Phenolic hybrid SiO2 mesoporous microsphere and application thereof

Abstract

The invention relates to the technical field of functional materials, in particular to phenolic aldehyde hybrid SiO2 mesoporous microspheres and application thereof. Mesopores with the pore diameter of 2-50 nm are formed in the surface and the interior of the phenolic aldehyde hybridized SiO2 mesoporous microsphere; the average diameter of the phenolic aldehyde hybrid SiO2 mesoporous microspheres is 10 to 100 microns; the phenolic hybrid SiO2 mesoporous microspheres can be applied to the fields of thermal protection, wave absorption, heat insulation and coatings. According to the phenolic hybrid SiO2 mesoporous microsphere disclosed by the invention, by virtue of a unique mesoporous structure and an organic-inorganic hybrid characteristic, excellent heat insulation performance and multifunctionality are realized, and meanwhile, the problems of insufficient protection performance, single function, poor processability, high cost and the like of an existing material are solved.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, and in particular to a phenolic hybrid SiO2 mesoporous microsphere and its applications. Background Technology

[0002] With the rapid development of aerospace technology, especially the increasing number of deep space exploration missions, the demand for high-performance thermal protection materials is becoming increasingly urgent. For example, in the Mars sample return mission, spacecraft face an extreme high-temperature ablation environment when entering the Martian atmosphere. Traditional thermal protection materials are prone to ablation and oxidation at high temperatures, leading to a decline in thermal protection performance and making it difficult to meet the requirements of modern aerospace missions for lightweight, efficient, and multifunctional thermal protection materials.

[0003] Furthermore, the demand for heat-insulating materials, radar-absorbing materials, and high infrared emissivity materials is constantly increasing in both military and civilian fields. For example, the nose cone of a high-speed missile needs to have excellent radar-absorbing and heat-insulating properties to ensure structural stability and stealth performance during high-speed flight; meanwhile, the application of high infrared emissivity films in multilayer heat-insulating materials can effectively improve the thermal protection performance of the materials.

[0004] In the prior art, there are already some materials used for thermal protection and insulation. For example, patent CN114507466A discloses a low-temperature self-drying, low-VOC camouflage-functional heat-insulating and cooling coating, its preparation method, and its application. Component A of the coating includes fillers such as aerogel, titanium dioxide, and hollow microspheres. The use of these fillers improves the coating's thermal insulation performance and camouflage function. Another example is patent CN119194359A, which discloses a method for preparing a low-cost, high-strength aerogel composite material resistant to 1100℃. The preparation method involves the process of preparing fillers, including the preparation, calcination, hydroxylation, and surface coating of nano-carbon. The use of these fillers gives the aerogel composite material excellent high-temperature resistance and mechanical properties.

[0005] Avcoat-5026 and SLA-561 are classic medium-density ablation heat protection materials developed by NASA during the Apollo lunar landing program and have been validated in actual engineering. US Patent 4031059 discloses the formulation and manufacturing process of SLA-561 ablation heat protection material. SLA-561 consists of: 25 wt% silicone resin, 3 wt% chopped silica fiber, 2 wt% chopped carbon fiber, 35 wt% hollow glass microspheres, 6 wt% hollow phenolic microspheres, and 29 wt% cork chips. The apparent density of SLA-561 lightweight ablation heat protection material is 0.225 g / cm³. 3Boeing disclosed the composition of BLA lightweight ablation heat protection material in US Patent 6,627,697, comprising 42 wt% silicone resin, 38 wt% hollow glass microspheres, 4 wt% resin curing agent and catalyst, and 16 wt% diluent. The apparent density of BLA lightweight ablation heat protection material is 0.32 g / cm³. 3 Boeing disclosed the formula and manufacturing process for the upgraded BLA in US Patent 10308789B2.

[0006] In China, the Institute of Aerospace Materials and Processes has developed a series of resin-based ablation thermal protection materials for lunar exploration, Mars exploration, and space station return projects (Feng Zhihai, et al. (2020). "Research progress on low-density ablation thermal protection materials for spacecraft thermal protection systems." Materials Engineering 48: 14~24.).

[0007] However, these materials often have the following problems: (1) Insufficient thermal protection performance: Traditional materials are prone to ablation in high-temperature environments, resulting in a decrease in thermal protection performance. (2) Single function: Most materials only have a single heat insulation or wave absorption function, which is difficult to meet the needs of multi-functional integration. (3) Poor processing performance: The preparation process of some high-performance materials is complex, making it difficult to achieve large-scale production and application. (4) High cost: High-performance materials often rely on rare materials or complex preparation processes, resulting in excessively high costs.

[0008] Therefore, developing a high-performance, multifunctional, and easily processed thermal protection material is of great practical significance for aerospace, military, and civilian applications. Summary of the Invention

[0009] This invention provides a phenolic hybrid SiO2 mesoporous microsphere and its application, which solves the problems of insufficient protective performance, single function, poor processing performance and high cost of existing materials used for thermal protection and insulation.

[0010] According to a first aspect of the present invention, the present invention provides a phenolic hybrid SiO2 mesoporous microsphere, wherein the surface and interior of the phenolic hybrid SiO2 mesoporous microsphere have mesopores with a pore size of 2~50 nm; and the average particle size of the phenolic hybrid SiO2 mesoporous microsphere is 10~100 μm.

[0011] The phenolic hybrid SiO2 mesoporous microspheres of this invention have mesopores with a pore size of 2-50 nm on both the surface and interior. This microstructure significantly reduces the thermal conductivity of the material. When gas molecules conduct heat in the mesopores, the path of freedom increases, and the thermal conductivity decreases. Simultaneously, the mesoporous structure increases the specific surface area of ​​the material, further hindering heat conduction within the solid framework. Through its unique mesoporous structure and organic-inorganic hybrid characteristics, the phenolic hybrid SiO2 mesoporous microspheres of this invention achieve excellent thermal insulation performance, multifunctionality, good processability, and thermal stability. These properties make them promising for applications in thermal protection, microwave absorption, thermal insulation, and coatings, effectively addressing the problems existing with current materials in these fields. Experiments have shown that the phenolic hybrid SiO2 mesoporous microspheres of this invention have higher compressive strength compared to hollow glass microspheres, are more robust during the preparation of ablation thermal protection materials, and are less prone to shell breakage.

[0012] Furthermore, the average particle size of the phenolic hybrid SiO2 mesoporous microspheres is 30~60 μm.

[0013] Furthermore, the particle size distribution of the phenolic hybrid SiO2 mesoporous microspheres has D10 = 1~30 μm, D50 = 20~80 μm, and D90 = 50~120 μm, and the particle size distribution width K = (D90-D10) / D50 satisfies: 1≤K≤6. By optimizing the particle size distribution of the phenolic hybrid SiO2 mesoporous microspheres, uniform dispersion and good processability of the microspheres in the composite material are ensured. This particle size distribution can effectively avoid particle aggregation, improve the overall performance of the material, and enhance the interfacial bonding strength of the microspheres in the composite material, thereby improving the mechanical and thermal insulation properties of the material. In addition, the uniform particle size distribution also helps to reduce the density of the material and improve its application effect in fields such as thermal insulation, microwave absorption, and coatings.

[0014] Preferably, the particle size distribution of the phenolic hybrid SiO2 mesoporous microspheres is D10=10~30μm, D50=40~60μm, D90=75~90μm, and the particle size distribution width K=(D90-D10) / D50 satisfies: 1≤K≤1.5.

[0015] Furthermore, the specific surface area of ​​the phenolic hybrid SiO2 mesoporous microspheres is 180~190 m². 2 The porosity is 70%~95%; the phenolic hybrid SiO2 mesoporous microspheres appear white or pale yellow. The high specific surface area means the microspheres have more active sites, significantly improving their adsorption and thermal insulation properties, resulting in superior performance in thermal insulation, adsorption, and thermal protection applications.

[0016] The phenolic hybrid SiO2 mesoporous microspheres are prepared from raw materials comprising the following components, by weight: 20-30 parts of hydrophilic fumed silica, 5-11 parts of water-soluble phenolic resin, and 200-500 parts of water.

[0017] The phenolic hybrid SiO2 mesoporous microspheres of this invention are prepared from hydrophilic fumed silica, water-soluble phenolic resin, and water. The raw materials are widely available. Hydrophilic fumed silica is an inorganic nanomaterial with high specific surface area and good dispersibility. It can form a stable network structure in composite materials, further enhancing the thermal insulation and mechanical properties of the material. Water-soluble phenolic resin has good thermal stability and mechanical properties, which can enhance the overall structural strength of the microspheres. By using specific raw material ratios, better synergistic effects are achieved between the raw materials, resulting in phenolic hybrid SiO2 mesoporous microspheres with specific structural characteristics. Both the surface and interior of these microspheres have mesopores with a pore size of 2-50 nm. This micro / nano structure can significantly reduce the thermal conductivity of the material. The presence of mesopores increases the free path of gas molecules conducting heat within the pores, thereby reducing the thermal conductivity of the gas. Furthermore, the mesoporous structure increases the specific surface area of ​​the material, further hindering heat conduction within the solid framework. The phenolic hybrid SiO2 mesoporous microspheres of the present invention achieve excellent thermal insulation performance and multifunctionality through their unique mesoporous structure and organic-inorganic hybrid characteristics, while solving the problems of insufficient protective performance, single function, poor processing performance and high cost of existing materials.

[0018] Preferably, the phenolic hybrid SiO2 mesoporous microspheres are prepared from raw materials comprising the following components, by weight: 20-30 parts of hydrophilic fumed silica, 5-6 parts of water-soluble phenolic resin, and 200-400 parts of water.

[0019] Furthermore, the specific surface area of ​​the hydrophilic fumed silica is 190~220 m². 2 / g, with an average particle size of 10~30nm. The high specific surface area and small particle size of hydrophilic fumed silica enable it to exert excellent reinforcing, heat insulation and dispersing properties in composite materials.

[0020] Furthermore, the mass concentration of the water-soluble phenolic resin is 40-60%, preferably 50%.

[0021] According to a second aspect of the present invention, the present invention also provides a method for preparing the above-mentioned phenolic hybrid SiO2 mesoporous microspheres, comprising the following steps: A slurry is prepared by mixing hydrophilic fumed silica, water-soluble phenolic resin, and water. The prepared slurry material is granulated using a centrifugal spray dryer.

[0022] The preparation method of this invention first mixes hydrophilic fumed silica, water-soluble phenolic resin, and water to form a slurry. The high specific surface area and small particle size of the hydrophilic fumed silica allow it to be uniformly dispersed in the slurry. The water-soluble phenolic resin, as the organic phase, forms an organic-inorganic hybrid system with the inorganic silica, providing a stable structural basis for the subsequent formation of microspheres. The prepared slurry is then granulated using a centrifugal spray dryer. Spray drying can achieve microsphere formation in a short time, and by adjusting spray parameters (such as flow rate, temperature, centrifugal speed, etc.), the particle size distribution of the microspheres can be precisely controlled to meet design requirements. The preparation method of this invention combines the high-efficiency forming capability of spray drying with the excellent dispersion characteristics of hydrophilic fumed silica, achieving rapid and uniform preparation of phenolic hybrid SiO2 mesoporous microspheres with good structural stability and controllability, making it suitable for large-scale industrial production.

[0023] Furthermore, the mixing conditions include: adding water-soluble phenolic resin and water to a paddle-type stirrer, stirring at 400-600 rpm for 20-40 minutes, then adding hydrophilic fumed silica to the mixing tank, and continuing to stir at 400-600 rpm for 3-8 minutes to obtain a paste-like material A, which can be applied to the subsequent granulation process; by optimizing the mixing conditions, a stable organic-inorganic hybrid system can be obtained, thereby providing a more stable structural basis for the subsequent formation of microspheres.

[0024] Furthermore, the granulation conditions include: a centrifugal pump speed of 5000~12000 rpm, a hot air inlet temperature of 300~400℃, an outlet temperature of 100~200℃, and a centrifuge evaporation water rate of 3~8 kg / h. Appropriate centrifugal pump speed and evaporation water rate can accelerate the atomization and drying speed of the slurry, thereby improving production efficiency and reducing production costs. The temperature range of the hot air ensures rapid solidification of the microspheres during the drying process while avoiding structural damage caused by excessively high temperatures. This optimized condition helps to form a stable microsphere structure. By optimizing the granulation conditions, a more uniform particle size distribution of the microspheres can be ensured, avoiding inconsistent particle sizes. This can significantly improve the quality and performance of phenolic hybrid SiO2 mesoporous microspheres, while reducing production costs and increasing production efficiency.

[0025] Preferably, the centrifugal pump speed is 10000-12000 rpm.

[0026] According to a third aspect of the present invention, the present invention also provides the application of the above-described phenolic hybrid SiO2 mesoporous microspheres or the phenolic hybrid SiO2 mesoporous microspheres prepared by the above-described preparation method in the fields of thermal protection, wave absorption, heat insulation, and coatings.

[0027] According to a fourth aspect of the present invention, the present invention also provides a honeycomb ablation thermal protection component for use in Mars sample return projects, the raw material of which includes resin filler, said resin filler being the above-mentioned phenolic hybrid SiO2 mesoporous microspheres.

[0028] The honeycomb ablation thermal protection components used in Mars sample return missions require multiple performance characteristics, including high-temperature ablation resistance, low density, excellent thermal insulation, resistance to aerodynamic shearing, and post-ablation surface stability. This invention utilizes phenolic hybrid SiO2 mesoporous microspheres with a specific structure as a resin filler in the honeycomb ablation thermal protection component, effectively improving its thermal protection and insulation performance to ensure the safety and reliability of spacecraft in complex thermal environments.

[0029] Preferably, the honeycomb ablation heat protection component is prepared from raw materials comprising the following components, by weight: Silicone resin A 35-40 parts 35-40 parts of phenolic hybrid SiO2 mesoporous microspheres Silicone resin B 3-5 parts 10-20 parts silicone oil thinner 1-3 parts of nano-SiO2 fiber fluff 1-3 parts of nano mullite fiber fluff 0.5 to 2 parts of short-cut carbon nanofibers.

[0030] In the formulation of the honeycomb ablation thermal protection component, the raw materials play a synergistic role in enhancing the overall performance of the material. Silicone resin A, as the main matrix resin, provides good thermal stability and mechanical strength, ensuring the structural integrity of the material under high-temperature conditions. Phenolic hybrid SiO2 mesoporous microspheres, with their unique mesoporous structure and organic-inorganic hybrid characteristics, significantly reduce the thermal conductivity and enhance thermal insulation performance. At the same time, their spherical structure and low density characteristics help reduce the weight of the component. Silicone resin B, as an auxiliary resin, further enhances the thermal stability and mechanical properties of the material and optimizes the molding process. Silicone oil diluent improves the processing performance of the material, enabling the components to be mixed uniformly and improving the workability and moldability of the material. Nano-SiO2 fiber fluff and nano-mullite fiber fluff form a multi-layer fiber structure, enhancing thermal insulation performance and further blocking heat transfer through the thermal insulation effect of the fibers. Short-cut carbon nanofibers improve the mechanical properties and aerodynamic shear resistance of the material, ensuring the structural stability of the material during ablation. The synergistic effect of these materials makes the honeycomb ablation thermal protection component perform well in terms of heat insulation, ablation resistance, low density and post-ablation surface stability, meeting the needs of spacecraft in complex thermal environments.

[0031] Preferably, the silicone resin A is methylphenyl vinyl silicone rubber raw rubber with a viscosity of 15000~25000 mPa·s; the silicone resin B is a mixture of vinylsiloxane platinum complex and hydrogen-containing silicone oil; and the silicone oil diluent is hydroxyl silicone oil diluent or dimethyl silicone oil diluent.

[0032] Preferably, in the silicone resin B, the mass ratio of the vinylsiloxane platinum complex to the hydrogen-containing silicone oil is 1:(80-120).

[0033] Preferably, the nano-SiO2 fiber wool is prepared according to the method disclosed in the invention patent with publication number CN110424067A.

[0034] Preferably, the nano-mullite fiber wool is prepared according to the method disclosed in the invention patent with publication number CN110846741A.

[0035] Preferably, the short-cut carbon nanofibers are prepared according to the method disclosed in the invention patent with publication number CN115110206A.

[0036] The honeycomb-shaped ablation heat protection component is prepared using conventional techniques in the art. In some specific embodiments, the preparation method of the honeycomb-shaped ablation heat protection component includes the following steps: using fiberglass honeycomb grids as the support, silicone resin A and silicone resin B as the matrix resins, and filling them with phenolic hybrid SiO2 mesoporous microspheres, Dow Corning DC-200 hydroxyl silicone oil diluent, nano-SiO2 fiber fibers, nano-mullite fiber fibers, and chopped carbon nanofibers.

[0037] According to a fifth aspect of the present invention, the present invention also provides a carbon-doped SiO2 material prepared from the above-mentioned phenolic hybrid SiO2 mesoporous microspheres.

[0038] The carbon-doped SiO2 material of the present invention is prepared by phenolic hybrid SiO2 mesoporous microspheres with a specific structure. It has excellent optical, thermal, electrical and mechanical properties and can show broad application prospects in many fields such as optoelectronic devices, thermal protection, sensors, rubber composites, environmental applications, coating protection and energy storage.

[0039] Furthermore, the carbon-doped SiO2 material is a spherical carbon-doped SiO2 material; the surface and interior of the spherical carbon-doped SiO2 material have mesopores with a pore size of 2-50 nm; the average particle size of the spherical carbon-doped SiO2 material is 10-100 μm (preferably 30-60 μm); the spherical carbon-doped SiO2 material appears black and has a full-spectrum emissivity of ≥0.80 for visible and infrared light.

[0040] The mesoporous structure (pore size 2-50 nm) and spherical morphology of spherical carbon-doped SiO2 materials effectively hinder heat conduction. This microstructural design significantly reduces the material's thermal conductivity, giving it excellent thermal insulation properties. The full-spectral emissivity of spherical carbon-doped SiO2 materials is ≥0.80, meaning it has extremely high absorption and emission capabilities for visible and infrared light. This characteristic gives it significant advantages in the fields of thermal protection and radiative cooling.

[0041] More preferably, the full infrared spectral hemispherical emissivity of the sheet-like carbon-doped SiO2 material is ≥0.8.

[0042] According to a sixth aspect of the present invention, the present invention also provides a method for preparing the above-mentioned carbon-doped SiO2 material, comprising the following steps: carbonizing the above-mentioned phenolic hybrid SiO2 mesoporous microspheres.

[0043] Carbonization is a relatively simple process that can directly convert phenolic hybrid SiO2 mesoporous microspheres into carbon-doped SiO2 materials. Phenolic resin, as a precursor, exhibits high thermal stability and high char formation rate, and retains its spherical morphology and mesoporous structure after carbonization. The method of preparing carbon-doped SiO2 materials through carbonization is not only simple and low-cost, but also maintains the excellent structure and properties of the materials, while possessing high controllability and multifunctionality to meet the needs of various application scenarios.

[0044] Furthermore, the carbonization treatment is carried out under inert gas conditions, with a carbonization temperature of 900-1500℃ and a carbonization time of 0.5-2 hours. By adjusting parameters such as carbonization temperature, time, and atmosphere, the pore structure, particle size, and surface properties of the carbon-doped SiO2 material can be precisely controlled. This controllability allows the material to meet the needs of different application scenarios. It should be noted that the inert gas is a conventionally used inert gas in the art, such as helium, neon, argon, krypton, xenon, and radon.

[0045] According to a seventh aspect of the present invention, the present invention also provides a heat-absorbing cap for the nose cone of a high-speed missile, comprising a mesoporous Si-OC ceramic matrix heat-insulating core material; wherein the mesoporous Si-OC ceramic matrix heat-insulating core material uses the aforementioned carbon-doped SiO2 material as the heat-insulating material.

[0046] The experiment of this invention found that using the carbon-doped SiO2 material with the specific structure of this invention as one of the raw materials for carbon matrix heat insulation core material in the heat-absorbing cap inside the nose cone of a high-speed missile, and preparing the heat-absorbing cap according to the process disclosed in Chinese Invention Patent Publication No. CN118565272A, can improve the temperature resistance and high-temperature absorption performance of the heat-absorbing cap inside the nose cone of a high-speed missile.

[0047] In some specific embodiments, the raw materials of the carbon-based heat-insulating core material include the aforementioned carbon-doped SiO2 material, short-cut carbon fibers with the surface sizing removed, and ceramic microsphere infrared shading agent. Preferably, the mass ratio of the carbon-doped SiO2 material, the short-cut carbon fibers with the surface sizing removed, and the ceramic microsphere infrared shading agent is (90-95):(3-7):(1-5). The high-speed missile nose cone heat-absorbing cap, through optimized material combination and structural design, achieves a comprehensive improvement in heat insulation, wave absorption, high-temperature stability, and mechanical properties, while simultaneously reducing manufacturing costs, demonstrating significant technical advantages.

[0048] According to an eighth aspect of the present invention, the present invention also provides a surface-toughened high infrared emissivity flexible thermal insulation material, comprising a flexible thermal insulation felt and a thermal insulation film disposed on the inner side of the high-temperature surface of the flexible thermal insulation felt; the thermal insulation film uses the aforementioned carbon-doped SiO2 material as a powder raw material.

[0049] The experiment of this invention found that by using the carbon-doped SiO2 material of this invention as a powder material to prepare a heat insulation film, and then applying it to a flexible heat insulation felt to prepare a flexible heat insulation material, the flexible heat insulation material has a hemispherical full spectrum emissivity (infrared) ≥0.80 at 1000℃, which can effectively radiate heat, thereby improving the thermal management capability of the heat insulation material.

[0050] In some specific embodiments, the heat-insulating film is obtained by mixing carbon-doped SiO2 material, a fiberizable binder, and optional additives, ball milling to obtain flocculent material, and then rolling the flocculent material into a film. The high-emissivity carbon-doped SiO2 film is prepared according to the process disclosed in Chinese Invention Patent Publication No. CN119241969A. Preferably, the mass percentage of carbon-doped SiO2 material is 85%-95%, and the mass percentage of the fiberizable binder is 1%-10%.

[0051] The fiberizable adhesive is selected from one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, and hexafluoropropylene-tetrafluoroethylene copolymer. The additives include one or more of infrared shading agents, reinforcing chopped inorganic fibers or whiskers; the infrared shading agent accounts for 1%-5% by mass, and the reinforcing chopped inorganic fibers or whiskers account for 1%-5% by mass.

[0052] In other specific embodiments, the heat-insulating film is made by rolling a mixture of raw materials; by weight, the mixture includes: 60-100 parts of powder material, 0.1-30 parts of polymer binder, 0-20 parts of high-temperature bonding agent, and 0-10 parts of light-blocking agent.

[0053] The flexible thermal insulation felt is a surface-strengthened flexible multilayer ceramic fiber thermal insulation felt disclosed in Chinese invention patent publication number CN118906580A. In some specific embodiments, the flexible thermal insulation felt includes a high-temperature alloy foil, a high-temperature alloy woven mesh, and a ceramic fiber layer stacked sequentially from a high-temperature side to a low-temperature side. The ceramic fiber layer includes a high-temperature side ceramic fiber cloth, several layers of ceramic fiber filling layers, and a low-temperature side ceramic fiber cloth stacked sequentially, with a reflective screen between adjacent ceramic fiber filling layers. The ceramic fiber layer is fixed by ceramic fiber sewing thread, and the high-temperature alloy woven mesh and the ceramic fiber layer are fixed together by high-temperature alloy sewing thread. A thermal insulation film is disposed inside the high-temperature side ceramic fiber cloth.

[0054] According to a ninth aspect of the present invention, the present invention also provides a coating that uses the above-mentioned phenolic hybrid SiO2 mesoporous microspheres or carbon-doped SiO2 materials as functional fillers.

[0055] Phenolic hybrid SiO2 mesoporous microspheres or carbon-doped SiO2 materials possess high infrared emissivity, enabling effective heat radiation and thus enhancing the thermal management capabilities of coatings. The porous structure and high specific surface area of ​​these materials result in low thermal conductivity, significantly reducing heat transfer. This insulating property allows the coatings to perform exceptionally well in high-temperature environments. Furthermore, the addition of phenolic hybrid SiO2 mesoporous microspheres or carbon-doped SiO2 materials can significantly improve the mechanical properties of coatings, including abrasion resistance, impact resistance, and flexibility.

[0056] Preferably, the coating can be a stealth coating, or a coating with specific cooling, thermal insulation, and heat preservation effects. The coating can be a civilian coating such as an interior wall coating, exterior wall coating, or floor coating. Experiments have shown that applying the phenolic hybrid SiO2 mesoporous microspheres of this invention as a functional filler to a radiation-cooling coating can achieve excellent radiation and cooling effects. Experiments have also shown that applying the carbon-doped SiO2 material of this invention as a functional filler to a stealth coating can absorb radar waves and improve the fluidity of the coating.

[0057] Preferably, the coating comprises the following raw materials by mass fraction: 40-50 parts acrylic emulsion, 20-30 parts water, 50-70 parts phenolic hybrid SiO2 mesoporous microspheres or carbon-doped SiO2 material, 1-3 parts nano carbon fiber velvet, 0.4-0.6 parts leveling agent, and 0.4-0.6 parts defoamer.

[0058] It should be noted that the acrylic emulsions, leveling agents, and defoamers used in the coatings can be common types of raw materials used in the field. Acrylic emulsions can be pure acrylic emulsions, silicone-acrylic emulsions, styrene-acrylic emulsions, and vinyl-acrylic emulsions, etc. Leveling agents can be acrylate-based, silicone-based, fluorocarbon-based, nonionic associative polyurethane-based, and polyether-siloxane-based leveling agents. Defoamers can be mineral oil-based, silicone-based, polyether-based, and higher alcohol-based defoamers. Nanofiber fiber flocking can be nanomullite fiber flocking or nanofiber fiber flocking.

[0059] In this coating formulation, the various raw materials work synergistically to enhance the overall performance of the coating. Acrylic emulsion, as the primary film-forming base, provides excellent adhesion, weather resistance, and mechanical properties, ensuring the coating's stability and durability on various substrates. Water, as a solvent, adjusts the coating's viscosity and flowability, facilitating application. Carbon-doped SiO2 material, with its high infrared emissivity, microwave absorption properties, and porous structure, significantly improves the coating's thermal insulation, stealth performance, and thermal management capabilities, while simultaneously reducing thermal conductivity. Nanofiber velvet further enhances the coating's mechanical properties, such as abrasion resistance, impact resistance, and flexibility, while also exhibiting some absorption of electromagnetic waves, further contributing to improved stealth performance. Leveling agents improve the coating's leveling properties, ensuring a smooth and even surface and enhancing the coating's appearance. Defoamers eliminate air bubbles generated during mixing and application, preventing pinholes or bubble defects and ensuring coating uniformity and integrity. The synergistic effect of these raw materials results in excellent performance in thermal insulation, stealth, mechanical properties, application performance, and functional characteristics, meeting the needs of various application scenarios.

[0060] Preferably, the carbon-doped SiO2 material is obtained by carbonizing phenolic hybrid SiO2 mesoporous microspheres at 1200℃-1400℃. Within this temperature range, the carbon element in the carbon-doped SiO2 material transforms from the glass phase to the graphite phase, improving the conductivity of the microspheres and ultimately achieving better impedance matching, thus resulting in better microwave absorption performance and giving the coating stealth capabilities.

[0061] According to a tenth aspect of the present invention, the present invention also provides a plastic injection molded part for household appliances, which uses the above-mentioned carbon-doped SiO2 material as a filler.

[0062] Plastic injection molded parts for home appliances using carbon-doped SiO2 materials as fillers exhibit significant advantages in mechanical properties, thermal stability, heat insulation performance, and environmental friendliness, meeting the modern home appliance industry's demand for high-performance, multi-functional materials.

[0063] The beneficial effects of this invention are: The phenolic hybrid SiO2 mesoporous microspheres provided by this invention achieve excellent thermal insulation performance and multifunctionality through their unique mesoporous structure and organic-inorganic hybrid characteristics. At the same time, they solve the problems of insufficient protective performance, single function, poor processing performance and high cost of existing materials, and can be better applied in the fields of thermal protection, wave absorption, heat insulation and coatings. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0065] Figure 1 This is an appearance diagram of the phenolic hybrid SiO2 mesoporous microspheres provided in Example 1 of the present invention.

[0066] Figure 2 This is one of the SEM images of the phenolic hybrid SiO2 mesoporous microspheres provided in Example 1 of the present invention.

[0067] Figure 3 This is the second SEM image of the phenolic hybrid SiO2 mesoporous microspheres provided in Example 1 of this invention.

[0068] Figure 4 This is a particle size distribution diagram of the phenolic hybrid SiO2 mesoporous microspheres provided in Example 1 of the present invention.

[0069] Figure 5 These are photographs of the ablation heat protection component after wind tunnel testing according to Embodiment 5 of the present invention. Figure a is an optical photograph of the ablation surface, and Figure b is a cross-sectional view in the thickness direction.

[0070] Figure 6 This is a SEM image of the ablation heat protection component provided in Embodiment 5 of the present invention.

[0071] Figure 7 This is an appearance diagram of the carbon-doped SiO2 material provided in Embodiment 6 of the present invention.

[0072] Figure 8 This is a view of the porous carbon-doped SiO2 glass sheet provided in Embodiment 9 of the present invention.

[0073] Figure 9 This is a SEM image of the porous carbon-doped SiO2 glass sheet provided in Embodiment 9 of the present invention.

[0074] Figure 10 The images show the XRD patterns of the carbon-doped SiO2 mesoporous microspheres from Example 1 and the porous carbon-doped SiO2 glass sheet from Example 9 of this invention.

[0075] Figure 11 These are microwave absorption effect diagrams of Si-OC mesoporous microsphere filler provided in Embodiment 13 of the present invention under different addition amounts in stealth coatings; Figure a shows the addition amount of 10 parts, Figure b shows the addition amount of 20 parts, Figure c shows the addition amount of 30 parts, Figure d shows the addition amount of 40 parts, and Figure e shows the addition amount of 50 parts.

[0076] Figure 12 These are microwave absorption effect diagrams of Si-OC mesoporous microsphere filler provided in Example 13 of the present invention under different addition amounts in stealth coatings; Figure a shows the addition amount of 60 parts, and Figure b shows the addition amount of 70 parts.

[0077] Figure 13 These are microwave absorption effect diagrams of Si-OC mesoporous microsphere filler provided in Comparative Example 1 of the present invention under different addition amounts in stealth coatings; Figure a shows the addition amount of 15 parts, Figure b shows the addition amount of 25 parts, and Figure c shows the addition amount of 35 parts.

[0078] Figure 14 These are microwave absorption effect diagrams of Si-OC mesoporous microsphere filler provided in Comparative Example 2 of the present invention under different addition amounts in stealth coatings; Figure a shows the addition amount of 10 parts, and Figure b shows the addition amount of 20 parts. Detailed Implementation

[0079] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0080] Example 1 This embodiment provides a phenolic hybrid SiO2 mesoporous microsphere, the preparation method of which includes the following steps: Step 1: Add 270g of hydrophilic fumed silica powder (Shandong Dongyue Chemical A-200 type, specific surface area 190~220m²) 2 A slurry was prepared by mixing 54g of water-soluble phenolic resin (CR-G-402U, Jinan Shengquan Group Co., Ltd.) with an average particle size of 10~30nm (SiO2 particles), 54g of water-soluble phenolic resin with a mass concentration of 50% (Jinan Shengquan Group Co., Ltd.), and 3000g of water.

[0081] Step 2: The prepared slurry material is granulated using a centrifugal spray dryer. The granulation conditions include: centrifugal pump speed of 10,000 rpm, hot air inlet temperature of 350°C, outlet temperature of 150°C, and centrifugal evaporation water rate of 5 kg / h.

[0082] like Figure 1 As shown, the obtained phenolic hybrid SiO2 mesoporous microspheres appear white. Figure 2 As shown, the obtained phenolic hybrid SiO2 mesoporous microspheres are spherical. Figure 3 As shown, a large number of mesoporous structures were observed on the surface of phenolic hybrid SiO2 mesoporous microspheres magnified 20,000 times, with pore sizes ranging from 20 to 50 nm. The specific surface area of ​​the mesoporous microspheres obtained after the granulation process decreased only slightly, from 200 nm. 2 / g reduced to 180m 2 / g. The particle size distribution of the prepared phenolic hybrid SiO2 mesoporous microspheres is shown in the figure. Figure 4 The particle size distribution is as follows: D10 = 11.1 μm, D50 = 44.7 μm, D90 = 75.7 μm, particle size distribution width K = (D90 - D10) / D50 = 1.445, and powder sphericity > 90%.

[0083] Example 2 This embodiment provides a phenolic hybrid SiO2 mesoporous microsphere. The preparation method of this phenolic hybrid SiO2 mesoporous microsphere differs from that of Example 1 in that: in step 1, the amount of 50wt% water-soluble phenolic resin is increased from 54g to 108g. Due to the increased phenolic resin content, the viscosity of the slurry increases. The final phenolic hybrid SiO2 mesoporous microsphere has the following particle size distribution: D10=20μm, D50=80μm, D90=120μm, particle size distribution width K=(D90-D10) / D50=1.25, powder sphericity >80%, and some microspheres couple into gourd-shaped particles.

[0084] Example 3 This embodiment provides a phenolic hybrid SiO2 mesoporous microsphere. The preparation method of this phenolic hybrid SiO2 mesoporous microsphere differs from that of Example 1 in that the amount of water used in step 1 is increased to 5000g. Due to the increased water content, the viscosity of the slurry decreases. The final phenolic hybrid SiO2 mesoporous microsphere has the following particle size distribution: D10=5μm, D50=15μm, D90=50μm, and pore distribution coefficient K=(D90-D10) / D50=3.0. Without adjusting the amount of water evaporated in the centrifuge, the final phenolic hybrid SiO2 mesoporous microsphere has a large number of pits and a sphericity rate of about 60%.

[0085] Example 4 This embodiment provides a phenolic hybrid SiO2 mesoporous microsphere. The preparation method of this phenolic hybrid SiO2 mesoporous microsphere differs from that of Example 1 in that: in step 2, the centrifugal pump speed is adjusted to 5000 rpm, and the particle size distribution of the finally obtained phenolic hybrid SiO2 mesoporous microsphere is D10=30μm, D50=60μm, D90=90μm, the particle size distribution coefficient K=(D90-D10) / D50=1.0, and the sphericity of the powder is >90%.

[0086] Example 5 This embodiment provides a honeycomb-shaped ablation heat protection component for use in Mars sample return projects. The raw materials of the honeycomb-shaped ablation heat protection component, by weight, include: Silicone A: Dow Corning Sylgard® 184 38 parts Silicone Resin B: A composite of platinum catalyst and Dow Corning Sylgard® 184 silicone resin (the weight ratio of platinum catalyst to Dow Corning Sylgard® 184 silicone resin is 1:100) 4 parts 16 parts of Dow Corning DC-200 hydroxy silicone oil thinner 38 portions of phenolic hybrid SiO2 mesoporous microspheres from Example 1 Nano-SiO2 fiber fluff (prepared according to Example 1 of Chinese Invention Patent CN110424067A) 2 parts Nano-mullite fiber flocking (prepared according to Example 1 of Chinese Invention Patent CN110846741A) 2 parts One part of short-cut carbon nanofibers (prepared according to Example 1 of Chinese Invention Patent CN115110206A).

[0087] The method for preparing honeycomb-shaped ablation heat protection components is as follows: using fiberglass honeycomb grids as the support, silicone resin A and silicone resin B as the matrix resins, and filling them with phenolic hybrid SiO2 mesoporous microspheres, Dow Corning DC-200 hydroxyl silicone oil diluent, nano SiO2 fiber fibers, nano mullite fiber fibers and short-cut carbon nanofibers.

[0088] The apparent density of the obtained honeycomb-shaped ablation heat protection component is 0.25 g / cm³. 3 The wall is 30mm thick and 150mm in diameter; a wind tunnel ablation test was conducted under simulated heat flow conditions for entering the Martian atmosphere: cold wall heat flow 1200W / cm². 2 Stagnation pressure 0.45 atm, total enthalpy 55 kJ / cm² 2 Heating time: 30 seconds. Figure 5These are photographs of ablation-resistant thermal protection components after wind tunnel testing. It can be seen that the surface carbon layer remains intact after ablation, with no localized flaking. The cross-section shows a distinct high-emissivity coke layer, a transitional carbonized layer, and the original, unablated layer. (For example...) Figure 6 As shown, the interface bonding of the ablation heat protection component, consisting of silicone rubber polymer matrix, phenolic hybrid SiO2 mesoporous microspheres, and nanofiber fibers, is good after wind tunnel testing.

[0089] The measured front temperature was 2250℃, the highest back temperature was 180℃, the linear ablation rate was 0.005mm / s, and the mass ablation rate was 1.25×10⁻⁶. -3 g / s.

[0090] Example 6 This embodiment provides a carbon-doped SiO2 material, which is prepared from the phenolic hybrid SiO2 mesoporous microspheres of Example 1. The preparation method is as follows: the phenolic hybrid SiO2 mesoporous microspheres of Example 1 are placed in an argon atmosphere sintering furnace, heated to 900℃ at 3℃ / min, and held for 1h to obtain carbon-doped SiO2 mesoporous microspheres.

[0091] The appearance of carbon-doped SiO2 mesoporous microspheres is as follows: Figure 7 As shown, the black, carbon-doped SiO2 mesoporous microspheres are composed of three elements: Si, O, and C, with an average diameter of 45 μm. The surface and interior of the microspheres are filled with mesopores with a diameter of 10~30 nm, and their full-spectrum emissivity to visible and infrared light is 0.83.

[0092] Example 7 This embodiment provides a high-speed missile nose cone heat-absorbing cap. The carbon-doped SiO2 mesoporous microspheres prepared in Example 6 are used to replace the HMQ-C10 nano carbon black produced by Jiangxi Black Cat Carbon Black Co., Ltd. as the main raw material. The high-speed missile nose cone heat-absorbing cap is prepared according to the method of Example 1 published in the patent document with application number CN202410776310.6.

[0093] Compared to HMQ-C10 nano-carbon black, the heat-absorbing cap inside the nose cone of a high-speed missile prepared using carbon-doped SiO2 mesoporous microspheres in this embodiment exhibits more stable temperature resistance and high-temperature absorption performance.

[0094] Example 8 This embodiment provides a surface-toughened high infrared emissivity flexible thermal insulation material. Using carbon-doped SiO2 mesoporous microspheres prepared in Example 6 as the main raw material, a high infrared emissivity thermal insulation film is prepared according to the method disclosed in patent applications CN202410980760.7 or CN202411000641.7. This thermal insulation film is then laid on the high-temperature surface (below the quartz cloth on the front) of a surface-toughened multilayer flexible thermal insulation felt (prepared according to the method disclosed in patent application CN202410894669.3), and quilted to obtain the surface-toughened high infrared emissivity flexible thermal insulation material.

[0095] The obtained flexible thermal insulation material has a hemispherical full-spectrum emissivity (infrared) ≥0.80 at 1000℃.

[0096] Example 9 This embodiment provides a carbon-doped SiO2 material, which is prepared from the phenolic hybrid SiO2 mesoporous microspheres of Example 1. The preparation method is as follows: the phenolic hybrid SiO2 mesoporous microspheres of Example 1 are pressed into a blank on a tablet press, and then placed in an argon atmosphere sintering furnace, heated to 900°C at 3°C / min, and held for 1 hour to obtain a porous carbon-doped SiO2 glass sheet with a thickness of 2 mm.

[0097] The appearance of porous carbon-doped SiO2 glass slides is as follows: Figure 8 As shown, it is black. Figure 9 This is a SEM image of a porous carbon-doped SiO2 glass slide. It can be seen that during the pressing process, the micron-sized spheres were crushed, and the micron-sized spherical microstructure is no longer present. (Example:) Figure 10 As shown, compared with the carbon-doped SiO2 mesoporous microspheres of Example 1, the characteristic peak of C disappears in the XRD pattern of the porous carbon-doped SiO2 glass slide of this example, indicating that silicon dioxide transforms from a crystalline state to a glassy state. The full infrared hemispherical emissivity of the porous carbon-doped SiO2 glass slide of this example at 300℃ is 0.82.

[0098] Example 10 This embodiment provides an application of the porous carbon-doped SiO2 glass sheet of Example 9. This porous carbon-doped SiO2 glass sheet has an emissivity ≥0.8 in the entire infrared band and conforms to the GB / T 42800-2023 standard for high-purity opaque quartz glass materials. It has wide applications in thermal management during semiconductor and photovoltaic silicon wafer manufacturing processes and can replace FSTQZ from Jingzhou Feilihua Co., Ltd. ® Type B or Heraeus HBQ ® Black quartz glass.

[0099] Example 11 This embodiment provides a radiation cooling coating, comprising, by weight, 45 parts acrylic emulsion, 25 parts water, 50 parts Si-OC mesoporous microsphere filler, 2 parts nano-mullite fiber flocking, 0.5 parts leveling agent, and 0.5 parts defoamer. The Si-OC mesoporous microsphere filler in this embodiment is the phenolic hybrid SiO2 mesoporous microsphere prepared in Example 1. The nano-mullite fiber flocking is prepared according to Example 1 of Chinese Invention Patent CN110846741A. The acrylic emulsion is Dow Chemical PRIMAL NW-5118 acrylic emulsion. The leveling agent is Tigo Glide 450. The defoamer is Tigo Airex 920.

[0100] The coating of this embodiment can be used as a radiation cooling coating because the Si-OC mesoporous microsphere filler therein has an emissivity of over 0.80 for infrared light in the 8~13μm range. After spraying this coating, a 1mm thick paint film is obtained, and the apparent thermal conductivity of the paint film is 0.030W / (mK), which has thermal insulation function.

[0101] Example 12 This embodiment provides a radiation cooling coating, comprising, by weight, 45 parts acrylic emulsion, 25 parts water, 50 parts Si-OC mesoporous microsphere filler, 2 parts nano-mullite fiber flocking, 0.5 parts leveling agent, and 0.5 parts defoamer. The Si-OC mesoporous microsphere filler in this embodiment is the phenolic hybrid SiO2 mesoporous microsphere prepared in Example 4. The nano-mullite fiber flocking is prepared according to Example 1 of Chinese Invention Patent CN110846741A. The acrylic emulsion is Dow Chemical PRIMAL NW-5118 acrylic emulsion. The leveling agent is Tigo Glide 450. The defoamer is Tigo Airex 920.

[0102] The coating of this embodiment can be used as a radiation cooling coating because the Si-OC mesoporous microsphere filler therein has an emissivity of over 0.80 for infrared light in the 8~13μm range. After spraying the coating, a 1mm thick paint film is obtained, which has an apparent thermal conductivity of 0.035W / (mK) and thus has thermal insulation properties.

[0103] Example 13 This embodiment provides a stealth coating, comprising, by weight, 45 parts acrylic emulsion, 25 parts water, several parts Si-OC mesoporous microsphere filler, 2 parts nano-carbon fiber fleece, 0.5 parts leveling agent, and 0.5 parts defoamer. The nano-carbon fiber fleece was prepared according to Example 1 of Chinese Invention Patent CN115110206A. The acrylic emulsion is Dow Chemical PRIMAL NW-5118 acrylic emulsion. The leveling agent is Tigo Glide 450. The defoamer is Tigo Airex 920.

[0104] The Si-OC mesoporous microsphere filler of this invention is obtained by carbonizing the phenolic hybrid SiO2 mesoporous microspheres prepared in Example 1 in a carbonization furnace at 1300℃. Its microwave absorption effect is shown in [the figure]. Figure 11 and Figure 12 Overall, it possesses wave-absorbing properties. For example... Figure 11 As shown, when the amount of Si-OC mesoporous microsphere filler added is ≤50 parts, it exhibits a certain absorption effect on electromagnetic waves of 2~18GHz, but it is not very significant. Figure 12 As shown, when the amount of Si-OC mesoporous microsphere filler increased to 60 or 70 parts, it exhibited a significant absorption effect on electromagnetic waves from 2 to 18 GHz. When the amount of Si-OC mesoporous microsphere filler was 60 parts, absorption extremes were observed at 4.47 mm and 7.68 GHz, with RL... min =-53.92dB; Effective absorption bandwidth EAB=6 GHz (12 GHz-18 GHz). When the Si-OC mesoporous microsphere filler content is 70 parts, there are absorption extremes at 1.96mm and 14.84GHz, RL min = -31.80dB; Effective absorption bandwidth EAB = 6.2 GHz (8.9 GHz - 15.1 GHz). As the carbonization temperature increases, the carbon element in the Si-OC mesoporous microspheres transforms from the glass phase to the graphite phase, which improves the conductivity of the microspheres and ultimately achieves better impedance matching, thus achieving better absorption performance.

[0105] Comparative Example 1 This embodiment provides a stealth coating, comprising, by weight, 45 parts acrylic emulsion, 25 parts water, 50 parts Si-OC mesoporous microsphere filler, 2 parts nano-carbon fiber flocking, 0.5 parts leveling agent, and 0.5 parts defoamer. The Si-OC mesoporous microsphere filler in this comparative example is obtained by carbonizing the phenolic hybrid SiO2 mesoporous microspheres prepared in Example 1 at 900°C.

[0106] The microwave absorption effect of the Si-OC mesoporous microsphere filler in this comparative example is shown in [reference needed]. Figure 13 Overall, the microwave absorption performance is poor. When the amount of Si-OC mesoporous microsphere filler added increased from 15 parts to 35 parts, there was no significant absorption effect on electromagnetic waves from 2 to 18 GHz. This is because the carbonization temperature is low, and the carbon elements in the Si-OC mesoporous microspheres exist in a glassy state, resulting in poor conductivity of the coating and an inability to effectively convert electromagnetic energy into heat energy, thus leading to poor microwave absorption performance.

[0107] Comparative Example 2 This comparative example provides a stealth coating, comprising, by weight, 45 parts acrylic emulsion, 25 parts water, 50 parts Si-OC mesoporous microsphere filler, 2 parts nano-carbon fiber flocking, 0.5 parts leveling agent, and 0.5 parts defoamer. The Si-OC mesoporous microsphere filler in this comparative example is prepared by carbonizing the phenolic hybrid SiO2 mesoporous microspheres prepared in Example 1 at 1100°C.

[0108] The microwave absorption effect of the Si-OC mesoporous microsphere filler in this comparative example is shown in [reference needed]. Figure 14 Overall, the microwave absorption performance is poor. When the amount of Si-OC mesoporous microsphere filler added increased from 10 parts to 20 parts, there was no significant absorption effect on electromagnetic waves from 2 to 18 GHz. This is because the carbonization temperature is low, and the carbon elements in the Si-OC mesoporous microspheres exist in a glassy state, resulting in poor conductivity of the coating and an inability to effectively convert electromagnetic energy into heat energy, thus leading to poor microwave absorption performance.

[0109] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phenolic hybrid SiO2 mesoporous microsphere, characterized in that, The phenolic hybrid SiO2 mesoporous microspheres have mesopores with a pore size of 2~50nm on both the surface and inside; the average particle size of the phenolic hybrid SiO2 mesoporous microspheres is 10~100μm.

2. The phenolic hybrid SiO2 mesoporous microspheres according to claim 1, characterized in that, The particle size distribution of the phenolic hybrid SiO2 mesoporous microspheres is as follows: D10 = 1~30μm, D50 = 10~80μm, D90 = 50~120μm, and the particle size distribution width K = (D90-D10) / D50 satisfies: 1≤K≤6. Preferably, the particle size distribution of the phenolic hybrid SiO2 mesoporous microspheres is D10=10~30μm, D50=40~60μm, D90=75~90μm, and the particle size distribution width K=(D90-D10) / D50 satisfies: 1≤K≤1.

5.

3. The phenolic hybrid SiO2 mesoporous microspheres according to claim 1 or 2, characterized in that, The specific surface area of ​​the phenolic hybrid SiO2 mesoporous microspheres is 180~190 m². 2 / g, with a porosity of 70%~95%; and / or, the phenolic hybrid SiO2 mesoporous microspheres appear white or pale yellow.

4. The application of the phenolic hybrid SiO2 mesoporous microspheres according to any one of claims 1-3, characterized in that, The phenolic hybrid SiO2 mesoporous microspheres are used in the fields of thermal protection, microwave absorption, heat insulation, and coatings.

5. A honeycomb-shaped ablation thermal protection component for use in Mars sample return projects, characterized in that, The phenolic hybrid SiO2 mesoporous microspheres according to any one of claims 1-3 are used as resin fillers.

6. The honeycomb-shaped ablation heat protection component according to claim 5, characterized in that, It is prepared from raw materials comprising the following components, by weight: Silicone resin A 35-40 parts 35-40 parts of phenolic hybrid SiO2 mesoporous microspheres Silicone resin B 3-5 parts 10-20 parts silicone oil thinner 1-3 parts of nano-SiO2 fiber fluff 1-3 parts of nano mullite fiber fluff Short-cut carbon nanofibers, 0.5-2 parts; Preferably, the silicone resin A is methylphenyl vinyl silicone rubber raw rubber with a viscosity of 15000~25000 mPa·s; the silicone resin B is a mixture of vinylsiloxane platinum complex and hydrogen-containing silicone oil; and the silicone oil diluent is hydroxyl silicone oil diluent or dimethyl silicone oil diluent.

7. A carbon-doped SiO2 material, characterized in that, Obtained by carbonization treatment of the phenolic hybrid SiO2 mesoporous microspheres according to any one of claims 1-3; Preferably, the carbonization treatment is carried out under inert gas conditions, with a carbonization temperature of 900-1500℃ and a carbonization time of 0.5-2h.

8. The carbon-doped SiO2 material according to claim 7, characterized in that, The carbon-doped SiO2 material is a spherical carbon-doped SiO2 material; Preferably, the spherical carbon-doped SiO2 material has mesopores with a pore size of 2-50 nm on both its surface and interior; the average particle size of the spherical carbon-doped SiO2 material is 10-100 μm. Preferably, the spherical carbon-doped SiO2 material has a black appearance and a full-spectrum emissivity of ≥0.80 for visible and infrared light; Preferably, the full infrared spectral hemispherical emissivity of the spherical carbon-doped SiO2 material is ≥0.

8.

9. A wave-absorbing and heat-insulating cap inside the nose cone of a high-speed missile, characterized in that, It includes a heat-insulating core material, wherein the heat-insulating core material is the carbon-doped SiO2 material as described in claim 8.

10. A flexible thermal insulation material, characterized in that, It includes a flexible heat insulation felt and a heat insulation film disposed on the inner side of the high-temperature surface of the flexible heat insulation felt; the heat insulation film uses the carbon-doped SiO2 material as the powder raw material as described in claim 8.

11. A coating, characterized in that, The phenolic hybrid SiO2 mesoporous microspheres as described in any one of claims 1-3 or the carbon-doped SiO2 material as described in claim 8 are used as functional fillers; Preferably, the coating comprises the following raw materials by mass fraction: 40-50 parts acrylic emulsion, 20-30 parts water, 50-70 parts phenolic hybrid SiO2 mesoporous microspheres or carbon-doped SiO2 material, 1-3 parts nanofiber flocking, 0.4-0.6 parts leveling agent, and 0.4-0.6 parts defoamer.

12. A plastic injection molded part for household appliances, characterized in that, The carbon-doped SiO2 material described in claim 8 is used as the filler.

Images