Flexible aerogel nanometer heat insulation felt

Abstract

The invention discloses a flexible aerogel nanometer heat insulation felt which comprises an aerogel layer, fire-resistant layers and a transition layer, the fire-resistant layers are arranged at the two ends of the aerogel layer, the transition layer is arranged between the aerogel layer and the fire-resistant layers, and the transition layer is arranged between the aerogel layer and the fire-resistant layers. The preparation method of the flexible aerogel nano heat insulation felt comprises the following steps: S1, preparing the aerogel layer; s2, preparing a fireproof layer; and S3, preparing the aerogel heat insulation felt, coating the two ends of the aerogel layer with a transparent adhesive, pasting the fireproof layers to the two ends of the aerogel layer, and heating and curing to obtain the aerogel heat insulation felt. According to the flexible aerogel nanometer heat insulation felt provided by the invention, the macromolecular flexible aerogel layer prepared by taking wool keratin as a raw material is taken as a main body, so that the flexibility and the high resilience effect of the aerogel heat insulation felt are ensured, and the high flame-retardant heat insulation performance of the aerogel heat insulation felt is also ensured by arranging the fire-resistant layers at the two ends of the aerogel layer; and the performance is more stable and more practical.

Description

Technical Field

[0001] The invention belongs to the field of aerogels, and in particular relates to a flexible aerogel nano thermal insulation felt. Background Art

[0002] Aerogel materials possess a three-dimensional porous network structure composed of nanoparticles. This structure imparts low density, high specific surface area, large nanopore volume, and porosity, resulting in excellent properties in thermal insulation, adsorption, catalysis, and electrochemistry. They are widely used in a wide range of fields, including aerospace, defense, military, petrochemicals, energy-saving architecture, and cutting-edge science. Compared to organic-inorganic elastic aerogels, cross-linked macromolecular elastic aerogels exhibit superior mechanical properties; however, these aerogels are constructed from purely organic compounds and therefore have poorer fire safety. Summary of the Invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a flexible aerogel nano-insulation felt.

[0004] To achieve the above objectives, the present invention provides the following technical solutions: A flexible aerogel nano thermal insulation felt comprises an aerogel layer, a refractory layer, and a transition layer, wherein the refractory layer is disposed at both ends of the aerogel layer, and the transition layer is disposed between the aerogel layer and the refractory layer. The preparation method of the flexible aerogel nano thermal insulation felt comprises the following steps: Step S1: Preparation of aerogel layer Step S1.1: Weigh an appropriate amount of wool keratin powder, add it to a 0.05 mol / L NaOH solution, and stir in a water bath at a temperature of 55-70°C for 2-4 hours until the keratin powder is completely dissolved to obtain a light yellow, uniform, and clear keratin solution; Step S1.2: Add an appropriate amount of carboxylated cellulose nanocrystals to the keratin solution and stir under ultrasonication for 60-100 minutes to fully disperse the carboxylated cellulose nanocrystals in the keratin solution. Then, add an appropriate amount of glutaraldehyde and stir in a water bath at 55-70°C for 60-100 minutes to fully crosslink the keratin and carboxylated cellulose nanocrystals to obtain a blended solution. Step S1.3: The blended solution is transferred to an aerogel mold and allowed to stand for a period of time until all small bubbles on the surface disappear, thereby obtaining a preliminary sample. The preliminary sample is then pre-frozen in an ultra-low temperature freezer at -80 to -100°C for 10 to -18 hours. The preliminary sample is then removed and transferred to a freeze dryer for 40 to 60 hours to obtain an aerogel layer. Step S2: Preparation of refractory layer Step S2.1: Mix a silicon source, aldehyde, silane coupling agent, pore structure modifier, alcohol, carbon black particles, and deionized water in appropriate proportions, stir evenly at a temperature of 20-50°C for 5-30 minutes, then add an organic acid and continue stirring for 5-30 minutes to obtain a mixed solution; Step S2.2: The mixed solution obtained in step S2.1 is subjected to a sol-gel reaction at a temperature of 20-60°C to obtain a wet gel. The wet gel is then immersed in a sealed hydrothermal reactor filled with a solvent and subjected to a solvent thermal treatment at a temperature of 50-250°C for 24-90 hours. The wet gel is then transferred to a container and dried at a temperature of 20-60°C to obtain a refractory layer. Step S3: Preparation of aerogel insulation felt Transparent adhesive is coated on both ends of the aerogel layer, and a fire-resistant layer is attached to both ends of the aerogel layer, which is heated and cured to obtain an aerogel insulation station.

[0005] Furthermore, the mass ratio of the wool keratin powder to the NaOH solution in step S1.1 is 1:11-15, and the carboxylated cellulose nanocrystals in step S1.2 account for 3-10% of the mass of the keratin solution.

[0006] Furthermore, the molar ratio of the silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol, carbon black particles and deionized water in step S2.1 is 0.1: (0.05-0.35): (0.05-0.35): (0.00005-0.005): (3-15): (0.1-0.3): (1-3).

[0007] Furthermore, the silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol and organic acid in step S2.2 are methyltrimethoxysilane, terephthalaldehyde, silane coupling agent KH791, triblock copolymer F127, methanol and ascorbic acid.

[0008] Furthermore, the transparent adhesive in step S3 is one of sodium silicate hydrate, potassium silicate hydrate, alkyd resin, epoxy resin, fluorocarbon resin, polyvinyl alcohol, polyvinyl butyral, and acrylamide.

[0009] The flexible aerogel nano-insulation felt disclosed in the present invention has the following beneficial effects compared with the prior art: a macromolecular flexible aerogel layer made of wool keratin as a main body ensures the flexibility and high resilience of the aerogel insulation felt; and a fire-resistant layer is provided at both ends of the aerogel layer, and carbon black is used as a flame retardant material, thereby providing good flame retardant properties for the fire-resistant layer aerogel, thereby also ensuring the high flame retardant and thermal insulation properties of the aerogel insulation felt, making the performance more stable and more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the structure of aerogel insulation felt according to a preferred embodiment of the present invention.

[0011] The reference numerals include: 1, aerogel layer; 2, transition layer; 3, fire-resistant layer. DETAILED DESCRIPTION

[0012] The present invention discloses a flexible aerogel nano thermal insulation felt. The specific implementation of the present invention is further described below in conjunction with preferred embodiments.

[0013] See attached figure Figure 1 , Figure 1 Schematic diagram of the structure of aerogel insulation felt according to a preferred embodiment of the present invention.

[0014] Preferred embodiment.

[0015] This embodiment provides a flexible aerogel nano-insulation felt, comprising an aerogel layer 1, a refractory layer 3, and a transition layer 2. The refractory layer 3 is disposed at both ends of the aerogel layer 1, and the transition layer 2 is disposed between the aerogel layer 1 and the refractory layer 3. The preparation method of the flexible aerogel nano-insulation felt comprises the following steps: Step S1: Preparation of aerogel layer Step S1.1: Weigh an appropriate amount of wool keratin powder, add it to a 0.05 mol / L NaOH solution, and stir in a water bath at a temperature of 55-70°C for 2-4 hours until the keratin powder is completely dissolved to obtain a light yellow, uniform, and clear keratin solution; Step S1.2: Add an appropriate amount of carboxylated cellulose nanocrystals to the keratin solution and stir under ultrasonication for 60-100 minutes to fully disperse the carboxylated cellulose nanocrystals in the keratin solution. Then, add an appropriate amount of glutaraldehyde and stir in a water bath at 55-70°C for 60-100 minutes to fully crosslink the keratin and carboxylated cellulose nanocrystals to obtain a blended solution. Step S1.3: The blended solution is transferred to an aerogel mold and allowed to stand for a period of time until all small bubbles on the surface disappear, thereby obtaining a preliminary sample. The preliminary sample is then pre-frozen in an ultra-low temperature freezer at -80 to -100°C for 10 to -18 hours. The preliminary sample is then removed and transferred to a freeze dryer for 40 to 60 hours to obtain an aerogel layer. Step S2: Preparation of refractory layer Step S2.1: Mix a silicon source, aldehyde, silane coupling agent, pore structure modifier, alcohol, carbon black particles, and deionized water in appropriate proportions, stir evenly at a temperature of 20-50°C for 5-30 minutes, then add an organic acid and continue stirring for 5-30 minutes to obtain a mixed solution; Step S2.2: The mixed solution obtained in step S2.1 is subjected to a sol-gel reaction at a temperature of 20-60°C to obtain a wet gel. The wet gel is then immersed in a sealed hydrothermal reactor filled with a solvent and subjected to a solvent thermal treatment at a temperature of 50-250°C for 24-90 hours. The wet gel is then transferred to a container and dried at a temperature of 20-60°C to obtain a refractory layer. Step S3: Preparation of aerogel insulation felt Transparent adhesive is coated on both ends of the aerogel layer, and a fire-resistant layer is attached to both ends of the aerogel layer, which is heated and cured to obtain an aerogel insulation station.

[0016] Furthermore, the mass ratio of the wool keratin powder to the NaOH solution in step S1.1 is 1:11-15, and the carboxylated cellulose nanocrystals in step S1.2 account for 3-10% of the mass of the keratin solution.

[0017] Furthermore, the molar ratio of the silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol, carbon black particles and deionized water in step S2.1 is 0.1: (0.05-0.35): (0.05-0.35): (0.00005-0.005): (3-15): (0.1-0.3): (1-3).

[0018] Furthermore, the silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol and organic acid in step S2.2 are methyltrimethoxysilane, terephthalaldehyde, silane coupling agent KH791, triblock copolymer F127, methanol and ascorbic acid.

[0019] Furthermore, the transparent adhesive in step S3 is one of sodium silicate hydrate, potassium silicate hydrate, alkyd resin, epoxy resin, fluorocarbon resin, polyvinyl alcohol, polyvinyl butyral, and acrylamide.

[0020] Working principle: First, prepare the wool keratin powder: (1) Weigh 5 g of untreated wool and wash it with deionized water to remove insoluble impurities such as fine sand. Then, place it in a 0.1 mol / L NaOH solution to remove grease from the wool surface. Finally, rinse the wool repeatedly with deionized water to remove residual NaOH on the wool fiber surface. After washing, dry the wool in a forced air drying oven at 60°C to constant weight.

[0021] (2) Weigh appropriate amounts of NaHSO3, urea, and SDS to prepare a mixed solution. Cut the wool into pieces of about 1 cm in length and immerse the wool in the mixed solution at a bath ratio of 1:20. Stir in an oil bath at a rate of 300 r / min to obtain a crude keratin solution.

[0022] (3) Filter the crude keratin solution to remove the coarse wool residue, and then centrifuge the filtered solution in a high-speed refrigerated centrifuge for 10 minutes (speed 8000 r / min). Pour the centrifugal supernatant into a dialysis bag with a molecular weight cutoff of 8-14 kDa. Place the dialysis bag in distilled water and dialyze for 48 hours. Change the distilled water every 12 hours to remove residual reducing agents, urea and other small molecules in the keratin solution. After dialysis, place the purified keratin solution in a glass dish and transfer it to a vacuum drying oven at 60°C for vacuum drying. After complete drying, place the keratin in a mortar and finely grind it to obtain wool keratin powder.

[0023] The wool keratin powder obtained is then used to prepare the aerogel layer, which forms the main body of the aerogel insulation felt. The refractory layer is then prepared by modifying the refractory layer aerogel with carbon black particles. The carbon black provides the aerogel in the refractory layer with excellent fire resistance and thermal insulation properties. Finally, a transparent adhesive is used to bond the refractory layer and the aerogel layer. Heat and cure the two layers together. The macromolecular aerogel layer, supported by the wool keratin powder, ensures the flexibility and high resilience of the main body of the aerogel insulation felt. The carbon black provides a highly insulating refractory layer, which together ensures the thermal insulation performance of the aerogel insulation felt.

[0024] It is worth mentioning that the technical features such as carbon black involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial arrangement method of these technical features can be selected by conventional means in the field and should not be regarded as the inventive point of this patent. This patent will not be further elaborated.

[0025] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flexible aerogel nano thermal insulation felt, characterized in that: The flexible aerogel nano-insulating felt comprises an aerogel layer, a refractory layer and a transition layer, wherein the refractory layer is arranged at both ends of the aerogel layer, and the transition layer is arranged between the aerogel layer and the refractory layer. The preparation method of the flexible aerogel nano-insulating felt comprises the following steps: Step S1: Preparation of aerogel layer Step S1.1: Weigh an appropriate amount of wool keratin powder, add it to a 0.05 mol / L NaOH solution, and stir in a water bath at a temperature of 55-70°C for 2-4 hours until the keratin powder is completely dissolved to obtain a light yellow, uniform, and clear keratin solution; Step S1.2: Add an appropriate amount of carboxylated cellulose nanocrystals to the keratin solution and stir under ultrasonication for 60-100 minutes to fully disperse the carboxylated cellulose nanocrystals in the keratin solution. Then, add an appropriate amount of glutaraldehyde and stir in a water bath at 55-70°C for 60-100 minutes to fully crosslink the keratin and carboxylated cellulose nanocrystals to obtain a blended solution. Step S1.3: The blended solution is transferred to an aerogel mold and allowed to stand for a period of time until all small bubbles on the surface disappear, thereby obtaining a preliminary sample. The preliminary sample is then pre-frozen in an ultra-low temperature freezer at -80 to -100°C for 10 to -18 hours. The preliminary sample is then removed and transferred to a freeze dryer for 40 to 60 hours to obtain an aerogel layer. Step S2: Preparation of refractory layer Step S2.1: Mix a silicon source, aldehyde, silane coupling agent, pore structure modifier, alcohol, carbon black particles, and deionized water in appropriate proportions, stir evenly at a temperature of 20-50°C for 5-30 minutes, then add an organic acid and continue stirring for 5-30 minutes to obtain a mixed solution; Step S2.2: The mixed solution obtained in step S2.1 is subjected to a sol-gel reaction at a temperature of 20-60°C to obtain a wet gel. The wet gel is then immersed in a sealed hydrothermal reactor filled with a solvent and subjected to a solvent thermal treatment at a temperature of 50-250°C for 24-90 hours. The wet gel is then transferred to a container and dried at a temperature of 20-60°C to obtain a refractory layer. Step S3: Preparation of aerogel insulation felt Transparent adhesive is coated on both ends of the aerogel layer, and a fire-resistant layer is attached to both ends of the aerogel layer, which is heated and cured to obtain an aerogel insulation station.

2. The flexible aerogel nano thermal insulation felt according to claim 1, characterized in that: The mass ratio of the wool keratin powder to the NaOH solution in step S1.1 is 1:11-15, and the carboxylated cellulose nanocrystals in step S1.2 account for 3-10% of the mass of the keratin solution.

3. The flexible aerogel nano thermal insulation felt according to claim 1, characterized in that: The molar ratio of the silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol, carbon black particles and deionized water in step S2.1 is 0.1: (0.05-0.35): (0.05-0.35): (0.00005-0.005): (3-15): (0.1-0.3): (1-3).

4. The flexible aerogel nano thermal insulation felt according to claim 1, characterized in that: The silicon source, aldehyde, silane coupling agent, pore structure regulator, alcohol and organic acid in step S2.2 are methyltrimethoxysilane, terephthalaldehyde, silane coupling agent KH791, triblock copolymer F127, methanol and ascorbic acid.

5. The flexible aerogel nano thermal insulation felt according to claim 1, characterized in that: The transparent adhesive in step S3 is one of sodium silicate hydrate, potassium silicate hydrate, alkyd resin, epoxy resin, fluorocarbon resin, polyvinyl alcohol, polyvinyl butyral, and acrylamide.

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