Preparation method of aerogel felt

Abstract

The invention relates to a preparation method of an aerogel felt, the aerogel felt is prepared by carrying out specific processes such as hot drying treatment, twice dipping treatment, aging treatment, drying and the like on a fiber material, and the aerogel felt has the characteristics of thinness, high temperature resistance and good flame-retardant and fireproof performance through experimental verification. Meanwhile, the preparation method can effectively control the resin content in the aerogel felt, ensure the thermal stability and safety in a high-temperature environment, improve the overall performance and use experience of the product, and meet the application of different surface appearance properties and processing requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aerogel, in particular to a preparation method of aerogel felt. BACKGROUND

[0002] The preparation process of aerogel felt is generally to immerse the fiber material in sol to form a gel composite, and then dry to obtain an aerogel felt product. Commonly used fiber materials such as glass fiber, aluminum silicate fiber, ceramic fiber and the like are usually made into a felt body and then used, which generally adopts dry method and wet method. Specifically, the glass fiber needle felt prepared by dry method is usually thick, and the aluminum silicate felt is usually thicker than 5 mm, which not only has high weight per unit area, but also reduces the space utilization of the integrated product, which is not conducive to the popularization and application in the field of batteries and the like. The fiber felt made by wet method such as surface felt, glass fiber surface felt, ceramic fiber surface felt and the like can be controlled to be less than 5 mm in thickness, and even less than 1 mm, but a significant disadvantage is that the fiber felt body will absorb a lot of resin during the preparation process, and the resin content can be as high as 15% or more, which leads to easy local decomposition and smoke generation in high temperature environment, and poor thermal stability, heat insulation performance and flame retardant and fireproof performance in high temperature. SUMMARY

[0003] Therefore, it is necessary to provide a preparation method of aerogel felt which is both high temperature resistant and light and thin.

[0004] The technical scheme of the present application is as follows:

[0005] In a first aspect of the present application, a preparation method of aerogel felt is provided, comprising the following steps:

[0006] After the surface felt layer is subjected to heat baking treatment, it is mixed with silica sol solution for first immersion;

[0007] The fiber material after the first immersion is subjected to second immersion with the sol solution subjected to catalytic treatment to prepare a fiber gel material;

[0008] The fiber gel material is mixed with an aging solution for aging treatment;

[0009] The fiber gel material after the aging treatment is dried, and the aerogel felt is obtained.

[0010] The thickness of the surface felt layer is 0.2-5 mm.

[0011] In some embodiments, the surface felt includes glass fiber surface felt, aluminum silicate fiber surface felt or ceramic fiber surface felt.

[0012] In some embodiments, the temperature of the heat baking treatment is 200-400℃; and / or

[0013] The time of the heat baking treatment is 5 min-20 min.

[0014] In some embodiments, the time of the first dipping is 5 s-90 s; and / or

[0015] The temperature of the first dipping is 5℃-30℃.

[0016] In some embodiments, the time of the second dipping is 10 s-180 s; and / or

[0017] The temperature of the second dipping is 5℃-30℃.

[0018] In some embodiments, the preparation raw material of the aging solution comprises an alcohol solvent and a modifier.

[0019] In some embodiments, the preparation of the aging solution satisfies at least one of the following conditions:

[0020] (1) The alcohol solvent comprises ethanol;

[0021] (2) The modifier comprises methyl triethoxysilane, dimethyl diethoxysilane, methyl trimethoxysilane or hexamethyldisilazane;

[0022] (3) The volume ratio of the alcohol solvent and the modifier is (7-50):1.

[0023] In some embodiments, the time of the aging treatment is 8h-36h.

[0024] In some embodiments, the drying method comprises supercritical drying, and the time of the supercritical drying is 3-7h, and the temperature is 60-110℃.

[0025] According to a second aspect of the present application, there is provided an aerogel felt prepared according to the preparation method of the aerogel felt.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] The present application uses heat baking treatment, twice dipping treatment, aging treatment and drying on the fiber material to prepare an aerogel felt. The aerogel felt has the characteristics of thinness, high temperature resistance and good fire resistance. At the same time, the preparation method can effectively control the resin content in the aerogel felt, ensure the thermal stability and safety in high temperature environment, and improve the overall performance and use experience of the product, and meet the application requirements of different surface appearance and processing. DETAILED DESCRIPTION

[0028] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the detailed description of the specific embodiments of the present application is made below. In the following description, a lot of specific details are set forth in order to give a full and thorough understanding of the present application. However, the present application can be implemented in many different ways other than those described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0030] Unless otherwise indicated or unless contradicted by context, the terms or phrases used herein have the following meanings:

[0031] Herein, "one or more" means any one, any two, or any two or more of the listed items.

[0032] Herein, the optional scope of "and / or", "or / and", "and / or" includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, which includes any two related listed items, any more related listed items, or a combination of all related listed items. (It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", "and / or", it should be understood that in the present application, the technical solution undoubtedly includes the technical solution connected by "logical and", and also undoubtedly includes the technical solution connected by "logical or". For example, "A and / or B" includes three parallel solutions of A, B, and A+B. For another example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (i.e., the technical solution connected by "logical or"), and also includes any and all combinations of A, B, C, and D, i.e., includes the combination of any two or any three of A, B, C, and D, and also includes the four-item combination of A, B, C, and D (i.e., the technical solution connected by "logical and").)

[0033] Herein, "further", "furthermore", "in particular", and the like are used to describe purposes, indicating differences in content, but should not be understood as limiting the scope of protection of the present application.

[0034] In this document, “first aspect”, “second aspect”, “third aspect”, “fourth aspect”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. In addition, “first”, “second”, “third”, “fourth”, etc. only serve the purpose of non-exhaustive enumeration and description, and should be understood as not constituting a closed limitation on quantity. Therefore, the features defined as “first” and “second” may explicitly or implicitly include at least one of such features. In the description of this application, “multiple” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of this application, “several” means at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0035] In this application, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0036] Specifically, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value, or with other lower limits or upper limits, to form an unspecified range. The use of numerical ranges expressed as endpoints includes all numbers within that range and any range within that range.

[0037] Unless otherwise specified, the percentage contents mentioned in this application refer to mass percentage for solid-liquid mixture and solid-solid mixture, and refer to volume percentage for liquid-liquid mixture.

[0038] The percentage concentrations mentioned in this application, unless otherwise specified, refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0039] The temperature parameters in the present application, unless otherwise specified, allow for constant temperature treatment, and also allow for treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuation is allowed within a range such as ±5°C, ±2°C, ±1°C, ±0.5°C, ±0.4°C, ±0.3°C, ±0.2°C, ±0.1°C. Normal temperature or room temperature in the present application refers to no temperature control operation, and generally refers to 4°C to 35°C, preferably 20±5°C.

[0040] In the present application, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0041] In a first aspect of the present application, a method for preparing an aerogel felt is provided, comprising the following steps:

[0042] After the surface felt layer is subjected to heat baking treatment, it is mixed with a silica sol solution for the first time to perform impregnation;

[0043] The fiber material after the first impregnation is subjected to the second impregnation with the sol solution subjected to catalytic treatment to prepare a fiber gel material;

[0044] The fiber gel material is mixed with an aging solution to perform aging treatment;

[0045] The fiber gel material after the aging treatment is subjected to drying, and the aerogel felt is obtained;

[0046] The thickness of the surface felt layer is 0.2mm-5mm.

[0047] In some examples, the fiber material includes a glass fiber surface felt, an aluminum silicate fiber surface felt, or a ceramic fiber surface felt.

[0048] Optionally, the thickness of the surface felt layer includes but is not limited to 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm.

[0049] In some examples, the temperature of the heat baking is 200-400℃. It can be understood that the temperature of the heat baking includes but is not limited to 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, 320℃, 340℃, 360℃, 380℃, 400℃.

[0050] In some examples, the time of the heat baking is 5-20min. It can be understood that the time of the heat baking includes but is not limited to 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min.

[0051] In some examples, the time of the first immersion is 5-90s. It can be understood that the time of the first immersion includes but is not limited to 5s, 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s.

[0052] In some examples, the temperature of the first immersion is 5-30℃. It can be understood that the temperature of the first immersion includes but is not limited to 5℃, 10℃, 15℃, 20℃, 25℃, 30℃.

[0053] In some examples, the time of the second immersion is 10-180s. It can be understood that the time of the first immersion includes but is not limited to 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s.

[0054] In some examples, the temperature of the second immersion is 5-30℃. It can be understood that the temperature of the second immersion includes but is not limited to 5℃, 10℃, 15℃, 20℃, 25℃, 30℃.

[0055] In some examples, the preparation raw material of the aging liquid includes an alcohol solvent and a modifier.

[0056] In some examples, the preparation condition of the aging liquid includes that the alcohol solvent includes ethanol or methanol.

[0057] In some examples, the preparation condition of the aging liquid includes that the modifier includes methyl triethoxysilane, dimethyl diethoxysilane, methyl trimethoxysilane or hexamethylsilazane.

[0058] In some examples, the preparation condition of the aging liquid includes that the volume ratio of the alcohol solvent and the modifier is (7-50):1.

[0059] In some examples, the method for preparing the aging solution comprises: mixing the ethanol and the modifier, stirring, and preparing the aging solution.

[0060] In some examples, the aging process is performed for 8-36 hours. It is understood that the aging process can be performed for 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, or 36 hours.

[0061] In some examples, the drying method comprises supercritical drying.

[0062] In some examples, the supercritical drying is performed for 3-7 hours at a temperature of 60-110°C.

[0063] In some examples, before the fibrous gel material is mixed with the aging solution, the multi-layered fibrous gel material is packaged with a separation layer to separate the fibrous gel materials in different layers and prevent direct contact between the fibrous gel materials in different layers. Optionally, the separation layer can be a water-permeable porous mesh. The thickness of the separation layer can be 1-3 mm. The packaging of the multi-layered fibrous gel material with the separation layer can improve the efficiency and uniformity of the subsequent impregnation and drying processes.

[0064] Optionally, the packaging method comprises rolling the fibrous gel material and the separation layer into a roll or stacking the sliced fibrous gel material and the separation layer. In the rolling step, the fibrous gel material is laid on a separation layer with a flat surface, and the fibrous gel material and the separation layer are rolled together. In the stacking step, the fibrous gel material and the separation layer are alternately stacked. The fibrous gel materials are separated by the separation layer, and the fibrous gel materials in different layers are in direct or indirect contact.

[0065] In some specific examples, the method for preparing the aerogel mat comprises the following steps:

[0066] 1. A thin surface felt (0.5mm-5mm thickness range) is pre-heated and then dried in a heat treatment device (setting parameters). After the resin content is completely released by heat treatment, it is then immersed in a silica sol solution (setting parameters) for the first impregnation treatment while maintaining residual heat. This is followed by a second impregnation treatment with the catalyzed sol solution for gelation, resulting in a fiber gel material. The purpose of this pre-heating treatment is to completely release the resin content. The first impregnation treatment forms a silica sol film on the surface of the material, preparing it for the subsequent catalytic treatment. The second impregnation treatment allows the sol to gel on the surface, enhancing the material's structural stability. These two impregnations with different sols are intended to improve the structural strength of the surface felt after the pre-treatment to remove the resin component, resulting in a thin aerogel felt product with structural strength and free of organic resin. This second impregnation treatment also enhances the high-temperature thermal insulation and strength of the thin aerogel felt product.

[0067] 2. The obtained fiber gel material can be packaged into a roll together with the isolation layer.

[0068] 3. The obtained fiber gel material can be sliced ​​and stacked with isolation layers for packaging.

[0069] After being rolled or packaged, the fiber gel material enters a circulating aging solution (with set parameters) for aging. This step further solidifies the material's structure and improves its heat resistance and waterproof properties. Specifically, this aging solution treatment not only produces thin aerogel felt products with strong structural strength but also allows for the adjustment of hydrophobicity or hydrophilicity, providing selectivity for subsequent processing.

[0070] 4. The aged fiber gel material is supercritically dried to obtain a high-temperature resistant thin aerogel felt product. Specifically, the rolled or sliced ​​aerogel can meet the needs of coil and sheet forming and meet the application requirements of different surface properties and processing requirements.

[0071] A second aspect of the present invention provides an aerogel felt produced according to the method for producing a high-temperature resistant thin aerogel felt as described above.

[0072] The third aspect of the present invention provides the use of the aerogel felt described above in the preparation of thermal insulation layers and protective layers for batteries and electrical appliances in the new energy field.

[0073] The following is further described with reference to specific examples. Unless otherwise specified, the raw materials involved in the following specific examples can all be sourced from commercial sources; the instruments used can all be sourced from commercial sources unless otherwise specified; and the processes involved can all be selected by those skilled in the art unless otherwise specified.

[0074] The following are specific examples.

[0075] Example 1

[0076] 1. Pretreatment: first, the glass fiber surface mat with a thickness of 1 mm is put into the baking equipment, treated at 300°C for 10 min, then injected into the first impregnation tank, and then injected into the sol solution for the first impregnation, the temperature of impregnation is 30°C, and the time is 10 s; the fiber material after the first impregnation is then immersed in the catalytically treated sol solution for the second impregnation, the temperature of impregnation is 25°C, and the time is 30 s. After the second impregnation, gelation is formed. The catalytically treated sol solution is prepared by using tetraethyl orthosilicate and ethanol under acid-base catalysis.

[0077] 2. The multi-layer fiber gel material after impregnation treatment is packaged into a roll with a separation layer, and is stored in a container.

[0078] 3. Aging liquid is configured: ethanol and modifier are mixed in a certain proportion to form an aging liquid; the volume ratio of ethanol to modifier is 20:1, and the modifier is specifically hexamethyldisilazane.

[0079] 4. The aging liquid is injected into the container to immerse the fiber gel material, and then the equipment circulating device is opened to circulate the aging liquid, and the fiber gel material is chemically aged in the aging liquid circulation for 12 h.

[0080] 5. The fiber gel material after aging treatment is taken out for supercritical drying: the water and solvent in the material are removed, and finally a roll-shaped hydrophobic high-temperature-resistant thin aerogel felt product is obtained. The drying time is 5 h, and the drying temperature is 80°C.

[0081] 6. Sample performance test: thermal conductivity, hydrophobicity, Shore hardness, and thermal insulation performance test.

[0082] Example 2

[0083] 1. Pretreatment: first, the glass fiber surface mat with a thickness of 1 mm is put into the baking equipment, treated at 300°C for 10 min, then injected into the first impregnation tank, and then injected into the sol solution for the first impregnation, the temperature of impregnation is 30°C, and the time is 20 s; the fiber material after the first impregnation is then immersed in the catalytically treated sol solution for the second impregnation, the temperature of impregnation is 25°C, and the time is 60 s. After the second impregnation, gelation is formed. The catalytically treated sol solution is prepared by using tetraethyl orthosilicate and ethanol under acid-base catalysis.

[0084] 2. The fiber gel material after impregnation treatment is cut into slices, stacked with a separation layer, and packaged into a pile, and then stored in a container.

[0085] 3. Aging liquid is configured: ethanol and modifier are mixed in a certain proportion to form an aging liquid; the volume ratio of ethanol to modifier is 20:1, and the modifier is specifically hexamethyldisilazane.

[0086] 4. The aged solution is injected into the container to immerse the fibrous gel material, and then the equipment circulating device is opened to circulate the aged solution, and the fibrous gel material is chemically aged in the aged solution circulation for 12 h.

[0087] 5. The fibrous gel material after aging treatment is taken out for supercritical drying: water and solvent in the material are removed, and finally a hydrophilic roll-shaped thin high-temperature-resistant aerogel felt product is obtained. The drying time is 5 h, and the drying temperature is 80°C.

[0088] 6. Performance testing: thermal conductivity, hydrophobicity, Shore hardness, and thermal insulation performance testing.

[0089] Example 3

[0090] 1. Pretreatment: first, the glass fiber surface mat with a thickness of 1 mm is put into the baking equipment and treated at 300°C for 10 min, and then it is put into the first impregnation tank and injected with a silica sol solution for the first impregnation, with an impregnation temperature of 30°C and an impregnation time of 20 s. After the first impregnation, the fibrous material is immersed in the catalytically treated sol solution for the second impregnation, with an impregnation temperature of 25°C and an impregnation time of 60 s. After the second impregnation, gelation is formed. The preparation method of the catalytically treated sol solution is to use tetraethyl orthosilicate and ethanol to prepare a sol solution under acid-base catalysis.

[0091] 2. The fibrous gel material after impregnation treatment is packed together with the isolation layer into a roll, and then adjusted into a container for storage.

[0092] 3. Preparation of the aging solution: ethanol and modifier are mixed in a certain proportion and stirred to form the aging solution; the volume ratio of ethanol to modifier is 10:1, and the modifier is specifically dimethyldiethoxysilane.

[0093] 4. The aging solution is injected into the container to immerse the fibrous gel material, and then the equipment circulating device is opened to circulate the aging solution, and the fibrous gel material is chemically aged in the aging solution circulation for 12 h.

[0094] 5. The fibrous gel material after aging treatment is taken out for supercritical drying: water and solvent in the material are removed, and finally a hydrophilic roll-shaped thin high-temperature-resistant aerogel felt product is obtained. The drying time is 5 h, and the drying temperature is 80°C.

[0095] 6. Performance testing: thermal conductivity, hydrophobicity, Shore hardness, and thermal insulation performance testing.

[0096] Comparative Example 1

[0097] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that no secondary impregnation treatment is performed.

[0098] Comparative Example 2

[0099] The preparation method of Comparative Example 2 is basically the same as that of Example 1, except that no aging treatment is performed.

[0100] Comparative Example 3

[0101] 1. Pretreatment: first, the glass fiber surface mat with a thickness of 1 mm is passed to the first impregnation tank, and then the silica sol solution is injected for the first impregnation, the impregnation temperature is 30℃, and the time is 10s; after the first impregnation, the fiber material is then immersed in the catalytically treated sol solution for the second impregnation, the impregnation temperature is 25℃, and the time is 30s. After the second impregnation, gelation is formed. The preparation method of the catalytically treated sol solution is to use tetraethyl orthosilicate and ethanol to prepare a sol solution under acid-base catalysis.

[0102] 2. The impregnated fiber gel material is packaged together with the isolation layer into a roll, and then adjusted into a container for storage.

[0103] 3. Prepare the aging solution: mix ethanol and modifier in a certain proportion, stir to form the aging solution; the volume ratio of ethanol to modifier is 20:1, and the modifier is specifically hexamethyldisilazane.

[0104] 4. Inject the aging solution into the container to immerse the fiber gel material, then open the equipment circulating device to circulate the aging solution, and the fiber gel material is subjected to chemical aging treatment in the aging solution circulation for 12h.

[0105] 5. Take out the fiber gel material after aging treatment for supercritical drying: remove the water and solvent in the material, and finally obtain a hydrophobic, roll-shaped, thin, high-temperature-resistant aerogel felt product. The drying time is 5h, and the drying temperature is 80℃.

[0106] 6. Perform performance testing: thermal conductivity, hydrophobicity, Shore hardness, and thermal insulation performance testing.

[0107] The high-temperature-resistant thin aerogel felt products prepared in Examples 1-3 and Comparative Examples 1-3 are subjected to performance tests such as thermal conductivity, hydrophobicity, and surface spray burning, and the test results are shown in Table 1 below.

[0108] Among them, the test conditions and test standards of each performance test item are as follows:

[0109] Thermal conductivity test according to GB / T 10295;

[0110] Hydrophobicity test method: GB / T 10299;

[0111] Thermal insulation performance test method: heat the heating table to 500℃, test for 10 minutes under 0.7 Mapa, and record the thermal insulation temperature difference.

[0112] Table 1

[0113]

[0114] From the above table 1, it can be seen that the aerogel felt product prepared by the embodiment of the application has good performance, which combines the advantages of needle punched felt and surface felt, solves the limitation that needle punched felt is difficult to be prepared into light and thin products, and at the same time retains the excellent properties of needle punched felt such as high temperature resistance and no organic resin component. On the other hand, the aerogel felt product is prepared by removing the resin component of the surface felt after heat treatment before compounding the aerogel, which effectively reduces the resin component, thereby realizing the overall optimization and improvement of performance, and the obtained aerogel felt product has the characteristics of thin type, high temperature resistance and good flame retardant and fireproof performance.

[0115] In summary, the application makes full use of the characteristic advantages of thin fiber felt to prepare, forming a new type of preparation method: (1) the thin surface felt is heat treated before compounding the aerogel felt, which can efficiently remove the resin organic component and at the same time improve the infiltration amount of the aerogel sol, and also improves the disadvantage of difficult heat treatment of the finished product. (2) the thin surface felt can effectively control the impregnation amount and control the difference between the two impregnations; 3) the thin surface felt is easy to age and cut and process, forming a variety of products which are flexible.

[0116] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0117] The above-described embodiments only express several implementation manners of the application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the protection scope of the application. Therefore, the patent protection scope of the application should be subject to the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A method for preparing an aerogel felt, characterized in that: The following steps are involved: After the surface felt layer is heat-baked, it is mixed with silica sol solution for the first impregnation; The fiber material after the first impregnation is impregnated with the catalytically treated sol solution for a second time to prepare a fiber gel material; mixing the fiber gel material with an aging solution to perform an aging treatment; The fiber gel material after the aging treatment is dried to obtain; Wherein, the thickness of the surface felt layer is 0.2mm-5mm.

2. The method for preparing aerogel felt according to claim 1, wherein: The surface felt includes glass fiber surface felt, aluminum silicate fiber surface felt or ceramic fiber surface felt.

3. The method for preparing aerogel felt according to claim 1, wherein: The temperature of the heat treatment is 200°C-400°C; and / or The time of the heat baking treatment is 5 min-20 min.

4. The method for preparing aerogel felt according to claim 1, wherein: The first dipping time is 5s-90s; and / or The temperature of the first dipping is 5°C-30°C.

5. The method for preparing aerogel felt according to claim 1, wherein: The second dipping time is 10s-180s; and / or The temperature of the second immersion is 5°C-30°C.

6. The method for preparing aerogel felt according to claim 1, wherein: The raw materials for preparing the aging solution include alcohol solvent and modifier.

7. The method for preparing aerogel felt according to claim 6, characterized in that: The preparation of the aging solution satisfies at least one of the following conditions: (1) The alcohol solvent includes ethanol; (2) The modifier includes methyltriethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane or hexamethyldisilazane; (3) The volume ratio of the alcohol solvent to the modifier is (7-50):

1.

8. The method for preparing aerogel felt according to any one of claims 1 to 7, characterized in that: The aging treatment time is 8h-36h.

9. The method for preparing an aerogel felt according to any one of claims 1 to 7, characterized in that: The drying method includes supercritical drying; The supercritical drying time is 3h-7h, and the temperature is 60°C-110°C.

10. An aerogel felt, characterized in that: The aerogel felt is prepared according to the preparation method of any one of claims 1 to 9.

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