阅读说明：本技术 多元烷基化亚纳米孔cof材料及其制备方法和用途 (Multi-alkylated sub-nanopore COF material and preparation method and application thereof ) 是由 马利建 贾志敏 李阳 于 2020-06-15 设计创作，主要内容包括：本发明属于放射化学领域,具体涉及多元烷基化亚纳米孔COF材料及其制备方法和用途。本发明提供了一种多元烷基化亚纳米孔COF材料,其结构式如式Ⅰ所示。本发明还提供了的中间体,和上述多元烷基化亚纳米孔COF材料的制备方法。还提供了上述多元烷基化亚纳米孔COF材料在制备吸附和筛分Xe/Kr材料中的应用。本发明提供的多元烷基化亚纳米孔COF材料,采用了多元位点烷基化的策略,更高效、更彻底地引入了功能基团,对Xe具有很高的吸附量,且对Xe/Kr的吸附选择性高达9.7,是一种高效筛分Xe/Kr的材料。同时,本发明提供的多元烷基化亚纳米孔COF材料的制备方法步骤简洁,操作条件便捷,对环境友好。<Image he="881" wi="700" file="DDA0002539633800000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention belongs to the field of radiochemistry, and particularly relates to a multi-alkylated sub-nanopore COF material, and a preparation method and application thereof. The invention provides a multi-alkylated sub-nanopore COF material, which has a structural formula shown in a formula I. The invention also provides an intermediate and a preparation method of the multi-alkylated sub-nanopore COF material. Also provides application of the multi-alkylated sub-nanopore COF material in preparation of adsorbed and sieved Xe/Kr materials. The multi-alkylation sub-nanopore COF material provided by the invention adopts a multi-site alkylation strategy, introduces functional groups more efficiently and thoroughly, has very high adsorption capacity on Xe, has adsorption selectivity on Xe/Kr as high as 9.7, and is high in adsorption selectivity on Xe/KrThe material of Xe/Kr is screened effectively. Meanwhile, the preparation method of the multi-alkylated sub-nanopore COF material provided by the invention is simple in steps, convenient and fast in operation conditions and environment-friendly.)

1. the structural formula of the multi-alkylated sub-nanopore COF material is shown as the formula I:

wherein R is-H or C1-C8 alkoxy.

2. The multiply alkylated sub-nanoporous COF material according to claim 1, wherein: r is-H or C1-C4 alkoxy; preferably, R is simultaneously-H or simultaneously C1-C4 alkoxy; most preferably, R is simultaneously n-butoxy.

3. The intermediate of the multi-alkylated sub-nanopore COF material has a structural formula shown in a formula II:

wherein R is₁is-H or-OH.

4. The intermediate of a multiply alkylated sub-nanoporous COF material according to claim 3, wherein: r₁And is simultaneously-H or-OH.

5. The preparation method of the multi-alkylated sub-nanopore COF material comprises the following steps:

a. r is to be₁Uniformly dispersing substituted benzene trimethyl aldehyde and tri (4-aminophenyl) amine in a mixed solvent of o-dichlorobenzene and N-butanol, adding acetic acid, and adding N₂Reacting for 2-4 days at 110-130 ℃ in the atmosphere, sequentially washing the obtained solid with acetone, tetrahydrofuran, N-dimethylformamide and methanol until the filtrate is clear, and drying the solid to obtain an intermediate of the multi-alkylated sub-nanopore COF material; wherein R is₁is-H or-OH;

b. and adding the intermediate into dioxane, simultaneously dropwise adding n-butyl iodide into the dioxane in which the intermediate is dissolved, heating to reflux reaction for 18-30 h, cooling, carrying out suction filtration, washing the obtained solid with acetone, ethanol and tetrahydrofuran until the filtrate is clear, and drying the solid to obtain the multi-alkylated sub-nanopore COF material.

6. The method of making a multiply alkylated sub-nanoporous COF material according to claim 5, wherein: the concentration of the acetic acid in the step a is 5-7 mol/L; the volume ratio of the o-dichlorobenzene to the n-butanol is 1: 1.

7. The method of making a multiply alkylated sub-nanoporous COF material according to claim 5, wherein: step a said R₁The molar ratio of substituted benzenetricarboxylic acid to tris (4-aminophenyl) amine was 1: 1.

8. The method of making a multiply alkylated sub-nanoporous COF material according to claim 5, wherein: the molar ratio of the intermediate to n-butyl iodide in the step b is 1: 10.

9. The method of making a multiply alkylated sub-nanoporous COF material according to claim 5, wherein: the drying conditions of the step a and the step b are vacuum drying for 6-10 hours at 50-70 ℃.

10. Use of a polyalkylated sub-nanoporous COF material according to any one of claims 1 to 4 and intermediates thereof for the preparation of adsorbed and sieved Xe/Kr materials.

Technical Field

The invention belongs to the field of radiochemistry, and particularly relates to a multi-alkylated sub-nanopore COF material, and a preparation method and application thereof.

Background

Nuclear energy, a high energy density energy source produced by controlled nuclear fission, is generally considered a clean, inexpensive alternative to fossil fuels and is now widely used^1,2. However, the potential safety risk of nuclear energy is one of the major obstacles to the development of nuclear energy worldwide. Volatile radioactive gases from nuclear fission are more difficult to handle than some of the radionuclide produced by nuclear fission that remains in a solid or liquid^3,4. Among the gaseous fission products, radioactive krypton and xenon (containing mainly radioactive nuclides)⁸⁵Kr and¹³³xe) is large, the treatment of these two gases currently faces major challenges^5-7. The half-life of Kr (krypton), which is radioactive in the nuclear fuel exhaust gas, is as long as 10.8 years, and therefore, it must be separated and removed during the reprocessing of the nuclear fuel exhaust gas to prevent its uncontrolled release into the atmosphere to pollute the environment. In contrast, Xe (xenon) has a short half-life (about 5.2 days), which has already decayed during reprocessing of nuclear fuel exhaust gases^1-3,5,8,9In addition, the purified Xe can be used in a wide variety of practical industries, for example, high purity Xe can be used in commercial lighting and medical applications, including neuroprotection, imaging, and anesthesia^2,7,10,11. Therefore, finding a suitable method for effectively separating and purifying Xe from Xe/Kr mixed fission gas has important significance for environmental protection and economic benefit improvement^10,12。

Currently, there are two main methods for Xe/Kr separation. One is solvent dissolution selective adsorption method, and the other is porous material physical adsorption method^1,4. Solvent-soluble selective adsorption is a relatively conventional method, mainly using cryogenic distillation to separate Xe and Kr according to their boiling points^12,13. However, this method is an energy-consuming and expensive process and, in addition, even after cryogenic distillation, the residual trace Kr radioactivity levels are still too high to be used further^6,14,15。

The porous material has proper pores and pairsThe Xe/Kr has larger adsorption capacity and certain selectivity, and the Xe/Kr separation process is simple and convenient to operate and low in energy consumption. Therefore, the physical adsorption method of the porous material has more outstanding advantages and application potential compared with the low-temperature distillation method^1,2. However, the related research for screening Xe/Kr using porous materials has just started, and only some reports have revealed excellent properties of porous materials for Xe/Kr separation, such as Youn-SangBae et al, which evaluated the separation properties of MOF-505 for Xe/Kr using dynamic column breakthrough experiments, with a screening selectivity of 9-10 for Xe/Kr at both pressures of 0.5bar and 1bar, which is in contrast to Ryan et al¹¹The selectivity calculated by the simulation at 298K is very close. Lim H M subject group studied the sieving effect of zeolites NaX and NaA on Xe/Kr, and the sieving selectivity of these two zeolites on Xe/Kr could reach 4-6¹⁶. However, porous materials such as MOF (metal organic framework material) and zeolite have low stability and large self weight, and the amount of adsorption of Xe/Kr is limited, which limits the application of these materials in the practical nuclear fuel post-treatment. On the other hand, the atomic kinetic diameters of krypton and xenon are 0.37nm and 0.41nm, respectively^17,18In general, the pore size of the material ideal for Xe/Kr sieving should match its kinetic diameter and be slightly larger than it^15,19. However, materials having such sub-nanometer-sized pore diameters and a uniform pore diameter distribution are not rare.

COFs (covalent organic frameworks) are a new type of porous crystalline material composed of light elements (such as H, O, C, N) through covalent bonds, and have the advantages of large specific surface area, adjustable pore size, diversity of species and the like²⁰Is widely applied to catalysis^21,22Photoelectron, and a method for producing the same²³Gas screening²⁴Energy storage²⁵And the like. As a novel crystalline porous material with a flexibly adjustable pore structure, the covalent organic framework material can enable the material to have a regular and uniform pore structure through the selection and regulation of the building units^26-28Moreover, by introducing functional groups with various shapes, the pore diameter can be further regulated and controlled to be matched with a target adsorption object^29,30. At present, a great deal of research shows that COFs material is used for CO₂/N₂ ^31,32、CO₂/H₂ ^33,34、CO₂/CH₄ ³⁵The mixed gas has good separation effect, but the mixed gas has no report of being used for Xe/Kr adsorption at present.

Disclosure of Invention

The invention provides a multi-alkylated sub-nanopore COF material, which has a structural formula shown as a formula I:

wherein R is-H or C1-C8 alkoxy.

In a preferred embodiment of the present invention, R is-H or a C1-C4 alkoxy group.

Preferably, R is simultaneously-H or simultaneously C1-C4 alkoxy.

Most preferably, R is simultaneously n-butoxy.

The invention also provides an intermediate of the multi-alkylated sub-nanopore COF material, and the structural formula of the intermediate is shown as the formula II:

wherein R is₁is-H or-OH.

As a preferred embodiment of the present invention, R₁And is simultaneously-H or-OH.

The invention also provides a preparation method of the multi-alkylated sub-nanopore COF material, which has the following reaction formula:

the preparation method of the multi-alkylated sub-nanopore COF material comprises the following steps:

a. r is to be₁Uniformly dispersing substituted benzene trimethyl aldehyde and tri (4-aminophenyl) amine in a mixed solvent of o-dichlorobenzene and N-butanol, adding acetic acid, and adding N₂Reacting at 110-130 ℃ in an atmosphereWashing the obtained solid with acetone, tetrahydrofuran, N-dimethylformamide and methanol respectively for 2-4 days until the filtrate is clear, and drying the solid to obtain an intermediate of the multi-alkylated sub-nanopore COF material; wherein R is₁is-H or-OH;

b. and adding the intermediate into dioxane, simultaneously dropwise adding n-butyl iodide into the dioxane in which the intermediate is dissolved, heating to reflux reaction for 18-30 h, cooling, carrying out suction filtration, washing the obtained solid with acetone, ethanol and tetrahydrofuran until the filtrate is clear, and drying the solid to obtain the multi-alkylated sub-nanopore COF material.

In the preparation method of the multi-alkylated sub-nanopore COF material, the concentration of acetic acid in the step a is 5-7 mol/L. The volume ratio of the o-dichlorobenzene to the n-butanol is 1: 1.

In the preparation method of the multi-alkylated sub-nanopore COF material, R in the step a₁The molar ratio of substituted benzenetricarboxylic acid to tris (4-aminophenyl) amine was 1: 1.

In the preparation method of the multi-alkylated sub-nanopore COF material, the molar ratio of the intermediate in the step b to n-butyl iodide is 1:10

In the preparation method of the multi-alkylated sub-nanopore COF material, the drying conditions in the steps a and b are 50-70 ℃ and vacuum drying is carried out for 6-10 hours.

The invention also provides application of the multi-alkylated sub-nanopore COF material and an intermediate thereof in preparation of the adsorption and screening Xe/Kr material.

The multi-alkylated subnanopore COF material provided by the invention realizes the purpose of adjusting the pore size of the COFs material by adjusting the number of hydroxyl groups of monomers, and further alkylates the two materials to obtain the subnanopore TFB-TAPA-BuCOF and TFP-TAPA-BuCOF, aiming at having higher screening capacity on Xe/Kr mixed gas. Meanwhile, the preparation method of the multi-alkylated sub-nanopore COF material provided by the invention is simple in steps, convenient and fast in operation conditions and environment-friendly. Different from the traditional functional material, the TFP-TAPA-Bu COF provided by the invention adopts a multi-site alkylation strategy, and functional groups are introduced more efficiently and thoroughly. The adsorption and selective screening performance of the material on Xe/Kr is researched through adsorption experiments, and the result shows that the product TFP-TAPA-Bu COF regulated and controlled by the multi-alkylation pore channel has very high adsorption capacity on Xe, the adsorption selectivity is as high as 9.7, and the material is a material for efficiently screening Xe/Kr.

Drawings

FIG. 1 is an infrared spectrum and an X-ray photoelectron spectrum (XPS) of TFB-TAPA COF, TFB-TAPA-Bu COF, TFP-TAPA COF and TFP-TAPA-Bu COF. (A) TFB, TAPA and TFB-TAPA COF, (B) TFB-TAPA COF and TFB-TAPA-BuCOF, (C) TFP, TAPA and TFP-TAPA COF, (D) infrared spectrogram of TFP-TAPA COF and TFP-TAPA-BuCOF; (E) TFB-TAPA COF, TFB-TAPA-Bu COF, (F) N1s spectrum for TFP-TAPA COF, TFP-TAPA-Bu COF and (G) O1 s spectrum for TFP-TAPA COF, TFP-TAPA-Bu COF.

FIG. 2 scanning electron micrograph of TFB-TAPA COF.

FIG. 3 scanning electron micrograph of TFB-TAPA-Bu COF.

FIG. 4 scanning electron micrograph of TFP-TAPA COF.

FIG. 5 scanning electron micrograph of TFP-TAPA-Bu COF.

FIG. 6 thermogravimetric curves of TFB-TAPA COF, TFB-TAPA-Bu COF, TFP-TAPA COF and TFP-TAPA-Bu COF.

FIG. 7 PXRD experimental spectrum and AA stacking simulation spectrum of TFB-TAPA COF.

FIG. 8 PXRD experimental spectrum and skewed AA stacking simulation spectrum of TFB-TAPA COF.

FIG. 9 PXRD experimental spectrum and AA stacking simulation spectrum of TFB-TAPA-Bu COF.

FIG. 10 PXRD experimental spectrum and skewed AA stacking simulation spectrum of TFB-TAPA-Bu COF.

FIG. 11 PXRD spectra of TFB-TAPA COF and TFB-TAPA-Bu COF are compared.

FIG. 12 PXRD experimental spectrum and AA stacking simulation spectrum of TFP-TAPA COF.

FIG. 13 PXRD experimental spectrum and skewed AA stacking simulation spectrum of TFP-TAPA COF.

FIG. 14 PXRD experimental spectrum and AA stacking simulation spectrum of TFP-TAPA-Bu COF.

FIG. 15 PXRD experimental spectrum and skewed AA stacking simulation spectrum of TFP-TAPA-Bu COF.

FIG. 16 PXRD spectra comparison of TFP-TAPA COF and TFP-TAPA-Bu COF.

FIG. 17N of TFB-TAPA COF, TFP-TAPA COF, TFB-TAPA-Bu COF and TFP-TAPA-Bu COF₂Adsorption and desorption curves and aperture distribution maps. (A) N of TFB-TAPA COF and TFB-TAPA-Bu COF₂An adsorption-desorption curve; (B) pore size distribution of TFB-TAPA COF (upper) and TFB-TAPA-Bu COF (lower); (C) n of TFP-TAPA COF and TFP-TAPA-BuCOF₂An adsorption-desorption curve; (D) pore size distribution of TFP-TAPA COF (top) and TFP-TAPA-Bu COF (bottom).

FIG. 18 Single component Xe and Kr adsorption profiles and Xe/Kr separation performance investigations in MOFs, COFs and porous organic cages. 298K, 1bar conditions, single component Xe and Kr adsorption curves for (A) TFB-TAPA COF and TFB-TAPA-Bu COF and (B) TFP-TAPA COF and TFP-TAPA-Bu COF.

FIG. 19 Xe/Kr separation Performance in MOFs, COFs and porous organic cages.

Detailed Description

The preparation method of the multi-alkylated sub-nanopore COF material comprises the following steps:

a. r is to be₁Uniformly dispersing substituted benzene trimethyl aldehyde and tri (4-aminophenyl) amine in a mixed solvent of o-dichlorobenzene and N-butanol at a volume ratio of 1:1, adding acetic acid, and adding into N₂Reacting for 2-4 days at 110-130 ℃ in the atmosphere, sequentially washing the obtained solid with acetone, tetrahydrofuran, N-dimethylformamide and methanol until the filtrate is clear, and drying the solid to obtain an intermediate of the multi-alkylated sub-nanopore COF material; wherein R is₁is-H or-OH; the concentration of the acetic acid is 5-7 mol/L; the R is₁The molar ratio of the substituted benzene tricarbonal to the tri (4-aminophenyl) amine is 1: 1;

b. adding the intermediate into dioxane, simultaneously dropwise adding n-butyl iodide into the dioxane in which the intermediate is dissolved, heating to reflux reaction for 18-30 h, cooling, carrying out suction filtration, washing the obtained solid with acetone, ethanol and tetrahydrofuran until the filtrate is clear, and drying the solid to obtain the multi-alkylated sub-nanopore COF material; the molar ratio of the intermediate to n-butyl iodide is 1: 10.

In the preparation method of the multi-alkylated sub-nanopore COF material, the drying conditions in the steps a and b are 50-70 ℃ and vacuum drying is carried out for 6-10 hours.

Reagents used in the examples of the present invention: trimesic aldehyde, 2,4, 6-trihydroxy-1, 3, 5-benzenetricarboxylic aldehyde, and tris (4-aminophenyl) amine were purchased from aladin Chemistry co.ltd. (China); ortho-dichlorobenzene, n-butanol, purchased from aladin Chemistry co.ltd. (China); the reagents such as acetone, 1, 4-dioxane, tetrahydrofuran, DMF, chloroform, methanol and the like are purchased from a chemical reagent factory of the Polygalaceae family; all reagents were AR grade and no further purification was required in use.

The instrument used in the examples of the present invention was used for measuring C, O, N content in CARLO ERBA 1106 (Italy) for elemental analysis, obtaining an infrared spectrum using a Nicolet Nexus 670spectrometer (USA), obtaining an XPS spectrum using a KratosASAM800spectrometer (UK), obtaining an electron micrograph using a JSM-7500F Scanning Electron microscope, obtaining a thermogravimetric curve using a Shimadzu DTG-60(H) (Japan) analyzer, obtaining an XRD spectrum using a Malvern spectral emission spectrum differential spectrometer (40kV,40mA), and obtaining an N spectrum using a Cu K α radiation (40kV,40mA)₂The adsorption-desorption curve was measured using a Micromeritics ASAP 2020 (USA) at a temperature of 77K; the Xe/Kr adsorption curve was measured using a QUADRASORB SI-M analyzer.