Building thermal insulation aerogel material and preparation method thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a building thermal insulation aerogel material and a preparation method, the aerogel material comprises the following components by mass: 25-35 parts of a silicon source, 40-80 parts of a solvent, 0.3-0.6 part of a catalyst, 4-13 parts of an aluminum source, 9-20 parts of reinforcing fibers, 4-10 parts of a modifier, and 20-40 parts of carrier fibers; the silicon source is ethyl orthosilicate or methyl trimethoxy silane; the solvent is absolute ethyl alcohol; the catalyst is hydrochloric acid or ammonia water; the aluminum source is aluminum nitrate nonahydrate or aluminum isopropoxide; the reinforced fibers are nano titanium dioxide fibers; the modifying agent is gamma-aminopropyl triethoxy silane or gamma-methacryloyloxy propyl trimethoxy silane, and the modifying agent is gamma-aminopropyl triethoxy silane or gamma-methacryloyloxy propyl trimethoxy silane; the carrier fiber is rock wool or mineral wool. According to the invention, the thermal insulation aerogel material for buildings, which is high in mechanical strength, good in weather resistance and excellent in thermal insulation performance, can be prepared, so that the requirements of the building industry on high-performance thermal insulation materials can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and in particular relates to a building thermal insulation aerogel material and a preparation method thereof. Background Art

[0002] Aerogel materials have shown great potential in the field of building insulation due to their ultra-low thermal conductivity.

[0003] Existing building thermal insulation aerogel materials still have many problems that need to be solved urgently. For example, during the construction process, due to the insufficient mechanical strength and low toughness of the aerogel material, it is prone to breakage and fragmentation. After long-term use, rainwater can easily penetrate through the gaps, affecting the thermal insulation effect. In addition, long-term exposure to outdoor environments, affected by factors such as ultraviolet rays, rain, and temperature changes, the structure of the aerogel will gradually be destroyed, resulting in a decrease in thermal insulation performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a building thermal insulation aerogel material and a preparation method, which can be used to prepare a building thermal insulation aerogel material with high mechanical strength, good weather resistance and excellent thermal insulation performance, so as to meet the demand of the construction industry for high-performance thermal insulation materials.

[0005] The technical solutions adopted by the present invention are as follows:

[0006] A building thermal insulation aerogel material, the aerogel material is composed of the following parts by weight: 25-35 parts of a silicon source, 40-80 parts of a solvent, 0.3-0.6 parts of a catalyst, 4-13 parts of an aluminum source, 9-20 parts of reinforcing fibers, 4-10 parts of a modifier, and 20-40 parts of a carrier fiber;

[0007] The silicon source is ethyl orthosilicate or methyltrimethoxysilane;

[0008] The solvent is anhydrous ethanol;

[0009] The catalyst is hydrochloric acid or ammonia;

[0010] The aluminum source is aluminum nitrate nonahydrate or aluminum isopropoxide;

[0011] The reinforcing fiber is nano titanium dioxide fiber;

[0012] The modifier is γ-aminopropyltriethoxysilane or γ-methacryloxypropyltrimethoxysilane;

[0013] The carrier fiber is rock wool or mineral wool.

[0014] A method for preparing a building thermal insulation aerogel material, the preparation method comprising the following steps:

[0015] S1: preparing a solution to obtain a sol material;

[0016] S11: adding 25-35 parts of silicon source to 40-80 parts of solvent, stirring uniformly by magnetic force to form a mixed solution;

[0017] S12: While the mixed solution is being stirred, 0.3-0.6 parts of the catalyst is slowly added dropwise at a rate of 0.5-1.5 ml / min. After the addition is complete, stirring is continued for 0.5-2 h to obtain a transparent sol material.

[0018] S2: mixing the aluminum source with the reinforcing fiber to obtain a liquid gel;

[0019] In S2, the specific steps of mixing the aluminum source and the reinforcing fiber are as follows:

[0020] S21: Select 40-80 parts of a solvent and dissolve 4-13 parts of an aluminum source in the solvent to form an aluminum source solution;

[0021] S22: stirring the transparent sol material, and at the same time slowly adding the aluminum source solution into the transparent sol material to form an aluminum source sol solution; the stirring speed is 350-550 rpm, and the stirring time is 30-70 minutes.

[0022] S23: 9-20 parts of reinforcing fibers are added to deionized water and ultrasonically dispersed for 15-30 minutes to form a fiber dispersion;

[0023] S24: Add the fiber dispersion to the aluminum source sol solution and stir for 60-120 minutes to obtain a liquid gel.

[0024] S3: Modification of liquid gel;

[0025] In the step S3, 4-10 parts of the modifier and the liquid gel are stirred at 40-60° C. for 2-3 hours.

[0026] S4: coating the modified liquid gel on 20-40 parts of carrier fibers and performing a curing treatment;

[0027] In said S4, the specific steps of the curing process are as follows:

[0028] S41: First, the carrier fiber is spread flat in the mold and pressed flat to maintain a uniform thickness;

[0029] S42: Then, the liquid gel is poured into the mold and the mold cover is covered to seal the mold;

[0030] S43: High-pressure gas is injected into the mold to increase the pressure inside the mold so that the liquid gel is immersed in the carrier fiber;

[0031] S44: Let stand at room temperature for 12-24 hours to form a gel;

[0032] S45: Remove the mold cover and place the gel and the mold together in an aging box for aging. The temperature is set at 60-70°C and the aging time is 24-36 hours.

[0033] S5: Drying the solidified gel.

[0034] In S5, the gel is taken out from the mold, placed in a dryer, pre-frozen at -40-50°C for 1-3 hours, and dried at a vacuum degree of 10-20 Pa for 12-24 hours to remove excess liquid in the gel to obtain an aerogel.

[0035] The technical effects achieved by the present invention are:

[0036] The building thermal insulation aerogel material and preparation method of the present invention enhance the compressive strength of the material to 2-3 times that of traditional aerogel materials by uniformly dispersing reinforcing fibers and introducing an aluminum source, effectively preventing damage during construction and use. In addition, the modifier significantly improves the hydrophobicity of the material. In a humid environment, the decline in thermal insulation performance is reduced by more than 70% compared with traditional materials.

[0037] The present invention provides a building thermal insulation aerogel material and preparation method. By introducing carrier fibers, the gel is coated inside the carrier fibers. After curing, the carrier fibers can be used to increase the internal support structure frame of the gel. The material also has good bending resistance, allowing it to be shaped during construction, making it easy to fill small gaps or small areas in buildings, effectively improving its usage needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flowchart of Example 2 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following examples. It should be understood that the following text is only used to describe one or more specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0040] Example 1:

[0041] A building thermal insulation aerogel material, the aerogel material is composed of the following parts by weight: 25-35 parts of a silicon source, 40-80 parts of a solvent, 0.3-0.6 parts of a catalyst, 4-13 parts of an aluminum source, 9-20 parts of reinforcing fibers, 4-10 parts of a modifier, and 20-40 parts of a carrier fiber;

[0042] The silicon source is ethyl orthosilicate or methyltrimethoxysilane;

[0043] The solvent is anhydrous ethanol;

[0044] The catalyst is hydrochloric acid or ammonia;

[0045] The aluminum source is aluminum nitrate nonahydrate or aluminum isopropoxide;

[0046] The reinforcing fiber is nano titanium dioxide fiber;

[0047] The modifier is γ-aminopropyltriethoxysilane or γ-methacryloxypropyltrimethoxysilane;

[0048] The carrier fiber is rock wool or mineral wool.

[0049] Example 2:

[0050] like Figure 1 As shown, a method for preparing a building thermal insulation aerogel material comprises the following steps:

[0051] S1: preparing a solution to obtain a sol material;

[0052] S11: adding 25-35 parts of silicon source to 40-80 parts of solvent, stirring uniformly by magnetic force to form a mixed solution;

[0053] S12: While the mixed solution is being stirred, 0.3-0.6 parts of the catalyst is slowly added dropwise at a rate of 0.5-1.5 ml / min. After the addition is complete, stirring is continued for 0.5-2 h to obtain a transparent sol material.

[0054] By strictly controlling the ratio of silicon source to solvent, the silicon source is ensured to be fully dissolved and dispersed. At the same time, the catalyst addition rate and stirring time are precisely controlled to allow the silicon source to fully undergo hydrolysis and polycondensation reactions, laying the foundation for the subsequent formation of a stable aerogel network structure.

[0055] S2: mixing the aluminum source with the reinforcing fiber to obtain a liquid gel;

[0056] In S2, the specific steps of mixing the aluminum source and the reinforcing fiber are as follows:

[0057] S21: Select 40-80 parts of a solvent and dissolve 4-13 parts of an aluminum source in the solvent to form an aluminum source solution;

[0058] S22: stirring the transparent sol material, and at the same time slowly adding the aluminum source solution into the transparent sol material to form an aluminum source sol solution; the stirring speed is 350-550 rpm, and the stirring time is 30-70 minutes.

[0059] S23: 9-20 parts of reinforcing fibers are added to deionized water and ultrasonically dispersed for 15-30 minutes to form a fiber dispersion;

[0060] S24: Add the fiber dispersion to the aluminum source sol solution and stir for 60-120 minutes to obtain a liquid gel.

[0061] This step allows the reinforcing fibers to be evenly dispersed in the sol system. The addition of an aluminum source introduces aluminum into the aerogel network, enhancing the aerogel's mechanical properties and high-temperature resistance. Ultrasonic dispersion and prolonged stirring of the reinforcing fibers ensure uniform dispersion of the fibers as individual strands, effectively increasing the aerogel's strength.

[0062] By enhancing the uniform dispersion of fibers and introducing aluminum sources, the compressive strength of the material is increased to 2-3 times that of traditional aerogel materials, effectively avoiding damage during construction and use. In addition, the effect of the modifier significantly improves the hydrophobicity of the material. In a humid environment, the decline in thermal insulation performance is reduced by more than 70% compared with traditional materials.

[0063] S3: Modification of liquid gel;

[0064] In S3, 4-10 parts of the modifier and the liquid gel are stirred continuously for 2-3 hours at 40-60° C. Through this modification step, the modifier can be firmly grafted onto the surface of the aerogel, significantly improving the hydrophobicity of the aerogel and its compatibility with other building materials.

[0065] S4: coating the modified liquid gel on 20-40 parts of carrier fibers and performing a curing treatment;

[0066] In said S4, the specific steps of the curing process are as follows:

[0067] S41: First, the carrier fiber is spread flat in the mold and pressed flat to maintain a uniform thickness;

[0068] S42: Then, the liquid gel is poured into the mold and the mold cover is covered to seal the mold;

[0069] S43: High-pressure gas is injected into the mold to increase the pressure inside the mold so that the liquid gel is immersed in the carrier fiber;

[0070] S44: Let stand at room temperature for 12-24 hours to form a gel;

[0071] S45: Remove the mold cover and place the gel and the mold together in an aging box for aging. The temperature is set at 60-70°C and the aging time is 24-36 hours.

[0072] Among them, rock wool or mineral wool is made of rock and slag, has good fire resistance (Grade A), but has strong hygroscopicity and high thermal conductivity (0.04-0.07W / (m·K)); when used in combination with aerogel, aerogel fills the large pores of rock wool, reducing air convection heat loss, while reducing the hygroscopicity of the material, avoiding the decline in thermal insulation performance of traditional rock wool after absorbing water. It is suitable for external insulation systems of building exterior walls, taking into account fire prevention, thermal insulation and resistance to water vapor penetration.

[0073] The impregnation coating process can improve the moisture absorption of the substrate. When combined with fireproof fiber felt (such as basalt and ceramic fiber), it can achieve "insulation + fireproof + waterproof" integration, meeting building energy conservation and safety standards. Traditional aerogel insulation materials are mostly single aerogel blocks or particles, which are easy to break and inconvenient to construct. Aerogel blankets, by combining with fiber felt, solve the following technical pain points:

[0074] Fiber felt serves as a skeleton to prevent brittle fracture of aerogel materials and can adapt to building deformation; the blanket-like structure can be directly cut and laid without complex anchoring, and the construction efficiency is 40% higher than that of traditional panels; through the selection of base materials (such as fire-resistant fibers and hydrophobic fibers), aerogel materials can simultaneously meet multiple building needs such as thermal insulation, fire prevention, and waterproofing, reducing the cost of multi-layer construction.

[0075] The gel network structure is further enhanced. Standing at room temperature ensures uniform gel formation. The aging process makes the gel network more dense and stable, improving the overall performance of the material.

[0076] By introducing carrier fibers, the gel is coated inside the carrier fibers. After curing, the carrier fibers can be used to increase the internal support structure frame of the gel, and it has good anti-bending properties, so that it can be shaped during construction, which is convenient for filling small gaps or small areas in the building, effectively improving its usage needs.

[0077] S5: Drying the solidified gel.

[0078] In S5, the gel is removed from the mold and placed in a dryer for pre-freezing at -40-50°C for 1-3 hours. The gel is then dried at a vacuum of 10-20 Pa for 12-24 hours to remove excess liquid and obtain an aerogel. The freeze-drying process prevents the aerogel's pore structure from collapsing, ensuring the material's high porosity and low thermal conductivity.

[0079] Implementation 3:

[0080] Based on Examples 1-2, this example is used to test the thermal insulation effect of the aerogel material prepared in Example 1, and the steps are as follows:

[0081] Based on Fourier's law of heat conduction, the thermal conductivity (λ) of a material is calculated by measuring its heat flux density, temperature difference and other parameters under steady-state heat flow conditions to evaluate its thermal insulation performance. The lower the thermal conductivity, the better the thermal insulation effect of the material.

[0082] S1: Sample preparation: Cut rectangular samples of 300 mm × 300 mm × 25 mm from the rock wool / mineral wool carrier aerogel material (the thickness can be adjusted according to actual needs, but uniformity must be ensured). Prepare at least three sets of parallel samples to reduce errors.

[0083] The sample surface must be flat and free of obvious defects (such as cracks and holes). The edges should be sealed with aluminum foil to prevent heat radiation and convection from affecting the test results.

[0084] S2: Select the test instrument: thermal conductivity tester (such as a flat plate tester that complies with GB / T 10294 or ASTM C177): including a heating plate, cooling plate, temperature sensor, and heat flow meter;

[0085] Constant temperature and humidity chamber (control the test environment temperature at 23±2℃ and humidity at 50±5%).

[0086] S3: Place the sample in a constant temperature and humidity chamber and let it stand for 48 hours to ensure that the moisture content of the sample is stable (moisture content ≤ 1%, which can be detected in advance by weighing method: mass difference before and after drying / mass before drying × 100%).

[0087] S4: Preheat the thermal conductivity tester for 30 minutes and calibrate it using a standard calibration plate (with known thermal conductivity, such as quartz glass or ceramic plate) to ensure that the instrument's measurement accuracy error is ≤±2%.

[0088] S5: Place the sample between the heating plate and the cooling plate, ensuring that the sample fits tightly against the plate surface with no air gaps (gaps can be eliminated by lightly pressing the sample or applying thermal grease, but the effect of the grease thickness on the results needs to be recorded); attach temperature sensors (accuracy ±0.1°C) to the center of the upper and lower surfaces of the sample, place the heat flow meter close to the sample surface, and connect it to the data acquisition system.

[0089] S6: Set the heating plate temperature to 60°C (simulating a high temperature environment on the building exterior wall) and the cooling plate temperature to 20°C (simulating room temperature), with the temperature difference controlled at 40°C ± 1°C. Turn on the instrument and record the changes in heat flux density and upper and lower surface temperatures over time until the data stabilizes (temperature fluctuation ≤ 0.5°C and heat flux fluctuation ≤ 1% within 30 consecutive minutes).

[0090] S7: Collect data and test three groups of parallel samples separately, calculate the average thermal conductivity and standard deviation. If the standard deviation exceeds 5% of the average, retest is required. Record the temperature and humidity of the test environment, instrument parameters, etc. to ensure data traceability.

[0091] The foregoing is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained herein shall, unless otherwise specified or limited, be implemented in accordance with conventional means in the art.

Claims

1. A building thermal insulation aerogel material, characterized by: The aerogel material is composed of the following parts by mass: 25-35 parts of silicon source, 40-80 parts of solvent, 0.3-0.6 parts of catalyst, 4-13 parts of aluminum source, 9-20 parts of reinforcing fiber, 4-10 parts of modifier, and 20-40 parts of carrier fiber; The silicon source is ethyl orthosilicate or methyltrimethoxysilane; The solvent is anhydrous ethanol; The catalyst is hydrochloric acid or ammonia; The aluminum source is aluminum nitrate nonahydrate or aluminum isopropoxide; The reinforcing fiber is nano titanium dioxide fiber; The modifier is γ-aminopropyltriethoxysilane or γ-methacryloxypropyltrimethoxysilane; The carrier fiber is rock wool or mineral wool.

2. A method for preparing a building thermal insulation aerogel material, characterized by: The preparation method comprises the following steps: S1: preparing a solution to obtain a sol material; S2: mixing the aluminum source with the reinforcing fiber to obtain a liquid gel; S3: Modification of liquid gel; S4: coating the modified liquid gel on 20-40 parts of carrier fibers and performing a curing treatment; S5: Drying the solidified gel.

3. The method for preparing a building thermal insulation aerogel material according to claim 2, wherein: In S1, the specific steps of solution preparation are as follows: S11: adding 25-35 parts of silicon source to 40-80 parts of solvent, stirring uniformly by magnetic force to form a mixed solution; S12: While the mixed solution is being stirred, 0.3-0.6 parts of the catalyst is slowly added dropwise at a rate of 0.5-1.5 ml / min. After the addition is complete, stirring is continued for 0.5-2 h to obtain a transparent sol material.

4. The method for preparing a building thermal insulation aerogel material according to claim 2, wherein: In S2, the specific steps of mixing the aluminum source and the reinforcing fiber are as follows: S21: Select 40-80 parts of a solvent and dissolve 4-13 parts of an aluminum source in the solvent to form an aluminum source solution; S22: stirring the transparent sol material, and slowly adding the aluminum source solution into the transparent sol material to form an aluminum source sol solution; S23: 9-20 parts of reinforcing fibers are added to deionized water and ultrasonically dispersed for 15-30 minutes to form a fiber dispersion; S24: Add the fiber dispersion to the aluminum source sol solution and stir for 60-120 minutes to obtain a liquid gel.

5. The method for preparing a building thermal insulation aerogel material according to claim 4, characterized in that: In the step S22, the stirring speed is 350-550 rpm, and the stirring time is 30-70 minutes.

6. The method for preparing a building thermal insulation aerogel material according to claim 2, characterized in that: In the step S3, 4-10 parts of the modifier and the liquid gel are stirred at 40-60° C. for 2-3 hours.

7. The method for preparing a building thermal insulation aerogel material according to claim 2, wherein: In said S4, the specific steps of the curing process are as follows: S41: First, the carrier fiber is spread flat in the mold and pressed flat to maintain a uniform thickness; S42: Then, the liquid gel is poured into the mold and the mold cover is covered to seal the mold; S43: High-pressure gas is injected into the mold to increase the pressure inside the mold so that the liquid gel is immersed in the carrier fiber; S44: Let stand at room temperature for 12-24 hours to form a gel; S45: Remove the mold cover and place the gel and the mold together in an aging box for aging. The temperature is set at 60-70°C and the aging time is 24-36 hours.

8. The method for preparing a building thermal insulation aerogel material according to claim 2, wherein: In S5, the gel is taken out from the mold, placed in a dryer, pre-frozen at -40-50°C for 1-3 hours, and dried at a vacuum degree of 10-20 Pa for 12-24 hours to remove excess liquid in the gel to obtain an aerogel.

Images