(1, 2, 4-triazolium)-based polymer for efficiently enriching deuterium / tritium and preparation method of (1, 2, 4-triazolium)-based polymer

Abstract

The invention relates to a (1, 2, 4-triazolium)-based polymer for efficiently enriching deuterium / tritium and a preparation method thereof, and the (1, 2, 4-triazolium)-based polymer is respectively a water-soluble (1, 2, 4-triazolium)-based polymer and a water-insoluble (1, 2, 4-triazolium)-based polymer which are respectively suitable for homogeneous-phase and heterogeneous-phase enrichment systems. The high activity of a C-H site in the (1, 2, 4-triazolium)-based polymer is utilized, reversible H / D and H / T exchange can occur in an aqueous solution, more stable C-D and C-T bonds are formed, and dynamic balance is gradually achieved, so that efficient fixation and enrichment of deuterium / tritium are achieved, and an effective way is provided for directional capture and solid phase locking of deuterium / tritium.

Description

Technical Field

[0001] This invention belongs to the field of isotope enrichment technology, and specifically relates to a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium and its preparation method. Background Technology

[0002] Deuterium (D), as a stable isotope of hydrogen, and its radioactive isotope tritium (T, with a half-life of approximately 12.3 years), possess irreplaceable strategic value in fields such as nuclear energy (e.g., heavy water moderators, fusion fuels), isotope tracing, and pharmaceutical synthesis (e.g., deuterated drugs, tritium-labeled tracers). However, the abundance of deuterium in nature is extremely low (approximately 0.0156%), while tritium is almost non-existent in the natural environment, primarily relying on artificial production (e.g., lithium targets irradiated by neutrons in nuclear reactors). The efficient enrichment of both faces severe challenges. Current mainstream processes (such as heavy water electrolysis, cryogenic distillation, and chromatographic separation methods suitable for tritium) generally rely on multi-stage separation systems, resulting in lengthy processes, high energy consumption, and complex equipment, making it difficult to meet the demand for large-scale, green, and low-carbon acquisition of deuterium / tritium resources.

[0003] In recent years, adsorption separation has become an emerging research direction in deuterium / tritium enrichment technology due to its simple operation, low energy consumption, and recyclable materials. The core of this technology lies in achieving highly selective recognition and capture of H / D and H / T at the molecular scale, and constructing an integrated "adsorption-fixation-release" pathway, thereby significantly simplifying the process and reducing separation energy consumption, providing a new approach for the efficient enrichment of deuterium / tritium in deuterium / tritium water mixed systems. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium and its preparation method. The polymer can undergo reversible H / D and H / T exchanges under mild conditions to form more stable CD and CT bonds and gradually reach dynamic equilibrium, thereby achieving efficient fixation and enrichment of deuterium / tritium.

[0005] This invention provides a first (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium, the polymer having the following structural formula: Where n = 40~140, denoted as Ptriaz-A.

[0006] This invention also provides a first method for preparing (1,2,4-triazolium)-based polymers for efficient enrichment of deuterium / tritium, comprising the following steps:

[0007] 4-Methyl-1-vinyl-1,2,4-triazolium iodide was dissolved in a solvent, and an initiator was added to initiate the polymerization reaction to obtain a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium.

[0008] Further, the preparation method of the 4-methyl-1-vinyl-1,2,4-triazolium iodide is as follows:

[0009] 1-Vinyl-1,2,4-triazole, iodomethane, and 2,6-di-tert-butyl-p-cresol were mixed in a molar ratio of 4-6: 7-8: 0.02-0.03 and reacted at 50-60°C for 20-28 h. After the reaction was completed, the precipitate was obtained by filtration. The precipitate was washed, filtered, and dried to obtain 4-methyl-1-vinyl-1,2,4-triazoleonium iodide.

[0010] Preferably, the solvent is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and ethanol (EtOH); the ratio of 4-methyl-1-vinyl-1,2,4-triazolium iodide to the solvent is 1~5 g:15~35 mL. When the solvent is a DMF / EtOH mixed solvent, the DMF accounts for 80%~90% of the volume.

[0011] Preferably, the initiator is azobisisobutyronitrile, and the mass ratio of 4-methyl-1-vinyl-1,2,4-triazolium iodide to the initiator is 1~5:0.01~0.05.

[0012] Preferably, the polymerization reaction temperature is 60~90℃ and the polymerization reaction time is 16~36 h.

[0013] This invention also provides a first application of (1,2,4-triazolium)-based polymers for the efficient enrichment of deuterium / tritium, comprising the following steps:

[0014] Ptriaz-A was added to a deuterium / tritium solution in an alkaline environment and stirred at room temperature to perform isotope adsorption and fixation. By exchanging hydrophobic counterions, the dynamic equilibrium was broken, causing the water-soluble polymer to precipitate, thus obtaining deuterium / tritium-rich Ptriaz-A.

[0015] Preferably, the mass-to-volume ratio of Ptriaz-A to the deuterium / tritium solution is 10-100 mg: 1-5 mL.

[0016] Preferably, the alkaline environment is created by a weak alkali, which is one of sodium carbonate, sodium bicarbonate, ammonia, potassium carbonate, and cesium carbonate.

[0017] Preferably, the room temperature stirring time is 6 to 48 hours.

[0018] Preferably, the hydrophobic counterion is lithium bis(trifluoromethanesulfonylimide) (LiTFSI), and the mass ratio of Ptriaz-A to the hydrophobic counterion is 1:1-2.

[0019] This invention provides a second (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium, the polymer having the following structural formula: It is denoted as Ptriaz-B.

[0020] The present invention also provides a second method for preparing the (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium, comprising the following steps:

[0021] 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzene tetrabromide was dissolved in a solvent, and an initiator was added to initiate the polymerization reaction to obtain a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium.

[0022] Further, the preparation method of the 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzene tetrabromide is as follows:

[0023] 1-Vinyl-1,2,4-triazole, 1,2,4,5-tetra(bromomethyl)benzene, and 2,6-di-tert-butyl-4-methylphenol were added to 10-25 mL of dimethylformamide (DMF) in a molar ratio of 8-10:15-25:0.05-0.12. The mixture was placed in an oil bath at 80-120°C and reacted for 24-72 h. After the reaction was completed, the mixture was cooled to room temperature, filtered to collect the precipitate, washed, filtered, and dried to obtain 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzene tetrabromide.

[0024] Preferably, the solvent is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol (EtOH), and water; the ratio of 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazoliumyl)methyl)benzene tetrabromide to the solvent is 1~5 g:15~35 mL. When the solvent is a DMF / EtOH mixed solvent, the DMF accounts for 80%~90% of the volume.

[0025] Preferably, the initiator is azobisisobutyronitrile, and the mass ratio of 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzenetetrabromide to the initiator is 1~5:0.01~0.05.

[0026] Preferably, the polymerization reaction temperature is 60~90℃ and the polymerization reaction time is 16~36 h.

[0027] The present invention also provides a second application of (1,2,4-triazolium)-based polymers for the efficient enrichment of deuterium / tritium, comprising the following steps:

[0028] Ptriaz-B was added to an alkaline deuterium / tritium solution, stirred at room temperature, and subjected to isotope adsorption and fixation. The resulting solution was then filtered to obtain deuterium / tritium-rich Ptriaz-B.

[0029] Preferably, the mass-to-volume ratio of Ptriaz-B to the deuterium / tritium solution is 10-100 mg: 1-5 mL.

[0030] Preferably, the alkaline environment is created by a weak alkali, which is one of sodium carbonate, sodium bicarbonate, ammonia, potassium carbonate, and cesium carbonate.

[0031] Preferably, the room temperature stirring time is 12~48 h.

[0032] Beneficial effects

[0033] Compared with existing technologies, the present invention has the following advantages:

[0034] (1) A novel integrated deuterium / tritium enrichment pathway of "dynamic isotope exchange-active site fixation" was constructed for the first time: Unlike traditional high-energy-consuming processes such as electrolysis or low-temperature distillation, this invention utilizes the reversible H / D and H / T exchange reactions between highly polarized active hydrogen at C3-H and C5-H sites in (1,2,4-triazolium)-based polymers and deuterium / tritium water to achieve selective capture of deuterium / tritium atoms. By forming stable CD and CT bonds, the efficient fixation and enrichment of deuterium / tritium are achieved, significantly improving the enrichment efficiency and selectivity.

[0035] (2) The enrichment process is mild, easy to operate and low in energy consumption: the entire adsorption and enrichment process can be carried out at normal temperature and pressure without the need for high temperature, high pressure or complex equipment support, which greatly reduces operating costs and energy consumption, and is in line with the technological trend of green and sustainable development.

[0036] (3) The material has excellent chemical stability and reusability potential: the 1,2,4-triazolium group structure is stable and can still maintain high enrichment performance after multiple adsorption-elution cycles, which is conducive to continuous industrial operation and long-term use, and reduces material loss.

[0037] (4) The enrichment efficiency is regulated by the ambient pH and the H / D and H / T exchange kinetics can be significantly accelerated by alkaline conditions: Experiments have shown that the enrichment efficiency of deuterium / tritium can be greatly improved under the condition of adding weak bases such as potassium carbonate, demonstrating good process controllability and flexibility. Attached Figure Description

[0038] Figure 1 For Ptriaz-A 1 H NMR spectrum and GPC curve in DMF.

[0039] Figure 2The graph shows the deuterium enrichment efficiency of Ptriaz-A under different adsorption times in neutral and alkaline environments.

[0040] Figure 3 For Ptriaz-B's solid-state 13 C NMR and FT-IR spectra.

[0041] Figure 4 The image shows the nitrogen adsorption-desorption isotherms and pore size distribution of Ptriaz-B.

[0042] Figure 5 This is a graph showing the deuterium enrichment efficiency of Ptriaz-B in solutions with different initial deuterium concentrations.

[0043] Figure 6 This is a graph showing the tritium enrichment efficiency of Ptriaz-A under different feed ratios in an alkaline environment. Detailed Implementation

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0045] Example 1

[0046] This embodiment provides a homogeneous deuterium-enriched Ptriaz-A, its preparation method, and its application, including the following steps:

[0047] (1) 1-Vinyl-1,2,4-triazole (5.0 g, 0.053 mol), CH3I (9.08 g, 0.064 mol), and BHT (0.05 g, 0.227 mmol) were added to a reaction flask, and the mixture was stirred at 50 °C for 24 h. After the reaction was completed, the precipitate was obtained by filtration and washed with a large amount of diethyl ether. Finally, the product 4-methyl-1-vinyl-1,2,4-triazoleonium iodide was obtained by filtration and dried under vacuum at room temperature.

[0048] (2) The above product (2.0 g, 0.00844 mol), AIBN (25 mg, 0.1524 mmol), and 20 mL DMF were added to a reaction flask. The oxygen in the system was removed by three cycles of vacuuming and nitrogen purging, and finally, nitrogen was introduced for protection. The mixture was then placed in an oil bath at 75 °C and reacted for 24 h. After the reaction was complete, the mixture was cooled to room temperature, and the resulting solution was transferred to a dialysis bag and dialyzed with deionized water for three days to remove the solvent and unreacted monomers. Finally, the target product, Ptriaz-A, was obtained by freeze-drying.

[0049] (3) The initial deuterium concentration of 20% was dispensed into three reaction flasks (5 mL in each flask). Then, 50.0 mg of Ptriaz-A was added to each flask, and the mixture was stirred at room temperature for 6 h, 12 h, and 24 h respectively. The reaction was terminated at each set time point, and 100 mg of LiTFSI was immediately added and the mixture was shaken for approximately 30 s to induce polymer precipitation. The supernatant sample was then collected and analyzed using deuterated acetonitrile as an internal standard. 2 The residual deuterium content in the solution was determined by ¹H NMR. The deuterium enrichment efficiency of Ptriaz-A was calculated using the following formula:

[0050]

[0051] K: Deuterium enrichment efficiency; m: equilibrium deuterium concentration; M: initial deuterium concentration.

[0052] (4) Test the deuterium enrichment efficiency of Ptriaz-A under alkaline conditions. The specific implementation is the same as repeating step (3). The difference is that before stirring the reaction, 7.5 mg of K2CO3 is added to make the solution alkaline.

[0053] use 1 The chemical structure and molecular weight of the prepared Ptriaz-A were characterized by 1H NMR and GPC. Figure 1 As shown, Ptriaz-A's 1 The characteristic peak positions in the 1H NMR spectrum were consistent with the expected structure, further confirming the occurrence of the polymerization reaction. GPC analysis showed that the obtained polymer had a molecular weight of 32568 g / mol and a polymer dispersibility index (PDI) of 1.50, indicating that the polymer has a relatively uniform molecular weight distribution.

[0054] The deuterium enrichment efficiency of Ptriaz-A under different adsorption times in neutral and alkaline environments was tested, see [reference needed]. Figure 2 Regarding adsorption time, the D enrichment efficiency of Ptriaz-A steadily increased with prolonged adsorption time, rising from 3.92% at 6 h to 5.88% at 24 h, indicating that the H / D exchange at the active C5-H sites of the material requires a certain amount of time to gradually reach equilibrium. Notably, under alkaline conditions, the D enrichment efficiency of Ptriaz-A significantly improved, reaching a maximum of 18.45%, far exceeding the results under neutral conditions. This demonstrates that an alkaline environment can effectively accelerate H / D exchange kinetics and promote the conversion of CH to CD.

[0055] Example 2

[0056] To expand the application scenarios of hydrogen isotope enrichment, a heterogeneous deuterium enrichment method, Ptriaz-B, is proposed, along with its preparation method and applications, including the following steps:

[0057] (1) 1-Vinyl-1,2,4-triazole (2.138 g, 0.0225 mol), 1,2,4,5-tetra(bromomethyl)benzene (2.25 g, 0.05 mol), 2,6-di-tert-butyl-4-methylphenol (BHT, 0.0496 g, 0.225 mmol) and 15 mL of dimethylformamide (DMF) were added to a reaction flask. Oxygen in the system was removed by three cycles of vacuum-nitrogen purging, followed by nitrogen purging for protection. The mixture was reacted in an oil bath at 110 °C for 48 h. After the reaction, the mixture was cooled to room temperature, the precipitate was collected by filtration, and washed three times in excess diethyl ether. Finally, the precipitate was dried under vacuum at room temperature to obtain the target product, 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazoliumyl)methyl)benzene tetrabromide (Ph-4MTriaz-Br).

[0058] (2) The above product (1.000 g, 1.205 mmol) and AIBN (0.0198 g, 0.121 mmol) were dissolved in a mixed solution of 20 mL ethanol and 5 mL water and placed in a reaction flask. A three-cycle refrigeration-vacuum-nitrogen purging was used to remove oxygen from the system, followed by nitrogen purging for protection. The mixture was placed in an oil bath at 80 °C and reacted for 24 h. After the reaction was complete, the mixture was cooled to room temperature, filtered to obtain the product, and washed successively with water and ethanol. Finally, the obtained product was dried under vacuum at 60 °C to obtain the target product Ptriaz-B.

[0059] (3) Add 50.0 mg of Ptriaz-B to 5 mL of deuterium aqueous solutions with initial deuterium concentrations of 5%, 10%, and 20%, respectively. Use an ultrasonic machine with a power of 1000 W for 10 min. Stir the reaction at room temperature for 24 h to ensure H / D exchange reaches equilibrium. Filter to obtain deuterium-enriched Ptriaz-B, then take the supernatant sample and use deuterated acetonitrile as an internal standard. 2 The residual deuterium content in the solution was determined by ¹H NMR, and the deuterium enrichment efficiency was calculated using the following formula:

[0060]

[0061] K: Deuterium enrichment efficiency; m: equilibrium deuterium concentration; M: initial deuterium concentration.

[0062] Ptriaz-B was tested 13 C NMR and FT-IR spectra, see Figure 3solid-state 13 The C10 NMR spectrum shows chemical shifts of δ 144.83, 134.17, 59.18, 48.80, and 35.21 ppm for each carbon, consistent with the target structure. The FT-IR spectrum at 1655 cm⁻¹... -1 The disappearance of the -CH=CH2 characteristic peak observed at the point indicates that the monomer has successfully polymerized. 13 Both C NMR and FT-IR spectra confirmed the successful synthesis of the polymer.

[0063] The nitrogen adsorption-desorption isotherms and pore size distribution of Ptriaz-B were tested, see [see details]. Figure 4 Based on the nitrogen adsorption-desorption curve analysis, the specific surface area of ​​Ptriaz-B material is 57 m². 2 The / g indicates high surface activity, which is beneficial for improving adsorption performance. Pore size distribution data shows that its pore size is concentrated at 1.6 nm, with a uniform pore size distribution, enhancing the material's selectivity and adsorption capacity. These properties allow the active sites of Ptriaz-B to be fully exposed, giving it a significant advantage in catalytic H / D exchange.

[0064] The deuterium enrichment efficiency of Ptriaz-B in solutions with different initial deuterium concentrations was tested, as shown in the figure. Figure 5 As the deuterium content in the initial solution increases, the enrichment efficiency of Ptriaz-B gradually increases. When the initial D content is 20%, the enrichment efficiency reaches 5.88%, which is significantly higher than 0.77% and 1.86% under low concentration conditions.

[0065] Example 3

[0066] This embodiment proposes a (1,2,4-triazolium)-based polymer for the enrichment of tritium isotopes in tritium water, comprising the following steps:

[0067] The initial tritium activity was 3.77 × 10⁻⁶. 5 Bq L -1 Tritium-water solutions were dispensed into five separate reaction flasks (2 mL in each flask), and 8 mg of K₂CO₃ was added to make the solutions alkaline. Then, 20 mg, 40 mg, 60 mg, 80 mg, and 100 mg of Ptriaz-A were added sequentially to each flask. The mixture was stirred at room temperature for two days. Upon completion of the reaction, excess LiTFSI was immediately added and the mixture was shaken for approximately 30 seconds to induce polymer precipitation. After standing and separation, the supernatant was collected and filtered using a filter. The tritium activity of each filtrate was finally determined using a liquid scintillation counter. The tritium enrichment efficiency of Ptriaz-A was calculated using the following formula:

[0068]

[0069] T: Tritium enrichment efficiency; n: equilibrium tritium concentration; N: initial tritium concentration.

[0070] The tritium enrichment efficiency of Ptriaz-A under different feed ratios in an alkaline environment was tested, as shown in the figure. Figure 6 The results showed that the enrichment efficiency of T in Ptriaz-A increased with the increase of its feed ratio, from 4.82% at a feed ratio of 20:1 to 14.38% at a feed ratio of 40:1, indicating that the CH active sites of the material have excellent enrichment effect on T.

Claims

1. A (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium, characterized in that, The structural formula of the polymer is: Where n = 40~140.

2. A method for preparing a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium as described in claim 1, characterized in that, Includes the following steps: 4-Methyl-1-vinyl-1,2,4-triazolium iodide was dissolved in a solvent, and an initiator was added to initiate the polymerization reaction to obtain a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium.

3. The preparation method according to claim 2, characterized in that: The preparation method of the 4-methyl-1-vinyl-1,2,4-triazolium iodide is as follows: 1-Vinyl-1,2,4-triazole, iodomethane, and 2,6-di-tert-butyl-p-cresol were mixed in a molar ratio of 4-6: 7-8: 0.02-0.03 and reacted at 50-60°C for 20-28 h. After the reaction was completed, the precipitate was obtained by filtration. The precipitate was washed, filtered, and dried to obtain 4-methyl-1-vinyl-1,2,4-triazoleonium iodide.

4. The preparation method according to claim 2, characterized in that: The solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, and ethanol; the ratio of 4-methyl-1-vinyl-1,2,4-triazolium iodide to solvent is 1~5g:15~35mL.

5. The preparation method according to claim 2, characterized in that: The initiator is azobisisobutyronitrile, and the mass ratio of 4-methyl-1-vinyl-1,2,4-triazolium iodide to the initiator is 1~5:0.01~0.05; the polymerization reaction temperature is 60~90℃, and the polymerization reaction time is 16~36 h.

6. A (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium, characterized in that, The structural formula of the polymer is: .

7. A method for preparing a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium as described in claim 6, characterized in that, Includes the following steps: 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzene tetrabromide was dissolved in a solvent, and an initiator was added to initiate the polymerization reaction to obtain a (1,2,4-triazolium)-based polymer for efficient enrichment of deuterium / tritium.

8. The preparation method according to claim 7, characterized in that: The preparation method of the 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzene tetrabromide is as follows: 1-Vinyl-1,2,4-triazole, 1,2,4,5-tetra(bromomethyl)benzene, and 2,6-di-tert-butyl-4-methylphenol were added to a solvent in a molar ratio of 8~10:15~25:0.05~0.

12. The mixture was placed in an oil bath at 80~120℃ and reacted for 24~72 h. After the reaction was completed, the mixture was cooled to room temperature, filtered to collect the precipitate, washed, filtered, and dried to obtain 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazoliumyl)methyl)benzene tetrabromide.

9. The preparation method according to claim 7, characterized in that: The solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, ethanol, and water; the ratio of 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazolium)methyl)benzenetetrabromide to the solvent is 1~5g:15~35mL.

10. The preparation method according to claim 7, characterized in that: The initiator is azobisisobutyronitrile, and the mass ratio of 1,2,4,5-tetra(4(1-vinyl-1,2,4-triazoliumyl)methyl)benzene tetrabromide to the initiator is 1~5:0.01~0.05; the polymerization reaction temperature is 60~90℃, and the polymerization reaction time is 16~36 h.

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