A molecularly woven polymer aerogel material and its preparation method

Abstract

This invention provides a molecularly woven polymer aerogel material and its preparation method. The preparation method of the molecularly woven polymer aerogel material includes the following steps: S1, dissolving the reactive monomer in a solvent, adding a metal ligand, and stirring to obtain a woven molecular monomer; S2, adding a chain extender to the woven molecular monomer obtained in step S1 to obtain a dynamic molecularly woven polymer wet gel; S3, subjecting the wet gel obtained in step S2 to aging treatment, solvent exchange treatment, and drying to obtain a lightweight and porous molecularly woven polymer aerogel material. This invention differs from traditional covalent cross-linked networks by constructing a high-density interlaced physical cross-linked network through a woven molecular strategy, resulting in materials with higher adaptability, dynamism, and processability.

Description

Technical Field

[0001] This invention belongs to the field of multifunctional (heat insulation, water treatment, noise reduction) and processable molecularly woven polymer aerogels. It relates to a molecularly woven polymer aerogel material and its preparation method. Specifically, it relates to a molecular monomer that uses hydrogen bonds, metallic bonds, etc. to construct a woven interlaced structure, and then uses a chain extender to extend it into a molecularly woven polymer network, thereby realizing a molecularly woven polymer aerogel material that is different from covalent cross-linked materials and its preparation method. Background Technology

[0002] Weaving technology has been involved in almost the entire process of human societal development. Through highly ordered coordination of warp and weft directions, unique topological networks are constructed, resulting in woven fabrics with excellent mechanical properties. Inspired by this, researchers initially hoped to mimic weaving technology at the molecular level to design molecular topologies, thereby constructing materials with special macroscopic properties. However, due to the lack of an external driving force like a loom and the random thermal motion of molecular chains, it is difficult to prepare polymer materials with woven networks on a large scale, as is the case with polymer polymerization. Currently realized woven polymer materials mainly include materials with rigid crystalline structures, such as covalent organic frameworks, metal-organic frameworks, and hydrogen-bonded organic frameworks (Science 2016, 351, 365-369; Nat. Commun. 2020, 11, 1434; Chem 2021, 7, 1–12). Additionally, there are some flexible woven polymer films (J. Am. Chem. Soc. 2020, 142, 14343-14349). The application of woven polymer networks in three-dimensional bulk materials remains a challenge.

[0003] The greatest advantage of multifunctional aerogel materials lies in their low density, high porosity, and high specific surface area, making them promising for applications in thermal insulation, noise reduction, electromagnetic shielding, energy storage, catalysis, sensing, and water treatment. However, their inherent fragility and shrinkage significantly hinder their development. Furthermore, research on designing aerogel materials with unique properties at the molecular level is scarce. This is primarily due to the complex and demanding processes involved in aerogel preparation, requiring researchers to invest considerable time and effort in process optimization; another factor is the selectivity of precursors in forming dryable wet gels. Combining the advantages of molecular weaving technology, the development of molecularly weaved polymer aerogels holds promise for a win-win situation—both promoting the development of woven polymers and providing new design ideas for the research of dynamically functional aerogels. Summary of the Invention

[0004] To address the bottlenecks in the development of woven polymers and the limitations of precursors in the design of aerogel materials, this invention aims to provide a molecularly woven polymer aerogel material and its preparation method. Starting from the molecular level, a polymer aerogel material with a woven topological network is designed. Utilizing the pre-defined molecular topological structure, and under the crosslinking of a chain extender, a complete, blocky novel polymer gel material is obtained. This novel woven polymer network exhibits richer dynamics, which facilitates the reprocessing of aerogel materials.

[0005] The first objective of this invention is to construct molecules with an interlaced pre-woven structure through molecular topological design, and then polymerize them into a three-dimensional cross-linked network through bonding. The molecular topological design (i.e., molecular weaving) method can utilize at least one of hydrogen bonds or metallic bonds. Due to the high directionality of metallic or hydrogen bonds, the resulting woven monomers are interlaced with each other in a specific direction. In the second step of polymerizing into a three-dimensional cross-linked network, under this specific direction, cross-linking can be achieved through reactions with certain bifunctional ligands, allowing this network with a specific direction to grow and spread, thus forming a new topological network similar to "latitude and longitude". The molecular weaving dimension is at least one of biaxial or triaxial. The obtained woven monomers are used as chain extenders with compounds containing two or more reactive groups to complete the sol-gel process. After aging, solvent exchange, and drying, a novel aerogel material with physical cross-linking and a spatially woven network is obtained. In addition to traditional characteristics such as low density, high specific surface area, and abundant micro / nanoporous structures, it also possesses processability.

[0006] Another objective of this invention is to obtain novel polymer aerogel materials with broader functional applications based on the aforementioned molecularly woven polymer gel materials.

[0007] The objective of this invention can be achieved through the following methods:

[0008] In a first aspect, the present invention provides a method for preparing a molecularly woven polymer aerogel material, comprising the following steps:

[0009] S1. Dissolve the reactive monomer in a solvent, add a metal ligand, and stir to obtain a woven molecular monomer; the reactive monomer is a bifunctional reactive monomer with metal coordination or hydrogen bonding sites.

[0010] S2. Add a chain extender to the braided molecular monomer obtained in step S1 to obtain a dynamic molecular braided polymer wet gel (with a certain crosslinking density); the chain extender is a compound containing two or more reactive groups;

[0011] S3. The wet gel obtained in step S2 is subjected to aging treatment, solvent exchange treatment, and drying to obtain a molecularly woven polymer aerogel material.

[0012] Preferably, in step S1, the bifunctional reactive monomer includes at least one of the compound monomers containing dialdehyde and diamine reactive groups.

[0013] More preferably, in step S1, the bifunctional reactive monomers include phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl ether, biphenylenediamine and its derivatives, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 4,4'-diaminodiphenylmethane, 4,4'-diaminotriphenylmethane, 2,5-dibutoxybenzyl-1,4-dicarboxaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenoxazine, 1,8-naphthidine-2,7-dibenzaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenthiazine, 3 At least one of the following: 3'-bipyridine-5,5'-dicarboxaldehyde, 2,5-diheptoxy-1,4-terephthalaldehyde, 2,3-anthracene dicarboxaldehyde, 3,5-pyridine dicarboxaldehyde, thiophene-2,4-dicarboxaldehyde, acetaldehyde-polyethylene glycol-acetaldehyde, phenylpropynyl acetal diacetaldehyde, thiazo[5,4-d]-triazole, o-phenanthroline, 1,10-o-diazanthroline-2-9-disubstituted-dicarboxaldehyde, 1,10-o-diazanthroline-2-9-disubstituted-diamine, and 1,10-o-diazanthroline-2-9-disubstituted-dicarboxaldehyde.

[0014] Preferably, in step S1, the solvent includes at least one of acetonitrile, anisole, N,N-dimethylacetamide, dichloromethane, chloroform, dimethyl sulfoxide, dioxane, isopropanol, benzene, toluene, xylene, thyleneacetone, methanol, ethanol, propanol, acetone, and THF.

[0015] Preferably, in step S1, the metal ligand includes at least one of Cu(Ι)(CH3CN)BF4 and Fe(BF4)2·6H2O.

[0016] Preferably, in step S1, the molar ratio of the reactant monomer to the metal ligand is 1-4:1, the reaction temperature is 20-30℃, and the reaction time is 0.5-24h.

[0017] In some embodiments, the molar ratio of the reactive monomer to the metal ligand is 2:1.

[0018] Preferably, in step S1, the braided monomers are braided through a braiding process, which includes at least one of hydrogen bonds and metallic bonds. The braiding dimension is at least one of biaxial and triaxial. The braided monomers are obtained by interlacing monomers containing hydrogen bond or metallic bond sites. The interlacing forms of the braided monomers include at least one of rotaxanes, corded hydrocarbons, daisy chains, and molecular knots with different warp and weft directions, biaxial or multiaxial structures.

[0019] Preferably, in step S1, the bifunctional reactive monomers with hydrogen bonding sites self-assemble through hydrogen bonding to form woven molecular monomers.

[0020] Alternatively, bifunctional reactive monomers with metal coordination sites can assemble with metal ligands through metal bonds to form woven molecular monomers.

[0021] In this invention, the self-assembly method involves high dilution, and the resulting woven molecular monomers can be directly used in subsequent reactions.

[0022] Preferably, in step S2, the chain extender is at least one of C6-C100 compounds containing two or more reactive groups.

[0023] More preferably, in step S2, the chain extender includes at least one of 1,4-di(4-aldehydephenyl)benzene, isophorone diisocyanate, 1,5-diamino-3-methylpentane, isophthalohydrazide and its derivatives, 1,5-hexadiene, 1,6-hexanedithiol, 4,4'-dicyclohexylmethane diisocyanate, 5-dihydroxy-1,4-benzaldehyde, 2,5-dibutoxybenzaldehyde-1,4-dicarboxaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenoxazine, 1,8-naphthyl-2,7-dibenzaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenthiazine, 3,3'-bipyridine-5,5'-dicarboxaldehyde, 2,5-diheptoxy-1,4-terephthalaldehyde, 2,3-anthracitedicarboxaldehyde, p-diaminobiphenyl, hexamethylenediamine, and 1,1'-biphenyl-3,3'-diamine.

[0024] Preferably, a catalyst may be added in step S2 to carry out the reaction; the catalyst includes an acetic acid solution with a concentration of 4-9 mol / L, and the amount of acetic acid solution added accounts for 0.005-0.02% of the total volume.

[0025] In some embodiments, the concentration of the acetic acid solution is 6 mol / L, and the volume fraction of the acetic acid solution added is 0.01%.

[0026] Preferably, in step S2, the molar ratio of the reactive groups of the chain extender to the reactive groups of the braided monomer is 0.5-2:1, the reaction temperature is 50-150℃, and the reaction time is 12-72h.

[0027] In some embodiments, the molar ratio of the reactive groups of the chain extender to the reactive groups of the braiding monomer is 1:1.

[0028] Preferably, in step S2, the reactive groups of the chain extender form a network bond with the reactive groups of the braiding monomer. The bond forms include: carbon-sulfur bonds formed by the reaction of double bonds with thiol groups, double bonds formed by the metathesis reaction of double bonds with double bonds, imine bonds formed by aldehyde groups and amino groups, and disulfide bonds formed by the reaction of thiol groups with thiol groups.

[0029] Preferably, in step S2, the dynamic molecularly woven polymer wet gel has a molecularly woven topological network.

[0030] Preferably, in step S3, the solvent for the solvent exchange treatment includes at least one of N,N-dimethylacetamide, methanol, ethanol, propanol, dichloromethane, chloroform, dimethyl sulfoxide, acetonitrile, anisole, dioxane, trimethylbenzene, acetone, benzene, toluene, and xylene.

[0031] Preferably, in step S3, the aging treatment temperature is 50-80℃ and the aging time is 24-72h.

[0032] Preferably, in step S3, the drying includes at least one of atmospheric pressure drying and supercritical drying. The drying conditions are determined according to different drying methods, with supercritical drying being the preferred method. Atmospheric pressure drying is only chosen when sample preparation cannot be achieved through atmospheric pressure drying. The supercritical drying is a conventional technique in the art, and its parameters are the operating parameters of the supercritical drying instrument.

[0033] Secondly, the present invention provides a molecularly woven polymer aerogel material prepared by the preparation method described above.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. This invention relates to a processable molecularly woven polymer aerogel material and its preparation method. By utilizing a molecular pre-weaving strategy, novel molecular monomers with interlaced structures are synthesized to construct dynamic woven polymer networks, thereby achieving processability and multifunctionality.

[0036] 2. This invention successfully combines the processability of molecularly woven polymers with the multifunctionality of aerogel materials to construct dynamic molecularly woven polymer aerogels, and expands their functional applications to include noise reduction, heat insulation, and adsorption.

[0037] 3. Compared to the randomly entangled polymer networks formed by traditional covalent cross-linking, this invention constructs a high-density interwoven physical cross-linked network by building a woven molecular strategy (i.e., metal coordination or hydrogen bonding). Since metal coordination or hydrogen bonding has a high degree of directionality, the resulting woven molecular monomers are interwoven with each other and have a certain direction, ultimately forming a network with warp and weft directions. This makes the material itself more adaptive, dynamic and processable, thereby realizing the regulation and design of macroscopic aerogel material properties from the molecular level. Attached Figure Description

[0038] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 Photograph of the molecularly woven polymer wet gel of the aerogel sample prepared in Example 1;

[0040] Figure 2 The appearance, integrity, and strength of the aerogel sample prepared in Example 2;

[0041] Figure 3 The reprocessability of the aerogel sample prepared in Example 3 under atmospheric pressure heating conditions;

[0042] Figure 4 The microstructure of the aerogel sample prepared in Example 4;

[0043] Figure 5 The thermal stability of the aerogel sample prepared in Example 5;

[0044] Figure 6 This is a photograph of the sample prepared in Comparative Example 1. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, providing detailed implementation methods and specific operating procedures, which will help those skilled in the art to further understand the present invention. It should be noted that the scope of protection of the present invention is not limited to the following embodiments; any adjustments and improvements made under the concept of the present invention are all within the scope of protection of the present invention.

[0046] The properties of the molecularly woven polymer aerogel obtained in this invention are characterized as follows:

[0047] The thermal stability of the aerogel was characterized by thermogravimetric analysis (TGA) test results. The test environment was a nitrogen atmosphere, the test temperature range was from room temperature to 800℃, and the heating rate was 20℃ / min.

[0048] The sound absorption coefficient of aerogel was determined using a standing wave tube tester, with reference to standard JJF1223-2009.

[0049] The morphology of the aerogel was obtained by field emission scanning electron microscopy (test voltage 10 kV).

[0050] The linear shrinkage rate of the aerogel was calculated by (diameter before drying / diameter after condensation and drying - 1) × 100%.

[0051] Example 1

[0052] This embodiment provides a method for preparing a molecularly woven polymer wet gel. Specifically, it includes the following steps:

[0053] Step 1: At 25°C, 0.16 mmol of 1,10-o-diazaphenanthroline-2-9-disubstituted dicarboxaldehyde and 0.08 mmol of Cu(Ι)(CH3CN)·BF4 were dissolved in 2 mL of anhydrous THF solution. The mixture was stirred in a sealed container for 12 h, and the solvent was evaporated to obtain Cu(PDB)2(BF4) braided monomers with aldehyde groups located at the four corners of the tetrahedral structure.

[0054] Step 2: At 25℃, dissolve 0.08 mmol Cu(PDB)₂(BF₄) and 0.16 mmol p-diaminobiphenyl in 1.5 mL tetrahydrofuran, add 10 μL 6 mol / L acetic acid solution, and then heat the mixed solvent in a sealed container to 120℃ for 3 days to react completely. The resulting gel material is washed three times with anhydrous THF to obtain a brownish-black solid block-shaped wet gel material. Figure 1 As shown, a wet gel obtained by polymerizing a tetrafunctional woven molecular ligand (composed of bifunctional molecules arranged in an alternating pattern) with a chain extender via a molecular weaving strategy exhibits excellent integrity, appearance, and strength. (Density of the obtained aerogel: 180 mg / cm³) 3 (Linear shrinkage rate 47%)

[0055] Comparative Example 1

[0056] The comparative example is traditional covalent crosslinking, and the steps are as follows:

[0057] At 25°C, 0.30 mmol of 1,10-o-diazanthroline-2-9-disubstituted dicarboxaldehyde and 0.30 mmol of p-diaminobiphenyl were dissolved in 1.0 mL of tetrahydrofuran. 10 μL of 6 mol / L acetic acid solution was added, and the mixed solvent was then heated to 80°C in a sealed container for two days to allow the reaction to proceed fully. Figure 6 As shown, it is impossible to obtain block-shaped gel material.

[0058] Comparing Comparative Example 1 with Example 1, it can be seen that Comparative Example 1 did not undergo molecular weaving, which resulted in the inability to form a network with warp and weft directions. This resulted in poor adaptability, dynamism, and processability of the material itself, and it could not form a block-shaped gel material.

[0059] Example 2

[0060] This embodiment provides a method for preparing molecularly woven polymer aerogels. Specifically, it includes the following steps:

[0061] Step 1: At 25℃, 0.20 mmol of 1,10-o-diazaphenanthroline-2-9-disubstituted dicarboxaldehyde and 0.10 mmol of Cu(Ι)(CH3CN)·BF4 were dissolved in 20 mL of acetonitrile and stirred for 12 h. The solvent was then evaporated to obtain Cu(PDB)2(BF4) woven molecular monomers, with the aldehyde groups located at the four corners of the tetrahedral structure.

[0062] Step 2: At 25°C, 0.1 mmol Cu(PDB)2(BF4) and 0.20 mmol p-diaminobiphenyl were dissolved in 1.0 mL tetrahydrofuran, and 10 μL 6 mol / L acetic acid solution was added. The mixed solvent was then heated to 100°C in a sealed container and reacted completely for 3 days. The resulting gel material was washed 3 times with anhydrous THF to obtain a brownish-black solid block wet gel material.

[0063] Step 3: After replacing the obtained wet gel material with acetone three times, it was aged in a 60℃ oven for 3 days, and then subjected to supercritical drying to obtain a brownish-black solid block aerogel material. (The density of the obtained aerogel is 200 mg / cm³) 3 (Linear shrinkage rate is 35%), such as Figure 2 As shown, the molecularly woven aerogel material obtained by drying wet gel using supercritical drying technology meets the requirements of traditional aerogel materials in terms of appearance, integrity, and strength.

[0064] Example 3

[0065] This embodiment provides a method for preparing molecularly woven polymer aerogels. Specifically, it includes the following steps:

[0066] Step 1: At 25℃, 0.30 mmol of 1,10-o-diazaphenanthroline-2-9-disubstituted dicarboxaldehyde and 0.15 mmol of Fe(BF4)2·6H2O were dissolved in 20 mL of acetone and stirred for 6 h. The solvent was then evaporated to obtain Fe(PDB)2(BF4) braided monomers, with the aldehyde groups located at the six corners of the hexahedral structure.

[0067] Step 2: At 25°C, 0.15 mmol Fe(PDB)2(BF4) and 0.45 mmol hexamethylenediamine were dissolved in 1.0 mL tetrahydrofuran, and 10 μL 6 mol / L acetic acid solution was added. The mixed solvent was then heated to 80°C in a sealed container and reacted completely for 2 days. The resulting gel material was washed 3 times with anhydrous THF to obtain a brownish-black solid block wet gel material.

[0068] Step 3: The obtained wet gel material was replaced three times with ethanol and acetone, then aged in a 60℃ oven for 3 days, followed by supercritical drying to obtain a brownish-black solid block aerogel material. (The density of the obtained aerogel is 280 mg / cm³) 3 (Linear shrinkage rate is 38%)

[0069] Step 4: After grinding the obtained aerogel material, disperse it in anisole and place it in a 150℃ oven for 3 days. Then wash it 3 times with anhydrous acetone. The resulting brownish-black wet gel is then subjected to supercritical drying to obtain a solid block aerogel material (the density of the obtained aerogel is 200 mg / cm³). 3 (Linear shrinkage rate is 33%), such as Figure 3 As shown, the reprocessability achieved under normal pressure heating conditions allows molecularly woven aerogel powders to be re-formed into new aerogel materials through a sol-coagulation process, which is of great significance for promoting green applications and sustainable development strategies.

[0070] Figure 1-3 The solid block aerogel material also confirms that the gel sample prepared based on the molecular weaving method of this invention has a high-density interlaced physical cross-linked network.

[0071] Example 4

[0072] This embodiment provides a method for preparing molecularly woven polymer aerogels. Specifically, it includes the following steps:

[0073] Step 1: At 25℃, 0.40 mmol of 1,10-o-diaphenanthrene-2-9-disubstituted diamine and 0.20 mmol of Cu(Ι)(CH3CN)·BF4 were dissolved in 20 mL of acetonitrile, stirred for 12 h, and the solvent was evaporated to obtain Cu(NH2)2(BF4) braided monomer, with the amino groups located at the four corners of the tetrahedral structure.

[0074] Step 2: At 25°C, 0.20 mmol Cu(NH2)2(BF4) and 0.40 mmol 1,4-bis(4-aldehyde phenyl)benzene were dissolved in 1.0 mL of ethanol, and 10 μL of 6 mol / L acetic acid solution was added. The mixed solvent was then heated to 80°C in a sealed container and reacted completely for 2 days. The resulting gel material was washed three times with anhydrous acetone to obtain a brownish-black solid block wet gel material.

[0075] Step 3: The obtained wet gel material was replaced three times with anhydrous acetone, aged in a 60℃ oven for 3 days, and then subjected to supercritical drying to obtain a brownish-black solid block aerogel material (the density of the obtained aerogel was 320 mg / cm³). 3 (Linear shrinkage rate is 34%), such as Figure 4 As shown, the microstructure of the obtained molecularly woven aerogel material clearly shows the aerogel skeleton formed by the accumulation of particles at the micro-nano scale.

[0076] Example 5

[0077] This embodiment provides a method for preparing molecularly woven polymer aerogels. Specifically, it includes the following steps:

[0078] Step 1: At 25℃, 0.40 mmol of 1,10-o-diazaphenanthroline-2-9-disubstituted dicarboxaldehyde and 0.20 mmol of Cu(Ι)(CH3CN)·BF4 were dissolved in 20 mL of acetonitrile, stirred for 12 h, and the solvent was evaporated to obtain the building block Cu(PBD)2(BF4) braided molecular monomer.

[0079] Step 2: At 25℃, 0.20 mmol Cu(NH2)2(BF4) and 0.40 mmol 1,1'-biphenyl-3,3'-diamine of the obtained tetrahedral building blocks were dissolved in 1.0 mL THF, and 10 μL 6 mol / L acetic acid solution was added. The mixed solvent was then heated to 100℃ in a sealed container and reacted completely for 3 days. The resulting gel material was washed 3 times with anhydrous acetone to obtain a brownish-black solid block wet gel material.

[0080] Step 3: The obtained wet gel material was replaced three times with anhydrous acetone, aged in a 75℃ oven for 3 days, and then supercritically dried to obtain a brownish-black solid block aerogel material (the density of the obtained aerogel was 380 mg / cm³). 3 (The linear shrinkage rate was 40%), and two parallel samples were prepared. Figure 5As shown, the molecularly woven polymer aerogel exhibits excellent thermal stability. The 95% mass retention indicates that it can be used at around 200 degrees Celsius. Based on the rigid structure of the benzene ring and the presence of its carbon-nitrogen heterocycles, the aerogel obtained in this invention exhibits higher thermal stability compared to covalent polymer aerogel materials.

[0081] Example 6

[0082] This embodiment provides a method for preparing molecularly woven polymer aerogels. Specifically, it includes the following steps:

[0083] Step 1: At 25°C, a solution containing 0.20 mmol of 1,10-o-diazanthroline-2-9-disubstituted dicarboxaldehyde and 0.10 mmol of Cu(Ι)(CH3CN)·BF4 was added to degassed acetonitrile. After stirring at room temperature for 5 h, the solvent was evaporated to obtain the tetrahedral building block Cu(PBD)2(BF4) with an interlaced structure.

[0084] Step 2: At 25℃, the obtained tetrahedral building blocks 0.10Cu(PBD)2(BF4) and 0.20mmol 1,1'-biphenyl-3,3'-diamine were dissolved in 1.0mL THF, and 10μL 6mol / L acetic acid solution was added. The mixed solvent was then heated to 80℃ in a sealed square container and reacted completely for 3 days. The resulting gel material was washed 3 times with anhydrous acetone to obtain a brownish-black solid block wet gel material.

[0085] Step 3: The obtained wet gel material was replaced three times with anhydrous acetone, aged in a 75℃ oven for 3 days, and then supercritically dried to obtain a brownish-black film-shaped aerogel material (the density of the obtained aerogel was 220 mg / cm³). 3 (Linear shrinkage rate is 50%).

[0086] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a molecularly woven polymer aerogel material, characterized in that, Includes the following steps: S1. Dissolve the reactive monomer in a solvent, add a metal ligand, and stir to obtain a woven molecular monomer; the reactive monomer is a bifunctional reactive monomer with metal coordination or hydrogen bonding sites. The bifunctional reactive monomers include at least one of 1,8-naphthyl-2,7-dibenzaldehyde, 10-ethyl-3,7-dicarboxylphenthiazide, 3,3'-bipyridine-5,5'-dicarboxaldehyde, 3,5-pyridinedicarboxaldehyde, thiazo[5,4-d]-triazole, o-phenanthroline, 1,10-o-diazaphenanthroline-2-9-disubstituted-dicarboxaldehyde, and 1,10-o-diazaphenanthroline-2-9-disubstituted-diamine; The metal ligand includes at least one of Cu(I)(CH3CN)BF4 and Fe(BF4)2·6H2O; S2. Add a chain extender to the braided molecular monomer obtained in step S1 to obtain a dynamic molecular braided polymer wet gel; the chain extender is a compound containing two or more reactive groups; S3. The wet gel obtained in step S2 is subjected to aging treatment, solvent exchange treatment, and drying to obtain a molecularly woven polymer aerogel material.

2. The preparation method according to claim 1, characterized in that, In step S1, the molar ratio of the reaction monomer to the metal ligand is 1-4:1; the reaction temperature is 20-30 °C; and the reaction time is 0.5-24 h.

3. The preparation method according to claim 1, characterized in that, In step S2, the chain extender is at least one of a compound containing two or more reactive groups in the C6-C100 group.

4. The preparation method according to claim 1, characterized in that, In step S2, the chain extender includes at least one of 1,4-di(4-aldehydephenyl)benzene, isophorone diisocyanate, 1,5-diamino-3-methylpentane, isophthalohydrazide and its derivatives, 1,5-hexadiene, 1,6-hexanedithiol, 4,4'-dicyclohexylmethane diisocyanate, 2,5-dibutoxybenzene-1,4-dicarboxaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenoxazine, 1,8-naphthyl-2,7-dibenzaldehyde, 10-ethyl-3,7-dicarboxaldehyde-phenthiazine, 3,3'-bipyridine-5,5'-dicarboxaldehyde, 2,5-diheptoxy-1,4-terephthalaldehyde, 2,3-anthracitedicarboxaldehyde, p-diaminobiphenyl, hexamethylenediamine, and 1,1'-biphenyl-3,3'-diamine.

5. The preparation method according to claim 1, characterized in that, In step S2, the molar ratio of the reactive groups of the chain extender to the reactive groups of the braided monomer is 0.5-2:1; the reaction temperature is 50-150 ℃; and the reaction time is 12-72 h.

6. The preparation method according to claim 1, characterized in that, In step S3, the aging treatment temperature is 50-80 ℃, and the aging time is 24-72 h; the solvent for the solvent exchange treatment includes at least one of N,N-dimethylacetamide, methanol, ethanol, propanol, dichloromethane, chloroform, dimethyl sulfoxide, acetonitrile, anisole, dioxane, trimethylbenzene, acetone, benzene, toluene, and xylene; the drying includes at least one of atmospheric pressure drying and supercritical drying.

7. A molecularly woven polymer aerogel material prepared by the preparation method according to any one of claims 1-6.

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