Covalent organic framework material as well as preparation method and application thereof

Abstract

The invention discloses a covalent organic framework material and a preparation method and application thereof, relates to the technical field of organic material preparation, and aims to solve the problem that the morphology is difficult to regulate and control in the preparation process of the covalent organic framework material.The preparation method of the covalent organic framework material comprises the steps that a triamino compound and a dialdehyde compound are dissolved in a solvent, and a mixture is obtained; obtaining a first solution; adding a catalyst into the first solution, and reacting the triamino compound with the dialdehyde compound to obtain a covalent organic framework material; wherein the mass ratio of the triamino compound to the dialdehyde compound ranges from 1: 1 to 5: 1; the mass ratio of the triamino compound to the dialdehyde compound is used for controlling the microstructure of the covalent organic framework material.

Description

Technical Field

[0001] The present application relates to the technical field of organic material preparation, and particularly relates to a covalent organic framework material, a preparation method thereof, and an application thereof. Background Art

[0002] Covalent Organic Frameworks (COFs) are a class of emerging porous organic crystal materials, which are composed of light elements connected by covalent bonds, showing a highly ordered two-dimensional or three-dimensional structure, as well as excellent porosity, thermal stability and chemical stability. These unique properties make covalent organic frameworks have great application potential in the fields of gas adsorption and separation, catalysis, energy storage, sensing, and drug delivery.

[0003] However, although covalent organic framework materials have many advantages, the morphology control in the synthesis process is still a challenging problem. Summary of the Invention

[0004] The purpose of the present application is to provide a covalent organic framework material, a preparation method thereof, and an application thereof, aiming to solve the problem that the morphology of covalent organic framework materials is difficult to control during the preparation process.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] In the first aspect, the present application provides a preparation method of a covalent organic framework material. The preparation method of the covalent organic framework material includes:

[0007] Dissolve a triamino compound and a dialdehyde compound in a solvent to obtain a first solution.

[0008] Add a catalyst to the first solution to cause the triamino compound and the dialdehyde compound to react to obtain a covalent organic framework material.

[0009] Among them, the mass ratio range of the triamino compound to the dialdehyde compound is 1:1 to 5:1. The mass ratio of the triamino compound to the dialdehyde compound is used to control the microscopic morphology of the covalent organic framework material.

[0010] In the preparation method of the covalent organic framework material provided by the embodiment of the present application, the triamino compound provides an amino (-NH2) functional group, and the dialdehyde compound provides an aldehyde (-CHO) functional group. The chemical reaction between the two generates a covalent bond to form a framework structure. That is, under the action of a catalyst, the triamino compound and the dialdehyde compound undergo a condensation reaction to form a three-dimensional network structure connected by covalent bonds, which can form a specific topological structure, thereby synthesizing a covalent organic framework material.

[0011] Moreover, by adjusting the mass ratio of the triamino compound to the dialdehyde compound within a lower range, the formed network structure can be made more uniform and dense, with smaller pores in the framework, making it easy to generate a covalent organic framework material with a solid structure. By adjusting the mass ratio of the triamino compound to the dialdehyde compound within a higher range, more triamino compounds can provide more crosslinking points during the reaction, resulting in an incomplete binding of the generated framework structure in some parts, forming a more open network structure, thereby constructing a more complex and diverse pore structure, and finally forming a covalent organic framework material with a hollow structure, achieving precise control of the morphology of the covalent organic framework material.

[0012] In some embodiments, the dialdehyde compound includes: one or more alkynyl groups.

[0013] In some embodiments, at least one of the triamino compound and the dialdehyde compound includes a benzene ring.

[0014] In some embodiments, the triamino compound includes: 1,3,5-tris(4-aminophenyl)benzene.

[0015] In some embodiments, the dialdehyde compound includes: 2,5-bis(2-propynyloxy)-1,4-benzenedicarboxaldehyde.

[0016] In some embodiments, the catalyst includes glacial acetic acid solution.

[0017] In some embodiments, the solvent of the first solution includes at least one of acetonitrile, acetone, methanol, ethanol, tetrahydrofuran, dichloromethane, and chloroform.

[0018] In some embodiments, the concentration range of the glacial acetic acid solution is 12 mol / L to 24 mol / L.

[0019] In some embodiments, the ratio of the volume of the glacial acetic acid solution to the mass of the dialdehyde compound ranges from (100 μL to 1000 μL):(14.53 mg to 71.93 mg).

[0020] In some embodiments, the solvent is acetonitrile, and the ratio of the volume of acetonitrile to the mass of the dialdehyde compound ranges from (5 mL to 10 mL):(14.53 mg to 71.93 mg).

[0021] In some embodiments, dissolving the triamino compound and the dialdehyde compound in the solvent includes: using an ultrasonic process to dissolve the triamino compound and the dialdehyde compound in the solvent.

[0022] In some embodiments, under the action of the catalyst, the reaction time of the triamino compound and the dialdehyde compound ranges from 0.5 hour to 24 hours.

[0023] In some embodiments, under the action of a catalyst, the reaction temperature of the triamino compound and the dialdehyde compound ranges from 20 °C to 30 °C.

[0024] In some embodiments, after adding a catalyst to the first solution to cause the triamino compound and the dialdehyde compound to react, the preparation method further includes:

[0025] Performing solid-liquid separation on the obtained reaction mixture to obtain a first precipitate.

[0026] Washing the first precipitate with tetrahydrofuran, acetonitrile, and ethanol respectively to remove at least one of the unreacted triamino compound, unreacted dialdehyde compound, catalyst, by-products, and inevitable impurities, to obtain a second precipitate.

[0027] Vacuum drying the second precipitate.

[0028] Among them, the drying temperature range of the second precipitate is 65 °C to 75 °C.

[0029] In some embodiments, the drying time range of the second precipitate is 11 h to 13 h.

[0030] In a second aspect, the present application provides a covalent organic framework material. The covalent organic framework material is prepared by using the preparation method of the covalent organic framework material in any one of the above embodiments.

[0031] In some embodiments, the specific surface area range of the covalent organic framework material is 782.81 m 2 / g to 1081.12 m 2 / g.

[0032] It can be understood that for the covalent organic framework material provided in the above embodiments of the present application, the beneficial effects that can be achieved can refer to the beneficial effects of the preparation method of the covalent organic framework material above, which will not be elaborated here.

[0033] In some embodiments, when the mass ratio of the triamino compound to the dialdehyde compound is 1:1, the microscopic morphology of the covalent organic framework material includes a solid spherical morphology.

[0034] In some embodiments, when the mass ratio of the triamino compound to the dialdehyde compound is 5:1, the microscopic morphology of the covalent organic framework material includes a hollow flower-like morphology.

[0035] In a third aspect, the present application provides an application of a covalent organic framework material. The covalent organic framework material is the covalent organic framework material in the above embodiments; the covalent organic framework material is used for loading biological macromolecules.

[0036] Understandably, the applications of the covalent organic framework materials provided in the above embodiments of the present application demonstrate broad application prospects in the fields of biomedicine, biosensing, catalytic separation, etc. It not only broadens the application scope of covalent organic framework materials but also provides new ideas for the cross-integration of biotechnology and materials science. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0038] Figure 1 It is a flowchart of a preparation method of a covalent organic framework material provided for an embodiment of the present application;

[0039] Figure 2 It is a transmission electron microscope image and a scanning electron microscope image of the covalent organic framework material of Example 1;

[0040] Figure 3 It is a transmission electron microscope image and a scanning electron microscope image of the covalent organic framework material of Example 2;

[0041] Figure 4 It is a transmission electron microscope image and a scanning electron microscope image of the covalent organic framework material of Example 3;

[0042] Figure 5 It is a transmission electron microscope image and a scanning electron microscope image of the covalent organic framework material of Example 4;

[0043] Figure 6 It is a transmission electron microscope image of the covalent organic framework materials of Example 5 and Example 6;

[0044] Figure 7 It is a fluorescence confocal microscope image of the covalent organic framework material of Application Example 1 loaded on chicken ovalbumin;

[0045] Figure 8 It is a fluorescence confocal microscope image of the covalent organic framework material of Application Example 2 loaded on chicken ovalbumin. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of them. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0048] In the embodiments of this application, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, article or device comprising the element.

[0049] In the embodiments of this application, words such as "exemplary" or "for example" are used to mean serving as an example, illustration or explanation. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0050] In the description of this specification, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0051] Covalent Organic Frameworks (COFs) are a class of emerging porous organic crystalline materials. They are composed of light elements connected by covalent bonds, exhibiting a highly ordered two-dimensional or three-dimensional structure, as well as excellent porosity, thermal stability and chemical stability. These unique properties make covalent organic frameworks have great application potential in the fields of gas adsorption and separation, catalysis, energy storage, sensing and drug delivery, etc.

[0052] However, despite the many advantages of covalent organic framework materials, the morphology control during their synthesis remains a challenging problem. Traditional covalent organic framework synthesis methods often rely on controlling reaction conditions such as temperature, pressure, etc. The reaction process is relatively complex and energy-consuming, and the product purification process may be rather cumbersome. For large-scale production and application, these disadvantages limit the popularization and optimization of the synthesis methods.

[0053] To solve the above problems, researchers began to explore green and environmentally friendly synthetic routes for covalent organic frameworks. The green synthetic route aims to use environmentally friendly raw materials, solvents, and catalysts to reduce or eliminate the generation of harmful waste while maintaining or improving the performance of the products. In the synthesis of covalent organic framework materials, the green synthetic route can not only reduce environmental pollution but also help to precisely control the morphology of covalent organic frameworks, thus meeting the application requirements in different fields.

[0054] Based on this, an embodiment of the present application provides a method for preparing a covalent organic framework material. As Figure 1 shown, the method for preparing the covalent organic framework material includes: S1 - S2.

[0055] S1: Dissolve a triamino compound and a dialdehyde compound in a solvent to obtain a first solution.

[0056] S2: Add a catalyst to the first solution to react the triamino compound with the dialdehyde compound to obtain a covalent organic framework material. Among them, the mass ratio range of the triamino compound to the dialdehyde compound is 1:1 - 5:1. The mass ratio of the triamino compound to the dialdehyde compound is used to control the microscopic morphology of the covalent organic framework material.

[0057] It can be understood that the triamino compound provides amino (-NH2) functional groups, while the dialdehyde compound provides aldehyde (-CHO) functional groups. The chemical reaction between the two generates covalent bonds to form a framework structure. That is, under the action of a catalyst, the triamino compound and the dialdehyde compound undergo a condensation reaction to form a three-dimensional network structure with covalent bonds, which can form a specific topological structure, thereby synthesizing a covalent organic framework material.

[0058] Moreover, by adjusting the mass ratio of the triamino compound to the dialdehyde compound within a lower range, the formed network structure can be relatively uniform and dense, and the pores in the framework are smaller, making it easy to generate a covalent organic framework material with a solid structure. By adjusting the mass ratio of the triamino compound to the dialdehyde compound within a higher range, more triamino compounds can provide more cross-linking points in the reaction, resulting in an incomplete combination of the generated framework structure in some parts, forming a more open network structure, thereby constructing a more complex and diverse pore structure, and finally forming a covalent organic framework material with a hollow structure, achieving precise control of the morphology of the covalent organic framework material.

[0059] In some embodiments, the dialdehyde compound includes: one or more alkynyl groups.

[0060] Understandably, the alkynyl group has relatively large non-polar characteristics, such that after the dialdehyde compound with an alkynyl group is formed into a covalent organic framework material, the non-polar degree of the overall covalent organic framework material increases, which helps to better interact with hydrophobic liquids (such as oil); and the alkynyl group has good reactivity, and one or more alkynyl groups are conducive to forming a complex network structure, which can form a more complex and hierarchical microporous structure, helping to improve the surface hydrophobic property of the covalent organic framework material; and the unsaturated alkyne bond also helps to enhance the mechanical properties and chemical stability of the covalent organic framework material.

[0061] In some embodiments, at least one of the triamino compound and the dialdehyde compound includes a benzene ring.

[0062] Understandably, due to its conjugated structure, the benzene ring can provide strong chemical stability, which can improve the thermal stability and mechanical strength of the covalent organic framework material; and the introduction of the benzene ring enables the framework of the covalent organic framework material to form different topological structures during the crosslinking reaction connection, thereby adjusting the pore size and further realizing the precise control of the morphology of the covalent organic framework material.

[0063] In some embodiments, the triamino compound includes: 1,3,5-tris(4-aminophenyl)benzene.

[0064] Understandably, 1,3,5-tris(4-aminophenyl)benzene (Tri(4-aminophenyl)benzene, TAPB) contains one benzene ring and three 4-aminophenyl side chains. This symmetric molecular structure enables it to provide multiple reaction sites during synthesis, thereby enhancing the crosslinking of the network structure. The amino functional group of TAPB can form a covalent bond through a condensation reaction with the aldehyde group in the dialdehyde compound, and can form an interconnected organic framework in three-dimensional space, thereby generating a covalent organic framework material with a stable framework structure.

[0065] In some embodiments, the dialdehyde compound includes: 2,5-bis(2-propynyloxy)-1,4-benzenedicarboxaldehyde.

[0066] Understandably, 2,5-bis(2-propynyl-1-oxy)-1,4-benzenedialdehyde (BPTA) contains two aldehyde groups (-CHO) and two propynyl (C≡C) side chains. The aldehyde groups can react with the amino groups in triamino compounds (such as TAPB) to form stable covalent bonds, constructing a three-dimensional network covalent framework. The alkynyl groups of BPTA have good reactivity, which is conducive to the formation of complex network structures, enabling the covalent organic framework materials to form more complex and hierarchical microporous structures, and helping to improve the surface hydrophobic properties of the covalent organic framework materials; moreover, the unsaturated alkynyl groups also contribute to enhancing the mechanical properties and chemical stability of the covalent organic framework materials. At the same time, by changing the ratio of BPTA to the triamino compound, the pore size and specific surface area of the synthesized covalent organic framework materials can be adjusted.

[0067] In some embodiments, the catalyst includes glacial acetic acid solution.

[0068] Understandably, glacial acetic acid can dissolve a variety of organic compounds, can effectively mediate the contact between reactants (triamino compounds and dialdehyde compounds), and promote the condensation reaction between triamino compounds (such as TAPB) and dialdehyde compounds (such as BPTA), thereby forming a covalently linked network structure, improving the reaction efficiency, and promoting the formation of covalent organic framework materials.

[0069] In some embodiments, the solvent of the first solution includes at least one of acetonitrile, acetone, methanol, ethanol, tetrahydrofuran, dichloromethane, and chloroform.

[0070] Understandably, acetonitrile (ACN) is a polar solvent that can effectively dissolve a variety of organic small molecules. In the synthesis of covalent organic framework materials, acetonitrile can promote the condensation reaction between triamino compounds and dialdehyde compounds to generate a stable framework structure.

[0071] Acetone, methanol, and ethanol are all polar solvents that can provide good solubility; methanol and ethanol are polar solvents that can well dissolve a variety of small molecules and are used for the dissolution of triamino compounds and dialdehyde compounds. The relatively low toxicity of methanol and ethanol makes them environmentally friendly solvents. Tetrahydrofuran (THF) is a polar solvent with good solubility that can dissolve a variety of organic compounds. THF can increase the reaction rate and help to form a relatively dense covalent organic framework structure. The high volatility of dichloromethane (DCM) makes it easy to remove after the reaction is completed. Chloroform can enhance the interaction between reactants and promote the synthesis of covalent organic framework materials.

[0072] Preferably, the solvent of the first solution can be acetonitrile.

[0073] In some embodiments, the concentration range of the glacial acetic acid solution is 12 mol / L to 24 mol / L.

[0074] Exemplarily, the concentration of the glacial acetic acid solution can be 12 mol / L, 16 mol / L, 20 mol / L, 24 mol / L, etc., and there is no limitation here.

[0075] It can be understood that the above settings can enable glacial acetic acid to provide sufficient catalytic activity, avoiding the situation that a lower concentration (<12 mol / L) may not provide a sufficient acidic environment to promote the reaction, while a higher concentration (>24 mol / L) may lead to an increase in side reactions or inhibit the progress of the target reaction, thereby promoting the condensation reaction of the triamino compound and the dialdehyde compound.

[0076] In some embodiments, the ratio of the volume of the glacial acetic acid solution to the mass of the dialdehyde compound ranges from (100 μL to 1000 μL):(14.53 mg to 71.93 mg).

[0077] Exemplarily, the volume of the glacial acetic acid solution can be 100 μL, 400 μL, 600 μL, 800 μL, 1000 μL, etc., and there is no limitation here.

[0078] Exemplarily, the mass of the dialdehyde compound can be 14.53 mg, 29 mg, 43.6 mg, 58.12 mg, 71.93 mg, etc., and there is no limitation here.

[0079] It can be understood that the above settings can ensure that the concentration of the reactants in the solution is sufficient to promote an effective cross-linking reaction after adding the catalyst to the first solution, while avoiding side reactions or inhibited reactions caused by the mismatch between the volume of the glacial acetic acid solution and the mass of the dialdehyde compound.

[0080] In some embodiments, the solvent is acetonitrile, and the ratio of the volume of acetonitrile to the mass of the dialdehyde compound ranges from (5 mL to 10 mL):(14.53 mg to 71.93 mg).

[0081] Exemplarily, the volume of acetonitrile can be 5 mL, 6 mL, 7 mL, 8 mL, 9 mL, 10 mL, etc., and there is no limitation here.

[0082] Exemplarily, the mass of the dialdehyde compound can be 14.53 mg, 29 mg, 43.6 mg, 58.12 mg, 71.93 mg, etc., and there is no limitation here.

[0083] Understandably, in the above settings, the polar properties of acetonitrile enable it to effectively dissolve a variety of reactants, promoting the reaction between the dialdehyde compound and the triamino compound. The volume of acetonitrile can provide a better reaction environment, ensuring that the reactants in the first solution are fully in contact in the solution, thereby increasing the reaction rate. At the same time, it avoids the situation where when the volume of acetonitrile is large (such as > 10 mL), it dilutes the reactants and reduces the reaction rate, and when the volume of acetonitrile is small (such as < 5 mL), it cannot dissolve the reactants (triamino compound and dialdehyde compound), resulting in an uneven reaction; the ratio of the appropriate volume of acetonitrile to the mass of the dialdehyde compound can promote the formation of a more ordered and uniform network structure between the dialdehyde compound and the triamino compound, ensuring that the reactants in the reaction system are mixed evenly, making the cross-linking reaction of the network structure of the covalent organic framework structure more efficient.

[0084] In addition, compared with traditional methods for synthesizing covalent organic framework materials that often rely on toxic and harmful organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), etc., these solvents not only cause environmental pollution, increasing the environmental burden and cost, but also may affect the final performance of covalent organic framework materials. Using acetonitrile as a solvent can reduce or eliminate the generation of harmful waste, reduce environmental pollution, and at the same time maintain or improve the performance of covalent organic framework materials, that is, it can not only reduce environmental pollution, but also help to achieve precise control of the morphology of covalent organic frameworks, thus meeting the application requirements in different fields.

[0085] In some embodiments, in S1, dissolving the triamino compound and the dialdehyde compound in a solvent includes: using an ultrasonic process to dissolve the triamino compound and the dialdehyde compound in the solvent.

[0086] Understandably, ultrasonic waves generate high-frequency vibrations in the liquid, forming rapid compression and tensile waves. These waves generate tiny bubbles (i.e., cavitation) in the solvent. When these bubbles collapse, a huge amount of energy is released. This energy can effectively increase the contact area between the reactants and the solvent, promoting the rapid mixing and dissolution of the triamino compound and the dialdehyde compound, and forming a uniform solution in the solvent (such as acetonitrile).

[0087] In some embodiments, under the action of a catalyst, the reaction time range of the triamino compound and the dialdehyde compound is 0.5 hours to 24 hours.

[0088] Exemplarily, the reaction time of the triamino compound and the dialdehyde compound can be 0.5 hours, 6 hours, 12 hours, 18 hours, or 24 hours, etc., and there is no limit here.

[0089] Understandably, the setting of the above reaction time reflects the flexibility and optimization space of the reaction between the triamino compound and the dialdehyde compound, enabling the reaction between the triamino compound and the dialdehyde compound to proceed under relatively loose conditions, which can be promoted and optimized for large-scale production and applications.

[0090] In some embodiments, under the action of a catalyst, the reaction temperature range between the triamino compound and the dialdehyde compound is 20°C to 30°C.

[0091] Exemplarily, the reaction temperature between the triamino compound and the dialdehyde compound can be 20°C, 22°C, 24°C, 26°C, 28°C, 30°C, etc., without limitation here.

[0092] Understandably, within the above reaction temperature range, the cross-linking reaction between the triamino compound and the dialdehyde compound can be promoted; and since the reaction temperature is relatively low (within the room temperature range), a covalent organic framework material with a controllable morphology can be synthesized, indicating that the reaction between the triamino compound and the dialdehyde compound can proceed under relatively loose conditions, which is a relatively green and environmentally friendly covalent organic framework synthesis route. It can not only reduce environmental pollution but also help achieve precise control of the morphology of the covalent organic framework, which can be promoted and optimized for large-scale production and applications to meet the application requirements of different fields.

[0093] In some embodiments, after adding a catalyst to the first solution in S2 to cause the reaction between the triamino compound and the dialdehyde compound, the preparation method further includes steps (1) to (3).

[0094] Step (1): Perform solid-liquid separation on the obtained reaction mixture to obtain a first precipitate.

[0095] Step (2): Wash the first precipitate with tetrahydrofuran, acetonitrile, and ethanol respectively to remove at least one of the unreacted triamino compound, unreacted dialdehyde compound, catalyst, by-products, and inevitable impurities, to obtain a second precipitate.

[0096] Step (3): Vacuum dry the second precipitate.

[0097] Exemplarily, the drying temperature range of the second precipitate is 65°C to 75°C.

[0098] Exemplarily, the drying temperature of the second precipitate can be 65°C, 68°C, 70°C, 73°C, 75°C, etc., without limitation here.

[0099] Exemplarily, the drying time range of the second precipitate is 11h to 13h.

[0100] Exemplarily, the drying time of the second precipitate can be 11 h, 11.5 h, 12 h, 12.5 h, 13 h, etc., without limitation here.

[0101] It can be understood that through the above treatment, at least one of the unreacted triamino compound, unreacted dialdehyde compound, catalyst, by-products and inevitable impurities can be removed, and the combined use of the three solvents can cover a wider range of impurity types, ensuring the purity and quality of the covalent organic framework material. Experiments show that the effect of washing and purification using three solvents is better than that of a single solvent or a combination of two solvents.

[0102] An embodiment of the present application provides a covalent organic framework material. The covalent organic framework material is prepared by using the preparation method of the covalent organic framework material in any one of the above embodiments.

[0103] In some embodiments, the specific surface area range of the covalent organic framework material is 782.81 m 2 / g to 1081.12 m 2 / g.

[0104] Exemplarily, the specific surface area of the covalent organic framework material can be 782.81 m 2 / g, 850 m 2 / g, 900 m 2 / g, 950 m 2 / g or 1081.12 m 2 / g, etc., without limitation here.

[0105] It can be understood that by precisely controlling the mass ratio of the triamino compound to the dialdehyde compound in the present application, the morphology of the covalent organic framework material is successfully and innovatively transformed from the traditional solid spherical structure to a hollow spherical shape, and further optimized into a unique spherical hollow nanoflower-like structure. This morphological transformation significantly increases the specific surface area of the material, from the basic 782.81 m 2 / g to a large extent up to 1081.12 m 2 / g, providing a richer reaction interface and a higher density of active sites for the covalent organic framework material.

[0106] In some embodiments, when the mass ratio of the triamino compound to the dialdehyde compound is 1:1, the microscopic morphology of the covalent organic framework material includes a solid spherical morphology.

[0107] In some embodiments, when the mass ratio of the triamino compound to the dialdehyde compound is 5:1, the microscopic morphology of the covalent organic framework material includes a hollow flower-like morphology.

[0108] Embodiments of the present application provide an application of a covalent organic framework material. The covalent organic framework material is the covalent organic framework material in the above embodiments. Using the covalent organic framework material to load biological macromolecules (such as chicken ovalbumin, OVA) demonstrates its broad application prospects in the fields of biomedicine, biosensing, catalytic separation, etc. This achievement not only broadens the application scope of covalent organic framework materials but also provides new ideas for the cross-integration of biotechnology and materials science.

[0109] The following further describes the covalent organic framework material through specific experimental examples. It should be noted that the chemical reagents and solvents used in the experiments are all of analytical purity; the raw materials can be purchased from chemical reagent companies or biopharmaceutical companies; the stirring is carried out by a magnetic stirrer.

[0110] Example 1

[0111] Example 1 provides a covalent organic framework material, and the preparation method of the covalent organic framework material is as follows:

[0112] Step (1): Take a clean beaker, add 14.10 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile to the beaker and ultrasonicate until the solution is clear.

[0113] Step (2): Under stirring, use a pipette to gradually add 300 μL of 12 mol / L glacial acetic acid solution to the beaker. After the addition is complete, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0114] Step (3): Tightly cover the beaker mouth with a sealing film to prevent solvent volatilization and entry of external impurities during the reaction. Subsequently, place the beaker at room temperature and let it stand for reaction for 24 hours to form a covalent organic framework material.

[0115] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate three times with tetrahydrofuran, acetonitrile, and ethanol respectively to obtain a covalent organic framework precipitate. After each solvent wash, it is necessary to centrifuge again and discard the wash solution to thoroughly remove unreacted TAPB, BPTA, catalyst, and by-products.

[0116] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and vacuum dry it at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 1:1.

[0117] As Figure 2 is the transmission electron microscope image and scanning electron microscope image of the covalent organic framework material of Example 1, Figure 2In (A) is the transmission electron microscopy image of the covalent organic framework material of Example 1. It can be seen that the microscopic morphology of the covalent organic framework material of Example 1 is mainly in the form of regular solid spheres, and the size distribution is about 500 nm. Figure 2 In (B) is the scanning electron microscopy image of the covalent organic framework material of Example 1. It can be seen that the external part of the microscopic morphology of the covalent organic framework material of Example 1 is relatively smooth.

[0118] Example 2

[0119] Example 2 provides a covalent organic framework material, and the preparation method of this covalent organic framework material is as follows:

[0120] Step (1): Take a clean beaker, add 28.20 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile into the beaker respectively, and ultrasonicate until the solution is clear.

[0121] Step (2): Under stirring, use a pipette to gradually add 300 μL of 12 mol / L glacial acetic acid solution dropwise into the beaker. After the addition is complete, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0122] Step (3): Tightly cover the beaker mouth with a sealing film to prevent the solvent from volatilizing and external impurities from entering during the reaction. Subsequently, place the beaker at room temperature and let it stand for reaction for 24 hours to form a covalent organic framework material.

[0123] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate three times with tetrahydrofuran, acetonitrile, and ethanol respectively to obtain a covalent organic framework precipitate. After each solvent washing, it is necessary to centrifuge again and discard the washing liquid to thoroughly remove the unreacted TAPB, BPTA, catalyst, and by-products.

[0124] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and vacuum dry it at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 2:1.

[0125] Such as Figure 3 are the transmission electron microscopy image and scanning electron microscopy image of the covalent organic framework material of Example 2, Figure 3 In (A) is the transmission electron microscopy image of the covalent organic framework material of Example 2. It can be seen that the microscopic morphology of the covalent organic framework material of Example 2 is mainly in the form of regular hollow spheres, and the size distribution is about 500 nm. Figure 3 In (B) is the scanning electron microscopy image of the covalent organic framework material of Example 2. It can be seen that the external part of the microscopic morphology of the covalent organic framework material of Example 2 begins to become rough.

[0126] Example 3

[0127] Example 3 provides a covalent organic framework material, and the preparation method of the covalent organic framework material is as follows:

[0128] Step (1): Take a clean beaker, add 42.30 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile into the beaker respectively, and ultrasonicate until the solution is clear.

[0129] Step (2): Under stirring, use a pipette to dropwise add 300 μL of 12 mol / L glacial acetic acid solution into the beaker. After the addition is completed, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0130] Step (3): Tightly cover the beaker mouth with a sealing film to prevent the solvent from volatilizing and external impurities from entering during the reaction. Subsequently, place the beaker at room temperature and let it stand for reaction for 24 hours to form a covalent organic framework material.

[0131] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate three times with tetrahydrofuran, acetonitrile, and ethanol respectively to obtain a covalent organic framework precipitate. After each solvent washing, it is necessary to centrifuge again and discard the washing liquid to completely remove the unreacted TAPB, BPTA, catalyst, and by-products.

[0132] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and dry it under vacuum at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 3:1.

[0133] As Figure 4 are the transmission electron microscopy image and scanning electron microscopy image of the covalent organic framework material of Example 3, Figure 4 in which (A) is the transmission electron microscopy image of the covalent organic framework material of Example 3. It can be seen that the micro-morphology of the covalent organic framework material of Example 3 is mainly in the shape of a hollow nano-flower structure, and the peripheral convex structure becomes obvious, and the size distribution is about 400 nm. Figure 4 in which (B) is the scanning electron microscopy image of the covalent organic framework material of Example 3. It can be seen that the external particle sense of the micro-morphology of the covalent organic framework material of Example 3 is more obvious.

[0134] Example 4

[0135] Example 4 provides a covalent organic framework material, and the preparation method of the covalent organic framework material is as follows:

[0136] Step (1): Take a clean beaker and add 70.50 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile into the beaker, and ultrasonicate until the solution becomes clear.

[0137] Step (2): Under stirring, use a pipette to gradually add 300 μL of 12 mol / L glacial acetic acid solution dropwise to the beaker. After the addition is complete, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0138] Step (3): Tightly cover the beaker mouth with a sealing film to prevent the solvent from volatilizing and external impurities from entering during the reaction. Subsequently, place the beaker at room temperature and let it stand for reaction for 24 hours to form a covalent organic framework material.

[0139] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate three times with tetrahydrofuran, acetonitrile, and ethanol respectively to obtain the covalent organic framework precipitate. After each solvent wash, centrifuge again and discard the washing solution to thoroughly remove the unreacted TAPB, BPTA, catalyst, and by-products.

[0140] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and dry it under vacuum at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 5:1.

[0141] As Figure 5 are the transmission electron microscopy (TEM) image and scanning electron microscopy (SEM) image of the covalent organic framework material of Example 4, Figure 5 in which (A) is the TEM image of the covalent organic framework material of Example 4. It can be seen that the microscopic morphology of the covalent organic framework material of Example 4 mainly shows a hollow nanosphere flower-like structure, and it can be seen that the peripheral convex structure becomes sharper. Figure 5 in which (B) is the SEM image of the covalent organic framework material of Example 4. It can be seen that the external granularity of the covalent organic framework material of Example 3 is more obvious.

[0142] The experimental results of the above Examples 1 to 4 show that by precisely regulating the mass ratio of the triamino compound to the dialdehyde compound and changing the reaction time, the present application successfully transforms the morphology of the covalent organic framework material from the traditional solid spherical structure to a hollow spherical shape, and further optimizes it to a unique spherical hollow nanosphere flower-like structure, providing a richer reaction interface and a higher density of active sites for the covalent organic framework material.

[0143] Moreover, as the mass ratio of the triamino compound to the dialdehyde compound gradually increases, the morphology of the covalent organic framework material transforms from a traditional solid spherical structure to a hollow spherical structure. It can be reasonably speculated that when the covalent organic framework material is used as an electrochemical substrate material, the charge transfer efficiency inside the covalent organic framework material can be improved, and the electrochemical impedance can be significantly reduced, which is of great significance for improving the performance of electrochemical energy storage and conversion devices.

[0144] In addition, as the mass ratio of the triamino compound to the dialdehyde compound gradually increases, the crystallinity of the covalent organic framework material is also significantly improved, enhancing the structural stability and thermal stability of the covalent organic framework material, providing a strong guarantee for the application of the covalent organic framework material in complex environments.

[0145] Example 5

[0146] Example 5 provides a covalent organic framework material, and the preparation method of the covalent organic framework material is as follows:

[0147] Step (1): Take a clean beaker, add 42.30 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile into the beaker and ultrasonicate until the solution is clear.

[0148] Step (2): Under stirring, use a pipette to gradually add 300 μL of 12 mol / L glacial acetic acid solution to the beaker. After the addition is complete, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0149] Step (3): Tightly cover the beaker mouth with a sealing film to prevent solvent volatilization and entry of external impurities during the reaction. Subsequently, place the beaker at room temperature and let it stand for reaction for 1 hour to form a covalent organic framework material.

[0150] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate three times with tetrahydrofuran, acetonitrile, and ethanol respectively to obtain a covalent organic framework precipitate. After each solvent wash, centrifuge again and discard the washing solution to thoroughly remove unreacted TAPB, BPTA, catalyst, and by-products.

[0151] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and vacuum dry it at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 3:1.

[0152] As Figure 6(A) is the transmission electron microscopy image of the covalent organic framework material of Example 5. It can be seen that the microscopic morphology of the covalent organic framework material of Example 4 mainly shows a hollow structure, that is, the hollow structure can be seen in the microscopic morphology of the covalent organic framework material.

[0153] Example 6

[0154] Example 6 provides a covalent organic framework material, and the preparation method of the covalent organic framework material is as follows:

[0155] Step (1): Take a clean beaker, add 42.30 mg of TAPB, 14.53 mg of BPTA, and 5 mL of acetonitrile into the beaker respectively, and ultrasonicate until the solution is clear.

[0156] Step (2): Under stirring, use a pipette to dropwise add 300 μL of 12 mol / L glacial acetic acid solution into the beaker. After the addition is completed, continue to stir the solution evenly for about 5 minutes to ensure that the catalyst is fully dispersed and mixed with TAPB and BPTA.

[0157] Step (3): Tightly cover the beaker mouth with a sealing film to prevent the solvent from volatilizing and external impurities from entering during the reaction process. Subsequently, place the beaker at room temperature and let it stand for reaction for 12 hours to form a covalent organic framework material.

[0158] Step (4): After the reaction is completed, centrifuge the mixture in the beaker to separate the precipitated covalent organic framework material and the supernatant. After discarding the supernatant, wash the precipitate with tetrahydrofuran, acetonitrile, and ethanol three times respectively to obtain a covalent organic framework precipitate. After each solvent washing, it is necessary to centrifuge again and discard the washing solution to thoroughly remove the unreacted TAPB, BPTA, catalyst, and by-products.

[0159] Step (5): Transfer the washed covalent organic framework precipitate to a vacuum drying oven and vacuum dry it at 60 °C for 12 hours to obtain a covalent organic framework material with a mass ratio of TAPB to BPTA of 3:1.

[0160] As Figure 6 (B) in is the transmission electron microscopy image of the covalent organic framework material of Example 6. It can be seen that the microscopic morphology of the covalent organic framework material of Example 6 mainly shows a hollow structure, that is, the overall microscopic morphology of the covalent organic framework material is regular and the hollow structure is more obvious.

[0161] Application Example 1

[0162] Application Example 1 provides an application of a covalent organic framework material, specifically:

[0163] (1) Preparation of 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin: Disperse 20 mg of chicken ovalbumin into 10 mL of phosphate - buffered saline (PBS buffer solution, pH = 7.4, 0.1 M), add 1 mg of 7 - amino - 4 - methylcoumarin, and then stir for 4 h under dark conditions. Finally, use a dialysis bag (MWCO = 8 kDa) for dialysis to remove excess reaction reagents and salts, and freeze - dry to obtain 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin for standby.

[0164] (2) Preparation of the composite of covalent organic framework material and fluorescent - labeled chicken ovalbumin: Take 3 mg of the covalent organic framework material of Example 1, add it to 1 mL of PBS buffer solution with pH 7.4 and ultrasonicate for 10 min to obtain a uniformly dispersed suspension. Treat it with 3 mg of the 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin obtained in step (1), and stir at 4 °C for 24 h to absorb the 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin into the pores of the covalent organic framework material of Example 1. After 24 h, centrifuge the solution, wash it three times with PBS buffer solution, and freeze - dry for standby.

[0165] Such as Figure 7 Figure for the fluorescence confocal microscopy of the covalent organic framework material loaded on chicken ovalbumin in Application Example 1. Among them, Figure 7 (A) shows that the chicken ovalbumin labeled with 7 - amino - 4 - methylcoumarin exhibits blue fluorescence; Figure 7 (B) shows that the covalent organic framework material itself exhibits red fluorescence, Figure 7 (C) shows that after the composite of the covalent organic framework material and the chicken ovalbumin labeled with 7 - amino - 4 - methylcoumarin, it presents a mixed state of blue fluorescence and red fluorescence. It can be seen that the covalent organic framework material of Application Example 1 is successfully loaded on chicken ovalbumin, indicating that the covalent organic framework material can effectively load biological macromolecules and maintain their biological activities, providing possibilities for applications in the fields of biomedicine and biosensing, etc.

[0166] Application Example 2

[0167] Application Example 2 provides an application of a covalent organic framework material, specifically as follows:

[0168] (1) Preparation of 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin: Disperse 20 mg of chicken ovalbumin into 10 mL of PBS buffer solution (pH = 7.4, 0.1 M), add 1 mg of 7 - amino - 4 - methylcoumarin, and then stir for 4 h under dark conditions. Finally, use a dialysis bag (MWCO = 8 kDa) for dialysis to remove excess reaction reagents and salts, and freeze - dry to obtain 7 - amino - 4 - methylcoumarin - labeled chicken ovalbumin for standby.

[0169] (2) Preparation of the composite of covalent organic framework material and fluorescently labeled chicken ovalbumin: Take 3 mg of the covalent organic framework material of Example 1, add it to 1 mL of PBS buffer solution with a pH of 7.4, and ultrasonicate for 10 min to obtain a uniformly dispersed suspension. Treat it with 3 mg of the 7-amino-4-methylcoumarin-labeled chicken ovalbumin obtained in step (1), and stir at 4 °C for 24 h to absorb the 7-amino-4-methylcoumarin-labeled chicken ovalbumin into the pores of the covalent organic framework material of Example 2. After 24 h, centrifuge the solution, wash it three times with PBS buffer solution, and freeze-dry for standby.

[0170] Figure 8 Figure of fluorescence confocal microscopy of the covalent organic framework material of Application Example 2 loaded on chicken ovalbumin. Among them, Figure 8 (A) shows that the chicken ovalbumin labeled with 7-amino-4-methylcoumarin exhibits blue fluorescence; Figure 8 (B) shows that the covalent organic framework material itself exhibits red fluorescence, Figure 8 (C) shows that after the covalent organic framework material is combined with the chicken ovalbumin labeled with 7-amino-4-methylcoumarin, it presents a mixed state of blue fluorescence and red fluorescence. It can be seen that the covalent organic framework material of Application Example 2 is successfully loaded on chicken ovalbumin; moreover, compared with Application Example 1, in the fluorescence color of the covalent organic framework material of Application Example 2 loaded on chicken ovalbumin, the blue fluorescence of the chicken ovalbumin labeled with 7-amino-4-methylcoumarin is significantly increased, indicating that when the micro-morphology of the covalent organic framework material is a hollow spherical shape, the loading effect of the covalent organic framework material on chicken ovalbumin is better.

[0171] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A preparation method of a covalent organic framework material, characterized in that, Comprising: Dissolve a triamino compound and a dialdehyde compound in a solvent to obtain a first solution; Add a catalyst to the first solution to react the triamino compound with the dialdehyde compound to obtain the covalent organic framework material; Wherein, the mass ratio range of the triamino compound to the dialdehyde compound is 1:1 to 5:1; the mass ratio of the triamino compound to the dialdehyde compound is used to control the micro-morphology of the covalent organic framework material.

2. The preparation method of the covalent organic framework material according to claim 1, characterized in that, The dialdehyde compound comprises: one or more alkynyl groups; and / or, At least one of the triamino compound and the dialdehyde compound comprises a benzene ring.

3. The preparation method of the covalent organic framework material according to claim 1, wherein The triamino compound comprises: 1,3,5-tris(4-aminophenyl)benzene; and / or, The aldehyde compound comprises: 2,5-bis(2-propynyloxy)-1,4-benzenedicarboxaldehyde.

4. The preparation method of the covalent organic framework material according to claim 1, characterized in that The catalyst comprises glacial acetic acid solution; and / or, The solvent of the first solution comprises at least one of acetonitrile, acetone, methanol, ethanol, tetrahydrofuran, dichloromethane and chloroform.

5. The preparation method of the covalent organic framework material according to claim 4, wherein The concentration range of the glacial acetic acid solution is 12 mol / L to 24 mol / L; and / or, The ratio of the volume of the glacial acetic acid solution to the mass of the dialdehyde compound ranges from (100 μL to 1000 μL):(14.53 mg to 71.93 mg); and / or, The solvent is acetonitrile, and the ratio of the volume of the acetonitrile to the mass of the dialdehyde compound ranges from (5 mL to 10 mL):(14.53 mg to 71.93 mg).

6. The preparation method of the covalent organic framework material according to claim 1, characterized in that, The dissolving of the triamino compound and the dialdehyde compound in the solvent comprises: using an ultrasonic process to dissolve the triamino compound and the dialdehyde compound in the solvent; and / or, Under the action of the catalyst, the reaction time range of the triamino compound and the dialdehyde compound is 0.5 hour to 24 hours; and / or, Under the action of the catalyst, the reaction temperature range of the triamino compound and the dialdehyde compound is 20 °C to 30 °C.

7. The preparation method of the covalent organic framework material according to any one of claims 1 to 6, characterized in that, After adding the catalyst to the first solution to react the triamino compound with the dialdehyde compound, the preparation method further comprises: Performing solid-liquid separation on the obtained reaction mixture to obtain a first precipitate; Washing the first precipitate with tetrahydrofuran, acetonitrile and ethanol respectively to remove at least one of the unreacted triamino compound, unreacted dialdehyde compound, catalyst, by-products and inevitable impurities to obtain a second precipitate; and, Vacuum drying the second precipitate; Wherein, the drying temperature range of the second precipitate is 65 °C to 75 °C; and / or, The drying time range of the second precipitate is 11 h to 13 h.

8. A covalent organic framework material, characterized in that, The covalent organic framework material is prepared by the preparation method of the covalent organic framework material according to any one of claims 1 to 7.

9. The covalent organic framework material according to claim 8, wherein The specific surface area of the covalent organic framework material ranges from 782.81 m 2 / g to 1081.12 m 2 / g; and / or, When the mass ratio of the triamino compound to the dialdehyde compound is 1:1, the micro-morphology of the covalent organic framework material comprises a solid spherical morphology; and / or, When the mass ratio of the triamino compound to the dialdehyde compound is 5:1, the microscopic morphology of the covalent organic framework material includes a hollow flower-like morphology.

10. Application of a covalent organic framework material, characterized in that, The covalent organic framework material is the covalent organic framework material according to claim 8 or 9; the covalent organic framework material is used for loading biological macromolecules.

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