CN-121973539-A - Preparation method of high-strength composite aerogel

Abstract

The invention belongs to the field of high-temperature resistant heat insulation materials, in particular to a preparation method of high-strength composite aerogel, which comprises the following steps of selecting inorganic sol as an inorganic precursor, adding a proper amount of polymer spinning auxiliary agent, and regulating the viscosity and the conductivity of a system to obtain a precursor solution; spinning the precursor solution under a high-voltage electrostatic field, collecting and forming inorganic precursor/polymer composite nanofiber aerogel, and adding a surface felt as a reinforcing framework to form a glass fiber surface felt-ceramic fiber aerogel-glass fiber surface felt high-strength composite structure. The invention comprehensively utilizes sol-gel and electrostatic spinning technology to prepare ceramic nanofiber-based aerogel, and the ceramic nanofiber-based aerogel is compounded with glass fiber surface felt to form the composite aerogel material with light heat insulation and high strength.

Inventors

• SHEN ZHIBIN
• Chen Haiken
• LEI FUWANG

Assignees

• 浙江柔荷新能源材料有限公司

Dates

Publication Date

20260505

Application Date

20260305

Claims (9)

1. 1. The preparation method of the high-strength composite aerogel is characterized by comprising the following steps of: S1, inorganic sol is selected as an inorganic precursor, a proper amount of polymer spinning aid and solvent are added, and the viscosity and the conductivity of the system are regulated to obtain a uniform spinnable precursor solution; S2, spinning the uniform spinnable precursor solution under a high-voltage electrostatic field, and collecting to form inorganic precursor/polymer nanofiber aerogel; S3, baking the fibers obtained in the step S2 through a step tunnel furnace, wherein the processing temperature is increased from 60 ℃ to 500 ℃ in a gradient manner, and thus, the dried ceramic fiber aerogel is obtained; S4, compounding copolyamide hot melt adhesive on the upper surface and the lower surface of the ceramic fiber aerogel obtained in the S3 to obtain primary composite aerogel, then placing a high-strength glass fiber surface felt on the surface of the copolyamide hot melt adhesive, and obtaining a high-strength composite structure of the glass fiber surface felt-ceramic fiber aerogel-glass fiber surface felt through a hot-pressing composite process.
2. 2. The method of claim 1, wherein the sol comprises aluminum sol, silica sol or a composite sol thereof.
3. 3. The method of claim 1, wherein the polymer co-spinning agent comprises polyvinyl alcohol PVA or polyethylene oxide PEO.
4. 4. The method of claim 1, wherein the solvent comprises ethanol or water.
5. 5. The method for preparing high-strength composite aerogel according to claim 1, wherein the mass ratio of the inorganic precursor, the polymer spinning aid and the solvent is 10-20:10-30:30-60.
6. 6. The method for preparing a high-strength composite aerogel according to claim 1, wherein the system viscosity is 30-50cP, the conductivity is 200-800 μS/cm, and the pH is 2.1-4.0.
7. 7. The method for preparing high-strength composite aerogel according to claim 1, wherein a needleless spinning machine is used, the spinning voltage is 25+/-5 kV, the coating rate is 200mm/s, and the collecting distance is 20-40cm.
8. 8. The method for preparing the high-strength composite aerogel according to claim 1, wherein the glass fiber surface felt, the copolyamide hot melt adhesive, the nanofiber aerogel, the copolyamide hot melt adhesive and the glass fiber surface felt are laminated in the order of forming a multi-layer high-strength composite structure.
9. 9. The method for preparing high-strength composite aerogel according to claim 8, wherein the hot pressing parameters are that the flat plate type compounding machine is hot pressed for 10s at the temperature of 150 ℃ and the pressure of 0.2 Pa.

Description

Preparation method of high-strength composite aerogel Technical Field The invention belongs to the field of nonmetallic material-increasing materials, and particularly relates to a preparation method of high-strength composite aerogel. Background In recent years, aerogels have received attention in the fields of aerospace, energy equipment, protective materials, and the like because of their extremely low density, excellent heat insulation performance, and high specific surface area. Especially, the ceramic-based aerogel is more suitable for heat protection in extreme environments due to the characteristics of high temperature resistance and non-combustion. However, the aerogels produced by conventional methods have the following limitations: (1) The block aerogel prepared by the sol-gel method generally has the problems of high energy consumption, complex process and high cost, so that large-area application cannot be carried out. (2) The traditional needle type electrospinning and batch drying modes are difficult to realize large-area and low-cost preparation, and the industrialized popularization of aerogel products is affected. (3) The ceramic nanofiber aerogel prepared by the traditional electrostatic spinning process is easy to absorb moisture in a wet and hot environment, and the mechanical and heat insulation properties are rapidly deteriorated after water absorption, which indicates that the environmental stability of the ceramic nanofiber aerogel still needs to be improved. Researchers improve the hygroscopicity of the aerogel through high-temperature baking, but organic matters are decomposed in the high-temperature treatment process, so that the shrinkage and the increase of holes of the fiber structure are caused, and the strength and the stability of the aerogel are weakened. And secondly, the whole aerogel framework formed by stacking the nano fibers is still fragile, and the structure retention in compression resistance, bending resistance and recycling is insufficient, so that the requirements of engineering practice on mechanical strength and durability are difficult to meet. Disclosure of Invention In order to overcome the deficiencies of the prior art, at least one technical problem presented in the background art is solved. The technical scheme adopted for solving the technical problems is that the preparation method of the high-strength composite aerogel comprises the following steps: s1, selecting sol as an inorganic precursor, adding a proper amount of polymer spinning aid and a solvent, and adjusting the viscosity and the conductivity of a system to obtain a uniform spinnable precursor solution; S2, spinning the uniform spinnable precursor solution under a high-voltage electrostatic field, and collecting to form inorganic precursor/polymer nanofiber aerogel; the continuous and uniform fiber network structure is obtained by optimizing the voltage, the spraying rate, the coating rate and the collecting distance process parameters; S3, compounding copolyamide hot melt adhesive on the upper surface and the lower surface of the ceramic fiber aerogel obtained in the S2 to obtain primary composite aerogel, then placing a high-strength glass fiber surface felt on the surface of the copolyamide hot melt adhesive, and performing hot pressing for 10S at the temperature of 150 ℃ and the pressure of 0.2Pa by using a flat plate type compounding machine to obtain the glass fiber surface felt-ceramic fiber aerogel-glass fiber surface felt high-strength composite structure. As a further technical scheme of the invention, the sol comprises aluminum sol, silica sol or composite sol thereof. As a further technical scheme of the invention, the polymer spinning aid comprises polyvinyl alcohol PVA or polyethylene oxide PEO. As a further technical scheme of the invention, the solvent comprises ethanol or water. As a further technical scheme of the invention, the mass ratio of the inorganic precursor, the polymer spinning aid and the solvent is 10-20:10-30:30-60. As a further technical scheme of the invention, the viscosity of the system is 50-300 mPas, and the conductivity is 20-200mS/cm. As a further technical scheme of the invention, the needleless spinning voltage is 25+/-5 kV, the coating rate is 200mm/s, and the collecting distance is 20-40cm. As a further technical scheme, the flat plate type compounding machine is subjected to hot pressing for 10s at the temperature of 150 ℃ and the pressure of 0.2 Pa. The beneficial effects of the invention are as follows: The invention effectively solves the problems of high brittleness and low strength of the ceramic aerogel through the multilayer composite structure, obviously improves the compressive strength and the tensile strength of the composite material, can keep the structural stability of the ceramic nanofiber matrix thermal insulation material at the temperature of more than 1000 ℃, and is favorable for industrial production by adopting a combined proc