Polyacid protonated covalent organic framework material as well as preparation method and application thereof

Abstract

The invention relates to a polyacid protonated covalent organic framework material as well as a preparation method and application thereof. The polyacid protonated covalent organic framework material is composed of a covalent organic framework material and polyacid embedded in a pore structure of the covalent organic framework material, the covalent organic framework materials are connected with one another through imine bonds, so that the covalent organic framework materials can absorb acidic small organic molecules in a solution so as to realize a protonation state; the absorbed acidic small organic molecules can be further polymerized in the pore channels of the covalent organic framework to form polyacid so as to stabilize the protonation state; the obtained polyacid protonated covalent organic framework material shows a stable protonated state and excellent photo-thermal conversion capability, and has an excellent application prospect in the field of photo-thermal wearable devices.

Description

Technical Field

[0001] This invention belongs to the field of covalent organic framework (COF) materials, specifically relating to a polyacid protonated covalent organic framework material and its preparation method, as well as its application in fields such as photothermal wearable devices. Background Technology

[0002] Wearable thermal management devices hold significant potential for enhancing human health and reducing energy consumption. Traditional space heating and cooling account for approximately 51% of residential energy use, with indoor temperature regulation (approximately 22%) being the primary function. o C) is the primary factor. For every 0.5 point adjustment to the air conditioning setpoint... o C, calculated energy savings can reach 5%. Unlike building-level temperature regulation, which wastes energy in unoccupied spaces, wearable thermal management devices focus on providing localized heating and cooling for individuals, offering a more efficient and cost-effective solution. Photothermal textiles can regulate localized thermal conditions around humans, achieving efficient solar energy utilization by rapidly converting light energy into heat energy, thus possessing sustainable, low-carbon, and energy-saving characteristics. These textiles demonstrate significant potential in reducing energy consumption and ensuring personal thermal comfort outdoors.

[0003] In wearable textiles, carbon-based fabrics, whether derived from biomass or polymers, have advantages in commercialization due to their lightweight, flexibility, and comfort. For example, polymer products from companies like Omni-heat, Gore-Tex, and Coolcore have achieved significant success in advanced thermal properties. Notably, traditional isotropic polymers suffer from weak phonon propagation, poor thermal conductivity, and limited delocalization of π electrons, restricting their thermal management capabilities. This underscores the need to develop crystalline soft materials to improve wearable thermal textiles. Covalent organic frameworks (COFs), as a class of porous crystalline materials, offer flexible molecular design, tunable nanoporosity, and customizable functionality, making them promising candidates for photothermal applications, particularly for efficient light absorption in the near-infrared region. However, the photothermal conversion efficiency of most reported COFs is typically insufficient to reach the required temperatures under typical sunlight intensities, limiting their application in areas such as personal thermal management.

[0004] The abundant porous structure and terminal functional groups of covalent organic frameworks (COFs), such as -N and -O, provide important opportunities for binding with small molecules. Recent studies have shown that COFs can be effectively protonated by adsorbing acidic molecules such as hydrochloric acid, acetic acid, and ascorbic acid. This protonation can broaden the light absorption edge and lower the band gap energy, thereby enhancing photocatalytic performance and potentially improving photothermal conversion efficiency. Achieving efficient light absorption through protonation is crucial for improving the photothermal conversion efficiency of COFs. However, the inherent weak interactions within COFs make them prone to deprotonation under organic conditions and high temperatures, leading to a decrease in stability and photothermal performance. Therefore, the practical application of protonated COFs in photothermal wearable devices faces significant challenges. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a polyacid protonated covalent organic framework material, its preparation method, and its applications. The polyacid protonated covalent organic framework material of this invention has promising application prospects in the field of photothermal wearable devices. This invention is specifically implemented using the following technical solutions: A polyacid protonated covalent organic framework material is disclosed, comprising a covalent organic framework material and a polyacid filling its nanopores; wherein the covalent organic framework material is a porous material formed by imine bonds; and the polyacid is formed by in-situ polymerization of acidic small organic molecules within the nanopores of the covalent organic framework material.

[0006] Furthermore, the covalent organic framework material is any one of TTPA-COF, TPB-TP-COF, TPA-COF, and TTPA-TP-COF, with TTPA-COF being preferred.

[0007] Furthermore, the acidic organic small molecule is an organic acid containing at least two thiol functional groups, selected from any one of dimercaptosuccinic acid, dithiooctanoic acid, dimercaptoglutaric acid, dithiocarboxylic acid, and dimercaptoadiic acid, preferably dimercaptosuccinic acid.

[0008] Furthermore, in the polyacid protonated covalent organic framework material, the mass ratio of the covalent organic framework material to the polyacid is 1:3-9, preferably 1:6.

[0009] The preparation method of the above-mentioned polyacid protonated covalent organic framework material includes the following steps: 1) The ligand small molecules for constructing covalent organic frameworks, reaction solvents and catalysts are mixed, degassed and sealed, and then reacted at 80-180℃ for 72-168 hours. After post-treatment, covalent organic framework materials are obtained. 2) The covalent organic framework material obtained in step 1) is mixed with acidic organic small molecules and deionized water, and allowed to stand at room temperature for 12 hours. The solid product is collected by centrifugation and dried to obtain polyacid protonated covalent organic framework material.

[0010] Further, in step 1), the reaction solvent is a mixed solvent of N,N-dimethylacetamide and o-dichlorobenzene, with a volume ratio of 1-5:1; the catalyst is an aqueous solution of acetic acid with a concentration of 6-9 mol / L.

[0011] Further, in step 1), the total molar amount of the ligand small molecules to the volume ratio of the reaction solvent is 1:20-60 mmol / mL; the amount of catalyst added is 8-20% of the volume of the reaction solvent.

[0012] Further, the post-treatment in step 1) is as follows: after the reaction is completed, the mixture is cooled to room temperature and the precipitate is collected by filtration. It is then washed sequentially with two or three of N,N-dimethylformamide, tetrahydrofuran, and acetone. The mixture is then extracted with tetrahydrofuran and acetone by Soxhlet for 24-48 h. After that, it is placed in a vacuum drying oven, vacuumed to 20 mTorr at 80 °C, and dried for 24 h to obtain covalent organic framework nanosheets.

[0013] The polyacid protonated covalent organic framework material described in this invention can be further made into photothermal textiles and applied in the field of photothermal wearable devices.

[0014] Specifically, by mixing the polyacid protonated covalent organic framework material of the present invention with polyurethane, photothermal textiles can be obtained through electrospinning technology. These textiles have a stable protonated state and excellent photothermal conversion capabilities.

[0015] The polyacid protonated covalent organic framework material designed in this invention has a stable protonated state and high photothermal conversion capability. The high-transparency photothermal textiles prepared from this material have excellent heating capability under sunlight and exhibit excellent dual-mode (photothermal heating and radiative cooling) management capability after being combined with polyurethane.

[0016] The technical principle of this invention is as follows: The covalent organic framework material has a negatively charged imine bond structure inside its pores, which allows the covalent organic framework material to absorb acidic small organic molecules in solution and thus achieve a protonated state. The absorbed acidic small organic molecules can further polymerize within the covalent organic framework pores to form polyacids, thereby stabilizing the protonated state. The obtained polyacid protonated covalent organic framework material exhibits a stable protonated state and excellent photothermal conversion capabilities, showing excellent application prospects in the field of photothermal wearable devices.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention synthesizes a polyacid protonated covalent organic framework material through reasonable structural design. This material has a stable protonated state and excellent photothermal conversion capability. 2) The polyacid protonated covalent organic framework material of the present invention has a simple synthesis step, requires low-priced monomers, and has good industrialization potential; 3) The polyacid protonated covalent organic framework material described in this invention, when mixed with polyurethane, can be used to prepare photothermal textiles with excellent photothermal conversion performance through simple electrospinning, which has excellent application prospects in the field of photothermal wearable devices. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the synthesis of protonated covalent organic framework materials made from polyacids. Figure 2 Characterization spectra of polyacid protonated covalent organic framework materials (PXRD, XPS, FTIR); Figure 3 A diagram illustrating the photothermal properties of protonated covalent organic framework materials made from polyacids. Figure 4 A schematic diagram illustrating the preparation of photothermal textiles using a protonated covalent organic framework of polyacid; Figure 5 This image illustrates the application of polyacid protonated covalent organic framework photothermal textiles in wearable devices and their corresponding performance. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments in order to better understand the technical solution. Example

[0020] Preparation of polyacid protonated covalent organic framework materials: See the synthesis schematic diagram. Figure 1The ligands tetraaminophenylenediamine (11 mg, 0.02 mmol) and tetraaldehyde phenylenediamine (10 mg, 0.02 mmol) were added to a mixed reaction solvent of o-dichlorobenzene (0.3 mL) and dimethylacetamide (0.9 mL), and ultrasonically dispersed in an ampoule to obtain an orange-yellow turbid solution. 6M acetic acid (0.10 mL) was added to the ampoule as a catalyst. The ampoule was rapidly frozen at 77 K in a liquid nitrogen bath, and degassed three times by a freeze-vacuum-thaw cycle, then sealed. The ampoule was placed in a 120 °C oven and kept at a constant temperature for 4 days. After the reaction was completed, it was cooled to room temperature and filtered to collect a yellow solid. The collected solid was washed sequentially with N,N-dimethylacetamide (3 × 10 mL) and acetone (3 × 10 mL). The solid was extracted with tetrahydrofuran and acetone, respectively, by Soxhlet extraction for 48 h, and then dried under vacuum at 80 °C for 24 h to obtain a covalent organic framework material. The obtained covalent organic framework material (5 mg) and dimercaptosuccinic acid (30 mg) were added to 10 mL of deionized water, allowed to stand at room temperature for 12 h, and then centrifuged to collect a black solid. The collected black solid was extracted with tetrahydrofuran and acetone by Soxhlet extraction for 48 h, respectively, and then dried under vacuum at 80 °C for 24 h to obtain the polyacid protonated covalent organic framework material.

[0021] Product characterization: See Figure 2 PXRD measurements showed peaks at 6.05, 8.41, 11.81, 13.32, 21.04, 38.12, and 44.28°, confirming the correctness of the structure. XPS and FTIR observations revealed the presence of disulfide bonds and the disappearance of the thiol peak, confirming the formation of the polyacid.

[0022] Photothermal performance demonstration: See Figure 3 The temperature of the polyacid protonated covalent organic framework material increased from 80°C to 120°C under one solar irradiation compared to the original covalent organic framework material, demonstrating the improvement of the photothermal performance of covalent organic framework materials by protonation.

[0023] Preparation of photothermal textiles using polyacid protonated covalent organic framework materials: See the preparation schematic diagram. Figure 4 10 mg of protonated covalent organic framework material of polyacid was physically mixed with 10 g of polyurethane (Shenzhen Yoshida Chemical Co., Ltd., model 1926) and placed in an electrospinning chamber maintained at an ambient temperature of 24 ± 2 ℃ and a humidity of 50 ± 5%. A collection distance of 30 cm was set, and the solution was dispensed at 3 mL / h... -1 The feed rate was adjusted while a stable 30 kV voltage was applied. The electrospinning process lasted for 6 hours, followed by drying at 50 °C for 4 hours to obtain the photothermal textile.

[0024] Wearable device application demonstration: See Figure 5 Photothermal textiles made of protonated covalent organic framework (PCA) and pure polyurethane textiles, when applied to the back, can achieve certain thermal management effects under sunlight. The temperature of PCA-protonated PCA textiles under sunlight exposure is approximately 10 degrees Celsius higher than the ambient temperature under the same conditions, while the temperature of pure polyurethane textiles under sunlight exposure is approximately 7 degrees Celsius lower than the ambient temperature under the same conditions.

Claims

1. A polyacid protonated covalent organic framework material, characterized in that, The material consists of a covalent organic framework material and a polyacid filling its nanopores; the covalent organic framework material is a porous material formed by imine bonds; the polyacid is formed by in-situ polymerization of acidic small organic molecules within the nanopores of the covalent organic framework material.

2. The polyacid protonated covalent organic framework material as described in claim 1, characterized in that, The covalent organic framework material is any one of TTPA-COF, TPB-TP-COF, TPA-COF, and TTPA-TP-COF.

3. The polyacid protonated covalent organic framework material as described in claim 1, characterized in that, The acidic organic molecule is an organic acid containing at least two thiol functional groups, selected from any one of dimercaptosuccinic acid, dithiooctanoic acid, dimercaptoglutarate, dithiocarboxylic acid, and dimercaptoadiic acid.

4. The polyacid protonated covalent organic framework material as described in claim 1, characterized in that, In the protonated covalent organic framework material of the polyacid, the mass ratio of the covalent organic framework material to the polyacid is 1:3-9.

5. A method for preparing a polyacid protonated covalent organic framework material according to any one of claims 1-4, characterized in that, Includes the following steps: 1) The ligand small molecules for constructing covalent organic frameworks, reaction solvents and catalysts are mixed, degassed and sealed, and then reacted at 80-180℃ for 72-168 hours. After post-treatment, covalent organic framework materials are obtained. 2) The covalent organic framework material obtained in step 1) is mixed with acidic organic small molecules and deionized water, allowed to stand at room temperature for reaction, the solid product is collected by centrifugation, and dried to obtain polyacid protonated covalent organic framework material.

6. The method for preparing a polyacid protonated covalent organic framework material as described in claim 5, characterized in that, In step 1), the reaction solvent is a mixture of N,N-dimethylacetamide and o-dichlorobenzene in a volume ratio of 1-5:1; the catalyst is an aqueous solution of acetic acid with a concentration of 6-9 mol / L.

7. The method for preparing a polyacid protonated covalent organic framework material as described in claim 5, characterized in that, In step 1), the total molar amount of the ligand small molecules is 1:20-60 mmol / mL to the volume ratio of the reaction solvent; the amount of catalyst added is 8-20% of the volume of the reaction solvent.

8. The method for preparing a polyacid protonated covalent organic framework material as described in claim 5, characterized in that, The post-treatment in step 1) is as follows: After the reaction is completed, the mixture is cooled to room temperature and the precipitate is collected by filtration. It is then washed with two or three of N,N-dimethylformamide, tetrahydrofuran, and acetone in sequence. The mixture is then extracted with tetrahydrofuran and acetone by Soxhlet for 24-48 h. After that, it is placed in a vacuum drying oven and vacuumed to 20 mTorr at 80 °C for 24 h to obtain covalent organic framework nanosheets.

9. A photothermal textile, characterized in that, It is made by electrospinning a mixture of the polyacid protonated covalent organic framework material as described in any one of claims 1-4 and polyurethane.

10. The use of the polyacid protonated covalent organic framework material according to any one of claims 1-4 or the photothermal textile according to claim 9 in the preparation of wearable photothermal management devices.

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