A method for preparing and applying a columnar aromatic hydrocarbon-based eutectic iodine adsorbent

Abstract

This application discloses a method for preparing a co-crystal iodine adsorbent based on columnar aromatic hydrocarbons, specifically relating to the field of adsorbents. The method includes: co-dissolving columnar aromatic hydrocarbons and a compound containing electron-withdrawing groups in a first solvent to obtain a first mixed solution; allowing the first mixed solution to stand at a preset temperature until blocky crystals precipitate, obtaining a charge-transfer co-crystal. Utilizing the advantages of electron-rich supramolecular macrocyclic columnar aromatic hydrocarbons readily undergoing charge transfer (CT) and possessing intrinsic cavities, the CT interaction between the columnar aromatic hydrocarbons and the compound containing electron-withdrawing groups generates intriguing channels, resulting in high iodine removal efficiency. Furthermore, the chemical composition and assembly structure of this co-crystal are precisely controlled using a macrocyclic host competition method, further improving the adsorption efficiency.

Description

Technical Field

[0001] This application relates to the field of adsorbents, and more particularly to a method for preparing and applying a columnar aromatic eutectic iodine adsorbent. Background Technology

[0002] Radioactive iodine is a major pollutant in nuclear fission wastewater, exhibiting extremely high reactivity and biohazard, necessitating the development of functional materials for efficient iodine removal. Constructing supramolecular assemblies through non-covalent interactions has become a cornerstone of functional material development. Among these interactions, charge transfer (CT) interactions are particularly noteworthy, as CT interactions can lead to the formation of highly ordered structures (eutectic) with unique electronic properties. Furthermore, CT interactions are crucial for enhancing the iodine adsorption performance of adsorbents; therefore, regulating CT performance is essential for improving iodine adsorption efficiency. Existing CT-based adsorption materials include metal-organic frameworks (MOFs), porous silica, and covalent organic frameworks. However, these materials still suffer from challenges such as demanding and complex preparation conditions, poor stability, and difficulty in controlling iodine adsorption performance. For example, MOFs, due to their highly ordered pore structure and functionalized surfaces, can effectively adsorb iodine molecules; however, some MOFs easily lose their pore structure in humid environments, leading to a decline in adsorption performance. Moreover, the high synthesis cost of MOFs limits their large-scale application. Porous silicon materials possess a large specific surface area and abundant pore structure, enabling them to adsorb iodine via charge transfer. However, porous silicon materials are susceptible to environmental influences, especially under humid conditions, which can reduce their adsorption performance. Furthermore, the preparation of high-quality porous silicon materials requires complex processing techniques, increasing costs. Therefore, existing adsorption materials cannot meet the application requirements for highly efficient iodine adsorption. Summary of the Invention

[0003] The main objective of this application is to provide a method for preparing and applying a eutectic iodine adsorbent based on columnar aromatics, aiming to solve the problem of poor adsorption performance of existing iodine adsorbent materials.

[0004] To achieve the above objectives, this application provides a method for preparing a eutectic iodine adsorbent based on columnar aromatics, comprising: co-dissolving columnar aromatics and a compound containing electron-withdrawing groups in a first solvent to obtain a first mixed solution; and allowing the first mixed solution to stand at a preset temperature until blocky crystals precipitate to obtain a charge-transfer eutectic.

[0005] Optionally, the compounds containing electron-withdrawing groups include benzene derivatives, pyridine compounds, or imidazole compounds; the molar ratio of columnar aromatics to compounds containing electron-withdrawing groups is 0.5-5.

[0006] Optionally, the columnar aromatic hydrocarbon is a columnar hexaaromatic hydrocarbon with a concentration of 1-20 mM, and the compound containing an electron-withdrawing group is tetrafluoroterephthalonitrile.

[0007] Optionally, after obtaining the charge transfer eutectic, the method further includes the following steps: placing the charge transfer eutectic in a first solvent to obtain a second mixed solution; mixing the regulator and the first solvent to obtain a third mixed solution; adding the third mixed solution to the second mixed solution; and allowing the first mixed solution to stand at a preset temperature.

[0008] Optionally, the regulator is a pentaaryl aromatic hydrocarbon, or a mixture of a pentaaryl aromatic hydrocarbon and a compound containing an electron-withdrawing group; when the regulator is a mixture of a pentaaryl aromatic hydrocarbon and a compound containing an electron-withdrawing group, the molar ratio of the pentaaryl aromatic hydrocarbon to the charge-transfer cocrystal is 0.2-1, and the molar ratio of the compound containing the electron-withdrawing group to the charge-transfer cocrystal is 1-2; when the regulator is a pentaaryl aromatic hydrocarbon, the molar ratio of the regulator to the charge-transfer cocrystal is 1-2.

[0009] Optionally, after obtaining the first mixed solution, the method further includes the step of adding a second solvent to the first mixed solution.

[0010] Optionally, the first solvent is dichloromethane and the second solvent is n-hexane.

[0011] Furthermore, the present invention also provides a columnar aromatic hydrocarbon-based eutectic iodine adsorbent, comprising a charge-transfer eutectic, wherein the charge-transfer eutectic is EtP6-TFTN. a Or EtP6-TFTN b The charge-transfer eutectic was obtained by the above-described method for preparing a eutectic iodine adsorbent based on columnar aromatics.

[0012] EtP6-TFTN a EtP6-TFTN b All belong to the triclinic crystal system and have space group P-1.

[0013] EtP6-TFTN a The unit cell parameters are: α=108.963(4)°, β=108.419(4)°, γ=105.431(4)°,

[0014] EtP6-TFTN b The unit cell parameters are: α=68.459(4)°, β=89.110(5)°, γ=66.900(4)°,

[0015] In addition, the present invention also provides an application of a columnar aromatic hydrocarbon-based adsorbent in the iodine adsorption process.

[0016] Compared with the prior art, the beneficial effects of this application are as follows:

[0017] This invention discloses a cocrystal iodine adsorbent based on columnar aromatic hydrocarbons. Utilizing the advantages of electron-rich supramolecular macrocyclic columnar aromatic hydrocarbons, which readily undergo charge transfer (CT) and possess intrinsic cavities, CT interaction between the columnar aromatic hydrocarbons and compounds containing electron-withdrawing groups generates intriguing channels, resulting in high iodine removal efficiency. The charge-transfer cocrystal of this application is grown in the liquid phase, and its structure is unaffected by humid environments, thus not affecting adsorption performance. Both the columnar aromatic hydrocarbons and the compounds containing electron-withdrawing groups are common organic compounds, resulting in lower costs compared to existing adsorbent materials. Furthermore, the cocrystal's chemical composition and assembly structure are precisely controlled using a macrocyclic host competition method, further improving adsorption efficiency. Attached Figure Description

[0018] Figure 1 The EtP6-TFTN obtained in Example 1 of the preparation method of the eutectic iodine adsorbent based on columnar aromatics in this application is an example of this application. a Powder X-ray diffraction pattern;

[0019] Figure 2 The EtP6-TFTN obtained in Example 1 of the preparation method of the eutectic iodine adsorbent based on columnar aromatics in this application is an example of this application. a EtP6-TFTN a Crystal structure diagram and packing diagram of host-guest complex;

[0020] Figure 3 The EtP6-TFTN obtained in Example 1 of the preparation method of the eutectic iodine adsorbent based on columnar aromatics in this application is an example of this application. a Graph showing the change in ultraviolet absorption spectrum after adding iodine to water;

[0021] Figure 4 This is a diagram showing the transformation of unit cell parameters of a crystal at different times during the crystal transformation process in the preparation method of a eutectic iodine adsorbent based on columnar aromatics according to this application.

[0022] Figure 5 EtP6-TFTN obtained in Example 2 of the preparation method of a eutectic iodine adsorbent based on columnar aromatics in this application. b Powder X-ray diffraction pattern;

[0023] Figure 6 EtP6-TFTN obtained in Example 2 of the preparation method of a eutectic iodine adsorbent based on columnar aromatics in this application. b EtP6-TFTN a Crystal structure diagram and packing diagram of host-guest complex;

[0024] Figure 7 EtP6-TFTN obtained in Example 2 of the preparation method of a eutectic iodine adsorbent based on columnar aromatics in this application. b Graph showing the change in ultraviolet absorption spectrum after adding iodine to water;

[0025] Figure 8 The diagram shows the iodine removal efficiency of the eutectic iodine adsorbent prepared by the method of preparing the eutectic iodine adsorbent based on columnar aromatics according to this application.

[0026] Figure 9 This is a diagram showing the transformation of unit cell parameters of a crystal at different times during the crystal transformation process in the preparation method of a eutectic iodine adsorbent based on columnar aromatics according to this application.

[0027] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The first embodiment of the present invention provides a method for preparing a eutectic iodine adsorbent based on columnar aromatic hydrocarbons, such as... Figure 1 As shown, the specific steps include:

[0030] Step S1: The columnar aromatic hydrocarbon and the compound containing electron-withdrawing groups are co-dissolved in a first solvent at a molar ratio of 0.5-5 to obtain a first mixed solution;

[0031] Among them, compounds containing electron-withdrawing groups include benzene derivatives, pyridine compounds, or imidazole compounds. The columnar aromatic hydrocarbon is a columnar hexaaromatic hydrocarbon; for example, a columnar hexaaromatic hydrocarbon can be ethoxy columnar hexaaromatic hydrocarbon (EtP6), with a concentration of 1-20 mM. EtP6 is prepared in advance using existing methods, and the prepared EtP6 is recrystallized and then vacuum dried to obtain a pure EtP6 compound. The recrystallization solvent includes, but is not limited to, chloroform or acetone. Compounds containing electron-withdrawing groups can be tetrafluoroterephthalonitrile (TFTN), and the first solvent can be dichloromethane.

[0032] The structural formula for EtP6 is as follows:

[0033]

[0034] The structural formula of TFTN:

[0035]

[0036] To prevent the solvent in the first mixed solution from evaporating too quickly and affecting the product performance, a second solvent is added to the first mixed solution after co-solventization. The second solvent can be n-hexane, and the ratio of the second solvent to the first solvent can be 2:1.

[0037] Step S2: The first mixed solution is allowed to stand for 3-5 days at a preset temperature until yellow or orange blocky crystals precipitate, thus obtaining a charge-transfer eutectic; wherein, the preset temperature is room temperature, i.e., about 25°C.

[0038] The reaction mechanism of the charge-transfer eutectic is as follows: EtP6 acts as a charge-transfer π donor, and TFTN is an electron-deficient π acceptor that readily interacts with the π donor. The electron-rich ethoxy groups in EtP6 readily undergo charge transfer with the electron-deficient fluorine and nitrile groups in TFTN, thus assembling together through supramolecular interactions. TFTN and EtP6 exhibit outer-wall supramolecular interactions, such as π-π stacking and CH···π interactions, within the EtP6-TFTN eutectic complex. b CH···F interactions also occurred.

[0039] A second embodiment of the present invention provides a eutectic iodine adsorbent based on columnar aromatics, obtained by the above method. Different products are obtained when the concentration of columnar aromatics and the molar ratio of columnar aromatics to compounds containing electron-withdrawing groups are different. Specifically, when the concentration of EtP6 is 1-2 mM and the molar ratio of EtP6 to TFTN is 0.5-5, the obtained charge-transfer eutectic is EtP6-TFTN. a When the concentration of EtP6 is 5-20 mM and the molar ratio of EtP6 to TFTN is 0.5-1, the eutectic iodine adsorbent based on columnar aromatics is EtP6-TFTN. a When the molar ratio of EtP6 to TFTN is 2-5, the eutectic iodine adsorbent based on columnar aromatics is EtP6-TFTN. b .

[0040] EtP6-TFTN a and EtP6-TFTN b All of them are two-dimensional layered supramolecular network structures, belonging to the triclinic crystal system, and all have space group P-1;

[0041] EtP6-TFTN a The unit cell parameters are: α=108.963(4)°, β=108.419(4)°, γ=105.431(4)°,

[0042] EtP6-TFTN b The unit cell parameters are: α=68.459(4)°, β=89.110(5)°, γ=66.900(4)°, Based on the above embodiments, the preparation method of the present invention further includes a control method, namely, controlling the charge transfer eutectic obtained in step 2 to make EtP6-TFTN b Convert to EtP6-TFTN a Or make EtP6-TFTN a Convert to EtP6-TFTN b The specific control methods are as follows:

[0043] Step S3: Place the charge transfer eutectic in the first solvent to obtain a second mixed solution; mix the regulator and the first solvent to obtain a third mixed solution; add the third mixed solution to the second mixed solution, and let the first mixed solution stand at a preset temperature for 2-4 hours to allow the EtP6-TFTN to react. b Convert to EtP6-TFTN a Or make EtP6-TFTN a Convert to EtP6-TFTN b .

[0044] Among them, when the charge transfer eutectic is EtP6-TFTN a When the modifier is a mixture of ethoxy-based pentaaryl aromatic hydrocarbons and compounds containing electron-withdrawing groups, the molar ratio of ethoxy-based pentaaryl aromatic hydrocarbons to charge-transfer cocrystal is 0.5-1, and the molar ratio of compounds containing electron-withdrawing groups to charge-transfer cocrystal is 1-2. When the charge-transfer cocrystal is EtP6-TFTN... b At that time, the regulator was ethoxylated pentaaryl aromatic hydrocarbon, and the molar ratio of the regulator to the charge transfer eutectic was 1-2. The regulator mechanism was as follows: EtP5 competed with EtP6 for TFTN to achieve EtP6-TFTN. b Convert to EtP6-TFTN a EtP5 achieves EtP6-TFTN through enriched TFTN. a Convert to EtP6-TFTN b This allows for precise control of the chemical composition of the eutectic iodine adsorbent.

[0045] The structural formula for EtP5 is as follows:

[0046]

[0047] Example 1

[0048] Weigh EtP6 and TFTN into a glass vial at a molar ratio of 1. Dissolve both in dichloromethane (EtP6 concentration greater than 5 mM / L) to obtain a first mixed solution. After the first mixed solution changes from clear to yellow and is thoroughly stirred, filter it through a 0.22-micron organic filter membrane. Add n-hexane, with the volume of n-hexane being twice that of dichloromethane. Slightly loosen the cap and allow it to stand at room temperature to allow the solvent to slowly evaporate. Yellow or orange blocky eutectic crystals will slowly precipitate. Grind the obtained yellow blocky crystals into powder and dry them overnight in a vacuum drying oven at 50°C to obtain EtP6-TFTN. a .

[0049] The EtP6-TFTN obtained in this embodiment a The crystal structure was characterized by powder X-ray diffraction, and the results are as follows: Figure 1 As shown, the diffraction peak signals of the prepared powder crystals all match the simulated XRD data, indicating the successful synthesis of the material.

[0050] The EtP6-TFTN obtained in this embodiment a Crystal structure diagram and stacking arrangement of host-guest complex as follows Figure 2 As shown, EtP6 interacts with two surrounding TFTN molecules (TFTNs in the same crystallographic sense) via supramolecular interactions, and also interacts with four other surrounding EtP6 molecules. Viewed along one axis, TFTNs and EtP6s intersect to form a supramolecular network, thus demonstrating the EtP6-TFTN structure. a The orderliness and porosity of the eutectic facilitate the adsorption of iodine through charge transfer effects.

[0051] Take 3 mg of the prepared EtP6-TFTN a Crush and mix 3 mg of EtP6-TFTN under normal pressure. a As an adsorbent, iodine was added to 3 mL of a 0.8 mM iodine aqueous solution for iodine adsorption experiments. The adsorption process was monitored using UV-Vis absorption spectroscopy, and the results are as follows: Figure 3 As shown, EtP6-TFTN is added. a Subsequently, the color of the iodine solution gradually changed from dark purple to colorless, indicating that EtP6-TFTN a It gradually absorbed iodine from the solution. The aqueous solution of iodine exhibits a distinct I₂ ultraviolet absorption peak at 460 nm and a distinct I₃ peak at 350 nm. - The UV absorption peak at 460 nm gradually decreased until it disappeared with increasing adsorption time. The absorption peak at 350 nm first increased and then decreased with time until it disappeared. This indicates that the addition of the adsorbent promoted the dissociation of iodine in water and subsequently adsorbed it.

[0052] Example 2

[0053] Based on Example 1, EtP6-TFTN a The mixture was placed in a dichloromethane solution to obtain a second mixed solution; EtP5, TFTN, and the dichloromethane solution were then mixed to obtain a third mixed solution, in which EtP5 and EtP6-TFTN were combined. a The molar ratio of TFTN to EtP6-TFTNa is 1; the molar ratio of TFTN to EtP6-TFTNa is 1. After standing for 2 days, EtP6-TFTN can be obtained. b Crystal.

[0054] The unit cell parameters of the crystal at different times during the crystal transformation process in this embodiment were recorded, and the results are as follows: Figure 4 As shown, a small amount of EtP5 was found to promote EtP6-TFTN. a Combined with TFTN to form EtP6-TFTN b Crystal; a large amount of EtP5 can promote EtP6-TFTN a Disassembling and reassembling with TFTN to form EtP6-TFTN a Crystal.

[0055] Example 3

[0056] Weigh EtP6 and TFTN in a glass vial at a molar ratio of 2. Dissolve both in dichloromethane (EtP6 concentration greater than 5 mM / L) to obtain a first mixed solution. After the first mixed solution changes from clear to yellow and is thoroughly stirred, filter it through a 0.22-micron organic filter membrane. Add n-hexane, with the volume of n-hexane being twice that of dichloromethane. Slightly loosen the cap and allow it to stand at room temperature to allow the solvent to slowly evaporate. Yellow or orange blocky eutectic crystals will slowly precipitate. Grind the obtained yellow blocky crystals into powder and dry them overnight in a vacuum drying oven at 50°C to obtain the charge-transfer eutectic EtP6-TFTN. b .

[0057] The charge-transfer eutectic obtained in this embodiment was characterized by powder X-ray diffraction, and the results are as follows: Figure 5 As shown, the diffraction peak signals of the prepared powder crystals all match the simulated XRD data, indicating that the obtained crystal is EtP6-TFTN. b EtP6-TFTN b Crystal structure diagram and stacking arrangement of host-guest complex as follows Figure 6 As shown, EtP6 interacts with two surrounding TFTN molecules (two types of TFTN in the crystallographic sense), and EtP6 also interacts with four other surrounding EtP6 molecules; viewed along one axis, TFTN and EtP6 appear alternately to form a supramolecular network.

[0058] Take 3 mg of the prepared EtP6-TFTN b Crush and mix 3 mg of EtP6-TFTN under normal pressure. b As an adsorbent, iodine was added to 3 mL of a 0.8 mM iodine aqueous solution for iodine adsorption experiments. The adsorption process was monitored using UV-Vis absorption spectroscopy, and the results are as follows: Figure 7 As shown, EtP6-TFTN is added. b Subsequently, the color of the iodine solution gradually changed from dark purple to colorless, indicating that EtP6-TFTN a It gradually absorbed iodine from the solution. The aqueous solution of iodine exhibits a distinct I₂ ultraviolet absorption peak at 460 nm and a distinct I₃ peak at 350 nm. - The UV absorption peak at 460 nm gradually decreased until it disappeared with increasing adsorption time. The absorption peak at 350 nm first increased and then decreased with time until it disappeared. This indicates that the addition of the adsorbent promoted the dissociation of iodine in water and subsequently adsorbed it.

[0059] Based on the UV absorption intensity of iodine aqueous solution at 350 nm and 460 nm with respect to EtP6-TFTN a and EtP6-TFTN b The changes in adsorption time were plotted to show the effects of the adsorbent material on I2 and I3 in aqueous solution. - The removal efficiency, the results are as follows Figure 8 As shown. EtP6-TFTN a With EtP6-TFTN b In water, for I2 and I 3- The removal efficiencies reached 99.04%, 91.13%, and 98.87%, 88.21%, respectively. This indicates that it is a high-performance liquid iodine adsorbent, demonstrating the superior performance of the EtP6-TFTN of this invention. a For I2 and I3 in aqueous solution - It has a better removal efficiency.

[0060] Example 4

[0061] Based on Example 3, the charge-transfer eutectic was placed in a dichloromethane solution to obtain a second mixed solution; EtP5 and the dichloromethane solution were mixed to obtain a third mixed solution, with a molar ratio of EtP5 to the charge-transfer eutectic of 2. The third mixed solution was added to the second mixed solution, and the first mixed solution was allowed to stand at room temperature for 4 days to allow the EtP6-TFTN to mature. b Convert to EtP6-TFTN a .

[0062] The unit cell parameters of the crystal at different times during the crystal transformation process in this embodiment were recorded, and the results are as follows: Figure 9 As shown, EtP5 can drive EtP6-TFTN b Disassembling and reassembling with TFTN to form EtP6-TFTN a Crystals were formed, and EtP6-TFTN was sequentially produced during the process. c and EtP6-TFTN d Two intermediate crystals. EtP6-TFTN c and EtP6-TFTN d All are two-dimensional layered supramolecular network structures, belonging to the triclinic crystal system, with space group P-1; EtP6-TFTN c The unit cell parameters are: α=81.421(4)°, β=78.371(4)°, γ=87.608(5)°, EtP6-TFTN d The unit cell parameters are: α=75.269(7)°, β=81.803(7)°, γ=76.734(7)°,

[0063] Example 5

[0064] Weigh EtP6 and TFTN into a glass vial at a molar ratio of 0.5. Dissolve both in dichloromethane (EtP6 concentration greater than 5 mM / L) to obtain a first mixed solution. After the first mixed solution changes from clear to yellow and is thoroughly stirred, filter it through a 0.22-micron organic filter membrane. Add n-hexane, with the volume of n-hexane being twice that of dichloromethane. Slightly loosen the cap and allow it to stand at room temperature to allow the solvent to slowly evaporate. Yellow or orange blocky eutectic crystals will slowly precipitate. Grind the obtained yellow blocky crystals into powder and dry them overnight in a vacuum drying oven at 50°C to obtain EtP6-TFTN. a ;

[0065] EtP6-TFTN a The mixture was placed in a dichloromethane solution to obtain a second mixed solution; EtP5, TFTN, and the dichloromethane solution were then mixed to obtain a third mixed solution, in which EtP5 and EtP6-TFTN were combined. a The molar ratio of TFTN to EtP6-TFTNa is 1; the molar ratio of TFTN to EtP6-TFTNa is 1. After standing for 2 days, EtP6-TFTN can be obtained. b Crystal.

[0066] Example 6

[0067] Weigh EtP6 and TFTN into a glass vial at a molar ratio of 3. Dissolve both in dichloromethane (EtP6 concentration greater than 5 mM / L) to obtain a first mixed solution. After the first mixed solution changes from clear to yellow and is thoroughly stirred, filter through a 0.22-micron organic filter membrane. Add n-hexane, with the volume of n-hexane being twice that of dichloromethane. Slightly loosen the cap and allow it to stand at room temperature to allow the solvent to slowly evaporate. Yellow or orange blocky eutectic crystals will slowly precipitate. Grind the obtained yellow blocky crystals into powder and dry them overnight in a vacuum drying oven at 50°C to obtain the charge-transfer eutectic EtP6-TFTN. b .

[0068] Based on Example 3, the charge-transfer eutectic was placed in a dichloromethane solution to obtain a second mixed solution; EtP5 and the dichloromethane solution were mixed to obtain a third mixed solution, with a molar ratio of EtP5 to the charge-transfer eutectic of 2. The third mixed solution was added to the second mixed solution, and the first mixed solution was allowed to stand at room temperature for 4-5 days to allow the EtP6-TFTN to develop. b Convert to EtP6-TFTN a .

[0069] This invention, through testing, reveals that when the EtP6 concentration is between 1-2 mM, if the molar ratio of EtP6 to TFTN is greater than 5 or less than 0.5, excess raw material will precipitate in the form of colorless crystals. When the EtP6 concentration is between 5-20 mM, if the molar ratio of EtP6 to TFTN is greater than 5 or less than 0.5, excess raw material will precipitate in the form of colorless crystals, and the collisions between excess raw materials in the liquid phase will not produce assemblies, thus affecting assembly efficiency. When the EtP6 concentration is less than 1 mM, it is more difficult for EtP6 and TFTN in the system to combine, leading to a decrease in the bonding rate. This manifests as mostly colorless crystals, making it difficult to grow colored charge-transfer eutectics. When the EtP6 concentration is greater than 20 mM, the system approaches saturation, and precipitates rapidly. The EtP6 and TFTN in the system do not have enough time to interact, resulting in mostly non-crystalline precipitates, making it difficult to grow colored charge-transfer eutectics.

[0070] If in EtP6-TFTN a Convert to EtP6-TFTN b During the process, if the molar ratio of added EtP5 to charge-transfer eutectic is greater than 1, the modulator will become ineffective, and the crystal will remain EtP6-TFTN. a If the molar ratio of added EtP5 to charge-transfer eutectic is less than 0.5, the crystal conversion will be incomplete. This applies to EtP6-TFTN. b Convert to EtP6-TFTN aDuring the process, if the molar ratio of added EtP5 to charge-transfer eutectic is less than 1, the modulator will become ineffective, and the crystal will remain EtP6-TFTN. b If the molar ratio of EtP5 to charge-transfer eutectic is greater than 2, the transformed crystal will adhere to EtP5, making separation difficult.

[0071] The third embodiment of the present invention provides an application of a columnar aromatic hydrocarbon-based eutectic adsorbent in the iodine adsorption process. As can be seen from the above embodiments, the charge-transfer eutectic of the present invention can be used to remove iodine from aqueous solutions. Furthermore, it can also be used for the adsorption of iodine in solid and gas phases, such as in the removal of iodine in masks, membranes, and vapor adsorption separation.

[0072] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A eutectic iodine adsorbent based on columnar aromatics, characterized in that, Includes a charge-transfer eutectic, wherein the charge-transfer eutectic is EtP6-TFTN. a Or EtP6-TFTN b ; The EtP6-TFTN a EtP6-TFTN b All belong to the triclinic crystal system and have space group P-1. The EtP6-TFTN a The unit cell parameters are: a = 12.1830(12) Å, b = 12.3422(12) Å, c = 13.7995(14) Å, α = 108.963(4)°,β = 108.419(4)°, γ = 105.431(4)°, V = 1697.3(3) Å 3 ; The EtP6-TFTN b The unit cell parameters are: a = 12.1303(13) Å, b = 13.3451(15) Å, c = 13.6341(14) Å, α = 68.459(4)°,β = 89.110(5)°, γ = 66.900(4)°, V = 1866.9(4) Å 3 。 2. A method for preparing the eutectic iodine adsorbent based on columnar aromatics as described in claim 1, characterized in that, include: A columnar aromatic hydrocarbon and a compound containing electron-withdrawing groups are co-dissolved in a first solvent to obtain a first mixed solution; The first mixed solution is allowed to stand at a preset temperature until blocky crystals precipitate, thus obtaining a charge-transfer eutectic. The columnar aromatic hydrocarbon is EtP6, and the compound containing electron-withdrawing groups is TFTN.

3. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 2, characterized in that, After the precipitation of bulk crystals, the method further includes the following steps: The charge-transfer eutectic is placed in a first solvent to obtain a second mixed solution; The regulator and the first solvent are mixed to obtain a third mixed solution; The third mixed solution is added to the second mixed solution, and the first mixed solution is allowed to stand at a preset temperature.

4. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 2, characterized in that, The molar ratio of the columnar aromatic hydrocarbon to the compound containing electron-withdrawing groups is 0.5-5.

5. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 2, characterized in that, The columnar aromatic hydrocarbon is a columnar hexa-aromatic hydrocarbon, and the concentration of the columnar hexa-aromatic hydrocarbon is 1-20 mM.

6. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 3, characterized in that, The regulator is a pentaaryl aromatic hydrocarbon, or a mixture of a pentaaryl aromatic hydrocarbon and a compound containing an electron-withdrawing group; When the regulator is a mixture of pentaary aromatic hydrocarbon and a compound containing electron-withdrawing groups, the molar ratio of the pentaary aromatic hydrocarbon to the charge-transfer cocrystal is 0.2-1, and the molar ratio of the compound containing electron-withdrawing groups to the charge-transfer cocrystal is 1-2. When the regulator is a pentaaryl aromatic hydrocarbon, the molar ratio of the regulator to the charge transfer eutectic is 1-2.

7. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 2, characterized in that, After obtaining the first mixed solution, the following steps are also included: A second solvent is added to the first mixed solution.

8. The method for preparing the eutectic iodine adsorbent based on columnar aromatics according to claim 7, characterized in that, The first solvent is dichloromethane, and the second solvent is n-hexane.

9. The application of the columnar aromatic hydrocarbon-based adsorbent as described in claim 1 in the iodine adsorption process.

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