CN115108809A - Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material - Google Patents
Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material Download PDFInfo
- Publication number
- CN115108809A CN115108809A CN202210809178.5A CN202210809178A CN115108809A CN 115108809 A CN115108809 A CN 115108809A CN 202210809178 A CN202210809178 A CN 202210809178A CN 115108809 A CN115108809 A CN 115108809A
- Authority
- CN
- China
- Prior art keywords
- modified silica
- ceramic fiber
- inorganic ceramic
- prefabricated part
- fiber prefabricated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B30/00—Compositions for artificial stone, not containing binders
- C04B30/02—Compositions for artificial stone, not containing binders containing fibrous materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/20—Mortars, concrete or artificial stone characterised by specific physical values for the density
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/30—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values
- C04B2201/32—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values for the thermal conductivity, e.g. K-factors
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Silicon Compounds (AREA)
- Thermal Insulation (AREA)
Abstract
The invention provides a preparation method of a modified silica aerogel heat insulation composite material, which comprises the following steps: firstly, preparing modified silica sol by using an organic silicon source and an inorganic aluminum source as precursors and adopting an acid-base two-step catalysis method; secondly, placing the inorganic ceramic fiber prefabricated part in a sealed container, dipping the modified silica sol in a vacuum pressurization dipping mode, and after the dipping is finished, carrying out pressure relief and then standing for aging to obtain a modified silica wet gel/inorganic ceramic fiber prefabricated part; and thirdly, carrying out ethanol supercritical drying on the modified silica wet gel/inorganic ceramic fiber prefabricated part to obtain the modified silica aerogel heat-insulation composite material. The product obtained by the method has high temperature resistance and excellent mechanical property.
Description
Technical Field
The invention relates to a heat insulation material and a preparation method thereof, in particular to a preparation method of a high-temperature modified silica aerogel heat insulation composite material.
Background
The aerogel has a unique three-dimensional nano-mesh structure (framework is 2-5 nm) and a large specific surface area (200-1000 m) 2 Per g), high porosity: (>95 percent), can effectively inhibit solid heat conduction and gas convection heat transfer, has excellent heat insulation property, is a solid material (normal temperature) with the lowest heat conductivity which is generally accepted at presentThermal conductivity of 0.015W/m.K) [ Paracyanine, Hexia, Chenyongyang, etc., nano-cellulose reinforced SiO 2 Mechanical properties and microstructure of aerogels, bulletin of composite materials, 2018, 35 (9): 2593-2599 ].
Currently, aerogel research has become a concern in all countries of the world, and among them, the more mature research is silica aerogel systems. Because Silica Aerogels have fine particles, large specific surface area, high inter-particle surface energy, and deteriorated nano-pore size and particle size at high temperatures, it is generally believed that conventional Silica Aerogels are used at temperatures no higher than 650 ℃ [ Shi F, Wang L, Liu J, et al.Effect of Heat Treatment on Silica Aerogels prepared by ViaAmphibit Drying, J mater.Sci.Technol.,2007,23(3): 402. 406; jean P, Florence D, Sylvee C, et al, company between registered and com-compressed aerogels, Opt. Mater.,2004(26): 167-.
To improve SiO 2 The high-temperature thermal stability of the aerogel can be improved by introducing metal oxide or adjusting the grain size of the aerogel 2 High temperature thermal stability of aerogels.
In the aspect of introducing metal oxides, patent publication No. CN113716572A relates to a preparation method of an alumina-silica aerogel composite material, after silica gel is prepared, an aluminum sol mixed solution is continuously impregnated on the surface of the silica gel, and a silica aerogel is coated by the alumina aerogel to form a silica-alumina aerogel composite network structure in a composite manner, wherein the silica aerogel network structure can play a role of supporting the alumina aerogel framework, the occurrence of collapse of the alumina aerogel structure at high temperature at present is reduced, the size shrinkage rate is 12-16% after the alumina aerogel is treated at 1000 ℃ for 30min, and the thermal conductivity range of the prepared aerogel felt is 0.021-0.025W/m.K (SiO. 2 Aerogel blanket thermal conductivity not higher than 0.020W/m · K, common general knowledge). Zhang Jun et al adopts sol-gel method to prepare blocky Y 2 O 3 -SiO 2 The result of the aerogel shows that Y is obtained after yttrium oxide is doped 2 O 3 -SiO 2 Aerogels not only with SiO 2 The aerogel has a certain space network structure and higher thermal stabilityAfter heat treatment at 900 ℃ for 2h, 10 wt% of Y 2 O 3 Doped Y 2 O 3 -SiO 2 The aerogel is still in an amorphous state and has a specific surface area of 643.8m 2 (g) [ Zhang Jun, Zhong ya, Shen Xiao Dong, etc. ], Yttrium oxide-doped bulk SiO 2 Preparation and characterization of aerogels, journal of inorganic chemistry 2014, 4 (30): 793-799 ]. Albeit in the conventional SiO 2 The introduction of metal oxides into aerogels can significantly improve their high temperature thermal stability, but can result in a significant increase in thermal conductivity (reducing the thermal insulation properties of the material).
SiO with controllable grain diameter is obtained by adjusting sol-gel preparation process in the aspect of increasing grain diameter of aerogel, Guo construction industry and the like 2 Mixing the sol with fiber to obtain SiO with large particle size 2 Although the high-temperature thermal stability of the aerogel heat insulation composite material is improved, the thermal conductivity of the material (the thermal conductivity at room temperature and 800 ℃ is 0.018W/m · K and 0.074W/m · K, respectively) [ guo jian, zhao ying min, li wen jing, and the like, the preparation of the high-temperature resistant silica aerogel composite material and the research on the thermal conductivity thereof, material introduction, 2021, 35: 90-93 is obviously higher than that of the traditional silicon oxide aerogel heat insulation composite material (the thermal conductivity at room temperature and 800 ℃ is 0.015W/m.K and 0.042W/m.K respectively) [ Von Jian, Gaoqingfu, Von June, and the like, and the fiber reinforced SiO 2 Preparation and performance of aerogel heat-insulation composite material, national defense science and technology university, 2010, 32 (1): 40-44.
In summary, in SiO 2 The metal oxide is doped in the aerogel, the temperature resistance of the silica aerogel heat-insulation composite material obtained by increasing the particle size of the aerogel particles is improved to different degrees, but the matrix (SiO) 2 Aerogel) structure is changed, so that the specific surface area of the silica aerogel is obviously reduced, and the high-temperature thermal conductivity of the prepared silica aerogel thermal insulation composite material is obviously increased.
How to solve the problems of low temperature resistance (traditional silica aerogel material) and high thermal conductivity (doping modification of traditional silica aerogel) of the existing silica aerogel heat-insulating composite material, and the silica aerogel heat-insulating composite material is prepared by mixing SiO with the traditional silica aerogel 2 Al element is partially embedded in molecular chain to inhibit its high molecular weightThe aerogel particles are fused in a warm environment, so that the high-temperature thermal stability of the aerogel particles is improved.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a modified silica aerogel heat insulation composite material with the highest use temperature of 1100 ℃ (which is higher than the temperature resistance of the traditional silica material by 450 ℃), light weight, low heat conductivity, high efficiency heat insulation and high mechanical property, and the preparation method of the composite material is provided, so that the process is simple, the time consumption is short, the cost is low, and the mass production is easy.
Inorganic aluminum and organic silicon are taken as precursors, and the modified silica sol is prepared by adopting an acid-base two-step catalysis method. The modified silica sol is completely infiltrated into the inorganic ceramic fiber prefabricated part by vacuum pressure impregnation, and then the modified silica aerogel heat-insulation composite material is obtained after gel aging and ethanol supercritical drying; the density of the modified silica aerogel heat-insulation composite material is 0.20-0.50 g/cm 3 The temperature can reach 1100 ℃. The thermal conductivity of the modified silica aerogel heat-insulating composite material is only 0.030-0.058W/m.K at 1100 ℃, the shrinkage rate of the material in the thickness direction is 1.2-2.9% after being subjected to radiation heating treatment by a quartz lamp at 1100 ℃/1800s, the back surface temperature is 190-281 ℃, and the stress corresponding to 3% deformation is 0.10-0.55 MPa, so that the modified silica aerogel heat-insulating composite material has high mechanical property, high temperature resistance and excellent heat-insulating property.
The preparation method of the high-temperature-resistant modified silica aerogel heat-insulation composite material comprises the following steps:
step one, preparing modified silica sol:
preparing modified silica sol by using an organic silicon source and an inorganic aluminum source as precursors and adopting an acid-base two-step catalysis method, wherein the organic silicon source comprises the following steps: an inorganic aluminum source: deionized water: anhydrous ethanol: acid: the mass ratio of alkali is 100: 0.02: 30: 140-720: 0.5 to 1.5 x 10 -3 ：0.5～1.5×10 -3 ，
The organic silicon source is any one of ethyl orthosilicate and methyl orthosilicate; the inorganic aluminum source is any one of aluminum chloride and aluminum nitrate; the acid is any one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and acetic acid; the alkali is any one of ammonium carbonate, urea and ammonia water
Step two, preparing a modified silica wet gel/inorganic ceramic fiber prefabricated part:
2.1, according to the volume and the apparent density of the inorganic ceramic fiber prefabricated part designed by a user, multiplying the volume of the inorganic ceramic fiber prefabricated part by the apparent density to obtain the mass of the required inorganic ceramic fiber, wherein the apparent density range of the designed inorganic ceramic fiber prefabricated part is 0.15-0.35 g/cm 3 Preferably, the weighed inorganic ceramic fibers are clamped and fixed by a mould, and the arrangement direction of the inorganic ceramic fibers is perpendicular to the heat flow direction in the heat insulation use process, so that an inorganic ceramic fiber prefabricated part is obtained;
2.2, placing the inorganic ceramic fiber prefabricated part in a sealed container, and impregnating the modified silica sol obtained in the first step in a vacuum pressurization impregnation mode: penetrating modified silica sol into an inorganic ceramic fiber prefabricated member by adopting a vacuum pressure impregnation mode, after the modified silica sol penetrates into the inorganic ceramic fiber prefabricated member, firstly adopting the vacuum impregnation mode, pumping the pressure in a container to-0.09 to-0.1 MPa, penetrating the modified silica sol obtained in the first step into the inorganic ceramic fiber prefabricated member, after the modified silica sol penetrates into the inorganic ceramic fiber prefabricated member, opening a valve to change the pressure in the container to normal pressure, then putting the inorganic ceramic fiber prefabricated member containing the modified silica into a high-pressure tank, filling the pressure of 1.0 to 3.0MPa, keeping the pressure for 1 to 3 hours, standing for 1 to 4 days after pressure relief, aging by using absolute ethyl alcohol (the absolute ethyl alcohol covers the surface of gel) in the standing process, and changing the modified silica sol penetrating into modified silica wet gel, obtaining the modified silica wet gel/inorganic ceramic fiber prefabricated member.
The fiber in the inorganic ceramic fiber prefabricated part is any one of aluminum silicate fiber, quartz fiber, alumina fiber, mullite fiber and zirconia fiber.
Thirdly, ethanol supercritical drying is carried out on the modified silica wet gel/inorganic ceramic fiber prefabricated part:
the modified silica aerogel/inorganic ceramic fiber prefabricated part is subjected to supercritical drying by ethanol, the treatment condition is that absolute ethanol is used as a medium for reinforcing a gel framework, the modified silica aerogel/inorganic ceramic fiber prefabricated part is placed into an autoclave, nitrogen with the pressure of 1.5-2.5 MPa is pre-filled, then the modified silica aerogel/inorganic ceramic fiber prefabricated part is heated to 255-265 ℃ at the speed of 1-5 ℃/min, the temperature is kept for 0.5-8 hours, the pressure is slowly released at the speed of 50-100 kPa/min, and finally the nitrogen is used for blowing for 15-60 minutes, so that the modified silica aerogel heat insulation composite material is obtained.
The high-temperature-resistant modified silica aerogel heat-insulation composite material consists of an inorganic ceramic fiber prefabricated part and a nano porous modified silica aerogel matrix; wherein the inorganic ceramic fiber prefabricated part is composed of inorganic ceramic fibers, and the inorganic ceramic fibers refer to any one of aluminum silicate fibers, quartz fibers, alumina fibers, mullite fibers and zirconia fibers; the inorganic ceramic fiber prefabricated part is formed by laying and arranging inorganic ceramic fibers or weaving fiber bundles, and the apparent density of the inorganic ceramic fiber prefabricated part is 0.15-0.35 g/cm 3 In the meantime.
The modified silica aerogel heat-insulating composite material which is high temperature resistant (the use temperature can reach 1100 ℃), light (the density is low), low in heat conductivity (excellent in heat-insulating property), high in strength and toughness (high in mechanical property), simple and convenient in preparation process, short in time consumption, low in cost and easy to produce in batches and the preparation method thereof are the technical problems which are paid great attention to by the technical personnel in the field.
The invention can achieve the following beneficial effects:
the preparation method is based on a sol-gel technology, takes an organic silicon source and an inorganic aluminum source as precursors, adopts an acid-base two-step catalysis method to prepare modified silica sol, then mixes the modified silica sol with an inorganic ceramic fiber prefabricated member, obtains a modified silica wet gel/inorganic ceramic fiber prefabricated member after gel aging, and obtains the modified silica aerogel heat-insulation composite material after hydrothermal treatment and heat treatment.
Therefore, compared with the prior art, the invention has the following technical effects:
(1) according to the invention, trace aluminum is introduced into the silica aerogel to improve the temperature resistance of the material, and meanwhile, the heat insulation (thermal conductivity), mechanics, density and the like are basically consistent with those of the traditional silica, the obtained modified silica aerogel heat insulation composite material has high use temperature, the highest use temperature can reach 1100 ℃, the modified silica aerogel heat insulation composite material is subjected to radiation heating by a quartz lamp at 1100 ℃ for 1800s, the average linear shrinkage rate of the heat insulation material in the thickness direction is less than or equal to 2.9%, and the back temperature is less than or equal to 281 ℃.
(2) The modified silica aerogel heat-insulating composite material has low heat conductivity, and the heat conductivity is 0.030-0.058W/(m.K) at 1100 ℃, which shows that the modified silica aerogel heat-insulating composite material has excellent heat-insulating property.
(3) The modified silica aerogel heat-insulating composite material has the advantages of lower density, high compressive strength and SiO 2 The density of the aerogel heat-insulation composite material is 0.30-0.50 g/cm 3 The material is adjustable, the room temperature 3% strain corresponding stress is 0.10-0.55 MPa, and the compressive strength of the material can be adjusted according to the actual working condition requirement.
(4) The method has simple preparation process and low cost, and is suitable for large-scale industrial production. According to the method, an organic silicon source and an inorganic aluminum source are used as precursors, an acid-base two-step catalysis method is adopted to prepare modified silica sol, the modified silica sol is infiltrated into an inorganic ceramic fiber prefabricated member through vacuum pressurization impregnation, the modified silica wet gel/inorganic ceramic fiber prefabricated member is obtained through gel aging, and then the modified silica wet gel/inorganic ceramic fiber prefabricated member is subjected to hydrothermal treatment and heat treatment to finally obtain the modified silica aerogel heat-insulation composite material. The method has low requirement on environment, short time consumption of the whole process flow and suitability for industrial production.
Detailed Description
The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.
Example 1:
(1) preparing modified silica sol:
1/2 of the total amount of absolute ethyl alcohol (EtOH) (the total amount of absolute ethyl alcohol required for preparing the modified silica sol) and Tetraethoxysilane (TEOS)) Uniformly mixing the Aluminum Nitrate (AN), slowly dropwise adding nitric acid (HN, the concentration of 1mol/L), stirring for 20 minutes, and continuously stirring for 60 minutes after dropwise adding is finished to obtain a mixed solution A for later use; mixing the rest anhydrous ethanol (total amount of anhydrous ethanol 1/2 at room temperature) with deionized water (H) 2 O) and ammonia water (NH, the concentration is 1mol/L) are mixed and stirred for 20 minutes to obtain a mixed solution B for standby; and dropwise adding the mixed solution B into the mixed solution A, controlling the dropwise adding time to be 30 minutes, stirring and dropwise adding the mixed solution at room temperature in the dropwise adding process, and continuously stirring for 20 minutes after the dropwise adding is finished, wherein the weight ratio of TEOS: AN: h 2 O：EtOH： HN：NH＝100：0.02：30：140：1.0×10 -3 ：1.0×10 -3 Obtaining modified silica sol;
(2) preparing a modified silica wet gel/mullite fiber preform: the apparent density of the mullite fiber prefabricated part is designed to be 0.15g/cm 3 Weighing mullite fibers according to the volume of an inner cavity of the mold, clamping and fixing the mullite fibers by using the mold, and enabling the fiber arrangement direction to be perpendicular to the heat flow direction during heat insulation use to obtain a mullite fiber prefabricated part; placing the prepared mullite fiber prefabricated member in a sealed container, dipping the modified silica sol in a vacuum pressurization dipping mode, firstly, dipping the modified silica sol in the mullite fiber prefabricated member in the vacuum dipping mode, opening a valve to change the pressure in the container to normal pressure after the modified silica sol is dipped in the mullite fiber prefabricated member, then, placing the fiber prefabricated member containing the modified silica sol in a high-pressure kettle, filling nitrogen with the pressure of 1.5MPa, keeping the pressure for 1 hour, standing for 2 days after pressure relief, changing the sol in the mullite fiber prefabricated member into gel in the standing process, pouring absolute ethyl alcohol (the absolute ethyl alcohol covers the surface of the wet gel) to age for 2 days, and obtaining a modified silica wet gel/mullite fiber prefabricated member mixture;
(3) supercritical drying of the modified silica wet gel/mullite fiber preform: the modified silica aerogel/mullite fiber prefabricated member is subjected to supercritical drying treatment under the supercritical drying condition that absolute ethyl alcohol is used as a drying medium, the modified silica aerogel/mullite fiber prefabricated member is placed in an autoclave, 2.0MPa of nitrogen is pre-filled, the temperature is increased to 300 ℃ at the speed of 3 ℃/min, the temperature is kept for 1 hour, the pressure is slowly released at the speed of 100kPa/min, and finally nitrogen is used for purging for 20 minutes, so that the modified silica aerogel heat-insulation composite material is obtained.
Example 1 the Material has a Density of 0.30g/cm 3 The 3% strain stress is 0.10MPa, the thermal conductivity at 1100 ℃ is 0.058W/m.K, the material shrinkage in the thickness direction after the radiation heating treatment at 1100 ℃/1800s by a quartz lamp is 2.0%, and the back surface temperature is 268 ℃.
Examples 2-15 are shown in table 1.
In the first step of preparing the modified silica sol, the dosage of an acid-base catalyst is mainly used for catalyzing sol-gel, the thermophysical property of the composite material is not influenced, the acid and the base are added and stirred for 10-20 minutes to promote the two solutions to be fully mixed uniformly, the thermophysical property of the composite material is not influenced, the stirring is continued for 60-120 minutes after the acid is added and stirred for 10-20 minutes, the aim is to fully hydrolyze the organic silicon source, when the stirring time is more than or equal to 60 minutes, the organic silicon source is considered to be fully hydrolyzed, the thermophysical property of the composite material is not influenced, but the stirring time is less than 60 minutes, the organic silicon is easily hydrolyzed insufficiently, so that the mechanical property, the thermal conductivity and other properties of the prepared composite material are obviously reduced, and the pressure charging and maintaining in a high-pressure tank are carried out to fully infiltrate the sol and the ceramic fiber prefabricated member in the second step of preparing the modified silica wet gel/ceramic fiber prefabricated member, the sol and the ceramic fiber prefabricated part can be promoted to be fully infiltrated as long as enough pressure and pressure maintaining time are kept. In the third step, the supercritical drying and pre-charging of nitrogen and the temperature rise of 255-265 ℃ are carried out to achieve the supercritical state (6MPa, 248 ℃) of absolute ethyl alcohol, and the heat preservation time is carried out to ensure that the supercritical balance in the kettle is achieved. Finally, the speed of air release and nitrogen sweeping has no obvious influence on the performance of the composite material. Therefore, the above conditions have no influence on the properties of the modified silica aerogel thermal insulation composite material, and except for the fiber density, the absolute ethanol dosage (the material prepared by increasing the dosage is subjected to radiation heating by a quartz lamp, the back temperature and the thermal conductivity of the material are increased, the density and the mechanical property are reduced, the influence on the thickness shrinkage rate is small, and vice versa), and the ceramic fiber types, the process parameters adopted in the examples 2 to 15 are shown in table 1, and the test process parameters not listed in the table are the same as those in the example 1.
The density of the high-temperature-resistant modified silica aerogel heat-insulation composite material prepared by the method is 0.30-0.50 g/cm 3 The heat resistance can reach 1100 ℃, the shrinkage rate of the material in the thickness direction after the material is heated by radiation of a quartz lamp at 1100 ℃/1800s is 1.2-2.9%, the back surface temperature is 190-281 ℃, the thermal conductivity at 1100 ℃ is only 0.030-0.058W/m.K, and the 3% deformation stress is 0.10-0.55 MPa (see table 1).
As can be seen from table 1, when the amount of ethanol is not used, the density, strength, back surface temperature and thermal conductivity of the thermal insulation material increase with the increase of the fiber density, and the thickness shrinkage rate slightly decreases, and when the fiber density in the thermal insulation material is the same, the density and mechanical properties of the thermal insulation material decrease with the increase of the amount of ethanol, while the back surface temperature and thermal conductivity of the material increase, and the thickness shrinkage rate is basically unchanged (the thickness shrinkage rate of the aluminum silicate fiber reinforced modified silica aerogel thermal insulation composite material increases slightly, because the examination temperature reaches the design use temperature of the aluminum silicate fiber). Therefore, the thermophysical property (density, mechanical property, thermal conductivity and the like) of the material is regulated and controlled by regulating the fiber density and the using amount of the absolute ethyl alcohol.
TABLE 1 preparation Process parameters and Material Performance parameters of modified silica aerogel thermal insulation composites
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. The preparation method of the modified silica aerogel heat insulation composite material is characterized by comprising the following steps:
step one, preparing modified silica sol: preparing modified silica sol by using an organic silicon source and an inorganic aluminum source as precursors and adopting a two-step catalysis method of acid catalysis and alkali catalysis;
step two, preparing a modified silica wet gel/inorganic ceramic fiber prefabricated part: placing an inorganic ceramic fiber prefabricated part in a sealed container, dipping the modified silica sol obtained in the first step in a vacuum pressure dipping mode, after the modified silica sol permeates into the inorganic ceramic fiber prefabricated part, opening a valve of the sealed container to change the pressure in the container to normal pressure, then placing the inorganic ceramic fiber prefabricated part containing the modified silica into a high-pressure tank, filling the pressure of 1.0-3.0 MPa, maintaining the pressure for 1-3 hours, standing for 1-4 days after pressure relief, covering the gel surface with absolute ethyl alcohol in the standing process for aging, and changing the modified silica sol permeated into the inorganic ceramic fiber prefabricated part into modified silica wet gel to obtain modified silica wet gel/inorganic ceramic fiber prefabricated part;
thirdly, ethanol supercritical drying is carried out on the modified silica wet gel/inorganic ceramic fiber prefabricated part: the modified silica aerogel/inorganic ceramic fiber prefabricated part is subjected to supercritical drying by ethanol, the treatment condition is that absolute ethanol is used as a medium for reinforcing a gel framework, the modified silica aerogel/inorganic ceramic fiber prefabricated part is placed into an autoclave, nitrogen with the pressure of 1.5-2.5 MPa is pre-filled, then the modified silica aerogel/inorganic ceramic fiber prefabricated part is heated to 255-265 ℃ at the speed of 1-5 ℃/min, the temperature is kept for 0.5-8 hours, the pressure is slowly released at the speed of 50-100 kPa/min, and finally the nitrogen is used for blowing for 15-60 minutes, so that the modified silica aerogel heat insulation composite material is obtained.
2. The method of claim 1, wherein the silica aerogel thermal insulation composite is prepared by the method comprising,
the raw materials in the first step also comprise absolute ethyl alcohol and deionized water;
the specific method in the first step is as follows:
uniformly mixing half of the total consumption of the absolute ethyl alcohol with an organic silicon source and an inorganic aluminum source, then dropwise adding an acid catalyst, stirring, and continuously stirring after dropwise adding to obtain a mixed solution A for later use;
mixing the other half of the absolute ethyl alcohol with deionized water and an alkali catalyst, and stirring to obtain a mixed solution B for later use;
and dropwise adding the mixed solution B into the mixed solution A, wherein the dropwise adding time is controlled to be 30 minutes, stirring and dropwise adding the mixed solution at room temperature in the dropwise adding process, and continuing stirring after the dropwise adding is finished.
3. The method of claim 2, wherein the silica aerogel composite is a composite of silica and aerogel insulation,
in the first step: an organic silicon source: an inorganic aluminum source: deionized water: anhydrous ethanol: acid catalyst: the mass ratio of the alkali catalyst is 100: 0.02: 30: (140-720): (0.5 to 1.5) x 10 -3 ：(0.5～1.5)×10 -3 。
4. The method of claim 2,
in the first step: the organic silicon source is tetraethoxysilane or methyl orthosilicate; the inorganic aluminum source is aluminum chloride or aluminum nitrate; the acid catalyst is any one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and acetic acid; the alkali catalyst is any one of ammonium carbonate, urea and ammonia water.
5. The method of claim 2,
in the first step: the dropping speed of the acid catalyst is 10-20 ml/min; adding acid catalyst and stirring for 10-30 min; the dropping speed of the alkali catalyst is 10-20ml/min when the alkali catalyst is mixed with the absolute ethyl alcohol and the deionized water; the time for continuing stirring after the completion of the dropwise addition is 60-120 minutes.
6. The method of claim 1, wherein the silica aerogel thermal insulation composite is prepared by the method comprising,
in the second step, the first step is carried out,
multiplying the preset volume size and the preset apparent density of the inorganic ceramic fiber prefabricated part to obtain the mass of the required inorganic ceramic fiber, wherein the preset apparent density range of the inorganic ceramic fiber prefabricated part is 0.15-0.35 g/cm 3 ；
The arrangement direction of the inorganic ceramic fibers is perpendicular to the thickness direction of the preset volume of the inorganic ceramic fiber prefabricated part.
7. The method of claim 1, wherein the silica aerogel thermal insulation composite is prepared by the method comprising,
in the second step, the first step is carried out,
the technological parameters of the vacuum pressurization impregnation mode are as follows: the vacuum impregnation pressure is-0.09 MPa to-0.1 MPa, and the pressurization impregnation pressure is 1.0 MPa to 3.0 MPa.
8. The method of claim 1, wherein the silica aerogel thermal insulation composite is prepared by the method comprising,
in the second step: the inorganic ceramic fiber is any one of aluminum silicate fiber, quartz fiber, alumina fiber, mullite fiber and zirconia fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210809178.5A CN115108809B (en) | 2022-07-11 | 2022-07-11 | Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210809178.5A CN115108809B (en) | 2022-07-11 | 2022-07-11 | Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115108809A true CN115108809A (en) | 2022-09-27 |
| CN115108809B CN115108809B (en) | 2023-04-07 |
Family
ID=83332714
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210809178.5A Active CN115108809B (en) | 2022-07-11 | 2022-07-11 | Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115108809B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103542230A (en) * | 2013-09-30 | 2014-01-29 | 余煜玺 | Method for preparing aluminum oxide-silicon dioxide flexible aerogel thermal insulation felt |
| WO2015016730A2 (en) * | 2013-08-02 | 2015-02-05 | Active Aerogels, Unipessoal, Lda. | Method for production of flexible panels of hydrophobic aerogel reinforced with fibre felts |
| CN108929074A (en) * | 2018-08-07 | 2018-12-04 | 长沙开润新材料科技有限公司 | A kind of silicon dioxide aerogel heat-insulating composite material plate and preparation method thereof |
| CN111302827A (en) * | 2020-04-10 | 2020-06-19 | 中国人民解放军国防科技大学 | Preparation method of high-temperature-resistant fiber-reinforced silica aerogel heat-insulation composite material |
| CN114100534A (en) * | 2021-11-12 | 2022-03-01 | 中国科学技术大学先进技术研究院 | Preparation method of silicon-aluminum binary aerogel composite material |
-
2022
- 2022-07-11 CN CN202210809178.5A patent/CN115108809B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015016730A2 (en) * | 2013-08-02 | 2015-02-05 | Active Aerogels, Unipessoal, Lda. | Method for production of flexible panels of hydrophobic aerogel reinforced with fibre felts |
| CN103542230A (en) * | 2013-09-30 | 2014-01-29 | 余煜玺 | Method for preparing aluminum oxide-silicon dioxide flexible aerogel thermal insulation felt |
| CN108929074A (en) * | 2018-08-07 | 2018-12-04 | 长沙开润新材料科技有限公司 | A kind of silicon dioxide aerogel heat-insulating composite material plate and preparation method thereof |
| CN111302827A (en) * | 2020-04-10 | 2020-06-19 | 中国人民解放军国防科技大学 | Preparation method of high-temperature-resistant fiber-reinforced silica aerogel heat-insulation composite material |
| CN114100534A (en) * | 2021-11-12 | 2022-03-01 | 中国科学技术大学先进技术研究院 | Preparation method of silicon-aluminum binary aerogel composite material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115108809B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101948296B (en) | High-performance thermal insulation material and preparation method thereof | |
| CN101698592B (en) | Silicon-aluminium aerogel composite material and manufacturing method thereof | |
| CN106946579B (en) | Preparation method of 1500 ℃ resistant light rigid ceramic fiber heat insulation tile | |
| CN111302827A (en) | Preparation method of high-temperature-resistant fiber-reinforced silica aerogel heat-insulation composite material | |
| He et al. | Large-scale and ultra-low thermal conductivity of ZrO2 fibrofelt/ZrO2-SiO2 aerogels composites for thermal insulation | |
| CN109251005B (en) | Preparation method of reinforced silica aerogel material | |
| CN101698583B (en) | Multi-element aerogel composite material and preparation method thereof | |
| CN106809842B (en) | A kind of preparation method of high temperature oxidation resisting Silica Aerogels | |
| CN104355647B (en) | A kind of Cr2O3Doping silicon dioxide aerogel material and preparation method thereof | |
| CN110790530A (en) | High-strength nano heat-insulating material and preparation method thereof | |
| CN110483082A (en) | A kind of micro-nano multi-scale nanometer heat insulation material and preparation method thereof | |
| CN112592150B (en) | Preparation method of alumina-silica aerogel heat-insulation composite material | |
| CN108774072B (en) | Rigid heat insulation tile and preparation method thereof | |
| CN105780126B (en) | A kind of preparation method of the porous mullite formed by generated in-situ whisker overlap joint | |
| CN109095883B (en) | Fiber-reinforced alumina-silica binary aerogel composite material and preparation method thereof | |
| CN106957179A (en) | A kind of SiBN fiber reinforcements SiO2‑BN‑Al2O3The preparation method of wave-penetrating composite material | |
| CN111018473B (en) | Heat insulation material containing gradient-distributed anti-radiation agent and preparation method and application thereof | |
| CN101948297B (en) | Autocatalytic aerogel heat insulation composite material and preparation method thereof | |
| CN112778017A (en) | Ceramic fiber composite aerogel thermal insulation material and preparation method thereof | |
| CN106854086A (en) | A kind of resistant to elevated temperatures mullite-type aerogel composite and preparation method thereof | |
| CN112079618A (en) | Preparation method of modified silica aerogel heat insulation sheet | |
| CN111362693A (en) | Preparation method and application of zirconium dioxide porous ceramic material | |
| CN115108809B (en) | Preparation method of high-temperature-resistant modified silica aerogel heat-insulation composite material | |
| CN112830760B (en) | Heat-insulating and high-temperature-resistant aerogel gradient composite material and preparation method thereof | |
| CN108439964B (en) | Nano-pore ceramic heat-insulating coiled material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |