Aerogel composite material and method for manufacturing aerogel composite material

Abstract

The invention discloses an aerogel composite material and a preparation method thereof. The aerogel composite material comprises a porous fiber material and aerogel powder distributed in the porous fiber material. The aerogel powder is impregnated within the porous fibrous material by applying an alternating electric field to the porous fibrous material. The aerogel powder is impregnated in the porous fiber material through the alternating electric field, and the impregnation amount of the aerogel powder is large and uniform, so that the aerogel composite material has better thermal insulation performance, the process is simple, and the production cost is low.

Description

Technical Field

[0001] This application relates to the field of aerogels, and more particularly to an aerogel composite material and a method for manufacturing the aerogel composite material. Background Technology

[0002] Aerogel composites are a new type of advanced material, made by combining nano-aerogel particles and fiber materials through a special process. They possess properties such as lightweight, high-efficiency thermal insulation, fire resistance, and environmental friendliness, and are widely used in construction, petroleum, aerospace, and other fields.

[0003] Currently, aerogel composites are mainly manufactured using supercritical drying. Supercritical drying utilizes the unique properties of supercritical fluids (such as carbon dioxide) to displace the solvent from a sol-gel pre-impregnated in a fiber material, thus achieving the transformation from sol-gel to aerogel. Simultaneously, the aerogel grows in situ within the fiber material, producing aerogel composites (e.g., Chinese patents CN100540257C and CN105906298A). Supercritical drying requires supercritical conditions, involves significant investment in supercritical drying equipment, has complex operation, extremely high energy consumption, and imposes certain limitations on the selection of precursors.

[0004] Besides supercritical drying, several technologies have been developed to produce aerogels using atmospheric pressure drying. Atmospheric pressure drying involves extensive hydrophobic modification of the sol-gel beforehand, converting it into an aerogel under atmospheric pressure and temperature or atmospheric pressure and high temperature conditions (e.g., Chinese patents CN103771428A and CN109806817A). While atmospheric pressure drying offers advantages such as low equipment cost and low energy consumption, its industrialization is limited by its ability to produce aerogel powder on a large scale, rather than for in-situ preparation of aerogel composite materials.

[0005] In recent years, many studies have focused on the secondary composite material preparation of aerogel powders prepared by atmospheric pressure drying into fiber mats through special processes. The most common technique is to prepare aerogel powder into an aerogel slurry, composite it into the fiber material through impregnation, and then evaporate the solvent (e.g., Chinese patents CN112301732B and CN114835435A). However, the nanoporous structure of the aerogel is damaged and its performance is lost during the slurry preparation process. Moreover, the entire process requires a large amount of solvent and drying equipment, resulting in high costs and energy consumption. Some techniques avoid the use of solvents by manually or electrostatically spraying aerogel powder onto the fiber mat and then composite it through a needle-punching process (CN 115874348B). However, the dispersion of aerogel powder in the fiber material remains poor, failing to achieve the good uniformity of aerogel composites prepared by supercritical drying.

[0006] Using aerogel powder for secondary composite preparation can greatly reduce the production cost of aerogel materials and expand their application in industrial production; however, limitations in composite technology hinder its development.

[0007] This paper proposes a secondary composite technology that features low process input cost, low production energy consumption, simple preparation process, excellent aerogel powder distribution effect, and good pore structure and performance. This technology is a technical problem that urgently needs to be solved in this field.

[0008] Application content The summary of this application introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0009] This application provides an aerogel composite material, the aerogel composite material comprising: Porous fiber materials; Aerogel powder distributed within the porous fiber material, wherein the aerogel powder is applied to the surface of the porous material by an electrostatic device and then an alternating electric field is applied to impregnate at least a portion of the aerogel powder within the porous material; the density of the aerogel powder distributed within the porous fiber material ranges from 0.01 g / cm3 to 0.5 g / cm3, and the average particle size of the aerogel powder is less than or equal to 500 μm.

[0010] In an optional embodiment, the electrostatic device includes at least one of an electrostatic spraying device, an electrostatic flocking device, and an electrostatic atomizing device.

[0011] In an optional embodiment, the voltage range of the alternating electric field is 0.1KV to 50KV, and the frequency range is 1HZ to 800HZ; the application time of the alternating electric field is 30 seconds to 5 minutes.

[0012] In an optional embodiment, the density of the aerogel powder distributed within the porous fiber material ranges from 0.03 g / cm³ to 0.1 g / cm³, and the average particle size of the aerogel powder is less than or equal to 50 μm.

[0013] In an optional embodiment, the porous fiber material is selected from glass fiber mat, glass fiber nonwoven fabric, glass fiber woven fabric, ceramic fiber mat, paper, polyurethane fiber mat, carbon fiber mat, polypropylene fiber mat, polypropylene and glass fiber composite mat, and combinations thereof.

[0014] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 20 g / m² and 500 g / m², a thickness between 0.3 mm and 4 mm, and an air permeability between 200 L / m² / s and 3000 L / m² / s.

[0015] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 50 g / m² and 150 g / m², a thickness between 0.5 mm and 1.5 mm, and an air permeability between 500 L / m² / s and 2000 L / m² / s.

[0016] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 90 g / m² and 135 g / m², a thickness between 0.8 mm and 1.3 mm, and an air permeability between 1100 L / m² / s and 1800 L / m² / s.

[0017] In an optional embodiment, the polypropylene and glass fiber composite felt is made of a blend of polypropylene fibers and glass fibers, and the density of the polypropylene and glass fiber composite felt is between 20 kg / m3 and 200 kg / m3, and the thickness is between 1 mm and 20 mm.

[0018] In an optional embodiment, the polypropylene and glass fiber composite mat has a density between 50 kg / m³ and 150 kg / m³ and a thickness between 3 mm and 10 mm.

[0019] In an optional embodiment, the aerogel powder contains an additive for suppressing thermal radiation, the additive being selected from at least one of silicon carbide, boron carbide, titanium oxide, and boron nitride, and the weight ratio of the additive to the aerogel powder is between 1 wt% and 15 wt%.

[0020] In an optional embodiment, the weight ratio of the additive to the aerogel powder ranges from 1 wt% to 15 wt%.

[0021] In an optional embodiment, the weight ratio of the aerogel powder to the aerogel composite material ranges from 1 wt% to 50 wt%.

[0022] This application also provides a method for manufacturing aerogel felt, the method comprising the steps of: Aerogel powder is applied to the surface of a porous material using an electrostatic device; An alternating electric field is applied such that at least a portion of the aerogel powder is impregnated within the porous material, wherein the voltage range of the alternating electric field is 0.1 kV to 50 kV, and the frequency range is 1 Hz to 800 Hz; the density of the aerogel powder is 0.01 g / cm³ to 0.5 g / cm³, and the average particle size of the aerogel powder is less than or equal to 500 μm.

[0023] In an optional embodiment, the electrostatic device includes at least one of an electrostatic spraying device, an electrostatic flocking device, and an electrostatic atomizing device.

[0024] In an optional embodiment, the alternating electric field is applied for 30 seconds to 5 minutes.

[0025] In an optional embodiment, the porous fiber material and the aerogel powder are placed between a lower electrode and an upper electrode, the electrodes being electrically insulated from each other by a dielectric and connected to a power source, so that the porous fiber material and the aerogel powder are subjected to the alternating electric field.

[0026] In an optional embodiment, the density of the aerogel powder ranges from 0.03 g / cm³ to 0.1 g / cm³, and the average particle size of the aerogel powder is less than or equal to 50 μm.

[0027] In an optional embodiment, the porous fiber material is selected from glass fiber mat, glass fiber nonwoven fabric, glass fiber woven fabric, ceramic fiber mat, paper, polyurethane fiber mat, carbon fiber mat, polypropylene fiber mat, polypropylene and glass fiber composite mat, and combinations thereof.

[0028] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 20 g / m2 and 500 g / m2, a thickness between 0.3 mm and 4 mm, and an air permeability between 200 L / m2 / s and 3000 L / m2 / s.

[0029] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 50 g / m2 and 150 g / m2, a thickness between 0.5 mm and 1.5 mm, and an air permeability between 500 L / m2 / s and 2000 L / m2 / s.

[0030] In an optional embodiment, the glass fiber nonwoven fabric has an areal density between 90 g / m2 and 135 g / m2, a thickness between 0.8 mm and 1.3 mm, and an air permeability between 1100 L / m2 / s and 1800 L / m2 / s.

[0031] In an optional embodiment, the polypropylene and glass fiber composite felt is made of a blend of polypropylene fibers and glass fibers, the density of the polypropylene and glass fiber composite felt is between 20 kg / m3 and 200 kg / m3, and the thickness is between 1 mm and 20 mm.

[0032] In an optional embodiment, the polypropylene and glass fiber composite mat has a density between 50 kg / m³ and 150 kg / m³ and a thickness between 3 mm and 10 mm.

[0033] In an optional embodiment, the aerogel powder contains an additive for suppressing thermal radiation, the additive including at least one of silicon carbide, boron carbide, titanium oxide, and boron nitride, the weight ratio of the additive to the aerogel powder ranging from 1 wt% to 15 wt%.

[0034] In an optional embodiment, the weight ratio of the additive to the aerogel powder ranges from 5 wt% to 12 wt%.

[0035] This application provides an aerogel composite material. One of the innovations of the aerogel composite material provided in this application is that an alternating electric field is applied to the process of preparing the aerogel composite material, thereby giving the aerogel composite material of this application a significant technical advantage compared to aerogel composite materials manufactured by supercritical drying, slurry impregnation, or other existing technologies. For example, compared to supercritical drying, it does not require complex supercritical equipment or high energy consumption to generate supercritical fluid. It only requires aerogel powder prepared by a simple alternating electric field and atmospheric pressure drying, and the manufacturing process is simple. It can produce aerogel composite materials while simultaneously meeting the requirement of uniform aerogel powder distribution, resulting in low investment cost and low energy consumption. Compared to aerogel slurry impregnation, because solvent impregnation is not required, the destruction of the aerogel powder structure is avoided, giving the aerogel composite material better performance. At the same time, the process does not involve the use of solvents or drying, reducing a significant amount of energy consumption. In addition, applying aerogel powder to the substrate using electrostatic devices, including electrostatic spraying devices, electrostatic flocking devices, and electrostatic atomization devices, can improve the efficiency of powder application and the distribution effect of aerogel in aerogel composite materials.

[0036] Aerogel powder is impregnated into porous fiber materials by an alternating electric field. The aerogel powder impregnation amount is large and uniform, which gives the aerogel composite material good thermal insulation performance. The process is simple and the production cost is low. Attached Figure Description

[0037] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions to explain the principles of the invention.

[0038] In the attached image: Figure 1 A scanning electron microscope (SEM) image of a vertical cross-section of the aerogel composite material according to Example 1 of this application; Figure 2a A scanning electron microscope (SEM) image of a vertical cross-section of the aerogel composite material according to Example 2 of this application; Figure 2b A scanning electron microscope (SEM) image of the front side of the aerogel composite material according to Example 2 of this application; Figure 2c A scanning electron microscope image of the back side of the aerogel composite material in Example 2 of this application; Figure 3a A scanning electron microscope image of a vertical cross-section of the aerogel composite material in Comparative Example 1 according to this application; Figure 3b A scanning electron microscope image of the front side of the aerogel composite material in Comparative Example 1 according to this application; Figure 3c A scanning electron microscope image of the back side of the aerogel composite material in Comparative Example 1 according to this application; Figure 4a A scanning electron microscope image of a vertical cross-section of the aerogel composite material in Comparative Example 2 according to this application; Figure 4b A scanning electron microscope image of the front side of the aerogel composite material in Comparative Example 2 according to this application; Figure 4c A scanning electron microscope image of the back side of the aerogel composite material in Comparative Example 2 according to this application; Figure 5 This is a schematic diagram showing the basis weight distribution of various nonwoven fabric substrates prepared by electrostatic spraying in this application; Figure 6a This is a schematic diagram showing the A4-sized sample prepared by electrostatic spraying in this application being cut into 32 equal parts; Figure 6b This is a schematic diagram showing how an A4-sized sample prepared using gravity powder spraying in this application is divided into six equal parts. Detailed Implementation

[0039] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been specifically described to avoid confusion with this application.

[0040] To fully understand this application, a detailed description is provided below to illustrate the aerogel composite material and the method for manufacturing the aerogel composite. Obviously, the implementation of this application is not limited to the specific details familiar to those skilled in the art of aerogels. Preferred embodiments of this application are described in detail below; however, other embodiments may be possible in addition to these detailed descriptions.

[0041] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0042] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0043] To at least partially address the aforementioned problems, the first aspect of this application provides an aerogel composite material. One innovation of the aerogel composite material provided by this application lies in the application of an alternating electric field in the preparation process. This gives the aerogel composite material of this application significant technical advantages compared to aerogel composite materials manufactured using supercritical drying, slurry impregnation, or other existing technologies. For example, compared to supercritical drying, it eliminates the need for complex supercritical equipment and high energy consumption to generate supercritical fluid. It only requires aerogel powder prepared using a simple alternating electric field and atmospheric pressure drying, and the manufacturing process is simple. It can produce aerogel composite materials while simultaneously meeting the requirement of uniform aerogel powder distribution, resulting in low investment costs and low energy consumption. Compared to aerogel slurry impregnation, it eliminates the need for solvent impregnation, thus avoiding damage to the aerogel powder structure and giving the aerogel composite material better performance. Furthermore, the process does not involve the use of solvents or drying, significantly reducing energy consumption.

[0044] Specifically, the aerogel composite material disclosed in this application may include a porous fiber material and aerogel powder distributed within the porous fiber material. By applying an alternating electric field to the porous fiber material, the aerogel powder is impregnated within it, ensuring not only that the aerogel powder is impregnated into the porous fiber material, but also that the impregnation is relatively uniform. See also Figure 1 as well as Figure 2a The image shown is a scanning electron microscope (SEM) image of the aerogel composite materials of Examples 1 and 2 in a vertical cross-section, compared to the comparative example. Figure 3a and Figure 4a As can be seen, the aerogel powder in the aerogel composite material of this application is relatively uniformly distributed and has a relatively large impregnation amount. In several embodiments, the weight ratio of aerogel powder to aerogel composite material can range from 1 wt% to 50 wt%.

[0045] An alternating electric field is an electric field whose magnitude and direction change with time. It is generated by an alternating current (AC) power source, where charges oscillate between positive and negative, causing changes in the electric field. Alternating electric fields are characterized by periodic changes, with their frequency describing the rate of change, measured in Hertz (Hz). The alternating electric field of this application has a voltage range of 0.1 kV to 50 kV, a frequency range of 1 Hz to 800 Hz, and an application time of 30 seconds to 5 minutes. Those skilled in the art can adjust any of these parameters according to actual usage requirements and product conditions during production.

[0046] The density range of the aerogel powder in the aerogel composite material of this application can be 0.01 g / cm³. 3 up to 0.5 g / cm 3 The aerogel powder has an average particle size of less than or equal to 500 μm. Preferably, the density of the aerogel powder can be in the range of 0.03 g / cm³. 3 Up to 0.1 g / cm 3 The aerogel powder has an average particle size of less than or equal to 50 μm. For example, the aerogel powder may be JIOS aerogel AeroVa® aerogel powder (Chinese Patent CN103771428B and US Patent US20220306833, which are incorporated herein by reference in their entirety).

[0047] The porous fiber material can be selected from glass fiber mat, glass fiber nonwoven fabric, glass fiber woven fabric, ceramic fiber mat, paper, polyurethane fiber mat, carbon fiber mat, polypropylene fiber mat, polypropylene and glass fiber composite mat, and combinations thereof. Preferably, the porous fiber material can be glass fiber nonwoven fabric with an areal density of 20 g / m³. 2 Up to 500g / m 2The thickness can range from 0.3mm to 4mm, and the air permeability can be 200L / m². 2 / s to 3000L / m 2 Between / s. More preferably, the areal density can be 50 g / m². 2 Up to 150 g / m 2 The thickness can range from 0.5mm to 1.5mm, and the air permeability can be 500L / m². 2 / s to 2000L / m 2 Between / s, or a surface density of 90 g / m 2 Up to 135 g / m 2 The thickness ranges from 0.8mm to 1.3mm, and the air permeability is 1100L / m². 2 / s to 1800L / m 2 Between / s.

[0048] As another preferred embodiment, the porous fiber material can also be selected with a density of 50 kg / m³. 3 Up to 150 kg / m 3 The composite felt is made of polypropylene and glass fiber with a thickness between 3 mm and 10 mm. It should be noted that this application is not limited to the specifically listed types of porous fiber materials; any porous fiber material known to those skilled in the art, or any material equivalent to a porous fiber material capable of containing aerogel powder, falls within the scope of protection defined in this application.

[0049] To improve the thermal insulation and heat preservation properties of aerogel composites, additives for suppressing heat radiation can be added to the aerogel powder. For example, the additive can be selected from at least one of silicon carbide, boron carbide, titanium oxide, and boron nitride. The weight ratio of the additive to the aerogel powder can range from 1 wt% to 15 wt%. Preferably, the weight ratio of the additive to the aerogel powder ranges from 5 wt% to 12 wt%.

[0050] A second aspect of this application also provides a method for manufacturing aerogel composite materials, which generally includes the following steps: Feeding: Applying aerogel powder to the surface of the porous fiber material and / or applying aerogel powder to a loader, the loader being at least partially subjected to an alternating electric field; for example, the loader may be a conveyor belt or a rotary feeder, the conveyor belt may be located above the porous fiber material and at least partially within the alternating electric field, the aerogel powder may be conveyed by the conveyor belt, and when the alternating electric field is applied, the aerogel powder located on the conveyor belt may be impregnated into the porous fiber material.

[0051] Processing: Aerogel powder is impregnated into porous fiber material by applying an alternating electric field, wherein the voltage range of the alternating electric field can be 0.1KV to 200KV, and the frequency range is 0.1HZ to 800HZ; the density of the aerogel powder ranges from 0.01g / cm³. 3 up to 0.5 g / cm 3 The aerogel powder has an average particle size of less than or equal to 500 μm. The alternating electric field is applied for 30 seconds to 5 minutes.

[0052] In an optional embodiment, the porous fiber material and aerogel powder are placed between the lower electrode and the upper electrode, which are electrically insulated from each other by a dielectric and connected to a power source so that the porous fiber material and aerogel powder are subjected to an alternating electric field.

[0053] Furthermore, in order to better illustrate the aerogel composite material and the method for manufacturing the aerogel composite material provided in this application, this application provides several embodiments and comparative examples to illustrate that the present application has significant technical advantages compared to the prior art.

[0054] Example 1: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Owens Corning fiberglass nonwoven fabric, 125 g / m² 2 Thickness 1.25mm, air permeability 1300~1350L / m 2 / s; High-voltage alternating electric field: It consists of two electrodes, one of which is grounded and the other is connected to a high-voltage alternating current with a maximum voltage of ±15kV, a sine wave, and a frequency of 600HZ. Implementation process: Spread the aerogel powder evenly on the fiberglass nonwoven fabric, place it in a high-voltage alternating electric field, turn on the power, and let the powder vibrate fully in it for 2 minutes. The powder will impregnate into the pores in the middle of the nonwoven fabric. Result: The final aerogel powder accounted for 42 wt% of the total material weight. Figure 1 The image shown is a scanning electron microscope (SEM) image of the vertical cross-section of the aerogel composite material in Example 1. It can be seen that the aerogel powder is uniformly impregnated in the pores of the nonwoven fabric between the upper and lower surfaces of the porous fiber material. Because the aerogel powder impregnation is large and uniform, the aerogel composite material has good thermal insulation properties.

[0055] Example 2: Materials: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03-0.1 g / cm3, porosity > 90%; Owens Corning fiberglass nonwoven fabric, basis weight 100 g / m2, thickness 1 mm, air permeability 1700~1750 L / m2 / s; High-voltage alternating electric field: It consists of two electrodes, one of which is grounded and the other is connected to a high-voltage alternating current with a maximum voltage of ±20kV, a sine wave, and a frequency of 600HZ. Implementation process: Spread the aerogel powder evenly on the fiberglass nonwoven fabric, place it in a high-voltage alternating electric field, turn on the power, and let the powder vibrate fully in it for 2 minutes. The powder will impregnate into the pores in the middle of the nonwoven fabric. Result: The final aerogel powder accounted for 32 wt% of the total material weight. Figure 2a , 2b 2c and 2c are scanning electron microscope images of the aerogel composite material in Example 2 in the vertical cross section, front and back sides, respectively.

[0056] Compared to the proportion Figure 3a and Figure 4a It can be seen that the aerogel powder in the aerogel composite material of Example 2 is more uniformly distributed and has a relatively larger impregnation amount. Compared with the comparative example... Figure 3b and Figure 4b It can be seen that the aerogel powder distribution on the front side of the aerogel composite material in Example 2 is relatively uniform and the impregnation amount is relatively large. (Comparative example) Figure 3c and Figure 4c The aerogel powder distribution on the back side of the aerogel composite material shown in the comparative examples can be seen as basically having no aerogel powder. This is due to reasons such as insufficient impregnation of aerogel powder and uneven distribution. However, the aerogel powder distribution on the back side of the aerogel composite material in Example 2 is more uniform and the impregnation amount is relatively larger.

[0057] Example 3: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; silicon carbide powder, particle size 0.5μm~0.7μm, density 0.8~0.9g / cm³. 3 etc.; Owens Corning fiberglass nonwoven fabric, 100 g / m² 2 Thickness 1mm, air permeability 1700~1750 L / m 2 / s; High-voltage alternating electric field: It consists of two electrodes, one of which is grounded and the other is connected to a high-voltage alternating current with a maximum voltage of ±20kV, a sine wave, and a frequency of 600HZ. Implementation process: Aerogel powder and silicon carbide powder are evenly dispersed and spread on glass fiber nonwoven fabric in a 9:1 ratio. The fabric is placed in a high voltage alternating electric field and energized to allow the powder to vibrate fully for 2 minutes. The powder will then penetrate into the pores of the nonwoven fabric. Result: The final weight ratio of aerogel and silicon carbide powder in the entire material was 41 wt%.

[0058] Example 4: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; glass fiber and polypropylene fiber blended felt, density ~90 kg / m³ 3 Thickness ~6mm, air permeability 380~420 L / m 2 / s High-voltage alternating electric field: It consists of two electrodes, one of which is grounded and the other is connected to a high-voltage alternating current with a maximum voltage of ±14kV, a sine wave, and a frequency of 600HZ. Implementation process: Spread the aerogel powder evenly on the fiberglass nonwoven fabric, place it in a high-voltage alternating electric field, turn on the power, and let the powder vibrate fully in it for 2 minutes. The powder will impregnate into the pores in the middle of the nonwoven fabric. Result: The final aerogel powder accounted for 35 wt% of the total material weight.

[0059] Comparative Example 1: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Owens Corning fiberglass nonwoven fabric, basis weight 125 g / m². 2 Thickness 1.25mm, air permeability 1300~1350L / m 2 / s; Electrostatic spraying: electrostatic high voltage 20KV, electrostatic current 40μA, powder output pressure 210KPa, atomization pressure 70KPa, powder supply hopper fluidization pressure 35KPa; Implementation process: Place the non-woven fabric on a horizontal table, connect the electrostatic spraying device to the powder tank, turn on the power, adjust the parameters, turn on the switch to evenly coat the aerogel powder onto the non-woven fabric, repeating this process three times in total. Result: The final aerogel powder accounted for 12 wt% of the total material weight. Figure 3a , 3b 3c are scanning electron microscope images of the aerogel composite material in Comparative Example 1 in the vertical cross section, front side, and back side, respectively.

[0060] Comparative Example 2: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Glass fiber and polypropylene fiber blended felt, basis weight 540 g / m² 2 Thickness 6mm, breathability 380~420L / m 2 / s.

[0061] Electrostatic spraying: electrostatic high voltage 20KV, electrostatic current 40μA, powder output pressure 210KPa, atomization pressure 70KPa, powder supply tank fluidization pressure 35KPa.

[0062] Implementation process: Place the blended felt on a horizontal table, connect the electrostatic spraying device to the powder tank, turn on the power, adjust the parameters, turn on the switch to evenly coat the aerogel powder onto the non-woven fabric, repeating this process three times in total. Result: The final aerogel powder accounted for 8 wt% of the total material weight. Figure 4a , 4b 4c are scanning electron microscope (SEM) images of the aerogel composite material in Comparative Example 2 in the vertical cross section, front side, and back side, respectively. Comparative Example 3: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Owens Corning needle-punched felt, basis weight 900 g / m² 2 Density 60kg / m³ 2 Thickness ~15mm, air permeability 100~300 L / m 2 / s; Solvent: Ethanol; Implementation process: Aerogel powder was dispersed in ethanol solvent by stirring to prepare a dispersion with a mass concentration of 10 wt% and a viscosity of 18.1 cP. The dispersion was added to a fiberglass mat, and negative pressure was used to ensure complete impregnation. The fiberglass mat was then allowed to dry naturally at room temperature for 24 hours and then immersed in 200... o Dry in oven C for 12 hours.

[0063] Results: The final aerogel powder accounted for 22 wt% of the total material. The specific surface area data of the aerogel after impregnation and drying of the dispersion are shown in Table 1.

[0064] Comparative Example 4: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Owens Corning needle-punched felt, basis weight 900 g / m² 2 Density 60kg / m³ 2 Thickness ~15mm, air permeability 100~300 L / m 2 / s; Solvent: n-hexane; Implementation process: Aerogel powder was dispersed in hexane solvent by stirring to prepare a dispersion with a mass concentration of 10 wt% and a viscosity of 6.24 cP. The dispersion was added to a fiberglass mat, and negative pressure was applied to ensure complete impregnation. The fiberglass mat was then allowed to dry naturally at room temperature for 24 hours and then immersed in 200... o Dry in oven C for 12 hours.

[0065] Results: The final aerogel powder accounted for 21 wt% of the total material. The specific surface area data of the aerogel after impregnation and drying of the dispersion are shown in Table 1.

[0066] Comparative Example 5: Material: Jios Aerogel AeroVa® aerogel powder, particle size D50 < 50 μm, density 0.03–0.1 g / cm³. 3 Porosity > 90%; Owens Corning fiberglass nonwoven fabric, basis weight ~60g / m² 2 Thickness ~0.6mm, air permeability 3000~3100L / m 2 / s; Solvent: 75% water + 25% ethanol; Procedure: The aerogel powder was placed in the solvent and stirred to prepare a dispersion with a mass concentration of 10wt% and a viscosity of 12.1 cP. The dispersion was added to a fiberglass mat and vacuum-sealed to ensure complete impregnation. The fiberglass mat was then allowed to dry naturally at room temperature for 24 hours and placed in a 200... o Dry in oven C for 12 hours.

[0067] Results: The final aerogel powder accounted for 20 wt% of the total material. The specific surface area data of the aerogel after impregnation and drying of the dispersion are shown in Table 1.

[0068] Table 1 shows the changes in pore structure of Comparative Examples 3, 4, and 5 after solvent treatment of the aerogel powder. The aerogel samples in Comparative Examples 3, 4, and 5, compared to the untreated AeroVa... ®Aerogel powders exhibit varying degrees of decrease in specific surface area and a significant reduction in porosity, or pore volume. This indicates that the nanopores within the aerogel powder are damaged to varying degrees, with the internal space of the nanopores collapsing, leading to a smaller pore volume and reduced specific surface area. This application avoids the problem of aerogel powder structure destruction caused by solution processing by directly impregnating the aerogel powder into a porous fiber material using an alternating electric field, thus giving the aerogel composite material of this application superior performance.

[0069] Table 1 Another aspect of this application concerns how to uniformly spread aerogel powder onto a substrate, which is also a technical problem this application aims to solve. As is well known, due to the inherent characteristics of aerogel powder, such as low density, easy flocculation, and small particle size, achieving uniform distribution using traditional gravity loading methods is quite difficult. Air / vacuum-assisted spraying / loading may achieve uniform distribution, but these methods have the disadvantage that aerogel powder may disperse in the air, leading to material waste during application. Furthermore, as in the method for manufacturing aerogel composite materials disclosed in this application, how to quickly and efficiently apply a large amount of aerogel powder onto the substrate during the manufacturing of aerogel composite materials is also a significant challenge to traditional loading processes.

[0070] In specific embodiments of this application, it may be necessary to uniformly apply up to 35% (by weight) of aerogel powder onto the substrate within a very limited time.

[0071] In summary, an ideal application process should be able to deposit aerogel powder onto the substrate quickly and uniformly while minimizing waste.

[0072] Based on this, this application innovatively utilizes electrostatic equipment such as electrostatic spraying, electrostatic flocking, or electrostatic atomization to first apply aerogel powder to porous materials such as nonwoven fabric substrates, and then uses plate-shaped electrodes in an alternating electric field to incorporate the aerogel powder into the nonwoven fabric material. This enables efficient aerogel / nonwoven fabric composite while ensuring rapid and uniform application, and the composite material has the advantage of uniform aerogel distribution.

[0073] To evaluate and compare the effects of gravity powder coating and electrostatic methods such as electrostatic spraying, electrostatic flocking, or electrostatic atomization used in this application to deposit aerogel powder onto nonwoven substrates, a series of comparative experiments were designed to demonstrate the technical advantages of the method used in this application. Aerogel powder was applied to an A4 (210mm × 297mm) substrate, followed by post-processing with an alternating electric field, and then the powder distribution was characterized. In the experiments, the aerogel weight distribution (WD) was used to evaluate the powder distribution. Specifically, an A4-sized piece of material was cut into a certain number of small pieces of equal area. The standard deviation of the weight of these small piece samples divided by the average weight is the weight distribution (WD). Therefore, the more pieces that can be cut, the smaller the WD%, and the better the aerogel powder distribution.

[0074] The specific experimental procedure may include the following steps: 1. Prepare an A4-sized nonwoven fabric substrate for each powdering method.

[0075] 2. Using gravity powder spraying and electrostatic spraying methods, 30%-40% (by weight) of aerogel powder is sprayed onto the nonwoven fabric substrate.

[0076] 3. The loaded nonwoven fabric substrate is post-treated by passing it through an alternating electric field.

[0077] 4. Cut the A4-sized nonwoven fabric substrate sample into a certain number of small pieces of the same size and weigh them: for gravity powder coating: refer to... Figure 6b As shown, the A4-sized sample was cut into 6 equal parts. Electrostatic spraying: Refer to... Figure 6a As shown, the A4-sized sample was divided into 32 equal parts. Furthermore, visual observation reveals that the substrate coated using electrostatic spraying exhibits a more uniform aerogel distribution.

[0078] 6. Calculate the WD% for these two powdering methods.

[0079] Experimental results: Gravity-based powdering: The WD% of 6 samples in the A4 size sample was approximately 5%.

[0080] Electrostatic spraying: The WD% of 32 A4-sized samples is approximately 5%.

[0081] Experimental results show that electrostatic spraying produces a significantly higher uniformity of the final aerogel nonwoven fabric compared to the traditional gravity loading method. Furthermore, the electrostatic spraying method requires far less time to add 35% powder compared to the traditional gravity powder application method, and it is also more convenient to operate. Therefore, electrostatic spraying is a more efficient method for achieving stable and uniform aerogel powder application on a substrate.

[0082] In another embodiment, Figure 5 The image shows the weight distribution of JIOS D50 on various substrates (including models CR33, EB2, B4A, and B1A0) prepared using electrostatic spraying. The numbers in each small grid represent the weight of that area, with darker colors indicating greater weight. The AC electric field parameters used were 10 kV and 50 Hz. DW% was calculated by cutting the A4 sample into 72 pieces. All samples were electrostatically sprayed and subjected to AC spraying using the same SOP and parameters. Figure 5 It can be seen that when aerogel powder is applied to different nonwoven fabric substrates using an electrostatic device, and then an alternating electric field is applied so that at least part of the aerogel powder is impregnated in the porous material, it can be observed that the aerogel powder is distributed relatively uniformly in different substrates. This proves that the electrostatic spraying method can be applied to different nonwoven fabric substrates and can achieve good aerogel distribution uniformity.

[0083] Those skilled in the art will recognize that the step of applying aerogel powder to a nonwoven fabric substrate using an electrostatic device can be applied to or replace all the above embodiments. That is, without changing other steps, using or replacing the powder application step with applying aerogel powder via an electrostatic device can improve the aerogel distribution effect in the final product. The electrostatic device includes at least one of an electrostatic spraying device, an electrostatic flocking device, and an electrostatic atomizing device. Of course, this application does not exclude other spraying devices utilizing electrostatic principles, all of which should be within the scope of protection of this application.

[0084] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the scope of the described embodiments. Furthermore, those skilled in the art will understand that this application is not limited to the above embodiments, and many variations and modifications can be made based on the teachings of this application, all of which fall within the scope of protection claimed in this application. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. An aerogel composite material, characterized in that, The aerogel composite material includes: Porous fiber materials; Aerogel powder distributed within the porous fiber material, wherein the aerogel powder is applied to the surface of the porous material by an electrostatic device and then an alternating electric field is applied to impregnate at least a portion of the aerogel powder within the porous material; the density of the aerogel powder distributed within the porous fiber material is in the range of 0.01 g / cm³. 3 up to 0.5 g / cm 3 The aerogel powder has an average particle size of less than or equal to 500 μm.

2. The aerogel composite material according to claim 1, characterized in that, The electrostatic device includes at least one of an electrostatic spraying device, an electrostatic flocking device, and an electrostatic atomizing device.

3. The aerogel composite material according to claim 1, characterized in that, The voltage range of the alternating electric field is 0.1KV to 50KV, and the frequency range is 1HZ to 800HZ; the application time of the alternating electric field is 30 seconds to 5 minutes.

4. The aerogel composite material according to claim 1, characterized in that, The density range of the aerogel powder distributed within the porous fiber material is 0.03 g / cm³. 3 Up to 0.1 g / cm 3 The average particle size of the aerogel powder is less than or equal to 50 μm.

5. The aerogel composite material according to claim 1, characterized in that, The porous fiber material is selected from glass fiber mat, glass fiber nonwoven fabric, glass fiber woven fabric, ceramic fiber mat, paper, polyurethane fiber mat, carbon fiber mat, polypropylene fiber mat, polypropylene and glass fiber composite mat, and combinations thereof.

6. The aerogel composite material according to claim 5, characterized in that, The areal density of the glass fiber nonwoven fabric is 20 g / m³. 2 Up to 500g / m 2 The thickness ranges from 0.3mm to 4mm, and the air permeability is 200L / m². 2 / s to 3000L / m 2 Between / s.

7. The aerogel composite material according to claim 6, characterized in that, The areal density of the glass fiber nonwoven fabric is 50 g / m². 2 Up to 150g / m 2 The thickness is between 0.5mm and 1.5mm, and the air permeability is 500L / m². 2 / s to 2000L / m 2 Between / s.

8. The aerogel composite material according to claim 7, characterized in that, The areal density of the glass fiber nonwoven fabric is 90 g / m³. 2 Up to 135g / m 2 The thickness ranges from 0.8mm to 1.3mm, and the air permeability is 1100L / m². 2 / s to 1800L / m 2 Between / s.

9. The aerogel composite material according to claim 5, characterized in that, The polypropylene and glass fiber composite mat is made of a blend of polypropylene fibers and glass fibers, and the density of the polypropylene and glass fiber composite mat is 20 kg / m³. 3 Up to 200kg / m 3 The thickness ranges from 1mm to 20mm.

10. The aerogel composite material according to claim 9, characterized in that, The density of the polypropylene and glass fiber composite mat is 50 kg / m³. 3 Up to 150kg / m 3 The thickness ranges from 3mm to 10mm.

11. The aerogel composite material according to claim 1, characterized in that, The aerogel powder contains an additive for suppressing thermal radiation. The additive is selected from at least one of silicon carbide, boron carbide, titanium oxide, and boron nitride. The weight ratio of the additive to the aerogel powder is between 1 wt% and 15 wt%.

12. The aerogel composite material according to claim 11, characterized in that, The weight ratio of the additive to the aerogel powder ranges from 1 wt% to 15 wt%.

13. The aerogel composite material according to claim 1, characterized in that, The weight ratio of the aerogel powder to the aerogel composite material ranges from 1 wt% to 50 wt%.

14. A method for manufacturing an aerogel composite material, characterized in that, The method includes the following steps: Aerogel powder is applied to the surface of a porous material using an electrostatic device; An alternating electric field is applied such that at least a portion of the aerogel powder is impregnated within the porous material, wherein the voltage range of the alternating electric field is 0.1 kV to 50 kV, and the frequency range is 1 Hz to 800 Hz; the density of the aerogel powder is 0.01 g / cm³. 3 up to 0.5 g / cm 3 The aerogel powder has an average particle size of less than or equal to 500 μm.

15. The method according to claim 14, characterized in that, The electrostatic device includes at least one of an electrostatic spraying device, an electrostatic flocking device, and an electrostatic atomizing device.

16. The method according to claim 14, characterized in that, The alternating electric field is applied for a period of 30 seconds to 5 minutes.

17. The method according to claim 14, characterized in that, The porous fiber material and the aerogel powder are placed between the lower electrode and the upper electrode. The electrodes are electrically insulated from each other by a dielectric and connected to a power source so that the porous fiber material and the aerogel powder are subjected to the alternating electric field.

18. The method according to claim 14, characterized in that, The density range of the aerogel powder is 0.03 g / cm³. 3 Up to 0.1 g / cm 3 The average particle size of the aerogel powder is less than or equal to 50 μm.

19. The method according to claim 14, characterized in that, The porous fiber material is selected from glass fiber mat, glass fiber nonwoven fabric, glass fiber woven fabric, ceramic fiber mat, paper, polyurethane fiber mat, carbon fiber mat, polypropylene fiber mat, polypropylene and glass fiber composite mat, and combinations thereof.

20. The method according to claim 19, characterized in that, The areal density of the glass fiber nonwoven fabric is 20 g / m³. 2 Up to 500 g / m 2 The thickness ranges from 0.3mm to 4mm, and the air permeability is 200L / m². 2 / s to 3000L / m 2 Between / s.

21. The method according to claim 20, characterized in that, The areal density of the glass fiber nonwoven fabric is 50 g / m². 2 Up to 150 g / m 2 The thickness is between 0.5mm and 1.5mm, and the air permeability is 500L / m². 2 / s to 2000L / m 2 Between / s.

22. The method according to claim 21, characterized in that, The areal density of the glass fiber nonwoven fabric is 90 g / m². 2 Up to 135 g / m 2 The thickness ranges from 0.8mm to 1.3mm, and the air permeability is 1100L / m². 2 / s to 1800L / m 2 Between / s.

23. The method according to claim 19, characterized in that, The polypropylene and glass fiber composite mat is made of a blend of polypropylene fibers and glass fibers, and the density of the polypropylene and glass fiber composite mat is 20 kg / m³. 3 Up to 200 kg / m 3 The thickness ranges from 1mm to 20mm.

24. The method according to claim 23, characterized in that, The density of the polypropylene and glass fiber composite mat is 50 kg / m³. 3 Up to 150 kg / m 3 The thickness ranges from 3mm to 10mm.

25. The method according to claim 14, characterized in that, The aerogel powder contains additives for suppressing thermal radiation. The additives include at least one of silicon carbide, boron carbide, titanium oxide, and boron nitride. The weight ratio of the additives to the aerogel powder ranges from 1 wt% to 15 wt%.

26. The method according to claim 25, characterized in that, The weight ratio of the additive to the aerogel powder ranges from 5 wt% to 12 wt%.

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