Preparation method and application of a self-supporting intrinsic microporous uranium adsorption film
By polymerizing benzaldehyde cyanide and spirotetraphenol, a large-scale pore structure and abundant uranium adsorption sites are constructed, which solves the problem of low adsorption capacity and efficiency of existing self-supporting microporous membranes and achieves a highly efficient uranium adsorption effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- EAST CHINA UNIV OF TECH
- Filing Date
- 2025-07-23
- Publication Date
- 2026-05-19
AI Technical Summary
Existing self-supporting microporous membranes have narrow micropores, which prevent hydrated uranyl ions from freely passing through. Most membrane materials have a single adsorption site, resulting in small adsorption capacity and low adsorption efficiency.
A self-supporting microporous uranium adsorption membrane was prepared by polymerizing cyanobenzaldehyde and spirocyclic tetraphenol under an inert atmosphere, forming a large molecular backbone through carbon-carbon single bond linkage, increasing the free volume, constructing a large-scale pore structure and increasing uranium adsorption sites.
It achieves high adsorption capacity and high adsorption efficiency, with an adsorption capacity of 183.1 mg/g for uranium and an enrichment efficiency of up to 91.5%.
Smart Images
Figure CN120865495B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of uranium adsorption materials technology, and in particular to a method for preparing and applying a self-supporting, inherently microporous uranium adsorption membrane. Background Technology
[0002] Uranium, as a clean energy source, has become an important pathway to achieving the "dual-carbon" strategic goal. However, the development of nuclear fuel cycles and related technologies generates uranium-containing wastewater with high radioactivity. Therefore, the enrichment and separation of uranium from this wastewater is a pressing public safety issue. Adsorption methods, with their significant advantages of high separation efficiency, low environmental pollution, simple operation, and strong economic applicability, have become the most commonly used and effective method for extracting and separating uranium from water. Organic polymer microporous membranes with self-supporting structures are ideal adsorption materials. However, the micropore channels of current inherent microporous membranes... Narrow, hydrated uranyl ion Uranium cannot move freely between membranes; moreover, most membrane materials have a single adsorption site, resulting in small adsorption capacity and low adsorption efficiency. Therefore, constructing large-scale microporous structures and increasing the number of effective sites on the membrane surface are key approaches to improving uranium adsorption capacity and efficiency. Summary of the Invention
[0003] In view of this, the purpose of this invention is to provide a method for preparing a self-supporting, inherently microporous uranium adsorption membrane and its application. The self-supporting, inherently microporous uranium adsorption membrane of this invention exhibits high adsorption capacity and adsorption efficiency when applied to the enrichment of uranium in wastewater.
[0004] To achieve the above objectives, the present invention provides the following technical solution:
[0005] One of the technical solutions of this invention is a polymer having the structural formula shown in Formula I:
[0006]
[0007] Where R1 is selected from structure a`, b` or c`; R2 is selected from structure d`, e` or f`; 208≤n≤212;
[0008]
[0009] The second technical solution of the present invention is a method for preparing the above-mentioned polymer, comprising the following steps:
[0010] Under an inert atmosphere, benzaldehyde cyanide, spirotetraphenol, and a catalyst undergo a polymerization reaction to obtain a polymer intermediate.
[0011] The polymer intermediate was reduced to obtain the polymer.
[0012] The cyanobenzaldehyde is selected from structure a, b, or c, and the spirocyclic tetraphenol is selected from structure d, e, or f.
[0013]
[0014] In a preferred embodiment of the present invention, the molar ratio of benzaldehyde cyanide to spirocycline is 1:1.
[0015] In a preferred embodiment of the present invention, the catalyst is selected from methanesulfonic acid, Eaton reagent, anhydrous ferric chloride, or anhydrous aluminum chloride; the amount of the catalyst used is 0.5 to 2% of the mass of benzaldehyde cyanide.
[0016] In a preferred embodiment of the present invention, the polymerization reaction is carried out at a temperature of 65–96°C for 5–8 hours and at a pressure of 1.5–2.2 MPa.
[0017] In a preferred embodiment of the present invention, the solvent used for the polymerization reaction is 1,4-dioxane, 1,2-dichloroethane, chloroform, or dichloromethane. The present invention does not impose any special limitation on the amount of solvent used, as long as it is sufficient to allow the polymerization reaction to proceed.
[0018] In a preferred embodiment of the present invention, after the polymerization reaction is completed, the reaction mixture is further further comprising the steps of pouring the reactants into ultrapure water, followed by filtration, washing, and drying.
[0019] In a preferred embodiment of the present invention, the reducing agent used to reduce the polymer intermediate is hydroxylamine hydrochloride.
[0020] In a preferred embodiment of the present invention, the specific steps for reducing the polymer intermediate are as follows: dispersing the polymer intermediate in water, controlling the solid content of the system to be 10 wt%, then adding hydroxylamine hydrochloride with a molar equivalent of 3 times the polymer intermediate, monitoring the changes of cyano and oxime functional groups by infrared spectroscopy, and after the reaction is completed, filtering, washing, and drying to obtain the polymer.
[0021] The third technical solution of this invention is a method for preparing a self-supporting, inherently microporous uranium adsorption membrane, comprising the following steps:
[0022] The above polymer was dissolved in an organic solvent to obtain a casting solution;
[0023] The casting solution is coated onto the surface of the substrate material, and then immersed in a non-solvent for phase transformation to obtain the self-supporting inherent microporous uranium adsorption membrane.
[0024] In a preferred embodiment of the present invention, the organic solvent is tetrahydrofuran, dimethyl sulfoxide, 1,4-dioxane, or sulfolane; the non-solvent is water, methanol, or ethanol.
[0025] In a preferred embodiment of the present invention, the temperature during phase transformation is 46–60°C and the time is 12–24 h.
[0026] The fourth technical solution of the present invention is a self-supporting inherently microporous uranium adsorption membrane prepared by the above preparation method.
[0027] The fifth technical solution of the present invention is the application of the above-mentioned polymer or the above-mentioned self-supporting inherent microporous membrane uranium adsorption membrane in the adsorption of uranium elements in wastewater.
[0028] In a preferred embodiment of the present invention, the concentration of uranium in the wastewater is 10 to 30 ppm; specifically, it is 10 ppm, 15 ppm, 20 ppm, 25 ppm, or 30 ppm.
[0029] The present invention discloses the following technical effects:
[0030] This invention achieves polymer molecular weight growth by linking benzaldehyde cyanide and spirotetraphenol through carbon-carbon single bonds. Triphenylmethane in the macromolecular backbone significantly increases the polymer's free volume while simultaneously retaining substituents in the monomers, creating favorable conditions for constructing a large-scale porous structure and enriching uranium adsorption sites. Experimental results show that the uranium adsorption membrane prepared from this polymer has an adsorption capacity of 183.1 mg / g for uranium and a uranium enrichment efficiency as high as 91.5%. Attached Figure Description
[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 The polymer intermediate in Example 1 1 H- 1 H COSY spectrum;
[0033] Figure 2 The images show the FTIR spectra of the polymer intermediate and the inherently microporous polymer membrane material in Example 1.
[0034] Figure 3 The BET diagrams are of the polymer intermediate (pink triangle) and the target membrane adsorption material (yellow circle) in Example 1.
[0035] Figure 4 This is a bar chart comparing the adsorption capacity and adsorption efficiency of uranium element by the inherent microporous membrane adsorbent material in Example 1 and the traditional inherent microporous polymer membrane adsorbent material.
[0036] Figure 5 The infrared spectra of the inherent microporous membrane adsorption materials obtained in Examples 2-4 are shown.
[0037] Figure 6 This is a pore size distribution diagram of the inherent microporous polymer membrane material in Example 2;
[0038] Figure 7 XPS spectra of the inherently microporous polymer membrane material before and after adsorption in Example 3;
[0039] Figure 8 This is a cross-sectional morphology of the membrane after the inherently microporous polymer membrane material in Example 4 has been recycled 5 times. Detailed Implementation
[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0041] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0042] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0043] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0044] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0045] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.
[0046] In the examples, benzaldehyde cyanide is selected from a to c, and spirotetraphenol is selected from d to f.
[0047]
[0048] The uranium adsorption test involved in the examples is as follows:
[0049] 10 mg of membrane adsorption material was placed in a 100 mL spiked uranium solution with an initial uranium concentration of 20 ppm. Adsorption experiments were conducted under magnetic stirring conditions. Azoarsine trioxide was used as the colorimetric reagent, and the uranium content in the aqueous solution was monitored by UV-Vis until adsorption equilibrium was reached.
[0050] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.
[0051] Example 1
[0052]
[0053] (1) Under a nitrogen atmosphere, 10 mmol of benzaldehyde cyanide a and 10 mmol of spirotetraphenol d were dissolved in 26 mL of 1,4-dioxane. After adding methanesulfonic acid at 0.5% of the mass of benzaldehyde cyanide a, the above system was transferred to a reaction vessel, heated to 65 °C, and the pressure of the vessel was controlled at 1.5 MPa. The reaction was stirred continuously for 8 h. The reactants were then poured into ultrapure water, filtered, washed, and dried to obtain a polymer intermediate.
[0054] (2) Disperse the above polymer intermediate in water and control the solid content of the system to 10 wt%. Then add hydroxylamine hydrochloride with a molar equivalent of 3 times that of the polymer intermediate. Monitor the changes of cyano and oxime functional groups by infrared spectroscopy. When the cyano functional group in the polymer intermediate completely disappears as monitored by infrared spectroscopy, the product ammonia oxime is completely formed and the reaction ends. After the reaction ends, filter, wash and dry to obtain the polymer.
[0055] 2g of polymer was dissolved in 12mL of tetrahydrofuran to obtain a uniform and transparent casting solution. The casting solution was then coated onto a dry and clean substrate and immediately immersed in ultrapure water at 46℃. After 14h of complete displacement, a self-supporting microporous membrane adsorbent material was obtained.
[0056] Figure 1 The polymer intermediate in Example 1 1 H- 1The HCl COSY spectrum shows that the hydrogen atoms in each environment of the polymer intermediate are well assigned; at the same time, compared with... Figure 2 The FTIR spectra of the polymer intermediate and the inherently microporous polymer membrane material show that the polymer at 1650 cm⁻¹... -1 and 931cm -1 The characteristic infrared absorptions of C=N and NO appear at 2232 cm⁻¹, respectively, and the FTIR spectrum of the polymer intermediate shows that... -1 The disappearance of the (C=N) characteristic peak indicates that the polymer intermediate has been completely converted into the target adsorbent molecule; in addition, both exhibit the characteristic absorption of the phenolic hydroxyl group (3700-3100 cm⁻¹). -1 ) and characteristic absorption of the adipose ring (2955~2859cm) -1 This indicates that the target polymer material was successfully prepared.
[0057] Figure 3 The BET diagrams for the polymer intermediate (pink triangle) and the target membrane adsorbent material (yellow circle) in Example 1 show that the target membrane adsorbent material has a high specific surface area of 318 m². 2 / g, the relatively high specific surface area contributes to a significant increase in uranium adsorption capacity.
[0058] Figure 4 The bar chart shows a comparison of the adsorption capacity and adsorption efficiency of the inherent microporous membrane adsorbent material in Example 1 with that of the traditional inherent microporous polymer membrane adsorbent material. It can be seen that, compared with the traditional inherent microporous membrane adsorbent material (Nat.Sustain.2022,5,71-80), the inherent microporous membrane adsorbent material of the present invention under the same conditions has a significantly improved adsorption capacity (183.1 mg / g) and adsorption efficiency (91.5%).
[0059] Example 2
[0060]
[0061] (1) Under a nitrogen atmosphere, 10 mmol of benzaldehyde cyanide c and 10 mmol of spirotetraphenol f were dissolved in 27 mL of dichloromethane. After adding methanesulfonic acid accounting for 2% of the mass of benzaldehyde cyanide c, the above system was transferred to a reaction vessel, heated to 96 °C, controlled the vessel pressure at 2.2 MPa, and stirred continuously for 8 h. Then the reactants were poured into ultrapure water, filtered, washed, and dried to obtain a polymer intermediate.
[0062] (2) Disperse the above polymer intermediate in water and control the solid content of the system to 10 wt%. Then add hydroxylamine hydrochloride with a molar equivalent of 3 times that of the polymer intermediate. Monitor the changes of cyano and oxime functional groups by infrared spectroscopy. When the cyano functional group in the polymer intermediate completely disappears as monitored by infrared spectroscopy, the product ammonia oxime is completely formed and the reaction ends. After the reaction ends, filter, wash and dry to obtain the polymer.
[0063] 2g of polymer was dissolved in 12mL of dimethyl sulfoxide to obtain a uniform and transparent casting solution. The casting solution was then coated onto a dry and clean substrate and immediately immersed in 60℃ ultrapure water. After 12 hours of complete displacement, a self-supporting microporous membrane adsorbent material was obtained.
[0064] Figure 5 Curve a in the middle is the infrared spectrum of the inherent microporous membrane adsorption material obtained in Example 2. The presence of characteristic functional groups indicates that the target structure molecule was successfully synthesized. Figure 6 The figure shows the pore size distribution of the inherently microporous polymer membrane material in Example 2. As can be seen from the figure, the average pore size of the target inherently microporous polymer membrane adsorbent material is... Greater than the hydration radius of uranyl ions The large-scale microporous structure provides channels for the free movement of uranium, which is beneficial to improving the adsorption efficiency of uranium.
[0065] The same uranium adsorption test as in Example 1 was conducted. The adsorption capacity of the inherent microporous membrane adsorbent material prepared in this example was 178 mg / g, and the adsorption efficiency was 89%.
[0066] Example 3
[0067]
[0068] (1) Under a nitrogen atmosphere, 10 mmol of benzaldehyde cyanide b and 10 mmol of spirotetraphenol e were dissolved in 30 mL of 1,2-dichloroethane. After adding 1.5 wt% ferric chloride (based on the mass of benzaldehyde cyanide b), the system was transferred to a reaction vessel, heated to 75 °C, and the pressure was controlled at 1.8 MPa. The reaction was stirred continuously for 8 h. The reactants were then poured into ultrapure water, filtered, washed, and dried to obtain a polymer intermediate.
[0069] (2) Disperse the above polymer intermediate in water and control the solid content of the system to 10 wt%. Then add hydroxylamine hydrochloride with a molar equivalent of 3 times that of the polymer intermediate. Monitor the changes of cyano and oxime functional groups by infrared spectroscopy. When the cyano functional group in the polymer intermediate completely disappears as monitored by infrared spectroscopy, the product ammonia oxime is completely formed and the reaction ends. After the reaction ends, filter, wash and dry to obtain the polymer.
[0070] 2g of polymer was dissolved in 12mL of sulfolane to obtain a uniform and transparent casting solution. The casting solution was then coated onto a dry and clean substrate and immediately immersed in 50℃ ethanol. After 12h of complete displacement, a self-supporting microporous membrane adsorbent material was obtained.
[0071] Figure 5 Curve b in the middle is the infrared spectrum of the inherent microporous membrane adsorption material obtained in Example 3. The presence of characteristic functional groups indicates that the target structure molecule was successfully synthesized. Figure 7 The XPS spectra of the inherent microporous polymer membrane material before and after adsorption in Example 3 show that the surface of the inherent microporous polymer membrane adsorption material after uranium enrichment contains abundant uranium.
[0072] The same uranium adsorption test as in Example 1 was conducted. The adsorption capacity of the inherent microporous membrane adsorbent material prepared in this example was 180 mg / g, and the adsorption efficiency was 90%.
[0073] Example 4
[0074]
[0075] (1) Under a nitrogen atmosphere, 10 mmol of benzaldehyde cyanide a and 10 mmol of spirotetraphenol f were dissolved in chloroform. After adding 1.8% anhydrous aluminum chloride by mass of benzaldehyde cyanide a, the above system was transferred to a reaction vessel, heated to 85°C, controlled at 2.0 MPa, and stirred for 8 hours. The reactants were then poured into ultrapure water, filtered, washed, and dried to obtain a polymer intermediate.
[0076] (2) Disperse the above polymer intermediate in water and control the solid content of the system to 10 wt%. Then add hydroxylamine hydrochloride with a molar equivalent of 3 times that of the polymer intermediate. Monitor the changes of cyano and oxime functional groups by infrared spectroscopy. When the cyano functional group in the polymer intermediate completely disappears as monitored by infrared spectroscopy, the product ammonia oxime is completely formed and the reaction ends. After the reaction ends, filter, wash and dry to obtain the polymer.
[0077] 2g of polymer was dissolved in 12mL of dimethyl sulfoxide to obtain a uniform and transparent casting solution. The casting solution was then coated onto a dry and clean substrate and immediately immersed in methanol at 55°C. After 12 hours of complete displacement, a self-supporting microporous membrane adsorbent material was obtained.
[0078] Figure 5 Curve c in the middle is the infrared spectrum of the inherent microporous membrane adsorption material obtained in Example 3. The presence of characteristic functional groups indicates that the target structure molecule was successfully synthesized. Figure 8 The figure shows the cross-sectional morphology of the inherent microporous polymer membrane material in Example 4 after 5 cycles of use. As can be seen from the figure, the macropores of the inherent microporous membrane adsorbent material obtained by the present invention were not significantly damaged after long-term use, and the structure remained relatively intact.
[0079] The same uranium adsorption test as in Example 1 was conducted. The adsorption capacity of the inherent microporous membrane adsorbent material prepared in this example was 182 mg / g, and the adsorption efficiency was 91%.
[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a self-supporting, inherently microporous uranium adsorption membrane, characterized in that, Includes the following steps: The polymer is dissolved in an organic solvent to obtain a casting solution; The casting solution is coated onto the surface of the substrate material, and then immersed in a non-solvent for phase transformation to obtain the self-supporting inherently microporous uranium adsorption membrane; the non-solvent is water, methanol or ethanol. The polymer has the structural formula shown in Formula I: Where R1 is selected from structure a`, b` or c`; R2 is selected from structure d`, e` or f`; 208≤n≤212; 。 2. The method for preparing a self-supporting inherently porous uranium adsorption membrane according to claim 1, characterized in that, The method for preparing the polymer includes the following steps: Under an inert atmosphere, benzaldehyde cyanide, spirotetraphenol, and a catalyst undergo a polymerization reaction to obtain a polymer intermediate. The polymer intermediate was reduced to obtain the polymer. The cyanobenzaldehyde is selected from structure a, b, or c, and the spirocyclic tetraphenol is selected from structure d, e, or f. 。 3. The method for preparing a self-supporting inherently porous uranium adsorption membrane according to claim 2, characterized in that, The molar ratio of benzaldehyde cyanide to spirotetraphenol is 1:
1.
4. The method for preparing a self-supporting inherently porous uranium adsorption membrane according to claim 2, characterized in that, The catalyst is selected from methanesulfonic acid, Eaton reagent, anhydrous ferric chloride, or anhydrous aluminum chloride; the amount of the catalyst used is 0.5-2% of the mass of benzaldehyde cyanide.
5. The method for preparing a self-supporting inherently porous uranium adsorption membrane according to claim 2, characterized in that, The polymerization reaction is carried out at a temperature of 65–96°C for 5–8 hours and at a pressure of 1.5–2.2 MPa.
6. The preparation method according to claim 2, characterized in that, The reducing agent used to reduce the polymer intermediate is hydroxylamine hydrochloride.
7. The method for preparing a self-supporting inherently porous uranium adsorption membrane according to claim 1, characterized in that, The organic solvent is tetrahydrofuran, dimethyl sulfoxide, 1,4-dioxane, or sulfolane.
8. A self-supporting inherently microporous uranium adsorption membrane prepared by the preparation method of claim 1.
9. The application of the self-supporting inherently porous uranium adsorption membrane according to claim 8 in the adsorption of uranium in wastewater.