CN109534351B - Yttrium silicate aerogel nanocomposite and preparation method thereof - Google Patents
Yttrium silicate aerogel nanocomposite and preparation method thereof Download PDFInfo
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- CN109534351B CN109534351B CN201910030443.8A CN201910030443A CN109534351B CN 109534351 B CN109534351 B CN 109534351B CN 201910030443 A CN201910030443 A CN 201910030443A CN 109534351 B CN109534351 B CN 109534351B
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Abstract
The invention relates to a yttrium silicate aerogel nano composite material and a preparation method thereof. The preparation components of the preparation method comprise a silicon precursor, soluble yttrium salt, ethanol aqueous solution and a gel auxiliary agent, the preparation components are prepared into wet gel by a sol-gel method, the wet gel is subjected to solvent replacement and drying to obtain aerogel, and then the aerogel is subjected to high-temperature heat treatment to obtain the yttrium silicate aerogel nanocomposite. The yttrium silicate aerogel nanocomposite prepared by the preparation method has the characteristics of high specific surface area, low density and low thermal conductivity, the preparation process is simple and easy to implement, good heat insulation performance and high-temperature stability are shown in an ultrahigh-temperature environment, and the yttrium silicate aerogel nanocomposite has positive significance for the service of various devices in the ultrahigh-temperature extreme environment.
Description
Technical Field
The invention relates to the technical field of nano materials with ultrahigh-temperature heat-insulating property, in particular to an yttrium silicate aerogel nano composite material and a preparation method thereof.
Background
With the increasingly strict requirements of the fields of aerospace, chemical metallurgy, high-temperature parts and the like on the heat insulation performance of materials, the traditional heat insulation material cannot meet the heat insulation requirement at ultrahigh temperature. Heat-insulating material systems common today, such as SiO2The porous ceramic has low strength and no high temperature resistance, and Al2O3The porous ceramic has good high temperature resistance, but the thermal conductivity is relatively high, so that the heat insulation effect is not good, the YSZ ceramic material has large high-temperature shrinkage and high density, the mullite ceramic material cannot meet the requirement on strength at high temperature, and the like, and the use condition of the mullite ceramic material at the ultrahigh temperature is difficult to meet. Therefore, there is an urgent need for a heat insulating material having excellent heat insulating properties, good stability, excellent mechanical properties, and the like, and being adaptable to an extremely high temperature environment.
Aerogel materials are porous materials with three-dimensional network structures formed by mutually crosslinking and aggregating nanoparticles. The aerogel has the characteristics of low density, low thermal conductivity, low dielectric constant, high porosity, high specific surface area and the like, and has a great application value in the fields of aerospace, building energy conservation, environmental management and the like. The unique structure of the aerogel can greatly reduce solid phase heat transfer and gas phase heat transfer, so that the aerogel has extremely low thermal conductivity coefficient and is a heat-insulating material with excellent performance. However, conventional aerogel materials do not operate stably in ultra-high temperature environments, such as SiO2The long-term stable service temperature of the aerogel is only 650 ℃, the carbon aerogel can not be used as a high-temperature heat-insulating material in an aerobic environment, and Al is introduced2O3SiO of component (A)2The aerogel has a phase change occurring under a high temperature environment to cause structural collapse and the like. Thus, it is a feasible method to further develop insulation materials by modifying aerogel materials to operate stably in ultra-high temperature environments.
Yttrium silicate (Y-Si-O) including Y2Si2O7，Y2SiO5And 2Y2O3·3SiO2It is a material with a wide variety of crystal structures. The yttrium silicate material has great potential in the research and development of novel heat insulation systems due to higher melting point, good oxidation resistance and excellent mechanical propertyForce. Wherein Y is2SiO5、Y2Si2O7The melting points of the two crystal forms are 1980 ℃ and 1775 ℃, the two crystal forms belong to refractory silicate materials, the two crystal forms can be used in an ultrahigh-temperature environment, and the excellent mechanical property and durability can ensure that the yttrium silicate materials are easy to process and manufacture. The yttrium silicate material serving as a novel heat insulation material system has good mechanical property, heat insulation property, high-temperature stability and corrosion resistance, and has good prospect in the field of high-temperature environment heat insulation.
Disclosure of Invention
The invention aims to provide a blocky yttrium silicate aerogel composite material based on the insufficient high-temperature performance of the existing light heat-insulating material, which has the characteristics of good high-temperature stability, effective heat insulation and excellent mechanical stability.
In order to achieve the purpose, the invention provides the following technical scheme:
1. the preparation components of the preparation method comprise a silicon precursor, soluble yttrium salt, ethanol aqueous solution and a gel additive, the preparation components are prepared into wet gel by a sol-gel method, the wet gel is subjected to solvent replacement and drying to obtain aerogel, and then the aerogel is subjected to high-temperature heat treatment to obtain the yttrium silicate aerogel nanocomposite; wherein the high temperature heat treatment comprises:
the first stage is as follows: heating from room temperature to a first temperature according to a heating rate of 2-4 ℃/min, and preserving heat at the first temperature for 1-2 hours, wherein the first temperature is 400-;
and a second stage: heating up from the first temperature to the second temperature according to the heating rate of 3-5 ℃/min, and preserving the heat at the second temperature for 1-2 hours, wherein the second temperature is 800-.
2. According to the preparation method of the technical scheme 1, the precursor of the silicon is selected from any one or more of ethyl orthosilicate, methyltrimethoxysilane and water glass.
3. The preparation method according to claim 1, wherein the soluble yttrium salt is selected from any one or more of yttrium chloride, yttrium nitrate and yttrium sulfate.
4. According to the preparation method of the technical scheme 3, the molar weight of the soluble yttrium salt is 1-6 times of that of the precursor of the silicon.
5. According to the preparation method of the technical scheme 1, the gel assistant is selected from any one or more of propylene oxide, methyl propylene oxide, ethylene oxide and epichlorohydrin.
6. According to the preparation method of the technical scheme 5, the molar weight of the gel assistant is 6-8 times of that of the soluble yttrium salt.
7. The production method according to any one of claims 1 to 6, comprising the steps of:
(1) mixing a silicon precursor, soluble yttrium salt and an ethanol water solution to obtain a primary solution;
(2) adding a gel auxiliary agent into the primary solution, uniformly dispersing to obtain sol, and standing to obtain wet gel;
(3) carrying out solvent replacement on the wet gel, and then drying to obtain aerogel;
(4) and carrying out high-temperature heat treatment on the aerogel to obtain the yttrium silicate aerogel composite material.
8. According to the preparation method of the technical scheme 7, ethanol is adopted for solvent replacement, the replacement times are 4-8, and the interval time of each time is 12-24 hours.
9. According to the preparation method of the technical scheme 7, a supercritical drying method is adopted for drying.
10. An yttrium silicate aerogel nanocomposite is prepared by the preparation method of any one of technical schemes 1 to 9.
Advantageous effects
The technical scheme of the invention has the following advantages:
(1) the yttrium silicate aerogel composite material combines the excellent characteristics of yttrium silicate and aerogel to obtain the yttrium silicate aerogel composite material which not only has low density, high porosity (89-93 percent) and low thermal conductivity (0.02-0.04W/m)-1·K-1) The combined characteristics of the nanoparticle structure and the nano-pore structure, and thermal insulationGood performance of oxidation resistance, high temperature resistance and high melting point.
(2) The yttrium silicate aerogel nanocomposite prepared by the preparation method provided by the invention has the advantages that the high-temperature stability is greatly improved, the high-temperature effect of more than 1500 ℃ can be resisted in an aerobic environment, and the yttrium silicate aerogel nanocomposite can be stably used.
(3) The heat insulation performance of the yttrium silicate aerogel nanocomposite prepared by the preparation method is greatly improved, the heating surface is in a high-temperature environment (1200-.
(4) The yttrium silicate aerogel nano composite material prepared by the preparation method can be obtained by a simple sol-gel method and supercritical drying, the preparation raw materials are easy to obtain, and the process can be repeated.
Drawings
FIG. 1 is an external view of a yttrium silicate aerogel nanocomposite prepared according to example 1 of the present invention;
FIG. 2 is an SEM image of a yttrium silicate aerogel nanocomposite prepared according to example 2 of the present invention;
fig. 3 is a graph showing the thermal insulation effect of the yttrium silicate aerogel nanocomposite prepared in example 4 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The invention provides a preparation method of yttrium silicate aerogel nanocomposite, which comprises the steps of preparing a precursor containing silicon, soluble yttrium salt, ethanol aqueous solution and a gel auxiliary agent by a sol-gel method, preparing wet gel from the prepared components, replacing the wet gel with a solvent, drying to obtain aerogel, and performing high-temperature heat treatment on the aerogel to obtain the yttrium silicate aerogel nanocomposite; wherein the high temperature heat treatment comprises:
the first stage is as follows: heating from room temperature to a first temperature according to a heating rate of 2-4 ℃/min, and preserving heat at the first temperature for 1-2 hours, wherein the first temperature is 400-;
and a second stage: heating up from the first temperature to the second temperature according to the heating rate of 3-5 ℃/min, and preserving the heat at the second temperature for 1-2 hours, wherein the second temperature is 800-.
Specifically, the preparation method comprises the following steps:
(1) mixing a silicon precursor, soluble yttrium salt and an ethanol water solution to obtain a primary solution;
the precursor of silicon can be selected from one or more of ethyl orthosilicate, methyltrimethoxysilane and water glass;
the soluble yttrium salt may be selected from any one or more of yttrium chloride, yttrium nitrate, yttrium sulfate, and the amount thereof may be determined with reference to the amount of the precursor of silicon under the following conditions: the molar weight of the soluble yttrium salt is 1-6 times of that of the precursor of the silicon;
the ethanol water solution is a mixed solution prepared from ethanol and water, the dosage of the ethanol water solution is not particularly limited, and the proportion of the ethanol to the water is not particularly limited;
(2) adding a gel auxiliary agent into the primary solution, uniformly dispersing to obtain sol, and standing to obtain wet gel; the gel assistant can be selected from one or more of propylene oxide, methyl propylene oxide, ethylene oxide and epichlorohydrin, the dosage of the gel assistant can refer to the dosage of the soluble yttrium salt, and the molar weight of the gel assistant is preferably 6-8 times of the molar weight of the soluble yttrium salt;
(3) carrying out solvent replacement on the wet gel, and then drying to obtain aerogel;
when the solvent replacement is carried out, the wet gel can be put into ethanol for carrying out the solvent replacement, the replacement frequency is preferably 4-8, and the interval time of each time is preferably 12-24 hours;
the drying method is preferably a supercritical drying method, and the displaced wet gel is put into a supercritical drying device to be dried to obtain aerogel;
(4) carrying out high-temperature heat treatment on the aerogel to obtain the yttrium silicate aerogel composite material; the high-temperature heat treatment comprises the following steps:
the first stage is as follows: heating from room temperature to a first temperature at a heating rate of 2-4 deg.C/min, and maintaining the temperature at the first temperature for 1-2 hr, wherein the first temperature is 400-;
and a second stage: heating from the first temperature to a second temperature at a heating rate of 3-5 deg.C/min, and maintaining the second temperature at 800-1200 deg.C, for example, 800 deg.C, 900 deg.C, 1000 deg.C, 1100 deg.C, 1200 deg.C for 1-2 hours.
The invention also provides an yttrium silicate aerogel nano composite material prepared by the preparation method provided by the invention. The composite material prepared by the method combines the excellent hot points of yttrium silicate and aerogel, has the characteristics of low density, low thermal conductivity, high porosity and combination of a nanoparticle structure and a nanometer pore size structure, and also has the performances of good heat insulation, oxidation resistance, high temperature resistance and high melting point. Through detection, the heat insulation efficiency of the composite material prepared by the preparation method provided by the invention can reach more than 80% (the heating surface is in a 1200-1500 environment), which shows that the heat insulation performance is greatly improved; can resist the high temperature action of more than 1500 ℃ in an aerobic environment and can be stably used, which shows that the high temperature stability of the composite material is greatly improved.
The following are examples of the present invention.
Example 1
4.15g of tetraethylorthosilicate was mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1 hour, then 2 times of the molar weight of the ethyl orthosilicate is added to the yttrium chloride hexahydrate, and stirring is carried out for 2 hours until the hydrolysis is completed. Then, dripping propylene oxide with the molar weight 8 times that of the yttrium chloride hexahydrate into the solution, stirring for 10min, then pouring the sol solution into a mould, and standing to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for carrying outDrying, namely performing heat treatment on the dried aerogel at 800 ℃, wherein the treatment steps are as follows: heating the mixture from room temperature to 500 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 500 ℃ to 800 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 800 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite, wherein the appearance diagram is shown in figure 1.
The density of the material prepared in this example was found to be 0.15g/cm3The thermal conductivity is 0.024W/m-1·K-1The porosity is 92%, the strength is 0.64Mpa, the heat insulation efficiency of the material is more than 80% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the overall linear shrinkage of the material is less than 4.8% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 2
4.15g of ethyl orthosilicate was mixed to 27.67g of EtOH/H2In solution of O, wherein H2O is 15 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium chloride hexahydrate with the molar weight 2 times that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. Then, propylene oxide with the molar weight 7 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 12h for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out heat treatment on the dried aerogel at 800 ℃, wherein the treatment steps are as follows: heating the mixture from room temperature to 500 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 500 ℃ to 800 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 800 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite, wherein an SEM picture is shown in figure 2.
The density of the material prepared in this example was found to be 0.12g/cm3The thermal conductivity is 0.022W/m-1·K-1The porosity is 93 percent, the strength is 0.60Mpa, the heat insulation efficiency of the material is more than 82 percent measured by a back temperature test of 1000s under the environment of 1200 ℃, and the integral linear shrinkage of the material is less than 4.4 percent measured by heat treatment of 1000s under the environment of 1500 ℃. .
Example 3
4.15g of tetraethylorthosilicate was mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 20 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium chloride hexahydrate with the molar weight 2 times that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. Then, dripping propylene oxide with the molar weight 8 times that of the yttrium chloride hexahydrate into the solution, stirring for 10min, then pouring the sol solution into a mould, and standing to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 6 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 600 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 600 ℃ to 1000 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 1000 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.19g/cm3The thermal conductivity is 0.028W/m-1·K-1The porosity is 91%, the strength is 0.70Mpa, the heat insulation efficiency of the material is more than 79% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the integral linear shrinkage of the material is less than 4.5% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 4
6.04g of tetraethylorthosilicate are mixed to 50.58g of EtOH/H2In solution of O, wherein H2O is 10 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium chloride hexahydrate with the molar weight being 1 time that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. Then, propylene oxide with the molar weight 6 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out heat treatment on the dried aerogel at 1000 ℃, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 5 ℃/min, and then keeping the temperature at 600 ℃ for 2 h; after the heat preservation is finished, the temperature is continuously raised from 600 ℃ to 100 DEG CThe temperature rise rate is 4 ℃/min at 0 ℃, and then the temperature is kept for 2 hours at 1000 ℃ to prepare the yttrium silicate aerogel nanocomposite, and the heat insulation effect is shown in figure 3.
The density of the material prepared in this example was found to be 0.22g/cm3The thermal conductivity is 0.031W/m-1·K-1The porosity is 90%, the strength is 0.69Mpa, the heat insulation efficiency of the material is more than 79% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the integral linear shrinkage of the material is less than 4.0% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 5
6.04g of tetraethylorthosilicate are mixed to 40.46g of EtOH/H2In solution of O, wherein H2O is 40 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium chloride hexahydrate with the molar weight being 1 time that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. Then, propylene oxide with the molar weight 6 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 1100 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 4 ℃/min, and then keeping the temperature at 600 ℃ for 2 h; and after the heat preservation is finished, continuing heating from 600 ℃ to 1100 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 1100 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.20g/cm3The thermal conductivity is 0.029W/m-1·K-1The porosity is 91%, the heat insulation efficiency at 1200 ℃ is 81%, the strength is 0.68Mpa, the heat insulation efficiency of the material is more than 81% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the integral linear shrinkage of the material is less than 3.8% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 6
6.04g of tetraethylorthosilicate are mixed to 40.46g of EtOH/H2In solution of O, wherein H2O is 20 percent of the mass of EtOH, stirring is carried out for 1 hour, and then 1 time of orthosilicic acid is addedEthyl ester molar amount of yttrium chloride hexahydrate, stirred for 2h until it was completely hydrolyzed. Then, propylene oxide with the molar weight 6 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 12h for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 1200 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 2 ℃/min, and then keeping the temperature at 600 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 600 ℃ to 1200 ℃, wherein the heating rate is 3 ℃/min, and then preserving the heat at 1200 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.18g/cm3The thermal conductivity is 0.026W/m-1·K-1The porosity is 91%, the strength is 0.62MPa, the heat insulation efficiency of the material is more than 79% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the overall linear shrinkage of the material is less than 3.2% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 7
2.77g of ethyl orthosilicate are mixed to 55.40g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1 hour, then yttrium chloride hexahydrate with the molar weight being 3 times that of ethyl orthosilicate is added, and stirring is carried out for 2 hours until the hydrolysis is completed. Then, propylene oxide with the molar weight 7 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 4 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 1200 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 5 ℃/min, and then keeping the temperature at 600 ℃ for 2 h; and after the heat preservation is finished, continuing heating from 600 ℃ to 1200 ℃, wherein the heating rate is 3 ℃/min, and then preserving the heat at 1200 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
Upon examination, this example was madeThe density of the obtained material was 0.23g/cm3Thermal conductivity of 0.033W/m-1·K-1The porosity is 89%, the strength is 0.75MPa, the heat insulation efficiency of the material is more than 82% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the overall linear shrinkage of the material is less than 3.3% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 8
2.77g of ethyl orthosilicate are mixed to 55.40g of EtOH/H2In solution of O, wherein H2O is 20 percent of the mass of EtOH, stirring is carried out for 1 hour, then yttrium chloride hexahydrate with the molar weight being 3 times that of ethyl orthosilicate is added, and stirring is carried out for 2 hours until the hydrolysis is completed. Then, propylene oxide with the molar weight 6 times that of the yttrium chloride hexahydrate is dripped into the solution, the solution is stirred for 10min, and then the sol solution is poured into a mould and stands to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 6 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 1100 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 4 ℃/min, and then keeping the temperature at 600 ℃ for 2 h; and after the heat preservation is finished, continuing heating from 600 ℃ to 1100 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 1100 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.20g/cm3Thermal conductivity of 0.027W/m-1·K-1The porosity is 91%, the strength is 0.70Mpa, the heat insulation efficiency of the material is more than 82% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the overall linear shrinkage of the material is less than 3.9% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 9
4.15g of tetraethylorthosilicate are mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium nitrate hexahydrate with the molar weight being 2 times that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. And dripping 8 times of methyl propylene oxide in the molar weight of yttrium nitrate hexahydrate into the solution, stirring for 10min, pouring the sol solution into a mold, and standing to obtain wet gel. Will be provided withThe wet gel was aged and solvent replaced in EtOH environment, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out heat treatment on the dried aerogel at 800 ℃, wherein the treatment steps are as follows: heating the mixture from room temperature to 500 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 500 ℃ to 800 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 800 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.16g/cm3The thermal conductivity is 0.023W/m-1·K-1The porosity is 92%, the strength is 0.61MPa, the heat insulation efficiency of the material is more than 81% measured by a back temperature test of 1000s at the temperature of 1200 ℃, and the overall linear shrinkage of the material is less than 5.0% measured by heat treatment of 1000s at the temperature of 1500 ℃.
Example 10
4.15g of tetraethylorthosilicate are mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1h, then yttrium sulfate octahydrate with the molar weight being 2 times that of ethyl orthosilicate is added, and stirring is carried out for 2h until the hydrolysis is completed. And dripping epoxy chloropropane with the molar weight 8 times that of the yttrium sulfate octahydrate into the solution, stirring for 10min, pouring the sol solution into a mould, and standing to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out heat treatment on the dried aerogel at 800 ℃, wherein the treatment steps are as follows: heating the mixture from room temperature to 500 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 500 ℃ to 800 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 800 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
The density of the material prepared in this example was found to be 0.13g/cm3The thermal conductivity is 0.021W/m-1·K-1The porosity is 93 percent, the strength is 0.55MPa, the heat insulation efficiency of the material is more than 82 percent measured by a back temperature test of 1000s under the environment of 1200 ℃, and the porosity is 1500 percentThe linear shrinkage of the whole material is less than 5.4 percent when the material is thermally treated for 1000s in an environment with the temperature being higher than the melting point of the raw material.
Example 11
4.15g of tetraethylorthosilicate are mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1 hour, then 2 times of the molar weight of the ethyl orthosilicate is added to the yttrium chloride hexahydrate, and stirring is carried out for 2 hours until the hydrolysis is completed. Then, dripping propylene oxide with the molar weight 8 times that of the yttrium chloride hexahydrate into the solution, stirring for 10min, then pouring the sol solution into a mould, and standing to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 700 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 400 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; and after the heat preservation is finished, continuing heating from 400 ℃ to 700 ℃, wherein the heating rate is 2 ℃/min, and then preserving the heat at 800 ℃ for 2h to prepare the yttrium silicate aerogel nanocomposite.
According to the detection, in the embodiment, the aerogel can not complete the phase change process of the material due to the excessively low heat treatment temperature, so that the prepared material is a yttrium silicate aerogel nanocomposite with partial content.
Example 12
4.15g of tetraethylorthosilicate are mixed to 41.50g of EtOH/H2In solution of O, wherein H2O is 30 percent of the mass of EtOH, stirring is carried out for 1 hour, then 2 times of the molar weight of the ethyl orthosilicate is added to the yttrium chloride hexahydrate, and stirring is carried out for 2 hours until the hydrolysis is completed. Then, dripping propylene oxide with the molar weight 8 times that of the yttrium chloride hexahydrate into the solution, stirring for 10min, then pouring the sol solution into a mould, and standing to obtain wet gel. The wet gel was placed in an EtOH environment for aging and solvent replacement, with the solution being replaced every 24 hours for a total of 8 times. Then putting the wet gel into a supercritical drying kettle for drying, and carrying out 1300 ℃ heat treatment on the dried aerogel, wherein the treatment steps are as follows: heating from room temperature to 600 ℃, wherein the heating rate is 3 ℃/min, and then keeping the temperature at 500 ℃ for 1 h; after the heat preservation is finished, the temperature is continuously raised from 600 ℃ to 1300 ℃, and the temperature raising rate is increasedAt the temperature of 2 ℃/min, and then keeping the temperature at 800 ℃ for 2h to prepare the yttrium silicate aerogel nano composite material.
It was determined that the aerogel shrinkage of this example was more pronounced due to the excessive heat treatment temperature, and therefore the resulting material was denser and had a tendency to densify relative to the other examples, resulting in an affected aerogel performance.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (7)
1. The preparation method of the yttrium silicate aerogel nanocomposite is characterized by comprising the preparation components of a silicon precursor, soluble yttrium salt, an ethanol aqueous solution and a gel auxiliary agent, wherein the preparation components are prepared into wet gel by a sol-gel method, the wet gel is subjected to solvent replacement and drying to obtain aerogel, and then the aerogel is subjected to high-temperature heat treatment to obtain the yttrium silicate aerogel nanocomposite; wherein the high temperature heat treatment comprises:
the first stage is as follows: heating from room temperature to a first temperature according to a heating rate of 2-4 ℃/min, and preserving heat at the first temperature for 1-2 hours, wherein the first temperature is 400-;
and a second stage: heating from the first temperature to a second temperature according to the heating rate of 3-5 ℃/min, and preserving the heat at the second temperature for 1-2 hours, wherein the second temperature is 800-;
the soluble yttrium salt is selected from any one or more of yttrium chloride, yttrium nitrate and yttrium sulfate; the molar weight of the soluble yttrium salt is 1-6 times of that of the precursor of the silicon; the gel auxiliary agent is selected from any one or more of propylene oxide, methyl propylene oxide, ethylene oxide and epichlorohydrin.
2. The preparation method according to claim 1, wherein the precursor of silicon is selected from one or more of ethyl orthosilicate, methyltrimethoxysilane and water glass.
3. The method of claim 1 wherein the molar amount of gelling aid is 6 to 8 times the molar amount of soluble yttrium salt.
4. The production method according to any one of claims 1 to 3, characterized by comprising the steps of:
(1) mixing a silicon precursor, soluble yttrium salt and an ethanol water solution to obtain a primary solution;
(2) adding a gel auxiliary agent into the primary solution, uniformly dispersing to obtain sol, and standing to obtain wet gel;
(3) carrying out solvent replacement on the wet gel, and then drying to obtain aerogel;
(4) and carrying out high-temperature heat treatment on the aerogel to obtain the yttrium silicate aerogel composite material.
5. The method according to claim 4, wherein the solvent substitution is carried out with ethanol for 4 to 8 times with an interval of 12 to 24 hours.
6. The method according to claim 4, wherein the drying is performed by a supercritical drying method.
7. An yttrium silicate aerogel nanocomposite, characterized by being produced by the production method according to any one of claims 1 to 6.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103086692A (en) * | 2013-01-17 | 2013-05-08 | 南京工业大学 | Preparation method of blocky SiO2-Y2O3 compound aerogel |
| CN102863201B (en) * | 2012-08-31 | 2014-03-05 | 航天材料及工艺研究所 | Preparation method of low-density high-temperature-resistant SiO2-MxOy compound aerogel heat insulating material |
| CN105780120A (en) * | 2016-01-29 | 2016-07-20 | 陕西科技大学 | Y2Si2O7 crystal whiskers and preparation method thereof |
-
2019
- 2019-01-14 CN CN201910030443.8A patent/CN109534351B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102863201B (en) * | 2012-08-31 | 2014-03-05 | 航天材料及工艺研究所 | Preparation method of low-density high-temperature-resistant SiO2-MxOy compound aerogel heat insulating material |
| CN103086692A (en) * | 2013-01-17 | 2013-05-08 | 南京工业大学 | Preparation method of blocky SiO2-Y2O3 compound aerogel |
| CN105780120A (en) * | 2016-01-29 | 2016-07-20 | 陕西科技大学 | Y2Si2O7 crystal whiskers and preparation method thereof |
Non-Patent Citations (6)
| Title |
|---|
| A novel silica aerogel/porousY2SiO5 ceramics with low thermal Conductivity and enhanced mechanical properties prepared by freeze casting and impregnation;Rubing Zhang et al.;《MaterialsLetters》;20160407;第175卷;第219–222页 * |
| A.J. Ferna＇ndez-Carrio＇n et al..Solid solubilityofYb2Si2O7 in b-, r- and δ-Y2Si2O7.《Journal of Solid State Chemistry》.2011,第184卷第1882–1889页. * |
| Enhanced mechanical and thermal properties of anisotropic fibrous porous mulliteezirconia composites produced using sol-gel impregnation;Rubing Zhang et al.;《Journal of Alloys and Compounds》;20170103;第699卷;第511-516页 * |
| Improvement in the high temperature thermal insulation performance of Y2O3 opacified silica aerogels;Vinayak G. Parale et al.;《Journal of Alloys and Compounds》;20170831;第871-878页 * |
| New multifunctional porous Yb2SiO5 ceramics prepared by freeze casting;Rubing Zhang et al.;《Ceramics International》;20160106;第42卷;第6046-6053页 * |
| Synthesis of Y2Si2O7:Eu nanocrystal and its optical properties;Pingle Zhou et al.;《Journal of Luminescence》;20060502;第124卷;第241–244页 * |
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