A lignin-based special material constructed by crimped fibers and a preparation method and application thereof
Patent Information
- Application Number
- CN202610880204.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-17
- Publication Date
- 2026-08-18
AI Technical Summary
[0009]本发明的目的是要解决现有陶瓷气凝胶在极端环境下脆性大、热-力稳定性差、功能单一的问题，而提供一种由卷曲纤维构筑的木质基特种材料及其制备方法与应用
[0022] I. Ultra-low density and ultra-high porosity: The aerogel density is as low as approximately 0.4 mg/cm³. 3 With a porosity of over 90%, it is an ideal material for achieving ultimate lightweighting;
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Figure CN122586448A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aerogel materials technology, specifically relating to a wood-based special material constructed from crimped fibers, its preparation method, and its application. Background Technology
[0002] Extreme environments such as aerospace, deep space exploration, and hypersonic vehicles place stringent requirements on materials: materials must simultaneously possess ultra-lightweight properties, extreme temperature stability (from -196 ℃ to above 1300 ℃), excellent thermal shock resistance, high elasticity, fatigue resistance, and electromagnetic interference (EMI) shielding capabilities.
[0003] Ceramic aerogels, due to their ultra-low density, high porosity, low thermal conductivity, and intrinsic flame retardancy, are considered ideal candidates for next-generation aerospace thermal protection and functional integrated materials. However, traditional ceramic aerogels (such as SiO2, Al2O3, and SiC aerogels) suffer from the following core defects:
[0004] 1. Intrinsic brittleness: Traditional ceramic aerogels are made up of stacked nanoparticles and lack a dislocation slip system. They are prone to irreversible damage under external forces, have poor compression resilience, and are difficult to achieve reversible deformation under large strain.
[0005] 2. Poor thermo-mechanical stability: Under severe temperature fluctuations (such as thermal shock) or long-term exposure to high temperatures, it is prone to microcrack propagation, volume shrinkage, strength reduction, and even structural collapse.
[0006] 3. Limited functionality: Most ceramic aerogels only have thermal insulation properties, making it difficult to simultaneously meet the integrated needs of multiple functions such as thermal protection, mechanical buffering, and electromagnetic shielding.
[0007] 4. Complex preparation process / high energy consumption: Some high-performance ceramic aerogels rely on high-energy-consuming processes such as supercritical drying and chemical vapor deposition, which limits their large-scale application.
[0008] Therefore, developing a multifunctional ceramic aerogel that combines superelasticity, fatigue resistance, wide temperature range thermo-mechanical stability, excellent thermal insulation, and efficient electromagnetic shielding is a technical challenge that urgently needs to be solved in this field. Summary of the Invention
[0009] The purpose of this invention is to solve the problems of high brittleness, poor thermal stability, and limited functionality of existing ceramic aerogels under extreme environments, and to provide a wood-based special material constructed from crimped fibers, its preparation method, and its application.
[0010] A wood-based specialty material constructed from crimped fibers is a three-component network consisting of silicon carbide nanoparticles, carbon nanotubes, and cellulose nanosheets. The cellulose nanosheets form a micro-rolled structure, the silicon carbide nanoparticles are loaded on the surface of the cellulose nanosheets, and the carbon nanotubes are interwoven between the cellulose nanosheets and the silicon carbide nanoparticles, together constructing a three-dimensional network with a multi-scale hierarchical porous structure.
[0011] A method for preparing a wood-based specialty material constructed from crimped fibers is specifically carried out according to the following steps:
[0012] I. Preparation of CN suspension:
[0013] Cellulose nanosheets were added to deionized water and ultrasonically broken up under ice bath conditions to obtain a CN suspension.
[0014] II. Preparation of precursor gel:
[0015] A uniform precursor gel was obtained by sonicating CN suspension, carbon nanotubes and silicon carbide nanoparticles under ice bath conditions.
[0016] III. Freezing and Setting:
[0017] The precursor gel was transferred into a polytetrafluoroethylene mold and then frozen to obtain the frozen-set sample.
[0018] IV. Freeze-drying:
[0019] The freeze-set sample was placed in a freeze dryer and then freeze-dried to obtain a wood-based specialty material constructed from crimped fibers.
[0020] Application of a wood-based specialty material constructed from crimped fibers in aerospace thermal protection, electromagnetic shielding, thermal insulation, flame retardant materials, or deep space exploration equipment.
[0021] The beneficial effects of this invention are:
[0022] I. Ultra-low density and ultra-high porosity: The aerogel density is as low as approximately 0.4 mg / cm³. 3 With a porosity of over 90%, it is an ideal material for achieving ultimate lightweighting;
[0023] II. Excellent mechanical properties: It can withstand more than 95% compressive strain, with a peak stress of 46.16 kPa, and completely recovers its original shape after unloading, exhibiting temperature-insensitive superelasticity; it can withstand 10 hours of stress at 60% strain. 4 After several cycles of compression, the stress retention rate reached 80%, and the height recovery exceeded 90%, demonstrating excellent fatigue resistance.
[0024] III. Wide temperature range thermo-mechanical stability: The structure remains intact after severe temperature shock within the range of -196℃ (liquid nitrogen) to 1300℃ (butane torch flame), with a bending strength retention rate of up to 90%.
[0025] IV. Excellent thermal insulation: Thermal conductivity in air is 35 mW·m -1 ·K -1 (-40℃ to 1000℃), as low as 3.6mW·m under vacuum. -1 ·K -1 The back surface temperature of a 10 mm thick sample is only about 300 °C under a 1300 °C flame, forming a temperature gradient of more than 1000 °C.
[0026] V. High-efficiency electromagnetic shielding performance: Within a wide frequency band of 8.2-40 GHz, the average total electromagnetic shielding effectiveness (EMI SE_T) reaches 50dB, with a maximum of 60dB, effectively blocking most incident electromagnetic waves; the shielding effectiveness per unit thickness (SSE / t) is as high as 1.7×10⁻⁶. 5 dB·cm 2 ·g -1 It is superior to most metals, polymer foams and traditional aerogels; after being exposed to liquid nitrogen (-196℃), 300℃ heating and direct flame exposure, it still maintains a military-grade shielding standard of more than 40dB.
[0027] VI. The preparation process is simple, mild, and easy to scale up: The freeze-drying method is used, which does not require supercritical drying or high-temperature sintering, resulting in low energy consumption and making it suitable for large-scale preparation. Attached Figure Description
[0028] Figure 1 Macroscopic images and their densities of the SiC@CNTs / CN wood-based specialty material prepared in Example 1;
[0029] Figure 2 The microstructure of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0030] Figure 3 The loading and unloading process of SiC@CNTs / CN wood-based special materials prepared in Example 1 under different loads;
[0031] Figure 4 Images of uniaxial compression tests of the SiC@CNTs / CN wood-based special material prepared in Example 1 under different strain conditions;
[0032] Figure 5 Electromagnetic shielding performance of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0033] Figure 6The shielding effectiveness per unit thickness of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0034] Figure 7 Flame retardant and heat insulation properties of SiC@CNTs / CN wood-based special material prepared in Example 1 with a thickness of 10 mm at 1300 °C;
[0035] Figure 8 The thermal conductivity of the SiC@CNTs / CN wood-based special material prepared in Example 1 under -40℃ atmospheric pressure, 1300℃ atmospheric pressure, -40℃ vacuum, and 1000℃ vacuum conditions were measured. Detailed Implementation
[0036] Specific Implementation Method 1: This implementation method is a wood-based special material constructed from curled fibers. It is a three-component network composed of silicon carbide nanoparticles, carbon nanotubes, and cellulose nanosheets. Among them, the cellulose nanosheets form a micro-rolled structure, the silicon carbide nanoparticles are loaded on the surface of the cellulose nanosheets, and the carbon nanotubes are interwoven between the cellulose nanosheets and the silicon carbide nanoparticles, together constructing a three-dimensional network with a multi-scale hierarchical porous structure.
[0037] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the hierarchical porous structure includes a macroscopic scale of >20cm, a unit cell scale of 1~3000µm, a micro-roll diameter scale of 0.1~3µm, and a SiC nanoparticle scale of 40~200nm. Other steps are the same as in Specific Implementation Method One.
[0038] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the density of the wood-based special material is 0.4 mg / cm³. 3 The porosity is ≥90%; the wood-based special material has a negative Poisson's ratio and / or a negative coefficient of thermal expansion; the negative Poisson's ratio is ≤-0.3; the negative coefficient of thermal expansion is ≤-4×10 at temperatures below 700℃. -6 ℃ -1 ≤-2×10 at temperatures above 700℃ -4 ℃ -1 The other steps are the same as in specific implementation method one or two.
[0039] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the wood-based special material has temperature-insensitive superelasticity, and after undergoing severe temperature shock in the temperature range of -196℃ to 1300℃, the bending strength retention rate is ≥99%; after undergoing 10 at 60% strain... 4 After each compression cycle, the stress retention rate is ≥85%, and the height recovery rate is ≥90%. Other steps are the same as in specific implementation methods one to three.
[0040] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the wood-based special material has an average total electromagnetic shielding effectiveness ≥50dB in the 8.2-40GHz frequency band, with a maximum of ≥60dB, and a shielding effectiveness per unit thickness ≥1.7×10⁻⁶. 5 dB·cm 2 ·g -1 Furthermore, it maintains an electromagnetic shielding effectiveness of ≥40dB even after exposure to liquid nitrogen, heating at 300℃, or direct flame. Other steps are the same as in specific implementation methods one to four.
[0041] Specific Implementation Method Six: This implementation method is a method for preparing a wood-based special material constructed from curled fibers, characterized in that the preparation method is specifically completed according to the following steps:
[0042] I. Preparation of CN suspension:
[0043] Cellulose nanosheets were added to deionized water and ultrasonically broken up under ice bath conditions to obtain a CN suspension.
[0044] II. Preparation of precursor gel:
[0045] A uniform precursor gel was obtained by sonicating CN suspension, carbon nanotubes and silicon carbide nanoparticles under ice bath conditions.
[0046] III. Freezing and Setting:
[0047] The precursor gel was transferred into a polytetrafluoroethylene mold and then frozen to obtain the frozen-set sample.
[0048] IV. Freeze-drying:
[0049] The freeze-set sample was placed in a freeze dryer and then freeze-dried to obtain a wood-based specialty material constructed from crimped fibers.
[0050] Specific Implementation Method Seven: The difference between this implementation method and Specific Implementation Methods One to Six is that the preparation method of cellulose nanosheets described in step one is specifically completed according to the following steps:
[0051] 1g of poplar powder was added to 150mL of sodium phosphate buffer containing 0.016g of 2,2,6,6-tetramethylpiperidine-1-oxy radical and 2.26g of sodium chlorite. Then, 3.7g of sodium hypochlorite and 150mL of sodium phosphate buffer were added. The mixture was magnetically stirred at 60℃ for 2h. After the reaction was completed, the mixture was cooled to room temperature, washed three times with deionized water, and then sonicated in an ice-water bath for 30min. Finally, it was freeze-dried to obtain cellulose nanosheets.
[0052] The sodium phosphate buffer solution is prepared by dissolving potassium dihydrogen phosphate and sodium hydroxide in deionized water to obtain the sodium phosphate buffer solution, wherein the mass-to-volume ratio of potassium dihydrogen phosphate, sodium hydroxide, and deionized water is 1.02 g: 0.142 g: 150 mL. Other steps are the same as in specific embodiments one through six.
[0053] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in the following ways: the mass fraction of the CN suspension in step one is 1%; the ultrasonic disruption time in step one is 10-15 minutes; the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is (0.122-9.9):1:(0.05-0.2); and the mass fraction of the precursor gel in step two is 1.2%-10%. Other steps are the same as in Specific Implementation Methods One to Seven.
[0054] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in the following ways: In step two, the ultrasonication time under ice bath conditions is 10 to 15 minutes; in step three, the cryo-setting temperature is -30°C to -50°C, and the cryo-setting time is 12 to 48 hours; in step four, the freeze-drying temperature is -50°C to -60°C, the vacuum degree is 1 to 100 μPa, and the time is 48 to 96 hours. The other steps are the same as in Specific Implementation Methods One to Eight.
[0055] Specific Implementation Method 10: This implementation method is an application of wood-based special materials constructed from crimped fibers in aerospace thermal protection, electromagnetic shielding, heat insulation, flame retardant materials, or deep space exploration equipment.
[0056] The beneficial effects of the present invention are verified using the following embodiments:
[0057] Example 1: A method for preparing a wood-based specialty material constructed from crimped fibers, specifically comprising the following steps:
[0058] I. Preparation of cellulose nanosheets:
[0059] 1 g of poplar powder was added to 150 mL of sodium phosphate buffer containing 0.016 g of 2,2,6,6-tetramethylpiperidine-1-oxy radical and 2.26 g of sodium chlorite. Then, 3.7 g of sodium hypochlorite and 150 mL of sodium phosphate buffer were added. The mixture was magnetically stirred at 60 °C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, washed three times with deionized water, and then sonicated in an ice-water bath for 30 min. Finally, it was freeze-dried to obtain cellulose nanosheets (CN).
[0060] The method for preparing the sodium phosphate buffer solution is as follows: potassium dihydrogen phosphate and sodium hydroxide are dissolved in deionized water to obtain sodium phosphate buffer solution, wherein the mass-volume ratio of potassium dihydrogen phosphate, sodium hydroxide and deionized water is 1.02g:0.142g:150mL;
[0061] II. Preparation of CN suspension:
[0062] Cellulose nanosheets (CN) were added to deionized water and ultrasonically broken up for 15 min under ice bath conditions to obtain a CN suspension.
[0063] The mass fraction of the CN suspension mentioned in step one is 1%;
[0064] II. Preparation of precursor gel:
[0065] A uniform precursor gel was obtained by sonicating CN suspension, carbon nanotubes (CNTs) and silicon carbide nanoparticles (SiC) in an ice bath for 15 min.
[0066] In step two, the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel is 0.733:1:0.1.
[0067] The precursor gel mentioned in step two has a mass fraction of 1.8%;
[0068] III. Freezing and Setting:
[0069] The precursor gel was transferred into a polytetrafluoroethylene mold and then frozen at -42℃ for 24 hours to obtain the frozen-fixed sample.
[0070] IV. Freeze-drying:
[0071] The frozen-fixed sample was placed in a freeze dryer and then freeze-dried at -55°C and a vacuum of about 10 μPa for 72 h to obtain wood-based special materials (SiC@CNTs / CN wood-based special materials) constructed from crimped fibers.
[0072] Figure 1 Macroscopic images and their densities of the SiC@CNTs / CN wood-based specialty material prepared in Example 1;
[0073] from Figure 1 It can be seen that the SiC@CNTs / CN wood-based specialty material prepared in Example 1 has an extremely low density, approximately 0.30~0.31 mg / cm³. 3 .
[0074] Figure 2 The microstructure of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0075] from Figure 2 It can be seen that the SiC@CNTs / CN wood-based special material prepared in Example 1 has a three-dimensional structure with mesoporous and microporous structures, which is also the source of its low density and low thermal conductivity.
[0076] Figure 3 The loading and unloading process of SiC@CNTs / CN wood-based special materials prepared in Example 1 under different loads;
[0077] from Figure 3 It can be seen that the SiC@CNTs / CN wood-based special material prepared in Example 1 can withstand a load of up to 2300 times its own weight, withstand large deformation without breaking, and completely restore its original structure after unloading.
[0078] Figure 4 Images of uniaxial compression tests of the SiC@CNTs / CN wood-based special material prepared in Example 1 under different strain conditions;
[0079] from Figure 4 It can be seen that the skeleton of the SiC@CNTs / CN wood-based special material prepared in Example 1 has a significant negative Poisson's ratio and negative Poisson effect behavior.
[0080] Figure 5 Electromagnetic shielding performance of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0081] from Figure 5 It can be seen that the SiC@CNTs / CN wood-based special material prepared in Example 1 exhibits stable and broad-spectrum electromagnetic interference suppression capability in the 8.2 to 40 GHz frequency band, with an average total electromagnetic interference suppression value of 56.95 dB, far exceeding the 40 dB threshold required for military-grade protection, and has a wide shielding bandwidth of 31.8 GHz.
[0082] Figure 6 The shielding effectiveness per unit thickness of the SiC@CNTs / CN wood-based special material prepared in Example 1;
[0083] from Figure 6 It can be seen that the 2 mm thick SiC@CNTs / CN wood-based special material exhibits excellent shielding performance per unit thickness (SSE / t) in the full broadband frequency range of 8~40 GHz.
[0084] (a) In the X-band (8.2–12.4 GHz), this aerogel achieved a peak density of 178,733.33 dB cm⁻¹. 2 g -1 The shielding effectiveness per unit thickness;
[0085] (b) In the Ku band (12.4–18 GHz), the aerogel maintained a high density of 178,500.00 dB cm⁻¹. 2 g -1 The shielding effectiveness per unit thickness;
[0086] (c) In the K-band (18~26.5GHz), SSE / t reaches 205066.57 dB cm. 2 g -1 ;
[0087] (d) In the Ka band (26.5~40GHz), SSE / t reaches 207700.00 dB cm. 2 g -1 .
[0088] Figure 7 Flame retardant and heat insulation properties of SiC@CNTs / CN wood-based special material prepared in Example 1 with a thickness of 10 mm at 1300 °C;
[0089] from Figure 7 It can be seen that SiC@CNTs / CN wood-based special materials still have excellent flame retardant and heat insulation properties after being heated in air with a butane torch (1300°C).
[0090] Figure 8 The thermal conductivity of the SiC@CNTs / CN wood-based special material prepared in Example 1 under atmospheric pressure at -40℃, atmospheric pressure at 1300℃, vacuum at -40℃, and vacuum at 1000℃ is measured.
[0091] from Figure 8 It can be seen that the thermal conductivity test shows that the thermal conductivity value of air in the range of -40℃ to 1000℃ is between 23.1 and 33.16 mW·m. -1 ·K -1 Between; in a vacuum environment, the value is even lower, reaching 3.6 mW·m at -40℃. -1 ·K -1 However, it is still below 27.7 mW·m at 1000℃. -1 ·K -1 .
[0092] Example 2: The difference between this example and Example 1 is that the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is 0.122:1:0.1; the mass fraction of the precursor gel in step two is 1.2%. All other steps and parameters are the same as in Example 1.
[0093] Example 3: The difference between this example and Example 1 is that the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is 0.472:1:0.1; the mass fraction of the precursor gel in step two is 1.56%. All other steps and parameters are the same as in Example 1.
[0094] Example 4: The difference between this example and Example 1 is that the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is 1.1:1:0.1; the mass fraction of the precursor gel in step two is 2.17%. All other steps and parameters are the same as in Example 1.
[0095] Example 5: The difference between this example and Example 1 is that the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is 2.567:1:0.1; the mass fraction of the precursor gel in step two is 3.57%. All other steps and parameters are the same as in Example 1.
[0096] Example 6: The difference between this example and Example 1 is that the mass ratio of silicon carbide nanoparticles, cellulose nanosheets, and carbon nanotubes in the precursor gel in step two is 9.9:1:0.1; the mass fraction of the precursor gel in step two is 10%. All other steps and parameters are the same as in Example 1.
[0097] Tests show that as the SiC content increases, the material's electrical conductivity gradually decreases, and the average total electromagnetic shielding effectiveness can be adjusted within a certain range, but the overall performance remains excellent.
Claims
1. A wood-based special material constructed from crimped fibers, characterized in that... The wood-based specialty material is a three-component network composed of silicon carbide nanoparticles, carbon nanotubes, and cellulose nanosheets. The cellulose nanosheets form a micro-roll structure, the silicon carbide nanoparticles are loaded on the surface of the cellulose nanosheets, and the carbon nanotubes are interwoven between the cellulose nanosheets and the silicon carbide nanoparticles, together constructing a three-dimensional network with a multi-scale hierarchical porous structure.
2. The wood-based special material constructed from crimped fibers according to claim 1, characterized in that... The hierarchical porous structure includes a macroscopic scale of >20 cm, a unit cell scale of 1~3000 µm, a micro-roll diameter scale of 0.1~3 µm, and a SiC nanoparticle scale of 40~200 nm.
3. A wood-based special material constructed from crimped fibers according to claim 1, characterized in that... The density of the wood-based specialty material is 0.4 mg / cm³. 3 The porosity is ≥90%; the wood-based special material has a negative Poisson's ratio and / or a negative coefficient of thermal expansion; the negative Poisson's ratio is ≤-0.3; the negative coefficient of thermal expansion is ≤-4×10 at temperatures below 700℃. -6 ℃ -1 ≤-2×10 at temperatures above 700℃ -4 ℃ -1 .
4. A wood-based special material constructed from crimped fibers according to claim 1, characterized in that... The wood-based specialty material exhibits temperature-insensitive superelasticity, retaining ≥99% of its bending strength after undergoing severe temperature shocks within a temperature range of -196℃ to 1300℃; and after undergoing 10 hours of stress at 60% strain. 4 After multiple compression cycles, the stress retention rate is ≥85%, and the height recovery rate is ≥90%.
5. A wood-based special material constructed from crimped fibers according to claim 1, characterized in that... The wood-based special material has an average total electromagnetic shielding effectiveness of ≥50dB and a maximum of ≥60dB in the 8.2-40GHz frequency band, with a shielding effectiveness per unit thickness of ≥1.7×10⁻⁶. 5 dB·cm 2 ·g -1 Furthermore, it maintains an electromagnetic shielding effectiveness of ≥40dB even after exposure to liquid nitrogen, heating at 300℃, or direct flame.
6. A method for preparing a wood-based special material constructed from crimped fibers as described in any one of claims 1 to 5, characterized in that... The preparation method is specifically carried out according to the following steps: I. Preparation of CN suspension: Cellulose nanosheets were added to deionized water and ultrasonically broken up under ice bath conditions to obtain a CN suspension. II. Preparation of precursor gel: A uniform precursor gel was obtained by sonicating CN suspension, carbon nanotubes and silicon carbide nanoparticles under ice bath conditions. III. Freezing and Setting: The precursor gel was transferred into a polytetrafluoroethylene mold and then frozen to obtain the frozen-set sample. IV. Freeze-drying: The freeze-set sample was placed in a freeze dryer and then freeze-dried to obtain a wood-based specialty material constructed from crimped fibers.
7. The method for preparing a wood-based special material constructed from crimped fibers according to claim 6, characterized in that... The method for preparing cellulose nanosheets described in step one is specifically carried out according to the following steps: 1g of poplar powder was added to 150mL of sodium phosphate buffer containing 0.016g of 2,2,6,6-tetramethylpiperidine-1-oxy radical and 2.26g of sodium chlorite. Then, 3.7g of sodium hypochlorite and 150mL of sodium phosphate buffer were added. The mixture was magnetically stirred at 60℃ for 2h. After the reaction was completed, the mixture was cooled to room temperature, washed three times with deionized water, and then sonicated in an ice-water bath for 30min. Finally, it was freeze-dried to obtain cellulose nanosheets. The sodium phosphate buffer solution is prepared by dissolving potassium dihydrogen phosphate and sodium hydroxide in deionized water to obtain sodium phosphate buffer solution, wherein the mass-volume ratio of potassium dihydrogen phosphate, sodium hydroxide and deionized water is 1.02g:0.142g:150mL.
8. The method for preparing a wood-based special material constructed from crimped fibers according to claim 6, characterized in that... The mass fraction of CN suspension mentioned in step one is 1%; the ultrasonic disruption time mentioned in step one is 10 min to 15 min; the mass ratio of silicon carbide nanoparticles, cellulose nanosheets and carbon nanotubes in the precursor gel mentioned in step two is (0.122~9.9):1:(0.05~0.2); the mass fraction of the precursor gel mentioned in step two is 1.2%~10%.
9. A method for preparing a wood-based special material constructed from crimped fibers according to claim 7, characterized in that... In step two, the ultrasonic treatment under ice bath conditions lasts for 10 to 15 minutes; in step three, the cryo-setting temperature is -30°C to -50°C, and the cryo-setting time is 12 to 48 hours; in step four, the freeze-drying temperature is -50°C to -60°C, the vacuum degree is 1 to 100 μPa, and the time is 48 to 96 hours.
10. An application of a wood-based specialty material constructed from crimped fibers as described in any one of claims 1 to 6, characterized in that... Application of a wood-based specialty material constructed from crimped fibers in aerospace thermal protection, electromagnetic shielding, thermal insulation, flame retardant materials, or deep space exploration equipment.