A high-strength silicone aerogel and its preparation method and application

Abstract

The present invention relates to a high-strength silicone aerogel and its preparation method and application. The preparation method comprises the following steps: Preparation of silicone sol: An amino silane with a primary amino group on the side chain, epichlorohydrin ether, and deionized water are mixed and dissolved in an alcohol solvent, stirred until the silane hydrolysis is complete, and then a catalyst is added and stirred again to obtain a silicone sol; High-temperature curing: The silicone sol is transferred to a sealed container and heated and aged to obtain a silicone wet gel; Atmospheric pressure drying: After the silicone wet gel is dried, a high-strength silicone aerogel is obtained. This aerogel is applied in the field of medium and low-temperature heat insulation. Compared with the prior art, the present invention has the advantages of simple and easy preparation process, can be directly obtained by atmospheric pressure drying without shrinkage, and has good application potential in the field of medium and low-temperature heat insulation, etc.

Description

Technical Field

[0001] The present invention relates to the field of silicone aerogels, and particularly relates to a high-strength silicone aerogel, a preparation method thereof, and an application thereof. Background Art

[0002] An aerogel is an amorphous lightweight solid material formed through a sol-gel process. It is composed of nano sol particles or polymer molecules and has a rich nano-porous structure inside, featuring a high specific surface area and high porosity. Due to its unique porous structure, the aerogel has excellent properties such as low thermal conductivity, light weight, and ablation resistance, and is widely used in tissue engineering, building materials, catalysis, aerospace and other fields. According to the composition of the aerogel material, it can be divided into silica-based aerogels, carbon-based aerogels, polymer-based aerogels, metal-based aerogels, and metal oxide-based aerogels. However, traditional aerogels have poor mechanical properties. Taking silica aerogel as an example, although it has been updated and improved for decades, the improvement of its mechanical properties is very limited, and there is still much room for improvement; at the same time, many existing technologies still rely on supercritical drying, and its high cost and cumbersome processes have posed a huge obstacle to the industrialization of aerogels.

[0003] In order to solve problems such as the poor mechanical properties of silica aerogels, researchers have made various attempts. Domestic patent CN 105565774B discloses a method for organically modifying nano-silicone aerogels. After using amino-terminated polysiloxane to modify halloysite, tetraethyl orthosilicate, absolute ethanol, hydrochloric acid, dimethylformamide, and ammonia water are added to form a gel. This method enhances its mechanical properties while maintaining the original porosity and heat insulation performance of silica, but the improvement is quite limited. At the same time, the product needs to be washed and then supercritically dried, and the preparation process is complex and costly, making it difficult to achieve industrial production.

[0004] Some scholars have also tried to introduce other components such as graphene oxide to prepare composite silicone aerogels. Domestic patent CN 10127705B discloses a method for preparing silicone aerogels at atmospheric pressure. By adding graphene oxide to the organosiloxane precursor solution, the silicone aerogel is modified with graphene oxide to prepare a composite aerogel. Although this method can directly obtain an aerogel through atmospheric pressure drying, solvent exchange is also required before atmospheric pressure drying, generating a large amount of waste liquid. At the same time, the aerogel prepared by this method still does not solve the problem of poor mechanical strength, and the cost of graphene oxide is expensive, which is not suitable for industrial production. Summary of the Invention

[0005] The purpose of the present invention is to overcome at least one of the defects of the above-mentioned prior art and to provide a high-strength silicone aerogel and its preparation method and application which has a simple and easy preparation process, can be directly obtained by drying at normal pressure, does not shrink, and has great application potential in the field of medium and low temperature insulation.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for preparing high-strength organosilicon aerogel, the method comprising the following steps:

[0008] Preparation of organic silica sol: aminosilane with primary amine groups on the side chain, epoxy glycidyl ether and deionized water are mixed in an alcohol solvent, stirred until the silane is completely hydrolyzed, and then a catalyst is added and stirred again to obtain an organic silica sol;

[0009] High temperature curing: the organosilicon sol is transferred to a sealed container and heated and aged to obtain an organosilicon wet gel;

[0010] Normal pressure drying: After the wet silicone gel is dried, a high-strength silicone aerogel is obtained.

[0011] In the preparation method of the present invention, aminosilane is used as a silicon source, epoxy glycidyl ether is added, isopropanol is used as a solvent, and a high-strength organosilicon aerogel is obtained by a sol-gel method. In the preparation process, the self-catalytic property of aminosilane is utilized to omit the steps of adding catalysts and replacing solvents multiple times in the preparation of traditional silicon aerogels, and the aerogel without shrinkage can be obtained directly by drying at normal pressure, which greatly reduces the production cost; at the same time, epoxy glycidyl ether is introduced, and the glycidyl ether can be connected to the Si-O-Si skeleton by the reaction of primary amine groups and epoxy groups; as the reaction temperature and time are prolonged, the epoxy groups will undergo intermolecular cyclization with the hydroxyl groups to form a better double-crosslinked three-dimensional structure, thereby greatly improving the mechanical strength of the aerogel. The present invention greatly simplifies the preparation process and greatly improves the mechanical strength of the silicon aerogel. Combined with the high-efficiency thermal insulation performance brought by the porous structure of the aerogel itself, the material is expected to play an important role in the field of medium and low temperature thermal insulation.

[0012] Furthermore, in the organosilica sol, the mass ratio of aminosilane to epoxy glycidyl ether is (20-40):(40-80), the mass fraction of the solute is 20-50%, the amount of water added is 5 times the molar amount of aminosilane; and the amount of catalyst added is 0-1% of the total mass.

[0013] Furthermore, in the organosilica sol, the mass ratio of aminosilane to epoxy glycidyl ether is (4.6-5):(10-11.5), the mass fraction of the solute is 35-45%, and the amount of the catalyst added is 0.2-0.5%.

[0014] Furthermore, the amino silane is one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane or 3-aminopropylmethyldiethoxysilane.

[0015] Furthermore, the amino silane is 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

[0016] Furthermore, the epoxy glycidyl ether is one of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether or diglycidyl ether; the alcohol solvent is one of ethanol, methanol or isopropanol; the catalyst is one of ammonia water, ammonium fluoride or tetramethylammonium hydroxide.

[0017] Furthermore, the time for stirring until the silane hydrolysis is complete is 2 - 60 min, preferably 10 - 30 min, the time for further stirring does not exceed 5 min, the temperature for heat aging is 60 - 120 °C, the time is 12 - 48 h, and the drying time is 24 - 72 h.

[0018] Too long hydrolysis time will lead to a decrease in mechanical properties. Because as the concentration of Si-OH increases, dehydration condensation reaction has occurred during the stirring process, and the strength of the Si-O-Si bond formed at low temperature is much lower than that of the skeleton formed by high-temperature gelation, so the strength will decrease. Too short time results in poor strength because the hydrolysis degree is too low, resulting in a very low concentration of Si-OH in the solution, so a complete skeleton cannot be formed. The best stirring time is 10 - 30 min. In the examples, 60 min is set for comparison, indicating that too long time will instead cause a decrease in performance.

[0019] Furthermore, the temperature for heat aging is 80 - 100 °C, and the time is 24 - 48 h.

[0020] An application of the high-strength organosilica aerogel as described above, and this aerogel is applied to the field of medium and low temperature thermal insulation.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The silicon source adopted in the present invention is amino silane. Since it has a primary amino group on its side chain, it has certain alkalinity and can achieve self-catalytic hydrolysis. At the same time, the primary amino group has good chemical activity and can undergo a ring-opening reaction with the epoxy group on the added epoxy glycidyl ether, thereby introducing it into the organosilicon main chain. As the curing temperature increases or the aging time prolongs, the epoxy group can further react with the hydroxyl group to open the ring and undergo intermolecular cyclization to form a better double-crosslinked three-dimensional structure, further enhancing the intermolecular crosslinking degree and greatly improving the mechanical properties of the aerogel;

[0023] (2) In terms of solvent selection in the present invention, an alcohol with a low boiling point and low surface tension is used as the solvent, which can not only ensure the full mixing of each component, but also reduce the capillary tension of the aerogel during the drying process. The wet gel can be directly dried under normal pressure to obtain an aerogel with a good pore structure and no volume shrinkage.

[0024] (3) In terms of the preparation method of the present invention, the aerogel product can be directly obtained by the sol-gel method, with a simple process and being suitable for industrial production. At the same time, the porous structure of the aerogel is retained, so it has good heat insulation performance. Combining its high-strength characteristics, it can achieve long-term heat insulation at medium and low temperatures. Description of the Drawings

[0025] Figure 1 It is a physical photograph of the high-strength organosilica aerogel of Example 7;

[0026] Figure 2 It is the scanning electron microscope (SEM) images of Example 2 (a, e), Example 3 (b, f), Example 5 (c, g), and Example 6 (d, h);

[0027] Figure 3 It is the reaction mechanism diagram of the high-strength organosilica aerogel of the present invention. Detailed Embodiments

[0028] The present invention will be described in detail below with reference to the drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0029] A high-strength organosilica aerogel and its preparation method and application, the preparation method comprising the following steps:

[0030] A. Preparation of organosilica sol: Mix amino silane, epoxy glycidyl ether, and deionized water in an alcohol solvent and stir for 2 - 60 min; after the silane hydrolysis is complete, add a catalyst and stir for 5 min to obtain the organosilica sol;

[0031] The amino silane is one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, or 3-aminopropylmethyldiethoxysilane. The epoxy glycidyl ether is one of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether, or diglycidyl ether. The alcohol solvent is one of ethanol, methanol, or isopropanol. The catalyst is one of ammonia water, ammonium fluoride, or tetramethylammonium hydroxide.

[0032] The mass components of the silicone sol are as follows: 20 - 40 parts of aminosilane and 40 - 80 parts of epoxy glycidyl ether; the mass fraction of the solute in the silicone sol is 20 - 50%; the addition amount of water is 5 times the molar amount of aminosilane; the addition amount of the catalyst is 0 - 1% of the total mass.

[0033] B. High-temperature curing: Transfer the silicone sol in A to a sealed container and place it in an environment of 60 - 120 °C for aging for 12 - 48 h to obtain a silicone wet gel.

[0034] C. Atmospheric drying: Dry the silicone wet gel obtained in step B at room temperature for 24 - 72 h to obtain a high-strength silicone aerogel. The wet gel prepared by this method can be directly dried into an aerogel at room temperature. Putting it in an oven is to accelerate the drying process, which has basically no impact on the structure and performance of the product.

[0035] The thermal conductivity is the room-temperature thermal conductivity. The instrument used is Netzsch, HFM446s, and it is based on the flat-plate heat flow method. Therefore, the test sample is a 20×20×10 mm flat plate ([ Figure 1 physical drawing) made using a mold to measure its room-temperature thermal conductivity. There is no difference in the manufacturing method from the small sample, only a simple magnification.

[0036] The Instron 3367 universal testing machine is used for the compressive strength test, and it follows the national standard GB / T1447 - 2006

[0037] The formula for calculating the shrinkage rate is: where V s is the volume shrinkage rate, and Vwetgel and Vaerogel represent the volumes of the wet gel and the aerogel respectively.

[0038] Example 1

[0039] Add 4.6 g of 3-aminopropyltriethoxysilane and 11.5 g of resorcinol diglycidyl ether to a container, then add 24 g of isopropanol and 1.86 g of deionized water to prepare a solution with a mass fraction of about 40%. Stir the obtained solution at room temperature for 10 min, then add 0.1 g of tetramethylammonium hydroxide (25 wt%) solution, and then stir at room temperature for 5 min to make the solution uniformly dispersed to obtain a silicone sol.

[0040] Seal the container and place it in an 80 °C oven. Gelation occurs within 40 min, and the transparent liquid in the bottle turns into a white solid. Continue to age for 24 h in the same temperature environment to obtain a white wet gel. Dry the silicone wet gel at room temperature for 12 h, then place it in a 50 °C oven for 12 h, and then place it in an 80 °C oven for 2 h to obtain a high-strength silicone aerogel.

[0041] Example 2

[0042] 4.6 g of 3-aminopropyltrimethoxysilane and 11.5 g of ethylene glycol diglycidyl ether were added to a container, and then 24 g of isopropanol and 1.86 g of deionized water were added to prepare a solution with a mass fraction of about 40%. The resulting solution was stirred at room temperature for 10 min, then 0.2 g of a tetramethylammonium hydroxide (25 wt%) solution was added, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0043] The container was sealed and placed in an oven at 80 °C. Gelation occurred within 20 min, and the transparent liquid in the bottle turned into a white solid. Aging was continued for 24 h in the same temperature environment to obtain a white wet gel. The organosilica wet gel was dried at room temperature for 12 h, then placed in an oven at 50 °C for 12 h, and then placed in an oven at 80 °C for 2 h to obtain a high-strength organosilica aerogel.

[0044] Example 3

[0045] 4.6 g of 3-aminopropyltriethoxysilane and 11.5 g of resorcinol diglycidyl ether were added to a container, and then 24 g of isopropanol and 1.86 g of deionized water were added to prepare a solution with a mass fraction of about 40%. The resulting solution was stirred at room temperature for 10 min, without adding a tetramethylammonium hydroxide solution, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0046] The container was sealed and placed in an oven at 80 °C. Gelation occurred within 60 min, and the transparent liquid in the bottle turned into a white solid. Aging was continued for 24 h in the same temperature environment to obtain a white wet gel. The organosilica wet gel was dried at room temperature for 12 h, then placed in an oven at 50 °C for 12 h, and then placed in an oven at 80 °C for 2 h to obtain a high-strength organosilica aerogel.

[0047] Example 4

[0048] 4 g of 3-aminopropylmethyldimethoxysilane and 12 g of resorcinol diglycidyl ether were added to a container, and then 24 g of isopropanol and 1.86 g of deionized water were added to prepare a solution with a mass fraction of about 40%. The resulting solution was stirred at room temperature for 10 min, then 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution was added, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0049] Seal the container and place it in an oven at 80 °C. Gelation occurs within 40 min, and the transparent liquid in the bottle turns into a white solid. Keep aging for 24 h in the same temperature environment to obtain a white wet gel. Dry the silicone wet gel at room temperature for 12 h, then place it in an oven at 50 °C for 12 h, and then in an oven at 80 °C for 2 h to obtain a high-strength silicone aerogel.

[0050] Example 5

[0051] Add 4.6 g of 3-aminopropyltriethoxysilane and 11.5 g of resorcinol diglycidyl ether to a container, then add 24 g of isopropanol and 1.86 g of deionized water to prepare a solution with a mass fraction of about 40%. Stir the resulting solution at room temperature for 10 min, then add 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution, and then stir at room temperature for 5 min to disperse the solution evenly to obtain a silicone sol.

[0052] Seal the container and place it in an oven at 100 °C. Gelation occurs within 40 min, and the transparent liquid in the bottle turns into a white solid. Keep aging for 24 h in the same temperature environment to obtain a white wet gel. Dry the silicone wet gel at room temperature for 12 h, then place it in an oven at 50 °C for 12 h, and then in an oven at 80 °C for 2 h to obtain a high-strength silicone aerogel.

[0053] Example 6

[0054] Add 4.6 g of 3-aminopropyltriethoxysilane and 11.5 g of resorcinol diglycidyl ether to a container, then add 24 g of isopropanol and 1.86 g of deionized water to prepare a solution with a mass fraction of about 40%. Stir the resulting solution at room temperature for 10 min, then add 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution, and then stir at room temperature for 5 min to disperse the solution evenly to obtain a silicone sol.

[0055] Seal the container and place it in an oven at 80 °C. Gelation occurs within 40 min, and the transparent liquid in the bottle turns into a white solid. Keep aging for 48 h in the same temperature environment to obtain a white wet gel. Dry the silicone wet gel at room temperature for 12 h, then place it in an oven at 50 °C for 12 h, and then in an oven at 80 °C for 2 h to obtain a high-strength silicone aerogel.

[0056] Example 7

[0057] 4 g of 3-aminopropyltriethoxysilane and 8 g of resorcinol diglycidyl ether were added to a container, and then 28 g of isopropanol and 1.62 g of deionized water were added to prepare a solution with a mass fraction of approximately 30%. The resulting solution was stirred at room temperature for 10 min, then 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution was added, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0058] The container was sealed and placed in an oven at 80 °C. Gelation occurred within 40 min, and the transparent liquid in the bottle turned into a white solid. Aging was continued for 24 h under the same temperature environment to obtain a white wet gel. The organosilica wet gel was dried at room temperature for 12 h, then placed in an oven at 50 °C for 12 h, and then placed in an oven at 80 °C for 2 h to obtain a high-strength organosilica aerogel, as Figure 1 . Figure 1 The prepared aerogel plate is shown. To demonstrate its light texture, it can be stably placed on a leaf.

[0059] Example 8

[0060] 4.6 g of 3-aminopropyltriethoxysilane and 11.5 g of resorcinol diglycidyl ether were added to a container, and then 24 g of isopropanol and 1.86 g of deionized water were added to prepare a solution with a mass fraction of approximately 40%. The resulting solution was stirred at room temperature for 60 min, then 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution was added, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0061] The container was sealed and placed in an oven at 80 °C. Gelation occurred within 40 min, and the transparent liquid in the bottle turned into a white solid. Aging was continued for 24 h under the same temperature environment to obtain a white wet gel. The organosilica wet gel was dried at room temperature for 12 h, then placed in an oven at 50 °C for 12 h, and then placed in an oven at 80 °C for 2 h to obtain a high-strength organosilica aerogel.

[0062] Example 9

[0063] 5 g of 3-aminopropyltriethoxysilane and 15 g of resorcinol diglycidyl ether were added to a container, and then 20 g of isopropanol and 2.03 g of deionized water were added to prepare a solution with a mass fraction of approximately 50%. The resulting solution was stirred at room temperature for 10 min, then 0.1 g of a tetramethylammonium hydroxide (25 wt%) solution was added, and then stirred at room temperature for 5 min to make the solution uniformly dispersed, obtaining an organosilica sol.

[0064] Seal the container and place it in an oven at 80 °C. Gelation occurs within 40 min, and the transparent liquid in the bottle turns into a white solid. Keep aging for 24 h in the same temperature environment to obtain a white wet gel. Dry the silicone wet gel at room temperature for 12 h, then place it in an oven at 50 °C for 12 h, and then in an oven at 80 °C for 2 h to obtain a high-strength silicone aerogel.

[0065] The basic physical parameters of the samples obtained in each example are summarized in Table 1 below.

[0066] Table 1

[0067]

[0068] Compared with Example 1, the main change in Example 2 is that the dosage of the catalyst tetramethylammonium hydroxide increases, resulting in slight changes in the parameters; compared with Example 1, the main change in Example 3 is that the dosage of tetramethylammonium hydroxide is reduced to 0, resulting in shrinkage, so the density increases. The reason is that the catalyst dosage can significantly change the gelation rate and make the gel structure more orderly at the same time. Adding too little will cause the structure to be in a molten state, the gel structure to be disordered, and the formed packing pores to be smaller. During the drying process, new Si-O-Si bonds will be formed due to the capillary force, so shrinkage occurs. Adding too much will make the gelation rate too fast, and the phase separation process will be completed rapidly at high temperature (even obvious gelation occurs at room temperature), resulting in the epoxy organic matter not forming a good cross-linked structure, but reducing the mechanical properties. Therefore, the optimal addition mass should be between 0.2-0.5% of the solution mass.

[0069] Compared with Example 1, the main change in Example 4 is that the type of silane is changed to 3-aminopropylmethyldimethoxysilane, and the mechanical properties have decreased significantly because its functionality has decreased compared with 3-aminopropyltriethoxysilane. Under the same conditions, its cross-linking degree has also decreased, so the mechanical strength has decreased. At the same time, with the increase in the content of glycidyl ether, due to steric hindrance and saturation effect, adding more glycidyl ether cannot improve the performance and even affects the cross-linking reaction of epoxy groups.

[0070] Compared with Example 1, the main change in Example 5 is that the curing temperature is increased; compared with Example 1, the main change in Example 6 is that the curing time is extended; increasing the temperature and extending the reaction time are both to further promote the intermolecular cyclization of epoxy groups (the principle is as Figure 3 ). It can be seen from the SEM images that obvious ring structures exist in both Example 5 and Example 6. This is because the epoxy groups have further reacted, greatly increasing the cross-linking degree of the aerogel, so the mechanical strength has increased.

[0071] In Example 7, compared with Example 1, the main change is the reduction of the solid content; in Example 6, compared with Example 1, the main change is the increase of the solid content; the change of the solid content will affect the density of the aerogel, so corresponding performance changes will occur. Samples with higher density have stronger mechanical properties and higher thermal conductivity; samples with lower density have weaker mechanical properties but lower thermal conductivity.

[0072] In Example 8, compared with Example 1, the main change is that a long time of stirring was carried out before adding the catalyst, resulting in a large decrease in the compressive strength. This is because the hydrolysis time is too long. As the concentration of Si-OH increases, dehydration condensation reactions occur during the stirring process. The strength of the Si-O-Si bonds formed at low temperature is much lower than that of the framework formed by high-temperature gelation, so the strength will decrease. Therefore, it is appropriate to stir for 10 - 30 minutes.

[0073] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of high-strength silicone aerogel, characterized in that, the method comprises the following steps: Preparation of silicone sol: An amino silane with a primary amino group on the side chain, epoxy glycidyl ether and deionized water are miscible in an alcohol solvent. After stirring until the silane hydrolysis is complete, a catalyst is added and stirred again to obtain a silicone sol; High-temperature curing: Transfer the silicone sol to a sealed container and heat and age it to obtain a silicone wet gel; Atmospheric drying: After drying the silicone wet gel, a high-strength silicone aerogel is obtained; In the silicone sol, the mass ratio of the amino silane to the epoxy glycidyl ether is (4.6 - 5):(10 - 11.5), the mass fraction of the solute is 35 - 45%, and the addition amount of the catalyst is 0.2 - 0.5%; The stirring time until the silane hydrolysis is complete is 10 - 30 min, the stirring time again does not exceed 5 min, the heating and aging temperature is 80 - 100 °C, the time is 24 - 48 h, and the drying time is 24 - 72 h; The catalyst is one of ammonia water, ammonium fluoride or tetramethylammonium hydroxide.

2. A preparation method of high-strength silicone aerogel according to claim 1, characterized in that, the amino silane is one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane or 3-aminopropylmethyldiethoxysilane.

3. A preparation method of high-strength silicone aerogel according to claim 2, characterized in that, the amino silane is 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

4. A preparation method of high-strength silicone aerogel according to claim 1, characterized in that, the epoxy glycidyl ether is one of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether or diglycidyl ether; the alcohol solvent is one of ethanol, methanol or isopropanol.

5. A high-strength silicone aerogel prepared by the method according to any one of claims 1 - 4.

6. An application of the high-strength silicone aerogel according to claim 5, characterized in that, the aerogel is applied to the field of medium and low temperature heat insulation.

Images