Preparation method and application of glass fiber powder-silicon dioxide aerogel composite material
Silica aerogel was prepared by combining it with glass fiber powder using the sol-gel method, forming a nano-network structure. This solved the problem of insufficient strength of traditional silica aerogel and enabled efficient and low-cost industrial applications.
Patent Information
- Application Number
- CN202511514314.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-22
- Publication Date
- 2026-01-09
AI Technical Summary
Traditional silica aerogels have insufficient skeletal strength and are prone to collapse, which limits their application range. In addition, the preparation process is costly and difficult to widely use in industry.
The sol-gel method is used to combine glass fiber powder with silica aerogel. A nano-network structure is formed through physical entanglement or chemical bonding, which enhances the mechanical strength and stability of the material. The cost is reduced by using an atmospheric pressure drying method.
The prepared glass fiber powder-silica aerogel composite material has good hydrophobicity and mechanical strength, can maintain stability in humid environments, reduces preparation costs, and maintains the high specific surface area and porous structure of silica aerogel, making it suitable for industrial waste gas and wastewater treatment and air purification.
Smart Images
Figure CN121292935A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to methods for preparing aerogel composite materials, and particularly to a method for preparing and applying a glass fiber powder-silica aerogel composite material. Background Technology
[0002] Silica aerogels are three-dimensional nanomaterials with pores filled with a gaseous dispersion medium. They possess abundant pore structures, ultra-large specific surface area, extremely low thermal conductivity, and are lightweight and low-density, making them widely used in thermal insulation, aerospace, and catalysis. The sol-gel method is a common preparation method for silica aerogels, generally including sol generation, gel preparation, gel aging, and gel drying. Gel aging and drying are crucial steps, determining the quality of the prepared silica aerogel. Compared to aging solutions such as ethanol solutions, ethanol-water solutions, surface modifier mixtures, and ion exchange resin treatment solutions, aging in a surface modifier mixture helps form a complete three-dimensional network structure. Compared to supercritical drying, freeze-drying, and subcritical drying methods, atmospheric pressure drying helps save costs. Traditional sol-gel methods produce silica aerogels with small pore sizes and high porosity. The nanoframework, composed of amorphous silica particles, exhibits weak interparticle bonding, making it prone to interlayer slippage or structural collapse. This results in a loose network and insufficient skeletal strength in the cross-linked three-dimensional structure, significantly limiting its applications. Introducing inexpensive inorganic surface-reinforcing glass fiber powder into the conventional sol-gel method, where the glass fiber powder acts as a rigid framework, interpenetrates with silica through physical entanglement or chemical bonding to form a nanonetwork structure, helps overcome the structural fragility, easy collapse, and low mechanical strength of pure silica aerogels. Summary of the Invention
[0003] To address the technical problems existing in the background art, the present invention provides a method for preparing glass fiber powder-silica aerogel composite material and its application.
[0004] This invention adopts the following technical solution: a method for preparing a glass fiber powder-silica aerogel composite material, comprising the following steps: Step 1: Mix tetraethyl orthosilicate and anhydrous ethanol in a certain mass ratio to obtain mixed solution A; Step 2: Mix concentrated sulfuric acid and anhydrous ethanol according to the molar ratio to obtain mixed solution B; Step 3: Mix and stir the mixed solution A from Step 1 and the mixed solution B from Step 2 to obtain mixed solution C; add water to mixed solution C to dilute and stir to obtain the polyoxysiloxane precursor; Step 4: Mix the polyoxysiloxane precursor prepared in Step 3 with the glass fiber powder ethanol solution and deionized water evenly, and while stirring, add the hexamethyldisiloxane and ammonia ethanol solution evenly. Stop stirring after a gel is formed. Step 5: Place the mixed gel from Step 4 in an oven to age it and obtain an aged gel. Immerse the aged gel in hydrochloric acid ethanol solution and hexamethyldisiloxane, seal it, and dry it in an oven to obtain a glass fiber powder-silica aerogel composite material.
[0005] In a further embodiment, the mass ratio of tetraethyl orthosilicate to anhydrous ethanol in step one is (5~6):1; In step three, the mass ratio of water to tetraethyl orthosilicate is 1:(6~7).
[0006] In a further embodiment, the mass ratio of concentrated sulfuric acid to anhydrous ethanol in step two is 1:(150~152).
[0007] In a further embodiment, step three specifically includes: Beforehand, place solution A in a magnetic stirrer and stir at room temperature. Then, add solution B dropwise over a predetermined time until solution B is completely added. Continue stirring for the predetermined time to ensure that solution A and solution B are uniformly mixed in a volume ratio of 1:1.
[0008] In a further embodiment, the glass fiber powder in the glass fiber powder ethanol solution has a mesh size of 800 mesh, 3000 mesh, or 8000 mesh. The content of glass fiber powder in the subsequently formed glass fiber powder-silica aerogel composite material is 3% to 15%.
[0009] In a further embodiment, the aging environment temperature of the aging gel in step five is 70℃~75℃, and the aging time is 1.5~2.5 hours.
[0010] In a further embodiment, the drying process in step five includes a first drying stage and a second drying stage; The drying environment temperature in the first drying stage is 85℃~95℃, and the duration is 0.5~2 hours. The drying environment temperature for the second drying stage is 110℃. After the temperature rises to 110℃, the seal is removed, and drying continues for 0.5 to 2 hours.
[0011] In a further embodiment, the glass fiber powder-silica aerogel composite material prepared in step five has a mesoporous structure, and the average pore size of BJH adsorption and desorption is less than 10 nm.
[0012] In a further embodiment, the contact angle of the glass fiber powder-silica aerogel composite material is greater than 115°.
[0013] An application of a glass fiber powder-silica aerogel composite material is disclosed, which is used in industrial waste gas treatment, industrial wastewater treatment and air purification; the glass fiber powder-silica aerogel composite material is prepared by the preparation method described above.
[0014] The beneficial effects of this invention are: This invention uses a simple sol-gel integrated synthesis and preparation technology, is prepared under normal pressure, and is simple to operate.
[0015] The silica aerogel composite material prepared by this invention consumes less solvent and has a shorter preparation time; the use of inexpensive glass fiber powder as the additive substrate reduces costs.
[0016] The prepared glass fiber powder-silica aerogel composite material has good hydrophobicity, which can reduce the erosion and penetration of water on the composite material, maintain the stability of the material in humid environments, and extend its service life.
[0017] The glass fiber powder-silica aerogel composite material of this invention uses rigid glass fiber powder as a base material, which crosslinks with the three-dimensional skeleton structure of silica aerogel during the gel formation process to form a composite material. The addition of glass fiber powder not only enhances the mechanical strength, durability, and corrosion resistance of the composite material, but also maintains the high specific surface area, porous structure, and high-temperature resistance of the silica aerogel itself, especially with the addition of 3% glass fiber powder. The regular variation in the surface area of the composite material allows for selective application in different scenarios such as industrial waste gas and wastewater treatment and air purification devices, reducing environmental hazards. Attached Figure Description
[0018] Figure 1 These are contact angle diagrams of silica aerogel and glass fiber powder-silica aerogel composite materials prepared in Examples 1, 2, 7, and 12.
[0019] Figure 2 The images show the infrared spectra of the silica aerogel, glass fiber powder-silica aerogel composite material, and the corresponding glass fiber powder itself prepared in Examples 1 to 16.
[0020] Figure 3 These are X-ray diffraction patterns of silica aerogel, glass fiber powder-silica aerogel composite material, and the corresponding glass fiber powder itself prepared in Examples 1 to 16.
[0021] Figure 4The thermogravimetric analysis curves are of glass fiber powder with different mesh sizes (content of 9%, 12% and 15%), silica aerogel composites, silica aerogel itself, and the corresponding glass fiber powder itself.
[0022] Figure 5 The attached diagram shows the N2 temperature adsorption and desorption of the silica aerogel composite materials prepared in Examples 1, 2, 7 and 12. Detailed Implementation
[0023] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The following content is merely illustrative and explanatory of the concept of the present invention. Various modifications, additions, or similar methods may be made to the described specific embodiments by those skilled in the art, as long as they do not deviate from the inventive concept or exceed the scope defined in these claims, and all such modifications and additions shall fall within the protection scope of the present invention.
[0024] Example 1 This embodiment discloses a method for preparing a glass fiber powder-silica aerogel composite material, including: Step 1: Mix tetraethyl orthosilicate and anhydrous ethanol in a certain mass ratio to obtain mixed solution A; in this embodiment, the mass ratio of tetraethyl orthosilicate to anhydrous ethanol is (5~6):1; more preferably 5.56:1, such as adding 3.5719g of anhydrous ethanol while stirring 19.7061g of tetraethyl orthosilicate.
[0025] Step 2: Mix concentrated sulfuric acid and anhydrous ethanol according to the molar ratio to obtain mixed solution B; the mass ratio of concentrated sulfuric acid to anhydrous ethanol is 1:(150~152), and more preferably 1:151, such as adding 0.0243g of concentrated sulfuric acid (98%) to 3.6627g of anhydrous ethanol while stirring.
[0026] Step 3: Mix and stir the mixed solution A from Step 1 and the mixed solution B from Step 2 to obtain mixed solution C; add water to mixed solution C to dilute and stir to obtain the polyoxysiloxane precursor; based on the above example, the amount of water added in this step is 3.0724 g, and the mixture is sealed and stirred at a constant speed at room temperature for 2 hours. As shown in Formula 1, the polyoxysiloxane sol precursor is generated after the solution mixing reaction.
[0027] Si(OC2H5)4+1.8H2O→PEDS-P900 (1) Furthermore, the specific steps include: placing the mixed solution A in a magnetic stirrer and stirring at room temperature, and adding the mixed solution B dropwise over a predetermined time until the mixed solution B is completely added; continuing to stir for a predetermined time to ensure that the mixed solution A and the mixed solution B are uniformly mixed in a volume ratio of 1:1. In this embodiment, the predetermined time is 1 hour.
[0028] Step 4: Mix the polyoxysiloxane precursor prepared in Step 3 with anhydrous ethanol solution and deionized water evenly and stir (200-300 rpm / min). Then, add hexamethyldisiloxane and ammonia in ethanol solution to obtain a mixed gel. Further, in this example, take 3.00 mL of polyoxysiloxane precursor, add 3.50 mL of anhydrous ethanol solution and 0.28 mL of deionized water in sequence, stir at a speed of 200-300 rpm / min, and then add 3.50 mL of hexamethyldisiloxane and 0.25 mL of 2M ammonia in ethanol solution in sequence to obtain a mixed gel.
[0029] Step 5: Place the mixed gel from Step 4 in an oven to age it and obtain an aged gel. Immerse the aged gel in hydrochloric acid ethanol solution and hexamethyldisiloxane, seal it, and dry it in an oven to obtain a silica aerogel composite material (0% glass fiber powder content, pure silica aerogel).
[0030] The aging environment temperature for the aged gel is 70℃~75℃, and the aging time is 1.5~2.5 hours. More preferably, the aging environment temperature is 75℃, and the aging time is 2 hours.
[0031] Furthermore, take 1cm 3 The aged gel was immersed in 2.00 mL of 1 M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane, and then sealed in a sealed bag and transferred to an oven for further processing.
[0032] The drying process includes a first drying stage and a second drying stage. The drying environment temperature in the first drying stage is 85℃~95℃, and the duration is 0.5~2 hours; more preferably, the drying environment temperature is 90℃, and the duration is 1 hour. The drying environment temperature for the second drying stage is 110℃. After the temperature rises to 110℃, the seal is removed, and drying continues for 0.5 to 2 hours, preferably 1 hour.
[0033] Example 2 Based on the description in Example 1, this example discloses a method for preparing a glass fiber powder-silica aerogel composite material, comprising: adding 3.5719g of anhydrous ethanol to 19.7061g of tetraethyl orthosilicate while stirring to obtain mixed solution A; adding 0.0243g of concentrated sulfuric acid (98%) to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; placing mixed solution A in a magnetic stirrer and stirring at room temperature; adding mixed solution B dropwise to mixed solution A within 0.50h to obtain mixed solution C; continuing to stir for 0.50h to ensure thorough mixing; and slowly adding mixed solution C... Add 3.0724 g of distilled water, seal and stir at room temperature for h to obtain a polyoxysiloxane precursor; take 3.00 mL of the polyoxysiloxane precursor, add 3.50 mL of a solution of 800-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.20 g of 800-mesh glass fiber powder) and 0.28 mL of deionized water, then add 3.50 mL of hexamethyldisiloxane and 0.25 mL of 2M ammonia in ethanol in sequence under vigorous and rapid stirring to obtain a mixed gel; place the rapidly and vigorously stirred mixed gel in a 75°C oven for 2 h to obtain an aged gel; take about 1 cm of the aged gel 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel; seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour, then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 3% content 800 mesh glass fiber powder-silica aerogel composite material.
[0034] Example 3 This embodiment discloses a method for preparing a glass fiber powder-silica aerogel composite material, comprising: adding 3.5719g of anhydrous ethanol to 19.7061g of tetraethyl orthosilicate while stirring to obtain mixed solution A; adding 0.0243g of concentrated sulfuric acid (98%) to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; placing mixed solution A in a magnetic stirrer and stirring at room temperature; adding mixed solution B dropwise to mixed solution A over 0.50h to obtain mixed solution C; continuing to stir for 0.50h to ensure thorough mixing; and slowly adding distilled water to mixed solution C. 3.0724 g of polyoxysiloxane was sealed and stirred at a constant speed at room temperature for 2 hours to obtain a polyoxysiloxane precursor. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 800-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.40 g of 800-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 6% content 800 mesh glass fiber powder-silica aerogel composite material.
[0035] Example 4 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2 hours. h, a polyoxysiloxane precursor was obtained; 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 800-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.60 g of 800-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of 2M ammonia in ethanol were added sequentially to obtain a mixed gel; the mixed gel, which was rapidly and vigorously stirred evenly, was placed in an oven at 75°C and dried for 2 h to obtain an aged gel; about 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 9% content 800 mesh glass fiber powder-silica aerogel composite material.
[0036] Example 5 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2 hours. h, a polyoxysiloxane precursor was obtained; 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 800-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.80 g of 800-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of 2M ammonia in ethanol were added sequentially to obtain a mixed gel; the mixed gel, which was rapidly and vigorously stirred evenly, was placed in an oven at 75 °C and dried for 2 h to obtain an aged gel; about 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 12% content 800 mesh glass fiber powder-silica aerogel composite material.
[0037] Example 6 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2 hours. h, a polyoxysiloxane precursor was obtained; 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 800-mesh glass fiber powder dissolved in anhydrous ethanol (containing 1.00 g of 800-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of 2M ammonia in ethanol were added sequentially to obtain a mixed gel; the mixed gel, which was rapidly and vigorously stirred evenly, was placed in an oven at 75°C and dried for 2 h to obtain an aged gel; about 1 cm of the aged gel was taken. 3Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 15% content 800 mesh glass fiber powder-silica aerogel composite material.
[0038] Example 7 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 3000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.20 g of 3000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 3% 3000-mesh glass fiber powder-silica aerogel composite material.
[0039] Example 8 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 3000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.40 g of 3000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 6% content 3000 mesh glass fiber powder-silica aerogel composite material.
[0040] Example 9 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 3000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.60 g of 3000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 9% content 3000 mesh glass fiber powder-silica aerogel composite material.
[0041] Example 10 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 3000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.80 g of 3000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 3000-mesh glass fiber powder-silica aerogel composite material with a content of 12%.
[0042] Example 11 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 3000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 1.00 g of 3000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 15% 3000-mesh glass fiber powder-silica aerogel composite material.
[0043] Example 12 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 8000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.20 g of 8000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 3% content 8000 mesh glass fiber powder-silica aerogel composite material.
[0044] Example 13 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 8000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.40 g of 8000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 6% content 8000 mesh glass fiber powder-silica aerogel composite material.
[0045] Example 14 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 8000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.60 g of 8000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 9% content 8000 mesh glass fiber powder-silica aerogel composite material.
[0046] Example 15 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 8000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 0.80 g of 8000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 12% content 8000 mesh glass fiber powder-silica aerogel composite material.
[0047] Example 16 19.7061g of tetraethyl orthosilicate was added to 3.5719g of anhydrous ethanol while stirring to obtain mixed solution A; 0.0243g of concentrated sulfuric acid (98%) was added to 3.6627g of anhydrous ethanol while stirring to obtain mixed solution B; mixed solution A was placed in a magnetic stirrer and stirred at room temperature. Mixed solution B was added dropwise to mixed solution A over 0.50h to obtain mixed solution C, and stirring was continued for another 0.50h to ensure thorough mixing; 3.0724g of distilled water was slowly added to mixed solution C, and the mixture was sealed and stirred at a constant speed at room temperature for 2h. A polyoxysiloxane precursor was obtained. 3.00 mL of the polyoxysiloxane precursor was taken, and 3.50 mL of a solution of 8000-mesh glass fiber powder dissolved in anhydrous ethanol (containing 1.00 g of 8000-mesh glass fiber powder) and 0.28 mL of deionized water were added sequentially. Then, under vigorous and rapid stirring, 3.50 mL of hexamethyldisiloxane and 0.25 mL of a 2M ammonia-ethanol solution were added sequentially to obtain a mixed gel. The rapidly and vigorously stirred mixed gel was placed in a 75°C oven and dried for 2 hours to obtain an aged gel. Approximately 1 cm of the aged gel was taken. 3 Add 2.00 mL of 1M hydrochloric acid ethanol solution and 2.00 mL of hexamethyldisiloxane to obtain an impregnated aging gel. Seal the impregnated aging gel and bake it in a 90℃ oven for 1 hour. Then open the sealed bag, raise the oven temperature to 150℃, and continue drying the sample for 1 hour to finally obtain a 15% content 8000 mesh glass fiber powder-silica aerogel composite material.
[0048] Based on the aerogel composite materials prepared in Examples 1 to 16, the contact angles were measured, and the hydrophobicity obtained in Examples 1 to 16 was analyzed according to the contact angles. Combined with... Figure 1 As shown in Table 1, Table 1. Summary of contact angles of aerogel composite materials from Examples 1 to 6 According to the analysis, Example 1 (0% glass fiber powder content, pure silica aerogel): contact angle 125.85°; Examples 2-6 (800-mesh glass fiber powder, content 3%, 6%, 9%, 12%, 15%): contact angles were 116.09°, 126.87°, 126.28°, 119.31°, and 119.12°, respectively. Examples 7-11 (3000 mesh glass fiber powder, content 3%, 6%, 9%, 12%, 15%): contact angles were 129.73°, 122.48°, 122.25°, 121.21°, and 115.84°, respectively; Examples 12-16 (8000 mesh glass fiber powder, content 3%, 6%, 9%, 12%, 15%): contact angles were 120.65°, 126.72°, 130.52°, 124.55°, and 124.17°, respectively.
[0049] Based on the contact angle data above, a systematic analysis of the hydrophobicity of the products in Examples 1-16 was conducted, and the conclusions are as follows: Overall hydrophobicity meets the standard and stability is strong: the contact angle of all products in Examples 1-16 is greater than 115°. This invention, through the sol-gel integrated synthesis process, combined with the surface modification effect of hexamethyldisiloxane in the drying stage (reacting with Si-OH on the gel surface to form Si-C hydrophobic groups), can stably impart good hydrophobicity to the products and avoid hydrophobicity failure due to component adjustment.
[0050] The contact angles of the products corresponding to different mesh sizes of glass fiber powder did not show a significant decreasing or increasing trend, but all remained in the high hydrophobicity range: the contact angle of the 800 mesh series fluctuated from 116.09° to 126.87°, the 3000 mesh series from 115.84° to 129.73°, and the 8000 mesh series from 120.65° to 130.52°. When the 3000-mesh and 8000-mesh glass fiber powders had a low content (3%), the contact angles reached 129.73° and 120.65°, respectively, both higher than those of pure aerogel (125.85° or close). It is speculated that because the high-mesh glass fiber powder particles are finer, they can form a more uniform surface structure when cross-linked with silica aerogel, reducing the distribution gaps of hydrophobic groups and further optimizing hydrophobicity. On the other hand, the 800-mesh glass fiber powder, due to its relatively coarse particles, has less impact on the surface structure, and the overall contact angle is similar to that of pure aerogel. This proves that glass fiber powders of different mesh sizes can all meet the hydrophobicity requirements, and only need to be selected according to the actual scenario.
[0051] The effect of glass fiber powder content on hydrophobicity: At the same mesh size, as the glass fiber powder content increased from 3% to 15%, the contact angle fluctuated but did not show a significant downward trend: In the 800 mesh series, the contact angle at 6% content (126.87°) was higher than that at 3% (116.09°), while at 15% content it remained at 119.12°; in the 3000 mesh series, the contact angle gradually decreased from 129.73° at 3% to 115.84° at 15%, but remained above 115°; in the 8000 mesh series, the peak value of 130.52° was reached at 9% content, while at 15% it remained at 124.17°. This phenomenon indicates that when the glass fiber powder content is in the range of 3% to 15%, the hydrophobic structure will not be damaged due to the increase in content. Even with a high content (15%) of filler, no hydrophilic groups are exposed on the surface of the glass fiber powder, and the modification effect of hexamethyldisiloxane can cover the material surface, ensuring the stability of hydrophobicity. This provides the feasibility of "controlling the specific surface area by adjusting the content" at the hydrophobic level, avoiding the sacrifice of the material's moisture resistance in pursuit of performance control.
[0052] In summary, the contact angle data of the products in Examples 1-16 fully demonstrate that the gel composite materials prepared by this invention (including pure silica aerogel and glass fiber powder composite materials) all have good hydrophobicity, and the hydrophobicity is not significantly affected by the adjustment of the mesh size and content of glass fiber powder. They have strong stability, which provides key performance guarantee for the long-term use of the materials in humid environments (such as industrial wastewater treatment and high humidity industrial exhaust gas adsorption). At the same time, it also verifies the ability of the process of this invention to accurately control the surface properties of the products.
[0053] Furthermore, infrared spectral composition analysis was performed on the prepared aerogel composite material. Figure 2 The changes in the major functional groups of aerogels and their composites are shown. 452 cm -1 This peak can be attributed to the symmetric stretching vibration of the Si-O-Si bond; 843 cm⁻¹ -1 The absorption peak at 1080 cm⁻¹ can be attributed to the Si-C stretching vibration absorption peak caused by Si-R functional groups; -1 The absorption peak at this point can be attributed to the antisymmetric stretching vibration of Si-O-Si caused by the ≡Si-O-Si≡ functional group; the absence of other obvious impurity peaks indicates the formation of a silica aerogel and its glass fiber powder composite mainly composed of Si-O-Si bonds. These findings demonstrate that glass fiber powders of different mesh sizes have achieved excellent composite formation with silica aerogel, resulting in a new composite material.
[0054] X-ray diffraction was used to analyze the configuration of silica aerogel and glass fiber powder-silica aerogel composites, such as... Figure 3As shown, the silica aerogels prepared in Examples 1 to 6 with different contents of 800-mesh glass fiber powder all still exhibit an amorphous structure. In Examples 7 to 16, the 3000-mesh and 8000-mesh glass fiber powders themselves have crystalline structures. The composite materials obtained after being compared with the amorphous silica aerogels still have a crystalline structure similar to that of the 3000-mesh and 8000-mesh glass fiber powders, but their strength is weaker. Figure 3 It can be seen that glass fiber powder of different mesh sizes is well combined with silica aerogel to form a new composite material.
[0055] Combination Figure 4 The thermogravimetric analysis curves show that 800-mesh glass fiber powder exhibits good thermal stability within a temperature range from room temperature to 850℃. In particular, the thermal stability of the 800-mesh glass fiber powder-silica aerogel composites with contents of 12% and 15% is greater than that of the uncomposite silica aerogel. Glass fiber powder-silica aerogel composites with other contents and mesh sizes show a weight loss of no more than 30% at 850℃, demonstrating good thermal stability.
[0056] Figure 5 The N2 isothermal adsorption-desorption plots of silica aerogels prepared in Examples 1, 2, 7, and 12, and silica aerogel composites with 3% glass fiber powder content of 800 mesh, 3000 mesh, and 8000 mesh, are shown in the figure. The BET surface area of all prepared glass fiber powder-silica aerogel composites can be obtained from the curves.
[0057] The BET surface areas of the silica aerogels and 800-mesh glass fiber powder-silica aerogel composites prepared in Examples 1 to 6 above were summarized, and the results are shown in Appendix Table 2. With the increase of glass fiber powder content, the BET surface area of the 800-mesh glass fiber powder-silica aerogel composite showed an increasing trend.
[0058] The BET surface areas of the silica aerogels and 3000-mesh glass fiber powder-silica aerogel composites prepared in Examples 7 to 11 above were summarized, and the results are shown in Appendix Table 2. With the increase of glass fiber powder content, the BET surface area of the 3000-mesh glass fiber powder-silica aerogel composite showed an increasing trend.
[0059] The BET surface areas of the silica aerogels and 8000-mesh glass fiber powder-silica aerogel composites prepared in Examples 12 to 16 above were summarized, and the results are shown in Appendix Table 2. With the increase of glass fiber powder content, the BET surface area of the 8000-mesh glass fiber powder-silica aerogel composite showed an increasing trend.
[0060] Table 2 Summary of BET specific surface area and average pore size for adsorption and desorption in Examples 1 to 16 Based on the above analysis, the rational and effective doping of silica aerogel with fibers, polymers, and other materials can effectively improve its brittleness. The inorganic fiber reinforcement method is used to improve the properties of silica aerogel, incorporating glass fibers of appropriate content and mesh size into the three-dimensional structure as a supporting framework to control the specific surface area of the composite material. The sol-gel method is used, with tetraethyl orthosilicate as the silicon source and glass fiber powder of different mesh sizes as additives, to prepare glass fiber powder-silica aerogel composite materials through steps such as hydrolysis, condensation, aging, solvent exchange, and drying. Its main advantages are: simple process, easy reaction control, and low cost.
[0061] The above are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a glass fiber powder-silica aerogel composite material, characterized in that, Includes the following steps: Step 1: Mix tetraethyl orthosilicate and anhydrous ethanol in a certain mass ratio to obtain mixed solution A; Step 2: Mix concentrated sulfuric acid and anhydrous ethanol according to the molar ratio to obtain mixed solution B; Step 3: Mix and stir the mixed solution A from Step 1 and the mixed solution B from Step 2 to obtain mixed solution C; add water to mixed solution C to dilute and stir to obtain the polyoxysiloxane precursor; Step 4: Mix the polyoxysiloxane precursor prepared in Step 3 with the glass fiber powder ethanol solution and deionized water evenly, and while stirring, add the hexamethyldisiloxane and ammonia ethanol solution evenly. Stop stirring after a gel is formed. Step 5: Place the mixed gel from Step 4 in an oven to age it and obtain an aged gel. Immerse the aged gel in hydrochloric acid ethanol solution and hexamethyldisiloxane, seal it, and dry it in an oven to obtain a glass fiber powder-silica aerogel composite material.
2. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The mass ratio of tetraethyl orthosilicate to anhydrous ethanol in step one is (5~6):1; In step three, the mass ratio of water to tetraethyl orthosilicate is 1:(6~7).
3. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The mass ratio of concentrated sulfuric acid to anhydrous ethanol in step two is 1:(150~152).
4. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, Step three specifically includes: Beforehand, place solution A in a magnetic stirrer and stir at room temperature. Then, add solution B dropwise over a predetermined time until solution B is completely added. Continue stirring for the predetermined time to ensure that solution A and solution B are uniformly mixed in a volume ratio of 1:
1.
5. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The glass fiber powder in the ethanol solution has a mesh size of 800 mesh, 3000 mesh, or 8000 mesh. The content of glass fiber powder in the subsequently formed glass fiber powder-silica aerogel composite material is 3% to 15%.
6. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The aging environment temperature for the aged gel in step five is 70℃~75℃, and the aging time is 1.5~2.5 hours.
7. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The drying process in step five includes a first drying stage and a second drying stage. The drying environment temperature in the first drying stage is 85℃~95℃, and the duration is 0.5~2 hours. The drying environment temperature for the second drying stage is 110℃. After the temperature rises to 110℃, the seal is removed, and drying continues for 0.5 to 2 hours.
8. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The glass fiber powder-silica aerogel composite material prepared in step five has a mesoporous structure, and the average pore size of BJH adsorption and desorption is less than 10 nm.
9. The method for preparing a glass fiber powder-silica aerogel composite material according to claim 1, characterized in that, The contact angle of the glass fiber powder-silica aerogel composite material is greater than 115°.
10. An application of a glass fiber powder-silica aerogel composite material, characterized in that, It is applied to industrial waste gas treatment, industrial wastewater treatment and air purification; the glass fiber powder-silica aerogel composite material is prepared by any one of the preparation methods of claims 1 to 9.