WO2023226710A1 - Method for preparing silicon dioxide aerogel or composite product thereof - Google Patents

Method for preparing silicon dioxide aerogel or composite product thereof Download PDF

Info

Publication number
WO2023226710A1
WO2023226710A1 PCT/CN2023/092220 CN2023092220W WO2023226710A1 WO 2023226710 A1 WO2023226710 A1 WO 2023226710A1 CN 2023092220 W CN2023092220 W CN 2023092220W WO 2023226710 A1 WO2023226710 A1 WO 2023226710A1
Authority
WO
WIPO (PCT)
Prior art keywords
acid
gel
water glass
mixed liquid
composite product
Prior art date
Application number
PCT/CN2023/092220
Other languages
French (fr)
Chinese (zh)
Inventor
熊风
陈翠翠
周杰
杨志国
郭卫疆
田�健
徐妥夫
周蕊
Original Assignee
中化学华陆新材料有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 中化学华陆新材料有限公司 filed Critical 中化学华陆新材料有限公司
Publication of WO2023226710A1 publication Critical patent/WO2023226710A1/en

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
    • C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/04—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by dissolving-out added substances
    • 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00017—Aspects relating to the protection of the environment
    • 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/20—Resistance against chemical, physical or biological attack
    • C04B2111/27—Water resistance, i.e. waterproof or water-repellent 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/20—Resistance against chemical, physical or biological attack
    • C04B2111/28—Fire resistance, i.e. materials resistant to accidental fires or high temperatures
    • 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/40—Porous or lightweight 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

Definitions

  • the present disclosure relates to methods for preparing silica aerogels, and in particular, to a low-cost and rapid method for preparing silica aerogels or composite products thereof.
  • Aerogel is a solid material with excellent thermal insulation properties. It has special microstructures such as high specific surface area, nanoscale pores, and low density. Based on these structures, it shows excellent thermal properties. Its thermal conductivity is as low as 0.012w/mk, its density is as low as 0.16mg/cm 3 , its specific surface area is 400-1000m 2 /g, and its porosity is 90-99.8%. Its chemical properties are stable, and 99% of its internal volume is composed of gas. Composition, it is the smallest dense solid known so far.
  • the main technologies used in industrialization are supercritical drying technology and normal pressure drying technology.
  • Other technologies that have not yet achieved mass production include vacuum freeze drying, subcritical drying, etc.
  • Supercritical drying technology is the earliest technology to realize batch preparation of aerogels. It is already relatively mature and is currently a technology used by many aerogel companies at home and abroad. Supercritical drying allows the gel to maintain an intact skeleton structure during the drying process.
  • Atmospheric pressure drying technology is a new type of airgel preparation technology. It is currently the most actively researched and most potential airgel batch production technology. The principle is to use hydrophobic groups to modify the gel skeleton to prevent the silicone hydroxyl groups on the surface of the gel holes from combining with each other and improve the elasticity. At the same time, a low surface tension liquid is used to replace the water or ethanol with a high specific surface area of the gel so that it can be used in normal conditions. Airgel materials with excellent performance are obtained by direct drying under pressure.
  • Patent CN104030301A discloses a silica aerogel material and its preparation method, especially involving the use of water glass as the silicon source, and the addition of acid-containing organic solvents that do not contain chloride ions and fluoride ions to generate sodium ions, potassium ions and other The precipitation of metal salt ions is then removed by filtration to obtain high-purity silica sol, and then through the sol-gel, aging, acidification, modification, and drying processes, the silica aerogel material is obtained.
  • the process of preparing silica aerogel materials described in this patent includes sol-gel, aging, acidification, modification and drying. The process is relatively complicated.
  • This disclosure only requires one step of catalyzing gel, one step of substitution modification, and then through Silica airgel materials can be obtained by drying under normal pressure, and the overall process is different. Moreover, the sol described in this patent needs to undergo a two-step treatment of acid and alkali to obtain a gel. After gelation, it still needs to undergo further acidification treatment. This disclosure only requires one step of acid catalytic gelation. The conditions for obtaining gel are different between the two, and this invention It is disclosed that no further acidification of the gel is required.
  • Patent CN105819457A discloses a method for preparing silica aerogels. It uses an acid-base catalyzed sol-gel two-step method to prepare silica wet gel, and then undergoes aging, a one-step solvent exchange-surface modification process, and finally often Press drying Silica aerogels with low density and high specific surface area were prepared. This patent adds silicon source, absolute ethanol and deionized water into a container.
  • silicon source: absolute ethanol: deionized water is 1: (3-7): (1-4), and stirs for 5- 15 minutes, mix well; add an acidic catalyst, adjust the pH to 4-6, stir for 10-30 minutes, distill the ethanol under reduced pressure to obtain silica sol; then redissolve the silica sol in absolute ethanol 1-2 times the volume of the silica sol , after dissolving, add deionized water 1-4 times the volume of the silica sol, add an alkaline catalyst, adjust the pH to 8-10, and let it stand to gel the silica sol to form a wet gel.
  • the present disclosure obtains wet gel through a one-step acid catalysis method, without the need for a two-step acid-base catalytic gel, and the process is simple; in addition, the silicon source is water glass, the raw materials are cheap, and the sol-gel system is an aqueous solution, which does not involve the introduction of ethanol. , the process is safer and suitable for industrial production.
  • Patent CN106865558A provides a method for preparing silica aerogel under normal pressure and the prepared silica aerogel, which includes the following steps: (1) After diluting the inorganic silicon source with water, it is mixed with acid to perform acid-base treatment. Reaction to obtain silicic acid sol; (2) Gel the silicic acid sol, and then perform aging treatment on the gel after the gel is formed to obtain a wet gel; (3) Add a modifier base solution to the wet gel Until the wet gel is completely infiltrated, add concentrated acid or concentrated alkali solution to the system, and perform surface modification treatment under closed conditions or in a device with condensation reflux equipment until the gel is completely modified from hydrophilic.
  • the property is hydrophobic; (4) drying the modified aerogel obtained in step (3) to obtain silica aerogel; wherein, the method also includes adding silica sol to the silicic acid sol obtained in step (1). And/or the operation of adding a polar organic solvent or a polar organic solvent aqueous solution to the system before adding concentrated acid or concentrated alkali in step (3).
  • This patent obtains silicic acid sol through acid treatment, and requires adding a polar organic solvent or polar organic solvent aqueous solution to the obtained silicic acid sol, and further gel aging treatment is required to obtain a wet gel.
  • the main problems in preparing silica aerogels at present are high production costs, technical difficulties, poor product stability, and the supercritical drying method is complex and risky, so it is not conducive to production and application.
  • the present disclosure provides a low-cost and rapid method for preparing silica aerogels or composite products thereof, using a low-cost, simple and high-safety sol-gel method and a normal pressure drying process to prepare silica aerogels.
  • Adhesive composite materials have been verified by scaled-up production and the product quality meets the requirements of Class A airgel composite products defined by the national airgel standard GB/T34336-2017.
  • the present disclosure provides a method for preparing silica aerogel or composite products thereof, including: providing water glass as a silicon source, and mixing water glass and desalted water at a volume ratio of 1:0.3 to 8 to form water glass.
  • Aqueous solution the water glass aqueous solution is catalyzed to gel through an acid solution in one step to form a wet gel, so that the water glass aqueous solution is optionally compounded with the carrier during the catalytic gel process, the wet gel is modified by a one-step displacement of the organic mixture, and is dried under constant pressure Preparation of silica aerogel or its composite Taste.
  • the one-step displacement modification process is an organic mixed liquid soaking process.
  • the organic mixed liquid is a mixed liquid of alcohol liquid, organic solvent, and hydrophobic modifier, wherein the alcohol liquid is one or two of methanol and ethanol, and the organic solvent It is one of n-hexane, hexamethyldisiloxane and n-heptane.
  • the hydrophobic modifier is trichloromethylsilane, dimethyldichlorosilane, hexamethyldisilazane, methyltrimethoxy One or more of methylsilane, methyltriethoxysilane, and trimethylchlorosilane.
  • the modulus of the water glass is 2.6 to 3.4, and the volume ratio of water glass to desalted water is preferably 1:1 to 5.
  • the acid solution is an aqueous acid solution of 0.1 mol/l to 10 mol/l, preferably 1 mol/l to 5 mol/l, wherein the acid is one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and oxalic acid.
  • the composite carrier is one of glass fiber mat, basalt fiber mat or ceramic fiber mat.
  • the drying temperature of the normal pressure drying is 50°C to 300°C, preferably 90°C to 150°C; the drying time is 30 minutes to 12 hours, preferably 1.5 to 5 hours.
  • volume mixing ratio of alcohol liquid, organic solvent and hydrophobic modifier in the organic mixed liquid is 1:0.5 ⁇ 20:0.001 ⁇ 1, preferably 1:3 ⁇ 10:0.006 ⁇ 0.3.
  • volume ratio of the organic mixed liquid to the silica aerogel or its composite product is 1:0.1-5, preferably 1:0.2-2.
  • the temperature of the one-step substitution modification is 30°C to 70°C, preferably 40°C to 60°C; the time of the one-step substitution modification is 0.5 to 48 hours, preferably 1 to 5 hours.
  • the temperature of the one-step catalytic gel is 0°C to 60°C, and the pH value range controlled during the catalytic gel process is 3 to 11.
  • the present disclosure provides a silica aerogel or a composite product thereof, which is prepared by the method described in the first aspect.
  • the silica airgel composite material prepared by the above method has the characteristics of high specific surface area, excellent hydrophobicity and low thermal conductivity, and has good formability. Functional materials with different properties and structures can be prepared as needed. .
  • a wet gel is obtained through one-step acid catalysis without adding polar organic solvents or polar organic solvent aqueous solutions.
  • the sol-gel process is safer; in addition, the present disclosure does not require the addition of polar organic solvents or polar organic solvent aqueous solutions.
  • wet gel can be obtained, and the process is simple and convenient; the sol-gel process of the present disclosure is a water system, the cost of raw materials is low, the process is safe, and it is suitable for industrial production.
  • the patented modification process needs to be carried out under the conditions of concentrated acid or concentrated alkali liquid, which requires high corrosion resistance of the equipment.
  • the modified liquid is replaced and modified in one step.
  • the modification process is a liquid solvent immersion process without the need for concentrated acid or concentrated alkali. Concentrated lye conditions.
  • the present disclosure has the following beneficial effects.
  • This disclosure adopts a normal pressure drying process, which is different from the supercritical drying process.
  • this disclosure uses water glass as the silicon source, does not require water washing to remove salt, uses methanol alcohol washing for replacement, and uses dimethyl Dichlorosilane or methyltrichlorosilane, as a hydrophobic modifier, reduces raw material costs, simplifies the process, and shortens the entire process time.
  • the entire process flow of this disclosure is under normal pressure, and the composite gel requires direct contact.
  • the sol-gel solvent is an aqueous solution, which is harmless to the human body. Alcohol washing, modification and replacement are carried out in a closed environment to avoid direct contact with personnel.
  • the production process Safe and harmless. There is no need for water washing and desalination during the production process, which solves the problem of large amounts of wastewater treatment caused by the need to produce 2 to 6 tons of wastewater to produce 1 cubic meter of finished product using the traditional atmospheric pressure process, and is environmentally friendly.
  • This project uses cheap water glass as the silicon source.
  • the cost of silicon source raw materials can be reduced by 10 to 30 times.
  • the price of water glass silicon source is stable and is not affected by market fluctuations.
  • the unit price of the modifier raw materials is reduced to 1/3 to 1/8.
  • the modifier dosage can be as low as 0.5%, and the cost of modifier usage is reduced. By 1/10 ⁇ 1/30, the comprehensive hydrophobic modification cost will drop to 10% ⁇ 20%.
  • This technology has obvious raw material cost advantages.
  • the disclosure only requires one step of replacement to quickly prepare silica aerogel or composite products thereof, eliminating the long and multiple solvent replacement processes required by the traditional normal pressure drying process, and the overall process is simple.
  • Figure 1 is a process flow diagram of the present disclosure.
  • Figure 2 is a graph showing the water contact angle test results of the silica airgel glass fiber composite mat made in Example 1 of the present disclosure.
  • Figure 3 is a graph showing the water contact angle test results of the silica basalt fiber composite felt produced in Example 2 of the present disclosure.
  • Figure 4 is the test report of Example 2.
  • Figure 5 is an appearance view of the silica aerogel produced in Example 3 of the present disclosure.
  • Figure 6 is the BET multi-point method fitting straight line and the BET multi-point method test results of the silica aerogel produced in Example 3.
  • Figure 7 is the BET multi-point method fitting straight line and the BET multi-point method test report of the silica aerogel produced in Example 3.
  • the present disclosure provides a low-cost and rapid method for preparing silica aerogel or composite products thereof.
  • water glass is used as the silicon source, and water glass and desalted water are mixed with a volume ratio of 1:0.3 to 8 to form a water glass aqueous solution.
  • the water glass aqueous solution is catalyzed by an acid solution in one step to form a wet gel.
  • the wet gel is modified in one step by displacement of the organic mixed liquid and dried under constant pressure to prepare silica aerogel or its composite products.
  • the treated gel was dried in a forced air oven at 180°C for 2 hours to obtain silica aerogel.
  • the water contact angle of the prepared silica aerogel is 158.122°
  • the BET specific surface area is 960.2108m 2 /g
  • the block shape is good.
  • the appearance is shown in Figure 5.
  • the BET multi-point method fitting straight line and BET multi-point method test results of the silica aerogel made in Example 3 of the present disclosure are shown in Figure 6.
  • the ratio of the silica aerogel made in Example 3 of the present disclosure is The comprehensive data report of the surface area test is shown in Figure 7.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Silicon Compounds (AREA)

Abstract

Disclosed in the present disclosure are a method for rapidly preparing a silicon dioxide aerogel or a composite product thereof at low cost, and the silicon dioxide aerogel or he composite product thereof prepared according to the method. The method comprises: providing sodium silicate as a silicon source, and mixing the sodium silicate and desalted water at a volume ratio of 1:0.3-8 to form an aqueous sodium silicate solution, carrying out one-step catalytic gelatinization on the aqueous sodium silicate solution by means of an acid solution to form a wet gel, and optionally, compounding the aqueous sodium silicate solution with a carrier in the catalytic gelatinization process, and carrying out one-step replacement modification on the wet gel by means of an organic mixed solution, and carrying out ambient pressure drying to obtain the silicon dioxide aerogel or the composite product thereof.

Description

制备二氧化硅气凝胶或其复合制品的方法Method for preparing silica aerogel or composite products thereof 技术领域Technical field
本公开涉及制备二氧化硅气凝胶的方法，尤其是涉及一种低成本快速制备二氧化硅气凝胶或其复合制品的方法。The present disclosure relates to methods for preparing silica aerogels, and in particular, to a low-cost and rapid method for preparing silica aerogels or composite products thereof.
背景技术Background technique
气凝胶是一种隔热性能优异的固体材料，具有高比表面积，纳米级孔洞，低密度等特殊的微观结构，基于这些结构在热学方面表现出优异的性能。它的导热率低至0.012w/mk、密度低至0.16mg/cm3、比表面积在400-1000m2/g、孔隙率为90-99.8％，它的化学性能稳定，内部体积99％由气体组成，是目前已知密度最小的固体。Aerogel is a solid material with excellent thermal insulation properties. It has special microstructures such as high specific surface area, nanoscale pores, and low density. Based on these structures, it shows excellent thermal properties. Its thermal conductivity is as low as 0.012w/mk, its density is as low as 0.16mg/cm 3 , its specific surface area is 400-1000m 2 /g, and its porosity is 90-99.8%. Its chemical properties are stable, and 99% of its internal volume is composed of gas. Composition, it is the smallest dense solid known so far.
目前产业化中主要使用的技术是超临界干燥技术和常压干燥技术，其他尚未实现批量生产技术还有真空冷冻干燥、亚临界干燥等。At present, the main technologies used in industrialization are supercritical drying technology and normal pressure drying technology. Other technologies that have not yet achieved mass production include vacuum freeze drying, subcritical drying, etc.
超临界干燥技术是最早实现批量制备气凝胶技术，已经较为成熟，也是目前国内外气凝胶企业采用较多的技术。超临界干燥可以实现凝胶在干燥过程中保持完好骨架结构。Supercritical drying technology is the earliest technology to realize batch preparation of aerogels. It is already relatively mature and is currently a technology used by many aerogel companies at home and abroad. Supercritical drying allows the gel to maintain an intact skeleton structure during the drying process.
常压干燥技术是一种新型的气凝胶制备工艺，是当前研究最活跃，发展潜力最大的气凝胶批产技术。其原理是采用疏水基团对凝胶骨架进行改性，避免凝胶孔洞表面的硅羟基相互结合并提高弹性，同时采用低表面张力液体置换凝胶原来高比表面积的水或乙醇从而可以在常压下直接干燥获得性能优异的气凝胶材料。Atmospheric pressure drying technology is a new type of airgel preparation technology. It is currently the most actively researched and most potential airgel batch production technology. The principle is to use hydrophobic groups to modify the gel skeleton to prevent the silicone hydroxyl groups on the surface of the gel holes from combining with each other and improve the elasticity. At the same time, a low surface tension liquid is used to replace the water or ethanol with a high specific surface area of the gel so that it can be used in normal conditions. Airgel materials with excellent performance are obtained by direct drying under pressure.
专利CN104030301A公开了一种二氧化硅气凝胶材料及其制备方法，特别涉及以水玻璃为硅源，通过添加不含氯离子和氟离子的含酸有机溶剂，生成钠离子、钾离子和其他金属盐离子的沉淀，再经过滤的方式去除沉淀，获得高纯硅溶胶，之后经溶胶-凝胶、老化、酸化、改性、干燥过程，获得二氧化硅气凝胶材料。该专利所述制备二氧化硅气凝胶材料的过程，包括溶胶-凝胶、老化、酸化、改性和干燥，过程比较繁多，本公开只需一步催化凝胶，一步置换改性，再通过常压干燥即可获得二氧化硅气凝胶材料，整体工艺过程不相同。且该专利所述溶胶需经过酸碱两步处理获得凝胶，凝胶后仍然需要经过进一步酸化处理，本公开只需一步酸液催化凝胶，两者获取凝胶的条件不相同，且本公开无须进一步对凝胶酸化处理。Patent CN104030301A discloses a silica aerogel material and its preparation method, especially involving the use of water glass as the silicon source, and the addition of acid-containing organic solvents that do not contain chloride ions and fluoride ions to generate sodium ions, potassium ions and other The precipitation of metal salt ions is then removed by filtration to obtain high-purity silica sol, and then through the sol-gel, aging, acidification, modification, and drying processes, the silica aerogel material is obtained. The process of preparing silica aerogel materials described in this patent includes sol-gel, aging, acidification, modification and drying. The process is relatively complicated. This disclosure only requires one step of catalyzing gel, one step of substitution modification, and then through Silica airgel materials can be obtained by drying under normal pressure, and the overall process is different. Moreover, the sol described in this patent needs to undergo a two-step treatment of acid and alkali to obtain a gel. After gelation, it still needs to undergo further acidification treatment. This disclosure only requires one step of acid catalytic gelation. The conditions for obtaining gel are different between the two, and this invention It is disclosed that no further acidification of the gel is required.
专利CN105819457A公开了一种二氧化硅气凝胶的制备方法，采用酸碱催化溶胶-凝胶两步法制备二氧化硅湿凝胶，再经老化，一步溶剂交换-表面改性过程，最后经常压干燥制 备出具有低密度高比表面积的二氧化硅气凝胶。该专利通过将硅源、无水乙醇和去离子水加入容器中，按体积比，硅源∶无水乙醇∶去离子水为1∶(3-7)∶(1-4)，搅拌5-15min，混匀；加入酸性催化剂，调节pH为4-6，搅拌10-30min，减压蒸馏除去乙醇，得到硅溶胶；再将硅溶胶重新溶解于硅溶胶体积1-2倍量的无水乙醇，溶解后再加入硅溶胶体积1-4倍量的去离子水，加入碱性催化剂，调节pH为8-10，静置，使硅溶胶凝胶化形成湿凝胶。本公开通过酸液一步催化法获得湿凝胶，无需通过酸碱两步催化凝胶，工艺过程简单；另外硅源为水玻璃，原料廉价，溶胶-凝胶体系为水溶液，不涉及乙醇的引入，工艺过程更安全，适合工业化生产。Patent CN105819457A discloses a method for preparing silica aerogels. It uses an acid-base catalyzed sol-gel two-step method to prepare silica wet gel, and then undergoes aging, a one-step solvent exchange-surface modification process, and finally often Press drying Silica aerogels with low density and high specific surface area were prepared. This patent adds silicon source, absolute ethanol and deionized water into a container. According to the volume ratio, silicon source: absolute ethanol: deionized water is 1: (3-7): (1-4), and stirs for 5- 15 minutes, mix well; add an acidic catalyst, adjust the pH to 4-6, stir for 10-30 minutes, distill the ethanol under reduced pressure to obtain silica sol; then redissolve the silica sol in absolute ethanol 1-2 times the volume of the silica sol , after dissolving, add deionized water 1-4 times the volume of the silica sol, add an alkaline catalyst, adjust the pH to 8-10, and let it stand to gel the silica sol to form a wet gel. The present disclosure obtains wet gel through a one-step acid catalysis method, without the need for a two-step acid-base catalytic gel, and the process is simple; in addition, the silicon source is water glass, the raw materials are cheap, and the sol-gel system is an aqueous solution, which does not involve the introduction of ethanol. , the process is safer and suitable for industrial production.
专利CN106865558A提供一种常压制备二氧化硅气凝胶的方法及制得的二氧化硅气凝胶，其包括以下步骤：(1)将无机硅源用水稀释后，与酸混合以进行酸碱反应，得到硅酸溶胶；(2)将硅酸溶胶进行凝胶，凝胶形成后再对该凝胶进行老化处理，得到湿凝胶；(3)向湿凝胶中加入改性剂基液至该湿凝胶完全浸润，再向体系中加入浓酸或浓碱液，并在密闭条件下或者在带有冷凝回流设备的装置中进行表面改性处理，直至该凝胶全部由亲水改性为疏水；(4)对步骤(3)中得到的改性后的气凝胶进行干燥处理，得到二氧化硅气凝胶；其中，该方法还包括向步骤(1)得到的硅酸溶胶和/或向步骤(3)加入浓酸或浓碱液前的体系中加入极性有机溶剂或极性有机溶剂水溶液的操作。该专利通过酸处理得到硅酸溶胶，且需要在得到的硅酸溶胶中，加入极性有机溶剂或极性有机溶剂水溶液，并需要进一步凝胶老化处理得到湿凝胶。Patent CN106865558A provides a method for preparing silica aerogel under normal pressure and the prepared silica aerogel, which includes the following steps: (1) After diluting the inorganic silicon source with water, it is mixed with acid to perform acid-base treatment. Reaction to obtain silicic acid sol; (2) Gel the silicic acid sol, and then perform aging treatment on the gel after the gel is formed to obtain a wet gel; (3) Add a modifier base solution to the wet gel Until the wet gel is completely infiltrated, add concentrated acid or concentrated alkali solution to the system, and perform surface modification treatment under closed conditions or in a device with condensation reflux equipment until the gel is completely modified from hydrophilic. The property is hydrophobic; (4) drying the modified aerogel obtained in step (3) to obtain silica aerogel; wherein, the method also includes adding silica sol to the silicic acid sol obtained in step (1). And/or the operation of adding a polar organic solvent or a polar organic solvent aqueous solution to the system before adding concentrated acid or concentrated alkali in step (3). This patent obtains silicic acid sol through acid treatment, and requires adding a polar organic solvent or polar organic solvent aqueous solution to the obtained silicic acid sol, and further gel aging treatment is required to obtain a wet gel.
目前制备二氧化硅气凝胶的主要问题是生产成本较高，技术难度较大，产品稳定性差，且超临界干燥方法操作复杂风险高等，因此不利于生产应用。The main problems in preparing silica aerogels at present are high production costs, technical difficulties, poor product stability, and the supercritical drying method is complex and risky, so it is not conducive to production and application.
发明内容Contents of the invention
本公开提供了一种低成本快速制备二氧化硅气凝胶或其复合制品的方法，采用低成本、简单化和安全系数高的溶胶-凝胶法和常压干燥工艺制备二氧化硅气凝胶复合材料，经放大化生产验证，产品质量满足气凝胶国家标准GB/T34336-2017定义的A级气凝胶复合产品的要求。The present disclosure provides a low-cost and rapid method for preparing silica aerogels or composite products thereof, using a low-cost, simple and high-safety sol-gel method and a normal pressure drying process to prepare silica aerogels. Adhesive composite materials have been verified by scaled-up production and the product quality meets the requirements of Class A airgel composite products defined by the national airgel standard GB/T34336-2017.
本公开在一方面提供了一种制备二氧化硅气凝胶或其复合制品的方法，包括：提供水玻璃作为硅源，将水玻璃与脱盐水以体积比1:0.3～8混合形成水玻璃水溶液，使水玻璃水溶液经酸溶液一步催化凝胶，形成湿凝胶，使水玻璃水溶液在催化凝胶过程可选地与载体复合，湿凝胶通过有机混合液一步置换改性，经常压干燥制得二氧化硅气凝胶或其复合制 品。In one aspect, the present disclosure provides a method for preparing silica aerogel or composite products thereof, including: providing water glass as a silicon source, and mixing water glass and desalted water at a volume ratio of 1:0.3 to 8 to form water glass. Aqueous solution, the water glass aqueous solution is catalyzed to gel through an acid solution in one step to form a wet gel, so that the water glass aqueous solution is optionally compounded with the carrier during the catalytic gel process, the wet gel is modified by a one-step displacement of the organic mixture, and is dried under constant pressure Preparation of silica aerogel or its composite Taste.
进一步地，一步置换改性过程为有机混合液浸泡过程，有机混合液为醇液、有机溶剂、疏水改性剂的混合液，其中醇液为甲醇、乙醇中的一种或两种，有机溶剂为正己烷、六甲基二硅氧烷、正庚烷中的一种，疏水改性剂为三氯甲基硅烷、二甲基二氯硅烷、六甲基二硅氮烷、甲基三甲氧基硅烷、甲基三乙氧基硅烷、三甲基氯硅烷中的一种或多种。Further, the one-step displacement modification process is an organic mixed liquid soaking process. The organic mixed liquid is a mixed liquid of alcohol liquid, organic solvent, and hydrophobic modifier, wherein the alcohol liquid is one or two of methanol and ethanol, and the organic solvent It is one of n-hexane, hexamethyldisiloxane and n-heptane. The hydrophobic modifier is trichloromethylsilane, dimethyldichlorosilane, hexamethyldisilazane, methyltrimethoxy One or more of methylsilane, methyltriethoxysilane, and trimethylchlorosilane.
进一步地，所述水玻璃的模数为2.6～3.4，其中，水玻璃与脱盐水体积比优选1:1～5。Further, the modulus of the water glass is 2.6 to 3.4, and the volume ratio of water glass to desalted water is preferably 1:1 to 5.
进一步地，酸溶液为0.1mol/l～10mol/l、优选1mol/l～5mol/l的酸的水溶液，其中酸为盐酸、硫酸、硝酸、磷酸、草酸中的一种或多种。Further, the acid solution is an aqueous acid solution of 0.1 mol/l to 10 mol/l, preferably 1 mol/l to 5 mol/l, wherein the acid is one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and oxalic acid.
进一步地，所述复合载体为玻璃纤维毡、玄武岩纤维毡或陶瓷纤维毡中的一种。Further, the composite carrier is one of glass fiber mat, basalt fiber mat or ceramic fiber mat.
进一步地，所述常压干燥的干燥温度为50℃～300℃，优选90℃～150℃；干燥时间为30分钟～12小时，优选1.5～5小时。Further, the drying temperature of the normal pressure drying is 50°C to 300°C, preferably 90°C to 150°C; the drying time is 30 minutes to 12 hours, preferably 1.5 to 5 hours.
进一步地，所述有机混合液中醇液、有机溶剂、疏水改性剂的体积混合比例为1:0.5～20：0.001～1，优选1:3～10：0.006～0.3。Further, the volume mixing ratio of alcohol liquid, organic solvent and hydrophobic modifier in the organic mixed liquid is 1:0.5~20:0.001~1, preferably 1:3~10:0.006~0.3.
进一步地，有机混合液与二氧化硅气凝胶或其复合制品的体积比为1:0.1～5，优选1:0.2～2。Further, the volume ratio of the organic mixed liquid to the silica aerogel or its composite product is 1:0.1-5, preferably 1:0.2-2.
进一步地，一步置换改性的温度为30℃～70℃，优选40℃～60℃；一步置换改性的时间为0.5～48小时，优选1～5小时。Further, the temperature of the one-step substitution modification is 30°C to 70°C, preferably 40°C to 60°C; the time of the one-step substitution modification is 0.5 to 48 hours, preferably 1 to 5 hours.
进一步地，所述一步催化凝胶的温度为0℃～60℃，催化凝胶过程控制PH值范围为3～11。Further, the temperature of the one-step catalytic gel is 0°C to 60°C, and the pH value range controlled during the catalytic gel process is 3 to 11.
本公开在第二方面提供了一种二氧化硅气凝胶或其复合制品，该制品是由第一方面所述的方法制备的。In a second aspect, the present disclosure provides a silica aerogel or a composite product thereof, which is prepared by the method described in the first aspect.
通过上述方法所制得的二氧化硅气凝胶复合材料具有高比表面积、优良的疏水性和低热导率等特性，具有良好的成型性，可根据需要制备出不同性能和结构的功能性材料。The silica airgel composite material prepared by the above method has the characteristics of high specific surface area, excellent hydrophobicity and low thermal conductivity, and has good formability. Functional materials with different properties and structures can be prepared as needed. .
与现有技术相比，在本公开的技术方案中，经一步酸液催化得到湿凝胶，无需添加极性有机溶剂或极性有机溶剂水溶液，溶胶-凝胶过程更安全；此外本公开无需进一步的凝胶和老化处理，即可得到湿凝胶，过程简单方便；本公开溶胶-凝胶过程为水体系，原料成本低廉，工艺过程安全，适合工业化生产。该专利改性过程需在浓酸或浓碱液的条件下，对设备耐腐蚀要求较高，本公开，经过改性液一步置换改性，改性过程为液体溶剂浸泡过程，无需浓酸或浓碱液条件。Compared with the existing technology, in the technical solution of the present disclosure, a wet gel is obtained through one-step acid catalysis without adding polar organic solvents or polar organic solvent aqueous solutions. The sol-gel process is safer; in addition, the present disclosure does not require the addition of polar organic solvents or polar organic solvent aqueous solutions. After further gel and aging treatment, wet gel can be obtained, and the process is simple and convenient; the sol-gel process of the present disclosure is a water system, the cost of raw materials is low, the process is safe, and it is suitable for industrial production. The patented modification process needs to be carried out under the conditions of concentrated acid or concentrated alkali liquid, which requires high corrosion resistance of the equipment. In this disclosure, the modified liquid is replaced and modified in one step. The modification process is a liquid solvent immersion process without the need for concentrated acid or concentrated alkali. Concentrated lye conditions.
具体地，本公开具有以下有益效果。 Specifically, the present disclosure has the following beneficial effects.
(1)技术新颖(1) Novel technology
本公开采用常压干燥工艺，有别于超临界干燥工艺，此外与传统常压干燥工艺相比，本公开使用水玻璃作为硅源，无需水洗除盐，采用甲醇醇洗置换，采用二甲基二氯硅烷或甲基三氯硅烷作为疏水改性剂，降低了原料成本，简化了工艺过程，缩短了整个工艺时长。This disclosure adopts a normal pressure drying process, which is different from the supercritical drying process. In addition, compared with the traditional normal pressure drying process, this disclosure uses water glass as the silicon source, does not require water washing to remove salt, uses methanol alcohol washing for replacement, and uses dimethyl Dichlorosilane or methyltrichlorosilane, as a hydrophobic modifier, reduces raw material costs, simplifies the process, and shortens the entire process time.
(2)安全环保(2) Safety and environmental protection
本公开全工艺流程均为常压，复合凝胶需直接接触的过程，其溶胶-凝胶溶剂为水溶液，对人体无害，醇洗、改性置换密闭环境进行，避免人员直接接触，生产过程安全无害。生产过程中无需水洗除盐，解决了传统常压工艺生产1立方成品，需要产生2～6吨废水带来的大量废水处理问题，环境友好。The entire process flow of this disclosure is under normal pressure, and the composite gel requires direct contact. The sol-gel solvent is an aqueous solution, which is harmless to the human body. Alcohol washing, modification and replacement are carried out in a closed environment to avoid direct contact with personnel. The production process Safe and harmless. There is no need for water washing and desalination during the production process, which solves the problem of large amounts of wastewater treatment caused by the need to produce 2 to 6 tons of wastewater to produce 1 cubic meter of finished product using the traditional atmospheric pressure process, and is environmentally friendly.
(3)成本低廉(3) Low cost
本项目使用廉价的水玻璃作为硅源，相比硅酸甲酯、硅酸乙酯等有机硅源，硅源原料成本能降低10～30倍，同时水玻璃硅源价格稳定，不受市场波动。采用二甲基二氯硅烷和甲基三氯硅烷作为改性剂，改性剂原料单价下降到1/3～1/8，同时改性剂用量最低可到0.5％，改性剂使用成本下降到1/10～1/30，综合疏水改性成本下降到10％～20％。该技术工艺原料成本优势明显。This project uses cheap water glass as the silicon source. Compared with organic silicon sources such as methyl silicate and ethyl silicate, the cost of silicon source raw materials can be reduced by 10 to 30 times. At the same time, the price of water glass silicon source is stable and is not affected by market fluctuations. . Using dimethyldichlorosilane and methyltrichlorosilane as modifiers, the unit price of the modifier raw materials is reduced to 1/3 to 1/8. At the same time, the modifier dosage can be as low as 0.5%, and the cost of modifier usage is reduced. By 1/10~1/30, the comprehensive hydrophobic modification cost will drop to 10%~20%. This technology has obvious raw material cost advantages.
(4)工艺简单(4) Simple process
本公开只需一步置换，即可快速制备出二氧化硅气凝胶或其复合制品，省去传统常压干燥工艺需要经过长时间多次的溶剂置换过程，整体工艺简单。The disclosure only requires one step of replacement to quickly prepare silica aerogel or composite products thereof, eliminating the long and multiple solvent replacement processes required by the traditional normal pressure drying process, and the overall process is simple.
附图说明Description of the drawings
图1是本公开工艺过程流程图。Figure 1 is a process flow diagram of the present disclosure.
图2是本公开实施例1制成的二氧化硅气凝胶玻璃纤维复合毡的水接触角测试结果图。Figure 2 is a graph showing the water contact angle test results of the silica airgel glass fiber composite mat made in Example 1 of the present disclosure.
图3是本公开实施例2制成的二氧化硅玄武岩纤维复合毡的水接触角测试结果图。Figure 3 is a graph showing the water contact angle test results of the silica basalt fiber composite felt produced in Example 2 of the present disclosure.
图4是实施例2的测试报告。Figure 4 is the test report of Example 2.
图5是本公开实施例3制成的二氧化硅气凝胶的外观图。Figure 5 is an appearance view of the silica aerogel produced in Example 3 of the present disclosure.
图6是实施例3制成的二氧化硅气凝胶的BET多点法拟合直线和BET多点法测试结果。Figure 6 is the BET multi-point method fitting straight line and the BET multi-point method test results of the silica aerogel produced in Example 3.
图7是实施例3制成的二氧化硅气凝胶的BET多点法拟合直线和BET多点法测试报告。 Figure 7 is the BET multi-point method fitting straight line and the BET multi-point method test report of the silica aerogel produced in Example 3.
具体实施方式Detailed ways
下面将结合本公开实施例，对本公开实施例中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本公开一部分实施例，而不是全部的实施例。基于本公开中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本公开保护的范围。The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the embodiments of the present disclosure. Obviously, the described embodiments are only some, but not all, of the embodiments of the present disclosure. Based on the embodiments in this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this disclosure.
如图1所示，本公开提供了一种低成本快速制备二氧化硅气凝胶或其复合制品的方法。在该方法中，以水玻璃为硅源，水玻璃与脱盐水以体积比1:0.3～8的混合液形成水玻璃水溶液，水玻璃水溶液经酸溶液一步催化凝胶，形成湿凝胶，在催化凝胶过程中可选地与一定的载体复合，湿凝胶通过有机混合液一步置换改性，经常压干燥，制得二氧化硅气凝胶或其复合制品。As shown in Figure 1, the present disclosure provides a low-cost and rapid method for preparing silica aerogel or composite products thereof. In this method, water glass is used as the silicon source, and water glass and desalted water are mixed with a volume ratio of 1:0.3 to 8 to form a water glass aqueous solution. The water glass aqueous solution is catalyzed by an acid solution in one step to form a wet gel. During the catalytic gel process, it is optionally compounded with a certain carrier. The wet gel is modified in one step by displacement of the organic mixed liquid and dried under constant pressure to prepare silica aerogel or its composite products.
实施例1Example 1
量取水玻璃溶液154g，加入500g脱盐水中，40℃水浴搅拌30min，标注为A液待用；准备玻璃纤维复合材料一份，尺寸为300mm*300mm*10mm，将其置于成型模具中；向150g的2mol/l的盐酸水溶液中滴加A液，控制混合液PH为4.5，并将混合液与模具中的纤维复合材料进一步复合，静置40min小时，得到玻璃纤维复合二氧化硅湿凝胶。将得到的湿凝胶浸泡于2L、50℃的体积含量为20％乙醇、75％六甲基二硅氧烷以及5％二甲基二氯硅烷的混合溶液中，2小时后，取出经处理过的产品，通过鼓风烘箱90℃干燥2小时，得到二氧化硅气凝胶玻璃纤维复合毡。所制产品25℃导热系数为0.01653W/(K*m)，憎水率99.95％，水接触角为153.896°，BET比表面积980.3037m2/g，孔隙率为97.25％，测试结果如图2所示。Measure 154g of the water glass solution, add it to 500g of desalted water, stir in a 40°C water bath for 30 minutes, mark it as liquid A for later use; prepare a glass fiber composite material with a size of 300mm*300mm*10mm, and place it in the forming mold; add 150g to Add liquid A dropwise into the 2 mol/l hydrochloric acid aqueous solution, control the pH of the mixed liquid to 4.5, further compound the mixed liquid with the fiber composite material in the mold, and let it stand for 40 minutes to obtain a glass fiber composite silica wet gel. Soak the obtained wet gel in 2L of a mixed solution with a volume content of 20% ethanol, 75% hexamethyldisiloxane and 5% dimethyldichlorosilane at 50°C. After 2 hours, take out the treated solution The processed product is dried in a blast oven at 90°C for 2 hours to obtain a silica airgel glass fiber composite mat. The thermal conductivity of the manufactured product at 25°C is 0.01653W/(K*m), the hydrophobicity is 99.95%, the water contact angle is 153.896°, the BET specific surface area is 980.3037m 2 /g, and the porosity is 97.25%. The test results are shown in Figure 2 shown.
实施例2Example 2
量取水玻璃溶液100g，加入450g脱盐水中，40℃水浴搅拌15min，标注为A液，待用；准备玄武岩纤维复合材料一份，尺寸为300mm*300mm*10mm，将其置于成型模具中；向A液中加入2mol/l硝酸和1mol/l的磷酸混合水溶液，控制溶液PH为9.5，并将混合液与模具中的纤维复合材料进一步复合，静置1小时，得到玄武岩纤维复合二氧化硅湿凝胶。将得到的湿凝胶浸泡于1.5L、70℃的体积含量为35％乙醇、64％正己烷以及1％甲基三氯硅烷的混合溶液中，1.5小时后，取出经处理过的产品，通过鼓风烘箱150℃干燥1.5小时，得到二氧化硅气凝胶玄武岩纤维复合毡。所制产品25℃导热系数为0.01689W/(K*m)，憎水率99.93％，水接触角为148.262°，BET比表面积890.2359m2/g，孔隙率为93.18％。本公开实施例2制成的二氧化硅气凝胶玄武岩纤维复合毡的25℃导热系数测试结果如图3所 示，测试报告如图4。Measure 100g of water glass solution, add 450g of desalted water, stir in a 40°C water bath for 15 minutes, label it as liquid A, and set aside; prepare a portion of basalt fiber composite material with a size of 300mm*300mm*10mm, and place it in the forming mold; Add 2 mol/l nitric acid and 1 mol/l phosphoric acid mixed aqueous solution to liquid A, control the pH of the solution to 9.5, further compound the mixed liquid with the fiber composite material in the mold, and let it stand for 1 hour to obtain the wet basalt fiber composite silica. gel. Soak the obtained wet gel in 1.5L of a mixed solution of 35% ethanol, 64% n-hexane and 1% methyltrichlorosilane at 70°C. After 1.5 hours, take out the treated product and pass it through Dry in a blast oven at 150°C for 1.5 hours to obtain the silica airgel basalt fiber composite felt. The thermal conductivity of the produced product at 25°C is 0.01689W/(K*m), the hydrophobicity is 99.93%, the water contact angle is 148.262°, the BET specific surface area is 890.2359m 2 /g, and the porosity is 93.18%. The 25°C thermal conductivity test results of the silica airgel basalt fiber composite felt made in Example 2 of the present disclosure are shown in Figure 3 shown, the test report is shown in Figure 4.
实施例3Example 3
量取水玻璃溶液35g，加入20g脱盐水中，25℃水浴搅拌60min，标注为A液，待用；向0.3mol/l硫酸水溶液中滴加A液，控制混合液PH为3.5，静置约1.5小时，混合液完全固化形成凝胶，将形成的凝胶浸泡于350ml、体积含量为20％甲醇、50％六甲基二硅氧烷、28％正庚烷、1.5％三氯甲基硅烷和0.5％三甲基氯硅烷的混合溶液中，70℃水浴处理4小时。将处理过的凝胶，通过鼓风烘箱180℃干燥2小时，得到二氧化硅气凝胶。所制二氧化硅气凝胶的水接触角为158.122°，BET比表面积为960.2108m2/g，成块型好。外观如图5所示。本公开实施例3制成的二氧化硅气凝胶的BET多点法拟合直线和BET多点法测试结果如图6所示，本公开实施例3制成的二氧化硅气凝胶比表面积测试的综合数据报告如图7。Measure 35g of the sodium silicate solution, add it to 20g of desalted water, stir in a water bath at 25°C for 60 minutes, label it as liquid A and set aside; add liquid A dropwise to the 0.3mol/l sulfuric acid aqueous solution, control the pH of the mixed solution to 3.5, and let it stand for about 1.5 hours , the mixed liquid is completely solidified to form a gel, and the formed gel is soaked in 350ml, with a volume content of 20% methanol, 50% hexamethyldisiloxane, 28% n-heptane, 1.5% trichloromethylsilane and 0.5 % trimethylchlorosilane mixed solution, and treated in a water bath at 70°C for 4 hours. The treated gel was dried in a forced air oven at 180°C for 2 hours to obtain silica aerogel. The water contact angle of the prepared silica aerogel is 158.122°, the BET specific surface area is 960.2108m 2 /g, and the block shape is good. The appearance is shown in Figure 5. The BET multi-point method fitting straight line and BET multi-point method test results of the silica aerogel made in Example 3 of the present disclosure are shown in Figure 6. The ratio of the silica aerogel made in Example 3 of the present disclosure is The comprehensive data report of the surface area test is shown in Figure 7.
实施例4Example 4
量取水玻璃溶液15kg，加入65kg脱盐水中，30℃水浴搅拌30min，标注为A液待用；准备玻璃纤维复合材料一份，尺寸为10000mm*1500mm*10mm，将其置于成型模具中；向中加入1mol/l的硝酸水溶液中加入A液，控制混合液PH为3.8，并将混合液与模具中的纤维复合材料进一步复合，静置25min，得到玻璃纤维复合二氧化硅湿凝胶。将得到的湿凝胶浸泡于300L、50℃的体积含量为44％乙醇、55％六甲基二硅氧烷以及1％二甲基二氯硅烷的混合溶液中，4小时后，取出经处理过的产品，通过工业鼓风炉130℃干燥2小时，得到二氧化硅气凝胶玻璃纤维复合毡。所制产品25℃导热系数为0.01636W/(K*m)，体积密度193kg/m3，憎水率99.88％，体积吸水率0.16％，质量吸湿率0.31％，最高使用温度＞500℃，燃烧等级为A2级，产品总体性能满足气凝胶国家标准GB/T34336-2017定义的A级气凝胶复合产品的要求，且大部分性能远优于该级别气凝胶复合制品的性能指标。Measure 15kg of water glass solution, add it to 65kg of desalted water, stir in a 30°C water bath for 30 minutes, mark it as liquid A for later use; prepare a glass fiber composite material with a size of 10000mm*1500mm*10mm, and place it in the forming mold; Add liquid A to 1 mol/l nitric acid aqueous solution, control the pH of the mixed liquid to 3.8, further compound the mixed liquid with the fiber composite material in the mold, and let it stand for 25 minutes to obtain a glass fiber composite silica wet gel. Soak the obtained wet gel in 300L of a mixed solution with a volume content of 44% ethanol, 55% hexamethyldisiloxane and 1% dimethyldichlorosilane at 50°C. After 4 hours, take out the treated solution The processed product is dried in an industrial blast furnace at 130°C for 2 hours to obtain a silica airgel glass fiber composite mat. The thermal conductivity of the product at 25℃ is 0.01636W/(K*m), the volume density is 193kg/m 3 , the hydrophobicity is 99.88%, the volume water absorption is 0.16%, the mass moisture absorption is 0.31%, the maximum operating temperature is >500℃, and the combustion The grade is A2. The overall performance of the product meets the requirements of Class A airgel composite products defined by the national airgel standard GB/T34336-2017, and most of the properties are far better than the performance indicators of airgel composite products of this level.
以上所述，仅为本公开较佳的具体实施方式，但本公开的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本公开揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本公开的保护范围之内。因此，本公开的保护范围应以所述权利要求的保护范围为准。 The above are only preferred specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope of the present disclosure. , should all be covered by the protection scope of this disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims (11)

  1. 一种制备二氧化硅气凝胶或其复合制品的方法，包括A method for preparing silica aerogel or composite products thereof, including
    提供水玻璃作为硅源，Providing water glass as a silicon source,
    将所述水玻璃与脱盐水以体积比1:0.3～8混合形成水玻璃水溶液，The water glass and desalted water are mixed at a volume ratio of 1:0.3 to 8 to form a water glass aqueous solution,
    使所述水玻璃水溶液经酸溶液一步催化凝胶，形成湿凝胶，The water glass aqueous solution is passed through an acid solution to catalyze the gel in one step to form a wet gel,
    可选地，在所述催化凝胶过程中将所述水玻璃水溶液与载体复合，Optionally, the water glass aqueous solution is compounded with a carrier during the catalytic gel process,
    将所述湿凝胶通过有机混合液一步置换改性，The wet gel is modified in one step by displacement of organic mixed liquid,
    经常压干燥制得所述二氧化硅气凝胶或其复合制品。The silica aerogel or its composite product is prepared by regular pressure drying.
  2. 根据权利要求1所述的方法，其中一步置换改性过程为有机混合液浸泡过程，所述有机混合液为醇液、有机溶剂、疏水改性剂的混合液，其中所述醇液为甲醇、乙醇中的一种或两种，所述有机溶剂为正己烷、六甲基二硅氧烷、正庚烷中的一种，所述疏水改性剂为三氯甲基硅烷、二甲基二氯硅烷、六甲基二硅氮烷、甲基三甲氧基硅烷、甲基三乙氧基硅烷、三甲基氯硅烷中的一种或多种。The method according to claim 1, wherein the one-step displacement modification process is an organic mixed liquid soaking process, the organic mixed liquid is a mixed liquid of alcohol liquid, organic solvent, and hydrophobic modifier, wherein the alcohol liquid is methanol, One or two kinds of ethanol, the organic solvent is one of n-hexane, hexamethyldisiloxane, and n-heptane, and the hydrophobic modifier is trichloromethylsilane, dimethyldisiloxane, One or more of chlorosilane, hexamethyldisilazane, methyltrimethoxysilane, methyltriethoxysilane, and trimethylchlorosilane.
  3. 根据权利要求2所述的方法，其中所述有机混合液中的所述醇液、所述有机溶剂、所述疏水改性剂的体积混合比例为1:0.5～20：0.001～1，优选1:3～10：0.006～0.3。The method according to claim 2, wherein the volume mixing ratio of the alcohol liquid, the organic solvent and the hydrophobic modifier in the organic mixed liquid is 1:0.5~20:0.001~1, preferably 1 :3～10: 0.006～0.3.
  4. 根据权利要求1至3中任一项所述的方法，其中所述有机混合液与所述二氧化硅气凝胶或其复合制品的体积比为1:0.1～5，优选1:0.2～2。The method according to any one of claims 1 to 3, wherein the volume ratio of the organic mixed liquid to the silica aerogel or its composite product is 1:0.1~5, preferably 1:0.2~2 .
  5. 根据权利要求1至4中任一项所述的方法，其中所述常压干燥的干燥温度为50℃～300℃，优选90℃～150℃；干燥时间为30分钟～12小时，优选1.5～5小时。The method according to any one of claims 1 to 4, wherein the drying temperature of the normal pressure drying is 50°C to 300°C, preferably 90°C to 150°C; the drying time is 30 minutes to 12 hours, preferably 1.5 to 150°C. 5 hours.
  6. 根据权利要求1至5中任一项所述的方法，其中所述一步置换改性的温度为30℃～70℃，优选40℃～60℃；所述一步置换改性的时间为0.5～48小时，优选1～5小时。The method according to any one of claims 1 to 5, wherein the temperature of the one-step displacement modification is 30°C to 70°C, preferably 40°C to 60°C; the time of the one-step displacement modification is 0.5 to 48 hours, preferably 1 to 5 hours.
  7. 根据权利要求1至6中任一项所述的方法，其中所述一步催化凝胶的温度为0℃～60℃，所述催化凝胶过程控制PH值范围为3～11。The method according to any one of claims 1 to 6, wherein the temperature of the one-step catalytic gel is 0°C to 60°C, and the pH value range of the catalytic gel process is controlled to be 3 to 11.
  8. 根据权利要求1至7中任一项所述的方法，其中所述水玻璃的模数为2.6～3.4，其中，所述水玻璃与所述脱盐水体积比优选为1:1～5。The method according to any one of claims 1 to 7, wherein the modulus of the water glass is 2.6 to 3.4, and the volume ratio of the water glass to the desalted water is preferably 1:1 to 5.
  9. 根据权利要求1至8中任一项所述的方法，其中所述酸溶液为0.1mol/l～10mol/l、优选1mol/l～5mol/l的酸的水溶液，其中所述酸为盐酸、硫酸、硝酸、磷酸、草酸中的一种或多种。The method according to any one of claims 1 to 8, wherein the acid solution is an aqueous acid solution of 0.1 mol/l to 10 mol/l, preferably 1 mol/l to 5 mol/l, wherein the acid is hydrochloric acid, One or more of sulfuric acid, nitric acid, phosphoric acid and oxalic acid.
  10. 根据权利要求1至9中任一项所述的方法，其中所述载体为玻璃纤维毡、玄武岩 纤维毡或陶瓷纤维毡中的一种。The method according to any one of claims 1 to 9, wherein the carrier is glass fiber mat, basalt One of the fiber felts or ceramic fiber felts.
  11. 一种根据权利要求1至10中任一项所述的方法制备的二氧化硅气凝胶或其复合制品。 A silica aerogel or a composite product thereof prepared according to the method of any one of claims 1 to 10.
PCT/CN2023/092220 2022-05-27 2023-05-05 Method for preparing silicon dioxide aerogel or composite product thereof WO2023226710A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210584394.4 2022-05-27
CN202210584394.4A CN115093197A (en) 2022-05-27 2022-05-27 Method for rapidly preparing silicon dioxide aerogel and composite product thereof at low cost

Publications (1)

Publication Number Publication Date
WO2023226710A1 true WO2023226710A1 (en) 2023-11-30

Family

ID=83289765

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/092220 WO2023226710A1 (en) 2022-05-27 2023-05-05 Method for preparing silicon dioxide aerogel or composite product thereof

Country Status (2)

Country Link
CN (1) CN115093197A (en)
WO (1) WO2023226710A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115093197A (en) * 2022-05-27 2022-09-23 中化学华陆新材料有限公司 Method for rapidly preparing silicon dioxide aerogel and composite product thereof at low cost
CN117360019A (en) * 2023-10-24 2024-01-09 波司登羽绒服装有限公司 Silicon dioxide aerogel composite heat-insulating fabric and preparation method and application thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105621419A (en) * 2014-12-02 2016-06-01 北京建工新型建材有限责任公司 Ambient preparation method for silica aerogel powder
CN106865558A (en) * 2017-03-22 2017-06-20 伊科纳诺（北京）科技发展有限公司 Normal pressure prepares the method and obtained aerosil of aerosil
US20180305215A1 (en) * 2016-09-12 2018-10-25 Lg Chem, Ltd. Method for producing silica aerogel and silica aerogel produced thereby
CN112592149A (en) * 2020-12-31 2021-04-02 山东大学 Method for rapidly preparing silicon dioxide aerogel composite material by taking water glass as raw material through single solvent exchange
CN115093197A (en) * 2022-05-27 2022-09-23 中化学华陆新材料有限公司 Method for rapidly preparing silicon dioxide aerogel and composite product thereof at low cost

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105621419A (en) * 2014-12-02 2016-06-01 北京建工新型建材有限责任公司 Ambient preparation method for silica aerogel powder
US20180305215A1 (en) * 2016-09-12 2018-10-25 Lg Chem, Ltd. Method for producing silica aerogel and silica aerogel produced thereby
CN106865558A (en) * 2017-03-22 2017-06-20 伊科纳诺（北京）科技发展有限公司 Normal pressure prepares the method and obtained aerosil of aerosil
CN112592149A (en) * 2020-12-31 2021-04-02 山东大学 Method for rapidly preparing silicon dioxide aerogel composite material by taking water glass as raw material through single solvent exchange
CN115093197A (en) * 2022-05-27 2022-09-23 中化学华陆新材料有限公司 Method for rapidly preparing silicon dioxide aerogel and composite product thereof at low cost

Also Published As

Publication number Publication date
CN115093197A (en) 2022-09-23

Similar Documents

Publication Publication Date Title
WO2023226710A1 (en) Method for preparing silicon dioxide aerogel or composite product thereof
Cai et al. Preparation of silica aerogels with high temperature resistance and low thermal conductivity by monodispersed silica sol
CN108002749B (en) Hydrophobic high-elasticity methylsilsesquioxane aerogel block and preparation method thereof
Shao et al. Superhydrophobic sodium silicate based silica aerogel prepared by ambient pressure drying
CN108484098B (en) Normal-pressure preparation method of silicon dioxide/attapulgite fiber composite aerogel
CN103333358B (en) A kind of reusable cheap silica aerogel oil suction sponge and preparation method thereof
KR100796253B1 (en) Method of fabricating superhydrophobic silica chain powders
CN110467421B (en) Functional cellulose aerogel composite material and preparation method thereof
Cui et al. Preparation of SiO 2 aerogel from rice husk ash
CN101456569A (en) Method for quick-speed preparing aerogel by hydro-thermal synthesis at low cost
Feng et al. Synthesis, structure, and properties of silicon oxycarbide aerogels derived from tetraethylortosilicate/polydimethylsiloxane
CN111607253B (en) Preparation method of silica aerogel thermal insulation filler
US20180016152A1 (en) Method for aerogel production and aerogel composite material
CN101633505A (en) SiO2 nanoscale porous material with aerogel property prepared by microwave reaction and preparation method thereof
KR20180029500A (en) Method of preparing for silica aerogel and silica aerogel prepared by the same
CN103864076A (en) Preparation method of silicon carbide aerogel on basis of SiO2 aerogel as template
CN105883828A (en) Bulk-shaped hydrophobic flexible silicon dioxide aerogel and preparation method thereof
WO2014110891A1 (en) Preparation method of silica aerogel
CN101259964A (en) Constant pressure and dry preparation method for high-performance silicon dioxide aerogel by using rice husk ash as raw material
US20190194027A1 (en) Method for producing silica aerogel and silica aerogel produced thereby
KR20180029501A (en) Method of preparing for silica aerogel and silica aerogel prepared by the same
CN102557052A (en) Method for rapidly preparing low-density silicon oxide aerogel
CN108793173A (en) A method of improved silica aerogel material is prepared using outer circulation mode constant pressure and dry
KR102113655B1 (en) Method of preparing for silica aerogel and silica aerogel prepared by the same
Shao et al. Rapid synthesis of amine cross-linked epoxy and methyl co-modified silica aerogels by ambient pressure drying

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23810783

Country of ref document: EP

Kind code of ref document: A1