Aerogel coating with high flexibility and use method thereof
By designing special microstructures in aerogels and using composite materials, the problems of aerogel brittleness and low mechanical strength are solved, and the high flexibility and versatility of the aerogel coating are achieved, which broadens its application areas.
Patent Information
- Application Number
- CN202510383634.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2025-06-27
AI Technical Summary
The brittleness and low mechanical strength of the aerogel limit its use in applications where flexibility and durability are required.
By designing special microstructures and using composite materials, the flexibility and impact resistance of the aerogel are enhanced while maintaining its original lightweight and excellent thermal insulation properties.
It achieves extremely strong flexibility, excellent energy absorption and buffering ability, good processability and appropriate hardness and modulus balance of aerogel coating, broadening its application range.
Smart Images
Figure CN120209646A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new material coatings, and particularly to a highly flexible aerogel coating and its usage method. Background Art
[0002] As a new type of porous material, since aerogel was first synthesized in the 1930s, it has become an important object in materials science research due to its extremely low density, ultra-high specific surface area, excellent thermal insulation performance, and adjustable pore structure. The application fields of aerogel cover multiple industries, including aerospace, energy, environmental protection, sensors, thermal insulation, adsorbents, etc. In the aerospace field, aerogel is used as a thermal insulation material for spacecraft and space vehicles due to its extremely light weight and high-efficiency thermal insulation performance. In the construction and energy fields, aerogel is widely used in thermal insulation materials for energy-saving buildings and technologies such as solar cells. With the increasing requirements for environmental protection and energy efficiency, the versatility and high efficiency of aerogel make it an ideal material. However, despite the excellent performance of aerogel in many fields, its brittleness and low mechanical strength are still serious limiting factors, especially in applications that require flexibility and durability. The fragility of aerogel makes it difficult to meet the actual usage requirements.
[0003] The special properties of aerogel mainly come from its porous structure. Aerogel is composed of three-dimensionally intertwined nanoscale particles, forming an open pore network with a porosity of up to over 90%. Due to its ultra-low density and extremely high specific surface area, aerogel can provide excellent thermal insulation and adsorption performance while ensuring light weight. These excellent physical and chemical properties give aerogel unique advantages in fields such as high-temperature thermal insulation, adsorption separation, and acoustic insulation. However, the mechanical properties of aerogel, especially its brittleness problem, limit the application of aerogel. Although the pore structure of aerogel endows it with lightweight characteristics, it also makes its compressive and tensile properties poor. Traditional aerogels are prone to cracking or fragmentation when subjected to external impact, compression, or bending, which greatly limits their application in fields that require flexible materials, such as flexible electronics, wearable devices, and smart textiles.
[0004] The brittleness of aerogel is not only caused by its low density and high porosity, but also closely related to the microstructure of aerogel. The pore structure of aerogel usually presents a large number of open pores, and the connection between the pores is relatively fragile, which makes the aerogel easy to break under the action of external force. The toughness and tensile strength of aerogel mainly depend on the stability and connectivity of its internal network structure. In the preparation process of aerogel, the microstructure of aerogel can be adjusted by controlling the concentration, crosslinking degree, temperature, humidity and other parameters of sol-gel, thereby improving its mechanical properties and flexibility. Researchers have found that the mechanical response of aerogel can be optimized by properly adjusting the porosity, pore size, pore distribution and other parameters of aerogel, so that it exhibits better ductility when subjected to external force. However, although the mechanical properties of aerogel can be improved to a certain extent by optimizing the microstructure of aerogel, the brittleness of aerogel itself still limits its application.
[0005] Although there have been many attempts to enhance the flexibility of aerogels, the essential characteristics of aerogels determine the challenges in mechanical properties. First, the low density and high porosity of aerogels determine that their mechanical strength cannot be compared with traditional metals, ceramics, and polymer materials. Secondly, the complex porous network structure in aerogels makes it easy to become locally unstable when subjected to stress, leading to brittle fracture. Therefore, how to improve flexibility without affecting other key properties of aerogels, such as thermal insulation, lightness, chemical stability, etc., is still a major challenge facing scientific researchers. Summary of the invention
[0006] The purpose of the present invention is to provide an aerogel coating with strong flexibility. The aerogel coating of the present invention not only improves the flexibility and impact resistance of the aerogel through special microstructure design and the use of composite materials, but also maintains its original light weight and excellent thermal insulation performance, thereby greatly broadening its application range.
[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A highly flexible aerogel coating, comprising the following steps:
[0008] Step 1, selecting polyvinyl alcohol with an alcoholysis degree of 85-99%;
[0009] Step 2, weigh polyvinyl alcohol and add it into ultrapure water to prepare a 0.5-10.0 g / ml polyvinyl alcohol solution;
[0010] Step 3, cooling the polyvinyl alcohol solution to room temperature;
[0011] Step 4: Adjust the pH to make the solution neutral and continue stirring the solution to ensure that the solutes are completely uniform;
[0012] Step 5: Add 3-aminopropyltriethoxysilane as a cross-linking agent, and stir the solution to transform it from a liquid state to a stable gel state.
[0013] Further preferably, in step 2, the solution is prepared by stirring at 60-95°C.
[0014] Further preferably, in step 6, the solution is heated to 40°C-80°C and stirred.
[0015] The present invention also discloses a method for using a flexible aerogel coating, comprising the following steps:
[0016] Step 1: polish the surface of the substrate and place it at dry room temperature for use;
[0017] Step 2: drip the prepared aerogel coating onto the surface of the polished substrate, and after it is in complete contact with the surface of the substrate, move the entire thing into a freeze drying box so that the aerogel coating is coated on the surface of the substrate.
[0018] Further preferably, in step 2, the temperature in the freeze drying chamber is -20°C to -80°C.
[0019] In summary, the present invention has the following beneficial effects:
[0020] First, strong flexibility: by increasing the content of flexible materials (such as polymers, flexible fibers, etc.) and improving the microstructure, the aerogel coating can quickly recover to its original state when impacted by external forces without brittle fracture. This characteristic makes the aerogel coating have high resilience and stability under dynamic stress.
[0021] Second, excellent energy absorption and buffering capabilities: The nanostructure not only enables aerogel to exhibit greater deformation capabilities under external forces, but also disperses stress in the material structure and reduces instantaneous impact forces. This enables the aerogel coating to respond quickly when subjected to external pressure and recover to its original state through its elasticity.
[0022] Third, good processability: The hardness of aerogel is 0.048GPa, which is much lower than that of hard materials such as metals and ceramics, giving it better processability. Low hardness enables aerogel to absorb and buffer external impact with less deformation when subjected to force, avoiding the risk of brittle fracture.
[0023] Fourth, proper balance between hardness and modulus: The modulus of aerogel is 1.02GPa, showing a certain rigidity and moderate elasticity. Such a modulus provides ideal support, especially in applications where materials need to have good recovery performance under dynamic loads (such as flexible electronics, aerospace, etc.). At the same time, low hardness ensures that the substrate can be effectively protected from damage in applications that require slight deformation and restoration to the original shape.
[0024] Fifth, wide applicability: The aerogel coating is applicable to a variety of application scenarios, including but not limited to high-temperature heat insulation, impact absorption, and anti-corrosion coatings. In particular, in those high-end application fields that require light weight, high temperature resistance, the ability to absorb external forces and quickly recover, this material shows broad application prospects. Description of the Drawings
[0025] Figure 1 is the surface topography diagram of the aerogel coating of the present invention;
[0026] Figure 2 is the nano-scratch diagram of the aerogel of the present invention. Detailed Embodiments
[0027] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.
[0028] Embodiment 1
[0029] A highly flexible aerogel coating, comprising the following steps:
[0030] Step 1, select a suitable polyvinyl alcohol material
[0031] The first step in preparing the aerogel material is to select the appropriate raw materials. Among them, polyvinyl alcohol (PVA) is a crucial component in the preparation of aerogels. Polyvinyl alcohol with a degree of alcoholysis between 85% and 99% must be selected to ensure its solubility in the solution and its binding properties with other components. Selecting the appropriate polyvinyl alcohol material is the first step to ensure the smooth progress of the preparation process and directly affects the quality and performance of the final aerogel film.
[0032] Step 2, prepare a polyvinyl alcohol solution
[0033] Weigh an appropriate amount of the selected polyvinyl alcohol powder and put it into the prepared ultrapure water. Under the temperature condition of 60°C to 95°C, continuously stir until the polyvinyl alcohol is completely dissolved to form a uniform solution with a concentration between 0.5 and 10.0 g / ml. During this process, by controlling the temperature and stirring speed, it is possible to ensure that the polyvinyl alcohol is completely dissolved and avoid the appearance of solid particles or insoluble substances in the solution.
[0034] Step 3, cool the solution to room temperature
[0035] After the polyvinyl alcohol solution is prepared, it needs to be naturally cooled to room temperature. This process is to gradually slow down the molecular movement in the solution, thereby creating stable conditions for subsequent chemical reactions. After cooling to room temperature, the activities of molecules and ions in the solution will slow down, which helps to improve the controllability of the reaction and avoid the reaction from being too fast and affecting the uniformity of the aerogel.
[0036] Step 4: Adjust the pH value of the solution
[0037] Adjust the pH of the solution to make it neutral. After completing the pH adjustment, continue to stir the above solution to ensure complete uniformity among the solutes. The purpose of stirring is to ensure that all solutes are fully dispersed, without forming precipitates or uneven regions, and to avoid uneven diffusion during the aerogel forming process, thereby affecting the quality of the final aerogel film.
[0038] Step 5: Add polyethylene glycol diglycidyl ether
[0039] To form a gel from the above solution, 3-aminopropyltriethoxysilane must be added as a cross-linking agent. This chemical cross-linking agent will form a cross-linked structure between polyvinyl alcohol molecules, converting the solution into a gel. After adding 3-aminopropyltriethoxysilane, heat the solution to 40°C to 80°C and stir, which can accelerate molecular movement, promote the occurrence of cross-linking reactions, and ensure that the solution transforms from a liquid state to a stable gel state.
[0040] Example 2
[0041] A method for using a highly flexible aerogel coating, comprising the following steps:
[0042] Step 1: Prepare the magnesium alloy sheet that needs to be coated. Before coating, it is necessary to ensure that the surface of the magnesium alloy sheet is smooth and free of any impurities. Therefore, the magnesium alloy sheet needs to be polished. Use sandpapers of different coarsenesses (such as 180# sandpaper, 320# sandpaper, etc.) to gradually polish the surface of the magnesium alloy sheet. Through this gradually refined polishing process, oxides, oil stains, and other impurities on the surface can be effectively removed, and the roughness of the magnesium alloy surface can be increased, thereby providing a larger contact surface and significantly enhancing the adhesion between the coating and the surface of the magnesium alloy sheet, ensuring that the coating can firmly adhere to the surface during application and is not easily detached. After completing the surface polishing, place the polished magnesium alloy sheet in a dry and room-temperature environment to ensure that the surface is not affected by moisture and is in a stable state. After the surface is completely dry, continue with the next step of coating treatment to ensure that the magnesium alloy sheet does not contain any moisture when the coating is applied, so as not to affect the quality and effect of the coating.
[0043] Step 2: Finally, the prepared aerogel solution is evenly drop-coated on the surface of the prepared magnesium alloy sheet, ensuring that the coating is completely covered and in full contact with the surface of the magnesium alloy sheet. After the coating is applied, the entire magnesium alloy sheet is placed in a freeze-drying oven at -20°C to -80°C. This process uses the method of low-temperature freeze-drying to quickly evaporate the liquid in the solution, leaving behind the aerogel material to form a strong and uniform aerogel coating, thereby achieving an effective anti-corrosion effect.
[0044] The morphology diagram of the prepared aerogel with good flexibility is as Figure 1 shown, and its morphology presents characteristics of an interlaced distribution similar to flakes and needles. From the image, the surface of this material is covered with dense and differently oriented nanosheets or microscale crystals, indicating its complex surface microstructure.
[0045] These flake-like structures on the material surface seem soft and intertwined, forming a microscopic skeleton with a certain degree of plasticity and flexibility. This structure can effectively disperse external stress, improving the toughness and durability of the material during deformation. In addition, these flake-like microstructures on the material surface provide a higher specific surface area, which helps to improve the adsorption capacity or catalytic activity of the material. Generally speaking, Figure 1 the shown material surface morphology indicates its good flexibility.
[0046] The present invention includes two core technologies (a highly flexible aerogel material and appropriate hardness and modulus), and compared with the corresponding prior art, the specific advantages are described as follows:
[0047] 1. A highly flexible aerogel material
[0048] The extremely high flexibility of the aerogel coating is as Figure 2 shown
[0049] The extremely high flexibility of the aerogel material enables them to quickly return to their original state when subjected to external impact without brittle fracture. The sharp peaks in the figure show that the material quickly bears and reflects a high-intensity normal force after the external force is applied. This rapid response and short peak time may indicate that the material has high elasticity and stress recovery ability.
[0050] Principle explanation:
[0051] Flexibility and high elasticity: The aerogel coating can effectively improve its anti-deformation ability when subjected to pressure or impact by increasing the components of flexible materials (such as polymers, flexible fibers, etc.) and improving the microstructure. The nanostructures in the coating have a large surface area and structural elasticity, which can quickly absorb and transfer the externally applied stress, thus avoiding rupture.
[0052] Energy absorption and buffering: In this type of material, the nanostructure not only enables the aerogel to exhibit a greater ability to deform under external forces, but also disperses stress in the material structure and reduces instantaneous impact forces. This is consistent with the sharp rise in the peak in the figure, indicating that the aerogel coating can quickly respond to external pressure and return to its original state through its elasticity.
[0053] Recovery ability: As shown in the figure, the peak value quickly returns to zero after the force is applied, indicating that the aerogel coating can quickly recover its original shape after the impact, with almost no permanent deformation. This ability is an important feature of the highly flexible aerogel coating.
[0054] In summary, through special microstructure design and the use of composite materials, aerogel coatings can demonstrate excellent flexibility, quickly absorb and relieve external mechanical pressure, and ensure high resilience and stability under dynamic stress.
[0055] 2. Appropriate hardness and modulus
[0056] Moderate modulus and excellent flexibility:
[0057] The modulus of aerogel is 1.02GPa, and aerogel exhibits a certain rigidity and moderate elasticity. This modulus value indicates that aerogel can provide a certain resistance when subjected to external forces without excessive deformation or fracture. For applications that require materials to have good recovery performance under dynamic loads (such as flexible electronics, aerospace, etc.), such a modulus provides ideal support.
[0058] Low hardness ensures excellent processability:
[0059] The hardness of aerogel is 0.048GPa, which is significantly lower than that of hard materials such as metals and ceramics, giving aerogel better processability during the preparation process. The low hardness allows aerogel to absorb and buffer external impact with less deformation when subjected to force, avoiding the risk of brittle fracture. Therefore, aerogel can effectively protect the substrate from damage in applications that require slight deformation and restoration of the original shape.
[0060] Balance of flexibility and strength:
[0061] The combination of low hardness and moderate modulus allows aerogel to have a certain hardness while maintaining excellent flexibility. This material property enables aerogel to not only effectively resist external stress, but also quickly recover its shape after being compressed. It is suitable for a variety of application scenarios that require materials to have toughness and elasticity, such as high-temperature insulation, impact absorption and anti-corrosion coatings.
[0062] The aerogel has a modulus of 1.02 GPa and a hardness of 0.048 GPa, enabling it to provide excellent flexibility and processability while maintaining high rigidity. This property makes the aerogel an ideal material, especially suitable for high-end application fields that require light weight, high temperature resistance, the ability to absorb external forces and quickly recover.
[0063] The above embodiments are merely explanations of the present invention and are not limitations thereof. Those skilled in the art can make modifications to the embodiments without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.
Claims
1. A highly flexible aerogel coating, characterized in that: The following steps are involved: Step 1, selecting polyvinyl alcohol with an alcoholysis degree of 85-99%; Step 2, weigh polyvinyl alcohol and add it into ultrapure water to prepare a 0.5-10.0 g / ml polyvinyl alcohol solution; Step 3, cooling the polyvinyl alcohol solution to room temperature; Step 4: Adjust the pH to make the solution neutral and continue stirring the solution to ensure that the solutes are completely uniform; Step 5: Add 3-aminopropyltriethoxysilane as a cross-linking agent, and stir the solution to transform it from a liquid state to a stable gel state.
2. The highly flexible aerogel coating according to claim 1, characterized in that: In step 2, the solution is prepared by stirring at 60-95°C.
3. The highly flexible aerogel coating according to claim 1, characterized in that: In step 6, the solution is heated to 40°C-80°C and stirred.
4. A method for using a highly flexible aerogel coating according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: polish the surface of the substrate and place it at dry room temperature for use; Step 2: drip the prepared aerogel coating onto the surface of the polished substrate, and after it is in complete contact with the surface of the substrate, move the entire thing into a freeze drying box so that the aerogel coating is coated on the surface of the substrate.
5. The method for using a flexible aerogel coating according to claim 4, characterized in that: In step 2, the temperature in the freeze drying chamber is -20°C to -80°C.