Claims:We claim:
1. A novel process for preparing Tropical heat resistant aerogel based on nanotechnology it includes the following steps:
Step S1:
Add ethyl orthosilicate and methyl- trimethoxy-silane to anhydrous ethanol, and stir at a constant speed for 15 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
Step S2:
Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 15 mL of sol per 45cm3 of thermal insulation blanket, transfer to 85% ethanol solution, seal, and age for 20hours, and then incubate at 60 ℃ for 3h. After 4 hours at 100 ° C, 2 hours at 160 ° C and 5 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.

2. The process for preparing a high-temperature-resistant ceramic aerogel based on nanotechnology according to claim 1, wherein the nano-zirconia fiber in step S2 is made by the following method:
3.
（1）Add zirconium carbonate and acetic acid to deionized water and stir at a constant speed for 10 minutes to prepare a mixed solution. Add yttrium nitrate, heat in a 50 ° C water bath and stir at 120r / min for 30min, add polyvinylpyrrolidone, heat to 65 ° C, and stir until uniform Polyvinylpyrrolidone is completely dissolved, and distilled under reduced pressure at this temperature to prepare a spinning solution.

（2）Electrospin the spinning solution prepared in step (1), control the spinning voltage to 22-25kV, the curing distance is 8-10cm, the advance speed is 0.5-1.0mL / h, and the spinning temperature is 35-50 ℃ The precursor fiber was prepared, and the precursor fiber was heat-treated to control the temperature to rise to 350 ° C at a rate of 5 ° C / min, and then to 550 ° C at a rate of 1 ° C / min, and then to 2 ° C / min. At 780 ° C, the temperature was maintained at this temperature for 2 hours, and then the temperature was raised to 1200 ° C at a rate of 5 ° C / min, and the temperature was maintained for 1 hour to prepare nano-zirconia fibers.

4. The method for preparing tropical heat resistant aerogel based on nanotechnology according to claim 1, wherein the average pore diameter of the high-temperature-resistant ceramic aerogel obtained in step S2 is 27-33 nm, and the specific surface area is 313- 345m2 / g.
, Description:FIELD OF INVENTION
The present invention discloses a nano method, more particularly this invention is related to the field of aerogel preparation based on nanotechnology. More specifically this invention targets a novel process for preparing tropical heat resistant aerogel based on nanotechnology.
BACKGROUND AND SUMMARY OF THE INVENTION:
Aerogel is a nano-porous material composed of nanoparticles. They have many special properties, such as high specific surface area, low density, and high porosity, so they have a wide range of applications in the fields of heat insulation, adsorption and catalysis. There are currently dozens of aerogels reported. According to their composition, they can be divided into three categories: oxide aerogels, organic (carbon) aerogels and carbide aerogels. The normal use temperature of SiO2 aerogel and its composite materials is up to 800 ℃, the pore structure above 800 ℃ is obviously reduced, and the material tends to be dense. Although carbon aerogel has good high temperature resistance in an inert atmosphere, its temperature resistance will greatly decrease in an aerobic environment, and generally does not exceed 400-600 ° C. Al2O3 aerogels have higher temperature resistance and can be used normally at 1000 ° C. However, with the development of technology, the requirements for the use of materials are becoming higher and higher. In many cases, materials need to reach 1200 in the atmospheric environment. Above ℃ and even higher temperature resistance, traditional oxide aerogels and carbon aerogels cannot meet the needs of applications, and it is necessary to develop an aerogel insulation material that can withstand higher temperatures.
DRAWINGS:
Figure 1 explains the steps involved in the current disclosed invention.

DETAILED DESCRIPTION:
In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
Technical problems to be solved by the present invention:
（1）Traditional oxide aerogels and carbon aerogels cannot meet the requirements for use at temperatures above 1300 ° C and even higher.
（2）In the prior art, during the preparation of zirconia fiber, the content of organic matter in the fiber is too high. During the heat treatment process, the removal of organic matter causes defects, reducing the strength of the fiber, and the molecular chain of the polymer aggregates, the density of the rubber particles increases, Collisions are prone to occur between particles, and the probability of cross-linking increases.
The object of the present invention can be achieved by the following technical solutions:
A novel process for preparing Tropical heat resistant aerogel based on nanotechnology it includes the following steps:
Step S1:
Add ethyl orthosilicate and methyl- trimethoxy-silane to anhydrous ethanol, and stir at a constant speed for 15 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
Step S2:
Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 15 mL of sol per 45cm3 of thermal insulation blanket, transfer to 85% ethanol solution, seal, and age for 20hours, and then incubate at 60 ℃ for 3h. After 4 hours at 100 ° C, 2 hours at 160 ° C and 5 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.

The process for preparing a high-temperature-resistant ceramic aerogel based on nanotechnology according to above steps mentioned , wherein the nano-zirconia fiber in step S2 is made by the following method:
（1）Add zirconium carbonate and acetic acid to deionized water and stir at a constant speed for 10 minutes to prepare a mixed solution. Add yttrium nitrate, heat in a 50 ° C water bath and stir at 120r / min for 30min, add polyvinylpyrrolidone, heat to 65 ° C, and stir until uniform Polyvinylpyrrolidone is completely dissolved, and distilled under reduced pressure at this temperature to prepare a spinning solution.

（2）Electrospin the spinning solution prepared in step (1), control the spinning voltage to 22-25kV, the curing distance is 8-10cm, the advance speed is 0.5-1.0mL / h, and the spinning temperature is 35-50 ℃ The precursor fiber was prepared, and the precursor fiber was heat-treated to control the temperature to rise to 350 ° C at a rate of 5 ° C / min, and then to 550 ° C at a rate of 1 ° C / min, and then to 2 ° C / min. At 780 ° C, the temperature was maintained at this temperature for 2 hours, and then the temperature was raised to 1200 ° C at a rate of 5 ° C / min, and the temperature was maintained for 1 hour to prepare nano-zirconia fibers.

The average pore diameter of the high-temperature-resistant ceramic aerogel obtained in step S2 is 27-33 nm, and the specific surface area is 313- 345m2 / g.
The advantages of the present invention:
In step S1, ethyl orthosilicate and methyltrimethoxysilane are used as raw materials, and 10% dilute hydrochloric acid is added to adjust the pH and serve as a catalyst in the hydrolysis process. Mixing liquid A and liquid B can generate silicic acid and semi-silicic acid monomers. After adding 10% ammonia water to adjust the pH on the one hand, it can be used as a catalyst for the polycondensation process.
In the preparation process of the nano-zirconia fiber of the present invention, in the step (1), zirconium carbonate is first reacted with acetic acid and then dissolved in water. On the one hand, acetic acid reacts with zirconium carbonate as a reaction reagent and can act as a complexing agent to make The molecules form linear molecules; controlling the weight ratio of zirconium carbonate to acetic acid to 1: 1 can form a spinning solution with good performance, prevent excessive acetic acid content, and excessively high organic content in the fiber after spinning. During the heat treatment process the elimination of organics produces defects, reduces the strength of the fiber, and can also prevent the content of zirconium from being too high, the molecular chain of the polymer aggregates, the density of the colloidal particles increasing, the colloidal particles are prone to collision, and the probability of cross-linking increases. Vinylpyrrolidone can increase the viscosity of the sol and promote the uniform dispersion of colloidal particles, further suppress the aggregation of colloidal particles, and improve the stability of the system; in step (2), the spinning voltage is controlled to be 22-25kV, because part of the spinning process The bead strings collapse and form a capsular structure. Increasing the spinning voltage can reduce the bead string structure and enhance the stability of the nano-zirconia fiber. It solves the existing technology During the preparation of zirconia fiber, the content of organic matter in the fiber is too high. During the heat treatment process, the removal of organic matter causes defects, reducing the strength of the fiber, and the molecular chain of the polymer aggregates, the density of the rubber particles increases, and the rubber particles are easily technical problems in which collision probability increases.
Examples:
A novel process for preparing Tropical heat resistant aerogel based on nanotechnology includes the following steps:
Step S1: Add ethyl orthosilicate and methyltrimethoxysilane to anhydrous ethanol, and stir at a constant speed for 10 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
The weight ratio of ethyl orthosilicate, methyltrimethoxysilane, absolute ethanol and deionized water was controlled to be 1: 1: 10: 10.
Using ethyl orthosilicate and methyltrimethoxysilane as raw materials, adding 10% dilute hydrochloric acid to adjust the pH and acting as a catalyst in the hydrolysis process. Mixing liquid A and liquid B can produce silicic acid and semisilicic acid monomers. The addition of 10% ammonia water can adjust the pH on the one hand and can be used as a catalyst for the polycondensation process. The hydrolyzed monomers are polycondensed to form smaller crosslinked bodies, and the crosslinked bodies are then stacked to form a sol;
Step S2: Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 20mL of sol per 48cm3 of thermal insulation blanket, transfer to 80% ethanol solution, seal and age for 18h, and then incubate at 60 ℃ for 2h After 4 hours at 100 ° C, 2 hours at 160 ° C and 4 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.
Nano zirconia fibers are made by the following methods:
（1）Add zirconium carbonate and acetic acid to deionized water and stir at a constant speed for 10 minutes to prepare a mixed solution. Add yttrium nitrate, heat in a 50 ° C water bath and stir at 120r / min for 30min, add polyvinylpyrrolidone, heat to 65 ° C, and stir until uniformly. Polyvinylpyrrolidone is completely dissolved, and distilled under reduced pressure at this temperature to prepare a spinning solution;
The weight ratio of zirconium carbonate, acetic acid, deionized water, yttrium nitrate and polyvinylpyrrolidone is controlled to be 1: 1: 10: 0.6: 0.1.
（2）Electrospin the spinning solution prepared in step (1), control the spinning voltage to 22-25kV, the curing distance is 8-10cm, the advance speed is 0.5-1.0mL / h, and the spinning temperature is 35-50 ℃ The precursor fiber was prepared, and the precursor fiber was heat-treated to control the temperature to rise to 350 ° C at a rate of 5 ° C / min, and then to 550 ° C at a rate of 1 ° C / min, and then to 2 ° C / min. At 780 ° C, the temperature was maintained at this temperature for 2 hours, and then the temperature was raised to 1200 ° C at a rate of 5 ° C / min, and the temperature was maintained for 1 hour to prepare nano-zirconia fibers.
Example 2
A novel process for preparing Tropical heat resistant aerogel based on nanotechnology includes the following steps::
Step S1: Add ethyl orthosilicate and methyltrimethoxysilane to anhydrous ethanol, and stir at a constant speed for 10 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
The weight ratio of ethyl orthosilicate, methyltrimethoxysilane, absolute ethanol and deionized water was controlled to be 2: 1: 10: 10.
Step S2: Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 20mL of sol per 48cm3 of thermal insulation blanket, transfer to 80% ethanol solution, seal and age for 18h, and then incubate at 60 ℃ for 2h. After 4 hours at 100 ° C, 2 hours at 160 ° C and 4 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.
Example 3
A novel process for preparing Tropical heat resistant aerogel based on nanotechnology includes the following steps::
Step S1: Add ethyl orthosilicate and methyltrimethoxysilane to anhydrous ethanol, and stir at a constant speed for 10 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
The weight ratio of ethyl orthosilicate, methyltrimethoxysilane, absolute ethanol and deionized water was controlled to be 2: 1: 5: 10.
Step S2: Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 20mL of sol per 48cm3 of thermal insulation blanket, transfer to 80% ethanol solution, seal and age for 18h, and then incubate at 60 ℃ for 2h. After 4 hours at 100 ° C, 2 hours at 160 ° C and 4 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.
Example 4
A novel process for preparing Tropical heat resistant aerogel based on nanotechnology includes the following steps:
Step S1: Add ethyl orthosilicate and methyltrimethoxysilane to anhydrous ethanol, and stir at a constant speed for 10 minutes to make liquid A; mix anhydrous ethanol with deionized water to make liquid B; heat the liquids A and B Incubate at 65 ° C and add liquid A to liquid B, mix well, add 10% dilute hydrochloric acid until pH = 3.6, and incubate for 2h, add 10% ammonia water to adjust the pH until pH = 7.5, prepare a sol, and concentrate until viscosity 6-7cp;
The weight ratio of ethyl orthosilicate, methyltrimethoxysilane, absolute ethanol and deionized water was controlled to be 2: 1: 10: 10.
Step S2: Apply the sol prepared in step S1 on the nano-zirconia fiber, control the coating of 20mL of sol per 48cm3 of thermal insulation blanket, transfer to 80% ethanol solution, seal and age for 18h, and then incubate at 60 ℃ for 2h. After 4 hours at 100 ° C, 2 hours at 160 ° C and 4 hours at 200 ° C, sintering was performed at 1100 ° C to obtain a high temperature resistant ceramic aerogel.