A transparent silica aerogel, aerogel membrane, its preparation method and application

Abstract

This invention discloses a transparent silica aerogel, an aerogel film, its preparation method, and its applications. The transparent silica aerogel comprises the following components: silica aerogel powder, an alcohol-based organosilicon-modified nanoresin sol, and a silane coupling agent; the silane coupling agent is selected from (3-aminopropyl)triethoxysilane, or a combination of (3-aminopropyl)triethoxysilane and long-chain alkylsilane coupling agents; the silica aerogel powder has a particle size of 5.8-6.2 nm. This invention achieves a breakthrough in the comprehensive performance of transparent silica aerogel, including high transparency, strong adhesion, and tunable hydrophobicity, by compounding silica aerogel powder, alcohol-based organosilicon-modified nanoresin sol, and a specific silane coupling agent.

Description

Technical Field

[0001] This invention relates to the field of glass coating technology, and in particular to a transparent silica aerogel, an aerogel film, its preparation method and application. Background Technology

[0002] Glass substrates, due to their excellent optical transparency, chemical stability, and mechanical strength, are widely used in various high-tech fields such as architectural windows, electronic displays, protective covers, optical instruments, and solar photovoltaic modules. In these applications, the requirements for surface functionalized coatings are extremely stringent: they must not only maintain the original high light transmittance of the substrate but also possess good thin-film forming ability, strong adhesion, and long-term environmental stability. In recent years, with the increasing demands for energy conservation and environmental protection, transparent coating technologies with functions such as heat insulation, anti-fogging, self-cleaning, or anti-reflection have become a research hotspot. Among them, functional coatings based on silica aerogel have attracted much attention due to their unique porous structure and extremely low thermal conductivity.

[0003] Silica aerogel is a three-dimensional network structure material composed of nanoscale silica particles. Its numerous mesopores exhibit excellent thermal insulation properties and low refractive index, theoretically making it ideal for preparing highly transparent thermal insulation coatings. However, in practical applications, especially when constructing coatings on glass surfaces requiring high optical clarity, several technical bottlenecks remain. The primary issue is that aerogel particles readily aggregate in liquid-phase dispersion systems, leading to an uneven film layer after coating and causing light scattering, significantly reducing the visible light transmittance of the coating and affecting visual effects. Furthermore, because aerogel is a brittle inorganic material, its three-dimensional network structure, while providing excellent thermal insulation, also results in poor mechanical properties and weak interfacial adhesion with the glass substrate, often leading to poor adhesion and easy peeling, limiting its durability in dynamic environments or outdoor conditions.

[0004] To address the aforementioned issues, researchers both domestically and internationally have conducted extensive exploratory work. In existing technologies, methods for preparing silica aerogels and their coatings mainly include the sol-gel method, solvent exchange method, and surface modification techniques. For example, some studies have used organosilicon sources as precursors to prepare silica gels via a two-step sol-gel method, adding a non-protic polar solvent during the gelation stage, and then using a liquid carbon dioxide displacement drying process to obtain bulk transparent silica aerogels. While this method can yield aerogel materials with excellent performance, the process is relatively complex, involving high-pressure equipment or supercritical drying steps, resulting in high energy consumption and difficulty in meeting the cost control requirements of large-scale industrial production. Other studies have attempted to use inexpensive industrial water glass as a silica source, obtaining a stable silica gel slurry through ion exchange, alkali-catalyzed polycondensation, solvent exchange, and surface modification, then coating it onto the surface of an object and drying it at room temperature and under normal pressure to obtain an aerogel coating. This method reduces production costs and avoids the harsh conditions of supercritical drying, but the transparency and adhesion of the resulting coating still need to be improved. Especially when applied to glass substrates with high optical clarity requirements, the uniformity of aerogel particle dispersion is difficult to control precisely, and light scattering caused by micro-agglomerates is likely to occur.

[0005] More complexly, besides the bonding issues with glass substrates, aerogel materials also face interfacial compatibility challenges when composited with other reinforcing materials. For example, research on the preparation of glass fiber reinforced silica aerogel composites revealed that the smooth surface of glass fibers and the lack of oxygen-containing active groups resulted in low mechanical and chemical bonding between the glass fibers and silica aerogel. This led to poor adhesion of the aerogel to the fibers in the composite material, resulting in flaking and a decrease in thermal insulation performance. This interfacial problem also exists in aerogel-polymer composite systems, becoming a key bottleneck restricting their application expansion.

[0006] In summary, glass substrates, as key materials in windows, displays, protective covers, optical devices, and solar energy, require coatings with high transparency, optimized film formation, strong adhesion, and stability in specific applications. Silica aerogels exhibit excellent thermal insulation potential due to their unique nanoporous structure; however, preparing aerogel-derived coatings on high-optical-resolution glass surfaces still faces three core challenges: aerogel particle aggregation leading to light scattering, insufficient adhesion between the coating and the substrate, and poor coating uniformity and repeatability. Current technologies, whether using direct aerogel slurry coating or indirect film formation via polymer composite systems, struggle to simultaneously meet the combined requirements of high transparency, strong adhesion, and ease of processing. Summary of the Invention

[0007] The technical solution adopted according to the first aspect of the present invention is as follows:

[0008] A transparent silica aerogel comprising the following components:

[0009] Silica aerogel powder, alcohol-based organosilicon modified nano-resin sol, and silane coupling agent;

[0010] The silane coupling agent is selected from (3-aminopropyl)triethoxysilane, or the silane coupling agent is selected from (3-aminopropyl)triethoxysilane and long-chain alkylsilane coupling agents;

[0011] The particle size of the silica aerogel powder is 5.8-6.2 nm.

[0012] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0013] This invention achieves a breakthrough in the comprehensive performance of transparent silica aerogel by compounding silica aerogel powder, alcohol-based organosilicon modified nano-resin sol, and a specific silane coupling agent, thereby realizing high transparency, strong adhesion, and adjustable hydrophobicity.

[0014] Among them, the particle size of silica aerogel powder, 5.8-6.2nm, is much smaller than the wavelength of visible light, which can fundamentally eliminate the light scattering loss caused by the size of the particles themselves.

[0015] In silane coupling agents, (3-aminopropyl)triethoxysilane replaces the hydroxyl groups (-OH) on the aerogel surface through a silanization reaction, forming Si-O- covalent bonds and introducing aminopropyl groups (-(CH2)3NH2). This reduces capillary shrinkage and structural collapse during drying, maintaining the integrity of the nanoporous network. The transparent silica aerogel modified with (3-aminopropyl)triethoxysilane exhibits significantly improved transmittance in the visible light range. Long-chain alkylsilane coupling agents impart low surface energy to the membrane, achieving hydrophobic functionality.

[0016] Alcohol-based organosilicon-modified nanoresin serves as a continuous phase matrix, supporting the aerogel and providing basic film-forming properties and adhesion. The synergistic effect of these components achieves comprehensive performance that cannot be attained by a single component.

[0017] According to one embodiment of the present invention, the porosity of the silica aerogel powder is >90%. The >90% porosity of the silica aerogel powder results in an extremely low effective refractive index of the particles, which, together with the low particle size of the silica aerogel powder, promotes the ultra-high transparency (up to 94.0%) of the transparent silica aerogel.

[0018] According to one embodiment of the present invention, the ratio of silica aerogel powder to the alcohol-based organosilicon modified nano-resin sol is 0.1-5 g:30 mL, and the ratio of silane coupling agent to the alcohol-based organosilicon modified nano-resin sol is 0.05-1.5 mL:30 mL. By adjusting the amounts of silica aerogel powder and silane coupling agent, transparency can be further improved.

[0019] According to one embodiment of the present invention, the amount of silica aerogel powder is 0.1-5g, and the amount of silane coupling agent is 0.05-1.5mL; preferably, the amount of silica aerogel powder is 0.2-1g, and the amount of (3-aminopropyl)triethoxysilane in the silane coupling agent is 0.05-0.1mL.

[0020] According to one embodiment of the present invention, the amount of silica aerogel powder used is 0.6-1g; more preferably, the amount of silica aerogel powder used is 0.6g.

[0021] According to one embodiment of the present invention, with the volume of the alcohol-based organosilicon modified nano-resin sol being 30 mL, the amount of the silica aerogel powder is 0.6 g or 1 g, the amount of the (3-aminopropyl)triethoxysilane is 0.05 mL or 0.1 mL, and the amount of the long-chain alkylsilane coupling agent is 0.05 mL to 0.7 mL.

[0022] According to one embodiment of the present invention, the silane coupling agent comprises (3-aminopropyl)triethoxysilane and a long-chain alkylsilane coupling agent, wherein the volume ratio of the (3-aminopropyl)triethoxysilane to the long-chain alkylsilane coupling agent is 1-2:1-14. By controlling the amount of the long-chain alkylsilane coupling agent, the present invention can further balance hydrophobic properties and optical transparency.

[0023] Furthermore, the concentration and dispersion uniformity of (3-aminopropyl)triethoxysilane directly affect the modification effect on silica aerogel powder. Excessive concentration leads to silane molecule aggregation, forming scattering centers; insufficient concentration fails to completely cover surface hydroxyl groups, resulting in decreased structural stability. A suitable amount of (3-aminopropyl)triethoxysilane can achieve a contact angle of 150° in the aerogel film while maintaining over 90% light transmittance, achieving a breakthrough in the combined performance of high transparency and high hydrophobicity.

[0024] According to one embodiment of the present invention, the long-chain alkylsilane coupling agent is hexadecyltrimethoxysilane; the silane coupling agent is composed of (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane in a volume ratio of 1-2:1-14; preferably, the silane coupling agent is composed of (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane in a volume ratio of 1:1-12.

[0025] The long carbon chain of hexadecyltrimethoxysilane provides excellent hydrophobicity, while the three methoxy groups provide reaction sites for strong bonding with inorganic surfaces. This structure enables the formation of dense, ordered self-assembled monolayers on glass surfaces, making it an ideal structure for achieving high hydrophobicity and high transparency. When (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane are combined, the contact angle of the aerogel film obtained after curing the transparent silica aerogel of this invention is ≥119°.

[0026] In particular, the combination of specific amounts of (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane enables the aerogel film obtained after curing the transparent silica aerogel of the present invention to have a contact angle of 150° while maintaining a light transmittance of more than 90%, achieving a breakthrough in the comprehensive performance of high transparency and high hydrophobicity.

[0027] According to one embodiment of the present invention, the transparent silica aerogel further comprises quantum dots; preferably, the quantum dots are molybdenum sulfide quantum dots. Molybdenum sulfide quantum dots play a synergistic role in enhancing transparency in the system of the present invention.

[0028] Specifically, MoS2 quantum dots differ from MoS2 in optical properties and size.

[0029] First, MoS2 quantum dots exhibit a significant blue shift due to quantum confinement, and their UV-vis absorption often shows a shoulder peak mainly near the ultraviolet region, rather than having stronger absorption in the visible region as larger-sized MoS2. In addition, the absorption of MoS2 quantum dots starts at about 400 nm, indicating that its absorption edge shifts generally towards shorter wavelengths, thereby reducing the absorption of visible light and making the transparent silica aerogel more transparent.

[0030] Secondly, MoS2 quantum dots are small in size, making them easy to disperse evenly and less prone to strong Mie scattering, thus reducing haze and increasing transparency.

[0031] In summary, MoS2 quantum dots, due to their smaller size, weaker absorption in the visible region, and more uniform dispersion, can further improve the transparency of transparent silica aerogels.

[0032] According to one embodiment of the present invention, the transparent silica aerogel further includes additives.

[0033] According to one embodiment of the present invention, the additives include at least one of defoamer, leveling agent, and wetting agent.

[0034] According to one embodiment of the present invention, the defoamer includes at least one of 3801 polysiloxane defoamer, polydimethylsiloxane defoamer, and hydroxyl-modified polysiloxane defoamer.

[0035] According to one embodiment of the present invention, the leveling agent includes at least one of 1050 polyether leveling agent, acrylate-modified polyether leveling agent, and silicone-modified polyether leveling agent.

[0036] According to one embodiment of the present invention, the wetting agent includes at least one of AKN-1148 wetting agent, polyether modified organosilicon wetting agent, and alkylolamide wetting agent.

[0037] Specifically, the technical solution adopted according to the second aspect of the present invention is as follows:

[0038] A method for preparing the transparent silica aerogel includes the following steps:

[0039] The transparent silica aerogel is obtained by mixing silica aerogel powder, alcohol-based organosilicon modified nano-resin sol, and silane coupling agent.

[0040] According to one embodiment of the present invention, the method for preparing the silica aerogel powder includes the following steps:

[0041] A sol is formed by mixing a silicon source, an alcohol solvent, and water.

[0042] The pH value of the sol is adjusted, and the sol is heated to undergo hydrolysis and condensation reactions to form a gel;

[0043] The gel is aged, dried, and ground to obtain silica aerogel powder.

[0044] This invention controls the pH to regulate the hydrolysis and condensation rate of the silicon source, thereby forming a gel with uniform size and a fine network structure. This fine structure is retained after drying, forming an aerogel with small particle size (5.8-6.2 nm), high porosity (>90%), and high transparency, laying the foundation for the high transparency of the final membrane from the source.

[0045] According to one embodiment of the present invention, the silicon source is tetraethyl orthosilicate, and the pH value of the sol is adjusted to 4.5-5.5. Maintaining a stable pH in the weakly acidic range of 4.5-5.5 facilitates the hydrolysis and condensation of tetraethyl orthosilicate, forming a uniform and dense nanonetwork structure, avoiding large particles or structural inhomogeneity caused by excessively rapid reactions, thereby ensuring the high transparency of the aerogel.

[0046] According to one embodiment of the present invention, in the method for preparing the silica aerogel powder, the molar ratio of tetraethyl orthosilicate to water is from 1:2.50 to 1:4.15. Preferably, the molar ratio of tetraethyl orthosilicate to water is 1:2.50, 1:3.40, or 1:4.15. By adjusting the molar ratio of tetraethyl orthosilicate to water, the microstructure of the aerogel can be optimized, thereby improving its transparency.

[0047] According to one embodiment of the present invention, in the method for preparing the silica aerogel powder, the volume fraction of ethanol is 30%-70%. Preferably, the volume fraction of ethanol is 40%-60%. By adjusting the volume fraction of ethanol, the average pore size and skeleton size of the aerogel can be optimized, so that the transmittance of the aerogel at a wavelength of 550 nm first increases and then decreases, and the highest transmittance is achieved at the optimal volume fraction of ethanol.

[0048] According to one embodiment of the present invention, the pH value of the sol is adjusted using a citric acid solution.

[0049] According to one embodiment of the present invention, the concentration of the citric acid solution is 0.002-0.003M.

[0050] According to one embodiment of the present invention, a surface modification step of the gel is included before the drying step. This surface modification step prevents the gel from collapsing due to capillary forces during drying, thus maintaining its high porosity and transparency.

[0051] According to one embodiment of the present invention, the surface modifier used for surface modification is selected from at least one of silazane modifiers, alkylchlorosilane modifiers, and alkylalkoxysilane modifiers; the silazane modifiers include hexamethyldisilazane, heptamethyldisilazane, and tetramethyldisilazane; the alkylchlorosilane modifiers include trimethylchlorosilane and dimethyldichlorosilane; the alkylalkoxysilane modifiers include methyltrimethoxysilane and dimethyldimethoxysilane; preferably, the surface modifier used for surface modification is hexamethyldisilazane (HMDZ).

[0052] Hexamethyldisilazane (HMDZ) can replace the hydrophilic hydroxyl groups on the surface of silica aerogel pores with hydrophobic groups, thereby greatly reducing capillary forces. This allows the gel to dry at normal pressure or lower temperatures without significant shrinkage and cracking, maintaining its nanoporous structure and the resulting high transparency.

[0053] In another aspect, the present invention provides a transparent silica aerogel film, which is obtained by coating and curing the transparent silica aerogel.

[0054] In another aspect, the present invention provides a highly transparent coated glass, comprising a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0055] According to one embodiment of the present invention, the curing temperature is 110-180°C, and / or the curing time is 2-3 hours.

[0056] According to one embodiment of the present invention, the curing temperature is 110-130°C.

[0057] According to one embodiment of the present invention, the coating method is brushing or spraying.

[0058] According to one embodiment of the present invention, the visible light transmittance of the film is not less than 90%.

[0059] According to one embodiment of the present invention, the water droplet contact angle on the membrane surface is greater than 110°.

[0060] Another aspect of the invention relates to the application of the high-transparency coated glass in architectural windows, electronic displays, solar photovoltaic modules, or automotive glass.

[0061] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0062] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0063] Figure 1 The flowchart shows the preparation method of the high-transparency coated glass in Examples 1-22.

[0064] Figure 2 The infrared spectrum of the silica aerogel powder prepared in Example 1 is shown.

[0065] Figure 3 The image shows a comprehensive characterization of the silica aerogel powder and aerogel membrane prepared in Example 1.

[0066] Figure 4 The image shows the transmittance test results of the transparent aerogel prepared under different ethanol volume fractions in Example 23.

[0067] Figure 5 The image shows the transmittance test results of the transparent aerogel prepared under different ethanol volume fractions in Example 24.

[0068] Figure 6 The image shows the transmittance test results of the transparent aerogels prepared under different ethanol volume fractions in Example 25.

[0069] Figure 7 The image shows a transmission electron microscope (TEM) image of the silica aerogel powder prepared in Example 1. Detailed Implementation

[0070] The terms "preferred," "more preferred," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0071] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0072] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present invention.

[0073] In this embodiment, transmittance (%) is the percentage of visible light that passes through the coated glass and is measured by a transmittance meter YT1010.

[0074] The principle of transmittance measurement is as follows: transmittance (T) is defined as the percentage ratio of transmitted luminous flux (Φt) to incident luminous flux (Φi), and the calculation formula is: T = (Φt / Φi) × 100%. The instrument can calculate the transmittance of the material by accurately measuring these two luminous flux values.

[0075] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0076] In the example, the 482 resin sol is the SJ-482 type high temperature resistant resin sol produced by Guangdong Shanjin New Materials Co., Ltd., with a molecular weight of 1000-2000.

[0077] In the examples, when the unit of component dosage is "drop", it can be converted to mL, and 20 "drops" equals 1 mL.

[0078] The flowcharts for the preparation methods of high-transparency coated glass in Examples 1-22 are as follows: Figure 1 As shown, Figure 1 In this context, TEOS stands for tetraethyl orthosilicate; EtOH for ethanol; Citric Acid for citric acid; Silica Aerogel Powder for silica aerogel powder; 482 Solution for 482 resin sol; Sol Preparation for sol preparation; Gelation for gelation; Grinding for grinding; Add Additive for adding additives; Stirring for stirring; Brush Coating for brushing; and Thermal Curing for thermosetting.

[0079] Example 1

[0080] A transparent silica aerogel having the following components:

[0081] Silica aerogel powder, 482 resin sol and silane coupling agent;

[0082] The aforementioned silane coupling agent is (3-aminopropyl)triethoxysilane (APTES);

[0083] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0084] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0085] 5g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 8 drops of (3-aminopropyl)triethoxysilane (APTES), 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added in sequence. The mixture was stirred continuously for 6 hours to obtain transparent silica aerogel.

[0086] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0087] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0088] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0089] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0090] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0091] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0092] Example 2

[0093] The difference between Example 2 and Example 1 is that in Example 2, when preparing the above-mentioned transparent silica aerogel, the amount of silica aerogel powder added is 2g, and the amount of (3-aminopropyl)triethoxysilane (APTES) added is 3 drops.

[0094] Example 3

[0095] The difference between Example 3 and Example 1 is that in Example 3, when preparing the above-mentioned transparent silica aerogel, the amount of silica aerogel powder added is 1g, and the amount of (3-aminopropyl)triethoxysilane (APTES) added is 2 drops.

[0096] Example 4

[0097] The difference between Example 4 and Example 1 is that in Example 4, when preparing the above-mentioned transparent silica aerogel, the amount of silica aerogel powder added is 0.6g, and the amount of (3-aminopropyl)triethoxysilane (APTES) added is 1 drop.

[0098] Specifically:

[0099] A transparent silica aerogel having the following components:

[0100] Silica aerogel powder, 482 resin sol and silane coupling agent;

[0101] The aforementioned silane coupling agent is (3-aminopropyl)triethoxysilane (APTES);

[0102] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0103] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0104] 0.6 g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 1 drop of (3-aminopropyl)triethoxysilane (APTES), 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added in sequence. The mixture was stirred continuously for 6 h to obtain transparent silica aerogel.

[0105] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0106] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0107] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0108] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0109] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0110] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0111] Example 5

[0112] The difference between Example 5 and Example 4 is that in Example 5, the amount of silica aerogel powder added is 0.4g when preparing the above-mentioned transparent silica aerogel.

[0113] Example 6

[0114] The difference between Example 6 and Example 4 is that in Example 6, the amount of silica aerogel powder added is 0.2g when preparing the above-mentioned transparent silica aerogel.

[0115] Example 7

[0116] The difference between Example 7 and Example 4 is that in Example 7, the amount of silica aerogel powder added is 0.1g when preparing the above-mentioned transparent silica aerogel.

[0117] Example 8

[0118] The difference between Example 8 and Example 3 is that the transparent silica aerogel in Example 8 also contains hexadecyltrimethoxysilane (DP-3116).

[0119] Specifically:

[0120] A transparent silica aerogel having the following components:

[0121] Silica aerogel powder, 482 resin sol and silane coupling agent;

[0122] The above-mentioned silane coupling agents are (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (DP-3116).

[0123] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0124] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0125] 1g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 2 drops of (3-aminopropyl)triethoxysilane (APTES), 1 drop of hexadecyltrimethoxysilane (DP-3116), 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added in sequence. The mixture was stirred continuously for 6 hours to obtain transparent silica aerogel.

[0126] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0127] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0128] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0129] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0130] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0131] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0132] Example 9

[0133] The difference between Example 9 and Example 8 is that, in the preparation of the above transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 9 is 2 drops.

[0134] Example 10

[0135] The difference between Example 10 and Example 8 is that, in the preparation of the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 10 is 3 drops.

[0136] Example 11

[0137] The difference between Example 11 and Example 8 is that, in the preparation of the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 11 is 5 drops.

[0138] Example 12

[0139] The difference between Example 12 and Example 8 is that, in the preparation of the above transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 12 is 10 drops.

[0140] Example 13

[0141] The difference between Example 13 and Example 8 is that, in the preparation of the above transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 13 is 12 drops.

[0142] Example 14

[0143] The difference between Example 14 and Example 8 is that, in the preparation of the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 14 is 14 drops.

[0144] Example 15

[0145] The difference between Example 15 and Example 4 is that, in the preparation of the above-mentioned transparent silica aerogel, Example 15 added 1 drop of DP-3116.

[0146] Specifically:

[0147] A transparent silica aerogel having the following components:

[0148] Silica aerogel powder, 482 resin sol and silane coupling agent;

[0149] The above-mentioned silane coupling agents are (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (DP-3116).

[0150] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0151] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0152] 0.6 g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 1 drop of (3-aminopropyl)triethoxysilane (APTES), 1 drop of hexadecyltrimethoxysilane (DP-3116), 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added sequentially. The mixture was stirred continuously for 6 h to obtain transparent silica aerogel.

[0153] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0154] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0155] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0156] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0157] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0158] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0159] Example 16

[0160] The difference between Example 16 and Example 15 is that, in preparing the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 16 is 2 drops.

[0161] Example 17

[0162] The difference between Example 17 and Example 15 is that, in preparing the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 17 is 3 drops.

[0163] Example 18

[0164] The difference between Example 18 and Example 15 is that, in preparing the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 18 is 5 drops.

[0165] Example 19

[0166] The difference between Example 19 and Example 15 is that, in preparing the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 19 is 10 drops.

[0167] Example 20

[0168] The difference between Example 20 and Example 15 is that, in the preparation of the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 20 was 12 drops.

[0169] Example 21

[0170] The difference between Example 21 and Example 15 is that, in preparing the above-mentioned transparent silica aerogel, the amount of hexadecyltrimethoxysilane (DP-3116) added in Example 21 was 14 drops.

[0171] Example 22

[0172] The difference between Example 22 and Example 15 is that molybdenum sulfide quantum dots were added in Example 22 when preparing the above-mentioned transparent silica aerogel.

[0173] Specifically:

[0174] A transparent silica aerogel having the following components:

[0175] Silica aerogel powder, 482 resin sol, silane coupling agent and quantum dots;

[0176] The above-mentioned silane coupling agents are (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (DP-3116).

[0177] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0178] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0179] 0.6 g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 1 drop of (3-aminopropyl)triethoxysilane (APTES), 1 drop of hexadecyltrimethoxysilane (DP-3116), 0.05 g of molybdenum sulfide quantum dots, 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added sequentially. The mixture was stirred continuously for 6 h to obtain transparent silica aerogel.

[0180] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0181] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0182] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0183] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0184] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0185] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0186] The preparation method of molybdenum sulfide quantum dots includes the following steps:

[0187] Ammonium molybdate tetrahydrate (0.91 g) was added to deionized water (30 mL) and magnetically stirred for 20 minutes until completely dissolved to obtain solution A. Separately, benzene disulfide (1.2813 g) was dissolved in anhydrous ethanol (45 mL) to obtain solution B. Solutions A and B were mixed and ultrasonically treated for 20 minutes to form a uniform white suspension. This suspension was transferred to a 100 mL PTFE-lined stainless steel autoclave and hydrothermally treated at 220°C for 20 hours. After the reaction system cooled to room temperature, the mixture was centrifuged at 10,000 rpm for 30 minutes, and the supernatant was collected. The supernatant was concentrated by rotary evaporation (40°C, 10 rpm, 30 minutes), rapidly frozen in liquid nitrogen, and then freeze-dried for 48 hours to finally obtain free-flowing, dark brown molybdenum sulfide quantum dot powder.

[0188] Example 23

[0189] The difference between Example 23 and Example 1 lies in the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water in the preparation method of silica aerogel powder. Specifically, in Example 1, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:7, while in Example 23, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:4.15.

[0190] Example 24

[0191] The difference between Example 24 and Example 1 lies in the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water in the preparation method of silica aerogel powder. Specifically, in Example 1, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:7, while in Example 24, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:3.40.

[0192] Example 25

[0193] The difference between Example 25 and Example 1 lies in the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water in the preparation method of silica aerogel powder. Specifically, in Example 1, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:7, while in Example 25, the molar ratio of tetraethyl orthosilicate (TEOS) to deionized water is 1:2.50.

[0194] Comparative Example

[0195] The difference between the comparative example and Example 12 is that (3-aminopropyl)triethoxysilane (APTES) was not added in the preparation of the above transparent silica aerogel.

[0196] Specifically:

[0197] A transparent silica aerogel having the following components:

[0198] Silica aerogel powder, 482 resin sol and silane coupling agent;

[0199] The silane coupling agent mentioned above is hexadecyltrimethoxysilane (DP-3116).

[0200] The particle size of the aforementioned silica aerogel powder is 6.0 nm.

[0201] A method for preparing the above-mentioned transparent silica aerogel comprises the following steps:

[0202] 1g of silica aerogel powder was transferred into a beaker, and 30 mL of 482 resin sol, 10 drops of hexadecyltrimethoxysilane (DP-3116), 0.3 mL of 3801 polysiloxane defoamer, 0.3 mL of 1050 polyether leveling agent, and 0.3 mL of AKN-1148 wetting agent were added in sequence. The mixture was stirred continuously for 6 hours to obtain transparent silica aerogel.

[0203] A transparent silica aerogel film is obtained by coating and curing the aforementioned transparent silica aerogel. The curing temperature is 130℃, and the curing time is 2 hours.

[0204] A highly transparent coated glass has a glass substrate and the aforementioned transparent silica aerogel film on the surface of the glass substrate.

[0205] The method for preparing the above-mentioned silica aerogel powder includes the following steps:

[0206] Mix 223.4 mL of tetraethyl orthosilicate (TEOS), 252 mL of ethanol and 126.1 mL of deionized water, stir to form a sol;

[0207] Add 0.002 M citric acid solution to adjust the pH of the sol to 4.5-5.5, and heat in a water bath at 50-75℃ for 12-24 hours to carry out hydrolysis and condensation reactions to form a gel network;

[0208] Add 40 mL of n-hexane, 50 mL of isopropanol, and 4 mL of HMDZ to obtain a mixture. Keep the mixture at room temperature for 6 hours. Wash the formed silica gel three times with ethanol to remove unreacted substances and byproducts. Dry the washed gel in an oven at 60°C for 16 hours and grind it to obtain silica aerogel powder with a particle size of 6.0 nm.

[0209] Performance testing:

[0210] Test 1: The infrared spectrum of the silica aerogel powder prepared in Example 1 is shown below. Figure 2 As shown, wavenumber is the wave number and transmittance is the transmittance. The silica aerogel powder prepared in this invention exhibits a significantly different infrared spectrum from traditional silica due to its unique nanostructure (small size effect and huge specific surface area). The following analysis focuses on the characteristic peak positions, intensities, and structural correlations:

[0211] (I) Vibration characteristics of silicon-oxygen skeleton

[0212] ①Si-O-Si antisymmetric stretching vibration: at 1090 cm⁻¹ -1 The peaks exhibit a characteristic peak, which shifts slightly towards higher wavenumbers and increases in peak width compared to traditional silica. This is attributed to the vibrational energy changes caused by a large number of dangling bonds and lattice strain on the surface of nanoparticles.

[0213] ②Si-O-Si symmetric stretching vibration: 650 cm -1 The strong absorption peak at this point is a hallmark of the silicon-oxygen tetrahedral network structure, directly reflecting the three-dimensional framework structure of the aerogel.

[0214] ③Si-O-Si bending vibration: 470 cm -1 The presence of a weak characteristic peak further confirms that the main component of the material is silicon dioxide.

[0215] (II) Surface hydroxyl groups and chemical environment

[0216] ①Si-OH stretching vibration: 950 cm -1 The peak intensity at this point is significantly higher than that of traditional silica, indicating that there are a large number of uncondensed silanol groups on the surface of the nano-aerogel. After high-temperature calcination, the peak weakens or disappears, confirming that the surface hydroxyl groups undergo a condensation reaction (Si-OH + HO-Si → Si-O-Si + H2O).

[0217] ② Evidence of mesoporous structure: Mesoporous silica at 960 cm⁻¹ -1 The area also exhibits a strong Si-OH peak, consistent with the high specific surface area and abundant surface hydroxyl characteristics of nano-aerogels, indirectly confirming their mesoporous structure properties.

[0218] (III) The Influence of Water and Organic Impurities

[0219] ① Characteristic peak of water molecules: 3450 cm⁻¹ -1 (OH stretching vibration) and 1630 cm -1 The peak signal at (HOH bending vibration) is significant, reflecting the presence of adsorbed water and structural water in the material.

[0220] ②Traces of organic functional groups: 3000-2800 cm -1 The presence of a CH stretching vibration peak in the region suggests the possible presence of residual organic precursors or surface-modifying groups.

[0221] Test 2: The transparent silica aerogel films prepared in Examples 1-7 and coated on the surface of the glass substrate were tested for light transmittance. The test results are shown in Table 1.

[0222] Table 1

[0223] Silica aerogel powder (g) 482 Resin Sol (mL) APTES (drop) Curing temperature (°C) Curing time (h) Light transmittance (%) Example 1 5.0 30 8 130 2 86.0 Example 2 2.0 30 3 130 2 89.0 Example 3 1.0 30 2 130 2 91.0 Example 4 0.6 30 1 130 2 91.7 Example 5 0.4 30 1 130 2 90.5 Example 6 0.2 30 1 130 2 90.0 Example 7 0.1 30 1 130 2 89.0

[0224] Table 1 shows that the amount of silica aerogel powder used has a non-linear relationship with transmittance. Excessive addition can lead to agglomeration or destruction of the pore structure, reducing transparency. The highest transmittance (91.7%) was achieved when the amount of silica aerogel powder added was 0.6 g.

[0225] Furthermore, the concentration and dispersion uniformity of APTES droplets directly affect the film transmittance. Excessive APTES concentration leads to silane molecule aggregation, forming scattering centers; insufficient concentration fails to completely cover the surface hydroxyl groups, resulting in decreased structural stability. A suitable amount of APTES (1-2 drops in the system of this invention) can maintain a transmittance of over 90% for the silica aerogel film.

[0226] Test 3: The transparent silica aerogel films prepared in Examples 3 and 8-14 and coated on the surface of glass substrates were used to test the light transmittance and hydrophobicity. The test results are shown in Table 2. The contact angle was tested using a JY-PHB contact angle analyzer manufactured by Chengde Jinhe Instrument Manufacturing Co., Ltd.

[0227] Table 2

[0228] Silica aerogel powder (g) APTES dosage (drops) DP-3116 dosage (drops) Optical transmittance (%) Hydrophobic properties (contact angle) in conclusion Example 3 1 2 0 91.0% General (110°) Transparency is average Example 8 1 2 1 91.6% Medium (119°) Moderate transparency Example 9 1 2 2 91.8% Lift (125°) Transparency slightly increased Example 10 1 2 3 91.9% Better (130°) Slight increase in transparency Example 11 1 2 5 92.1% Significant improvement (135°) Transparency significantly improved Example 12 1 2 10 92.6% Optimal hydrophobicity (contact angle 150°) Optimal balance point Example 13 1 2 12 91.0% Hydrophobicity decreases (125°) Transparency reduced compared to Example 12 Example 14 1 2 14 90.0% Hydrophobicity further decreased (125°). The transparency is significantly reduced compared to Example 12.

[0229] As shown in Table 2, the optimal amount of DP-3116 in the system of this invention is 10 drops. The membrane prepared in Example 12 achieves a contact angle of 150° with an optical transmittance of 92.6%, achieving the best balance between hydrophobicity and transparency. From the comparison between Example 3 and Examples 8-14, it can be seen that only when APTES and DP-3116 are used in combination can the membrane contact angle be ≥119°.

[0230] Meanwhile, it can be seen that when DP-3116 is added in excess (>10 drops), it will lead to excessive aggregation of hydrophobic groups, reduce transparency, and may cause film defects (such as cracks). When DP-3116 is added in insufficient amounts (<5 drops), it will result in insufficient hydrophobicity, which will not meet the requirements of practical applications.

[0231] Similarly, the optical transmittance of the membrane decreases when DP-3116 is added in excess (>10 drops) or when DP-3116 is added in insufficient amounts (<5 drops).

[0232] Therefore, the long-chain hydrophobic silane coupling agent DP-3116 has a significant impact on the transparency and hydrophobicity of aerogel films. This hydrophobic agent, through synergistic effects with silica aerogel nanoparticles and APTES coupling agent, forms a uniform and transparent hydrophobic film on the glass surface. Its long-chain alkyl structure not only imparts a 110° water droplet contact angle to the film for self-cleaning, but also reduces light scattering through molecular-level dispersibility, thereby optimizing optical transmittance while maintaining hydrophobic properties.

[0233] Test 4: The transparent silica aerogel films prepared in Examples 3-4 and Examples 15-22 and coated on the surface of the glass substrate were tested for light transmittance and hydrophobicity. The test results are shown in Table 3.

[0234] Table 3

[0235] Silica aerogel powder (g) 482 Resin Sol (mL) APTES (drop) DP 3116 (drop) Molybdenum sulfide quantum dots (g) Curing temperature (°C) Curing time (h) Light transmittance (%) Example 3 1.0 30 2 0 0 130 2 91.0 Example 4 0.6 30 1 0 0 130 2 91.7 Example 15 0.6 30 1 1 0 130 2 92.1 Example 16 0.6 30 1 2 0 130 2 92.3 Example 17 0.6 30 1 3 0 130 2 92.7 Example 18 0.6 30 1 5 0 130 2 93.1 Example 19 0.6 30 1 10 0 130 2 93.5 Example 20 0.6 30 1 12 0 130 2 92.0 Example 21 0.6 30 1 14 0 130 2 91.0 Example 22 0.6 30 1 10 0.05 130 2 94.0

[0236] Test 5: The silica aerogel membrane prepared in Example 1 was subjected to Fourier transform infrared spectroscopy. The test results are as follows: Figure 3 As shown in (a), from Figure 3 As can be seen in (a), the main component of the silica aerogel film is silica, with additional surface-modifying substances. Specifically, Figure 3 (a) shows aerogel powder at 1070 cm⁻¹ -1 The strong zone at 795 cm -1 and 461 cm -1 The peak at 960 cm⁻¹ is characteristic of the tensile and bending vibrations of the Si-O-Si network, confirming the formation of the SiO₂ aerogel framework. -1 The spectral band is assigned to the Si-OH (silanol) group, while 3450 cm⁻¹-1 Spectral bands and 1645 cm -1 The spectral bands correspond to the OH stretching and HOH bending of the adsorbed water / silanol-related water, which are characteristic of porous silicon materials, indicating that silica aerogels have been successfully prepared.

[0237] Test 6: The silica aerogel membranes prepared in Examples 1-4 and Example 22 were subjected to Fourier transform infrared spectroscopy. The test results are as follows: Figure 3 As shown in (b), curves (a), (b), (c), and (d) correspond to the spectra of Examples 1-4, and (e) corresponds to the spectrum of Example 22. It can be seen that spectrum (ae) shows that the silica aerogel film still contains silica bands (e.g., ~1020 cm⁻¹). -1 770 cm -1 and 454 cm -1 This indicates that the silica network structure still exists in the film. However, a new absorption appears at 2980 cm⁻¹. -1 (C-H stretching) and 1270 cm -1 (Usually attributed to Si-CH3 deformation), this indicates the introduction of organic groups and methylsilanized silica into the surface changes or organosilane additives in the film formulation. 3462 cm -1 The band and 1635 cm -1 The wavelength range again reflects the surface hydroxyl groups and adsorbed water (which may overlap with the contribution of NH if aminosilanes are present). 2375 cm⁻¹ -1 The faint characteristics at this location are consistent with atmospheric carbon dioxide. In summary, the spectral analysis confirms that the aerogel powder mainly consists of SiO2 and surface silanol groups, while the silica aerogel film contains SiO2 and additional organic groups, indicating that the 482 resin sol and silane coupling agent were successfully added / combined, and that the silica aerogel film underwent successful surface modification. The spectrum at 1635 cm⁻¹... -1 The peaks become sharper, indicating that QDs have been grafted into the membrane.

[0238] Test 7: Figure 3 Image (c) is a transmission electron microscope image of the silica aerogel powder prepared in Example 1. As can be seen from the image, the aerogel has a clear white appearance and an irregular sheet-like geometry, indicating that the aerogel has a continuous silica network.

[0239] Test 8: Figure 3Image (d) is a scanning electron microscope image of the silica aerogel film prepared in Example 1. As can be seen from the image, the film surface is essentially continuous and relatively smooth throughout the entire field of view, indicating that the silica aerogel film forms a uniform thin film at the micrometer scale, rather than a highly fragmented or porous discontinuous layer. Only a few dispersed particles are visible on the silica aerogel film; there are no dense clusters, large cracks, or severe delamination features, indicating that the silica aerogel film has good coverage after curing, which contributes to its high optical transparency.

[0240] Test 9: Effect of different ethanol volume fractions on the transmittance of silica aerogel.

[0241] To further optimize the transparency of silica aerogel powder, this invention conducted an in-depth study on the factors affecting the transmittance of the silica aerogel powders prepared in Examples 23, 24, and 25. It should be noted that the difference between Examples 23, 24, and 25 lies in the different molar ratios of tetraethyl orthosilicate (TEOS) to deionized water during the preparation of the silica aerogel powder, which are 1:4.15, 1:3.40, and 1:2.50, respectively. Based on the above three examples, this invention further investigated the influence of the ethanol volume fraction during the preparation process on the final aerogel transmittance.

[0242] The transmittance of silica aerogels prepared with different ethanol volume fractions is significantly affected by the average pore size. Within the range of lower ethanol volume fractions, the transmittance of the aerogel increases with increasing average pore size, because larger pore structures facilitate the direct passage of visible light through the aerogel network. However, with further increases in ethanol volume fraction, although the pore size of the aerogel continues to increase, its transmittance gradually decreases. The mechanism is that excessively high ethanol volume fractions lead to overgrowth of the gel skeleton, forming a larger skeleton structure, thereby enhancing the light scattering effect and ultimately reducing transmittance.

[0243] Based on the above principles, this invention prepared transparent aerogels for the three systems corresponding to Examples 23, 24, and 25 under different ethanol volume fractions. Transmittance was tested using a UV-2102 PCS UV-Vis spectrophotometer in the wavelength range of 500 nm to 800 nm. The test results for Examples 23, 24, and 25 are as follows: Figure 4 , Figure 5 , Figure 6 As shown in the figure, it can be clearly seen that as the volume fraction of ethanol increases, the transmittance of the aerogel in all three systems shows a trend of "first increasing and then decreasing".

[0244] Furthermore, this invention compared the aerogel samples that achieved the highest transmittance at a wavelength of 550 nm for each system. The results showed that the highest transmittance of the system in Example 23 (TEOS:H2O=1:4.15) was 86.5%; the highest transmittance of the system in Example 24 (TEOS:H2O=1:3.40) was 87.5%; and the highest transmittance of the system in Example 25 (TEOS:H2O=1:2.50) was 88.0%. The aerogel samples that achieved the highest transmittance were then ball-milled at high speed for 6 hours to obtain nanoscale powder, which is the silica aerogel powder described in this invention.

[0245] The above results indicate that by adjusting the volume fraction of ethanol to optimize the pore size and framework structure of the aerogel, its intrinsic transparency can be significantly improved.

[0246] Test 10: To verify the particle size range of the silica aerogel powder used in this invention, the silica aerogel powder prepared in Example 1 was used as a sample and characterized by transmission electron microscopy. The results are as follows: Figure 7 As shown. By Figure 7 It is known that the aerogel powder has a concentrated particle size distribution, with a particle size of about 6 nm. This ultra-small particle size can fundamentally eliminate the light scattering loss caused by the particle size itself, laying a key foundation for obtaining aerogel films with high transparency.

[0247] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A transparent silica aerogel, characterized in that: Includes the following components: Silica aerogel powder, alcohol-based organosilicon modified nano-resin sol, and silane coupling agent; The silane coupling agent is selected from (3-aminopropyl)triethoxysilane, or the silane coupling agent is selected from (3-aminopropyl)triethoxysilane and long-chain alkylsilane coupling agents; The particle size of the silica aerogel powder is 5.8-6.2 nm.

2. The transparent silica aerogel according to claim 1, characterized in that: The ratio of silica aerogel powder to alcohol-based organosilicon modified nano-resin sol is 0.1-5 g: 30 mL, and the ratio of silane coupling agent to alcohol-based organosilicon modified nano-resin sol is 0.05-1.5 mL: 30 mL.

3. The transparent silica aerogel according to claim 2, characterized in that: The amount of silica aerogel powder used is 0.1-5g, and the amount of silane coupling agent used is 0.05-1.5mL; preferably, the amount of silica aerogel powder used is 0.2-1g, and the amount of (3-aminopropyl)triethoxysilane in the silane coupling agent is 0.05-0.1mL.

4. The transparent silica aerogel according to claim 1, characterized in that: The silane coupling agent comprises (3-aminopropyl)triethoxysilane and a long-chain alkylsilane coupling agent, wherein the volume ratio of (3-aminopropyl)triethoxysilane to the long-chain alkylsilane coupling agent is 1-2:1-14.

5. The transparent silica aerogel according to claim 4, characterized in that: The long-chain alkylsilane coupling agent is hexadecyltrimethoxysilane; the silane coupling agent is composed of (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane in a volume ratio of 1-2:1-14; preferably, the silane coupling agent is composed of (3-aminopropyl)triethoxysilane and hexadecyltrimethoxysilane in a volume ratio of 1:1-12.

6. The transparent silica aerogel according to claim 1, characterized in that: The transparent silica aerogel also includes quantum dots; preferably, the quantum dots are molybdenum sulfide quantum dots.

7. A method for preparing a transparent silica aerogel as described in any one of claims 1 to 6, characterized in that: Includes the following steps: The transparent silica aerogel is obtained by mixing silica aerogel powder, alcohol-based organosilicon modified nano-resin sol, and silane coupling agent.

8. The method according to claim 7, characterized in that: The method for preparing the silica aerogel powder includes the following steps: A sol is formed by mixing a silicon source, an alcohol solvent, and water. The pH value of the sol is adjusted, and the sol is heated to undergo hydrolysis and condensation reactions to form a gel; The gel was aged, dried, and ground to obtain silica aerogel powder.

9. A transparent silica aerogel membrane, characterized in that: It is obtained by coating and curing the transparent silica aerogel as described in any one of claims 1 to 6.

10. A high-transparency coated glass, characterized in that: Includes a glass substrate and a transparent silica aerogel film as described in claim 9 on the surface of the glass substrate.

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