Cationic organic polymer and its preparation method and application

Abstract

The present invention provides a cationic organic polymer and a preparation method and application thereof, belonging to the technical field of nuclear fuel post-processing. The monomer and the cross-linking agent in the present invention react to generate a rich microporous structure, and the quaternization reaction constructs a cationic site N in the cationic organic polymer. + For ReO 4 ‑ On the one hand, the unquaternized N can be further quaternized to increase the adsorption capacity of the cationic organic polymer. On the other hand, the introduction of a hydrophobic alkyl chain at the N position can not only greatly enhance the alkaline stability of the cationic organic polymer, but also improve the hydrophobicity of the cationic organic polymer.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel post-processing, and in particular relates to a cationic organic polymer and a preparation method and application thereof. Background Art

[0002] With the development of society and the increase in energy demand, nuclear energy has attracted much attention as a clean and efficient energy source. In recent years, my country has vigorously developed nuclear power, and nuclear energy has become one of the most important components of my country's energy system. The development of nuclear energy has produced a large amount of spent fuel. Reasonable disposal of spent fuel is the key to achieving sustainable development of nuclear energy. In the process of spent fuel reprocessing, technetium-99 is one of the important fission products. Technetium-99 is a pure β decay product with a high fission yield (6.1%) and a long half-life (t 1 / 2 =2.12×10 5 a). Technetium-99 exists mainly in the form of pertechnetate in the environment. Once leaked, it is difficult to be blocked by mineral soil in nature due to its long half-life, high solubility, and difficulty in complexation. It is easy to enter the biosphere and endanger biological health. Therefore, it is of great significance to effectively separate and fix pertechnetate from nuclear waste liquid and radioactive sewage, especially to develop materials with stable structure and good performance under extreme conditions such as high acid, high alkali, and strong radiation.

[0003] Based on the characteristics of pertechnetate, the current methods for removing pertechnetate from nuclear waste liquid and radioactive sewage mainly include adsorption, solvent extraction, electrochemical reduction, membrane treatment, biological reduction and adsorption. Among them, the adsorption method is a method of capturing target ions by utilizing the physical or chemical adsorption properties of solid adsorbents. It has the characteristics of simple operation, high treatment selectivity and low cost. As a mainstream technical method, it has been widely studied and applied. Since technetium and rhenium have similar chemical and physical properties, non-radioactive pertechnetate is generally used instead of radioactive pertechnetate for experiments.

[0004] At present, various types of adsorbent materials have been used to treat wastewater containing pertechnetate / perrhenate. Among them, cationic skeleton materials are considered to be one of the effective materials for removing oxygen-containing acid radicals / perrhenate anion pollutants in the environment due to the positive charge of their main skeleton and the exchangeability of anions in the skeleton structure. Cationic organic polymers have the advantages of high specific surface area, orderly pore structure, strong modifiability, etc., and usually have the characteristics of high adsorption capacity, fast adsorption kinetics, good selectivity, etc., and can efficiently capture pertechnetate / perrhenate in solution. In the studies reported so far, most of the cationic organic polymer materials that can be used for the adsorption and separation of pertechnetate / perrhenate lack good alkali resistance, especially under the condition of the presence of a large number of competitive ions, the adsorption capacity is greatly affected, and it is impossible to achieve efficient and selective separation of pertechnetate / perrhenate, which greatly limits the application of such materials in the adsorption and separation of technetium or rhenium in strong alkaline media.

[0005] In summary, a cationic organic polymer is urgently needed to separate and remove technetium or rhenium in a strong alkaline medium. Summary of the invention

[0006] The purpose of the present invention is to provide a cationic organic polymer and its preparation method and application. The cationic organic polymer prepared by the present invention has strong alkali resistance and has an excellent removal rate for technetium or rhenium.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a cationic organic polymer, comprising the following steps:

[0009] (1) Mixing a monomer, a cross-linking agent, a catalyst and a first organic solvent, and performing a quaternization reaction to obtain an intermediate product I; the monomer comprises 2,4,5-triphenylimidazole or 4,5-diphenylimidazole; the cross-linking agent comprises p-dichlorobenzyl or biphenyl dichlorobenzyl; the molar ratio of the monomer to the cross-linking agent in step (1) is 1:(0.5-1.5);

[0010] (2) mixing the intermediate product I obtained in step (1) with an alkylating agent and a second organic solvent to carry out an alkylation reaction to obtain an intermediate product II; the alkylating agent is iodomethane; the mass ratio of the intermediate product I to the alkylating agent in step (2) is 2:(10-20);

[0011] (3) The intermediate product II obtained in step (2) is mixed with a metal chloride and water to carry out an ion exchange reaction to obtain a cationic organic polymer.

[0012] Preferably, in step (1), the mass ratio of monomer to catalyst is 1.5:(0.8-1.2).

[0013] Preferably, in step (1), the mass ratio of the monomer to the volume of the first organic solvent is 1.5 g: (10-50) mL.

[0014] Preferably, the temperature of the quaternization reaction in step (1) is 70-90° C., and the time of the quaternization reaction is 12-48 hours.

[0015] Preferably, the temperature of the alkylation reaction in step (2) is 110-140° C., and the time of the alkylation reaction is 12-48 hours.

[0016] Preferably, in step (3), the mass ratio of the intermediate product II to the volume of water is (0.1-1) g: (250-500) mL.

[0017] The present invention also provides a cationic organic polymer prepared by the preparation method described in the above technical solution.

[0018] The present invention also provides the use of the cationic organic polymer described in the above technical solution in the adsorption and separation of technetium and / or rhenium.

[0019] The monomers and crosslinking agents in the present invention react to generate a rich microporous structure, and the quaternization reaction constructs a cationic site N in the cationic organic polymer. + For ReO4 - The adsorption of rhenium or technetium is then carried out by alkylation. On the one hand, the unquaternized N can be further quaternized to increase the adsorption capacity of the cationic organic polymer. On the other hand, the introduction of a hydrophobic alkyl chain at the N position can not only greatly enhance the alkaline stability of the cationic organic polymer, but also improve the hydrophobicity of the cationic organic polymer. The results of the embodiment show that the adsorption rate of the cationic organic polymer prepared by the present invention for rhenium or technetium in a strong alkaline medium is as high as 93.65%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 TEM image of the cationic organic polymer prepared in Example 1;

[0021] Figure 2 TEM image of the cationic organic polymer prepared in Example 2;

[0022] Figure 3 is the adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 of Application Example 1 at different times;

[0023] Figure 4 The adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 of Application Example 2 under different pH conditions;

[0024] Figure 5The adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 of Application Example 3 in NaOH solutions of different concentrations;

[0025] Figure 6 The adsorption removal rate of rhenium in simulated waste liquid by the cationic organic polymer prepared in Example 1 of Application Example 4 at different solid-liquid ratios. DETAILED DESCRIPTION

[0026] The present invention provides a method for preparing a cationic organic polymer, comprising the following steps:

[0027] (1) Mixing a monomer, a cross-linking agent, a catalyst and a first organic solvent, and performing a quaternization reaction to obtain an intermediate product I; the monomer comprises 2,4,5-triphenylimidazole or 4,5-diphenylimidazole; the cross-linking agent comprises p-dichlorobenzyl or biphenyl dichlorobenzyl; the molar ratio of the monomer to the cross-linking agent in step (1) is 1:(0.5-1.5);

[0028] (2) mixing the intermediate product I obtained in step (1) with an alkylating agent and a second organic solvent to carry out an alkylation reaction to obtain an intermediate product II; the alkylating agent is iodomethane; the mass ratio of the intermediate product I to the alkylating agent in step (2) is 2:(10-20);

[0029] (3) The intermediate product II obtained in step (2) is mixed with a metal chloride and water to carry out an ion exchange reaction to obtain a cationic organic polymer.

[0030] Unless otherwise specified, the present invention has no particular limitation on the sources of the raw materials, and commercially available products known to those skilled in the art may be used.

[0031] The present invention mixes a monomer, a cross-linking agent, a catalyst and a first organic solvent, and performs a quaternization reaction to obtain an intermediate product I.

[0032] In the present invention, the monomer includes 2,4,5-triphenylimidazole or 4,5-diphenylimidazole.

[0033] In the present invention, the cross-linking agent includes p-dichlorobenzyl or biphenyl dichlorobenzyl.

[0034] In the present invention, the molar ratio of the monomer to the cross-linking agent is 1:(0.5-1.5). As an embodiment, the molar ratio of the monomer to the cross-linking agent may be specifically 1:0.5, 1:0.8, 1:1, 1:1.2 or 1:1.5. The present invention controls the molar ratio of the monomer to the cross-linking agent within the above range to further improve the adsorption effect of the cationic organic polymer on rhenium or technetium.

[0035] In the present invention, the catalyst is preferably anhydrous ferric chloride.

[0036] In the present invention, the mass ratio of the monomer to the catalyst is preferably 1.5:(0.8-1.2). As an embodiment, the mass ratio of the monomer to the catalyst may be specifically 1.5:0.8, 1.5:0.9, 1.5:1, 1.5:1.1 or 1.5:1.2. The present invention controls the mass ratio of the monomer to the catalyst within the above range, which can make the reaction more complete.

[0037] In the present invention, the first organic solvent preferably includes 1,2-dichloroethane, dichloromethane or chloroform.

[0038] In the present invention, the mass ratio of the monomer to the volume ratio of the first organic solvent is preferably 1.5 g: (10-50) mL. As an embodiment, the mass ratio of the monomer to the volume ratio of the first organic solvent may be specifically 1.5 g: 10 mL, 1.5 g: 20 mL, 1.5 g: 30 mL, 1.5 g: 40 mL or 1.5 g: 50 mL. The present invention controls the mass ratio of the monomer to the volume ratio of the first organic solvent within the above range, so that the raw material can be fully dissolved.

[0039] The present invention has no special limitation on the mixing operation of the monomer, crosslinking agent, catalyst and first organic solvent, and the technical scheme of material mixing well known to those skilled in the art can be adopted. In the present invention, the mixing is preferably carried out under nitrogen atmosphere.

[0040] In the present invention, the temperature of the quaternization reaction is preferably 70-90° C. As an embodiment, the temperature of the quaternization reaction can be specifically 70° C., 75° C., 80° C., 85° C. or 90° C.

[0041] In the present invention, the time of the quaternization reaction is preferably 12 to 48 hours. As an embodiment, the time of the quaternization reaction can be specifically 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, 25 hours, 28 hours, 30 hours, 32 hours, 35 hours, 38 hours, 40 hours, 42 hours, 45 hours or 48 hours. In the present invention, the quaternization reaction is preferably carried out under anhydrous and oxygen-free conditions. The temperature, time, etc. of the quaternization reaction are controlled within the above range by the present invention, so that the reaction can be fully carried out.

[0042] After the quaternization reaction is completed, the product of the quaternization reaction is preferably washed with methanol, ethanol, deionized water and dried in sequence to obtain an intermediate product I.

[0043] The present invention has no special limitation on the operations of methanol washing, ethanol washing, deionized water washing and drying, and the technical solutions well known to those skilled in the art can be adopted.

[0044] After obtaining the intermediate product I, the present invention mixes the intermediate product I with an alkylating agent and a second organic solvent to carry out an alkylation reaction to obtain the intermediate product II.

[0045] In the present invention, the alkylating agent is methyl iodide.

[0046] In the present invention, the mass ratio of the intermediate product I to the alkylating agent is 2:(10-20). As an embodiment, the mass ratio of the intermediate product I to the alkylating agent may be specifically 2:10, 2:11, 2:12, 2:13, 2:14, 2:15, 2:16, 2:17, 2:18, 2:19 or 2:20. The present invention controls the mass ratio of the intermediate product I to the alkylating agent within the above range, so that the reaction can be fully carried out.

[0047] In the present invention, the second organic solvent preferably includes N,N-dimethylformamide or xylene.

[0048] In the present invention, the mass ratio of the intermediate product I to the volume ratio of the second organic solvent is 0.2g: (200-400) mL. As an embodiment, the mass ratio of the intermediate product I to the volume ratio of the second organic solvent can be specifically 0.2g: 200mL, 0.2g: 250mL, 0.2g: 300mL, 0.2g: 350mL or 0.2g: 400mL. The present invention controls the mass ratio of the intermediate product I to the volume ratio of the second organic solvent within the above range, so that the raw material can be fully dissolved.

[0049] The present invention has no special limitation on the operation of mixing the intermediate product I with the alkylating agent and the second organic solvent, and a technical scheme for mixing materials well known to those skilled in the art can be adopted.

[0050] In the present invention, the temperature of the alkylation reaction is preferably 110-140° C. As an embodiment, the temperature of the alkylation reaction may be specifically 110° C., 115° C., 120° C., 125° C., 130° C., 135° C. or 140° C.

[0051] In the present invention, the time of the alkylation reaction is preferably 12 to 48 hours. As an embodiment, the time of the alkylation reaction can be specifically 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, 25 hours, 28 hours, 30 hours, 32 hours, 35 hours, 38 hours, 40 hours, 42 hours, 45 hours or 48 hours. The present invention controls the parameters such as the temperature and time of the alkylation reaction within the above range, so that the reaction can be fully carried out.

[0052] After the alkylation reaction is completed, the product of the alkylation reaction is preferably washed with N,N-dimethylformamide, ethanol, deionized water and vacuum dried in sequence to obtain an intermediate product II.

[0053] The present invention has no special limitation on the operations of N,N-dimethylformamide washing, ethanol washing, deionized water washing and vacuum drying, and the technical solutions well known to those skilled in the art can be adopted.

[0054] After obtaining the intermediate product II, the present invention mixes the intermediate product II with metal chloride and water to carry out ion exchange reaction to obtain a cationic organic polymer.

[0055] In the present invention, the metal chloride preferably includes sodium chloride or potassium chloride.

[0056] In the present invention, the mixing of the intermediate product II with the metal chloride and water is preferably carried out by mixing the metal chloride and water to obtain a metal chloride aqueous solution, and then adding the intermediate product II.

[0057] In the present invention, the concentration of the metal chloride aqueous solution is preferably 1 to 3 mol / L. As an embodiment, the concentration of the metal chloride aqueous solution may be specifically 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L or 3 mol / L.

[0058] In the present invention, the mass ratio of the intermediate product II to the volume of water is preferably (0.1-1) g: (250-500) mL. As an embodiment, the mass ratio of the intermediate product II to the volume of water can be specifically 0.1 g: 200 mL, 0.1 g: 500 mL or 1 g: 500 mL. The present invention controls the amount of each component within the above range, so that the raw materials can be fully dissolved and the reaction can be more complete.

[0059] In the present invention, the temperature of the ion exchange reaction is preferably room temperature; the time of the ion exchange reaction is preferably 12 to 24 hours; the ion exchange reaction is preferably carried out under stirring conditions. The present invention has no special restrictions on the stirring method and rate, and the technical solutions familiar to those skilled in the art can be adopted. The present invention controls the temperature and time of the ion exchange reaction within the above range, so that the reaction can be fully carried out. In the present invention, during the ion exchange process, chloride ions replace iodide ions, which, on the one hand, avoids the adverse effects of iodine ions on the adsorption of technetium or rhenium, and on the other hand, chloride ions are more environmentally friendly than iodine ions.

[0060] After the ion exchange reaction is completed, the product of the ion exchange reaction is preferably washed with water and dried in sequence to obtain a cationic organic polymer.

[0061] The present invention has no special limitation on the washing and drying operations, and the technical solutions well known to those skilled in the art can be adopted.

[0062] The invention uses phenylimidazole as a monomer and aromatic small molecules containing dichloromethyl as a crosslinking agent, generates a cationic organic polymer through quaternization reaction and alkylation reaction, and improves the alkali resistance and selectivity of the product.

[0063] The present invention also provides a cationic organic polymer prepared by the preparation method described in the above technical solution.

[0064] The cationic organic polymer prepared by the invention has excellent alkali resistance, can adsorb rhenium or technetium in a strong alkali medium, and has an excellent adsorption rate.

[0065] In the present invention, when the monomer is 2,4,5-triphenylimidazole and the crosslinking agent is benzyl dichloride, the structural formula of the prepared cationic organic polymer is as follows:

[0066] ,in The other parts of the polymer are almost the same as those shown and there are countless of them. It is impossible to draw them one by one, so we use replace.

[0067] The present invention also provides the use of the cationic organic polymer described in the above technical solution in the adsorption and separation of technetium and / or rhenium.

[0068] The present invention has no special limitation on the operation of the application, and the technical solutions of the application well known to those skilled in the art may be adopted.

[0069] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] Example 1

[0071] A method for preparing a cationic organic polymer comprises: (1) mixing 1.50 g of 2,4,5-triphenylimidazole and 1.33 g of p-dichlorobenzyl chloride (the molar ratio of 2,4,5-triphenylimidazole to p-dichlorobenzyl chloride is 1:1.5), adding 50 mL of 1,2-dichloroethane (the mass ratio of 2,4,5-triphenylimidazole to the volume ratio of 1,2-dichloroethane is 1.5 g:50 mL), introducing nitrogen, adding 1.0 g of anhydrous ferric chloride (the mass ratio of 2,4,5-triphenylimidazole to anhydrous ferric chloride is 1.5:1), reacting under condensation reflux at 80° C. under anhydrous and oxygen-free conditions for 24 h, and after the reaction is completed, washing with methanol, ethanol and deionized water in sequence, and vacuum drying to obtain 1.80 g of intermediate product I with a yield of 63.6%;

[0072] (2) 200 mg of intermediate product I, 1.5 g of methyl iodide (the mass ratio of intermediate product I to methyl iodide is 2:15) and 250 mL of N,N-dimethylformamide (the mass ratio of intermediate product I to N,N-dimethylformamide is 0.2 g:250 mL) were mixed, and the mixture was condensed and refluxed at 120°C for 24 h. After the reaction was completed, the mixture was washed with N,N-dimethylformamide, ethanol and deionized water in sequence, and dried in vacuo to obtain intermediate product II.

[0073] (3) Sodium chloride and water are mixed to obtain a sodium chloride aqueous solution with a concentration of 3 mol / L. 1.0 g of the intermediate product II is mixed with 500 mL of a 3 mol / L sodium chloride aqueous solution (the mass ratio of the intermediate product II to the volume of water is 1 g:500 mL). The mixture is stirred at room temperature for 24 h. After the reaction is completed, the mixture is washed three times with deionized water and dried in vacuo to obtain a cationic organic polymer.

[0074] The transmission electron microscopy image of the cationic organic polymer prepared in Example 1 is as follows: Figure 1 As shown. Figure 1 It can be seen that the morphology of the cationic organic polymer prepared in Example 1 is aggregated spherical particles.

[0075] Example 2

[0076] A method for preparing a cationic organic polymer comprises: (1) mixing 1.50 g of 4,5-diphenylimidazole and 1.79 g of p-dichlorobenzyl chloride (the molar ratio of 4,5-diphenylimidazole to p-dichlorobenzyl chloride is 1:1.5), adding 50 mL of 1,2-dichloroethane (the mass ratio of 4,5-diphenylimidazole to the volume ratio of 1,2-dichloroethane is 1.5 g:50 mL), introducing nitrogen, adding 1.0 g of anhydrous ferric chloride (the mass ratio of 4,5-diphenylimidazole to anhydrous ferric chloride is 1.5:1), reacting under condensation reflux at 80° C. under anhydrous and oxygen-free conditions for 24 h, and after the reaction is completed, washing with methanol, ethanol and deionized water in sequence, and vacuum drying to obtain 2.0 g of intermediate product I with a yield of 60.8%;

[0077] (2) 200 mg of intermediate product I, 1.5 g of methyl iodide (the mass ratio of intermediate product I to methyl iodide is 2:15) and 250 mL of N,N-dimethylformamide (the mass ratio of intermediate product I to N,N-dimethylformamide is 0.2 g:250 mL) were mixed, and the mixture was condensed and refluxed at 120°C for 24 h. After the reaction was completed, the mixture was washed with N,N-dimethylformamide, ethanol and deionized water in sequence, and dried in vacuo to obtain intermediate product II.

[0078] (3) Sodium chloride and water are mixed to obtain a sodium chloride aqueous solution with a concentration of 3 mol / L. 1.0 g of the intermediate product II is mixed with 500 mL of a 3 mol / L sodium chloride aqueous solution (the mass ratio of the intermediate product II to the volume of water is 1 g:500 mL). The mixture is stirred at room temperature for 24 h. After the reaction is completed, the mixture is washed three times with deionized water and dried in vacuo to obtain a cationic organic polymer.

[0079] The transmission electron microscopy image of the cationic organic polymer prepared in Example 2 is as follows: Figure 2 As shown. Figure 2 It can be seen that the morphology of the cationic organic polymer prepared in Example 2 is aggregated spherical particles.

[0080] Application Example 1

[0081] 30 mg of the cationic organic polymer prepared in Example 1 was mixed with 30 mL of a 30 ppm aqueous perrhenate solution with a pH value of 7. A small amount of the supernatant was taken at 0.5 min, 1 min, 2 min, 15 min, 30 min, 60 min and 120 min, respectively, and filtered with a 0.22 μm water filter membrane. The concentration of residual rhenium therein was tested by ICP-MS.

[0082] The adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 at different times is as follows: Figure 3 As shown. Figure 3It can be seen that at a time of 0.5 min, the cationic organic polymer material almost completely removes rhenium from the solution, which indicates that the material has an extremely fast adsorption rate for rhenium and can reach adsorption equilibrium in 30 s, which is better than most materials that adsorb and remove rhenium.

[0083] Application Example 2

[0084] 10 mg of the cationic organic polymer prepared in Example 1 was mixed with 10 mL of a 30 ppm aqueous solution of perrhenate, and the pH values ​​were adjusted to 0, 1, 3, 5, 7, 9, 11, 13 and 14, respectively, with a high concentration of sodium hydroxide solution and hydrochloric acid. After stirring at room temperature for 24 h, the supernatant was filtered with a 0.22 μm water filter membrane, and the concentration of residual rhenium therein was tested by ICP-OES.

[0085] The adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 under different pH conditions is as follows: Figure 4 As shown. Figure 4 It can be seen that at a pH value of 1 to 14, the removal rate of the cationic organic polymer material for the rhenium-containing solution is almost close to 100%, indicating that even under acidic or alkaline conditions, the material's ability to remove rhenium is not significantly affected.

[0086] Application Example 3

[0087] Sodium hydroxide aqueous solutions containing 30 ppm of perrhenate were prepared respectively, wherein the concentration of sodium hydroxide in the sodium hydroxide aqueous solutions was 1 mol / L, 3 mol / L, 5 mol / L and 10 mol / L respectively. The sodium hydroxide aqueous solutions containing 30 ppm of perrhenate were mixed with 10 mg of the cationic organic polymer prepared in Example 1, stirred at room temperature for 24 hours, and the supernatant was filtered with a 0.22 μm water filter membrane, and the concentration of residual rhenium therein was tested by ICP-OES.

[0088] The adsorption removal rate of rhenium by the cationic organic polymer prepared in Example 1 in a sodium hydroxide aqueous solution containing 30 ppm perrhenate at different sodium hydroxide concentrations is as follows: Figure 5 As shown. Figure 5 It can be seen that with the increase of the concentration of NaOH solution, the removal rate slightly decreases; under the condition of 10 mol / L NaOH aqueous solution, the removal rate of rhenium by the cationic organic polymer material can be as high as 93.65%.

[0089] Application Example 4

[0090] According to the reported concentrations of various components in alkaline high-radioactive waste liquid in a certain region, simulated waste liquid was prepared, in which pertechnetate was replaced by perrhenate with similar properties. 25 mg, 50 mg, 75 mg, and 100 mg of the cationic organic polymer prepared in Example 1 were mixed with 5 mL of the simulated waste liquid, respectively. After stirring at room temperature for 24 h, the supernatant was filtered with a 0.22 μm water filter membrane, and the concentration of residual rhenium therein was tested by ICP-OES.

[0091] The composition of the simulated waste liquid in Application Example 4 is shown in Table 1.

[0092] Table 1 Composition of simulated wastewater in Application Example 4

[0093]

[0094] The adsorption removal rate of rhenium in the simulated waste liquid by the cationic organic polymer prepared in Example 1 at different solid-liquid ratios is as follows: Figure 6 As shown. Figure 6 It can be seen that when the solid-liquid ratio is 5, 10, 15 and 20 g / L, the adsorption removal rate of rhenium by the cationic organic polymer material is 61.51%, 75.18%, 79.66% and 84.26%, respectively. This shows that the cationic organic polymer material has a very strong adsorption and removal ability for rhenium in the alkaline simulated wastewater.

[0095] In summary, the cationic organic polymer prepared by the present invention has excellent alkali resistance, high adsorption rate and high selectivity, and can be used for adsorption and separation of technetium or rhenium in a strong alkaline medium.

[0096] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a cationic organic polymer, characterized in that: It consists of the following steps: (1) Mixing a monomer, a cross-linking agent, a catalyst and a first organic solvent, and performing a quaternization reaction to obtain an intermediate product I; the monomer is 2,4,5-triphenylimidazole or 4,5-diphenylimidazole; the cross-linking agent is p-dichlorobenzyl or biphenyl dichlorobenzyl; the molar ratio of the monomer to the cross-linking agent in step (1) is 1:(0.5-1.5); the temperature of the quaternization reaction in step (1) is 70-90°C, and the time of the quaternization reaction is 12-48h; (2) The intermediate product I obtained in step (1) is mixed with an alkylating agent and a second organic solvent to carry out an alkylation reaction to obtain an intermediate product II; the alkylating agent is iodomethane; the mass ratio of the intermediate product I to the alkylating agent in step (2) is 2:(10-20); the temperature of the alkylation reaction in step (2) is 110-140° C., and the time of the alkylation reaction is 12-48 hours; (3) The intermediate product II obtained in step (2) is mixed with a metal chloride and water to carry out an ion exchange reaction to obtain a cationic organic polymer.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the monomer to the catalyst in step (1) is 1.5:(0.8-1.2).

3. The preparation method according to claim 1, characterized in that: In the step (1), the mass ratio of the monomer to the volume of the first organic solvent is 1.5 g: (10-50) mL.

4. The preparation method according to claim 1, characterized in that: In the step (3), the mass ratio of the intermediate product II to the volume of water is (0.1-1) g: (250-500) mL.

5. The cationic organic polymer prepared according to the preparation method according to any one of claims 1 to 4.

6. Use of the cationic organic polymer according to claim 5 in the adsorption separation of technetium and / or rhenium.

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