Macrocyclic aromatic hydrocarbon polymer material, synthesis method thereof and application of macrocyclic aromatic hydrocarbon polymer material in iodine adsorption

Abstract

The invention discloses a macrocyclic aromatic hydrocarbon polymer material, a synthesis method thereof and application of the macrocyclic aromatic hydrocarbon polymer material in iodine adsorption. The polymer material is a nonporous amorphous solid prepared by taking benzophenone [3] aromatic hydrocarbon as a macrocyclic aromatic hydrocarbon monomer and 4, 4 '-diamino terphenyl as a comonomer through catalytic polymerization reaction in a chlorobenzene solvent under the common catalysis of titanium tetrachloride and 1, 4-diazabicyclo [2.2. 2] octane. The material has high saturated adsorption capacity (greater than 2.4 g / g) for iodine steam, has rapid adsorption capacity for water phase iodine (the removal rate for 1 mM of iodine aqueous solution within 1 hour can reach 100%), can be desorbed and regenerated through an organic solvent, and has excellent recycling performance. The material disclosed by the invention is simple in synthesis path and good in reproducibility, and has a wide application prospect in the fields of radioactive iodine capture, environmental restoration, industrial iodine recovery and the like.

Description

Technical Field

[0001] This invention belongs to the field of functional polymer materials and pollutant adsorption technology, and relates to a macrocyclic aromatic hydrocarbon-based polymer material and its synthesis method, as well as the application of this material in the field of iodine adsorption and separation, especially in the capture of radioactive iodine or industrial iodine in nuclear waste treatment and environmental remediation. Background Technology

[0002] The rapid development of the nuclear energy industry and the widespread application of nuclear medicine have led to the use of radioactive iodine (such as...) 129 I and 131 The treatment of iodine vapors (I) has become a significant challenge concerning environmental safety and public health. These isotopes are highly volatile and mobile, and if released from nuclear waste or accidents, they will pose a long-term threat to ecosystems. Furthermore, the recovery of iodine vapors and the purification of the precious metal iodine in industrial processes also have significant economic value. Currently, while commercial adsorbent materials (such as activated carbon and silver zeolite) have shown some effectiveness, they generally suffer from limited adsorption capacity, poor selectivity, high cost, or insufficient stability. Therefore, developing novel adsorbent materials that combine high adsorption efficiency, excellent selectivity, and good stability is of urgent importance for nuclear waste treatment, environmental remediation, and resource recovery.

[0003] Macrocyclic aromatic hydrocarbon (MAP)-based polymer materials have shown great potential in the field of iodine adsorption due to their unique structural advantages. These materials use rigid, electron-rich MAPs (such as calixarenes and columnararenes) as basic building blocks, forming a stable network with abundant π-electron systems and tunable microporous structures through polymerization. Their core advantages are twofold: first, their cavity structure and electron-rich surfaces can interact strongly and specifically with iodine molecules through mechanisms such as host-guest inclusion, π-π stacking, and charge transfer, thereby achieving high adsorption capacity and excellent selectivity; second, the polymer framework endows the materials with good chemical stability and mechanical strength, and their topology, pore size, and surface properties can be precisely controlled through monomer design and polymerization strategies, thereby optimizing their adsorption kinetics, cycle stability, and practical application performance.

[0004] However, despite the excellent molecular recognition potential of macrocyclic aromatic units, their inherent three-dimensional cavity structure and steric hindrance pose challenges to traditional post-synthetic modification methods, including low reaction efficiency, poor selectivity of functionalization sites, and complex product purification. This, to some extent, limits the controllable preparation and performance maximization of macrocyclic aromatic-based functional polymer materials. Therefore, developing efficient and universal strategies to controllably integrate macrocyclic aromatic skeletons into functional polymer networks to fully leverage their structural advantages and overcome processing and modification difficulties is of great significance for promoting the practical application of such materials in nuclear environment remediation and high-value separation, and is also one of the key issues currently facing supramolecular materials chemistry. Summary of the Invention

[0005] The purpose of this invention is to provide a macrocyclic aromatic hydrocarbon-based polymer material and its synthesis method; Another objective of this invention is to provide an application of macrocyclic aromatic polymer materials in iodine adsorption separation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a macrocyclic aromatic polymer material, which is prepared by catalytic polymerization of benzophenone[3]arene (BP[3]) monomer and 4,4'-diaminoterphenyl (DPT) monomer. The molar ratio of benzophenone[3]arene to 4,4'-diaminoterphenyl is 1:3. This material has non-porous and amorphous physical properties, and its basic structure is as follows: .

[0007] The method for synthesizing macrocyclic aromatic polymer materials of the present invention includes the following process steps: Using chlorobenzene as solvent and 1,4-diazabicyclo[2,2,2]octane and titanium tetrachloride as co-catalysts, benzophenone[3]arene (BP[3]) and 4,4'-diaminoterphenyl (DPT) were reacted at a molar ratio of 1:3 under nitrogen protection at reflux temperature of 100-130℃ for 48-72 h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain the crude product. The crude product was then washed multiple times with dichloromethane, ethanol, and distilled water, and dried to obtain a brown solid powder, which is the polymer material BPD. The synthetic route is as follows: The amount of 1,4-diazabicyclo[2,2,2]octane used was 6 to 7 times the molar amount of BP[3]; the amount of titanium tetrachloride used was 1.5 to 2 times the molar amount of BP[3]. The titanium tetrachloride catalyst was added in batches, and after all the catalyst was added, it was stirred and activated at room temperature for 20 to 40 minutes, and then heated to carry out the catalytic polymerization reaction. Synthesis of benzophenone[3] aromatics (BP[3]): Refer to the literature Org. Lett. 2025, 27, 40, 11231–11236.

[0008] This invention provides the application of the above-mentioned macrocyclic aromatic polymer materials in iodine adsorption separation.

[0009] The material is used for iodine in iodine vapor or aqueous phase. Experiments show that the BPD material prepared by this invention has excellent adsorption performance for iodine vapor, with a saturated adsorption capacity greater than 2.4 g / g. The BPD material prepared by this invention has a rapid adsorption capacity for iodine in aqueous phase; for a 1 mM iodine aqueous solution, the adsorption removal rate can reach 100% within 1 hour. Furthermore, after adsorbing iodine, the macrocyclic aromatic hydrocarbon polymer material can be desorbed and regenerated using an organic solvent (such as n-hexane). The desorbed material can be reused for iodine adsorption, and it still maintains excellent adsorption performance after multiple cycles.

[0010] The beneficial effects of this invention are as follows: 1. Novel material design: This invention prepares a polymer material by catalytic polymerization of benzophenone[3] aromatics, a specific macrocyclic aromatic monomer, and 4,4'-diaminoterphenyl. This material combines the electron-rich cavity of macrocyclic aromatics with the stability of polymer networks.

[0011] 2. The synthesis method is simple and efficient: a one-pot polymerization method is adopted, with TiCl4 / DABCO as the catalytic system and chlorobenzene as the solvent. The reaction conditions are mild, the operation is simple, the reproducibility is good, and it is easy to prepare on a large scale.

[0012] 3. Excellent iodine adsorption performance: Although the obtained BPD material is non-porous amorphous, it has a high adsorption capacity for iodine vapor (>2.4 g / g) and an extremely fast adsorption rate for aqueous iodine (complete removal of 1 mM iodine solution within 1 hour), showing a synergistic adsorption effect far exceeding that of its monomer (BP[3]).

[0013] 4. Good recyclability: The material after adsorbing iodine can be desorbed and regenerated through simple solvent treatment. After being recycled 5 times, the adsorption performance did not show a significant decline, which has good practicality and economy.

[0014] 5. Broad application prospects: This material has significant application potential in fields such as the capture of radioactive iodine in nuclear waste, the treatment and resource recovery of iodine-containing industrial waste gas / wastewater, and environmental emergency remediation. Attached Figure Description

[0015] Figure 1 The macrocyclic aromatic hydrocarbon-based polymer material BPD of this invention 13 C NMR spectrum.

[0016] Figure 2 (a) Scanning electron microscope image, (b) BET image, (c) EDS elemental analysis image, and (dg) EDS-Mapping analysis image of the macrocyclic aromatic polymer material BPD prepared for this invention.

[0017] Figure 3The time-dependent solid vapor adsorption diagram of iodine vapor on macrocyclic aromatic polymer materials BPD and BP[3] powder prepared in this invention.

[0018] Figure 4 This is a linear fit graph of the iodine adsorption capacity of the macrocyclic aromatic polymer material BPD prepared in this invention over time.

[0019] Figure 5 The adsorption kinetics data of the macrocyclic aromatic polymer materials prepared in this invention were linearly fitted using a pseudo-second-order model.

[0020] Figure 6 The time-dependent solid-liquid adsorption diagram of the macrocyclic aromatic polymer material BPD and BP[3] powder prepared in this invention on iodine aqueous solution is shown.

[0021] Figure 7 The diagram shows the cycling performance of the macrocyclic aromatic polymer material BPD prepared in this invention for capturing iodine. Detailed Implementation

[0022] The synthesis of the macrocyclic aromatic hydrocarbon-based polymer material and its application in iodine adsorption are further illustrated below through specific embodiments.

[0023] Example 1: Synthesis of macrocyclic aromatic hydrocarbon-based polymer material BPD BP[3] (200 mg, 0.143 mmol) and DPT (115 mg, 0.443 mmol) were dissolved in chlorobenzene, and 1,4-diazabicyclo[2,2,2]octane (96 mg, 0.857 mmol) was added and stirred at room temperature under N2 atmosphere until completely dissolved. Titanium tetrachloride (41 mg, 0.214 mmol) was added in four portions, each 5 min apart, and stirred at room temperature for 20 min. The mixture was heated to 120 °C and refluxed for 72 h. After the reaction was completed, it was cooled to room temperature and filtered to obtain the crude product. The crude product was then washed multiple times with dichloromethane, ethanol, and distilled water, and dried to obtain a brown solid powder, which was the polymer material BPD.

[0024] Figure 1 BPD is a macrocyclic aromatic polymer material. 13 ¹³C NMR spectrum. The ¹³C NMR spectrum confirms the formation of the polymer structure.

[0025] Figure 2The morphology and composition characterization results of the macrocyclic aromatic polymer material BPD are shown, including (a) scanning electron microscope (SEM) images, (b) N2 adsorption-desorption isotherms (BET), (c) energy dispersive X-ray spectroscopy (EDS) analysis diagrams, and (d–g) corresponding elemental distribution maps (EDS-Mapping). The SEM images show that BPD exhibits a loose blocky morphology compared with the vesicular structure of the monomer BP[3]. The BET test shows that the specific surface area of ​​the material is only 2.2995 m² / g, indicating that it has a non-porous structure. The EDS spectrum and elemental distribution map further confirm that the polymer material contains three elements: carbon (C), nitrogen (N) and oxygen (O).

[0026] Example 2: Iodine adsorption performance test of macrocyclic aromatic hydrocarbon-based polymer material BPD (1) Material activation: 100 mg of BPD powder prepared in Example 1 and BP[3] monomer powder as a comparison were placed in an oven at 70°C for 5 hours to dry and activate them to remove any adsorbed moisture and solvent.

[0027] (2) Iodine vapor adsorption experiment (solid-gas adsorption): Accurately weigh 10.0 mg each of activated BPD and BP[3] powder and place them in small sample vials. Place the small sample vials containing BPD and BP[3] powder into a large sample vial containing solid iodine. Heat in an oven at 75°C, and use an analytical balance to detect the weight change of the small sample vials at intervals to determine the amount of iodine adsorbed by BPD and BP[3].

[0028] The results are as follows Figure 3 As shown, BPD material exhibits strong adsorption of iodine vapor, with the adsorption amount increasing rapidly over time, reaching saturation after about 7 hours, with a saturation adsorption amount as high as 2.47 g / g. In contrast, BP[3] powder does not adsorb iodine at all. This indicates that the polymerization process produces a significant performance improvement. Figure 4 Linear fitting showed that the average adsorption rate of BPD in the first hour was approximately 1.40 gg⁻¹ h⁻¹. Figure 5 The pseudo-second-order kinetic model fits well, with a kinetic rate of 0.438 gg. − 1 h −1 This suggests that chemisorption may be the main rate-controlling step.

[0029] (3) Iodine aqueous solution adsorption experiment (solid-liquid adsorption): BPD and BP[3] powders were weighed and placed in an aqueous solution of iodine. The concentration of the iodine solution was 1 mM, and the content of BPD and BP[3] was 2 mg / mL. The adsorption rate of the two materials to the aqueous solution of iodine was determined by testing the UV-Vis absorption spectrum of iodine at 459 nm. The results are as follows. Figure 6 As shown, the adsorption of iodine aqueous solution by BPD material is very rapid, and nearly 100% removal can be achieved within 60 minutes. In contrast, the adsorption rate of iodine aqueous solution by BP[3] monomer is relatively low. This proves that BPD material also has excellent and rapid capture ability for iodine in the liquid phase.

[0030] (4) Cyclic adsorption-desorption experiment: Take the saturated BPD material (which has adsorbed iodine) from Example 2 (2), immerse it in 20 mL of n-hexane, and let it stand at room temperature for 48 hours for desorption. During this period, fresh n-hexane can be replaced 1-2 times to promote complete desorption. After desorption, filter and collect the solid, and wash it 2-3 times with a small amount of n-hexane. Then place the solid in a 75℃ oven to dry, and obtain the regenerated BPD material. Use this regenerated BPD material again in the above iodine vapor adsorption experiment ((2)) to test its adsorption capacity. Repeat this "adsorption-desorption-re-adsorption" process 5 times. The results are as follows. Figure 7 As shown, after 5 cycles, the saturated adsorption capacity of the BPD material for iodine vapor decreased only slightly, remaining above 90% of the initial capacity, demonstrating excellent cycle stability and regeneration capability.

[0031] In summary, this invention successfully prepared a novel macrocyclic aromatic hydrocarbon-based polymer material, BPD. The synthesis method of this material is simple and reliable, and it exhibits excellent high-capacity, rapid, and recyclable adsorption performance for both gaseous and liquid iodine, making it of significant application value in the field of iodine pollution control and resource recovery.

Claims

1. A macrocyclic aromatic hydrocarbon-based polymer material, characterized in that: The benzophenone[3] aromatic hydrocarbon was prepared by catalytic polymerization using benzophenone[3] as the macrocyclic aromatic hydrocarbon monomer and 4,4'-diaminoterphenyl as the comonomer; the structural formula of benzophenone[3] aromatic hydrocarbon is: 。 2. The macrocyclic aromatic polymer material according to claim 1, characterized in that, The molar ratio of benzophenone[3] aromatic hydrocarbon to 4,4'-diaminoterphenyl is 1:3; the polymer material is a non-porous, amorphous solid powder.

3. A method for synthesizing a macrocyclic aromatic polymer material as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Dissolve benzophenone[3] aromatic hydrocarbon and 4,4'-diaminoterphenyl in chlorobenzene, add 1,4-diazabicyclo[2,2,2]octane, and stir to dissolve under inert gas protection; (2) Add titanium tetrachloride catalyst to the system obtained in step (1) and carry out catalytic polymerization reaction under inert gas protection; (3) After the reaction is completed, the reaction solution is post-treated to obtain macrocyclic aromatic polymer materials.

4. The synthesis method according to claim 2, characterized in that: In step (1), the amount of 1,4-diazabicyclo[2,2,2]octane used is 5 to 7 times the molar amount of benzophenone[3] aromatic hydrocarbon; in step (2), the amount of titanium tetrachloride used is 1.5 to 2 times the molar amount of benzophenone[3] aromatic hydrocarbon.

5. The synthesis method according to claim 2, characterized in that: In step (2), the temperature of the catalytic polymerization reaction is 100-130℃ and the time is 48-72 hours.

6. The synthesis method according to claim 2, characterized in that: In step (2), the titanium tetrachloride catalyst is added in batches. After all the catalyst is added, it is stirred and activated at room temperature for 20-40 minutes, and then heated to carry out the catalytic polymerization reaction. In step (3), the post-processing includes: adding water to the system after the reaction to quench the reaction, filtering to obtain a crude product, washing the crude product sequentially with dichloromethane, ethanol and water, and drying to obtain the macrocyclic aromatic polymer material.

7. The application of the macrocyclic aromatic polymer material as described in claim 1 in iodine adsorption.

8. The application according to claim 7, characterized in that: The material is used for the adsorption and separation of iodine vapor or aqueous iodine.

9. The application according to claim 8, characterized in that: The macrocyclic aromatic hydrocarbon-based polymer material has a saturated adsorption capacity of iodine vapor greater than 2.4 g / g; the macrocyclic aromatic hydrocarbon-based polymer material achieves a 100% adsorption and removal rate of iodine aqueous solution with a concentration of 1 mM within 1 hour.

10. The application according to claim 7, characterized in that: The macrocyclic aromatic polymer material can be regenerated and reused after adsorbing iodine by desorption with organic solvents.

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