Preparation method of aerogel mosquito-repelling material

Abstract

The invention provides a preparation method of an aerogel mosquito-repelling material, and belongs to the technical field of aerogel composite material preparation and daily necessity material preparation. Hydrolyzing the silicon source precursor, adding a catalyst 1 and a pore size adjusting additive 1, and gelling in a container to obtain silica gel; the preparation method comprises the following steps: uniformly mixing and stirring silica gel and ethanol to obtain a silica gel alcoholic solution A; adding a structure enhancing aid into the obtained silica gel alcoholic solution A, and then uniformly stirring to obtain a silica gel alcoholic solution B; adding a modifier and a catalyst 2 into the obtained silica gel alcoholic solution B, heating the mixed solution, and carrying out hydrophobic modification; separating the obtained modified mixed solution to obtain a white emulsion; putting the mixture into a shaping disc for drying to obtain the structure-enhanced hydrophobic blocky aerogel material. Processing the aerogel material and the mosquito repellent; the aerogel mosquito-repelling material is obtained. The aerogel mosquito-repelling material can slowly release effective components, has a continuous mosquito-repelling effect, is hydrophobic and not easy to damage in an outdoor environment, can be conveniently and quickly used, and improves the adaptability of a use scene.

Description

Technical Field

[0001] The invention relates to a method for preparing an aerogel mosquito repellent material. The aerogel material is used as a carrier and the adsorption and hydrophobicity of the aerogel material and the volatility of the mosquito repellent are utilized to make the aerogel mosquito repellent material have multiple functions of waterproofing, slow release and mosquito repellent, which greatly expands the environmental adaptability and durability of the mosquito repellent product and also improves the economic efficiency of the product compared with direct application products. Background Art

[0002] Aerogel is a nanoscale porous amorphous solid material and one of the lowest density solids in the world, with a density as low as 0.002 g / cm 3 . Currently, the main silica aerogel on the market is formed by the sol-gel method, which uses a specific drying method to replace the liquid phase in the gel with gas. Aerogel has an extremely high porosity of more than 90%, which allows aerogel to absorb a large amount of liquid and is an excellent adsorption material.

[0003] The main ingredients of mosquito repellents include DEET, Imonim, Icaridin, etc., and their working principle is to repel insects by volatile odors. In addition, the main ingredient in electric mosquito coils is pyrethroid pesticides, which are neurotoxins that selectively act on the sodium ion channels of the mosquito's nerve cell membranes to knock down mosquitoes. It should be noted that although these ingredients perform well in repelling mosquitoes, safety should still be taken into consideration when using mosquito repellents to avoid direct contact with the skin or eyes, especially for infants and children. Adverse reactions caused by improper use should be avoided. Therefore, it is of great significance to develop non-direct contact mosquito repellent products.

[0004] Patent CN117717072A discloses a porous gel solid mosquito repellent carrier and its preparation method and application. The mosquito repellent composite material prepared by the method using the porous gel solid mosquito repellent carrier can be used without plugging in electricity, and the porous gel solid is used as the carrier of the mosquito repellent. The loose porous structure can make the mosquito repellent work quickly and effectively. This type of porous gel solid mosquito repellent has no open flame safety hazards and is safe and environmentally friendly. However, the product of this method is a hydrophilic product, and the problem of long-term storage and use in damp weather absorbing water to become a wet gel is not solved. After absorbing water, the pores of the loose porous structure are blocked, affecting the efficiency of production capacity and the user experience.

[0005] CN116872593A discloses a mosquito repellent textile and a production method thereof. This method provides a method for preparing non-woven products by using cellulose nanoporous aerogel and plant-derived mosquito repellent functional masterbatch. However, the hydrophilicity of the aerogel can cause pore blockage, affecting the product's use effect and the functional singularity of the textile, and hindering the product's adaptability to other application scenarios.

[0006] CN205995464U discloses a method for preparing a polyurea aerogel adsorbent. The method involves a polyurea aerogel adsorbent including a carrier and a liquid adsorbed by the carrier. The carrier is a polyurea aerogel, and the surface tension of the adsorbed liquid needs to be less than 0.07N / m. The strict characteristics of the adsorbed liquid reduce the universality of the method. At the same time, the hydrophilicity of the polyurea aerogel will cause pore blockage, affecting the use effect of the product.

[0007] CN104525132B discloses an aerogel material and its preparation method and application. The aerogel material described in the method has good liquid adsorption capacity and excellent sustained-release performance. However, from the perspective of effect evaluation, the release amount in 1 hour is 0%, and the release amount in 12 hours is 2%-3%. The average release amount of the product is too low, which seriously affects the mosquito repellent effect. This is related to the diameter of the aerogel pores used in it being 5nm-80nm, which affects the free volatilization of the effective volatile components, and the aerogel pore size needs to be modified and improved. Summary of the invention In order to solve the above problems, the present invention provides a method for preparing an aerogel mosquito repellent material. The aerogel mosquito repellent composite material is used for the preparation of the aerogel mosquito repellent composite material, and the aerogel material is compounded with the mosquito repellent, which fully utilizes the adsorption of the aerogel and the efficacy of the mosquito repellent. By adding the pore size regulating additive and the structural reinforcing agent, the structural strength and pore size of the aerogel material are enhanced, and the mosquito repellent efficacy of the product is increased. In addition, the hydrophobicity also ensures the good environmental applicability of the product. The technical solution of the present invention is: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1, after hydrolysis of the silicon source precursor, adding catalyst 1 and pore size adjustment additive 1, gelling in a container to obtain silica gel; S2, silicone gel and ethanol are mixed and stirred in a volume ratio of (1-5):1 to obtain silicone gel alcohol solution A; S3, adding a structural reinforcement additive to the silicone gel alcohol solution A obtained in S2, and then uniformly stirring to obtain a silicone gel alcohol solution B; S4, adding a modifier and a catalyst 2 to the silicone gel alcohol solution B obtained in S3, and then heating the mixed solution to perform hydrophobic modification; S5, separating the modified mixed solution obtained in S4 to obtain a white emulsion; S6, placing the white emulsion obtained in S5 into a shaping plate for drying to obtain a structure-enhanced hydrophobic block aerogel material; S7. Processing the aerogel material and mosquito repellent obtained in S6 to obtain an aerogel mosquito repellent material.

[0008] Preferably, in step S1, the silicon source precursor is at least one of methyl orthosilicate, ethyl orthosilicate, water glass, and rice husk ash, and the hydrolysis conditions are hydrolysis at room temperature for 0.5-1 hour, or hydrolysis at a pH of 3-5 for 0.5-1 hour.

[0009] Preferably, the pore size adjusting additive 1 in step S1 is at least one of iron oxide, calcium oxide and ferrosoferric oxide; Catalyst 1 is an acidic catalyst or an alkaline catalyst, the acidic catalyst is one or more of nitric acid, oxalic acid, formic acid, acetic acid, phosphoric acid, hydrochloric acid, and sulfuric acid; the alkaline catalyst is any one or more of sodium carbonate, potassium carbonate, potassium acetate, sodium hydroxide, potassium hydroxide, urea, and ammonia water; the dosage of catalyst 1 is 0.01%-5% of the dosage of the silicon source precursor, and the dosage of the pore size adjustment additive 1 is 1%-6% of the dosage of the silicon source precursor. Preferably, the reaction conditions for adding the catalyst 1 and the pore size regulating additive 1 in step S1 are 40-60° C. for 0.5-6 hours to obtain the silica gel.

[0010] Preferably, the structural reinforcement additive in S3 is any one or more of phenolic resin, urea-formaldehyde resin and polyvinyl acetate.

[0011] Preferably, the catalyst 2 in S4 is an alkaline catalyst, and the alkaline catalyst is any one or more of sodium carbonate, potassium carbonate, potassium acetate, sodium hydroxide, potassium hydroxide, urea, and ammonia water; the amount of the catalyst 2 is 0.1%-5% of the amount of the silica gel; The modifier is one or more of methyltriethoxysilane, trimethylchlorosilane, dimethyldiethoxysilane, and hexamethylsilazane; the amount of the modifier is 10%-50% of the amount of the silicone gel; In S4, the gel heating temperature is 25-80°C and the modification time is 3-24 hours.

[0012] Preferably, the drying temperature of S6 is 50-230° C., and the drying time is 4-24 hours. The aerogel material obtained in S6 is in a complete block. The obtained structurally enhanced hydrophobic block aerogel material has better mechanical properties than ordinary hydrophobic silica aerogel materials and is not easy to break. Preferably, the mosquito repellent in S7 is a volatile substance, specifically at least one of DEET, Imonim, and Icaridin.

[0013] Preferably, the processing step S7 includes: 1) cutting and shaping the aerogel material. 2) mixing and soaking the liquid mosquito repellent with the aerogel material to make them uniformly dispersed; the mixing time of the liquid and the aerogel is 0.5-60 hours.

[0014] The beneficial effects of the present invention are: First, the prepared aerogel material has excellent hydrophobicity and adsorption properties, can absorb sufficient mosquito repellent, and is hydrophobic and moisture-proof; second, the adsorption of mosquito repellent in the aerogel material can effectively release the mosquito repellent ingredients to achieve the purpose of long-term mosquito repellent; third, the composite of aerogel material and mosquito repellent can improve the environmental adaptability of mosquito repellent products and broaden the experimental scenarios, especially the adaptability to the field environment; fourth, the durability of aerogel composite mosquito repellent materials greatly improves the economy of the product; fifth, the structurally enhanced hydrophobic block aerogel material has better mechanical properties than ordinary hydrophobic silica aerogel materials, is not easy to break, and increases the diversity of usage scenarios. DETAILED DESCRIPTION

[0015] The following will be combined with the specific embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0016] Example 1 A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. 100 kg of ethyl orthosilicate with a purity of 99% is diluted with 30 kg of deionized water, and then 200 kg of ethanol is added for hydrolysis, and then 20 g of sodium hydroxide and 200 g of iron oxide are added, and the mixed solution forms a silica gel.

[0017] S2, mixing silicone gel and ethanol in a volume ratio of 1.5:1 and stirring to obtain silicone gel alcohol solution A; S3, adding 30 kg of phenolic resin to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 33 kg of dimethyldiethoxysilane and 2.6 kg of ammonia water to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated three times every three hours at 50° C. to complete the extraction of water and the aging and modification of the gel. S6. Drying is carried out at 110° C. under normal pressure to obtain a block aerogel product.

[0018] S7. Weigh 5 g of an aerogel block, soak the aerogel block in DEET at a mass ratio of 1:3, and take out the aerogel block after soaking for 5 hours to obtain a product.

[0019] Embodiment 2: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. 100 kg of ethyl orthosilicate with a purity of 99% is diluted with 30 kg of deionized water, and then 200 kg of ethanol is added for hydrolysis, and then 5 kg of oxalic acid and 300 g of calcium oxide are added, and the mixed solution forms a silica gel; S2, mixing silicone gel and ethanol in a volume ratio of 1:1 and stirring to obtain silicone gel alcohol solution A; S3, adding 30 kg of phenolic resin to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 53 kg of hexamethylsiloxane and 5.6 kg of ammonia water to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated twice every 3 hours at 50° C. to complete the extraction of water and the aging and modification of the gel. S6. Drying is carried out at 90° C. under normal pressure to obtain a block aerogel product.

[0020] S7. Weigh 10 g of an aerogel block, soak the aerogel block in DEET at a mass ratio of 1:3, and take out the aerogel block after soaking for 5 hours to obtain a product.

[0021] Embodiment 3: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. 100 kg of ethyl orthosilicate with a purity of 99% is diluted with 30 kg of deionized water, and then 200 kg of ethanol is added for hydrolysis, followed by 10 kg of formic acid and 350 kg of calcium oxide, until the mixed liquid forms a wet silica gel.

[0022] S2, the silicone gel and ethanol in a volume ratio of 1: 1 mixed and stirred to obtain a silicone gel alcohol solution A; S3, adding 15 kg of urea-formaldehyde resin to the silicone gel alcohol solution A, stirring for 1 hour, to obtain silicone gel alcohol solution B; S4, adding 53 kg of hexamethylsiloxane and 2 kg of potassium carbonate to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated three times every three hours at 60° C. to complete the extraction of water and the aging and modification of the gel. S6. Drying is carried out at 80° C. under normal pressure to obtain a block aerogel product.

[0023] S7. Weigh 10 g of aerogel blocks, soak the aerogel blocks in icaridin at a mass ratio of 1:3, and take out after soaking for 8 hours to obtain a product.

[0024] Embodiment 4: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. 93 kg of methyl orthosilicate with a purity of 99% is diluted with 30 kg of deionized water, and then 200 kg of ethanol is added for hydrolysis, and then 11 kg of formic acid and 350 kg of calcium oxide are added, and the mixed liquid forms a wet silica gel.

[0025] S2, mixing silicone gel and ethanol in a volume ratio of 1:1 and stirring to obtain silicone gel alcohol solution A; S3, adding 18 kg of urea-formaldehyde resin to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 53 kg of hexamethylsiloxane and 13 kg of ammonia water to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5, circulating the mixed soaking liquid three times every 5 hours at 50°C to complete the extraction of water and the aging and modification of the gel; S6, drying at 80°C under normal pressure to obtain a block aerogel product.

[0026] S7, weighing 10 g of aerogel blocks, soaking the aerogel blocks in Imonene at a mass ratio of 1:8, and taking them out after soaking for 10 hours to obtain a product.

[0027] Embodiment 5: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. Dilute 250 kg of 95% pure water glass with a silicon content of 26% in 220 kg of deionized water. Dilute 48 kg of 98% concentrated sulfuric acid in 192 kg of deionized water. Then slowly add the diluted water glass to the diluted sulfuric acid for 30 minutes. After the addition is completed, slowly add ammonia water to the silica sol and stir until the pH of the sol is 7, then add 470 g of iron oxide, and wait for the mixed liquid to form a wet silica gel.

[0028] S2, the silicone gel and ethanol in a volume ratio of 1: 1 mixed and stirred to obtain a silicone gel alcohol solution A; S3, adding 20 kg of phenolic resin to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 53 kg of hexamethylsiloxane and 18 kg of ammonia water to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5, circulating the mixed soaking solution twice every 3 hours at 50° C. to complete the extraction of water and the aging and modification of the gel; S6. Drying at 100° C. under normal pressure to obtain a block aerogel product.

[0029] S7. Weigh 10 g of an aerogel block, soak the aerogel block in DEET at a mass ratio of 1:1, and take out the aerogel block after soaking for 5 hours to obtain a product.

[0030] Embodiment 6: A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1. Dilute 250 kg of 95% pure water glass with a silicon content of 26% in 220 kg of deionized water. Dilute 48 kg of 98% concentrated sulfuric acid in 192 kg of deionized water. Then slowly add the diluted water glass to the diluted sulfuric acid for 30 minutes. After the addition is completed, slowly add ammonia water to the silica sol and stir until the pH of the sol is 7, then add 470 g of iron oxide, and wait for the mixed liquid to form a wet silica gel.

[0031] S2, the silicone gel and ethanol in a volume ratio of 1: 1 mixed and stirred to obtain a silicone gel alcohol solution A; S3, adding 25 kg of polyvinyl acetate to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 42 kg of dimethyl diethoxysilane and 20 kg of sodium carbonate to the obtained silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated twice every 3 hours at 70° C. to complete the extraction of water and the aging and modification of the gel. S6. Drying is carried out at 130° C. under normal pressure to obtain a block aerogel product.

[0032] S7. Weigh 10 g of aerogel blocks, soak the aerogel blocks in Imonene at a mass ratio of 1:5, and take them out after soaking for 5 hours to obtain a product.

[0033] Embodiment 7: S1. Dilute 250 kg of 95% pure water glass with a silicon content of 26% in 220 kg of deionized water. Dilute 48 kg of 98% concentrated sulfuric acid in 192 kg of deionized water. Then slowly add the diluted water glass to the diluted sulfuric acid for 30 minutes. After the addition is completed, slowly add sodium hydroxide to the silica sol and stir until the pH of the sol is 7, then add 500 g of iron oxide, and wait for the mixed liquid to form a wet silica gel.

[0034] S2, mixing silicone gel and ethanol in a volume ratio of 1:1 and stirring to obtain silicone gel alcohol solution A; S3, adding 25 kg of polyvinyl acetate to the silicone gel alcohol solution A, stirring for 1 hour to obtain silicone gel alcohol solution B; S4, adding 53 kg of dimethyldiethoxysiloxane and 17 kg of urea to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated twice every 3 hours at 70° C. to complete the extraction of water and the aging and modification of the gel. S6. Drying is carried out at 130° C. under normal pressure to obtain a block aerogel product.

[0035] S7. Weigh 10 g of aerogel blocks, soak the aerogel blocks in icaridin at a mass ratio of 1:5, and take out after soaking for 6 hours to obtain a product.

[0036] Embodiment 8: S1. Dilute 250 kg of water glass with a purity of 95% and a silicon content of 26% in 220 kg of deionized water. Dilute 47 kg of concentrated sulfuric acid with a concentration of 98% in 192 kg of deionized water. Then slowly add the diluted water glass to the diluted sulfuric acid for 30 minutes. After the addition is completed, slowly add formic acid to the silica sol and stir until the pH of the sol is 7, then add 500 g of calcium oxide, and wait for the mixed liquid to form a wet silica gel.

[0037] S2, mixing silicone gel and ethanol in a volume ratio of 1:1 and stirring to obtain silicone gel alcohol solution A; S3, adding 25 kg of polyvinyl acetate to the silicone gel alcohol solution A, stirring for 1 hour, to obtain silicone gel alcohol solution B; S4, adding 50 kg of methyltriethoxysilane and 18 kg of urea to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5, circulating the mixed soaking solution twice every 3 hours at 70° C. to complete the extraction of water and the aging and modification of the gel; S6. Drying at 130° C. under normal pressure to obtain a block-shaped aerogel product.

[0038] S7. Weigh 10 g of aerogel blocks, soak the aerogel blocks in icaridin at a mass ratio of 1:1, and take out after soaking for 3 hours to obtain a product.

[0039] Embodiment 9: S1. Dilute 250 kg of water glass with a purity of 95% and a silicon content of 26% in 220 kg of deionized water. Dilute 48 kg of concentrated sulfuric acid with a concentration of 98% in 192 kg of deionized water. Then slowly add the diluted water glass to the diluted sulfuric acid for 30 minutes. After the addition is completed, slowly add ammonia water to the silica sol and stir until the pH of the sol is 7, then add 475 g of ferrosoferric oxide in a catalytic amount, and the mixed solution forms a wet silica gel.

[0040] S2, the silicone gel and ethanol in a volume ratio of 1: 1 mixed and stirred to obtain a silicone gel alcohol solution A; S3, adding 25 kg of phenolic resin to the silicone gel alcohol solution A, stirring for 1 hour, to obtain silicone gel alcohol solution B; S4, adding 50 kg of dimethyldiethoxysiloxane and 10 kg of potassium acetate as a modifier to the silicone gel alcohol solution B to obtain a modified mixed soaking solution; S5. The mixed soaking liquid is circulated twice every 3 hours at 70° C. to complete the extraction of water and the aging and modification of the gel; S6. Drying is carried out at 130° C. under normal pressure to obtain a block aerogel product.

[0041] S7. Weigh 10 g of an aerogel block, soak the aerogel block in DEET at a mass ratio of 1:1, and take out the aerogel block after soaking for 3 hours to obtain a product. Comparative Example 1 The common aerogel and DEET were soaked in a mass ratio of 1:3 for 5 hours and then taken out to obtain a product.

[0042] Comparative Example 2 Based on Example 1, pore size regulator 1 is not added in step S1. Other steps are the same as Example 1.

[0043] Comparative Example 3 Based on Example 1, no structural enhancement agent is added in step S3. Others are the same as in Example 1. Comparative Example 4 Based on Example 1, no modifier is added in step S4. Other steps are the same as Example 1.

[0044] Comparative Example 5 An ordinary sponge and DEET are soaked in a mass ratio of 1:3 for 5 hours and then taken out to obtain a product.

[0045] Aerogel performance testing method: 1. Volatile volume test: weigh the mass of the product before the test m1, then leave it open at room temperature for 24 hours, and weigh the mass of the product m2; the volatile volume is calculated as: x = (m1-m2) / m1 2. Shore hardness measurement: Put the Shore hardness tester in contact with the product and directly read the Shore hardness tester reading.

[0046] 3. Hydrophobicity test: weigh the mass of the product before the test, m3, then spray it with water for 20 minutes, wipe it dry with a dry cloth, and weigh the mass of the product after the test, m4; the hydrophobicity calculation method is: x=1-(m4-m3) / m3 4. Mosquito repellent effect: Put these mosquito repellent products into a cage filled with densely packed mosquitoes. After 1 hour, the number of dead mosquitoes is used to determine the mosquito repellent effect. The number of mosquito deaths in all items is B1, and the maximum number is B2. Mosquito repellent effect: x=B1 / B2 Aerogel material volatility test: The use of pore size regulator makes the pore size distribution of the improved thickness aerogel between 80-100nm, which is larger than the average free path of the molecule 70-80nm, which is more conducive to the volatilization of the mosquito repellent active ingredients. The volatilization amount of the mosquito repellent after standing at room temperature for 1 day was tested. The results show that the aerogel mosquito repellent material prepared by the method of the present invention has better release than the ordinary aerogel mosquito repellent material.

[0047] Aerogel material hardness performance test (the higher the hardness of the aerogel material, the less likely the material is to break): The use of structural reinforcing agents, at the macro level, adds structural support materials, and at the micro level, the hydroxyl groups, amino groups, and ethylene agents present in the resin react with the hydroxyl groups present in the aerogel, and the strength stability of the aerogel material and the structural reinforcing agent is enhanced in the form of chemical bonds. The method of the present invention is used to prepare the resulting aerogel material, and the hardness of the aerogel material is tested by a Shore hardness tester. The higher the hardness, the less likely it is to break. Aerogel mosquito repellent material performance test: The aerogel mosquito repellent material was prepared by the method of the present invention. After being left open for 30 days, the aerogel mosquito repellent material showed good performance in terms of hydrophobicity, the amount of mosquito repellent remaining, and the mosquito repellent effect.

[0048] Aerogel mosquito repellent material performance test: The aerogel mosquito repellent material was prepared by the method of the present invention. After being heated at 40°C for 10 hours, the aerogel mosquito repellent material showed good performance in terms of hydrophobicity, residual amount of mosquito repellent, and mosquito repellent effect.

[0049] Table 1 Performance evaluation of aerogel mosquito repellent materials

[0050] Through Example 1 and Comparative Example 1, it can be seen that its hardness is low, the mosquito repellent volatile amount is low, and the mosquito repellent effect is medium. This may be because the product strength is not enough and it is fragile without adding a structural enhancer, and the product pore size is small without adding a structural regulator, which affects the product release amount, thereby affecting the mosquito repellent effect. Through Example 1 and Comparative Example 2, it can be seen that its mosquito repellent volatile amount is low, and the mosquito repellent effect is medium. This may be because the product is fragile without adding a structural enhancer, and the product pore size is small without adding a structural regulator, which affects the product release amount, thereby affecting the mosquito repellent effect. The mosquito repellent volatile amount is low, and the mosquito repellent effect is medium. Through Example 1 and Comparative Example 3, it can be seen that its hardness is poor, and the product is fragile. This may be because the product strength is not enough and it is fragile without adding a structural enhancer. Through Example 1 and Comparative Example 4, it can be seen that its hardness is poor, the product is easy to absorb water, and the mosquito repellent effect is poor. This may be because the product is not hydrophobic without adding a hydrophobic agent, which absorbs moisture during storage, blocks the pores, and affects the mosquito repellent effect. It can be seen from Example 1 and Comparative Example 5 that it is too volatile and does not have a sustained release effect. This may be because the lack of aerogel results in the product having no sustained release effect, which is not conducive to long-term storage.

[0051] In summary, through performance testing, aerogel mosquito repellent products with modified pore size and enhanced structure release more effective mosquito repellents than ordinary aerogel mosquito repellent products, have better product rigidity, are not easy to break, and have good mosquito repellent effects; compared with ordinary mosquito repellent liquids, aerogel mosquito repellent products have better hydrophobicity and sustained release properties and have good mosquito repellent effects.

Claims

1. A method for preparing an aerogel mosquito repellent material, the method comprising the following steps: S1, after hydrolysis of the silicon source precursor, adding catalyst 1 and pore size adjustment additive 1, gelling in a container to obtain silica gel; S2, the silicone gel and ethanol are mixed and stirred evenly to obtain a silicone gel alcohol solution A; S3, adding a structural reinforcement additive to the silicone gel alcohol solution A obtained in S2, and then uniformly stirring to obtain a silicone gel alcohol solution B; S4, adding a modifier and a catalyst 2 to the silicone gel alcohol solution B obtained in S3 and heating the mixed solution to perform hydrophobic modification; S5, separating the modified mixed solution obtained in S4 to obtain a white emulsion; S6, placing the white emulsion obtained in S5 into a shaping plate for drying to obtain a structure-enhanced hydrophobic block aerogel material; S7. Processing the aerogel material and mosquito repellent obtained in S6 to obtain an aerogel mosquito repellent material.

2. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: In step S1, the silicon source precursor is at least one of methyl orthosilicate, ethyl orthosilicate, water glass, and rice husk ash, and the hydrolysis conditions are hydrolysis at room temperature for 0.5-1 hour, or hydrolysis at pH 3-5 for 0.5-1 hour.

3. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: The pore size adjustment additive 1 in step S1 is at least one of iron oxide, calcium oxide and ferrosoferric oxide; Catalyst 1 is an acidic catalyst or an alkaline catalyst, the acidic catalyst is one or more of nitric acid, oxalic acid, formic acid, acetic acid, phosphoric acid, hydrochloric acid, and sulfuric acid; the alkaline catalyst is any one or more of sodium carbonate, potassium carbonate, potassium acetate, sodium hydroxide, potassium hydroxide, urea, and ammonia water; the dosage of catalyst 1 is 0.01%-5% of the dosage of the silicon source precursor, and the dosage of the pore size adjustment additive 1 is 0.1%-6% of the dosage of the silicon source precursor.

4. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: The reaction conditions of adding the catalyst 1 and the pore size regulating additive 1 in step S1 are 40-60° C. and 0.5-6 hours to obtain the silica gel.

5. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: In step S2, the volume ratio of the silicone gel to ethanol is (1-5):

1.

6. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: The structural reinforcement additive in S3 is any one or more of phenolic resin, urea-formaldehyde resin and polyvinyl acetate.

7. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: In S4, the catalyst 2 is an alkaline catalyst, and the alkaline catalyst is any one or more of sodium carbonate, potassium carbonate, potassium acetate, sodium hydroxide, potassium hydroxide, urea, and ammonia water; the amount of the catalyst 2 is 0.1%-2% of the amount of the silicone gel; The modifier is one or more of methyltriethoxysilane, trimethylchlorosilane, dimethyldiethoxysilane, and hexamethylsilazane; the amount of the modifier is 10%-50% of the amount of the silicone gel; In S4, the gel heating temperature is 25-80°C and the modification time is 3-24 hours.

8. The method for preparing the aerogel mosquito repellent material according to claim 1, characterized in that: The drying temperature of S6 is 50-230° C., and the drying time is 4-24 hours.

9. The method for preparing an aerogel mosquito repellent material according to claim 1, characterized in that: The mosquito repellent in S7 is a volatile substance, specifically at least one of DEET, Imonim, and Icaridin.

10. The method for preparing an aerogel mosquito repellent material according to claim 1, characterized in that: The processing step S7 includes: 1) cutting and shaping the aerogel material; 2) mixing and soaking the liquid mosquito repellent with the aerogel material to make them uniformly dispersed; the mixing time of the liquid mosquito repellent and the aerogel is 0.5-60 hours.

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