Pollution-free excellent heat insulation composite aerogel coating and preparation method thereof

Abstract

The invention discloses a pollution-free excellent heat insulation composite aerogel coating and a preparation method thereof. The preparation method comprises the following steps: S1, selecting a proper polyvinyl alcohol material; s2, preparing a polyvinyl alcohol solution; s3, adding an environment-friendly toughening agent into the polyvinyl alcohol solution, and adding a functional nano material; s4, performing functional modification on the surface of the aerogel by adopting a fluorinated surface treatment agent, silanization treatment and other methods, and ensuring uniform dispersion of a functional material and nanoparticles by adopting an electrostatic spinning method; s5, an innovative cross-linking agent is introduced, a cross-linking reaction is carried out, and the use amount is 5% of the total volume; and S6, adopting an innovative double drying process, namely combining a freeze drying technology and a supercritical CO2 drying technology. The coating has the advantages of being environmentally friendly, high in heat stability, excellent in heat insulation performance and low in production cost, meets the requirements of modern society for high-efficiency heat insulation materials, further meets the requirements of sustainable development and has wide application prospects and market potential.

Description

Technical Field

[0001] This invention relates to the field of polymer coating technology, and in particular to a pollution-free, high-quality thermal insulation composite aerogel coating and its preparation method. Background Technology

[0002] With the increasing severity of global energy problems and growing environmental awareness, improving energy efficiency and reducing energy waste have become critical issues urgently needing to be addressed in global scientific research and industry. Effective thermal insulation and control have become key to improving energy efficiency and reducing energy consumption in various fields such as industrial production, construction, transportation, and electronic equipment. Traditional insulation materials, such as polyurethane foam, glass wool, and mineral wool, have achieved certain results in terms of insulation performance, but these materials still have many problems in practical applications, particularly limitations in thermal stability, environmental pollution, and performance degradation after long-term use.

[0003] First, traditional thermal insulation materials often suffer from significant thermal degradation under high-temperature conditions. Prolonged exposure to high temperatures can cause these materials to age, deform, or even burn, leading to a sharp decline in their insulation performance. For example, common organic materials easily decompose and release toxic gases at high temperatures, which not only affects product lifespan but also causes significant environmental pollution. Furthermore, with the advancement of industrialization, the production of traditional thermal insulation materials often relies on energy-intensive and polluting manufacturing processes, further exacerbating global energy consumption and environmental pollution.

[0004] Secondly, traditional insulation materials have relatively short performance and lifespan, especially in the construction industry, where their performance gradually declines over time. For example, common materials such as mineral wool and glass wool are prone to problems like dampness, compaction, and weathering during long-term use. This not only affects the insulation effect but can also lead to structural damage to buildings. Therefore, in recent years, the market demand for more heat-resistant and durable insulation materials has been increasing, especially in high-demand fields such as aerospace, automotive, and construction, where the performance requirements for insulation materials are becoming increasingly stringent.

[0005] Meanwhile, aerogels, as a novel thermal insulation material, have attracted widespread attention due to their unique structural characteristics. Aerogels are materials with ultra-low density, high specific surface area, and high porosity, and their excellent thermal insulation properties make them ideal for thermal insulation. Aerogels have extremely low thermal conductivity, which can effectively reduce heat conduction, thus showing broad application potential in aerospace, construction, and electronic equipment. However, the production process of aerogel materials is complex and costly, requiring high-temperature and high-pressure equipment, and their brittleness makes them prone to breakage and damage, which limits their widespread adoption in practical applications.

[0006] In recent years, researchers have addressed these issues by improving the preparation process of aerogels, developing various composite aerogel materials to enhance their performance and reduce costs. For example, aerogels are combined with polymers, inorganic materials, and nanomaterials to enhance their mechanical strength and thermal stability, thereby improving their performance in high-temperature environments. Furthermore, the development of nanotechnology has provided new ideas for aerogel preparation. The incorporation of nanomaterials can further improve the thermal insulation performance and structural stability of aerogels. However, these composite aerogel materials still face some challenges in terms of environmental friendliness; many composite materials still contain harmful chemical components, failing to meet modern green and environmentally friendly requirements.

[0007] Therefore, developing a pollution-free, environmentally friendly, and high-quality thermal insulation composite aerogel coating has become an important direction in current thermal insulation technology research. Summary of the Invention

[0008] The purpose of this invention is to provide a pollution-free, high-quality thermal insulation composite aerogel coating and its preparation method. With its green and environmentally friendly properties, high thermal stability, excellent thermal insulation performance and low production cost, it successfully solves the problems of environmental pollution, poor thermal stability and limited thermal insulation effect in the prior art.

[0009] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating includes the following steps: S1. Select suitable polyvinyl alcohol materials: Select high-purity polyvinyl alcohol with a degree of alcoholysis between 98% and 100%; S2. Preparation of polyvinyl alcohol solution: Dissolve the selected high-purity polyvinyl alcohol powder in deionized water; S3. Add an environmentally friendly toughening agent with toughening and UV resistance properties to a polyvinyl alcohol solution, and add functional nanomaterials as reinforcing materials. S4. The aerogel surface is functionalized by methods such as fluorinated surface treatment agents and silanization treatment, and the electrospinning method is used to ensure the uniform dispersion of functional materials and nanoparticles. S5. Introduce an innovative crosslinking agent to carry out the crosslinking reaction, using 5% of the total volume; S6 employs an innovative dual drying process, combining freeze drying and supercritical CO2 drying technology.

[0010] More preferably, in step S2, 2g of selected high-purity polyvinyl alcohol powder is dissolved in deionized water.

[0011] More preferably, in step S2, an ultrasonic oscillation-assisted dissolution method is used, in which the polyvinyl alcohol solution is stirred in the range of 70°C to 95°C, and ultrasonic oscillation is applied simultaneously to help the polyvinyl alcohol to dissolve completely, and the solution concentration is set to 1.0 to 5.0 g / ml.

[0012] More preferably, in step S3, the amount of the environmentally friendly toughening agent added is 2 ml, and the environmentally friendly toughening agent includes natural plant extracts or bio-based polymers.

[0013] More preferably, in S3, the functional nanomaterials include titanium dioxide nanoparticles and carbon nanotubes.

[0014] More preferably, in step S5, the innovative crosslinking agent includes diethylenetriamine and triaminopropyltriethoxysilane, the crosslinking reaction is carried out under temperature control conditions of 50°C to 70°C, and the amount of crosslinking agent added and the reaction rate are controlled using spin coating or electrospinning technology.

[0015] More preferably, in step S6, firstly, the aerogel coating sample is placed in a freeze-drying oven and freeze-dried at a temperature between -40°C and -80°C to ensure that moisture is removed through the sublimation process and to maintain its high porosity. Then, supercritical CO2 drying technology is used to further remove residual solvents and moisture from the aerogel, ensuring that the final product has ultra-low density and high thermal insulation performance.

[0016] A pollution-free, high-quality thermal insulation composite aerogel coating is prepared according to the above-described method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating.

[0017] In summary, the present invention has the following beneficial effects: Firstly, the coating in this invention has the advantages of being green and environmentally friendly, having high thermal stability, excellent thermal insulation performance, and low production cost. It meets the needs of modern society for high-efficiency thermal insulation materials, and also meets the requirements of sustainable development, thus having broad application prospects and market potential.

[0018] Secondly, this invention employs a highly efficient dispersion technology to uniformly disperse functional nanomaterials in a polyvinyl alcohol solution. The addition of these nanomaterials significantly enhances the multifunctionality of the aerogel, including improving its mechanical strength, thermal stability, and UV resistance. Through high-shear stirring and ultrasonic-assisted dispersion techniques, the nanomaterials are ensured to be uniformly distributed in the solution, avoiding material agglomeration or unevenness, thereby improving the overall performance of the aerogel material. This technology also improves the surface properties of the aerogel, giving it excellent anti-fouling and water-resistant properties, providing a more robust and durable aerogel material for applications in multiple fields.

[0019] Thirdly, the combination of supercritical drying technology and temperature control optimization in this invention ensures that the aerogel maintains its high specific surface area and low density while possessing higher stability and strength. Supercritical CO2 drying technology can completely remove the solvent without damaging the aerogel's pore structure, resulting in a more uniform and high-quality aerogel. Combined with temperature control optimization, temperature and pressure changes during the drying process can be precisely controlled, preventing shrinkage or deformation of the aerogel and ensuring that the final product has stable physical properties and excellent thermal insulation and mechanical properties. Attached Figure Description

[0020] Figure 1 This is a thermal image of the coating of the present invention under a light source at 90°C; Figure 2 This is a three-dimensional spectrum of the coating in this invention, obtained by combining thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings.

[0022] Example: A method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating includes the following steps: S1. Select suitable polyvinyl alcohol (PVA) material: Choose high-purity PVA with a degree of hydrolysis between 98% and 100%. Compared to PVA with a lower degree of hydrolysis, PVA with a higher degree of hydrolysis has better solubility and can provide a stronger cross-linking effect during the chemical reaction, further improving the strength and stability of the aerogel.

[0023] S2. Preparation of polyvinyl alcohol solution: Dissolve 2g of selected high-purity polyvinyl alcohol powder in deionized water. To improve its dissolution efficiency and ensure higher molecular uniformity, an ultrasonic oscillation-assisted dissolution method is adopted. The polyvinyl alcohol solution is stirred in the range of 70℃ to 95℃, and ultrasonic oscillation is applied at the same time to help the polyvinyl alcohol dissolve completely. The solution concentration is set to 1.0 to 5.0g / ml to ensure a uniform solution system.

[0024] S3. Add 2 ml of environmentally friendly toughening agent with toughening and UV resistance properties to the polyvinyl alcohol solution. The environmentally friendly toughening agent includes natural plant extracts or bio-based polymers. These toughening agents can improve the mechanical strength of the aerogel and prevent degradation caused by environmental UV radiation. Add functional nanomaterials as reinforcing materials, including titanium dioxide nanoparticles and carbon nanotubes, to effectively improve the antibacterial properties, thermal stability, and antioxidant properties of the aerogel.

[0025] S4. The aerogel surface is functionalized using methods such as fluorinated surface treatment agents and silanization treatment. These surface treatments effectively improve the aerogel's water resistance and antifouling ability, prevent water vapor from penetrating into the material's interior, and maintain its high-efficiency thermal insulation performance. Simultaneously, electrospinning is used to ensure the uniform dispersion of functional materials and nanoparticles.

[0026] S5. Introduce innovative crosslinking agents to carry out the crosslinking reaction, using 5% of the total volume. The innovative crosslinking agents include diethylenetriamine and triaminopropyltriethoxysilane. These crosslinking agents can form a highly crosslinked three-dimensional network structure between molecular chains, thereby improving the mechanical strength, heat resistance, and long-term stability of the aerogel. The crosslinking reaction is carried out under temperature-controlled conditions of 50°C to 70°C, and the amount of crosslinking agent added and the reaction rate are controlled using spin coating or electrospinning techniques to further enhance the mechanical properties and thermal stability of the aerogel.

[0027] S6 employs an innovative dual drying process, combining freeze-drying and supercritical CO2 drying. First, the aerogel coating sample is placed in a freeze-drying chamber and freeze-dried between -40°C and -80°C to ensure moisture removal through sublimation, maintaining its high porosity. Then, supercritical CO2 drying further removes residual solvents and moisture from the aerogel, ensuring the final product has ultra-low density and high thermal insulation properties. This results in an aerogel material with ultra-high specific surface area and low density.

[0028] Of course, the substrate for the coating needs to be prepared before spraying to ensure the coating effect. This includes the following steps: 1. Grinding aluminum alloy sheets A variety of substrates can be selected, with aluminum alloy being the primary choice. First, prepare the aluminum alloy to be coated. Before coating, it is crucial to ensure the surface of the sheet is smooth and free of any impurities. Use sandpaper of varying grits to sand the surface. This progressively finer sanding method effectively removes the oxide layer, oil, and other impurities from the surface, and increases the surface roughness of the magnesium alloy, thereby increasing the surface contact area. This significantly improves the adhesion between the coating and the magnesium alloy surface, ensuring a firm bond during application and reducing the risk of peeling.

[0029] 2. Let it dry before use. After sanding, the magnesium alloy sheet needs to be placed in a dry, temperature-stable environment to ensure the surface is not affected by moisture and remains stable. Only after the surface is completely dry should the next coating treatment be carried out. Ensure the sheet surface is completely free of moisture to avoid affecting the quality and effect of the coating.

[0030] It should be noted that this invention employs a highly efficient dispersion technology to uniformly disperse functional nanomaterials in a polyvinyl alcohol solution. The addition of these nanomaterials significantly enhances the multifunctionality of the aerogel, including improving its mechanical strength, thermal stability, and UV resistance. Advanced technologies such as high-shear stirring and ultrasonic-assisted dispersion ensure uniform distribution of the nanomaterials in the solution, preventing agglomeration or uneven distribution, thereby improving the overall performance of the aerogel material. This technology also improves the surface properties of the aerogel, giving it excellent anti-fouling and water-resistant properties, providing a more robust and durable aerogel material for applications in various fields.

[0031] This invention combines supercritical drying technology with optimized temperature control to ensure that the aerogel maintains its high specific surface area and low density while possessing higher stability and strength. Traditional drying methods often result in incomplete removal of moisture from the aerogel, affecting its pore structure and properties. This invention, however, employs supercritical CO2 drying technology, which can completely remove the solvent without damaging the aerogel's pore structure, yielding a more uniform and high-quality aerogel. Combined with optimized temperature control, temperature and pressure changes during the drying process can be precisely controlled, preventing shrinkage or deformation of the aerogel and ensuring that the final product possesses stable physical properties and excellent thermal insulation and mechanical properties.

[0032] like Figure 1 The image shows thermal images of two materials captured by a FLIR infrared camera, designed to assess their surface temperature distribution. The image displays a color gradient from 33.7°C (blue) to 93.2°C (red), and marks five measurement points (points 1 to 5) with corresponding temperatures of: point 1 (75.5°C), point 2 (92.6°C), point 3 (67.4°C), point 4 (71.9°C), and point 5 (83.5°C). The highest temperature at point 2 (92.6°C) indicates that this area is a heat source, possibly due to localized heating or significant heat absorption, while the lower temperature at point 3 (67.4°C) indicates that this area is cooler, possibly due to heat loss or insulation effects. The temperature gradient from highest to lowest temperature indicates typical heat conduction behavior, with heat diffusing from the hot spot to the surrounding area. This distribution highlights the differences in the thermal properties of the materials, emphasizing the importance of thermal management in applications requiring effective heat dissipation. These results provide valuable insights into the thermal behavior of materials and their suitability for environments requiring thermal regulation.

[0033] like Figure 2 As shown, a three-dimensional spectrum combining thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) is presented, where the horizontal axis represents the wavenumber (cm²). -1The vertical axis represents temperature (°C), and the color bars in the graph represent absorbance (i.e., the absorption intensity of the material for infrared light of different wavelengths). The graph shows that the absorbance of the sample changes at different wavenumbers as the temperature increases, revealing the changes in functional groups during pyrolysis. Several absorption features are marked in the graph, such as the C=C (carbon-carbon double bond vibration) located at 1600 cm⁻¹. -1 Nearby, CO (carbon-oxygen single bond vibration) is at 1000-1300 cm⁻¹ -1 Within the range, C=O (carbonyl vibration) is at 1700 cm⁻¹ -1 Nearby, CO2 (carbon dioxide) is at 2350 cm⁻¹ -1 At this location, the CH (CH bond vibration of alkyl or aromatic hydrocarbons) is at 2800-3000 cm⁻¹. -1 The OH (hydroxyl vibration) is at 3200-3400 cm⁻¹. -1 The characteristic absorption peaks, combined with temperature changes, reveal the gradual decomposition or transformation of different functional groups during the pyrolysis process. A significant transformation occurred, particularly at 252℃, potentially indicating pyrolysis or structural changes in some functional groups. Overall, Figure 2 This provides valuable information about the pyrolysis behavior and thermal stability of the material.

[0034] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating, characterized in that, Includes the following steps: S1. Select suitable polyvinyl alcohol materials: Select high-purity polyvinyl alcohol with a degree of alcoholysis between 98% and 100%; S2. Preparation of polyvinyl alcohol solution: Dissolve the selected high-purity polyvinyl alcohol powder in deionized water; S3. Add an environmentally friendly toughening agent with toughening and UV resistance properties to a polyvinyl alcohol solution, and add functional nanomaterials as reinforcing materials. S4. The aerogel surface is functionalized by methods such as fluorinated surface treatment agents and silanization treatment, and the electrospinning method is used to ensure the uniform dispersion of functional materials and nanoparticles. S5. Introduce an innovative crosslinking agent to carry out the crosslinking reaction, using 5% of the total volume; S6 employs an innovative dual drying process, combining freeze drying and supercritical CO2 drying technology.

2. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 1, characterized in that: In step S2, 2g of selected high-purity polyvinyl alcohol powder is dissolved in deionized water.

3. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 2, characterized in that: In step S2, an ultrasonic oscillation-assisted dissolution method is used. The polyvinyl alcohol solution is stirred in the range of 70°C to 95°C, and ultrasonic oscillation is applied simultaneously to help the polyvinyl alcohol to dissolve completely. The solution concentration is set to 1.0 to 5.0 g / ml.

4. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 3, characterized in that: In step S3, the amount of the environmentally friendly toughening agent added is 2 ml, and the environmentally friendly toughening agent includes natural plant extracts or bio-based polymers.

5. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 4, characterized in that: In S3, the functional nanomaterials include titanium dioxide nanoparticles and carbon nanotubes.

6. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 5, characterized in that: In S5, the innovative crosslinking agent includes diethylenetriamine and triaminopropyltriethoxysilane. The crosslinking reaction is carried out under temperature control conditions of 50°C to 70°C, and the amount of crosslinking agent added and the reaction rate are controlled using spin coating or electrospinning technology.

7. The method for preparing a pollution-free, high-quality thermal insulation composite aerogel coating according to claim 6, characterized in that: In step S6, firstly, the aerogel coating sample is placed in a freeze-drying oven and freeze-dried between -40°C and -80°C to ensure that moisture is removed through the sublimation process and maintain its high porosity. Then, supercritical CO2 drying technology is used to further remove residual solvents and moisture from the aerogel, ensuring that the final product has ultra-low density and high thermal insulation performance.

8. A pollution-free, high-quality thermal insulation composite aerogel coating, characterized in that, The coating is prepared according to any one of claims 1-7.

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