JP2023095841A - Carbon-based composite aerogel with fire early warning function and high compression performance and preparation method therefor - Google Patents

Abstract

To provide a carbon-based composite aerogel with a fire early warning function and high compression performance and a preparation method for the carbon-based aerogel.SOLUTION: The main structure of the aerogel is built by using graphene oxide and carbon nanotubes with a thermal reduction property and excellent mechanical characteristics; and a continuous network is constructed through dual effects of surface enhancement of the graphene oxide nanosheets by the amino carbon nanotubes and interface crosslinking of the ferroferric oxide nanoparticles, so that high compression performance and a fire early warning function are realized. The prepared carbon-based composite aerogel can be applied to the fields of heat insulation, fire protection, energy storage, mechanical devices and the like.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to the technical field of functional nanocomposites, specifically to carbon-based composite airgel with fire alarm function and high compression performance and its preparation method.

Although 2D graphene nanosheets have excellent flexibility, elasticity, tensile strength and compressive strength, direct and randomly assembled graphene aerogels due to weak interactions often exhibit obvious brittleness during compression and tension, which is not suitable for applications. difficult to meet the demands of Currently, there are two main approaches to overcome the brittleness of carbon-based composite aerogels, one is to use 3D printing and other co-assembly techniques to generate hierarchical structures and enhance the toughness of aerogels. For example, Guo et al. and colleagues (Highly stretchable carbon aerogels. Nat. Commun. 2018, 9, 881) adopted smart 3D ink printing technology to achieve low energy consumption, high fatigue resistance, and excellent environmental stability. We fabricated a highly ductile graphene/multiwalled carbon nanotube composite aerogel with a four-step layered structure. However, due to the limitations of 3D printing technology, this method requires high requirements for synthesis technology, and mass production of airgel materials could not be realized. Another is to introduce an elastic polymer or small molecule into the matrix as a cross-linking agent, for example, Qiu et al. Based on reductive preparation, we propose a process that integrates functionalization, assembly and subsequent microwave irradiation treatment to fabricate ultralight graphene aerogels with high compressibility. However, this aerogel has weak intermolecular interactions and poor stability under severe chemical and physical conditions.

Based on this, how to use a simple synthesis technology to strengthen the interaction between airgel molecules and prepare multi-functional carbon-based composite aerogels with fire alarm function and high compressibility is still a challenge. exists and requires further consideration.

In view of the above technical problems at present, the present invention relates to a carbon-based composite aerogel with fire alarm function and high compression performance and a preparation method thereof.

In order to achieve the inventive objectives of the present invention, the following technical solutions are proposed.

A carbon-based composite airgel having a fire alarm function and high compression performance,
The carbon-based composite airgel is prepared by self-assembly of amino carbon nanotubes and graphene oxide nanosheets through surface adsorption and interfacial cross-linking of Fe ₃ O ₄ nanoparticles, followed by freeze-drying.

The amino carbon nanotubes are one or a combination of single-walled carbon nanotubes or multi-walled carbon nanotubes.

The Fe ₃ O ₄ nanoparticles are pre-synthesized amino triiron tetroxide nanoparticles (Fe ₃ O ₄ @NH ₂ ) or Fe ₃ O ₄ nanoparticles grown in-situ by coprecipitation of graphene sheets, and the particle size is is 5 to 200 nm.

Preferably, in the composite airgel, the mass ratio of the graphene oxide nanosheets and the amino carbon nanotubes is 1:(50-150), and the mass ratio of the Fe ₃ O ₄ nanoparticles and the graphene oxide nanosheets is 1. : 4 to 1:1.

A method for preparing a carbon-based composite airgel having the fire alarm function and high compression performance,
Carbon nanotubes were adsorbed on the surface of graphene oxide sheets, that is, N-hydroxysuccinimide (NHS) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) were added to an aqueous solution of graphene oxide nanosheets. ) is added to form a mixed solution, and after hydroxy is activated, this mixed solution is slowly added to the carbon nanotube dispersion, and the interaction between amino and hydroxy is used to form the surface of graphene oxide nanosheets. a step (1) of adsorbing carbon nanotubes;
Preparation of _Fe3O4 nanoparticles: a) in _- situ growth of _Fe3O4 magnetic nanoparticles by co-precipitation on the edges of the graphene oxide nanosheets obtained _in step (1) via alkaline catalyst and heating; or b) silane ligand exchange on the surface of Fe ₃ O ₄ nanoparticles pre-synthesized by pre-synthesis methods including conventional solvothermal, hydrothermal and co-precipitation methods to amino-modified triiron tetroxide. a step ( ₂ ) of preparing nanoparticles ( _Fe3O4 @NH2) _;
step (3) of _interfacial crosslinking of _Fe3O4 nanoparticles, wherein magnetic _dipole interactions between _Fe3O4 nanoparticles are used to interfacially bridge adjacent graphene oxide sheets;
Prepare a carbon-based composite aerogel with fire alarm function and high compressibility, that is, add ethylenediamine (EDA) to the system obtained in step (3), and conduct self-assembly of graphene oxide nanosheets under the condition of heating. and (4) aging and freeze-drying the obtained hydrogel to obtain said carbon-based composite aerogel.

Preferably, in step (1), specifically, first, the graphene oxide nanosheets are uniformly dispersed in water with ultrasonic waves, and then N-hydroxysuccinimide (NHS) and 1-(3-dimethyl Aminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) is added to form a mixed solution, activated at room temperature for 12-18 min, and then slowly added to the mixed solution into the amino carbon nanotube dispersion for more than 2-4 h. Carbon nanotubes are adsorbed on the surface of the graphene oxide nanosheets by acoustic wave reaction.

Here, the graphene oxide nanosheet: water: amino carbon nanotube dispersion is (38-42 mg): (7-9 mL): (2-6 g), N-hydroxysuccinimide: 1-(3-dimethylamino The molar ratio of propyl)-3-ethylcarbodiimide hydrochloride to graphene oxide hydroxy is 1:(1.1-1.5):1.

Preferably, in step (2), specifically:
a) dispersing the system obtained in step (1) in water, introducing an inert gas to remove oxygen for 1-3 h, then adding Fe ³⁺ and Fe ²⁺ as precursors, in an inert atmosphere, After stirring at room temperature for 2-6 hours, the temperature is raised to 70-90° C., an alkaline solution is added to adjust the pH of the solution to 9.5-12.5, and the reaction is continued for 0.5-2 hours. and rinsed 2-4 times to obtain in situ grown Fe ₃ O ₄ nanoparticles, or
b) After pre _- synthesizing the _Fe3O4 nanoparticles by conventional pre-synthesis methods, dispersing the _Fe3O4 nanoparticles in toluene, normal hexane or ethanol, then adding aminosilane, after adding acid catalyst _; , stirred or ultrasonically reacted for 24-48 h, washed with solvent 2-4 times and collected with a magnet to obtain amino-modified triiron tetroxide nanoparticles (Fe ₃ O ₄ @NH ₂ ).

Preferably, in step (2) a), the inert gas is high-purity nitrogen gas or argon gas, the alkaline solution is ammonia water, sodium hydroxide or potassium hydroxide, and the Fe ³⁺ and Fe ²⁺ The molar ratio is 1: (1.05-1.2),
When the system obtained in step (1) is dispersed in water, the ratio of the amount of water for dispersion and the graphene oxide nanosheets is 20 mL: (38-42 mg),
In step (2) b), said aminosilane is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 4-aminobutyldimethylmethoxysilane, one or more of 4-aminobutyltriethoxysilane, 3-[(2-aminoethylamino)propyl]dimethoxysilane, and (3-aminopropyl)dimethylethoxysilane; The acid catalyst is acetic acid, dilute hydrochloric acid or dilute sulfuric acid, and the amount of the acid catalyst added is 0.01 to 0.5% (v/v) with respect to the volume of the solvent. 03% (v/v).

Preferably, in step (3), specifically, the intermediate product obtained in step (2) is redispersed in water and subjected to an ultrasonic reaction at room temperature for 1 to 2 hours to generate a reaction between the Fe ₃ O ₄ nanoparticles. exploiting the magnetic dipole interaction to achieve interfacial bridging of adjacent graphene oxide sheets,
When the intermediate product obtained in step (2) is redispersed in water, the ratio of the amount of water for dispersion and the graphene oxide nanosheets is 20 mL: (38-42 mg).

Preferably, in step (4), specifically, 0.3 to 0.5% (v/v) of ethylenediamine ( EDA) is added and mixed uniformly, then the temperature is raised to 80 to 90° C. and reacted for 24 to 36 hours to self-assemble the graphene oxide nanosheets, and the obtained hydrogel is aged and freeze-dried. Obtaining a carbon-based composite airgel,
The aging time of the hydrogel is 2-6h, the freeze-drying temperature is (-20)-(-80)°C, and the freeze-drying time is 12-24h.

The use of carbon-based composite airgel in the fields of heat insulation, fire fighting, energy storage and mechanical devices, wherein the carbon-based composite airgel is the carbon-based composite airgel described above or the carbon-based composite airgel prepared by the preparation method described above.

Preferably, when the carbon-based composite airgel is used, the fire alarm function uses the thermal reduction action of amino carbon nanotubes and graphene oxide nanosheets to remove the functional groups at high temperatures, resulting in a rapid resistance. The _high compressibility is achieved by the alarm-inducing _drop in This is achieved in combination with the strong interaction between adjacent sheets generated.

Technical effects of the present invention are as follows.
In view of the current demand for aerogels with excellent fire safety and mechanical comprehensive performance and the limitations of conventional manufacturing techniques, the present invention provides fire alarm function and fire alarm function by simple graphene oxide nanosheet surface-interface dual reinforcement We propose to prepare carbon-based composite aerogels with high compressibility. In the technical solution of the present invention, graphene oxide and carbon nanotubes, which are thermally reducible and have excellent mechanical properties, are used to construct the body structure of the airgel, and the unique adsorption behavior is used to form carbon nanotubes. is adsorbed on the basal surface of the graphene oxide nanosheets and builds a continuous network. Using the thermal reduction action of amino carbon nanotubes and graphene oxide nanosheets, when the corresponding functional groups are removed at high temperature, the resistance drops sharply, which is expected to serve as a fire alarm function. In the present invention, by rationally setting each step of the preparation method and experimental parameters, an aerogel with both fire alarm function and high compressibility is prepared, which can be used in the fields of heat insulation, fire fighting, energy storage, mechanical devices, etc. can be applied to

It is a schematic diagram of the preparation process of the carbon-based composite airgel of the present invention. 1 is a scanning electron microscope SEM image (800x) of the carbon-based composite airgel of the present invention. 1 is a schematic diagram of the fire alarm process of the carbon-based composite airgel of the present invention; FIG. It is compression deformation of the carbon-based composite airgel of the present invention.

Preferred embodiments of the present invention will now be described in detail with reference to examples. It should be noted that the following examples are for illustrative purposes only and are not intended to limit the scope of the invention. Various modifications and substitutions can be made to the invention by those skilled in the art without departing from the spirit and spirit of the invention.

The experimental methods used in the examples below are general methods unless otherwise noted. Materials and reagents used in the following examples are commercially available unless otherwise specified.

<Example 1>
This example provides a carbon-based composite airgel material with the fire alarm function and high compression performance _of the present invention, wherein the interfacially crosslinked _Fe3O4 nanoparticles are pre-synthesized and have a size of about 10 nm. A schematic diagram of the preparation process is shown in FIG. 1, specifically comprising steps (1)-(4).
(1) Adsorption of carbon nanotubes to the surface of graphene oxide nanosheets 40 mg of graphene oxide nanosheets were uniformly ultrasonically dispersed in 8 mL of water, and 62 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC was added thereto. 31 mg of N-hydroxysuccinimide NHS was added and activated at room temperature for 15 minutes, then slowly added to 2 g of the amino carbon nanotube dispersion and subjected to ultrasonic reaction for 2 hours to adsorb the carbon nanotubes to the base surface of the graphene nanosheets. .
(2) Synthesis of Fe ₃ O ₄ @NH ₂ nanoparticles (A) Fe ₃ O ₄ nanoparticles of about 10 nm were synthesized by a solvothermal method: 100 mL of sodium oleate aqueous solution (0.2 M) and anhydrous iron chloride (III) was mixed with 100 mL of aqueous solution (0.2 M) and stirred well to produce a reddish brown precipitate, filtered, rinsed with deionized water and placed in a vacuum oven to dry. The dried waxy substance was dissolved in 60 mL of ethanol, 6 mL of oleic acid was added, mixed uniformly, transferred to a polytetrafluoroethylene high-pressure reactor, and reacted at 180° C. for 5 hours. After washing with absolute ethanol and separating with a magnet, it was dispersed in toluene (20 mg/mL).
(B) Fe ₃ O ₄ @NH ₂ nanoparticles were prepared by silane ligand exchange _: 0.5 _% (v/v) 3-aminopropyl Ethoxysilane and 0.01% (v/v) acetic acid were added and reacted with stirring at room temperature for 24 hours. It was washed with toluene, separated with a magnet and then lyophilized.
(3) Adsorption of Fe ₃ O ₄ @NH ₂ nanoparticles on the edges of graphene oxide sheets 31 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC in the reaction system of step (1) and 16 mg of N-hydroxysuccinimide NHS, activated at room temperature for 15 min, then added with 10 mg of Fe ₃ O ₄ @NH ₂ nanoparticles synthesized in step (2), while still being ultrasonicated, The Fe ₃ O ₄ @NH ₂ nanoparticles were adsorbed to the edges of the graphene nanosheets by ultrasonication for 2 h.
(4) Interfacial _cross -linking of _Fe3O4 nanoparticles After centrifuging the intermediate product obtained in step (3), it was redispersed in 20 mL of _water and subjected to ultrasonic reaction at room temperature for 1 h to obtain _Fe3O4 nanoparticles. Interfacial cross-linking was performed using magnetic dipole interaction between particles.
(5) Preparation of carbon-based composite airgel with fire alarm function and high compressibility Add 60 μL of ethylenediamine EDA to the reaction system of step (4), raise the temperature to 80 ° C., react for 24 h, and black suspension hydrogel. Obtained. The resulting crosslinked hydrogel was aged at room temperature for 3 hours and freeze-dried (-45°C, 260 Pa) for 12 hours to prepare the aerogel. As a result of observing the cross section of this airgel material with a scanning electron microscope SEM, as shown in FIG. 2, a porous structure with a pore size of about 5 μm was observed. It is an SEM image in the case of

<Example 2>
This example provides a carbon-based _composite airgel material with the fire alarm function and high compression performance of the present invention, where the interfacially crosslinked _Fe3O4 nanoparticles are grown in situ and have a size of about 30 nm. Specifically, steps (1) to (4) are included.
(1) Adsorption of carbon nanotubes on the surface of graphene oxide nanosheets 40 mg of graphene oxide nanosheets were uniformly ultrasonically dispersed in 8 mL of water, and 62 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC was added thereto. and 31 mg of N-hydroxysuccinimide NHS were added and activated at room temperature for 15 minutes, then slowly added to 6 g of amino carbon nanotube dispersion and subjected to ultrasonic reaction for 2 hours to adsorb the carbon nanotubes to the base surface of the graphene nanosheet. rice field.
(2) Adsorption of Fe ₃ O ₄ nanoparticles on the edges of graphene oxide sheets Disperse the intermediate product obtained in step (1) in 50 mL of deionized water, introduce N ₂ and remove oxygen for 2 h. After that, 0.4 g of FeCl _{3.6H 2} O and 0.25 g of FeSO _{4.7H 2} O were added thereto, stirred at room temperature for 5 h under N ₂ atmosphere, then heated to 80° C., and ammonia water was added. Additionally, the pH of the solution was adjusted to 12 and reacted for 1 h to adsorb the Fe ₃ O ₄ nanoparticles to the edge of the graphene nanosheets.
(3) Interfacial cross-linking of _Fe3O4 nanoparticles The intermediate product obtained in _step (2) was collected with a magnet, rinsed with deionized water three times, and then re-dispersed in 20 mL of water, and was stirred at room temperature for more than 1 h. Interfacial cross-linking was achieved by sonic reaction and magnetic dipole interaction between Fe ₃ O ₄ nanoparticles.
(4) Preparation of carbon-based composite airgel with fire alarm function and high compressibility Add 60 μL of ethylenediamine EDA to the reaction system of step (3), raise the temperature to 80 ° C. and react for 24 h to form a black suspended hydrogel. Obtained. The resulting crosslinked hydrogel was aged at room temperature for 3 hours and freeze-dried (-45°C, 260 Pa) for 12 hours to prepare the aerogel.

(Application example)
The carbon-based composite aerogel with fire alarm function and high compressibility of the present invention fully utilizes the thermal reduction action of amino carbon nanotubes and graphene oxide nanosheets, and the corresponding functional groups are removed at high temperature. A sudden decrease in resistance triggers an alarm, and a schematic diagram of the fire alarm process is shown in FIG. In the event of a fire, functional groups such as amino and hydroxy detach from amino carbon nanotubes and graphene oxide in aerogels, resulting in a rapid decrease in their resistance and a change in the current in the closed circuit, triggering a fire alarm. . In addition, high compressibility is realized by the double reinforcing means of continuous network structure by adsorption of carbon nanotubes on the surface of graphene oxide nanosheets and interfacial Fe ₃ O ₄ nanoparticle bridging, and this airgel is compressed under force. FIG. 4 shows the process of deformation by pressing. As shown, the maximum compressive deformation of the airgel reaches 95% at maximum, and when the external force is removed, it recovers to its original volume, and there is no volume reduction. It is possible.

The carbon-based composite airgel of the present invention has fire alarm capability and high compressibility, and can be applied in the fields of thermal insulation, fire fighting, energy storage and mechanical devices.

(a) graphene oxide nanosheets (b) adsorption of amino carbon nanotubes on the basal surface of graphene oxide nanosheets (c) adsorption of _Fe3O4 nanoparticles on the edges of graphene _oxide nanosheets (d) adjacent graphene Fe ₃ O ₄ nanoparticle cross-linking of oxide nanosheets (e) Self-assembly of graphene oxide nanosheets I Original state II In case of compression III After recovery

Claims (8)

A method for preparing a carbon-based composite airgel having a fire alarm function and high compression performance,
The carbon-based composite airgel is prepared by self-assembly by adsorption of amino carbon nanotubes on the surface of graphene oxide nanosheets and interfacial cross-linking of Fe ₃ O ₄ nanoparticles, followed by freeze-drying. In terms of
Carbon nanotubes were adsorbed on the surface of graphene oxide sheets, that is, N-hydroxysuccinimide (NHS) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) were added to an aqueous solution of graphene oxide nanosheets. ) is added to form a mixed solution, and after hydroxy is activated, this mixed solution is slowly added to the carbon nanotube dispersion, and the interaction between amino and hydroxy is used to form the surface of graphene oxide nanosheets. A step of adsorbing carbon nanotubes,
Graphene oxide nanosheets: water: amino carbon nanotube dispersion is (38-42 mg): (7-9 mL): (2-6 g), N-hydroxysuccinimide: 1-(3-dimethylaminopropyl)- step (1), wherein the molar ratio of 3-ethylcarbodiimide hydrochloride:graphene oxide hydroxy is 1:(1.1-1.5):1;
Preparation of _Fe3O4 nanoparticles: a) in _- situ growth of _Fe3O4 magnetic nanoparticles by co-precipitation on the edges of the graphene oxide nanosheets obtained _in step (1) via alkaline catalyst and heating; or b) silane ligand exchange on the surface of Fe ₃ O ₄ nanoparticles pre-synthesized by pre-synthesis methods including conventional solvothermal, hydrothermal and co-precipitation methods to amino-modified triiron tetroxide. a step ( ₂ ) of preparing nanoparticles ( _Fe3O4 @NH2) _;
step (3) of _interfacial crosslinking of _Fe3O4 nanoparticles, wherein magnetic _dipole interactions between _Fe3O4 nanoparticles are used to interfacially bridge adjacent graphene oxide sheets;
A carbon-based composite aerogel with fire alarm function and high compressibility is prepared, that is, the system obtained in step (3) is added with 0.3-0.5% (v/v) reducing agent to the solvent volume A step (4) of adding ethylenediamine (EDA) as, self-assembling graphene oxide nanosheets under heating conditions, aging and freeze-drying the obtained hydrogel to obtain the carbon-based composite aerogel; including
the amino carbon nanotubes are single-walled carbon nanotubes or multi-walled carbon nanotubes, or a combination thereof;
The Fe ₃ O ₄ nanoparticles are pre-synthesized amino triiron tetroxide (Fe ₃ O ₄ @NH ₂ ) particles or Fe ₃ O ₄ nanoparticles grown in-situ by coprecipitation of graphene sheets, and the Fe ₃ O ₄ nanoparticles have a particle size of 5 to 200 nm,
In the airgel, the mass ratio of the graphene oxide nanosheets and the amino carbon nanotubes is 1:(50-150), and the mass ratio of the Fe ₃ O ₄ nanoparticles and the graphene oxide nanosheets is 1:4-1: 1. A preparation method characterized by being 1. Specifically, in step (1), first, the graphene oxide nanosheets are uniformly dispersed in water with ultrasonic waves, and then N-hydroxysuccinimide (NHS) and 1-(3-dimethylaminopropyl) - Add 3-ethylcarbodiimide hydrochloride (EDC) to form a mixed solution, activate at room temperature for 12 to 18 minutes, then slowly add this mixed solution to the amino carbon nanotube dispersion for 2 to 4 hours of ultrasonic reaction. , The method for preparing carbon-based composite airgel with fire alarm function and high compression performance according to claim 1, characterized in that carbon nanotubes are adsorbed on the surface of graphene oxide nanosheets. Specifically, in step (2),
a) dispersing the system obtained in step (1) in water, introducing an inert gas to remove oxygen for 1-3 h, then adding Fe ³⁺ and Fe ²⁺ as precursors, in an inert atmosphere, After stirring at room temperature for 2-6 hours, the temperature is raised to 70-90° C., an alkaline solution is added to adjust the pH of the solution to 9.5-12.5, and the reaction is continued for 0.5-2 hours. and rinsed 2-4 times to obtain in situ grown Fe ₃ O ₄ nanoparticles, or
b) After pre _- synthesizing the _Fe3O4 nanoparticles by conventional pre-synthesis methods, dispersing the _Fe3O4 nanoparticles in toluene, normal hexane or ethanol, then adding aminosilane, after adding acid catalyst _; , stirring or ultrasonically reacting for 24-48 h, washing with a solvent 2-4 times, and collecting with a magnet to obtain amino-modified triiron tetroxide nanoparticles (Fe ₃ O ₄ @NH ₂ ). The method for preparing carbon-based composite airgel with fire alarm function and high compression performance according to claim 1. In step (2) a), the inert gas is high-purity nitrogen gas or argon gas, the alkaline solution is ammonia water, sodium hydroxide or potassium hydroxide, and the molar ratio of Fe ³⁺ and Fe ²⁺ is 1: (1.05 to 1.2),
When the system obtained in step (1) is dispersed in water, the ratio of the amount of water for dispersion and the graphene oxide nanosheets is 20 mL: (38-42 mg),
In step (2) b), said aminosilane is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 4-aminobutyldimethylmethoxysilane, one or more of 4-aminobutyltriethoxysilane, 3-[(2-aminoethylamino)propyl]dimethoxysilane, and (3-aminopropyl)dimethylethoxysilane; The acid catalyst is acetic acid, dilute hydrochloric acid or dilute sulfuric acid, and the amount of the acid catalyst added is 0.01 to 0.5% (v/v) with respect to the volume of the solvent. 03% (v/v), the preparation method of carbon-based composite airgel with fire alarm function and high compression performance according to claim 4. Specifically, in step (3), the intermediate product obtained in step (2) is re-dispersed in water and subjected to an ultrasonic reaction at room temperature for 1-2 hours to form a magnetic dipole between Fe ₃ O ₄ nanoparticles. exploiting the interaction to achieve interfacial bridging of adjacent graphene oxide sheets,
Claim 1, characterized in that when the intermediate product obtained in step (2) is redispersed in water, the ratio of the amount of water for dispersion and the graphene oxide nanosheets is 20 mL: (38 to 42 mg). A method for preparing a carbon-based composite airgel having a fire alarm function and high compression performance according to . Specifically, in step (4), ethylenediamine (EDA) is added as a reducing agent to the system obtained in step (3), mixed uniformly, and then heated to 80 to 90° C. for 24 to 36 hours. reacting to self-assemble the graphene oxide nanosheets, aging the obtained hydrogel and freeze-drying to obtain the carbon-based composite aerogel,
The fire alarm function according to claim 1, wherein the aging time of the hydrogel is 2-6 hours, the freeze-drying temperature is (-20)-(-80) ° C., and the freeze-drying time is 12-24 hours. and a method for preparing carbon-based composite aerogels with high compressibility. The use of carbon-based composite airgel in the fields of thermal insulation, fire fighting, energy storage and mechanical devices,
Use characterized in that the carbon-based composite airgel is a carbon-based composite airgel prepared by the preparation method according to any one of claims 1 to 7. When adopting carbon-based composite airgel, the fire alarm function uses the thermal reduction action of amino carbon nanotubes and graphene oxide nanosheets to eliminate functional groups at high temperatures, resulting in a rapid decrease in resistance. , the high compressibility was achieved by triggering the alarm, and _the high compressibility was generated by assembly, a dual reinforcing means of adsorption of carbon nanotubes to the surface of graphene oxide nanosheets and interfacial bridging of _Fe3O4 nanoparticles. 9. Use according to claim 8, characterized in that it is realized in combination with strong interactions between adjacent sheets.

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