Colloidal covalent organic framework solution and preparation method thereof

Abstract

The invention discloses a preparation method of a colloidal covalent organic framework solution, which comprises the following steps: directly dispersing covalent organic framework powder in a certain amount of solvent and pyrrole combined solvent without any other reaction conditions such as heating, pressurizing and the like, and carrying out tip ultrasound to successfully prepare the stable colloidal covalent organic framework solution. The preparation method provided by the invention is simple and easy to implement, has strong universality, and does not need the reaction conditions of the traditional solvothermal-assisted method. The prepared colloid covalent organic framework solution has good dispersity and processability, and has good potential application prospects in the fields of heterogeneous catalysis, energy storage, photoelectric devices and the like.

Description

Technical Field

[0001] The invention relates to the technical field of new material preparation, and in particular to a method for preparing a covalent organic framework solution. Background Art

[0002] Covalent Organic Frameworks (COFs) are a class of organic polymers with porous crystal structures composed of light elements such as C, H, N and O and strong covalent bonds. They have the advantages of large specific surface area, light weight and porosity, and adjustable topology and chemical structure. They have good application prospects in heterogeneous catalysis, energy storage, sensing and optoelectronics. However, their easy aggregation and limited processing performance have severely restricted their effective use in many fields.

[0003] Compared with the powder state, COF colloids have good dispersibility and easy processing, as well as photoelectrochemical properties different from traditional powder aggregates. At the same time, the colloidal state makes COF materials easier to process into various shapes and devices, such as functional devices such as films and coatings. However, due to the strong interlayer force of COF materials, they are very easy to aggregate and are almost not dispersed in any solvent.

[0004] The Chinese patent application with publication number CN117899671A relates to a zwitterionic covalent organic framework nanofiltration membrane and a preparation method thereof. It mainly targets a coating process and a zwitterionic covalent organic framework colloidal solution synthesized by a single-phase method. Although it solves the problem of COF colloidal solution in a small range, it requires the addition of a catalyst and an amination agent. Moreover, it targets zwitterions and cannot target a large range of COF, nor is it suitable for the process of preparing COF powder into a colloidal solution.

[0005] The Chinese patent application with publication number CN115975139A relates to a preparation method and application of a covalent organic framework material for CO2 desorption. The brown colloidal product D provided by the patent application cannot be used to process into various shapes and devices, such as colloidal solutions of functional devices such as films and coatings, that is, it cannot solve the problem of making COF powder easier to process into various functional devices.

[0006] The Chinese patent application with publication number CN117430766A relates to a biocomposite material based on covalent organic framework materials (COFs), its preparation and application. It performs in-situ encapsulation in a one-pot method to construct a new composite catalyst, and for the first time proposes the in-situ immobilization of enzymes using COFs under room temperature, aqueous phase and short-time conditions. It cannot solve the problem of efficiently and quickly preparing a colloidal solution with good stability for the subsequent preparation of functional devices.

[0007] In addition, the current methods for preparing COF colloids are mostly surfactant-assisted solvent thermal synthesis, but they still face the bottleneck of complex synthesis process and difficulty in precise control, resulting in low product purity, uneven particle size distribution, and generally low yield. In addition, the prepared COF colloidal solution is not stable and processable, and cannot be used in the processing of functional devices. It cannot be mass-produced and widely used. Therefore, it is urgent to develop technology for colloidal COF materials with processability. Summary of the invention

[0008] The object of the present invention is to avoid the deficiencies of the prior art and provide a colloidal covalent organic framework solution and a preparation method thereof for efficiently and quickly preparing a colloid having stable dispersion and processability.

[0009] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a colloidal covalent organic framework solution, comprising the following steps:

[0010] Ultrasonic dispersion of imine and ketoamine covalent organic framework powders in a combined solvent to obtain a suspension with a concentration of 0.1-5 mg / ml, and subjecting the suspension to tip ultrasound to obtain a colloidal covalent organic framework solution;

[0011] The combined solvent is a combined solvent of a solvent and pyrrole, and the volume ratio of the combined solvent to pyrrole is equal to 3-5.

[0012] Furthermore, the aldehyde precursor of the obtained colloidal covalent organic framework is trialdehyde phloroglucinol.

[0013] Furthermore, the amine precursor of the obtained colloidal covalent organic framework is any one of p-phenylenediamine, m-phenylenediamine, biphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-diaminoterphenyl, 1,3,5-tris(4-aminophenyl)benzene, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

[0014] Furthermore, the solvent is any one of pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, tetrahydrofuran, ethanol, methanol, dimethyl sulfoxide, sulfolane, and water.

[0015] Furthermore, the ultrasonic dispersion time is 1 to 30 minutes.

[0016] The tip ultrasound of the suspension is carried out in an ultrasonic homogenizer, and the power of ultrasonic homogenization is 8-12 kHz, the frequency is 25-30 kHz, and the time is 3-5 minutes.

[0017] The present invention also provides a covalent organic framework colloidal solution obtained by the preparation method, wherein the colloidal solution contains colloidal nanowires with uniform length and diameter, wherein the length of the colloidal nanowires is at the micrometer level and the width is at the nanometer level.

[0018] The microscopic principle of uniformity of colloidal nanowire particles is mainly due to the particle size effect. The uniformity of particle size helps to form nanowires with consistent structure, thus showing good uniformity. Nanowire particles often carry charges, and the repulsion between these charges helps to maintain the spacing between particles, thereby further enhancing the uniformity of the nanowires. The particles remain stable in the dispersion medium and are not prone to agglomeration or sedimentation, ensuring the uniformity of the nanowires during preparation and processing. At the same time, nanoscale colloidal nanowire particles have high plasticity, which makes colloidal nanowires easy to shape and manipulate during processing.

[0019] The surface area and high surface activity of the nanowire particles, the fluidity of the dispersion medium and the intermolecular forces jointly enhance the processability and efficiency of the nanowire particles as well as the structural stability and integrity.

[0020] The beneficial effects of the present invention are as follows: the preparation method provided by the present invention overcomes the shortcomings of the traditional method for preparing colloidal covalent organic framework solutions, and is simple, efficient, and common for preparing covalent organic framework colloids. COF powder is evenly dispersed in the proposed combined solvent by a cutting-edge ultrasonic dispersion method. The cutting-edge ultrasonic dispersion effectively overcomes the interlayer force of the COF material, breaks up the COF powder to make it evenly dispersed, and efficiently and quickly prepares a colloidal solution with good stability and processability, so that it can be used for processing into various shapes and devices, such as thin films, coatings and other functional devices, and is expected to be widely used in the fields of multiphase catalysis, energy storage, optoelectronic devices, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical picture of the COF powder and colloidal covalent organic framework solution of the present invention under the irradiation of a laser pen;

[0022] Among them, (a), (b), and (c) are powders of COF1, 2, and 3, respectively, and (d), (e), and (f) are physical pictures of the colloidal covalent organic framework solutions of COF1, 2, and 3 prepared in the experimental examples of the present invention under the irradiation of a laser pen, respectively;

[0023] Figure 2 The colloidal nanowires of the solution prepared for the experiment of the present invention observed under a compound microscope;

[0024] Among them, (a) is the colloidal nanowires of COF1 observed under a compound microscope; (b) is the colloidal nanowires of COF2 observed under a compound microscope. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] In order to achieve the above object, the present invention provides the following specific implementation methods:

[0027] Example 1: A method for preparing a colloidal covalent organic framework solution, comprising the following steps:

[0028] The imine and ketoamine covalent organic framework powders are ultrasonically dispersed in a combined solvent for 1 to 30 minutes; a suspension with a concentration of 0.1 to 5 mg / ml is obtained, and the suspension is subjected to cutting-edge ultrasound in an ultrasonic homogenizer, with a power of 8 to 12 kHz, a frequency of 25 to 30 kHz, and a time of 3 to 5 minutes; thus, a colloidal covalent organic framework solution is obtained;

[0029] The aldehyde precursor of the obtained colloidal covalent organic framework is trialdehyde phloroglucinol.

[0030] The amine precursor of the obtained colloidal covalent organic framework is any one of p-phenylenediamine, m-phenylenediamine, biphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-diaminoterphenyl, 1,3,5-tris(4-aminophenyl)benzene and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

[0031] The combined solvent is a combined solvent of a solvent and pyrrole, and the volume ratio of the combined solvent to pyrrole is equal to 3 to 5. The solvent is any one of pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, tetrahydrofuran, ethanol, methanol, dimethyl sulfoxide, sulfolane, and water.

[0032] In order to further illustrate the present invention, an experimental example is provided, in which the prepared colloidal covalent organic framework solution is abbreviated as colloidal COFX solution, wherein X is used to distinguish COF synthesized by any combination of aldehyde and amine monomers, and X is equal to 1, 2, 3, etc.

[0033] Experimental Example 1: In this experimental example, the solvent is pyrrolidone, N,N-dimethylacetamide, ethanol or water. The selected amine monomer is 1,4-naphthalene diamine, the aldehyde monomer is trialdehyde phloroglucinol, and the synthesized COF is COF1.

[0034] Specifically, the preparation of colloidal COF1 solution:

[0035] 2 mg of COF1 powder was dispersed in 5 ml of a combined solvent of pyrrolidone and pyrrole by ordinary ultrasonication and then subjected to tip ultrasonication for 10 min to obtain a colloidal COF1 solution.

[0036] Specific Experimental Example 1: Preparation of Colloidal COF1 Solution:

[0037] 2 mg of COF1 powder was dispersed in 5 ml of a combined solvent of N,N-dimethylacetamide and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF1 solution.

[0038] Specific Experimental Example 2: Preparation of Colloidal COF1 Solution:

[0039] 2 mg of COF1 powder was dispersed in 5 ml of a combined solvent of ethanol and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 15 min to obtain a colloidal COF1 solution.

[0040] Specific Experimental Example 3: Preparation of Colloidal COF1 Solution:

[0041] 2 mg of COF1 powder was dispersed in 5 ml of a combined solvent of water and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 20 min to obtain a colloidal COF1 solution.

[0042] Experimental Example 2: The difference from Experimental Example 1 is:

[0043] The solvent is tetrahydrofuran, methanol or dimethyl sulfoxide, the amine monomer is 1,5-naphthalene diamine, the aldehyde monomer is trialdehyde phloroglucinol, and the synthesized COF is COF2.

[0044] Specific Experimental Example 4: Preparation of Colloidal COF2 Solution:

[0045] 2 mg of COF2 powder was dispersed in 5 ml of tetrahydrofuran and pyrrole combined solvent by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF2 solution.

[0046] Specific Experimental Example 5: Preparation of Colloidal COF2 Solution:

[0047] 2 mg of COF2 powder was dispersed in 5 ml of a combined solvent of methanol and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 15 min to obtain a colloidal COF2 solution.

[0048] Specific Experimental Example 6: Preparation of Colloidal COF2 Solution:

[0049] 2 mg of COF2 powder was dispersed in 5 ml of a combined solvent of dimethyl sulfoxide and pyrrole by conventional ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF2 solution.

[0050] Experimental Example 3: The difference from Experimental Example 1 is:

[0051] The solvent is N,N-dimethylformamide, tetrahydrofuran, and cyclopentane sulfone. The amine monomer is 2,6-naphthalenediamine, the aldehyde monomer is trialdehyde phloroglucinol, and the synthesized COF is COF3.

[0052] Specific Experimental Example 7: Preparation of Colloidal COF3 Solution:

[0053] 2 mg of COF3 powder was dispersed in 8 ml of a combined solvent of N,N-dimethylformamide and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF3 solution.

[0054] Specific Experimental Example 8: Preparation of Colloidal COF3 Solution:

[0055] 2 mg of COF3 powder was dispersed in 5 ml of tetrahydrofuran and pyrrole combined solvent by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF3 solution.

[0056] Specific Experimental Example 9: Preparation of Colloidal COF3 Solution:

[0057] 2 mg of COF3 powder was dispersed in 8 ml of a combined solvent of sulfolane and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 15 min to obtain a colloidal COF3 solution.

[0058] Experimental Example 4: The difference from Experimental Example 1 is:

[0059] The solvent is pyrrolidone, N,N-dimethylacetamide, and tetrahydrofuran, the amine monomer is 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, the aldehyde monomer is trialdehyde phloroglucinol, and the synthesized COF is COF4.

[0060] Specific Experimental Example 10: Preparation of Colloidal COF4 Solution:

[0061] 2 mg of COF4 powder was dispersed in 5 ml of a combined solvent of pyrrolidone and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF4 solution.

[0062] Specific Experimental Example 11: Preparation of Colloidal COF4 Solution:

[0063] 2 mg of COF4 powder was dispersed in 5 ml of tetrahydrofuran and pyrrole combined solvent by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF4 solution.

[0064] Specific Experimental Example 12: Preparation of Colloidal COF4 Solution:

[0065] 2 mg of COF4 powder was dispersed in 5 ml of a combined solvent of N,N-dimethylacetamide and pyrrole by ordinary ultrasonication and subjected to tip ultrasonication for 10 min to obtain a colloidal COF4 solution.

[0066] Example 2: Figure 1 , Figure 2 As shown, the present invention also provides a covalent organic framework colloidal solution obtained by the preparation method, wherein the colloidal solution contains colloidal nanowires with uniform length and diameter, wherein the length of the colloidal nanowires is at the micrometer level and the width is at the nanometer level.

[0067] Figure 1 (a), (b), and (c) are COF1, COF2, and COF3 powders, respectively. It can be seen from the figures that COF powders are very easy to aggregate; (d), (e), and (f) are the actual pictures of the COF1, 2, and 3 colloidal covalent organic framework solutions prepared in the experimental examples under the irradiation of a laser pen, respectively. It can be seen from the figures that when the laser pen is irradiated, a bright "pathway" can be seen in the solution, namely the Tyndall effect, proving that the colloidal covalent organic framework solution prepared in this experiment has good dispersibility and stability;

[0068] Figure 2 (a) and (b) show that colloidal nanowires can be observed under a compound microscope in the colloidal covalent organic framework solution prepared by the present invention, and the size and distribution are very uniform;

[0069] In summary, the colloidal covalent organic framework solution prepared by the present invention has nano-scale dispersion and exhibits good stability and processability. In addition, the preparation method provided by the present invention is simple, universal and easy to implement, and has good potential application prospects in the fields of heterogeneous catalysis, energy storage and optoelectronics.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a colloidal covalent organic framework solution, characterized in that: The following steps are involved: Ultrasonic dispersion of imine and ketoamine covalent organic framework powders in a combined solvent to obtain a suspension with a concentration of 0.1-5 mg / ml, and subjecting the suspension to tip ultrasound to obtain a colloidal covalent organic framework solution; The combined solvent is a combined solvent of a solvent and pyrrole, and the volume ratio of the combined solvent to pyrrole is equal to 3-5.

2. The method for preparing a covalent organic framework colloid according to claim 1, characterized in that: The aldehyde precursor of the obtained colloidal covalent organic framework is trialdehyde phloroglucinol.

3. The method for preparing a covalent organic framework colloid according to claim 1, characterized in that: The amine precursor of the obtained colloidal covalent organic framework is any one of p-phenylenediamine, m-phenylenediamine, biphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-diaminoterphenyl, 1,3,5-tris(4-aminophenyl)benzene and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

4. The method for preparing a covalent organic framework colloid according to claim 1, characterized in that: The solvent is any one of pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, tetrahydrofuran, ethanol, methanol, dimethyl sulfoxide, sulfolane and water.

5. The method for preparing a covalent organic framework colloid according to claim 1, characterized in that: The ultrasonic dispersion time is 1 to 30 minutes.

6. The method for preparing a covalent organic framework colloid according to any one of claims 1 to 5, characterized in that: The tip ultrasound of the suspension is carried out in an ultrasonic homogenizer, and the power of ultrasonic homogenization is 8-12 kHz, the frequency is 25-30 kHz, and the time is 3-5 minutes.

7. A covalent organic framework colloidal solution obtained by the preparation method according to claims 1-6, characterized in that: The colloidal solution contains colloidal nanowires with uniform length and diameter. The length of the colloidal nanowires is at the micrometer level, and the width is at the nanometer level.

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