Heat insulation and sound insulation aerogel-based flexible material with multi-layer composite structure and preparation method of heat insulation and sound insulation aerogel-based flexible material

Abstract

The invention relates to a heat-insulation sound-insulation aerogel-based flexible material with a multi-layer composite structure and a preparation method thereof, and the preparation method comprises the following steps: adding a surfactant into a solvent, and dissolving to obtain micelles; adding acetic acid and a silicon source, and after the silicon source is completely hydrolyzed, adding an ammonia water solution and fully mixing to obtain sol; laying a fiber material in a mold, pouring the sol into the mold, and carrying out vacuum filtration, so that the sol is thoroughly impregnated, and waiting for gel completion; after gel is formed, deionized water is added into the mold to submerge the upper surface of the gel, and the mold is sealed and aged; demolding after aging is completed, and replacing with deionized water and absolute ethyl alcohol; carrying out supercritical drying to obtain the flexible SiO2 aerogel-based heat insulation and sound insulation composite material. And the sound absorption material and the sound insulation material are bonded, and the heat insulation and sound insulation aerogel-based flexible material of the multi-layer composite structure is obtained. The flexible material disclosed by the invention has excellent heat insulation performance and sound insulation performance, and can be widely applied to the fields of heat insulation, sound insulation protection and the like of industrial and marine pipelines and equipment.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, and in particular to a multilayer composite thermal insulation and sound insulation aerogel-based flexible material and its preparation method. Background Technology

[0002] Ships, nuclear power plants, and thermal power plants contain numerous thermal systems, which can easily cause high-temperature and noise pollution. High-temperature environments accelerate the corrosion and aging of mechanical equipment, while loud noise can harm the physical and mental health of personnel, reduce work efficiency, and increase safety risks. Currently, the high-silica fibers and glass fibers widely used in ships, nuclear power plants, and thermal power plants have problems such as high density, easy moisture absorption, and poor thermal insulation performance. This not only increases the weight of equipment but also occupies a large amount of usable space, affecting the economy and safety of the equipment. On the other hand, existing sound insulation materials are mostly rubber-based organic materials, which are heavy, not resistant to high temperatures, and lack thermal insulation capabilities.

[0003] With the rapid development of industry, the comfort, energy efficiency, and environmental protection of ships, nuclear power plants, and thermal power plants are receiving increasing attention. In these areas, thermal insulation and soundproofing materials play a crucial role. From a comfort perspective, the operation of various equipment in the engine rooms of ships, nuclear power plants, and thermal power plants generates a significant amount of noise. This noise propagates through the air and structures, severely impacting the working and living environment of personnel, easily causing fatigue, lack of concentration, and even potential hearing damage. From an energy efficiency perspective, ships operate in the marine environment, and the piping in the engine rooms is easily affected by external temperature changes. Without good insulation materials, in cold seas, a large amount of heat is lost, requiring equipment to consume more energy to maintain normal operation. In hot seas, the influx of external heat also affects equipment performance and cabin comfort. Nuclear power plants and thermal power plants are similarly affected by temperature environments. From an environmental perspective, the thermal insulation and sound insulation materials used in ships, nuclear power plants, and thermal power plants also need to meet relevant standards. Some early materials may produce harmful substances during the production process or be difficult to degrade after use, causing pollution to the environment.

[0004] Currently, traditional high-temperature heat insulation and sound insulation materials can no longer meet the needs of modern ships, nuclear power plants, and thermal power plants. In order to better meet the relevant needs, a multi-layer composite heat insulation and sound insulation aerogel-based flexible material has been developed. This composite material can be widely used on regular or irregular surfaces, such as walls, pipes, flanges, equipment, valves, etc., and this material can perform better.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-layer composite thermal insulation and sound insulation aerogel-based flexible material and its preparation method. This material has excellent thermal insulation and sound insulation properties and can be widely used in industrial and marine pipelines, equipment thermal insulation and sound insulation protection and other fields.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a multilayer composite thermal insulation and sound insulation aerogel-based flexible material, comprising the following steps: S1. Add a surfactant to the solvent and dissolve it completely to obtain micelles; S2. Add acetic acid and silicon source to micelles. After the silicon source is completely hydrolyzed, add ammonia solution and stir to mix thoroughly to obtain a sol. Dilute the sol with deionized water. S3. Lay fiber material in the mold, pour the sol into the mold and vacuum filter it to ensure thorough sol impregnation, and wait for the gel to complete. S4. After the gel is formed, add deionized water to the mold to cover the top surface of the gel, seal the mold and then age it. S5. After the gel has aged, demold the gel and replace it with deionized water and anhydrous ethanol. S6. The replaced gel is subjected to supercritical drying to obtain a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material. S7. Using an inorganic adhesive, sound-absorbing materials and sound-insulating materials are sequentially bonded to the surface of a flexible SiO2 aerogel-based thermal insulation and sound-insulating composite material to obtain a multi-layered composite thermal insulation and sound-insulating aerogel-based flexible material.

[0008] Preferably, in step S1, the surfactant is hexadecyltrimethylammonium bromide (CTAB), and the solvent is deionized water.

[0009] In this invention, the surfactant can effectively inhibit the phase separation process during the siloxane gelation process, promote the transformation of the skeleton network from dense particle packing to fiber-like morphology, and control the pore structure of the aerogel by adjusting the amount of surfactant, thereby optimizing the thermal insulation and sound insulation performance of the material.

[0010] Preferably, in step S1, the amount of surfactant used accounts for 1.40% to 3.61% of the sol mass; more preferably, it is 2.5% to 2.6%.

[0011] Preferably, in step S2, the silicon source is one or both of methyltrimethoxysilane (MTMS) and methyltriethoxysilane (MTES); when the silicon source is methyltrimethoxysilane, stirring is required for 30 minutes, and when the silicon source is methyltriethoxysilane, stirring is required for 3 hours.

[0012] Preferably, in step S2, the amount of silicon source used accounts for 21.11% to 30.05% of the sol mass, more preferably 25% to 26%; the amount of acetic acid used accounts for 0.07% to 0.24% of the sol mass; and the amount of ammonia solution used accounts for 6.01% to 7.04% of the sol mass.

[0013] Preferably, in step S2, the ammonia solution is prepared by mixing ammonia and deionized water at a volume ratio of 1:10, and the ammonia solution is added dropwise until the pH reaches about 7-8.

[0014] Preferably, in step S2, the stirring process is carried out in an ice bath to promote complete hydrolysis of the silicon source.

[0015] Preferably, in step S2, the sol is diluted with deionized water at a volume ratio of 1:(1~3).

[0016] Preferably, in step S3, the fiber material is a fiber preform.

[0017] Preferably, in step S3, the fiber material includes, but is not limited to, one or more of glass fiber (preferably glass fiber needled felt), PI fiber, and aluminosilicate fiber.

[0018] Preferably, in step S3, after the sol is poured into the mold, the mold sample should be quickly placed in a vacuum filtration device and kept under vacuum for 5 minutes to ensure thorough sol impregnation. To prevent the sol from gelling during impregnation, which would result in no sol soaking inside the glass fiber mat, the entire impregnation process should be continuous and rapid, and gelation should be completed after about 30 minutes.

[0019] Preferably, in step S4, to prevent the gel from cracking, the deionized water covers the upper surface of the gel by 1-3 mm, and the gel is sealed with a plastic film and aged in a 60°C oven for 48 hours.

[0020] Preferably, in step S5, the replacement is first performed with deionized water, ensuring the deionized water completely covers the gel. The deionized water is replaced every 4-6 hours, and this process is repeated 3-6 times. Then, anhydrous ethanol is used for replacement, ensuring the anhydrous ethanol completely covers the gel. The anhydrous ethanol is replaced every 4-6 hours, and this process is repeated 3-6 times until the replacement is complete. During replacement, the sample should be placed in a 60°C oven. This process is crucial for the gel's rebound effect during subsequent supercritical drying, therefore thorough replacement is necessary.

[0021] Preferably, in step S6, the supercritical drying includes, but is not limited to, using CO2 supercritical drying.

[0022] Preferably, in step S7, the inorganic adhesive is a phosphate-based inorganic adhesive, which has advantages such as high temperature resistance, moisture resistance, environmental friendliness, corrosion resistance, low curing shrinkage rate, and excellent bonding performance.

[0023] Preferably, in step S7, the sound-absorbing material is ultrafine fiberglass felt, and the sound-insulating material is aluminum foil fiberglass cloth. Of course, there are many types of sound-absorbing and sound-insulating materials, not limited to ultrafine fiberglass felt and aluminum foil fiberglass cloth. Those skilled in the art can replace them with other sound-absorbing and sound-insulating materials as needed.

[0024] Preferably, step S7 includes the following steps: S71. Using an inorganic adhesive, a layer of sound-absorbing material is evenly and smoothly bonded to the surface of the flexible SiO2 aerogel-based thermal insulation and sound insulation composite material. S72. Use inorganic adhesive to evenly and smoothly bond a layer of sound insulation material to the surface of the sound absorption material. S73. After standing at room temperature until the inorganic adhesive is completely dry, the sound-absorbing material and the sound-insulating material are firmly bonded to the flexible SiO2 aerogel-based thermal insulation and sound-insulating composite material, thus obtaining a multi-layer composite structure thermal insulation and sound-insulating aerogel-based flexible material.

[0025] The multi-layer composite thermal insulation and sound insulation aerogel-based flexible material produced by the present invention within the above parameter range can better balance the two properties of thermal insulation and sound insulation. Otherwise, only one property may be good, or even both properties may be bad.

[0026] In a second aspect, the present invention provides a multilayer composite thermal insulation and sound insulation aerogel-based flexible material, prepared by the aforementioned method, having a density of 163-192 kg / m³. 3 The maximum stress at 10% strain is 0.108-0.159 MPa, the sound insulation of a 15 mm thickness is 30.1-31.3 dB, and the thermal conductivity is 0.0214-0.0233 W / (m·K).

[0027] A third aspect of the present invention provides applications of the aforementioned multilayer composite thermal insulation and sound insulation aerogel-based flexible material, including but not limited to applications in industrial and marine pipelines, equipment thermal insulation and sound insulation protection, etc.

[0028] Preferably, the multi-layer composite thermal insulation and sound insulation aerogel-based flexible material is covered on the surface of regular equipment and pipelines, such as walls and pipes, to achieve thermal insulation and sound insulation.

[0029] The present invention has at least the following beneficial effects: The present invention discloses a multi-layered composite thermal insulation and sound insulation aerogel-based flexible material with optimized proportions, comprising a silicon source (MTMS, MTES), deionized water, hexadecyltrimethylammonium bromide (CTAB), ammonia, acetic acid, anhydrous ethanol, fiber materials, sound-absorbing materials, and sound-insulating materials. These materials are processed to form a flexible composite material with a certain degree of hardness, which can be applied to regular surfaces such as walls and pipes to provide thermal insulation and sound insulation. The prepared multi-layered composite thermal insulation and sound insulation aerogel-based flexible material has a density of 163-192 kg / m³. 3 The maximum stress at 10% strain is 0.108-0.159 MPa, and it has good compression and resilience. The sound insulation of the 15 mm thick sample is 30.1-31.3 dB, which shows excellent sound insulation performance. The thermal conductivity is 0.0214-0.0233 W / (m·K), which shows good thermal insulation performance. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 The process flow diagram shows the preparation method of the multilayer composite thermal insulation and sound insulation aerogel-based flexible material provided by the present invention.

[0032] Figure 2 Macroscopic morphology diagrams of the fiber materials and flexible SiO2 aerogel-based thermal insulation and sound insulation composite materials provided in Examples 1-3 of this invention.

[0033] Figure 3 These are scanning electron microscope images of the flexible SiO2 aerogel-based thermal insulation and sound insulation composite materials provided in Examples 1-3 of the present invention.

[0034] Figure 4 The compressive stress curves of the flexible SiO2 aerogel-based thermal insulation and sound insulation composite materials provided in Examples 1-3 of the present invention are shown.

[0035] Figure 5 This is a macroscopic morphology diagram of the multilayer composite thermal insulation and sound insulation aerogel-based flexible material provided in Embodiment 5 of the present invention.

[0036] Figure 6 Scanning electron microscope images of aerogels with different silicon sources (MTMS) provided for experimental examples of the present invention.

[0037] Figure 7Scanning electron microscope images of aerogels with different silicon sources (MTMS) provided for experimental examples of the present invention.

[0038] Figure 8 Scanning electron microscope images of aerogels with different silicon sources (MTES) provided for experimental examples of the present invention.

[0039] Figure 9 Scanning electron microscope images of aerogels with different silicon sources (MTES) provided for experimental examples of the present invention.

[0040] Figure 10 Macroscopic morphology images of aerogels with different amounts of surfactant (silicon source: MTMS) provided for experimental examples of this invention.

[0041] Figure 11 Scanning electron microscope images of aerogels with different amounts of surfactants (silicon source: MTMS) provided for experimental examples of this invention.

[0042] Figure 12 Macroscopic morphology images of aerogels with different amounts of surfactant (silicon source: MTES) provided for experimental examples of this invention.

[0043] Figure 13 Scanning electron microscope images of aerogels with different amounts of surfactants (silicon source: MTES) provided for experimental examples of this invention. Detailed Implementation

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and implementations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0045] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0046] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0047] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0048] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0049] The raw materials used in the following examples are shown in Table 1.

[0050] Table 1 Example 1

[0051] like Figure 1 As shown in the figure, this embodiment provides a method for preparing a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material, including the following steps: Step 1: Referring to the typical experimental material ratios in Table 2, first use a 100mL graduated cylinder as a measuring tool to add 50mL of deionized water as a solvent to a 250mL beaker. Then add 2g of CTAB to the beaker and stir vigorously with a magnetic stirrer for 5 minutes at room temperature (25℃) to fully dissolve the CTAB and obtain an aqueous solution filled with CTAB micelles.

[0052] Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Then, slowly add the prepared ammonia solution to the beaker using a dropper while stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8.

[0053] Step 3: After the sol is prepared, pour it into the mold in time. The mold contains pre-laid glass fiber needle-punched felt. Place the mold sample in a vacuum filtration device and maintain the vacuum for 5 minutes to ensure that the sol is thoroughly impregnated.

[0054] Step 4: After gelation, to prevent the gel from cracking, pour deionized water into the mold until it covers the top surface of the gel by 1-3 mm, seal it with plastic film, and place it in a 60℃ oven for aging for 48 hours.

[0055] Step 5: After the gel has aged, demold the gel and place it in a beaker. Pour in 500mL of deionized water to replace the sample. The water should completely cover the sample. Replace the deionized water every 4-6 hours. After 3-6 replacements, replace the sample with anhydrous ethanol in the same way. The anhydrous ethanol should completely cover the sample. Replace the anhydrous ethanol every 4-6 hours. After 3-6 replacements, the replacement is complete. During replacement, place the gel in a 60℃ oven.

[0056] Step 6: Use a CO2 supercritical drying device to dry the replaced gel. The resulting flexible SiO2 aerogel-based thermal insulation and sound insulation composite material is denoted as GF-SA.

[0057] Step 7: Test various data.

[0058] Table 2 name Proportion MTMS (mL) 20 Deionized water (mL) 50 Ammonia (mL) 5 Acetic acid (μL) 100 CTAB(g) 2 Example 2

[0059] This embodiment provides a method for preparing a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material, including the following steps: Step 1: Referring to the typical experimental material ratios in Table 2, first use a 100mL graduated cylinder as a measuring tool to add 50mL of deionized water as a solvent to a 250mL beaker. Then add 2g of CTAB to the beaker and stir vigorously with a magnetic stirrer for 5 minutes at room temperature (25℃) to fully dissolve the CTAB and obtain an aqueous solution filled with CTAB micelles.

[0060] Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Then, slowly add the prepared ammonia solution to the beaker using a dropper while stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8.

[0061] Step 3: After the sol is prepared, pour it into the mold in time. The mold contains PI fibers that have been laid in advance. Place the mold sample in a vacuum filtration device and maintain the vacuum for 5 minutes to ensure that the sol is thoroughly impregnated.

[0062] Step 4: After gelation, to prevent the gel from cracking, pour deionized water into the mold until it covers the top surface of the gel by 1-3 mm, seal it with plastic film, and place it in a 60℃ oven for aging for 48 hours.

[0063] Step 5: After the gel has aged, demold the gel and place it in a beaker. Pour in 500mL of deionized water to replace the sample. The water should completely cover the sample. Replace the deionized water every 4-6 hours. After 3-6 replacements, replace the sample with anhydrous ethanol in the same way. The anhydrous ethanol should completely cover the sample. Replace the anhydrous ethanol every 4-6 hours. After 3-6 replacements, the replacement is complete. During replacement, place the gel in a 60℃ oven.

[0064] Step 6: Use a CO2 supercritical drying device to dry the replaced gel. The resulting flexible SiO2 aerogel-based thermal insulation and sound insulation composite material is denoted as PIF-SA.

[0065] Step 7: Test various data. Example 3

[0066] This embodiment provides a method for preparing a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material, including the following steps: Step 1: Referring to the typical experimental material ratios in Table 2, first use a 100mL graduated cylinder as a measuring tool to add 50mL of deionized water as a solvent to a 250mL beaker. Then add 2g of CTAB to the beaker and stir vigorously with a magnetic stirrer for 5 minutes at room temperature (25℃) to fully dissolve the CTAB and obtain an aqueous solution filled with CTAB micelles.

[0067] Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Then, slowly add the prepared ammonia solution to the beaker using a dropper while stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8.

[0068] Step 3: After the sol is prepared, pour it into the mold in time. The mold contains pre-laid aluminum silicate fibers. Place the mold sample in a vacuum filtration device and maintain the vacuum for 5 minutes to ensure that the sol is thoroughly impregnated.

[0069] Step 4: After gelation, to prevent the gel from cracking, pour deionized water into the mold until it covers the top surface of the gel by 1-3 mm, seal it with plastic film, and place it in a 60℃ oven for aging for 48 hours.

[0070] Step 5: After the gel has aged, demold the gel and place it in a beaker. Pour in 500mL of deionized water to replace the sample. The water should completely cover the sample. Replace the deionized water every 4-6 hours. After 3-6 replacements, replace the sample with anhydrous ethanol in the same way. The anhydrous ethanol should completely cover the sample. Replace the anhydrous ethanol every 4-6 hours. After 3-6 replacements, the replacement is complete. During replacement, place the sample in a 60℃ oven.

[0071] Step 6: Use a CO2 supercritical drying device to dry the replaced gel. The resulting flexible SiO2 aerogel-based thermal insulation and sound insulation composite material is denoted as ASF-SA.

[0072] Step 7: Test various data.

[0073] The macroscopic morphology of the fiber materials and flexible SiO2 aerogel-based thermal and sound insulation composite materials in Examples 1 to 3 are as follows: Figure 2 As shown, the scanning electron microscope image of the flexible SiO2 aerogel-based thermal and sound insulation composite material is as follows: Figure 3 As shown, the compressive stress curve of the flexible SiO2 aerogel-based thermal and sound insulation composite material is as follows: Figure 4 As shown.

[0074] The properties of the flexible SiO2 aerogel-based thermal and sound insulation composite materials prepared in Examples 1 to 3 were tested, and the test results are shown in Table 3: the density was 192-201 kg / m³. 3 The maximum stress at 25% strain is 0.32-0.42 MPa, and it has good compression and resilience. The sound insulation of the 15 mm thick sample is 25.4-30.6 dB, indicating that the material has excellent sound insulation performance. The thermal conductivity is 0.0233-0.0341 W / (m·K), indicating that the material has good thermal insulation performance.

[0075] Table 3 sample <![CDATA[Density (kg / m 3 )]]> Average sound insulation (dB) Thermal conductivity (W / (m·K)) Maximum stress (MPa) GF-SA 201 27.7 0.0252 0.42 PIF-SA 192 25.4 0.0233 0.32 ASF-SA 196 30.6 0.0341 0.35 Example 4

[0076] This embodiment provides a method for preparing a multilayer composite thermal insulation and sound insulation aerogel-based flexible material, including the following steps: Step 1: Referring to the typical experimental material ratios in Table 2, first use a 100mL graduated cylinder as a measuring tool to add 50mL of deionized water as a solvent to a 250mL beaker. Then add 2g of CTAB to the beaker and stir vigorously with a magnetic stirrer for 5 minutes at room temperature (25℃) to fully dissolve the CTAB and obtain an aqueous solution filled with CTAB micelles.

[0077] Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Then, slowly add the prepared ammonia solution to the beaker using a dropper while stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8. Dilute the sol with deionized water at a 1:1 volume ratio.

[0078] Step 3: After the sol is prepared, pour it into the mold in time. The mold contains pre-laid glass fiber needle-punched felt. Place the mold sample in a vacuum filtration device and maintain the vacuum for 5 minutes to ensure that the sol is thoroughly impregnated.

[0079] Step 4: After gelation, to prevent the gel from cracking, pour deionized water into the mold until it covers the top surface of the gel by 1-3 mm, seal it with plastic film, and place it in a 60℃ oven for aging for 48 hours.

[0080] Step 5: After the gel has aged, demold the gel and place it in a beaker. Pour in 500mL of deionized water to replace the sample. The water should completely cover the sample. Replace the deionized water every 4-6 hours. After 3-6 replacements, replace the sample with anhydrous ethanol in the same way. The anhydrous ethanol should completely cover the sample. Replace the anhydrous ethanol every 4-6 hours. After 3-6 replacements, the replacement is complete. During replacement, place the gel in a 60℃ oven.

[0081] Step 6: Use a CO2 supercritical drying device to dry the replaced gel to obtain a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material.

[0082] Step 7: Using an inorganic adhesive, smoothly bond the ultrafine glass fiber mat to the surface of the flexible SiO2 aerogel-based thermal insulation and sound insulation composite material. Then, using the same method, evenly and smoothly bond the aluminum foil fiberglass cloth to the surface of the ultrafine glass fiber mat. Allow it to stand at room temperature until the adhesive is completely dry. The ultrafine glass fiber mat and the aluminum foil fiberglass cloth will be firmly bonded to the flexible SiO2 aerogel-based thermal insulation and sound insulation composite material, resulting in a multi-layered composite structure of aerogel-based flexible thermal insulation and sound insulation material.

[0083] Step 8: Test various data. Example 5

[0084] This embodiment is basically the same as embodiment 4, and the similarities will not be repeated. The differences are as follows: Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Then, slowly add the prepared ammonia solution to the beaker using a dropper while stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8. Dilute the sol with deionized water at a volume ratio of 1:2. Example 6

[0085] This embodiment is basically the same as embodiment 4, and the similarities will not be repeated. The differences are as follows: Step 2: Add 100 μL of acetic acid to a beaker using a 20-200 μL pipette. After the acetic acid dissolves, add 20 mL of MTMS silicon source to the beaker using a 1-10 mL pipette. Stir in an ice bath for 30 minutes until the silicon source is completely hydrolyzed. Slowly add the prepared ammonia solution to the beaker using a dropper, stirring slowly to ensure it is fully mixed in the sol. Stop stirring when the pH of the solution increases to 7-8. Dilute the sol with deionized water at a volume ratio of 1:3.

[0086] The macroscopic morphology of the multilayer composite thermal insulation and sound insulation aerogel-based flexible material of Example 5 is shown in the figure. Figure 5 As shown.

[0087] The properties of the multilayer composite thermal insulation and sound insulation aerogel-based flexible materials prepared in Examples 4 to 6 were tested, and the test results are shown in Table 4: the density is 163-192 kg / m³. 3 The maximum stress at 10% strain is 0.108-0.159 MPa, and it has good compression resilience. The sound insulation of the 15 mm thick sample is 30.1-31.3 dB, indicating that the flexible material has excellent sound insulation performance. The thermal conductivity is 0.0214-0.0233 W / (m·K), indicating that the flexible material has good thermal insulation performance.

[0088] Table 4 sample <![CDATA[Density (kg / m 3 )]]> Average sound insulation (dB) Thermal conductivity (W / (m·K)) Maximum stress (MPa) Example 4 192 31.3 0.0214 0.159 Example 5 176 30.5 0.0231 0.135 Example 6 163 30.1 0.0233 0.108 As can be seen from the above results, the multilayer composite thermal and sound-insulating aerogel-based flexible materials prepared in Examples 4-6 exhibit improved sound and thermal insulation performance compared to the flexible SiO2 aerogel-based thermal and sound-insulating composite materials prepared in Examples 1-3. Since this material is flexible, and the material prepared in Example 4 has higher hardness and the material prepared in Example 6 has lower compressive stress, the formulation of Example 5 was ultimately selected after comprehensive consideration. The best flexible material was obtained by diluting the sol with deionized water at a volume ratio of 1:2.

[0089] Test case

[0090] This experimental example is basically the same as Example 1, and the similarities will not be repeated. The difference is that the material composite in step three was not performed. By studying the two key gelation factors of different silicon source amounts and different surfactant amounts, the main performance comparison of MTMS-based and MTES-based aerogels under different silicon source amounts is shown in Table 5. Figure 6-9 Table 6 shows a comparison of the main properties of MTMS-based and MTES-based aerogels under different surfactant dosages. Figure 10-13 As can be seen from the results in the table and attached figures: (1) The concentration of surfactant CTAB has a significant impact on the microstructure of aerogels. With the increase of CTAB dosage, the change in micelle morphology gradually transforms the gel skeleton structure from a coarse, granular structure to a continuous, fibrous structure. Furthermore, with the refinement of the structure, the aerogel exhibits good transparency. However, more CTAB is not necessarily better. Too much CTAB will make it difficult to remove residual surfactant from the aerogel, affecting its performance, while too little CTAB will not be able to fully exert its effect. The preferred dosage ratio is 2g surfactant, 20ml silicon source, and 50ml deionized water.

[0091] (2) Both MTMS-based and MTES-based gel composites have good hydrophobic properties and good mechanical properties. They also have good thermal insulation properties, and the thermal conductivity increases with increasing density. Samples with a more uniform skeleton structure have a lower thermal conductivity. The sound insulation performance increases with increasing density, and a uniform skeleton structure can also improve the average sound insulation of the sample.

[0092] (3) Under the same silicon source content and surfactant dosage, the specific surface area and hydrophobic angle of MTMS-based aerogel and MTES-based aerogel are not significantly different. However, MTMS-based aerogel has a lower bulk density. Under the condition of roughly the same density, MTMS-based aerogel has a lower thermal conductivity and better sound insulation performance than MTES-based aerogel. It also has advantages in mechanical properties and preparation cycle. At the same time, since using MTES as a silicon source requires stirring for 3 hours, it has a longer preparation cycle. However, using MTMS only requires stirring for 30 minutes, which can greatly reduce the preparation cycle. As can be seen from the table, MTMS and MTES silicon sources have similar performance. On this basis, MTMS-based aerogel has a lower bulk density and a shorter preparation cycle.

[0093] Table 5 sample <![CDATA[Density (g / cm 3 )]]> Thermal conductivity (W / (m·K)) Average sound insulation (dB) Maximum stress (MPa) MTMS-10ml 0.057 0.0160 17.05 0.049 MTMS-15ml 0.098 0.0189 20.34 0.127 MTMS-20ml 0.131 0.0225 23.02 0.244 MTMS-25ml 0.174 0.0238 28.99 0.752 MTES-14ml 0.210 0.0183 17.32 0.28 MTES-21ml 0.279 0.0195 21.58 0.53 MTES-28ml 0.353 0.0221 21.75 0.64 MTES-35ml 0.536 0.0323 33.53 - Table 6 sample <![CDATA[Density (kg / m 3 )]]> Maximum stress (MPa) Thermal conductivity (W / (m·K)) Average sound insulation (dB) MTMSCTAB-0.5 134 0.194 0.0262 18.98 MTMSCTAB-1.0 132 0.246 0.0249 20.29 MTMSCTAB-1.5 135 0.267 0.0229 20.62 MTMSCTAB-2.5 131 0.331 0.022 22.06 MTESCTAB-0.5 272 0.14 0.0264 14.96 MTESCTAB-1.0 277 0.42 0.0226 21.58 MTESCTAB-1.5 275 0.47 0.0204 21.33 MTESCTAB-2.0 279 0.53 0.0195 21.58 In summary, the preparation method of the present invention achieves high thermal insulation performance, reduces coating thickness, improves space utilization, and also improves cabin noise, protects the physical and mental health of crew members, and has broad application prospects.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a multi-layered composite thermal insulation and sound insulation aerogel-based flexible material, characterized in that, Includes the following steps: S1. Add a surfactant to the solvent and dissolve it completely to obtain micelles; S2. Add acetic acid and silicon source to micelles. After the silicon source is completely hydrolyzed, add ammonia solution and stir to mix thoroughly to obtain a sol. Dilute the sol with deionized water. S3. Lay fiber material in the mold, pour the sol into the mold and vacuum filter it to ensure thorough sol impregnation, and wait for the gel to complete. S4. After the gel is formed, add deionized water to the mold to cover the top surface of the gel, seal the mold and then age it. S5. After the gel has aged, demold the gel and replace it with deionized water and anhydrous ethanol. S6. The replaced gel is subjected to supercritical drying to obtain a flexible SiO2 aerogel-based thermal insulation and sound insulation composite material. S7. Using an inorganic adhesive, sound-absorbing materials and sound-insulating materials are sequentially bonded to the surface of a flexible SiO2 aerogel-based thermal insulation and sound-insulating composite material to obtain a multi-layered composite thermal insulation and sound-insulating aerogel-based flexible material.

2. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S1, the surfactant is hexadecyltrimethylammonium bromide, the solvent is deionized water, and the amount of surfactant used accounts for 1.40% to 3.61% of the sol mass.

3. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S2, the silicon source is one or both of methyltrimethoxysilane and methyltriethoxysilane.

4. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S2, the amount of silicon source used accounts for 21.11% to 30.05% of the sol mass; the amount of acetic acid used accounts for 0.07% to 0.24% of the sol mass; and the amount of ammonia solution used accounts for 6.01% to 7.04% of the sol mass.

5. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S3, the fiber material is one or more of glass fiber, PI fiber, and aluminum silicate fiber.

6. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S4, the deionized water covers the upper surface of the gel by 1-3 mm, and the gel is sealed with a plastic film and aged in a 60°C oven for 48 hours.

7. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S5, the replacement is first performed with deionized water, which covers the gel. The deionized water is replaced every 4-6 hours, and after 3-6 replacements, anhydrous ethanol is used for replacement, which covers the gel. The anhydrous ethanol is replaced every 4-6 hours, and after 3-6 replacements, the replacement is completed.

8. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S6, the supercritical drying is performed using CO2 supercritical drying.

9. The method for preparing the multilayer composite thermal insulation and sound insulation aerogel-based flexible material according to claim 1, characterized in that, In step S7, the inorganic adhesive is a phosphate-based inorganic adhesive, the sound-absorbing material is ultra-fine fiberglass felt, and the sound-insulating material is aluminum foil fiberglass cloth.

10. A multi-layered composite thermal and sound-insulating aerogel-based flexible material, characterized in that, The material is prepared by the method according to any one of claims 1-9, and its density is 163-201 kg / m³. 3 The maximum stress at 10% strain is 0.108-0.159 MPa, the sound insulation of a 15 mm thickness is 30.1-31.3 dB, and the thermal conductivity is 0.0214-0.0233 W / (m·K).

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