Fiber-reinforced gel composite material and preparation method thereof

Abstract

The invention relates to the technical field of aerogel, and provides a fiber-reinforced gel compound and a preparation method thereof.The method comprises the steps that 1, a fiber-reinforced material and sol are mixed, and a mixed felt is obtained; (2) carrying out calendering and gelation treatment on the mixed felt to obtain a gel felt; (3) drying the gel felt to obtain a fiber reinforced gel compound; in the step (1), the use amount of the sol enables the thickness of the mixed felt to be 130%-145% of the thickness of the fiber reinforced material; in the step (2), the thickness of the gel felt is 80%-90% of the thickness of the mixed felt under the condition of the calendaring treatment. According to the method, the gelation degree in the gel composite material can be adjusted, so that the heat insulation performance of the gel composite material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aerogels, and in particular to a preparation method of a fiber-reinforced gel composite and a fiber-reinforced gel composite obtained by this method. Background Art

[0002] An aerogel refers to a solid structure that does not collapse after the liquid in the gel structure is replaced by a gas. Silica aerogel is a continuous three-dimensional network structure formed by the aggregation of nanoparticles at the nanometer scale. Due to its special nano-scale micropores and skeleton structure, its thermal conductivity efficiency, convective heat transfer efficiency, and radiative heat transfer efficiency are all effectively limited. Therefore, aerogel has a very low thermal conductivity and is currently the solid material with the lowest thermal conductivity in the world.

[0003] In the sol-gel process, by controlling the hydrolysis and polycondensation reaction conditions of the solution, nanoclusters with different structures are formed in the sol, and the mutual adhesion between the clusters forms a gel body. And around the solid skeleton of the gel body is filled with the liquid reagents remaining after the chemical reaction. Therefore, it is necessary to dry the gel body subsequently to obtain a porous, disordered, low-density aerogel material with a nanometer-scale continuous network structure.

[0004] However, in the process of preparing the fiber-reinforced gel composite, due to the different contents of the gel liquid in the fiber-reinforced material, the pore sizes of the aerogel formed by the gel are different, and the structures and densities of the aerogels are different. Furthermore, there is a risk of reduction in the heat insulation performance of the fiber-reinforced aerogel composite, which has a certain impact on the subsequent use of the product. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art, and provide a preparation method of a fiber-reinforced gel composite and a fiber-reinforced gel composite obtained by this method. This method can adjust the degree of gel in the gel composite material to improve the heat insulation performance of the gel composite material.

[0006] To achieve the above purpose, the first aspect of the present invention provides a preparation method of a fiber-reinforced gel composite, which includes:

[0007] (1) Mixing a fiber-reinforced material and a sol to obtain a mixed felt;

[0008] (2) Performing calendering and gelation treatment on the mixed felt to obtain a gel felt;

[0009] (3) Performing drying treatment on the gel felt to obtain a fiber-reinforced gel composite;

[0010] In step (1), the amount of the sol is such that the thickness of the mixed felt is 130% - 145% of the thickness of the fiber-reinforced material;

[0011] In step (2), the conditions of the calendering treatment are such that the thickness of the gel felt is 80% to 90% of the thickness of the mixed felt.

[0012] Preferably, the thickness tolerance of the fiber reinforcement is within ±1 mm.

[0013] The second aspect of the present invention provides a fiber-reinforced gel composite, which is the fiber-reinforced gel composite prepared by the method as described above.

[0014] The gelation process is completed by generating pores to form a network skeleton structure. Due to the relatively large thickness tolerance of the fiber reinforcement itself, the calendering method can reduce the thickness tolerance of the prepared aerogel felt. At the same time, the inventors of the present invention found that when the compression ratio of the gel felt is too high, the pores of the gel skeleton formed during the gelation process are relatively fine, the density of the formed aerogel layer is relatively large, and the solid conduction is relatively more, resulting in a decrease in the heat insulation performance of the prepared finished felt and more uneven thickness; however, when the compression ratio is too low, the pores of the gel skeleton generated during the gelation process of the aerogel liquid are relatively large, the structure is relatively loose, easy to break, and the surface flatness is also poor, resulting in uneven heat insulation performance of the finished felt and poor mechanical and heat insulation properties of the prepared wet aerogel felt. By controlling the relative thickness of the mixed felt and the gel felt in the manner described in the present invention, the sol is redistributed in the fiber reinforcement, and a suitable compression ratio is selected, so that the size of the pore skeleton generated during the gelation process of the liquid is more uniform and moderate, thereby making the heat insulation performance of the prepared fiber-reinforced gel composite better and the thickness more uniform.

[0015] The method provided by the present invention is simple to operate and suitable for large-scale production.

[0016] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values and individual point values of each range, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In this article, unless otherwise specified, the data ranges include the endpoints. Detailed Description of the Invention

[0017] The following provides a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0018] Unless otherwise defined, all scientific and technical terms used in the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention pertains.

[0019] The first aspect of the present invention provides a method for preparing a fiber-reinforced gel composite, the method comprising:

[0020] (1) Mixing a fiber reinforcement material and a sol to obtain a mixed felt;

[0021] (2) Calendering and gelating the mixed felt to obtain a gel felt;

[0022] (3) Drying the gel felt to obtain a fiber-reinforced gel composite;

[0023] In step (1), the amount of the sol is such that the thickness of the mixed felt is 130% to 145% of the thickness of the fiber reinforcement material, for example, it can be 130, 132, 134, 136, 138, 140, 142, 144, 145%, and any range formed between any two values;

[0024] In step (2), the conditions of the calendering treatment are such that the thickness of the gel felt is 80% to 90% of the thickness of the mixed felt, for example, it can be 80, 82, 84, 86, 88, 90%, and any range formed between any two values.

[0025] The fiber reinforcement material can be any fiber material in the art that can enhance the performance of the aerogel. In some embodiments, the fiber reinforcement material may include, but is not limited to, silica-based fiber felt, ceramic fiber felt, or pre-oxidized fiber felt. The silica-based fiber felt can be needled glass fiber felt, wet-process glass fiber felt, etc. The fiber reinforcement material can be a sheet or a roll.

[0026] In some embodiments, the thickness tolerance of the fiber reinforcement material is within ±1 mm, for example, within ±0.1 mm, within ±0.2 mm, within ±0.4 mm, within ±0.6 mm, within ±0.8 mm, or within ±1 mm.

[0027] In some embodiments, the sol is a silica sol, an alumina sol, or a silica-alumina composite sol for preparing an aerogel.

[0028] In some embodiments, the sol is a silica sol, and the precursor of the silica sol is an alkyl orthosilicate and / or an alkylalkoxysilane.

[0029] In some embodiments, the alkyl orthosilicate includes at least one of tetramethyl orthosilicate, tetraethyl orthosilicate, methyltriethyl orthosilicate, dimethyldiethyl orthosilicate, tetrapropyl orthosilicate, tetra-isopropyl orthosilicate, tetrabutyl orthosilicate, tetra-sec-butyl orthosilicate, tetra-tert-butyl orthosilicate, tetrahexyl orthosilicate, tetracyclohexyl orthosilicate, and tetra-icosyl orthosilicate.

[0030] In some embodiments, the alkylalkoxysilane includes one or more of methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, and propyltriethoxysilane.

[0031] The silica sol may further contain a gel catalyst for catalyzing the gelation of the silica sol. In some embodiments, the gel catalyst is selected from inorganic bases and / or organic bases.

[0032] In some embodiments, the inorganic base is any one or more of sodium hydroxide, potassium hydroxide, ammonia water, ammonium fluoride, ammonium bicarbonate, sodium carbonate, and sodium bicarbonate.

[0033] In some embodiments, the organic base is any one or more of ethanolamine, diethanolamine, methylamine, dimethylamine, ethylamine, diethylamine, propylamine, dipropylamine, isopropanolamine, aniline, o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine.

[0034] In some embodiments, the content of the gel catalyst makes the pH of the silica sol between 7 and 11, and more specifically, the content of the gel catalyst makes the pH of the sol between 7 and 8, which can increase the porosity of the product and has an extremely fast gel time.

[0035] In some embodiments, the silica sol may further contain an alcohol, and the alcohol may be at least one of methanol, ethanol, isopropanol, and butanol (such as n-butanol).

[0036] In some embodiments, the silica sol may further contain water.

[0037] The contents of the components in the silica sol may be conventional contents in the art and will not be elaborated here.

[0038] In one embodiment, the precursor of the silica sol, the gel catalyst, the alcohol, and water are mixed evenly to obtain the silica sol.

[0039] In some embodiments, the sol is an alumina sol, and the precursor of the alumina sol includes at least one of aluminum isopropoxide, aluminum sec-butoxide, and aluminum nitrate.

[0040] In some embodiments, the alumina sol may further contain a chelating agent, a catalyst for aluminum sol, an alcohol, and water.

[0041] In some embodiments, the chelating agent includes at least one of acetylacetone, acetic acid, and ethyl acetoacetate.

[0042] In some embodiments, the catalyst for the alumina sol comprises at least one of sodium hydroxide, potassium hydroxide, ammonia water, and ammonium fluoride. The content of the catalyst for the alumina sol is such that the pH of the alumina sol is between 7 and 11, preferably 7 - 8.

[0043] In some embodiments, the alcohol in the alumina sol comprises at least one of ethanol, isopropanol, and n-butanol.

[0044] The content of each component in the alumina sol can be a conventional content in the art and will not be elaborated here.

[0045] In one embodiment, the silica-alumina composite sol comprises a precursor of silica sol, a precursor of alumina sol, a catalyst, a chelating agent, an alcohol, and water.

[0046] The types of each component can be referred to the above-mentioned content, and their dosages can be conventional dosages in the art and will not be elaborated here.

[0047] In some embodiments, in step (1), the mixing method may include applying the sol to the fiber-reinforced material by at least one of pouring, spraying, brushing, and soaking.

[0048] In step (2), the mixed felt is calendered and gelated to obtain a gel felt. It should be understood that after mixing the fiber-reinforced material with the sol, gelation starts. When the mixed felt is calendered during the initial gelation, on the one hand, the excess sol is removed, and on the other hand, the compression ratio of the gel felt is controlled. During the gelation process after calendering, a springback phenomenon will occur, and its thickness will increase. In the present invention, the increased thickness due to springback is ignored, that is, the thickness of the mixed felt after calendering is regarded as the same as the thickness of the gel felt.

[0049] In some embodiments, in step (2), the calendering includes roller calendering or mold calendering.

[0050] In some embodiments, the roller calendering is single-roller calendering or double-roller calendering.

[0051] In some embodiments, the conditions of the roller calendering include: the distance between the lowest end of the roller and the side of the mixed felt away from the roller is 80% - 90% of the thickness of the mixed felt. For example, the mixed felt can be placed on a conveying platform, and the mixed felt can be calendered by a single roller or successively calendered by two rollers.

[0052] In some embodiments, when double-roller calendering is used, the distance between the two rollers is such that the time interval between two presses on the same part of the fiber-reinforced material does not exceed 1 min.

[0053] The mold pressing and calendering can refer to the conventional operations in the art, as long as the thickness of the gel felt can be 80% - 90% of the thickness of the mixed felt.

[0054] After calendering, the gel felt undergoes a normal gelation process, and no additional pressure needs to be applied during this process.

[0055] In step (3), the gel felt is dried to obtain a fiber-reinforced gel composite.

[0056] In some embodiments, in step (3), the method further includes: before the drying treatment, subjecting the gel felt to an aging treatment.

[0057] In some embodiments, the aging treatment method is to use an aging agent to age the gel felt. The aging agent can be an alcohol solvent, such as ethanol, etc. The specific aging treatment method can be to immerse the gel felt in the alcohol solvent for 4 - 6h.

[0058] In some embodiments, the aging treatment method is to use a film material to wrap the gel felt and perform an aging treatment. The film material can be a conventional film material in the art, as long as it can wrap the gel felt, such as it can be PET or PVC, etc.

[0059] In some embodiments, in step (3), the method further includes: before or after the drying treatment of the gel felt, using a hydrophobic agent to perform hydrophobic modification treatment on the gel felt. For example, the dried gel felt can be placed in a closed gas rich in the hydrophobic agent for gas-phase hydrophobic treatment.

[0060] In some embodiments, the hydrophobic agent for hydrophobic modification includes at least one of hydrophobic alkoxysilanes, hexamethyldisiloxane, and hexamethyldisilazane.

[0061] In some embodiments, the formula of the hydrophobic alkoxysilanes is R 1m Si(OR2) (4-m) , where R1 is a hydrophobic group, R2 is an alkyl group, m is the number of hydrophobic groups, 4 - m is the number of alkyl groups, and the value of m is an integer between 1 and 3.

[0062] In some embodiments, the hydrophobic agent includes at least one of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, chloropropyltriethoxysilane, chloropropyltrimethoxysilane, chloropropylmethyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylchlorosilane, hexamethyldisiloxane, and hexamethyldisilazane.

[0063] In some embodiments, the drying method is supercritical drying, atmospheric drying or freeze drying.

[0064] In some embodiments, the supercritical drying is ethanol supercritical drying and / or CO2 supercritical drying.

[0065] In some embodiments, the conditions for ethanol supercritical drying include: the drying temperature is 245 - 260 °C, the drying pressure is 8 MPa - 11 MPa, the heating rate is 5 - 20 °C / min, the holding time in the supercritical state is 0.5 h - 3 h, and the deflation time is 3 h - 9 h.

[0066] In some embodiments, the conditions for CO2 supercritical drying include: the drying temperature is 40 - 65 °C, the drying pressure is 8 MPa - 20 MPa, the heating rate is 1 - 5 °C / min, the replacement time is 3 h - 12 h, and the deflation time is 3 h - 12 h.

[0067] In some embodiments, the method of atmospheric drying is to perform solvent replacement with normal paraffin solvent for 6 h - 24 h and then perform atmospheric drying at 50 - 80 °C for 6 h - 24 h.

[0068] In some embodiments, the conditions for freeze drying include: the pre-freezing time is 3 - 12 h, the pre-freezing temperature is -30 °C - -5 °C, the cold trap temperature is -60 - -40 °C, the vacuum degree is 10 Pa - 500 Pa, and the drying time is 12 h - 36 h.

[0069] The second aspect of the present invention provides a fiber-reinforced gel composite, and the fiber-reinforced gel composite is the fiber-reinforced gel composite prepared by the method as described above.

[0070] The effect of the present invention on the needled glass fiber mat is more obvious. Because the gel product obtained after the needled glass fiber mat is impregnated and gelled has the characteristic of large thickness tolerance compared with other products, it will cause the thickness tolerance of the gel product to be non-compliant and affect the heat insulation performance of the gel product; by the method of the present invention, the thickness tolerance of the needled glass fiber mat can be significantly reduced, and the qualification rate of the needled fiber gel mat can be improved.

[0071] The thickness tolerance and volume density deviation are tested according to the standard GB / T34336-2017 Nanoporous Aerogel Composite Thermal Insulation Products (Appendix A Dimension and Volume Density Test Methods).

[0072] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0073] Materials, reagents, etc. used in the following examples can be obtained from commercial sources without special instructions.

[0074] The sol used in the following examples is silica sol.

[0075] The present invention will be described in detail below with reference to specific examples, which are for understanding rather than limiting the present invention.

[0076] Example 1

[0077] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0078] Place the sol in an impregnation tank, and then place a 3-mm-thick needled glass fiber sheet in the impregnation tank to impregnate and mix with the sol in the impregnation tank to obtain a mixed felt with a thickness of 4 mm. The thickness tolerance of the needled glass fiber sheet is ±0.8 mm.

[0079] Place the mixed felt on a transfer platform for transfer, and perform a single calendering on the mixed felt by pressing at the start of the transfer, so that the thickness of the calendered mixed felt is 85% of the thickness of the mixed felt before calendering. Then, the mixed felt continues to gel for 6 min during the transfer process to form a gel felt (no pressure is applied during this process), and then the CO2 supercritical drying method is used, with a drying temperature of 55 °C, a drying pressure of 14.5 MPa, a heating rate of 3 °C / min, a replacement time of 7 h, and a deflation time of 6 h; a fiber-reinforced gel composite, that is, a finished felt, is prepared.

[0080] Example 2

[0081] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0082] Operate according to the method described in Example 1, except that after the pressing treatment, the thickness of the calendered mixed felt is different. Specifically:

[0083] Example 2-1: The thickness of the calendered mixed felt is 82% of the thickness of the mixed felt before calendering;

[0084] Example 2-2: The thickness of the calendered mixed felt is 88% of the thickness of the mixed felt before calendering;

[0085] Example 2-3: The thickness of the calendered mixed felt is 80% of the thickness of the mixed felt before calendering;

[0086] Example 2-4: The thickness of the calendered mixed felt is 90% of the thickness of the mixed felt before calendering.

[0087] Example 3

[0088] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0089] Operate according to the method described in Example 1. The difference is that before the gel felt is subjected to CO2 supercritical drying, the obtained gel felt is first aged. Specifically:

[0090] Example 3-1: The aging treatment method is to wrap the gel felt with a PET film and keep it static for 5 h for aging treatment, and then remove the PET film;

[0091] Example 3-2: The aging treatment method is to soak the gel felt in an ethanol solution for 5 h.

[0092] Example 4

[0093] This example is used to illustrate the fiber-reinforced gel composites prepared from different fiber-reinforcing materials.

[0094] Example 4-1: Operate according to the method described in Example 1. The difference is that a ceramic fiber felt is used to replace the needled glass fiber felt in Example 1;

[0095] Example 4-2: Operate according to the method described in Example 1. The difference is that a PAN-based oxidized fiber felt is used to replace the needled glass fiber felt in Example 1;

[0096] Example 4-3: Operate according to the method described in Example 1. The difference is that a wet-process glass fiber felt is used to replace the needled glass fiber felt in Example 1.

[0097] Example 5

[0098] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0099] Example 5-1: Operate according to the method described in Example 1. The difference is that a single roll is used instead of molding for the first calendering;

[0100] Example 5-2: Operate according to the method described in Example 1. The difference is that two rolls are used instead of molding for continuous calendering twice; the distance between the two rolls is such that the time interval between two presses at the same place of the needled glass fiber sheet is 10 s.

[0101] Example 6

[0102] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0103] Operate according to the method described in Example 1. The difference is that after the finished felt is prepared before the gel felt is subjected to CO2 supercritical drying, the obtained finished felt is placed in a heated methyltrimethoxysilane atmosphere for gas-phase hydrophobic modification treatment, and thus obtained.

[0104] Example 7

[0105] This example is used to illustrate the preparation method of the fiber-reinforced gel composite.

[0106] Place the sol in the impregnation tank, and then place the 3-mm-thick needled glass fiber sheet in the impregnation tank for impregnation and mixing with the sol in the tank to prepare a mixed felt with a thickness of 4 mm. The thickness tolerance of the needled glass fiber sheet is ±0.8 mm.

[0107] Place the mixed felt on the conveyor platform for conveyance, and perform a primary calendering on the mixed felt by molding at the start of conveyance, so that the thickness of the calendered mixed felt is 85% of the thickness of the mixed felt before calendering. Then, during the conveyance process, the mixed felt continues to gel for 6 min to form a gel felt (no pressure is applied during this process). Then, wrap the gel felt with a PET film and let it stand for 5 h for aging treatment. Then, remove the PET film, and perform CO2 supercritical drying on the aged gel felt. The drying temperature is 55 °C, the drying pressure is 14.5 MPa, the heating rate is 3 °C / min, the replacement time is 7 h, and the deflation time is 6 h; then, perform gas-phase hydrophobic modification treatment on the obtained product by placing it in a heated methyltrimethoxysilane atmosphere to obtain the finished felt.

[0108] Comparative Example 1

[0109] This comparative example is used to illustrate the preparation method of the reference fiber-reinforced gel composite.

[0110] Comparative Example 1-1: Operate according to the method described in Example 1, except that the thickness of the calendered mixed felt is 95% of the thickness of the mixed felt before calendering;

[0111] Comparative Example 1-2: Operate according to the method described in Example 1, except that the thickness of the calendered mixed felt is 75% of the thickness of the mixed felt before calendering.

[0112] Comparative Example 2

[0113] This comparative example is used to illustrate the preparation method of the reference fiber-reinforced gel composite.

[0114] Comparative Example 2-1: Operate according to the method described in Example 3-1, except that the thickness of the calendered mixed felt is 95% of the thickness of the mixed felt;

[0115] Comparative Example 2-2: Operate according to the method described in Example 3-1, except that the thickness of the calendered mixed felt is 75% of the thickness of the mixed felt;

[0116] Comparative Example 2-3: The operation was carried out according to the method described in Example 3-2, except that the thickness of the mixed felt after calendering was 95% of the thickness of the mixed felt;

[0117] Comparative Example 2-4: The operation was carried out according to the method described in Example 3-2, except that the thickness of the mixed felt after calendering was 75% of the thickness of the mixed felt.

[0118] Comparative Example 3

[0119] This comparative example is used to illustrate the preparation method of the reference fiber-reinforced gel composite.

[0120] Comparative Example 3-1: The operation was carried out according to the method described in Example 4-1, except that the thickness of the mixed felt after calendering was 95% of the thickness of the mixed felt;

[0121] Comparative Example 3-2: The operation was carried out according to the method described in Example 4-1, except that the thickness of the mixed felt after calendering was 75% of the thickness of the mixed felt;

[0122] Comparative Example 3-3: The operation was carried out according to the method described in Example 4-2, except that the thickness of the mixed felt after calendering was 95% of the thickness of the mixed felt;

[0123] Comparative Example 3-4: The operation was carried out according to the method described in Example 4-2, except that the thickness of the mixed felt after calendering was 75% of the thickness of the mixed felt;

[0124] Comparative Example 3-5: The operation was carried out according to the method described in Example 4-3, except that the thickness of the mixed felt after calendering was 95% of the thickness of the mixed felt;

[0125] Comparative Example 3-6: The operation was carried out according to the method described in Example 4-3, except that the thickness of the mixed felt after calendering was 75% of the thickness of the mixed felt.

[0126] Comparative Example 4

[0127] This comparative example is used to illustrate the preparation method of the reference fiber-reinforced gel composite.

[0128] The operation was carried out according to the method described in Example 1, except that the mixed felt was placed on the conveying platform and conveyed and gelled for 6 minutes without calendering during this process.

[0129] Test Example

[0130] 1. Thickness Tolerance Test Method

[0131] Five points were randomly selected on the surface of the finished felt and the mixed felt prepared in the examples and preparation examples. The five points were randomly distributed on the surfaces of the mixed felt and the gel felt. The thicknesses corresponding to the five points were measured, and the thickness tolerance was calculated. The results are shown in Table 1.

[0132] 2. Thermal insulation performance of the finished product

[0133] Take a heating table, place the finished felts prepared in the examples and preparation examples on the heating table, set the heating temperature of the heating table to 700 °C, set the heating time to 20 min, then measure the temperature of the cold surface of the finished felt, and calculate the temperature difference between the hot and cold surfaces. The results are shown in Table 1.

[0134] Table 1

[0135]

[0136]

[0137] It should be noted that in this article, the terms "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without more limitations, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0138] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a fiber-reinforced gel composite, characterized in that, The method includes: (1) Mixing a fiber-reinforced material and a sol to obtain a mixed felt; (2) Performing calendering and gelation treatment on the mixed felt to obtain a gel felt; (3) Performing drying treatment on the gel felt to obtain a fiber-reinforced gel composite; In step (1), the amount of the sol is such that the thickness of the mixed felt is 130% - 145% of the thickness of the fiber-reinforced material; In step (2), the conditions of the calendering treatment are such that the thickness of the gel felt is 80% - 90% of the thickness of the mixed felt.

2. The method according to claim 1, characterized in that, In step (1), the fiber-reinforced material is a silica-based fiber felt, a ceramic fiber felt, or a pre-oxidized fiber felt.

3. The method according to claim 2, characterized in that The thickness tolerance of the fiber-reinforced material is within ±1 mm.

4. The method according to any one of claims 1 to 3, characterized in that, The sol is a silica sol, an alumina sol, or a silica-alumina composite sol for preparing an aerogel.

5. The method according to any one of claims 1-4, characterized in that In step (2), the calendering includes roll calendering or die calendering; Preferably, the roll calendering is single-roll calendering or double-roll calendering.

6. The method according to any one of claims 1-5, characterized in that, In step (3), the method further includes: before the drying treatment, performing an aging treatment on the gel felt.

7. The method according to claim 6, wherein The aging treatment method is to perform an aging treatment on the gel felt using an aging agent, and / or coating the gel felt with a membrane material and performing an aging treatment; Preferably, the aging agent is an alcohol solvent.

8. The method according to any one of claims 1-7, characterized in that, In step (3), the method further includes: before or after the drying treatment of the gel felt, performing a hydrophobic modification treatment on the gel felt using a hydrophobic agent; Preferably, the hydrophobic agent includes at least one of hydrophobic alkoxysilanes, hexamethyldisiloxane, and hexamethyldisilazane.

9. The method according to any one of claims 1 to 8, characterized in that, The drying method is supercritical drying, atmospheric drying, or freeze drying.

10. A fiber-reinforced gel composite, characterized in that, The fiber-reinforced gel composite is the fiber-reinforced gel composite prepared by the method according to any one of claims 1 - 9.

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