A multifunctional laser-protective aerogel composite material and its preparation method

Abstract

This invention relates to a multifunctional laser-protective aerogel composite material and its preparation method. The method includes: uniformly dispersing rare-earth high-entropy ceramic nanofibers and boron nitride nanosheets in an aqueous solution containing polyethylene oxide and a high-temperature binder to obtain a dispersion; then pre-freezing, freeze-drying, and high-temperature calcining the dispersion to obtain a double-network structure aerogel; sequentially stacking carbon fiber woven fabric, the double-network structure aerogel, and the carbon fiber woven fabric; then sewing the resulting sandwich structure with carbon fiber sutures to obtain a lattice structure sandwich body; and spraying a high-reflectivity coating component onto the surface of one side of the carbon fiber woven fabric of the lattice structure sandwich body to form a reflectivity coating, thus producing a multifunctional laser-protective aerogel composite material. The material prepared by this invention possesses multiple functions such as resistance to continuous impact, high-strength impact, heat insulation, and high reflectivity, effectively solving the engineering application challenges of aerogels in the field of laser protection.

Description

Technical Field

[0001] This invention belongs to the field of multifunctional laser protection materials technology, and particularly relates to a multifunctional laser protection aerogel composite material and its preparation method. Background Technology

[0002] With the rapid development of laser weapons, traditional single-function laser protection materials, such as metal screens and high-density ablation protection materials, have more or less problems such as insufficient temperature resistance, high density, high thermal conductivity and low reflection efficiency, which make it difficult to meet the requirements of efficient protection against high-energy laser rays.

[0003] Aerogel materials, characterized by their lightweight and low thermal conductivity, have wide applications in fields such as super thermal insulation, impact protection, and photothermal conversion. Ultra-white boron nitride aerogel was the first aerogel material used for laser protection, possessing both thermal insulation and reflective properties. However, the reflectivity of a single-system material is insufficient, and the porous structure of aerogels makes them easily penetrated by continuous laser impacts, hindering the effective utilization of their high reflectivity. Furthermore, the synthesized aerogel materials lack rigidity, exhibiting poor impact resistance and are easily damaged, limiting their use to certain fixed locations. Therefore, there is an urgent need to improve the overall performance of aerogels and solve the current engineering challenges in their application in laser protection. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides a multifunctional laser-protective aerogel composite material and its preparation method.

[0005] The present invention provides a method for preparing a multifunctional laser-protective aerogel composite material in a first aspect, the method comprising the following steps:

[0006] (1) Rare earth high-entropy ceramic nanofibers and boron nitride nanosheets were uniformly dispersed in an aqueous solution containing polyethylene oxide and a high-temperature binder to obtain a dispersion. The dispersion was then subjected to pre-freezing, freeze-drying and high-temperature calcination in sequence to obtain a double-network structure aerogel.

[0007] (2) Stack carbon fiber woven fabric, double network structure aerogel and carbon fiber woven fabric in sequence to obtain a sandwich structure. Then sew the sandwich structure with carbon fiber suture to obtain a lattice structure sandwich sewn body.

[0008] (3) A high reflectivity coating component is sprayed onto the surface of one side of the carbon fiber woven fabric of the sandwich stitch body of the lattice structure to form a reflectivity coating, thereby producing a multifunctional laser protection aerogel composite material.

[0009] Preferably, in step (1): the rare earth high-entropy ceramic nanofibers are rare earth zirconate high-entropy ceramic nanofibers A2Zr2O7 and / or rare earth hafnium salt high-entropy ceramic nanofibers B2Hf2O7; A is any five rare earth elements La, Sr, Ce, Er, Y and Yb, and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1 to 3%; B is any five rare earth elements Nd, Sm, Eu, Gd, Dy and Er, and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1 to 3%.

[0010] Preferably, in step (1): the mass ratio of the rare earth high-entropy ceramic nanofibers to boron nitride nanosheets is 1:(1-4).

[0011] Preferably, in step (1): the high-temperature adhesive is silica sol, and the solid content of the silica sol is 20-40 wt%; the aqueous solution contains 0.5-1.5% polyethylene oxide by mass and 4-8% high-temperature adhesive by mass; and / or the dispersion contains 10-20% rare earth high-entropy ceramic nanofibers and boron nitride nanosheets by mass.

[0012] Preferably, in step (1): the pre-freezing is freezing in liquid nitrogen for 10–60 min; the freeze-drying temperature is -10℃ to 0℃, and the freeze-drying time is 60–80 h; the high-temperature calcination temperature is 500–900℃, and the high-temperature calcination time is 1–4 h; and / or the density of the dual-network structure aerogel is 0.1–0.2 g / cm³. 3 .

[0013] Preferably, in step (2): the thickness of the carbon fiber woven fabric is 0.05 to 0.3 mm; and / or the thickness of the double network structure aerogel is 3 to 20 mm.

[0014] Preferably, in step (2): when suturing with carbon fiber sutures, the dot matrix distance of the sutures is 5 to 30 mm.

[0015] Preferably, in step (3): a high reflectivity coating component is sprayed onto the surface of one side of the carbon fiber woven fabric of the sandwich stitch body of the lattice structure by plasma spraying to form a reflectivity coating; and / or the thickness of the reflectivity coating is 20nm to 2000nm.

[0016] Preferably, in step (3): the high reflectivity coating component is a ternary oxide of Sr-Ti-Si, and the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:(0.2~1).

[0017] In a second aspect, the present invention provides a multifunctional laser-protective aerogel composite material prepared by the preparation method described in the first aspect of the present invention.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] This invention constructs a dual-network aerogel composite material with a density gradient (a multifunctional laser-protective aerogel composite material). This material possesses multiple functions, including resistance to continuous impact, high-intensity impact, thermal insulation, and high reflectivity, effectively solving the engineering application challenges of aerogels in the field of laser protection. This invention uses high-entropy ceramic nanofibers and boron nitride nanoribbons (i.e., boron nitride nanosheets) as assembly units. High-entropy nanofibers and boron nitride possess excellent reflectivity; the cross-dimensional design of one-dimensional and two-dimensional layers increases the laser reflection path and strengthens the aerogel structure. Furthermore, this invention employs a sandwich and lattice-based synergistic reinforcement scheme to construct a high-strength, impact-resistant aerogel composite material. Finally, this invention utilizes a surface plasmon coating design to obtain a homogeneous, defect-free, high-reflectivity coating, enhancing the material's resistance to continuous impact. The surface densification design further maximizes the thermal insulation effect of the core aerogel, preventing structural penetration and damage under prolonged high-energy laser impact. This invention provides a novel method for preparing multifunctional laser protection materials, and a structural design method for laser protection composite materials based on aerogel. The technical solution of this invention comprehensively improves the mechanical strength and laser reflection performance of aerogel composite materials, laying the foundation for the engineering application of aerogel materials in the field of laser protection. Detailed Implementation

[0020] 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 in conjunction with the embodiments thereof. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] The present invention provides a method for preparing a multifunctional laser-protective aerogel composite material in a first aspect, the method comprising the following steps:

[0022] (1) Rare earth high-entropy ceramic nanofibers and boron nitride nanosheets are uniformly dispersed in an aqueous solution containing polyethylene oxide and a high-temperature binder to obtain a dispersion. The dispersion is then subjected to pre-freezing, freeze-drying, and high-temperature calcination in sequence to obtain a double-network structure aerogel. In this invention, rare earth high-entropy ceramic nanofibers and boron nitride nanoribbons (boron nitride nanosheets) are used as assembly units to prepare a double-network structure aerogel. Specifically, for example, boron nitride nanosheets and high-entropy ceramic nanofibers are weighed and uniformly dispersed in an aqueous solution containing polyethylene oxide and a high-temperature binder. The double-network structure aerogel is obtained by rapid pre-freezing, freeze-drying, and high-temperature calcination. This invention does not specifically limit the source of boron nitride nanosheets and polyethylene oxide and can use directly purchased products.

[0023] (2) Carbon fiber woven fabric, double-network aerogel, and carbon fiber woven fabric are stacked sequentially to obtain a sandwich structure. The sandwich structure is then sewn together with carbon fiber sutures to obtain a lattice structure sandwich body. This invention does not have special requirements for the technology of sewing the sandwich body into a lattice structure, which is a conventional technology in the field. For example, the double-network aerogel layer can be sewn between two layers of carbon fiber woven fabric by interlacing stitching according to the stitching lattice. That is, in this invention, carbon fiber woven fabric is used to sandwich the double-network aerogel between two layers of carbon fiber woven fabric in a sandwich manner (using the stacking order of carbon fiber woven fabric + double-network aerogel + carbon fiber woven fabric). Then, carbon fiber sutures are used to sew the double-network aerogel and carbon fiber woven fabric together by interlacing stitching in a lattice manner to complete the surface toughening treatment of the double-network aerogel. This invention does not specifically limit the source of carbon fiber woven fabric and carbon fiber sutures, and can use directly purchased products.

[0024] (3) A high reflectivity coating component is sprayed onto the surface of one side of the carbon fiber woven fabric of the sandwich structure to form a reflectivity coating, thereby producing a multifunctional laser protective aerogel composite material; In this invention, a plasma spraying method is used to spray the high reflectivity coating component onto the surface of one side of the carbon fiber woven fabric of the sandwich structure to complete the surface coating design, and a reflectivity coating is prepared on the material surface to form a laser protective aerogel composite material with high reflectivity / low thermal conductivity integrated by a density gradient; In this invention, the density gradient refers to the high density of the formed reflectivity coating, which forms a density gradient with the relatively low density of the sandwich structure.

[0025] This invention constructs a dual-network structure aerogel composite material with a density gradient (a multifunctional laser-protective aerogel composite material). This material possesses multiple functions, including resistance to continuous impact, high-intensity impact, thermal insulation, and high reflectivity, effectively solving the engineering application challenges of aerogels in the field of laser protection. This invention uses high-entropy ceramic nanofibers and boron nitride nanoribbons (boron nitride nanosheets) as assembly units. High-entropy nanofibers and boron nitride have excellent reflectivity; the cross-dimensional design (one-dimensional and two-dimensional) increases the laser reflection path and strengthens the aerogel structure. Furthermore, this invention employs a sandwich and lattice-based synergistic strengthening scheme to construct a high-strength, impact-resistant aerogel composite material. Finally, this invention uses a surface plasmon coating design to obtain a homogeneous, defect-free, high-reflectivity coating, enhancing the material's resistance to continuous impact. The surface densification design further maximizes the thermal insulation effect of the core aerogel, preventing structural penetration and damage under prolonged high-energy laser impact. This invention provides a novel method for preparing multifunctional laser protection materials, and a structural design method for laser protection composite materials based on aerogel. The technical solution of this invention comprehensively improves the mechanical strength and laser reflection performance of aerogel composite materials, laying the foundation for the engineering application of aerogel materials in the field of laser protection.

[0026] According to some preferred embodiments, the multifunctional laser protective aerogel composite material has a room temperature thermal conductivity of 0.029–0.035 W / (m·K), a 500℃ thermal conductivity of 0.052–0.057 W / (m·K), a compressive strength of 0.11–0.15 MPa, and a reflectivity of 98–99% in the wavelength range of 1–30 μm.

[0027] According to some preferred embodiments, in step (1): the rare earth high-entropy ceramic nanofibers are rare earth zirconate high-entropy ceramic nanofibers A2Zr2O7 and / or rare earth hafnium salt high-entropy ceramic nanofibers B2Hf2O7; A is any five of the rare earth elements La (lanthanum), Sr (strontium), Ce (cerium), Er (erbium), Y (yttrium), and Yb (ytterbium), and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1-3%; B is any five of the rare earth elements Nd (neodymium), Sm (samarium), Eu (eurypium), Gd (gadolinium), Dy (dysprosium), and Er (erbium), and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1-3%.

[0028] According to some preferred embodiments, the rare-earth high-entropy ceramic nanofibers are (La 0.2 Sr 0.2 Ce 0.2 Er0.2 Yb 0.2 )2Zr2O7 high-entropy ceramic nanofibers, (La 0.2 Sr 0.2 Ce 0.2 Er 0.2 Y 0.2 )2Zr2O7 high-entropy ceramic nanofibers, (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 )2Hf2O7 high-entropy ceramic nanofibers or (Nd 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 This invention relates to 2Hf₂O₇ high-entropy ceramic nanofibers. These high-entropy ceramic nanofibers exhibit superior performance compared to other high-entropy ceramic nanofibers in terms of high-temperature stability, thermal conductivity, and optical reflectivity. This allows for the preparation of multifunctional laser-protective aerogel composite materials with superior performance. The rational combination of rare earth elements provides various beneficial physical and chemical properties, such as excellent optical performance, thermal stability, and chemical stability. This rational combination significantly improves the overall performance of the material. Furthermore, the rational combination of rare earth elements in these high-entropy ceramic nanofibers results in lower thermal conductivity, effectively blocking heat conduction and enhancing the thermal insulation performance of the composite material. Additionally, this rational combination of rare earth elements helps to increase the reflectivity of the material, thereby enhancing its laser protection effect. This high reflectivity is particularly important for preventing laser damage.

[0029] This invention does not specifically limit the source of rare earth zirconate high-entropy ceramic nanofibers A2Zr2O7 and / or rare earth hafnium salt high-entropy ceramic nanofibers B2Hf2O7. For example, they can be directly purchased products or products prepared by existing methods. In this invention, specifically, the source of (La) high-entropy ceramic nanofibers B2Hf2O7 is used to prepare... 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 Taking Zr2O7 high-entropy ceramic nanofibers as an example, the preparation steps can be as follows:

[0030] ①Prepared by sol-gel method (La 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 )2Zr2O7 high-entropy ceramic dispersion: Lanthanum acetate, Strontium acetate, Cerium acetate, Erbium acetate, and basic zirconium carbonate are used as raw materials, and aqueous acetic acid solution is used as solvent; according to (La0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 The molar ratio of each element in 2Zr2O7 was determined by adding the raw material to an aqueous acetic acid solution (acetic acid to water mass ratio of 1:1) and stirring for 0.5 h to obtain (La) 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 )2Zr2O7 high-entropy ceramic dispersion, making (La 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 The solid content (concentration) of the Zr2O7 high-entropy ceramic dispersion is 15 wt%.

[0031] ② Add polyethylene oxide to the (La) obtained in step ① 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 In a high-entropy ceramic dispersion of 2Zr2O7, the mixture is stirred evenly to prepare a spinning solution, such that the spinning solution contains 2% polyethylene oxide by mass.

[0032] ③ The prepared spinning solution is drawn into the syringe of the electrospinning equipment. The electrospinning parameters are set as follows: voltage 20kV, injection speed 0.4mm / min, and distance 15cm. After setting the parameters, the spinning solution is electrospinned, then dried in a 70℃ forced-air drying oven for 12 hours, followed by calcination at 1200℃ in air atmosphere for 2 hours to obtain (La). 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 )2Zr2O7 high-entropy ceramic nanofibers.

[0033] In this invention, (Sm) is prepared 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 Taking 2Hf2O7 high-entropy ceramic nanofibers as an example, the preparation steps can be as follows:

[0034] ①Prepared by sol-gel method (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2)2Hf2O7 high-entropy ceramic dispersion: samarium acetate, europium acetate, gadolinium acetate, dysprosium acetate, erbium acetate, and hafnium chloride are used as raw materials, and an aqueous acetic acid solution is used as the solvent; according to (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The molar ratio of each element in 2Hf₂O₇ was determined by adding the raw material to an aqueous acetic acid solution (acetic acid to water mass ratio of 1:1) and stirring for 0.5 h to obtain (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The high-entropy ceramic dispersion of 2Hf2O7 makes (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The solid content (concentration) of the 2Hf2O7 high-entropy ceramic dispersion is 15wt%.

[0035] ② Add polyethylene oxide to the (Sm) obtained in step ① 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 In a high-entropy ceramic dispersion of 2Hf2O7, the mixture is stirred evenly to prepare a spinning solution, such that the spinning solution contains 2% polyethylene oxide by mass.

[0036] ③ The prepared spinning solution is drawn into the syringe of the electrospinning equipment. The electrospinning parameters are set as follows: voltage 20kV, injection speed 0.4mm / min, and distance 15cm. After setting the parameters, the spinning solution is electrospinned, then dried in a 70℃ forced-air drying oven for 12 hours, followed by calcination at 1200℃ in air atmosphere for 2 hours to obtain (Sm 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 )2Hf2O7 high-entropy ceramic nanofibers.

[0037] According to some preferred embodiments, in step (1): the mass ratio of the rare earth high-entropy ceramic nanofibers to boron nitride nanosheets is 1:(1-4) (e.g., 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5 or 1:4); in this invention, it is preferred to control the mass ratio of rare earth high-entropy ceramic nanofibers to boron nitride nanosheets to be between 1:(1-4), which enables the prepared multifunctional laser-protective aerogel composite material to achieve optimal performance in terms of mechanical strength, thermal conductivity and reflectivity; this invention finds that a reasonable mass ratio helps to form a stable double-network structure and enhance the aerogel. The compressive strength of rare-earth high-entropy ceramic nanofibers is important. If the proportion of rare-earth high-entropy ceramic nanofibers is too high, the material will become too rigid, leading to increased brittleness and decreased compressive strength. Conversely, if the proportion of boron nitride nanosheets is too high, the aerogel may easily deform or break. A reasonable mass ratio can effectively control the high-temperature thermal conductivity of the material, ensuring that the material still has good thermal insulation performance in high-temperature environments. This invention has found that high-entropy nanofibers and boron nitride have excellent reflective properties, which can improve the reflectivity of the material and enhance the protection against lasers. By adjusting the appropriate ratio of the two components, the reflective properties of the composite material can be optimized to achieve the best effect in laser protection.

[0038] According to some preferred embodiments, in step (1): the high-temperature adhesive is silica sol, and the solid content of the silica sol is 20-40 wt%; the present invention does not specifically limit the source of silica sol, and any product that can be directly purchased can be used; the aqueous solution contains 0.5-1.5% (e.g., 0.5%, 0.8%, 1% or 1.5%) of polyethylene oxide by mass, and 4-8% (e.g., 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 8%) of high-temperature adhesive by mass; and / or the dispersion contains a total of 10-20% (e.g., 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%) of rare earth high-entropy ceramic nanofibers and boron nitride nanosheets by mass.

[0039] According to some preferred embodiments, in step (1): the pre-freezing is freezing in liquid nitrogen for 10–60 min (e.g., 10, 20, 30, 40, 50, or 60 min); the freeze-drying temperature is -10°C to 0°C, and the freeze-drying time is 60–80 h; the high-temperature calcination temperature is 500–900°C, and the high-temperature calcination time is 1–4 h; in this invention, the high-temperature calcination is carried out in an air atmosphere; and / or the density of the dual-network aerogel is 0.1–0.2 g / cm³. 3 .

[0040] According to some preferred embodiments, in step (2): the thickness of the carbon fiber woven fabric is 0.05 to 0.3 mm (e.g., 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3 mm); and / or the thickness of the double network structure aerogel is 3 to 20 mm (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 mm).

[0041] According to some preferred embodiments, in step (2): when suturing with carbon fiber sutures, the lattice spacing of the sutures is 5 to 30 mm (e.g., 5, 10, 15, 20, 25 or 30 mm).

[0042] According to some preferred embodiments, in step (3): a high reflectivity coating component is sprayed onto the surface of the carbon fiber woven fabric on one side of the sandwich stitch body of the lattice structure by plasma spraying to form a reflectivity coating; the present invention does not specifically limit the operation of plasma spraying, and conventional technology can be used to spray the high reflectivity coating component onto the surface of the carbon fiber woven fabric on one side of the sandwich stitch body of the lattice structure to form a reflectivity coating; and / or the thickness of the high reflectivity coating is 20nm to 2000nm (e.g. 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900 or 2000nm).

[0043] According to some preferred embodiments, in step (3): the high reflectivity coating component is a Sr-Ti-Si ternary oxide, wherein the molar ratio of Sr, Ti, and Si in the Sr-Ti-Si ternary oxide is 1:1:(0.2-1) (e.g., 1:1:0.2, 1:1:0.3, 1:1:0.4, 1:1:0.5, 1:1:0.6, 1:1:0.7, 1:1:0.8, 1:1:0.9, or 1:1:1); in this invention, preferably... The high-reflectivity coating is composed of a Sr-Ti-Si ternary oxide, and the molar ratio of Sr, Ti, and Si in the Sr-Ti-Si ternary oxide is 1:1:(0.2-1). This optimizes laser reflection performance, resulting in a material with high reflectivity. Controlling the molar ratio to 1:1:(0.2-1) allows for the formation of a stable and efficient reflective layer, providing excellent laser protection. Furthermore, this invention reveals that the Sr-Ti-Si ternary oxide exhibits good chemical properties at high temperatures. The coating exhibits excellent stability and antioxidant properties, resisting decomposition or oxidation, thus ensuring its long-lasting performance under high-temperature environments. Furthermore, the ternary oxide possesses good mechanical stability, capable of withstanding thermal cycling and mechanical stress, and is not prone to peeling or cracking, extending the service life of the composite material. Controlling the molar ratio of Sr-Ti-Si ternary oxide at 1:1:(0.2~1) further contributes to the formation of a dense and uniform coating, ensuring consistent protective effects across the entire surface. This coating also exhibits good adhesion to carbon fiber woven fabric, ensuring it is not easily peeled off during use and maintaining long-term laser protection performance. In addition, this invention reveals that the Sr-Ti-Si ternary oxide has low thermal conductivity, effectively blocking heat conduction. This matches the low thermal conductivity characteristics of the aerogel composite material. Selecting an appropriate molar ratio optimizes high reflectivity and enhances the material's resistance to continuous impact, further maximizing the thermal insulation effect of the core aerogel and preventing structural penetration and damage under prolonged high-energy laser impact.

[0044] This invention does not specifically limit the source of the Sr-Ti-Si ternary oxide; for example, it can be a directly purchased product or a product prepared by existing methods.

[0045] In this invention, the preparation of the Sr-Ti-Si ternary oxide can be, for example, as follows:

[0046] ① Slurry preparation: The main components of the slurry are SrCl4, TiCl4 and tetraethyl orthosilicate. Each substance is weighed according to the molar ratio of Sr:Ti:Si and dissolved separately in an ethanol aqueous solution (the volume ratio of ethanol to water in the ethanol aqueous solution is 8:2). The concentration of each solute is controlled at 2 mol / L. The three are mixed evenly to obtain the slurry.

[0047] ② Thermal decomposition process: The slurry prepared in step ① is evaporated at 80°C, then solidified at 150°C for 10 hours, and then oxidized and sintered in a box furnace at 400°C for 2 hours. After being removed from the furnace and cooled to room temperature, Sr-Ti-Si ternary oxides with a particle size of less than 5 μm are obtained by grinding and sieving. In this invention, the particle size of the Sr-Ti-Si ternary oxides is, for example, less than 5 μm.

[0048] In a second aspect, the present invention provides a multifunctional laser-protective aerogel composite material prepared by the preparation method described in the first aspect of the present invention.

[0049] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments.

[0050] Example 1

[0051] (1) Weigh boron nitride nanosheets and (Sm) in a mass ratio of 4:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and Sm...) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 10wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 3 mm.

[0052] (2) A carbon fiber woven fabric with a thickness of 0.05 mm, a double network structure aerogel with a thickness of 3 mm and a carbon fiber woven fabric with a thickness of 0.05 mm are stacked in sequence to obtain a sandwich structure. Then, the sandwich structure is sewn together with carbon fiber sutures to obtain a dot matrix structure sandwich sewn body. The dot matrix distance of the sewn sewn body is 30 mm.

[0053] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.2) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 20nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0054] Example 2

[0055] (1) Weigh boron nitride nanosheets and (Sm) in a mass ratio of 1:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and Sm...) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 10 mm.

[0056] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, a double network structure aerogel with a thickness of 10 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then, the sandwich structure is sewn together with carbon fiber sutures to obtain a lattice structure sandwich sewn body. The lattice distance of the sewn parts is 5 mm.

[0057] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:1) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 50nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0058] Example 3

[0059] (1) Weigh boron nitride nanosheets and (Sm) in a mass ratio of 1.5:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and Sm...) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 20wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0060] (2) A carbon fiber woven fabric with a thickness of 0.3 mm, a double network structure aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.3 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix structure sandwich sewn body. When sewing with carbon fiber suture, the distance between the sewn dots is 20 mm.

[0061] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 2000nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0062] Example 4

[0063] (1) Weigh boron nitride nanosheets and (La) in a mass ratio of 1.5:1. 0.2 Sr 0.2 Ce 0.2 Er 0.2 Y 0.2 2Zr2O7 ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and (La...) 0.2 Sr 0.2 Ce 0.2 Er 0.2 Y 0.2 The total mass percentage of Zr2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0064] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, a double network structure aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix structure sandwich sewn body. When sewing with carbon fiber suture, the dot matrix distance is 20 mm.

[0065] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0066] Example 5

[0067] (1) Weigh boron nitride nanosheets and (La) in a mass ratio of 1.5:1. 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 2Zr2O7 ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and (La...) 0.2 Sr 0.2 Ce 0.2 Er 0.2 Yb 0.2 The total mass percentage of Zr2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0068] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, a double network structure aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix structure sandwich sewn body. When sewing with carbon fiber suture, the dot matrix distance is 20 mm.

[0069] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0070] Example 6

[0071] (1) Weigh boron nitride nanosheets and (Nd) in a mass ratio of 1.5:1. 0.2 Eu 0.2 Gd 0.2 Dy0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and (Nd₂O₇) nanofibers.) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0072] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, a double network structure aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix structure sandwich sewn body. When sewing with carbon fiber suture, the dot matrix distance is 20 mm.

[0073] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0074] Example 7

[0075] Example 7 is basically the same as Example 6, except that:

[0076] (1) Weigh boron nitride nanosheets and (Nd) in a mass ratio of 0.5:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and (Nd₂O₇) nanofibers.) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0077] Example 8

[0078] Example 8 is basically the same as Example 6, except that:

[0079] (1) Weigh boron nitride nanosheets and (Nd) in a mass ratio of 6:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanosheets and (Nd₂O₇) nanofibers.) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0080] Example 9

[0081] Example 9 is basically the same as Example 6, except that:

[0082] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.1) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0083] Example 10

[0084] Example 10 is basically the same as Example 6, except that:

[0085] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:2) is sprayed onto the surface of the carbon fiber woven fabric on one side of the above-mentioned sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a multifunctional laser protection aerogel composite material (surface densified gradient protection composite material).

[0086] Example 11

[0087] Example 11 is basically the same as Example 6, except that:

[0088] (3) The ternary oxide of Zr-Sn-Ru (the molar ratio of Zr, Sn and Ru in the ternary oxide of Zr-Sn-Ru is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a surface-densified gradient protective composite material.

[0089] Comparative Example 1

[0090] (1) Weigh boron nitride nanosheets and uniformly disperse them in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol to form a dispersion (the mass percentage of boron nitride nanosheets in the dispersion is 15 wt%). Then, the dispersion is rapidly frozen with liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain an aerogel with a thickness of 20 mm.

[0091] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, an aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix sandwich body. When sewing with carbon fiber suture, the distance between the sewn dots is 20 mm.

[0092] (3) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto the surface of the carbon fiber woven fabric on one side of the sandwich stitch body by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a material with a dense surface.

[0093] Comparative Example 2

[0094] (1) Weigh boron nitride nanosheets and (Nd) in a mass ratio of 1.5:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol to form a dispersion. (The dispersion contained boron nitride nanosheets and (Nd) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0095] (2) The high reflectivity coating component Sr-Ti-Si ternary oxide (the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:0.6) is sprayed onto one side of the above-mentioned double network structure aerogel by plasma spraying to complete the construction of a 100nm reflectivity coating on the surface and form a surface-densified material.

[0096] Comparative Example 3

[0097] (1) Weigh boron nitride nanosheets and (Nd) in a mass ratio of 1.5:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol to form a dispersion. (The dispersion contained boron nitride nanosheets and (Nd) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0098] (2) A carbon fiber woven fabric with a thickness of 0.1 mm, a double network structure aerogel with a thickness of 20 mm and a carbon fiber woven fabric with a thickness of 0.1 mm are stacked in sequence to obtain a sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain a dot matrix structure sandwich sewn body. When sewing with carbon fiber suture, the dot matrix distance is 20 mm.

[0099] Comparative Example 4

[0100] Comparative Example 4 is basically the same as Example 6, except that:

[0101] (1) Weigh boron nitride nanosheets and silica nanofibers with a mass ratio of 1.5:1 and disperse them uniformly in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of silica sol is 30 wt%) to form a dispersion (the total mass percentage of boron nitride nanosheets and silica nanofibers in the dispersion is 15 wt%). Then, the dispersion is rapidly frozen with liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double network structure aerogel with a thickness of 20 mm.

[0102] Comparative Example 5

[0103] Comparative Example 5 is basically the same as Example 6, except that:

[0104] (1) Weigh out boron nitride nanopowder and (Nd) in a mass ratio of 1.5:1. 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 2Hf₂O₇ ceramic nanofibers were uniformly dispersed in an aqueous solution containing 1 wt% polyethylene oxide and 5 wt% silica sol (the solid content of the silica sol was 30 wt%) to form a dispersion. (The dispersion contained boron nitride nanoparticles and (Nd₂O₇) nanofibers.) 0.2 Eu 0.2 Gd 0.2 Dy 0.2 Er 0.2 The total mass percentage of 2Hf2O7 ceramic nanofibers was 15wt%. The nanofibers were then rapidly frozen in liquid nitrogen for 30 min, and finally freeze-dried at -10℃ for 72 h and calcined at 600℃ for 2 h to obtain a double-network structure aerogel with a thickness of 20 mm.

[0105] The thermal conductivity, compressive strength at 10% deformation, and reflectivity of the materials prepared in each embodiment and comparative example of the present invention were measured, and the results are shown in Table 1. As can be seen from Table 1, the materials prepared in the preferred embodiment of the present invention have low thermal conductivity, high compressive strength, and high reflectivity, and have excellent laser protection performance.

[0106] Table 1

[0107]

[0108]

[0109] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0110] 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 method for preparing a multifunctional laser-protective aerogel composite material, characterized in that, The method includes the following steps: (1) Rare earth high-entropy ceramic nanofibers and boron nitride nanosheets are uniformly dispersed in an aqueous solution containing polyethylene oxide and a high-temperature binder to obtain a dispersion. The dispersion is then subjected to pre-freezing, freeze-drying and high-temperature calcination in sequence to obtain a double-network structure aerogel. In step (1): the rare earth high-entropy ceramic nanofibers are rare earth zirconate high-entropy ceramic nanofibers A2Zr2O7 and / or rare earth hafnium salt high-entropy ceramic nanofibers B2Hf2O7; A is any five rare earth elements La, Sr, Ce, Er, Y and Yb, and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1~3%; B is any five rare earth elements Nd, Sm, Eu, Gd, Dy and Er, and the sum of the atomic molar percentages of each rare earth element is 100%, and the atomic molar percentages of each rare earth element are equal, or the difference in atomic molar percentages does not exceed 1~3%. (2) The carbon fiber woven fabric, the double network structure aerogel and the carbon fiber woven fabric are stacked in sequence to obtain the sandwich structure. Then the sandwich structure is sewn together with carbon fiber suture to obtain the lattice structure sandwich sewn body. (3) A high reflectivity coating component is sprayed onto the surface of the carbon fiber woven fabric on one side of the sandwich stitch body of the lattice structure to form a reflectivity coating, thereby producing a multifunctional laser protection aerogel composite material.

2. The preparation method according to claim 1, characterized in that, In step (1): The mass ratio of the rare earth high-entropy ceramic nanofibers to boron nitride nanosheets is 1:(1~4).

3. The preparation method according to claim 1, characterized in that, In step (1): The high-temperature adhesive is silica sol, and the solid content of the silica sol is 20~40 wt%. The aqueous solution contains 0.5-1.5% polyethylene oxide by mass and 4-8% high-temperature adhesive by mass; and / or The dispersion contains a total mass percentage of 10-20% rare earth high-entropy ceramic nanofibers and boron nitride nanosheets.

4. The preparation method according to claim 1, characterized in that, In step (1): The pre-freezing is freezing in liquid nitrogen for 10-60 minutes; The freeze-drying temperature is -10℃ to 0℃, and the freeze-drying time is 60 to 80 hours. The high-temperature calcination temperature is 500~900℃, and the high-temperature calcination time is 1~4h; and / or The density of the dual-network structured aerogel is 0.1~0.2 g / cm³. 3 .

5. The preparation method according to claim 1, characterized in that, In step (2): The thickness of the carbon fiber woven fabric is 0.05~0.3mm; and / or The thickness of the dual-network structure aerogel is 3~20mm.

6. The preparation method according to claim 1, characterized in that, In step (2): When using carbon fiber sutures for suturing, the dot spacing of the sutures is 5~30mm.

7. The preparation method according to claim 1, characterized in that, In step (3): A high-reflectivity coating component is sprayed onto the surface of one side of the carbon fiber woven fabric of the sandwich stitch body of the lattice structure by plasma spraying to form a reflectivity coating. and / or The thickness of the reflective coating is 20nm~2000nm.

8. The preparation method according to claim 1, characterized in that, In step (3): The high reflectivity coating is composed of a ternary oxide of Sr-Ti-Si, wherein the molar ratio of Sr, Ti and Si in the Sr-Ti-Si ternary oxide is 1:1:(0.2~1).

9. A multifunctional laser-protective aerogel composite material prepared by any one of claims 1 to 8.

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