A conjugated microporous cesium ion exchanger containing sulfonic acid groups and a preparation method thereof

Abstract

The present invention belongs to the technical field of polymer ion exchangers, and discloses a conjugated microporous cesium ion exchanger containing a sulfonic acid group and a preparation method thereof, wherein the preparation method comprises: S1. preparing a conjugated microporous polymer using 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl, and 1,6-dibromopyrene as raw materials; S2. placing the conjugated microporous polymer prepared in step S1 in dichloroethane and stirring and swelling at room temperature, and then adding chlorosulfonic acid dropwise under ice bath conditions to obtain a mixture solution a; S3. placing the mixture solution a in ice water for quenching to obtain a crude product b; S4. filtering and washing the crude product b to neutrality using deionized water and methanol, and then successively extracting and purifying with methanol Soxhlet and vacuum drying to obtain a conjugated microporous cesium ion exchanger containing a sulfonic acid group. In summary, the conjugated microporous cesium ion exchanger prepared by the present invention has a large number of sulfonic acid adsorption active sites, thereby effectively improving the equilibrium adsorption amount and adsorption selectivity.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer ion exchangers, and in particular relates to a conjugated microporous cesium ion exchanger containing a sulfonic acid group and a preparation method thereof. Background Art

[0002] Precipitation, extraction and ion exchange are commonly used methods for cesium separation. Among them:

[0003] The precipitation method is very effective in removing high-concentration Cs+, but its use in systems with low concentrations of the target substance will greatly increase costs.

[0004] Solvent extraction has extremely high selectivity and can effectively remove Cs+ in low-concentration systems. However, the inevitable loss of the extractant, the need for a strong acid or alkaline environment, the high price of the extractant, and the need to add a large amount of organic diluent during extraction still limit the development of this technology.

[0005] The ion exchange method is highly anticipated because it can effectively remove Cs+ in low-concentration systems, has a large adsorption capacity, low cost and low pollution. According to the composition of the ion exchanger, it can be divided into inorganic ion exchangers and organic ion exchangers. However, all existing ion exchangers have problems such as poor stability, difficulty in recovery after adsorption, and easy agglomeration, which leads to reduced adsorption and desorption rates.

[0006] The conjugated microporous polymer (CMPs) skeleton is generally composed of light elements connected by strong covalent bonds, contains a large number of benzene rings and triple bonds, has strong main chain rigidity, high thermal and chemical stability, is difficult to dissolve in various solvents, and has the advantages of high specific surface area and many active sites. Based on this, the applicant proposes in this application an ion exchanger for cesium separation using a conjugated microporous polymer skeleton as a carrier. Summary of the invention

[0007] In view of this, in order to solve the problems raised in the above background technology, the object of the present invention is to provide a conjugated microporous cesium ion exchanger containing sulfonic acid groups and a preparation method thereof.

[0008] A method for preparing a conjugated microporous cesium ion exchanger containing a sulfonic acid group comprises the following steps:

[0009] S1. Preparation of conjugated microporous polymer using 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene as raw materials;

[0010] S2. The conjugated microporous polymer prepared in step S1 is placed in dichloroethane and stirred at room temperature to swell, and then chlorosulfonic acid is added dropwise under ice bath conditions to obtain a mixture solution a;

[0011] S3. The mixture solution a is placed in ice water to quench the reaction to obtain a crude product b;

[0012] S4. The crude product b is filtered and washed with deionized water and methanol until it is neutral, and then purified by methanol Soxhlet extraction and vacuum drying to obtain a conjugated microporous cesium ion exchanger containing sulfonic acid groups.

[0013] Preferably, the conjugated microporous cesium ion exchanger containing sulfonic acid groups is a brown solid.

[0014] Preferably, the mixing mass ratio of the conjugated microporous polymer to the chlorosulfonic acid is 1:40-45 (preferably 1:43.8), and the mixing volume ratio of the ethylene dichloride to the chlorosulfonic acid is 2-3:1 (preferably 2.6:1).

[0015] Preferably, the conjugated microporous polymer is placed in dichloroethane and stirred at room temperature for 0.5 to 3 hours (preferably 2 hours) to completely swell the conjugated microporous polymer.

[0016] Preferably, chlorosulfonic acid is added dropwise in an ice bath and stirred at room temperature for 10 to 70 h (preferably 60 h).

[0017] Preferably, the methanol Soxhlet extraction purification time is 80 hours.

[0018] Preferably, the preparation of the conjugated microporous polymer using 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene as raw materials comprises the following steps:

[0019] S11. Adding the raw materials and the catalyst to a mixed solvent of triethylamine and toluene under nitrogen protection to obtain a mixture solution c with a concentration of 0.8 to 1 mol / L, wherein the raw materials include 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl, and 1,6-dibromopyrene, and the catalyst includes Pd(PPh3)2Cl2, CuI, and PPh3;

[0020] S12. The mixture solution c is placed in an oil bath and heated at 80°C to 95°C for 7 to 30 hours to obtain a crude product d;

[0021] S13. The crude product d was filtered and washed with toluene, chloroform and KI aqueous solution, and then purified by dichloromethane Soxhlet extraction and vacuum drying to obtain a conjugated microporous polymer.

[0022] Preferably, the mixing mass ratio of the 1,3,5-tris[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene is 26-28:16-18:17-19.

[0023] Preferably, the mixing mass ratio of Pd(PPh3)2Cl2, CuI and PPh3 in the catalyst is 3-4:1:12-14.

[0024] Preferably, the mixing volume ratio of triethylamine to toluene in the mixed solvent is 1:1-3.

[0025] A conjugated microporous cesium ion exchanger containing sulfonic acid groups is prepared based on the preparation method disclosed above.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The preparation method of the present invention uses a conjugated microporous polymer as a carrier, chlorosulfonic acid as a sulfonating agent, and controls the sulfonation reaction time to prepare an ion exchanger with a large number of sulfonic acid group adsorption active sites modified on the surface, which has the advantages of simple preparation process, sufficient raw materials and low cost.

[0028] The ion exchanger prepared by the present invention retains the advantages of the conjugated microporous polymer itself, such as large specific surface area, multiple adsorption active sites, high thermal stability and chemical stability, and its active sites are all modified with sulfonic acid groups, thereby effectively improving the equilibrium adsorption capacity and adsorption selectivity of the ion exchanger. In addition, the ion exchanger prepared by the present invention is easy to recycle and reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an infrared comparison image of a conjugated microporous polymer (Polymer A) and a conjugated microporous cesium ion exchanger (SCMP) containing a sulfonic acid group;

[0030] Figure 2 This is a scanning electron micrograph of a conjugated microporous cesium ion exchanger (SCMP) containing sulfonic acid groups.

[0031] Figure 3 The cesium adsorption curve of the conjugated microporous cesium ion exchanger (SCMP) containing sulfonic acid groups. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0033] A method for preparing a conjugated microporous cesium ion exchanger containing a sulfonic acid group comprises the following steps:

[0034] S1. Preparation of Conjugated Microporous Polymers

[0035] S11. Adding raw materials and catalysts to a mixed solvent of triethylamine and toluene under nitrogen protection to obtain a mixed solution c, wherein the raw materials include 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl, and 1,6-dibromopyrene in a mixing mass ratio of 26 to 28:16 to 18:17 to 19, and the catalyst includes Pd(PPh3)2Cl2, CuI, and PPh3 in a mixing mass ratio of 3 to 4:1:12 to 14, and the mixing volume ratio of triethylamine to toluene in the mixed solvent is 1:1 to 3;

[0036] S12. The mixture solution c is placed in an oil bath and heated at a temperature of 80°C to 95°C (preferably 89.9°C) for 7 to 30 hours (preferably 15 hours) to obtain a crude product d;

[0037] S13. The crude product d was filtered and washed with toluene, chloroform and KI aqueous solution, and then purified by Soxhlet extraction with dichloromethane and vacuum drying to obtain a conjugated microporous polymer;

[0038] S2. placing the conjugated microporous polymer prepared in step S1 in dichloroethane and stirring at room temperature to swell, and then adding chlorosulfonic acid under ice bath conditions to obtain a mixture solution a, wherein the mixing mass ratio of the conjugated microporous polymer to the chlorosulfonic acid is 1:40-45 (preferably 1:43.8), and the mixing volume ratio of the dichloroethane to the chlorosulfonic acid is 2-3:1 (preferably 2.6:1);

[0039] S3. The mixture solution a is placed in ice water for quenching to obtain a crude product b;

[0040] S4. The crude product b is filtered and washed with deionized water and methanol until it is neutral, and then purified by methanol Soxhlet extraction and vacuum drying to obtain a conjugated microporous cesium ion exchanger containing sulfonic acid groups.

[0041] Based on the above steps, the present invention provides the following specific embodiments:

[0042] Preparation of conjugated microporous polymers

[0043] Weigh 378 mg of 1,3,5-tri[(4-ethynyl)phenyl]benzene, 234 mg of 4,4'-dibromobiphenyl, and 270 mg of 1,6-dibromopyrene, and use them as raw materials; weigh 52.6 mg of Pd(PPh3)2C l2, 14.3 mg of Cu I, and 197 mg of PPh3, and use them as catalysts; under nitrogen protection, mix the above raw materials and catalysts and add them into a mixed solvent of triethylamine and toluene to obtain a mixture solution c with a concentration of 0.8 to 1 mol / L; wherein the mixing volume ratio of triethylamine to toluene is 1:1.5;

[0044] The mixture solution c was placed in an oil bath at 90±0.1°C and heated under reflux for 15 h to obtain a crude product d;

[0045] The crude product d was filtered and washed multiple times with toluene, chloroform and KI aqueous solution, wherein toluene and chloroform can wash away the catalyst dissolved in the crude product d, and the KI aqueous solution can wash away the triethylamine salt dissolved in the crude product d, and then the crude product d was purified by Soxhlet extraction with dichloromethane for 80 hours and vacuum dried to obtain a conjugated microporous polymer as a yellow solid; (the yield exceeded 81%).

[0046] Specifically, the chemical reaction steps of the above conjugated microporous polymer are as follows:

[0047]

[0048] Preparation of conjugated microporous cesium ion exchangers containing sulfonic acid groups

[0049] Weigh 200 mg of the above conjugated microporous polymer and 13 mL of dichloroethane, place the conjugated microporous polymer in dichloroethane at room temperature, and stir for 0.5 to 3 h (preferably 2 h) until the conjugated microporous polymer swells;

[0050] 5 mL of chlorosulfonic acid was measured and added dropwise to the swollen mixture under ice bath conditions, and the mixture was mixed and stirred at room temperature for 10 to 70 h (preferably 60 h) to obtain a mixture solution a;

[0051] The mixture solution a is slowly placed in ice water at 0°C for quenching until the mixture solution a no longer dissipates heat, to obtain a crude product b;

[0052] The crude product b was filtered and washed with deionized water and methanol until it was neutral, thereby removing the unreacted chlorosulfonic acid in the crude product b, and then subjected to methanol Soxhlet extraction and purification for 80 hours and vacuum drying to obtain a brown solid, which was a conjugated microporous cesium ion exchanger containing sulfonic acid groups (yield exceeding 97%).

[0053] Specifically, the chemical reaction steps of the above-mentioned conjugated microporous cesium ion exchanger containing sulfonic acid groups are as follows:

[0054]

[0055] For the conjugated microporous polymer and the conjugated microporous cesium ion exchanger containing sulfonic acid groups prepared in the above examples:

[0056] Figure 1 This is an infrared comparison of the two. -1 Characteristic peaks of -OH in sulfonic acid group, 1360, 1176, 1044 cm -1 It is the characteristic peak of -S=O in sulfonic acid group;

[0057] Figure 2 This is a scanning electron microscope image of a conjugated microporous cesium ion exchanger containing sulfonic acid groups. The image shows that the size of the conjugated microporous cesium ion exchanger containing sulfonic acid groups is about 2 μm, and its morphology is a staggered distribution of spheres and tubes, with a large specific surface area.

[0058] Figure 3 The cesium adsorption curve of the conjugated microporous cesium ion exchanger containing sulfonic acid groups is shown in the figure. The conjugated microporous cesium ion exchanger containing sulfonic acid groups sulfonated for 60 hours can quickly and efficiently adsorb Cs+ in aqueous solution, and the adsorption amount within 1 min can reach 99% of the equilibrium adsorption amount, which can almost reach adsorption equilibrium.

[0059] In summary, the successful preparation of the conjugated microporous cesium ion exchanger containing sulfonic acid groups is proved. In addition, the conjugated microporous cesium ion exchanger containing sulfonic acid groups has a permanent porous structure and a large specific surface area, which increases the adsorption active sites of the ion exchanger, thereby effectively improving the equilibrium adsorption capacity and adsorption selectivity.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a conjugated microporous cesium ion exchanger containing a sulfonic acid group, characterized in that: The steps include: S1. Preparation of conjugated microporous polymer using 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene as raw materials; S2. The conjugated microporous polymer prepared in step S1 is placed in dichloroethane and stirred at room temperature to swell, and then chlorosulfonic acid is added dropwise under ice bath conditions, and mixed evenly to obtain a mixture solution a; S3. The mixture solution a is placed in ice water for quenching to obtain a crude product b; S4. The crude product b is filtered and washed with deionized water and methanol until it is neutral, and then purified by methanol Soxhlet extraction and vacuum drying to obtain a conjugated microporous cesium ion exchanger containing sulfonic acid groups.

2. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 1, characterized in that: The conjugated microporous cesium ion exchanger containing sulfonic acid groups is a brown solid.

3. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 1, characterized in that: The mixing mass ratio of the conjugated microporous polymer to the chlorosulfonic acid is 1:40-45, and the mixing volume ratio of the ethylene dichloride to the chlorosulfonic acid is 2-3:

1.

4. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 1, characterized in that: Chlorosulfonic acid was added dropwise in an ice bath, and the mixture was stirred for 10 to 70 hours.

5. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 1, characterized in that: The methanol Soxhlet extraction purification time is 80 hours.

6. The method for preparing a conjugated microporous cesium ion exchanger containing a sulfonic acid group according to claim 1, characterized in that: The preparation of a conjugated microporous polymer using 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene as raw materials includes the following steps: S11. Adding the raw materials and the catalyst to a mixed solvent of triethylamine and toluene under nitrogen protection to obtain a mixture solution c with a concentration of 0.8 to 1 mol / L, wherein the raw materials include 1,3,5-tri[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl, and 1,6-dibromopyrene, and the catalyst includes Pd(PPh3)2Cl2, CuI, and PPh3; S12. The mixture solution c is placed in an oil bath and heated at 80°C to 95°C for 7 to 30 hours to obtain a crude product d; S13. The crude product d was filtered and washed with toluene, chloroform and KI aqueous solution, and then purified by dichloromethane Soxhlet extraction and vacuum drying to obtain a conjugated microporous polymer.

7. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 6, characterized in that: The mixing mass ratio of the 1,3,5-tris[(4-ethynyl)phenyl]benzene, 4,4'-dibromobiphenyl and 1,6-dibromopyrene is 26-28:16-18:17-19.

8. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 6, characterized in that: The mixing mass ratio of Pd(PPh3)2Cl2, CuI and PPh3 in the catalyst is 3-4:1:12-14.

9. The method for preparing the conjugated microporous cesium ion exchanger containing sulfonic acid groups according to claim 6, characterized in that: The mixing volume ratio of triethylamine to toluene in the mixed solvent is 1:1-3.

10. The conjugated microporous cesium ion exchanger containing sulfonic acid groups prepared by the preparation method according to any one of claims 1 to 9.

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