CN-121976282-A - Needle-like monocrystal covalent organic framework material and preparation method and application thereof

Abstract

The invention discloses a needle-shaped monocrystal covalent organic framework material, a preparation method and application thereof, and belongs to the technical field of chromatographic materials. Adding two covalent organic framework building elements respectively containing aldehyde groups and amino groups into an organic solvent, uniformly dispersing by ultrasonic, quickly adding an alkaline regulator and a catalyst, and performing Schiff base reaction to prepare the needle-shaped monocrystal covalent organic framework material. The preparation method has the advantages of simple preparation process, mild reaction and short reaction time, and the prepared needle-shaped covalent organic framework material has the advantages of excellent monodispersity, highly ordered pore channels, large specific surface area, good crystal structure, good chemical stability and mechanical stability and the like, and can be used as a chromatographic stationary phase to remarkably improve the sample loading quantity. Meanwhile, benzene rings densely distributed on the surface of the material are combined with a three-dimensional through pore canal structure, so that a unique pi-pi conjugated effect and hydrophobic interaction synergistic enhancement phenomenon can be generated, an important basis is provided for high-efficiency chromatographic separation of hydrophobic small organic molecules, and the method has a good application prospect.

Inventors

• SONG JIAMIN
• LIN ZIAN
• ZHANG QIUTING
• WU LUSHA

Assignees

• 福州大学

Dates

Publication Date

20260505

Application Date

20260204

Claims (9)

1. 1. A preparation method of a needle-shaped single crystal covalent organic framework material is characterized in that two covalent organic framework building elements respectively containing aldehyde groups and amino groups are added into an organic solvent, an alkaline regulator and a catalyst are rapidly added after uniform ultrasonic dispersion, and the needle-shaped single crystal covalent organic framework material is prepared after standing reaction for 7 days at room temperature.
2. 2. The method according to claim 1, wherein the covalent organic framework building element containing an aldehyde group is 2, 3-dihydroxyterephthalaldehyde, and the covalent organic framework building element containing an amino group is tetrakis (4-aminophenyl) methane.
3. 3. The method of claim 2, wherein the organic solvent is benzyl alcohol.
4. 4. The process according to claim 2, wherein the alkaline regulator is trifluoroethylamine.
5. 5. The process according to claim 2, wherein the catalyst is trifluoroacetic acid and the concentration is 6.00 mol/L.
6. 6. The preparation method of the catalyst according to claim 2, wherein the ratio of each component is that the mole number mmol of the covalent organic framework building element containing the amino group, the mole number mmol of the covalent organic framework building element containing the aldehyde group, the volume mL of the alkaline regulator and the volume mL of the organic solvent are equal to the volume mL=0.25-0.5:0.5-1:0.5-1:5-10:0.5-1.
7. 7. A needle-like single crystal covalent organic framework material made by the method of any one of claims 1-6.
8. 8. The method of preparing a needle-shaped single crystal covalent organic framework material according to any one of claims 1-6, wherein the needle-shaped single crystal covalent organic framework material is used as a stationary phase of a liquid chromatographic column.
9. 9. The method according to claim 8, wherein the liquid chromatography column using needle-like single crystal covalent organic framework material as stationary phase is used for separating small hydrophobic organic molecules from isomers.

Description

Needle-like monocrystal covalent organic framework material and preparation method and application thereof Technical Field The invention belongs to the technical field of chromatographic materials, and particularly relates to a preparation method of a needle-shaped monocrystal covalent organic framework material and application of the needle-shaped monocrystal covalent organic framework material serving as a stationary phase in liquid chromatographic separation. Background Isomer separation is of great practical significance in the agricultural, industrial and pharmaceutical fields, but the separation process still faces serious challenges due to its highly similar physicochemical properties. With the rapid development of life science, pharmaceutical chemical industry and other fields, high performance liquid chromatography (High Performance Liquid Chromatography, HPLC) has been attracting attention due to its advantages of wide application range, high separation efficiency, good reproducibility and the like. The stationary phase is used as a core component of chromatographic separation, and the performance of the stationary phase directly determines the separation efficiency of a chromatographic column. Commercial C18 chromatographic columns widely used at present can realize hydrophobic molecular separation based on a hydrophobic mechanism of action, but have significant limitations in treating isomers with highly similar structures. Therefore, the development of a novel stationary phase that can effectively separate isomers has important practical value. Covalent organic framework materials (Covalent Organic Frameworks, COFs) are porous crystal materials connected by covalent bonds, and are widely applied to the fields of gas storage, catalysis, photoelectricity and the like due to the advantages of high specific surface area, adjustable pore diameter, low density, good chemical stability, good thermal stability and the like. In recent years, COFs have great application value in the field of separation analysis due to the advantages of regular pore channel structure, high specific surface area, multiple synthetic methods, easiness in functional modification and the like. Cui Yong the problem group is that the liquid chromatographic column prepared by mixing the irregular three-dimensional polycrystalline COFs material and the silicon spheres is used for separating xylene isomers from ethylbenzene, and a good separation effect is obtained. Compared with polycrystalline COFs, single-crystal COFs have regular geometric shapes and macroscopic properties of various parts inside the crystal are the same, and thus single-crystal COFs have great potential as chromatographic stationary phase separation positional isomers. However, currently, the application of single crystal COFs in the field of chromatographic stationary phases is still in a preliminary exploration stage, and the available materials are limited, so that development of more types of single crystal COF stationary phases is needed to improve the isomer separation capability. At present, a chromatographic column using needle-shaped monocrystal COF as a stationary phase is not reported. The synthesis of single crystal materials typically relies on conventional methods that are time consuming and lengthy. In particular, in order to obtain micron-sized single crystals useful for structural analysis under room temperature conditions, it is generally necessary to employ a solvent evaporation method or a diffusion method, and these processes often last for several weeks or even months. For covalent organic framework materials, the formation of covalent bonds thereof typically requires thermal energy to drive, and synthesis of single crystals thereof at room temperature is a further great challenge. The kinetics of the reaction are extremely slow at pure room temperature, and the formation of crystallites, usually amorphous precipitates or extremely small in size (nano-scale), is extremely difficult to grow into high quality single crystals of micron scale in a reasonable time (e.g. within a month), and no effective method for obtaining single crystals of micron scale COF in one week at room temperature has been found in the prior art. The invention successfully prepares the single crystal COFs material (A-SCOFs) with uniform needle-like morphology for only 7 days at room temperature for the first time. Disclosure of Invention The invention aims to provide a needle-shaped monocrystal covalent organic framework material, a preparation method and application thereof, and the prepared needle-shaped monocrystal covalent organic framework material has the advantages of excellent monodispersity, highly ordered pore canal, large specific surface area, good crystal structure, good chemical stability and mechanical stability, and the like, can be used as a liquid chromatography stationary phase for separating hydrophobic molecules from isomers, and has good applica