High-temperature-resistant anti-radiation ceramic nanofiber composite material, preparation method and electrostatic spinning device

Abstract

The application relates to a high-temperature-resistant anti-radiation type ceramic nanofiber composite material, a preparation method and an electrostatic spinning device. The composite material is composed of high-temperature-resistant ceramic nanofibers and anti-radiation type ceramic nanobands which are interwoven to form a three-dimensional porous network structure, the high-temperature-resistant ceramic nanofibers have curled circular cross sections, and the anti-radiation type ceramic nanobands have curled flat cross sections. The preparation method comprises the following steps: preparing high-temperature-resistant precursor spinning liquid and anti-radiation type precursor spinning liquid; the two are respectively transported to a rotating nozzle through independent liquid supply paths, are synchronously sprayed to form jets under the action of a high-voltage electric field, the rotating nozzle is rotated at a rotating speed of 30-60 r / min, the jets are dynamically interwoven in the air and are deposited to form a precursor composite material; and the precursor composite material is calcined at high temperature to obtain the composite material. Compared with the prior art, the technical problems of insufficient thermodynamic performance of a single type of fiber, uneven dispersion when two types of fibers are combined and performance attenuation at high temperature are solved.

Description

Technical Field

[0001] This invention relates to the intersection of nanomaterial forming technology and special machinery manufacturing technology, and in particular to a high-temperature resistant, anti-radiation ceramic nanofiber composite material, its preparation method, and an electrospinning device. Background Technology

[0002] Ceramic nanofiber materials are mainly used in aerospace, new energy high-temperature equipment, metallurgical high-end kilns and other demanding service scenarios that require both high-temperature insulation and near-infrared radiation protection.

[0003] High-temperature resistant ceramic nanofiber materials use high-temperature stable ceramic components such as mullite, alumina, and silica as main raw materials. Due to their low bulk density and high porosity, they possess excellent high-temperature thermal stability and low thermal conductivity, allowing them to withstand temperatures above 1000℃ for extended periods, making them a mainstream material in the field of high-temperature insulation. However, existing high-temperature resistant ceramic nanofiber materials have limited functionality, only possessing high-temperature insulation and heat conduction barrier properties. Their near-infrared radiation reflection capability is weak, resulting in limited protective effects in service scenarios where high-temperature radiative heat is the primary characteristic, making them unsuitable for service environments combining high temperatures and radiation.

[0004] As a core material for near-infrared radiation protection, anti-radiation ceramic nanofiber materials primarily use ceramic components with high refractive indices, such as titanium dioxide and zirconium dioxide, as the matrix. The nanoscale fibers, relying on the Mie scattering effect, efficiently scatter and reflect electromagnetic waves in the near-infrared band, significantly reducing the penetration and transfer of radiative heat, exhibiting excellent performance in near-infrared anti-radiation and radiative heat blocking. Simultaneously, the nanofiber structure of these materials possesses a certain porosity, enabling basic thermal conductivity blocking. However, limited by their compositional characteristics, anti-radiation ceramic nanofiber materials suffer from insufficient high-temperature resistance. At high temperatures, they are prone to malignant grain growth, rapid decrease in porosity, and a sharp increase in thermal conductivity. Furthermore, they cannot withstand long-term high-temperature conditions above 800℃, making them unsuitable for the needs of high-end equipment in high-temperature insulation scenarios. Single anti-radiation nanofiber materials are insufficient for service environments involving both high temperatures and radiation.

[0005] However, existing composite preparation technologies are difficult to achieve uniform composite and structural adaptation of two nanofibers with significantly different properties. Conventional physical mixing and post-doping methods can easily lead to uneven dispersion of the anti-radiation components, which cannot fully exert the anti-radiation effect of Mie scattering and can easily damage the porous structure of the high-temperature resistant matrix, resulting in a decrease in thermal insulation performance. At the same time, existing technologies lack dedicated devices adapted to the molding of two-component nanofibers, making it difficult to achieve synchronous and uniform interweaving molding of the two fibers. This results in uneven distribution of the composite material's composition and structure, and problems such as interface separation and performance degradation are prone to occur at high temperatures.

[0006] Common preparation processes for bicomponent nanofiber composites include: hydrothermal / solvothermal composite modification, in-situ doping-sol-gel, freeze-drying-post-treatment strengthening, carbothermal reduction-layer molding, and impregnation-grafting composite. Chinese invention patent application CN114804199A discloses a titanium dioxide-alumina aerogel material and its preparation method, which uses a hydrothermal reaction-composite modification process. This method suffers from insufficient interfacial bonding at high temperatures, leading to easy delamination. Patent application CN113831581A discloses a highly elastic radiation-resistant nanofiber aerogel material and its preparation method, which uses an in-situ doping-sol-gel process. This method suffers from the defect of easy fiber breakage during high-speed stirring. Patent application CN113648940A discloses an ultralightweight, highly elastic radiation-resistant nanofiber aerogel material and its preparation method. The preparation method employs a freeze-drying-post-treatment strengthening process, which suffers from the defect that the ultralight structure is prone to shrinkage in high-temperature environments. Patent CN116180330A discloses a titanium suboxide-based ceramic fiber composite material and its preparation method and application. This technology employs a carbothermal reduction-layer-by-layer molding preparation process, which suffers from the defect that it is difficult to accurately control the purity of titanium oxide during the carbothermal reduction process. Chinese invention application CN113603470A discloses a high-temperature resistant and radiation-resistant sandwich thermal protection material and its preparation method. This method utilizes an impregnation-grafting composite process, which suffers from the defects of complex multi-step processes and high cost for large-scale production.

[0007] Therefore, there is an urgent need to develop a high-temperature resistant, anti-radiation ceramic nanofiber composite material to solve the technical problems of insufficient thermodynamic properties of existing single-type fibers, uneven dispersion when two types of fibers are combined, and performance degradation at high temperatures. Summary of the Invention

[0008] The purpose of this invention is to overcome the defects of the prior art by providing a high-temperature resistant anti-radiation ceramic nanofiber composite material, its preparation method, and an electrospinning device. This invention addresses the technical problems of single-type fiber having limited function, uneven dispersion after two types of fibers are combined, easy grain growth of anti-radiation fibers at high temperatures, and low temperature resistance limit of high-temperature resistant fibers. It achieves the technical effects of synergistic high-temperature insulation and anti-radiation functions, uniform interweaving of two components, and stable high-temperature structure.

[0009] The objective of this invention can be achieved through the following technical solutions: The first aspect of the present invention provides a high-temperature resistant anti-radiation ceramic nanofiber composite material, comprising a three-dimensional porous network structure formed by the interweaving of high-temperature resistant ceramic nanofibers and anti-radiation ceramic nanoribbons. Based on the total mass of the composite material, the mass content of the high-temperature resistant ceramic nanofibers is 10%~90%, and the mass content of the anti-radiation ceramic nanoribbons is 10%~90%. The high-temperature resistant ceramic nanofibers have a curled circular cross-section, and the anti-radiation ceramic nanoribbons have a curled flat cross-section.

[0010] Furthermore, the diameter of the high-temperature resistant ceramic nanofibers is 400~600nm; The anti-radiation ceramic nanoribbon has a width of 500 nm to 5 μm and a thickness of 20 to 200 nm.

[0011] Furthermore, the high-temperature resistant ceramic nanofibers are selected from one or more of mullite fibers, zirconium oxide fibers, alumina fibers, silica fibers, and molybdenum dioxide fibers; The anti-radiation ceramic nanoribbons are selected from one or more of the following: titanium oxide nanoribbons, zirconium dioxide nanoribbons, hafnium dioxide nanoribbons, cerium dioxide nanoribbons, yttrium oxide nanoribbons, scandium oxide nanoribbons, lanthanum oxide nanoribbons, neodymium oxide nanoribbons, and samarium oxide nanoribbons.

[0012] Furthermore, the high-temperature resistant ceramic nanofibers have a mass content of 50% to 70%, and the anti-radiation ceramic nanoribbons have a mass content of 30% to 50%.

[0013] Furthermore, the bulk density of the high-temperature resistant, anti-radiation ceramic nanofiber composite material is ≤0.1 g / cm³. 3 The porosity is 85%~95%; The composite material has a thermal conductivity of ≤0.06 W / (m·K) at 1000℃ and a compressive elastic recovery rate of ≥90%.

[0014] A second aspect of the present invention provides a method for preparing the high-temperature resistant, anti-radiation ceramic nanofiber composite material as described above, comprising the following steps: S1. Prepare a high-temperature resistant precursor spinning solution and a radiation-resistant precursor spinning solution, wherein the high-temperature resistant precursor spinning solution has a viscosity of 150~6000 mPa·s and a solid content of 5%~70%, and the radiation-resistant precursor spinning solution has a viscosity of 100~5000 mPa·s and a solid content of 10%~65%; S2. The high-temperature resistant precursor spinning solution and the anti-radiation precursor spinning solution are respectively delivered to a rotating nozzle via independent supply paths. The rotating nozzle is equipped with alternating high-temperature resistant fiber spinning needles and anti-radiation fiber spinning needles. Under the action of a high-voltage electric field, the two spinning solutions are sprayed out synchronously to form a jet. At the same time, the rotating nozzle rotates at a speed of 30~60 r / min, causing the jet to dynamically intertwine in the air and deposit on the receiving device to form a precursor composite material. The high-temperature resistant precursor spinning solution is solidified into nanofibers with a curled circular cross-section, and the anti-radiation precursor spinning solution is solidified into nanoribbons with a curled flat cross-section. S3. The precursor composite material is subjected to high-temperature calcination at a temperature of 600~1300℃ and a holding time of 1~3h to obtain the high-temperature resistant anti-radiation ceramic nanofiber composite material.

[0015] Further, in step S2, the supply flow rates of the high-temperature resistant precursor spinning solution and the anti-radiation precursor spinning solution are independently adjusted by the flow control component, so that the mass flow rate ratio of the two is 9:1 to 1:9; the flow control component performs real-time closed-loop control of the two spinning solutions according to the preset ratio; the rotation amplitude of the rotating nozzle is 45~135°; the voltage of the high-voltage electric field is -150~150 kV; and the distance between the spinning needle and the receiving device is 10~50 cm.

[0016] Further, the method for preparing the high-temperature resistant precursor spinning solution in step S1 includes: mixing a high-temperature resistant metal alkoxide, an acid catalyst, and a spinning aid, and obtaining the solution after hydrolysis and acidification. The high-temperature resistant metal alkoxide is selected from one or more of the following: n-butyl aluminate, aluminum triethoxylate, aluminum isopropoxide, isopropyl zirconate, zirconium tetraethanolamine, and tetraethyl orthosilicate. The method for preparing the anti-radiation precursor spinning solution in step S1 includes: dissolving the anti-radiation metal alkoxide in an alcohol solvent, adding a reaction regulator, a carboxylic acid compound, and a spinning aid in sequence, and mixing them evenly to obtain the solution; wherein the anti-radiation metal alkoxide is selected from one or more of tetrabutyl titanate, isopropyl titanate, tetrabutyl zirconate, and tetraethanolamine.

[0017] A third aspect of the present invention provides an electrospinning apparatus for preparing the high-temperature resistant, anti-radiation ceramic nanofiber composite material as described above, comprising: The uniformly supplied spinneret has an internally independent high-temperature resistant precursor spinning solution porous supply pipe and a reverse radiation precursor spinning solution porous supply pipe, which are used to connect the high-temperature resistant precursor spinning solution source and the reverse radiation precursor spinning solution source, respectively. At least one circular spinneret is rotatably connected below the uniformly supplied spinneret. The circular spinneret has a high-temperature resistant precursor spinning solution storage chamber and a radiation-resistant precursor spinning solution storage chamber that are isolated from each other by a partition. The bottom of both storage chambers is provided with a diversion channel. Multiple high-temperature resistant fiber spinning needles and multiple anti-radiation fiber spinning needles are respectively connected to the end of the diversion channel at the bottom of the corresponding liquid storage chamber, and are alternately arranged along the bottom of the circular spinneret; The high-temperature resistant precursor spinning solution porous supply pipe is connected to the high-temperature resistant precursor spinning solution storage chamber via a pipe, and the anti-radiation precursor spinning solution porous supply pipe is connected to the anti-radiation precursor spinning solution storage chamber via a pipe, and the connecting pipe is equipped with a control component for independently regulating the flow rate.

[0018] Furthermore, the inner diameter of the high-temperature resistant fiber spinning needle and the anti-radiation fiber spinning needle is 0.2~0.8mm; The uniform liquid supply spinneret is equipped with a high-voltage power interface.

[0019] The principle of this invention is as follows: This invention utilizes a four-pronged approach: precise control of fiber morphology via precursor spinning solution, independent and uniform electrospinning of two components, in-situ interwoven and loose deposition, and high-temperature calcination for structural stabilization. This approach achieves deep coupling and synergistic enhancement of high-temperature resistant ceramic nanofibers and anti-radiation ceramic nanoribbons in terms of composition, structure, and function. From the molecular scale and microstructure to macroscopic properties, the entire chain is controllable, ultimately producing a composite thermal insulation and protection material with ultra-low thermal conductivity, high near-infrared anti-radiation efficiency, and ultra-high temperature structural stability.

[0020] The high-temperature resistant precursor spinning solution of this invention uses metal alkoxides such as aluminum and silicon as the main raw materials. Through a sol-gel method, it achieves high hydrolysis and molecular chain decoiling of the precursor. The specific reaction mechanism and process control are as follows: First, an acid catalyst is added to the high-temperature resistant metal alkoxide. Under continuous stirring, a hydrolysis reaction occurs fully. The alkoxy groups in the metal alkoxide molecules such as aluminum and silicon are gradually replaced by hydroxyl groups, resulting in an irreversible hydrolysis reaction. Simultaneously, the molecular chains decoil, allowing them to unwind and expose more active sites, laying the foundation for subsequent polycondensation reactions. In the sol system formed after the hydrolysis reaction, a protonation reaction occurs on the surface of the colloidal particles, adsorbing a large number of hydrogen ions to form a positively charged adsorption layer. Anions in the solution form a diffusion layer outside the adsorption layer. Together, they constitute a stable electric double layer structure. This electric double layer allows the colloidal particles to carry the same positive charge, effectively inhibiting particle aggregation and flocculation through strong electrostatic repulsion, thereby fundamentally preventing gelation of the sol before spinning and ensuring the long-term stability of the spinning solution. Then, the resulting sol system is acidified. The pH of the sol is precisely adjusted to maintain a certain concentration of hydrogen ions in the system, thereby strictly controlling the protonation level of the sol system and further promoting the continuous high-level hydrolysis reaction of the metal alkoxide. Simultaneously, the reactivity of the sol in the subsequent spinning process is adjusted. Under the combined action of the acid catalyst and acidification treatment, cross-linking and polycondensation reactions occur between the hydrolysis product molecular chains, forming a stable inorganic oligomer network. By precisely controlling the concentration of the acid catalyst and performing acidification treatment, the uniform hydrolysis rate and the stable, non-gelling sol system are further ensured. To ensure a high degree of hydrolysis while avoiding system instability caused by excessive hydrolysis, a spinning aid is introduced into the system and stirred continuously to ensure its full dispersion in the sol system, thereby obtaining a spinnable solution with a high degree of hydrolysis. Simultaneously, a polymeric spinning aid is added, whose molecular chains can form entanglements with the inorganic oligomer network, significantly improving the spinnability and chain segment entanglement strength of the spinning solution without reducing the solution viscosity. Furthermore, the addition of hydrated salts such as aluminum chloride enhances the conductivity of the spinning solution and strengthens the whipping effect of the jet in the electric field, providing a foundation for subsequent fluffy deposition.

[0021] The anti-radiation precursor spinning solution of this invention uses high-refractive-index metal alkoxides such as titanium and zirconium as its core. Its preparation is also based on the sol-gel method, combined with coordination protection to achieve system stability. Addressing the highly hydrolytic nature of titanium and zirconium metal alkoxides, the hydrolysis rate is precisely controlled to suppress excessive hydrolysis and prevent agglomeration instability. First, an alcohol solvent is added to the anti-radiation metal alkoxide, and the metal alkoxide is fully dissolved under continuous stirring. Due to the high ionic potential of titanium and zirconium ions, they have a strong attraction to water molecules. Their metal alkoxides readily undergo rapid hydrolysis upon contact with water or trace amounts of water, generating hydroxide precipitates that lead to agglomeration instability. Therefore, an alcohol solvent is used as a dispersion medium to reduce free water molecules in the system and initially suppress the hydrolysis reaction. Next, a reaction regulator is added to adjust the pH of the sol, making the system weakly acidic or neutral. The system is further improved by slowing down the hydrolysis rate and forming a stable, dispersed sol system. Then, carboxylic acid compounds are introduced. The carboxyl groups in these compounds can form stable coordination bonds with metal ions such as titanium and zirconium, constructing a coordination protective shell. This shell tightly wraps around the surface of the metal ions, shielding them from contact with water molecules and fundamentally inhibiting the excessively rapid hydrolysis of the precursor. Simultaneously, the synergistic coordination effect of the reaction regulator and the carboxylic acid compounds further inhibits the rapid hydrolysis and aggregation of metal alkoxides, effectively solving the technical problem of their easy hydrolysis and ensuring long-term solution stability. While ensuring the matching of viscosity and conductivity of the spinning solution, uniform dispersion of precursor molecules is achieved, avoiding spinning defects caused by uneven hydrolysis. Finally, a spinning aid is introduced into the system, and stirring continues to obtain a spinnable solution with a low degree of hydrolysis, providing a prerequisite for the subsequent formation of continuous and uniform anti-radiation nanoribbons.

[0022] Under the influence of a high-voltage electrostatic field, the two precursor spinning solutions form Taylor cones at the tips of independent spinning needles. Under the combined action of electric field force, surface tension, and viscoelastic force, they are uniformly stretched into ultrafine jets. Simultaneously, the spinneret rotates continuously. The core purpose is to drive the two types of spinning needles in synchronous circular motion, ensuring that the ejected ultrafine jets are uniformly distributed in space, avoiding localized agglomeration caused by concentrated jet accumulation. This further promotes the uniform interweaving of the high-temperature resistant precursor jet and the anti-radiation precursor jet, providing a guarantee for the subsequent formation of a three-dimensional fluffy composite structure. The entire spinning process relies on a built-in high-precision flow monitoring element, which can sense the actual flow rate changes of the two spinning solutions in real time and feed the data back to the control center. The control center automatically adjusts the supply circuit, dynamically correcting flow deviations, achieving real-time monitoring, feedback, and adjustment of the flow rate. This ensures that the supply rate of the two spinning solutions remains consistent and free of crosstalk, providing a stable supply guarantee for the uniform stretching and shaping of the jets.

[0023] During flight, the high-temperature resistant precursor jet, being a highly hydrolyzed system, experiences rapid solvent evaporation, leading to a gradual decrease in the interparticle spacing and a weakening of electrostatic repulsion due to the double-layer structure on the particle surface. Simultaneously, the retained hydrogen ions continuously protonate the colloidal particles, inducing condensation reactions. This causes the particles to rapidly aggregate and solidify under the curling deformation during jet flight, ultimately forming a continuous, uniform, and smooth nanofiber precursor free from defects such as breakage or beading. The curling mechanism primarily stems from the whipping effect of the jet in the high-voltage electric field and the difference in solvent evaporation rate. Under the influence of the electric field, the jet oscillates at high frequencies, and the surface solvent evaporates faster than the interior, resulting in inconsistent shrinkage rates between the surface and interior. This causes the jet to naturally curl, ultimately forming a curled, circular nanofiber structure.

[0024] The anti-radiation precursor spinning solution is a system with a low degree of hydrolysis. During its preparation, a carboxylic acid compound introduced forms a bidentate coordination structure with the central metal ion in the anti-radiation metal alkoxide, constructing a coordination protection shell to protect the metal alkoxide and inhibit its rapid hydrolysis. Under the stretching and whipping action of a high-voltage electric field, the jet is subjected to strong external force stretching, while the solvent rapidly evaporates, causing the carboxylic acid ligand to change from bidentate to monodentate coordination, and further undergoing a decoordination reaction. This releases the coordination protection, destabilizes the central metal ion coordination structure, and transforms it into a highly reactive... The active state of the jet then rapidly undergoes a hydrolysis-condensation reaction. Simultaneously, during the jet's flight, a non-uniform solidified structure is formed, where the surface layer solidifies preferentially while the interior remains fluid. Under the continuous stretching action of the electric field, the solidified surface structure collapses and is further stretched and shaped, gradually flattening from a cylindrical jet into a ribbon-like structure. Its curling mechanism is similar to that of high-temperature resistant nanofibers, both originating from the jet whipping effect and the difference in solvent evaporation rate. Because the difference in shrinkage between the surface and the interior is more significant after the anti-radiation jet flattens, a curled flat nanoribbon precursor is ultimately formed, ensuring uniform thickness and consistent width.

[0025] Through the above-mentioned uniform liquid supply and precise spinning control, relying on the precise flow control function of the flow control component, and the design of alternating arrangement and synchronous spinning of the two-component needles driven by the rotating nozzle, the fiber formation process of high-temperature resistant nanofibers and anti-radiation nanoribbons is synchronously controllable, ensuring that the two are structurally matched and morphologically complementary at the microscale. The size and curling degree of the curled circular nanofibers and the curled flat nanoribbons are adapted to each other. Through the subsequent rotation of the spinneret, they are dynamically interwoven and uniformly deposited, finally forming a regular three-dimensional interwoven high-temperature resistant anti-radiation nanofiber precursor.

[0026] The aforementioned composite precursor was placed in a high-temperature calcination furnace, and the entire process of organic phase removal and inorganic phase crystallization was completed through precise temperature control, achieving structural transformation and performance optimization in stages. The initial calcination stage is a low-temperature zone, primarily achieving the full decomposition and volatilization of organic components such as spinning aids and solvents, thoroughly removing organic impurities from the precursor, thus creating space for subsequent inorganic phase crystallization, while avoiding high-temperature sintering defects caused by residual organic components. In the intermediate-temperature zone, the inorganic components in the precursor gradually undergo nucleation reactions, forming tiny crystal nuclei, laying the foundation for subsequent crystal growth. Upon reaching the high-temperature zone, the crystal nuclei continue to grow and develop, completing the densification of the crystal structure, and completely transforming the precursor into a stable ceramic structure.

[0027] During this calcination process, the fibers formed by the high-temperature resistant precursor are the first to crystallize, transforming into stable ceramic fibers and forming a rigid supporting framework. Thanks to their excellent high-temperature structural stability, they effectively prevent the overall structure of the composite material from collapsing or deforming. Simultaneously, these ceramic fibers, acting as a physical barrier layer, are uniformly distributed around the nanoribbons formed by the anti-radiation precursor, effectively suppressing problems such as malignant grain growth, interface sintering, and pore collapse of the anti-radiation component under high-temperature conditions. This completely protects the nanoscale morphology and high specific surface area of ​​the anti-radiation nanoribbons, ensuring its anti-radiation function remains intact. Supported by the ceramic fiber framework, the nanoribbons formed by the anti-radiation precursor maintain a continuous and complete structure. After high-temperature crystallization, they form high-refractive-index crystalline phases such as rutile and tetragonal zirconia. Utilizing the optical properties of these high-refractive-index crystalline phases, they generate strong Mie scattering and interface reflection of the dominant near-infrared radiation heat in high-temperature environments, significantly blocking the conduction path of radiative heat. After the complete calcination process described above, the ceramic fibers and ceramic nanoribbons ultimately form an orderly alternating arrangement, achieving a regular structure in which ceramic nanofibers and ceramic nanoribbons are closely adjacent to each other. The ceramic nanofibers act as a rigid supporting framework, while the ceramic nanoribbons alternately connect and tightly adhere to the fibers, filling the gaps between them. They interpenetrate and support each other, effectively preventing close packing in the same direction, thus forming a three-dimensional network ceramic composite material with high porosity, high elasticity, high bulkiness, and structural stability. This orderly alternating three-dimensional coiled and interpenetrating structure retains a large number of interconnected micropores, effectively blocking solid-phase heat conduction paths and significantly reducing the bulk thermal conductivity of the composite material. Simultaneously, the high porosity and regular alternating structure enhance the material's elasticity and high-temperature structural stability, strengthening its comprehensive thermal insulation and anti-radiation performance.

[0028] Compared with the prior art, the present invention has the following beneficial effects: Overall, through a unique three-dimensional porous network composite structure design (composed of interwoven high-temperature resistant ceramic nanofibers with curled circular cross-sections and anti-radiation ceramic nanoribbons with curled flat cross-sections) and a dedicated dual-path independent liquid supply-rotating nozzle synchronous spinning preparation method, the material components with both high-temperature resistant (thermal insulation) and anti-radiation functions are tightly combined and their performance synergistic at the microscale is achieved, overcoming the single-function defect of single-type fibers. The rotating nozzle enables the two spinning jets to interweave dynamically in the air, and the flow control component monitors and adjusts the flow rate in real time, fundamentally ensuring the uniform dispersion of the two components in the composite material and avoiding the problem of uneven dispersion. The optimized high-temperature calcination process enables the composite material to form a stable ceramic structure, which can still maintain ultra-low thermal conductivity (≤0.06 W / (m·K)) and high elastic recovery rate (≥90%) at 1000℃, effectively suppressing performance degradation at high temperatures.

[0029] Furthermore, the method for preparing a high-temperature resistant anti-radiation ceramic nanofiber composite material of the present invention has the characteristics of strong universality, simple process operation, and continuous controllability. The composite material can be obtained by using the corresponding spinning solution and adjusting the spinning process on existing electrospinning production equipment.

[0030] Furthermore, the dedicated bicomponent spinning device of this invention adopts an independent parallel dual-path liquid supply structure and a rotating nozzle design. The spinneret can achieve reciprocating rotation and precise speed adjustment. Combined with the alternating annular arrangement of needles, the two spinning liquid jets form a dynamic cross trajectory, ensuring that nanofibers and nanoribbons are uniformly interwoven and deposited in the air. This effectively avoids the problems of uneven component dispersion and poor structural adaptability in existing composite technologies, and ensures the uniformity of the composition and structure of the composite material throughout its entire range.

[0031] Furthermore, the high-temperature resistant and anti-radiation ceramic nanofiber composite material prepared by this invention effectively reduces the thermal conductivity of the composite material through the high-temperature resistant component, while forming a high-temperature structural protection for the anti-radiation component to prevent it from sintering and densifying at high temperatures; the anti-radiation component significantly increases the critical tolerance temperature of the composite material, achieving synergistic performance of heat insulation and anti-radiation, which can meet the technical application requirements in the field of high-temperature radiation composite protection, and the composite material has high mass production efficiency per spinneret, taking into account both high performance and large-scale production characteristics. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of an electrospinning device for preparing uniformly shaped blended fibers according to the present invention. Figure 2 This is a schematic diagram of the operation of the circular spinneret of the present invention; Figure 3 This is a cross-sectional schematic diagram of the circular spinneret power transmission device of the present invention; Figure 4This is a schematic diagram of the helical turbine in the rotary drive device of the present invention; Figure 5 This is a perspective view of the circular spinneret of the present invention; Figure 6 This is a schematic diagram of the longitudinal central section of the circular spinneret body of the present invention; Figure 7 This is a schematic diagram showing the distribution of the circular spinneret needles of the present invention; Figure 8 This is a schematic diagram of the flow control component.

[0033] Explanation of markings in the diagram: 1-Hollow cylindrical shaft, 2-Helical turbine housing, 3-Motor assembly box, 4-Solid rotating shaft, 5-High temperature resistant precursor spinning solution reservoir, 6-Anti-radiation precursor spinning solution reservoir, 7-High temperature resistant precursor spinning solution distribution channel, 8-Anti-radiation precursor spinning solution distribution channel, 9-High temperature resistant precursor spinning solution reservoir supply pipe, 10-Anti-radiation precursor spinning solution reservoir supply pipe, 11-High temperature resistant fiber spinning needle, 12-Anti-radiation fiber spinning needle 13-Needle, 14-Receiving substrate, 15-Reversible motor, 16-High temperature resistant precursor spinning solution supply port, 17-Anti-radiation precursor spinning solution supply port, 18-Spinneret, 19-High temperature resistant precursor spinning solution porous supply tube, 20-Anti-radiation precursor spinning solution porous supply tube, 21-First helical gear, 22-Second helical gear, 23-Rolling bearing, 24-Spiral hose, 25-Flow control assembly, 26-Circular spinneret. Detailed Implementation

[0034] In this invention, the key terms involved are first explained. "High-temperature resistant ceramic nanofibers" refer to fibers made of ceramic materials with excellent high-temperature thermal stability, such as mullite, zirconium oxide, alumina, silicon dioxide, and molybdenum dioxide. In this invention, it specifically refers to fibers with a curled circular cross-section. "Anti-radiation ceramic nanoribbons" refer to nanoribbons made of ceramic materials with high refractive index, such as titanium oxide, zirconium dioxide, alumina, and hafnium dioxide. In this invention, it specifically refers to ribbon-like morphology with a curled flat cross-section. "Curled circular cross-section" refers to the high-temperature resistant ceramic nanofibers exhibiting a curled shape similar to a spring or spiral at the microscopic level, with a circular cross-section. "Curled flat cross-section" refers to the anti-radiation ceramic nanoribbons exhibiting a curled shape at the microscopic level, with a flat cross-section, possessing dimensional characteristics in both width and thickness dimensions. "Three-dimensional porous network structure" refers to a three-dimensional structure with numerous pores formed by the intertwining, weaving, and stacking of the aforementioned fibers and nanoribbons.

[0035] Overall, this invention achieves synergistic performance by combining high-temperature resistant ceramic nanofibers with anti-radiation ceramic nanofibers: the high-temperature resistant fiber, acting as the matrix, effectively reduces the bulk thermal conductivity of the composite material, providing high-temperature structural protection for the anti-radiation fiber and inhibiting its malignant grain growth and structural sintering at high temperatures; the anti-radiation fiber, through its flat-section, curled nanoribbon structure, increases the specific surface area, enhances the reflectivity of near-infrared radiation heat, reduces surface heat absorption, and significantly improves the critical withstand temperature of the composite material, enabling it to maintain stable performance at higher temperatures, thus meeting the application requirements in the field of high-temperature radiation composite protection. In the service environment of high-temperature radiation composites, single anti-radiation nanofiber materials or high-temperature resistant nanofiber materials have significant performance shortcomings and cannot simultaneously meet the comprehensive technical requirements of near-infrared radiation reflection, high temperature and low thermal conductivity, and high-temperature structural stability. Therefore, preparing composite structural materials from anti-radiation nanofibers and high-temperature resistant nanofibers has become a key direction for solving the above-mentioned technical problems. High-temperature resistant nanofibers are used as the temperature-resistant framework of composite materials, relying on their excellent high-temperature thermal stability, low thermal conductivity and porous structure to ensure the thermal insulation performance and structural integrity of composite materials at high temperatures. At the same time, anti-radiation nanofibers are introduced to endow composite materials with efficient anti-radiation performance that reflects near-infrared waves. Through the Mie scattering effect, radiative heat transfer is blocked, achieving dual blocking of heat conduction and radiative heat.

[0036] In this invention, the composite material uses high-temperature resistant ceramic nanofibers as the matrix skeleton, which plays a role in high-temperature structural support and heat insulation; and uses anti-radiation ceramic fiber nanoribbons as the functional component to achieve anti-radiation protection effect; the two-component fibers are uniformly deposited and shaped by the device to form a composite structure in which the high-temperature resistant fibers and anti-radiation nanoribbons are tightly interwoven.

[0037] Precursor spinning solution performance indicators: The high-temperature resistant precursor spinning solution has a viscosity controlled at 150~6000 mPa·s, a surface tension of 28~150 mN / m, a solid content of 5%~70%, and an electrical conductivity of 80~1300 μS / cm to ensure a high degree of hydrolysis and meet the requirements for spinning. The anti-radiation precursor spinning solution has a viscosity controlled at 100~5000 mPa·s, a surface tension of 20~100 mN / m, a solid content of 10%~65%, and an electrical conductivity of 50~1200 μS / cm to meet the forming requirements of flat cross-section nanoribbons. The performance parameters of the two spinning solutions are matched to ensure the interlacing effect during synchronous spinning.

[0038] S2. Device Structural Design: The present invention utilizes a two-component spinning device with a uniform liquid supply spinneret, a rotating nozzle, and a flow control assembly as its core components, combined with an insulation and sealing structure, to achieve crosstalk-free liquid supply, uniform weaving, and stable molding of dual-path spinning solutions. The specific structure is as follows: Uniform liquid supply spinneret: Two multi-hole liquid supply pipes are arranged in parallel at the same horizontal height inside the plate body. Each multi-hole liquid supply pipe has 6 to 10 threaded through holes on its lower side, and the horizontal distance between adjacent threaded through holes is 120 to 150 mm. A single spinneret can connect 6 to 10 circular spinnerets in parallel. Positioning holes are set on the bottom side of the spinneret body to ensure assembly accuracy. The roughness of the inner wall of the spinneret body and the circular spinnerets is controlled to Ra≤0.045μm to reduce the flow resistance of the spinning solution.

[0039] The flow control component described in this invention employs the ACU20FE series Coriolis mass controller manufactured by Beijing AccuFLOW Technology Co., Ltd. This device can directly and accurately measure the mass flow rate of liquids under complex operating conditions, unaffected by changes in fluid pressure, temperature, density, and viscosity.

[0040] This controller model features fast response and no thermal drift. Through its built-in digital communication interface (RS485 / Modbus protocol), real-time flow data from two spinning solutions can be integrated into the central control system, enabling precise digital switching and dynamic control of the precursor compound ratio within the range of 9:1 to 1:9. The circular spinneret features a dual liquid storage chamber with an outer diameter of 70-80mm, an internal height of 30-40mm, and a wall thickness of 6-8mm. The partition structure between the liquid storage chambers has a wall thickness of 4-5mm to ensure structural strength and liquid storage stability. The hollow cylindrical shaft has an inner diameter of 25-35mm, a wall thickness of 4-5mm, and protrudes 60-70mm from the dual liquid storage chambers, adapting to rotary drive and liquid supply connections. Three independent diversion channels extend from the bottom of the liquid storage chambers; the high-temperature resistant type has an included angle of 120° between the axes of adjacent channels, and the channel wall thickness is 2-3mm. The cross-sectional diameter is 3~5mm to achieve uniform distribution of spinning solution; the spinning needles are arranged alternately along the bottom circumference of the spinneret, 8~12mm from the edge, with a center-to-center distance of 15~20mm between adjacent needles, and the inner diameter of the needles is selectable from 0.2~0.8mm. The tip flatness error is ≤0.05mm to ensure synchronous jet ejection; the spinneret reciprocates and rotates at an amplitude of 45~135° and a speed of 30~60r / min, with the rotation accuracy controlled within ±1° to ensure the uniformity of dynamic interweaving of the two-component jets.

[0041] S3. Core process parameter range: The core process parameters of spinning and calcination described in this invention are precisely controlled within the following ranges: the electrospinning output voltage is -150~150kV, and the positive or negative electric field can be flexibly selected according to the properties of the spinning solution and the molding requirements; the spinning solution injection rate is 1~100mL / h, and the receiving distance between the spinning needle and the receiving substrate 13 is 10~50cm, so as to achieve full stretching and solidification of the jet; the mass ratio of the two spinning solutions is 9~1:1, which can be flexibly adjusted according to the high temperature resistance and anti-radiation performance requirements of the actual service scenario; the peak temperature of high-temperature calcination is 600~1300℃, and the holding time is 1~3h, so as to achieve full decomposition of the organic phase of the precursor and stable crystallization of the inorganic phase.

[0042] S4. Composite Material Performance and Mass Production Specifications The high-temperature resistant, anti-radiation ceramic nanofiber composite material prepared by this invention has a bulk density ≤100 mg / cm³. 3 The porosity is 85%~95%, the thermal conductivity at room temperature is ≤0.025W / (m·K), the thermal conductivity at 1000℃ is ≤0.06W / (m·K), the compression elastic recovery rate is ≥90%, and there is no structural collapse after being kept at 1400℃ for 2 hours. It has the comprehensive characteristics of being lightweight, highly insulating, highly resilient, and structurally stable at high temperatures. Moreover, the preparation method of this invention achieves synchronous and uniform interweaving and stable molding of bicomponent fibers, and the mass production efficiency of single spinneret spinning can reach 5~15kg / day, meeting the needs of large-scale production.

[0043] In a specific implementation, preferably, the high-temperature resistant anti-radiation ceramic nanofiber composite material has a circular cross-section structure for its high-temperature resistant ceramic fibers, with the fiber diameter controlled between 400 and 600 nm. It is prepared by selecting one or more of mullite, zirconium oxide, alumina, silicon dioxide, and molybdenum dioxide, and has excellent high-temperature thermal stability, can withstand high-temperature conditions for a long time without structural collapse.

[0044] In a preferred embodiment, the high-temperature resistant anti-radiation ceramic nanofiber composite material has anti-radiation ceramic fibers that are flat-section nanoribbon structures with a width of 500nm~5μm and a thickness of 20~200nm. The nanoribbons are prepared by selecting one or more of titanium oxide, zirconium dioxide, aluminum oxide, hafnium dioxide, and cerium dioxide, and have stable anti-radiation performance.

[0045] In a preferred embodiment, the high-temperature resistant, anti-radiation ceramic nanofiber composite material is prepared by a dedicated bicomponent spinning device. The device is equipped with a flow control component as the core CNC component, and combined with an independent parallel dual-path liquid supply structure and a rotating nozzle design, it can achieve independent, crosstalk-free, and precise liquid supply and synchronous spinning of the two spinning solutions. Through the digital flow acquisition, closed-loop control, and dual-path collaborative function of the connector, it ensures that the liquid supply rates of the two spinning solutions are stably matched, so that the bicomponent fibers are uniformly deposited during the dynamic interweaving process, effectively avoiding the problem of local aggregation or imbalance of component distribution, and ensuring the uniformity of the overall structure and component distribution of the composite material.

[0046] In a specific implementation, preferably, the high-temperature resistant, anti-radiation ceramic nanofiber composite material has a bulk density ≤0.1 g / cm³. 3 It has a porosity of 85%~95%, a thermal conductivity of ≤0.025W / (m·K) at room temperature, a thermal conductivity of ≤0.06W / (m·K) at 1000℃, a compressive elastic recovery rate of ≥90%, and no structural collapse after being kept at 1400℃ for 2 hours. It has the comprehensive characteristics of being lightweight, highly insulating, highly resilient, and structurally stable at high temperatures.

[0047] This invention also provides a method for preparing the above-mentioned high-temperature resistant, anti-radiation ceramic nanofiber composite material, comprising the following steps: Step 1): Add an acid catalyst to the high-temperature resistant metal alkoxide solution and allow the hydrolysis reaction to occur fully under continuous stirring. This allows the colloidal particles in the sol to form an electric double layer structure to inhibit particle aggregation. Acidify the sol system to adjust the pH value and control the degree of protonation and subsequent spinning reaction activity. Finally, introduce a spinning aid into the system and continue stirring until fully dispersed to obtain a high-temperature resistant precursor spinning solution with a high degree of hydrolysis that meets the spinning requirements.

[0048] Step 2): Add an alcohol solvent to the anti-radiation metal alkoxide and stir continuously until the metal alkoxide is completely dissolved; add a reaction regulator to the system to adjust the pH value of the sol and form a stable and dispersed sol system; introduce a carboxylic acid compound to form coordination protection and inhibit the excessively rapid hydrolysis of the precursor; finally add a spinning aid and stir evenly to obtain an anti-radiation precursor spinning solution with a low degree of hydrolysis and suitable for nanobelt forming.

[0049] Step 3): Inject the prepared high-temperature resistant precursor spinning solution and anti-radiation precursor spinning solution into the corresponding liquid storage structures of the device, respectively. Adjust the liquid supply flow rate through the flow control component of the device to ensure uniform and non-interference supply of spinning solution in both channels. This completes the spinning solution filling and preliminary debugging of the equipment, ensuring the stable operation of the subsequent spinning process.

[0050] Step 4): Start the high-voltage power supply and rotary drive device of the equipment. Under the action of the high-voltage electric field, the dual spinning solutions are synchronously sprayed out by the alternately arranged spinning needles. Due to the high degree of hydrolysis, the colloidal particles in the jet quickly aggregate and solidify after the solvent evaporates, forming a curled circular nanofiber structure. Due to the low degree of hydrolysis, the anti-radiation spinning solution undergoes a change in coordination structure under the action of electric field stretching and solvent evaporation. The surface layer of the jet is preferentially solidified and stretched and shaped to form a flat cross-section curled nanoribbon structure. At the same time, the nozzles continue to rotate, so that the circular high-temperature resistant fibers and the flat anti-radiation nanoribbons are dynamically intertwined in the air and uniformly deposited on the receiving device to obtain the precursor nanofibers with a composite structure.

[0051] Step 5): Place the composite precursor nanofibers deposited on the receiving device into a high-temperature calcination equipment, heat them to the peak temperature according to the preset process, and keep them at the temperature to complete the high-temperature calcination treatment. This allows the precursor to complete the organic phase decomposition and inorganic phase crystallization at high temperature, forming a stable ceramic fiber structure, and finally obtaining a high-temperature resistant anti-radiation ceramic nanofiber composite material.

[0052] In a specific implementation, preferably, the high-temperature resistant metal alkoxide in step 1) is selected from n-butyl aluminate, trimethoxyaluminum, triethoxyaluminum, tri-n-propoxyaluminum, sec-butoxide aluminum, triethanolamine aluminum, isopropoxide aluminum, tert-butoxide aluminum, isobutoxide aluminum, diethyl aluminate, dimethyl aluminate, triisobutoxyaluminum, isopropyl zirconate, tert-butyl zirconate, tetraethanolzirconium, tetramethanolzirconium, n-propoxidezirconium, isobutoxidezirconium, n-butoxidezirconium, tetrapentoxidezirconium, diethyl zirconate, dimethyl zirconate, and so on. Molybdenum propoxide, molybdenum n-butoxide, molybdenum tert-butoxide, molybdenum triethoxy, molybdenum trimethoxy, molybdenum tri-n-propoxy, molybdenum triisobutoxy, molybdenum tetraethanolamine, molybdenum tetramethoxy, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate, and n-butyl orthosilicate; the acid catalyst is selected from hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, boric acid, formic acid, glacial acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, and malic acid. The reaction mixture contains one or more of the following: citric acid, fumaric acid, oxalic acid, malonic acid, and succinic acid; the spinning aid is selected from one or more of the following: polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyvinyl ether, polylactic acid, polycaprolactone, polyacrylonitrile, polyvinyl acetate, polyurethane, polyethylene glycol, polypropylene glycol, polyamide, polymethyl methacrylate, polyvinyl chloride, polypropylene, polystyrene, polyethylene terephthalate, polybutylene adipate, polylactic acid-glycolic acid copolymer, polyethersulfone, and polyimide; the concentrations are all based on the total mass of the reaction system; the amount of high-temperature resistant metal alkoxide added is 6-90 wt% of the total mass of the reaction system; the amount of acid catalyst added is 1-8 wt% of the total mass of the reaction system; the amount of auxiliary agent added is 2-10 wt% of the total mass of the reaction system; the stirring rate is 500-1000 r / min, and the stirring time is 2-5 h.

[0053] In a specific implementation, preferably, the anti-radiation metal alkoxide in step 2) is selected from isopropyl titanate, tetrabutyl titanate, ethyl titanate, methoxyethyl titanate, isobutyl titanate, n-propyl titanate, tert-butyl titanate, tetrabutyl zirconate, isopropyl zirconate, n-propyl zirconate, tert-butyl zirconate, isopropyl aluminate, n-butyl aluminate, tert-butyl aluminate, titanium tetraethanolamine, titanium isobutoxide, and n-propanol. Titanium, titanium n-butoxide, titanium tetramethanol, titanium tetrapentoxide, zirconium tetraethanoloxide, zirconium n-propoxide, zirconium isobutoxide, zirconium n-butoxide, zirconium tetrapentoxide, hafnium tetramethanol, hafnium tetraethanoloxide, hafnium n-propoxide, hafnium n-butoxide, hafnium isobutoxide, hafnium tert-butoxide, hafnium tetrapentoxide, cerium isopropoxide, cerium n-butoxide, cerium tert-butoxide, cerium tetraethanoloxide, yttrium isopropoxide, yttrium n-butoxide, yttrium tert-butoxide, scandium isopropoxide, scandium n-butoxide, etc. The solvent is selected from one or more of the following: lanthanum propoxide, lanthanum n-butoxide, lanthanum tert-butoxide, neodymium isopropoxide, neodymium n-butoxide, samarium isopropoxide, and samarium n-butoxide; the alcohol solvent is selected from one or more of the following: anhydrous ethanol, isopropanol, n-butanol, tert-butanol, n-propanol, isobutanol, ethylene glycol monomethyl ether, propylene glycol methyl ether, ethylene glycol monoethyl ether, propylene glycol ethyl ether, n-pentanol, isopentanol, cyclohexanol, benzyl alcohol, ethylene glycol, propylene glycol, butanediol, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, phenethyl alcohol, hexanol, and isohexanol; the reaction regulator is selected from one or more of the following: hydrochloric acid, nitric acid, ethylene glycol, ethylenediaminetetraacetic acid, acetylacetone, glycerol, diethanolamine, triethanolamine, lactic acid, salicylic acid, phosphoric acid, boric acid, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetraamine, and butylenediamine. The chemical compound is selected from one or more of the following: pentanediamine, hexamethylenediamine, diethanolamine, triisopropanolamine, malic acid, tartaric acid, and citric acid; the carboxylic acid compound is selected from one or more of the following: citric acid, oxalic acid, glacial acetic acid, malonic acid, glycolic acid, succinic acid, maleic acid, malic acid, tartaric acid, benzoic acid, phthalic acid, azelaic acid, sebacic acid, fumaric acid, itaconic acid, sorbic acid, lactic acid, salicylic acid, glutaric acid, adipic acid, pimelic acid, succinic acid, azelaic acid, stearic acid, and palmitic acid; the spinning aid is selected from one or more of the following: polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyvinyl ether, polylactic acid, polycaprolactone, polyacrylonitrile, polyvinyl acetate, polyurethane, polyethylene glycol, polypropylene glycol, polyamide, polymethyl methacrylate, and polyvinyl chloride. The reaction mixture comprises one or more of the following: olefins, polypropylene, polystyrene, polyethylene terephthalate, polybutylene adipate, polylactic acid-glycolic acid copolymer, polyethersulfone, and polyimide; based on the total mass of the reaction system, the amount of the anti-radiation metal alkoxide added is 5-80 wt% of the total mass of the reaction system; the amount of the alcohol solvent added is 3-10 times the mass of the anti-radiation metal alkoxide; the amount of the reaction regulator added is 0.5-5 wt% of the total mass of the reaction system; the amount of the carboxylic acid compound added is 2-9 wt% of the total mass of the reaction system; the concentration of the spinning aid added is 2-10 wt% of the total mass of the anti-radiation precursor spinning solution; the stirring rate is 500-1000 r / min; and the stirring time is 2-5 h.

[0054] In a preferred embodiment, the liquid storage structure described in step 3) is a dual-chamber independently sealed liquid storage tank, with an effective volume of 50~500mL per tank and a working pressure of 0.02~0.1MPa. An anti-settling stirring device is installed inside the tank, with a stirring speed of 30~120r / min to ensure the concentration and dispersion uniformity of the spinning solution. The flow control component has a flow adjustment accuracy of ±0.1mL / h, a liquid supply flow range of 0.5~10mL / h, and a pressure resistance of 0.15MPa. It possesses real-time flow acquisition and closed-loop control functions, enabling independent, stable, and crosstalk-free synchronous delivery of the dual-path spinning solution.

[0055] In a specific implementation, preferably, the spinning needle in step 4) is a stainless steel flat-mouth needle with an inner diameter of 0.1~0.8mm, an outer diameter of 0.3~1.2mm, a needle length of 8~20mm, a polished surface, a needle tip angle of 15°~30°, and a single needle flow rate controlled at 0.5~10mL / h; the nozzle is a dual-component independent flow channel rotary nozzle with a rotation speed of 10~120r / min, a spinneret diameter of 30~120mm, and high-temperature resistant and anti-radiation spinning needles arranged in an alternating ring, with a spacing of 3~15mm between adjacent needles, and a spacing of 10~30cm between the nozzle and the receiving device.

[0056] Preferably, in specific implementation, the calcination equipment in step 5) is a program-controlled temperature box-type atmosphere furnace with a temperature control accuracy of ±1℃, a heating rate of 1~10℃ / min, a calcination temperature range of 600~1400℃, a holding time of 1~6h, an air atmosphere inside the furnace, and an effective working volume of 10~200L; the composite material is a fiber and nanoribbon interwoven composite structure, with fiber diameter of 400~800nm, nanoribbon thickness of 20~200nm, width of 500nm~5μm, and bulk density of 50~150kg / m³. 3 It has a porosity of 85%~95%, a thermal conductivity of ≤0.06W / (m·K) at 1000℃, and a long-term operating temperature of up to 1300℃.

[0057] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, circuit structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0058] Example 1 The preparation method of the high-temperature resistant anti-radiation ceramic nanofiber composite material in this embodiment includes: preparing a high-temperature resistant precursor spinning solution and an anti-radiation precursor spinning solution using the sol-gel method; then, conveying the two spinning solutions to a uniformly supplied spinneret, extruding them through a rotating nozzle, and controlling the fiber formation mode to interweave and assemble the prepared nanoribbons and nanofibers, and uniformly depositing them on a receiving device to form precursor nanofibers; further, calcining the precursor nanofibers at high temperature to obtain the high-temperature resistant anti-radiation ceramic nanofiber composite material; the specific steps are as follows: S1. First, an acid catalyst is added to a high-temperature resistant metal alkoxide solution, and a hydrolysis reaction is fully carried out under continuous stirring. A double electric layer structure is formed on the surface of the colloidal particles in the sol, and the aggregation of colloidal particles is inhibited by electrostatic repulsion, thereby preventing the sol from gelling before spinning. Then, the system in the obtained sol is acidified to adjust the pH value of the sol, so that a certain concentration of hydrogen ions is retained in the system, thereby controlling the degree of protonation of the sol system and adjusting the reactivity of the sol in the subsequent spinning process. Finally, a spinning aid is introduced into the system and stirring is continued to ensure that it is fully dispersed in the sol system, thereby obtaining a spinnable solution with a high degree of hydrolysis. S2. The anti-radiation precursor spinning solution is first prepared by adding an alcohol solvent to the anti-radiation metal alkoxide and ensuring the full dissolution of the metal alkoxide under continuous stirring. Then, a reaction regulator is added to the system to adjust the pH value of the sol and form a stable and dispersed sol system. Subsequently, a carboxylic acid compound is introduced to form coordination protection and inhibit the excessively rapid hydrolysis of the precursor. Finally, a spinning aid is introduced into the system and stirring is continued to obtain a spinnable solution with a low degree of hydrolysis. S3. The high-temperature resistant precursor spinning solution prepared in S1 and the anti-radiation precursor spinning solution prepared in S2 are respectively fed to a spinneret and introduced into the spinneret disk through a supply pipe. Spinning is carried out under the action of a high-voltage electric field. During the spinning process, the high-temperature resistant precursor spinning solution is a system with a high degree of hydrolysis. As the solvent in the jet evaporates, the distance between colloidal particles decreases, and the electrostatic repulsion of the double-layer structure gradually weakens. At the same time, the hydrogen ions retained in the system protonate the colloidal particles and induce condensation reaction, causing the colloidal particles to rapidly aggregate and solidify during the jet curling deformation process, thereby forming a curled circular nanofiber structure. The anti-radiation precursor spinning solution has a low degree of hydrolysis. In this system, under the stretching effect of a high-voltage electric field and rapid solvent evaporation, the carboxylic acid ligand changes from bidentate coordination to monodentate coordination and undergoes decoordination, causing the central ion coordination structure to become unstable. Subsequently, a hydrolysis-condensation reaction occurs rapidly, and the mixture solidifies under jet whipping conditions. Simultaneously, during jet flight, a structure is formed where the surface layer solidifies preferentially while the interior remains fluid. Under the continuous stretching effect of the electric field, the surface structure collapses and is stretched and shaped, thereby forming a flat cross-section curled nanoribbon structure. Furthermore, the nozzle rotates continuously during the spinning process, causing the curled circular nanofibers and curled flat nanoribbons to intertwine in the air and be uniformly deposited on the receiving device, ultimately obtaining a composite structure precursor nanofiber. S4. The precursor nanofibers prepared in S3 are calcined at high temperature to obtain high-temperature resistant anti-radiation ceramic nanofiber materials.

[0059] The preparation process in this embodiment specifically includes the following steps: Step 1): Dilute hydrochloric acid (36.5% by mass) with anhydrous ethanol at a mass ratio of 1:10, and slowly add it dropwise to deionized water (the mass ratio of deionized water to hydrochloric acid is 70:1) to adjust the pH of the system to about 3.0.

[0060] Under continuous stirring, slowly add aluminum isopropoxide (the mass ratio of aluminum isopropoxide to deionized water is 1:7) until it is evenly dispersed.

[0061] Finally, polyethylene oxide (PEO) was added as a spinning aid (the mass ratio of aluminum isopropoxide to polyethylene oxide was 10:3), and stirring was continued for 6 hours to obtain a uniform and stable high-temperature resistant precursor spinning solution.

[0062] In the resulting spinning solution, based on the total mass of the reaction system, the mass concentrations of each component were as follows: aluminum isopropoxide 10 wt%, hydrochloric acid (36.5%) 1 wt%, polyethylene oxide 3 wt%, anhydrous ethanol 10 wt%, and deionized water 76 wt%, totaling 100 wt%. The mass ratio of aluminum isopropoxide, hydrochloric acid (36.5%), and polyethylene oxide was 10:1:3.

[0063] Step 2): Tetrabutyl titanate, as a radiation-resistant metal alkoxide, was added to anhydrous ethanol (the mass ratio of tetrabutyl titanate to anhydrous ethanol was 1:2). The solution was stirred at 30°C and a stirring rate of 800 r / min for 4 hours until completely dissolved, preparing a homogeneous alkoxide solution. Acetylacetone was added as a reaction regulator (the mass ratio of tetrabutyl titanate to acetylacetone was 1:0.25) to adjust the pH of the system to 4. Glacial acetic acid was then added as a carboxylic acid compound (the mass ratio of tetrabutyl titanate to glacial acetic acid was 1:0.5), and the mixture was stirred for 30 minutes to construct a coordination protective shell. Finally, polyvinylpyrrolidone (PVP) was introduced as a spinning aid (the mass ratio of tetrabutyl titanate to PVP was 1:0.5), and the mixture was stirred for another 2 hours until uniformly dispersed, yielding a homogeneous and stable radiation-resistant precursor spinning solution. In the resulting spinning solution, based on the total mass of the reaction system, the mass concentrations of each component were as follows: tetrabutyl titanate 23.5 wt%, anhydrous ethanol 47.1 wt%, acetylacetone 5.9 wt%, glacial acetic acid 11.8 wt%, and polyvinylpyrrolidone 11.8 wt%.

[0064] Step 3): The two spinning solutions mentioned above are injected into the two supply pipes of the flow control component 25 (ACU20FE series Coriolis mass controller produced by Beijing Jingliang Technology Co., Ltd.) at a mass ratio of 7:3. Electrospinning is carried out by electric field stretching. The spinning process parameters are set as follows: spinning voltage 30kV, injection speed 20mL / h, receiving distance 20cm, spinneret rotation amplitude 90°, speed 40r / min, spinning environment temperature 25℃, humidity 50%. The supply rate of the two spinning solutions is adjusted in real time by the flow control component 25 to ensure no crosstalk and consistent rate, so as to obtain composite precursor nanofibers with uniform interweaving of fibers and nanobelts, without breakage or beading defects.

[0065] Step 4): Place the composite precursor nanofibers in a continuous calcination furnace and raise the temperature using a programmed temperature control method at a rate of 5℃ / min. After raising the temperature to 800℃, hold the temperature for 2 hours and allow it to cool naturally to room temperature to obtain a high-temperature resistant anti-radiation ceramic nanofiber composite material.

[0066] The performance test results of the prepared composite material are as follows: bulk density 60 mg / cm³ 3 It has a porosity of 90%, a thermal conductivity of 0.020 W / (m·K) at room temperature (25℃), a thermal conductivity of 0.045 W / (m·K) at 1000℃, a compression elastic recovery rate of 95%, no structural collapse after being kept at 1400℃ for 2 hours, and a near-infrared radiation reflectivity of ≥85%, meeting the requirements for use under extreme high-temperature radiation composite working conditions.

[0067] This embodiment also provides an electrospinning apparatus for preparing the above-mentioned high-temperature resistant, anti-radiation ceramic nanofiber composite material, such as... Figures 1 to 8 As shown, the device includes: Uniform Spinneret: The spinneret body 17 is internally equipped with independent high-temperature resistant precursor spinning solution porous supply pipes 19 and anti-radiation precursor spinning solution porous supply pipes 20, which are used to connect to the high-temperature resistant precursor spinning solution source and the anti-radiation precursor spinning solution source, respectively. The spinneret body 17 is equipped with a high-voltage power interface 18 for connecting to a high-voltage electric field (its internal and external circuit structures are existing technologies and will not be described in detail). The high-temperature resistant precursor spinning solution porous supply pipe 19 and the anti-radiation precursor spinning solution porous supply pipe 20 are connected to external spinning solution sources through the high-temperature resistant precursor spinning solution supply port 15 and the anti-radiation precursor spinning solution supply port 16, respectively.

[0068] Circular spinneret and its drive system: At least one circular spinneret 26 is rotatably connected to the spinneret body 17 below via a hollow cylindrical shaft 1. A helical turbine housing 2 is mounted on the hollow cylindrical shaft 1. Inside the helical turbine housing 2, a first helical gear 21 is fixedly sleeved on the hollow cylindrical shaft 1. The first helical gear 21 meshes with a second helical gear 22 fixedly sleeved on a solid rotating shaft 4. The solid rotating shaft 4 is driven by a reversible motor 14, which is installed in a motor assembly housing 3. The inner ring of a rolling bearing 23 is fitted onto the outer wall of the solid rotating shaft 4, and the outer ring of the rolling bearing 23 is connected to the spinneret body 17 to support the solid rotating shaft 4 and ensure smooth rotation. A spiral hose 24 is connected in the liquid supply pipeline to accommodate pipeline deformation during rotation. One end of the spiral hose 24 is connected to the liquid supply pipes fixed in the spinneret body 17, namely the high-temperature resistant precursor spinning liquid porous supply pipe 19 and the anti-radiation precursor spinning liquid porous supply pipe 20, and the other end is connected to the top of the hollow cylindrical shaft 1 through the rotary joint 25.

[0069] The spinning solution enters the spiral hose 24 through the supply pipe, passes through the flow control component 25, and then flows into the central channel of the hollow cylindrical shaft 1. The spiral hose 24 is arranged in a spiral spring shape, the purpose of which is to counteract the relative displacement and vibration between the pipes when the hollow cylindrical shaft 1 rotates or adjusts its position with the overall mechanism.

[0070] Dual reservoirs and diversion channels: The circular spinneret 26 is internally separated by a partition into a high-temperature resistant precursor spinning solution reservoir 5 and a reverse-radiation precursor spinning solution reservoir 6. The bottom of each reservoir is equipped with a high-temperature resistant precursor spinning solution diversion channel 7 and a reverse-radiation precursor spinning solution diversion channel 8, respectively. See [reference needed]. Figure 6 It is used to evenly distribute the spinning solution to each spinning needle. The high-temperature resistant precursor spinning solution storage chamber 5 and the anti-radiation precursor spinning solution storage chamber 6 are respectively connected to the corresponding high-temperature resistant precursor spinning solution porous supply pipe 19 and anti-radiation precursor spinning solution porous supply pipe 20 through the high-temperature resistant precursor spinning solution storage chamber supply pipe 9 and the anti-radiation precursor spinning solution storage chamber supply pipe 10.

[0071] Spinning needles and flow control: Multiple high-temperature resistant fiber spinning needles 11 and multiple anti-radiation fiber spinning needles 12 are respectively connected to the ends of the high-temperature resistant precursor spinning solution distribution channel 7 and the anti-radiation precursor spinning solution distribution channel 8, and are alternately arranged along the bottom of the circular spinneret 26. A flow control component 25 is provided on the liquid supply pipeline to independently and precisely regulate the liquid supply flow of the two spinning solutions, ensuring no crosstalk and consistent rates.

[0072] Receiving device: During the spinning process, the jet is deposited on the receiving substrate 13 to form a precursor composite material. The distance between the receiving substrate 13 and the spinning needle is adjustable to optimize the deposition effect.

[0073] This device, through independent parallel dual-path liquid supply, rotating nozzle design, and digital flow control, achieves synchronous and uniform interweaving of two-component spinning solutions, fundamentally solving the problem of uneven component distribution.

[0074] In practice: The uniformly supplied spinneret 17 has an independent high-temperature resistant precursor spinning solution porous supply pipe 19 and a radiation-resistant precursor spinning solution porous supply pipe 20 inside, which are used to connect the high-temperature resistant precursor spinning solution source and the radiation-resistant precursor spinning solution source, respectively. At least one circular spinneret 26 is rotatably connected to the bottom of the uniformly supplied spinneret 17 via a hollow cylindrical shaft 1. The circular spinneret 26 is provided with a high-temperature resistant precursor spinning solution storage chamber 5 and a radiation-resistant precursor spinning solution storage chamber 6, which are isolated from each other by a partition. The bottom of both storage chambers is provided with a diversion channel. Multiple high-temperature resistant fiber spinning needles 11 and multiple anti-radiation fiber spinning needles 12 are respectively connected to the end of the diversion channel at the bottom of the corresponding liquid storage chamber, and are arranged alternately along the bottom circumference of the circular spinneret 26. The high-temperature resistant precursor spinning solution porous supply pipe 19 is connected to the high-temperature resistant precursor spinning solution storage chamber 5 via a pipe, and the anti-radiation precursor spinning solution porous supply pipe 20 is connected to the anti-radiation precursor spinning solution storage chamber 6 via a pipe, and a flow control component 25 for independently regulating the flow rate is provided on the connecting pipe.

[0075] This device achieves physical isolation between the two spinning solutions through an independently and parallel dual-supply structure, avoiding premixing and mutual interference during the supply process. The rotation of the circular spinneret 26 drives the alternating high-temperature resistant fiber spinning needles 11 and anti-radiation fiber spinning needles 12 to rotate synchronously, causing the two sets of jets ejected from the needles to form dynamically intersecting trajectories in space. This achieves uniform interweaving of the two fibers / nanobelts in three-dimensional space, fundamentally solving the problem of uneven component distribution in traditional physical mixing methods. The flow control component 25 can independently and precisely control the flow rate of the two spinning solutions, thereby accurately adjusting the component ratio of the composite material.

[0076] To further improve spinning precision and process integration, the inner diameter of the high-temperature resistant fiber spinning needle and the anti-radiation fiber spinning needle is 0.2~0.8mm; the uniform liquid supply spinneret is equipped with a high-voltage power interface. A suitable needle inner diameter is crucial for ensuring the stability of the spinning jet and forming the desired cross-sectional shape. For example, an excessively large needle inner diameter can lead to uneven jet diameter, making it difficult to form fine nanostructures. The high-voltage power interface 18 facilitates the direct application of a high-voltage electric field to the spinneret 17, the high-temperature resistant fiber spinning needle 11, and the anti-radiation fiber spinning needle 12, eliminating the need for additional wire connections, resulting in a compact structure and reduced high-voltage losses. Through the above technical solutions, this application effectively improves the control precision and integration level of the device, providing a guarantee for further large-scale and automated production.

[0077] Example 2 This embodiment describes a method for preparing a high-temperature resistant, anti-radiation ceramic nanofiber composite material, comprising the following steps: Step 1): Mix concentrated nitric acid (65% by mass) with anhydrous ethanol to dilute (the mass ratio of concentrated nitric acid to anhydrous ethanol is 1:9) to prepare a dilute nitric acid solution (HNO3 mass concentration is about 10%).

[0078] Add the dilute nitric acid solution to deionized water (mass ratio of deionized water to dilute nitric acid solution is 4.42:0.78) to adjust the pH of the system to 2.5.

[0079] Under continuous stirring, tetraethyl orthosilicate (tetraethyl orthosilicate to deionized water in a mass ratio of 1:4.42) was slowly added as a silicon source and mixed thoroughly.

[0080] Then, aluminum sec-butoxide was added as the aluminum source (the mass ratio of tetraethyl orthosilicate to aluminum sec-butoxide was 1:1), and stirring was continued until completely dispersed.

[0081] Finally, polyvinyl alcohol (PVA) was slowly added as a spinning aid (the mass ratio of tetraethyl orthosilicate to PVA was 5:4), and the mixture was stirred for 8 hours at 28°C and 700 r / min to obtain a uniform and stable high-temperature resistant precursor spinning solution.

[0082] The mass concentrations of each component in the resulting spinning solution, based on the total mass of the reaction system, are as follows: tetraethyl orthosilicate 10wt%, aluminum sec-butoxide 10wt%, concentrated nitric acid (65% mass concentration) 0.78wt%, polyvinyl alcohol 8wt%, anhydrous ethanol 7.02wt%, and deionized water 64.2wt%.

[0083] Step 2): Tetrabutyl zirconate and hafnium tetraethanolamine (mass ratio of 2:1) are added to isopropanol as dispersion solvent (the amount of isopropanol is 3 times the total mass of the metal alkoxide), and stirred for 5 hours until completely dissolved to prepare a homogeneous mixed alkoxide solution.

[0084] Triethanolamine was added as a reaction regulator (the mass ratio of tetrabutyl zirconate to triethanolamine was 1:0.5), and the pH of the system was adjusted to 5.

[0085] Citric acid was then added as a carboxylic acid compound (the mass ratio of tetrabutyl zirconate to citric acid was 1:0.3), and the mixture was stirred for 1 hour to achieve synergistic coordination protection.

[0086] Finally, polyethylene glycol (PEG) was introduced as a spinning aid (the mass ratio of tetrabutyl zirconate to PEG was 1:0.6), and the mixture was stirred for another 3 hours until the system was homogeneous, resulting in a uniform and stable anti-radiation precursor spinning solution.

[0087] The resulting spinning solution, based on the total mass of the reaction system, contained the following components: isopropanol 58.1 wt%, tetrabutyl zirconate 12.9 wt%, polyethylene glycol 7.7 wt%, tetraethanolamine 6.5 wt%, triethanolamine 6.5 wt%, and citric acid 3.9 wt%, totaling 100 wt%.

[0088] Step 3): The two spinning solutions are supplied at a mass ratio of 5:5. An electro-pneumatic mixed drawing method is used, with nitrogen as the auxiliary gas. The gas temperature is 30℃ and the humidity is 40%. The spinning process parameters are: spinning voltage 50kV, injection speed 30mL / h, receiving distance 25cm, spinneret rotation amplitude 120° and speed 50r / min, spinning ambient temperature 30℃ and humidity 45%. The flow rate of the supply solution is precisely controlled by the flow control component to ensure that the two spinning solutions are formed synchronously to obtain the composite precursor.

[0089] Step 4): Place the composite precursor in a calcination furnace, heat at a rate of 8℃ / min, raise the temperature to 900℃ and hold for 1.5h, then cool to obtain the composite material.

[0090] The performance test results of the prepared composite material are as follows: bulk density 70 mg / cm³ 3 It has a porosity of 88%, a thermal conductivity of 0.022 W / (m·K) at room temperature, a thermal conductivity of 0.050 W / (m·K) at 1000℃, a compressive elastic recovery rate of 93%, no structural collapse after being kept at 1400℃ for 2 hours, and a near-infrared radiation reflectivity of ≥82%. It exhibits excellent synergy between mechanical properties and anti-radiation properties.

[0091] Example 3 The preparation method of the high-temperature resistant anti-radiation ceramic nanofiber composite material in this embodiment includes the following steps: Step 1): Mix hydrochloric acid (36.5% by mass) with anhydrous ethanol at a mass ratio of 1:8 and slowly add it dropwise to deionized water (the mass ratio of deionized water to hydrochloric acid is 70:1) to adjust the pH of the system to 3.5.

[0092] Under continuous stirring, slowly add isopropyl zirconate (the mass ratio of isopropyl zirconate to deionized water is 1:7) until it is evenly dispersed.

[0093] Finally, a mixture of polyethylene oxide (PEO) and polyvinyl alcohol (PVA) was added as a spinning aid (the mass ratio of the two was 1:1; the mass ratio of isopropyl zirconate to the total mass of the spinning aid was 10:3). The mixture was stirred for 7 hours at 22°C and 500 r / min to obtain a uniform and stable high-temperature resistant precursor spinning solution.

[0094] The resulting spinning solution, based on the total mass of the reaction system, has the following mass concentrations: isopropyl zirconate 10wt%, hydrochloric acid (mass concentration 36.5%) 1wt%, polyethylene oxide 1.5wt%, polyvinyl alcohol 1.5wt%, anhydrous ethanol 8wt%, and deionized water 78wt%, totaling 100wt%.

[0095] Step 2): Isopropyl titanate and cerium isopropoxide are used as anti-radiation metal alkoxide monomers (mass ratio of the two is 3:1), and added to n-butanol (the amount of n-butanol is 3 times the total mass of the metal alkoxide). Stir for 4 hours until completely dissolved to prepare a homogeneous mixed alkoxide solution.

[0096] Hydrochloric acid (36.5% by mass) was added as a reaction regulator (the mass ratio of isopropyl titanate to hydrochloric acid was 1:0.1) to adjust the pH of the system to 4.5.

[0097] Lactic acid was then added as a carboxylic acid compound (the mass ratio of isopropyl titanate to lactic acid was 1:0.4), and the mixture was stirred for 40 minutes to construct a coordination-protected structure.

[0098] Finally, polyvinylpyrrolidone (PVP) was introduced as a spinning aid (the mass ratio of isopropyl titanate to PVP was 1:0.5), and stirring was continued for 2.5 h to obtain a uniform and stable anti-radiation precursor spinning solution.

[0099] The resulting spinning solution contained the following components, based on the total mass of the reaction system: n-butanol 73.6 wt%, isopropyl titanate 6.1 wt%, polyvinylpyrrolidone 3.1 wt%, lactic acid 2.5 wt%, cerium isopropoxide 2.0 wt%, and hydrochloric acid (mass concentration 36.5%) 0.6 wt%, totaling 100 wt%.

[0100] Step 3): The two spinning solutions are supplied at a mass ratio of 8:2. The electric field stretching method is adopted. The spinning process parameters are: spinning voltage 20kV, injection speed 10mL / h, receiving distance 15cm, spinneret rotation amplitude 60°, speed 35r / min, spinning environment temperature 22℃, humidity 55%. The supply rate is precisely controlled to ensure uniform stretching of the jet and obtain composite precursor nanofibers.

[0101] Step 4): Place the composite precursor in a calcination furnace, raise the temperature at a rate of 4℃ / min, raise it to 700℃ and hold it for 2.5h, then cool it to room temperature to obtain the composite material.

[0102] The performance test results of the prepared composite material are as follows: bulk density 50 mg / cm³ 3 It has a porosity of 92%, a room temperature thermal conductivity of 0.018 W / (m·K), a 1000℃ thermal conductivity of 0.040 W / (m·K), a compression elastic recovery rate of 96%, no structural collapse after 2 hours of heat preservation at 1400℃, and a near-infrared radiation reflectivity of ≥88%, exhibiting outstanding heat insulation and anti-radiation performance.

[0103] Example 4 The preparation method of the high-temperature resistant anti-radiation ceramic nanofiber composite material in this embodiment includes the following steps: Step 1): Use n-butyl aluminate and molybdenum n-butoxide as high-temperature resistant metal alkoxide monomers (mass ratio of the two is 2:1).

[0104] Prepare a dilute nitric acid solution by mixing and diluting nitric acid (65% by mass) with anhydrous ethanol at a mass ratio of 1:8.

[0105] Mix the above dilute nitric acid solution with deionized water (the mass ratio of dilute nitric acid solution to deionized water is 1:3.33) and adjust the pH of the system to 2.

[0106] Under continuous stirring, slowly add n-butyl aluminate and molybdenum n-butoxide (the total mass ratio of n-butyl aluminate and molybdenum n-butoxide to deionized water is 1:1.5) until they are evenly dispersed.

[0107] Finally, polyethylene glycol (PEG) was introduced as a spinning aid (the mass ratio of n-butyl aluminate to PEG was 1:0.8), and the mixture was stirred for 10 hours at 35°C and 1000 r / min to obtain a uniform and stable high-temperature resistant precursor spinning solution.

[0108] The resulting spinning solution contained the following components, based on the total mass of the reaction system: deionized water 46.8 wt%, n-butyl aluminate 26.0 wt%, polyethylene glycol 20.8 wt%, molybdenum n-butanol 13.0 wt%, and nitric acid (65%) 1.6 wt%, totaling 100 wt%.

[0109] Step 2): Using cerium tert-butoxide and yttrium isopropoxide as anti-radiation metal alkoxide monomers (mass ratio of the two is 4:1), add them to ethylene glycol monomethyl ether (the amount of ethylene glycol monomethyl ether is 3 times the total mass of the metal alkoxide), stir for 6 hours until completely dissolved, and prepare a homogeneous mixed alkoxide solution.

[0110] Add acetylacetone and triethanolamine in a 1:1 mass ratio as a reaction regulator (the mass ratio of cerium tert-butoxide to the total mass of the reaction regulator is 1:0.4) and adjust the pH of the system to 5.5.

[0111] Tartaric acid was then added as a carboxylic acid compound (the mass ratio of cerium tert-butoxide to tartaric acid was 1:0.25), and the mixture was stirred for 1.5 h to achieve synergistic coordination protection.

[0112] Finally, polyethylene oxide (PEO) was introduced as a spinning aid (the mass ratio of cerium tert-butoxide to polyethylene oxide was 1:0.6), and stirring was continued for 4 hours to obtain a uniform and stable anti-radiation precursor spinning solution.

[0113] The resulting spinning solution, based on the total mass of the reaction system, contains the following concentrations of each component: ethylene glycol monomethyl ether 75.0 wt%, cerium tert-butoxide 5.0 wt%, polyethylene oxide 3.0 wt%, yttrium isopropoxide 1.25 wt%, tartaric acid 1.25 wt%, acetylacetone 1.0 wt%, and triethanolamine 1.0 wt%, totaling 100 wt%.

[0114] Step 3): The two spinning solutions are supplied at a mass ratio of 3:7. An electro-pneumatic mixed drafting method is adopted. The auxiliary gas is compressed air and helium with a volume ratio of 1:1. The gas temperature is 40℃ and the humidity is 60%. The spinning process parameters are: spinning voltage 80kV, injection speed 80mL / h, receiving distance 40cm, spinneret rotation amplitude 135° and rotation speed 60r / min, spinning ambient temperature 35℃ and humidity 40%. The liquid supply flow rate is adjusted in real time through the flow control component to ensure uniform interweaving of the two jets.

[0115] Step 4): Place the composite precursor in a calcination furnace, heat at a rate of 10℃ / min, hold at 1200℃ for 1 hour, and then cool to obtain the composite material.

[0116] The performance test results of the prepared composite material are as follows: bulk density 90 mg / cm³ 3 It has a porosity of 86%, a room temperature thermal conductivity of 0.024 W / (m·K), a 1000℃ thermal conductivity of 0.058 W / (m·K), a compressive elastic recovery rate of 91%, no structural collapse after being kept at 1400℃ for 2 hours, a near-infrared radiation reflectance of ≥80%, and excellent high-temperature structural stability.

[0117] Example 5 The preparation method of the high-temperature resistant anti-radiation ceramic nanofiber composite material in this embodiment includes the following steps: Step 1): Use mullite and tetraethyl orthosilicate as high-temperature resistant metal alkoxide monomers (mass ratio of the two is 1:2).

[0118] Hydrochloric acid (36.5% by mass) was mixed and diluted with anhydrous ethanol at a mass ratio of 1:8 to prepare a dilute hydrochloric acid solution.

[0119] Mix the above dilute hydrochloric acid solution with deionized water (the mass ratio of dilute hydrochloric acid solution to deionized water is 1:4.44) and adjust the pH of the system to 3.

[0120] Under continuous stirring, slowly add mullite and tetraethyl orthosilicate (the mass ratio of mullite and tetraethyl orthosilicate to deionized water is 1:4) until they are evenly dispersed.

[0121] Finally, polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) were mixed at a mass ratio of 2:1 as a spinning aid (the mass ratio of mullite to PVP was 1:0.67, and the mass ratio of mullite to PEG was 1:0.33). The mixture was stirred for 9 hours at 20°C and 400 r / min to obtain a uniform and stable high-temperature resistant precursor spinning solution.

[0122] The resulting spinning solution contained the following components, based on the total mass of the reaction system: deionized water 44.6 wt%, tetraethyl orthosilicate 24.8 wt%, mullite 12.4 wt%, polyvinylpyrrolidone 8.3 wt%, polyethylene glycol 4.1 wt%, anhydrous ethanol 4.9 wt%, and hydrochloric acid (mass concentration 36.5%) 0.6 wt%, totaling 100 wt%.

[0123] Step 2): Using zirconium n-butoxide and aluminum tert-butoxide as anti-radiation metal alkoxide monomers (mass ratio of 3:2), add them to a dispersion solvent in which isopropanol and n-butanol are mixed in a volume ratio of 1:1 (the amount of solvent is 3 times the total mass of the metal alkoxide), stir for 5 hours until completely dissolved, and prepare a uniform mixed alkoxide solution.

[0124] Add acetylacetone as a reaction regulator (the mass ratio of zirconium n-butoxide to acetylacetone is 1:0.15) to adjust the pH of the system to 4.

[0125] Citric acid and glacial acetic acid were then added and mixed in a mass ratio of 1:1 to form a carboxylic acid compound (the mass ratio of zirconium butoxide to the total mass of the carboxylic acid compound was 1:0.4). The mixture was stirred for 50 min to construct a coordination protective shell.

[0126] Finally, polyvinyl alcohol (PVA) was introduced as a spinning aid (the mass ratio of zirconium butyrate to polyvinyl alcohol was 1:0.5), and stirring was continued for 3 hours to obtain a uniform and stable anti-radiation precursor spinning solution.

[0127] In the resulting spinning solution, based on the total mass of the reaction system, the mass concentrations of each component are as follows: mixed solvent 65wt%, zirconium n-butoxide 13wt%, aluminum tert-butoxide 9wt%, polyvinyl alcohol 7wt%, citric acid 3wt%, glacial acetic acid 3wt%, acetylacetone 2wt%, totaling 100wt%.

[0128] Step 3): The two spinning solutions are supplied at a mass ratio of 9:1. The electric field drawing method is adopted. The spinning process parameters are: spinning voltage 10kV, injection speed 5mL / h, receiving distance 10cm, spinneret rotation amplitude 45°, rotation speed 30r / min, spinning environment temperature 20℃, humidity 60%. The supply rate is precisely controlled to ensure stable jet formation and obtain composite precursor.

[0129] Step 4): Place the composite precursor in a calcination furnace, heat at a rate of 3℃ / min, raise the temperature to 600℃ and hold for 3 hours, then cool to room temperature to obtain the composite material.

[0130] The performance test results of the prepared composite material are as follows: bulk density 40 mg / cm³ 3 It has a porosity of 95%, a thermal conductivity of 0.015 W / (m·K) at room temperature, a thermal conductivity of 0.035 W / (m·K) at 1000℃, a compressive elastic recovery rate of 97%, no structural collapse after being kept at 1400℃ for 2 hours, and a near-infrared radiation reflectivity of ≥90%, making it the best in terms of overall performance.

[0131] Comparative Example 1 The difference from Example 1 is that the high-temperature resistant precursor spinning solution was not acidified to adjust the pH value, and the spinning aid was directly introduced. The rest of the preparation process and parameters are completely the same as those in Example 1.

[0132] The performance test results of the prepared composite material are as follows: bulk density 120 mg / cm³ 3 The porosity is 75%, the thermal conductivity at room temperature is 0.035 W / (m·K), the thermal conductivity at 1000℃ is 0.075 W / (m·K), the compression elastic recovery rate is 75%, slight structural collapse occurs after holding at 1400℃ for 1 hour, and the near-infrared radiation reflectance is ≤65%. The cause of the failure is that the pH was not adjusted by acidification, which led to uneven hydrolysis of the high-temperature resistant precursor, poor stability of the sol system, and easy jet breakage during spinning. Ultimately, the composite material has insufficient structural density and degraded performance.

[0133] Comparative Example 2 The difference from Example 2 is that no carboxylic acid compounds were added to the anti-radiation precursor spinning solution, so there was no coordination protection effect. The rest of the preparation process and parameters are completely the same as those in Example 2.

[0134] The performance test results of the prepared composite material are as follows: the nanoribbon structure is severely fractured, with no complete flat cross-section, and the bulk density is 110 mg / cm³. 3 The composite material has a porosity of 78%, a room temperature thermal conductivity of 0.032 W / (m·K), a 1000℃ thermal conductivity of 0.070 W / (m·K), a compressive elastic recovery rate of 78%, and exhibits structural collapse after being kept at 1400℃ for 1.5 hours. Its near-infrared radiation reflectivity is ≤60%. The analysis suggests that the composite material lacks a carboxylic acid compound to construct a coordination protective shell, leading to rapid hydrolysis of the anti-radiation metal alkoxide, resulting in hydroxide precipitation and spinning defects. Consequently, the composite material exhibits poor structural integrity and a significant decrease in anti-radiation performance.

[0135] Comparative Example 3 The difference from Example 3 is that the spinneret does not rotate in the spinning process, and the fibers and nanoribbons do not have an interwoven structure. The rest of the preparation process and parameters are completely consistent with Example 3.

[0136] The performance test results of the prepared composite material are as follows: uneven component distribution, bulk density 130 mg / cm³. 3 The material exhibits a porosity of 70%, a room temperature thermal conductivity of 0.040 W / (m·K), a 1000℃ thermal conductivity of 0.080 W / (m·K), a compressive elastic recovery rate of 70%, and significant collapse after 0.5 hours of heat treatment at 1400℃. Its near-infrared reflectivity is ≤58%. The cause is attributed to the spinneret not rotating, resulting in concentrated jet accumulation and preventing the fibers and nanoribbons from forming a uniformly interwoven three-dimensional network structure, thus significantly deteriorating the material's mechanical and thermal insulation properties.

[0137] Comparative Example 4 The difference from Example 4 is that the high-temperature calcination temperature is 500℃, which is lower than the temperature range designed in this invention, and the holding time is 0.5h. The rest of the preparation process and parameters are completely consistent with Example 4.

[0138] The performance test results of the prepared composite material are as follows: the precursor was not fully crystallized, and the bulk density was 105 mg / cm³. 3 The porosity is 80%, the thermal conductivity at room temperature is 0.030 W / (m·K), the thermal conductivity at 1000℃ is 0.065 W / (m·K), the compressive elastic recovery rate is 80%, structural collapse occurs after holding at 1400℃ for 0.8 h, and the near-infrared radiation reflectance is ≤62%. The reasons are: the calcination temperature is too low, the holding time is insufficient, the inorganic phase of the precursor is not fully crystallized, the ceramic structure is not fully formed, and the high-temperature stability and comprehensive performance cannot meet the requirements.

[0139] Comparative Example 5 The difference from Example 5 is that the spinning solution mass ratio is 10:0, it is a single component, and it is a non-radiation spinning solution. The rest of the preparation process and parameters are the same as those in Example 5.

[0140] The test results of the prepared material are as follows: no anti-radiation properties, bulk density 50 mg / cm³. 3 It has a porosity of 93%, a room temperature thermal conductivity of 0.016 W / (m·K), a 1000℃ thermal conductivity of 0.036 W / (m·K), a compressive elastic recovery rate of 95%, and no structural collapse after being kept at 1400℃ for 2 hours. However, its near-infrared radiation reflectivity is ≤30%, indicating that it does not have anti-radiation function and cannot meet the requirements for high-temperature resistant anti-radiation composites. The reason for this is that it lacks anti-radiation components, cannot form a high-refractive-index crystal phase, and cannot block near-infrared radiation heat conduction, which does not meet the core design purpose of this invention.

[0141] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-temperature resistant, radiation-reflective ceramic nanofiber composite material, characterized in that, This includes a three-dimensional porous network structure composed of interwoven high-temperature resistant ceramic nanofibers and anti-radiation ceramic nanoribbons; Based on the total mass of the composite material, the mass content of the high-temperature resistant ceramic nanofibers is 10%~90%, and the mass content of the anti-radiation ceramic nanoribbons is 10%~90%. The high-temperature resistant ceramic nanofibers have a curled circular cross-section, and the anti-radiation ceramic nanoribbons have a curled flat cross-section.

2. The high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 1, characterized in that, The diameter of the high-temperature resistant ceramic nanofibers is 400~600nm; The anti-radiation ceramic nanoribbon has a width of 500 nm to 5 μm and a thickness of 20 to 200 nm.

3. The high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 1, characterized in that, The high-temperature resistant ceramic nanofibers are selected from one or more of mullite fiber, zirconium oxide fiber, alumina fiber, silica fiber, and molybdenum dioxide fiber. The anti-radiation ceramic nanoribbons are selected from one or more of the following: titanium oxide nanoribbons, zirconium dioxide nanoribbons, hafnium dioxide nanoribbons, cerium dioxide nanoribbons, yttrium oxide nanoribbons, scandium oxide nanoribbons, lanthanum oxide nanoribbons, neodymium oxide nanoribbons, and samarium oxide nanoribbons.

4. The high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 1, characterized in that, The high-temperature resistant ceramic nanofibers have a mass content of 50% to 70%, and the anti-radiation ceramic nanoribbons have a mass content of 30% to 50%.

5. The high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 1, characterized in that, The bulk density of the high-temperature resistant, anti-radiation ceramic nanofiber composite material is ≤0.1 g / cm³. 3 The porosity is 85%~95%; The composite material has a thermal conductivity of ≤0.06 W / (m·K) at 1000℃ and a compressive elastic recovery rate of ≥90%.

6. The method for preparing the high-temperature resistant, radiation-reflective ceramic nanofiber composite material according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Prepare a high-temperature resistant precursor spinning solution and a radiation-resistant precursor spinning solution, wherein the high-temperature resistant precursor spinning solution has a viscosity of 150~6000 mPa·s and a solid content of 5%~70%, and the radiation-resistant precursor spinning solution has a viscosity of 100~5000 mPa·s and a solid content of 10%~65%; S2. The high-temperature resistant precursor spinning solution and the anti-radiation precursor spinning solution are respectively delivered to a rotating nozzle via independent supply paths. The rotating nozzle is equipped with alternating high-temperature resistant fiber spinning needles and anti-radiation fiber spinning needles. Under the action of a high-voltage electric field, the two spinning solutions are sprayed out synchronously to form a jet. At the same time, the rotating nozzle rotates at a speed of 30~60 r / min, so that the jet dynamically interweaves in the air and is deposited on the receiving device to form a precursor composite material. The high-temperature resistant precursor spinning solution is solidified into nanofibers with a curled circular cross-section, and the anti-radiation precursor spinning solution is solidified into nanoribbons with a curled flat cross-section. S3. The precursor composite material is subjected to high-temperature calcination at a temperature of 600~1300℃ and a holding time of 1~3h to obtain the high-temperature resistant anti-radiation ceramic nanofiber composite material.

7. The method for preparing the high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 6, characterized in that, In step S2, the supply flow rates of the high-temperature resistant precursor spinning solution and the anti-radiation precursor spinning solution are independently adjusted by the flow control component so that the mass flow rate ratio of the two is 9:1 to 1:

9. The flow control component adjusts the two spinning solutions in real time according to a preset flow ratio; The rotation range of the rotary nozzle is 45~135°; The voltage of the high-voltage electric field is -150~150kV, and the distance between the spinning needle and the receiving device is 10~50cm.

8. The method for preparing the high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 6, characterized in that, The method for preparing the high-temperature resistant precursor spinning solution in step S1 includes: mixing a high-temperature resistant metal alkoxide, an acid catalyst, and a spinning aid, and obtaining the solution after hydrolysis and acidification. The high-temperature resistant metal alkoxide is selected from one or more of the following: n-butyl aluminate, aluminum triethoxylate, aluminum isopropoxide, isopropyl zirconate, zirconium tetraethanolamine, and tetraethyl orthosilicate. The method for preparing the anti-radiation precursor spinning solution in step S1 includes: dissolving the anti-radiation metal alkoxide in an alcohol solvent, adding a reaction regulator, a carboxylic acid compound, and a spinning aid in sequence, and mixing them evenly to obtain the solution; wherein the anti-radiation metal alkoxide is selected from one or more of tetrabutyl titanate, isopropyl titanate, tetrabutyl zirconate, and tetraethanolamine.

9. An electrospinning apparatus for preparing high-temperature resistant, anti-radiation ceramic nanofiber composite materials according to any one of claims 1 to 5, characterized in that, include: The uniformly supplied spinneret has an internally independent high-temperature resistant precursor spinning solution porous supply pipe and a reverse radiation precursor spinning solution porous supply pipe, which are used to connect the high-temperature resistant precursor spinning solution source and the reverse radiation precursor spinning solution source, respectively. At least one circular spinneret is rotatably connected below the uniformly supplied spinneret. The circular spinneret has a high-temperature resistant precursor spinning solution storage chamber and a radiation-resistant precursor spinning solution storage chamber that are isolated from each other by a partition. The bottom of both storage chambers is provided with a diversion channel. Multiple high-temperature resistant fiber spinning needles and multiple anti-radiation fiber spinning needles are respectively connected to the end of the diversion channel at the bottom of the corresponding liquid storage chamber, and are alternately arranged along the bottom of the circular spinneret; The high-temperature resistant precursor spinning solution porous supply pipe is connected to the high-temperature resistant precursor spinning solution storage chamber via a pipe, and the anti-radiation precursor spinning solution porous supply pipe is connected to the anti-radiation precursor spinning solution storage chamber via a pipe, and a flow control component for independently regulating the flow rate is provided on the connecting pipe.

10. The electrospinning apparatus for the high-temperature resistant, anti-radiation ceramic nanofiber composite material according to claim 9, characterized in that, The inner diameter of the high-temperature resistant fiber spinning needle and the anti-radiation fiber spinning needle is 0.2~0.8 mm; The uniform liquid supply spinneret is equipped with a high-voltage power interface.

Images