Silica aerogel slurry and its preparation method

Abstract

This application provides a silica aerogel slurry and its preparation method. The aerogel slurry is prepared from the following materials, by weight: 10-90 parts water, 1-25 parts hydrophobic silica aerogel powder, 0.01-3 parts anionic surfactant, 0.01-0.9 parts polymeric electrolyte, 0.01-1 parts suspending agent, 0.001-0.01 parts pH adjuster, 0.001-0.02 parts defoamer, and 0.001-0.01 parts double-layer microcapsule antifungal agent. The double-layer microcapsule antifungal agent by weight includes 1-3 parts antifungal agent, 1-3 parts sodium alginate, 0.5-2 parts calcium chloride, 5-10 parts acetic acid, 5-10 parts chitosan, and 100-200 parts water. The double-layer microcapsule antifungal agent of this application not only exerts the antifungal effect of the antifungal agent, but also reduces the impact on the performance of the aerogel slurry.

Description

Technical Field

[0001] This application relates to the field of coating technology, and more particularly to a silica aerogel slurry and its preparation method. Background Technology

[0002] Silica (SiO2) aerogel (hereinafter referred to as aerogel) is a porous material composed of a three-dimensional nanoparticle framework and nanoscale pores. It has the characteristics of low density, high porosity, high specific surface area, low thermal conductivity and strong fire resistance, which brings new development opportunities to traditional thermal insulation materials and provides a possibility for resolving the contradiction between building energy conservation and building fire protection.

[0003] Currently, to improve the thermal insulation performance of existing building materials, a dispersion process is typically used to disperse aerogel powder in an aqueous system to obtain aerogel slurry. However, the static stability of silica aerogel slurry obtained by existing dispersion processes or systems is often difficult to guarantee.

[0004] In addition, commercially available aerogel slurries can develop mold after being left for a long time. This not only affects the quality of the aerogel slurry, but also has a significant impact on the quality of aerogel-based composite building materials. If moldy aerogel-based composite building materials are put on the market, it may endanger people's lives and health.

[0005] Therefore, there is a need for a high-performance, stable, and durable aerogel slurry and its preparation method. Summary of the Invention

[0006] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection of this application.

[0007] This application provides a silica aerogel slurry, which is prepared from the following materials in parts by weight: 10-90 parts water, 1-25 parts hydrophobic silica aerogel powder, 0.01-3 parts anionic surfactant, 0.01-0.9 parts polymeric electrolyte, 0.01-1 parts suspending agent, 0.001-0.01 parts pH adjuster, 0.001-0.02 parts defoamer, and 0.001-0.01 parts double-layer microcapsule antifungal agent. The double-layer microcapsule antifungal agent includes, by weight, 1-3 parts antifungal agent, 1-3 parts sodium alginate, 0.5-2 parts calcium chloride, 5-10 parts acetic acid, 5-10 parts chitosan, and 100-200 parts water.

[0008] In one embodiment, the anionic surfactant is selected from one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl polyoxyethylene ether sulfate, sodium alkyl polyoxyethylene ether carboxylate, sodium dodecyl sulfonate, sodium methylene bisnaphthalene sulfonate, and sodium oleoylmethyl taurate.

[0009] In one embodiment, the anionic surfactant is sodium dodecylbenzenesulfonate (SDBS).

[0010] In one embodiment, the suspending agent is selected from one or more of hydroxypropyl methylcellulose ether, methylcellulose, hydroxyethylcellulose, and carboxymethylcellulose.

[0011] In one embodiment, the suspending agent is hydroxyethyl cellulose (HEC).

[0012] In one embodiment, the polymeric electrolyte is selected from one or more of sodium polyacrylate, ammonium polyacrylate, polyacrylamide, sodium polystyrene sulfonate, and polystyrene-maleic anhydride copolymer.

[0013] In one embodiment, the polymeric electrolyte is polyacrylamide (PAM).

[0014] In one embodiment, the polymeric electrolyte has a number-average molecular weight in the range of 500,000 to 3,000,000.

[0015] In one embodiment, the polymeric electrolyte has a number-average molecular weight in the range of 2,000,000 to 3,000,000.

[0016] In one embodiment, the defoamer is selected from one or more of BASF 2410 defoamer, Nopco 1375, Nopco 1370, BYK 024, and DIGIC 901W.

[0017] In one embodiment, the defoamer is a combination of Dego 901W and BASF 2410 defoamer in a weight ratio of 1:1-5.

[0018] In one embodiment, the hydrophobic silica aerogel powder has a particle size of 0.5 μm-500 μm and a bulk density of 60 kg / m³. 3 -120 kg / m 3 The thermal conductivity is 0.018 W / m·K to 0.021 W / m·K, and the contact angle is 146° to 149°.

[0019] In one embodiment, the water is distilled water or deionized water.

[0020] In one embodiment, the pH adjuster is selected from one or more of ammonia, triethylamine, dimethylethanolamine, and 2-aminomethyl-1-propanol (AMP-95).

[0021] In one embodiment, the pH of the silica aerogel slurry is in the range of 7.5-9.5.

[0022] In one embodiment, the antifungal agent is selected from one or more of 2-n-octyl-4-isothiazolin-3-one (OIT), 2-butyl-1,2-benzisothiazolin-3-one (BBIT), methylisothiazolinone, N-octyl-4-isothiazolin-3-one, 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT), 1,2-benzisothiazolin-3-one, n-butyl-1,2-isothiazolin-3-one, and dialcyldimethylammonium chloride (DDAC).

[0023] In one embodiment, the antifungal agent is a composite antifungal agent consisting of 2-n-octyl-4-isothiazolin-3-one (OIT) and 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) in a weight ratio of 1:2.

[0024] In one embodiment, the bilayer microcapsule antifungal agent is prepared by the following steps:

[0025] 1) Mix the antifungal agent with water to form an antifungal agent solution;

[0026] 2) Sodium alginate, the antifungal agent solution, and water are mixed to form a mixed solution; calcium chloride is mixed with water to form a calcium chloride solution; then the mixed solution is added to the calcium chloride solution, allowed to stand, and filtered to form a single-layer microcapsule antifungal agent;

[0027] 3) At room temperature, acetic acid and chitosan are added to water in sequence to form a microcapsule wall material solution;

[0028] 4) Add the single-layer microcapsule antifungal agent to the microcapsule wall material solution, stir, wash, filter, and dry to obtain the double-layer microcapsule antifungal agent.

[0029] In one embodiment, mixing the antifungal agent with water to form an antifungal agent solution may include adding 1-3 parts by weight of the antifungal agent to 10-30 parts by weight of water and stirring at a speed of 300-600 r / min to form an antifungal agent solution;

[0030] In one embodiment, mixing sodium alginate, the antifungal agent solution, and water to form a mixed solution may include adding 1-3 parts by weight of sodium alginate and the prepared antifungal agent solution sequentially to 20-40 parts by weight of water, and stirring at a speed of 300-600 r / min to form a mixed solution.

[0031] In one embodiment, mixing calcium chloride with water to form a calcium chloride solution may include mixing 0.5-2 parts by weight of calcium chloride with 30-50 parts by weight of water to form a calcium chloride solution.

[0032] In one embodiment, adding the mixed solution to the calcium chloride solution, allowing it to stand, and filtering to form a single-layer microcapsule antifungal agent may include adding the obtained mixed solution to the calcium chloride solution, allowing it to stand for 5-30 minutes, and then filtering to form a single-layer microcapsule antifungal agent.

[0033] In one embodiment, adding acetic acid and chitosan sequentially to water at room temperature to form a microcapsule wall material solution may include adding 5-10 parts by weight of acetic acid and 5-10 parts by weight of chitosan sequentially to 80-100 parts by weight of water at room temperature and stirring at a speed of 300-700 r / min to form a microcapsule wall material solution.

[0034] In one embodiment, obtaining the double-layer microcapsule antifungal agent may include adding a single-layer microcapsule antifungal agent to a microcapsule wall material solution, stirring at 500-1000 r / min for 20-60 min, washing and filtering multiple times with distilled water, and then drying to obtain the double-layer microcapsule antifungal agent.

[0035] On the other hand, this application provides a method for preparing the above-mentioned silica aerogel slurry, the method comprising the following steps:

[0036] 1) Weigh each component;

[0037] 2) Add anionic surfactant, polymeric electrolyte, suspending agent, defoamer and double-layer microcapsule antifungal agent to water, and stir at room temperature and pressure to form a composite dispersion solution;

[0038] 3) The hydrophobic silica aerogel powder is stirred and mixed with the composite dispersion solution, and then a pH adjuster is added to adjust the pH value of the solution to 7.5-9.5 to obtain the initial slurry;

[0039] 4) The initial slurry is subjected to a vacuum degassing process to obtain the silica aerogel slurry.

[0040] In one embodiment, in step 2), the stirring speed can be 300-500 r / min, and the stirring time can be 5-15 minutes.

[0041] In one embodiment, in step 3), the stirring speed can be 1000-4500 r / min, and the stirring time can be 5-30 minutes.

[0042] This application introduces a ternary composite system into an aqueous system, utilizing the synergistic effect of small and large molecules on steric hindrance, and the hydrogen bonding between the suspending stabilizer and water molecules to form a high steric repulsion force. The polymer electrolyte and surfactant dissolved in water form polymer ions and small ions that are adsorbed on the surface of aerogel particles, forming a stable dispersion layer with a double-thickness charged ions. At the same time, by adjusting the pH range of the slurry (e.g., 7.5-9.5), the absolute value of the zeta potential of the slurry is further increased, achieving a zeta potential with an absolute value of greater than 20mV on the surface of the aerogel particles, forming a strong electrostatic repulsion between the particles, thereby ensuring the dispersion stability of the slurry.

[0043] This application introduces a double-layer microcapsule antifungal agent into aerogel slurry. The antifungal agent serves as the core material, while the wall material forms a double-layer microcapsule around the core material, providing dual encapsulation and protection for the antifungal agent and achieving highly efficient and safe antifungal performance. The double-layer microcapsule antifungal agent of this application controls the release rate of the antifungal substance through microcapsules, continuously releasing the antifungal substance to achieve a long-lasting antifungal effect. This effectively improves the mold growth problem of aerogel slurry after long-term storage and enhances the durability and stability of the antifungal effect.

[0044] This application improves the stability of the antifungal agent by using a double-layer microcapsule antifungal agent, avoiding problems such as decomposition, oxidation and loss of the effective components of the antifungal agent caused by environmental factors such as light, temperature and other chemical substances.

[0045] This application enhances the compatibility of the antifungal agent with other aerogel slurry components (i.e., the ternary composite dispersion system of surfactant, polymeric electrolyte, and suspending agent of this application) by using a double-layer microcapsule antifungal agent. This not only achieves the desired antifungal effect with a smaller amount of additive, but also avoids adverse effects on the performance of the aerogel slurry obtained from the ternary composite dispersion system of this application. As a result, the prepared aerogel slurry maintains high hydrophobicity, low thermal conductivity, and long-lasting stability after drying.

[0046] This application improves product safety and reduces harm to human health and environmental pollution by using a double-layer microcapsule antifungal agent combined with other components of the slurry.

[0047] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application may be realized and obtained by means of the methods described in the description. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application are described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0049] Unless otherwise specified, all materials used in the following examples and comparative examples are commercially available.

[0050] The hydrophobic silica aerogel powder used in the following examples and comparative examples can have an average particle size of about 50 μm and a bulk density of about 80 kg / m³. 3 A commercially available product with a thermal conductivity of approximately 0.019 W / m·K and a contact angle of approximately 148°.

[0051] Example 1

[0052] (1) Add 2 parts by weight of antifungal agent (DCOIT) to 25 parts by weight of water and stir evenly at 600 r / min to form an antifungal agent solution.

[0053] (2) Add 3 parts by weight of sodium alginate and 3 parts by weight of antifungal agent solution to 40 parts by weight of water in sequence, and stir evenly at 600 r / min to form a mixed solution; mix 2 parts by weight of calcium chloride with 50 parts by weight of water to form a calcium chloride solution; then add the above mixed solution to the calcium chloride solution, let stand for 25 min, filter, and form a single-layer microcapsule antifungal agent.

[0054] (3) At room temperature, 5 parts by weight of acetic acid and 10 parts by weight of chitosan are added to 80 parts by weight of water and stirred evenly at a speed of 500 r / min to form a second layer of microcapsule wall material solution.

[0055] (4) Add the single-layer microcapsule antifungal agent to the microcapsule wall material solution, stir at 500 r / min for 50 min, wash and filter with distilled water multiple times, and then dry to obtain the double-layer microcapsule antifungal agent.

[0056] (5) Add 0.1 parts by weight of sodium dodecylbenzenesulfonate (SDBS), 0.2 parts by weight of polyacrylamide (PAM) with a number average molecular weight of 2,000,000, 0.01 parts by weight of hydroxyethyl cellulose (HEC), 0.004 parts by weight of a combination of Deger 901W and BASF 2410 defoamer (weight ratio of 1:3), and 0.02 parts by weight of double-layer microcapsule antifungal agent to 60 parts by weight of deionized water, and stir at 500 r / min for 10 minutes in a high-speed disperser at room temperature and pressure to obtain a uniform and stable composite dispersion solution.

[0057] (6) Add 6 parts by weight of hydrophobic silica aerogel powder to the composite dispersion solution, stir at 1000 r / min until the hydrophobic silica aerogel powder is completely immersed in the composite dispersion solution, then stir at 2500 r / min for 30 min, add 0.005-0.01 parts by weight of ammonia water to adjust the pH value of the slurry to about 9.5 to obtain the initial slurry; perform vacuum degassing process on the initial slurry to prepare silica aerogel slurry.

[0058] Example 2-3

[0059] The preparation methods of Examples 2-3 are similar to those of Example 1, except that the composite antifungal agent of 2-n-octyl-4-isothiazolin-3-one (OIT) and 4,5-dichloro-N-octyl-4-isothiazolin-3-one (DCOIT) with a weight ratio of 1:2 was used in Examples 2 and 3 when preparing the bilayer microcapsule antifungal agent, and the pH value of the prepared aerogel slurry is different. The pH values ​​are shown in Table 1 below.

[0060] Comparative Example 1

[0061] (1) 0.1 parts by weight of sodium dodecylbenzenesulfonate (SDBS), 0.2 parts by weight of polyacrylamide (PAM) with a number average molecular weight of 2,000,000, 0.01 parts by weight of hydroxyethyl cellulose (HEC), 0.004 parts by weight of a combination of DEG 901W and BASF 2410 defoamer (weight ratio of 1:3), and 0.02 parts by weight of DCOIT were added to 60 parts by weight of deionized water. The mixture was stirred for 10 minutes at 500 r / min using a high-speed disperser at room temperature and pressure to obtain a uniform and stable composite dispersion solution.

[0062] (2) Add 6 parts by weight of hydrophobic silica aerogel powder to the composite dispersion solution and stir at 1000 r / min until the hydrophobic silica aerogel powder is completely immersed in the composite dispersion solution. Then stir at 2500 r / min for 30 min and add 0.005-0.01 parts by weight of ammonia water to adjust the pH value of the slurry to about 9.5 to obtain the initial slurry. Perform a vacuum degassing process on the initial slurry to prepare the silica aerogel slurry.

[0063] Comparative Example 2

[0064] (1) 0.1 parts by weight of sodium dodecylbenzenesulfonate (SDBS), 0.2 parts by weight of polyacrylamide (PAM) with a number average molecular weight of 2,000,000, 0.01 parts by weight of hydroxyethyl cellulose (HEC), 0.004 parts by weight of a combination of DIG 901W and BASF 2410 defoamer (weight ratio 1:3), and 0.02 parts by weight of a composite antifungal agent (OIT:DCOIT = 1:2) were added to 60 parts by weight of deionized water. The mixture was stirred for 10 minutes at 500 r / min using a high-speed disperser at room temperature and pressure to obtain a uniform and stable composite dispersion solution.

[0065] (2) Add 6 parts by weight of hydrophobic silica aerogel powder to the composite dispersion solution and stir at 1000 r / min until the hydrophobic silica aerogel powder is completely immersed in the composite dispersion solution. Then stir at 2500 r / min for 30 min and add 0.005-0.01 parts by weight of ammonia water to adjust the pH value of the slurry to about 9.5 to obtain the initial slurry. Perform a vacuum degassing process on the initial slurry to prepare the silica aerogel slurry.

[0066] Comparative Example 3

[0067] (1) Add 0.1 parts by weight of sodium dodecylbenzenesulfonate (SDBS), 0.2 parts by weight of polyacrylamide (PAM) with a number average molecular weight of 2,000,000, 0.01 parts by weight of hydroxyethyl cellulose (HEC), 0.004 parts by weight of DIG 901W and BASF 2410 defoamer (weight ratio of 1:3) to 60 parts by weight of deionized water, and stir at 500 r / min for 10 minutes in a high-speed disperser at room temperature and pressure to obtain a uniform and stable composite dispersion solution.

[0068] (2) Add 6 parts by weight of hydrophobic silica aerogel powder to the composite dispersion solution and stir at 1000 r / min until the hydrophobic silica aerogel powder is completely immersed in the composite dispersion solution. Then stir at 2500 r / min for 30 min and add 0.005-0.01 parts by weight of ammonia water to adjust the pH value of the slurry to about 9.5 to obtain the initial slurry. Perform a vacuum degassing process on the initial slurry to prepare the silica aerogel slurry.

[0069] Comparative Examples 4-7

[0070] The preparation methods of Comparative Examples 4-7 are basically the same as those of Example 1, but only include aerogel slurries prepared by a single dispersion system or a binary composite dispersion system. The dispersion systems and proportions of Comparative Examples 4-7 are shown in Table 1 below.

[0071] Table 1

[0072] project Distributed system slurry pH value Number of copies Example 2 SDBS / PAM / HEC 8.9 0.1 / 0.2 / 0.01 Example 3 SDBS / PAM / HEC 9.1 0.1 / 0.2 / 0.01 Comparative Example 4 SDBS 9.2 0.1 Comparative Example 5 PAM 9.5 0.2 Comparative Example 6 SDBS / PAM 9.3 0.1 / 0.2 Comparative Example 7 SDBS / HEC 9.2 0.1 / 0.01

[0073] Performance testing

[0074] The silica aerogel slurries prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to Zeta potential testing. Simultaneously, samples were dried at 60℃ and then tested for thermal conductivity and contact angle. Thermal conductivity was tested according to the national standard GB / T 10297-2015. Furthermore, regarding the long-term static stability of the aerogel slurries, the aerogel slurries prepared in Examples 1-3 and Comparative Examples 1-7 were tested. The slurries were placed in a constant temperature and humidity environment of 25±2℃ and 40-50% relative humidity for 180 days. After this period, tests were conducted to determine if mold growth occurred and whether unstable phenomena such as sedimentation, stratification, or water seepage occurred. The test results are shown in Table 2 below.

[0075] Table 2

[0076]

[0077] According to the results in Table 2, the aerogel slurry prepared in Comparative Example 3, without the addition of a mildew inhibitor, showed an absolute value of Zeta potential greater than 20mV after standing in a constant temperature and humidity environment for 180 days. No obvious sedimentation, stratification, or water seepage was observed. However, due to the lack of a mildew inhibitor, severe mold growth occurred, with large black spots appearing in the moldy areas, which seriously affected the appearance color of the aerogel slurry. At the same time, it also had the problems of high thermal conductivity and low contact angle, which adversely affected the thermal conductivity and hydrophobicity of the aerogel slurry. This indicates that mold growth can seriously affect the product quality of aerogel slurry.

[0078] In Comparative Examples 1 and 2, the aerogel slurries prepared with single and composite antifungal agents, respectively, showed no severe mold growth after 180 days of standing in a constant temperature and humidity environment. The aerogel slurries maintained a low thermal conductivity and high contact angle after drying, indicating that their thermal conductivity and hydrophobicity were unaffected. However, both comparative examples showed a small number of black mold spots on their surfaces, indicating mold growth. This may be due to some decomposition and loss of the antifungal agent during slurry preparation and storage, leading to a weakened antifungal effect. After standing, the slurries in both comparative examples also exhibited water separation and stratification. This may be because, although the absolute value of the zeta potential of the aerogel slurry is greater than 20 mV, the addition of the antifungal agent affected the complexation between other components in the aerogel slurry, leading to instability during long-term storage.

[0079] In Comparative Examples 4-7, aerogel slurries were prepared with either a single dispersant or a binary composite dispersant, and the antifungal agent was a double-layer microcapsule composite antifungal agent. After standing in a constant temperature and humidity environment for 180 days, the aerogel slurries did not exhibit severe mold growth and maintained low thermal conductivity and high contact angle after drying. This indicates that the double-layer microcapsule composite antifungal agent has excellent antifungal effect and does not adversely affect the thermal conductivity and hydrophobicity of the aerogel slurry. However, the aerogel slurries prepared using a single dispersion system or a binary composite dispersion system had an absolute Zeta potential of less than 20 mV and weak electrostatic and steric repulsion, resulting in water separation after standing. This may be because the single dispersion system or the binary composite dispersion system cannot guarantee the stability of the system.

[0080] In contrast, the aerogel slurry prepared in Examples 1-3 of this application uses a ternary composite dispersion system. After standing in a constant temperature and humidity environment for 180 days, the aerogel slurry still retains its anti-mold effect and does not develop mold. After drying, it still maintains a low thermal conductivity and a high contact angle, and does not affect the composite with other components of the aerogel slurry. The slurry quality remains stable, and there are no obvious unstable phenomena such as sedimentation, stratification, or water seepage. This may be because the use of small and large molecules in synergy and the hydrogen bonding association between the suspending stabilizer and water molecules increases the steric hindrance and repulsion, ensuring the stability of the aerogel slurry. At the same time, the addition of a double-layer microcapsule composite anti-mold agent, using chitosan and sodium alginate to double-encapsulate and protect the composite anti-mold agent, inhibits the decomposition and loss of the anti-mold agent during the preparation and storage of the slurry.

[0081] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A silica aerogel slurry, characterized in that, The silica aerogel slurry is prepared from the following materials, by weight: 10-90 parts water, 1-25 parts hydrophobic silica aerogel powder, 0.01-3 parts anionic surfactant, 0.01-0.9 parts polymeric electrolyte, 0.01-1 parts suspending agent, 0.001-0.01 parts pH adjuster, 0.001-0.02 parts defoamer, and 0.02 parts double-layer microcapsule antifungal agent. The double-layer microcapsule antifungal agent by weight includes 1-3 parts antifungal agent, 1-3 parts sodium alginate, 0.5-2 parts calcium chloride, 5-10 parts acetic acid, 5-10 parts chitosan, and 100-200 parts water. The suspending agent is selected from one or more of hydroxypropyl methylcellulose ether, methylcellulose, hydroxyethylcellulose, and carboxymethylcellulose; The polymeric electrolyte is selected from one or more of sodium polyacrylate, ammonium polyacrylate, polyacrylamide, sodium polystyrene sulfonate, and polystyrene-maleic anhydride copolymer; The double-layer microcapsule antifungal agent is prepared through the following steps: 1) Mix the antifungal agent with water to form an antifungal agent solution; 2) Sodium alginate, the antifungal agent solution, and water are mixed to form a mixed solution; calcium chloride is mixed with water to form a calcium chloride solution; then the mixed solution is added to the calcium chloride solution, allowed to stand, and filtered to form a single-layer microcapsule antifungal agent; 3) At room temperature, acetic acid and chitosan are added to water in sequence to form a microcapsule wall material solution; 4) Add the single-layer microcapsule antifungal agent to the microcapsule wall material solution, stir, wash, filter, and dry to obtain the double-layer microcapsule antifungal agent.

2. The silica aerogel slurry according to claim 1, characterized in that, The anionic surfactant is selected from one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl polyoxyethylene ether sulfate, sodium alkyl polyoxyethylene ether carboxylate, sodium dodecyl sulfonate, sodium methylene bisnaphthalene sulfonate, and sodium oleoyl methyl taurate.

3. The silica aerogel slurry according to claim 2, characterized in that, The anionic surfactant is sodium dodecylbenzenesulfonate.

4. The silica aerogel slurry according to claim 1, characterized in that, The suspending agent is hydroxyethyl cellulose.

5. The silica aerogel slurry according to claim 1, characterized in that, The polymeric electrolyte is polyacrylamide.

6. The silica aerogel slurry according to claim 1, characterized in that, The polymeric electrolyte has a number-average molecular weight in the range of 500,000 to 3,000,000.

7. The silica aerogel slurry according to claim 6, characterized in that, The polymeric electrolyte has a number-average molecular weight in the range of 2,000,000 to 3,000,000.

8. The silica aerogel slurry according to claim 1, characterized in that, The defoamer is selected from one or more of BASF 2410 defoamer, Nopco 1375, Nopco 1370, BYK 024, and DIGIC 901W; and / or, The hydrophobic silica aerogel powder has a particle size of 0.5 μm-500 μm and a bulk density of 60 kg / m³. 3 -120kg / m 3 The thermal conductivity is 0.018 W / m·k - 0.021 W / m·k and the contact angle is 146°-149°.

9. The silica aerogel slurry according to claim 8, characterized in that, The defoamer is a combination of Dego 901W and BASF 2410 defoamer in a weight ratio of 1:1-5.

10. The silica aerogel slurry according to claim 1, characterized in that, The water is distilled water or deionized water; and / or, The pH adjuster is selected from one or more of ammonia, triethylamine, dimethylethanolamine, and 2-aminomethyl-1-propanol; and / or, The pH of the silica aerogel slurry is in the range of 7.5-9.

5.

11. The silica aerogel slurry according to claim 1, characterized in that, The antifungal agent is selected from one or more of 2-n-octyl-4-isothiazolin-3-one, 2-butyl-1,2-benzisothiazolin-3-one, methylisothiazolinone, N-octyl-4-isothiazolin-3-one, 4,5-dichloro-N-octyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, and n-butyl-1,2-isothiazolin-3-one.

12. The silica aerogel slurry according to claim 11, characterized in that, The antifungal agent is a composite antifungal agent consisting of 2-n-octyl-4-isothiazolin-3-one and 4,5-dichloro-N-octyl-4-isothiazolin-3-one in a weight ratio of 1:

2.

13. A method for preparing silica aerogel slurry according to any one of claims 1-12, characterized in that, The method includes the following steps: 1) Weigh each component; 2) Add anionic surfactant, polymeric electrolyte, suspending agent, defoamer and double-layer microcapsule antifungal agent to water, and stir at room temperature and pressure to form a composite dispersion solution; 3) Mix the hydrophobic silica aerogel powder with the composite dispersion solution, and then add a pH adjuster to adjust the pH of the solution to 7.5-9.5 to obtain the initial slurry; 4) The initial slurry is subjected to a vacuum degassing process to obtain the silica aerogel slurry.

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