48h. Filter, wash and dry the obtained material to obtain epoxy-modified foam-like mesoporous silica. (3) Dissolve 5-50g of polyethyleneimine in 50-500mL of methanol / water mixture, add 5-50g of epoxy-modified foam mesoporous silica obtained in step (2), and then stir and reflux at 60-100℃ for 1-8h; filter, wash and dry the obtained material to obtain polyethyleneimine-modified foam mesoporous silica. (4) Disperse 2-20g of the polyethyleneimine-modified foamed mesoporous silica obtained in step (3) into 20-200mL of methanol, add 4-40mL of acrylonitrile under inert gas protection, and stir and reflux at 40-80℃ for 6-24h; filter, wash and dry the obtained material to obtain poly(acrylonitrile-ethyleneimine) modified foamed mesoporous silica; (5) Dissolve 2-20g of NH2OH·HCl in 20-200mL of methanol / water mixture and adjust the pH to neutral. Then disperse 2-20g of poly(acrylonitrile-ethyleneimine) modified foam mesoporous silica in it and stir and reflux at 60-100℃ for 1-8h. Filter, wash and dry the obtained material to obtain poly(acrylonitrile-ethyleneimine) modified foam mesoporous silica.

2. The preparation method according to claim 1, characterized in that, The average molecular weight of Pluronic P123 mentioned in step (1) is 5800; the concentration of the HCl aqueous solution is 0.4-4M; the calcination temperature is 500-700℃ and the calcination time is 4-8h; the concentration of the HCl aqueous solution mentioned in step (2) is 2-4M.

3. The preparation method according to claim 1, characterized in that, The average molecular weight of the polyethyleneimine mentioned in step (3) is 600, 1800, 10000, 25000 or 70000.

4. The preparation method according to claim 1, characterized in that, The inert gases mentioned in steps (2) and (4) include nitrogen, argon and helium.

5. The preparation method according to claim 1, characterized in that, The volume ratio of methanol to water in the methanol / water mixture described in steps (3) and (5) is 1:5 to 5:

1.

6. The preparation method according to claim 1, characterized in that, The solutions used to adjust the pH in step (5) include NaHCO3 solution, Na2CO3 solution, and NaOH solution.

7. Poly(geminoxime-ethyleneimine) modified foam mesoporous silica prepared by the preparation method according to any one of claims 1-6.

8. The application of the poly(geminoxime-ethyleneimine) modified foam mesoporous silica as described in claim 7 as an adsorbent for the enrichment and extraction of uranyl ions.

9. The application according to claim 8, characterized in that, The poly(aminoxime-ethyleneimine) modified foam mesoporous silica is used as an adsorbent to enrich and extract low to medium concentrations of uranyl ions from simulated and real seawater.

10. The application according to claim 9, characterized in that, The concentration of uranyl ions is 8.5–503.5 ppb.

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