A basalt fiber aerogel composite material

Abstract

This invention provides a basalt fiber aerogel composite material, relating to the field of inorganic non-metallic materials, obtained through the following method: preparation of an interface modifier; modification of basalt fibers; step three, magnetron sputtering; and composite formation between the interface-modified basalt fibers and silica aerogel. The interface modifier is prepared by mixing maleic anhydride, a long-chain diaminosilane coupling agent, silane coupling agent KH550, and a solvent composed of anhydrous ethanol and deionized water. Magnetron sputtering involves depositing a titanium dioxide layer on the surface of the modified basalt fibers. The basalt fiber aerogel composite material obtained by the above method has advantages such as strong interfacial bonding, good mechanical properties, high thermal insulation performance, and stable long-term performance.

Description

[0001] This invention is a divisional application of patent application number 202411028056.8, entitled "A method for enhancing the interfacial compatibility of basalt fiber aerogel". Technical Field

[0002] This invention relates to the field of inorganic non-metallic materials technology, specifically to a basalt fiber aerogel composite material. Background Technology

[0003] Silica aerogel is a lightweight porous nanomaterial with a complex three-dimensional network structure. It features low density, low thermal conductivity, high porosity, high light transmittance, low refractive index, and chemical stability. Its network structure, formed by three-dimensional condensation polymers linked by silicon-oxygen bonds, possesses high porosity and extremely small pore size, making it an excellent thermal insulation material for effectively suppressing heat conduction. However, high-purity silica aerogel is inherently brittle and has low mechanical strength (due to the inherently weak strain resistance of silicon-oxygen covalent bonds). This makes it prone to breakage and damage in demanding applications, compromising the long-term integrity of its structure and performance. Furthermore, the poor chemical stability and difficult processing of high-purity silica aerogel limit its direct application in complex thermal insulation environments. In existing technologies, high-strength and high-toughness reinforcing materials are typically composited with silica aerogel to improve the low strength, poor toughness, and poor stability of high-purity silica aerogel. However, using inappropriate reinforcing materials and inappropriate composite methods not only fails to achieve the reinforcement purpose but also easily affects the inherent properties of silica aerogel. Therefore, existing technologies often use fiber-reinforcing materials to composite with silica aerogel to avoid affecting the thermal insulation performance of silica aerogel itself. However, due to the high porosity of silica aerogel and the smooth surface of fiber-reinforcing materials, the interface structure between aerogel and fiber-reinforcing materials is very weak. Under load impact, cracks easily appear at the interface and propagate along the interface, leading to detachment and peeling of reinforcing fibers from the aerogel, resulting in interface failure and aerogel fracture. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a basalt fiber aerogel composite material that can effectively improve the interfacial compatibility between reinforcing fibers and aerogel, and has the characteristics of strong interfacial bonding, good corrosion resistance, no pollution, and excellent thermal insulation performance.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A basalt fiber aerogel composite material is obtained by the following method, including:

[0007] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed to obtain a modifying solvent. Then, maleic anhydride, long-chain diaminosilane coupling agent (chemical formula NH2(CH2)2NH(CH2)3Si(OCH3)3), and silane coupling agent KH550 (chemical formula NH2CH2CH2CH2Si(OC2H5)3) are weighed out separately. The modifying solvent is then slowly added dropwise under vigorous stirring. After the addition is complete, stirring is continued for 20-40 minutes until no obvious oily substance remains, thus obtaining the interface modifier. Step 2: Basalt Fiber Modification: First, basalt is uniformly mixed in a high-speed mixer at a length / diameter ratio of 40-45. Basalt fiber precursors are produced on an extruder; then, after the extruded basalt fiber precursors are cooled, they are immersed in an interface modifier for modification; then, the modified basalt fiber precursors are bundled and wound using an automatic winding machine; finally, the bundled and wound fiber precursors are dried at room temperature and then placed in an oven for drying; Step 3, magnetron sputtering: First, the modified basalt fibers from step 2 are placed in the vacuum chamber of a magnetron sputtering equipment, with TiO2 as the magnetron sputtering target, and a vacuum is drawn; then, argon gas is introduced into the vacuum chamber, and the magnetron sputtering equipment is turned on for magnetron sputtering; finally, after magnetron sputtering is completed, the magnetron sputtered fibers are removed and placed in an oven for storage.

[0008] Based on further optimization of the above scheme, the volume ratio of maleic anhydride, long-chain diaminosilane coupling agent, silane coupling agent KH550, and modified solvent is 1.5~2.5:1~2:1~2:98~102.

[0009] First, a specific formulation of interface modifier is hydrolyzed to generate silanol groups, which then undergo sufficient condensation with the silanol groups on the surface of basalt fibers through hydrogen bonding. This ensures that the interface modifier is uniformly and stably adhered to the surface of the basalt fibers. Next, a titanium dioxide layer is prepared using magnetron sputtering. The numerous polar covalent bonds generated during the condensation process of the interface modifier are used to attract the titanium dioxide and bond it using van der Waals forces, effectively enhancing the compatibility between the sputtered titanium dioxide layer and the basalt fiber surface. Simultaneously, the fully condensed interface modifier attracts the titanium dioxide during magnetron sputtering, effectively ensuring the dispersion of titanium dioxide on the basalt fiber surface and reducing titanium dioxide agglomerates. This improves the density of the titanium dioxide coating layer and enhances the solution fluidity on the basalt fiber surface. In subsequent composites with silica aerogel, as the porosity of the silica aerogel increases, the solution fluidity increases the contact area between the coating layer and the aerogel pores, improving the interfacial compatibility between the aerogel and the fiber.

[0010] Furthermore, by utilizing the magnetron sputtering of titanium dioxide, through Ti... 4+The titanium dioxide coating, in the form of tetracoordinate (TiO4), enters the network structure on the fiber surface. During the composite process with aerogel, it can form a mixed framework of titanyl silicate with SiO2, which not only enhances the fiber network structure but also improves the connection strength between the fiber structure and the aerogel, thus increasing the tensile strength. Furthermore, the dense titanium dioxide coating can slow down the erosion of basalt fibers, generating Ti(OH)4 layered on the fiber surface during corrosion, thereby combining with Ti... 4+ The combined effect enhances the degree of fiber polymerization, effectively improving the alkali resistance of basalt fibers.

[0011] Based on further optimization of the above scheme, the volume ratio between anhydrous ethanol and deionized water in step one is 1:1.

[0012] Based on further optimization of the above scheme, in step two, the extrusion temperature of the extruder is 180–220℃, and the extrusion speed is 90–110 rpm. In step two, the basalt fiber is soaked in the interface modifier for 25–35 minutes. In step two, the drying temperature of the oven is 90–100℃, and the drying time is 8–10 hours.

[0013] Based on further optimization of the above scheme, the vacuum degree in step three is 3x10. -3 ~5x10 -3 Pa, substrate temperature 200~500℃, bias voltage -100~-200V; magnetron sputtering parameters: target sputtering power 50~120W, working gas pressure 0.25~0.5Pa, sputtering time 30~40min. In step three, the oven storage time is 8~12h, and the storage temperature is 30~50℃.

[0014] Based on further optimization of the above scheme, after step three, a composite process is performed between interface-modified basalt fibers and silica aerogel. Specifically, the process is as follows: First, tetraethyl orthosilicate, ethanol, and deionized water are thoroughly stirred in a stirring flask to obtain a mixed solution. Then, the pH of the mixed solution is adjusted to 1-2 using hydrochloric acid. Next, the modified basalt fibers from step three are woven and layered. The layered basalt fibers are then added to the mixed solution adjusted to an acidic environment. The temperature is adjusted to 43-47°C, and the reaction is carried out for 0.8-1.5 hours. The pH is then adjusted to 7-8 using ammonia water to obtain a wet composite gel. Finally, the wet composite gel is poured into a mold and pressure filtered (at atmospheric pressure) using a vacuum-assisted system. After aging and drying, the basalt fiber aerogel composite material is obtained.

[0015] Based on further optimization of the above scheme, the volume ratio of tetraethyl orthosilicate, ethanol and deionized water is 2.8-3.2:2.1-2.5:0.1.

[0016] Based on further optimization of the above scheme, the ratio of basalt fiber to the mixed solution is 0.1–0.2 g : 35–45 ml. The basalt fiber single layer is woven by interlacing warp and weft yarns. The concentration of hydrochloric acid is 0.05–0.15 mol / L, and the concentration of ammonia is 0.1 mol / L.

[0017] Based on further optimization of the above scheme, the aging process is as follows: First, aging is carried out in anhydrous ethanol at a temperature of 55-65°C for 1.5-2.5 days; then, aging is carried out in an aging solution at room temperature for 1.5-2.5 days; wherein, the aging solution includes trimethylchlorosilane, anhydrous ethanol and n-hexane, and their volume ratio is 8-12:10:48-52.

[0018] The following are the effects of the technical solution of the present invention:

[0019] This invention employs an interface modifier composed of maleic anhydride, a long-chain diaminosilane coupling agent, and silane coupling agent KH550 to modify the interface of basalt fiber. This, combined with magnetron sputtering deposition of a titanium dioxide layer, effectively enhances the interfacial similarity between the basalt fiber and silica aerogel during the composite process. This ensures sufficient and uniform contact between the fiber and aerogel, preventing problems such as cracks, crack propagation, and fiber-aerogel detachment caused by external loads. Consequently, it avoids failures in the mechanical and thermal insulation properties of the composite material. The interface enhancement between basalt fiber and silica aerogel through specific interface modifiers and magnetron sputtering deposition of titanium dioxide is not only simple to prepare and uses low-cost raw materials, but also effectively avoids waste generation and has a high degree of greenness in the preparation process. Therefore, it can be effectively used in large-scale industrial production and manufacturing, demonstrating high practical value.

[0020] The basalt fiber aerogel composite material obtained by this invention has advantages such as good mechanical properties, high thermal insulation performance, and stable performance over long-term use. Compared with traditional basalt fiber reinforced aerogel materials, the basalt fiber aerogel composite material provided by this invention has a thermal conductivity that is reduced by more than 20% and a mechanical property that is improved by more than 15%, exhibiting excellent mechanical and thermal insulation properties. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the surface modification of basalt fibers in an embodiment of the present invention.

[0022] Figure 2 Here is a SEM image of basalt fibers in an embodiment of the present invention; wherein, Figure 2 (a) is a surface view of basalt fibers without magnetron sputtering. Figure 2 (b) is a surface image of basalt fibers after magnetron sputtering. Figure 2(c) is a diagram of basalt fiber corrosion pits after magnetron sputtering.

[0023] Figure 3 This is a schematic diagram of the basalt fiber weaving structure in an embodiment of the present invention.

[0024] Among them, 10 is unmodified fiber; 20 is interface modifier; 30 is modified fiber; and 40 is automatic winding machine. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. The processes, conditions, experimental methods, etc., for implementing the present invention, except as specifically mentioned below, are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations; furthermore, the described embodiments are not intended to further limit the present invention.

[0026] Example 1:

[0027] A basalt fiber aerogel composite material is obtained by the following method, including:

[0028] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed at a volume ratio of 1:1 to obtain a modifying solvent. Then, maleic anhydride (using commonly available maleic anhydride in this field), long-chain diaminosilane coupling agent (chemical formula NH2(CH2)2NH(CH2)3Si(OCH3)3, with a product purity consistently above 99%), and silane coupling agent KH550 (chemical formula NH2CH2CH2CH2Si(OC2H5)3, with a product purity consistently above 99%) are weighed separately. Under vigorous stirring (stirring speed determined according to actual conditions, generally 80 r / min), the modifying solvent is slowly added dropwise. The volume ratio of maleic anhydride, long-chain diaminosilane coupling agent, silane coupling agent KH550, and modifying solvent is 1.5:1:1:98. After the addition is complete, stirring is continued for 20 minutes until no obvious oily substance remains, thus obtaining the interface modifier.

[0029] Step 2, Basalt Fiber Modification: First, uniformly mix basalt in a high-speed mixer (mixing speed is generally 800 rpm), and produce basalt fiber precursors on an extruder with a length / diameter ratio of 40. The extrusion temperature is 180℃, and the extrusion speed is 90 rpm. Then, after the extruded basalt fiber precursors have cooled (cooling can be done with cold water or other methods, depending on the actual situation), immerse them in an interface modifier for 25 minutes for modification. Afterward, use an automatic winding machine to bundle and wind the modified basalt fiber precursors. For details of the modification process, please refer to [link to relevant documentation]. Figure 1As shown; finally, the bundled and wound fiber filaments are dried at room temperature and then placed in an oven to dry at a temperature of 90℃ for 8 hours.

[0030] Step 3, Magnetron Sputtering: First, place the modified basalt fibers from Step 2 into the vacuum chamber of the magnetron sputtering equipment. The magnetron sputtering target is TiO2. Evacuate the equipment to a vacuum level of 3 x 10⁻⁶. -3 Pa; then, argon gas is introduced into the vacuum chamber, and the magnetron sputtering equipment is turned on for magnetron sputtering, wherein the substrate temperature is 200℃, the bias voltage is -100V, and the magnetron sputtering parameters are: target sputtering power 50W, working gas pressure 0.25Pa, sputtering time 30min; finally, after the magnetron sputtering is completed, the magnetron sputtered fiber is removed and placed in an oven for storage, the oven storage time is 8h, and the storage temperature is 30℃.

[0031] Step 4: Composite of interface-modified basalt fiber and silica aerogel: First, tetraethyl orthosilicate, ethanol, and deionized water are thoroughly stirred in a stirring flask to obtain a mixed solution. The volume ratio of tetraethyl orthosilicate, ethanol, and deionized water is 2.8:2.1:0.1. Then, the pH of the mixed solution is adjusted to 2 using hydrochloric acid at a concentration of 0.05 mol / L. Next, the modified basalt fiber from Step 3 is woven and layered. The weaving method for a single layer of basalt fiber is an interlaced winding of warp and weft yarns (e.g., ...). Figure 3 As shown in the figure, the layered basalt fibers were added to a mixed solution adjusted to an acidic environment. The ratio of basalt fibers to the mixed solution was 0.1g:35ml. The temperature was adjusted to 43℃, and after reacting for 0.8h, the pH was adjusted to 7 with ammonia water at a concentration of 0.1mol / L to obtain a wet gel of the composite material. Finally, the wet gel of the composite material was poured into a mold and pressure filtered through a vacuum-assisted system (at normal pressure). Then, it was aged and dried. The aging process was as follows: first, it was aged in anhydrous ethanol at 55℃ for 2.5 days; then, it was aged in an aging solution at room temperature for 2.5 days. The aging solution included trimethylchlorosilane, anhydrous ethanol, and n-hexane in a volume ratio of 8:10:48. The drying process was carried out using conventional drying processes in the art, and no specific limitation was made in this embodiment. The basalt fiber aerogel composite material was obtained.

[0032] Example 2:

[0033] A basalt fiber aerogel composite material is obtained by the following method, including:

[0034] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed at a volume ratio of 1:1 to obtain a modified solvent. Then, maleic anhydride (using commonly available maleic anhydride in this field), long-chain diaminosilane coupling agent (chemical formula NH2(CH2)2NH(CH2)3Si(OCH3)3, with a product purity consistently above 99%), and silane coupling agent KH550 (chemical formula NH2CH2CH2CH2Si(OC2H5)3, with a product purity consistently above 99%) are weighed separately. Under vigorous stirring (stirring speed determined according to actual conditions, generally 100 r / min), the modified solvent is slowly added dropwise. The volume ratio of maleic anhydride, long-chain diaminosilane coupling agent, silane coupling agent KH550, and modified solvent is 2:1.5:1.5:100. After the addition is complete, stirring is continued for 30 minutes until no obvious oily substance remains, thus obtaining the interface modifier.

[0035] Step 2, Basalt Fiber Modification: First, basalt is uniformly mixed in a high-speed mixer (mixing speed is generally 900 rpm), and basalt fiber precursors are produced on an extruder with a length / diameter ratio of 43. The extrusion temperature is 200℃ and the extrusion speed is 100 rpm. Then, after the extruded basalt fiber precursors have cooled (cooling can be done with cold water or other methods, depending on the actual situation), they are immersed in an interface modifier for 30 minutes for modification. Afterward, the modified basalt fiber precursors are bundled and wound using an automatic winding machine. For details of the modification process, please refer to [link to relevant documentation]. Figure 1 As shown; finally, the bundled and wound fiber filaments are dried at room temperature and then placed in an oven to dry at a temperature of 95°C for 9 hours.

[0036] Step 3, Magnetron Sputtering: First, place the modified basalt fibers from Step 2 into the vacuum chamber of the magnetron sputtering equipment. The magnetron sputtering target is TiO2. Evacuate the equipment to a vacuum level of 4 x 10⁻⁶. -3 Pa; then, argon gas is introduced into the vacuum chamber, and the magnetron sputtering equipment is turned on for magnetron sputtering, wherein the substrate temperature is 350℃, the bias voltage is -150V, and the magnetron sputtering parameters are: target sputtering power 85W, working gas pressure 0.35Pa, sputtering time 35min; finally, after the magnetron sputtering is completed, the magnetron sputtered fiber is removed and placed in an oven for storage, the oven storage time is 10h, and the storage temperature is 40℃.

[0037] Step 4: Composite of interface-modified basalt fiber and silica aerogel: First, tetraethyl orthosilicate, ethanol, and deionized water are thoroughly stirred in a stirring flask to obtain a mixed solution. The volume ratio of tetraethyl orthosilicate, ethanol, and deionized water is 3:2.3:0.1. Then, the pH of the mixed solution is adjusted to 1 using hydrochloric acid at a concentration of 0.15 mol / L. Next, the modified basalt fiber from Step 3 is woven and layered. The weaving method for a single layer of basalt fiber is an interlaced winding of warp and weft yarns (e.g.,...). Figure 3 As shown in the figure, the layered basalt fibers were added to a mixed solution adjusted to an acidic environment. The ratio of basalt fibers to the mixed solution was 0.15g:40ml. The temperature was adjusted to 45℃, and after reacting for 1.2h, the pH was adjusted to 8 with ammonia water at a concentration of 0.1mol / L to obtain a wet gel of the composite material. Finally, the wet gel of the composite material was poured into a mold and pressure filtered (at normal pressure) using a vacuum-assisted system. Then, it was aged and dried. The aging process was as follows: first, it was aged in anhydrous ethanol at 60℃ for 2 days; then, it was aged in an aging solution at room temperature for 2 days. The aging solution included trimethylchlorosilane, anhydrous ethanol, and n-hexane in a volume ratio of 10:10:50. The drying process was carried out using conventional drying processes in the art, and no specific limitation was made in this embodiment. The basalt fiber aerogel composite material was obtained.

[0038] Example 3:

[0039] A basalt fiber aerogel composite material is obtained by the following method, including:

[0040] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed at a volume ratio of 1:1 to obtain a modifying solvent. Then, maleic anhydride (using commonly available maleic anhydride in this field), long-chain diaminosilane coupling agent (chemical formula NH2(CH2)2NH(CH2)3Si(OCH3)3, with a product purity consistently above 99%), and silane coupling agent KH550 (chemical formula NH2CH2CH2CH2Si(OC2H5)3, with a product purity consistently above 99%) are weighed separately. Under vigorous stirring (stirring speed determined according to actual conditions, generally 120 r / min), the modifying solvent is slowly added dropwise. The volume ratio of maleic anhydride, long-chain diaminosilane coupling agent, silane coupling agent KH550, and modifying solvent is 2.5:2:2:102. After the addition is complete, stirring is continued for 40 min until no obvious oily substance remains, thus obtaining the interface modifier.

[0041] Step 2, Basalt Fiber Modification: First, uniformly mix basalt in a high-speed mixer (mixing speed is generally 1000 rpm), and produce basalt fiber precursors on an extruder with a length / diameter ratio of 45. The extrusion temperature is 220℃, and the extrusion speed is 110 rpm. Then, after the extruded basalt fiber precursors have cooled (cooling can be done with cold water or other methods, depending on the actual situation), immerse them in an interface modifier for 35 minutes for modification. Afterward, use an automatic winding machine to bundle and wind the modified basalt fiber precursors. For details of the modification process, please refer to [link to relevant documentation]. Figure 1 As shown; finally, the bundled and wound fiber filaments are dried at room temperature and then placed in an oven to dry at 100℃ for 10 hours.

[0042] Step 3, Magnetron Sputtering: First, place the modified basalt fibers from Step 2 into the vacuum chamber of the magnetron sputtering equipment. The magnetron sputtering target is TiO2. Evacuate the equipment to a vacuum level of 5 x 10⁻⁶. -3 Pa; then, argon gas is introduced into the vacuum chamber, and the magnetron sputtering equipment is turned on for magnetron sputtering, wherein the substrate temperature is 500℃, the bias voltage is -200V, and the magnetron sputtering parameters are: target sputtering power 120W, working gas pressure 0.5Pa, sputtering time 40min; finally, after the magnetron sputtering is completed, the magnetron sputtered fiber is removed and placed in an oven for storage, the oven storage time is 12h, and the storage temperature is 50℃.

[0043] Step 4: Composite of interface-modified basalt fiber and silica aerogel: First, tetraethyl orthosilicate, ethanol, and deionized water are thoroughly stirred in a stirring flask to obtain a mixed solution. The volume ratio of tetraethyl orthosilicate, ethanol, and deionized water is 3.2:2.5:0.1. Then, the pH of the mixed solution is adjusted to 1 using hydrochloric acid at a concentration of 0.15 mol / L. Next, the modified basalt fiber from Step 3 is woven and layered. The weaving method for a single layer of basalt fiber is an interlaced winding of warp and weft yarns (e.g.,...). Figure 3As shown in the figure, the layered basalt fibers were added to a mixed solution adjusted to an acidic environment. The ratio of basalt fibers to the mixed solution was 0.2g:45ml. The temperature was adjusted to 47℃, and after reacting for 1.5h, the pH was adjusted to 7 with ammonia water at a concentration of 0.1mol / L to obtain a wet gel of the composite material. Finally, the wet gel of the composite material was poured into a mold and pressure filtered through a vacuum-assisted system (at normal pressure). Then, it was aged and dried. The aging process was as follows: first, it was aged in anhydrous ethanol at 65℃ for 1.5 days; then, it was aged in an aging solution at room temperature for 1.5 days. The aging solution included trimethylchlorosilane, anhydrous ethanol, and n-hexane in a volume ratio of 12:10:52. The drying process was carried out using conventional drying processes in the art, and no specific limitation was made in this embodiment. The basalt fiber aerogel composite material was obtained.

[0044] Comparative Example 1:

[0045] A fiber aerogel composite material is obtained by the following method, comprising:

[0046] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed at a volume ratio of 1:1 to obtain a modified solvent. Then, maleic anhydride (using commonly available maleic anhydride in this field) and silane coupling agent KH550 (chemical formula NH2CH2CH2CH2Si(OC2H5)3, with a product purity consistently above 99%) are weighed separately. Under vigorous stirring (stirring speed determined according to actual conditions, generally 100 r / min), the modified solvent is slowly added dropwise. The volume ratio of maleic anhydride, silane coupling agent KH550, and modified solvent is 2:1.5:100. After the addition is complete, stirring is continued for 30 minutes until no obvious oily substance remains, thus obtaining the interface modifier.

[0047] Step 2: Basalt fiber modification: Same as in Example 2. Step 3: Magnetron sputtering: Same as in Example 2. Step 4: Composite of interface-modified basalt fiber and silica aerogel: Same as in Example 2.

[0048] Comparative Example 2:

[0049] A fiber aerogel composite material is obtained by the following method, comprising:

[0050] Step 1: Preparation of Interface Modifier: First, anhydrous ethanol and deionized water are mixed at a volume ratio of 1:1 to obtain a modifying solvent. Then, maleic anhydride (using commonly available maleic anhydride in this field), long-chain diaminosilane coupling agent (chemical formula NH2(CH2)2NH(CH2)3Si(OCH3)3, with a product purity consistently above 99%), and silane coupling agent KH560 (chemical formula CH2CH(O)CH2O(CH2)3Si(OCH3)3, with a product purity consistently above 99%) are weighed separately. Under vigorous stirring (stirring speed determined according to actual conditions, generally 100 r / min), the modifying solvent is slowly added dropwise. The volume ratio of maleic anhydride, long-chain diaminosilane coupling agent, silane coupling agent KH560, and modifying solvent is 2:1.5:1.5:100. After the addition is complete, stirring is continued for 30 minutes until no obvious oily substance remains, thus obtaining the interface modifier.

[0051] Step 2: Basalt fiber modification: Same as in Example 2. Step 3: Magnetron sputtering: Same as in Example 2. Step 4: Composite of interface-modified basalt fiber and silica aerogel: Same as in Example 2.

[0052] Comparative Example 3:

[0053] A fiber aerogel composite material is obtained by the following method, comprising:

[0054] Step 1, Preparation of interface modifier: Same as in Example 2. Step 2, Modification of basalt fibers: Same as in Example 2.

[0055] Step 3, Magnetron Sputtering: First, place the modified basalt fibers from Step 2 into the vacuum chamber of the magnetron sputtering equipment. The magnetron sputtering target is Ti. Evacuate the system to a vacuum level of 4 x 10⁻⁶. -3 Pa; then, argon gas is introduced into the vacuum chamber, and the magnetron sputtering equipment is turned on for magnetron sputtering, wherein the substrate temperature is 350℃, the bias voltage is -150V, and the magnetron sputtering parameters are: target sputtering power 85W, working gas pressure 0.35Pa, sputtering time 35min; finally, after the magnetron sputtering is completed, the magnetron sputtered fiber is removed and placed in an oven for storage, the oven storage time is 10h, and the storage temperature is 40℃.

[0056] Step 4: Composite of interface-modified basalt fiber and silica aerogel: Same as the steps in Example 2.

[0057] The performance of the basalt fiber aerogel composite materials prepared in Examples 1-3 and the basalt fiber aerogel composite materials prepared in Comparative Examples 1-3 were tested respectively, and the specific performance is shown in the table below:

[0058]

[0059] As shown in the table above, when the bulk density and porosity are roughly the same, surface modification of basalt fibers using a specific interface modifier and magnetron sputtering of TiO2 can effectively improve the interfacial compatibility between basalt fibers and silica aerogel, thereby reducing the overall thermal conductivity of the composite material and improving the overall mechanical properties (i.e., compressive strength, flexural modulus, etc.). However, Comparative Examples 1-2 did not use the specific interface modifier of this application, and Comparative Example 3 did not use TiO2 for magnetron sputtering. Therefore, compared with the composite material of this application, the composite materials prepared by them have low interfacial compatibility and low bonding strength between basalt fibers and silica aerogel, and cannot form an integral material without obvious microscopic boundaries (thus failing to fully utilize the synergistic effect between the two materials), directly affecting its thermal insulation (i.e., thermal conductivity) and mechanical properties. That is, compared with Examples 1-3, Comparative Examples 1-3 have higher thermal conductivity and lower mechanical properties (i.e., compressive strength, flexural modulus, etc.).

Claims

1. A basalt fiber aerogel composite material, characterized in that: Obtained by the following method, comprising: Step one, interface modifier preparation: first, the anhydrous ethanol and deionized water mixed, obtained modified solvent, then, respectively take maleic anhydride, long chain diamino silane coupling agent and silane coupling agent KH550, and under the condition of stirring, slowly drop the modified solvent, after drop completion, continue stirring 20-40 min, until no obvious oil, obtain interface modifier; wherein, the volume ratio of maleic anhydride, long chain diamino silane coupling agent, silane coupling agent KH550, modified solvent is 1.5-2.5:1-2:1-2:98-102; Step two, basalt fiber modification: first, in the high speed mixer uniform mixing basalt, and in the length / diameter ratio of 40-45 extruder production basalt fiber filament, the extruder extrusion temperature is 180-220 ℃, the extrusion speed is 90-110 rpm; then, after the extruded basalt fiber filament cooling, it is soaked in the interface modifier, modification; after that, the modified basalt fiber filament is collected and wound by automatic winding machine; finally, the fiber filament after drying in the air at room temperature, again in the oven drying; Step three, magnetron sputtering: first, the modified basalt fiber in step two is put into the vacuum chamber of magnetron sputtering equipment, the magnetron sputtering target material is TiO2, vacuumizing; then, argon is introduced into the vacuum chamber, and the magnetron sputtering equipment is started to carry out magnetron sputtering; finally, after the magnetron sputtering is completed, the fiber after magnetron sputtering is removed and placed in the oven for storage; Step four, the composite between the interface modified basalt fiber and the silica aerogel: first, take tetraethyl orthosilicate, ethanol and deionized water in the stirring bottle to stir thoroughly, get the mixed solution, then adjust the pH of the mixed solution to 1-2 with hydrochloric acid; then, the modified basalt fiber in step three is woven and layered, and the layered basalt fiber is added to the mixed solution adjusted to acidic environment, the ratio of basalt fiber to mixed solution is 0.1-0.2g:35-45ml, the temperature is adjusted to 43-47℃, and the reaction is carried out for 0.8-1.5h, then the pH is adjusted to 7-8 with ammonia water, to obtain the composite wet gel; finally, the composite wet gel is poured into the mold, pressure filtration is carried out through the vacuum assisted system, and then aging and drying treatment are carried out, to obtain the basalt fiber aerogel composite material; wherein, the aging treatment process is: first, aging in anhydrous ethanol at a temperature of 55-65℃ for 1.5-2.5 days; then, aging in the aging liquid at room temperature for 1.5-2.5 days; wherein, the aging liquid includes trimethylchlorosilane, anhydrous ethanol and n-hexane, and their volume ratio is 8-12:10:48-52.

2. The basalt fiber aerogel composite of claim 1, wherein: The volume ratio between the anhydrous ethanol and the deionized water in step one is 1:

1.

3. The basalt fiber aerogel composite of claim 2, wherein: The drying temperature of the oven is 90-100℃, and the drying time is 8-10h.

4. The basalt fiber aerogel composite of claim 1, wherein: The vacuum degree in the third step is 3x10 -3 ~5x10 -3 Pa, the substrate temperature is 200~500℃, the bias voltage is -100~-200V; the magnetron sputtering parameters are: the target sputtering power is 50~120W, the working pressure is 0.25~0.5Pa, and the sputtering time is 30~40min.

5. The basalt fiber aerogel composite of claim 1, wherein: The volume ratio of tetraethyl orthosilicate, ethanol and deionized water is 2.8-3.2:2.1-2.5:0.

1.

6. A basalt fiber aerogel composite material according to claim 5, characterized in that: The concentration of the hydrochloric acid is 0.05-0.15 mol / L, and the concentration of the ammonia water is 0.1 mol / L.

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