Phosphorus acid source catalyzed high-flame-retardant ultraviolet-resistant aerogel powder and preparation method thereof

Abstract

The invention discloses phosphorus-based acid source catalyzed high-flame-retardant ultraviolet-resistant aerogel powder and a preparation method of the phosphorus-based acid source catalyzed high-flame-retardant ultraviolet-resistant aerogel powder. The preparation method comprises the following steps: S1, adding TiO2 powder into ethanol; adding nitric acid to adjust the pH value; amino alkyl triethoxy silane is added, and stirring is carried out; after heating reaction, washing and vacuum drying are performed to obtain modified TiO2; s2, tetraethyl orthosilicate, absolute ethyl alcohol and deionized water are mixed, a phosphorus acid source is dropwise added while stirring is conducted, and water bath hydrolysis is conducted after dropwise adding is completed; s3, adding modified TiO2 into the solution obtained in S2, stirring, and dropwise adding ammonia water to induce the system to generate gelation reaction; s4, adding absolute ethyl alcohol and normal hexane after gelling, and carrying out solvent exchange; s5, adding a mixed solution of a hydrophobic modifier and n-hexane for surface modification to obtain a wet gel composite material; s6, drying to obtain the flame-retardant hydrophobic silicon dioxide / modified TiO2 aerogel composite material. The fireproof and anti-ultraviolet performance of the HSA composite material disclosed by the invention is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of aerogel material technology, specifically relating to a phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder and its preparation method. Background Technology

[0002] In high-altitude and frigid regions, extreme climatic conditions and intense ultraviolet radiation place higher demands on the performance of thermal insulation materials. In such environments, insulation materials not only need excellent thermal insulation properties but also must effectively resist ultraviolet radiation. Traditional insulation materials are mainly divided into organic and inorganic types. While organic insulation materials (such as EPS insulation boards) have advantages such as being lightweight and easy to install, their flammability and aging properties limit their application. Inorganic insulation materials (such as rock wool), although possessing good fire resistance, often suffer from water absorption problems in practical applications, affecting their effectiveness. Therefore, there is an urgent need to develop an insulation material that combines excellent thermal insulation performance, flame retardancy, water resistance, and ultraviolet resistance.

[0003] Hydrophobic silica aerogel (HSA) has become an ideal high-efficiency thermal insulation material due to its low density, excellent thermal insulation properties, and high porosity, especially suitable for high-altitude and cold regions. However, although HSA possesses a certain degree of UV resistance and can effectively block UV penetration, its performance gradually degrades with prolonged exposure to strong UV radiation in environments with high UV intensity. Furthermore, the hydrophobicity of HSA is achieved through hydrophobic modification of the silica aerogel. However, hydrophobic modification typically requires the introduction of organic groups. While these organic groups enhance hydrophobicity, they may also increase the flammability of the aerogel, posing a fire risk. Therefore, effectively improving the UV resistance and flame retardant properties of HSA has become a pressing technical challenge.

[0004] Currently, research on improving the UV resistance of HSA (High-Strength Acrylic Acid) is relatively limited. Existing UV-resistant technologies mainly achieve UV absorption by doping with titanium dioxide (TiO2). For example, Zhai et al. enhanced the UV resistance of aramid fibers by doping with TiO2. However, TiO2 doping methods often face the problem of uneven material dispersion and negatively impact other properties (such as thermal insulation and hydrophobicity). Therefore, modification treatment is particularly important to enhance the compatibility of TiO2 with the matrix. Li et al. improved the compatibility of TiO2 with the polylactic acid matrix by modifying TiO2, thereby effectively improving the performance of the composite material. Therefore, by modifying TiO2 to further improve its compatibility with the HSA matrix, the UV protection performance of HSA can be significantly enhanced while maintaining or improving its thermal insulation and hydrophobicity.

[0005] Some progress has been made in improving the flame retardant properties of HSA (Hypericum Sedimentae). Dopants such as sepiolite, halloysite nanotubes, aluminum hydroxide, and magnesium hydroxide have been added to the HSA matrix to enhance its flame retardancy. However, while these dopants improve flame retardancy, they often sacrifice key properties of HSA, such as thermal insulation and hydrophobicity. Therefore, there is an urgent need to develop new strategies to improve the flame retardant properties of HSA without compromising other important properties. Traditional HSA preparation often relies on strong acid catalysts (such as nitric acid and hydrochloric acid). These strong acids are not only highly corrosive and may damage equipment in industrial production, but they also generate large amounts of acidic wastewater, leading to serious environmental problems (such as water acidification and soil pollution). In addition, the use of strong acids brings additional safety hazards and may endanger the health of operators.

[0006] However, current methods for adding dopants to HSA matrices still have certain limitations, making it difficult to simultaneously achieve UV protection, flame retardancy, and other key properties. Therefore, there is a need to design a novel phosphoric acid-based catalytic highly flame-retardant and UV-resistant aerogel powder and its preparation method. Summary of the Invention

[0007] The purpose of this invention is to provide a phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder and its preparation method, so as to solve the problem that the current method of adding dopants to the HSA matrix still has certain limitations and it is difficult to take into account ultraviolet protection, flame retardant performance and other key properties.

[0008] To achieve the above objectives, the present invention provides a method for preparing a phosphorus-based acid-catalyzed highly flame-retardant and UV-resistant aerogel powder, comprising the following steps:

[0009] S1. Add TiO2 powder to ethanol, and use an ultrasonic treatment device to ultrasonically treat the solution to form a homogeneous solution; then, add nitric acid to adjust the pH of the solution to 2-3; next, add aminoalkyltriethoxysilane and stir; heat to 70°C to continue the reaction, and wash the sample after the reaction is completed; vacuum dry the sample to obtain modified TiO2.

[0010] S2. Mix tetraethyl orthosilicate, anhydrous ethanol, and deionized water, then place them in a stirring container. While stirring, add phosphoric acid source dropwise to adjust the pH of the mixed solution to 2-3. After the addition is complete, place the resulting solution in a water bath for hydrolysis.

[0011] S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then mix it evenly using an ultrasonic disperser after stirring at room temperature and pressure; then add ammonia water dropwise to induce a gelation reaction in the system.

[0012] S4. After gelation, anhydrous ethanol is added for solvent exchange, followed by n-hexane for solvent exchange.

[0013] S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immerse the gel, modify the surface, and obtain a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material.

[0014] S6. The obtained flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material is dried to obtain flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material.

[0015] In one specific embodiment, in step S5, the hydrophobic modifier includes hexamethyldisiloxane, hexamethyldisilazane, and hexamethyldisiloxane; the hydrophobic modifier accounts for 1% to 20% of the volume fraction of the mixture.

[0016] In one specific embodiment, in step S1, aminoalkyltriethoxysilane is added and stirred for 30-60 minutes; the mixture is heated to 70-80°C and the reaction continues for 8-12 hours. After the reaction is completed, the sample is repeatedly washed with ethanol and deionized water until it is neutral. Finally, the sample is vacuum dried at 80-100°C.

[0017] In one specific embodiment, in step S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5~6:15:1~1.5, and then placed in a stirring container. While stirring, a phosphoric acid source is added dropwise. After the addition is completed, stirring is continued for 5~10 minutes. Then, the resulting solution is placed in a water bath at 45~55℃ and hydrolyzed for 12~16 hours.

[0018] In one specific embodiment, in step S3, after stirring at 300-500 r / min for 3-5 minutes at room temperature and pressure, an ultrasonic disperser is used to mix the mixture evenly.

[0019] In one specific embodiment, in step S4, after gelation for 3-4 hours, anhydrous ethanol is added for solvent exchange 2-3 times, followed by solvent exchange with n-hexane 2-3 times.

[0020] In one specific embodiment, in step S5, a mixture of hydrophobic modifier and n-hexane is added to the gel obtained in step S4, and the gel is placed in an environment of 30~60°C for surface modification for 24~48 hours.

[0021] In one specific embodiment, in step S6, the obtained flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material is dried at 100~150℃ for 1~4 hours to obtain flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material.

[0022] The present invention also provides a phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder, wherein the phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder is prepared by the preparation method of phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder as described above.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention employs in-situ doping technology to introduce modified TiO2 into an HSA matrix and combines it with a phosphoric acid source as an acid catalyst to prepare an HSA composite material that possesses excellent UV resistance, flame retardancy, good thermal insulation, and hydrophobicity. This invention solves the problems of performance constraints and cost increases inherent in traditional doping techniques, providing a highly efficient and low-cost solution. Furthermore, it opens up new avenues for applications in energy-saving building materials for high-altitude and cold regions, aerospace, and other high-performance materials fields, demonstrating broad application prospects.

[0025] Compared with existing HSA materials, the HSA composite material prepared by this invention has significantly improved fire resistance and UV resistance, and does not require the addition of additional flame retardants, making it particularly suitable for applications in extreme environments such as high altitudes and cold regions.

[0026] This invention utilizes phosphorus-based acid sources (such as DOPO, triphenyl phosphate, phosphoric acid, and aluminate phosphate) which possess certain acidic properties and can serve as catalysts to replace traditional strong acids, reducing the adverse effects of strong acids. Phosphorus-based acid sources can not only replace traditional acid catalysts in the preparation of HSA, but also significantly reduce the fire risk of HSA, while simultaneously reducing production costs associated with the introduction of flame retardants.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The present invention will now be described in further detail. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a comparison diagram of the hydrophobic angle and thermal conductivity of a hydrophobic silica aerogel composite material according to an embodiment of the present invention.

[0030] Figure 2 This is a comparison chart of the heat release rates of a hydrophobic silica aerogel composite material according to an embodiment of the present invention;

[0031] Figure 3 This is a comparative diagram of the total heat release of a hydrophobic silica aerogel composite material according to an embodiment of the present invention;

[0032] Figure 4 This is a comparison chart of the total calorific value of a hydrophobic silica aerogel composite material according to an embodiment of the present invention.

[0033] Figure 5 This is a UV / Vis / NIR / diffuse reflectance test spectrum of a hydrophobic silica aerogel composite material according to an embodiment of the present invention. Detailed Implementation

[0034] The following provides a detailed description of the embodiments of the present invention. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0035] Example 1

[0036] A phosphorus-based acid-catalyzed, highly flame-retardant, and UV-resistant aerogel powder is prepared according to the following steps, wherein all components are in parts by weight:

[0037] S1. Add an appropriate amount of TiO2 powder to 50 mL of ethanol. Use an ultrasonic treatment device to ultrasonically treat the solution for 20 minutes to ensure that the TiO2 powder is uniformly dispersed in the ethanol, forming a homogeneous solution. Then, add nitric acid (HNO3) to adjust the pH of the solution to 2-3. Next, add aminoalkyltriethoxysilane (APTES) and stir for 30 minutes. Heat to 70℃ and continue the reaction for 8 hours. Wash the sample repeatedly with ethanol and deionized water until neutral. Finally, vacuum dry the sample at 80℃ to obtain modified TiO2.

[0038] S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of DOPO is added dropwise to adjust the pH of the solution to 2-3. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0039] S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then stir at 300 r / min for 4 minutes at room temperature and pressure, followed by ultrasonic dispersion to ensure uniform mixing. Then, add ammonia water dropwise to induce a gelation reaction in the system.

[0040] S4. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0041] S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material. The above-mentioned hydrophobic modifier includes hexamethyldisiloxane (HMDSO), hexamethyldisilazane (HMDZ), and hexamethyldisiloxane (HMDS), wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0042] S6. The flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain the flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material (DSA / TiO2). Specific parameters: Compared with pure HSA, the peak heat release rate, total heat release, and total calorific value are reduced by 19.0%, 48.9%, and 34.1%, respectively.

[0043] Example 2

[0044] A phosphorus-based acid-catalyzed, highly flame-retardant, and UV-resistant aerogel powder is prepared according to the following steps, wherein all components are in parts by weight:

[0045] S1. Add an appropriate amount of TiO2 powder to 50 mL of ethanol. Use an ultrasonic treatment device to ultrasonically treat the solution for 20 minutes to ensure that the TiO2 powder is uniformly dispersed in the ethanol, forming a homogeneous solution. Then, add HNO3 to adjust the pH of the solution. Next, add APTES and stir for 30 minutes. Heat to 70℃ and continue the reaction for 8 hours. Wash the sample repeatedly with ethanol and deionized water. Finally, vacuum dry the sample at 80℃ to obtain modified TiO2.

[0046] S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of hypophosphoric acid is added dropwise to adjust the pH of the solution to 2-3. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0047] S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then stir at 300 r / min for 4 minutes at room temperature and pressure, followed by ultrasonic dispersion to ensure uniform mixing. Then, add ammonia water dropwise to induce a gelation reaction in the system.

[0048] S4. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0049] S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material. The above-mentioned hydrophobic modifiers include HMDSO, HMDZ, and HMDS, wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0050] S6. The flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain the flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material (HPSA / TiO2). Specific parameters: Compared with pure HSA, the peak heat release rate, total heat release, and total calorific value are reduced by 17.3%, 29.5%, and 23.0%, respectively.

[0051] Example 3

[0052] A phosphorus-based acid-catalyzed, highly flame-retardant, and UV-resistant aerogel powder is prepared according to the following steps, wherein all components are in parts by weight:

[0053] S1. Add an appropriate amount of TiO2 powder to 50 mL of ethanol. Use an ultrasonic treatment device to ultrasonically treat the solution for 20 minutes to ensure that the TiO2 powder is uniformly dispersed in the ethanol, forming a homogeneous solution. Then, add HNO3 to adjust the pH of the solution. Next, add APTES and stir for 30 minutes. Heat to 70℃ and continue the reaction for 8 hours. Wash the sample repeatedly with ethanol and deionized water. Finally, vacuum dry the sample at 80℃ to obtain modified TiO2.

[0054] S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of phytic acid is added dropwise. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0055] S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then stir at 300 r / min for 4 minutes at room temperature and pressure, followed by ultrasonic dispersion to ensure uniform mixing. Then, add ammonia water dropwise to induce a gelation reaction in the system.

[0056] S4. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0057] S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material. The above-mentioned hydrophobic modifiers include HMDSO, HMDZ, and HMDS, wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0058] S6. The flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain the flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material (PSA / TiO2). Specific parameters: Compared with pure HSA, the peak heat release rate, total heat release, and total calorific value are reduced by 22.1%, 58.2%, and 27.2%, respectively.

[0059] Example 4

[0060] A phosphorus-based acid-catalyzed, highly flame-retardant, and UV-resistant aerogel powder is prepared according to the following steps, wherein all components are in parts by weight:

[0061] S1. Add an appropriate amount of TiO2 powder to 50 mL of ethanol. Use an ultrasonic treatment device to ultrasonically treat the solution for 20 minutes to ensure that the TiO2 powder is uniformly dispersed in the ethanol, forming a homogeneous solution. Then, add HNO3 to adjust the pH of the solution. Next, add APTES and stir for 30 minutes. Heat to 70℃ and continue the reaction for 8 hours. Wash the sample repeatedly with ethanol and deionized water. Finally, vacuum dry the sample at 80℃ to obtain modified TiO2.

[0062] S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of triphenyl phosphate is added dropwise. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0063] S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then stir at 300 r / min for 4 minutes at room temperature and pressure, followed by ultrasonic dispersion to ensure uniform mixing. Then, add ammonia water dropwise to induce a gelation reaction in the system.

[0064] S4. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0065] S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material. The above-mentioned hydrophobic modifiers include HMDSO, HMDZ, and HMDS, wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0066] S6. The flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain the flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material (TPSA / TiO2). Specific parameters: Compared with pure HSA, the total heat release and total calorific value are reduced by 48.7% and 23.8%, respectively.

[0067] Table 1. Basic physicochemical properties of hydrophobic silica aerogel composites

[0068] Note: HSA is an aerogel prepared using nitric acid as an acid catalyst; ASA is prepared using acetic acid as an acid catalyst; DSA is prepared using DOPO as an acid catalyst; HPSA is prepared using hypophosphite as an acid catalyst; PSA is an aerogel prepared using phytic acid as an acid catalyst; and TPSA is prepared using triphenyl phosphate as an acid catalyst.

[0069] Compare with Example 1

[0070] S1, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of nitric acid is added dropwise to adjust the pH of the solution to 2-3. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0071] S2. After stirring at 300 rpm for 4 minutes at room temperature and pressure, use an ultrasonic disperser to mix thoroughly. Then add ammonia water dropwise to induce a gelation reaction in the system.

[0072] S3. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0073] S4. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S3, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a hydrophobic silica wet gel composite material. The above-mentioned hydrophobic modifiers include HMDSO, HMDZ, and HMDS, wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0074] S5. The hydrophobic silica wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain hydrophobic silica aerogel composite material (HSA).

[0075] Compare with Example 2

[0076] S1, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5.75:15:1, and then placed on a magnetic stirrer. While stirring, an appropriate amount of acetic acid is added dropwise. Stirring is continued for 5 minutes, and then the solution is placed in a 45°C water bath for hydrolysis for 12 hours.

[0077] S2. After stirring at 300 rpm for 4 minutes at room temperature and pressure, use an ultrasonic disperser to mix thoroughly. Then add ammonia water dropwise to induce a gelation reaction in the system.

[0078] S3. After gelling for 3-4 hours, exchange the solvent twice with anhydrous ethanol, and then twice with n-hexane.

[0079] S4. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S3, completely immersing the gel, and place it in an environment of 30~60℃ for surface modification for 24~48 hours, finally obtaining a hydrophobic silica wet gel composite material. The above-mentioned hydrophobic modifiers include HMDSO, HMDZ, and HMDS, wherein the volume fraction of the hydrophobic modifier in the mixture is 1%~20%;

[0080] S5. The hydrophobic silica wet gel composite material obtained above is dried at 100~150℃ for 1~4 hours to obtain hydrophobic silica aerogel composite material (ASA).

[0081] Compare with Example 3

[0082] Except for the absence of modified TiO2, the other preparation processes were the same as in Example 1, ultimately yielding a flame-retardant hydrophobic silica aerogel composite material (DSA). Specific flame-retardant performance enhancement parameters: compared to pure HSA, the peak heat release rate, total heat release, and total calorific value decreased by 29.0%, 23.7%, and 24.7%, respectively.

[0083] Compare with Example 4

[0084] Except for the absence of modified TiO2, the other preparation processes were the same as in Example 2, ultimately yielding a flame-retardant hydrophobic silica aerogel composite material (HPSA). Specific flame-retardant performance enhancement parameters: compared to pure HSA, the peak heat release rate, total heat release, and total calorific value decreased by 14.2%, 48.6%, and 15.1%, respectively.

[0085] Compare with Example 5

[0086] Except for the absence of modified TiO2, the other preparation processes were the same as in Example 3, ultimately yielding a flame-retardant hydrophobic silica aerogel composite material (PSA). Specific flame-retardant performance enhancement parameters: compared to pure HSA, the peak heat release rate, total heat release, and total calorific value decreased by 10.7%, 53.0%, and 16.8%, respectively.

[0087] Compare with Example 6

[0088] Except for the absence of modified TiO2, the other preparation processes were the same as in Example 4, ultimately yielding a flame-retardant hydrophobic silica aerogel composite material (TPSA). Specific flame-retardant performance enhancement parameters: compared to pure HSA, the peak heat release rate, total heat release, and total calorific value decreased by 4.4%, 21.7%, and 19.4%, respectively.

[0089] Table 2 Thermal safety performance parameters of hydrophobic silica aerogel composites

[0090] When using phosphoric acid sources as catalysts to prepare hydrophobic silica aerogels, the resulting hydrophobic silica aerogels exhibit superior thermal safety performance compared to preparation methods using strong or weak acids as catalysts. Specifically, the total calorific value of the material can be reduced by up to approximately 25%, the peak heat release rate by up to approximately 30%, and the total heat release by up to approximately 53%.

[0091] pass Figure 5 It is known that the reflectivity of the titanium dioxide-doped hydrophobic silica aerogel in the ultraviolet band is about 10%, which is significantly lower than that of the undoped pure hydrophobic silica aerogel (about 40%). This indicates that the introduction of titanium dioxide can enhance the absorption / attenuation of ultraviolet radiation, thereby improving its UV resistance and service stability, making it suitable for applications in environments with strong ultraviolet radiation.

[0092] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions and substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a phosphorus-based acid-catalyzed, highly flame-retardant, UV-resistant aerogel powder, characterized in that, Includes the following steps: S1. Add TiO2 powder to ethanol, and use an ultrasonic treatment device to ultrasonically treat the solution to form a homogeneous solution; then, add nitric acid to adjust the pH of the solution to 2-3; next, add aminoalkyltriethoxysilane and stir. The reaction was continued at 70°C. After the reaction was completed, the sample was washed. The sample was then vacuum dried to obtain modified TiO2. S2. Mix tetraethyl orthosilicate, anhydrous ethanol, and deionized water, then place them in a stirring container. While stirring, add phosphoric acid source dropwise to adjust the pH of the mixed solution to 2-3. After the addition is complete, place the resulting solution in a water bath for hydrolysis. S3. Add the modified TiO2 synthesized in step S1 to the solution obtained in step S2, and then mix it evenly using an ultrasonic disperser after stirring at room temperature and pressure; then add ammonia water dropwise to induce a gelation reaction in the system. S4. After gelation, anhydrous ethanol is added for solvent exchange, followed by n-hexane for solvent exchange. S5. Add a mixture of hydrophobic modifier and n-hexane to the gel obtained in step S4, completely immerse the gel, modify the surface, and obtain a flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material. S6. The obtained flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material is dried to obtain flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material.

2. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S5, the hydrophobic modifier includes hexamethyldisiloxane, hexamethyldisilazane, and hexamethyldisiloxane; the hydrophobic modifier accounts for 1% to 20% of the volume fraction of the mixture.

3. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S1, aminoalkyltriethoxysilane is added and stirred for 30-60 minutes; the mixture is heated to 70-80°C and the reaction continues for 8-12 hours. After the reaction is completed, the sample is repeatedly washed with ethanol and deionized water until it is neutral. Finally, the sample is vacuum dried at 80-100°C.

4. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S2, tetraethyl orthosilicate, anhydrous ethanol, and deionized water are mixed in a volume ratio of 5-6:15:1-1.5, and then placed in a stirring container. While stirring, a phosphoric acid source is added dropwise. After the addition is complete, stirring is continued for 5-10 minutes. The resulting solution is then placed in a water bath at 45-55°C for hydrolysis for 12-16 hours.

5. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S3, after stirring at 300-500 r / min for 3-5 minutes at room temperature and pressure, an ultrasonic disperser is used to mix the mixture evenly.

6. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S4, after gelation for 3-4 hours, anhydrous ethanol is added for solvent exchange 2-3 times, followed by solvent exchange with n-hexane 2-3 times.

7. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S5, a mixture of hydrophobic modifier and n-hexane is added to the gel obtained in step S4, and the mixture is placed in an environment of 30~60℃ for surface modification for 24~48 hours.

8. The method for preparing highly flame-retardant and UV-resistant aerogel powder catalyzed by a phosphorus-based acid source according to claim 1, characterized in that, In step S6, the obtained flame-retardant hydrophobic silica / modified @TiO2 wet gel composite material is dried at 100~150℃ for 1~4 hours to obtain flame-retardant hydrophobic silica / modified @TiO2 aerogel composite material.

9. A phosphorus-based acid-catalyzed, highly flame-retardant, UV-resistant aerogel powder, characterized in that, The phosphoric acid source-catalyzed highly flame-retardant and UV-resistant aerogel powder is prepared by the method described in any one of claims 1 to 8.

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